E. Van Belle

Effect of percutaneous adenovirus-mediated Gax gene delivery to the arterial wall in double-injured atheromatous stented rabbit iliac arteries.

Though the efficacy of intravascular gene transfer has been demonstrated in native vessels following acute injury, this methodology has not been validated in complex models of vascular injury that more closely mimic clinical angioplasty procedures. Previous studies have shown that Gax gene overexpression modulates the injury-induced remodeling of the vessel in rat carotid and normal rabbit iliac arteries. Here, we evaluated the effect of the Gax gene delivery in atheromatous stented vessels. Rabbits were fed 120 g daily of 1% cholesterol diet for 3 weeks. At 1 week they underwent initial injury on the external iliac artery, then balloon angioplasty was performed at 3 weeks at the same site with a 2.5 mm diameter channel balloon catheter (three times 1 min at 6 atm). Either saline (n = 4) or the control viral construct Ad-CMVluc (5 × 109p.f.u.) (n = 5) or Ad-CMVGax (5 × 109 p.f.u.) (n = 4) was delivered with a poloxamer mixture via a channel balloon (6 atm, 30 min), and a 15 mm long Palmaz–Schatz stent (PS154) was then deployed at the site (1 min, 8 atm). Arteries were analyzed 1 month later. At 1 month, the Ad-CMVGax treated arteries exhibited a lower maximal intimal area (1.15 ± 0.1 mm2) than saline (1.87 ± 0.15 mm2, P = 0.007) or Ad-CMVluc-treated vessels (1.98 ± 0.31 mm2, P = 0.04). Likewise Ad-CMVGax-treated vessels displayed a lower maximal percentage cross-sectional area narrowing (35.1 ± 3.5%) than saline (65.3 ± 9.4%, P = 0.01) or Ad-CMVluc-treated vessels (62.7 ± 6.7%, P = 0.02). Angiographic analysis revealed larger minimal lumen diameter in Ad-CMVGax treated arteries (2.0 ± 0.1 mm) than saline (1.14 ± 0.36 mm, P = 0.06) or Ad-CMVluc-treated vessels (1.23 ± 0.25 mm, P = 0.02). Overexpression of the Gax gene inhibits neointimal hyperplasia and lumen loss in atheromatous stented rabbit iliac arteries.

Long-term safety of intramuscular gene transfer of non-viral FGF1 for peripheral artery disease

Peripheral artery disease is a progressive disease. Primary ischemic leg symptoms are muscle fatigue, discomfort or pain during ambulation, known as intermittent claudication. The most severe manifestation of peripheral artery disease is critical limb ischemia (CLI). The long-term safety of gene therapy in peripheral artery disease remains unclear. This four center peripheral artery disease registry was designed to evaluate the long-term safety of the intramuscular non-viral fibroblast growth factor-1 (NV1FGF), a plasmid-based angiogenic gene for local expression of fibroblast growth factor-1 versus placebo in patients with peripheral artery disease who had been included in five different phase I and II trials. Here we report a 3-year follow-up in patients suffering from CLI or intermittent claudication. There were 93 evaluable patients, 72 of them in Fontaine stage IV (47 NV1FGF versus 25 placebo) and 21 patients in Fontaine stage IIb peripheral artery disease (15 NV1FGF versus 6 placebo). Safety parameters included rates of non-fatal myocardial infarction (MI), stroke, death, cancer, retinopathy and renal dysfunction. At 3 years, in 93 patients included this registry, there was no increase in retinopathy or renal dysfunction associated with delivery of this angiogenic factor. There was also no difference in the number of strokes, MI or deaths, respectively, for NV1FGF versus placebo. In the CLI group, new cancer occurred in two patients in the NV1FGF group. Conclusions that can be drawn from this relatively small patient group are limited because of the number of patients followed and can only be restricted to safety. Yet, data presented may be valuable concerning rates in cancer, retinopathy, MI or strokes following angiogenesis gene therapy in the absence of any long-term data in angiogenesis gene therapy. It may take several years until data from larger patient populations will become available.

Thérapie cellulaire et insuffisance cardiaque

Resume Introduction. – L’insuffisance cardiaque resulte frequemment d’une alteration de la fonction systolique ventriculaire gauche dans les suites d’un infarctus du myocarde. Malgre toutes les recentes avancees therapeutiques, le pronostic des stades evolues reste plus pejoratif que celui de certains cancers, avec un taux de survie de 30 % a 5 ans. Exegese. – Les traitements actuellement disponibles ne peuvent que retarder l’evolution vers le stade terminal de l’insuffisance cardiaque. Au stade terminal, la seule issue therapeutique est la mise en place d’un systeme d’assistance ventriculaire gauche dans l’attente d’une greffe cardiaque. Or, la greffe cardiaque ne permet de prendre en charge qu’un nombre minime de patients. Dans le contexte particulier du post-infarctus, la therapie cellulaire apparait comme une technique d’avenir innovante pouvant corriger la perte aigue des cardiomyocytes ; cette solution est en outre applicable a une majorite de patients et potentiellement peu invasive. Conclusion. – Apres des resultats experimentaux prometteurs, une etude de phase I en France a montre la faisabilite d’une greffe intracardiaque de myoblastes autologues. D’autres equipes, en Europe et aux Etats-Unis, etudient d’autres types cellulaires et des voies d’administration differentes. Enfin, la premiere etude de phase II a debute en France.

A004 L’hyperméthylation du gène du tissue factor pathway inhibitor-2 est associée à une diminution de son expression dans la plaque d’athérosclérose carotidienne

Le Tissue Factor Pathway Inhibitor-2 (TFPI-2) est un inhibiteur de serineprotease de type Kunitz exprime dans la plaque d’atherosclerose. Le TFPI-2 y presenterait un effet atheroprotecteur en neutralisant les metalloproteases matricielles (MMP). Le promoteur du gene du TFPI-2 presente plusieurs ilots CpG dont l’hypermethylation est associee a une diminution de son expression. Cette regulation epigenetique de l’expression du TFPI-2 a ete mise en evidence dans la cancer mais n’a pas encore ete etudiee dans l’atherosclerose. L’objectif de ce travail a ete d’etudier la methylation du gene du TFPI-2 dans l’atherosclerose carotidienne avec ses consequences sur l’expression du transcrit TFPI-2. Le statut de methylation du gene du TFPI-2 a egalement ete confronte aux donnees cliniques des patients et a la morphologie des plaques. La methylation de 18 motifs CpG du promoteur du TFPI-2 a ete etudiee par Methylation Specific PCR (MSP) et pyrosequencage (PyroMark MD, Biotage) dans 59 plaques d’atherosclerose carotidienne et 26 arteres mammaires controle. Seize plaques (27 %) etaient retrouvees methylees par MSP (groupe MSP+) alors qu’aucune artere mammaire ne l’etait. Le pyrosequencage a confirme que les plaques MSP+ presentaient des niveaux de methylation significativement plus eleves que les plaques MSP- mais aussi que les arteres (p = 0,03 et 0,01, respectivement). Le niveau de transcrit TFPI-2 etait significativement plus bas dans les plaques methylees que dans les non methylees et que dans les arteres (pxa0=xa00,04 et Cette etude demontre pour la premiere fois que l’expression du TFPI-2 peut etre regulee par hypermethylation de son gene dans l’atherosclerose. L’hypermethylation du gene du TFPI-2 est associee a une diminution de l’expression de son transcrit mais egalement a des plaques morphologiquement moins severes. L’impact de la methylation du TFPI-2 sur la regulation des MMP et sur la fragilite de la plaque d’atherosclerose reste a determiner.