Objectives: To elucidate the main source of circulating visfatin and its potential roles in pathogenesis of gestational diabetes mellitus (GDM).
Methods: We examined serum concentrations of visfatin with ELISA and its expression in subcutaneous adipose tissue, visceral adipose tissue and placenta with RT-PCR and western blot both in women with GDM and normal pregnant controls at term. Moreover, BeWo cells were treated with tumor necrosis factor-alpha (TNF-alpha) and then the intra- and extra-cellular changes of visfatin expression were measured.
Results: Serum visfatin concentrations were significantly higher in women with GDM than controls, which reduced obviously three days after delivery compared with antepartum. Visfatin expressions in placenta were significantly higher in GDM women than controls but there was no difference in its expressions in adipose tissue between the two groups. Moreover, serum visfatin concentrations correlated positively with its expressions in placenta, rather than adipose tissue. We demonstrated that visfatin secretion from BeWo cells was significantly increased but the intracellular expression was decreased at 48h incubation with TNF-alpha in a dose-depended way.
Conclusions: The oversecretion of visfatin from placenta, probably induced by the elevated TNF-alpha level, contributes to the increased serum visfatin concentrations in women with GDM.