SRSF3 degradation in liver disease and hepatocellular carcinoma

肝脏疾病和肝细胞癌中的 SRSF3 降解

• 批准号: 10618856
• 负责人: NICHOLAS J WEBSTER
• 金额: --
• 依托单位: VA SAN DIEGO HEALTHCARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10618856
• 关键词: Acute; Automobile Driving; Benign; Biochemical; Biological; Biological Process; Carbon Tetrachloride; Cell Nucleus; Cells; Chemicals; Cholesterol; Chronic; Cirrhosis; Complex; Cytoplasm; DNA Damage; Data; Development; Diagnosis; Diet; Diethylnitrosamine; Disease Progression; Equilibrium; Event; Fatty Liver; Fatty acid glycerol esters; Fibrosis; Freezing; Fructose; Functional disorder; Gatekeeping; Genetic; Genetic Models; Genetic Transcription; Half-Life; HepG2; Hepatic; Hepatitis C; Hepatocarcinogenesis; Hepatocyte; Histologic; Human; In Vitro; Incidence; Individual; Inflammation; Knock-out; Knockout Mice; Knowledge; Lipids; Liver; Liver Cirrhosis; Liver Fibrosis; Liver diseases; Lysine; Malignant Neoplasms; Malignant neoplasm of liver; Measurement; Mediating; Metabolic; Metabolic dysfunction; Modeling; Molecular; Mus; Pathologic; Pathway interactions; Persons; Physiological; Predisposition; Prevention; Primary carcinoma of the liver cells; Proteins; Publishing; RNA Splicing; Research Personnel; Resistance; Risk Factors; Role; Sampling; Series; Steatohepatitis; Stress; Sucrose; Surveys; Survival Rate; System; Testing; Thioacetamide; Tumor Suppressor Genes; Ubiquitin; Ubiquitin Like Proteins; Virus Diseases; Work; carcinogenesis; effective therapy; experimental study; fatty liver disease; glucose metabolism; hepatoma cell; in vivo; innovation; insight; knock-down; lipid metabolism; liver cancer model; liver injury; mouse model; multicatalytic endopeptidase complex; mutant; non-alcoholic fatty liver disease; nonalcoholic steatohepatitis; novel; overexpression; pharmacologic; prevent; proteostasis; receptor; recruit; response; tumor; ubiquitin-protein ligase

We have published that eliminating a particular RNA splicing factor SRSF3 in hepatocytes causes chronic liver damage, disruptions in glucose and lipid metabolism, inflammation, fibrosis, and eventually liver cancer. So the loss of the splicing factor does not cause tumors but rather creates a pre-disposition to cancer, similar to a tumor suppressor gene. We have since shown that loss of SRSF3 is found in early liver disease in both humans and mice, in addition to being lost in liver cancer which we had shown previously. While the pathological changes that occur during the progression of fatty liver disease to steatohepatitis and cirrhosis have been well documented, we still do not know why some people can maintain relatively benign fatty livers while others progress to more serve liver disease including liver cirrhosis and cancer. Based on extensive preliminary data, we have found that the SRSF3 protein has a short half-life and its levels are acutely regulated by proteosomal degradation. This is not the usual ubiquitin mediated pathway but rather a novel pathway involving conjugation to the NEDD8 protein in response to lipid-induced stress. We believe that SRSF3 may be the gatekeeper that determines whether liver disease progresses or is stable. An individual’s susceptibility to progression is determined by the susceptibility of SRSF3 to stress-induced degradation. So we are proposing a comprehensive series of experiments to understand how SRSF3 is degraded in response to stress and whether stabilizing SRSF3 and preventing its degradation can halt the progression to NASH, cirrhosis and liver cancer. These studies will address key questions concerning the fundamental biological process of protein homeostasis and carcinogenesis and will integrate biochemical, cell and molecular biological experiments with physiological studies in mice lacking specific splicing factors in liver. We will determine the components of the E3-ligase complex that targets SRSF3 for neddylation, the pathway leading to destruction of SRSF3, and how the balance of SRSF3 conjugation and deconjugation is maintained. We investigate whether expressing a degradation-resistant SRSF3 or blocking neddylation in mice will prevent the progression of early liver disease to inflammation, fibrosis and cirrhosis, and we will determine whether this approach prevents liver cancer or can be used to reverse liver cancer in mice.

我们发表了消除肝细胞中特定 RNA 剪接因子 SRSF3 会导致 慢性肝损伤、葡萄糖和脂质代谢紊乱、炎症、纤维化，最终导致肝损伤 癌症。因此，剪接因子的丢失不会导致肿瘤，而是会产生癌症的倾向， 类似于肿瘤抑制基因。此后我们发现，在早期肝病中发现了 SRSF3 的缺失。 人类和小鼠，除了我们之前展示的肝癌中的损失之外。虽然 脂肪肝发展为脂肪性肝炎和肝硬化过程中发生的病理变化 已经有充分的文献记载，我们仍然不知道为什么有些人可以维持相对良性的脂肪肝 而另一些则进展更多地服务于肝脏疾病，包括肝硬化和癌症。 基于大量的初步数据，我们发现SRSF3蛋白的半衰期很短，其 水平受到蛋白酶体降解的强烈调节。这不是通常的泛素介导的途径，而是 相反，这是一种新的途径，涉及与 NEDD8 蛋白缀合以响应脂质诱导的应激。我们 相信SRSF3可能是决定肝病是否进展或稳定的把关人。一个 个体对进展的易感性取决于 SRSF3 对应激诱导的易感性 降解。因此，我们提出了一系列全面的实验来了解 SRSF3 的作用 响应应激而降解，以及稳定 SRSF3 并防止其降解是否可以阻止 进展为 NASH、肝硬化和肝癌。这些研究将解决有关的关键问题 蛋白质稳态和致癌作用的基本生物过程，并将整合生化、细胞 以及在肝脏中缺乏特定剪接因子的小鼠中进行的分子生物学实验和生理研究。 我们将确定针对 SRSF3 进行 neddylation 的 E3 连接酶复合物的组成部分， 导致 SRSF3 破坏的途径，以及 SRSF3 缀合和解缀合的平衡如何 维持。我们研究是否在小鼠中表达抗降解的 SRSF3 或阻断 neddylation 将阻止早期肝病进展为炎症、纤维化和肝硬化，我们将确定 这种方法是否可以预防肝癌或可用于逆转小鼠肝癌。