TGIF1 Gene Silencing in Tendon-Derived Stem Cells Improves the Tendon-to-Bone Insertion Site Regeneration
TGIF1 Gene Silencing in Tendon-Derived Stem Cells Improves the Tendon-to-Bone Insertion Site Regeneration
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肌腱干细胞中的 TGIF1 基因沉默可改善肌腱至骨插入位点的再生
DOI：
10.1159/000438568
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发表时间：
2015-01-01
影响因子：
--
通讯作者：
Cheng, Biao
中科院分区：
文献类型：
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作者：
Chen, Liyang;Jiang, Chaoyin;Cheng, Biao
背景/目的：通过植入具有沉默转化生长相互作用因子 1 (TGIF1) 基因的肌腱衍生干细胞 (TDSC)，可以加速肌腱与骨连接处的缓慢愈合过程。腱骨插入位点是常见结缔祖细胞结缔组织衍生物的特殊形式，其中TGF-β通过不同阶段的不同信号通路发挥双向作用（软骨形成或纤维形成）。最近的一项研究表明，TGF-β 直接诱导软骨形成基因 Sox9。然而，TGIF1 抑制软骨主控 Sox9 基因的表达，并改变其针对纤维发生基因 Scleraxis (Scx) 的表达率。方法：在肌腱干细胞中转导TGIF1 siRNA或过表达TGIF1。皮上肌腱修复后，用转导的 TDSC 或非转导的 TDSC 治疗大鼠。两组均进行组织学检查和Western blot。结果：在这项研究中，TGIF1 的沉默显着上调了软骨形成基因和标记。同样，TGIF1 通过与 TGF-β 激活的 Smad2 相互作用抑制 TDSC 分化为软骨，并抑制 Smad2 的磷酸化。在动物模型的早期阶段，与对照组和TGIF1过表达组相比，TGIF1(-)组的腱-骨界面处的纤维软骨面积显着增加。 4周时，TGIF1（-）组的肌腱和骨骼之间的界面显示出新骨和纤维软骨的增加。在TGIF1过表达组和仅纤维蛋白胶组中观察到纤维血管疤痕组织。 TDSC 组中发现低水平的纤维软骨和纤维血管疤痕组织。结论：总的来说，这项研究表明，TGIF1 基因沉默修饰的肌腱干细胞对肌腱-骨愈合具有良好的效果，可以作为再生医学的治疗工具进一步探索。
Background/Aims: The slow healing process of tendon-to-bone junctions can be accelerated via implanted tendon-derived stem cells (TDSCs) with silenced transforming growth interacting factor 1 (TGIF1) gene. Tendon-to-bone insertion site is the special form of connective tissues derivatives of common connective progenitors, where TGF-β plays bidirectional effects (chondrogenic or fibrogenic) through different signaling pathways at different stages. A recent study revealed that TGF-β directly induces the chondrogenic gene Sox9. However, TGIF1 represses the expression of the cartilage master Sox9 gene and changes its expression rate against the fibrogenesis gene Scleraxis (Scx). Methods: TGIF1 siRNA was transduced or TGIF1 was over-expressed in tendon-derived stem cells. Following suprapinatus tendon repair, rats were either treated with transduced TDSCs or nontransduced TDSCs. Histologic examination and Western blot were performed in both groups. Results: In this study, the silencing of TGIF1 significantly upregulated the chondrogenic genes and markers. Similarly, TGIF1 inhibited TDSC differentiation into cartilage via interactions with TGF-β-activated Smad2 and suppressed the phosphorylation of Smad2. The area of fibrocartilage at the tendon-bone interface was significantly increased in the TGIF1 (-) group compared with the control and TGIF1-overexpressing groups in the early stages of the animal model. The interface between the tendon and bone showed a increase of new bone and fibrocartilage in the TGIF1 (-) group at 4 weeks. Fibrovascular scar tissue was observed in the TGIF1-overexpressing group and the fibrin glue only group. Low levels of fibrocartilage and fibrovascular scar tissue were found in the TDSCs group. Conclusion: Collectively, this study shows that the tendon-derived stem cell modified with TGIF1 gene silencing has promising effects on tendon-to-bone healing which can be further explored as a therapeutic tool in regenerative medicine.