MAM Proteins in Lung Vascular Injury

MAM 蛋白在肺血管损伤中的作用

基本信息

批准号：
10680808
负责人：
Fabeha Fazal
金额：
$ 69.49万
依托单位：
UNIVERSITY OF ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-05-01 至 2027-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10680808
关键词：
Acute Lung Injury Acute Respiratory Distress Syndrome Admission activity Affect Agonist American Blood Vessels COVID-19 Case Study Clinical Collaborations Communication Complementary DNA Critical Illness Development Dose Endoplasmic Reticulum Endothelial Cells Endothelium Functional disorder GRP75 GRP78 gene Gene Transfer Goals Human ITPR1 gene In Vitro Inflammasome Inflammation Mediators Inflammatory Injury Intensive Care Knockout Mice Life Link Liposomes Lung Mediating Mediator Membrane Membrane Proteins Mitochondria Molecular Chaperones Mus Outcome Pathogenesis Patients Permeability Pharmaceutical Preparations Plasma Preventive Proteins Public Health Respiratory Failure Rest Role Sepsis Signal Transduction Site Supportive care Testing Therapeutic Thrombin cecal ligation puncture chelation clinically relevant design effective therapy improved in vivo inhibitor insight lung injury lung vascular injury mitochondrial dysfunction mortalin mortality mouse model novel novel therapeutic intervention overexpression prevent response sepsis induced acute lung injury septic septic patients small hairpin RNA therapeutic target uptake vascular inflammation

项目摘要

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a life-threatening condition which affects ~200,000 Americans each year with 10-15% of intensive care admissions and a mortality rate of ~ 25-40%. Sepsis is a prominent extrapulmonary cause of ALI in humans. Nearly 50% of patients with severe sepsis develop ALI/ARDS. All current therapies for ALI/ARDS still rely on supportive care; thus, there is an urgent need to develop new treatment strategies for ALI/ARDS that are safe and effective. Because endothelial cell (EC) barrier dysfunction is an early and critical component of ALI in sepsis, a better understanding of the mechanisms of EC permeability is key to developing effective therapy for ALI. The goal of this proposal is to understand how aberrant communication between endoplasmic reticulum (ER) and mitochondrion in sepsis, mediated by ER chaperone BiP/GRP78 and mitochondrial (MITO) chaperone Mortalin/GRP75, promotes EC barrier dysfunction to cause ALI. Our hypothesis is that a close interaction and functional cooperation between BiP/GRP78 and Mortalin/GRP75 at the MAMs (mitochondrial associated endoplasmic reticulum membranes) serves to increase cytosolic Ca2+ and ER-MITO contact sites to cause mitochondrial Ca2+ overload and inflammasome activation, leading to lung vascular injury in sepsis. We further hypothesize that targeting BiP/GRP78 and Mortalin/GRP75 in combination may prove a superior therapeutic approach against sepsis-induced ALI and mortality. The proposal is based on our novel findings that BiP/GRP78 and Mortalin/GRP75 are key regulators of Ca2+ signaling and ER-MITO contact sites in EC and silencing BiP/GRP78 or Mortalin/GRP75 each prevents EC barrier disruption caused by plasma from septic patients and other clinically relevant edemagenic agonists such as thrombin and LPS. BiP/GRP78 is induced in septic lung and overexpressing BiP/GRP78 in the resting lung endothelium is sufficient to cause lung injury in mice. Moreover, inhibiting BiP/GRP78 or Mortalin/GRP75 each mitigates ALI in mice. Importantly, combined inhibition of BiP/GRP78 or Mortalin/GRP75 is far more effective (requires ~5-fold less dose of BiP/GRP78 or Mortalin/GRP75 inhibitors) in improving survival in mice with sepsis. The proposal will address the following aims. Aim 1 will determine the role of BiP/GRP78 and Mortalin/GRP75 in regulating cytosolic Ca2+ to cause EC permeability. Aim 2 will determine the role of BiP/GRP78 and Mortalin/GRP75 in increasing ER-MITO contact sites and mitochondrial Ca2+ uptake to cause mitochondrial dysfunction and inflammasome activation leading to EC permeability. Aim 3 will determine (i) the contribution of endothelial BiP/GRP78 and Mortalin/GRP75 in causing lung injury, and (ii) assess the therapeutic potential of inhibiting BiP/GRP78 and Mortalin/GRP75 together against sepsis-induced ALI and mortality. These studies will provide valuable insight into the ER-MITO communication and its relevance in the pathogenesis of ALI and may lead to development of a safe and efficacious therapeutic strategy that relies on combined inhibition of BiP/GRP78 and Mortalin/GRP75 to control ALI and improve survival in sepsis.

急性肺损伤（ALI）/急性呼吸窘迫综合征（ARDS）是一种危及生命的疾病，影响每年约有 200,000 名美国人接受重症监护，死亡率约为 25-40%。脓毒症是人类 ALI 的一个重要肺外原因。近50%的患者患有严重败血症发展 ALI/ARDS。目前所有针对 ALI/ARDS 的治疗方法仍然依赖于支持性护理；因此，迫切需要开发安全有效的 ALI/ARDS 新治疗策略。因为内皮细胞（EC）屏障功能障碍是脓毒症 ALI 的早期且关键的组成部分，更好地了解其机制 EC 通透性的研究是开发有效治疗 ALI 的关键。该提案的目标是了解如何脓毒症中内质网 (ER) 和线粒体之间的异常通讯，由 ER 介导伴侣 BiP/GRP78 和线粒体 (MITO) 伴侣 Mortalin/GRP75，促进 EC 屏障功能障碍导致 ALI。我们的假设是 BiP/GRP78 和 MAM（线粒体相关内质网膜）上的 Mortalin/GRP75 有助于增加胞浆 Ca2+ 和 ER-MITO 接触位点导致线粒体 Ca2+ 过载和炎性体激活，导致脓毒症中的肺血管损伤。我们进一步假设针对 BiP/GRP78 和 Mortalin/GRP75 联合用药可能是针对脓毒症引起的 ALI 和死亡率的一种更好的治疗方法。这该提案基于我们的新发现，即 BiP/GRP78 和 Mortalin/GRP75 是 Ca2+ 信号传导的关键调节因子 EC 中的 ER-MITO 接触位点和沉默 BiP/GRP78 或 Mortalin/GRP75 均可以防止 EC 屏障由脓毒症患者的血浆和其他临床相关的水肿激动剂引起的破坏，例如凝血酶和脂多糖。 BiP/GRP78 在脓毒症肺中被诱导，并在静息肺中过度表达 BiP/GRP78 内皮足以引起小鼠肺损伤。此外，分别抑制 BiP/GRP78 或 Mortalin/GRP75 减轻小鼠的 ALI。重要的是，BiP/GRP78 或 Mortalin/GRP75 的联合抑制要有效得多（需要约 5 倍剂量的 BiP/GRP78 或 Mortalin/GRP75 抑制剂）提高脓毒症小鼠的存活率。该提案将实现以下目标。目标 1 将确定 BiP/GRP78 和 Mortalin/GRP75 的作用调节细胞质 Ca2+ 导致 EC 通透性。目标 2 将确定 BiP/GRP78 的作用和 Mortalin/GRP75 增加 ER-MITO 接触位点和线粒体 Ca2+ 摄取，导致线粒体功能障碍和炎症小体激活导致 EC 通透性。目标 3 将确定 (i) 的贡献内皮 BiP/GRP78 和 Mortalin/GRP75 引起肺损伤，以及 (ii) 评估其治疗潜力抑制 BiP/GRP78 和 Mortalin/GRP75 共同对抗脓毒症引起的 ALI 和死亡率。这些研究将为 ER-MITO 通讯及其与 ALI 发病机制的相关性提供有价值的见解，并可能导致开发出一种安全有效的治疗策略，该策略依赖于联合抑制 BiP/GRP78 和 Mortalin/GRP75 可控制 ALI 并提高脓毒症患者的生存率。