25(OH)D3 and 1.25(OH)2D3 inhibits TNF-α expression in human monocyte derived macrophages.

Purpose: We wanted to investigate effects of vitamin D3 (25(OH)D3 and 1.25(OH)2D3) on inflammatory cytokine expression in both activated and non-activated Mφ.

Materials And Methods: Mononuclear cells, isolated from healthy donor buffy coats were cultured for a 6-day differentiation-period. Fully differentiated Mφ were pre-treated with either 25(OH)D3 or 1.25(OH)2D3 for (4, 12 or 24 hours) +/-LPS challenge for 4 hours. Gene expression analyses of VDR, Cyp27b1 and pro-inflammatory markers TNF-α, IL-6, NF-κB, MCP-1, was performed using RT-quantitative PCR. TNF-α protein levels from Mφ culture media were analysed by ELISA.

Results: Both 25(OH)D3 and 1.25(OH)2D3 significantly inhibited TNF-α expression in both LPS-stimulated and unstimulated Mφ. Also, NF-κB, and to a lesser extend IL-6 and MCP-1 were inhibited. LPS up-regulated Cyp27b1 gene expression which was partly reverted by 1.25(OH)2D3.

Conclusion: These data show anti-inflammatory effects of vitamin D3 (25(OH)D3 and 1.25(OH)2D3) in human macrophages, and support, that means for targeting high dose vitamin D3 to the immune system may have beneficial clinical effect in inflammatory conditions.