基于端粒酶响应的CdSe/ZnS@DNA纳米探针用于低氧诱导心肌细胞增殖再生的机制研究

Myocardial infarction (MI) leads to the irreversible loss of cardiomyocyte (CM), and further forms heart failure. Thus people are still looking for the way to effectively stimulate CM proliferation. According to previous report, hypoxic environment delay CM cycle-arrest, but its molecular mechanism is still poorly understood. Our previous study found that the telomerase was closely related to the proliferation capacity of CM, and telomerase expression was positively correlated with hypoxic inducible factor 1α. However, due to the lack of methods to dynamically monitor telomerase activity in living cells in real time, the core scientific question whether oxygen concentrations affect CM proliferation by regulating telomerase activity remains not clarified. We have constructed a series of new nanoprobes which provide powerful tools for answering this scientific question. We will use constructed nucleic acid nanoprobes on the surface of CdSe/ZnS quantum dots to reveal the dynamic relationship between oxygen concentrations and telomerase activity of CM. Furthermore, we will use genetic manipulation, ChIP-seq and other technologies to further elucidate the molecular mechanism of hypoxia regulating telomerase activity and CM proliferation. In summary, this study will deepen our understanding of the mechanism behind CM proliferation and regeneration, and provide theoretical basis for the establishment of new myocardial infarction treatment strategies.

心肌梗塞(MI)导致心肌细胞(CM)不可逆的丢失，并进一步引起心脏衰竭，如何促进内源CM增殖成为亟待解决的问题。研究表明低氧环境可以延缓CM周期阻滞并促进心肌再生，然而其分子机制仍知之甚少。申请人前期研究发现端粒酶与CM增殖能力紧密相关，而且端粒酶表达与缺氧诱导因子1α呈正相关，然而，由于缺少可在活细胞和动物体内实时动态监测端粒酶活性的方法，氧气浓度是否通过调控端粒酶活性影响CM增殖这一核心科学问题仍未被阐明。申请人前期构建了一系列新型纳米探针，为在CM中实时动态检测端粒酶活性，阐明上述科学问题提供了有力工具。本项目拟通过在CdSe/ZnS量子点表面构建核酸纳米探针，揭示氧气浓度与CM端粒酶活性之间的动态调控关系；并通过基因操作、ChIP-seq等技术进一步阐明低氧调节端粒酶活性和CM增殖的分子机制。本研究将加深我们对CM增殖再生机制的理解，为建立新的MI治疗策略提供理论依据。

心肌梗塞(MI)是当前危害人类健康和生命的主要疾病之一，如何促进MI后丧失的心肌细胞(CM)恢复，从根本上修复损伤的心肌组织成为心脏再生医学的主要研究目标之一。本项目以CM端粒酶活性为切入点，构建了端粒酶响应的纳米探针，原位、实时动态研究了端粒酶活性；揭示氧气浓度与CM端粒酶浓度之间的动态调控关系；在项目实施过程中，项目申请人围绕着端粒酶影响心肌细胞增殖，研究了端粒酶活性对胚胎干细胞分化为心肌细胞的影响；并设计合成了端粒酶逆转录酶mRNA响应的传感成像平台等。本研究将加深我们对心肌细胞增殖再生机制的理解，为建立新的心肌梗塞治疗策略提供理论依据。