小檗碱抑制内质网应激炎症通路对2型糖尿病大鼠局部脑缺血再灌注损伤的探讨

目的观察小檗碱(BBR)对2型糖尿病大鼠局部脑缺血再灌注损伤半影区内质网应激相关炎症通路的影响。方法72只健康雄性Sprague-Dawley大鼠,采用高脂饮食和链尿佐菌素注射建立2型糖尿病大鼠模型,数字抽签随机将糖尿病大鼠分为假手术组(Sham组)、糖尿病大鼠+BBR治疗组(BBR组)、糖尿病大鼠大脑中动脉栓塞(MCAO)模型组(MCAO组)、糖尿病大鼠MCAO+BBR治疗组(MCAO+BBR组),纳入研究每组6只。治疗组在术前48 h、24 h和术后6 h经胃灌注给予相应剂量药物。采用线拴法制备大鼠MCAO模型,进行神经缺损评分,酶联免疫吸附法(ELISA)检测肿瘤坏死因子(TNF)-α和白细胞介素(IL)-1β的表达;实时定量聚合酶链反应(RT-qPCR)检测内质网应激标志蛋白葡萄糖调控蛋白78(GRP78)的mRNA表达;蛋白质印迹法(Western blot)检测内质网应激相关炎症通路蛋白GRP78、胰腺内质网激酶(PERK)、磷酸化PERK(p-PERK)、核因子(NF)-κB p65表达情况。结果在脑缺血半影区,缺血2 h再灌注24 h后,MCAO组大鼠神经功能缺损评分(2.83±0.41)分,高于MCAO+BBR组大鼠(1.67±0.52)分(P<0.05),促炎因子TNF-α和IL-1β和内质网应激相关炎症通路蛋白GRP78、PERK和NF-κB p65的表达水平亦增高(P<0.05)。BBR治疗亦可降低脑缺血再灌注半影区促炎因子(TNF-α和IL-1β)和内质网应激相关炎症通路蛋白(GRP78、PERK和NF-κB p65)的表达水平。结论BBR可通过抑制内质网应激相关炎症通路降低2型糖尿病大鼠局部脑缺血再灌注损伤的炎症反应,发挥神经保护作用。

Berberine alleviates cerebral ischemia-reperfusion injury in type 2 diabetic rats by inhibiting endoplasmic reticulum stress-related inflammatory pathways

Objective To examine the effects of Berberine(BBR)on inflammatory pathways related to endoplasmic reticulum stress(ERS)in the penumbra area following focal cerebral ischemia-reperfusion injury in type 2 diabetic rats.Methods A total of 72 healthy male Sprague-Dawley rats were fed a high-fat,high-sugar diet and injected with streptozotocin to establish a type 2 diabetes mellitus model.The diabetic rats were randomly divided by digital lottery method into a Sham operation group(Sham group),a diabetic rat+BBR treatment group(BBR group),a diabetic middle cerebral artery occlusion(MCAO)model group(MCAO group),and a diabetic rats MCAO+BBR treatment group(MCAO+BBR group).Six rats were included in each group.The two treatment groups received prespecified doses of BBR through gastric perfusion at 48 h,24 h before surgery,and 6h after surgery.The MCAO model was prepared by a suture occlusion method.The neurological deficit scores were performed,and the expression of tumor necrosis factor-α(TNF-α)and interleukin-1β(IL-1β)was detected by enzyme-linked immunosorbent assay(ELISA).The mRNA expression of ERS marker protein GRP78 was detected by quantitative real time polymerase chain reaction(RT-qPCR),and the expression of ERS-related inflammatory pathway proteins78 Glucoseregulated protein(GRP78)、Pancreatic endoplasmic reticulum Rinase(PERK)、nuclear factor-κB(NF-κB)]was detected by Western blot.Results the cerebral ischemic penumbra area,after 2 h of ischemia and 24 h of reperfusion,the neurological deficit score in the MCAO group was higher than that in the MACO+BBR group(2.83±0.41)vs.(1.67±0.52),P<0.05],and the expression levels of pro-inflammatory cytokines(TNF-αand IL-1β)and ERS-related inflammatory pathway proteins(GRP78,PERK and NF-κB p65)were also significantly increased(all P<0.05).However,BBR treatment was able to alleviate the neurological dysfunction caused by cerebral ischemia-reperfusion in type 2 diabetic rats(P<0.05).Similarly,BBR treatment also reduced the expression levels of pro-inflammatory factors(TNF-αand IL-1β)and ERS-related inflammatory pathway proteins(GRP78,PERK and NF-κB p65)in the cerebral ischemic penumbra area(all P<0.05).Conclusions Through inhibiting ERS-related inflammatory pathways,BBR plays a neuroprotective role to alleviate cerebral ischemia-reperfusion injury in type 2 diabetic rats.