reverses existing IH. Methods: Sprague-Dawley rats were random- ized for treatment with vehicle or oral nitrite (9.6 umol/kg/day), the equivalent nitrite load that is produced from a serving of spinach in a human, daily starting 2 weeks after balloon injury. Oral chloroquin (60mg/Kg/day) was used as an autophagic inhibitor and some rats were treated daily starting 2 weeks after balloon injury. These treat- ments were performed for an additional 2 weeks and IH was assessed at 28 days by intima:media ratios. Immunohistochemistry for prolif- eration, apoptosis, or autophagic signaling was performed in order to determine mechanisms of negative vascular remodeling. Signifi- cance was determined by ANOVA. Results: Vascular injury resulted in IH at 28 days (1.1560.07), and oral nitrite supplementation initi- ated 14 days after injury resulted in decreased IH at 28 days (0.4560.03; P<0.01 compared to control injured vessels). Daily chloro- quine initiated 14 days after injury resulted in increased IH at 28 days (1.9760.1; P<0.01 compared to control injured and nitrite treated ves- sels), and the ability of nitrite in reversing IH was prevented by chlo- roquine. Nitrite supplementation was associated with decreased apoptosis and increased autophagic signaling within the neointima. Chloroquine inhibited nitrite’s ability to increase autophagic signal- ing. Proliferation indicators, however, did not differ between the groups. Conclusions: Low dose oral nitrite supplementation re- verses IH through a mechanism that involves autophagy. Nitrite based therapies may prove to be useful adjuncts in the treatment of vascular disease. 29.7. The Effects Of Thrombospondin-2 Silencing In Human Aortic Smooth Muscle Cells In-Vitro. S. Yoshida, C. S. Nabzdyk, M. C. Chun, L. Pradhan, F. W. LoGerfo; Beth Israel Deaconess Medical Center, Boston, MA Introduction: Millions of Americans suffer from peripheral arterial disease and those with significant affliction undergo bypass grafting. Patency rates of these grafts are poor, failing by way of intimal hyper- plasia (IH). Our lab’s efforts have focused on silencing key genes that are thought to contribute to IH. Previous reports showed significant upregulation of Thrombospondin-2 (TSP-2) protein in the vascular smooth muscle layer of the distal anastomosis in canine prosthetic arterial bypass studies. TSP-2 is a matricellular protein involved in remodeling of tissue after injury and is considered an inhibitor of an- giogenesis. Its interactions with the CD36 receptor are anti-prolifera- tive for endothelial cells while at the LRP-1 receptor, TSP-2/ metalloproteinase complexes are internalized leaving behind an ex- tracellular matrix that is less permissive to cell migration. To our knowledge, the relationship between TSP-2 and vascular smooth muscle cells (VSMCs) as a cause of IH has not been studied. Here in, we describe our efforts to transfect human aortic smooth muscle cells (HAoSMCs) in-vitro in an attempt to characterize this relation- ship. Methods: HAoSMCs were transfected with TSP-2 siRNA using HiPerFect transfection reagent in culture. Silencing of gene expres- sion was evaluated using qRT-PCR. Cell culture supernatants were subjected to ELISA for protein quantification. The same supernatant samples were used to assess levels of MMP2 in gelatin zymography. CD36 receptor expression was revealed using fluorescent antibodies. Finally, cultured cells were evaluated for proliferation and scratch wound migration. Results: Our method of TSP-2 siRNA transfection successfully achieved the silencing of the TSP-2 gene at 48 hours. The results show a consistent mRNA knockdown of over 80% compared to the negative control group exposed to non-targeting siRNA. Further- more, we have found that this single transfection allows suppression of protein expression for over two weeks in culture (figure shown). The proliferation and scratch wound assays showed no difference in VSMC proliferation or migration through TSP-2 silencing. MMP-2 levels were also unaffected despite silencing 70% of TSP-2 protein in the culture media. However, preliminary data suggests a downre- gulation of CD36 at the cell surface as a result of TSP-2 silencing. Conclusions: One-time transfection of TSP-2 siRNA in HAoSMCs has a lasting effect on protein silencing of TSP-2 and downregulation of its receptor CD36 with minimal effect on its classical signaling partner MMP2. The knowledge of this interaction will aid future in- vivo studies that will evaluate the effects of TSP-2 silencing on IH. Further work is needed to characterize the downstream signaling of TSP-2 in VSMCs. 29.8. Ginkolide A-Gold Nanoparticles Inhibit Vascular Smooth Muscle Proliferation And Migration In Vitro And Reduces Intimal Hyperplasia In A Mouse Model. S. M. Weakley, X. Wang, H. Mu, P. H. Lin, Q. Yao, C. Chen; Baylor College of Medicine, Houston, TX Introduction: Neointimal formation is an important mediator of restenosis in autologous, synthetic, and allogeneic grafts; it occurs when vascular smooth muscle cells (SMCs) undergo phenotypic changes, migrating to the intima where they stimulate proliferation. Gold nanoparticles (GNPs), with their high surface to volume ratio and easily modifiable nature, represent a powerful new vehicle for the delivery of anti-proliferative and anti-migratory ligands. By con- jugating Ginkolide A (GA) to gold nanoparticles (GA-GNPs), we deter- mined the effect of GA delivery on SMC proliferation and migration in vitro and neointimal hyperplasia a mouse model with carotid artery ligation. Methods: GA was conjugated to 80nm GNP in an overnight incubation. Murine P53LMAC01 vascular SMCs were treated with various doses of GA-GNP, GA alone, GNP alone, and no treatment control. Cell proliferation and migration were anlyzed by MTS and Boyden chamber analysis, respectively. DHE staining and flow cy- tometry analysis were also performed to determine superoxide anion levels. The phosphorylation status of ERK1/2 was determined using western blot analysis. Mice underwent ligation of the common carotid artery and were treated as follows: sham surgery, ligation and GNPs, and ligation and GA-GNP administered in the surgical wound. After sacrifice, the carotid artery was harvested and subjected to immuno- histochemical analysis. Results: GA-GNP treatment inhibited SMC proliferation in vitro by up to 25%, which was significantly greater than GNP treatment only (p<0.01). This effect persisted for up to 72 hours after treatment (p<0.01). Treatment with GA-GNP also in- hibited mouse SMC migration by 35% compared with GNP treatment only, with a maximum effect at 50 mmol/L (p<0.01). This effect was dose dependent and detectable as early as 4 hours after cell seeding; the most significant effect was observed at 24 hours. Treatment with 50 mmol/L GA-GNP reduced superoxide anion levels by 29% (p<0.01). Using western blot we determined that phospho-ERK1/2 in- creased 5 minutes after PDGF-BB treatment, peaked (up to 6 fold) at 10 minutes, and recovered 30 minutes after PDGF-BB treatment; this effect was reduced after GA-GNP treatment compared to GNPs only. GA-GNPs significantly reduced neointimal hyperplasia after injury in mice; intimal area was decreased from 3056166368 mm 2 in the GNP- only group to 1611762589 mm 2 in the group treated with GA-GNPs ASSOCIATION FOR ACADEMIC SURGERY AND SOCIETY OF UNIVERSITY SURGEONS—ABSTRACTS 253