Effects of inflammation on LDLr, HMGCoAR and SREBP2 expression in THP-1 macrophages.

<p>THP-1 macrophages were incubated in serum free medium for 24 h at 37°C. The medium was then replaced by fresh serum-free medium in the absence (control) or presence of 40 ng/ml IL-6 or 50 ng/ml TNF-α or 25 µg/ml LDL alone or 40 ng/ml IL-6 plus 25 µg/ml LDL or 50 ng/ml TNF-α plus 25 µg/ml LDL for 24 h at 37°C. The mRNA levels were determined following the ΔΔ threshold cycle (Ct) protocol for real time RT-PCR as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0075650#s2" target="_blank">Materials and Methods</a> section. β-Actin served as a reference gene. Results represent the mean± SD from 4 experiments (A). The protein levels were examined by Western blotting (B). The histogram represents mean± SD of the densitometric scans of N-SREBP2, HMGCoAR and LDLr protein bands from four experiments, normalized by comparison with β-Actin and expressed as a percentage of control (C). ^*P<0.05 vs control; ^**P<0.01 vs control; ^#P<0.05 vs LDL; ^## P<0.01 vs LDL.