College of Animal Science, ALLTECH-SCAU Animal Nutrition Control Research Alliance, South China Agricultural University, Guangzhou, Guangdong, 510642, P. R. China.
Poult Sci. 2014 Jan;93(1):138-46. doi: 10.3382/ps.2013-03300.
Decorin, a small leucine-rich proteoglycan as a component of the extracellular matrix, plays an important role in the skeletal muscle development. It has been reported that decorin promoted proliferation and differentiation of muscle cells by restraining myostatin activity in rodents. However, the effects and mechanisms of decorin on avian myoblast proliferation are not understood clearly. Thus, in our research, decorin overexpressing and knocking-down quail myoblast-7 (QM7) myoblasts were established to explore the effects of decorin on avian myoblast proliferation by flow cytometry. The results showed that overexpression of decorin enhanced the proliferation of QM7 myoblasts, which was accompanied by the upregulation of follistatin and primary muscle regulatory factors (i.e., myogenic factor 5, myogenic factor 1, myogenin), and downregulation of myostatin expression, as well as the decreased phosphorylation level of SMAD family member 3 (Smad3). In line with expectations, decorin RNAi displayed an opposite effect on the proliferation and gene expression pattern of QM7 cells. In conclusion, our in vitro studies suggested the decorin-mediated myostatin/Smad signaling pathway might be involved in the regulation of avian myoblast proliferation.
核心蛋白聚糖（Decorin）是细胞外基质的一种小型富含亮氨酸的蛋白聚糖，在骨骼肌发育中起着重要作用。有报道称，核心蛋白聚糖通过抑制肌生成抑制素（myostatin）在啮齿动物中的活性，促进肌肉细胞的增殖和分化。然而，核心蛋白聚糖对禽类成肌细胞增殖的影响及其机制尚不清楚。因此，在我们的研究中，通过流式细胞术建立了核心蛋白聚糖过表达和敲低鹌鹑成肌细胞-7（QM7）的细胞系，以探索核心蛋白聚糖对禽类成肌细胞增殖的影响。结果表明，核心蛋白聚糖的过表达增强了 QM7 成肌细胞的增殖，同时伴随着卵泡抑素和主要肌肉调节因子（即肌生成因子 5、肌生成因子 1、肌细胞生成素）的上调，以及肌生成抑制素表达的下调，以及 SMAD 家族成员 3（Smad3）的磷酸化水平降低。与预期一致的是，核心蛋白聚糖 RNAi 对 QM7 细胞的增殖和基因表达模式产生了相反的影响。综上所述，我们的体外研究表明，核心蛋白聚糖介导的肌生成抑制素/Smad 信号通路可能参与了禽类成肌细胞增殖的调节。
