MKK3 and -6-dependent activation of p38alpha MAP kinase is required for cytoskeletal changes in pulmonary microvascular endothelial cells induced by ICAM-1 ligation.
Previous studies demonstrated that neutrophil adherence induces ICAM-1-dependent cytoskeletal changes in TNF-alpha-treated pulmonary microvascular endothelial cells that are prevented by a pharmacological inhibitor of p38 MAP kinase. This study determined whether neutrophil adherence induces activation of p38 MAP kinase in endothelial cells, the subcellular localization of phosphorylated p38, which MAP kinase kinases lead to p38 activation, which p38 isoform is activated, and what the downstream targets may be. Confocal microscopy showed that neutrophil adhesion for 2 or 6 min induced an increase in phosphorylated p38 in endothelial cells that was punctate and concentrated in the central region of the endothelial cells. Studies using small interfering RNA (siRNA) to inhibit the protein expression of MAP kinase kinase 3 and 6, either singly or in combination, showed that both MAP kinase kinases were required for p38 phosphorylation. Studies using an antisense oligonucleotide to p38alpha demonstrated that inhibition of the protein expression of p38alpha 1) inhibited activation of p38 MAP kinase without affecting the protein expression of p38beta; 2) prevented phosphorylation of heat shock protein 27, an actin binding protein that may induce actin polymerization upon phosphorylation; 3) attenuated cytoskeletal changes; and 4) attenuated neutrophil migration to the EC borders. Thus MAP kinase kinase3- and 6-dependent activation of the alpha-isoform of p38 MAP kinase is required for the cytoskeletal changes induced by neutrophil adherence and influences subsequent neutrophil migration toward endothelial cell junctions.
Wang
Qin
Q
Division of Integrative Biology, Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio, USA.
Yerukhimovich
Michael
M
Gaarde
William A
WA
Popoff
Ian J
IJ
Doerschuk
Claire M
CM
D000199:Actins / Q000737:chemistry / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D003432:Cross-Linking Reagents / Q000494:pharmacology; D003599:Cytoskeleton / Q000648:ultrastructure*; D042783:Endothelial Cells / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism* / Q000648:ultrastructure*; D055551:HSP27 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000187:drug effects / Q000378:metabolism*; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008168:Lung / Q000098:blood supply*; D048371:MAP Kinase Kinase 3 / Q000378:metabolism*; D048669:MAP Kinase Kinase 6 / Q000378:metabolism*; D018832:Molecular Chaperones; D009363:Neoplasm Proteins / Q000378:metabolism; D009504:Neutrophils / Q000502:physiology; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D015398:Signal Transduction; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*
D000199:Actins; D003432:Cross-Linking Reagents; D055551:HSP27 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D007527:Isoenzymes; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; D016376:Oligonucleotides, Antisense; D018799:Intercellular Adhesion Molecule-1; D048051:p38 Mitogen-Activated Protein Kinases; D048371:MAP Kinase Kinase 3; D048669:MAP Kinase Kinase 6; C482530:MAP2K3 protein, human; C482566:MAP2K6 protein, human