title: The Src family tyrosine kinases src and yes have differential effects on inflammation-induced apoptosis in human pulmonary microvascular endothelial cells.
abstract: Endothelial cells are essential for normal lung function: they sense and respond to circulating factors and hemodynamic alterations. In inflammatory lung diseases such as acute respiratory distress syndrome, endothelial cell apoptosis is an inciting event in pathogenesis and a prominent pathological feature. Endothelial cell apoptosis is mediated by circulating inflammatory factors, which bind to receptors on the cell surface, activating signal transduction pathways, leading to caspase-3-mediated apoptosis. We hypothesized that yes and src have differential effects on caspase-3 activation in human pulmonary microvascular endothelial cells (hPMVEC) due to differential downstream signaling effects. To test this hypothesis, hPMVEC were treated with siRNA against src (siRNAsrc), siRNA against yes (siRNAyes), or their respective scramble controls. After recovery, the hPMVEC were treated with cytomix (LPS, IL-1β, TNF-α, and IFN-γ). Treatment with cytomix induced activation of the extracellular signal-regulated kinase (ERK) pathway and caspase-3-mediated apoptosis. Treatment with siRNAsrc blunted cytomix-induced ERK activation and enhanced cleaved caspase-3 levels, while treatment with siRNAyes enhanced cytomix-induced ERK activation and attenuated levels of cleaved caspase-3. Inhibition of the ERK pathway using U0126 enhanced cytomix-induced caspase-3 activity. Treatment of hPMVEC with cytomix induced Akt activation, which was inhibited by siRNAsrc. Inhibition of the phosphatidylinositol 3-kinase/Akt pathway using LY294002 prevented cytomix-induced ERK activation and augmented cytomix-induced caspase-3 cleavage. Together, our data demonstrate that, in hPMVEC, yes activation blunts the ERK cascade in response to cytomix, resulting in greater apoptosis, while cytomix-induced src activation induces the phosphatidylinositol 3-kinase pathway, which leads to activation of Akt and ERK and attenuation of apoptosis.
authors.affiliation: Pulmonary Hypertension Group, Center for Perinatal Research, Research Institute at Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio Leif.Nelin@nationwidechildrens.org.
authors.forename: Leif D
authors.initials: LD
authors.lastname: Nelin
authors.affiliation: Pulmonary Hypertension Group, Center for Perinatal Research, Research Institute at Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio.
authors.forename: Hilary A
authors.initials: HA
authors.lastname: White
authors.affiliation: Pulmonary Hypertension Group, Center for Perinatal Research, Research Institute at Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio.
authors.forename: Yi
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Pulmonary Hypertension Group, Center for Perinatal Research, Research Institute at Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio.
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Trittmann
authors.affiliation: Pulmonary Hypertension Group, Center for Perinatal Research, Research Institute at Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio.
authors.forename: Bernadette
authors.initials: B
authors.lastname: Chen
authors.affiliation: Pulmonary Hypertension Group, Center for Perinatal Research, Research Institute at Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio.
authors.forename: Yusen
authors.initials: Y
authors.lastname: Liu
mesh_terms: D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000502:physiology*; D004730:Endothelium, Vascular / Q000276:immunology / Q000473:pathology; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D020935:MAP Kinase Signaling System; D055806:Microvessels / Q000201:enzymology / Q000276:immunology; D051575:Proto-Oncogene Proteins c-yes / Q000502:physiology*; D012128:Respiratory Distress Syndrome / Q000201:enzymology / Q000276:immunology / Q000473:pathology; D019061:src-Family Kinases / Q000502:physiology*
chemical_list: D008070:Lipopolysaccharides; D051575:Proto-Oncogene Proteins c-yes; C489834:YES1 protein, human; D019061:src-Family Kinases; C505407:CASP3 protein, human; D053148:Caspase 3
keywords: caspase-3; cytokines; extracellular signal-regulated kinase