Xie Xin, Tsai Sophia Y, Tsai Ming-Jer
J Clin Invest. 2016 Oct 3;126(10):3929-3941. doi: 10.1172/JCI87414. Epub 2016 Sep 12.
Duchenne muscular dystrophy (DMD) is a severe and progressive muscle-wasting disease caused by mutations in the dystrophin gene. Although dystrophin deficiency in myofiber triggers the disease's pathological changes, the degree of satellite cell (SC) dysfunction defines disease progression. Here, we have identified chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) hyperactivity as a contributing factor underlying muscular dystrophy in a dystrophin-deficient murine model of DMD. Ectopic expression of COUP-TFII in murine SCs led to Duchenne-like dystrophy in the muscles of control animals and exacerbated degenerative myopathies in dystrophin-deficient mice. COUP-TFII-overexpressing mice exhibited regenerative failure that was attributed to deficient SC proliferation and myoblast fusion. Mechanistically, we determined that COUP-TFII coordinated a regenerative program through combined regulation of multiple promyogenic factors. Furthermore, inhibition of COUP-TFII preserved SC function and counteracted the muscle weakness associated with Duchenne-like dystrophy in the murine model, suggesting that targeting COUP-TFII is a potential treatment for DMD. Together, our findings reveal a regulatory role of COUP-TFII in the development of muscular dystrophy and open up a potential therapeutic opportunity for managing disease progression in patients with DMD.
杜兴氏肌肉营养不良症(DMD)是一种严重的进行性肌肉萎缩疾病,由肌营养不良蛋白基因的突变引起。虽然肌纤维中肌营养不良蛋白的缺乏引发了该疾病的病理变化,但卫星细胞(SC)功能障碍的程度决定了疾病的进展。在此,我们发现在DMD的肌营养不良蛋白缺陷小鼠模型中,鸡卵清蛋白上游启动子转录因子II(COUP-TFII)的过度活跃是导致肌肉营养不良的一个因素。COUP-TFII在小鼠卫星细胞中的异位表达导致对照动物肌肉出现杜兴氏样营养不良,并加剧了肌营养不良蛋白缺陷小鼠的退行性肌病。过表达COUP-TFII的小鼠表现出再生失败,这归因于卫星细胞增殖和成肌细胞融合不足。从机制上讲,我们确定COUP-TFII通过对多种促肌生成因子的联合调节来协调一个再生程序。此外,抑制COUP-TFII可保留卫星细胞功能,并抵消小鼠模型中与杜兴氏样营养不良相关的肌肉无力,这表明靶向COUP-TFII是治疗DMD的一种潜在方法。总之,我们的研究结果揭示了COUP-TFII在肌肉营养不良发展中的调节作用,并为控制DMD患者的疾病进展开辟了一个潜在的治疗机会。