滋补脾阴方药对脾阴虚糖尿病大鼠大脑皮质内质网应激的影响

目的观察脾阴虚糖尿病大鼠大脑皮质磷酸化(p)RNA依赖的蛋白激酶样内质网激酶(PERK)、真核起始因子2α-亚单位(eIF2α)、p-eIF2α、葡萄糖调节蛋白78(GRP78)的变化,探讨脾阴虚糖尿病相关认知下降发病机制及滋补脾阴方药的作用机制。方法将大鼠随机分为对照组、糖尿病组、脾阴虚组、脾阴虚糖尿病组(病证组)、脾阴虚糖尿病+滋补脾阴方药组(治疗组)。采用高脂喂养4周联合小剂量链脲佐菌素注射方法建立2型糖尿病模型。在此基础上采用饮食不节、劳倦过度及灌服伤阴药方法建立脾阴虚糖尿病模型。治疗组给予滋补脾阴方药灌胃,其余各组给予等体积生理盐水灌胃,连续15 d,取大脑皮质。采用Western Blot、RT-PCR方法观察PERK、eIF2α、p-eIF2α、GRP78表达变化。结果糖尿病组、脾阴虚组、病证组PERK、p-eIF2α蛋白表达及GRP78 mRNA表达较对照组增强(P0.05),糖尿病组、病证组GRP78蛋白表达较对照组增强(P0.05),治疗组上述分子表达较糖尿病组、病证组均减弱(P0.05)。结论内质网应激参与脾阴虚糖尿病相关认知下降的发病,滋补脾阴方药通过减轻内质网应激改善学习记忆障碍。

Effects of Zibu Piyin Recipe on Endoplasmic Reticulum Stress in Cortex of Spleen Yin Deficiency Diabetes-associated Cognitive Decline Rats

Objective To clarify the pathogenesis of spleen yin deficiency diabetes-associated cognitive decline （DACD） and mechanism of Zinu Piyin Recipe （ZBPYR） by observing the expression of phosphorylated RNA-dependent protein kinase-like endoplasmic reticulum kinase （PERK）, eukaryotic initiation factor 2α subunit （eIF2α）, p-eIF2α, glucose-regulated protein 78 （GRP78） in cerebral cortex of spleen yin deficiency diabetes mellitus rats. Methods The rats were randomly divided into control group, diabetes mellitus group, spleen yin deficiency group, spleen yin deficiency diabetes mellitus group （disease-syndrome group） and spleen yin deficiency diabetes mellitus＋ZBPYR group （treatment group）. Type 2 diabetes mellitus models were established by high-fat food feeding for 4 weeks and low dose STZ intraperitoneal injection. Then the classical compound method was used to construct spleen yin deficiency rats model by improper diet, over exertion and yin fluids exhaustion. The reatment group was given ZBPYR and other groups were given equal volume of normal saline for 15 days, then cerebral cortex was obtained. The expression of p-PERK, p-eIF2α, eIF2α and GRP78 were observed by Western Blot and RT-PCR. Results The protein expression of p-PERK, p-eIF2α, and mRNA expression of GRP78 of diabetes mellitus group, spleen yin deficiency group and disease-syndrome group was enhanced compared with control group （P〈0.05）. GRP78 protein expression of diabetes mellitus group, disease-syndrome group was increased compared with control group （P〈0.05）. The protein expression of p-PERK, p-eIF2α, GRP78 and mRNA expression of GRP78 of treatment group was decreased compared with diabetes mellitus group and disease-syndrome group （P〈0.05）. Conclusion Endoplasmic reticulum stress is involved in spleen yin deficiency DACD. ZBPYR improves learning and memory ability by reducing endoplasmic reticulum stress.