OMNT1

This study identifies a novel visceral fat-specific adipokine, named omentin, which may play a role in regulating insulin sensitivity. The researchers sequenced 10,437 expressed sequence tags (ESTs) from a human omental fat cDNA library and discovered omentin as a secretory protein expressed predominantly in visceral adipose tissue. Omentin mRNA was found to be abundant in omental tissue compared to subcutaneous (sc) fat, and was expressed in stromal vascular cells rather than adipocytes. Protein analysis revealed that omentin, a 313-amino-acid peptide, contains a secretory signal sequence and a fibrinogen-related domain. Recombinant omentin enhanced insulin-stimulated glucose uptake in both sc and omental adipocytes, with the effect being more pronounced in sc fat cells. Additionally, omentin increased Akt phosphorylation, suggesting it enhances insulin signaling. The findings highlight the potential role of omentin in modulating insulin action and its potential contribution to the metabolic dysfunction observed in visceral obesity.