Lcn10 in Sepsis-Induced Vascular Leakage and Heart Failure

Lcn10 在脓毒症引起的血管渗漏和心力衰竭中的作用

基本信息

批准号：
10532242
负责人：
Guo-Chang Fan
金额：
$ 66.61万
依托单位：
UNIVERSITY OF CINCINNATI
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-12-01 至 2025-11-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10532242
关键词：
Actin-Binding Protein Actins Acute Respiratory Distress Syndrome Adherens Junction Animals Antibiotic Therapy Antisepsis Blood Vessels Blood capillaries Cardiac Cardiac Edema Cardiac Myocytes Cardiovascular system Cause of Death Cell physiology Cells Cessation of life Coronary Critical Care Critical Illness Cytoskeleton Data Development Edema Endothelial Cells Endothelium Endotoxins Extravasation Fibroblasts Future Heart Heart Injuries Heart failure Homologous Gene Human In Vitro Inflammatory Injections Intensive Care Units Intercellular Junctions Knock-out Knockout Mice Knowledge Leucocytic infiltrate Link Liquid substance Lung Measures Mediating Mediator Microfilaments Mission Monitor Mus Myocardial Myocardial dysfunction Operative Surgical Procedures Organ failure Partner in relationship Pathway interactions Patients Permeability Phosphoric Monoester Hydrolases Physiology Play Protein Dephosphorylation Protein Secretion Proteins Public Health Pulmonary Edema RNA analysis Recombinants Regulation Research Resistance Resuscitation Role Sepsis Septic Shock Small Interfering RNA Survival Rate Testing Therapeutic Tight Junctions Time Tissues Transgenic Mice Translating United States National Institutes of Health Up-Regulation Vascular Permeabilities Wild Type Mouse Work animal mortality autocrine cardiac depression cecal ligation puncture cell type cofilin comparison control disability heart function improved in vivo knock-down member monolayer mortality mouse model novel novel therapeutics overexpression polymicrobial sepsis potential biomarker pre-clinical septic septic patients survival outcome tool transcriptome sequencing translational study

项目摘要

Vascular hyperpermeability is well-recognized to be responsible for sepsis-triggered organ failure and patient mortality. Despite decades of intensive study, there is no specific treatment available for targeting such vascular leakage thus far. This is due in part to the incomplete knowledge of the mediators and mechanisms underlying sepsis-elicited disruption of the endothelial barrier integrity. At present, most prior work has focused on pulmonary vascular leakage that results in lung edema and acute respiratory distress syndrome. Few studies have investigated coronary vascular leakage, which is a major cause of heart failure and death in human patients with septic shock. We recently discovered that expression of lipocalin 10 (Lcn10), a poorly characterized member of the lipocalin superfamily, was significantly downregulated in the hearts of both endotoxin LPS- and cecal ligation- puncture (CLP)-treated mice, compared to their controls. Interestingly, further cell-type specific analysis showed that such reduction of Lcn10 did not occur in either cardiomyocytes or fibroblasts but only in cardiac endothelial cells (ECs). These compelling data implicate a potential role of Lcn10 in sepsis-induced cardiovascular leakage. Indeed, using a global knockout mouse model, we observed that deficiency of Lcn10 significantly augmented LPS- induced vascular leakage, leading to greater cardiac depression and higher mortality, compared to LPS-treated wild-type control mice. By contrast, in vitro forced overexpression of Lcn10 in ECs showed greater resistance to LPS-induced monolayer leak relative to control cells. An initial mechanistic analysis by RNA-sequencing and RT- qPCR showed that both endogenous and exogenous elevation of Lcn10 in ECs caused significant upregulation of slingshot homolog 1 (Ssh1). Ssh1 is a phosphatase known to dephosphorylate and thus activate Cofilin, a key actin-binding protein that plays an essential role in controlling actin filament dynamics. Most importantly, knockdown of Ssh1 in ECs offsets the Lcn10-induced reduction of monolayer leakage upon LPS exposure. Based on these preliminary data, we hypothesize that Lcn10 is critical for protecting against sepsis-induced vascular leak via the activation of the Ssh1-Cofilin pathway. This hypothesis will be tested by pursuing three specific aims: 1) Define the precise role of Lcn10 in vascular permeability during polymicrobial sepsis, using a global knockout and an EC-specific Lcn10-transgenic mouse model; 2) Identify the mechanism by which Lcn10- elicited reduction of cardiovascular leakage is dependent on Ssh1-mediated actin dynamics, using a cross mouse model by mating EC-specific Lcn10-transgenic mice with Ssh1-KO mice; and 3) Investigate the therapeutic potential of recombinant Lcn10 protein in treating sepsis. The proposed studies are expected to identify Lcn10 as a potent and novel regulator of vascular permeability and a new protector against sepsis-induced heart failure. If completed, the findings from this proposal are likely to provide new therapeutic options for reducing vascular leakage during sepsis, with the hope of improving the survival of septic patients.

血管过敏性已被众所周知，以使败血症触发的器官衰竭和患者负责死亡。尽管进行了数十年的深入研究，但尚无针对这种血管的特定治疗方法到目前为止泄漏。这部分是由于对调解人和机制的不完整知识败血症的内皮屏障完整性的破坏。目前，大多数先前的工作都集中在肺血管渗漏导致肺水肿和急性呼吸窘迫综合征。很少有研究研究了冠状动脉血管泄漏，这是人类患者心力衰竭和死亡的主要原因败血性冲击。我们最近发现，Lipocalin 10（LCN10）的表达是一个不良特征的成员 Lipocalin超家族在内毒素LPS-和CECAL连接的心脏中显着下调与对照相比，穿刺（CLP）处理的小鼠。有趣的是，进一步的细胞类型特异性分析显示在心肌细胞或成纤维细胞中，这种LCN10的这种降低均未发生，而仅在心脏内皮中细胞（EC）。这些引人注目的数据暗示了LCN10在败血症诱导的心血管泄漏中的潜在作用。实际上，使用全局敲除小鼠模型，我们观察到LCN10的缺乏显着增加了LPS- 与LPS治疗相比野生型对照小鼠。相比之下，EC中LCN10的体外强制表达表现出更大的抵抗力 LPS诱导的单层泄漏相对于对照细胞。通过RNA测序和RT-进行初步机械分析 QPCR表明，EC中LCN10的内源性和外源性升高都引起了显着上调弹弓同源物1（SSH1）。 SSH1是一种磷酸酶，已知可以脱磷酸化，从而激活Cofilin，键是一种钥匙肌动蛋白结合蛋白在控制肌动蛋白丝动力学中起着至关重要的作用。最重要的是， ECS中SSH1的敲低抵消了LCN10诱导的LPS暴露时单层泄漏的减少。基于在这些初步数据上，我们假设LCN10对于防止败血症引起的血管泄漏至关重要通过激活SSH1-Cofilin途径。该假设将通过追求三个具体目标来检验：1）使用全局敲除和EC特异性LCN10-转基因小鼠模型； 2）确定LCN10-的机制使用十字通过与SSH1-KO小鼠交配EC特异性LCN10-转基因小鼠的小鼠模型； 3）调查重组LCN10蛋白在治疗败血症中的治疗潜力。拟议的研究预计将将LCN10识别为有效且新颖的血管渗透调节剂，并且是针对败血症诱导的新保护者心脏衰竭。如果完成，该提案的发现可能会提供新的治疗选择来减少败血症期间的血管泄漏，希望改善化粪池患者的存活率。