Figure 6. Leptin reduces Ser-46 p53 phosphorylation level in placenta.

A) Swan-71 cells (1×10⁶ cells) were plated in DMEM-F12 10% FBS. After 24 h cells were incubated during 24 h with increasing doses of leptin in DMEM-F12 in the absence of serum. Cell extracts were prepared as indicated in Materials and Methods and proteins were separated on SDS-PAGE gels. B) Placental explants were processed as described in Material and Methods and incubated in DMEM-F12 0% FBS media supplemented with increasing leptin doses during 24 h. DMEM-F12 10% FBS was used as a control. Placental extracts were prepared and proteins were separated on SDS-PAGE gels. In both cases (A and B) Phospho Ser-46 p53 was determined by Western blot analysis. DMEM-F12 media supplemented with 10% FBS was used as control. Molecular weights were estimated using standard protein markers. Molecular mass (kDa) is indicated at the right of the blot. Loading controls were performed by immunoblotting the same membranes with anti-GAPDH. Bands densitometry is shown in lower panels. Results are expressed as mean ± SD for three independent experiments. Statistical analyzes were performed by ANOVA. Asterisks indicate significant differences from the control according to Bonferroni's multiple comparison post hoc test, relative to FBS 10% (#) or FBS 0% (*). ## p<0.01 * p<0.05, ** p<0.01.