Platelet-derived growth factor (PDGF)-BB induces monocyte chemoattractant protein 1 (MCP-1) mRNA and protein expression in human astrocytes. (A,B) Time-dependence of PDGF-BB-mediated induction of MCP-1 mRNA expression in human A172 astrocytes. Total RNA isolated from human A172 astrocytes was subjected to reverse-transcriptase polymerase chain reaction (RT-PCR) and real-time RT-PCR analysis using primers for human MCP-1 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and 18S, respectively. PDGF-BB-mediated induction of MCP-1 mRNA expression peaked at 6 h and decline thereafter. (C) Time-dependence of PDGF-BB-mediated induction of MCP-1 protein expression in human A172 astrocytes. Supernatant fluid from human A172 cells treated with PDGF-BB for various time points were assessed for release of chemokine MCP-1 using the human MCP-1 enzyme-linked immunosorbent assay (ELISA) kit. PDGF-BB treatment resulted in a time-dependent induction of MCP-1 expression. All the data are presented as mean ± SD of three individual experiments. **P <0.01, ***P <0.001 versus control group; sfm = serum-free media.