肝细胞来源的iNOS通过HSF1/HSP70对小鼠肝脏缺血再灌注损伤的保护作用

缺血再灌注损伤是肝胆外科亟需解决的一项难题，是影响心死亡供肝移植效果的重要因素。缺血再灌注损伤的病理机制尚未完全阐明，iNOS来源的NO在肝脏缺血再灌注损伤中的作用一直存在争议。我们前期的研究已证实丁酸钠具有肝保护作用，抑制炎症细胞iNOS的同时却促进肝细胞iNOS的表达；另外利用SMT抑制原代肝细胞的iNOS，降低了肝细胞HSP70表达，加重肝细胞缺氧复氧损伤。我们推测不同细胞来源的iNOS在肝脏缺血再灌注损伤中所起的作用不同，其中肝细胞的iNOS起保护作用的。本课题拟对iNOS基因敲除小鼠及其野生型小鼠进行骨髓移植制备嵌合体小鼠，再用氯膦酸二钠脂质体清除Kupffer细胞，探讨非髓性细胞（肝细胞）来源的iNOS在肝脏缺血再灌注损伤中的作用；并利用肝细胞缺氧复氧模型研究HSF1/HSP70通路在iNOS肝保护中的作用，为肝脏缺血再灌注损伤机制提供新的视角，为临床防治提供新的理论依据。

Ischemia reperfusion injury represents one of the most critical problems for hepatobiliary surgery, is an important factor that significantly impacts clinical outcomes of liver transplanting using grafts from donation of cardiac death. The pathophysiologic mechanism of ischemia reperfusion injury is unclarified yet, the role of nitric oxide (NO) from inducible nitric oxide synthase (iNOS) in liver ischemia reperfusion injury is controversial. Our previous study has shown that sodium butyrate significantly reduced liver ischemia reperfusion injury, inhibiting the expression of iNOS in inflammatory cells, but at the same time promoting the expression of iNOS in hepatocytes. Inhibiting the expression of iNOS in hepatocytes, reduced HSP70 expression, aggravating hepatocytes hypoxia/reoxygenation injury. We hypothesized that the role of different cellular sources of iNOS may be different, iNOS in hepatocytes is protective. To test this hypothesis, we created chimeric mice with iNOS+/+ and iNOS-/- C57Bl/6 mice by transplanting bone marrow after lethal irradiation, depleting Kupffer cells with liposomal clodronate. The goal of the present study was to elucidate the effect of iNOS in hepatocytes on liver ischemia reperfusion injury, with focus particularly on the role of HSF1/HSP70 pathway in hepatoprotection of iNOS with hepatocytes hypoxia reoxygenation model. This study will offer new insights into the mechanism of ischemia reperfusion, and have significant clinical implications for developing new anti-ischemic interventions.