IFN-? and CIITA modulate IL-6 expression in skeletal muscle.

ABSTRACT: Interleukin 6 (IL-6) is a secreted cytokine that is an important mediator of the immune response in numerous tissues, including skeletal muscle. IL-6 is considered a myokine as it can be secreted by muscle. IL-6 is secreted following exercise, where it exerts both pro-myogenic effects as well as anti-myogenic effects such as promoting atrophy and muscle wasting. The regulation of IL-6 in skeletal muscle is not well understood. The purpose of this study was to determine if IFN-? and TNF-? stimulate IL-6 in skeletal muscle. We found that both IFN-? and TNF-? stimulate IL-6 in skeletal muscle, but the stimulation is not cooperative as seen in monocytes. We have previously shown that the IFN-? stimulated class II major histocompatibility complex transactivator (CIITA) mediates many of the effects of IFN-? in skeletal muscle and we show here that CIITA directly stimulates IL-6. The regulation of IL-6 by CIITA is clearly complex, as we found that CIITA both stimulates and restrains IL-6 expression. To show that these effects could be observed in a physiological setting, mice were treated with IFN-? and we found that both CIITA and IL-6 were upregulated in skeletal muscle.

SUBMITTER: Adhikari A 

PROVIDER: S-EPMC7885875 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature