Zhang Y, Cong X, Wang A, Jiang H
Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg 24061-0306.
Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg 24061-0306
J Anim Sci. 2014 Aug;92(8):3284-90. doi: 10.2527/jas.2014-7656. Epub 2014 Jun 19.
Recent studies in mice and zebrafish suggest that the unannotated Src homology 3 and cysteine rich domain 3 (STAC3) gene plays an important role in skeletal muscle development and contraction. The objective of this study was to determine the tissue specificity of the bovine STAC3 gene and its potential role in the proliferation and differentiation of bovine satellite cells. The STAC3 mRNA was detected only in skeletal muscle among 18 bovine tissues examined by reverse transcription PCR. Western blotting revealed the expression of STAC3 protein in bovine skeletal muscle and the absence of it in 6 bovine tissues analyzed. Transfection of the bovine satellite cells with a pool of 2 STAC3 small interfering RNA (siRNA) caused a 90% reduction in STAC3 mRNA. Cell proliferation assays revealed that STAC3 knockdown had no effect on the proliferation rate of bovine satellite cells. Approximately 60% of bovine satellite cells transfected with STAC3 siRNA formed myotubes by 72 h of differentiation, whereas that percentage was 40% for those transfected with negative control siRNA (P < 0.05). At 24, 48, and 72 h of differentiation, bovine satellite cells transfected with STAC3 siRNA had greater mRNA expression of myogenin, myosin heavy chain 3, and myosin heavy chain 7, markers of myotubes, than those transfected with negative control siRNA (P < 0.05). These results suggest that the STAC3 gene is a negative regulator of the differentiation and fusion of bovine satellite cells into myotubes. However, STAC3 expression was increased during the differentiation of bovine satellite cells into myotubes. This suggests that STAC3 might have different functions in bovine myotubes than in bovine satellite cells.
最近在小鼠和斑马鱼身上进行的研究表明，未注释的Src同源3和富含半胱氨酸结构域3（STAC3）基因在骨骼肌发育和收缩中起重要作用。本研究的目的是确定牛STAC3基因的组织特异性及其在牛卫星细胞增殖和分化中的潜在作用。通过逆转录PCR在18种牛组织中检测到STAC3 mRNA仅在骨骼肌中存在。蛋白质免疫印迹法显示牛骨骼肌中有STAC3蛋白表达，而在所分析的6种牛组织中未检测到。用2种STAC3小干扰RNA（siRNA）转染牛卫星细胞导致STAC3 mRNA减少90%。细胞增殖试验表明，敲低STAC3对牛卫星细胞的增殖率没有影响。转染STAC3 siRNA的牛卫星细胞在分化72小时后约60%形成肌管，而转染阴性对照siRNA的细胞形成肌管的比例为40%（P<0.05）。在分化的24、48和72小时，转染STAC3 siRNA的牛卫星细胞中肌管标志物肌细胞生成素、肌球蛋白重链3和肌球蛋白重链7的mRNA表达高于转染阴性对照siRNA的细胞（P<0.05）。这些结果表明，STAC3基因是牛卫星细胞分化和融合成肌管的负调节因子。然而，在牛卫星细胞分化成肌管的过程中，STAC3的表达增加。这表明STAC3在牛肌管中的功能可能与在牛卫星细胞中的功能不同。
