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.

血管通透性过高被公认为是脓毒症引发的器官衰竭和患者死亡的原因。死亡。尽管经过了数十年的深入研究，仍然没有针对此类血管的特异性治疗方法。到目前为止的泄漏。这部分是由于对底层中介和机制的了解不完整。脓毒症引起内皮屏障完整性的破坏。目前，大多数前期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。很少有研究表明研究了冠状血管渗漏，这是人类患者心力衰竭和死亡的主要原因败血性休克。我们最近发现脂质运载蛋白 10 (Lcn10) 的表达，这是一个尚未被充分表征的成员。脂质运载蛋白超家族在内毒素 LPS 和盲肠结扎的心脏中显着下调与对照组相比，穿刺（CLP）治疗的小鼠。有趣的是，进一步的细胞类型特异性分析表明 Lcn10 的这种减少并未发生在心肌细胞或成纤维细胞中，而仅发生在心脏内皮细胞中细胞（EC）。这些令人信服的数据表明 Lcn10 在脓毒症引起的心血管渗漏中具有潜在作用。事实上，使用全局基因敲除小鼠模型，我们观察到 Lcn10 的缺乏显着增强了 LPS- 与 LPS 治疗相比，诱导血管渗漏，导致更大的心脏抑制和更高的死亡率野生型对照小鼠。相比之下，在 EC 中体外强制过度表达 Lcn10 显示出更大的抗性相对于对照细胞，LPS 诱导的单层渗漏。通过 RNA 测序和 RT- 进行初步机制分析 qPCR 显示 EC 中 Lcn10 的内源性和外源性升高均导致 EC 中 Lcn10 的显着上调。弹弓同源物 1 (Ssh1)。 Ssh1 是一种磷酸酶，已知可以去磷酸化，从而激活 Cofilin，这是一个关键肌动蛋白结合蛋白，在控制肌动蛋白丝动力学中发挥重要作用。最重要的是， ECs 中 Ssh1 的敲低抵消了 Lcn10 诱导的 LPS 暴露后单层渗漏的减少。基于根据这些初步数据，我们假设 Lcn10 对于预防脓毒症引起的血管渗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）使用全局模型定义 Lcn10 在多种微生物败血症期间血管通透性中的精确作用敲除和 EC 特异性 Lcn10 转基因小鼠模型； 2) 确定 Lcn10- 的机制引起的心血管渗漏减少取决于 Ssh1 介导的肌动蛋白动力学，使用交叉通过将 EC 特异性 Lcn10 转基因小鼠与 Ssh1-KO 小鼠交配来建立小鼠模型； 3) 调查重组 Lcn10 蛋白在治疗脓毒症中的治疗潜力。拟议的研究预计将确定 Lcn10 是一种有效的新型血管通透性调节剂和针对脓毒症引起的新保护剂心脏衰竭。如果完成，该提案的结果可能会提供新的治疗选择，以减少脓毒症期间的血管渗漏，有望提高脓毒症患者的生存率。