title: Investigations of the anti-inflammatory effects of vitamin D in adipose tissue: results from an in vitro study and a randomized controlled trial.
abstract: Inflammation is a key feature of obesity and type 2 diabetes. The active vitamin D metabolite, 1,25-dihydroxyvitamin D [1,25(OH)₂D], modulates the inflammation in vitro. We studied whether inflammation in adipose tissue (AT) cultures could be reduced by incubation with 1,25(OH)₂D in vitro, or by oral treatment with vitamin D in vivo in obese subjects with low plasma levels of 25-hydroxyvitamin D. Samples of subcutaneous AT were stimulated with IL-1β to induce inflammation. In the in vitro study, samples were concomitantly incubated with or without 1,25(OH)₂D, and analyzed for mRNA and protein levels of inflammatory markers IL-6, IL-8, and MCP-1. In the in vivo study, samples of subcutaneous AT from obese subjects obtained before and after treatment with 7,000 IU of vitamin D daily or placebo in a randomized controlled trial were stimulated with IL-1β. The samples were analyzed for AT gene expression and compared with plasma markers of inflammation. In the in vitro study, concomitant incubation with 1,25(OH)₂D reduced mRNA levels of MCP-1 by 45% (p=0.01), of IL-6 by 32% (p=0.002), and of IL-8 by 34% (p=0.03), and reduced secretion of IL-8 protein by 18% (p=0.005). In vivo treatment with vitamin D did not reduce AT expression or circulating levels of MCP-1, IL-6, or IL-8. 1,25(OH)₂D has significant anti-inflammatory effects in AT in vitro. However, a similar reduction in AT and systemic inflammation cannot be obtained by oral treatment with vitamin D in obese subjects.
authors: Department of Endocrinology and Internal Medicine MEA, Aarhus University Hospital, Aarhus, Denmark. louisewamberg@dadlnet.dk
authors: L
authors: L
authors: Wamberg
authors: K B
authors: KB
authors: Cullberg
authors: L
authors: L
authors: Rejnmark
authors: B
authors: B
authors: Richelsen
authors: S B
authors: SB
authors: Pedersen
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects* / Q000276:immunology; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D053583:Interleukin-1beta / Q000235:genetics / Q000276:immunology; D015850:Interleukin-6 / Q000235:genetics / Q000276:immunology; D016209:Interleukin-8 / Q000235:genetics / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000188:drug therapy* / Q000235:genetics / Q000276:immunology; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives*
chemical_list: D000893:Anti-Inflammatory Agents; D053583:Interleukin-1beta; D015850:Interleukin-6; D016209:Interleukin-8; D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D