受体相互作用蛋白激酶调控非酒精性脂肪肝中细胞程序性坏死的研究进展

非酒精性脂肪性肝病（NAFLD）是一种常见的慢性肝病,如果得不到有效控制,则会进一步发展为非酒精性脂肪性肝炎（NASH）,进而引起肝纤维化、肝硬化,甚至癌变。程序性坏死是近年来发现的一种新型细胞程序性死亡方式,由受体相互作用蛋白激酶（RIPK）介导所致,最终可以导致细胞膜溶解破裂,引发炎症。RIPK家族作为细胞内和细胞外应激的重要传感器,诱导调控程序性坏死的发生,并参与炎症及其他免疫反应。近年来研究表明,RIPK调控的程序性坏死在非酒精性脂肪性肝病的发生发展中具有重要作用,在动物NAFLD/NASH模型中,RIPK的表达情况与肝脂肪变性程度密切相关。在一些临床研究中亦观察到,NAFLD/NASH患者比健康人RIPK表达水平上升。但程序性坏死到底是加速肝病进程的因素,还是肝病发展过程中的保护因素,仍然没有定论。有研究表明,RIPK抑制剂可能为NAFLD治疗提供方向。我们综述了程序性坏死的分子机制及与非酒精性脂肪性肝病的关系,以及RIPK在其中扮演的重要角色,并总结了其在NAFLD/NASH治疗方面的研究进展,为进一步探究其机制,探索新的治疗手段提供理论依据。     

Fatty liver disease

It is now widely accepted that fatty liver disease is one of the commonest causes of cirrhosis and liver cell cancer (even in the absence of cirrhosis), in its own right as well as being an important cofactor for the progression of other diseases e.g. viral hepatitis. While much work has been done on developing non-invasive techniques for assessing liver disease, the liver biopsy remains the benchmark against which these tests have to be validated as well as providing information that cannot be obtained in any other way. This review describes the histological features that alcoholic and non-alcoholic liver disease have in common (e.g. fatty change, ballooning and Mallory–Denk bodies) as well as identifying those that are more characteristic of each of them (e.g. nuclear vacuolation in non-alcoholic fatty liver disease and a florid fatty liver hepatitis in alcoholic fatty liver disease). Recent developments in the assessment of the degree of fatty change are described.     

二甲双胍对非酒精性脂肪性肝病大鼠肝脏基因表达谱的影响

目的 探讨二甲双胍对非酒精性脂肪性肝病(NAFLD)大鼠造模过程中肝脏基因表达谱的影响.方法 雄性Sprague-Dawley大鼠随机分为3组:对照组6只,模型组和治疗组各12只.治疗组在给予高脂饮食的同时,于实验开始第4周起按每天250 mg/kg加入二甲双胍干预.于实验第24周时处死,应用大鼠U230A芯片检测肝脏基因表达的改变.结果 与模型组相比,二甲双胍治疗组出现差异表达的基因共483条,其中上调基因133条,主要为激素受体基因、细胞周期相关基因及离子通道基因等,胰岛素受体及其底物、瘦素受体基因均有不同程度的表达上调,与模型组比较上升约3～7倍;下调基因350条,包括代谢酶相关基因、脂肪酸结合蛋白基因、细胞色素P450相关基因、炎症和凋亡相关基因,与纤维化相关的基因也略有下降.结论 从基因学角度分析显示二甲双胍可减轻肝脂肪变,改善肝脏炎症损伤和纤维化程度.     

TNF-α在非酒精性脂肪性肝病中的作用及其机制

肿瘤坏死因子-α(TNF-α)是介导肝损伤的主要细胞因子,除对肝细胞的直接作用外,还可通过促进胰岛素抵抗和游离脂肪酸含量的增高,加强葡萄糖毒性和脂毒性造成的肝损害,从而在非酒精性脂肪性肝病(NAFLD)发病中具有重要作用。     

A novel radiomics signature based on T2-weighted imaging accurately predicts hepatic inflammation in individuals with biopsy-proven nonalcoholic fatty liver disease: a derivation and independent validation study

BackgroundCurrently, there are no effective methods for assessing hepatic inflammation without resorting to histological examination of liver tissue obtained by biopsy. T2-weighted images (T2WI) are routinely obtained from liver magnetic resonance imaging (MRI) scan sequences. We aimed to establish a radiomics signature based on T2WI (T2-RS) for assessment of hepatic inflammation in people with nonalcoholic fatty liver disease (NAFLD).MethodsA total of 203 individuals with biopsy-confirmed NAFLD from two independent Chinese cohorts with liver MRI examination were enrolled in this study. The hepatic inflammatory activity score (IAS) was calculated by the unweighted sum of the histologic scores for lobular inflammation and ballooning. One thousand and thirty-two radiomics features were extracted from the localized region of interest (ROI) in the right liver lobe of T2WI and, subsequently, selected by minimum redundancy maximum relevance and least absolute shrinkage and selection operator (LASSO) methods. The T2-RS was calculated by adding the selected features weighted by their coefficients.ResultsEighteen radiomics features from Laplacian of Gaussian, wavelet, and original images were selected for establishing T2-RS. The T2-RS value differed significantly between groups with increasing grades of hepatic inflammation (P<0.01). The T2-RS yielded an area under the receiver operating characteristic (ROC) curve (AUROC) of 0.80 [95% confidence interval (CI): 0.71–0.89] for predicting hepatic inflammation in the training cohort with excellent calibration. The AUROCs of T2-RS in the internal cohort and external validation cohorts were 0.77 (0.61–0.93) and 0.75 (0.63–0.84), respectively.ConclusionsThe T2-RS derived from radiomics analysis of T2WI shows promising utility for predicting hepatic inflammation in individuals with NAFLD.     

细胞因子在脂肪性肝病中的作用

无论是酒精性脂肪肝还是非酒精性脂肪肝,其发病机制都与细胞因子息息相关.此文综述了多种细胞因子在脂肪肝发生发展过程中的作用,以及其介导的细胞凋亡在脂肪肝发病机制中的作用,阐述了某些细胞因子对脂肪肝的治疗应用.     

非酒精性脂肪性肝炎的临床病理研究

目的：探讨非酒精性脂肪性肝炎（Nonalcoholic steatohepatitis,NASH)的临床和病理学特征。方法：对40例NASH患者的临床资料和穿刺肝组织进行临床和病理学分析,并与酒精性脂肪性肝炎（Alcoholic steatohepatitis,ASH)和丙型肝炎（HCV）患者各20例作对照。结果：90％ NASH患者肥胖（P＜0．01）,血浆总蛋白平均水平高于ASH（P＜0．05）,血清ALT、AST、GGT、TBA、TG平均水平分别是正常范围上限值的2．6、1．5、1．2、1．3倍,但白蛋白水平是正常范围下限值的0．96倍。NASH的组织学改变类似ASH,但有些组织学改变如脂肪变性、汇管区的炎症程度,Mallory小体和空泡状核的出现频率等两者间存在着差异性（P＜0．05或P＜0．01）。NASH有其相对的病理特征：大小泡混合型脂肪变性,以大泡为主;肝组织气球样变性,小叶中央区较常见,气球样变性的细胞胞浆内常常有嗜碱性的细颗粒;肝小叶内炎症,不典型的Mallory小体,汇管区周围易见空泡状核细胞。多数NASH患者的肝小叶中央区（腺泡Ⅲk带）有不同程度的窦周纤维化。结论：结果显示NASH有一些相对的临床和病理学特征,临床、病理及实验室检查相结合能对NASH作出肯定的诊断,其中病理活检仍然是诊断NASH的“金标准”。