Investigating the role of PHD3 in lipid homeostasis

研究 PHD3 在脂质稳态中的作用

• 批准号: 10304448
• 负责人: MARCIA HAIGIS
• 金额: $ 42.25万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10304448
• 关键词: 5' -AMP-activated protein kinase; Acetyl-CoA Carboxylase; Acute; Affect; Biochemical; Biological Assay; Biological Markers; Catabolism; Cell Energetics; Cell Respiration; Cells; Cues; Dioxygenases; Elements; Energy Metabolism; Enzymes; Exercise; Exercise Tolerance; Family; Fatty Acids; Fatty acid glycerol esters; Goals; Health; Homeostasis; Human; Hydroxylation; Hypoxia Inducible Factor; Kinetics; Knockout Mice; Knowledge; Laboratories; Link; Lipids; Mammals; Mediating; Metabolic; Metabolism; Mitochondria; Modeling; Molecular; Muscle; Muscle Cells; Muscle Fibers; Muscle function; Nutrient; Oxygen; Pathway interactions; Phosphorylation; Physiological; Physiology; Procollagen-Proline Dioxygenase; Proline; Protein Family; Protein Kinase; Proteins; Recombinants; Rest; Role; Signal Pathway; Signal Transduction; Skeletal Muscle; Specificity; Stress; Tertiary Protein Structure; Testing; Therapeutic; Tissues; addiction; arm; exercise capacity; fatty acid metabolism; fatty acid oxidation; hydroxyl group; hypoxia inducible factor 1; improved; in vitro activity; in vivo; innovation; insight; lipid metabolism; member; metabolic fitness; muscle metabolism; muscle physiology; new therapeutic target; novel; oxidation; personalized medicine; prevent; response; therapeutic biomarker

Project Summary Adaptation of cellular metabolism is crucial for maintaining tissue and whole-body homeostasis. In response to low energy or stress, cells activate AMP-activated protein kinase (AMPK) to phosphorylate acetyl-CoA carboxylase (ACC), which increases mitochondrial fatty acid oxidation (FAO) and ATP levels. However, how FAO is downregulated in energy abundance states is not fully understood. As pathways that drive fuel addiction may provide new therapeutic targets or biomarkers for personalized therapy, there is a critical need to identify pathways that regulate metabolic homeostasis. We have discovered a new nutrient-dependent signaling pathway that controls fat oxidation via a little studied member of the prolyl hydroxylase domain protein family, PHD3. PHDs are a family of -ketoglutarate dependent dioxygenases that hydroxylate substrate proline residues and have been linked to fuel switching. We find that PHD3 regulates fatty acid metabolism by hydroxylating acetyl-CoA carboxylase (ACC2), a regulator of mitochondrial FAO. In response to nutrient abundance, PHD3 activates ACC2 to inhibit catabolism of fatty acids. Since ACC2 and PHD3 are highly expressed in oxidative tissues such as skeletal muscle, this proposal will test the hypothesis that the loss of PHD3 in skeletal muscle deregulates energy homeostasis by preventing ACC2 hydroxylation, hence causing constitutive mitochondrial oxidative metabolism. This proposal will test these ideas by: 1) defining the kinetics and determining the specificity by which PHD3-mediated hydroxylation regulates ACC2, 2) defining the role of PHD3 in nutrient signaling in skeletal muscle cell energetics, and 3) testing the physiological relevance of PHD3 in muscle energy homeostasis in vivo. First, we will utilize recombinant purified PHD3 to quantify the kinetic parameters of PHD3 hydroxylation of ACC2 versus HIF1. Next we will examine the specificity of ACC2 hydroxylation by PHD1-3 (Aim 1). We will also examine the effect of PHD3 on cellular metabolism in skeletal muscle cells in response to nutrient cues. We will examine the necessity of AMPK, ACC2, and HIF1 signaling on the metabolic roles of PHD3 (Aim 2). Finally, we will examine the consequences of PHD3 activity on skeletal muscle physiology in a resting state and during acute energy challenge (Aim 3). Our overarching goal is to elucidate the molecular elements of PHD3 signaling that control cellular metabolism and to leverage these findings to ultimately develop therapeutic strategies to promote improved muscle function and metabolic fitness.

项目概要 细胞代谢的适应对于维持组织和全身稳态至关重要。在 对低能量或压力的反应，细胞激活 AMP 激活蛋白激酶 (AMPK) 进行磷酸化 乙酰辅酶A羧化酶 (ACC)，可增加线粒体脂肪酸氧化 (FAO) 和 ATP 水平。然而，粮农组织如何在能源丰富的国家下调监管尚不完全清楚。作为 导致燃料成瘾的途径可能为个性化治疗提供新的治疗靶点或生物标志物 治疗中，迫切需要确定调节代谢稳态的途径。我们有 通过一些研究发现了一种新的营养依赖性信号通路，可以控制脂肪氧化 脯氨酰羟化酶结构域蛋白家族成员，PHD3。 PHD 是 α-酮戊二酸家族 羟基化底物脯氨酸残基并与燃料相关的依赖性双加氧酶 交换。我们发现PHD3通过羟基化乙酰辅酶A羧化酶来调节脂肪酸代谢 (ACC2)，线粒体FAO的调节因子。为了应对营养丰富，PHD3 激活 ACC2 抑制脂肪酸的分解代谢。由于 ACC2 和 PHD3 在氧化组织中高表达 例如骨骼肌，该提案将检验骨骼肌中 PHD3 缺失的假设 通过阻止 ACC2 羟基化来解除能量稳态的调节，从而导致组成性 线粒体氧化代谢。该提案将通过以下方式测试这些想法：1）定义动力学和 确定 PHD3 介导的羟基化调节 ACC2 的特异性，2) 定义作用 PHD3 在骨骼肌细胞能量学营养信号传导中的作用，以及 3) 测试生理学 PHD3 在体内肌肉能量稳态中的相关性。首先，我们将利用重组纯化 PHD3 来量化 ACC2 与 HIF1α 的 PHD3 羟基化动力学参数。接下来我们将 通过 PHD1-3 检查 ACC2 羟基化的特异性（目标 1）。我们还将检查效果 PHD3 对骨骼肌细胞响应营养信号的细胞代谢的影响。我们将检查 AMPK、ACC2 和 HIF1α 信号传导对 PHD3 代谢作用的必要性（目标 2）。最后，我们将 检查静息状态和运动期间 PHD3 活性对骨骼肌生理学的影响 严重的能源挑战（目标 3）。我们的首要目标是阐明 PHD3 的分子元件 控制细胞代谢的信号传导并利用这些发现最终开发 促进改善肌肉功能和代谢健康的治疗策略。