Study On The Mechanism Of DAXX Overexpression In Inhibiting VSMC Proliferation After Aortic Balloon Injury In Rats

Objective: DAXX overexpression may inhibit the proliferation of vascular smooth muscle cells after abdominal aortic balloon injury in SD rats through the PTEN/AKT/NF-?B signaling pathway.Methods: Forty-eight male SD rats were randomly divided into sham-operated group,model group,lentivirus empty vector(pCDH-EGFP)group and recombinant lentivirus(pCDH-Daxx-EGFP)group,12 in each group.The sham-operation group and the model group received 100 ul of normal saline through the tail vein each time,twice at an interval of 2 days.The lentivirus empty vector group(pCDH-EGFP)and the recombinant lentivirus group(pCDH-Daxx-EGFP)were injected with 100 ul of pCDH-EGFP virus solution(lentivirus titer 1×109TU/ml)and 100 ul of pCDH-Daxx-EGFP virus solution respectively through the tail vein,twice at an interval of 2 days.On the 14 th day after the operation,HE staining was performed on the lower abdominal aorta of the kidney of the rats to observe intimal hyperplasia and the ratio of intimal and middle membrane thickness was calculated.Immunofluorescence staining was used to detect the expression of DAXX and ?-SMA in rat abdominal aortic smooth muscle cells.Expression of Daxx,PTEN,p-AKT and NF-?B in abdominal aortic smooth muscle cells was detected by western blot.Results: 1.HE staining showed that the arterial vessels in the operation-group were narrowed to different degrees and the intima was thickened;Among the model group and the lentiviral empty vector(pCDH-EGFP)group,the thickening of the vascular intima was the most obvious.The ratio of the thickness of the vascular intima and media of the recombinant lentivirus(pCDH-Daxx-EGFP)group was lower than the model group and the lentiviral empty vector(PCDH-EGFP)group(P <0.05);2.Immunofluorescence staining showed that the expression of Daxx/?-SMA in smooth muscle cells of the sham-group was lower than that in the surgery group;the expression of Daxx in the recombinant lentivirus group was higher than that in the model group and the lentiviral empty vector group,while the expression of ?-SMA protein was lower than the model group and the lentiviral empty vector group.3.Western blot showed that the expression levels of Daxx,PTEN,p-AKT and NF-?B in smooth muscle cells the operation group were higher than those in the sham-group(P<0.05).The expression of Daxx and PTEN in the recombinant lentivirus group was higher than the model group and the lentiviral empty vector group(P<0.05),while the expression of p-AKT and NF-?B was lower than the model group and the lentiviral empty vector group(P<0.05),all the above results were statistically significant.Conclusions: 1.DAXX overexpression can inhibit the proliferation of VSMC after balloon injury of abdominal aorta in rats;2.The mechanism of DAXX overexpression inhibiting the proliferation of VSMC after abdominal aortic balloon injury may be related to the down-regulation of PTEN / AKT / NF-?B signaling pathway.