Acute lung injury often results from endothelial cell (EC) barrier dysfunction secondary to reactive oxygen species (ROS). Treatments that increase cGMP decrease this EC dysfunction by an unknown mechanism. Our objective is to examine the molecular mechanisms by which cGMP prevents ROS-induced EC barrier dysfunction. In EC, cGMP activates cyclic G kinase (cGK), which phosphorylates vasodilator-stimulated phosphoprotein (VASP). Unphosphorylated VASP binds to cytoskeletal F-actin and proteins in cell-cell and cell-matrix attachments and promotes F-actin stress fiber formation and cell ruffling; the effect on EC permeability is unknown Phosphorylation of VASP reverses these effects. Our preliminary data in pulmonary conduit and microvascular EC monolayers show that H2O2 decreases cGMP and barrier function with cytoskeletal rearrangement and increased [Ca2+]i cGMP prevents the H2O2-induced changes and enhances baseline EC barrier function. We hypothesize that CBMP prevents a H2O2-induced decrease in the P-VASP/VASP ratio by 1) increasing P-VASP through cGK1a and 2) decreasing phosphatase (PPase) activity, in part through decreased [Ca2+]i.
In Aim 1, assessments of permeability and cytoskeletal structure following cGK1a agonists/antagonists and over-expression of dominant negative and constitutively active cGK1a constructs, will define the role of cGK1a in H2O2 induced events.
Aim 2 will examine VASP phosphorylation as the key molecular switch mediating the opposing effects of cGMP and H2O2. Measurements of barrier function following transfection with antisense and phosphorylation-resistant VASP will define its function and highlight critical phosphorylation sites.
In Aim 3, the VASP PPase will be identified using specific inhibitors, activity assays, and co-localization experiments. PPase regulation by CGK1a [Ca2+]i, and H2O2 will be determined and the effect of over-expression vs. inhibition of PPase on VASP and H2O2 included barrier dysfunction will be examined. A better understanding of cGMP-induced EC barrier protection will provide a basis for new treatments of ROS-mediated vascular disease.
| Rentsendorj, Otgonchimeg; D'Alessio, Franco R; Pearse, David B (2014) Phosphodiesterase 2A is a major negative regulator of iNOS expression in lipopolysaccharide-treated mouse alveolar macrophages. J Leukoc Biol 96:907-15 |
| Stephens, R Scott; Servinsky, Laura E; Rentsendorj, Otgonchimeg et al. (2014) Protein kinase G increases antioxidant function in lung microvascular endothelial cells by inhibiting the c-Abl tyrosine kinase. Am J Physiol Cell Physiol 306:C559-69 |
| Rentsendorj, Otgonchimeg; Damarla, Mahendra; Aggarwal, Neil R et al. (2011) Knockdown of lung phosphodiesterase 2A attenuates alveolar inflammation and protein leak in a two-hit mouse model of acute lung injury. Am J Physiol Lung Cell Mol Physiol 301:L161-70 |
| McLaren, Christine E; Barton, James C; Eckfeldt, John H et al. (2010) Heritability of serum iron measures in the hemochromatosis and iron overload screening (HEIRS) family study. Am J Hematol 85:101-5 |
| Rentsendorj, Otgonchimeg; Mirzapoiazova, Tamara; Adyshev, Djanybek et al. (2008) Role of vasodilator-stimulated phosphoprotein in cGMP-mediated protection of human pulmonary artery endothelial barrier function. Am J Physiol Lung Cell Mol Physiol 294:L686-97 |
| Schmidt, Eric P; Damarla, Mahendra; Rentsendorj, Otgonchimeg et al. (2008) Soluble guanylyl cyclase contributes to ventilator-induced lung injury in mice. Am J Physiol Lung Cell Mol Physiol 295:L1056-65 |
| Dodd-o, Jeffrey M; Hristopoulos, Maria L; Kibler, Kathleen et al. (2008) The role of natriuretic peptide receptor-A signaling in unilateral lung ischemia-reperfusion injury in the intact mouse. Am J Physiol Lung Cell Mol Physiol 294:L714-23 |
| Moldobaeva, Aigul; Welsh-Servinsky, Laura E; Shimoda, Larissa A et al. (2006) Role of protein kinase G in barrier-protective effects of cGMP in human pulmonary artery endothelial cells. Am J Physiol Lung Cell Mol Physiol 290:L919-30 |
| Dodd-o, Jeffrey M; Welsh, Laura E; Salazar, Jorge D et al. (2004) Effect of NADPH oxidase inhibition on cardiopulmonary bypass-induced lung injury. Am J Physiol Heart Circ Physiol 287:H927-36 |
| Dodd-o, Jeffrey M; Welsh, Laura E; Salazar, Jorge D et al. (2004) Effect of bronchial artery blood flow on cardiopulmonary bypass-induced lung injury. Am J Physiol Heart Circ Physiol 286:H693-700 |
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