title: Activation of extracellular signal regulated kinase 1/2 in human dermal microvascular endothelial cells stimulated by anti-endothelial cell antibodies in sera of patients with Behçet's disease.
abstract: Anti-endothelial cell antibodies (AECA) have been detected in the sera of patients with Behçet's disease (BD). The isotype of AECA from BD is IgM recognizing 44 kDa antigen (IgM-AECA) of human dermal microvascular endothelial cells (HDMEC). After stimulation of HDMEC with AECA-positive sera from BD patients, the expression of intercellular cell adhesion molecule-1 (ICAM-1) on HDMEC increases significantly. Mitogen-activated protein kinase (MAPK) cascade is one of protein kinase families activated by a wide spectrum of extracellular stimuli. There are several subtypes, including extracellular signal regulated kinase (ERK)1/2, c-Jun NH(2) terminal kinase (JNK), and p38 cascades, and they regulate various cellular processes such as cell growth, differentiation, and inflammation. We examined the involvement of MAPK as a signal transduction pathway in the IgM-AECA-induced ICAM-1 expression. We used enzyme-linked immunosorbent assay (ELISA) and fluorescence-activated cell sorting (FACS) for detecting the induction of ICAM-1 on HDMEC. We also examined the production of tumor necrosis factor alpha (TNFalpha) or interleukin-1alpha (IL-1alpha) by HDMEC after stimulation with IgM-AECA, and checked the involvement of MAPK by Western blot assay. IgM-AECA cocktail from 8 patients with BD induced expression of the ICAM-1 on HDMEC. Neither TNFalpha nor IL-1alpha was detected by ELISA, FACS or reverse transcriptase-polymerase chain reaction in activated HDMEC cultures. IgM-AECA cocktail activated ERK1/2 and showed peak activities at 5 min after the stimulation. Specific MAPK/ERK kinase inhibitor PD98059 inhibited IgM-AECA-induced ERK1/2 activities and ICAM-1 expression on HDMEC at a concentration of 60 microM. IgM-AECA can play a pathogenic role in induction of vasculitis and inflammatory lesions of BD by directly activating endothelial cells, not by production of TNFalpha or IL-1alpha from HDMEC. ERK1/2 are involved in expression of ICAM-1 on HDMEC stimulated with IgM-AECA.
mesh_terms: D001323:Autoantibodies / Q000494:pharmacology; D001528:Behcet Syndrome / Q000097:blood / Q000201:enzymology* / Q000235:genetics; D004730:Endothelium, Vascular / Q000201:enzymology*; D004789:Enzyme Activation; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics; D007375:Interleukin-1 / Q000235:genetics; D008833:Microcirculation / Q000502:physiology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D012016:Reference Values; D012867:Skin / Q000098:blood supply*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
chemical_list: D001323:Autoantibodies; D007375:Interleukin-1; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; C087589:anti-endothelial cell antibody; D018799:Intercellular Adhesion Molecule-1; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases