Evolocumab抑制PCSK9在糖尿病性视网膜病变中的神经保护作用及机制研究

Recent studies indicated that Dyslipidemia may be the important pathological changes in the diabetic retinopathy (DR). The research showed that hyperlipemia-induced accumulation of proprotein convertase subtilisin/Kexin type 9 (PCSK9) may mediate apoptosis in hippocampal neurons and upregulate the expression of p62, but the effect were unclear in the DR. Our preliminary findings showed that the secretion of PCSK9 was increased in the plasma and vitreous humor of proliferative DR patients and PCSK9 participated in the regulation of apoptosis in retinal nerve cells exposed to High Glucose and High Lysophosphatidylcholine. Therefore, we propose this research hypothesis: PCSK9 in retinal nerve cells will be activated under DR conditions. PCSK9 increases mitochondria damage and endoplasmic reticulum stress to induce apoptosis and through the activation of mTORC1/c-Jun signaling pathway leads to the expression of autophagy related factors. While evolocumab, the specific inhibitor of PCSK9, can block the pathological process. In addition, PCSK9 may regulate interaction between autophagy and apoptosis. To test this hypothesis, we will investigate the regulatory effect and mechanism of PCSK9 and its specific inhibitor on retinal nerve cells from molecular, cellular and animal level by increasing or inhibiting PCSK9 gene expression. This study will provide completely new drug in treatment of DR.

血脂异常在糖尿病性视网膜病变（DR）进程中发挥重要作用。近期研究表明高脂状态下海马神经元中蓄积的前蛋白转化酶枯草溶菌素9（PCSK9）可参与凋亡信号的传递，同时促进自噬蛋白p62的高表达，但其在DR进程中的作用仍尚未明确。我们前期研究发现增殖性DR患者的血浆和玻璃体液中PCSK9分泌增多，PCSK9参与高糖高脂环境下视网膜神经细胞的凋亡调控，由此我们提出科研假说：DR环境可诱导视网膜神经细胞中PCSK9分泌增加，加重线粒体损伤和内质网应激诱导凋亡，还可通过调控mTORC1/c-Jun途径导致自噬，而采用evolocumab特异性抑制PCSK9后可阻断该病理过程，同时PCSK9调控的自噬和凋亡之间可能相互影响。为验证此假说，我们将在增加或抑制PCSK9基因表达的基础上，从分子、细胞和动物水平探讨PCSK9及其特异性抑制剂对视网膜神经细胞的调控作用及机制，为延缓和控制DR发展提供潜在治疗药物。

血脂异常在糖尿病性视网膜病变（DR）进程中发挥重要作用。近期研究表明高脂状态下海马神经元中蓄积的前蛋白转化酶枯草溶菌素9（PCSK9）可参与凋亡信号的传递，同时促进自噬蛋白p62的高表达，但其在DR进程中的作用仍尚未明确。本研究前期发现增殖性DR患者的血浆和玻璃体液中PCSK9分泌增多，PCSK9参与高糖高脂环境下视网膜神经细胞的凋亡调控，本研究中我们通过棕榈酸+高糖刺激muller细胞及原代培养视网膜神经节细胞（RGCs）糖尿病的高脂高糖环境，发现糖尿病环境下muller细胞和RGCs细胞的PCSK9表达增加，同时伴随muller细胞和RGCs细胞凋亡的增加；而阻断PCSK9的表达后，muller细胞和RGCs 细胞中凋亡相关因子的表达明显降低，揭示了PCSK9在 DR发病中对神经损伤的可能机制，为寻找早期防治DR的靶向药物提供实验依据。