Pathogenesis and Novel Therapeutic Targets of Fatty Liver Disease and Cancer

脂肪肝疾病和癌症的发病机制和新的治疗靶点

• 批准号: 10004417
• 负责人: bin gao
• 金额: $ 111.62万
• 依托单位: NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10004417
• 关键词: Acetaldehyde; Affect; Aging; Alcohol consumption; Alcohol-Related Hepatocellular Carcinoma; Alcoholic Liver Diseases; Alcohols; Anti-inflammatory; Asians; BCL2 gene; CXCL10 gene; Carbon Tetrachloride; Chronic; Cirrhosis; DNA; Development; Disease; Disease Progression; Enzymes; Ethanol; Ethanol Metabolism; Fatty Liver; Fibrosis; Genes; Genetic; Genetic Polymorphism; Goals; Heavy Drinking; Hepatic; Hepatitis B; Hepatocyte; High Fat Diet; Human; Immunologics; In Vitro; Inflammation; Inflammatory; Knock-in; Knockout Mice; Laboratories; Liver; Liver Fibrosis; Liver diseases; MAPK8 gene; Malignant Epithelial Cell; Malignant Neoplasms; Malignant neoplasm of liver; Messenger RNA; MicroRNAs; Microarray Analysis; Mitochondrial DNA; Modeling; Mus; Mutant Strains Mice; Oncogenic; Oxides; Pathogenesis; Pathway interactions; Patients; Play; Population; Primary carcinoma of the liver cells; Resistance; Risk; STAT3 gene; Sampling; Transcriptional Coactivator with PDZ-Binding Motif; Wild Type Mouse; acetaldehyde dehydrogenase; alcohol exposure; alcohol risk; aldehyde dehydrogenases; chemokine; clinically relevant; experimental study; extracellular vesicles; in vivo; liver injury; new therapeutic target; non-alcoholic fatty liver disease; nonalcoholic steatohepatitis; novel; overexpression; therapeutic target

Our laboratory has been actively studying the pathogenesis of alcoholic liver disease, focusing on how acetaldehyde dehydrogenase 2 (ALDH2)and miRNA-223 on fatty liver disease and its associated liver cancer. First, we have demonstrated that ALDH2 deficiency promotes alcohol-associated liver cancer by activating oncogenic pathways via oxidized DNA enriched extracellular vesicles. Abstracts: BACKGROUND & AIMS: Excessive alcohol drinking is one of the major causes of hepatocellular carcinoma (HCC). Approximately 30-40% Asian population are deficient for aldehyde dehydrogenase 2 (ALDH2), a key enzyme to detoxify the ethanol metabolite acetaldehyde. However, how ALDH2 deficiency affects alcohol-related HCC remains obscure. METHODS: ALDH2 polymorphism in 646 patients with viral hepatitis B (HBV) infection with or without alcohol drinking was studied. A new model of HCC induced by chronic carbon tetrachloride (CCl4) and alcohol administration was developed and studied in three lines of Aldh2-deficient mice: including Aldh2 global knockout (KO) mice, Aldh2*1/*2 knock-in mutant mice, and liver-specific Aldh2 KO mice. RESULTS: We demonstrated that ALDH2 deficiency was not associated with liver disease progression but was associated with an increased risk of HCC development in cirrhotic HBV patients with excessive alcohol consumption. The mechanisms underlying HCC development associated with cirrhosis and alcohol consumption were studied in Aldh2-deficient mice. We found that all three lines of Aldh2-deficient mice were more susceptible to CCl4 plus alcohol-associated liver fibrosis and HCC development. Furthermore, our results from in vivo and in vitro mechanistic studies revealed that after CCl4 plus ethanol exposure, Aldh2-deficient hepatocytes produced a large amount of harmful oxidized mtDNA via extracellular vesicles (EVs), which were then transferred into neighboring HCC cells and together with acetaldehyde activated multiple oncogenic pathways (JNK, STAT3, BCL-2, and TAZ), thereby promoting HCC. CONCLUSIONS: ALDH2 deficiency is associated with an increased risk of alcohol related-HCC development from fibrosis in patients and in mice. Mechanistic studies reveal a novel mechanism that Aldh2-deficient hepatocytes promote alcohol-associated HCC by transferring harmful oxidized mtDNA-enriched EVs into HCC and subsequently activating multiple oncogenic pathways in HCC. Second, we have demonstrated that microRNA-223 ameliorates nonalcoholic steatohepatitis and cancer by targeting multiple inflammatory and oncogenic genes in hepatocytes. Abstract: Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of diseases ranging from simple steatosis to more severe forms of liver injury including nonalcoholic steatohepatitis (NASH), fibrosis, and hepatocellular carcinoma (HCC). In humans, only 20%-40% of patients with fatty liver progress to NASH, and mice fed a high-fat diet (HFD) develop fatty liver but are resistant to NASH development. To understand how simple steatosis progresses to NASH, we examined hepatic expression of anti-inflammatory microRNA-223 (miR-223) and found that this miRNA was highly elevated in hepatocytes in HFD-fed mice and in human NASH samples. Genetic deletion of miR-223 induced a full spectrum of NAFLD in long-term HFD-fed mice including steatosis, inflammation, fibrosis, and HCC. Furthermore, microarray analyses revealed that, compared to wild-type mice, HFD-fed miR-223 knockout (miR-223KO) mice had greater hepatic expression of many inflammatory genes and cancer-related genes, including (C-X-C motif) chemokine 10 (Cxcl10) and transcriptional coactivator with PDZ-binding motif (Taz), two well-known factors that promote NASH development. In vitro experiments demonstrated that Cxcl10 and Taz are two downstream targets of miR-223 and that overexpression of miR-223 reduced their expression in cultured hepatocytes. Hepatic levels of miR-223, CXCL10, and TAZ mRNA were elevated in human NASH samples, which positively correlated with hepatic levels of several miR-223 targeted genes as well as several proinflammatory, cancer-related, and fibrogenic genes. Conclusion: HFD-fed miR-223KO mice develop a full spectrum of NAFLD, representing a clinically relevant mouse NAFLD model; miR-223 plays a key role in controlling steatosis-to-NASH progression by inhibiting hepatic Cxcl10 and Taz expression and may be a therapeutic target for the treatment of NASH.

本实验室一直在积极研究酒精性肝病的发病机制，重点研究乙醛脱氢酶2（ALDH 2）和miRNA-223如何对脂肪肝及其相关肝癌起作用。 首先，我们已经证明，ALDH 2缺乏促进酒精相关的肝癌激活致癌途径，通过氧化DNA富集细胞外囊泡。摘要：背景与目的：过量饮酒是肝细胞癌（HCC）的主要原因之一。大约30-40%的亚洲人缺乏醛脱氢酶2（ALDH 2），这是一种解毒乙醇代谢产物乙醛的关键酶。然而，ALDH 2缺乏如何影响酒精相关的HCC仍然不清楚。方法：对646例乙型肝炎（B）患者进行ALDH 2基因多态性研究。建立了一种新的四氯化碳（CCl 4）和酒精诱导的肝细胞癌（HCC）模型，并在三种Aldh 2缺陷小鼠（包括Aldh 2全基因敲除（KO）小鼠、Aldh 2 *1/*2基因敲入突变小鼠和肝脏特异性Aldh 2 KO小鼠）中进行研究。研究结果：我们证明ALDH 2缺乏与肝病进展无关，但与过量饮酒的HBV感染患者发生HCC的风险增加有关。在Aldh 2缺陷小鼠中研究了与肝硬化和饮酒相关的HCC发展的潜在机制。我们发现，所有三种Aldh 2缺陷型小鼠更容易受到CCl 4加酒精相关肝纤维化和HCC发展的影响。此外，我们的体内和体外机制研究结果显示，在CCl 4+乙醇暴露后，Aldh 2缺陷肝细胞通过细胞外囊泡（EV）产生大量有害的氧化mtDNA，然后将其转移到邻近的HCC细胞中，并与乙醛一起激活多种致癌途径（JNK，STAT 3，BCL-2和TAZ），从而促进HCC。结论：ALDH 2缺乏与患者和小鼠中酒精相关肝细胞癌纤维化发展的风险增加有关。机制研究揭示了一种新的机制，即Aldh 2缺陷肝细胞通过将有害的氧化mtDNA富集的EV转移到HCC中并随后激活HCC中的多种致癌途径来促进酒精相关HCC。 其次，我们已经证明microRNA-223通过靶向肝细胞中的多种炎症和致癌基因来改善非酒精性脂肪性肝炎和癌症。摘要：非酒精性脂肪性肝病（NAFLD）代表了一系列疾病，从简单的脂肪变性到更严重形式的肝损伤，包括非酒精性脂肪性肝炎（NASH）、纤维化和肝细胞癌（HCC）。在人类中，只有20%-40%的脂肪肝患者进展为NASH，而喂食高脂肪饮食（HFD）的小鼠会发展为脂肪肝，但对NASH的发展具有抵抗力。为了了解简单脂肪变性如何发展为NASH，我们检查了抗炎microRNA-223（miR-223）的肝脏表达，发现这种miRNA在HFD喂养的小鼠和人类NASH样本的肝细胞中高度升高。miR-223的遗传缺失在长期HFD喂养的小鼠中诱导了全谱的NAFLD，包括脂肪变性、炎症、纤维化和HCC。此外，微阵列分析显示，与野生型小鼠相比，HFD喂养的miR-223敲除（miR-223 KO）小鼠的许多炎症基因和癌症相关基因的肝脏表达更高，包括（C-X-C基序）趋化因子10（Cxcl 10）和具有PDZ结合基序的转录共激活因子（Taz），这两种众所周知的促进NASH发展的因子。体外实验表明，Cxcl 10和Taz是miR-223的两个下游靶点，miR-223的过表达降低了它们在培养肝细胞中的表达。在人类NASH样本中，miR-223、CXCL 10和TAZ mRNA的肝脏水平升高，这与几种miR-223靶向基因以及几种促炎基因、癌症相关基因和纤维化基因的肝脏水平呈正相关。结论：HFD喂养的miR-223 KO小鼠产生全谱NAFLD，代表临床相关的小鼠NAFLD模型; miR-223通过抑制肝脏Cxcl 10和Taz表达在控制脂肪变性向NASH进展中起关键作用，可能是治疗NASH的治疗靶点。