Hepatic TGFbeta1 in Control of Type 2 Diabetes and NASH via FoxO1 Signaling

肝脏 TGFbeta1 通过 FoxO1 信号传导控制 2 型糖尿病和 NASH

• 批准号: 10532783
• 负责人: Shaodong Guo
• 金额: $ 51.34万
• 依托单位: TEXAS A&M AGRILIFE RESEARCH
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-12-01 至 2025-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10532783
• 关键词: Alanine; Alcohol abuse; Amino Acids; Apoptosis; Aspartate; Binding; Bioinformatics; Biology; Blood; Bone Marrow; Cell Separation; Cell physiology; Charge; Chemicals; Clinical; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cytoplasm; Data; Diabetes Mellitus; Diet; Disease; Disease model; Extracellular Matrix; Extracellular Matrix Proteins; FOXO1A gene; Fibrosis; Gene Expression; Genes; Genetic; Genetic Models; Genomics; Glucagon; Gluconeogenesis; Grant; Hepatic; Hepatic Stellate Cell; Hepatocyte; High Fat Diet; Homeostasis; Human; Hyperglycemia; IRS1 gene; In Vitro; Inflammation; Insulin; Insulin Receptor; Insulin Resistance; Knock-in; Knockout Mice; Lipids; Liver; Liver Failure; Liver Fibrosis; Liver diseases; Macrophage; Metabolic; Metabolic stress; Molecular; Morbidity - disease rate; Mus; Mutant Strains Mice; Mutation; Non-Insulin-Dependent Diabetes Mellitus; Nuclear; Nuclear Export; Nuclear Protein; Nuclear Translocation; Overnutrition; PIK3CG gene; Pathway interactions; Phosphorylation; Play; Prevention; Proteins; Proto-Oncogene Proteins c-akt; Public Health; Research; Risk Factors; Role; Serine; Shapes; Signal Pathway; Signal Transduction; Site; Steatohepatitis; System; TGFB1 gene; Testing; Therapeutic; Tissues; Transforming Growth Factor beta; Transforming Growth Factors; Ubiquitination; Virus Diseases; antagonist; autocrine; chronic liver injury; cytokine; effective therapy; feeding; forkhead protein; genetic approach; genomic locus; genomic tools; glucose metabolism; glucose production; high risk; inhibitor; insight; insulin signaling; lipid biosynthesis; liver function; liver inflammation; member; non-alcoholic; non-alcoholic fatty liver disease; nonalcoholic steatohepatitis; novel; overexpression; paracrine; pharmacologic; programs; protein expression; receptor; response; single-cell RNA sequencing; transcription factor; transcriptome; transcriptome sequencing

Project Summary Overnutrition induces insulin resistance, which is a high-risk factor for T2D and NASH. The mechanism underlying insulin resistance-induced hepatic lipogenesis, fibrosis, apoptosis, and inflammation for NASH is unclear. High levels of transforming growth factor-β1 (TGFβ1) in blood and tissues were observed in both human and mice with T2D and NASH. TGF-β1 plays a pivotal role in a diverse range of cellular responses, including extracellular matrix (ECM) synthesis and apoptosis which are essential for tissue homeostasis, but the molecular mechanism by which TGFβ1 regulates glucose metabolism and liver function is incompletely understood. The forkhead transcription factor Foxo1 is a key downstream target of the insulin→ PI3K→protein kinase B (Akt) signaling pathway and the glucagon→cAMP→protein kinase A (PKA) signaling pathway. Akt phosphorylates Foxo1-Ser253, triggering Foxo1 nuclear export and cytoplasmic sequestration for ubiquitination. By contrast, PKA phosphorylates Foxo1-Ser273 to promote Foxo1 nuclear translocation and protein stability in hepatocytes. Upon metabolic stress such as overnutrition, Foxo1 hyperactivation promotes hepatic glucose production (HGP) and hyperglycemia. In this proposal, the PI hypothesizes that hepatic TGFβ1 plays key role in control of Foxo1 via phosphorylation at S273 (Foxo1-pS273), enhancing Foxo1 nuclear activity, and inducing hyperglycemia, liver fibrosis and inflammation, and promoting T2D and NASH. In Aim 1, PI and his team will use genetic approaches to 1) delete the TGFβ1 gene in the liver of mice (L-TGFβ1KO) with or without active Foxo1-S273D/D mutation, or 2) generate liver-specific overexpression TGFβ1 mice (L-TGFβ1OE) with or without inactive Foxo1-S273A/A mutation, investigating whether hepatic TGFβ1 is a key controller for Foxo1-pS273 in promoting HGP, apoptosis, liver fibrosis and inflammation following the NASH diet feeding. Aim2 is to use mouse primary hepatocytes, bone marrow- derived macrophages, and hepatic stellate cells (HSC) to determine the mechanisms by which TGFβ1 promotes macrophage depolarization and HSC activation via Foxo1-pS273 in hepatocytes. The specific- domain interactions of Smad3 and Foxo1 and related target genes expression in hepatocytes will be further investigated. Aim 3 is to investigate whether suppression of systematic or hepatic TGFβ1 signaling is sufficient for the prevention of T2D and NASH in mice, in a Foxo1 dependent manner. Overall, using the genetic, genomic, bioinformatic, and pharmacological approaches, the PI and his team are fully equipped to investigate the new pathophysiological role of hepatic TGF-β1→Foxo1-pS273→TGFβ1 looping system in control of T2D and NASH, which will provide novel insights on mechanism of diabetes and NASH.

项目摘要 营养不良会诱导胰岛素抵抗，这是T2D和NASH的高风险因素。这 胰岛素抵抗引起的肝脂肪生成，纤维化，凋亡和炎症的机制 因为纳什不清楚。血液和组织中高水平的生长因子-β1（TGFβ1）为 在用T2D和NASH的人和小鼠中观察到。 TGF-β1在潜水员范围内起关键作用 细胞反应，包括细胞外基质（ECM）合成和凋亡，这对于 组织稳态，但TGFβ1调节葡萄糖代谢和肝脏的分子机制 功能是不完全理解的。 叉头转录因子FOXO1是胰岛素→PI3K→蛋白质的关键下游靶标 激酶B（AKT）信号通路和胰高血糖素→CAMP→蛋白激酶A（PKA）信号通路。 akt 磷酸化FOXO1-SER253，触发FOXO1核出口和细胞质隔离以进行 泛素化。相比之下，PKA磷酸化FOXO1-SER273以促进FOXO1核易位和 肝细胞中的蛋白质稳定性。在代谢压力（例如营养不良）中，FOXO1过度激活 促进肝葡萄糖产生（HGP）和高血糖。在此提案中，PI假设 HEPATITGFβ1通过S273（FOXO1-PS273）在FOXO1控制中起关键作用，增强 FOXO1核活动，并诱导高血糖，肝纤维化和注射，并促进T2D和 纳什。在AIM 1中，PI和他的团队将使用遗传方法1）删除TGFβ1基因 带有或没有活性FOXO1-S273D/D突变的小鼠（L-TGFβ1KO），或2）产生肝脏特异性 过表达TGFβ1小鼠（L-TGFβ1OE），有或没有非活性FOXO1-S273A/A突变，研究 在促进HGP，凋亡，肝纤维化和 纳什饮食喂养后的炎症。 AIM2是使用小鼠初级肝细胞，骨髓 - 衍生的巨噬细胞和肝星状细胞（HSC）确定TGFβ1的机制 通过肝细胞中的FOXO1-PS273促进巨噬细胞沉积和HSC激活。特定 - SMAD3和FOXO1和相关靶基因在肝细胞中的表达的域相互作用将进一步 调查。 AIM 3是研究抑制系统或肝TGFβ1信号是否是 足以以FoxO1的方式预防小鼠T2D和NASH。总体而言，使用 遗传，基因组，生物信息学和药物方法，PI和他的团队完全有能力 研究丙型肝炎TGF-β1→FOXO1-PS273→TGFβ1循环系统的新病理生理作用 控制T2D和NASH，这将提供有关糖尿病和NASH机制的新见解。