title: TNFR1 and TNFR2 signaling interplay in cardiac myocytes.
abstract: Tumor necrosis factor alpha (TNFalpha) plays a major role in chronic heart failure, signaling through two different receptor subtypes, TNFR1 and TNFR2. Our aim was to further delineate the functional role and signaling pathways related to TNFR1 and TNFR2 in cardiac myocytes. In cardiac myocytes isolated from control rats, TNFalpha induced ROS production, exerted a dual positive and negative action on [Ca(2+)] transient and cell fractional shortening, and altered cell survival. Neutralizing anti-TNFR2 antibodies exacerbated TNFalpha responses on ROS production and cell death, arguing for a major protective role of the TNFR2 pathway. Treatment with either neutralizing anti-TNFR1 antibodies or the glutathione precursor, N-acetylcysteine (NAC), favored the emergence of TNFR2 signaling that mediated a positive effect of TNFalpha on [Ca(2+)] transient and cell fractional shortening. The positive effect of TNFalpha relied on TNFR2-dependent activation of the cPLA(2) activity, independently of serine 505 phosphorylation of the enzyme. Together with cPLA(2) redistribution and AA release, TNFalpha induced a time-dependent phosphorylation of ERK, MSK1, PKCzeta, CaMKII, and phospholamban on the threonine 17 residue. Taken together, our results characterized a TNFR2-dependent signaling and illustrated the close interplay between TNFR1 and TNFR2 pathways in cardiac myocytes. Although apparently predominant, TNFR1-dependent responses were under the yoke of TNFR2, acting as a critical limiting factor. In vivo NAC treatment proved to be a unique tool to selectively neutralize TNFR1-mediated effects of TNFalpha while releasing TNFR2 pathways.
authors.affiliation: INSERM, Unité 841, Institut Mondor de Recherche Biomedicale, Equipe 19, Créteil, F-94010, France.
authors.forename: Nicole
authors.initials: N
authors.lastname: Defer
authors.forename: Anie
authors.initials: A
authors.lastname: Azroyan
authors.forename: Françoise
authors.initials: F
authors.lastname: Pecker
authors.forename: Catherine
authors.initials: C
authors.lastname: Pavoine
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects*; D002135:Calcium-Binding Proteins / Q000378:metabolism; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002908:Chronic Disease; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D016166:Free Radical Scavengers / Q000494:pharmacology; D006333:Heart Failure / Q000378:metabolism / Q000473:pathology; D008297:Male; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000473:pathology; D054510:Phospholipases A2, Cytosolic / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000037:antagonists & inhibitors / Q000378:metabolism*; D047889:Receptors, Tumor Necrosis Factor, Type II / Q000037:antagonists & inhibitors / Q000378:metabolism*; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000378:metabolism; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism / Q000494:pharmacology*; D000099211:Phospholamban
chemical_list: D000111:Acetylcysteine; D000906:Antibodies; D002118:Calcium; D002135:Calcium-Binding Proteins; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D048049:Extracellular Signal-Regulated MAP Kinases; D016166:Free Radical Scavengers; D054510:Phospholipases A2, Cytosolic; D011493:Protein Kinase C; D017382:Reactive Oxygen Species; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; D038744:Ribosomal Protein S6 Kinases, 90-kDa; D014409:Tumor Necrosis Factor-alpha; D000099211:Phospholamban; C506237:Tnfrsf1a protein, rat; C116919:mitogen and stress-activated protein kinase 1