Zanotti Simona, Gibertini Sara, Curcio Maurizio, Savadori Paolo, Pasanisi Barbara, Morandi Lucia, Cornelio Ferdinando, Mantegazza Renato, Mora Marina
Neuromuscular Diseases and Neuroimmunology Unit, Foundation IRCCS Neurological Institute C. Besta, Milano, Italy.
Neuromuscular Diseases and Neuroimmunology Unit, Foundation IRCCS Neurological Institute C. Besta, Milano, Italy.
Biochim Biophys Acta. 2015 Jul;1852(7):1451-64. doi: 10.1016/j.bbadis.2015.04.013. Epub 2015 Apr 17.
Excessive extracellular matrix deposition progressively replacing muscle fibres is the endpoint of most severe muscle diseases. Recent data indicate major involvement of microRNAs in regulating pro- and anti-fibrotic genes. To investigate the roles of miR-21 and miR-29 in muscle fibrosis in Duchenne muscle dystrophy, we evaluated their expression in muscle biopsies from 14 patients, and in muscle-derived fibroblasts and myoblasts. In Duchenne muscle biopsies, miR-21 expression was significantly increased, and correlated directly with COL1A1 and COL6A1 transcript levels. MiR-21 expression was also significantly increased in Duchenne fibroblasts, more so after TGF-β1 treatment. In Duchenne fibroblasts the expression of miR-21 target transcripts PTEN (phosphatase and tensin homolog deleted on chromosome 10) and SPRY-1 (Sprouty homolog 1) was significantly reduced; while collagen I and VI transcript levels and soluble collagen production were significantly increased. MiR-29a and miR-29c were significantly reduced in Duchenne muscle and myoblasts, and miR-29 target transcripts, COL3A1, FBN1 and YY1, significantly increased. MiR-21 silencing in mdx mice reduced fibrosis in the diaphragm muscle and in both Duchenne fibroblasts and mdx mice restored PTEN and SPRY-1 expression, and significantly reduced collagen I and VI expression; while miR-29 mimicking in Duchenne myoblasts significantly decreased miR-29 target transcripts. These findings indicate that miR-21 and miR-29 play opposing roles in Duchenne muscle fibrosis and suggest that pharmacological modulation of their expression has therapeutic potential for reducing fibrosis in this condition.
过量的细胞外基质沉积逐渐取代肌纤维是大多数严重肌肉疾病的终点。最近的数据表明，微小RNA在调节促纤维化和抗纤维化基因方面起主要作用。为了研究miR-21和miR-29在杜兴氏肌营养不良症肌肉纤维化中的作用，我们评估了它们在14例患者肌肉活检组织、肌肉来源的成纤维细胞和成肌细胞中的表达。在杜兴氏肌肉活检组织中，miR-21表达显著增加，且与COL1A1和COL6A1转录水平直接相关。在杜兴氏成纤维细胞中，miR-21表达也显著增加，经TGF-β1处理后增加更明显。在杜兴氏成纤维细胞中，miR-21靶转录本PTEN（第10号染色体缺失的磷酸酶和张力蛋白同源物）和SPRY-1（Sprouty同源物1）的表达显著降低；而胶原蛋白I和VI转录水平以及可溶性胶原蛋白的产生显著增加。miR-29a和miR-29c在杜兴氏肌肉和成肌细胞中显著降低，miR-29靶转录本COL3A1、FBN1和YY1显著增加。在mdx小鼠中沉默miR-21可减少膈肌纤维化，在杜兴氏成纤维细胞和mdx小鼠中恢复PTEN和SPRY-1表达，并显著降低胶原蛋白I和VI的表达；而在杜兴氏成肌细胞中模拟miR-29可显著降低miR-29靶转录本。这些发现表明，miR-21和miR-29在杜兴氏肌肉纤维化中起相反作用，并表明对其表达进行药理学调节具有减少这种情况下纤维化的治疗潜力。
