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

Summary

Principal Investigator: Fabeha Fazal
Abstract: 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. PUBLIC HEALTH RELEVANCE: These studies will provide novel insights into the mechanisms regulating translocation of RelA/p65 into the nucleus and thereby expression of ICAM-1, and its consequences on lung PMN sequestration and lung vascular injury. The information gained may lead to the development of strategies for interfering with specific signaling events controlling ICAM-1 expression and thereby preventing or limiting lung PMN uptake and lung vascular injury associated with inflammatory disease states as Acute Respiratory Distress Syndrome (ARDS).
Funding Period: 2010-04-01 - 2015-03-31
more information: NIH RePORT

Top Publications

  1. pmc GPR56 Regulates VEGF production and angiogenesis during melanoma progression
    Liquan Yang
    Departments of Biomedical Genetics, University of Rochester Medical Center, Rochester, New York 14612, USA
    Cancer Res 71:5558-68. 2011
  2. pmc Blocking NF-κB: an inflammatory issue
    Arshad Rahman
    Department of Pediatrics, Box 850, Lung Biology and Disease Program, University of Rochester School of Medicine, Rochester, New York 14642, USA
    Proc Am Thorac Soc 8:497-503. 2011
  3. pmc Regulation of Rela/p65 and endothelial cell inflammation by proline-rich tyrosine kinase 2
    Kaiser M Bijli
    Department of Pediatrics, Lung Biology and Disease Program, University of Rochester School of Medicine, Rochester, NY 14642, USA
    Am J Respir Cell Mol Biol 47:660-8. 2012
  4. pmc Critical role of non-muscle myosin light chain kinase in thrombin-induced endothelial cell inflammation and lung PMN infiltration
    Fabeha Fazal
    Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
    PLoS ONE 8:e59965. 2013
  5. pmc Thrombin selectively engages LIM kinase 1 and slingshot-1L phosphatase to regulate NF-κB activation and endothelial cell inflammation
    Antony Leonard
    Dept of Pediatrics, Lung Biology and Disease Program, Univ of Rochester School of Medicine, 601 Elmwood Ave Box 850, Rochester, NY
    Am J Physiol Lung Cell Mol Physiol 305:L651-64. 2013

Detail Information

Publications5

  1. pmc GPR56 Regulates VEGF production and angiogenesis during melanoma progression
    Liquan Yang
    Departments of Biomedical Genetics, University of Rochester Medical Center, Rochester, New York 14612, USA
    Cancer Res 71:5558-68. 2011
    ..We propose that components of the GPR56-mediated signaling pathway may serve as new targets for antiangiogenic treatment of melanoma...
  2. pmc Blocking NF-κB: an inflammatory issue
    Arshad Rahman
    Department of Pediatrics, Box 850, Lung Biology and Disease Program, University of Rochester School of Medicine, Rochester, New York 14642, USA
    Proc Am Thorac Soc 8:497-503. 2011
    ....
  3. pmc Regulation of Rela/p65 and endothelial cell inflammation by proline-rich tyrosine kinase 2
    Kaiser M Bijli
    Department of Pediatrics, Lung Biology and Disease Program, University of Rochester School of Medicine, Rochester, NY 14642, USA
    Am J Respir Cell Mol Biol 47:660-8. 2012
    ..Thus, specific targeting of Pyk2 may be an effective anti-inflammatory strategy in vascular diseases associated with EC inflammation and intravascular coagulation...
  4. pmc Critical role of non-muscle myosin light chain kinase in thrombin-induced endothelial cell inflammation and lung PMN infiltration
    Fabeha Fazal
    Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
    PLoS ONE 8:e59965. 2013
    ..These results provide mechanistic insight into lung inflammatory response associated with intravascular coagulation and identify nmMLCK as a critical target for modulation of lung inflammation...
  5. pmc Thrombin selectively engages LIM kinase 1 and slingshot-1L phosphatase to regulate NF-κB activation and endothelial cell inflammation
    Antony Leonard
    Dept of Pediatrics, Lung Biology and Disease Program, Univ of Rochester School of Medicine, 601 Elmwood Ave Box 850, Rochester, NY
    Am J Physiol Lung Cell Mol Physiol 305:L651-64. 2013
    ..Thus this study provides evidence for a novel role of LIMK1 and SSH-1L in selectively regulating EC inflammation associated with intravascular coagulation. ..

Research Grants30

  1. AMPK Endothelial Cell Dysfunction and the Metabolic Syndrome (PROGRAM PROJECT)
    Neil B Ruderman; Fiscal Year: 2013
    ..The proposed studies should both yield novel insights into the biological bases for the premature atherosclerosis and impaired angiogenesis associated with this entity and suggest new therapeutic targets for their prevention...
  2. Role of Non-muscle MLCK in Neutrophil-mediated Acute Lung Injury
    Jingsong Xu; Fiscal Year: 2013
    ..We hope that through the understanding of the novel function of this MLCK isoform, more effective strategies will be developed for the prevention and treatment of lung inflammation and the resultant injury. ..
  3. Immune-Based Interventions Against Infectious Diseases
    Alan L Rothman; Fiscal Year: 2013
    ..3. Recruit promising junior investigators and provide mentoring by established NIH-funded researchers. 4. Support a multidisciplinary research program led by junior investigators in translational infectious diseases immunology. ..
  4. Endothelial Injury and Repair: CardioPulmonary Vascular Biology COBRE
    SHARON IRENE SMITH ROUNDS; Fiscal Year: 2013
    ..abstract_text> ..
  5. Signaling of Endothelial Permeability and Lung Vascular Injury
    Asrar B Malik; Fiscal Year: 2013
    ..Moreover the depth of understanding to be gained of the signaling pathways mediating the increase in lung vascular permeability will provide novel insights into the mechanisms of protein-rich pulmonary edema and ARDS. ..
  6. Mechanically Stressed VSMC: A Role for Slingshot Phosphatase in Inflammation
    Alejandra San Martin; Fiscal Year: 2013
    ....
  7. Pathophysiology of Alveolar Epithelial Lung Injury
    Jacob I Sznajder; Fiscal Year: 2013
    ..The insights gained from the data generated from these studies will provide novel molecular targets for the development of new therapeutic strategies to treat patients with lung injury. ..
  8. Digitalis-Induced Signaling by Cardiac Na+/K+-ATPase
    Amir Askari; Fiscal Year: 2013
    ..abstract_text> ..
  9. Role of Cten in Prostate Cancer
    Su Hao Lo; Fiscal Year: 2013
    ..Our animal studies will reveal cten's in vivo function and provide better mouse prostate cancer models for studying prostate tumorigenesis and drug screening. ..
  10. RAGE and Mechanisms of Vascular Dysfunction
    Shi Fang Yan; Fiscal Year: 2013
    ..Using novel and state-of-the-art techniques, floxed mice and molecular approaches to gene regulation, we are well-positioned to lead the study of RAGE in the next cycle of this Program. ..