On the role of placental growth factor in murine adipogenesis

The potential role of placental growth factor (PlGF) in early stages of adipogenesis was investigated in vivo using a murine model of obesity, as well as in vitro using cultured preadipocytes. PlGF-deficient (PlGF-/-) and wild-type (WT) mice, kept on high fat diet (HFD) for 3 weeks, had comparable body weight and weight of subcutaneous (SC) and gonadal (GON) adipose tissues. Blood vessel size and blood vessel density, normalized to adipocyte number, were not significantly different in SC and GON adipose tissues of both genotypes. Differentiation of embryonic fibroblasts derived from WT or PlGF-/- mice into mature adipocytes was comparable. Furthermore, addition of recombinant PlGF, of the PlGF neutralizing MAb PL5D11D4 or of the anti-Flk-1 MAb DC101 to cultured 3T3-F442A preadipocytes did not significantly affect their differentiation into mature adipocytes. Ex vivo blood vessel outgrowth following seeding of adipose tissue-derived microvessel fragments in 3D-collagen gels was not affected by PlGF deficiency. Thus, in murine model systems, PlGF does not seem to play an important role in early adipogenesis.