Analysis of mRNA expression of specific early and late genes involved in adipogenesis by quantitative real time RT-PCR. MSCs were challenged with HIV-1 strains (5 ng/ml) and gp120 (1 μg/ml) in the presence or absence of anti-gp120 pAb, anti p24 pAb and p5p. Panel A and C show the up-regulation of two transcription factor gene expressions such as C/EBP β and C/EBP δ involved in the early stages of differentiation. The analysis was performed at day 3 post-stimulation and the two mRNA were significantly increased with respect to adipogenesis differentiated cell cultures. In B and D, some late markers of adipogenic differentiation such as adipsin and UCP-1 mRNA expression were analyzed. Adipsin was significantly up-regulated at day 10 whereas UCP-1 a marker of brown fat was barely expressed and without any significant difference with respect to the controls. The results were expressed by the ratio between samples and the control represented by adipogenesis differentiated cell cultures after 18S ribosomial normalization. The adipogenesis differentiated cell culture mRNA was set at 1. The data represent the mean (+SD) of three independent experiments performed in duplicate. Statistical significance was determined using Student's t test with *p < 0.05.