NDNF在老年间充质干细胞年轻化和治疗缺血性心肌损伤中的作用及机制研究

Ischemic heart disease leads to very high morbidity and mortality despite existing treatment options. Autologous stem cell transplantation has been developed and proposed as a promising new therapy, but has not been as effective at the clinical level as was seen in pre-clinical studies. One factor contributing to this discrepancy is advanced patient age, which is correlated with decreases in both the quantity and quality of stem cells. Effective methods to rejuvenate aged stem cells are required. The gene encoding NDNF (neuron-derived neurotrophic factor) was first described in the nervous system. It has several biological functions that align with the goals of stem cell functional restoration, including promoting cell growth, inhibiting apoptosis and activating angiogenesis in injured tissue. Our preliminary work indicated that the expression of NDNF decreased significantly with age in human bone marrow mesenchymal stem cells (hBM-MSCs). In this study, we propose to overexpress NDNF in aged hBM-MSCs using a viral vector to investigate the role and mechanism of NDNF function on senescence, proliferation and apoptosis in aged hBM-MSCs. We also propose to investigate the efficacy and functional mechanisms of NDNF secretion from hBM-MSCs provided as cardiac stem cell therapy in promoting cardiomyocyte survival and angiogenesis. Stem cells will be injected into the infarcted myocardium of rats after coronary artery ligation. We will also explore the functional effects of NDNF over-expression in aged hBM-MSCs during heart repair to assess if NDNF has rejuvenation function in these cells. This study will explore a novel target for stem cell rejuvenation and provide experimental support for more effective autologous stem cell transplantation in aged patients with ischemic heart disease.

缺血性心脏病发病率高、致死率高，现有治疗手段尚不能解决此类疾病的全部问题。自体干细胞移植是较有前景的治疗手段，但随患者年龄增大，体内干细胞数量减少质量降低成为限制其疗效的瓶颈，须寻求干细胞年轻化的有效途径。NDNF是神经系统首先发现的新基因，具有干细胞在损伤局部发挥修复再生作用所需的促进细胞生长、抑制凋亡、促进血管新生等作用。我们前期研究结果显示随年龄增长，人骨髓间充质干细胞中NDNF表达显著减少。本课题拟应用慢病毒载体实现老年骨髓间充质干细胞NDNF过表达，探讨其逆转干细胞自身衰老，促进增殖，抑制凋亡,及通过分泌NDNF促进心肌细胞存活、促进血管新生的作用及其分子机制；细胞注射至大鼠心梗局部，观察NDNF修饰后的优质老年骨髓间充质干细胞对心脏的修复功能并初步探讨其机制。本课题旨在寻求恢复年老间充质干细胞修复再生能力的新靶标，为老年患者自体干细胞移植治疗提供实验支持。

缺血性心脏病发病率高、致死率高，现有治疗手段尚不能解决此类疾病的全部问题。自体干细胞移植是较有前景的治疗手段，但随患者年龄增大，体内干细胞数量减少质量降低成为限制其疗效的瓶颈，须寻求提升老年自体干细胞移植治疗效果的有效途径。NDNF是神经系统首先发现的新基因，具有干细胞在损伤局部发挥修复再生作用所需的抑制凋亡、促进血管新生等作用。.本项目应用慢病毒载体实现老年人骨髓间充质干细胞NDNF过表达，探讨其对老年干细胞增殖、迁移、抗凋亡、衰老表型、成血管等功能的影响，结果显示NDNF过表达可以实现老年干细胞年轻化并通过增强NDNF的分泌来促进血管新生，上述保护作用与AKT信号通路的激活有关；细胞注射至小鼠心梗局部，NDNF修饰后的优质老年人骨髓间充质干细胞能够改善心梗小鼠心功能。同时研究了NDNF过表达还可以实现人脂肪间充质干细胞年轻化并提高其促进损伤修复的能力。初步证实NDNF可以作为实现老年间充质干细胞年轻化的可行靶点，为老年患者自体干细胞移植治疗提供实验支持。在上述研究的基础上进一步证实microRNA 145与心脏损伤后局部成纤维细胞向肌成纤维细胞转化的关系，探索心脏功能修复的可行机制。分离培养具有更高增殖能力，更好血管新生能力的可供快速临床转化的干细胞种子。.本项目靶向全球范围和我国的高发病：心肌梗死等缺血性疾病，探索新的有益的治疗手段补充；同时为实现老年干细胞年轻化以及提升其促血管新生能力的有效手段提供了实验支持，探索具有更好修复再生能力的干细胞种子和修复机制；该治疗策略可拓展至干细胞移植治疗的其他领域以提高干细胞移植治疗效果。后续在完成大动物安全性，有效性等评测的基础上，有望推动成果转化。.围绕本课题及相关领域发表SCI收录II区论文2篇，另有1篇已投稿SCI期刊，1篇正在整理撰写中；1篇国家核心期刊已收录，另1篇投稿后已完成小修；申请国家发明专利5项，PCT2项；参加国内学术交流5人次；联合培养博士研究生3名，硕士研究生5名，本科生4名。