2 research outputs found

    Understanding the Role of Androgen Receptor Signaling in Modulating p38-alpha Mitogen-Activated Protein Kinase in Experimental Autoimmune Encephalomyelitis

    Get PDF
    Multiple Sclerosis (MS) is an inflammatory autoimmune disease of the central nervous system, characterized by axonal demyelination and multifocal inflammation. Like many autoimmune diseases, it is a sexually dimorphic disease, being 3-4 times more common in females than in males. p38α MAP kinase (MAPK) has an integral role in modulating inflammatory processes in autoimmunity. Conditionally ablating p38α MAPK in myeloid cells in B6 mice shows a sex difference in the animal model of MS, experimental autoimmune encephalomyelitis (EAE). In the absence of sex hormones, this sex difference was reversed, suggesting a role for sex hormones in modulating p38α MAPK signaling in EAE. Based on these findings, we hypothesized that pro-inflammatory functions in EAE is p38-indepdendent in the presence of androgens and p38-dependent in the presence of estrogens. For the purposes of this project, the role of androgens was evaluated. Both in vivo and in vitro techniques were used to assess how androgen receptor (AR) signaling: 1) impacts EAE pathogenesis, and 2) impacts the role of p38α in EAE pathogenesis and macrophage function. To this end, using Cre-Lox technology, we generated mice deficient in: 1) AR globally or conditionally in macrophages, as well as 2) mice doubly deficient in AR and p38α. In vivo results from p38α-sufficient global AR knockout mice show no effect of global AR deletion on EAE pathogenesis. Surprisingly, results from p38α-sufficient conditional AR knockout mice showed significant worsening in disease compared to WT counterparts, suggesting that AR signaling in myeloid cells has a protective role in EAE pathogenesis. These findings implicate a protective role for AR signaling in EAE. Studies with mice doubly deficient in p38α and AR to determine whether AR regulates the role of p38α in EAE are ongoing, but so far show no effect on AR deletion on the role of p38α MAPK. Further studies with larger cohorts of mice are needed elucidate the relationship between AR and p38α MAPK signaling in myeloid cells in EAE pathogenesis. In vitro studies using the immortalized macrophage cell line RAW 264.7 showed that pharmacologic inhibition of p38 MAPK after stimulation with LPS reduced the production of classic pro-inflammatory cytokines IL-6 and TNFα, and effect that was not affected by treatment with 5-dihydrotestosterone, suggesting that the AR does not modulate the role of p38α in cytokine production. These findings implicate no direct role of AR signaling on the functional role of p38α MAPK in the myeloid cell lineage in inflammatory and autoimmune responses

    Understanding the Role of Androgen Receptor Signaling in Modulating p38 MAPK in EAE

    No full text
    Multiple Sclerosis (MS) is an inflammatory autoimmune disease of the central nervous system (CNS), characterized by axonal demyelination and multifocal inflammation. Like many autoimmune diseases, MS is a sexually dimorphic disease, being 3-4 times more common in females than in males. p38 MAP kinase (MAPK) has an integral role in modulating inflammatory processes in autoimmunity. Conditionally knocking p38 MAPK out of myeloid cells in B6 mice shows a sexually dimorphic response to disease, which can be reversed by removal of sex hormones. This suggests that sex hormones may modulate the role of p38 MAPK. It is hypothesized that pathogenic inflammation in the animal model of MS, experimental autoimmune encephalomyelitis (EAE), is p38-independent in the presence of androgens and p38-dependent in the presence of estrogens. We tested this hypothesis by conditional or global genetic ablation of the primary mediator of androgenic effects, the androgen receptor (AR). Both in vivo and in vitro techniques were used to assess how AR signaling impacts the role of p38 in EAE pathogenesis and macrophage function. In vivo results from p38WT global AR knockout mice show no direct impact of AR signaling on EAE pathogenesis. In vitro results show no effect of androgens on pharmacologic p38 inhibition in the immortalized cell line RAW 264.7 macrophages. EAE results from p38 conditional knockout and AR knockout mice are pending
    corecore