CS5931, a Novel Polypeptide in Ciona savignyi,Represses Angiogenesis via Inhibiting Vascular Endothelial Growth Factor (VEGF) and Matrix Metalloproteinases (MMPs)

CS5931 is a novel polypeptide from Ciona savignyi with anticancer activities. Previous study in our laboratory has shown that CS5931 can induce cell death via mitochondrial apoptotic pathway. In the present study, we found that the polypeptide could inhibit angiogenesis both in vitro and in vivo. CS5931 inhibited the proliferation, migration and formation of capillary-like structures of HUVECs (Human Umbilical Vein Endothelial Cell) in a dose-dependent manner. Additionally, CS5931 repressed spontaneous angiogenesis of the zebrafish vessels. Further studies showed that CS5931 also blocked vascular endothelial growth factor (VEGF) production but without any effect on its mRNA expression. Moreover, CS5931 reduced the expression of matrix metalloproteinases (MMP-2 and MMP-9) both on protein and mRNA levels in HUVEC cells. We demonstrated that CS5931 possessed strong anti-angiogenic activity both in vitro and in vivo, possible via VEGF and MMPs. This study indicates that CS5931 has the potential to be developed as a novel therapeutic agent as an inhibitor of angiogenesis for the treatment of cancer.     

Marine Compound Catunaregin Inhibits Angiogenesis through the Modulation of Phosphorylation of Akt and eNOS in vivo and in vitro

Angiogenesis is the formation of blood vessels from pre-existing vasculature. Excessive or uncontrolled angiogenesis is a major contributor to many pathological conditions whereas inhibition of aberrant angiogenesis is beneficial to patients with pathological angiogenesis. Catunaregin is a core of novel marine compound isolated from mangrove associate. The potential anti-angiogenesis of catunaregin was investigated in human umbilical vein endothelial cells (HUVECs) and zebrafish. HUVECs were treated with different concentrations of catunaregin in the presence or absence of VEGF. The angiogenic phenotypes including cell invasion cell migration and tube formation were evaluated following catunaregin treatment in HUVECs. The possible involvement of AKT, eNOS and ERK1/2 in catunaregin-induced anti-angiogenesis was explored using Western blotting. The anti-angiogenesis of catunaregin was further tested in the zebrafish embryo neovascularization and caudal fin regeneration assays. We found that catunaregin dose-dependently inhibited angiogenesis in both HUVECs and zebrafish embryo neovascularization and zebrafish caudal fin regeneration assays. In addition, catunaregin significantly decreased the phosphorylation of Akt and eNOS, but not the phosphorylation of ERK1/2. The present work demonstrates that catunaregin exerts the anti-angiogenic activity at least in part through the regulation of the Akt and eNOS signaling pathways.     

Evaluation of a Brown Seaweed Extract from Dictyosiphon foeniculaceus as a Potential Therapeutic Agent for the Treatment of Glioblastoma and Uveal Melanoma

Ingredients of brown seaweed like fucoidans are often described for their beneficial biological effects, that might be interesting for a medical application. In this study, we tested an extract from Dictyosiphon foeniculaceus (DF) to evaluate the effects in glioblastoma and uveal melanoma, looking for a possible anti-cancer treatment. We investigated toxicity, VEGF (vascular endothelial growth factor) secretion and gene expression of tumor and non-tumor cells. SVGA (human fetal astrocytes), the human RPE (retinal pigment epithelium) cell line ARPE-19, the tumor cell line OMM-1 (human uveal melanoma), and two different human primary glioblastoma cultures (116-14 and 118-14) were used. Tests for cell viability were conducted with MTS-Assay (3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium), and the proliferation rate was determined with cell counting. VEGF secretion was assessed with ELISA (enzyme-linked immunosorbent assay). The gene expression of VEGF receptor 1 (VEGFR1), VEGF receptor 2 (VEGFR2) and VEGF-A was determined with real-time qPCR (quantitative polymerase chain reaction). DF lowered the cell viability of OMM-1. Proliferation rates of ARPE-19 and OMM-1 were decreased. The VEGF secretion was inhibited in ARPE-19 and OMM-1, whereas it was increased in SVGA and 116-14. The expression of VEGFR1 was absent and not influenced in OMM-1 and ARPE-19. VEGFR2 expression was lowered in 116-14 after 24 h, whereas VEGF-A was increased in 118-14 after 72 h. The extract lowered cell viability slightly and was anti-proliferative depending on the cell type investigated. VEGF was heterogeneously affected. The results in glioblastoma were not promising, but the anti-tumor properties in OMM-1 could make them interesting for further research concerning cancer diseases in the human eye.     

Influence of Fucoidan Extracts from Different Fucus Species on Adult Stem Cells and Molecular Mediators in In Vitro Models for Bone Formation and Vascularization

Fucoidans, sulfated polysaccharides extracted from brown algae, are marine products with the potential to modulate bone formation and vascularization processes. The bioactivity and safety of fucoidans are highly associated with their chemical structure, which may vary with algae species and extraction method. Thus, in depth evaluation of fucoidan extracts in terms of endotoxin content, cytotoxicity, and their detailed molecular biological impact on the individual cell types in bone is needed. In this study, we characterized fucoidan extracts from three different Fucus species including Fucus vesiculosus (Fv), Fucus serratus (Fs), and Fucus distichus subsp. evanescens (Fe) for their chemical features, endotoxin content, cytotoxicity, and bioactive effects on human outgrowth endothelial cells (OEC) and human mesenchymal stem cells (MSC) as in vitro models for bone function and vascularization. Extracts contained mainly high molecular weight (HMW) fucoidans and were free of endotoxins that may cause inflammation or influence vascularization. OEC tolerated fucoidan concentrations up to 200 µg/mL, and no indication of cytotoxicity was observed. The inflammatory response, however, investigated by real-time PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) and endothelial barrier assessed by impedance measurement differed for the individual extracts. MSC in comparison with endothelial cells were more sensitive to fucoidans and showed partly reduced metabolic activity and proliferation at higher doses of fucoidans. Further results for MSC indicated impaired osteogenic functions in alkaline phosphatase and calcification assays. All tested extracts consistently lowered important molecular mediators involved in angiogenesis, such a VEGF (vascular endothelial growth factor), ANG-1 (angiopoietin 1), and ANG-2 (angiopoietin 2), as indicated by RT-PCR and ELISA. This was associated with antiangiogenic effects at the functional level using selected extracts in co-culture models to mimic bone vascularization processes during bone regeneration or osteosarcoma.     

Protective Effect of Flavonoids from a Deep-Sea-Derived Arthrinium sp. against ox-LDL-Induced Oxidative Injury through Activating the AKT/Nrf2/HO-1 Pathway in Vascular Endothelial Cells

Oxidized low-density lipoprotein (ox-LDL)-induced oxidative injury in vascular endothelial cells is crucial for the progression of cardiovascular diseases, including atherosclerosis. Several flavonoids have been shown cardiovascular protective effects. Recently, our research group confirmed that the novel flavonoids isolated from the deep-sea-derived fungus Arthrinium sp., 2,3,4,6,8-pentahydroxy-1-methylxanthone (compound 1) and arthone C (compound 2) effectively scavenged ROS in vitro. In this study, we further investigated whether these compounds could protect against ox-LDL-induced oxidative injury in endothelial cells and the underlying mechanisms. Our results showed that compounds 1 and 2 inhibited ox-LDL-induced apoptosis and adhesion factors expression in human umbilical vein vascular endothelial cells (HUVECs). Mechanistic studies showed that these compounds significantly inhibited the ROS level increase and the NF-κB nuclear translocation induced by ox-LDL. Moreover, compounds 1 and 2 activated the Nrf2 to transfer into nuclei and increased the expression of its downstream antioxidant gene HO-1 by inducing the phosphorylation of AKT in HUVECs. Importantly, the AKT inhibitor MK-2206 2HCl or knockdown of Nrf2 by RNA interference attenuated the inhibition effects of these compounds on ox-LDL-induced apoptosis in HUVECs. Meanwhile, knockdown of Nrf2 abolished the effects of the compounds on ox-LDL-induced ROS level increase and the translocation of NF-κB to nuclei. Collectively, the data showed that compounds 1 and 2 protected endothelial cells against ox-LDL-induced oxidative stress through activating the AKT/Nrf2/HO-1 pathway. Our study provides new strategies for the design of lead compounds for related cardiovascular diseases treatment.     

6″-Debromohamacanthin A,a Bis (Indole) Alkaloid,Inhibits Angiogenesis by Targeting the VEGFR2-Mediated PI3K/AKT/mTOR Signaling Pathways

Hamacanthins, bis (indole) alkaloids, are found in a few marine sponges, including Spongosorites sp. Hamacanthins have been shown to possess cytotoxic, antibacterial and antifungal activities. However, the precise mechanism for the biological activities of hamacanthins has not yet been elucidated. In the present study, the anti-angiogenic effects of 6″-debromohamacanthin A (DBHA), an active component of isolated hamacanthins, were evaluated in cultured human umbilical vascular endothelial cells (HUVEC) and endothelial-like cells differentiated from mouse embryonic stem (mES) cells. DBHA significantly inhibited vascular endothelial growth factor (VEGF)-induced cell proliferation, migration and tube formation in the HUVEC. DBHA also suppressed the capillary-like structure formation and the expression of platelet endothelial cell adhesion molecule (PECAM), an endothelial biomarker, in mES cell-derived endothelial-like cells. To further understand the precise molecular mechanism of action, VEGF-mediated signaling pathways were analyzed in HUVEC cells and mES cell-derived endothelial-like cells. DBHA suppressed the VEGF-induced expression of MAPKs (p38, ERK and SAPK/JNK) and the PI3K/AKT/mTOR signaling pathway. In addition, DBHA inhibited microvessel sprouting in mES/EB-derived embryoid bodies. In an ex vivo model, DBHA also suppressed the microvessel sprouting of mouse aortic rings. The findings suggest for the first time that DBHA inhibits angiogenesis by targeting the vascular endothelial growth factor receptor 2 (VEGFR2)-mediated PI3K/AKT/mTOR signaling pathway in endothelial cells.     

Heparanase and Syndecan-4 Are Involved in Low Molecular Weight Fucoidan-Induced Angiogenesis

Induction of angiogenesis is a potential treatment for chronic ischemia. Low molecular weight fucoidan (LMWF), the sulfated polysaccharide from brown seaweeds, has been shown to promote revascularization in a rat limb ischemia, increasing angiogenesis in vivo. We investigated the potential role of two heparan sulfate (HS) metabolism enzymes, exostosin-2 (EXT2) and heparanase (HPSE), and of two HS-membrane proteoglycans, syndecan-1 and -4 (SDC-1 and SDC-4), in LMWF induced angiogenesis. Our results showed that LMWF increases human vascular endothelial cell (HUVEC) migration and angiogenesis in vitro. We report that the expression and activity of the HS-degrading HPSE was increased after LMWF treatment. The phenotypic tests of LMWF-treated and EXT2- or HPSE-siRNA-transfected cells indicated that EXT2 or HPSE expression significantly affect the proangiogenic potential of LMWF. In addition, LMWF increased SDC-1, but decreased SDC-4 expressions. The effect of LMWF depends on SDC-4 expression. Silencing EXT2 or HPSE leads to an increased expression of SDC-4, providing the evidence that EXT2 and HPSE regulate the SDC-4 expression. Altogether, these data indicate that EXT2, HPSE, and SDC-4 are involved in the proangiogenic effects of LMWF, suggesting that the HS metabolism changes linked to LMWF-induced angiogenesis offer the opportunity for new therapeutic strategies of ischemic diseases.     

Differentiation of Umbilical Cord Lining Membrane-Derived Mesenchymal Stem Cells into Endothelial-Like Cells

Background: Stem cell therapy for the treatment of vascular-related diseases through functional revascularization is one of the most important research areas in tissue engineering. The aim of this study was to investigate the in vitro differentiation of umbilical CL-MSC into endothelial lineage cells. Methods: In this study, isolated cells were characterized for expression of MSC-specific markers and osteogenic and adipogenic differentiation. They were induced to differentiate into endothelial-like cells and then examined for expression of the endothelial-specific markers, karyotype, and functional behavior of cells. Results: Isolated cells expressed MSC-specific markers and differentiated into adipocytes and osteoblasts. After endothelial differentiation, they expressed CD31, vWF, VE-cadherin, VEGFR1, and VEGFR2 at both mRNA and protein level, but their morphological changes were not apparent when compared with those of undifferentiated cells. There were no significant changes in karyotype of differentiated cells. Furthermore, angiogenesis assay and LDL uptake assay showed that differentiated cells were able to form the capillary-like structures and uptake LDL, respectively. Conclusion: The results indicated that umbilical CL-MSC could differentiate into functional endothelial-like cells. Also, they are suitable for basic and clinical studies to cure several vascular-related diseases. Key Words: Endothelial differentiation, Endothelial-like cells, Mesenchymal stem cells, Umbilical cord lining membrane     

Decreased levels of metalloproteinase-9 and angiogenic factors in skin lesions of patients with psoriatic arthritis after therapy with anti-TNF-α

Background

Inflammation represents an early and key event in the development of both the cutaneous psoriasis and psoriatic arthritis. Compelling evidences indicate that the production of TNF-α plays a central role in psoriasis by sustaining the inflammatory process in the skin as well as in the joints. Among the multiple effects produced by TNF-α on keratinocytes, the induction of matrix metalloproteinase-9 (MMP-9), a collagenase implicated in joint inflammatory arthritis which acts as an angiogenesis promoting factor, might represent a key mechanism in the pathogenesis of the disease. Aims of the present study were to investigate a) the role of MMP-9 in the development of psoriasis by assessing the presence of MMP-9 in lesional skin and in sera of psoriatic patients; b) the association of MMP-9 with the activity of the disease; c) the relationship between MMP-9 and TNF-α production.

Methods

Eleven psoriatic patients, clinically presenting joint symptoms associated to the cutaneous disease, were included in a therapeutic protocol based on the administration of anti-TNF-α monoclonal antibody (Infliximab). Sera and skin biopsies were collected before treatment and after 6 weeks of therapy. Tissues were kept in short term cultures and production soluble mediators such as TNF-α, MMP-9, MMP-2, VEGF and E-Selectin, which include angiogenic molecules associated to the development of plaque psoriasis, were measured in the culture supernatants by immunoenzymatic assays (ng/ml or pg/ml per mg of tissue). MMP-9 concentrations were also measured in the sera. The cutaneous activity of disease was evaluated by the Psoriasis Area and Severity Index (PASI).

Results

Clinical and laboratory assessment indicated that all but one patients had a significant improvement of the PASI score after three months of therapy. The clinical amelioration was associated to a significant decrease of MMP-9 (P = 0.017), TNF-α (P = 0.005) and E-selectin (P = 0.018) levels, spontaneously released by lesional biopsies before and after therapy. In addition, significant correlations were found between the PASI measurements and TNF-α (r² = 0.33, P = 0.005), MMP-9 (r² = 0.25, P = 0.017), E-selectin (r² = 0.24, P = 0.018) production. MMP-9 levels were significantly correlated with those of TNF-α (r² = 0.30, P = 0.008). A significant decrease of MMP-9 in the sera, associated to the clinical improvement was also found.

Conclusion

Our findings show the existence of a direct relationship between MMP-9 and TNF-α production strongly suggesting that MMP-9 may play a key role in the skin inflammatory process in psoriasis.

     

The Marine Fungal Metabolite,AD0157, Inhibits Angiogenesis by Targeting the Akt Signaling Pathway

In the course of a screening program for the inhibitors of angiogenesis from marine sources, AD0157, a pyrrolidinedione fungal metabolite, was selected for its angiosupressive properties. AD0157 inhibited the growth of endothelial and tumor cells in culture in the micromolar range. Our results show that subtoxic doses of this compound inhibit certain functions of endothelial cells, namely, differentiation, migration and proteolytic capability. Inhibition of the mentioned essential steps of in vitro angiogenesis is in agreement with the observed antiangiogenic activity, substantiated by using two in vivo angiogenesis models, the chorioallantoic membrane and the zebrafish embryo neovascularization assays, and by the ex vivo mouse aortic ring assay. Our data indicate that AD0157 induces apoptosis in endothelial cells through chromatin condensation, DNA fragmentation, increases in the subG1 peak and caspase activation. The data shown here altogether indicate for the first time that AD0157 displays antiangiogenic effects, both in vitro and in vivo, that are exerted partly by targeting the Akt signaling pathway in activated endothelial cells. The fact that these effects are carried out at lower concentrations than those required for other inhibitors of angiogenesis makes AD0157 a new promising drug candidate for further evaluation in the treatment of cancer and other angiogenesis-related pathologies.     

Identification and Biological Characterization of Angiogenic and Tumor Growth Inhibitors derived from Sinica cetorhinus maximum Cartilage

Shark (Sinica cetorhinus maximum) cartilage was extracted in 1 mol/L Gu- HCl guanidine. Two purified active proteins with apparent molecular weights of 15.2×10³ Da and 8.0×10³ Da (designated as Sp15 and Sp8, respectively) were obtained through ultrafiltration and Superdex 75 chromatography. The activities of the samples were studied in terms of their potential inhibition of vascular endothelial cell growth in vitro, of angiogenesis both in rabbit cornea and chick embryo chorioallantoic membrane (CAM) assay models in vivo, and of growth of transplanted S180 sarcoma in mice in vivo. The results showed that Sp15 expressed a typical lysozymatic activity up to 223,000 U/mg and its N-terminus was highly homologous to lysozymes of various mammalian origins. Sp15 exhibited a strong anti-angiogenic activity only in vitro, whereas Sp8 shared this effect both in vitro and in vivo. Both Sp15 and Sp8 provided an effective anti-tumor activity in mice bearing transplanted S180 sarcoma. These results suggest that Sp15 is a shark cartilage-derived lysozyme that participates in the defense to bacterial invasion to the body, while Sp8 is an angiogenic inhibitor that mediates at least part of the anti-tumor activity associated with shark cartilage probably through the inhibition of tumor-induced angiogenesis.     

Discovery of Novel Antiangiogenic Marine Natural Product Scaffolds

Marine natural products (MNPs) are recognized for their structural complexity, diversity, and novelty. The vast majority of MNPs are pharmacologically relevant through their ability to modulate macromolecular targets underlying human diseases. Angiogenesis is a fundamental process in cancer progression and metastasis. Targeting angiogenesis through selective modulation of linked protein kinases is a valid strategy to discover novel effective tumor growth and metastasis inhibitors. An in-house marine natural products mini-library, which comprises diverse MNP entities, was submitted to the Lilly’s Open Innovation Drug Discovery platform. Accepted structures were subjected to in vitro screening to discover mechanistically novel angiogenesis inhibitors. Active hits were subjected to additional angiogenesis-targeted kinase profiling. Some natural and semisynthetic MNPs, including multiple members of the macrolide latrunculins, the macrocyclic oxaquinolizidine alkaloid araguspongine C, and the sesquiterpene quinone puupehenone, showed promising results in primary and secondary angiogenesis screening modules. These hits inhibited vascular endothelial growth factor (VEGF)-mediated endothelial tube-like formation, with minimal cytotoxicity at relevant doses. Secondary kinase profiling identified six target protein kinases, all involved in angiogenesis signaling pathways. Molecular modeling and docking experiments aided the understanding of molecular binding interactions, identification of pharmacophoric epitopes, and deriving structure-activity relationships of active hits. Marine natural products are prolific resources for the discovery of chemically and mechanistically unique selective antiangiogenic scaffolds.     

Micrometam C Protects against Oxidative Stress in Inflammation Models in Zebrafish and RAW264.7 Macrophages

Micrometam C is a core of novel marine compound isolated from the mangrove associates Micromelum falcatum. In this study, we investigated the protective effects of micrometam C in inflammation models in the transgenic zebrafish line Tg (corola: eGFP) and RAW264.7 macrophages. We found that micrometam C significantly suppressed the migration of immune cells in tail-cutting-induced inflammation in transgenic zebrafish and reduced lipopolysaccharide (LPS)-induced reactive oxygen species (ROS) in both zebrafish and macrophages. In addition, micrometam C also restored LPS-induced reduction of endogenous antioxidants, such as catalase (CAT), glutathione (GSH) and superoxide dismutase (SOD). The protective effects of micrometam C were in parallel to its inhibition of NADPH oxidase and nuclear factor-kappa-binding (NF-κB) activity. Thus, the present results demonstrate that micrometam C protects against LPS-induced inflammation possibly through its antioxidant property.     

Omega-3 Fatty Acids Modulate Weibel-Palade Body Degranulation and Actin Cytoskeleton Rearrangement in PMA-Stimulated Human Umbilical Vein Endothelial Cells

Long chain omega-3 polyunsaturated fatty acids (LC n-3 PUFAs) produce cardiovascular benefits by improving endothelial function. Endothelial cells store von Willebrand factor (vWF) in cytoplasmic Weibel-Palade bodies (WPBs). We examined whether LC n-3 PUFAs regulate WPB degranulation using cultured human umbilical vein endothelial cells (HUVECs). HUVECs were incubated with or without 75 or 120 µM docosahexaenoic acid or eicosapentaenoic acid for 5 days at 37 °C. WPB degranulation was stimulated using phorbol 12-myristate 13-acetate (PMA), and this was assessed by immunocytochemical staining for vWF. Actin reorganization was determined using phalloidin-TRITC staining. We found that PMA stimulated WPB degranulation, and that this was significantly reduced by prior incubation of cells with LC n-3 PUFAs. In these cells, WPBs had rounded rather than rod-shaped morphology and localized to the perinuclear region, suggesting interference with cytoskeletal remodeling that is necessary for complete WPB degranulation. In line with this, actin rearrangement was altered in cells containing perinuclear WPBs, where cells exhibited a thickened actin rim in the absence of prominent cytoplasmic stress fibers. These findings indicate that LC n-3 PUFAs provide some protection against WBP degranulation, and may contribute to an improved understanding of the anti-thrombotic effects previously attributed to LC n-3 PUFAs.     

New angiotensin-converting enzyme inhibitory peptide from Coix prolamin and its influence on the gene expression of renin-angiotensin system in vein endothelial cells

Coix seed, which is a traditional Chinese medicine, has been used to treat hypertension for thousands of years. It has been shown that Coix prolamin peptides display high levels of angiotensin I converting enzyme (ACE) inhibitory activity. Hence, we purified the ACE inhibitory peptides from Coix prolamin hydrolysates and evaluated the influence of the most potent peptide on the renin-angiotensin system (RAS) genes expression in human umbilical vein endothelial cells (HUVECs). In this study, Coix prolamin peptides were sequentially separated by ultrafiltration, ion exchange chromatography, gel filtration chromatography and RP-HPLC, while the peptide structure was analyzed by mass spectrometry. Next, in silico proteolysis, pharmacophore and molecular docking were further applied to screen and optimize the structure of peptides. Finally, a novel ACE inhibitory peptide VDMF was obtained, in which its influence on the gene expression of RAS signaling pathway in AngⅡ-injury HUVECs was evaluated by quantitative real-time PCR. VDMF significantly down-regulated ACE, AngII type 1 receptor (AT1R) and ACE2 mRNA expression in comparation with model group, while up-regulating Mas gene expression. Hence, we obtained a novel antihypertensive candidate that was derived from the Coix peptides, which could involve a multi-modulation mechanism that regulates blood pressure.     

Xyloketal B Attenuates Atherosclerotic Plaque Formation and Endothelial Dysfunction in Apolipoprotein E Deficient Mice

Our previous studies demonstrated that xyloketal B, a novel marine compound with a unique chemical structure, has strong antioxidant actions and can protect against endothelial injury in different cell types cultured in vitro and model organisms in vivo. The oxidative endothelial dysfunction and decrease in nitric oxide (NO) bioavailability are critical for the development of atherosclerotic lesion. We thus examined whether xyloketal B had an influence on the atherosclerotic plaque area in apolipoprotein E-deficient (apoE^−/−) mice fed a high-fat diet and investigated the underlying mechanisms. We found in our present study that the administration of xyloketal B dose-dependently decreased the atherosclerotic plaque area both in the aortic sinus and throughout the aorta in apoE^−/− mice fed a high-fat diet. In addition, xyloketal B markedly reduced the levels of vascular oxidative stress, as well as improving the impaired endothelium integrity and NO-dependent aortic vasorelaxation in atherosclerotic mice. Moreover, xyloketal B significantly changed the phosphorylation levels of endothelial nitric oxide synthase (eNOS) and Akt without altering the expression of total eNOS and Akt in cultured human umbilical vein endothelial cells (HUVECs). Here, it increased eNOS phosphorylation at the positive regulatory site of Ser-1177, while inhibiting phosphorylation at the negative regulatory site of Thr-495. Taken together, these findings indicate that xyloketal B has dramatic anti-atherosclerotic effects in vivo, which is partly due to its antioxidant features and/or improvement of endothelial function.     

大豆异黄酮对小鼠肝癌移植瘤血管生成的抑制作用

为了探讨大豆异黄酮对肝癌移植瘤血管生成的抑制作用,建立小鼠H22肝癌皮下移植瘤模型。用大豆异黄酮干预10 d,利用免疫组化染色法检测肿瘤组织内微血管密度,利用免疫印迹法检测肿瘤组织内血管内皮细胞生长因子(VEGF)、血管内皮细胞生长因子受体2(VEGFR2)和缺氧诱导因子-1α(HIF-1α)的表达,酶联免疫吸附测定(ELISA)法检测转化生长因子-β1(TGF-β1)和基质金属蛋白酶2(MMP2)的水平。结果显示,大豆异黄酮组移植瘤细胞生长受到抑制,细胞坏死较严重。与模型组比较,大豆异黄酮组肿瘤组织内微血管密度降低;VEGF、VEGFR2和HIF1α的蛋白表达降低;TGF-β1及MMP2蛋白表达下降。提示,大豆异黄酮对小鼠H_(22)移植瘤组织的血管生成具有抑制作用,机制可能与下调移植瘤组织VEGF和TGF-β1蛋白表达有关。