NAMPT

Adipocytokines, predominantly derived from adipocytes, play a crucial role in regulating metabolism and insulin resistance, with some, such as adiponectin and leptin, also influencing immune and inflammatory functions. Visfatin, identified as a new adipocytokine, is known to impact insulin resistance by binding to the insulin receptor. In this study, recombinant visfatin was shown to activate human leukocytes and induce cytokine production, particularly IL-1β, TNF-α, and IL-6 in CD14(+) monocytes. Additionally, visfatin increased the expression of costimulatory molecules (CD54, CD40, and CD80) and enhanced the uptake of FITC-dextran, as well as the ability of monocytes to induce lymphocyte proliferation. The effects of visfatin were found to involve the p38 and MEK1 pathways, with activation of NF-kB observed. In vivo, visfatin increased circulating IL-6 levels in BALB/c mice. Furthermore, elevated visfatin levels and increased mRNA expression were observed in the plasma and colonic tissue of patients with inflammatory bowel diseases (IBD), such as Crohn's disease and ulcerative colitis. Macrophages, dendritic cells, and colonic epithelial cells were identified as potential sources of visfatin. This study suggests that visfatin plays a role as a proinflammatory mediator, contributing to inflammatory conditions such as IBD