促红细胞生成素衍生肽通过PI3K/Akt信号转导通路对小鼠肾缺血再灌注损伤保护作用

Protective effect of erythropoietin derived peptide on renal ischemia-reperfusion injury in mice through PI3K/Akt signal transduction pathway

摘要:

目的：探究促红细胞生成素衍生肽对小鼠肾缺血再灌注损伤的保护作用及对PI3K/Akt信号转导通路的影响。方法：将小鼠分为假手术组、模型组和研究组，复制肾缺血再灌注损伤动物模型，在手术前6 h模型组腹腔注射促红细胞生成素衍生肽，假手术组和模型组腹腔注射生理盐水。使用苦味酸速率法检测各组小鼠血清中血肌酐（serum creatinine，Scr），使用酶学速率法检测各组小鼠血清中尿氮素（blood urea nitrogen，BUN）水平；病理切片检查肾脏病理变化；原位末端标记法分析肾脏细胞凋亡；Western blot检测肾脏蛋白激酶B（protein kinase B，Akt）、磷酸化蛋白激酶B（phosphorylated protein kinase B，p-Akt）、半胱氨酸天冬氨酸蛋白酶-3（cysteine aspartate protease，Caspase-3）蛋白表达水平。结果：模型组小鼠血清中的Scr和BUN水平明显高于假手术组，研究组小鼠血清中的Scr和BUN水平明显低于模型组（P<0.05）；研究组肾脏的病理损伤程度明显弱于模型组，仅有少部分肾小管上皮细胞出现肿胀，少见肾小管上皮细胞坏死脱落，肾小管管腔正常，模型组小鼠的肾脏病理损伤评分明显大于假手术组，研究组小鼠的肾脏病理损伤评分明显小于模型组（P<0.05）；模型组小鼠的肾小管上皮细胞凋亡评分明显大于假手术组，研究组小鼠的肾小管上皮细胞凋亡评分明显小于模型组（P<0.05）；模型组小鼠肾脏中Caspase-3蛋白表达水平明显高于假手术组，Akt和p-Akt蛋白表达水平明显低于假手术组（P<0.05）；研究组小鼠肾脏中的Caspase-3蛋白表达水平明显低于假手术组，Akt和p-Akt蛋白表达水平明显高于假手术组（P<0.05）。结论：促红细胞生成素衍生肽对肾缺血再灌注有明显改善作用，该作用可能是通过调控PI3K/Akt信号转导通路调控机体凋亡蛋白的表达来实现的。

Abstract:

Objective：To explore the protective effect of erythropoietin derived peptide on renal ischemia-reperfusion injury in mice and to investigate its influence on PI3K/Akt signal transduction pathway. Methods：The mice were divided into the sham operation group，the model group and the study group. The animal model of renal ischemia-reperfusion injury was repeated. Erythropoietin derived peptide was injected into the abdominal cavity of mice in the model group 6 hours before operation，and normal saline was injected into the abdominal cavity in the sham operation group and the model group. Serum creatinine（Scr） in different groups was detected by picric acid rate method，urine nitrogen（BUN） level was detected by enzymology rate method，renal pathological changes were examined through pathological section，renal cell apoptosis was analyzed by in situ end labeling，and expression levels of nase B，protein kinase B（Akt），phosphorylated protein kinase B（p-Akt），cysteine aspartate protease（caspase-3） were detected by Western blot. Results：Levels of SCR and BUN in the model group were significantly higher than those in the sham operation group，while in the study group were significantly lower than those in the model group（P<0.05）. The renal pathological damage in the study group was significantly weaker than that in the model group，only a small part of the renal tubular epithelial cells were swollen，rare renal tubular epithelial cells had necrosis and abscission and the renal tubular lumen was normal. The score of renal pathological in－jury was significantly higher than that in the sham operation group，and in the study group was significantly lower than that in the model group（P<0.05）. The apoptosis score of the renal tubular epithelial cells in the model group was significantly higher than that in the sham operation group，and in the study group was significantly lower than that in the model group（P<0.05）. The expression level of renal caspase-3 protein in the model group was significantly higher than that in the sham operation group（P<0.05） and the expression level of Akt and p-Akt protein in the operation group was significantly lower than that in the sham operation group（P<0.05）；the expression level of renal caspase-3 protein in the study group was significantly lower than that in the sham oper－ation group，and the expression level of Akt and p-Akt protein was significantly higher than that in the sham operation group（P<0.05）. Conclusion：Erythropoietin derived peptide has a significant improvement on renal ischemia-reperfusion，which may be achieved by regulating PI3K/Akt signal transduction pathway and regulating the expression of apoptotic protein.