Molecular Architecture and Functional Model of the Complete Yeast ESCRT-I Heterotetramer

SummaryThe endosomal sorting complex required for transport-I (ESCRT-I) complex, which is conserved from yeast to humans, directs the lysosomal degradation of ubiquitinated transmembrane proteins and the budding of the HIV virus. Yeast ESCRT-I contains four subunits, Vps23, Vps28, Vps37, and Mvb12. The crystal structure of the heterotetrameric ESCRT-I complex reveals a highly asymmetric complex of 1:1:1:1 subunit stoichiometry. The core complex is nearly 18 nm long and consists of a headpiece attached to a 13 nm stalk. The stalk is important for cargo sorting by ESCRT-I and is proposed to serve as a spacer regulating the correct disposition of cargo and other ESCRT components. Hydrodynamic constraints and crystallographic structures were used to generate a model of intact ESCRT-I in solution. The results show how ESCRT-I uses a combination of a rigid stalk and flexible tethers to interact with lipids, cargo, and other ESCRT complexes over a span of ∼25 nm

Preoptic leptin signaling modulates energy balance independent of body temperature regulation

© Yu et al. The adipokine leptin acts on the brain to regulate energy balance but specific functions in many brain areas remain poorly understood. Among these, the preoptic area (POA) is well known to regulate core body temperature by controlling brown fat thermogenesis, and we have previously shown that glutamatergic, long-form leptin receptor (Lepr)-expressing neurons in the POA are stimulated by warm ambient temperature and suppress energy expenditure and food intake. Here we further investigate the role of POA leptin signaling in body weight regulation and its relationship to body temperature regulation in mice. We show that POA Lepr signaling modulates energy expenditure in response to internal energy state, and thus contributes to body weight homeostasis. However, POA leptin signaling is not involved in ambient temperature-dependent metabolic adaptations. Our study reveals a novel cell population through which leptin regulates body weight

Artemisinin-based combinations versus amodiaquine plus sulphadoxine-pyrimethamine for the treatment of uncomplicated malaria in Faladje, Mali

<p>Abstract</p> <p>Background</p> <p>Because of the emergence of chloroquine resistance in Mali, artemether-lumefantrine (AL) or artesunate-amodiaquine (AS+AQ) are recommended as first-line therapy for uncomplicated malaria, but have not been available in Mali until recently because of high costs.</p> <p>Methods</p> <p>From July 2005 to January 2006, a randomized open-label trial of three oral antimalarial combinations, namely AS+AQ, artesunate plus sulphadoxine-pyrimethamine (AS+SP), and amodiaquine plus sulphadoxine-pyrimethamine (AQ+SP), was conducted in Faladje, Mali. Parasite genotyping by polymerase chain reaction (PCR) was used to distinguish new from recrudescent <it>Plasmodium falciparum </it>infections.</p> <p>Results</p> <p>397 children 6 to 59 months of age with uncomplicated <it>Plasmodium falciparum </it>malaria were enrolled, and followed for 28 days to assess treatment efficacy. Baseline characteristics were similar in all three treatment groups. The uncorrected rates of adequate clinical and parasitologic response (ACPR) were 55.7%, 90.8%, and 97.7% in AS+AQ, AS+SP, and AQ+SP respectively (p < 0.001); after PCR correction ACPR rates were similar among treatment groups: 95.4%, 96.9%, and 99.2% respectively (p = 0.17). Mean haemoglobin concentration increased across all treatment groups from Day 0 (9.82 ± 1.68 g/dL) to Day 28 (10.78 ± 1.49 g/dL) (p < 0.001), with the greatest improvement occurring in children treated with AQ+SP. On Day 2, the prevalence of parasitaemia was significantly greater among children treated with AQ+SP (50.8%) than in children treated with AS+AQ (10.5%) or AS+SP (10.8%) (p < 0.001). No significant difference in gametocyte carriage was found between groups during the follow-up period.</p> <p>Conclusion</p> <p>The combination of AQ+SP provides a potentially low cost alternative for treatment of uncomplicated <it>P. falciparum </it>infection in Mali and appears to have the added value of longer protective effect against new infection.</p

State–Space Forecasting of Schistosoma haematobium Time-Series in Niono, Mali

Adequate forecasting and early warning systems are based upon observations of human behavior, population, disease time-series, climate, environment, and/or a combination thereof, whichever option best compromises among realism, feasibility, robustness, and parsimony. Fully automatic and user-friendly state–space forecasting frameworks, incorporating myriad options (e.g., expert opinion, univariate, multivariate, and spatial-temporal), could considerably enhance disease control and hazard mitigation efforts in regions where vulnerability to neglected tropical diseases is pervasive and statistical expertise is scarce. The operational simplicity, generality, and flexibility of state–space frameworks, encapsulating multiple methods, could conveniently allow for 1) unsupervised model selection without disease-specific methodological tailoring, 2) on-line adaptation to disease time-series fluctuations, and 3) automatic switches between distinct forecasting methods as new time-series perturbations dictate. In this investigation, a univariate state–space framework with the aforementioned properties was successfully applied to the Schistosoma haematobium time-series for the district of Niono, Mali, to automatically generate contemporaneous on-line forecasts and hence, providing a basis for local re-organization and strengthening public health programs in this and potentially other Sahelian districts

DETORQUEO, QUIRKY, and ZERZAUST Represent Novel Components Involved in Organ Development Mediated by the Receptor-Like Kinase STRUBBELIG in Arabidopsis thaliana

Intercellular signaling plays an important role in controlling cellular behavior in apical meristems and developing organs in plants. One prominent example in Arabidopsis is the regulation of floral organ shape, ovule integument morphogenesis, the cell division plane, and root hair patterning by the leucine-rich repeat receptor-like kinase STRUBBELIG (SUB). Interestingly, kinase activity of SUB is not essential for its in vivo function, indicating that SUB may be an atypical or inactive receptor-like kinase. Since little is known about signaling by atypical receptor-like kinases, we used forward genetics to identify genes that potentially function in SUB-dependent processes and found recessive mutations in three genes that result in a sub-like phenotype. Plants with a defect in DETORQEO (DOQ), QUIRKY (QKY), and ZERZAUST (ZET) show corresponding defects in outer integument development, floral organ shape, and stem twisting. The mutants also show sub-like cellular defects in the floral meristem and in root hair patterning. Thus, SUB, DOQ, QKY, and ZET define the STRUBBELIG-LIKE MUTANT (SLM) class of genes. Molecular cloning of QKY identified a putative transmembrane protein carrying four C2 domains, suggesting that QKY may function in membrane trafficking in a Ca2+-dependent fashion. Morphological analysis of single and all pair-wise double-mutant combinations indicated that SLM genes have overlapping, but also distinct, functions in plant organogenesis. This notion was supported by a systematic comparison of whole-genome transcript profiles during floral development, which molecularly defined common and distinct sets of affected processes in slm mutants. Further analysis indicated that many SLM-responsive genes have functions in cell wall biology, hormone signaling, and various stress responses. Taken together, our data suggest that DOQ, QKY, and ZET contribute to SUB-dependent organogenesis and shed light on the mechanisms, which are dependent on signaling through the atypical receptor-like kinase SUB

Place du paludisme en saison de haute transmission dans les urgences fébriles au Centre Hospitalier Universitaire Gabriel Touré de Bamako

Le but de cette étude est d’évaluer la fréquence du paludisme parmi les causes de fièvres chez les patients admis au Service d’Accueil des Urgences (SAU) du CHU –Gabriel Touré de Bamako. Il s’agissait d’une étude transversale allant du 1er août au 30 novembre 2015. Tous les patients admis au Service d’Accueil des Urgences étaient inclus dans notre étude. La goutte épaisse ou le Test de Diagnostic rapide étaient utilisés pour la confirmation biologique des cas de paludisme. Nous avions enregistré 6 641 patients parmi lesquels 5,07 % étaient fébriles. L’âge moyen des patients était de 21 ans avec une prédominance de la tranche d’âge de 18-40 ans soit 52 %. Le sex-ratio était de 1,5 en faveur des hommes. Les élèves-étudiants représentaient 34,85 % des cas suivis des ménagères avec 20,71 %. Le diagnostic clinique réalisé par des médecins avait donné un taux de 74,5 % de paludisme contre 58,8 % selon la GE/TDr. L’incidence du paludisme comme cause de la fièvre était de 58,8 %. Tous les cas de paludisme simple ont été traités avec les CTA et les cas graves avec des formes injectables de l’artesunate dans 68,38 %, l’artemether dans 17,65 % et la quinine dans 13,17 %. Le paludisme est fréquent parmi les urgences fébriles au SAU du CHU-GT. Les dispositions doivent être renforcées pour une confirmation biologique systématique de tous les cas suspects de paludisme pour éviter les erreurs diagnostics.Mots-clés: Paludisme, Fièvre, Service d’urgence, Gabriel Touré, BamakoEnglish Title: Place of malaria in high transmission season among emergency fever cases at the University Hospital Gabriel Touré of BamakoEnglish AbstractThe objective of the study was to assess the incidence of malaria among patients admitted with fever to the Emergency Department of the CHU -Gabriel Touré of Bamako. A cross-sectional study has been performed from August first to November 30, 2015, corresponding to the period of high malaria transmission in Mali. All consenting patients admitted to the emergency department were included in this research. Thick blood smear or rapid Diagnostic Test (rDT) were used for biological confirmation of suspected malaria cases. The average age of patients admitted for fever was 21 years with a predominance of the age group of 18-40 years. The sex ratio was 1.5 for men. Students represented 34.85% of cases followed by housewives with 20.71%. Clinical diagnosis of malaria rate from doctors was 74.5% compared to 58.8% from the biological test. The prevalence of malaria as a cause of fever was 58.8%. All cases of simple malaria were treated with ACTs while severe cases were treated with injectable forms of artesunate in 68.38%, artemether 17.65% and quinine 13.17%. Malaria is frequent among fever cases in emergencies at the CHU-GT some dispositions should be made to strengthen systematic biological confirmation of all suspected cases of malaria to avoid misdiagnosis.Keywords: Malaria, fever, Emergency service, Gabriel Touré, Bamak

Independent chondrogenic potential of canine bone marrow-derived mesenchymal stem cells in monolayer expansion cultures decreases in a passage-dependent pattern

Although chondroinductive growth factors are considered necessary for chondrogenesis of bone marrow-derived mesenchymal stem cells (BMSC), independent and spontaneous chondrogenesis has been previously demonstrated in adult horses, bovine calves and adult human BMSC. Surprisingly, adult canine BMSC under similar culture conditions previously failed to demonstrate chondrogenesis. The present study evaluated independent chondrogenic potential of BMSC sourced from three young dogs in the absence of known chondroinductive factors. BMSC were culture expanded in 10% DMEM up to third passage (P3). At each passage, the phenotype of BMSC was evaluated by RT-PCR gel electrophoresis and qPCR. BMSC exhibited a chondrogenic phenotype in the absence of dexamethasone and TGF-beta 1 as verified by the expression of Sox-9, type II collagen and aggrecan. Sox-9 was significantly downregulated (P<0.05) from P1-P3 compared to P0 while type II and X collagen, and aggrecan were significantly downregulated at P3 compared to P0. There was a significant (P<0.01) negative correlation between passaging and Sox-9, type II collagen and aggrecan gene expression. These results indicate that independent chondrogenic potential and phenotype retention of BMSC decreases in a passage-dependent pattern. Therefore, caution should be exercised for future experiments evaluating the chondrogenic potential of BMSC after extensive expansion cultures in 10% DMEM

Pentosan polysulfate inhibits IL-1 beta-induced iNOS, c-Jun and HIF-1 alpha upregulation in canine articular chondrocytes

Osteoarthritic (OA) chondrocytes are shown to express inducible nitric oxide synthase (iNOS) which produces high concentrations of nitric oxide (NO), particularly when stimulated with proinflammatory cytokines. NO is involved in OA cartilage degradation. On the other hand, c-Jun N-terminal Kinase (JNK) pathway mediates the activation and transcription of c-Jun, which is required for interleukin-1 (IL-1)-induction of matrix metalloproteinases-13 (MMP-13) in OA pathogenesis. Therefore, the selective inhibition of iNOS and c-Jun is a promising target for treatment and prevention of OA. The purpose of the study was to investigate the inhibitory effects of pentosan polysulfate (PPS) on IL-1 beta-induced iNOS, c-Jun and HIF-alpha isoforms upregulation in canine articular chondrocytes (CACs). Primary (P0) chondrocytes were isolated and cultured from femoral head cartilages of three (3) dogs. First passage (P1) chondrocytes were preincubated with 0, 1, 5, 15 and 40 mu g/mL of PPS for 4 hr before treatment with 10 ng/mL rhIL-1 beta for a further 8 hr. In addition, we evaluated the effects of single and multiple cytokine with or without LPS on iNOS protein induction. PPS significantly inhibited (P < 0.05) IL-1 beta-induced iNOS, c-Jun and HIF-1 alpha mRNA upregulation in a dose-dependent pattern. iNOS mRNA was significantly inhibited at 15 and 40 mu g/mL whereas c-Jun and HIF-1 alpha were significantly downregulated at 5, 15 and 40 mu g/mL of PPS compared to chondrocytes treated with only rhIL-1 beta. Intriguingly, CACs were recalcitrant to single IL-1 beta, TNF-alpha or LPS-induction of iNOS protein including to a combination of IL-1 beta+TNF-alpha, IL-1 beta+LPS except to TNF-alpha+LPS and IL-1 beta+TNF-alpha+LPS suggestive of a protective mechanism from iNOS detrimental effects on perpetuating OA. IL-1 beta+TNF-alpha+LPS-induced iNOS protein expression was significantly abrogated by PPS. We demonstrate for the first time that PPS is a novel inhibitor of IL-1 beta-induced iNOS, c-Jun, and HIF-1 alpha mRNA upregulation and iNOS protein induction which may be beneficial for prevention and treatment OA