过氧化物酶体增殖物激活受体-α激动剂 Wy-14,643 短期治疗可保护小鼠脂肪肝免受缺血再灌注损伤。

Short-term therapy with peroxisome proliferation-activator receptor-alpha agonist Wy-14,643 protects murine fatty liver against ischemia-reperfusion injury.

机构信息

Gastroenterology and Hepatology Unit, and Australian National University Medical School, Level 2, Building 1, The Canberra Hospital, Garran, ACT 2604, Australia.

出版信息

Hepatology. 2010 Mar;51(3):996-1006. doi: 10.1002/hep.23420.

DOI:10.1002/hep.23420

PMID:20131406

Abstract

UNLABELLED

Steatosis increases operative morbidity/mortality from ischemia-reperfusion injury (IRI); few pharmacological approaches have been protective. Using novel genetic/dietary models of nonalcoholic steatohepatitis (NASH) and simple steatosis (SS) in Alms1 mutant (foz/foz) mice, we characterized severity of IRI in NASH versus SS and lean liver and tested our hypothesis that the lipid-lowering effects of the peroxisome proliferation-activator receptor (PPAR)-alpha agonist Wy-14,643 would be hepatoprotective. Mice were subjected to 60-minute partial hepatic IRI. Microvascular changes were assessed at 15-minute reperfusion by in vivo microscopy, injury at 24 hours by serum alanine aminotransferase (ALT), and hepatic necrosis area. Injury and inflammation mediators were determined by way of immunoblotting for intercellular cellular adhesion molecule, vascular cellular adhesion molecule, p38, c-jun N-terminal kinase, IkappaB-alpha, interleukin (IL)-1a, IL-12, tumor necrosis factor-alpha (TNF-alpha) and IL-6, cell cycle by cyclin D1 and proliferating cell nuclear antigen immunohistochemistry. In foz/foz mice fed a high-fat diet (HFD) to cause NASH or chow (SS), IRI was exacerbated compared with HFD-fed or chow-fed wild-type littermates by ALT release; corresponding necrotic areas were 60 +/- 22% NASH, 29 +/- 9% SS versus 7 +/- 1% lean. Microvasculature of NASH or SS livers was narrowed by enormous lipid-filled hepatocytes, significantly reducing numbers of perfused sinusoids, all exacerbated by IRI. Wy-14,643 reduced steatosis in NASH and SS livers, whereas PPAR-alpha stimulation conferred substantial hepatoprotection against IRI by ALT release, with reductions in vascular cellular adhesion molecule-1, IL-1a, TNF-alpha, IL-12, activated nuclear factor-kappaB (NF-kappaB), p38, IL-6 production and cell cycle entry.

CONCLUSION

NASH and SS livers are both more susceptible to IRI. Mechanisms include possible distortion of the microvasculature by swollen fat-laden hepatocytes, and enhanced production of several cytokines. The beneficial effects of Wy-14,643 may be exerted by dampening adhesion molecule and cytokine responses, and activating NF-kappaB, IL-6 production, and p38 kinase to effect cell cycle entry.

摘要

目的

脂肪变性增加了缺血再灌注损伤（IRI）的手术发病率/死亡率；很少有药物治疗方法具有保护作用。本研究使用非酒精性脂肪性肝炎（NASH）和单纯性脂肪变性（SS）的新型基因/饮食模型，在 Alms1 突变（foz/foz）小鼠中研究了 NASH 与 SS 以及瘦肝IRI 的严重程度，并验证了我们的假设，即过氧化物酶体增殖物激活受体（PPAR）-α激动剂 Wy-14,643 的降脂作用将具有肝保护作用。将小鼠进行 60 分钟的部分肝IRI。通过体内显微镜在再灌注 15 分钟时评估微血管变化，在 24 小时时通过血清丙氨酸转氨酶（ALT）评估损伤，并用肝坏死面积评估。通过免疫印迹法测定细胞间黏附分子、血管细胞黏附分子、p38、c-jun N 末端激酶、IkappaB-α、白细胞介素（IL）-1a、IL-12、肿瘤坏死因子-α（TNF-α）和 IL-6 来测定损伤和炎症介质，通过 cyclin D1 和增殖细胞核抗原免疫组织化学测定细胞周期。在高脂肪饮食（HFD）喂养的 foz/foz 小鼠中引起 NASH 或饲料（SS），与 HFD 喂养或饲料喂养的野生型同窝仔相比，IRI 通过 ALT 释放使 NASH 或 SS 肝脏的IRI 加重；相应的坏死面积分别为 60%±22%的 NASH、29%±9%的 SS 和 7%±1%的瘦肝。NASH 或 SS 肝脏的微血管狭窄，充满巨大的脂肪细胞，显著减少了灌注的窦状隙数量，IRI 加重了这种情况。Wy-14,643 可减少 NASH 和 SS 肝脏的脂肪变性，而 PPAR-α 刺激通过 ALT 释放，降低血管细胞黏附分子-1、IL-1a、TNF-α、IL-12、激活的核因子-κB（NF-κB）、p38、IL-6 的产生和细胞周期进入，对 IRI 具有显著的肝保护作用。