RESUMEN
Perlecan is a proteoglycan composed of a 470-kDa core protein linked to three heparan sulfate (HS) glycosaminoglycan chains. The intact proteoglycan inhibits the smooth muscle cell (SMC) response to vascular injury. Hspg2(Δ3/Δ3) (MΔ3/Δ3) mice produce a mutant perlecan lacking the HS side chains. The objective of this study was to determine differences between these two types of perlecan in modifying SMC activities to the arterial injury response, in order to define the specific role of the HS side chains. In vitro proliferative and migratory activities were compared in SMC isolated from MΔ3/Δ3 and wild-type mice. Proliferation of MΔ3/Δ3 SMC was 1.5× greater than in wild type (P < 0.001), increased by addition of growth factors, and showed a 42% greater migratory response than wild-type cells to PDGF-BB (P < 0.001). In MΔ3/Δ3 SMC adhesion to fibronectin, and collagen types I and IV was significantly greater than wild type. Addition of DRL-12582, an inducer of perlecan expression, decreased proliferation and migratory response to PDGF-BB stimulation in wild-type SMC compared with MΔ3/Δ3. In an in vivo carotid artery wire injury model, the medial thickness, medial area/lumen ratio, and macrophage infiltration were significantly increased in the MΔ3/Δ3 mice, indicating a prominent role of the HS side chain in limiting vascular injury response. Mutant perlecan that lacks HS side chains had a marked reduction in the inhibition of in vitro SMC function and the in vivo arterial response to injury, indicating the critical role of HS side chains in perlecan function in the vessel wall.
Asunto(s)
Traumatismos de las Arterias Carótidas/metabolismo , Proteoglicanos de Heparán Sulfato/metabolismo , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/metabolismo , Remodelación Vascular , Lesiones del Sistema Vascular/metabolismo , Animales , Becaplermina , Arterias Carótidas/metabolismo , Arterias Carótidas/patología , Traumatismos de las Arterias Carótidas/genética , Traumatismos de las Arterias Carótidas/patología , Adhesión Celular , Movimiento Celular , Proliferación Celular , Células Cultivadas , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Factor 2 de Crecimiento de Fibroblastos/farmacología , Genotipo , Proteoglicanos de Heparán Sulfato/química , Proteoglicanos de Heparán Sulfato/genética , Ratones Endogámicos C57BL , Ratones Mutantes , Ratones Transgénicos , Estructura Molecular , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/lesiones , Músculo Liso Vascular/patología , Mutación , Miocitos del Músculo Liso/efectos de los fármacos , Miocitos del Músculo Liso/patología , Fenotipo , Proteínas Proto-Oncogénicas c-sis/farmacología , Relación Estructura-Actividad , Factores de Tiempo , Remodelación Vascular/efectos de los fármacos , Lesiones del Sistema Vascular/genética , Lesiones del Sistema Vascular/patologíaRESUMEN
AIMS: Percutaneous revascularisation of chronic total occlusions (CTO) is limited by failure of guidewire crossing. Neovascularisation within the proximal CTO segment may be important for guidewire crossing and dramatically declines in CTO beyond six weeks of age. The aims of the current study were to determine whether local delivery of a pro-angiogenic growth factor increases neovascularisation in mature CTO and facilitates guidewire crossings. METHODS AND RESULTS: CTO (n=51) were created in the femoral arteries of 44 New Zealand white rabbits using the thrombin injection model. At 12 weeks, CTO were treated with poly-lactic-glycolic-acid (PLGA) microspheres containing either bovine serum albumin (BSA) (n=15) or recombinant mouse VEGF164 (n=14), or received no intervention (controls, n=12). Contrast-enhanced magnetic resonance angiography (CEMRA) was performed prior to treatment and at three weeks post treatment. Animals were sacrificed at three weeks post treatment and arterial samples were excised for micro-computed tomography imaging (µCT) and histologic morphometric analysis. Guidewire crossing was assessed at three weeks post treatment in an additional 10 VEGF164-treated CTO. In comparison to BSA-treated and control non-intervened CTO, VEGF164-treated CTO showed a significant increase in relative blood volume index in the proximal segment of the CTO lesion as determined by CEMRA and by µCT. Histologic measurements of microvessel area were also higher in VEGF164-treated CTO. Guidewire crossing across the proximal fibrous cap was successful in eight out of 10 VEGF164-treated CTO. CONCLUSIONS: Angiogenic therapy appears to be a promising strategy to improve neovascularisation and guidewire crossing rates in CTO.
Asunto(s)
Inductores de la Angiogénesis/uso terapéutico , Arteriopatías Oclusivas/cirugía , Procedimientos Endovasculares/instrumentación , Procedimientos Endovasculares/métodos , Arteria Femoral , Factor A de Crecimiento Endotelial Vascular/uso terapéutico , Inductores de la Angiogénesis/administración & dosificación , Inductores de la Angiogénesis/farmacología , Animales , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Enfermedad Crónica , Modelos Animales de Enfermedad , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Técnicas In Vitro , Inyecciones Intraarteriales , Masculino , Ratones , Microesferas , Microvasos/citología , Microvasos/efectos de los fármacos , Conejos , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/farmacología , Proteínas Recombinantes/uso terapéutico , Resultado del Tratamiento , Factor A de Crecimiento Endotelial Vascular/administración & dosificación , Factor A de Crecimiento Endotelial Vascular/farmacologíaRESUMEN
Four drug-eluting stents were deployed in the right coronary artery (RCA) of a symptomatic young woman who presented with a chronic total occlusion (CTO) of the RCA. The occlusion was successfully crossed using the recently described STAR technique. However, the patient died suddenly 15 hr later. Autopsy demonstrated a long segment of subintimal stenting in the proximal and mid RCA that was intraluminal in the distal vessel. Acute stent thrombosis in the subintimal stents was responsible for sudden death. This case highlights the potential risk of performing extensive subintimal stenting for CTO.