Ahmad Sarafraz, Jan Arif Tasleem, Baig Mohammad Hassan, Lee Eun Ju, Choi Inho
Department of Medical Biotechnology, Yeungnam University, Gyeongsan 38541, Republic of Korea.
Department of Medical Biotechnology, Yeungnam University, Gyeongsan 38541, Republic of Korea.
Life Sci. 2017 Mar 1;172:55-63. doi: 10.1016/j.lfs.2016.12.011. Epub 2016 Dec 21.
Skeletal muscle development involves interactions between intracellular and extracellular factors that act in concert to regulate the myogenic process. Matrix gla protein (MGP), a well-known inhibitor of calcification in soft tissues, has been reported to be highly up-regulated during myogenesis. Our interest in the regulation of muscle satellite cells (MSCs) by extracellular matrix (ECM) led us to investigate the effects of MGP during the progression of myogenesis.
Participation of MGP in the myogenic process was investigated in vitro using C2C12 cells, and knockdown of its gene was performed to determine its effects on the expression of myogenic regulatory factors (MRFs) and other ECM genes. In addition, interactions between MGP, Fibromodulin (FMOD), and Myostatin (MSTN) were investigated by conducting co-immunoprecipitation and in silico studies.
Matrix gla protein knockdown (MGP) shows pronounced effects during myogenesis as evidenced by the down regulation of myogenic marker (MYOG and MYOD), and ECM (COL1α1 and FMOD) genes. Down-regulation of MSTN expression in MGP cells suggests its role in coordinating the regulation of MSTN expression. Having strong affinity for ACVRIIB receptor, in silico data confirms MGP interference in the interaction of MSTN with ACVRIIB. These findings show MGP inhibits MSTN functionally by disrupting its binding to receptor.
The present study provides insights of an ECM protein that participates in the regulation of the myogenic program by inhibiting the activity of the myogenic negative regulator MSTN, which suggests that MGP might be used for designing novel inhibitors that can promote muscle regeneration or treat muscle atrophy.
骨骼肌发育涉及细胞内和细胞外因子之间的相互作用，这些因子协同作用以调节肌生成过程。基质γ-羧基谷氨酸蛋白（MGP）是一种众所周知的软组织钙化抑制剂，据报道在肌生成过程中高度上调。我们对细胞外基质（ECM）对肌肉卫星细胞（MSC）的调节作用感兴趣，这促使我们研究MGP在肌生成进程中的作用。
使用C2C12细胞在体外研究MGP在肌生成过程中的参与情况，并对其基因进行敲低以确定其对肌生成调节因子（MRF）和其他ECM基因表达的影响。此外，通过进行免疫共沉淀和计算机模拟研究，研究了MGP、纤调蛋白（FMOD）和肌肉生长抑制素（MSTN）之间的相互作用。
基质γ-羧基谷氨酸蛋白敲低（MGP）在肌生成过程中显示出显著作用，肌生成标志物（MYOG和MYOD）以及ECM（COL1α1和FMOD）基因的下调证明了这一点。MGP细胞中MSTN表达的下调表明其在协调MSTN表达调节中的作用。计算机模拟数据证实MGP对MSTN与ACVRIIB受体相互作用的干扰，因为MGP对ACVRIIB受体具有很强的亲和力。这些发现表明MGP通过破坏MSTN与受体的结合在功能上抑制MSTN。
本研究提供了一种ECM蛋白的见解，该蛋白通过抑制肌生成负调节因子MSTN的活性参与肌生成程序的调节，这表明MGP可能用于设计新型抑制剂，以促进肌肉再生或治疗肌肉萎缩。
