MIP-1α expression induced by TGF-β1 is mediated through RhoA. (A) Cells were incubated with none, 1 μg/mL LPS, TGF-β1, 10 μg/mL Tat-C3, or 30 μM H89 for 1 hour, and then incubated followed by 5 ng/mL TGF-β1 for 1 hour. (B) Cells were either not transfected (N) or transfected with 4 μg/mL mock vector (M), cDNA constructs encoding WT-RhoA (W), CA-RhoA (C), or DN-RhoA (D). (C) After 36 hours, cells were incubated with or without 5 ng/mL TGF-β1 for 1 hour or 24 hours. The levels of MIP-1α and GAPDH mRNAs were measured by RT-PCR (A-B). Raw 264 cells were transiently transfected with mock vector, DN-N19RhoA, and DN-N17Cdc42, and then MIP-1α secreted from Raw264 cells in response to TGF-β1 for 6 hours was measured by ELISA technique. Data are expressed as mean ± SE of 3 independent experiments (**P < .01).