National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China.
Mol Biol Rep. 2013 Jun;40(6):4101-8. doi: 10.1007/s11033-013-2494-6. Epub 2013 Apr 20.
Myostatin is a transforming growth factor-β family member that acts as a negative regulator of skeletal muscle mass. To identify possible myostatin inhibitors that may promote muscle growth, we used RNA interference mediated by a lentiviral vector to knockdown myostatin in goat fetal fibroblast cells. We also investigated the expression changes in relevant myogenic regulatory factors (MRFs) and adipogenic regulatory factors in the absence of myostatin in goat fetal fibroblasts. Quantitative RT-PCR revealed that myostatin transcripts were significantly reduced by 75 % (P < 0.01). Western blot showed that myostatin protein expression was reduced by 95 % (P < 0.01). We also found that the mRNA expression of activin receptor IIB (ACVR2B) significantly increased by 350 % (P < 0.01), and p21 increased 172 % (P < 0.01). Furthermore, myostatin inhibition decreased Myf5 and increased MEF2C mRNA expression in goat fetal fibroblasts, suggesting that myostatin regulates MRFs differently in fibroblasts compared to muscle. In addition, the expression of adipocyte marker genes peroxisome proliferator-activated receptor (PPAR) γ and leptin, but not CCAAT/enhance-binding protein (C/EBP) α and C/EBPβ, were upregulated at the transcript level after myostatin silencing. These results suggest that we have generated a novel way to block myostatin in vitro, which could be used to improve livestock meat production and gene therapy of musculoskeletal diseases. This also suggests that myostatin plays a negative role in regulating the expression of adipogenesis related genes in goat fetal fibroblasts.
肌肉生长抑制素是转化生长因子-β家族的一员，作为骨骼肌质量的负调节剂。为了鉴定可能促进肌肉生长的肌肉生长抑制素抑制剂，我们使用慢病毒载体介导的 RNA 干扰在山羊胎儿成纤维细胞中敲低肌肉生长抑制素。我们还研究了在山羊胎儿成纤维细胞中缺乏肌肉生长抑制素时相关的肌生成调节因子（MRFs）和脂肪生成调节因子的表达变化。定量 RT-PCR 显示肌肉生长抑制素转录本显著降低了 75%（P<0.01）。Western blot 显示肌肉生长抑制素蛋白表达降低了 95%（P<0.01）。我们还发现激活素受体 IIB（ACVR2B）的 mRNA 表达显著增加了 350%（P<0.01），p21 增加了 172%（P<0.01）。此外，肌肉生长抑制素抑制降低了山羊胎儿成纤维细胞中 Myf5 的表达，增加了 MEF2C 的 mRNA 表达，表明肌肉生长抑制素在成纤维细胞中对 MRFs 的调节不同于肌肉。此外，在肌肉生长抑制素沉默后，脂肪细胞标记基因过氧化物酶体增殖物激活受体（PPAR）γ和瘦素的表达在转录水平上调，但脂肪细胞分化相关基因 CCAAT/增强子结合蛋白（C/EBP）α和 C/EBPβ的表达没有上调。这些结果表明，我们已经在体外产生了一种新的阻断肌肉生长抑制素的方法，这可用于提高家畜肉产量和肌肉骨骼疾病的基因治疗。这也表明肌肉生长抑制素在调节山羊胎儿成纤维细胞中脂肪生成相关基因的表达中起负作用。
