Inactivation of Wnt/尾-catenin signaling in human adipose-derived stem cells is necessary for chondrogenic differentiation and maintenance

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• 作者：Simin Luo ; Qiping Shi ; Zhengang Zha ; Ping Yao ; Hongsheng Lin ; Ning Liu ; Hao Wu ; Shangyun Sun
• 关键词：Wnt/尾-catenin signaling ; HADSCs ; Chondroid cells ; Dedifferentiation
• 刊名：Biomedicine and Pharmacotherapy
• 出版年：October, 2013
• 年：2013
• 卷：67
• 期：8
• 页码：819-824
• 全文大小：1279 K

文摘

The Wnt/尾-catenin signaling pathway plays critical roles in self-renewal and differentiation of mesenchymal stem cells. However, very little is known about its role in the chondrogenesis of human adipose-derived stem cells (hADSCs). In this study, we analyzed protein expression of several key components of the Wnt/尾-catenin signaling pathway using a 21-day in vitro model of hADSC chondrogenesis. Wnt1, 尾-catenin, and GSK3尾 levels increased sharply at day聽12, peaked at day聽18, and then declined. Expression of TCF1, a target gene of Wnt/尾-catenin signaling, closely followed that of Wnt1. These results were consistent with changes in endonuclear 尾-catenin levels. Gene expression of the chondrocyte-specific markers, collagen type聽II (COL II), SOX9, and aggrecan, increased during hADSC chondrogenesis, peaked at day 12, and then declined. Adding a Wnt inhibitor (days 0-21) resulted in consistently elevated levels of COL II, SOX9, and aggrecan mRNA. In contrast, adding Wnt1 (days 0-21) to cultures led to sustained Wnt/尾-catenin signaling over the 21聽days and suppressed expression of chondrocyte-specific markers. Moreover, adding Wnt1 at late stages of differentiation (day聽18) further diminished chondrocyte-specific marker expression. Together, these results showed that inactivation of Wnt/尾-catenin signaling is needed for the progression of chondrogenesis and the maturation and phenotype maintenance of chondroid cells.