Growth factors stimulate neointimal cells in vitro and increase the thickness of the neointima formed at the neck of porcine aneurysms treated by embolization

Citation
Ac. Desfaits et J. Raymond, Growth factors stimulate neointimal cells in vitro and increase the thickness of the neointima formed at the neck of porcine aneurysms treated by embolization, STROKE, 31(2), 2000, pp. 498-507
Citations number
70
Categorie Soggetti
Neurology,"Cardiovascular & Hematology Research
Journal title
STROKE
ISSN journal
00392499 → ACNP
Volume
31
Issue
2
Year of publication
2000
Pages
498 - 507
Database
ISI
SICI code
0039-2499(200002)31:2<498:GFSNCI>2.0.ZU;2-2
Abstract
Background and Purpose-Growth factors (GFs) techniques by stimulating neoin tima formation. Methods-Bilateral carotid aneurysms were constructed with venous pouches in 50 pigs and embolized intraoperatively with collagen sponges with and with out GFs (platelet-derived growth factor-BE [PDGF-BB] 0.15 or 1.5 mu g or tr ansforming growth factor-beta(1) [TGF-beta(1)] 60 or 600 ng) in each animal . DNA synthesis, cell proliferation, and collagen secretion assays were per formed to assess the in vitro effects of GFs on neointimal cells harvested from the treated aneurysms. I-125-PDGF-BB was used to study in vivo GF rele ase from sponges. The thickness of the neointima at the surface of the spon ges was measured 2 weeks after surgery. Since porcine aneurysms tend to hea l after collagen sponge embolization, this experiment was repeated in dogs, which have shown a propensity for recurrence with the same technique, with 600 ng TGF-beta(1) or platelet extracts. Results-PDGF-BB stimulated DNA synthesis and cell proliferation, while TGF- beta(1) strongly increased collagen synthesis of neointimal cells in vitro. Clearance of I-125-PDGF-BB from the sponges followed a biphasic curve, wit h 1.5% of exogenous PDGF-BB remaining at 1 week. The local delivery of PDGF -BB (0.15 or 1.5 mu g) and TGF-beta(1) (600 ng) significantly increased neo intimal thickness at the neck of porcine aneurysms, while 60 ng of TGF-beta (1) had no demonstrable effect. TGF-beta(1) (600 ng) or platelet extracts h ad no influence on canine aneurysms. Conchcsions-PDGF-BB and TGF-beta(1) can stimulate neointimal cells in vitro and neointima formation in vivo, but TGF-beta(1) and platelet extracts do not compensate for deficient thrombosis in canine aneurysms. Effects on the long-term results of embolization remain speculative.