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The role of glycolysis and glucose oxidation in hematopoiesis

糖酵解和葡萄糖氧化在造血中的作用

基本信息

批准号：
10340134
负责人：
Michalis Agathocleous
金额：
$ 40.36万
依托单位：
UT SOUTHWESTERN MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-02-01 至 2026-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10340134
关键词：
Ablation Acetyl Coenzyme A Address B-Lymphocytes Biochemical Bone Marrow Bone Marrow Cells Carbon Cell Respiration Cells Cellular Metabolic Process Cellular biology Citric Acid Cycle Dependence Embryo Enzymes Equilibrium Erythropoiesis Fermentation Frequencies Gatekeeping Genetic Glucose Glutathione Glycolysis Hematopoiesis Hematopoietic Hematopoietic System Hematopoietic stem cells Homeostasis Impairment In Vitro Individual Isotopes Label Lactate Dehydrogenase Measures Mediating Metabolic Metabolic Pathway Metabolism Methods Myelogenous Myeloid Cells NADH Natural regeneration Nature Neurons Nutrient Oxidation-Reduction Pathway interactions Positioning Attribute Production Protein Isoforms Pyruvate Role Specificity Stable Isotope Labeling T-Lymphocyte Testing Textbooks Thymus Gland Tissues Work cell type experimental study flexibility glucose metabolism hematopoietic differentiation in vivo innovation metabolome metabolomics mouse model nerve stem cell novel nutrient metabolism oxidation progenitor pyruvate dehydrogenase stable isotope stem cell function stem cells thymic regeneration

项目摘要

PROJECT SUMMARY: The metabolism of nutrients has been studied using unfractionated tissues, or in vitro. An unresolved question is how nutrients are metabolized by stem cells in vivo. Our understanding of stem cell metabolism has been limited by the fact that metabolomics typically requires millions of cells, while stem cells are rare. We developed methods to profile the metabolome and to trace stable isotope labeled nutrients in hematopoietic stem cells (HSCs) and other rare cell types purified from tissues. We found that T cell progenitors in the thymus are glucose avid as compared to HSCs, myeloid and B cell restricted progenitors, in contrast to the prevailing view that HSCs are more glycolytic than hematopoietic progenitors. Stable isotope tracing experiments showed that in the bone marrow but not the thymus, glycolysis and the TCA cycle are disconnected. Hematopoietic loss of pyruvate dehydrogenase (PDH), the gatekeeper enzyme that connects glycolysis to the TCA cycle, reduced the number of double positive (DP) T cell progenitors but did not affect HSCs or other hematopoietic cell types. Loss of PDH paradoxically did not impair the TCA cycle in the thymus, but caused accumulation of pyruvate and aberrant redox balance. Cells which do not oxidize glucose in the TCA cycle are classically thought to ferment glucose through glycolysis to lactate via lactate dehydrogenase (LDH). Hematopoietic loss of LDHA, one of the two LDH isoforms, impaired development of erythroid progenitors but not HSCs, T cell progenitors or other restricted hematopoietic progenitors. The cell type specificity in the requirement of LDH and PDH in the hematopoietic system raises the question of why different stem or progenitor cell types choose to use LDH-mediated fermentation or PDH-mediated oxidation in vivo. This application’s objective is to systematically dissect the role of glycolytic as compared to oxidative metabolism in HSCs and restricted progenitors. Our hypothesis is that T cell progenitors require oxidation of glucose via PDH to regulate pyruvate levels and redox homeostasis, in contrast to HSCs, myeloid and B cell progenitors which are metabolically flexible. In Aim 1 we will test the metabolic mechanisms which mediate the effects of PDH on DP cells. In Aim 2 we will determine the cellular and metabolic effects of blocking LDHA/B or PDH alone or in combination in HSCs and restricted progenitors. In Aim 3 we will investigate the role of LDHA/B and PDH in hematopoietic and thymopoietic regeneration. These experiments will identify the contribution of glucose to metabolite pools in HSCs and progenitors in vivo, systematically test the idea that HSCs are glycolytic, and identify mechanisms by which central carbon metabolism regulates hematopoietic differentiation and regeneration. More generally our experiments will address a fundamental metabolic question by testing if stem or progenitor cells in vivo switch between glucose fermentation or oxidation, as is the textbook view, or if some cell types in vivo tolerate the loss of both major glucose catabolic pathways.

项目总结: