The non-muscle myosin light chain kinase (MLCK) isoform contributes to the mechanism of increased vascular endothelial permeability in lipopolysaccharide (LPS) induced model of inflammatory lung injury, the primary cause of the acute respiratory distress syndrome (ARDS). However, the role of MLCK in the anti-microbial activity of neutrophils remains poorly understood. Based on our preliminary data, we will test the hypothesis that MLCK regulates neutrophil anti-microbial functions including cell attachment, motility, and oxidant generation. The proposed studies have the following specific aims: i) to dissect the myosin light chain (MLC) independent pathway of non-muscle MLCK that is required for the full activation of (2 integrins via the tyrosine kinases Src and Pyk2 and that in turn mediate neutrophil transmigration;ii) to determine the role of non-muscle MLCK in NADPH oxidase mediated oxidant production and to identify a potentially critical positive feedback loop between oxidant triggered Ca2+ signaling and MLCK activity;and iii) to address the role of LPS activated TLR4 signaling in the mechanism of MLCK activation via an ERK-dependent pathway. In these studies, we will identify the MLCK-regulated signaling pathways that mediate neutrophil transmigration and oxidant production, which in turn are crucial in the mechanism of acute lung injury. Our goal is to understand the molecular mechanisms of the non-muscle MLCK-mediated activation of neutrophils and its role in the genesis of the lung inflammatory response. 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.

Public Health Relevance

We propose to study the role of a protein kinase, non-muscle myosin light chain kinase (MLCK) in bacterial induced inflammatory lung injury, the primary cause of the acute respiratory distress syndrome (ARDS). 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.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL095716-05
Application #
8423736
Study Section
Lung Injury, Repair, and Remodeling Study Section (LIRR)
Program Officer
Harabin, Andrea L
Project Start
2009-04-01
Project End
2015-01-31
Budget Start
2013-02-01
Budget End
2015-01-31
Support Year
5
Fiscal Year
2013
Total Cost
$428,299
Indirect Cost
$152,223
Name
University of Illinois at Chicago
Department
Dermatology
Type
Schools of Medicine
DUNS #
098987217
City
Chicago
State
IL
Country
United States
Zip Code
60612
Liu, Xiaowen; Ma, Bo; Malik, Asrar B et al. (2012) Bidirectional regulation of neutrophil migration by mitogen-activated protein kinases. Nat Immunol 13:457-64