The research program outlined in this application is designed to extend our prior observations on the pathogenesis of inflammatory edema. It is built around the observations that inflammatory edema, whether caused by histamine, bradykinin or activated neutrophils, is invariably associated with the retraction of adjacent endothelial cells. In the past we have identified neutrophil derived mediators that activate signal transduction pathways that cause retraction of endothelial cells. Histamine and bradykinin activate these same pathways and also cause cell retraction. We have recently found that these pathways lead to phosphorylation of the light chain of myosin (MLC), and phosphorylation of the light chain is necessary for cell retraction in response to histamine or when cell attachment to substrate is interrupted by chelating extracellular calcium. In the proposed experiments we will determine if histamine, bradykinin, and thrombin increase centripetal tension in endothelial cells, and if they do, if the increase in tension is dependent on phosphorylation of MLC. We will also determine if histamine, bradykinin or thrombin cause endothelial cells to release from substrate and cell-cell attachments, and if they do, if this is occurs in the absence of an increase in centripetal tension. We have new preliminary data that are consistent with a paradigm in which agonists such as histamine and bradykinin release endothelial cells from attachments without increasing centripetal tension. In our recent experiments we have also observed that the magnitude and duration of MLC phosphorylation in response to histamine and bradykinin are very limited. These same experiments identify a potentially important role for phosphatases in the control of light chain phosphorylation. We will extend these observations to more precisely determine the role of phosphatases in controlling the extent of MLC phosphorylation in endothelium. We expect these investigations to increase our understanding of how inflammatory edema occurs; and to direct our future investigations into understanding how cell attachments can be regulated and whether some edemagenic agonists may directly alter the activity of endothelial phosphatases.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL033540-13
Application #
2735088
Study Section
Lung Biology and Pathology Study Section (LBPA)
Project Start
1989-08-01
Project End
2000-06-30
Budget Start
1998-07-01
Budget End
1999-06-30
Support Year
13
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of Iowa
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
041294109
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Shasby, D Michael; Winter, Michael C (2011) H1 and PAR2 receptors enhance delivery of immune-competent cells and molecules by interrupting E-cadherin adhesion in epithelia. Trans Am Clin Climatol Assoc 122:217-28
Winter, Michael C; Shasby, Sandra; Shasby, D Michael (2008) Compromised E-cadherin adhesion and epithelial barrier function with activation of G protein-coupled receptors is rescued by Y-to-F mutations in beta-catenin. Am J Physiol Lung Cell Mol Physiol 294:L442-8
Winter, Michael C; Shasby, Sandra S; Ries, Dana R et al. (2006) PAR2 activation interrupts E-cadherin adhesion and compromises the airway epithelial barrier: protective effect of beta-agonists. Am J Physiol Lung Cell Mol Physiol 291:L628-35
Winter, Michael C; Shasby, Sandra S; Ries, Dana R et al. (2004) Histamine selectively interrupts VE-cadherin adhesion independently of capacitive calcium entry. Am J Physiol Lung Cell Mol Physiol 287:L816-23
Zabner, Joseph; Winter, Michael; Excoffon, Katherine J D Ashbourne et al. (2003) Histamine alters E-cadherin cell adhesion to increase human airway epithelial permeability. J Appl Physiol 95:394-401
Moy, A B; Winter, M; Kamath, A et al. (2000) Histamine alters endothelial barrier function at cell-cell and cell-matrix sites. Am J Physiol Lung Cell Mol Physiol 278:L888-98
Winter, M C; Kamath, A M; Ries, D R et al. (1999) Histamine alters cadherin-mediated sites of endothelial adhesion. Am J Physiol 277:L988-95
Moy, A B; Bodmer, J E; Blackwell, K et al. (1998) cAMP protects endothelial barrier function independent of inhibiting MLC20-dependent tension development. Am J Physiol 274:L1024-9
Shasby, D M; Stevens, T; Ries, D et al. (1997) Thrombin inhibits myosin light chain dephosphorylation in endothelial cells. Am J Physiol 272:L311-9
Bodmer, J E; Van Engelenhoven, J; Reyes, G et al. (1997) Isometric tension of cultured endothelial cells: new technical aspects. Microvasc Res 53:261-71

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