title: Adenosine prevents TNFα-induced decrease in endothelial mitochondrial mass via activation of eNOS-PGC-1α regulatory axis.
abstract: We tested whether adenosine, a cytoprotective mediator and trigger of preconditioning, could protect endothelial cells from inflammation-induced deficits in mitochondrial biogenesis and function. We examined this question using human microvascular endothelial cells exposed to TNFα. TNFα produced time and dose-dependent decreases in mitochondrial membrane potential, cellular ATP levels, and mitochondrial mass, preceding an increase in apoptosis. These effects were prevented by co-incubation with adenosine, a nitric oxide (NO) donor, a guanylate cyclase (GC) activator, or a cell-permeant cyclic GMP (cGMP) analog. The effects of adenosine were blocked by a nitric oxide synthase inhibitor, a soluble guanylate cyclase inhibitor, a morpholino antisense oligonucleotide to endothelial nitric oxide synthase (eNOS), or siRNA knockdown of the transcriptional coactivator, PGC-1α. Incubation with exogenous NO, a GC activator, or a cGMP analog reversed the effect of eNOS knockdown, while the effect of NO was blocked by inhibition of GC. The protective effects of NO and cGMP analog were prevented by siRNA to PGC-1α. TNFα also decreased expression of eNOS, cellular NO levels, and PGC-1α expression, which were reversed by adenosine. Exogenous NO, but not adenosine, rescued expression of PGC-1α in cells in which eNOS expression was knocked down by eNOS antisense treatment. Thus, TNFα elicits decreases in endothelial mitochondrial function and mass, and an increase in apoptosis. These effects were reversed by adenosine, an effect mediated by eNOS-synthesized NO, acting via soluble guanylate cyclase/cGMP to activate a mitochondrial biogenesis regulatory program under the control of PGC-1α. These results support the existence of an adenosine-triggered, mito-and cytoprotective mechanism dependent upon an eNOS-PGC-1α regulatory pathway, which acts to preserve endothelial mitochondrial function and mass during inflammatory challenge.
authors.affiliation: Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, United States of America.
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Kalogeris
authors.affiliation: Department of Biomedical Sciences, University of Missouri, Columbia, Missouri, United States of America; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, United States of America.
authors.forename: Christopher
authors.initials: C
authors.lastname: Baines
authors.affiliation: Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, United States of America; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, United States of America.
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Korthuis
mesh_terms: D000241:Adenosine / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D006152:Cyclic GMP / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000378:metabolism*; D006162:Guanylate Cyclase / Q000378:metabolism; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D063269:Mitochondrial Turnover / Q000187:drug effects; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D000071756:Soluble Guanylyl Cyclase; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D016207:Cytokines; C486497:PPARGC1A protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D000255:Adenosine Triphosphate; D052250:Nitric Oxide Synthase Type III; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase; D006152:Cyclic GMP; D000241:Adenosine