Research On Regional Ischemic Preconditioning In Resection For Hepatocellular Carcinoma With Cirrhosis And MAPK Pathways Mechanism

Objective:Many studies showed that ischemic preconditioning has protective effect on ischemia/reperfusion injury in hepatectomy. However, most studies were focus on patients of hepatocellular carcinoma (HCC) without liver cirrhosis. There were only few studying patients with cirrhosis, and almost all received Pringle maneuver. Therefore, considering the controversy in ischemic preconditioning and the advantages of hemi-hepatic vascular inflow occlusion(HHV), we planned to determine whether regional ischemic preconditioning(RIP) has protective effect on ischemia/reperfusion injury in hepatocellular carcinoma patients with liver cirrhosis. Meanwhile, we analyzed activation of different MAPKs in hepatic ischemia/reperfusion and hepatic ischemic preconditioning settings, in order to explore its roles and mechanism in protection of hepatic preconditioning.Methods:Firstly,54 patients with HCC underwent hepatectomy, They were divided into two groups:RIP group(n=15)) and HHV group (n=39). These two sets of clinical data including blood loss, postoperative liver function, morbidity rates, hospital stay and etc were retrospectively analyzed to preliminarily observe whether RIP has a protective effect. Then animal models of hepatic ischemia/reperfusion and ischemic preconditioning were established. Twenty-eight male SD rats were divided into different blood occlusion groups:ischemic preconditioning group (IP group), ischemia/reperfusion group (IR group) and sham operation group. Specimen was harvested at 2,6 and 12 hour respectively, Serum ALT and AST were detected by automatic biochemical analyzer and liver tissues were stained with Hematoxylin Eosin(HE) for histologic study. The protein levels of JNK, p38, ERK phosphorylation were estimated by Immunohistochemistry and Western blotting. Thirdly, A non-randomized concurrent controlled trial was performed from May 2014 to December 2014, a total of 72 hepatocellular carcinoma patients with liver cirrhosis underwent hepatectomy similarly with RIP group of 23 patients and HHV group of 49. Clinical data were analyzed. HE staining was used for liver morphology. The protein levels of JNK, p38, ERK phosphorylation before ischemia and thirty minutes after reperfusion were estimated also by Immunohistochemistry and Western blotting.Results:Retrospective study found intraoperative volume of blood loss had significant difference between two groups(RIP:300ml, HHV:400ml, P=0.039), Postoperative transfusion cases showed significant difference (RIP group:1 case (6.7%), HHV group: 17 cases (43.6%),P=0.010). RIP group had a significantly higher level of PTA value at Day 3 and 5 postoperation(P<0.05). No significant differences were found between two groups regarding postoperative liver function, hospital stay, postoperative morbidity and intestinal ventilation time (all P>0.05). However, Cases of ALT recovering within one week had significant difference (RIP group:5 cases (33.3%), HHV group:1 case (2.7%), P=0.006). Animal experiments showed that the levels of ALT and AST in IP group were lower significantly compared with IR group (P<0.05), IP group showed less hepatocyte injury and inflammatory cell infiltration in liver. Both pJNK and pp38 were localized in the liver cells, while pERK was positioned in the hepatic mesenchyme cells. The expression of pJNK and pp38 in IP group especially at 6h and 12h reperfusion periods were lower than IR group (P＜0.05), whereas the expression of pERK was significantly higher than IR group (P＜0.05). The prospective clinical study found that postoperative blood transfusion was 400ml in IP group and 1200ml in HHV group (P=0.015). Meanwhile, pp38 was localized mainly in the hepatic mesenchyme cells instead of liver cells while pERK and pJNK were same position with the rat liver. Compared with IR group, pERK increased significantly at thirty minutes after reperfusion in IP group (P< 0.001), with both pp38 and pJNK decreased significantly (both P<0.001).Conclusion:We identified RIP has protective effect on ischemia/reperfusion injury in hepatocellular carcinoma patients with cirrhosis, what may reduce blood loss and blood transfusion, increase postoperative PTA and accelerate early recovery of liver function compared with HHV. It is possible that RIP protective mechanism may be mediated through regulating the MAPK pathways by increasing the phosphorylation level of ERK and decreasing the phosphorylation levels of JNK and p38. Besides, Activation of ERK after reperfusion may be primarily related to protection of the liver stromal cells, p38 activation may damage liver cells or hepatic mesenchyme cells at different periods of reperfusion and JNK activation may lead to major damage in liver cells.