Technical Note: A comparison among adipogenic induction protocols for dedifferentiated fat (DFAT) cells obtained from subcutaneous fat of pigs

In the current study we have performed two experiments to evaluate the effects of adipogenic induction media on dedifferentiated fat (DFAT) cells redifferentiation into mature adipocytes. In experiment 1, we aimed to evaluate whether it is necessary to use insulin in the induction media to allow DFAT cells differentiation into mature adipocytes by establishing two experimental treatments where insulin was either withdrawn from the culture medium, after 72 h of a normal induction period (Treatment 1: Insulin-) or kept in culture media (Treatment 2: Insulin+) for 16 d. In experiment 2, we aimed to evaluate if the lack of 3-isobutyl-1-methylxanthine (IBMX) in the induction medium would affect the differentiation of DFAT cells into mature adipocytes. For that, DFAT cells were induced to differentiate into lipid assimilating adipocytes using an induction medium containing IBMX (Treatment 1: IBMX+) or without IBMX (Treatment 2: IBMX-) during the first 72 h of induction. In both experiments we have evaluated the mRNA expression of lipid metabolism markers and cell morphology through Oil-Red staining as indicators of differentiation of DFAT cells into lipid-assimilating cells. The results of Experiment 1 revealed no differences in mRNA expression for any of the lipid metabolism markers with exception of GLUT4 (P=0.02), which was greater in Insulin- compared to Insulin+ treatment. Similarly, no differences were observed for mRNA expression of adipogenic markers between IBMX+ and IBMX- treatments with exception of FABP4 (P=0.01), which was greater for the IBMX- compared to IBMX+ treatment. In both experiments we did not observed any differences in cell morphology among treatments. Our results suggest that neither insulin nor IBMX are required to accelerate redifferentiation process of pig-derived DFAT cells.