葡萄籽原花青素调控NLRP3/Caspase-1通路介导的焦亡途径对糖尿病视网膜病变大鼠的保护作用

目的　探讨葡萄籽原花青素调控NLRP3/Caspase-1通路介导的焦亡途径对糖尿病视网膜病变（DR）大鼠的保护作用。方法　建立DR大鼠模型，随机分为模型组、葡萄籽原花青素组、VX-765组、葡萄籽原花青素+VX-765组（每组各12只），另取12只大鼠为对照组，药物干预14 d，HE染色观察各组大鼠视网膜组织病理学变化；TUNEL染色检测各组大鼠视网膜神经节细胞（RGC）焦亡情况；采用试剂盒测定各组大鼠视网膜组织超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、活性氧（ROS）、丙二醛（MDA）及血清中炎症因子糖基化终末产物（AGEs）、白细胞介素（IL）-1β与IL-18水平；Western blot检测各组大鼠视网膜组织NLRP3/Caspase-1通路蛋白表达水平。结果　与对照组相比，模型组大鼠视网膜组织明显变薄，结构疏松，细胞结构层次紊乱、排列不规则，RGC变少、稀疏，呈现严重病理损伤变化，RGC焦亡率，ROS与MDA水平，AGEs、IL-1β、IL-18水平，NLRP3与Caspase-1蛋白表达水平均显著升高（均为P<0.05），SOD与CAT水平均显著降低（均为P<0.05）。与模型组相比，葡萄籽原花青素组、VX-765组大鼠视网膜组织形态结构得到恢复，病理损伤均有不同程度减轻，RGC焦亡率，ROS与MDA水平，AGEs、IL-1β与IL-18水平，NLRP3与Caspase-1蛋白表达水平均降低（均为P<0.05），SOD与CAT水平均升高（均为P<0.05）。与葡萄籽原花青素组及VX-765组分别相比，葡萄籽原花青素+VX-765组大鼠视网膜组织病理损伤进一步减轻，形态结构几乎恢复正常，RGC焦亡率，ROS与MDA水平，AGEs、IL-1β与IL-18水平，NLRP3与Caspase-1蛋白表达水平均降低（均为P<0.05），SOD与CAT水平均升高（均为P<0.05）。结论　葡萄籽原花青素可以抑制炎症发生发展，增强DR大鼠抗氧化活性，减轻过氧化反应，缓解视网膜组织病理学损伤，减少RGC焦亡，可能是通过抑制NLRP3/Caspase-1信号通路实现的。

Protective effect of grape seed proanthocyanidins extract on diabetic retinopathy rats by regulating the NLRP3/Caspase-1-mediated pyroptosis pathway

Objective　To investigate the protective effect of grape seed proanthocyanidins extract (GSPE) on rats with diabetic retinopathy (DR) by regulating the pyroptosis pathway mediated by NLRP3/Caspase-1.Methods　DR model rats were randomly divided into the model group, GSPE group, VX-765 group, and GSPE+VX-765 group, with 12 rats in each group. Another 12 rats were selected as the control group. After drug intervention for 14 days, hematoxylin and eosin (HE) staining was used to detect the histopathological changes in the retina of rats. TUNEL staining was used to detect the pyroptosis of retinal ganglion cells (RGC) in rats. Kits were used to determine the levels of superoxide dismutase (SOD), catalase (CAT), reactive oxygen species (ROS), malondialdehyde (MDA), advanced glycation end products (AGEs), interleukin (IL)-1β, and IL-18 in the retinal tissue of rats. Western blot was used to detect the expression of NLRP3/Caspase-1 in the retinal tissue of rats.Results　Compared with the control group, the retinal tissue of rats in the model group was significantly thinner; the structure was loose; the cell hierarchy was disordered; the cell arrangement was irregular; the RGCs were reduced and showed severe pathological damage; the pyroptosis rate of RGCs, the levels of ROS, MDA, AGEs, IL-1β, and IL-18, and the expression of NLRP3 and Caspase-1 were significantly increased (all P<0.05); and the levels of SOD and CAT were significantly reduced (all P<0.05). Compared with the model group, the morphological structure of the retinal tissue in the GSPE group and VX-765 group was restored; the pathological damage was alleviated to varying degrees; the pyroptosis rate of RGCs, the levels of ROS, MDA, AGEs, IL-1β, and IL-18, and the expression of NLRP3 and Caspase-1 were significantly reduced (all P<0.05); and the levels of SOD and CAT were significantly increased (all P<0.05). Compared with the GSPE group and the VX-765 group, the pathological damage of the retinal tissue in the GSPE+VX-765 group was alleviated; the morphological structure almost returned to normal; the pyroptosis rate of RGCs, the levels of ROS, MDA, AGEs, IL-1β, and IL-18, and the expression of NLRP3 and Caspase-1 were significantly reduced (all P<0.05); and the levels of SOD and CAT were significantly increased (all P<0.05).Conclusion　GSPE can inhibit the occurrence and development of inflammation, enhance the antioxidant activity of DR rats, relieve retinal histopathological damage, and reduce peroxidation and RGC pyroptosis, which may be achieved by inhibiting the NLRP3/Caspase-1 signaling pathway.