The Role of Glutamine Metabolism for P. gingivalis-Induced Non-Canonical Autophagy in Epithelial Cells

谷氨酰胺代谢对牙龈卟啉单胞菌诱导的上皮细胞非典型自噬的作用

基本信息

批准号：
10537625
负责人：
Bridgette Frances Wellslager
金额：
$ 4.76万
依托单位：
MEDICAL UNIVERSITY OF SOUTH CAROLINA
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：
2022-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10537625
关键词：
Affect Amino Acids Anaerobic Bacteria Antioxidants Autophagocytosis Autophagosome Bacteria Biogenesis Biology Cell physiology Cells Chronic Chronic Disease Complex Coupling Critical Pathways Data Degradation Pathway Dependence Development Disease Elements Endoplasmic Reticulum Environment Epithelial Epithelial Cells Event Fellowship Fostering Foundations GTP-Binding Protein alpha Subunits, Gs Gene Proteins Generations Gingiva Glutamine Glutathione Goals Homeostasis Human Immune Impairment Infection Knowledge Life Lipids Maintenance Mediating Membrane Metabolic Metabolic Pathway Metabolism Microtubule-Associated Proteins Molecular Mucous Membrane Oral Oral cavity Oral health Oral mucous membrane structure Oxidation-Reduction Oxidative Stress Pathway interactions Periodontitis Porphyromonas gingivalis Production Protein Isoforms Publishing Recycling Regulation Research Role Route Scientist Secure Testing Time Training Ultraviolet Rays Vacuole Variant amino acid metabolism antimicrobial cellular pathology combat dysbiosis glutathione peroxidase microbial microorganism molecular phenotype new therapeutic target novel novel therapeutics oral biology pathobiont pathogen radiation resistance recruit therapeutically effective

项目摘要

Growing evidence underlines that Glutamine (Gln) metabolism can influence key metabolic and autophagic cellular events. Porphyromonas gingivalis (P.g) is a major periodontopathic, fastidious, pathobiont and successful colonizer of gingival mucosa, which has recently been identified to induce a special form of autophagy in human gingival epithelial cells (GECs). While GECs function as an intrinsically important first line of immune defense of the gingiva, GECs can be exploited by P.g for securing a successful persistence niche in the oral mucosa and a potential systemic dissemination route. Despite the growing evidence pinpointing that altered Gln metabolism can contribute to cellular pathologies, knowledge gaps remain regarding how host Gln metabolism could be influenced by bacteria to regulate host redox homeostasis and potentially promote bacterial survival in the GECs. Recently, we discovered that P.g steadily increases robust Glutathione (GSH) production in GECs to combat host-mediated oxidative stress-driven pathogen clearance. Our novel findings, for the first time, show that P.g infection alters host Gln metabolism, a component of GSH synthesis, in GECs. In addition, we recently demonstrated that P.g induces a pro-bacterial form of autophagy in GECs, where Endoplasmic Reticulum-rich (ER)/Microtubule-associated protein 1A/1B-light chain 3 (LC3) double membrane autophagosomes act as replicative niches for P.g and protect the bacteria from antimicrobial degradation pathways. Our novel data shows that the biogenesis and maintenance of these P.g-containing autophagosomes is dependent on the critical redox molecule, Glutathione Peroxidase 1 (GpX1). The dependency on GpX1 can be markedly altered by increasing free Gln levels in GECs' cellular environment. Thus, our overarching hypothesis for this proposal is that P.g alters host Gln metabolism in GECs to maintain host redox homeostasis and specifically contributes to the biogenesis of a GpX1-driven, pro-bacterial form of autophagy. Two Specific Aims are proposed to test this hypothesis. Aim 1 will characterize the phenotypic molecular events occurring during P.g infection that specifically associate with host cell Gln metabolism and the host cell redox state, allowing for the intracellular survival of P.g in GECs. Aim 2 will mechanistically determine the molecular interactome involved in P.g-induced autophagy through the modulation of host Gln metabolism in GECs. These collectively will identify what elements of the Gln metabolic pathways are critical for the autophagic survival of P.g in GECs, and will elucidate the specific molecular machineries involved in pro-bacterial autophagy driven by changes in host Gln metabolism upon P.g infection. Overall, this proposal will contribute to the identification of novel targeted therapeutic strategies to control the chronic intracellular colonization of P.g in the oral mucosa and beyond. Receiving the F31 Fellowship for this proposal will further the applicant's research goals, critically contribute to her training in the field of Oral Biology, and will foster her unique development as an oral health academic scientist.

越来越多的证据强调谷氨酰胺 (Gln) 代谢可以影响关键的代谢和自噬细胞事件。牙龈卟啉单胞菌 (P.g) 是一种主要的牙周病、挑剔、致病生物，牙龈粘膜的成功定植者，最近已被鉴定可诱导一种特殊形式的人牙龈上皮细胞（GEC）中的自噬。虽然 GEC 发挥着本质上重要的第一线作用牙龈的免疫防御，GEC 可以被 P.g 用来确保成功的持久性生态位口腔粘膜和潜在的全身传播途径。尽管越来越多的证据表明谷氨酰胺代谢的改变可能导致细胞病理，但关于宿主谷氨酰胺如何发挥作用的知识差距仍然存在新陈代谢可能受到细菌的影响来调节宿主氧化还原稳态并可能促进 GEC 中细菌的存活率。最近，我们发现 P.g 稳步增加强效谷胱甘肽 (GSH) GEC 中的生产可对抗宿主介导的氧化应激驱动的病原体清除。我们的新发现，首次表明，P.g 感染会改变 GEC 中宿主 Gln 代谢（GSH 合成的一个组成部分）。此外，我们最近证明 P.g 在 GEC 中诱导亲细菌形式的自噬，其中富含内质网 (ER)/微管相关蛋白 1A/1B-轻链 3 (LC3) 双膜自噬体充当 P.g 的复制生态位并保护细菌免遭抗菌药物降解途径。我们的新数据表明这些含 P.g 的生物发生和维持自噬体依赖于关键的氧化还原分子谷胱甘肽过氧化物酶 1 (GpX1)。这通过增加 GEC 细胞环境中的游离 Gln 水平，可以显着改变对 GpX1 的依赖性。因此，我们对该提议的总体假设是 P.g 改变 GEC 中的宿主 Gln 代谢，维持宿主氧化还原稳态，特别有助于 GpX1 驱动的亲细菌的生物发生自噬的形式。提出了两个具体目标来检验这一假设。目标 1 将描述 P.g感染期间发生的与宿主细胞Gln特异性相关的表型分子事件代谢和宿主细胞氧化还原状态，允许 P.g 在 GEC 中存活。目标2将通过机制确定参与 P.g 诱导自噬的分子相互作用组 GEC 中宿主 Gln 代谢的调节。这些共同将确定谷氨酰胺代谢的哪些元素途径对于 GEC 中 P.g 的自噬存活至关重要，并将阐明特定的分子参与亲细菌自噬的机制是由 P.g 感染后宿主 Gln 代谢的变化驱动的。总体而言，该提案将有助于确定新的靶向治疗策略来控制 P.g 在口腔粘膜及其以外的慢性细胞内定植。为此获得 F31 奖学金提案将进一步推进申请人的研究目标，对她在口腔领域的培训做出重要贡献生物学，并将促进她作为口腔健康学术科学家的独特发展。