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

基本信息

批准号：
10365367
负责人：
Shaodong Guo
金额：
$ 51.99万
依托单位：
TEXAS A&M AGRILIFE RESEARCH
依托单位国家：
美国
项目类别：
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/10365367
关键词：
AKT Signaling Pathway Alanine Alcohol abuse Amino Acids Apoptosis Aspartate Bioinformatics Biology Blood Bone Marrow Cell physiology Cells Charge Chemicals Clinical Cyclic AMP Cyclic AMP-Dependent Protein Kinases 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 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 Pathway interactions Pharmacology Phosphorylation Play Prevention Protein Kinase 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 alpha Transforming Growth Factor beta Transforming Growth Factors Ubiquitination Virus Diseases antagonist autocrine base 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 macrophage member non-alcoholic non-alcoholic fatty liver disease nonalcoholic steatohepatitis novel overexpression paracrine programs protein expression receptor response single-cell RNA sequencing transcription factor transcriptome transcriptome sequencing

项目摘要

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.

项目概要营养过剩会诱发胰岛素抵抗，这是 T2D 和 NASH 的高危因素。胰岛素抵抗诱导肝脏脂肪生成、纤维化、细胞凋亡和炎症的机制血液和组织中高水平的转化生长因子-β1 (TGFβ1) 与 NASH 的关系尚不清楚。在患有 T2D 和 NASH 的人类和小鼠中观察到 TGF-β1 在多种疾病中发挥着关键作用。细胞反应，包括细胞外基质 (ECM) 合成和细胞凋亡，这对于细胞生长至关重要组织稳态，但TGFβ1调节糖代谢和肝脏的分子机制功能理解不完全。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。磷酸化 Foxo1-Ser253，触发 Foxo1 核输出和细胞质隔离相比之下，PKA 磷酸化 Foxo1-Ser273 以促进 Foxo1 核转位和肝细胞中的蛋白质稳定性在营养过剩等代谢应激下，Foxo1 过度激活。促进肝葡萄糖生成 (HGP) 和高血糖在该提案中，PI 捕获了这一点。肝脏 TGFβ1 通过 S273 (Foxo1-pS273) 磷酸化在控制 Foxo1 中发挥关键作用，增强 Foxo1 核活性，诱导高血糖、肝纤维化和炎症，促进 T2D 和在目标 1 中，PI 和他的团队将使用基因方法 1) 删除肝脏中的 TGFβ1 基因。具有或不具有活性 Foxo1-S273D/D 突变的小鼠 (L-TGFβ1KO)，或 2) 产生肝脏特异性过度表达 TGFβ1 小鼠 (L-TGFβ1OE)，有或没有失活 Foxo1-S273A/A 突变，正在研究肝脏TGFβ1是否是Foxo1-pS273促进HGP、细胞凋亡、肝纤维化和 NASH 饮食喂养后的炎症目的 2 是使用小鼠原代肝细胞、骨髓。衍生的巨噬细胞和肝星状细胞 (HSC) 以确定 TGFβ1 的机制通过肝细胞中的 Foxo1-pS273 促进巨噬细胞去极化和 HSC 激活。 Smad3和Foxo1的结构域相互作用及相关靶基因在肝细胞中的表达有待进一步研究研究目的 3 是研究系统或肝脏 TGFβ1 信号传导是否受到抑制。总体而言，使用 Foxo1 足以预防小鼠 T2D 和 NASH。遗传学、基因组学、生物信息学和药理学方法，PI 和他的团队完全有能力探讨肝TGF-β1→Foxo1-pS273→TGFβ1循环系统在肝细胞中的新的病理生理作用控制T2D和NASH，这将为糖尿病和NASH的机制提供新的见解。