培养表面硬度对于肌腱阶段性分化的效应和机制研究

发布时间：2018-06-08 01:42

本文选题：基质硬度 + Integrin　；参考：《浙江大学》2017年硕士论文

【摘要】：肌腱损伤是一种非常常见的运动损伤。目前以物理治疗、外科缝合以及移植为代表的治疗手段,疗效十分有限。目前,干细胞和组织工程等新技术的手段还是只能部分改善肌腱的修复效果,这其中问题在于没有有效方法能够使细胞向成熟功能细胞分化,实现肌腱完全再生。所以,我们在之前对干细胞协同生物支架的研究成果基础之上,对干细胞阶段性向肌腱分化与成熟展开研究,提出假说:物理与化学微环境通过肌腱细胞特异整合素(integrin)调控肌腱干细胞向肌腱系分化成熟。实验室前期的研究证明,物理微环境与肌腱相关转录因子可以用来诱导干细胞向肌腱干细胞分化,并且integrin基因参与了肌腱的分化成熟。因此,本课题基于以下三部分内容。在第一部分中,我们通过基因芯片筛选,发现力学相关转录因子Fos基因在早期肌腱中高表达,通过体内外过表达与敲降实验,发现在早期肌腱干细胞中过表达Fos基因可以促进肌腱干细胞向早期肌腱分化。第二部分我们探索力学微环境对肌腱晚期分化与成熟的影响,利用PDMS凝胶构建梯度杨氏模量的基质材料,我们发现合适的基质硬度能够促进肌腱干细胞的Scx表达和腱系表型维持,并协同TGF-β1诱导向肌腱系分化。进一步实验利用无支架体外组织工程肌腱模型,在不同基质硬度上诱导组织工程肌腱。在体内膑腱损伤修复实验中,我们发现合适基质硬度能诱导肌腱干细胞向成熟肌腱分化并促进损伤肌腱的再生。整合素(integrin)家族为细胞力学传导的第一类感受器,因此第三部分为探索integrin在肌腱干细胞分化中的机制,我们发现肌腱干细胞特异性表达integrinam亚型,进一步实验发现硬度与Fos基因均可能通过肌腱特异integrin诱导肌腱分化。本研究揭示了物理与化学信号通过肌腱干细胞特异性integrin亚型的改变诱导干细胞向成熟肌腱分化,为在体外大量扩增肌腱组织工程细胞和实现肌腱组织完全再生提供了全新的思路。
[Abstract]:Tendon injury is a very common sport injury. At present, physical therapy, surgical suture and transplantation as the representative of the treatment, the efficacy is very limited. At present, new techniques such as stem cells and tissue engineering can only partially improve the repair effect of tendon. The problem is that there is no effective way to make cells differentiate into mature functional cells and achieve complete tendon regeneration. So, on the basis of previous research on stem cells co-scaffolds, we started to study the stage differentiation and maturation of stem cells into tendons. It is hypothesized that the physical and chemical microenvironment regulates the differentiation and maturation of tendon stem cells into tendon system through tendon cell specific integrin. Previous laboratory studies have shown that physical microenvironment and tendon related transcription factors can be used to induce stem cells to differentiate into tendon stem cells, and integrin gene is involved in tendon differentiation and maturation. Therefore, this subject is based on the following three parts. In the first part, we found that Fos gene was highly expressed in early tendon by gene chip screening, and was overexpressed and knocked down in vivo and in vitro. It was found that overexpression of Fos gene in early tendon stem cells could promote the differentiation of tendon stem cells into early tendon. In the second part, we explore the effect of mechanical microenvironment on the late differentiation and maturation of tendon. We use PDMS gel to construct the matrix material with gradient Young's modulus. We found that suitable matrix hardness could promote SCX expression and phenotypic maintenance of tendon stem cells, and induce tendon differentiation in coordination with TGF- 尾 1. The tissue engineered tendon was induced on different matrix hardness by using scaff-free tissue engineered tendon model in vitro. In vivo patellar tendon repair experiments, we found that suitable matrix hardness can induce the differentiation of tendon stem cells into mature tendon and promote the regeneration of damaged tendon. Integrin family is the first type receptor of cellular mechanical conduction. Therefore, the third part is to explore the mechanism of integrin in the differentiation of tendon stem cells. We found that tendon stem cells specifically express integrinam subtypes. Furthermore, it was found that both hardness and Fos gene could induce tendon differentiation by tendon specific integrin. This study revealed that physical and chemical signals induce stem cells to differentiate into mature tendons through the alteration of specific integrin subtypes of tendon stem cells. It provides a new idea for the expansion of tendon tissue engineering cells in vitro and the complete regeneration of tendon tissue.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R68;R318.08

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