Exercise Trainning Inhibiting TGFβ Pathway and Improving D-Glactose Injection-induced Senescent Muscle Loss in Rat

Objectvie:To explore the functions of (canonical and uncanonical) TGFβpathway in exercise-induced improvement of sarcopenia.Method:24 male wistar rats were divided into 3groups:C group (quiet young group) , S group (40day D-Glactose injection-induced senecence) , E group (40days D-Glactose injection-induced senecence+6weeks exercise trainning on treadmill) .To detect body wet weight, gastrocnemius wet weight (by weighment) , TGFβpathway component-TGFβ1, MSTN, Phospho-smad2/3, Phospho-MAPK (p38, JNK1/2, ERK1/2) , TGFβpathway effector-p21, Pax7 by WB and MyoD mRNA, MyoG mRNA by RT-PCR in each group.Result:The ratio of gastrocnemius weight to body weight decreased, but TGFβ1, MSTN, Phospho-smad2, 3, Phospho-p38, Phospho-JNK1, 2, Phospho-ERK1, 2, p21, MyoD mRNA, MyoG mRNA increased and Pax7 decreased in S group vs C group.The ratio of gastrocnemius weight to body weight increased, but TGFβ1, MSTN, Phospho-smad2, 3, Phospho-JNK1, 2, Phospho-ERK1, 2decreased, Phospho-p38 unchanged, and p21, Pax7, MyoD mRNA, MyoG mRNA increased in E group vs S group.Conclusion:Exericse trainning can improve senescene-induced muscle loss by inhibiting TGFβcanonical and uncanonical pathway with the mediation of Pax7, p21, MyoD and MyoG.