Suppression of alpha-tocopherol ether-linked acetic acid in VEGF-induced angiogenesis and the possible mechanisms in human umbilical vein endothelial cells

Histamine promotes angiogenesis through a histamine H1 receptor-PKC-VEGF-mediated pathway in human endothelial cells

Histamine is a well-known inflammatory mediator, but how histamine induces angiogenesis remains poorly understood. In the present study, we demonstrated a dose-dependent dynamic tube formation in the human endothelial cell line EA.hy926 in the presence of histamine that was completely blocked by histamine H1 receptor (H1R) and protein kinase C (PKC) inhibitors. However, histamine H2, H3, and H4 receptor inhibitors did not inhibit tube formation, suggesting that H1R-PKC signaling is involved in histamine-induced tube formation. Moreover, we found an H1-specific induction of vascular endothelial growth factor (VEGF) expression. Inhibition of VEGF receptor 2 (VEGFR2) suppressed the histamine-induced tube formation, indicating that VEGF is downstream of histamine signaling. Additionally, we demonstrated that histamine stimulation induces the expression of critical regulators of angiogenesis such as matrix metalloproteinase (MMP)-9 and MMP-14 metalloproteases, as histamine-induced tube formation is blocked by MMP inhibitors. In summary, our study indicates that histamine can activate the H1R in human endothelial cells and thereby promote tube formation through the PKC, MMP, and VEGF signaling pathways.

Isorhamnetin inhibited migration and invasion via suppression of Akt/ERK-mediated epithelial-to-mesenchymal transition (EMT) in A549 human non-small-cell lung cancer cells

In the present study, we investigated the potential effects of Isorhamnetin on the growth and metastasis of A549 human lung cancer cells, as well as the underlying mechanism. Treatment with Isorhamnetin exhibited a dose- and time-dependent inhibition on A549 cell proliferation. Furthermore, the cell adhesion and Transwell assay showed that treatment with Isorhamnetin (2.5, 5, and 10 μM) for 48 h resulted in a significant inhibition effect on cell adhesion, invasion and migration of A549 cells, depending on concentration, which was associated with the suppression of matrix metalloproteinase (MMP)-2 and MMP-9 activity and protein expression. Moreover, Isorhamnetin effectively suppressed the expressions of epithelial-to-mesenchymal transition (EMT) markers, as evidenced by the down-regulation of N-cadherin, vimentin and snail, as well as up-regulation of E-cadherin protein expression. Additionally, these inhibitions were mediated by interrupting AKT/ERK1/2 signaling pathways. Taken together, the results of the current study demonstrated that Isorhamnetin may become a good anti-metastastic agent against lung cancer A549 cell line by the suppression of EMT via interrupting Akt/ERK1/2 signaling pathway.

MicroRNA-34a attenuates VEGF-mediated retinal angiogenesis via targeting Notch1

Pathological angiogenesis in the retina is one of the main ocular diseases closely associated with vision loss. This work investigated the roles of microRNA-34a (miR-34a) and its potential target Notch1, in retinal angiogenesis. For this we used oxygen-induced retinopathy (OIR) rats and human retinal microvascular endothelial cells (HRMECs) stimulated with vascular endothelial growth factor (VEGF). We performed hematoxylin-eosin staining, Western blot for VEGF, and immunofluorescence staining for CD31 to verify the establishment of our OIR model. We observed down-regulation of miR-34a, and up-regulation of Notch1 and Hey1 in retinas from OIR rats. We found similar results with the VEGF-stimulated HRMECs. By performing MTT assay, cell scratch assay, tube formation assay, and by detecting the expression of matrix-metalloproteinase-2 (MMP-2), MMP-9, tissue inhibitors of metalloproteinases-1 (TIMP-1), and TIMP-2, we found that transfection of miR-34a ameliorated VEGF-mediated angiogenesis of HRMECs. We further observed that siRNA-induced gene silencing of Notch1 prevented VEGF-induced angiogenesis via regulating cell proliferation, cell migration, and tube formation of HRMECs. Additionally, activation of Notch1 by transfection of Notch1 plasmid attenuated the inhibitory effects of miR-34a on tube formation, in the present of VEGF. Results from our dual-luciferase reporter gene assay suggested that miR-34a targets Notch1. In summary, our data demonstrate that miR-34a attenuates retinal angiogenesis via targeting Notch1.

Anti-metastatic effects of isolinderalactone via the inhibition of MMP-2 and up regulation of NM23-H1 expression in human lung cancer A549 cells

Metastatic lung cancer is a leading cause of mortality and has a mortality rate of ≥90%. Isolinderalactone (ILL) is a sesquiterpene lactone compound that has been used in traditional Chinese medicine. Research has demonstrated that ILL has anti-inflammatory and anti-proliferative properties; however, to the best of our knowledge, studies investigating whether ILL can inhibit lung cancer cell metastasis have not been conducted. In the present study, 1-10 µM ILL was applied in the culturing of the A549 lung cancer cell line to investigate the effects of ILL on the invasion and migration of lung cancer cells, including whether the possible mechanisms of ILL are associated with the expression of matrix metalloproteinase (MMP)-2 and NME/NM23 nucleoside diphosphate kinase 1 (NM23-H1) genes. The results of the present study indicated that ILL inhibited the invasion and migration of the A549 cancer cells and exhibited a dose-response association. ILL also significantly inhibited the protein expression and activity of MMP-2 (P<0.05), exhibiting a trend similar to that of its invasion- and migration-associated properties. Further research revealed that ILL significantly increased the expression of NM23-H1 protein and inhibited the expression of β-catenin protein (P<0.05). The results of the present study is, to the best of our knowledge, the first to confirm that ILL can inhibit the invasion and migration of A549 cancer cells, with the possible mechanisms potentially involving the inhibition of MMP-2 and β-catenin protein expression resulting from the up regulation of NM23-H1 expression.

Multi-Carotenoids at Physiological Levels Inhibit VEGF-Induced Tube Formation of Endothelial Cells and the Possible Mechanisms of Action Both In Vitro and Ex Vivo

Carotenoids have been shown to exhibit antiangiogenic activities. Several studies have indicated that carotenoids used in combination were more effective on antioxidation and anticancer actions than carotenoids used singly. However, it is unclear whether multi-carotenoids have antiangiogenic effects. We investigated the effects of multi-carotenoids at physiological plasma levels of Taiwanese (abbreviated as MCT, with a total of 1.4 μM) and Americans (abbreviated as MCA, with a total of 1.8 μM), and of post-supplemental plasma levels (abbreviated as HMC with a total of 3.55 μM) on vascular endothelial growth factor (VEGF)-induced tube formation in human umbilical vein endothelial cells (HUVECs) and rat aortic rings. MCT, MCA, and HMC inhibited VEGF-induced migration, invasion, and tube formation of HUVECs as well as new vessels formation in rat aortic rings. MCT, MCA, and HMC inhibited activities o\f matrix metalloproteinase (MMP)-2, urokinase plasminogen activator, and phosphorylation of VEGF receptor 2 induced by VEGF. Moreover, MCT, MCA, and HMC significantly upregulated protein expression of tissue inhibitors of MMP-2 and plasminogen activator inhibitor-1. These results demonstrate the antiangiogenic effect of multi-carotenoids both in vitro and ex vivo with possible mechanistic actions involving attenuation of VEGF receptor 2 phosphorylation and extracellular matrix degradation.

Induction of cellular and molecular Immunomodulatory pathways by vitamin E and vitamin C

INTRODUCTION

Vitamins E and C are well known small molecules that have been used to maintain health for decades. Recent studies of the cellular and molecular pathways leading to immunomodulation by these molecules have been of interest, as have their anti-oxidant properties and signal transduction pathways for curing or improving infectious diseases and cancer. Areas covered: Herein, the authors provide a definition and the structural classification of vitamins E and C and how these molecules influence cellular function. The studies include in vitro, ex vivo and in vivo studies in animal models as well as clinical trials. The authors give particular focus to the scientifically factual and putative roles of these molecules in innate and adaptive immunomodulation and prevention or cure of diseases. Expert opinion: The antioxidant properties of vitamins E and C are well studied. However, whether there is a link between their antioxidant and immunomodulation properties is unclear. In addition, there is a strong, albeit putative, prevailing notion that vitamin C can prevent or cure infectious diseases or cancer. Presently, while there is proven evidence that vitamin E possesses immunomodulatory properties that may play a positive role in disease outcomes, this evidence is less available for vitamin C.

Quercetin metabolites inhibit MMP-2 expression in A549 lung cancer cells by PPAR-γ associated mechanisms

Our previous study demonstrated that quercetin-metabolite-enriched plasma (QP) but not quercetin itself upregulates peroxisome proliferator-activated receptor gamma (PPAR-γ) expression to induce G2/M arrest in A549 cells. In the present study, we incubated A549 cells with QP as well as quercetin-3-glucuronide (Q3G) and quercetin-3'-sulfate (Q3'S), two major metabolites of quercetin, to investigate the effects of quercetin metabolites on cell invasion and migration, the possible mechanisms and the role of PPAR-γ. We also compared the effects of QP with those of quercetin and troglitazone (TGZ), a PPAR-γ ligand. The results showed that QP significantly suppressed cell invasion and migration, as well as matrix metalloproteinases (MMPs)-2 activity and expression in a dose-dependent manner. The effects of 10% QP on those parameters were similar to those of 10μM quercetin and 20μM TGZ. However, QP and TGZ rather than quercetin itself increased the expressions of nm23-H1 and tissue inhibitor of metalloproteinase (TIMP-2). Furthermore, we demonstrated that Q3G and Q3'S also inhibited the protein expression of MMP-2. GW9662, a PPAR-γ antagonist, significantly diminished such an effect of Q3G and Q3'S. Silencing PPAR-γ expression in A549 cells also significantly diminished the suppression effect of Q3G and Q3'S on MMP-2 expression. Taken together, our study demonstrated that QP inhibited cell invasion and migration through nm23-H1/TIMP-2/MMP-2 associated mechanisms. The upregulation of PPAR-γ by quercetin metabolites such as Q3G and Q3'S could play an important role in the effects of QP.

High VEGF-D and Low MMP-2 Serum Levels Predict Nodal-Positive Disease in Invasive Bladder Cancer

Background

To investigate stromal variables including angiogenesis, lymphangiogenesis, and matrix metalloproteinase (MMP) in the serum of patients with urothelial carcinoma of the bladder (UCB) and to evaluate their association with histopathological characteristics and clinical outcome.

Material/Methods

Protein levels of vascular endothelial growth factors-A, -C, -D (VEGF-A/-C/-D), their receptors- VEGF-R2 and -R3 (VEGF-R2/-R3), and matrix metalloproteinases 2, -3, and -7 (MMP-2, MMP-3, MMP-7) were quantified in the blood serum samples of 71 patients with UCB before radical cystectomy (RC). Samples of patients with non-invasive UCB or no history of UCB were investigated as controls (n=20). Protein levels in the serum were measured using a flow cytometric cytokine assay.

Results

A positive association for VEGF-D (p<0.001) and an inverse association for MMP-2 (p=0.017) were observed in patients with positive lymph node (LN) status at the time of RC. VEGF-A (p<0.001), VEGF-C (p<0.001), MMP-2 (p<0.001), and MMP-7 (p=0.005) serum levels were different in serum of patients with invasive UCB compared with non-invasive UCB or healthy individuals. None of the serum markers were associated with disease progression.

Conclusions

High VEGF-D and low MMP-2 serum levels predict LN metastasis in patients with UCB at the time of RC. VEGF-A, VEGF-C, MMP-2, and MMP-7 serum levels varied significantly between invasive and non-invasive disease as well as in comparison with healthy individuals. Clinical implementation of these marker serum measurements may be valuable to select high-risk patients with more invasive or nodal-positive disease.