Plasma retinol-binding protein-4 concentrations are elevated in human subjects with impaired glucose tolerance and type 2 diabetes.

Objective: The dysregulation of adipokines is closely associated with the pathogenesis of insulin resistance and type 2 diabetes. Retinol-binding protein-4 (RBP4), a new adipokine, was recently reported to provide a link between obesity and insulin resistance. Here, we examined the relation between plasma RBP4 concentrations and various metabolic parameters in humans.

The role of adipocytokines in adipocyte-related pathological processes.

It is becoming clear that adipose tissue is not merely a storage for excess energy but that it secretes a number of biologically active soluble factors collectively termed adipocytokines that control glucose and fatty acid metabolism. Of these adipocytokines, adiponectin and resistin have been the objects of intensive research, as they are implicated in obesity and diabetes-related diseases. In this review, we summarize recent advances in understanding the roles of adiponectin and resistin in the causation of metabolic diseases and consider the prospects for treating metabolic disorders by targeting these two adipocytokines.

Plasma resistin concentrations measured by enzyme-linked immunosorbent assay using a newly developed monoclonal antibody are elevated in individuals with type 2 diabetes mellitus.

Resistin is an adipocyte-derived peptide that might play a role in obesity and insulin resistance. However, its role in humans is largely unclear. Although many studies have measured the expression of human resistin in tissues, the circulating concentrations of resistin and its relation to metabolic parameters in humans are unknown.

Identification of a ligand for glucocorticoid-induced tumor necrosis factor receptor constitutively expressed in dendritic cells.

Glucocorticoid-induced tumor necrosis receptor (GITR) has been implicated in regulation of T cell suppression by CD25(+)CD4(+) regulatory T cells (Tregs). We isolated a cDNA encoding GITR ligand (GITRL) from mouse endothelioma cells. When stably expressed in HEK293 cells, its specific interaction with GITR was confirmed by flow cytometry with the use of GITR-Fc.