Effects of 1,25-Dihydroxyvitamin D3 on the Inflammatory Responses of Stromal Vascular Cells and Adipocytes from Lean and Obese Mice

• Main Authors: Chan Yoon Park, Tae Yeon Kim, Ji Su Yoo, Yeonkyung Seo, Munkyong Pae, Sung Nim Han
• Format: Article
• Language: English
• Published: MDPI AG 2020-01-01
• Series: Nutrients
• Subjects: obesity; 1,25-dihydroxyvitamin d; stromal vascular cell; adipose tissue inflammation; vitamin d supplementation; macrophage infiltration
• Online Access: https://www.mdpi.com/2072-6643/12/2/364

Vitamin D status has been implicated in obesity and adipose tissue inflammation. In the present study, we explored the effects of dietary vitamin D supplementation on adipose tissue inflammation and immune cell population, and the effects of in vitro 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) treatment on pro-inflammatory cytokine production by stromal vascular cells (SVCs) and adipocytes in lean and high-fat diet-induced obese mice. The results show that epididymal fat <i>Mcp-1</i> and <i>Rantes</i> mRNA levels, which were higher in obese mice compared with lean mice, were significantly down-regulated by vitamin D supplementation. While obese mice had higher numbers of macrophages and natural killer (NK) cells within adipose tissue, these remained unaltered by vitamin D supplementation. In accordance with these in vivo findings, the in vitro 1,25(OH)2D3 treatment decreased IL-6, MCP-1, and IL-1&#946; production by SVCs from obese mice, but not by adipocytes. In addition, 1,25(OH)2D3 treatment significantly decreased <i>Tlr2</i> expression and increased mRNA levels of <i>I&#954;ba</i> and <i>Dusp1</i> in SVCs. These findings suggest that vitamin D supplementation attenuates inflammatory response in adipose tissue, especially in SVCs, possibly through inhibiting NF-&#954;B and MAPK signaling pathways in SVCs but not by the inhibition of macrophage infiltration.