title: Regulation of adipokine production in human adipose tissue by propionic acid.
abstract: BACKGROUND
  Dietary fibre (DF) has been shown to be protective for the development of obesity, insulin resistance and type 2 diabetes. Short-chain fatty acids, produced by colonic fermentation of DF might mediate this beneficial effect. Adipose tissue plays a key role in the regulation of energy homeostasis, therefore, we investigated the influence of the short-chain fatty acid propionic acid (PA) on leptin, adiponectin and resistin production by human omental (OAT) and subcutaneous adipose tissue (SAT). As PA has been shown to be a ligand for G-protein coupled receptor (GPCR) 41 and 43, we investigated the role of GPCR's in PA signalling.
  
  
  METHODS
  Human OAT and SAT explants were obtained from gynaecological patients who underwent surgery. Explants were incubated for 24 h with PA. Adipokine secretion and mRNA expression were determined using ELISA and RT-PCR respectively.
  
  
  RESULTS
  We found that PA significantly stimulated leptin mRNA expression and secretion by OAT and SAT, whereas it had no effect on adiponectin. Furthermore, PA reduced resistin mRNA expression. Leptin induction, but not resistin reduction, was abolished by inhibition of Gi/o-coupled GPCR signalling. Moreover, GPCR41 and GPCR43 mRNA levels were considerably higher in SAT than in OAT.
  
  
  CONCLUSIONS
  We demonstrate that PA stimulates expression of the anorexigenic hormone leptin and reduces the pro-inflammatory factor resistin in human adipose tissue depots. This suggests that PA is involved in regulation of human energy metabolism and inflammation and in this way may influence the development of obesity and type 2 diabetes.
authors.affiliation: Top Institute Food and Nutrition, Wageningen, The Netherlands. s.lahham@med.umcg.nl
authors.forename: Sa'ad H
authors.initials: SH
authors.lastname: Al-Lahham
authors.forename: Han
authors.initials: H
authors.lastname: Roelofsen
authors.forename: Marion
authors.initials: M
authors.lastname: Priebe
authors.forename: Desiree
authors.initials: D
authors.lastname: Weening
authors.forename: Martijn
authors.initials: M
authors.lastname: Dijkstra
authors.forename: Annemieke
authors.initials: A
authors.lastname: Hoek
authors.forename: Farhad
authors.initials: F
authors.lastname: Rezaee
authors.forename: Koen
authors.initials: K
authors.lastname: Venema
authors.forename: Roel J
authors.initials: RJ
authors.lastname: Vonk
mesh_terms: D054392:Adipokines / Q000378:metabolism*; D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D000368:Aged; D004305:Dose-Response Relationship, Drug; D005260:Female; D015870:Gene Expression; D006801:Humans; D008875:Middle Aged; D011422:Propionates / Q000627:therapeutic use*; D012333:RNA, Messenger / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D054392:Adipokines; D011422:Propionates; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; C029658:propionic acid