Inhibition effect of small interfering RNA of connective tissue growth factor on the expression of vascular endothelial growth factor and connective tissue growth factor in cultured human peritoneal mesothelial cells

Background The peritoneum response to peritoneal dialysis can lead to fibrosis.The transforming growth factor β(TGF-β)plays a key role in regulating tissue repair and remodelling after injury.Connective tissue growth factor(CTGF),a downstream mediator of TGF-βinducing fibrosis,has been implicated in peritoneal fibrosis.Vascular endothelialgrowth factor(VEGF)plays a key role in angiogenesis that can hasten peritoneal fibrosis.In this study,we investigatedthe effect of small interfering RNA(siRNA)of CTGF by pRETRO-SUPER(PRS)retrovirus vector on the expression ofCTGF and VEGF in human peritoneal mesothelial cells.Methods Retrovirus producing CTGF siRNA were constructed from the inverted oligonucleotides and transferred intopackaging cell line PT67 with lipofectamine,and the virus supernatant was used to infect human peritoneal mesothelialcell(HPMC).The cells were divided into seven groups:low glucose DMEM,low glucose DMEM+TGF-β5 ng/ml,lowglucose DMEM+TGF-β5 ng/ml+PRS-CTGF-siRNAand low glucose DMEM+TGF-β5 ng/ml+PRS.Theexpression of CTGF and VEGF were measured by semiquantitative RT-PCR and Western blot.Results Low levels of CTGF and VEGF were detected in confluent HPMCs.Following stimulation with TGF-β,thelevels of CTGF and VEGF were significantly upregulated(P<0.01).Introduction of PRS-CTGF-siRNAresulted in thesignificant reduction of CTGF mRNA and protein,and VEGF mRNA(P<0.01),especially in groups PRS-CTGF-siRNAand PRS-CTGF-siRNA.The introduction of PRS void vector did not have these effects(P>0.05).Conclusions The expression of CTGF siRNA mediated by PRS retrovirus vector can effectively reduce the level ofCTGF and VEGF induced by TGF-βin cultured HPMCs.This study may provide potential therapeutic strategies toprevent the peritoneal fibrosis.