Macrophage-secreted factors decrease RBP4 production.

<p>SGBS adipocytes (A, B, C) were treated with increasing concentrations of MacCM (5, 10, 20, 50%) or the corresponding vehicle control. (A) Representative pictures of cells treated for 48 hours with 10% of MacCM. (B) RBP4 mRNA expression was measured by quantitative PCR. RBP4 expression was normalized to succinate dehydrogenase complex subunit A (SDHA) and related to medium control using 2^−ΔΔCT method. Data are presented as mean+SEM of three independent experiments. *p<0.05 (treatment vs. vehicle). (C) Accumulation of RBP4 in the medium supernatant was measured by ELISA. Measurements were related to untreated medium control. Data are presented as mean+SEM of three independent experiments. *p<0.05 (treatment vs. vehicle). (D, E) Human primary adipocytes obtained from three different donors were treated with 10% of MacCM or vehicle. (D) mRNA expression and (E) secretion of RBP4 was performed as described above. *p<0.05 (treatment vs. vehicle). (F) SGBS adipocytes were treated with 10% MacCM or vehicle for 24, 48, and 72 hours. mRNA expression of RBP4 was measured by quantitative PCR. RBP4 expression was normalized to SDHA and related to medium control at 0 hours using 2^−ΔΔCT method. *p<0.05 (treatment vs. vehicle).