Branched-chain Keto-acids and Aerobic Glycolysis in Vascular Smooth Muscle Cells

血管平滑肌细胞中的支链酮酸和有氧糖酵解

• 批准号: 10731096
• 负责人: Joseph Loscalzo
• 金额: $ 69.62万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-15 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10731096
• 关键词: Address; Aerobic; Affect; Animal Model; Atherosclerosis; Binding; Biological Markers; Blood Vessels; Branched-Chain Amino Acids; Cardiovascular Diseases; Cell physiology; Cells; Cellular Metabolic Process; Complex; Data; Disease; Dose; Energy-Generating Resources; Essential Amino Acids; Family; Gene Expression; Generations; Genes; Genetic Transcription; Glutamates; Glycolysis; HK2 gene; Human; Hydroxylation; Hypertension; Hypoxia; Hypoxia Inducible Factor; Impairment; Isoleucine; Keto Acids; Leucine; Mediating; Metabolic; Metabolism; Molecular; Molecular Weight; Monitor; Oxidative Phosphorylation; Oxygen; PDPK1 gene; Parents; Patients; Phenotype; Platelet-Derived Growth Factor; Process; Procollagen-Proline Dioxygenase; Proteins; Public Health; Pulmonary Hypertension; Reaction; Regulation; Research; Rodent Model; Role; SLC2A1 gene; Smooth Muscle Myocytes; Source; Stimulus; Tertiary Protein Structure; Transaminases; Ubiquitination; VHL protein; Valine; Vascular Smooth Muscle; aerobic glycolysis; alpha ketoglutarate; branched-chain-amino-acid transaminase; c-myc Genes; caldesmon; calponin; cell type; experimental study; insight; mRNA Expression; normoxia; novel; overexpression; platelet-derived growth factor BB; prevent; programs; protein expression; pulmonary arterial hypertension; small molecule; transcription factor; transcriptome

Project Summary. Vascular smooth muscle cells (VSMCs) of a synthetic phenotype meet their energy requirements largely via aerobic glycolysis. Hypoxia-inducible factor-1α (Hif-1α) induces a complex transcriptional program that facilitates glycolysis in the setting of low oxygen tension. In normoxia, Hif-1α undergoes proteasomal degradation via prolyl hydroxylation and ubiquitination. In VSMCs engaged in aerobic glycolysis, however, Hif-1α is stabilized by mechanisms that remain unclear. Preliminary data provide insight into the mechanism of this normoxic stabilization of Hif-1α, showing that Hif-1α-dependent aerobic glycolysis remains the primary source of ATP; that conditioned media obtained from VSMCs contains low-molecular-weight factors that stabilize Hif-1α; and that initial identification of these factors indicates that they comprise the family of branched-chain keto-acids (BCKAs), α-ketoisocaproate (KIC), α- keto-β-methylvalerate (KMV), and α-ketoisovalerate (KIV), derived from their parent branched-chain essential amino acids (BCAAs), leucine, valine, and isoleucine, respectively. Given these preliminary results, the central hypothesis of this proposal is that synthetic VSMCs engage in aerobic glycolysis through the effect of BCKAs on Hif-1α stabilization. To address this hypothesis, we propose the following specific aims: 1) we will examine the determinants of BCKA synthesis in VSMCs and their regulation; 2) we will examine the effect of BCKAs on Hif-1α stabilization and explore potential underlying molecular mechanisms; and 3) we will examine the effect of BCKAs on VSMC phenotype and examine the relationship between phenotype switching and metabolic re-programming. The role of BCKAs on VSMC phenotype and metabolism will also be studied in animal models of pulmonary hypertension. The results of these studies should provide useful insight into molecular mechanisms underlying Hif-1α stabilization and aerobic glycolysis in VSMCs, the role of BCKAs in that process, and the relationship between BCKA- dependent aerobic glycolysis and VSMC phenotype and pathophenotype.

项目摘要：合成表型的血管平滑肌细胞 (VSMC) 满足其能量需求。 缺氧诱导因子 1α（Hif-1α）主要通过有氧糖酵解来诱导复合物。 Hif-1α 在低氧张力环境下促进糖酵解的转录程序。 在参与的 VSMC 中通过脯氨酰羟基化和泛素化经历蛋白酶体降解。 然而，Hif-1α 的有氧糖酵解稳定机制尚不清楚。 深入了解 Hif-1α 的常氧稳定机制，表明 Hif-1α 依赖 有氧糖酵解仍然是从 VSMC 获得的条件培养基的主要来源； 含有稳定 Hif-1α 的低分子量因子以及这些因子的初步鉴定； 表示它们包含支链酮酸 (BCKA)、α-酮异己酸 (KIC)、α- 酮-β-甲基戊酸 (KMV) 和 α-酮异戊酸 (KIV)，源自其母体支链 分别给出了必需氨基酸（BCAA）、亮氨酸、缬氨酸和异亮氨酸。 结果，该提案的中心假设是合成 VSMC 参与有氧糖酵解 通过 BCKA 对 Hif-1α 稳定性的影响 为了解决这一假设，我们提出以下建议。 具体目标：1) 我们将研究 VSMC 中 BCKA 合成的决定因素及其调节；2) 我们将检查 BCKA 对 Hif-1α 稳定的影响并探索潜在的潜在分子 机制；3) 我们将检查 BCKA 对 VSMC 表型的影响并检查 表型转换和代谢重编程之间的关系 BCKA 对 VSMC 的作用。 还将在肺动脉高压动物模型中研究表型和代谢。 这些研究应该为 Hif-1α 稳定化的分子机制提供有用的见解 VSMC 中的有氧糖酵解、BCKA 在该过程中的作用以及 BCKA 与有氧糖酵解之间的关系 依赖的有氧糖酵解和 VSMC 表型和病理表型。