title: The role of mitogen-activated protein kinase-activated protein kinase 2 in the p38/TNF-alpha pathway of systemic and cutaneous inflammation.
abstract: Mitogen-activated protein kinase-activated protein kinase 2 (MK2) is a downstream molecule of p38, involved in the production of TNF-alpha, a key cytokine, and an established drug target for many inflammatory diseases. We investigated the role of MK2 in skin inflammation to determine its drug target potential. MK2 deficiency significantly decreased plasma TNF-alpha levels after systemic endotoxin application. Deficient mice showed decreased skin edema formation in chronic 2-O-tetradecanoylphorbol-13-acetate (TPA)-induced irritative dermatitis and in subacute 2,4-dinitrofluorobenzene (DNFB)-induced contact hypersensitivity. Surprisingly, MK2 deficiency did not inhibit edema formation in subacute 2,4-dinitrochlorobenzene (DNCB)-induced contact allergy and even increased TNF-alpha and IL-1beta levels as well as granulocyte infiltration in diseased ears. Ear inflammation in this model, however, was inhibited by TNF-alpha neutralization as it was in the subacute DNFB model. MK2 deficiency also did not show anti-inflammatory effects in acute DNFB-induced contact hypersensitivity, whereas the p38 inhibitor, SB203580, ameliorated skin inflammation supporting a pathophysiological role of p38. When evaluating possible mechanisms, we found that TNF-alpha production in MK2-deficient spleen cells was strongly diminished after TLR stimulation but less affected after T-cell receptor stimulation. Our data suggest that MK2, in contrast to its downstream effector molecule, TNF-alpha, has a rather elusive role in T-cell-dependent cutaneous inflammation.
authors: Bayer Schering Pharma AG, Berlin, Germany.
authors: Arndt J
authors: AJ
authors: Schottelius
authors: Ulrich
authors: U
authors: Zügel
authors: Wolf-Dietrich
authors: WD
authors: Döcke
authors: Thomas M
authors: TM
authors: Zollner
authors: Lars
authors: L
authors: Röse
authors: Anne
authors: A
authors: Mengel
authors: Bernd
authors: B
authors: Buchmann
authors: Andreas
authors: A
authors: Becker
authors: Gerald
authors: G
authors: Grütz
authors: Sandra
authors: S
authors: Naundorf
authors: Anke
authors: A
authors: Friedrich
authors: Matthias
authors: M
authors: Gaestel
authors: Khusru
authors: K
authors: Asadullah
mesh_terms: D000818:Animals; D003877:Dermatitis, Contact; D004139:Dinitrofluorobenzene / Q000737:chemistry; D005260:Female; D006098:Granulocytes / Q000166:cytology; D006720:Homozygote; D007249:Inflammation; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D012867:Skin / Q000201:enzymology / Q000473:pathology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*; D000099190:MAP-Kinase-Activated Kinase 2
chemical_list: D004139:Dinitrofluorobenzene; D047908:Intracellular Signaling Peptides and Proteins; D017346:Protein Serine-Threonine Kinases; D011948:Receptors, Antigen, T-Cell; D013755:Tetradecanoylphorbol Acetate; D014409:Tumor Necrosis Factor-alpha; D048051:p38 Mitogen-Activated Protein Kinases; D000099190:MAP-Kinase-Activated Kinase 2