Feb. 3, 2009 Individuals who are obese have an increased risk of
developing type 2 diabetes, in part because they often become
resistant to the effects of the hormone insulin. Resistin is a
soluble factor produced by fat cells (adipocytes) that is linked
to the development of insulin resistance in mice. However,
studies have thus far failed to determine such a clear
association in humans. But now, Mitchell Lazar and colleagues,
at the University of Pennsylvania, Philadelphia, have determined
that human resistin contributes to the development of insulin
resistance in mice. The research appears online, Feb. 2nd, 2009,
in the Journal of Clinical Investigation. One factor that has
complicated studies attempting to determine the role of resistin
in the development of insulin resistance in humans, is that
resistin is produced mainly by immune cells known as macrophages
in humans, whereas it is produced by adipocytes in mice. To
overcome this issue, the authors generated mice lacking mouse
resistin and expressing hu