Monocyte chemoattractant protein-1 and osteopontin expression in NZB/W mesangial cells with lipopolysaccharide treatment. Growth-arrested (under 2% fetal bovine serum (FBS)) mesangial cells were incubated with 10 μg/ml lipopolysaccharide (LPS) for different periods of time, and then levels of (a) monocyte chemoattractant protein-1 (MCP-1) mRNA or (b) osteopontin (OPN) mRNA were examined by real-time PCR. (c) MCP-1 protein levels in the culture supernatant were measured by ELISA. (d) OPN protein levels in the cell lysate were measured by western blot analysis; semiquantitative data are shown. The MCP-1 protein expression levels at various time points were normalized to total protein (pg/mg). The experiment was performed in triplicate, and results are expressed as the mean ± standard error, n = 6. The last time point without LPS stimulation (unstimulated) was presented as the negative control. *P < 0.05, **P < 0.01, ***P < 0.005.