Regulation of Endothelial ICAM-1 and PMN-Mediated Lung Injury by Actin Dynamics

肌动蛋白动力学对内皮 ICAM-1 和 PMN 介导的肺损伤的调节

基本信息

批准号：
8446994
负责人：
Fabeha Fazal
金额：
$ 29.12万
依托单位：
UNIVERSITY OF ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-04-01 至 2015-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8446994
关键词：
Actin-Binding Protein Actins Acute Lung Injury Address Adhesions Adhesives Adult Respiratory Distress Syndrome Binding Biochemical Blood Vessels Cell Nucleus Cell surface Coagulation Process Cytoplasm Cytoskeleton Data Development Disease Edema Emigrations Endothelial Cells Endothelium Event Genetic ICAM1 gene Immigration Infiltration Inflammation Inflammatory Injury Intercellular adhesion molecule 1 LIM Domain Kinase 1 Lead Lung MYLK gene Mediating Modeling Molecular and Cellular Biology Mus Myosin ATPase Myosin Light Chain Kinase Myosin Type II Nonmuscle Myosin Type IIA Nuclear Nuclear Import Nuclear Translocation Pathway interactions Phosphoric Monoester Hydrolases Phosphorylation Phosphotransferases Physiology Play Positioning Attribute Proteins Regulation Role Secondary to Sepsis Serine Protease Signal Transduction Testing Thrombin Tissues base cofilin depolymerization in vivo insight interdisciplinary approach intraperitoneal lung injury lung vascular injury migration mouse model neutrophil novel nucleocytoplasmic transport p65 prevent promoter public health relevance trafficking transcription factor uptake

项目摘要

DESCRIPTION (provided by applicant): The overall objective of the proposed studies is to address the mechanisms by which thrombin, a serine protease released during clotting initiated by sepsis or vascular injury, regulates the expression of adhesive protein intercellular adhesion molecule-1 (ICAM-1; CD54) in endothelial cells, and how this event promotes sequestration and migration of polymorphonuclear leukocytes (PMN) in the lung and thus contributes to development of lung vascular injury. The basis of ICAM-1 expression involves activation of RelA/p65 subunit of the transcription factor NF-(B. Activation of RelA/p65 requires its release from the inhibitory protein I(B( in the cytoplasm and subsequently, its translocation to the nucleus. Whereas the mechanisms of its release have been elucidated, the cytoplasmic events regulating the translocation of RelAp65 to the nucleus remain elusive. We previously showed that activation of RhoA/ROCK and the dynamic changes in actin cytoskeleton induced by thrombin are crucial for NF-(B activation and ICAM-1 expression. We now have evidence that cofilin, an actin binding protein that promotes actin depolymerization, occupies a central position in RhoA-actin pathway mediating ICAM-1 expression by virtue of facilitating the nuclear translocation of RelA/p65. Interestingly, LIM kinase 1 (LIMK1), a cofilin kinase, and slingshot (SSH1L), a cofilin phosphatase, also regulate ICAM-1 expression. Additionally, MLCK and its target myosin IIA play an important role in thrombin-induced NF-(B activation. Based upon these findings, we hypothesize that thrombin engages LIMK1 and SSH1L as well as MLCK to regulate actin-myosin interaction, which in turn facilitates nuclear translocation of RelA/p65, and expression of ICAM-1 in endothelial cells. We will also test the hypothesis that MLCK signaling of ICAM-1-dependent endothelial adhesivity by this mechanism contributes to lung PMN sequestration and PMN-mediated lung vascular injury and tissue edema in mice. We will pursue the following specific aims to test this hypothesis. Specific Aim 1 will determine the role of LIMK1 and SSH1L in regulating the changes in the actin cytoskeleton leading to nuclear translocation of RelA/p65 and expression of ICAM-1 in endothelial cells. Specific Aim 2 will address the role of MLCK in regulating actin-myosin interaction leading to nuclear transport of RelA/p65 and expression of ICAM-1 in endothelial cells. Specific Aim 3 will evaluate the in vivo role of endothelial MLCK in regulating thrombin-induced ICAM-1 expression, lung PMN infiltration, and PMN-mediated lung vascular injury in mice. We will use multidisciplinary approaches ranging from biochemical, cellular, and molecular biology to lung physiology to carry out these studies. With the information gained, we believe that it will be possible to block PMN-mediated lung vascular injury by inhibiting the specific signaling events controlling ICAM-1 expression associated with intravascular coagulation and consequent inflammation.