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

• 批准号: 10340332
• 负责人: Guo-Chang Fan
• 金额: $ 69.85万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 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/10340332
• 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; Infiltration; Inflammatory; Injections; Intensive Care Units; Intercellular Junctions; Knock-out; Knockout Mice; Knowledge; Lead; Leukocytes; Link; Liquid substance; Lung; Measures; Mediating; Mediator of activation protein; Microfilaments; Mission; Monitor; Mus; Myocardial; Myocardial dysfunction; Operative Surgical Procedures; Organ failure; Partner in relationship; Pathway interactions; Patients; Permeability; Phosphoric Monoester Hydrolases; Physiology; Play; 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; base; cardiac depression; cecal ligation puncture; cell type; cofilin; 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

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触发的器官衰竭和患者死亡的原因。 mortality.尽管进行了数十年的深入研究，但仍没有针对此类血管病变的特异性治疗方法。 到目前为止，泄漏。这部分是由于对调解人及其机制的了解不全面 脓毒症引起的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 研究了冠状动脉血管渗漏，这是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（Lcn 10）的表达， 脂质运载蛋白超家族，在内毒素LPS和盲肠结扎的心脏中均显著下调， 穿刺（CLP）治疗的小鼠相比，其控制。有趣的是，进一步的细胞类型特异性分析显示 这种Lcn 10的减少并不发生在心肌细胞或成纤维细胞中，而只发生在心脏内皮细胞中， 细胞（EC）。这些令人信服的数据暗示了Lcn 10在脓毒症诱导的心血管渗漏中的潜在作用。 事实上，使用整体敲除小鼠模型，我们观察到Lcn 10的缺乏显著增加了LPS-1的表达。 诱导的血管渗漏，导致更大的心脏抑制和更高的死亡率，与LPS治疗相比， 野生型对照小鼠。相比之下，在体外强制过表达Lcn 10的内皮细胞显示出更大的抵抗力， 相对于对照细胞，LPS诱导的单层渗漏。通过RNA测序和RT-PCR进行初步机制分析。 qPCR显示，内皮细胞中内源性和外源性Lcn 10的升高均导致内皮细胞中Lcn 10的表达显著上调。 弹弓同源物1（Ssh 1）。Ssh 1是一种磷酸酶，已知可以去磷酸化，从而激活Cofilin，这是一种关键的磷酸酶。 在控制肌动蛋白丝动力学中起重要作用的肌动蛋白结合蛋白。最重要的是， 敲低内皮细胞中的Ssh 1抵消了LPS暴露后Lcn 10诱导的单层渗漏的减少。基于 根据这些初步的数据，我们假设Lcn 10对于防止脓毒症引起的血管渗漏至关重要 通过激活Ssh 1-Cofilin途径。这一假设将通过追求三个具体目标来检验：1） 使用一个全球性的，定义Lcn 10在多微生物败血症期间血管通透性中的确切作用。 基因敲除和EC特异性Lcn 10转基因小鼠模型; 2）鉴定Lcn 10- 心血管渗漏的减少依赖于Ssh 1介导的肌动蛋白动力学，使用交叉 通过将EC特异性Lcn 10转基因小鼠与Ssh 1-KO小鼠交配建立小鼠模型;以及3）研究 重组Lcn 10蛋白在治疗脓毒症中的治疗潜力。预计拟议的研究将 鉴定Lcn 10为一种有效和新血管通透性调节剂和一种抗脓毒症诱导的新保护剂 心衰如果完成，这项提案的发现可能会为减少癌症提供新的治疗选择。 脓毒症期间的血管渗漏，以期提高脓毒症患者的生存率。