RESEARCH ARTICLE Macrophage Migration Inhibitory Factor in Acute Adipose Tissue Inflammation

Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine and has been impli-cated in inflammatory diseases. However, little is known about the regulation of MIF in adi-pose tissue and its impact on wound healing. The aim of this study was to investigate MIF expression in inflamed adipose and determine its role in inflammatory cell recruitment and wound healing. Adipose tissue was harvested from subcutaneous adipose tissue layers of 24 healthy subjects and from adipose tissue adjacent to acutely inflamed wounds of 21 patients undergoing wound debridement. MIF protein and mRNA expression were mea-sured by ELISA and RT-PCR. Cell-specific MIF expression was visualized by immunohis-tochemistry. The functional role of MIF in cell recruitment was investigated by a chemotaxis assay and by flow cytometry of labeled macrophages that were injected intoMif–/–and wild-type mice. Wound healing was evaluated by an in vitro scratch assay on human fibroblast monolayers. MIF protein levels of native adipose tissue and supernatants from acutely inflamed wounds were significantly elevated when compared to healthy controls. MIF mRNA expression was increased in acutely inflamed adipose tissue indicating the activa