Hyperimmune activation is one of the strong predictors of disease progression during pathogenic immunodeficiency virus infections and is mediated in part by sustained type I interferon (IFN) signaling. Combination antiretroviral therapy suppresses hyperimmune activation only partially in HIV-infected individuals. Here, we show that blockade of Programmed Death-1 (PD-1) during chonic SIV infection significantly reduces the expression of transcripts associated with type I IFN signaling in the blood and colorectal tissue of rhesus macaques (RM). The effect of PD-1 blockade on type I IFN signaling was durable and persisted under high viremia, a condition that is seen in nonprogressive SIV infection in their natural hosts. The reduced type I IFN signaling was associated with enhanced expression of some of the junction-associated genes in the colorectal tissue and a profound decrease in LPS levels in plasma suggesting a possible repair of gut associated junctions and decreased microbial translocation. The reduced type I IFN signaling was also associated with enhanced immunity against gut resident pathogenic bacteria, control of gut associated opportunistic infections and survival of SIV-infected RMs. These results reveal novel mechanisms by which PD-1 blockade enhances survival of SIV-infected RMs and have implications for development of novel therapeutic approaches to control HIV/AIDS.
PD-1 blockade during chronic SIV infection reduces hyperimmune activation and microbial translocation in rhesus macaques.
Specimen part, Disease, Disease stage, Treatment
View SamplesCircadian and metabolic processes are codependent. This experiment was designed to understand how a high fat diet affects circadian gene expression in the liver. Circadian gene expression in the liver is necessary for energy balance.
Reprogramming of the circadian clock by nutritional challenge.
Specimen part
View SamplesIn almost every countries the proportion of people over 60 years is growing faster that any other age group. Increased life expectancy is leading to the characterization of specific aspects of aging for the various physiological systems. The study of healthy aging is important to design strategies capable to maximize the health and to prevent chronic diseases in older people. Immunosenscence reflects the age-related changes of the immune system and the reduced capacity of elderly people to cope with new infections. To elucidate changes in gene expression related to systemic aging and immunosenescence in an unbiased manner we performed comparative microarray analysis on whole blood cell from healthy middle-aged versus elderly men, and correlated results with functional measurements of aerobic capacity. Blood cells from elderly subjects showed age-related changes in the expression of several markers of immunosenescence, inflammation and oxidative stress, and showed impairments in metabolic and biosynthetic capacities.
Aging: a portrait from gene expression profile in blood cells.
No sample metadata fields
View SamplesThe myogenic regulatory factor MRF4 is expressed at high levels in myofibers of adult skeletal muscle, but its function is unknown. Here we show that knockdown of MRF4 in adult muscle causes hypertrophy and prevents denervation-induced atrophy. This effect is accompanied by increased protein synthesis and the widespread activation of genes involved in muscle contraction, excitation-contraction coupling and energy metabolism, many of which are known targets of MEF2 transcription factors. Genes regulated by MEF2 represent the top-ranking gene set enriched after Mrf4 RNAi, and a MEF2 reporter is inhibited by co-transfected MRF4 and activated by Mrf4 RNAi. The role of MEF2 in mediating the effect of MRF4 knockdown is supported by the finding that Mrf4 RNAi-dependent increase in fiber size is prevented by dominant negative MEF2, while constitutively active MEF2 is able to induce myofiber hypertrophy. The nuclear localization of the MEF2 co-repressor HDAC4 is impaired by Mrf4 knockdown, suggesting that MRF4 acts by stabilizing a repressor complex that controls MEF2 activity. The demonstration that fiber size in adult skeletal muscle is controlled by the MRF4-MEF2 axis opens new perspectives in the search for therapeutic targets to prevent muscle wasting, in particular sarcopenia and cachexia.
MRF4 negatively regulates adult skeletal muscle growth by repressing MEF2 activity.
Specimen part
View SamplesTo investigate the role of the circadian clock gene Bmal1 in skeletal muscle, we compared the circadian transcriptomes of fast tibialis anterior (TA) and slow soleus (SOL) skeletal muscles from muscle-specific Bmal1 KO (mKO) and their control Cre- littermates (Ctrl).
Muscle insulin sensitivity and glucose metabolism are controlled by the intrinsic muscle clock.
Sex, Specimen part, Time
View SamplesExpression profiling of mRNA abundance in the adult mouse olfactory epithelium during replacement of OSNs forced by the bilateral ablation of the olfactory bulbs. The experiment was done on 6 week old male C57Bl/6 mice. Olfactory epithelium tissue samples were collected on days 1, 5, and 7 after bulbectomy. The cellular processes activated by bulbectomy include apoptosis of mature olfactory sensory neurons, infiltration of macrophages and dendritic cells, stimulation of proliferation of basal cell progenitors, and differentation of new sensory neurons.
Transcriptional changes during neuronal death and replacement in the olfactory epithelium.
No sample metadata fields
View SamplesTransciptome analysis using a panel of WM793 melanoma cell lines following stable overexpression of wild-type or mutant forms of human NME1
Identification of a gene expression signature associated with the metastasis suppressor function of NME1: prognostic value in human melanoma.
Cell line
View SamplesAnalysis of hormone effects on irradiated LBNF1 rat testes, which contain only somatic cells except for a few type A spermatgogonia. Rats were treated for 2 weeks with either sham treatment (group X), hormonal ablation (GnRH antagonist and the androgen receptor antagonist flutamide, group XAF), testosterone supplementation (GnRH antagonist and testosterone, group XAT), and FSH supplementation ((GnRH antagonist, androgen receptor antagonist, and FSH, group XAFF). Results provide insight into identifying genes in the somatic testis cells regulated by testosterone, LH, or FSH.
Changes in gene expression in somatic cells of rat testes resulting from hormonal modulation and radiation-induced germ cell depletion.
Specimen part, Treatment
View SamplesAnalysis of LBNF1 rat testes from controls, containing both somatic and all germ cell types and from irradiated rats in which all cells germ cells except type A spermatgogonia are eliminated. Results provide insight into distinguishing germ and somatic cell genes and identification of somatic cell genes that are upregulated after irradiation.
Changes in gene expression in somatic cells of rat testes resulting from hormonal modulation and radiation-induced germ cell depletion.
Specimen part
View SamplesIn SIV/HIV infection, the gastrointestinal tissue dominates as an important site due to the impact of massive mucosal CD4 depletion and immune activation-induced tissue pathology. Unlike AIDS-susceptible rhesus macaques, natural hosts do not progress to AIDS and resolve immune activation earlier. Here, we examine the role of dendritic cells in mediating immune activation and disease progression. We demonstrate that plasmacytoid dendritic cells (pDC) in the blood upregulate 7-integrin and are rapidly recruited to the colorectum following a pathogenic SIV infection in rhesus macaques. These pDC were capable of producing proinflammatory cytokines and primed a Tc1 response in vitro. Consistent with the upregulation of 7-integrin on pDC, in vivo blockade of 47-integrin dampened pDC recruitment to the colorectum and resulted in reduced immune activation. The upregulation of 7-integrin expression on pDC in the blood was also observed in HIV-infected humans but not in chronically SIV-infected sooty mangabeys that show low levels of immune activation. Our results uncover a new mechanism by which pDC influence immune activation in colorectal tissue following pathogenic immunodeficiency virus infections.
Plasmacytoid dendritic cells are recruited to the colorectum and contribute to immune activation during pathogenic SIV infection in rhesus macaques.
Specimen part
View Samples