去分化重编排脂肪干细胞在张应力刺激下成骨分化的研究

Osteogenic differentiation of dedifferentiation reprogrammed adipose-derived stem cells stimulatedby tensile strain

目的探讨去分化重编排脂肪干细胞在张应力刺激下的成骨分化并探讨其分子机制。方法分离人脂肪干细胞（hASCs），取第3代hASCs进行去分化重编排并标记为去分化重编排脂肪干细胞（De—hASCs）。张应力刺激条件下，将De．hASCs和hASCs在成骨诱导液中培养1周。并于培养4d和7d后检测碱性磷酸酶（ALP）活性，Runx2的mRNA和蛋白表达水平，骨形态发生蛋白（BMP）-2和基质金属蛋白酶（MMP）-3的mRNA表达水平。结果张应力刺激4d后，De—hASCs组的ALP活性高于hASCs组，但差异无统计学意义（P〉0．05）。张应力刺激7d后，De—hASCs组ALP活性高于hASCs组，且差异有统计学意义（P〈0．05）。张应力刺激4d和7d后，De—hASCs组Runx2的mRNA和蛋白表达水平均明显高于hASCs组，且差异有统计学意义（P〈0．05）。张应力刺激4d和7d后，De—hASCs组BMP-2和MMP-3的mRNA表达水平均明显高于hASCs组，差异有统计学意义（P〈0．05）。结论张应力刺激条件下，去分化重编排脂肪干细胞具有更强的成骨分化能力，且与其上调BMP-2和MMP-3基因表达相关。

Objective To study the osteogenic differentiation of dedifferentiation reprogrammed human adiposederived stem cells （DehASCs） stimulated by tensile strain and related molecular mecha nisms. Methods hASCs were isolated from six volunteers, hASCs of third generations were subjected to the dedifferentiation reprogrammed process and denoted as DehASCs. Both DehASCs and hASCs were then cultured in the osteogenic differentiation medium stimulated by tensile strain for a total period of one week. Alkaline phosphatase （ALP） activity of cells cultured for 4 and 7 days was measured. The expres sion levels of Runx2 mRNA and protein, bone morphogenetic protein （BMP） 2 mRNA and matrix metallo proteinase （MMP） 3 mRNA in the cells cultured for 4 and 7 days were detected. Results ALP activity of the DehASCs at 4th day after culture was stronger than that of hASCs, but there was no significant differ ence. ALP acitivty of the DehASCs at 7th day after culture was stronger than that of hASCs with significant difference. Runx2 mRNA and protein expression levels of the DehASCs were higher than those of hASCs at 4th and 7th day after culture with siginificant difference. BMP2 and MMP3 mRNA expression levels of DehASCs were higher than those of hASCs at 4th and 7th day after culture with significant difference. Con clusion When stimulated by tensile strain, DehASCs possessed a stronger osteogenic differentiation ca pacity than hASCs by upregulating expression of BMP2 and MMP3.