6-ketoprostaglandin-f1-alpha and Carotid-Stenosis

A disordered proliferative process in the vascular wall is thought to underlie the pathogenesis of restenosis after percutaneous transluminal angioplasty and carotid endarterectomy. A growth inhibitory property of overexpressed prostacyclin (PGI2) synthase (PGIS) was recently implicated in the pathological proliferation of vascular smooth muscle cells (VSMC) in vitro. Here, we investigated the effects of increased PGI2 synthesis on the pathological proliferation of VSMCs.. The cDNA encoding human PGIS was transfected into endothelium-denuded rat carotid arteries after arterial balloon injury with the use of hemagglutinating virus Japan (HVJ). HVJ liposome vector complex without PGIS cDNA was used for vehicle control. The level of 6-keto PGF1alpha, a stable hydrolyzed metabolite of PGI2, the histological distribution of the immunoreactivity for human PGIS and the ratio of neointimal/medial area were analyzed.. In the analyses of 6-keto PGF1alpha, the level in the carotid arteries was significantly elevated 3 days after PGIS expression-vector transfection compared with that in the arteries after vehicle transfection. Seven days after human PGIS expression-vector transfection, the PGIS cDNA-transfected neointimal cells were strongly positive for human PGIS immunoreactivity in 81% sections examined. Fourteen days after the injury, the ratio of neointimal/medial area was 1.2+/-0.4 in the PGIS expression-vector transfected group, which was significantly smaller than that of the vehicle control group, 1.7+/-0.5; P<0.01.. It was thus demonstrated that the gene transfer of human PGIS expression-vector into rat carotid arteries resulted in the increased production of human PGI2 in the vascular wall, the expression of human PGIS in the developing neointima and significantly inhibited the neointimal formation generated after balloon injury.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Antibodies; Carotid Artery Injuries; Carotid Artery, Common; Carotid Stenosis; Catheterization; Cell Division; Cytochrome P-450 Enzyme System; Endothelium, Vascular; Epoprostenol; Follow-Up Studies; Gene Transfer Techniques; Genetic Vectors; Humans; Immunoblotting; Intramolecular Oxidoreductases; Liposomes; Male; Muscle, Smooth, Vascular; Rabbits; Rats; Rats, Sprague-Dawley; Respirovirus; Tunica Intima

Prostacyclin (PGI2), a metabolite of arachidonic acid, has the vasoprotective effects of vasodilation, anti-platelet aggregation, and inhibition of smooth muscle cell proliferation. We hypothesized that an overexpression of endogenous PGI2 may accelerate the recovery from endothelial damage and inhibit neointimal formation in the injured artery. To test this hypothesis, we investigated in vivo transfer of the PGI2 synthase (PCS) gene into balloon-injured rat carotid arteries by a nonviral lipotransfection method. Seven days after transfection, a significant regeneration of endothelium was observed in the arteries transfected with a plasmid carrying the rat PCS gene (pCMV-PCS), but little regeneration was seen in those with the control plasmid carrying the lacZ gene (pCMV-lacZ) (percent luminal circumference lined by newly regenerated endothelium: 87. 1+/-6.9% in pCMV-PCS-transfected vessels and 6.9+/-0.2% in pCMV-lacZ vessels, P<0.001). BrdU staining of arterial segments demonstrated a significantly lower incorporation in pCMV-PCS-transfected vessels (7. 5+/-0.3% positive nuclei in vessel cells) than in pCMV-lacZ (50. 7+/-9.6%, P<0.01). Moreover, 2 weeks after transfection, the PCS gene transfer resulted in a significant inhibition of neointimal formation (88% reduction in ratio of intima/media areas), whereas medial area was similar among the groups. Arterial segments transfected with pCMV-PCS produced significantly higher levels of 6-keto-PGF1alpha, the main metabolite of PGI2, compared with the segments transfected with pCMV-lacZ (10.2+/-0.55 and 2.1+/-0.32 ng/mg tissue for pCMV-PCS and pCMV-placZ, P<0.001). In conclusion, this study demonstrated that an in vivo PCS gene transfer increased the production of PGI2 and markedly inhibited neointimal formation with accelerated reendothelialization in rat carotid arteries after balloon injury.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Aorta; Carotid Arteries; Carotid Artery Injuries; Carotid Stenosis; Catheterization; Cell Division; Cytochrome P-450 Enzyme System; Endothelium, Vascular; Gene Expression Regulation, Enzymologic; Gene Transfer Techniques; Genes, Reporter; Intramolecular Oxidoreductases; Lac Operon; Male; Muscle, Smooth, Vascular; Rats; Rats, Sprague-Dawley; Thromboxane A2; Transformation, Genetic; Tunica Intima