title: Fatty acids do not pay the toll: effect of SFA and PUFA on human adipose tissue and mature adipocytes inflammation.
abstract: BACKGROUND
  On the basis that high fat diet induces inflammation in adipose tissue, we wanted to test the effect of dietary saturated and polysunsaturated fatty acids on human adipose tissue and adipocytes inflammation. Moreover we wanted to determine if TLR2 and TLR4 are involved in this pathway.
  
  
  METHODS
  Human adipose tissue and adipocytes primary cultures were treated with endotoxin-free BSA conjugated with SFA (lauric acid and palmitic acid--LA and PA) and PUFA (eicosapentaeneic acid, docosahexaenoic acid and oleic acid--EPA, DHA and OA) with or without LPS. Cytokines were then assayed by ELISA (TNF-alpha, IL-6 and MCP-1). In order to determine if TLR2 and TLR4 are activated by fatty acid (FA), we used HEK-Blue cells transfected by genes from TLR2 or TLR4 pathways associated with secreted alkaline phosphatase reporter gene.
  
  
  RESULTS
  None of the FA tested in HEK-Blue cells were able to activate TLR2 or TLR4, which is concordant with the fact that after FA treatment, adipose tissue and adipocytes cytokines levels remain the same as controls. However, all the PUFA tested: DHA, EPA and to a lesser extent OA down-regulated TNF-alpha, IL-6 and MCP-1 secretion in human adipose tissue and adipocytes cultures.
  
  
  CONCLUSIONS
  This study first confirms that FA do not activate TLR2 and TLR4. Moreover by using endotoxin-free BSA, both SFA and PUFA tested were not proinflammatory in human adipose tissue and adipocytes model. More interestingly we showed that some PUFA exert an anti-inflammatory action in human adipose tissue and adipocytes model. These results are important since they clarify the relationship between dietary fatty acids and inflammation linked to obesity.
authors.affiliation: GEICO-Study Group on Chronic Inflammation and Obesity, Platform 'Cyclotron Reunion Ocean Indien' CYROI, 2 Rue Maxime Rivière, Sainte-Clotilde, Reunion Island 97490, France.
authors.forename: Ravi Kumar
authors.initials: RK
authors.lastname: Murumalla
authors.forename: Manoj Kumar
authors.initials: MK
authors.lastname: Gunasekaran
authors.forename: Jibesh Kumar
authors.initials: JK
authors.lastname: Padhan
authors.forename: Karima
authors.initials: K
authors.lastname: Bencharif
authors.forename: Lydie
authors.initials: L
authors.lastname: Gence
authors.forename: Franck
authors.initials: F
authors.lastname: Festy
authors.forename: Maya
authors.initials: M
authors.lastname: Césari
authors.forename: Régis
authors.initials: R
authors.lastname: Roche
authors.forename: Laurence
authors.initials: L
authors.lastname: Hoareau
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000187:drug effects; D000273:Adipose Tissue / Q000187:drug effects / Q000254:growth & development; D000818:Animals; D002478:Cells, Cultured; D059305:Diet, High-Fat; D015536:Down-Regulation / Q000187:drug effects; D005227:Fatty Acids / Q000008:administration & dosage; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage; D006801:Humans; D007249:Inflammation / Q000235:genetics / Q000378:metabolism; D051379:Mice; D051195:Toll-Like Receptor 2 / Q000378:metabolism*; D051197:Toll-Like Receptor 4 / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4