Increases of M2a macrophages and fibrosis in aging muscle are influenced by bone marrow aging and negatively regulated by muscle-derived nitric oxide.

ABSTRACT: Muscle aging is associated with changes in myeloid cell phenotype that may influence age-related changes in muscle structure. We tested whether preventing age-related reductions in muscle neuronal nitric oxide synthase (nNOS) would obviate age-related changes in myeloid cells in muscle. Our findings show that muscle aging is associated with elevations of anti-inflammatory M2a macrophages that can increase muscle fibrosis. Expression of a muscle-specific nNOS transgene in mice prevented age-related increases in M2a macrophages. Transgene expression also reduced expression of collagens and decreased muscle fibrosis. The nNOS transgene prevented age-related increases in arginase-1 but did not influence TGFβ expression, indicating that the transgene may prevent age-related muscle fibrosis by i

SUBMITTER: Wang Y 

PROVIDER: S-EPMC4531081 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature