HDAC3抑制剂RGFP966通过miRNA-200a与Sulforaphane协同激活Nrf2抗氧化应激功能防治糖尿病心肌病的增效作用研究

Diabetic cardiomyopathy (DCM) is an independent complication of diabetes and is one of the leading causes of death in diabetic patients. Our previous studies found that HDAC3 inhibitor not only attenuated DCM but also cut down cardiac miRNA-200a and promoted expression of Keap1; Nrf2 activator SFN was also effective at improving DCM. Thus we suppose that cardiac HDAC3 can induce Nrf2 inactivation and degradation and impair its endogenous antioxidant system via regulating miRNA-200a-Keap1 pathway, which leads to exacerbation of DCM performance. Whereas stimulating Nrf2 activation may be the key target of preventing DCM. The current project intends to develop diabetes in HDAC3 cardiac-specific knockout mice and in Nrf2-KO mice, respectively and by applying miRNA-200a inhibitor and miRNA-200a mimic treatment, thus clarify the underlying mechanism of HDAC3-miRNA-200a-Keap1/Nrf2 in the development of DCM. We also combine the application of SFN and HDAC3 inhibitor RGFP966 to clarify the synergistic effect and related mechanisms of Nrf2 as a common target for preventing and curing DCM and provide further evidence for the prevention and treatment of DCM with the combination of translational medicine.

糖尿病心肌病（DCM）是糖尿病患者的主要死因之一。我们前期工作发现组蛋白去乙酰化酶3（HDAC3）抑制剂不仅减轻了DCM，还下调了心肌miRNA-200a、促进了Keap1表达；Nrf2激活剂sulforaphane（SFN）已被我们证明可改善DCM。因此我们假设：糖尿病心脏HDAC3可能通过miRNA-200a-Keap1途径导致Nrf2降解，从而弱化内源性抗氧化系统，促进DCM发生，上调Nrf2功能可能是防治DCM的关键靶点。本项目拟在HDAC3心脏特异性敲除小鼠、Nrf2-KO小鼠建立DCM模型，通过miRNA-200a抑制剂和类似物处理，阐明HDAC3-miRNA-200a-Keap1/Nrf2在DCM发病进程中的作用机制；联合应用SFN与HDAC3抑制剂RGFP966明确以Nrf2为共同靶点防治DCM的协同增效作用及相关机制，为具有转化医学意义的联合用药防治DCM提供有益提示。

Hsa-miR200a-3p在调节糖代谢和糖尿病进展中发挥重要作用。但是hsa-miR200a-3p如何影响糖尿病心肌病的发展仍不清楚。在本研究中，我们发现高糖刺激后小鼠心肌细胞HL-1细胞中hsa-miR200a-3p的表达显著降低。我们系统地研究了hsa-miR200a-3p模拟物或HL-1在高糖条件下的抑制剂处理下的总体mRNA表达水平。高通量测序结果显示，744个基因在高糖诱导下表达显著差异。与对照组相比，hsa-miR200a-3p过表达后有414个基因表达差异;经过hsa-miR200a-3p inhibitor处理后，有33个基因表达有差异。WGCNA分析发现所有的差异基因(differential expressed gene, DEGs)可分为5个模块，其中黄色模块的基因表达模式与hsa-miR200a-3p过表达组呈正相关，与hsa-miR200a-3p抑制剂组呈负相关。我们观察到这些DEGs主要富集在RrRNA加工、翻译和RNA运输中。然后，我们进一步鉴定出三个DEGs (Gm13205、Flnc和Ntmt1)在hsa-miR200a-3p mimics组的下调DEGs和hsa-miR200a-3p inhibitor/高糖组的上调DEGs中普遍表达。此外，我们预测Srm和tspan4是HL-1细胞中hsa-miR200a-3p的两个主要靶点。这些结果表明，高糖在体外抑制hsa-miR200a-3p, hsa-miR200a-3p可能参与糖尿病心肌病的发展。