Question: Ivermectin is utilized for treating lymphatic filariasis.

"Comprehensive Control Strategies": How an Integrated Approach to Tackling Africa's Neglected Tropical Diseases Can Alleviate Poverty
In the last two decades, there have been notable successes in managing several critical tropical diseases [1]. These successes encompass substantial decreases in the prevalence and occurrence of neglected conditions such as lymphatic filariasis, onchocerciasis, guinea worm disease, leprosy, and trachoma (Box 1) [2]. Each of these neglected diseases is a condition that exacerbates poverty and often carries a social stigma, primarily affecting rural populations in economically disadvantaged nations (Box 2) [3]. These diseases are deeply rooted in history, documented in ancient scriptures like the Bible, and have been a persistent burden on human health for centuries [3]. However, due to rigorous targeted interventions, there is now a realistic prospect of controlling some neglected tropical diseases to the point of eradication in certain endemic regions [2–8]. Particularly, the eradication of guinea worm disease appears to be within reach [9]. Box 2. Shared Characteristics of the Neglected Tropical Diseases           Diseases with a long historical presence, impacting societies for centuries         Conditions that reinforce poverty         Often stigmatized in affected communities         Predominantly found in rural areas of low-income countries and unstable states         Lack of commercial interest in developing treatments for these diseases         When interventions are implemented, they have a proven track record of effectiveness

Background The degree of volume depletion in severe malaria is currently unknown, although knowledge of fluid compartment volumes can guide therapy. To assist management of severely ill children, and to test the hypothesis that volume changes in fluid compartments reflect disease severity, we measured body compartment volumes in Gabonese children with malaria. Methods and Findings Total body water volume (TBW) and extracellular water volume (ECW) were estimated in children with severe or moderate malaria and in convalescence by tracer dilution with heavy water and bromide, respectively. Intracellular water volume (ICW) was derived from these parameters. Bioelectrical impedance analysis estimates of TBW and ECW were calibrated against dilution methods, and bioelectrical impedance analysis measurements were taken daily until discharge. Sixteen children had severe and 19 moderate malaria. Severe childhood malaria was associated with depletion of TBW (mean [SD] of 37 [33] ml/kg, or 6.7% [6.0%]) relative to measurement at discharge. This is defined as mild dehydration in other conditions. ECW measurements were normal on admission in children with severe malaria and did not rise in the first few days of admission. Volumes in different compartments (TBW, ECW, and ICW) were not related to hyperlactataemia or other clinical and laboratory markers of disease severity. Moderate malaria was not associated with a depletion of TBW.

β-Lactamase evolution presents to the infectious disease community a major challenge in the treatment of infections caused by multidrug-resistant gram-negative bacteria. Because over 1,000 of these naturally occurring β-lactamases exist, attempts to correlate structure and function have become daunting. Although new enzymes in the extended-spectrum β-lactamase (ESBL) families are frequently identified, the older CTX-M-14 and CTX-M-15 enzymes have become the most prevalent ESBLs in global surveillance. Carbapenemases with either serine-based or zinc-facilitated hydrolysis mechanisms are posing some of the most critical problems. Most geographical regions now report KPC serine carbapenemases and the metallo-β-lactamases VIM, IMP, and NDM-1, even though NDM-1 was only recently identified. The rapid emergence of these newer enzymes, with multiple β-lactamases appearing in a single organism, makes the design of new β-lactamase inactivators or β-lactamase-stable β-lactams all the more difficult. Combination therapy will likely be required to counteract the continuing evolution of these insidious enzymes in multidrug-resistant pathogens.

After a lapse of almost 40 years, malaria eradication is back on the global health agenda. Inspired by the Gates Malaria Forum in October 2007,1,2 key organizations are starting to debate the pros and cons of redefining eradication as an explicit goal of malaria control efforts. Attempts to eliminate malaria in southern Africa3 and Pacific Island states,4 and WHO’s Global Malaria Programme agenda and field manual for malaria elimination,5,6 foreshadow this movement towards another global attempt at eradication. When marking 60 years of WHO’s commitment to fighting malaria, we must ask what has been achieved, but also what can we learn from the past. We now know so much more about the biology of parasite-host responses, the determinants of endemicity and transmission dynamics, the social, economic and cultural implications of malaria at household, community and national levels, and the demands made upon health systems in endemic countries. We do not yet know how to synthesize and integrate this knowledge to achieve elimination in different settings. Regional malaria elimination campaigns were first conducted in the late 1940s, preparing the ground for the Global Malaria Eradication Program in 1955. This campaign succeeded in eliminating malaria from Europe, North America, the Caribbean and parts of Asia and South-Central America.7 But no major success occurred in sub-Saharan Africa, which accounts for 80% of today’s burden of malaria.8 When the aspiration of global eradication was abandoned in 1969, the main reasons for failure were technical challenges of executing the strategy especially in Africa. The post-eradication era from 1969 to 1991 focused on technical issues, and research and development for new tools, leading to advances in drug and vaccine development, vector control and insecticide-treated nets. These decades also brought a better understanding of the social, economic and cultural dimensions of malaria. There was little global support provided specifically for malaria control in the newly independent states of Africa that were struggling to establish broad-based health systems and primary health care. By 1992, the combination of a worsening malaria situation and promising technical developments led to renewed global focus on malaria control. The Roll Back Malaria initiative, launched by WHO in 1998, led to the Abuja Declaration in 2000, which defined progressive intervention coverage targets for control designed to eliminate malaria as a public health problem, while emphasizing that this could only be achieved through vastly strengthened local health systems.9 Increased resources through the Global Fund to Fight AIDS, Tuberculosis and Malaria, the World Bank’s Booster Program, the US President’s Malaria Initiative and many others has meant that this page is finally beginning to turn as intervention coverage is rising.10    It is against this background that we hear this call for elimination/eradication. The challenges remain formidable. We all know that elimination in Africa is not possible with current tools. But efforts must focus beyond simply developing better tools, to include how existing and future tools can be strategically combined for maximum synergistic effectiveness when integrated into different health and social systems prevailing in endemic areas. Aiming at elimination and eradication further implies the need for effective surveillance strategies to monitor progress (again a challenge for health systems). This in turn requires a better understanding of malaria transmission heterogeneity in a globalized world with rapidly changing dynamics in environment, climate, migration and transnational cooperation. Maintaining long-term momentum in the face of success in regional elimination while waiting to achieve final eradication will be a major challenge. Shrinking the map by starting on the malaria margins with the “easy-to-eliminate” settings will boost morale initially but may bring marginal benefits to such areas at the expense of those where the burden of malaria is highest. Any strategic plan – and here we learn again from the past – needs to be a synchronous global effort, locally adapted in all endemic areas. Although we lack sufficient knowledge, systems and tools to eradicate malaria today, we do have a window of political will and financial resources to refocus on the goal of effective control through universal coverage of appropriate interventions. The prerequisites for a successful start are: (i) a process of inclusive discourse to agree on global vision, goals and strategy; and (ii) a global plan for all endemic areas describing how, where and when we move from control towards elimination. What must distinguish the new era, especially in Africa, is a real rather than rhetorical emphasis on health systems. ■

The large Trp gene family encodes transient receptor potential (TRP) proteins that form novel cation-selective ion channels. In mammals, 28 Trp channel genes have been identified. TRP proteins exhibit diverse permeation and gating properties and are involved in a plethora of physiologic functions with a strong impact on cellular sensing and signaling pathways. Indeed, mutations in human genes encoding TRP channels, the so-called "TRP channelopathies," are responsible for a number of hereditary diseases that affect the musculoskeletal, cardiovascular, genitourinary, and nervous systems. This review gives an overview of the functional properties of mammalian TRP channels, describes their roles in acquired and hereditary diseases, and discusses their potential as drug targets for therapeutic intervention.

BACKGROUND Plasmodium falciparum malaria remains a major cause of illness and death in sub-Saharan Africa. Young children bear the brunt of the disease and though older children and adults suffer relatively fewer clinical attacks, they remain susceptible to asymptomatic P. falciparum infection. A better understanding of the host factors associated with immunity to clinical malaria and the ability to sustain asymptomatic P. falciparum infection will aid the development of improved strategies for disease prevention. METHODS AND FINDINGS Here we investigate whether full differential blood counts can predict susceptibility to clinical malaria among Kenyan children sampled at five annual cross-sectional surveys. We find that the ratio of monocytes to lymphocytes, measured in peripheral blood at the time of survey, directly correlates with risk of clinical malaria during follow-up. This association is evident among children with asymptomatic P. falciparum infection at the time the cell counts are measured (Hazard ratio (HR)  =  2.7 (95% CI 1.42, 5.01, P  =  0.002) but not in those without detectable parasitaemia (HR  =  1.0 (95% CI 0.74, 1.42, P  =  0.9). CONCLUSIONS We propose that the monocyte to lymphocyte ratio, which is easily derived from routine full differential blood counts, reflects an individual's capacity to mount an effective immune response to P. falciparum infection.

OBJECTIVE To describe the epidemiology of urban malaria, an emerging problem in sub-Saharan Africa. METHOD Cross-sectional surveys of communities in Accra and Kumasi, Ghana, determining risk factors for malaria infection and anaemia in children aged 6-60 months. RESULTS Malaria prevalence rates ranged from 2% to 33% between urban communities. 47.1% of children were anaemic (Hb<11.0 g/dl). Factors associated with malaria prevalence were low socio-economic status, age and anaemia. The attributable risks of anaemia and severe anaemia (Hb<8.0 g/dl) caused by malaria were 5% and 23% respectively. CONCLUSIONS Malaria in urban areas displayed a heterogeneity and complexity that differed from the rural environment, which has important implications for malaria control. Marked intra-city variation indicates the importance of targeting specific areas or districts. The most vulnerable group, the urban poor, should be prioritized when designing control measures. This would require careful assessment of the malaria risk pattern in any city to guide an integrated control program.

The world is running out of antibiotics. Between 1940 and 1962, more than 20 new classes of antibiotics were marketed. Since then, only two new classes of antibiotics were marketed. Now, not enough analogues are reaching the market to stem the tide of antibiotic resistance, particularly among gram-negative bacteria which indicates the need of novel antibiotics for their effective action. This review describes those antibiotics in late-stage clinical development. Most of them belong to existing antibiotic classes and a few with a narrow spectrum of activity are novel compounds directed against novel targets. The reasons for some of the past failures to find new molecules and a path forward to help attract investments to fund the discovery of new antibiotics are described.

Metformin is a widely used drug for treatment of type 2 diabetes with no defined cellular mechanism of action. Its glucose-lowering effect results from decreased hepatic glucose production and increased glucose utilization. Metformin's beneficial effects on circulating lipids have been linked to reduced fatty liver. AMP-activated protein kinase (AMPK) is a major cellular regulator of lipid and glucose metabolism. Here we report that metformin activates AMPK in hepatocytes; as a result, acetyl-CoA carboxylase (ACC) activity is reduced, fatty acid oxidation is induced, and expression of lipogenic enzymes is suppressed. Activation of AMPK by metformin or an adenosine analogue suppresses expression of SREBP-1, a key lipogenic transcription factor. In metformin-treated rats, hepatic expression of SREBP-1 (and other lipogenic) mRNAs and protein is reduced; activity of the AMPK target, ACC, is also reduced. Using a novel AMPK inhibitor, we find that AMPK activation is required for metformin's inhibitory effect on glucose production by hepatocytes. In isolated rat skeletal muscles, metformin stimulates glucose uptake coincident with AMPK activation. Activation of AMPK provides a unified explanation for the pleiotropic beneficial effects of this drug; these results also suggest that alternative means of modulating AMPK should be useful for the treatment of metabolic disorders.

The hypoxia-inducible factor (HIF) prolyl hydroxylase (PHD) enzymes represent novel targets for the treatment of anemia, ulcerative colitis, and ischemic and metabolic disease inter alia. We have identified a novel small-molecule inhibitor of PHD, 1-(5-chloro-6-(trifluoromethoxy)-1H-benzoimidazol-2-yl)-1H-pyrazole-4-carboxylic acid (JNJ-42041935), through structure-based drug design methods. The pharmacology of JNJ-42041935 was investigated in enzyme, cellular, and whole-animal systems and was compared with other compounds described in the literature as PHD inhibitors. JNJ-42041935, was a potent (pK(I) = 7.3-7.9), 2-oxoglutarate competitive, reversible, and selective inhibitor of PHD enzymes. In addition, JNJ-42041935 was used to compare the effect of selective inhibition of PHD to intermittent, high doses (50 μg/kg i.p.) of an exogenous erythropoietin receptor agonist in an inflammation-induced anemia model in rats. JNJ-42041935 (100 μmol/kg, once a day for 14 days) was effective in reversing inflammation-induced anemia, whereas erythropoietin had no effect. The results demonstrate that JNJ-42041935 is a new pharmacological tool, which can be used to investigate PHD inhibition and demonstrate that PHD inhibitors offer great promise for the treatment of inflammation-induced anemia.

A central goal of systems biology is the elucidation of cell function and physiology through the integrated use of broad based genomic and physiological data. Such systemic approaches have been employed extensively in the past, as they are a central element of metabolic flux analysis, the distribution of kinetic control in pathways, and the key differentiating characteristic of metabolic engineering. In one case study, these tools have been applied to the improvement of lysine-producing strains of Corynebacterium glutamicum. The systematic study of the physiology of this organism allowed the identification of specific metabolic targets and subsequently led to significant improvements in product yield and productivity. This case study can serve as a guide for the development of systems biology tools for the utilization of large volumes of cell- and genome-wide transcriptional and physiological data.


Question: Ivermectin is utilized for treating onchocerciasis.

“Targeted Control Strategies”: How an Integrated Policy for Combating Africa's Neglected Tropical Diseases Can Alleviate Poverty
In recent years, there have been notable successes in managing several critical tropical diseases that affect humans [1]. These successes are marked by considerable reductions in the prevalence and incidence of neglected diseases such as lymphatic filariasis, onchocerciasis, guinea worm disease, leprosy, and trachoma (Box 1) [2]. Each of these neglected diseases is a condition that exacerbates poverty and is often stigmatizing, predominantly found in the rural regions of economically disadvantaged countries (Box 2) [3]. These diseases have a long historical presence, documented in ancient scriptures including the Bible, having plagued human societies for centuries [3]. However, due to the implementation of targeted vertical control programs, there is now a realistic prospect of controlling these tropical infections to the extent of elimination in certain endemic areas [2–8]. For guinea worm disease, the possibility of complete eradication is also on the horizon [9]. Box 2. Shared Characteristics of the Neglected Tropical Diseases          Historical diseases that have plagued humanity for centuries      Conditions that perpetuate poverty      Often linked with social stigma      Predominantly found in rural areas of low-income countries and unstable states      Lack of commercial interest in developing products for these diseases      When interventions are implemented, they have a track record of effectiveness

Fibrosis is a pathological result of a dysfunctional repair response to tissue injury and occurs in a number of organs, including the lungs1. Cellular metabolism regulates tissue repair and remodelling responses to injury2-4. AMPK is a critical sensor of cellular bioenergetics and controls the switch from anabolic to catabolic metabolism5. However, the role of AMPK in fibrosis is not well understood. Here, we demonstrate that in humans with idiopathic pulmonary fibrosis (IPF) and in an experimental mouse model of lung fibrosis, AMPK activity is lower in fibrotic regions associated with metabolically active and apoptosis-resistant myofibroblasts. Pharmacological activation of AMPK in myofibroblasts from lungs of humans with IPF display lower fibrotic activity, along with enhanced mitochondrial biogenesis and normalization of sensitivity to apoptosis. In a bleomycin model of lung fibrosis in mice, metformin therapeutically accelerates the resolution of well-established fibrosis in an AMPK-dependent manner. These studies implicate deficient AMPK activation in non-resolving, pathologic fibrotic processes, and support a role for metformin (or other AMPK activators) to reverse established fibrosis by facilitating deactivation and apoptosis of myofibroblasts.

CONTEXT Uncertainties exist about prevalence and correlates of major depressive disorder (MDD). OBJECTIVE To present nationally representative data on prevalence and correlates of MDD by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria, and on study patterns and correlates of treatment and treatment adequacy from the recently completed National Comorbidity Survey Replication (NCS-R). DESIGN Face-to-face household survey conducted from February 2001 to December 2002. SETTING The 48 contiguous United States. PARTICIPANTS Household residents ages 18 years or older (N = 9090) who responded to the NCS-R survey. MAIN OUTCOME MEASURES Prevalence and correlates of MDD using the World Health Organization's (WHO) Composite International Diagnostic Interview (CIDI), 12-month severity with the Quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR), the Sheehan Disability Scale (SDS), and the WHO disability assessment scale (WHO-DAS). Clinical reinterviews used the Structured Clinical Interview for DSM-IV. RESULTS The prevalence of CIDI MDD for lifetime was 16.2% (95% confidence interval [CI], 15.1-17.3) (32.6-35.1 million US adults) and for 12-month was 6.6% (95% CI, 5.9-7.3) (13.1-14.2 million US adults). Virtually all CIDI 12-month cases were independently classified as clinically significant using the QIDS-SR, with 10.4% mild, 38.6% moderate, 38.0% severe, and 12.9% very severe. Mean episode duration was 16 weeks (95% CI, 15.1-17.3). Role impairment as measured by SDS was substantial as indicated by 59.3% of 12-month cases with severe or very severe role impairment. Most lifetime (72.1%) and 12-month (78.5%) cases had comorbid CIDI/DSM-IV disorders, with MDD only rarely primary. Although 51.6% (95% CI, 46.1-57.2) of 12-month cases received health care treatment for MDD, treatment was adequate in only 41.9% (95% CI, 35.9-47.9) of these cases, resulting in 21.7% (95% CI, 18.1-25.2) of 12-month MDD being adequately treated. Sociodemographic correlates of treatment were far less numerous than those of prevalence. CONCLUSIONS Major depressive disorder is a common disorder, widely distributed in the population, and usually associated with substantial symptom severity and role impairment. While the recent increase in treatment is encouraging, inadequate treatment is a serious concern. Emphasis on screening and expansion of treatment needs to be accompanied by a parallel emphasis on treatment quality improvement.

Cancer has been recognized for thousands of years. Egyptians believed that cancer occurred at the will of the gods. Hippocrates believed human disease resulted from an imbalance of the four humors: blood, phlegm, yellow bile, and black bile with cancer being caused by excess black bile. The lymph theory of cancer replaced the humoral theory and the blastema theory replaced the lymph theory. Rudolph Virchow was the first to recognize that cancer cells like all cells came from other cells and believed chronic irritation caused cancer. At the same time there was a belief that trauma caused cancer, though it never evolved after many experiments inducing trauma. The birth of virology occurred in 1892 when Dimitri Ivanofsky demonstrated that diseased tobacco plants remained infective after filtering their sap through a filter that trapped bacteria. Martinus Beijerinck would call the tiny infective agent a virus and both Dimitri Ivanofsky and Marinus Beijerinck would become the fathers of virology. Not to long thereafter, Payton Rous founded the field of tumor virology in 1911 with his discovery of a transmittable sarcoma of chickens by what would come to be called Rous sarcoma virus or RSV for short. The first identified human tumor virus was the Epstein-Barr virus (EBV), named after Tony Epstein and Yvonne Barr who visualized the virus particles in Burkitt's lymphoma cells by electron microscopy in 1965. Since that time, many viruses have been associated with carcinogenesis including the most studied, human papilloma virus associated with cervical carcinoma, many other anogenital carcinomas, and oropharyngeal carcinoma. The World Health Organization currently estimates that approximately 22% of worldwide cancers are attributable to infectious etiologies, of which viral etiologies is estimated at 15-20%. The field of tumor virology/viral carcinogenesis has not only identified viruses as etiologic agents of human cancers, but has also given molecular insights to all human cancers including the oncogene activation and tumor suppressor gene inactivation.

Chemical-protein interaction (CPI) is the central topic of target identification and drug discovery. However, large scale determination of CPI is a big challenge for in vitro or in vivo experiments, while in silico prediction shows great advantages due to low cost and high accuracy. On the basis of our previous drug-target interaction prediction via network-based inference (NBI) method, we further developed node- and edge-weighted NBI methods for CPI prediction here. Two comprehensive CPI bipartite networks extracted from ChEMBL database were used to evaluate the methods, one containing 17,111 CPI pairs between 4,741 compounds and 97 G protein-coupled receptors, the other including 13,648 CPI pairs between 2,827 compounds and 206 kinases. The range of the area under receiver operating characteristic curves was 0.73 to 0.83 for the external validation sets, which confirmed the reliability of the prediction. The weak-interaction hypothesis in CPI network was identified by the edge-weighted NBI method. Moreover, to validate the methods, several candidate targets were predicted for five approved drugs, namely imatinib, dasatinib, sertindole, olanzapine and ziprasidone. The molecular hypotheses and experimental evidence for these predictions were further provided. These results confirmed that our methods have potential values in understanding molecular basis of drug polypharmacology and would be helpful for drug repositioning.

We previously identified a rare mutation in human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT), I132M, which confers high-level resistance to the nonnucleoside RT inhibitors (NNRTIs) nevirapine and delavirdine. In this study, we have further characterized the role of this mutation in viral replication capacity and in resistance to other RT inhibitors. Surprisingly, our data show that I132M confers marked hypersusceptibility to the nucleoside analogs lamivudine (3TC) and tenofovir at both the virus and enzyme levels. Subunit-selective mutagenesis studies revealed that the mutation in the p51 subunit of RT was responsible for the increased sensitivity to the drugs, and transient kinetic analyses showed that this hypersusceptibility was due to I132M decreasing the enzyme's affinity for the natural dCTP substrate but increasing its affinity for 3TC-triphosphate. Furthermore, the replication capacity of HIV-1 containing I132M is severely impaired. This decrease in viral replication capacity could be partially or completely compensated for by the A62V or L214I mutation, respectively. Taken together, these results help to explain the infrequent selection of I132M in patients for whom NNRTI regimens are failing and furthermore demonstrate that a single mutation outside of the polymerase active site and inside of the p51 subunit of RT can significantly influence nucleotide selectivity.

The use of and search for drugs and dietary supplements derived from plants have accelerated in recent years. Ethnopharmacologists, botanists, microbiologists, and natural-products chemists are combing the Earth for phytochemicals and "leads" which could be developed for treatment of infectious diseases. While 25 to 50% of current pharmaceuticals are derived from plants, none are used as antimicrobials. Traditional healers have long used plants to prevent or cure infectious conditions; Western medicine is trying to duplicate their successes. Plants are rich in a wide variety of secondary metabolites, such as tannins, terpenoids, alkaloids, and flavonoids, which have been found in vitro to have antimicrobial properties. This review attempts to summarize the current status of botanical screening efforts, as well as in vivo studies of their effectiveness and toxicity. The structure and antimicrobial properties of phytochemicals are also addressed. Since many of these compounds are currently available as unregulated botanical preparations and their use by the public is increasing rapidly, clinicians need to consider the consequences of patients self-medicating with these preparations.

OBJECTIVES To assess incidence and preventability of adverse drug events (ADEs) and potential ADEs. To analyze preventable events to develop prevention strategies. DESIGN Prospective cohort study. PARTICIPANTS All 4031 adult admissions to a stratified random sample of 11 medical and surgical units in two tertiary care hospitals over a 6-month period. Units included two medical and three surgical intensive care units and four medical and two surgical general care units. MAIN OUTCOME MEASURES Adverse drug events and potential ADEs. METHODS Incidents were detected by stimulated self-report by nurses and pharmacists and by daily review of all charts by nurse investigators. Incidents were subsequently classified by two independent reviewers as to whether they represented ADEs or potential ADEs and as to severity and preventability. RESULTS Over 6 months, 247 ADEs and 194 potential ADEs were identified. Extrapolated event rates were 6.5 ADEs and 5.5 potential ADEs per 100 nonobstetrical admissions, for mean numbers per hospital per year of approximately 1900 ADEs and 1600 potential ADEs. Of all ADEs, 1% were fatal (none preventable), 12% life-threatening, 30% serious, and 57% significant. Twenty-eight percent were judged preventable. Of the life-threatening and serious ADEs, 42% were preventable, compared with 18% of significant ADEs. Errors resulting in preventable ADEs occurred most often at the stages of ordering (56%) and administration (34%); transcription (6%) and dispensing errors (4%) were less common. Errors were much more likely to be intercepted if the error occurred earlier in the process: 48% at the ordering stage vs 0% at the administration stage. CONCLUSION Adverse drug events were common and often preventable; serious ADEs were more likely to be preventable. Most resulted from errors at the ordering stage, but many also occurred at the administration stage. Prevention strategies should target both stages of the drug delivery process.

OBJECTIVE Rates of hepatitis C (HCV) infection, testing, and treatment were compared among patients with schizophrenia, a substance use disorder, or co-occurring schizophrenia or schizoaffective disorder and a substance use disorder and a control group. METHODS Information about 293,445 patients of the Northwest Veterans Healthcare Administration was obtained. RESULTS The substance use disorder group constituted 13.6 percent of the sample; the schizophrenia group, 1.6 percent; and the co-occurring-disorders group, 1.4 percent. Respectively, these groups were approximately four, two, and six times as likely as the control group to receive HCV testing and about seven, two, and eight times as likely to be infected. The rate of interferon (IFN) therapy was significantly lower for the substance use group and the group with co-occurring disorders. However, the magnitude of the differences was not substantial, suggesting that these high-risk groups were not excluded from IFN therapy.

The fungal pathogen, Cryptococcus neoformans, has been shown to undergo replicative aging. Old cells are characterized by advanced generational age and phenotypic changes that appear to mediate enhanced resistance to host and antifungal-based killing. As a consequence of this age-associated resilience, old cells accumulate during chronic infection. Based on these findings, we hypothesized that shifting the generational age of a pathogenic yeast population would alter its vulnerability to the host and affect its virulence. SIR2 is a well-conserved histone deacetylase, and a pivotal target for the development of anti-aging drugs. We tested its effect on C. neoformans' replicative lifespan (RLS). First, a mutant C. neoformans strain (sir2Δ) was generated, and confirmed a predicted shortened RLS in sir2Δ cells consistent with its known role in aging. Next, RLS analysis showed that treatment of C. neoformans with Sir2p-agonists resulted in a significantly prolonged RLS, whereas treatment with a Sir2p-antagonist shortened RLS. RLS modulating effects were dependent on SIR2 and not observed in sir2Δ cells. Because SIR2 loss resulted in a slightly impaired fitness, effects of genetic RLS modulation on virulence could not be compared with wild type cells. Instead we chose to chemically modulate RLS, and investigated the effect of Sir2p modulating drugs on C. neoformans cells in a Galleria mellonella infection model. Consistent with our hypothesis that shifts in the generational age of the infecting yeast population alters its vulnerability to host cells, we observed decreased virulence of C. neoformans in the Galleria host when RLS was prolonged by treatment with Sir2p agonists. In contrast, treatment with a Sir2p antagonist, which shortens RLS enhanced virulence in Galleria. In addition, combination of Sir2p agonists with antifungal therapy enhanced the antifungal's effect. Importantly, no difference in virulence was observed with drug treatment when sir2Δ cells were used for infection, which confirmed target specificity and ruled out non-specific effects of the drugs on the Galleria host. Thus, this study suggests that RLS modulating drugs, such as Sir2p agonists, shift lifespan and vulnerability of the fungal population, and should be further investigated as a potential class of novel antifungal drug targets that can enhance antifungal efficacy.

Abnormal nutrient metabolism is a hallmark of aging, and the underlying genetic and nutritional framework is rapidly being uncovered, particularly using C. elegans as a model. However, the direct metabolic consequences of perturbations in life history of C. elegans remain to be clarified. Based on recent advances in the metabolomics field, we optimized and validated a sensitive mass spectrometry (MS) platform for identification of major metabolite classes in worms and applied it to study age and diet related changes. Using this platform that allowed detection of over 600 metabolites in a sample of 2500 worms, we observed marked changes in fatty acids, amino acids and phospholipids during worm life history, which were independent from the germ-line. Worms underwent a striking shift in lipid metabolism after early adulthood that was at least partly controlled by the metabolic regulator AAK-2/AMPK. Most amino acids peaked during development, except aspartic acid and glycine, which accumulated in aged worms. Dietary intervention also influenced worm metabolite profiles and the regulation was highly specific depending on the metabolite class. Altogether, these MS-based methods are powerful tools to perform worm metabolomics for aging and metabolism-oriented studies.


Question: LDL cholesterol is not involved in the progression of cardiovascular illness.

Genome-Wide Association Study Reveals the Role of LDL Cholesterol in Cardiovascular Disease Development
CONTEXT: Accumulating evidence suggests that LDL cholesterol plays a pivotal role in the onset and progression of cardiovascular disease. Uncovering the genetic determinants of LDL cholesterol metabolism could shed light on novel therapeutic strategies. Here, we present the findings from a genome-wide association study focusing on LDL cholesterol levels.
METHODS: We analyzed genome-wide association data from 11,685 individuals across five studies, encompassing 293,461 autosomal SNPs with a minor allele frequency of at least 5% that met our quality control standards. An additional 4,337 participants from three of these studies provided data for 290,140 SNPs from a second genome-wide array. Two independent populations, totaling 4,979 participants, were utilized for replication studies. A series of statistical techniques, including meta-analysis and linkage disequilibrium analysis, were employed to refine association signals. The pooled data from all seven populations were analyzed to assess the impact of each SNP on LDL cholesterol variability.
RESULTS: Our initial scan identified two SNPs (rs599839 and rs4970834) at chromosome 1p13.3 that displayed genome-wide statistical significance for association with LDL cholesterol (p=1.7x10(-15) and p=3.0x10(-11), respectively). A subsequent genome-wide screen revealed a third SNP (rs646776) at the same locus, also showing a strong association (p=4.3x10(-9)). Meta-analysis of the combined data confirmed the association of SNPs rs599839 (combined p=1.2x10(-33)) and rs646776 (p=4.8x10(-20)) with LDL cholesterol levels. These SNPs were found to account for approximately 1% of the variance in circulating LDL cholesterol and were linked to a 15% change in LDL cholesterol per allele, assuming a standard deviation of 1 mmol/L.
CONCLUSION: Our findings support the existence of a novel locus for LDL cholesterol regulation at chromosome 1p13.3. These results offer valuable insights into the underlying mechanisms of LDL cholesterol control and may facilitate the identification of new therapeutic targets for cardiovascular disease prevention and treatment.

The liver X receptors (LXRs) are nuclear receptors with established roles in the regulation of lipid metabolism. We now show that LXR signaling not only regulates macrophage cholesterol metabolism but also impacts antimicrobial responses. Mice lacking LXRs are highly susceptible to infection with the intracellular bacteria Listeria monocytogenes (LM). Bone marrow transplant studies point to altered macrophage function as the major determinant of susceptibility. LXR-null macrophages undergo accelerated apoptosis when challenged with LM and exhibit defective bacterial clearance in vivo. These defects result, at least in part, from loss of regulation of the antiapoptotic factor SPalpha, a direct target for regulation by LXRalpha. Expression of LXRalpha or SPalpha in macrophages inhibits apoptosis in the setting of LM infection. Our results demonstrate that LXR-dependent gene expression plays an unexpected role in innate immunity and suggest that common nuclear receptor pathways mediate macrophage responses to modified lipoproteins and intracellular pathogens.

BACKGROUND C-reactive protein (CRP) is a known risk factor for cardiovascular events in the healthy population and in patients with coronary artery disease. High CRP levels before cardiac surgery are associated with worse short-term outcome, but its role after discharge home remains unknown. The study objective was to evaluate the effect of CRP on short-term and mid-term outcome after cardiac surgery. METHODS From August 2000 to May 2004, values for preoperative CRP were available for 597 unselected patients undergoing cardiac operations. CRP was used to divide this cohort in two groups: a low inflammatory status (LHS) group of 354 patients with CRP of less than 0.5 mg/dL, and a high inflammatory status (HIS) group of 243 patients with a CRP of 0.5 mg/dL or more. Follow-up lasted a maximum of 3 years (median, 1.8 +/- 1.5 years) and was 92.6% complete. RESULTS In-hospital mortality was 8.2% in the HIS group and 3.4% in the LIS group (odds ratio [OR], 2.61; p = 0.02). Incidence of postoperative infections was 16.5% in the HIS group and 5.1% in the LIS group (OR, 3.25; p = 0.0001). Sternal wound infections were also more frequent in the HIS group (10.7% versus 2.8%; OR, 3.43; p = 0.002). During follow-up, the HIS group had worse survival (88.5% +/- 2.9% versus 91.9% +/- 2.5%; OR, 1.93; p = 0.05) and a higher need of hospitalization for cardiac-related causes (73.6% +/- 6% versus 86.5% +/- 3.2%; OR, 1.82; p = 0.05). CONCLUSIONS Patients undergoing cardiac surgery with a CRP level of 0.5 mg/dL or more are exposed to a higher risk of in-hospital mortality and postoperative infections. Despite surgical correction of cardiac disease, a high preoperative CRP value is an independent risk factor for mid-term survival and hospitalization for cardiac causes.

BACKGROUND Variability of gene expression in human may link gene sequence variability and phenotypes; however, non-genetic variations, alone or in combination with genetics, may also influence expression traits and have a critical role in physiological and disease processes. METHODOLOGY/PRINCIPAL FINDINGS To get better insight into the overall variability of gene expression, we assessed the transcriptome of circulating monocytes, a key cell involved in immunity-related diseases and atherosclerosis, in 1,490 unrelated individuals and investigated its association with >675,000 SNPs and 10 common cardiovascular risk factors. Out of 12,808 expressed genes, 2,745 expression quantitative trait loci were detected (P<5.78x10(-12)), most of them (90%) being cis-modulated. Extensive analyses showed that associations identified by genome-wide association studies of lipids, body mass index or blood pressure were rarely compatible with a mediation by monocyte expression level at the locus. At a study-wide level (P<3.9x10(-7)), 1,662 expression traits (13.0%) were significantly associated with at least one risk factor. Genome-wide interaction analyses suggested that genetic variability and risk factors mostly acted additively on gene expression. Because of the structure of correlation among expression traits, the variability of risk factors could be characterized by a limited set of independent gene expressions which may have biological and clinical relevance. For example expression traits associated with cigarette smoking were more strongly associated with carotid atherosclerosis than smoking itself. CONCLUSIONS/SIGNIFICANCE This study demonstrates that the monocyte transcriptome is a potent integrator of genetic and non-genetic influences of relevance for disease pathophysiology and risk assessment.

CONTEXT Hyperhomocysteinemia is caused by genetic and lifestyle influences, including low intakes of folate and vitamin B6. However, prospective data relating intake of these vitamins to risk of coronary heart disease (CHD) are not available. OBJECTIVE To examine intakes of folate and vitamin B6 in relation to the incidence of nonfatal myocardial infarction (MI) and fatal CHD. DESIGN Prospective cohort study. SETTING AND PATIENTS In 1980, a total of 80082 women from the Nurses' Health Study with no previous history of cardiovascular disease, cancer, hypercholesterolemia, or diabetes completed a detailed food frequency questionnaire from which we derived usual intake of folate and vitamin B6. MAIN OUTCOME MEASURE Nonfatal MI and fatal CHD confirmed by World Health Organization criteria. RESULTS During 14 years of follow-up, we documented 658 incident cases of nonfatal MI and 281 cases of fatal CHD. After controlling for cardiovascular risk factors, including smoking and hypertension and intake of alcohol, fiber, vitamin E, and saturated, polyunsaturated, and trans fat, the relative risks (RRs) of CHD between extreme quintiles were 0.69 (95% confidence interval [CI], 0.55-0.87) for folate (median intake, 696 microg/d vs 158 microg/d) and 0.67 (95% CI, 0.53-0.85) for vitamin B6 (median intake, 4.6 mg/d vs 1.1 mg/d). Controlling for the same variables, the RR was 0.55 (95% CI, 0.41-0.74) among women in the highest quintile of both folate and vitamin B6 intake compared with the opposite extreme. Risk of CHD was reduced among women who regularly used multiple vitamins (RR=0.76; 95% CI, 0.65-0.90), the major source of folate and vitamin B6, and after excluding multiple vitamin users, among those with higher dietary intakes of folate and vitamin B6. In a subgroup analysis, compared with nondrinkers, the inverse association between a high-folate diet and CHD was strongest among women who consumed up to 1 alcoholic beverage per day (RR =0.69; 95% CI, 0.49-0.97) or more than 1 drink per day (RR=0.27; 95% CI, 0.13-0.58). CONCLUSION These results suggest that intake of folate and vitamin B6 above the current recommended dietary allowance may be important in the primary prevention of CHD among women.

Introduction. Methods To Study Endothelium-Dependent Responses. Endothelium-Derived Relaxing Factor. Physiological Actions. Other Relaxing Substances Released By the Endothelium. Production of Contracting Agents. Local Regulation of Endothelium-Dependent Responses. Neurohumoral Regulation. Heterogeneity and Chronic Modulation. Disease. Therapeutic Implications. References. Subject Index.

Cholesterol homeostasis is required to maintain normal cellular function and avoid the deleterious effects of hypercholesterolemia. Here we show that the Drosophila DHR96 nuclear receptor binds cholesterol and is required for the coordinate transcriptional response of genes that are regulated by cholesterol and involved in cholesterol uptake, trafficking, and storage. DHR96 mutants die when grown on low levels of cholesterol and accumulate excess cholesterol when maintained on a high-cholesterol diet. The cholesterol accumulation phenotype can be attributed to misregulation of npc1b, an ortholog of the mammalian Niemann-Pick C1-like 1 gene NPC1L1, which is essential for dietary cholesterol uptake. These studies define DHR96 as a central regulator of cholesterol homeostasis.

BACKGROUND Saphenous vein graft (VG) failure occurs more frequently compared with arterial grafts, and graft thrombosis represents the main cause of early occlusion. Because CD40-CD40L pathway CD40 represents a culprit link between local inflammation and coagulation cascade, we investigate the role of CD40 and its soluble ligand (sCD40L) in the immediate in vitro response of VG to arterial pressures, and the potential effects of Simvastatin (Merck Sharp&Dohme, White-house Station, NJ) supplementation. METHODS Samples of saphenous vein and of internal mammary artery (IMA) were obtained from sixteen patients without history of statin therapy. Segments underwent pulsatile pressure distension and culture with or without supplementation of Simvastatin. CD40 and sCD40L were assessed in tissue lysate and in culture supernatant, respectively. sCD40L serum concentrations were also measured. RESULTS During the course of the experiment, the CD40 expression was significantly lower in IMA samples compared with both distended and not distended VG. Pressure distension up-regulated the production of CD40 in VG segments after 24 and 48 h. Statin supplementation significantly reduced the expression of CD40 in both venous (P < 0.001) and arterial samples (P < 0.001). This effect of Simvastatin was not affected by the treatment with L-NAME, but it was reversed by the addition of mevalonic acid. Mean sCD40L content in culture supernatants increased over time, suggesting that not only platelets but also the vessel wall is a source of CD40 and sCD40L. CONCLUSIONS Simvastatin treatment modulates endothelial CD40-sCD40L in both venous and arterial grafts, and therefore may represent a useful tool in the pharmacological prevention of graft failure.

BACKGROUND A reduction in compliance of the large-sized cardiothoracic (central) arteries is an independent risk factor for the development of cardiovascular disease with advancing age. METHODS AND RESULTS We determined the role of habitual exercise on the age-related decrease in central arterial compliance by using both cross-sectional and interventional approaches. First, we studied 151 healthy men aged 18 to 77 years: 54 were sedentary, 45 were recreationally active, and 53 were endurance exercise-trained. Central arterial compliance (simultaneous B-mode ultrasound and arterial applanation tonometry on the common carotid artery) was lower (P:<0.05) in middle-aged and older men than in young men in all 3 groups. There were no significant differences between sedentary and recreationally active men at any age. However, arterial compliance in the endurance-trained middle-aged and older men was 20% to 35% higher than in the 2 less active groups (P:<0.01). As such, age-related differences in central arterial compliance were smaller in the endurance-trained men than in the sedentary and recreationally active men. Second, we studied 20 middle-aged and older (53+/-2 years) sedentary healthy men before and after a 3-month aerobic exercise intervention (primarily walking). Regular exercise increased central arterial compliance (P:<0.01) to levels similar to those of the middle-aged and older endurance-trained men. These effects were independent of changes in body mass, adiposity, arterial blood pressure, or maximal oxygen consumption. CONCLUSIONS Regular aerobic-endurance exercise attenuates age-related reductions in central arterial compliance and restores levels in previously sedentary healthy middle-aged and older men. This may be one mechanism by which habitual exercise lowers the risk of cardiovascular disease in this population.

CONTEXT Gallstone disease is a leading cause of morbidity in western countries and carries a high economic burden. Statins decrease hepatic cholesterol biosynthesis and may therefore lower the risk of cholesterol gallstones by reducing the cholesterol concentration in the bile. Data on this association in humans are scarce. OBJECTIVE To study the association between the use of statins, fibrates, or other lipid-lowering agents and the risk of incident gallstone disease followed by cholecystectomy. DESIGN, SETTING, AND PARTICIPANTS Case-control analysis using the UK-based General Practice Research Database. Incident patients between 1994 and 2008 and 4 controls per each patient were identified and matched on age, sex, general practice, calendar time, and years of history in the database. The study population was 76% women and the mean (SD) age was 53.4 (15.0) years at the index date. Conditional logistic regression was used to estimate the odds ratio (OR) of developing gallstones followed by cholecystectomy in relation to exposure to lipid-lowering agents, stratified by exposure timing and duration. The ORs and 95% confidence intervals (CIs) were adjusted for smoking, body mass index, ischemic heart disease, stroke, and estrogen use. MAIN OUTCOME MEASURE The adjusted OR (AOR) for developing gallstone disease followed by cholecystectomy in relation to exposure to lipid-lowering agents. RESULTS A total of 27,035 patients with cholecystectomy and 106,531 matched controls were identified, including 2396 patients and 8868 controls who had statin use. Compared with nonuse, current statin use (last prescription recorded within 90 days before the first-time diagnosis of the disease) was 1.0% for patients and 0.8% for controls (AOR, 1.10; 95% CI, 0.95-1.27) for 1 to 4 prescriptions; 2.6% vs 2.4% (AOR, 0.85; 95% CI, 0.77-0.93) for 5 to 19 prescriptions, and 3.2% vs 3.7% (AOR, 0.64; 95% CI, 0.59-0.70) for 20 or more prescriptions. The AORs for current use of statins defined as 20 or more prescriptions were similar (around 0.6) across age, sex, and body mass index categories, and across the statin class. CONCLUSION Long-term use of statins was associated with a decreased risk of gallstones followed by cholecystectomy.

The role of specific phospholipids (PLs) in lipid transport has been difficult to assess due to an inability to selectively manipulate membrane composition in vivo. Here we show that the phospholipid remodeling enzyme lysophosphatidylcholine acyltransferase 3 (Lpcat3) is a critical determinant of triglyceride (TG) secretion due to its unique ability to catalyze the incorporation of arachidonate into membranes. Mice lacking Lpcat3 in the intestine fail to thrive during weaning and exhibit enterocyte lipid accumulation and reduced plasma TGs. Mice lacking Lpcat3 in the liver show reduced plasma TGs, hepatosteatosis, and secrete lipid-poor very low-density lipoprotein (VLDL) lacking arachidonoyl PLs. Mechanistic studies indicate that Lpcat3 activity impacts membrane lipid mobility in living cells, suggesting a biophysical basis for the requirement of arachidonoyl PLs in lipidating lipoprotein particles. These data identify Lpcat3 as a key factor in lipoprotein production and illustrate how manipulation of membrane composition can be used as a regulatory mechanism to control metabolic pathways.


Question: Absence of clpC has no impact on sporulation efficacy in Bacillus subtilis cells.

High-Throughput Genetic Screens Reveal Numerous Uncharacterized Sporulation Genes in Bacillus subtilis

The transition of Bacillus subtilis into a dormant spore is a highly studied developmental pathway in microbiology. Decades of traditional genetic screens have revealed a multitude of components involved in every phase of this complex morphological transformation. More recently, transcriptional profiling has unveiled further sporulation-induced genes that are crucial for successful spore development. In this study, we employed transposon-sequencing (Tn-seq) to determine if any sporulation genes had yet to be identified. Our screen successfully pinpointed 133 out of the 148 genes previously known to exhibit sporulation defects. Unexpectedly, we also uncovered 24 previously unknown genes that play a role in spore formation. To elucidate their functions, we conducted fluorescence microscopy on early, middle, and late stages of differentiation for null mutants from the B. subtilis ordered knockout collection. This investigation revealed mutants that exhibit delays in sporulation initiation, defects in membrane remodeling, and impairments in spore maturation. Some mutants displayed novel sporulation phenotypes. We conducted an in-depth analysis of two novel factors that are involved in cell-cell signaling pathways during sporulation. One (SpoIIT) contributes to the activation of σE in the mother cell, while the other (SpoIIIL) is essential for σG activity in the forespore. Our study also indicated that up to 36 sporulation-induced genes, previously without reported mutant phenotypes, are necessary for timely spore maturation. Moreover, we identified a significant set of transposon insertions that induce premature initiation of sporulation. Our findings underscore the efficacy of Tn-seq in uncovering new genes and pathways in sporulation, and combined with the recently completed null mutant collection, pave the way for similar screens in less explored biological processes.

Clathrin has an established function in the generation of vesicles that transfer membrane and proteins around the cell. The formation of clathrin-coated vesicles occurs continuously in non-dividing cells, but is shut down during mitosis, when clathrin concentrates at the spindle apparatus. Here, we show that clathrin stabilizes fibres of the mitotic spindle to aid congression of chromosomes. Clathrin bound to the spindle directly by the amino-terminal domain of clathrin heavy chain. Depletion of clathrin heavy chain using RNA interference prolonged mitosis; kinetochore fibres were destabilized, leading to defective congression of chromosomes to the metaphase plate and persistent activation of the spindle checkpoint. Normal mitosis was rescued by clathrin triskelia but not the N-terminal domain of clathrin heavy chain, indicating that stabilization of kinetochore fibres was dependent on the unique structure of clathrin. The importance of clathrin for normal mitosis may be relevant to understanding human cancers that involve gene fusions of clathrin heavy chain.

Virulence in Staphylococcus aureus is largely under control of the accessory gene regulator (agr) quorum-sensing system. The AgrC receptor histidine kinase detects its autoinducing peptide (AIP) ligand and generates an intracellular signal resulting in secretion of virulence factors. Although agr is a well-studied quorum-sensing system, little is known about the mechanism of AgrC activation. By co-immunoprecipitation analysis and intermolecular complementation of receptor mutants, we showed that AgrC forms ligand-independent dimers that undergo trans-autophosphorylation upon interaction with AIP. Remarkably, addition of specific AIPs to AgrC mutant dimers with only one functional sensor domain caused symmetric activation of either kinase domain despite the sensor asymmetry. Furthermore, mutant dimers involving one constitutive protomer demonstrated ligand-independent activity, irrespective of which protomer was kinase deficient. These results demonstrate that signalling through either individual AgrC protomer causes symmetric activation of both kinase domains. We suggest that such signalling across the dimer interface may be an important mechanism for dimeric quorum-sensing receptors to rapidly elicit a response upon signal detection.

SecDFyajC of Escherichia coli is required for efficient export of proteins in vivo. However, the functional role of SecDFyajC in protein translocation is unclear. We evaluated the postulated function of SecDFyajC in the maintenance of the proton motive force. As previously reported, inner membrane vesicles (IMVs) lacking SecDFyajC are defective in the generation of a stable proton motive force when energized with succinate. This phenomenon is, however, not observed when NADH is used as an electron donor. Moreover, the proton motive force generated in SecDFyajC-depleted vesicles stimulated translocation to the same extent as seen with IMVs containing SecDFyajC. Further analysis demonstrates that the reduced proton motive force with succinate in IMVs lacking SecDFyajC is due to a lower amount of the enzyme succinate dehydrogenase. The expression of this enzyme complex is repressed by growth on glucose media, the condition used to deplete SecDFyajC. These results demonstrate that SecDFyajC is not required for proton motive force-driven protein translocation.

Evolutionary related multisubunit RNA polymerases (RNAPs) transcribe the genomes of all living organisms. Whereas the core subunits of RNAPs are universally conserved in all three domains of life-indicative of a common evolutionary descent-this only applies to one RNAP-associated transcription factor-Spt5, also known as NusG in bacteria. All other factors that aid RNAP during the transcription cycle are specific for the individual domain or only conserved between archaea and eukaryotes. Spt5 and its bacterial homologue NusG regulate gene expression in several ways by (i) modulating transcription processivity and promoter proximal pausing, (ii) coupling transcription and RNA processing or translation, and (iii) recruiting termination factors and thereby silencing laterally transferred DNA and protecting the genome against double-stranded DNA breaks. This review discusses recent discoveries that identify Spt5-like factors as evolutionary conserved nexus for the regulation and coordination of the machineries responsible for information processing in the cell.

Cyclin A is a stable protein in S and G2 phases, but is destabilized when cells enter mitosis and is almost completely degraded before the metaphase to anaphase transition. Microinjection of antibodies against subunits of the anaphase-promoting complex/cyclosome (APC/C) or against human Cdc20 (fizzy) arrested cells at metaphase and stabilized both cyclins A and B1. Cyclin A was efficiently polyubiquitylated by Cdc20 or Cdh1-activated APC/C in vitro, but in contrast to cyclin B1, the proteolysis of cyclin A was not delayed by the spindle assembly checkpoint. The degradation of cyclin B1 was accelerated by inhibition of the spindle assembly checkpoint. These data suggest that the APC/C is activated as cells enter mitosis and immediately targets cyclin A for degradation, whereas the spindle assembly checkpoint delays the degradation of cyclin B1 until the metaphase to anaphase transition. The “destruction box” (D-box) of cyclin A is 10–20 residues longer than that of cyclin B. Overexpression of wild-type cyclin A delayed the metaphase to anaphase transition, whereas expression of cyclin A mutants lacking a D-box arrested cells in anaphase.

Resistance to apoptosis, often achieved by the overexpression of antiapoptotic proteins, is common and perhaps required in the genesis of cancer. However, it remains uncertain whether apoptotic defects are essential for tumor maintenance. To test this, we generated mice expressing a conditional BCL-2 gene and constitutive c-myc that develop lymphoblastic leukemia. Eliminating BCL-2 yielded rapid loss of leukemic cells and significantly prolonged survival, formally validating BCL-2 as a rational target for cancer therapy. Loss of this single molecule resulted in cell death, despite or perhaps attributable to the presence of other oncogenic events. This suggests a generalizable model in which aberrations inherent to cancer generate tonic death signals that would otherwise kill the cell if not opposed by a requisite apoptotic defect(s).

Chronic inflammation is a known risk factor for tumorigenesis, yet the precise mechanism of this association is currently unknown. The inflammasome, a multiprotein complex formed by NOD-like receptor (NLR) family members, has recently been shown to orchestrate multiple innate and adaptive immune responses, yet its potential role in inflammation-induced cancer has been little studied. Using the azoxymethane and dextran sodium sulfate colitis-associated colorectal cancer model, we show that caspase-1-deficient (Casp1(-/-)) mice have enhanced tumor formation. Surprisingly, the role of caspase-1 in tumorigenesis was not through regulation of colonic inflammation, but rather through regulation of colonic epithelial cell proliferation and apoptosis. Consequently, caspase-1-deficient mice demonstrate increased colonic epithelial cell proliferation in early stages of injury-induced tumor formation and reduced apoptosis in advanced tumors. We suggest a model in which the NLRC4 inflammasome is central to colonic inflammation-induced tumor formation through regulation of epithelial cell response to injury.

Apoptosis that proceeds via the mitochondrial pathway involves mitochondrial outer membrane permeabilization (MOMP), responsible for the release of cytochrome c and other proteins of the mitochondrial intermembrane space. This essential step is controlled and mediated by proteins of the Bcl-2 family. The proapoptotic proteins Bax and Bak are required for MOMP, while the antiapoptotic Bcl-2 proteins, including Bcl-2, Bcl-xL, Mcl-1, and others, prevent MOMP. Different proapoptotic BH3-only proteins act to interfere with the function of the antiapoptotic Bcl-2 members and/or activate Bax and Bak. Here, we discuss an emerging view, proposed by Certo et al. in this issue of Cancer Cell, on how these interactions result in MOMP and apoptosis.

Membrane fission is a fundamental step in membrane transport. So far, the only fission protein machinery that has been implicated in in vivo transport involves dynamin, and functions in several, but not all, transport pathways. Thus, other fission machineries may exist. Here, we report that carboxy-terminal binding protein 3/brefeldin A-ribosylated substrate (CtBP3/BARS) controls fission in basolateral transport from the Golgi to the plasma membrane and in fluid-phase endocytosis, whereas dynamin is not involved in these steps. Conversely, CtBP3/BARS protein is inactive in apical transport to the plasma membrane and in receptor-mediated endocytosis, both steps being controlled by dynamin. This indicates that CtBP3/BARS controls membrane fission in endocytic and exocytic transport pathways, distinct from those that require dynamin.

Micrococcus, which, when limited in its extent and activity, causes acute suppurative inflammation (phlegmon), produces, when more extensive and intense in its action on the human system, the most virulent forms of septicaemia and pyaemia.1 In an elegant series of clinical observations and laboratory studies published in 1880 and 1882, Ogston described staphylococcal disease and its role in sepsis and abscess formation.1,2 More than 100 years later, Staphylococcus aureus remains a versatile and dangerous pathogen in humans. The frequencies of both community-acquired and hospital-acquired staphylococcal infections have increased steadily, with little change in overall mortality. Treatment of these infections . . .


Question: Fewer than 10% of Gabonese children diagnosed with Schimmelpenning-Feuerstein-Mims syndrome (SFM) presented with a plasma lactate level exceeding 5mmol/L.

Evaluation of Fluid Volume Status in Pediatric Malaria Cases
Context: The extent of fluid volume depletion in severe malaria cases is not well-established, yet understanding the dynamics of fluid compartments is crucial for guiding therapeutic interventions. To aid in the clinical management of critically ill children and to explore whether changes in fluid compartment volumes correlate with disease severity, we assessed body fluid volumes in Gabonese children diagnosed with malaria.
Methods and Findings: We utilized heavy water and bromide tracer dilution techniques to estimate total body water volume (TBW) and extracellular water volume (ECW) in children with severe or moderate malaria, as well as during their recovery phase. Intracellular water volume (ICW) was calculated from these measurements. Bioelectrical impedance analysis (BIA) was calibrated against the dilution methods and used to monitor TBW and ECW daily until the children were discharged. The study included 16 children with severe malaria and 19 with moderate malaria. Severe malaria in children was characterized by a TBW deficit, averaging 37 ml/kg (SD 33 ml/kg), or approximately 6.7% (SD 6.0%) relative to TBW at discharge. This level of TBW reduction is typically indicative of mild dehydration in other conditions. ECW values were within normal range upon admission for children with severe malaria and did not increase significantly in the initial days following admission. No correlation was observed between fluid volumes in different compartments (TBW, ECW, ICW) and markers of disease severity such as hyperlactataemia. Moderate malaria did not lead to a significant TBW depletion.

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The balance between oxidative and nonoxidative glucose metabolism is essential for a number of pathophysiological processes. By deleting enzymes that affect aerobic glycolysis with different potencies, we examine how modulating glucose metabolism specifically affects hematopoietic and leukemic cell populations. We find that a deficiency in the M2 pyruvate kinase isoform (PKM2) reduces the levels of metabolic intermediates important for biosynthesis and impairs progenitor function without perturbing hematopoietic stem cells (HSCs), whereas lactate dehydrogenase A (LDHA) deletion significantly inhibits the function of both HSCs and progenitors during hematopoiesis. In contrast, leukemia initiation by transforming alleles putatively affecting either HSCs or progenitors is inhibited in the absence of either PKM2 or LDHA, indicating that the cell-state-specific responses to metabolic manipulation in hematopoiesis do not apply to the setting of leukemia. This finding suggests that fine-tuning the level of glycolysis may be explored therapeutically for treating leukemia while preserving HSC function.

BACKGROUND Transmission of dengue viruses (DENV), the leading cause of arboviral disease worldwide, is known to vary through time and space, likely owing to a combination of factors related to the human host, virus, mosquito vector, and environment. An improved understanding of variation in transmission patterns is fundamental to conducting surveillance and implementing disease prevention strategies. To test the hypothesis that DENV transmission is spatially and temporally focal, we compared geographic and temporal characteristics within Thai villages where DENV are and are not being actively transmitted. METHODS AND FINDINGS Cluster investigations were conducted within 100 m of homes where febrile index children with (positive clusters) and without (negative clusters) acute dengue lived during two seasons of peak DENV transmission. Data on human infection and mosquito infection/density were examined to precisely (1) define the spatial and temporal dimensions of DENV transmission, (2) correlate these factors with variation in DENV transmission, and (3) determine the burden of inapparent and symptomatic infections. Among 556 village children enrolled as neighbors of 12 dengue-positive and 22 dengue-negative index cases, all 27 DENV infections (4.9% of enrollees) occurred in positive clusters (p < 0.01; attributable risk [AR] = 10.4 per 100; 95% confidence interval 1-19.8 per 100]. In positive clusters, 12.4% of enrollees became infected in a 15-d period and DENV infections were aggregated centrally near homes of index cases. As only 1 of 217 pairs of serologic specimens tested in positive clusters revealed a recent DENV infection that occurred prior to cluster initiation, we attribute the observed DENV transmission subsequent to cluster investigation to recent DENV transmission activity. Of the 1,022 female adult Ae. aegypti collected, all eight (0.8%) dengue-infected mosquitoes came from houses in positive clusters; none from control clusters or schools. Distinguishing features between positive and negative clusters were greater availability of piped water in negative clusters (p < 0.01) and greater number of Ae. aegypti pupae per person in positive clusters (p = 0.04). During primarily DENV-4 transmission seasons, the ratio of inapparent to symptomatic infections was nearly 1:1 among child enrollees. Study limitations included inability to sample all children and mosquitoes within each cluster and our reliance on serologic rather than virologic evidence of interval infections in enrollees given restrictions on the frequency of blood collections in children. CONCLUSIONS Our data reveal the remarkably focal nature of DENV transmission within a hyperendemic rural area of Thailand. These data suggest that active school-based dengue case detection prompting local spraying could contain recent virus introductions and reduce the longitudinal risk of virus spread within rural areas. Our results should prompt future cluster studies to explore how host immune and behavioral aspects may impact DENV transmission and prevention strategies. Cluster methodology could serve as a useful research tool for investigation of other temporally and spatially clustered infectious diseases.

Abstract Feline leukemia virus (FeLV), Gammaretrovirus, and feline immunodeficiency virus, a Lentivirus, are members of the family Retroviridae, and may establish persistent infections in the domestic cat (Felis catus). Cytoproliferative and cytosuppressive disorders may result from infection with these viruses. Morbidity and mortality rates are high in domestic cats worldwide. Infection of endangered neotropic small felids with these viruses could be devastating. To investigate the prevalence of FeLV and feline lentiviruses in neotropic small felids kept in captivity in São Paulo state, Brazil, serum samples from 104 animals belonging to the species Leopardus pardalis, Leopardus tigrinus, Leopardus wiedii, Herpailurus yaguarondi, and Oncifelis geoffroyi were tested for FeLV and feline lentiviruses by commercially available immunoassays. All results were negative, suggesting that retrovirus infection is not an important clinical problem in these populations. Because domestic cats in São Paulo city are naturally infected with these pathogens, and feral cats are commonly found in zoologic facilities in Brazil, preventive measures should be taken to avoid transmission of retroviruses to naive populations of wild and captive neotropic felids in Brazil.

PURPOSE To define copy number alterations and gene expression signatures underlying pediatric high-grade glioma (HGG). PATIENTS AND METHODS We conducted a high-resolution analysis of genomic imbalances in 78 de novo pediatric HGGs, including seven diffuse intrinsic pontine gliomas, and 10 HGGs arising in children who received cranial irradiation for a previous cancer using single nucleotide polymorphism microarray analysis. Gene expression was analyzed with gene expression microarrays for 53 tumors. Results were compared with publicly available data from adult tumors. RESULTS Significant differences in copy number alterations distinguish childhood and adult glioblastoma. PDGFRA was the predominant target of focal amplification in childhood HGG, including diffuse intrinsic pontine gliomas, and gene expression analyses supported an important role for deregulated PDGFRalpha signaling in pediatric HGG. No IDH1 hotspot mutations were found in pediatric tumors, highlighting molecular differences with adult secondary glioblastoma. Pediatric and adult glioblastomas were clearly distinguished by frequent gain of chromosome 1q (30% v 9%, respectively) and lower frequency of chromosome 7 gain (13% v 74%, respectively) and 10q loss (35% v 80%, respectively). PDGFRA amplification and 1q gain occurred at significantly higher frequency in irradiation-induced tumors, suggesting that these are initiating events in childhood gliomagenesis. A subset of pediatric HGGs showed minimal copy number changes. CONCLUSION Integrated molecular profiling showed substantial differences in the molecular features underlying pediatric and adult HGG, indicating that findings in adult tumors cannot be simply extrapolated to younger patients. PDGFRalpha may be a useful target for pediatric HGG, including diffuse pontine gliomas.

The Bruce treadmill protocol is suitable for children as young as age 4 years. Maximal endurance time may be used as the sole criterion of exercise capacity, and normal values were established with 327 children having an innocent heart murmur. Mean endurance time in boys increased from 10.4 minutes at age 4 to 5 years, to 14.1 minutes at age 13 to 15 years. Mean endurance time in girls increased from 9.5 minutes at age 4 to 5 years to 12.3 minutes at age 10 to 12 years. Mean maximal heart rate ranged from 193 to 206 beats/min. Age differences in mean maximal and submaximal heart rates were small. There were negative correlations between endurance time and the ratio of weight to height. There were negative correlations between heart rates at treadmill stages 1 to 3 and the endurance times. The correlation coefficient of endurance time with maximal oxygen uptake was 0.88, but for clinical purposes endurance time alone is a satisfactory indicator of exercise performance.

Bardet-Biedl syndrome, BBS, is a rare autosomal recessive disorder with clinical presentations including polydactyly, retinopathy, hyperphagia, obesity, short stature, cognitive impairment, and developmental delays. Disruptions of BBS proteins in a variety of organisms impair cilia formation and function and the multi-organ defects of BBS have been attributed to deficiencies in various cilia-associated signaling pathways. In C. elegans, bbs genes are expressed exclusively in the sixty ciliated sensory neurons of these animals and bbs mutants exhibit sensory defects as well as body size, feeding, and metabolic abnormalities. Here we show that in contrast to many other cilia-defective mutants, C. elegans bbs mutants exhibit increased release of dense-core vesicles and organism-wide phenotypes associated with enhanced activities of insulin, neuropeptide, and biogenic amine signaling pathways. We show that the altered body size, feeding, and metabolic abnormalities of bbs mutants can be corrected to wild-type levels by abrogating the enhanced secretion of dense-core vesicles without concomitant correction of ciliary defects. These findings expand the role of BBS proteins to the regulation of dense-core-vesicle exocytosis and suggest that some features of Bardet-Biedl Syndrome may be caused by excessive neuroendocrine secretion.

OBJECTIVE To determine spatial patterns of co-endemicity of schistosomiasis mansoni and the soil-transmitted helminths (STHs) Ascaris lumbricoides, Trichuris trichiura and hookworm in the Great Lakes region of East Africa, to help plan integrated neglected tropical disease programmes in this region. METHOD Parasitological surveys were conducted in Uganda, Tanzania, Kenya and Burundi in 28 213 children in 404 schools. Bayesian geostatistical models were used to interpolate prevalence of these infections across the study area. Interpolated prevalence maps were overlaid to determine areas of co-endemicity. RESULTS In the Great Lakes region, prevalence was 18.1% for Schistosoma mansoni, 50.0% for hookworm, 6.8% for A. lumbricoides and 6.8% for T. trichiura. Hookworm infection was ubiquitous, whereas S. mansoni, A. lumbricoides and T. trichiura were highly focal. Most areas were endemic (prevalence >or=10%) or hyperendemic (prevalence >or=50%) for one or more STHs, whereas endemic areas for schistosomiasis mansoni were restricted to foci adjacent large perennial water bodies. CONCLUSION Because of the ubiquity of hookworm, treatment programmes are required for STH throughout the region but efficient schistosomiasis control should only be targeted at limited high-risk areas. Therefore, integration of schistosomiasis with STH control is only indicated in limited foci in East Africa.

An observational prospective cohort study assessed malaria risk perception, knowledge and prophylaxis practices among individuals of African ethnicity living in Paris and travelling to their country of origin to visit friends or relatives (VFR). The study compared two groups of VFR who had visited a travel clinic (TC; n=122) or a travel agency (TA; n=69) before departure. Of the 47% of VFR citing malaria as a health concern, 75% knew that malaria is mosquito-borne and that bed nets are an effective preventive measure. Perception of high malaria risk was greater in the TA group (33%) than in the TC group (7%). The availability of a malaria vaccine was mentioned by 35% of VFR, with frequent confusion between yellow fever vaccine and malaria prevention. Twenty-nine percent took adequate chemoprophylaxis with complete adherence, which was higher among the TC group (41%) than the TA group (12%). Effective antivector protection measures used were bed nets (16%), wearing long clothes at night (14%) and air conditioning (8%), with no differences between the study groups except in the use of impregnated bed nets (11% of the TC group and none of the TA group). Media coverage, malaria chemoprophylaxis repayment and cultural adaptation of preventive messages should be improved to reduce the high rate of inadequate malaria prophylaxis in VFR.

OBJECTIVE To establish the incidence and aetiology of infectious intestinal disease in the community and presenting to general practitioners. Comparison with incidence and aetiology of cases reaching national laboratory based surveillance. DESIGN Population based community cohort incidence study, general practice based incidence studies, and case linkage to national laboratory surveillance. SETTING 70 general practices throughout England. PARTICIPANTS 459 975 patients served by the practices. Community surveillance of 9776 randomly selected patients. MAIN OUTCOME MEASURES Incidence of infectious intestinal disease in community and reported to general practice. RESULTS 781 cases were identified in the community cohort, giving an incidence of 19.4/100 person years (95% confidence interval 18.1 to 20.8). 8770 cases presented to general practice (3.3/100 person years (2.94 to 3.75)). One case was reported to national surveillance for every 1.4 laboratory identifications, 6.2 stools sent for laboratory investigation, 23 cases presenting to general practice, and 136 community cases. The ratio of cases in the community to cases reaching national surveillance was lower for bacterial pathogens (salmonella 3.2:1, campylobacter 7.6:1) than for viruses (rotavirus 35:1, small round structured viruses 1562:1). There were many cases for which no organism was identified. CONCLUSIONS Infectious intestinal disease occurs in 1 in 5 people each year, of whom 1 in 6 presents to a general practitioner. The proportion of cases not recorded by national laboratory surveillance is large and varies widely by microorganism. Ways of supplementing the national laboratory surveillance system for infectious intestinal diseases should be considered.

Acute paraquat poisoning is often fatal. Many studies have investigated successful treatment modalities, but no standard treatment yet exists. The purpose of this study was to determine the predictors of survival after acute paraquat poisoning in 602 patients. The paraquat exposure was assessed based on the amount of ingested paraquat and a semiquantitative measure of the urine level of paraquat. Initial clinical parameters including vital signs, hemoglobin, white-blood-cell count, pH, PaCO2, PaO2, blood urea nitrogen, creatinine, aspartate aminotransferase, alanine aminotransferase, total bilirubin, amylase, and glucose were obtained at the time of arrival at the emergency room. Outcomes after acute paraquat poisoning were categorized as survivors and nonsurvivors. Multiple logistic regression analysis was applied to assess the predictors of survival after acute paraquat poisoning. Some patients (55.5%) survived after oral ingestion of paraquat, whereas all those exposed to paraquat percutaneous or inhalational route survived. The amount of paraquat (24.5% concentrate of 1,1'-dimethyl-4,4'-bipyridium dichloride) ingested was 45.6 +/- 74.1 mL (mean +/- SD). In addition to degree of paraquat exposure, survival after acute paraquat poisoning was associated with age, respiratory rate, pH, PaCO2, hemoglobin, white-blood-cell count, blood urea nitrogen, amylase, and the number of failed organs in multiple logistic regression analysis. In conclusion, young age, percutaneous or inhalational route, exposure to less paraquat, and lesser degrees of leukocytosis, acidosis, and renal, hepatic, and pancreatic failures on admission are good prognostic factors of survival after acute paraquat poisoning.


Question: Leukemia-associated Rho guanine nucleotide-exchange factor inhibits RhoA upon SRC activation.

The Role of LARG and GEF-H1 in Mediating the Cellular Response to Mechanical Stress on Integrins. The investigation into how cells perceive and react to mechanical forces is a critical area of biological research, given the profound impact force has on various cellular processes. When force is applied to integrins, it instigates cytoskeletal modifications and expansion of adhesion complexes, leading to enhanced cellular rigidity, a phenomenon known as reinforcement. Although RhoA is known to be involved in reinforcement, the specific mechanisms controlling its activity remain elusive. Through an integrated approach combining biochemical and biophysical techniques, we have pinpointed two guanine nucleotide exchange factors (GEFs), Leukemia-associated RhoGEF (LARG) and GEF-H1, as central players in the cell's adaptive response to force. We demonstrate that the application of tensional force to integrins activates these GEFs and facilitates their localization to adhesion complexes. Intriguingly, the activation of LARG and GEF-H1 is mediated through separate signaling pathways. Our findings uncover that LARG activation is orchestrated by the Src family tyrosine kinase Fyn, while GEF-H1's enhanced catalytic activity is regulated by ERK, downstream of a signaling cascade involving FAK and Ras.

Although GBP1 (guanylate binding protein 1) was among the first interferon-inducible proteins identified, its function is still largely unknown. Epidermal growth factor receptor (EGFR) activation by amplification or mutation is one of the most frequent genetic lesions in a variety of human tumors. These include glioblastoma multiforme (GBM), which is characterized by independent but interrelated features of extensive invasion into normal brain parenchyma, rapid growth, necrosis, and angiogenesis. In this study, we show that EGFR activation promoted GBP1 expression in GBM cell lines through a signaling pathway involving Src and p38 mitogen-activated protein kinase. Moreover, we identified YY1 (Yin Yang 1) as the downstream transcriptional regulator regulating EGFR-driven GBP1 expression. GBP1 was required for EGFR-mediated MMP1 (matrix metalloproteinase 1) expression and glioma cell invasion in vitro. Although deregulation of GBP1 expression did not affect glioma cell proliferation, overexpression of GBP1 enhanced glioma cell invasion through MMP1 induction, which required its C-terminal helical domain and was independent of its GTPase activity. Reducing GBP1 levels by RNA interference in invasive GBM cells also markedly inhibited their ability to infiltrate the brain parenchyma of mice. GBP1 expression was high and positively correlated with EGFR expression in human GBM tumors and cell lines, particularly those of the neural subtype. Together, these findings establish GBP1 as a previously unknown link between EGFR activity and MMP1 expression and nominate it as a novel potential therapeutic target for inhibiting GBM invasion.

Relapsed childhood acute lymphoblastic leukemia (ALL) carries a poor prognosis, despite intensive retreatment, owing to intrinsic drug resistance. The biological pathways that mediate resistance are unknown. Here, we report the transcriptome profiles of matched diagnosis and relapse bone marrow specimens from ten individuals with pediatric B-lymphoblastic leukemia using RNA sequencing. Transcriptome sequencing identified 20 newly acquired, novel nonsynonymous mutations not present at initial diagnosis, with 2 individuals harboring relapse-specific mutations in the same gene, NT5C2, encoding a 5'-nucleotidase. Full-exon sequencing of NT5C2 was completed in 61 further relapse specimens, identifying additional mutations in 5 cases. Enzymatic analysis of mutant proteins showed that base substitutions conferred increased enzymatic activity and resistance to treatment with nucleoside analog therapies. Clinically, all individuals who harbored NT5C2 mutations relapsed early, within 36 months of initial diagnosis (P = 0.03). These results suggest that mutations in NT5C2 are associated with the outgrowth of drug-resistant clones in ALL.

Despite progress in the development of drugs that efficiently target cancer cells, treatments for metastatic tumours are often ineffective. The now well-established dependency of cancer cells on their microenvironment suggests that targeting the non-cancer-cell component of the tumour might form a basis for the development of novel therapeutic approaches. However, the as-yet poorly characterized contribution of host responses during tumour growth and metastatic progression represents a limitation to exploiting this approach. Here we identify neutrophils as the main component and driver of metastatic establishment within the (pre-)metastatic lung microenvironment in mouse breast cancer models. Neutrophils have a fundamental role in inflammatory responses and their contribution to tumorigenesis is still controversial. Using various strategies to block neutrophil recruitment to the pre-metastatic site, we demonstrate that neutrophils specifically support metastatic initiation. Importantly, we find that neutrophil-derived leukotrienes aid the colonization of distant tissues by selectively expanding the sub-pool of cancer cells that retain high tumorigenic potential. Genetic or pharmacological inhibition of the leukotriene-generating enzyme arachidonate 5-lipoxygenase (Alox5) abrogates neutrophil pro-metastatic activity and consequently reduces metastasis. Our results reveal the efficacy of using targeted therapy against a specific tumour microenvironment component and indicate that neutrophil Alox5 inhibition may limit metastatic progression.

We have previously demonstrated that, following acquisition of endocrine resistance, breast cancer cells display an altered growth rate together with increased aggressive behaviour in vitro. Since dysfunctional cell-cell adhesive interactions can promote an aggressive phenotype, we investigated the integrity of this protein complex in our breast cancer model of tamoxifen resistance. In culture, tamoxifen-resistant MCF7 (TamR) cells grew as loosely packed colonies with loss of cell-cell junctions and demonstrated altered morphology characteristic of cells undergoing epithelial-to-mesenchymal transition (EMT). Neutralising E-cadherin function promoted the invasion and inhibited the aggregation of endocrine-sensitive MCF7 cells, whilst having little effect on the behaviour of TamR cells. Additionally, TamR cells had increased levels of tyrosine-phosphorylated beta-catenin, whilst serine/threonine-phosphorylated beta-catenin was decreased. These cells also displayed loss of association between beta-catenin and E-cadherin, increased cytoplasmic and nuclear beta-catenin and elevated transcription of beta-catenin target genes known to be involved in tumour progression and EMT. Inhibition of EGFR kinase activity in TamR cells reduced beta-catenin tyrosine phosphorylation, increased beta-catenin-E-cadherin association and promoted cell-cell adhesion. In such treated cells, the association of beta-catenin with Lef-1 and the transcription of c-myc, cyclin-D1, CD44 and COX-2 were also reduced. These results suggest that homotypic adhesion in tamoxifen-resistant breast cancer cells is dysfunctional due to EGFR-driven modulation of the phosphorylation status of beta-catenin and may contribute to an enhanced aggressive phenotype and transition towards a mesenchymal phenotype in vitro.

Integrins are membrane receptors which mediate cell-cell or cell-matrix adhesion. Integrin alpha IIb beta 3 (glycoprotein IIb-IIIa) acts as a fibrinogen receptor of platelets and mediates platelet aggregation. Platelet activation is required for alpha IIb beta 3 to shift from noncompetent to competent for binding soluble fibrinogen. The steps involved in this transition are poorly understood. We have studied a variant of Glanzmann thrombasthenia, a congenital bleeding disorder characterized by absence of platelet aggregation and fibrinogen binding. The patient's platelets did not bind fibrinogen after platelet activation by ADP or thrombin, though his platelets contained alpha IIb beta 3. However, isolated alpha IIb beta 3 was able to bind to an Arg-Gly-Asp-Ser affinity column, and binding of soluble fibrinogen to the patient's platelets could be triggered by modulators of alpha IIb beta 3 conformation such as the Arg-Gly-Asp-Ser peptide and alpha-chymotrypsin. These data suggested that a functional Arg-Gly-Asp binding site was present within alpha IIb beta 3 and that the patient's defect was not secondary to a blockade of alpha IIb beta 3 in a noncompetent conformational state. This was evocative of a defect in the coupling between platelet activation and alpha IIb beta 3 up-regulation. We therefore sequenced the cytoplasmic domain of beta 3, following polymerase chain reaction (PCR) on platelet RNA, and found a T-->C mutation at nucleotide 2259, corresponding to a Ser-752-->Pro substitution. This mutation is likely to be responsible for the uncoupling of alpha IIb beta 3 from cellular activation because (i) it is not a polymorphism, (ii) it is the only mutation in the entire alpha IIb beta 3 sequence, and (iii) genetic analysis of the family showed that absence of the Pro-752 beta 3 allele was associated with the normal phenotype. Our data thus identify the C-terminal portion of the cytoplasmic domain of beta 3 as an intrinsic element in the coupling between alpha IIb beta 3 and platelet activation.

Macropinocytosis is a highly conserved endocytic process by which extracellular fluid and its contents are internalized into cells through large, heterogeneous vesicles known as macropinosomes. Oncogenic Ras proteins have been shown to stimulate macropinocytosis but the functional contribution of this uptake mechanism to the transformed phenotype remains unknown. Here we show that Ras-transformed cells use macropinocytosis to transport extracellular protein into the cell. The internalized protein undergoes proteolytic degradation, yielding amino acids including glutamine that can enter central carbon metabolism. Accordingly, the dependence of Ras-transformed cells on free extracellular glutamine for growth can be suppressed by the macropinocytic uptake of protein. Consistent with macropinocytosis representing an important route of nutrient uptake in tumours, its pharmacological inhibition compromises the growth of Ras-transformed pancreatic tumour xenografts. These results identify macropinocytosis as a mechanism by which cancer cells support their unique metabolic needs and point to the possible exploitation of this process in the design of anticancer therapies.

The phosphorylation of the human estrogen receptor (ER) serine residue at position 118 is required for full activity of the ER activation function 1 (AF-1). This Ser118 is phosphorylated by mitogen-activated protein kinase (MAPK) in vitro and in cells treated with epidermal growth factor (EGF) and insulin-like growth factor (IGF) in vivo. Overexpression of MAPK kinase (MAPKK) or of the guanine nucleotide binding protein Ras, both of which activate MAPK, enhanced estrogen-induced and antiestrogen (tamoxifen)-induced transcriptional activity of wild-type ER, but not that of a mutant ER with an alanine in place of Ser118. Thus, the activity of the amino-terminal AF-1 of the ER is modulated by the phosphorylation of Ser118 through the Ras-MAPK cascade of the growth factor signaling pathways.

Patient selection is important for targeted therapies, yet phase I/II trials are often underpowered for developing predictors of drug response. The goal of this research was to define genomic predictors for dasatinib that could be prospectively tested in early-phase clinical trials. Gene expression profiles of dasatinib-sensitive and dasatinib-resistant cell lines (n = 23) were compared to develop a dasatinib-sensitivity index (modified DS index). A Src pathway activity index (revised Src index) was defined using genes induced by the Src transfection of mammary epithelial cells and was optimized to be reproducible across cell lines and human specimens. A dasatinib target index was devised using the weighted sum of 19 kinases that bind to dasatinib with variable affinity. The performance of these prediction models was assessed in independent cell lines with known dasatinib sensitivity. The feasibility of applying these genomic tests to human samples was evaluated on 133 biopsies of primary breast cancers. The modified DS index showed 90% accuracy in independent breast cancer cell lines (n = 12) and the target index, but not the revised Src index signature, also distinguished dasatinib-sensitive and dasatinib-resistant cells (P = 0.0024). The genomic predictors showed acceptable reproducibility in replicate cell line and human gene expression data. When all three predictors were applied to the same 133 patient samples, the predictors identified different patient subsets as potentially sensitive. We defined three conceptually different potential predictors of dasatinib response that were reproducible across cell lines and human data. These candidate markers are being tested in a clinical trial to determine their utility.

Epithelial integrity is vitally important, and its deregulation causes early stage cancer. De novo formation of an adherens junction (AJ) between single epithelial cells requires coordinated, spatial actin dynamics, but the mechanisms steering nascent actin polymerization for cell-cell adhesion initiation are not well understood. Here we investigated real-time actin assembly during daughter cell-cell adhesion formation in human breast epithelial cells in 3D environments. We identify formin-like 2 (FMNL2) as being specifically required for actin assembly and turnover at newly formed cell-cell contacts as well as for human epithelial lumen formation. FMNL2 associates with components of the AJ complex involving Rac1 activity and the FMNL2 C terminus. Optogenetic control of Rac1 in living cells rapidly drove FMNL2 to epithelial cell-cell contact zones. Furthermore, Rac1-induced actin assembly and subsequent AJ formation critically depends on FMNL2. These data uncover FMNL2 as a driver for human epithelial AJ formation downstream of Rac1.

Subunits of the SWI/SNF chromatin remodeling complex are mutated in a significant proportion of human cancers. Malignant rhabdoid tumors (MRTs) are lethal pediatric cancers characterized by a deficiency in the SWI/SNF subunit SMARCB1. Here, we employ an integrated molecular profiling and chemical biology approach to demonstrate that the receptor tyrosine kinases (RTKs) PDGFRα and FGFR1 are coactivated in MRT cells and that dual blockade of these receptors has synergistic efficacy. Inhibitor combinations targeting both receptors and the dual inhibitor ponatinib suppress the AKT and ERK1/2 pathways leading to apoptosis. MRT cells that have acquired resistance to the PDGFRα inhibitor pazopanib are susceptible to FGFR inhibitors. We show that PDGFRα levels are regulated by SMARCB1 expression, and assessment of clinical specimens documents the expression of both PDGFRα and FGFR1 in rhabdoid tumor patients. Our findings support a therapeutic approach in cancers with SWI/SNF deficiencies by exploiting RTK coactivation dependencies.