【摘要】 目的:探讨血糖波动的糖尿病大鼠发生肾小管上皮细胞凋亡的信号转导机制。方法:健康SD大鼠随机分为正常对照组(A)、糖尿病稳定高血糖组(B)和糖尿病波动高血糖组(C),采用链脲佐菌素(STZ)65 mg/kg腹腔注射诱发糖尿病,血糖波动组每天定时腹腔注射速效胰岛素,并错时给予葡萄糖,造成一天中血糖浓度大幅度波动模型。制模12周后,采用比色法检测肾组织匀浆中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量,免疫组化法和Western blot检测肾脏Nox4和JNK蛋白表达,原位缺口末端标记法(TUNEL)检测肾脏细胞凋亡。结果:与A组比较,B组和C组肾组织MDA含量增加、SOD活性下降,肾小管上皮细胞Nox4表达增加,肾小管磷酸化JNK(P-JNK)蛋白表达上调,细胞凋亡率明显增加,且C组的以上变化均较B组更加明显(P<0.05,P<0.01)。结论:波动性高血糖较稳定性高血糖更易促进糖尿病肾小管上皮细胞凋亡,其机制与JNK信号转导通路激活有关。更多还原

【Abstract】 Objective: To explore the signal transduction mechanisms of apoptosis in renal tubular epithelial cells in diabetic rats with fluctuant high blood glucose.Methods: Healthy SD rats were randomly divided into 3 groups: normal control group(A),stable high blood glucose group(B) and fluctuant high blood glucose group(C).Diabetic rats were induced by intraperitoneal injection of streptozotocin(STZ,65 mg/kg),and the fluctuant high blood glucose animal model was induced by intraperitoneal injection of ordinary insulin and glucose at different time point every day.The superoxide dismutase(SOD) activity and the content of malonaldehyde(MDA) in renal tissue homogenate were detected with colorimetry.The protein expression of Nox4 and JNK were examined by immunohistochemistry and Western blot.Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling(TUNEL).Results: After 12 experimental weeks,significantly increased cell apoptosis,up-regulation of Nox4 and P-JNK expression in renal tubular epithelial cells were observed in B and C groups compared with those in A group.The MDA content increased and SOD activity decreased in renal tissue in B and C groups.Above effects were more obviously shown in C group.Conclusion: Fluctuant high blood glucose induced more apoptosis of renal tubular epithelial cell than stable high blood glucose in diabetic kidney,which might be related to the activation of JNK signal transduction pathway.更多还原