ABSTRACT
Objective To use the antisense of Platelet-derived growth factor ? chain (PDGF-?) gene to inhibit the proliferation of rabbit vascular smooth muscle cells(VSMCs) in order to provide in situ basis on prevention and treatment of human restenosis. Methods A rabbit restenotic vascular model was constrcted and an antisense designed according to PDGF-? cDNA sequence as a drug was used to observe its effects on the expression of proliferating cell nuclear antigen and in situ expression of platele-derived growth factor ? chain by the VSMCs and the formation of neointima after injury. Results The antisense could significantly inhibit the expression of proliferating cell nuclear antigen and downregulate in situ expression of PDGF-? mRNA by intimal VSMCs one week after injury with inhibitory rates of 93.44% and 88.40%, respectively. Conclusion The antisense designed could inhibit the formation of neointima after injury through downregulating the expression of PDGF-? mRNA by local VSMCs, which provides the experimental basis of the antisense for the prevention and treatment the human restenosis.
ABSTRACT
AIM: To elucidate the in vivo mechanisms of the proliferation of vascular smooth muscle cells (VSMCS) in injuried arteries. METHODS: A VSMCS proliferative model was constructed by injury of rabbit iliac arteries with balloon catheters and a probe designed for rabbit platelet-derived growth factor B chain (PDGF-B ) mRNA was used to detect the expression of it by intimal VSMCS on the vascular cross sections using an in situ hybridization technique at the indicated times. The relation of this expression to the proliferation of VSMCS by their expression of proliferating cell nuclear antigen (PCNA) and vascular intimal areas were estimated. RESULTS: The expression of PDGF-B mRNA of intimal VSMCS was increased when calculating the intimal PDGF-B mRNA positive cells per millimetre area at ?400 magnification with average numbers of 31.93?14.64 in 1 week group, 26 50?9 25 in 2 weeks group and 24 85?13 65 in 4 weeks group. This was in accordance with the expression of PCNA by VSMCS and the increase of intimal areas. CONCLUSION: The local production of PDGF-B by VSMCS via an autocrine mechanism is responsible for the continuous proliferation of these cells and formation of neointima after the injury. The probe designed is very useful for detecting rabbit PDGF-B mRNA.
ABSTRACT
AIM: To elucidate the co-transfection of platelet derived growth factor B(PDGF-B) antisense oligonucleotide and tissue-type plasminogen activator gene to prevent vascular anastomotic restenosis after coronary bypass.METHODS: A dog model of vascular anastomotic restenosis after coronary bypass was constructed. A constructed tissue-type plasminogen activator(tPA) gene plasmid and a designed PDGF-B oligonucleotide were used to transfect into the dog cardiomyocytes and anastomotic vascular smooth muscle cells(VSMCs) at the same time of coronary bypass, using a therapeutic ultrasound for the gene delivery. Effects of these two genes on thrombosis in local anastomotic vessels, the expressions of proliferating cell nuclear antigen(PCNA) and PDGF-B mRNA by VSMCs and the proliferation of vascular intima were observed with the methods of routine pathological, immuno-histochemical staining, in situ hybridization and morphometry. RESULTS: PDGF-B antisense oligonucleotide and tissue-type plasminogen activator gene were succesfully transfected. These two genes significantly inhibited the expressions of PCNA and PDGF-B mRNA in intimal VSMCs with the inhibitory rates of 65.01% and 81.75%, respectively. The local intimal thickness and area also reduce markablely and the thrombosis of the anastomosis was prevented followed by the reduction of the anastomotic restenotic rate of 62.63%. CONCLUSION: Co-transfection of PDGF-B antisense oligonucleotide and tissue-type plasminogen activator gene inhibits the dog experimental anastomotic restenosis after coronary bypass.