Pro-apoptotic effect of decorin on rat mesangial cells in vitro

Abstract

To investigate the effects of over-expression of decorin (DCN) gene on apoptosis of cultured rat mesangial cells (MsC). PcDNA3.1A-DCN plasmid was transfected into cultured rat MsC by the induction of liposome and positive clones were selected by treating the cells with G418. The MsC clones stably expressing DCN (MsC/DCN) were confirmed by cellular immunofluorescence, reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot. The DCN-siRNA was used for blocking DCN expression in MsC/DCN, and was confirmed by Western blot. The apoptosis of MsC was assayed by flow cytometry and Hoechst staining. Expression of Caspase-3 was assayed by Western blot. Positive clones with DCN over-expression were established. The apoptotic rate in MsC/DCN was (20.40 +/- 8.01)% and was much higher than the (2.07 +/- 0.99)% in MsC (P < 0.01). Some of the MsC/DCN cells showed typical morphologic changes of apoptosis. The protein expression of active Caspase-3 was also significantly increased in MsC/DCN compared to MsC (P < 0.01). DCN-siRNA transfection not only significantly blocked the expression of DCN and reduced the rate of apoptotic cells, but also down-regulated the expression of active Caspase-3. Over-expression of DCN induces apoptosis of cultured rat MsC in vitro. This effect of DCN inducing apoptosis suggests a novel strategy for regulating the proliferation of MsC in glomerular diseases.