Role of TRPM2-CnA-Drp1 pathway in propofol-induced reduction of renal injury induced by hepatic ischemia-reperfusion in mice / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the role of transient receptor potential melastatin 2 (TRPM2)-calcineurin A (CnA)-dynamin-related protein 1 (Drp1) pathway in propofol-induced reduction of renal injury induced by hepatic ischemia-reperfusion (I/R) in mice.Methods:Twenty-four SPF male C57BL6 mice, aged 8 weeks, weighing 20-23 g, were divided into 4 groups ( n=6 each) using a random number table method: sham operation group (group S), hepatic I/R group (group IR), propofol group (group P) and TRPM2 agonist (ADPR) combined with propofol group (AP group). Hepatic I/R injury was induced by occluding the portal vein and hepatic artery supplying the left and middle lobes of the liver for 60 min followed by reperfusion in anesthetized rats.In group P, 0.2 ml normal saline was injected intraperitoneally at 1 h before establishing the model and 1% propofol 30 mg/kg was injected intraperitoneally at 30 min before establishing the model.In group AP, ADPR 10 mg/kg (in 0.2 ml of normal saline) was injected intraperitoneally at 1 h before establishing the model, and 1% propofol 30 mg/kg was injected intraperitoneally at 30 min before establishing the model.The equal volume of normal saline was given intraperitoneally at 1 h and at 30 min before establishing the model in group S and group IR.Blood samples were taken from the eyeballs for determination of the levels of serum urea nitrogen (BUN), creatinine (Cr), aminotransferase (ALT) and aspartate aminotransferase (AST) at 6 h of reperfusion.The animals were then sacrificed and the kidney tissues were taken, the ultrastructure of myocardial mitochondria was observed using transmission electron microscopy, the average diameter of mitochondria was calculated, and the expression of TRPM2, CnA, phospho-Drp1 Ser637 (p-Drp1 Ser637) and cleaved caspase-3 was detected (by Western blot). Results:Compared with group S, the concentrations of serum BUN and Cr were significantly increased, the expression of TRPM2, CnA and cleaved caspase-3 in kidney tissues was up-regulated, the expression of p-Drp1 ser637 was down-regulated, and the average diameter of mitochondria was shortened in IR, P and AP groups ( P<0.05). Compared with group IR, the concentrations of serum BUN and Cr were significantly decreased, the expression of TRPM2, CnA and cleaved caspase-3 in kidney tissues was down-regulated, the expression of p-Drp1 Ser637 was up-regulated, the average diameter of mitochondria was prolonged ( P<0.05), mitochondrial injury was attenuated, and no significant change was found in the serum ALT and AST concentrations in group P, and no significant change was found in concentrations of BUN and Cr in serum in group AP ( P>0.05). Compared with group P, concentrations of BUN and Cr in serum was significantly increased, the expression of TRPM2, CnA and cleaved caspase-3 in kidney tissues was up-regulated, the expression of p-Drp1 Ser637 in kidney tissues was down-regulated, and the average diameter of mitochondria was shortened ( P<0.05), and mitochondrial injury was accentuated in group AP. Conclusion:The mechanism of propofol-induced reduction of renal injury induced by hepatic I/R is related to inhibiting the expression of TRPM2 in kidney tissues, decreasing the level of intracellular CnA and inhibiting dephosphorylation of Drp1 Ser637 in mice.