Santa María Lorena, Rojas Cecilia V, Minguell José J
Programa de Terapias Celulares, INTA, Universidad de Chile, Santiago, Chile.
Exp Cell Res. 2004 Nov 1;300(2):418-26. doi: 10.1016/j.yexcr.2004.07.017.
The regenerative capacity of skeletal muscle has been usually attributed to resident satellite cells, which, upon activation by local or distant stimuli, initiate a myogenic differentiation program. Although recent studies have revealed that bone-marrow-derived progenitor cells may also participate in regenerative myogenesis, the signals and mechanisms involved in this process have not been elucidated. This study was designed to investigate whether signals from injured rat skeletal muscle were competent to induce a program of myogenic differentiation in expanded cultures of rat bone-marrow-derived mesenchymal stem cells (MSC). We observed that the incubation of MSC with a conditioned medium prepared from chemically damaged but not undamaged muscle resulted in a time-dependent change from fibroblast-like into elongated multinucleated cells, a transient increase in the number of MyoD positive cells, and the subsequent onset of myogenin, alpha-actinin, and myosin heavy chain expression. These results show that damaged rat skeletal muscle is endowed with the capacity to induce myogenic differentiation of bone-marrow-derived mesenchymal progenitors.
骨骼肌的再生能力通常归因于驻留卫星细胞，这些卫星细胞在受到局部或远处刺激激活后，启动成肌分化程序。尽管最近的研究表明，骨髓来源的祖细胞也可能参与再生性肌生成，但这一过程中涉及的信号和机制尚未阐明。本研究旨在调查来自受伤大鼠骨骼肌的信号是否能够诱导大鼠骨髓来源的间充质干细胞（MSC）扩增培养物中的成肌分化程序。我们观察到，将MSC与由化学损伤而非未损伤的肌肉制备的条件培养基孵育，会导致细胞从成纤维细胞样形态随时间变化为伸长的多核细胞，MyoD阳性细胞数量短暂增加，随后肌细胞生成素、α-肌动蛋白和肌球蛋白重链表达开始。这些结果表明，受损的大鼠骨骼肌具有诱导骨髓来源的间充质祖细胞成肌分化的能力。
