Jiawei Shi

Fabrication of a Novel Hybrid Heart Valve Leaflet for Tissue Engineering: An In Vitro Study

The objective of this study was to fabricate biomatrix/polymer hybrid heart valve leaflet scaffolds using an electrospinning technique and seeded by mesenchymal stem cells. Mesenchymal stem cells were obtained from rats. Porcine aortic heart valve leaflets were decellularized, coated with basic fibroblast growth factor/chitosan/poly-4-hydroxybutyrate using an electrospinning technique, reseeded, and cultured over a time period of 14 days. Controls were reseeded and cultured over an equivalent time period. Specimens were examined biochemically, histologically, and mechanically. Recellularization of the hybrid heart valve leaflet scaffolds was significantly improved compared to controls. Biochemical and mechanical analysis revealed a significant increase of cell mass, 4-hydroxyproline, collagen, and strength in the hybrid heart valve leaflets compared to controls. This is the first attempt in tissue-engineered heart valves to fabricate hybrid heart valve leaflets using mesenchymal stem cells combined with a slow release technique and an electrospinning technique.

Application of decellularized scaffold combined with loaded nanoparticles for heart valve tissue engineering in vitro

The purpose of this study was to fabricate decelluarized valve scaffold modified with polyethylene glycol nanoparticles loaded with transforming growth factor-β1 (TGF-β1), by which to improve the extracellular matrix microenvironment for heart valve tissue engineering in vitro. Polyethylene glycol nanoparticles were obtained by an emulsion-crosslinking method, and their morphology was observed under a scanning electron microscope. Decelluarized valve scaffolds, prepared by using trypsinase and TritonX-100, were modified with nanoparticles by carbodiimide, and then TGF-β1 was loaded into them by adsorption. The TGF-β1 delivery of the fabricated scaffold was measured by asing enzyme-linked immunosorbent assay. Whether unseeded or reseeded with myofibroblast from rats, the morphologic, biochemical and biomechanical characteristics of hybrid scaffolds were tested and compared with decelluarized scaffolds under the same conditions. The enzyme-linked immunosorbent assay revealed a typical delivery of nanoparticles. The morphologic observations and biological data analysis indicated that fabricated scaffolds possessed advantageous biocompatibility and biomechanical property beyond decelluarized scaffolds. Altogether this study proved that it was feasible to fabricate the hybrid scaffold and effective to improve extracellular matrix microenvironment, which is beneficial for an application in heart valve tissue engineering.SummaryThe purpose of this study was to fabricate decelluarized valve scaffold modified with polyethylene glycol nanoparticles loaded with transforming growth factor-β1 (TGF-β1), by which to improve the extracellular matrix microenvironment for heart valve tissue engineering in vitro. Polyethylene glycol nanoparticles were obtained by an emulsion-crosslinking method, and their morphology was observed under a scanning electron microscope. Decelluarized valve scaffolds, prepared by using trypsinase and TritonX-100, were modified with nanoparticles by carbodiimide, and then TGF-β1 was loaded into them by adsorption. The TGF-β1 delivery of the fabricated scaffold was measured by asing enzyme-linked immunosorbent assay. Whether unseeded or reseeded with myofibroblast from rats, the morphologic, biochemical and biomechanical characteristics of hybrid scaffolds were tested and compared with decelluarized scaffolds under the same conditions. The enzyme-linked immunosorbent assay revealed a typical delivery of nanoparticles. The morphologic observations and biological data analysis indicated that fabricated scaffolds possessed advantageous biocompatibility and biomechanical property beyond decelluarized scaffolds. Altogether this study proved that it was feasible to fabricate the hybrid scaffold and effective to improve extracellular matrix microenvironment, which is beneficial for an application in heart valve tissue engineering.

Fabrication of a novel hybrid scaffold for tissue engineered heart valve

The aim of this study was to fabricate biomatrix/polymer hybrid scaffolds using an electrospinning technique. Then tissue engineered heart valves were engineered by seeding mesenchymal stromal cells (MSCs) onto the scaffolds. The effects of the hybrid scaffolds on the proliferation of seed cells, formation of extracellular matrix and mechanical properties of tissue engineered heart valves were investigated. MSCs were obtained from rats. Porcine aortic heart valves were decellularized, coated with poly(3-hydroxybutyrate-co-4-hydroxybutyrate) using an electrospinning technique, and reseeded and cultured over a time period of 14 days. In control group, the decellularized valve scaffolds were reseeded and cultured over an equivalent time period. Specimens of each group were examined histologically (hematoxylin-eosin [HE] staining, immunohistostaining, and scanning electron microscopy), biochemically (DNA and 4-hydroxyproline) and mechanically. The results showed that recellularization was comparable to the specimens of hybrid scaffolds and controls. The specimens of hybrid scaffolds and controls revealed comparable amounts of cell mass and 4-hydroxyproline (P>0.05). However, the specimens of hybrid scaffolds showed a significant increase in mechanical strength, compared to the controls (P<0.05). This study demonstrated the superiority of the hybrid scaffolds to increase the mechanical strength of tissue engineered heart valves. And compared to the decellularized valve scaffolds, the hybrid scaffolds showed similar effects on the proliferation of MSCs and formation of extracellular matrix. It was believed that the hybrid scaffolds could be used for the construction of tissue engineered heart valves.SummaryThe aim of this study was to fabricate biomatrix/polymer hybrid scaffolds using an electrospinning technique. Then tissue engineered heart valves were engineered by seeding mesenchymal stromal cells (MSCs) onto the scaffolds. The effects of the hybrid scaffolds on the proliferation of seed cells, formation of extracellular matrix and mechanical properties of tissue engineered heart valves were investigated. MSCs were obtained from rats. Porcine aortic heart valves were decellularized, coated with poly(3-hydroxybutyrate-co-4-hydroxybutyrate) using an electrospinning technique, and reseeded and cultured over a time period of 14 days. In control group, the decellularized valve scaffolds were reseeded and cultured over an equivalent time period. Specimens of each group were examined histologically (hematoxylin-eosin [HE] staining, immunohistostaining, and scanning electron microscopy), biochemically (DNA and 4-hydroxyproline) and mechanically. The results showed that recellularization was comparable to the specimens of hybrid scaffolds and controls. The specimens of hybrid scaffolds and controls revealed comparable amounts of cell mass and 4-hydroxyproline (P>0.05). However, the specimens of hybrid scaffolds showed a significant increase in mechanical strength, compared to the controls (P<0.05). This study demonstrated the superiority of the hybrid scaffolds to increase the mechanical strength of tissue engineered heart valves. And compared to the decellularized valve scaffolds, the hybrid scaffolds showed similar effects on the proliferation of MSCs and formation of extracellular matrix. It was believed that the hybrid scaffolds could be used for the construction of tissue engineered heart valves.

Evaluation of a novel tetra‐functional branched poly(ethylene glycol) crosslinker for manufacture of crosslinked, decellularized, porcine aortic valve leaflets

To address concerns over limitations in the clinical use of glutaraldehyde (GA) fixation in bioprosthetic heart valves, we manufactured novel, branched poly(ethylene glycol) tetraacrylate (PEG-TA) crosslinked valve leaflets and evaluated cytotoxic, thrombogenic, hemolytic, and anticalcification effects, thermal stability, and mechanical properties, in comparison to decellularized valves (control) and GA crosslinked valves. Thermal denaturation temperatures were higher for PEG-TA valve leaflets compared to control and GA crosslinked valves (p < 0.001). Leaflet hydrolyzation rate was lower for the PEG-TA group than for GA and control groups (p < 0.05). Superior cytocompatibility was found for PEG-TA group leaflets (MTT, p < 0.01. apoptosis assay, p > 0.05). No thrombogenesis was found in platelet activation tests (p < 0.0001). Hemolysis assays showed that PEG-TA leaflets would not cause damage to blood cells (p > 0.05). Excellent anticalcification properties were confirmed by von Kossa staining, western blot, and atomic absorption spectroscopy (p < 0.0001) in a rat subcutaneous embedding model. Finally, the novel PEG-TA crosslinked material exhibits improved mechanical properties as compared to GA crosslinked materials (tensile strength, p < 0.001, Youngs modulus, p < 0.001). On the basis of all results presented, it is clear that the performance characteristics of PEG-TA crosslinked valve leaflets make PEG-TA crosslinked leaflets a promising alternative for the next generation of bioprosthetic heart valve.

Immobilization of decellularized valve scaffolds with Arg-Gly-Asp-containing peptide to promote myofibroblast adhesion

The cell adhesive properties of decellularized valve scaffolds were promoted by immobilization of valve scaffold with arginine-glycine-aspartic acid (RGD)-containing peptides. Porcine aortic valves were decellularized with trypsin/EDTA, and detergent Triton X-100. With the help of a coupling reagent Sulfo-LC-SPDP, the valve scaffolds were immobilized with glycine-arginine-glycine-aspartic acid-serine-proline-cysteine (GRGDSPC) peptide. X-ray photoelectron spectroscopy (XPS) was used for surface structure analysis. Myofibroblasts harvested from rats were seeded onto the valve scaffolds. Cell count by using microscopy and modified MTT assay were performed to assess cell adhesion. Based on the spectra of XPS, the conjugation of GRGDSPC peptide with decellularized valve scaffolds was confirmed. Both cell count and MTT assay showed that myofibroblasts were much easier to adhere to the modified valve scaffolds, which was also confirmed histologically. Our findings suggest that it is feasible to immobilize RGD-containing peptides onto decellularized valve scaffolds. And the technique can effectively promote cell adhesion, which is beneficial for in vitro tissue engineering of heart valves.SummaryThe cell adhesive properties of decellularized valve scaffolds were promoted by immobilization of valve scaffold with arginine-glycine-aspartic acid (RGD)-containing peptides. Porcine aortic valves were decellularized with trypsin/EDTA, and detergent Triton X-100. With the help of a coupling reagent Sulfo-LC-SPDP, the valve scaffolds were immobilized with glycine-arginine-glycine-aspartic acid-serine-proline-cysteine (GRGDSPC) peptide. X-ray photoelectron spectroscopy (XPS) was used for surface structure analysis. Myofibroblasts harvested from rats were seeded onto the valve scaffolds. Cell count by using microscopy and modified MTT assay were performed to assess cell adhesion. Based on the spectra of XPS, the conjugation of GRGDSPC peptide with decellularized valve scaffolds was confirmed. Both cell count and MTT assay showed that myofibroblasts were much easier to adhere to the modified valve scaffolds, which was also confirmed histologically. Our findings suggest that it is feasible to immobilize RGD-containing peptides onto decellularized valve scaffolds. And the technique can effectively promote cell adhesion, which is beneficial for in vitro tissue engineering of heart valves.

Aortic valve replacement for severe aortic regurgitation in asymptomatic patients with normal ejection fraction and severe left ventricular dilatation

OBJECTIVES According to current guidelines, aortic valve surgery is a Class II indication for asymptomatic patients with severe aortic regurgitation (AR) accompanied by left ventricular (LV) ejection fraction (LVEF) ≥ 50% and left ventricular end-diastolic dimension (LVEDD) >70 mm. This study aims to assess the postoperative outcomes of asymptomatic patients with severe AR accompanied by LVEF ≥ 50% and LVEDD >70 mm after aortic valve replacement (AVR) and to identify prognostic indicators of the surgery, especially in terms of LV ejection fraction and degree of LV dilatation. METHODS We retrospectively identified 192 consecutive asymptomatic patients with severe AR accompanied by LVEF ≥ 50% and LVEDD > 70 mm who underwent isolated AVR from January 2003 to December 2013. Postoperative outcomes and prognostic indicators were evaluated and analysed. RESULTS Patients had a mean age of 52.4 ± 16.1 years, and 69.3% were male. The mean LVEF and the mean LVEDD were 58.6 ± 6.6% and 76.0 ± 6.9 mm, respectively. The in-hospital mortality rate was 2.1% and survival rates at 5 and 10 years were 94.5 and 86.6%, respectively. Multivariable analysis indicated that postoperative mortality was associated with age [hazard ratio (HR) 1.059, 95% confidence interval (CI): 1.010-1.125, P = 0.049], preoperative LVEF (HR 0.860 95% CI: 0.748-0.989, P = 0.035) and LVEDD (HR 1.094 95% CI: 1.008-1.188, P = 0.032). Receiver-operating characteristic analysis showed that preoperative LVEF < 55% and LVEDD ≥ 81 mm were the best cut-off values for predicting postoperative mortality. By subgroup analysis, patients with 50 ≤ LVEF < 55% had poorer 5- and 10-year survival rates of 87.4 and 74.8% compared with 97.3% and 91.7% for patients with LVEF ≥ 55% (P = 0.023). Patients with LVEDD ≥ 81 mm had poorer 5- and 10-year survival rates of 85.6 and 72.6% compared with 98.2% and 85.6% for those with LVEDD < 81 mm (P = 0.027). CONCLUSIONS AVR can be performed with satisfactory outcomes for severe aortic regurgitation in asymptomatic patients with severe AR accompanied by LVEF ≥ 50% and LVEDD > 70 mm. It is observed that 50% ≤ LVEF < 55% or LVEDD ≥ 81 mm are associated with poorer prognosis in patients undergoing AVR.

Suppressor of Cytokine Signaling 3 Is a Negative Regulator for Neointimal Hyperplasia of Vein Graft Stenosis

Coronary artery bypass graft (CABG) surgery is one of the most effective treatments for coronary artery disease. However, neointimal hyperplasia and ultimate luminal occlusion that is caused by vascular smooth muscle cell (VSMC) migration, proliferation and inflammatory response impede the long-term prognosis. The SOCS3 protein is involved in modulating various autoimmune and inflammatory diseases. However, the role of SOCS3 in vein graft disease is still unclear. We found that the mRNA and protein expression levels of IL-1β, IL-6, MCP-1, ICAM-1, TNF-α, STAT3, P-STAT3 and SOCS3 were significantly higher in the graft samples compared to normal veins. After transfecting the recombinant adenovirus carrying the rat SOCS3 gene into cultured rat VSMCs or grafting veins in rat, SOCS3 overexpression was found to significantly inhibit VSMC migration and proliferation in vitro and neointimal hyperplasia in vivo, respectively. Furthermore, SOCS3 overexpression inhibited VSMC migration and growth in vitro and alleviated VSMC inflammation in vitro by inhibiting STAT3 activation and phosphorylation. In conclusion, SOCS3 is a crucial physiological negative regulator for vein graft failure and provides a novel target for vein graft stenosis therapy after CABG.

Lazaroid U-74389G inhibits the osteoblastic differentiation of IL-1β-indcued aortic valve interstitial cells through glucocorticoid receptor and inhibition of NF-κB pathway.

BACKGROUND Aortic valve calcification is characterized as the active process of aortic valve interstitial cells (AVICs), and considered as an inflammatory disease. As an antioxidant, the anti-inflammatory activity of Lazaroid has been exhibited in various models. We hypothesized that Lazaroid U-74389G would inhibit the osteoblastic differentiation of AVICs induced by IL-1β. METHODS Normal tricuspid aortic valve leaflets were collected from patients with acute aortic dissection (Type A) undergoing the Bentall procedure. AVICs were isolated and stimulated with IL-1β in presence or absence of U-74389G in culture. Cell lysates were analyzed for osteogenic markers and nuclear factor-κB using real-time PCR and Immunoblotting. Culture media was analyzed for IL-6 and IL-8 with enzyme-linked immunosorbent assay. Alizarin Red Staining was adopted to demonstrate the calcium deposition. RESULTS The expression of alkaline phosphatase and bone morphogenetic protein, accompanied by the production of IL-6 and IL-8, was up-regulated in response to IL-1β and was inhibited by the addition of U-74389G. The NF-κB pathway was activated by IL-1β and involved in the suppression of U-74389G on osteoblastic differentiation in AVICs. The negative effects of U-74389G on ostengenic gene expression and mineralization of AVICs were blocked by glucocorticoid receptor antagonist mifepristone and the NF-κB inhibitor Bay 11-7082. CONCLUSIONS U-74389G inhibits the pro-osteogenic response to IL-1β stimulation in AVICs. The osteoblastic differentiation and mineralization of AVICs were inhabited by U-74389G though the modulation of NF-κB activation, and this pathway could be potential therapeutic targets for medical treatment of calcified aortic valve disease.

Mid- to long-term outcome comparison of the Medtronic Hancock II and bi-leaflet mechanical aortic valve replacement in patients younger than 60 years of age: a propensity-matched analysis

OBJECTIVE This study aims to compare mid-long-term clinical outcomes between patients younger than 60 years of age undergoing bioprosthetic and mechanical aortic valve replacement. METHODS From January 2002 to December 2009, patients younger than 60 years of age who received Medtronic Hancock II porcine bioprostheses were selected and compared with those who received mechanical bi-leaflet valves in the aortic position. A stepwise logistic regression propensity score identified a subset of 112 evenly matched patient-pairs. Mid-long-term outcomes of survival, valve-related reoperations, thromboembolic events and bleeding events were assessed. RESULTS The follow-up was only 95.1% complete. Fourteen measurable variables were statistically similar for the matched cohort. Postoperative in-hospital mortality was 3.6% (bioprosthetic valves) and 2.7% (mechanical valves) (P = 0.700). Survival at 5 and 10 years was 96.3 and 88.7% for patients receiving bioprosthetic valve replacement versus 96.3 and 87.9% for patients receiving mechanical valve replacement (P = 0.860), respectively. At 5 and 10 years after operations, freedom from valve-related reoperation was 97.2 and 94.8% for patients receiving mechanical valve replacement, and 96.3 and 90.2% for patients receiving bioprosthetic valve replacement (P = 0.296), respectively. There was no difference between freedom from thromboembolic events (P = 0.528) and bleeding events (P = 0.128) between the matched groups during the postoperative 10 years. CONCLUSIONS In patients younger than 60 years of age undergoing aortic valve replacement, mid-long-term survival rate was similar for patients receiving bioprosthetic versus mechanical valve replacement. Bioprosthetic valves were associated with a trend for a lower risk of anticoagulation treatment and did not have significantly greater likelihood of a reoperation. These findings suggest that a bioprosthetic valve may be a reasonable choice for AVR in patients younger than 60 years of age.

Inhibitory effects of suppressor of cytokine signaling 3 on inflammatory cytokine expression and migration and proliferation of IL-6/IFN-γ-induced vascular smooth muscle cells

The main pathogenesis of saphenous vein graft neointimal hyperplasia after coronary artery bypass grafting (CABG) is inflammation-caused migration and proliferation of vascular smooth muscle cells (VSMCs). Janus kinase 2/signal transducer and activators of transcription 3 (JAK2/STAT3) pathway is an important signaling pathway through which VSMCs phenotype conversion occurs. Suppressor of cytokine signaling 3 (SOCS3) is the classic negative feedback inhibitor of JAK2/STAT3 pathway. Growing studies show that SOCS3 plays an important anti-inflammatory role in numerous autoimmune diseases, inflammatory diseases and inflammation-related tumors. However, the effect and mechanism of SOCS3 on vein graft disease is unclear. The purpose of this study was to investigate the effects of SOCS3 on the inflammation, migration and proliferation of VSMCs in vitro and the mechanism. The small interference RNA plasmid targeting rat SOCS3 (SiRNA-rSOCS3) and the recombinant adenovirus vector carrying rat SOCS3 gene (pYrAd-rSOCS3) were constructed, and the empty plamid (SiRNA-control) and vector (pYrAd-GFP) only carrying GFP reported gene were constructed as control. The rat VSMCs were cultured. There were two large groups of A (SOCS3 up-regulated): control group, IL-6/IFN-γ group, IL-6/IFN-γ+pYrAd-rSOCS3 group, IL-6/IFN-γ+pYrAd-GFP group; and B (SOCS3 down-regulated): control group, IL-6/IFN-γ group, IL-6/IFN-γ+SiRNA-rSOCS3 group and IL-6/ IFN -γ+SiRNA-control group. The pYrAd-rSOCS3 and SiRNA-rSOCS3 were transfected into VSMCs induced by IL-6/IFN-γ. After 24 h, real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were used to detect the mRNA and protein expression of SOCS3, STAT3 (only by Western blotting), P-STAT3 (only by Western blotting), IL-1β, IL-6, TNF-α, MCP-1 and ICAM-1. The MTT, Transwell assay and flow cytometry were used to examine VSMCs proliferation, migration and cell cycle progression, respectively. As compared with control group, the mRNA and protein expression of SOCS3, STAT3, P-STAT3, IL-1β, IL-6, TNF-α, MCP-1 and ICAM-1 was significantly up-regulated in VSMCs stimulated by IL-6/IFN-γ. However, in VSMCs transfected with pYrAd-rSOCS3 before stimulation with IL-6/IFN-γ, the expression of SOCS3 mRNA and protein was further up-regulated, and that of STAT3, P-STAT3, IL-1β, IL-6, TNF-α, MCP-1 and ICAM-1 was significantly down-regulated as compared with IL-6/IFN-γ group and IL-6/IFN-γ+pYrAd-GFP group. The expression of those related-cytokines in IL-6/IFN-γ+SiRNA-rSOCS3 group was markedly increased as compared with IL-6/IFN-γ group and IL-6/IFN-γ+SiRNA-control group. The absorbance (A) values, the number of cells migrating to the lower chamber, and percentage of cells in the G2/M+S phase were increased in VSMCs stimulated by IL-6/IFN-γ. In VSMCs incubated with pYrAd-rSOCS3 or SiRNA-rSOCS3 before IL-6/IFN-γ stimulation, the A values, the number of cells migrating to the lower chamber, and the percentage of cells in the G2/M+S phase were significantly decreased, and increased respectively. These results imply that IL-6/IFN-γ, strong inflammatory stimulators, can promote transformation of VSMCs phenotype form a quiescent contractile state to a synthetic state by activating JAK2/STAT3 pathway. Over-expresssed SOCS3 might inhibit pro-inflammatory effect, migration and growth of VSMCs by blocking STAT3 activation and phosphorylation. These data in vitro confirm that SOCS3 may play a negatively regulatory role in development and progression of vein graft failure. These conclusions can provide a novel strategy for clinical treatment of vein graft diseases and a new theoretic clue for related drug development.SummaryThe main pathogenesis of saphenous vein graft neointimal hyperplasia after coronary artery bypass grafting (CABG) is inflammation-caused migration and proliferation of vascular smooth muscle cells (VSMCs). Janus kinase 2/signal transducer and activators of transcription 3 (JAK2/STAT3) pathway is an important signaling pathway through which VSMCs phenotype conversion occurs. Suppressor of cytokine signaling 3 (SOCS3) is the classic negative feedback inhibitor of JAK2/STAT3 pathway. Growing studies show that SOCS3 plays an important anti-inflammatory role in numerous autoimmune diseases, inflammatory diseases and inflammation-related tumors. However, the effect and mechanism of SOCS3 on vein graft disease is unclear. The purpose of this study was to investigate the effects of SOCS3 on the inflammation, migration and proliferation of VSMCs in vitro and the mechanism. The small interference RNA plasmid targeting rat SOCS3 (SiRNA-rSOCS3) and the recombinant adenovirus vector carrying rat SOCS3 gene (pYrAd-rSOCS3) were constructed, and the empty plamid (SiRNA-control) and vector (pYrAd-GFP) only carrying GFP reported gene were constructed as control. The rat VSMCs were cultured. There were two large groups of A (SOCS3 up-regulated): control group, IL-6/IFN-γ group, IL-6/IFN-γ+pYrAd-rSOCS3 group, IL-6/IFN-γ+pYrAd-GFP group; and B (SOCS3 down-regulated): control group, IL-6/IFN-γ group, IL-6/IFN-γ+SiRNA-rSOCS3 group and IL-6/ IFN -γ+SiRNA-control group. The pYrAd-rSOCS3 and SiRNA-rSOCS3 were transfected into VSMCs induced by IL-6/IFN-γ. After 24 h, real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting were used to detect the mRNA and protein expression of SOCS3, STAT3 (only by Western blotting), P-STAT3 (only by Western blotting), IL-1β, IL-6, TNF-α, MCP-1 and ICAM-1. The MTT, Transwell assay and flow cytometry were used to examine VSMCs proliferation, migration and cell cycle progression, respectively. As compared with control group, the mRNA and protein expression of SOCS3, STAT3, P-STAT3, IL-1β, IL-6, TNF-α, MCP-1 and ICAM-1 was significantly up-regulated in VSMCs stimulated by IL-6/IFN-γ. However, in VSMCs transfected with pYrAd-rSOCS3 before stimulation with IL-6/IFN-γ, the expression of SOCS3 mRNA and protein was further up-regulated, and that of STAT3, P-STAT3, IL-1β, IL-6, TNF-α, MCP-1 and ICAM-1 was significantly down-regulated as compared with IL-6/IFN-γ group and IL-6/IFN-γ+pYrAd-GFP group. The expression of those related-cytokines in IL-6/IFN-γ+SiRNA-rSOCS3 group was markedly increased as compared with IL-6/IFN-γ group and IL-6/IFN-γ+SiRNA-control group. The absorbance (A) values, the number of cells migrating to the lower chamber, and percentage of cells in the G2/M+S phase were increased in VSMCs stimulated by IL-6/IFN-γ. In VSMCs incubated with pYrAd-rSOCS3 or SiRNA-rSOCS3 before IL-6/IFN-γ stimulation, the A values, the number of cells migrating to the lower chamber, and the percentage of cells in the G2/M+S phase were significantly decreased, and increased respectively. These results imply that IL-6/IFN-γ, strong inflammatory stimulators, can promote transformation of VSMCs phenotype form a quiescent contractile state to a synthetic state by activating JAK2/STAT3 pathway. Over-expresssed SOCS3 might inhibit pro-inflammatory effect, migration and growth of VSMCs by blocking STAT3 activation and phosphorylation. These data in vitro confirm that SOCS3 may play a negatively regulatory role in development and progression of vein graft failure. These conclusions can provide a novel strategy for clinical treatment of vein graft diseases and a new theoretic clue for related drug development.