慢性间歇低氧对大鼠糖代谢及肝脏 TRB3、P-AKT 表达的影响

目的：通过建立慢性间歇低氧(chronic intermittent hypoxia,CIH)大鼠模型,观察CIH 对大鼠糖代谢的影响以及肝脏胰岛素相关信号通路 Tribbles 同源蛋白3(TRB3)、磷酸化蛋白激酶 B (P-AKT)的变化。方法将40只健康雄性 SD 大鼠随机分为5组,每组8只。正常对照组(NC组)、慢性间歇 低 氧 2 周 组(CIH2组)、慢 性 间 歇 低 氧 4 周 组(CIH4组)、慢性间歇低氧6周组(CIH6组)、慢性间歇低氧8周组(CIH8组),实验组每天给予8 h 间歇低氧处理。实验结束后检测5组大鼠空腹血糖,采用酶联免疫吸附试验(ELISA)检测空腹胰岛素,用稳态模型胰岛素抵抗指数(HOMA-IR)系统评价胰岛素抵抗。采用 HE 染色观察各组肝脏组织形态变化,SABC 法免疫组织化学试剂盒检测大鼠肝细胞 TRB3蛋白以及胰岛素信号通路中关键激酶蛋白激酶 B (AKT)磷酸化水平蛋白的表达,以平均灰度值表示 TRB3、P-AKT 的蛋白表达量。结果随着间歇低氧暴露时间延长,各组与 NC 组比较,其空腹血糖水平(F =116.185,P <0.05)、胰岛素水平(F =45.189,P <0.05)、HOMA-IR (F =110.876,P <0.05)、TRB3蛋白表达水平(F =11 5.253,P <0.05)升高,而 P-AKT 蛋 白 表 达 水 平(F =99.553,P <0.05) 降 低,且以 CIH8组 最 为 显 著 (P <0.05)。Pearson 相关分析显示： HMOA-IR 与 TRB3平均灰度值呈负相关(r =-0.828,P <0.05),与P-AKT平均灰度值呈正相关(r =0.903,P <0.05)。结论 CIH 可导致大鼠肝细胞受损,糖代谢异常,发生胰岛素抵抗,并随着间歇低氧暴露时间的延长,胰岛素抵抗程度加重。CIH 使肝脏中 TRB3蛋白表达增加,P-AKT 显著降低,且与 HOMA-IR 具有明显的相关性,TRB3的激活可能在 CIH 所致的糖代谢异常中起重要作用。

The effects of glycometabolism and TRB3 and P-AKT expression in rats liver during chronic intermittent ;hypoxia

Objective To establish models of rats in chronic intermittent hypoxia(CIH)condiction observe the effects of glycometabolism in CIH rats condition and the changes of tribbles homolog 3 (TRB3) and phosphorylated protein kinase B (P-AKT) signaling pathway related to insulin in hepatic. Methods Forty healthy male Sprauge-Dawley rats were randomly divided into five groups,8 rats in each group.Normal control group (NC group),CIH in 2 weeks group (CIH2 group),CIH in 4 weeks group (CIH4 group),CIH in 6 weeks group (CIH6 group) and CIH in 8 weeks group (CIH8 group). Experience groups were exposed to CIH 8 hours a day.After the experiment,measure fasting blood glucose and insulin by enzyme-linked immunosorbent assay (ELISA) in the 5 groups,and insulin resistance index(HOMA-IR) was used to evaluate insulin resistance.Observe liver tissue morphological changes by using HE staining and detect the expresstion of TRB3 protein and the phosphorylation level of P-AKT protein which is a key protein in insulin signaling pathway with SABC immunohistochemical assay kit,and the average gray value was represent TRB3 and P-AKT protein expression.Results With the intermittent hypoxic exposure time prolonged,compared to NC group fasting blood glucose (F =1 1 6.185,P <0.05),insulin level(F =45.189,P <0.05),HOMA-IR(F =1 10.876,P <0.05),TRB3 protein expression level increased(F = 1 1 5.253,P < 0.05),and P-AKT protein expression level decreased(F =99.553,P < 0.05),and in CIH8 group was the most significant (P < 0.05).Pearson correlation analysis showed that HOMA-IR was negatively correlated with TRB3 protein(r =-0.828,P <0.05),and positively correlated with P-AKT(r =0.903,P <0.05).Conclusions CIH can lead to liver cell damage,abnormal glucose metabolism and insulin resistance.with the intermittent hypoxia exposure time prolonged,the degree of insulin resistance was increased.CIH lead to the expression of TRB3 protein increased,P-AKT decreased significantly and is significantly correlated with HOMA-IR.TRB3 activation may play an important role in the abnormal glycometabolism induced by CIH.