RIPK1参与Parthanatos通路的调控及其在老年性聋中的作用机制研究

Presbycusis is the most common auditory disorder in the elderly population. So far the exact mechanisms involved in presbycusis remains elusive. RIPK1 (Receptor-interacting protein kinase 1) is a protein Ser/Thr kinase that mediates both cell survival and death signaling in response to cellular stress. Our previous study indicated that, glucose oxidase induced activation of RIPK1 and PARP-1 , accumulation of poly ADP-ribose (PAR) polymers, decline of mitochondrial membrane potential (MMP) and nuclear translocation of apoptosis-inducing factor (AIF), demonstrating the involvement of Parthanatos in oxidative stress-induced stria marginal cells death. Pretreatment with RIPK1 inhibitor Nec-1 reduced the expression and activity of PARP-1. However, whether RIPK1 regulates parthanatos pathway and the mechanism involved in presbycusis remains unknown. In this study, after treatment of RIPK1 inhibitor Nec-1, and transfection of stria marginal cells with RIPK1 siRNA, we examined cellular biological characteristics , the protein levels of PARP-1, PAR, AIF of Parthanatos pathway and necroptosis related protein RIPK1, RIPK3, MLKL to identify the mechanism of RIPK1 involved in presbycusis. This research may shed light on providing novel therapeutic interventions for presbycusis.

老年性聋是老年人群最常见的听觉功能障碍，迄今为止该病发病机制尚不明确。RIPK1是一种丝/苏氨酸激酶，应激状态下在调控细胞生存和死亡相关信号通路中发挥重要作用。我们前期研究发现，在GO诱导的血管纹边缘细胞氧化应激损伤中，RIPK1及PARP-1激活，PAR聚合物累积，MMP下降，AIF核转位，揭示Parthanatos参与边缘细胞氧化应激损伤，RIPK1抑制剂Nec-1处理后PARP-1表达降低。但RIPK1是否参与调控Parthanatos通路及其在老年性聋中的作用机制尚不明确。本项目拟通过RIPK1抑制剂Nec-1和转染RIPK1siRNA抑制边缘细胞RIPK1表达，检测细胞生物学活性，检测Parthanatos通路及RIPK1介导的坏死性凋亡通路相关蛋白水平，阐明RIPK1在边缘细胞氧化应激损伤中的作用机制，为老年性聋的防治提供新的靶点和方向。

研究表明老年性聋的发生与氧化应激密切相关，然而该病的具体发病机制尚不明确。RIPK1是一种丝/苏氨酸激酶，应激状态下在调控细胞生存和死亡相关的信号通路中发挥重要作用。我们研究发现在葡萄糖氧化酶诱导的大鼠耳蜗血管纹边缘细胞氧化应激损伤过程中，RIPK1及PARP-1激活，PAR聚合物累积，MMP下降，AIF核转位，研究证明 Parthanatos参与边缘细胞氧化应激损伤过程。通过转染RIPK1 siRNA抑制边缘细胞中RIPK1的表达后，我们检测了转染后Parthanatos通路相关蛋白PARP-1, PAR, AIF表达水平及细胞生物学活性， 发现Parthanatos通路相关蛋白 PARP-1 、PAR表达下降，AIF 由线粒体向细胞核的转移减少，细胞生物学活性增加。本研究表明抑制RIPK1表达可有效改善耳蜗血管纹边缘细胞的氧化应激损伤水平，阐明RIPK1参与调控Parthanatos通路及RIPK1在边缘细胞氧化应激损伤中的作用机制，这为老年性聋的防治提供了新的靶点和方向。