Role of IGF-I in brown adipocytes proliferation and differentiation

Abstract

Fetal brown adipocyte in primary culture undergoes proliferation in the presence of IG-I and also induces the adipogenic-program related to lipid synthesis and the thermogenic-program associated with the expression of the uncoupling protein. Moreover, we have recently described an endogenous expression of IGF-I mRNA in brown adipose tissue at day 20 of fetal development and also an increase in the IGF-I receptor mRNA content at the end of the fetal life, which runs parallel to the onset of late tissue differentiation. Thus, IGF-I, in an autocrine/paracrine fashion may be a major signal involved in brown adipose tissue development prior to birth.