摘要
目的:探讨丝胶通过调节c-Jun氨基末端激酶(JNK)信号通路抑制糖尿病大鼠视网膜神经细胞凋亡的作用。方法:高脂高糖饲料喂养联合链脲佐菌素腹腔内注射制备糖尿病大鼠模型,SD大鼠随机分为丝胶治疗组、糖尿病模型组和正常对照组。丝胶治疗组大鼠于成模后给予丝胶溶液2.4g·kg~(-1)·d~(-1)灌胃,连续35d。各组大鼠采用过量麻醉法处死并制备视网膜标本;采用Western blot法检测大鼠视网膜中磷酸化c-Jun氨基末端激酶(p-JNK)、细胞色素C(Cyt-c)和半胱氨酸天冬氨酸激酶-9(caspase-9)蛋白的相对表达量,分光光度法检测视网膜组织中半胱氨酸天冬氨酸激酶-3(caspase-3)活性,采用TUNEL法检测并计算大鼠视网膜神经细胞的凋亡指数(AI),并对各组检测结果进行比较。结果:丝胶治疗组大鼠视网膜中p-JNK、Cyt-c、caspase-9蛋白的相对表达量,caspase-3活性,AI较糖尿病模型组均明显下降,差异均有统计学意义(均P<0.05)。结论:丝胶可以通过调节JNK信号通路,减少DR视网膜神经细胞的凋亡。
Objective: This study was to investigate the effects of sericin on the inhibition of retinal neuron apoptosi via regulation of JNK signaling pathway in diabetic rat. Methods: The diabetic rat models were established by feeding high lipid foods and intraperitoneal injection of small-dose streptozotocin. Rats were randomly divided into three groups,sericine-treatment group,diabetes model group and normal control group.The sericin solution dissolved in normal saline solution 2.4 g·kg-1·d-1 was used for 35 days in gavage method in the sericin-treated group. The rats were sacrificed by an overdose of anesthesia and retinal sections were prepared. The expressions of phosphorylation c-Jun N-terminal kinase( p-JNK),Cytochrome( Cyt-c) and Cysteine aspartate kinase 9( caspase-9) in retinas in protein levels were detected by Western blot. The activity of Cysteine aspartate kinase 3( caspase-3) in the retina was detected by spectrophotometry. TUNEL staining was employed to detect retinal neuron apoptosis. Results: The relative expression levels of p-JNK,Cyt-c and caspase-9 proteins,the activity of caspase-3,the apoptotic index( AI) in rat retinas in the sericintreated group were significantly lower than those in the diabetic model group( all at P < 0. 05). Conclusion: Sericin can inhibit retinal neuron apoptosis by regulating JNK signaling pathway in diabetic rats.
引文
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