title: The role of RIP2 in p38 MAPK activation in the stressed heart.
abstract: The activation of p38 MAPK by dual phosphorylation aggravates myocardial ischemic injury and depresses cardiac contractile function. SB203580, an ATP-competitive inhibitor of p38 MAPK and other kinases, prevents this dual phosphorylation during ischemia. Studies in non-cardiac tissue have shown receptor-interacting protein 2 (RIP2) lies upstream of p38 MAPK, is SB203580-sensitive and ischemia-responsive, and aggravates ischemic injury. We therefore examined the RIP2-p38 MAPK signaling axis in the heart. Adenovirus-driven expression of wild-type RIP2 in adult rat ventricular myocytes caused robust, SB203580-sensitive dual phosphorylation of p38 MAPK associated with activation of p38 MAPK kinases MKK3, MKK4, and MKK6. The effect of SB203580 was recapitulated by unrelated inhibitors of RIP2 or the downstream MAPK kinase kinase, TAK1. However, overexpression of wild-type, kinase-dead, caspase recruitment domain-deleted, or kinase-dead and caspase recruitment domain-deleted forms of RIP2 had no effect on the activating dual phosphorylation of p38 MAPK during simulated ischemia. Similarly, p38 MAPK activation and myocardial infarction size in response to true ischemia did not differ between hearts from wild-type and RIP2 null mice. However, both p38 MAPK activation and the contractile depression caused by the endotoxin component muramyl dipeptide were attenuated by SB203580 and in RIP2 null hearts. Although RIP2 can cause myocardial p38 MAPK dual phosphorylation in the heart under some circumstances, it is not responsible for the SB203580-sensitive pattern of activation during ischemia.
authors.affiliation: Cardiovascular Division, King's College London, The Rayne Institute, St. Thomas' Hospital, London SE1 7EH, United Kingdom.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Jacquet
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Nishino
authors.forename: Sarawut
authors.initials: S
authors.lastname: Kumphune
authors.forename: Pierre
authors.initials: P
authors.lastname: Sicard
authors.forename: James E
authors.initials: JE
authors.lastname: Clark
authors.forename: Koichi S
authors.initials: KS
authors.lastname: Kobayashi
authors.forename: Richard A
authors.initials: RA
authors.lastname: Flavell
authors.forename: Jan
authors.initials: J
authors.lastname: Eickhoff
authors.forename: Matt
authors.initials: M
authors.lastname: Cotten
authors.forename: Michael S
authors.initials: MS
authors.lastname: Marber
mesh_terms: D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects; D007093:Imidazoles / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009200:Myocardial Contraction / Q000187:drug effects; D009203:Myocardial Infarction / Q000139:chemically induced / Q000201:enzymology / Q000473:pathology; D009206:Myocardium / Q000201:enzymology* / Q000473:pathology*; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000201:enzymology; D017434:Protein Structure, Tertiary; D011725:Pyridines / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D051381:Rats; D053475:Receptor-Interacting Protein Serine-Threonine Kinase 2 / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: C412373:AG 1879; D007093:Imidazoles; D011725:Pyridines; D011743:Pyrimidines; D000119:Acetylmuramyl-Alanyl-Isoglutamine; D053475:Receptor-Interacting Protein Serine-Threonine Kinase 2; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580