52 research outputs found
Adrenalectomy alters the sensitivity of the central nervous system melanocortin system
Removal of adrenal steroids by adrenalectomy (ADX) reduces food intake and body weight in rodents and prevents excessive weight gain in many genetic and dietary models of obesity. Thus, glucocorticoids appear to play a key role to promote positive energy balance in normal and pathological conditions. By comparison, central nervous system melanocortin signaling provides critical inhibitory tone to regulate energy balance. The present experiments sought to test whether glucocorticoids influence energy balance by altering the sensitivity to melanocortin receptor ligands. Because melanocortin-producing neurons are hypothesized to be downstream of leptin in a key weight-reducing circuit, we tested rats for their sensitivity to leptin and confirmed reports that the hypophagic response to third ventricular (i3vt) leptin is increased in ADX rats and is normalized by glucocorticoid replacement. Next we tested rats for their sensitivity to the melanocortin agonist melanotan II and found that, as for leptin, ADX enhanced the hypophagic response via a glucocorticoid-dependent mechanism. The central nervous system melanocortin system is unique in that it includes the endogenous melanocortin receptor antagonist, AgRP. The orexigenic effect of i3vt AgRP was absent in ADX rats and restored by glucocorticoid replacement. We conclude that the potent weight-reducing effects of ADX likely involve heightened responsiveness to melanocortin receptor stimulation
Small Molecule Inhibition of HIV-1–Induced MHC-I Down-Regulation Identifies a Temporally Regulated Switch in Nef Action
Nef assembles a multi-kinase complex triggering MHC-I down-regulation. We identify an inhibitor that blocks MHC-I down-regulation, identifying a temporally regulated switch in Nef action from directing MHC-I endocytosis to blocking cell surface delivery. These findings challenge current dogma and reveal a regulated immune evasion program
Sequencing of \u3ci\u3eAspergillus nidulans\u3c/i\u3e and comparative analysis with \u3ci\u3eA. fumigatus\u3c/i\u3e and \u3ci\u3eA. oryzae\u3c/i\u3e
The aspergilli comprise a diverse group of filamentous fungi spanning over 200 million years of evolution. Here we report the genome sequence of the model organism Aspergillus nidulans, and a comparative study with Aspergillus fumigatus, a serious human pathogen, and Aspergillus oryzae, used in the production of sake, miso, and soy sauce. Our analysis of genome structure provided a quantitative evaluation of forces driving long-term eukaryotic genome evolution. It also led to an experimentally validated model of mating-type locus evolution, suggesting the potential for sexual reproduction in A. fumigatus and A. oryzae. Our analysis of sequence conservation revealed over 5,000 non-coding regions actively conserved across all three species. Within these regions, we identified potential functional elements including a previously uncharacterized TPP riboswitch and motifs suggesting regulation in filamentous fungi by Puf family genes. We further obtained comparative and experimental evidence indicating widespread translational regulation by upstream open reading frames. These results enhance our understanding of these widely studied fungi as well as provide new insight into eukaryotic genome evolution and gene regulation. Document includes all supplementary information (820 pages). Supplementary files are also attached below as Related files. THERE IS NO SUPPLEMENTARY FILE #7. PDF file size (with supplementary files included) is 10 Mbytes. An optimized version of the ARTICLE ONLY is attached as a Related File and is 1.9 Mbytes
Sequencing of \u3ci\u3eAspergillus nidulans\u3c/i\u3e and comparative analysis with \u3ci\u3eA. fumigatus\u3c/i\u3e and \u3ci\u3eA. oryzae\u3c/i\u3e
The aspergilli comprise a diverse group of filamentous fungi spanning over 200 million years of evolution. Here we report the genome sequence of the model organism Aspergillus nidulans, and a comparative study with Aspergillus fumigatus, a serious human pathogen, and Aspergillus oryzae, used in the production of sake, miso, and soy sauce. Our analysis of genome structure provided a quantitative evaluation of forces driving long-term eukaryotic genome evolution. It also led to an experimentally validated model of mating-type locus evolution, suggesting the potential for sexual reproduction in A. fumigatus and A. oryzae. Our analysis of sequence conservation revealed over 5,000 non-coding regions actively conserved across all three species. Within these regions, we identified potential functional elements including a previously uncharacterized TPP riboswitch and motifs suggesting regulation in filamentous fungi by Puf family genes. We further obtained comparative and experimental evidence indicating widespread translational regulation by upstream open reading frames. These results enhance our understanding of these widely studied fungi as well as provide new insight into eukaryotic genome evolution and gene regulation. Document includes all supplementary information (820 pages). Supplementary files are also attached below as Related files. THERE IS NO SUPPLEMENTARY FILE #7. PDF file size (with supplementary files included) is 10 Mbytes. An optimized version of the ARTICLE ONLY is attached as a Related File and is 1.9 Mbytes
Sequencing of Culex quinquefasciatus establishes a platform for mosquito comparative genomics
Culex quinquefasciatus (the southern house mosquito) is an important mosquito vector of viruses such as West Nile virus and St. Louis encephalitis virus, as well as of nematodes that cause lymphatic filariasis. C. quinquefasciatus is one species within the Culex pipiens species complex and can be found throughout tropical and temperate climates of the world. The ability of C. quinquefasciatus to take blood meals from birds, livestock, and humans contributes to its ability to vector pathogens between species. Here, we describe the genomic sequence of C. quinquefasciatus: Its repertoire of 18,883 protein-coding genes is 22% larger than that of Aedes aegypti and 52% larger than that of Anopheles gambiae with multiple gene-family expansions, including olfactory and gustatory receptors, salivary gland genes, and genes associated with xenobiotic detoxification
Structure, function and diversity of the healthy human microbiome
Author Posting. © The Authors, 2012. This article is posted here by permission of Nature Publishing Group. The definitive version was published in Nature 486 (2012): 207-214, doi:10.1038/nature11234.Studies of the human microbiome have revealed that even healthy individuals differ remarkably in the microbes that occupy habitats such as the gut, skin and vagina. Much of this diversity remains unexplained, although diet, environment, host genetics and early microbial exposure have all been implicated. Accordingly, to characterize the ecology of human-associated microbial communities, the Human Microbiome Project has analysed the largest cohort and set of distinct, clinically relevant body habitats so far. We found the diversity and abundance of each habitat’s signature microbes to vary widely even among healthy subjects, with strong niche specialization both within and among individuals. The project encountered an estimated 81–99% of the genera, enzyme families and community configurations occupied by the healthy Western microbiome. Metagenomic carriage of metabolic pathways was stable among individuals despite variation in community structure, and ethnic/racial background proved to be one of the strongest associations of both pathways and microbes with clinical metadata. These results thus delineate the range of structural and functional configurations normal in the microbial communities of a healthy population, enabling future characterization of the epidemiology, ecology and translational applications of the human microbiome.This research was supported in
part by National Institutes of Health grants U54HG004969 to B.W.B.; U54HG003273
to R.A.G.; U54HG004973 to R.A.G., S.K.H. and J.F.P.; U54HG003067 to E.S.Lander;
U54AI084844 to K.E.N.; N01AI30071 to R.L.Strausberg; U54HG004968 to G.M.W.;
U01HG004866 to O.R.W.; U54HG003079 to R.K.W.; R01HG005969 to C.H.;
R01HG004872 to R.K.; R01HG004885 to M.P.; R01HG005975 to P.D.S.;
R01HG004908 to Y.Y.; R01HG004900 to M.K.Cho and P. Sankar; R01HG005171 to
D.E.H.; R01HG004853 to A.L.M.; R01HG004856 to R.R.; R01HG004877 to R.R.S. and
R.F.; R01HG005172 to P. Spicer.; R01HG004857 to M.P.; R01HG004906 to T.M.S.;
R21HG005811 to E.A.V.; M.J.B. was supported by UH2AR057506; G.A.B. was
supported by UH2AI083263 and UH3AI083263 (G.A.B., C. N. Cornelissen, L. K. Eaves
and J. F. Strauss); S.M.H. was supported by UH3DK083993 (V. B. Young, E. B. Chang,
F. Meyer, T. M. S., M. L. Sogin, J. M. Tiedje); K.P.R. was supported by UH2DK083990 (J.
V.); J.A.S. and H.H.K. were supported by UH2AR057504 and UH3AR057504 (J.A.S.);
DP2OD001500 to K.M.A.; N01HG62088 to the Coriell Institute for Medical Research;
U01DE016937 to F.E.D.; S.K.H. was supported by RC1DE0202098 and
R01DE021574 (S.K.H. and H. Li); J.I. was supported by R21CA139193 (J.I. and
D. S. Michaud); K.P.L. was supported by P30DE020751 (D. J. Smith); Army Research
Office grant W911NF-11-1-0473 to C.H.; National Science Foundation grants NSF
DBI-1053486 to C.H. and NSF IIS-0812111 to M.P.; The Office of Science of the US
Department of Energy under Contract No. DE-AC02-05CH11231 for P.S. C.; LANL
Laboratory-Directed Research and Development grant 20100034DR and the US
Defense Threat Reduction Agency grants B104153I and B084531I to P.S.C.; Research
Foundation - Flanders (FWO) grant to K.F. and J.Raes; R.K. is an HHMI Early Career
Scientist; Gordon&BettyMoore Foundation funding and institutional funding fromthe
J. David Gladstone Institutes to K.S.P.; A.M.S. was supported by fellowships provided by
the Rackham Graduate School and the NIH Molecular Mechanisms in Microbial
Pathogenesis Training Grant T32AI007528; a Crohn’s and Colitis Foundation of
Canada Grant in Aid of Research to E.A.V.; 2010 IBM Faculty Award to K.C.W.; analysis
of the HMPdata was performed using National Energy Research Scientific Computing
resources, the BluBioU Computational Resource at Rice University
A framework for human microbiome research
A variety of microbial communities and their genes (the microbiome) exist throughout the human body, with fundamental roles in human health and disease. The National Institutes of Health (NIH)-funded Human Microbiome Project Consortium has established a population-scale framework to develop metagenomic protocols, resulting in a broad range of quality-controlled resources and data including standardized methods for creating, processing and interpreting distinct types of high-throughput metagenomic data available to the scientific community. Here we present resources from a population of 242 healthy adults sampled at 15 or 18 body sites up to three times, which have generated 5,177 microbial taxonomic profiles from 16S ribosomal RNA genes and over 3.5 terabases of metagenomic sequence so far. In parallel, approximately 800 reference strains isolated from the human body have been sequenced. Collectively, these data represent the largest resource describing the abundance and variety of the human microbiome, while providing a framework for current and future studies
Evolution of extensively drug-resistant tuberculosis over four decades: whole genome sequencing and dating analysis of Mycobacterium tuberculosis isolates from KwaZulu-Natal.
CAPRISA, 2015.Abstract available in pdf
Adrenalectomy Alters the Sensitivity of the Central Nervous System Melanocortin System
Removal of adrenal steroids by adrenalectomy (ADX) reduces food intake and body weight in rodents and prevents excessive weight gain in many genetic and dietary models of obesity. Thus, glucocorticoids appear to play a key role to promote positive energy balance in normal and pathological conditions. By comparison, central nervous system melanocortin signaling provides critical inhibitory tone to regulate energy balance. The present experiments sought to test whether glucocorticoids influence energy balance by altering the sensitivity to melanocortin receptor ligands. Because melanocortin-producing neurons are hypothesized to be downstream of leptin in a key weight-reducing circuit, we tested rats for their sensitivity to leptin and confirmed reports that the hypophagic response to third ventricular (i3vt) leptin is increased in ADX rats and is normalized by glucocorticoid replacement. Next we tested rats for their sensitivity to the melanocortin agonist melanotan II and found that, as for leptin, ADX enhanced the hypophagic response via a glucocorticoid-dependent mechanism. The central nervous system melanocortin system is unique in that it includes the endogenous melanocortin receptor antagonist, AgRP. The orexigenic effect of i3vt AgRP was absent in ADX rats and restored by glucocorticoid replacement. We conclude that the potent weight-reducing effects of ADX likely involve heightened responsiveness to melanocortin receptor stimulation.
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