齐墩果酸预处理对大鼠肝脏缺血再灌注损伤中PI3K-AKT-GSK-3β信号传导通路的影响

Influence of oleanolic acid pretreatment to the PI3K-AKT-GSK-3β signaling pathway during Rat’s HIRI

目的:齐墩果酸(oleanolic acid,OA)预处理可使大鼠肝糖原增加并使肝脏缺血再灌注损伤(hepatic ischemic reperfu-sion injury,HIRI)减轻,但机制不详。本研究拟探讨OA预处理对大鼠HIRI前后的PI3K-AKT-GSK-3β信号传导通路的影响。方法:128只SD大鼠随机分为假手术组(SH组)、缺血再灌注组(IR组)、0.5%羧甲基纤维素钠组(CM组)和齐墩果酸预处理组(OA组)。OA组以100mg/kg的齐墩果酸混悬液,SH和IR组以相同容积的水,CM组以相同容积的0.5%CMC-Na分别每日灌胃1次,连续7天。第8天建立70%肝脏缺血再灌注模型,肝脏缺血60min后行再灌注。于术前(第8天)、再灌注0、3、6h取肝组织。用Western blot法测定肝组织的p-PI3K(p85)、p-AKT(ser473)、AKT、p-GSK-3β(ser9)、GSK-3β的蛋白表达量。结果:术前、再灌注0h时,OA组的p-PI3K(p85)、p-AKT(ser473)、p-GSK-3β(ser9)的蛋白表达量分别比其他3组明显增加(P<0.05);此时SH组、IR组、CM组的各蛋白表达量之间比较未见统计学差异(P>0.05)。再灌注3、6h时,OA组的p-PI3K(p85)、p-AKT(ser473)、p-GSK-3β(ser9)蛋白含量分别比其他3组显著增加(P<0.05),SH组相应时点的各蛋白含量均比其他3组的含量明显降低(P<0.05),IR组与CM组相应时点的各蛋白含量之间比较未见差异(P>0.05);各组的AKT与GSK-3β蛋白含量在各个时间点之间均未见统计学差异(P>0.05)。结论:OA预处理可使HIRI前后的p-PI3K(p85)、p-AKT(ser473)和p-GSK-3β(ser9)蛋白含量增加,激活肝脏PI3K-AKT-GSK-3β信号通路,此可能是OA减轻HIRI的机制之一。

Objective：It is proved that the pretreatment of oleanolic acid （OA） increases rat’s hepatic glycogen and alleviates the hepatic ischemic reperfusion injury（HIRI）,but the mechanism is still not quite clear. This research is focused on the influence of OA pretreatment to rat’s PI3K-AKT-GSK-3β signaling pathway around its HIRI. Methods：Total of 128 male Sprague-Dawley （SD） rats were indvided into sham group（SH）,ischemic reperfusion group（IR）,0.5% sodium carboxymethycellulose（CMC-Na） group（CM）,OA＋ 0.5% CMC-Na group （OA） equally. Before operation all rats got intragastric administration one time a day for seven days,OA group with OA （100 mg / kg）＋0.5% CMC-Na,SH group and IR group with water of the same volume,CM group with 0.5% CMC-Na of the same volume. At the 8th day,rats were suffered from segmental（70%） hepatic ischemia for 60 min and were followed by different periods of reperfusion. In the 8th day before the operation,the hepatic tissu were reperfused at the point of 0 h,3 h,and 6 h. The protein expressions of p-PI3K（p85）,p-AKT（ser473）,AKT,p-GSK-3β（ser9） and GSK-3β were evaluated. Results：Before operation,at the point of 0h,the protein expressions of p-PI3K（p85）,p-AKT（ser473）and p-GSK-3β（ser9） in the OA group increased much more remarkably than other three groups（P〈0.05）,while the protein expresions of SH group,IR group and CM group were no differences（P〉0.05）. At the reperfusion point of 3 h,6 h,the protein expressions of p-PI3K （p85）,p-AKT （ser473）and p-GSK-3β （ser9） in the OA group increased much more remarkably than other three groups（P〈0.05）,while the protein expressions of SH group were lower than those of other three groups（P〈0.05）. There was no difference between IR and CM group in the 3 proteins expression （P〉0.05）. The protein expressions of AKT and GSK-3β in all the groups at all the points were no differences （P〉0.05）. Conclusion：The pretreated OA increases the protein expressions of p-PI3K （p85）,p-AKT （ser473）and pGSK-3β（ser9） before and after HIRI,activating the signaling pathway of hepatic PI3K-AKT-GSK-3β,which may be one of the mechanisms of OA alleviating HIRI.