人胚胎干细胞来源的间充质干细胞和fos基因促进肌腱分化和修复的研究

发布时间：2018-04-16 17:37

本文选题：肌腱组织工程 + 肌腱分化　；参考：《浙江大学》2014年博士论文

【摘要】：肌腱损伤是最常见的运动性损伤之一,是骨科和运动医学中公认的治疗难题。统计表明,全球每年至少有3000万的肌腱损伤病例,严重影响患者的生活质量,并断送了许多优秀运动员的职业生命。目前,临床上对肌腱损伤的治疗主要停留在理疗、手术缝合以及移植阶段,虽有一定效果,但是疗效有限。肌腱修复后的组织和功能特性与正常肌腱相距甚远,常伴随有腱粘连、组织形态不佳(形成疤痕组织),力学差(最多达到40%强度),易二次损伤。因此,寻找肌腱再生修复新手段具有重要的临床意义。近年来,干细胞与组织工程技术的发展为提高肌腱等软组织的修复质量带来了全新的机会,人们开始尝试采用肌腱组织工程技术来治疗和修复肌腱缺损。种子细胞是组织工程的关键要素之一。当前肌腱组织工程研究中备受关注的种子细胞包括胚胎干细胞(ESCs)、间充质干细胞(MSCs)和肌腱干细胞(TSPCs)等。然而目前研究发现以干细胞作为种子细胞修复后的肌腱在力学性能上与正常肌腱仍有显著区别,在微观结构上表现为生成大量的小直径的胶原纤维,而这些小直径胶原纤维正是导致愈后肌腱力学性能低下的直接因素。这些结果表明目前的组织工程手段仍然只能部分提高肌腱的修复质量,尚缺乏有效手段使干细胞完全分化为功能性肌腱细胞,达到肌腱完全再生。本论文立足于本研究室前期研究发现——胚胎干细胞可作为肌腱种子细胞,开展胚胎干细胞定向分化为MSCs后进行肌腱组织工程研究以及寻找肌腱早期发育的重要调控因子用于促进肌腱分化和修复,最终目的为调控胚胎干细胞的肌腱分化,构建组织工程肌腱,促进肌腱修复和再生。本论文研究内容包含：第一部分是胚胎干细胞构建组织工程肌腱用于肌腱修复的研究。通过运用胚胎干细胞来源的间充质干细胞(ESC-MSCs)与网状-蚕丝胶原复合支架构建组织工程肌腱,用于肌腱修复。第二部分是肌腱分化相关重要基因筛选的研究。通过发育生物学研究,我们首次将肌腱发育、成熟分为不同的阶段,评估肌腱正常发育过程中的组织形态与内在分子信号改变,结合生物芯片数据进行筛选,发现fos基因在肌腱阶段性分化过程中发挥着重要调控作用,并进一步通过基因过表达和基因沉默实验得到验证。第三部分是fos基因用于胚胎干细胞向早期肌腱分化的研究。通过在胚胎干细胞来源的间充质干细胞中过表达fos基因,促进细胞向早期肌腱分化。本研究的成果和发现为利用胚胎干细胞修复再生肌腱提供了新的实验依据和分化知识,并根据肌腱发育提出肌腱阶段性分化作为肌腱组织工程诱导的手段,为未来肌腱损伤治疗带来新的种子细胞和技术手段。
[Abstract]:Tendon injury is one of the most common sports injuries and is recognized as a difficult problem in orthopedics and sports medicine.Statistics show that there are at least 30 million cases of tendon injury every year in the world, which seriously affects the quality of life of patients and results in the loss of professional life of many excellent athletes.At present, the clinical treatment of tendon injury mainly stays at the stage of physiotherapy, surgical suture and transplantation, although it has certain effect, but the curative effect is limited.The tissue and functional characteristics of tendon repair are far from normal tendon, often accompanied by tendon adhesion, poor tissue morphology (formation of scar tissue, mechanical poor (up to 40% strength, easy to secondary injury).Therefore, it is of great clinical significance to find a new method of tendon regeneration and repair.In recent years, the development of stem cells and tissue engineering technology has brought a new opportunity to improve the quality of soft tissue repair, such as tendons. People began to try to use tendon tissue engineering technology to treat and repair tendon defects.Seed cells are one of the key elements in tissue engineering.Currently, seed cells in tendon tissue engineering include embryonic stem cells ESCs, mesenchymal stem cells (MSCs) and tendon stem cells (TSPCs).However, it has been found that the tendon repaired with stem cells as seed cells is still different from the normal tendon in terms of mechanical properties, and the microstructure of the tendon is characterized by the formation of a large number of small diameter collagen fibers.These small diameter collagen fibers are the direct factors leading to the lower mechanical properties of the tendon.These results suggest that the current tissue engineering methods can only partially improve the quality of tendon repair and lack of effective means to make stem cells fully differentiate into functional tendon cells to achieve complete tendon regeneration.This paper is based on the previous research in our laboratory and found that embryonic stem cells can be used as seed cells of tendon.After directional differentiation of embryonic stem cells into MSCs, the study of tendon tissue engineering and the search for important regulatory factors for early development of tendon were carried out to promote tendon differentiation and repair, with the ultimate aim of regulating tendon differentiation of embryonic stem cells.To construct tissue engineered tendon to promote tendon repair and regeneration.The main contents of this thesis are as follows: the first part is about the construction of tissue engineered tendon by embryonic stem cells (ESC) for tendon repair.The mesenchymal stem cells derived from embryonic stem cells (ESC-MSCs) and reticular-silk collagen composite scaffolds were used to construct tissue engineered tendons for tendon repair.The second part is about the selection of important genes related to tendon differentiation.Through the research of developmental biology, we divide tendon development and maturation into different stages for the first time, evaluate the changes of tissue morphology and intrinsic molecular signal during normal development of tendon, and screen them with biochip data.It was found that fos gene played an important role in the process of tendon differentiation, and was further verified by gene overexpression and gene silencing.The third part is the research of fos gene used to differentiate embryonic stem cells into early tendon.Fos gene was overexpressed in mesenchymal stem cells derived from embryonic stem cells to promote the differentiation of cells into early tendon.The results and findings of this study provide a new experimental basis and knowledge of differentiation for the repair of regenerated tendons using embryonic stem cells. According to tendon development, the periodic differentiation of tendons is proposed as a means of inducing tendon tissue engineering.To bring new seed cells and techniques for the treatment of tendon injury in the future.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R686

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