A role for autophagy in gut barrier disruption after alcohol and traumatic injury

自噬在酒精和创伤性损伤后肠道屏障破坏中的作用

• 批准号: 9122037
• 负责人: Adam Hammer
• 金额: $ 2.86万
• 依托单位: LOYOLA UNIVERSITY CHICAGO
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9122037
• 关键词: 3-methyladenine; Accounting; Acute; Alcohol abuse; Alcoholic Intoxication; Alcoholic Liver Diseases; Alcohols; Animals; Apoptosis; Autophagocytosis; Autophagosome; Bacteria; Bacterial Translocation; Blood; Blood alcohol level measurement; CCL2 gene; Caring; Cell Proliferation; Cell physiology; Cessation of life; Chloroquine; Clinical Research; Data; Epithelial Cell Proliferation; Epithelial Cells; Ethanol; Healed; Homeostasis; Hospitalization; Image; In Situ Nick-End Labeling; Infection; Inflammation Mediators; Inflammatory; Inflammatory Bowel Diseases; Inflammatory Response; Inflammatory disease of the intestine; Injury; Interleukin-18; Interleukin-6; Intestinal Diseases; Intestines; Knock-out; Knockout Mice; LAMP-1; Laboratories; Length of Stay; Light; Lysosomes; Membrane; Messenger RNA; Microtubules; Modeling; Morbidity - disease rate; Multiple Organ Failure; Operative Surgical Procedures; Patients; Phase; Play; Proteins; Recovery; Reporting; Risk Factors; Role; Sepsis; Serum; Signal Pathway; Testing; Therapeutic Intervention; Tight Junctions; Time; Tissues; Transcript; Transmission Electron Microscopy; Trauma; Traumatic injury; Validation; Western Blotting; Work; alcohol exposure; claudin-1 protein; experience; fluorescein isothiocyanate dextran; fluorescence imaging; gastrointestinal; healing; heat injury; high risk; improved; in vivo; inflammatory marker; inhibition of autophagy; inhibitor/antagonist; insight; mortality; mouse model; occludin; outcome forecast; pathogen; premature; protein expression; public health relevance; research study; response

 DESCRIPTION (provided by applicant): Alcohol abuse remains one of the leading causes of morbidity and premature death in the world, and is a major risk factor associated with traumatic injury. Thermal injury is a major trauma that accounts for 40,000 hospitalizations annually, and over 50% of these patients have detectable blood alcohol (ethanol) levels at the time of admittance. In addition to the many complications associated directly with traumatic injury, disruptions of the gastrointestinal barrier and function frequently occur. This compromise of the gut barrier and subsequent translocation of bacteria and other pathogens can result in sepsis, multiple organ failure, and death. Our laboratory has previously shown decreases in gut epithelial cell proliferation, increases in inflammatory mediators, and bacterial translocation across the intestinal barrier when alcohol intoxication is present at the time of traumatic thermal injury. However, the mechanism by which gut inflammation and healing are perturbed following the combined insult is currently unknown. Autophagy is a highly conserved cellular process, and has been shown to be a key regulator of cellular proliferation and apoptosis, which are integral to maintaining gut homeostasis. Changes in autophagy may disrupt the inflammatory response and barrier integrity within the intestines. Thus, we hypothesize that the accumulation of autophagosomes in intestinal epithelial cells contributes to gut inflammation and barrier leakiness following combined alcohol and thermal injury. We have shown that the combined insult leads to an increase in LC3II/LC3I ratio. We have also shown that increased autophagy and inflammation markers can be rescued by treatment with the autophagy inhibitor 3- methyladenine given at the time of insult, further suggesting a role for autophagy in response to gut injury. The present study will investigate the role autophagy plays in inflammation and gut barrier leakiness following combined injury. Aim 1 will characterize the changes in autophagic flux following combined injury in intestinal epithelial cells, focusing on hallmark proteins within the autophagy signaling pathway. Aim 2 will determine if 3-MA treatment and/or LC3β-knockout suppress autophagic flux and restore tight junction protein expression and reduce acute inflammation and gut leakiness following combined injury. We expect this study will illuminate potential translational contributions to patient treatment to improve prognosis and survival following traumatic injury in the presence of alcohol intoxication.

 描述（由申请人提供）：酒精滥用仍然是世界上发病率和过早死亡的主要原因之一，是与创伤性损伤相关的主要风险因素。热损伤是一种主要的创伤，每年有40，000人住院，其中超过50%的患者在入院时血液中有可检测到的酒精（乙醇）水平。除了与创伤性损伤直接相关的许多并发症之外，经常发生胃肠屏障和功能的破坏。肠道屏障的这种损害以及随后的细菌和其他病原体的移位可导致败血症、多器官衰竭和死亡。我们的实验室先前已经表明，当创伤性热休克时存在酒精中毒时，肠上皮细胞增殖减少，炎症介质增加，细菌移位穿过肠屏障。 损伤然而，肠道炎症和愈合在联合损伤后受到干扰的机制目前尚不清楚。自噬是一种高度保守的细胞过程，并且已被证明是细胞增殖和凋亡的关键调节剂，细胞增殖和凋亡是维持肠道稳态不可或缺的。自噬的变化可能会破坏肠道内的炎症反应和屏障完整性。因此，我们假设自噬体在肠上皮细胞中的积累有助于酒精和热损伤联合后的肠道炎症和屏障渗漏。我们已经表明，组合的损伤导致LC 3 II/LC 3 I比率的增加。我们还表明，增加的自噬和炎症标志物可以通过在损伤时给予自噬抑制剂3-甲基腺嘌呤的治疗来挽救，进一步表明自噬在响应肠道损伤中的作用。本研究将探讨自噬在复合伤后炎症和肠屏障渗漏中的作用。目的1将描述肠上皮细胞联合损伤后自噬通量的变化，重点关注肠上皮细胞内的标志蛋白， 自噬信号通路。目的2将确定3-MA治疗和/或LC 3 β-敲除是否抑制自噬通量并恢复紧密连接蛋白表达并减少联合损伤后的急性炎症和肠渗漏。我们希望这项研究将阐明潜在的翻译贡献，病人治疗，以改善预后和生存创伤后，在酒精中毒的存在。