Protective Effects of @entity16959 against @entity619 -Induced XXXX and @entity3998 Transition.

@entity1 @entity9170 @entity3998 @entity1184 @entity16959 @entity49162 @entity442 @entity32062 @entity584 @entity3202 @entity3446 @entity619 @entity3470 @entity35 @entity2057
BACKGROUND: Glucocorticoid has a direct catabolic effect on skeletal muscle, leading to @entity2057 , but no effective pharmacotherapy is available. We reported that @entity16959 (CB) induced @entity32062 and slow-to-fast @entity3998 ( @entity3998 ) isoform transition through direct muscle b2-adrenergic receptor stimulation. Thus, we hypothesized that CB would antagonize glucocorticoid ( @entity619 ; @entity9170 )-induced @entity2057 and fast-to-slow @entity3998 isoform transition. METHODOLOGY: We examined the effect of CB on @entity9170 -induced @entity2057 by measuring masseter muscle weight, fiber diameter, cross-sectional area, and @entity3998 ( @entity3998 ) composition. To elucidate the mechanisms involved, we used immunoblotting to study the effects of CB on muscle @entity1184 signaling ( @entity442 ( @entity442 ) expression, @entity584 / @entity1 target of @entity3446 ( @entity3470 ) pathway, and calcineurin pathway) and @entity3202 signaling ( @entity584 /Forkhead box-O (FOXO) pathway and @entity49162 expression) in masseter muscle of @entity35 treated with @entity9170 and/or CB. RESULTS AND CONCLUSION: Masseter muscle weight in the @entity9170 -treated group was significantly lower than that in the Control group, as expected, but co-treatment with CB suppressed the @entity9170 -induced @entity2057 , concomitantly with inhibition of fast-to-slow @entity3998 isoforms transition. Activation of the @entity584 / @entity3470 pathway in masseter muscle of the @entity9170 -treated group was significantly inhibited compared to that of the Control group, and CB suppressed this inhibition. @entity9170 also suppressed expression of @entity442 (positive regulator of muscle growth), and CB attenuated this inhibition. @entity49162 protein expression was unchanged. CB had no effect on activation of the @entity584 /FOXO pathway. These results indicate that CB antagonizes @entity9170 -induced @entity2057 and fast-to-slow @entity3998 isoform transition via modulation of @entity584 / @entity3470 activity and @entity442 expression. CB might be a useful pharmacological agent for treatment of glucocorticoid-induced @entity2057 .
