BLOOD FLOW RESTRICTED RESISTANCE TRAINING ATTENUATES MYOSTATIN GENE EXPRESSION IN A PATIENT WITH INCLUSION BODY MYOSITIS

Inclusion body myositis is a rare idiopathic inflammatory myopathy that produces extreme muscle weakness. Blood flow restricted resistance training has been shown to improve muscle strength and muscle hypertrophy in inclusion body myositis. Objective: The aim of this study was to evaluate the effects of a resistance training programme on the expression of genes related to myostatin (MSTN) signalling in one inclusion body myositis patient. Methods: A 65-year-old man with inclusion body myositis underwent blood flow restricted resistance training for

12 weeks. The gene expression of MSTN, follistatin, follistatin-like 3, activin II B receptor, SMAD-7, MyoD, FOXO-3, and MURF-2 was quantified. Results: After 12 weeks of training, a decrease (25%) in MSTN mRNA level was observed, whereas follistatin and follistatin-like 3 gene expression increased by 40% and 70%, respectively. SMAD-7 mRNA level was augmented (20%). FOXO-3 and MURF-2 gene expression increased by 40% and 20%, respectively.

No change was observed in activin II B receptor or MyoD gene expression. Conclusions: Blood flow restricted resistance training attenuated MSTN gene expression and also increased expression of myostatin endogenous inhibitors. Blood flow restricted resistance training evoked changes in the expression of genes related to MSTN signalling pathway that could in part explain the muscle hypertrophy previously observed in a patient with inclusion body myositis.