Comparative Investigation on the Phytochemicals and Biological Activities of Jackfruit (Artocarpus heterophyllus Lam.) pulp from Five Cultivars.

Jackfruit is one of the major tropical fruits, but information on the phytochemicals and biological benefits of its pulp is limited. In this study, the phytochemicals and biological activities including antioxidant, antitumor and anti-inflammatory activities of five jackfruit pulp cultivars (M1, M2, M3, M7 and T5) were comparatively investigated. A total of 11 compounds were identified in all cultivars of jackfruit pulp, among which 4-hydroxybenzoic acid, caffeic acid, ferulic acid and tryptophan N-glucoside were reported for the first time in jackfruit. T5 exhibited the highest total phenolic content (7.69 ± 0.73 mg GAE/g DW), antioxidant capacity (109.8, 96.7 and 207 mg VCE/g DW for DPPH, ABTS and FRAP, respectively), antitumor activity (80.31%) and anti-inflammatory activity (78.44%) among five cultivars. These results can provide a reference for growers to choose jackfruit cultivar and offer an insight into the industrial application of jackfruit pulp derived-products.

Membrane rafts-redox signalling pathway contributes to renal fibrosis via modulation of the renal tubular epithelial-mesenchymal transition.

KEY POINTS: Membrane rafts (MRs)-redox signalling pathway is activated in response to transforming growth factor-ß1 (TGF-ß1) stimulation in renal tubular cells. This pathway contributes to TGF-1ß-induced epithelial-mesenchymal transition (EMT) in renal tubular cells. The the MRs-redox signalling pathway is activated in renal tubular cells isolated from angiotensin II (AngII)-induced hypertensive rats. Inhibition of this pathway attenuated renal inflammation and fibrosis in AngII-induced hypertension. ABSTRACT: The membrane rafts (MRs)-redox pathway is characterized by NADPH oxidase subunit clustering and activation through lysosome fusion, V-type proton ATPase subunit E2 (encoded by the Atp6v1e2 gene) translocation and sphingomyelin phosphodiesterase 1 (SMPD1, encoded by the SMPD1 gene) activation. In the present study, we hypothesized that the MRs-redox-derived reactive oxygen species (ROS) are involved in renal inflammation and fibrosis by promoting renal tubular epithelial-mesenchymal transition (EMT). Results show that transforming growth factor-ß1 (TGF-ß1) acutely induced MR formation and ROS production in NRK-52E cells, a rat renal tubular cell line. In addition, transfection of Atp6v1e2 small hairpin RNAs (shRNA) and SMPD1 shRNA attenuated TGF-ß1-induced changes in EMT markers, including E-cadherin, α-smooth muscle actin (α-SMA) and fibroblast-specific protein-1 (FSP-1) in NRK-52E cells. Moreover, Erk1/2 activation may be a downstream regulator of the MRs-redox-derived ROS, because both shRNAs significantly inhibited TGF-ß1-induced Erk1/2 phosphorylation. Further in vivo study shows that the renal tubular the MRs-redox signalling pathway was activated in angiotensin II (AngII)-induced hypertension, as indicated by the increased NADPH oxidase subunit Nox4 fraction in the MR domain, SMPD1 activation and increased ROS content in isolated renal tubular cells. Finally, renal transfection of Atp6v1e2 shRNA and SMPD1 shRNA significantly prevented renal fibrosis and inflammation, as indicated by the decrease of α-SMA, fibronectin, collagen I, monocyte chemoattractant protein-1 (MCP-1), intercellular cell adhesion molecule-1 (ICAM-1) and tumour necrosis factor-α (TNF-α) in kidneys from AngII-infused rats. It was concluded that the the MRs-redox signalling pathway is involved in TGF-ß1-induced renal tubular EMT and renal inflammation/fibrosis in AngII-induced hypertension.

Adenovirus-Mediated Overexpression of Septin 2 Attenuates α-Smooth Muscle Actin Expression and Adventitial Myofibroblast Migration Induced by Angiotensin II.

Phenotypic transformation from adventitial fibroblasts (AFs) to myofibroblasts (MFs) is critical for vascular remodeling. Septin 2 was found to be downregulated during the differentiation of AFs to MFs induced by angiotensin II (Ang II); however, the role of septin 2 in this process is still unknown. In this study, we investigate whether septin 2 contributes to the adventitial MF phenotypic modulation caused by Ang II. The decreased level of septin 2 and the increased expression of α-smooth muscle actin (α-SMA), a marker of MFs, were readily observed in Ang II-stimulated MF differentiation. After gene transfer of septin 2, the expression of α-SMA was markedly decreased and the MF migration response to Ang II was inhibited. Furthermore, the inhibition of RhoA, another molecule involved in MF phenotypic modulation, decreased the motility of MFs and the expression of septin 2 triggered in Ang II. Finally, transfection of septin 2 rescued the level of acetyl-α-tubulin in MFs. These findings demonstrate that, as a downstream molecule of RhoA, septin 2 blunted the responses of AFs to Ang II by protecting α-tubulin acetylation, which suggests that septin 2 may serve as a potential therapeutic target for vascular injury.

Hepatitis B virus mutation may play a role in hepatocellular carcinoma recurrence: A systematic review and meta-regression analysis.

BACKGROUND AND AIMS: A number of studies have confirmed that antiviral therapy with nucleotide analogs (NAs) can improve the prognosis of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) after curative therapy. However, what factors affected the prognosis of HBV-HCC after removal of the primary tumor and inhibition of HBV replication? A meta-regression analysis was conducted to explore the prognostic factor for this subgroup of patients. METHODS: MEDLINE, EMBASE, Web of Science, and Cochrane library were searched from January 1995 to February 2014 for clinical trials evaluating the effect of NAs on the prognosis of HBV-HCC after curative therapy. Data were extracted for host, viral, and intervention information. Single-arm meta-analysis was performed to assess overall survival (OS) rates and HCC recurrence. Meta-regression analysis was carried out to explore risk factors for 1-year OS rate and HCC recurrence for HBV-HCC patients after curative therapy and antiviral therapy. RESULTS: Fourteen observational studies with 1284 patients met the inclusion criteria. Influential factors for prognosis of HCC were mainly baseline HBeAg positivity, cirrhotic stage, advanced Tumor-Node-Metastasis (TNM) stage, macrovascular invasion, and antiviral agent type. The 1-year OS rate decreased by more than four times (coefficient -4.45, P<0.001) and the 1-year HCC recurrence increased by more than one time (coefficient 1.20, P=0.003) when lamivudine was chosen for HCC after curative therapy, relative to entecavir for HCC. CONCLUSIONS: HBV mutation may play a role in HCC recurrence. Entecavir or tenofovir, a high genetic barrier to resistance, should be recommended for HBV-HCC patients.

[Angiotensin II induces expression of inflammatory mediators in vascular adventitial fibroblasts].

Vascular adventitial fibroblasts (AF) may play an important role in vascular inflammation. This study was aimed to investigate the expression pattern of inflammatory mediators in AF induced by angiotensin II (AngII) and to explore the effects of AF-derived inflammatory mediators on the adhesion and migration of macrophages both in vitro and in vivo. We used real-time RT-PCR to detect the mRNA expression of inflammatory mediators in cultured AF. The results showed that AngII (1 × 10(-7) mol/L) up-regulated mRNA expression of 4 inflammatory mediators, including P-selectin, ICAM-1, IL-6 and MCP-1, in cultured AF. Western blot analysis or ELISA revealed that AngII up-regulated P-selectin and ICAM-1 protein expression and IL-6 secretion in cultured AF, but did not alter MCP-1 secretion. We further detected the effects of AF-derived inflammatory mediators on the adhesion and chemotaxis of RAW264.7, a macrophage cell line. We found that AF stimulated with AngII could enhance the adhesion of RAW264.7 and the conditioned medium from AngII-stimulated AF could enhance the migration of RAW264.7. Immunofluorescence study showed an enhanced accumulation of CD68 positive cells and the up-regulation of P-selectin, ICAM-1, IL-6 and MCP-1 in aortic adventitia of AngII-infused (200 ng/kg per min for 2 weeks) rats. We concluded that AF may contribute to vascular inflammation via expression of certain inflammatory mediators and the subsequent adhesion and chemotaxis of macrophages.

RhoA-Rho kinase signaling pathway mediates adventitial fibroblasts differentiation to myofibroblasts induced by TGF-ß1.

Vascular adventitial fibroblasts (AF) differentiation to myofibroblasts (MF) is the critical physiopathologic feature of vascular remodeling. This study was to investigate the role of RhoA-Rho kinase signaling pathway in AF differentiation to MF induced by transforming growth factor ß1 (TGF-ß1). The results showed that TGF-ß1 up-regulated total RhoA protein expression and RhoA activity in cultured AF by Western blotting and Rho pull-down assay, respectively. TGF-ß1 up-regulated phospho-Myosin phosphatase target subunit (MYPT1, a downstream substrate of Rho kinase) expression without altering Rho kinase protein expression, indicating TGF-ß1 induced the enhancement of activity of Rho kinase. Ad-N19RhoA-hrGFP virus infection and Y27632, a specific inhibitor of Rho kinase, dose-dependently inhibited TGF-ß1-induced α-SM-actin and Calponin expression, as markers of MF differentiation. In conclusion, the RhoA-Rho kinase pathway is involved in AF differentiation to MF induced by TGF-ß1.

[Adenovirus mediated N19RhoA gene transfer attenuates neointimal formation in rats after carotid artery balloon injury].

OBJECTIVE: To investigate the role of small G-protein RhoA in neointimal formation following rat carotid artery balloon injury and related mechanisms. METHODS: Male 3-4-month-old Sprague-Dawley rats were used in the present study (10 rats per group). Group A: control; Group B: carotid artery balloon injury; Group C: injury + Ad-CMV-eGFP + Pluronic F-127; Group D: injury + Ad-CMV-N19RhoA-eGFP + Pluronic F-127; Group E: non injury + Ad-CMV-eGFP + Pluronic F-127. Perivascular gene transfer of an adenovirus co-expressing N19RhoA was performed to rat carotid artery following balloon injury and the effect on neointimal formation and the expressions of PCNA and α-SM-actin examined. Rats were killed after 14 days. RESULTS: The protein expression of RhoA in group B was significantly higher than in group A (P = 0.001), and the positive cells rate of PCNA and α-SM-actin which were assessed by immunohistochemistry in group C (45.2% and 75.6%) was significantly higher than in group D (28.4% and 51.9%, all P < 0.01). The area of neointima was significantly smaller [(0.14 ± 0.08) mm(2) vs. (0.23 ± 0.10) mm(2), P < 0.01], the luminal area was significantly larger [(0.47 ± 0.11) mm(2) vs. (0.31 ± 0.06) mm(2), P < 0.01] in group D than in group C. CONCLUSION: Gene transfer of N19RhoA attenuates neointimal formation after balloon injury in rat carotid arteries possibly related to the modulating capacities of small G-protein RhoA on the proliferation, phenotypic differentiation and migration of vascular adventitial fibroblasts.

[Extraction technology and antioxidant activity of total flavonoids and total triterpenoids from Tetrastigma planicaule].

OBJECTIVE: To study the optimum extraction technology of total flavonoids and total triterpenoids from Tetrastigma planicaule and their antioxidant activity. METHODS: Optimized the extraction of total flavonoids and total triterpenoids using an L9 (3(4)) orthogonal array design, and the antioxidant activity was extimated by FRAP assay, salicylicl acid assay and ABTS assay. RESULTS: The best extraction conditions for total flavonoids from Tetrastigma planicaule were as follows: 70 degrees C of 70% ethanol ultrasound-assisted extracting for 1 h and extracting three times, and total triterpenoids was:70 degrees C of 60% ethanol microwave extracting for 5 min and extracting two times. Compared with the positive control samples VC and tea polyphenol, the activity of reducing Fe3+ antioxidant and scavenging ABTS + * of flavonoids from Tetrastigma planicaule was higher than that of tea polyphenol, but scavenging OH * was lower than theirs; CONCLUSION: The method of using ultrasound-assisted extraction to extract total flavonoids and microwave extraction to extract total triterpenoids is the best, the extracts of Tetrastigma planicaule also shows certain antioxidative activity.

MicroRNA-155 regulates angiotensin II type 1 receptor expression and phenotypic differentiation in vascular adventitial fibroblasts.

MicroRNAs (miRNAs), which are genomically encoded small RNAs, negatively regulate target gene expression at the post-transcriptional level. Our recent study indicated that microRNA-155 (miR-155) might be negatively correlated with blood pressure, and it has been suggested that miR-155-mediated target genes could be involved in the cardiovascular diseases. Bioinformatic analyses predict that angiotensin II type 1 receptor (AT(1)R) is a miR-155 target gene. The present study investigated the potential role of miR-155 in regulating AT(1)R expression and phenotypic differentiation in rat aortic adventitial fibroblasts (AFs). Luciferase assay demonstrated that miR-155 suppressed AT(1)R 3'-UTR reporter construct activity. miR-155 overexpression in AFs did not reduce target mRNA levels, but significantly reduced target protein expression. In addition, AFs transfected with pSUPER/miR-155 exhibited reduced Ang II-induced ERK1/2 activation. miR-155 overexpression in cells attenuated Ang II-induced α-smooth muscle actin (α-SMA, produces myofibroblast) expression, but did not transform growth factor beta-1 (TGF-ß1). This study demonstrated that miR-155 could have an important role in regulating adventitial fibroblast differentiation and contribute to suppression of AT(1)R expression.

The PDE1A-PKCalpha signaling pathway is involved in the upregulation of alpha-smooth muscle actin by TGF-beta1 in adventitial fibroblasts.

BACKGROUND: Increasing evidence has suggested that differentiation of adventitial fibroblasts (AFs) to myofibroblasts plays an important role in arterial remodeling. The molecular mechanisms by which myofibroblast formation is regulated still remain largely unknown. This study aimed to evaluate the role of cyclic nucleotide phosphodiesterase 1A (PDE1A) in the formation of adventitial myofibroblasts induced by transforming growth factor (TGF)-beta(1). METHODS AND RESULTS: AFs were cultured by the explant method. Western blot and immunocytochemistry were applied for alpha-smooth muscle actin (SMA) or protein kinase C (PKC) alpha protein analysis. Results showed that TGF-beta(1) upregulated PDE1A protein expression in rat aortic AFs and pharmacological inhibition of PDE1A blocked TGF-beta(1)-induced alpha-SMA expression, a marker of myofibroblast formation, suggesting that the upregulation of PDE1A may mediate TGF-beta(1)-induced AF transformation. Moreover, calphostin C (a PKC inhibitor) inhibited TGF-beta(1)-induced alpha-SMA expression, whereas phorbol-12-myristate-13-acetate (a PKC activator) induced it. Finally, the upregulation of PKCalpha expression by TGF-beta(1) was also inhibited by PDE1A inhibition. CONCLUSIONS: Taken together, our data suggest that TGFbeta(1) induces alpha-SMA expression and myofibroblast formation via a PDE1A-PKCalpha-dependent mechanism. Our study thus unveils a novel signaling mechanism underlying TGF-beta(1)-induced adventitial myofibroblast formation.

Real-world cost-effectiveness associated with infliximab maintenance therapy for moderate to severe Crohn's disease in China.

BACKGROUND: Infliximab was the first approved biologic treatment for moderate to severe Crohn's disease (MS-CD) in China. However, the cost-effectiveness of infliximab maintenance therapy (IMT) for MS-CD relative to conventional maintenance therapy remained unclarified. AIM: To assess the cost-effectiveness of IMT for MS-CD in Chinese patients from the perspective of Chinese public insurance payer. METHODS: A cohort of MS-CD patients managed in a Chinese tertiary care hospital was created to compare IMT with conventional maintenance therapy (CMT) for clinical outcomes and direct medical costs over a 1-year observation time using conventional regression analyses. A decision-analytic model with the generated evidence was constructed to assess the cost-effectiveness of IMT relative to CMT using reimbursed medical costs. RESULTS: Based on the included 389 patients, IMT was associated with significantly higher disease remission chance [odds ratio: 4.060, P = 0.003], lower risk of developing new complications (odds ratio: 0.527, P = 0.010), higher utility value for quality of life (coefficient 0.822, P = 0.008), and lower total hospital costs related to disease management (coefficient -0.378, P = 0.008) than CMT. Base-case cost-effectiveness analysis estimated that IMT could cost Chinese health insurance payers ¥55260 to gain one quality-adjusted life year (QALY). The cost-effectiveness of IMT was mainly driven by the estimate of quality of life, treatment efficacy of maintenance therapy, mortality risk associated with active disease, and unit price of infliximab. The probability that IMT was cost-effective at a willingness-to-pay threshold of three times gross domestic product [2018 Chinese gross domestic product per capita (GDPPC)] was 86.4%. CONCLUSION: IMT significantly improved real-world health outcomes and cost the Chinese public health insurance payers less than one GDPPC to gain one QALY in Chinese MS-CD patients.

SGK1-FoxO1 Signaling Pathway Mediates Th17/Treg Imbalance and Target Organ Inflammation in Angiotensin II-Induced Hypertension.

It has been demonstrated that serum/glucocorticoid regulated kinase 1 (SGK1) and the downstream transcription factor forkhead box O1 (FoxO1) plays a critical role in the differentiation of T helper 17 cells/regulatory T cells (Th17/Treg). In the present study, we hypothesized that this SGK1-FoxO1 signaling pathway is involved in Th17/Treg imbalance and target organ damage in angiotensin II (AngII)-induced hypertensive mice. Results show that SGK1 inhibitor EMD638683 significantly reversed renal dysfunction and cardiac dysfunction in echocardiography as indicated by decreased blood urine nitrogen and serum creatinine in AngII-infused mice. Flow cytometric assay shows that there was significant Th17/Treg imbalance in spleen and in renal/cardiac infiltrating lymphocytes as indicated by the increased Th17 cells (CD4+-IL17A+ cells) and decreased Treg cells (CD4+-Foxp3+). Consistently, real-time PCR shows that Th17-related cytokines including IL-17A, IL-23, and tumor necrosis factor α (TNF-α) was increased and Treg-related cytokine IL-10 was decreased in renal and cardiac infiltrating lymphocytes in AngII-infused mice. Meanwhile, SGK1 protein level, as well as its phosphorylation and activity, was significantly increased in spleen in AngII-infused rats. Furthermore, it was found that splenic phosphorylated FoxO1 was significantly increased, whereas total FoxO1 in nuclear preparation was significantly decreased in AngII-infused mice, suggesting that increased FoxO1 phosphorylation initiate its translocation from cytoplasm to nucleus. Notably, all changes were significantly inhibited by the treatment of EMD638683. These results suggest that SGK1 was involved in Th17/Treg imbalance and target organ damage in AngII-induced hypertension.

Gene profile for differentiation of vascular adventitial myofibroblasts.

Our previous study demonstrated that TGF-beta1 could induce the differentiation of vascular adventitial fibroblasts (AFs) to myofibroblasts (MFs). The aim of this study was to identify the genes which might be responsible for the cell phenotypic change using genechips. Cultured rat AFs were treated with TGF-beta1 (10 ng/ml) for 0 min, 5 min, 15 min, 2 h, 12 h and 24 h, respectively. Then the cells were gathered to prepare total RNA. We examined TGF-beta1-induced gene expression profiling using Affymetrix oligonucleotide microarrays and analyzed data by GCOS1.2 software. Moreover, expressional similarity was measured by hierarchical clustering. Some of genechip results were confirmed by real-time quantitative RT-PCR. Microarray analysis identified 2121 genes with a 2-fold change or above after TGF-beta1 stimulation. 1318 genes showed a greater than 2-fold increase and 761 genes were reduced 2 folds or more at mRNA levels, whereas a small portion of the total regulated genes (42 genes) displayed dynamically up- and down-regulated pattern. Genes were further segregated for early (peak at 5 min, 15 min and/or 2 h), late (peak at 12 h and/or 24 h), and sustained (2-fold change or above at five time points) temporal response groups according to the time of their peak expression level. Among 1318 up-regulated genes, 333 genes (25.3%) responded rapidly to TGF-beta1 and 159 genes (12.1%) responded in a sustained manner. Most genes (826, 62.6%) were regulated at 12 h or later. For the 761 down-regulated genes, numbers of early and late responsive genes were 335 (44%) and 267 (36.1%), respectively. There were also 159 genes, 19.9% of total down-regulated genes, decreased at five time points treated by TGF-beta1. The results suggested that the gene expressions of secreted phosphoprotein 1 (APP1) and Rho-associated coiled-coil forming kinase 2 (ROCK2) had the same trends as alpha-smooth muscle-actin, a marker of MF differentiation. In addition, the gene expression of potassium voltage-gated channel, Shal-related family and member 2 (KCND2) was up-regulated. Furthermore, it was found that endothelin 1 (EDN1), some complement components, NADPH oxidase 4 (NOX4) and NAD(P)H dehydrogenase, quinone 1 (NQO1) might be involved in MF differentiation. Using microarrary technique, we confirmed some genes that have been identified by other techniques were implicated in MF differentiation and observed new genes involved in this process. Our results suggest that gene expression profiling study is helpful in identifying genes and pathways potentially involved in cell differentiation.

Ca2+ -regulated lysosome fusion mediates angiotensin II-induced lipid raft clustering in mesenteric endothelial cells.

It has been reported that intracellular Ca2+ is involved in lysosome fusion and membrane repair in skeletal cells. Given that angiotensin II (Ang II) elicits an increase in intracellular Ca2+ and that lysosome fusion is a crucial mediator of lipid raft (LR) clustering, we hypothesized that Ang II induces lysosome fusion and activates LR formation in rat mesenteric endothelial cells (MECs). We found that Ang II acutely increased intracellular Ca2+ content, an effect that was inhibited by the extracellular Ca2+ chelator ethylene glycol tetraacetic acid (EGTA) and the inositol 1,4,5-trisphosphate (IP3)-induced Ca2+ release inhibitor 2-aminoethoxydiphenyl borate (2-APB). Further study showed that EGTA almost completely blocked Ang II-induced lysosome fusion, the translocation of acid sphingomyelinase (ASMase) to LR clusters, ASMase activation and NADPH (nicotinamide adenine dinucleotide phosphate) oxidase activation. In contrast, 2-APB had a slight inhibitory effect. Functionally, both the lysosome inhibitor bafilomycin A1 and the ASMase inhibitor amitriptyline reversed Ang II-induced impairment of vasodilation. We conclude that Ca2+ -regulated lysosome fusion mediates the Ang II-induced regulation of the LR-redox signaling pathway and mesenteric endothelial dysfunction.

[Real-time analysis of polyvinyl chloride thermal decomposition/combustion products with single photon ionization/photoelectron ionization online mass spectrometer].

With the features of a broad range of ionizable compounds, reduced fragments and simple mass spectrum, a homemade magnetic field enhanced photoelectron ionization (MEPEI) source combined with single photon ionization (SPI) for time-of-flight mass spectrometer was built and applied to analyze thermal decomposition/combustion products of polyvinyl chloride (PVC). The combined ion source can be switched very fast between SPI mode and SPI-MEPEI mode for detecting different targeted compounds, and only adjusting the voltage of the electrode in the ionization region to trigger the switch. Among the PVC thermal decomposition/combustion products, HCl and CO2, which ionization energies (12.74 eV, 13.77 eV respectively) were higher than the energy of photon (10.60 eV), were ionized by MEPEI, while alkenes, dichloroethylene, benzene and its homologs, monochlorobenzene, styrene, indane, naphthalene and its homologs were ionized by SPI and MEPEI simultaneously. Spectra of interested products as a function of temperatures indicated that products are formed via two main mechanisms: (1) dechlorination and intramolecular cyclization can lead to the formation of HCl, benzene and naphthalene at 250-370 degrees C; (2) intermolecular crosslinking leads to the formation of alkyl aromatics such as toluene and xylene/ethylbenzene at 380-510 degrees C. The experimental results show that the combined ion source of SPI/ SPI-MEPEI for TOF-MS has broad application prospects in the online analysis field.

Expression and function of vascular endothelial growth factor receptors (Flt-1 and Flk-1) in vascular adventitial fibroblasts.

Vascular endothelial growth factor receptors (VEGFRs) are previously considered to exist exclusively in endothelial cells. However, little is known if the receptors are expressed in other non-endothelial cells. In this study, we measured activation of two VEGFRs, Flk-1 and Flt-1, and their biological functions in cultured adventitial fibroblasts and injured rat carotid injury arteries induced by balloon angioplasty. Our results indicated that Flt-1, but not Flk-1, existed in adventitial fibroblasts. Angiotensin II increased Flt-1 protein expression in a time- and concentration-dependent manner. Adventitial fibroblast migration stimulated by vascular endothelial growth factor (VEGF) and placental growth factor (PIGF) required Flt-1 expression. The Flt-1-induced adventitial fibroblast migration was blocked by anti-Flt-1 neutralizing antibody and soluble VEGFR1 protein (sFlt-1). However, Flt-1 activation did not enhance cell proliferation. In addition, Flt-1 expression was significantly increased in the neointima and adventitia in injured rat carotid arteries. We concluded that functional expression of Flt-1 in adventitial fibroblasts might be an important mediator in the pathogenesis of vascular remodeling after arterial injury.