SUMO化修饰Drp1-BNIP3依赖线粒体自噬途径介导apelin-13促心肌细胞肥大

Applicant reported that autophagy can mediate cardiomyocyte hypertrophy induced by apelin-13, an endogeneous ligand of the static pressure sensitive receptor APJ.Preliminary experiments found that apelin-13 increases the expression of small ubiquitin-related modifier 1 (SUMO1),SUMOylation of dynamin-related protein 1(Drp1), and the mitophagy marker protein BNIP3 .According to that, the scientific hypothesis "SUMOylation of Drp1-BNIP3 dependent mitophagy pathway mediates cardiomyocyte hypertrophy induced by apelin-13"can be proposed.We adopt IP and other methods to explore whether apelin-13 can induce the expression of cardiomyocyte SUMOylation of Drp1;To confirm whether apelin-13 can induce cardiomyocyte BNIP3-dependent mitophagy,whether SUMOylation of Drp1 regulates apelin-13 induced cardiomyocyte BNIP3-dependent mitophagy;To analyze SUMOylation of Drp1-BNIP3 dependent mitophagy pathway mediates cardiomyocyte hypertrophy induced by apelin-13. From the new perspective that SUMOylation of Drp1,BNIP3-dependent mitophagy,we can clarify a new mechanism of apelin/APJ system to promote cardiomyocyte hypertrophy.The apelin/APJ system would be a novel target for cardiomyocyte hypertrophy and other-related diseases.

申请者报道自噬介导压应力感受器APJ受体的内源性配体apelin-13促心肌细胞肥大；预实验发现apelin-13促类泛素化蛋白1（SUMO1)、动力相关蛋白Drp1及线粒体自噬标志蛋白BNIP3表达，据此提出“SUMO化修饰Drp1-BNIP3依赖线粒体自噬途径介导apelin-13促心肌细胞肥大”科学假说。课题采用IP等方法，探讨apelin-13是否诱导心肌细胞Drp1的SUMO化修饰；明确apelin-13是否诱导心肌细胞BNIP3依赖线粒体自噬,SUMO化修饰Drp1是否调控apelin-13诱导的心肌细胞BNIP3依赖线粒体自噬；阐明SUMO化修饰Drp1-BNIP3依赖线粒体自噬途径是否介导apelin-13促心肌细胞肥大。课题从SUMO化修饰Drp1、BNIP3依赖线粒体自噬视角揭示apelin/APJ促心肌细胞肥大新机理，apelin/APJ有望成为抗心肌肥厚治疗新靶点。

课题从SUMO化修饰动力相关蛋白Drp1、BNIP3依赖线粒体自噬等视角揭示apelin/APJ系统促心肌细胞肥大新机理，为筛选以apelin/APJ系统为靶点的新型抗心肌肥厚治疗药物提供依据。研究发现：Apelin-13 浓度和时间依赖性促进H9c2细胞中类泛素化蛋白SUMO1、线粒体分裂蛋白Drp1表达;2. Apelin-13 浓度和时间依赖性促进H9c2细胞中线粒体自噬标志蛋白 BNIP3、自噬标志蛋白Beclin1、LC3II/I表达，增加H9c2心肌细胞ROS生成; 3. APJ 受体阻断剂F13A明显降低类泛素化蛋白SUMO1、线粒体分裂蛋白Drp1、线粒体自噬标志蛋白 BNIP3的表达; 4. Drp1特异性抑制剂Mdivi-1显著抑制类泛素化蛋白SUMO1、线粒体分裂蛋白Drp1、线粒体自噬标志蛋白 BNIP3和自噬标志蛋白Beclin1、LC3II/I的表达; 5. 线粒体靶向抗氧化剂Mito-TEMPO显著抑制类泛素化蛋白SUMO1、线粒体分裂蛋白Drp1、线粒体自噬标志蛋白 BNIP3、自噬标志蛋白Beclin1、LC3II/I的表达; 6. Drp1特异性抑制剂Mdivi-1逆转apelin-13诱导的H9c2心肌细胞直径、体积增大以及心肌肥大因子BNP表达; 7. 线粒体靶向抗氧化剂Mito-TEMPO显著抑制apelin-13诱导的H9c2心肌细胞直径、体积增大以及心肌肥大因子BNP的表达; 8. 应用siRNA干扰技术合成SUMO1-siRNA沉默SUMO1表达，apelin-13诱导的H9c2心肌细胞直径、体积增大以及心肌肥大因子BNP表达明显减少; 9. 应用siRNA干扰技术合成BNIP3-siRNA沉默 BNIP3表达，apelin-13诱导的H9c2心肌细胞直径、体积增大以及心肌肥大因子BNP表达明显减少; 10. 外源性注射apelin-13的大鼠心脏组织BNP，SUMO1，Drp1，BNIP3呈现高表达。 以上结果基本阐明SUMO化修饰Drp1-BNIP3依赖线粒体自噬途径介导apelin-13促心肌细胞肥大新机理.