Objective: Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS), characterized by a global increasing incidence driven by relapsing-remitting disease in females. p38 MAP kinase (MAPK) has been described as a key regulator of inflammatory responses in autoimmunity, but its role in the sexual dimorphism in MS or MS models remains unexplored. Methods: Toward this end, we used experimental autoimmune encephalomyelitis (EAE), the principal animal model of MS, combined with pharmacologic and genetic inhibition of p38 MAPK activity and transcriptomic analyses. Results: Pharmacologic inhibition of p38 MAPK selectively ameliorated EAE in female mice. Conditional deletion studies demonstrated that p38 signaling in macrophages/myeloid cells, but not T cells or dendritic cells, recapitulated this sexual dimorphism. Analysis of CNS inflammatory infiltrates showed that female, but not male mice lacking p38 in myeloid cells exhibited reduced immune cell activation compared with controls, while peripheral T cell priming was unaffected in both sexes. Transcriptomic analyses of myeloid cells revealed differences in p38-controlled transcripts comprising female- and male-specific gene modules, with greater p38 dependence of pro-inflammatory gene expression in females. Interpretation: Our findings demonstrate a key role for p38 in myeloid cells in CNS autoimmunity and uncover important molecular mechanisms underlying sex differences in disease pathogenesis. Taken together, our results suggest that the p38 MAPK signaling pathway represents a novel target for much needed disease modifying therapies for MS
Sex-specific control of central nervous system autoimmunity by p38 mitogen-activated protein kinase signaling in myeloid cells.
Sex, Specimen part
View SamplesHistamine H3 receptor (Hrh3/H3R) is primarily expressed by neurons in the central nervous system (CNS) where it functions as a presynaptic inhibitory autoreceptor and heteroreceptor. Previously, we identified an H3R-mediated central component in susceptibility to experimental allergic encephalomyelitis (EAE), the principal autoimmune model of multiple sclerosis (MS), related to neurogenic control of blood brain barrier permeability and peripheral T cell effector responses. Furthermore, we identified Hrh3 as a positional candidate for the EAE susceptibility locus Eae8. Here, we characterize Hrh3 polymorphisms between EAE-susceptible and resistant SJL and B10.S mice, respectively, and show that Hrh3 isoform expression in the CNS is differentially regulated by acute peripheral inflammatory stimuli in an allele-specific fashion. Next, we show that Hrh3 is not expressed in any subpopulations of the immune compartment, and that secondary lymphoid tissue is anatomically poised to be regulated by central H3R signaling. Accordingly, using transcriptome analysis, we show that, inflammatory stimuli elicit unique transcriptional profiles in the lymph nodes of H3RKO mice compared to WT mice, which is indicative of negative regulation of peripheral immune responses by central H3R signaling. These results further support a functional link between the neurogenic control of T cell responses and susceptibility to CNS autoimmune disease coincident with acute and/or chronic peripheral inflammation. Pharmacological targeting of H3R may therefore be useful in preventing the development and formation of new lesions in MS, thereby limiting disease progression.
Histamine H(3) receptor integrates peripheral inflammatory signals in the neurogenic control of immune responses and autoimmune disease susceptibility.
Specimen part
View SamplesIL-6, a proinflammtory cytokine produced by antigen presenting cells and non-hematopoietic cells in response to external stimuli, acts as an important bridge between the innate and adaptive immune responses. IL-6 together with IL-4 can promote Th2 polarization, while in combination with TGFbeta mediates Th17 differentiation. We examined early changes in gene expression in mouse CD4+ T cells induced by IL-6.
The induction of antibody production by IL-6 is indirectly mediated by IL-21 produced by CD4+ T cells.
No sample metadata fields
View SamplesProduction of reactive oxygen species (ROS) is one of the important antimicrobial mechanisms of phagocytic cells. Enhanced oxidative burst requires these cells to be primed with agents such as IFNg and LPS with a synergistic effect of these agents on the level of the burst. However, excessive ROS generation will lead to tissue damage and has been implicated in a variety of inflammatory and autoimmune disease. Therefore, this process needs to be tightly regulated. In order to understand the genes regulating this process, we will treat bone marrow derived macrophages with above mentioned priming agents and study the gene expression.
NRROS negatively regulates reactive oxygen species during host defence and autoimmunity.
Specimen part, Treatment
View SamplesIron-deficiency affects 500 million people, yet the molecular role of iron in gene expression remains poorly characterized. Moreover, the alterations in global gene expression after iron chelation remains unclear and are important to assess for understanding the molecular pathology of iron-deficiency and the biological effects of iron chelators. We assessed the effect on whole genome gene expression of two iron chelators (desferrioxamine and 2-hydroxy-1-napthylaldehyde isonicotinoyl hydrazone) that have markedly different permeability properties. Sixteen genes were significantly regulated by both chelators, while a further 50 genes were regulated by either ligand. Most of the genes identified in this study have not been previously described to be iron-regulated and are important for understanding the molecular and cellular effects of iron-deficiency.
Iron chelator-mediated alterations in gene expression: identification of novel iron-regulated molecules that are molecular targets of hypoxia-inducible factor-1 alpha and p53.
Cell line, Time
View SamplesReactive astrogliosis is characterized by a profound change in astrocyte phenotype in response to all CNS injuries and diseases. To better understand the reactive astrocyte state, we used Affymetrix GeneChip arrays to profile gene expression in populations of reactive astrocytes isolated at various time points after induction using two different mouse injury models, ischemic stroke and neuroinflammation.
Genomic analysis of reactive astrogliosis.
Sex, Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Gene reactivation by 5-aza-2'-deoxycytidine-induced demethylation requires SRCAP-mediated H2A.Z insertion to establish nucleosome depleted regions.
Specimen part, Disease, Disease stage, Cell line, Treatment
View SamplesThe purpose of the study is to understand the impacts of cohesin knockdown on epidermal gene expression. Primary human keratinocytes were knocked down for SMC1A, SMC3, or control to determine its genome-wide gene expression profile.
The Cohesin Complex Is Necessary for Epidermal Progenitor Cell Function through Maintenance of Self-Renewal Genes.
No sample metadata fields
View SamplesRecent identification of IL28B gene polymorphisms associated with hepatitis C virus (HCV) clearance suggests a role for type III interferons (IFNs) in hepatitis C infection. The function of type III IFNs in intrinsic antiviral immunity is poorly understood. Here we show that HCV infection of primary human hepatocytes results in a robust induction of type III but not type I IFNs, leading to IFN- stimulated gene (ISG) expression. In addition, HCV infection elicits a much broader range of gene expression alterations in addition to ISG induction. The induction of type III IFNs is mediated by IRF3 and NFkB- dependent pathways. Type III IFN, aside from upregulating ISGs with a different kinetic profile, induces a distinct set of genes from type I IFN, potentially explaining the functional difference between the two types of IFNs. Chimpanzees undergoing experimental HCV infection demonstrated a prompt hepatic induction of IL28, associating with ISG upregulation, but minimal type I IFN induction. Analysis of liver biopsies from HCV-infected patients supported a close correlation among hepatic expression of IL28 and ISGs, but not with type I IFNs. Our study demonstrates that HCV infection results predominantly in type III IFN induction in the liver and the level of induction correlates with hepatic ISG levels, thus providing a mechanistic explanation for the association between IL28, ISG levels and recovery from HCV infection as well as a potential therapeutic strategy for the treatment of non-responders.
HCV infection induces a unique hepatic innate immune response associated with robust production of type III interferons.
Specimen part, Treatment, Time
View SamplesRecent identification of IL28B gene polymorphisms associated with hepatitis C virus (HCV) clearance suggests a role for type III interferons (IFNs) in hepatitis C infection. The function of type III IFNs in intrinsic antiviral immunity is poorly understood. Here we show that HCV infection of primary human hepatocytes results in a robust induction of type III but not type I IFNs, leading to IFN- stimulated gene (ISG) expression. In addition, HCV infection elicits a much broader range of gene expression alterations in addition to ISG induction. The induction of type III IFNs is mediated by IRF3 and NFkB- dependent pathways. Type III IFN, aside from upregulating ISGs with a different kinetic profile, induces a distinct set of genes from type I IFN, potentially explaining the functional difference between the two types of IFNs. Chimpanzees undergoing experimental HCV infection demonstrated a prompt hepatic induction of IL28, associating with ISG upregulation, but minimal type I IFN induction. Analysis of liver biopsies from HCV-infected patients supported a close correlation among hepatic expression of IL28 and ISGs, but not with type I IFNs. Our study demonstrates that HCV infection results predominantly in type III IFN induction in the liver and the level of induction correlates with hepatic ISG levels, thus providing a mechanistic explanation for the association between IL28, ISG levels and recovery from HCV infection as well as a potential therapeutic strategy for the treatment of non-responders.
HCV infection induces a unique hepatic innate immune response associated with robust production of type III interferons.
Specimen part, Time
View Samples