Anti-Human MYOD1 (Phospho-Ser200) polyclonal antibody

Background: Denervation-induced skeletal muscle atrophy results in significant biochemical and physiological changes potentially leading to devastating outcomes including increased mortality. Effective treatments for skeletal muscle diseases are currently not available. Muscle-specific miRNAs, such as miR-206, play an important role in the regulation of muscle regeneration. The aim of the present study was to examine the beneficial effects of miR-206 treatment during the early changes in skeletal muscle atrophy, and to study the underlying signaling pathways in a rat skeletal muscle atrophy model. Material/Methods: The rat denervation-induced skeletal muscle atrophy model was established. miRNA-206 was overexpressed with or without TGF-b1 inhibitor in the rats. The mRNA and protein expression of HDAC4, TGF-beta 1, and Smad3 was determined by real-time PCR and western blot. The gastrocnemius muscle cross-sectional area and relative muscle mass were measured. MyoD1, TGF-beta 1, and Pax7 were determined by immunohistochemical staining. Results: After sciatic nerve surgical transection, basic muscle characteristics, such as relative muscle weight, deteriorated continuously during a 2-week period. Injection of miR-206 (30 mu g/rat) attenuated morphological and physiological deterioration of muscle characteristics, prevented fibrosis effectively, and inhibited the expression of TGF-beta 1 and HDAC4 as assessed 2 weeks after denervation. Moreover, miR-206 treatment increased the number of differentiating (MyoD1(+)/Pax7(+)) satellite cells, thereby protecting denervated muscles from atrophy. Interestingly, the ability of miR-206 to govern HDAC4 expression and to attenuate muscle atrophy was weakened after pharmacological blockage of the TGF-b1/Smad3 axis. Conclusions: TGF-beta 1/Smad3 signaling pathway is one of the crucial signaling pathways by which miR-206 counteracts skeletal muscle atrophy by affecting proliferation and differentiation of satellite cells. miR-206 may be a potential target for development of a new strategy for treatment of patients with early denervation-induced skeletal muscle atrophy.

New Findings What is the central question of this study?Does Dnmt3a play a crucial role in regulating diabetic muscle atrophy? What is the main finding and its importance?Muscle atrophy is one of the major long-term complications of diabetes mellitus. However, little is known about the molecular mechanism involved. In this paper, we demonstrated that Dnmt3a overexpression effectively improves the diabetic muscle health in mice and documented the underlying mechanisms. DNMT3A might become a promising target to prevent muscle atrophy in patients with diabetes. Muscle atrophy is one of the major long-term complications of diabetes mellitus, which greatly affects the mobility of patients. Epigenetic processes mediated by DNA methyltransferases (DNMTs) play crucial roles in the locomotor system, but little is known about the functions of DNMTs in diabetic muscle atrophy. Here, we investigated the function of Dnmt3a in diabetic muscle atrophy and explored the mechanisms involved. Adeno-associated virus AAV2 overexpressing Dnmt3a or its vector control was injected into the tibialis anterior muscle of streptozotocin-induced diabetic mice. Muscle mass and muscle cross-sectional area were used to evaluate muscle atrophy.In vitro, adeno-associated virus AAV2 overexpressing Dnmt3a or its vector control was transfected into C2C12 myoblasts. Horse serum was used to induce differentiation and palmitate to stimulate the C2C12 myoblasts. The expressions of myogenic regulatory factors were examined by real-time PCR and western blot analysis. Overexpression of Dnmt3a attenuated muscle atrophy in diabetic mice and promoted myotube formation of C2C12 myoblasts. Overexpression of Dnmt3a restored the expressions of myogenic regulatory factors atrogin-1, MuRF1, Pax7, Myod1 and myogenin, bothin vivoandin vitro. Moreover, overexpression of Dnmt3a activated the phosphorylation of Akt by inhibiting the activation of Pten. This study demonstrates that overexpression of Dnmt3a prevents diabetic muscle atrophy by modulating the Pten/Akt pathway.