Vitamin D limits chemokine expression in adipocytes and macrophage migration in vitro and in male mice

Abstract

Vitamin D (VD) displays immunoregulatory effects and reduces adipocyte inflammation, which may participate to a reduction of adipose tissue macrophage infiltration in the context of obesityassociated low-grade inflammation. These observations have been described mainly in vitro, through the evaluation of a limited number of inflammatory markers. Here, we studied the effects of 1,25 dihydroxy-VD on chemokine network expression in adipocytes (by transcriptomic approach), and we confirm the physiological relevance of these data in vivo, by demonstrating the effect of VD on cytokine and chemokine gene expression as well as on macrophage infiltration in adipose tissue. 1,25 dihydroxy-VD down-regulated (-1.3- to -10.8-fold) the mRNA expression of 29 chemokines and limited macrophage migration in TNFα-conditioned adipocyte medium (1.5- fold; P < .05). This effect was associated with a reduction in p65 and IκB (nuclear factor of kappa light polypeptidegeneenhancer in B-cells inhibitor, alpha) phosphorylation (2-foldcomparedwith TNFα;