三维仿生胶原纤维/蚕丝支架通过调控KDM6A-HOXA11轴促进前交叉韧带修复的效应及机制研究

Anterior cruciate ligament (ACL) injury is one of the most common locomotor system damage in clinic, which will eventually lead to serious knee joint dysfunction. And the lack of an ideal biological scaffold used for reconstruction of the ACL is still pending. The latest research shows that the topology of the extracellular matrix could modify the epigenetic state, and ultimately affect the differentiation of cells. Therefore, this study is based on our previous stem cell research and biological scaffold investigation,(Biomaterials, 2010, 2014; Cell Transplant, 2012), according to the alignment of extracellular matrix of tendon/ligament organization, design a three-dimensional biomimetic collagen fiber - silk scaffolds. The first step is to improve the fabrication of ligament tissue engineering three-dimensional biomimetic collagen fiber and isolate ACL-derived stem cells, detect different topologies on the stem cell self-renewal and multiple differentiation in vitro; The second step is to evaluate the composite scaffolds on promoting regeneration of ACL, and inhibiting bone arthritis efficiency in vivo; The last step is to study the mechanism of material's surface topology physical signal regulating the tendon differentiation by epigenetics (KDM6A - Hoxa11 axis). Our study will explore and identify how topology participate in the regulation of stem cell differentiation through epigenetics, provide a new idea for the regulation of stem cells to tendon/ligament differentiation, and provides a new theory and new technology for the use of stem cells and biological materials to ACL regeneration.

前交叉韧带（ACL）损伤会导致骨关节炎，最终影响膝关节功能，然而目前尚缺乏理想的生物支架用于 ACL 的再生。最新研究表明胞外基质的拓扑结构会影响细胞的表观状态，进而影响细胞的分化。因而，本课题首先立足前期成果（Biomaterials 2010，2014；Cell Transplant 2012），仿造韧带的平行胞外基质构建三维仿生胶原纤维/蚕丝支架，体外培养体系明确不同拓扑结构对前交叉韧带来源干/祖细胞（LSPCs）分化的影响；其次运用组织工程手段在体内评估新型组织工程韧带促进 ACL 修复的效能；最后探讨材料表面拓扑结构这一物理学信号影响表观遗传学（KDM6A-Hoxa11轴），进而调控腱系分化的可能机制。该研究将探索并明确拓扑结构如何通过表观遗传修饰参与调控干细胞的定向分化，将为调控干细胞向韧带分化提供全新的思路，并为利用组织工程技术再生修复ACL提供了新理论依据和新技术手段。

前交叉韧带（ACL）损伤会导致骨关节炎，最终影响膝关节功能，然而目前尚缺乏理想的生物支架用于 ACL 的再生。最新研究表明胞外基质的拓扑结构会影响细胞的表观状态，进而影响细胞的分化。因而，本课题首先仿造韧带的平行胞外基质构建了三维仿生胶原纤维/蚕丝支架（平行蚕丝胶原支架和紊乱蚕丝胶原支架），平行的支架具有平行胶原纤维结构，与天然的肌腱韧带的平行的胶原纤维极为为类似；然后我们分离了韧带干细胞并且将其在体外接种于三维仿生胶原纤维/蚕丝支架上，体外培养体系明确不同拓扑结构对前交叉韧带来源干/祖细胞（LSPCs）分化的影响，发现平行仿生的蚕丝胶原支架可以促进表面的肌腱干细胞成肌腱分化，；其次运用组织工程手段在体内评估新型组织工程韧带促进肌腱/韧带修复的效能。发现平行蚕丝胶原支架较紊乱的蚕丝胶原支架可以更好的促进；qpcr结果显示平行/紊乱拓扑结构表面接种的肌腱干细胞表观遗传学（组蛋白甲基化，组蛋白乙酰化）发生改变，体外实验通过chipseq确认了表观相关的酶HDAC3通过TGFb信号通路促进肌腱干细胞的成肌腱分化以及再生。该研究将探索并明确拓扑结构如何通过表观遗传修饰参与调控干细胞的定向分化，将为调控干细胞向韧带分化提供全新的思路，并为利用组织工程技术再生修复肌腱韧带提供了新理论依据和新技术手段。具有非常重要的科学意义。