Calcitriol prevents inflammatory gene expression in macrovascular endothelial cells

BACKGROUND: Calcitriol (vitamin D) supplementation has been proposed for therapeutical use in vascular diseases due to its immunomodulatory activity, preventing inflammation and promoting angiogenesis. In the present study, we hypothesised whether calcitriol downregulates pro-inflammatory gene expression without affecting angiogenesis and anti-inflammatory gene expression in LPS-induced endothelial cells. METHOD: In order to evaluate the effect of calcitriol in suppressing inflammatory gene expression in the endothelium, endothelial cells were exposed to the physiological concentration of calcitriol followed by stimulation with lipopolysaccharide (LPS). Gene expression of interleukin (IL)-1β, Transforming Growth Factor (TGF)-β, Human β-defensin (HBD)-2, angiogenin (ANG) and cathelicidin (LL-37) were quantified by quantitative polymerase chain reaction. RESULTS: The results from six independent experiments conducted in duplicate, showed that calcitriol decreased IL-1β (p < 0.01) and HBD-2 expression (p < 0.01) when compared to non-treated cells. However, calcitriol treatment had no effect on TGF-β, ANG and LL-37 gene expression. CONCLUSION: Calcitriol prevents inflammatory gene expression, but does not affect expression of angiogenic genes in endothelial cells, which suggest the potential use of calcitriol to prevent endothelial activation through the downregulation of IL-1β and HBD-2.