title: Effects of type 5-phosphodiesterase inhibition on energy metabolism and mitochondrial biogenesis in human adipose tissue ex vivo.
abstract: OBJECTIVE
  An excess of adipose tissue (AT) in obese individuals is linked to increased cardiovascular risk and mitochondria have been shown to be defective in the muscle and AT of patients with metabolic disorders such as obesity and Type 2 diabetes. Nitric oxide (NO) generated by endothelial NO synthase (eNOS) plays a role in mitochondrial biogenesis through cyclic-GMP (cGMP). AT harbors the whole molecular signaling pathway of NO, together with type 5-phosphodiesterase (PDE- 5), the main cGMP catabolising enzyme.
  
  
  OBJECTIVE
  Our aim was to evaluate the effect of the modulation of NO pathway, through PDE-5 inhibition, on energy metabolism and mitochondria biogenesis in human omental AT.
  
  
  METHODS
  Cultured human omental AT was stimulated with PDE-5 inhibitor, vardenafil, at different concentration for 24 and 72 h. Analysis of the expression of both key-regulator genes of adipocyte metabolism and mitochondria-biogenesis markers was performed.
  
  
  RESULTS
  We found an increased gene expression of peroxisome proliferator-activated receptor-γ (PPAR-γ), adiponectin, and proliferator- activated receptor gamma coactivator-1 α (PGC-1α) after a 24-h stimulation with vardenafil at the lowest concentration employed compared to controls (p<0.05). After 72 h of stimulation, a significant increase of mitochondrial DNA was found compared to control samples (p<0.05).
  
  
  CONCLUSIONS
  Our data suggest that PDE-5 inhibition could have an impact on mitochondrial content of human AT suggesting a positive effect on energy metabolism and adding new elements in the comprehension of AT pathophysiology.
authors.affiliation: Department of Histology, Microbiology and Medical Biotechnologies, Section of Clinical Pathology and Centre for Human Reproduction Pathology, University of Padua, Via Gabelli 63, 35121 Padua, Italy.
authors.forename: L
authors.initials: L
authors.lastname: De Toni
authors.forename: G
authors.initials: G
authors.lastname: Strapazzon
authors.forename: L
authors.initials: L
authors.lastname: Gianesello
authors.forename: N
authors.initials: N
authors.lastname: Caretta
authors.forename: C
authors.initials: C
authors.lastname: Pilon
authors.forename: A
authors.initials: A
authors.lastname: Bruttocao
authors.forename: C
authors.initials: C
authors.lastname: Foresta
mesh_terms: D052242:Adiponectin / Q000096:biosynthesis; D000368:Aged; D004272:DNA, Mitochondrial / Q000096:biosynthesis*; D004734:Energy Metabolism / Q000187:drug effects*; D006360:Heat-Shock Proteins / Q000096:biosynthesis; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology*; D050152:Intra-Abdominal Fat / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000378:metabolism; D009569:Nitric Oxide / Q000502:physiology; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009603:Nitroso Compounds / Q000494:pharmacology; D047495:PPAR gamma / Q000096:biosynthesis; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D058986:Phosphodiesterase 5 Inhibitors / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology*; D013450:Sulfones / Q000494:pharmacology; D014157:Transcription Factors / Q000096:biosynthesis; D014227:Triazines / Q000494:pharmacology; D015854:Up-Regulation; D000069058:Vardenafil Dihydrochloride
chemical_list: C499918:ADIPOQ protein, human; D052242:Adiponectin; D004272:DNA, Mitochondrial; D006360:Heat-Shock Proteins; D007093:Imidazoles; D020030:Nitric Oxide Donors; D009603:Nitroso Compounds; D047495:PPAR gamma; C486497:PPARGC1A protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D013450:Sulfones; D014157:Transcription Factors; D014227:Triazines; C094210:2,2'-(hydroxynitrosohydrazono)bis-ethanamine; D009569:Nitric Oxide; D000069058:Vardenafil Dihydrochloride