Leptin restores plasma cholesterol, glucose and weight loss induced by IFNalpha treatment

Leptin, an adipokine, a major regulator of food intake, was recently suggested to play a role in immune response. We previously showed that weight reduction following IFNalpha therapy is due, at least in part, to direct induction of adipose tissue apoptosis. We now studied the effect of leptin on IFNalpha treated adipocytes in vitro and in vivo. Diet induced obese C57/B6 mice were treated continually with recombinant (r) IFNalphaA/D + leptin (100 U/g body weight + 10 microg/day, respectably) or leptin (10 microg/day) alone for 8 days. Co-administration of IFNalphaA/D + leptin significantly reduced plasma cholesterol (P<0.001), glucose (P<0.007) and pro-apoptotic protein levels (P<0.05). Additionally, co-administration prevented loss of body weight due to adipocyte apoptosis. Thus, leptin co-administration with IFNalphaA/D decreases some of the side effects of IFNalpha administration such as weight loss, cholesterol and glucose levels.