Inhibition of sphingosine-1-phosphate- and vascular endothelial growth factor-induced endothelial cell chemotaxis by red grape skin polyphenols correlates with a decrease in early platelet-activating factor synthesis

Comprehensive metabolomics study on the pathogenesis of anaplastic astrocytoma via UPLC-Q/TOF-MS

Anaplastic astrocytoma (AA) is a malignant carcinoma whose pathogenesis remains to be fully elucidated. System biology techniques have been widely used to clarify the mechanism of diseases from a systematic perspective. The present study aimed to explore the pathogenesis and novel potential biomarkers for the diagnosis of AA according to metabolic differences. Patients with AA (n = 12) and healthy controls (n = 15) were recruited. Serum was assayed with untargeted ultraperformance liquid chromatography-quadrupole/time-of-flight-mass spectrometry (UPLC-Q/TOF-MS) metabolomic techniques. The data were further evaluated using multivariate analysis and bioinformatic methods based on the KEGG database to determine the distinct metabolites and perturbed pathways. Principal component analysis and orthogonal projections to latent structures-discriminant analysis (OPLS-DA) identified the significance of the distinct metabolic pattern between patients with AA and healthy controls (P < .001) in both ESI modes. Permutation testing confirmed the validity of the OPLS-DA model (permutation = 200, Q2 < 0.5). In total, 24 differentiated metabolites and 5 metabolic pathways, including sphingolipid, glycerophospholipid, caffeine, linoleic acid, and porphyrin metabolism, were identified based on the OPLS-DA model. 3-Methylxanthine, sphinganine, LysoPC(18:1), and lactosylceramide were recognized as potential biomarkers with excellent sensitivity and specificity (area under the curve > 98%). These findings indicate that the perturbed metabolic pattern related to immune regulation and cellular signal transduction is associated with the pathogenesis of AA. 3-Methylxanthine, sphinganine, LysoPC(18:1), and lactosylceramide could be used as biomarkers of AA in future clinical practice. This study provides a therapeutic basis for further studies on the mechanism and precise clinical diagnosis of AA.

Targeting Angiogenic Factors for the Treatment of Medulloblastoma

OPINION STATEMENT

Medulloblastoma (MB) is the most frequent pediatric brain tumor. Despite conventional therapy, MB patients have high mortality and morbidity rates mainly due to the incomplete understanding of the molecular and cellular processes involved in development of this cancer. Similar to other solid tumors, MB demonstrated high endothelial cell proliferation and angiogenic activity, wherein new blood vessels arise from the pre-existing vasculature, a process named angiogenesis. MB angiogenesis is considered a hallmark for MB development, progression, and metastasis emphasizing its potential target for antitumor therapy. However, angiogenesis is tightly regulated by a set of angiogenic factors making it a complex process to be targeted. Although agents targeting these factors and their receptors are early in development, the potential for their targeting may translate into improvement in the clinical care for MB patients. In this review, we focus on the most potent angiogenic factors and their corresponding receptors, highlighting their basic properties and expression in MB. We describe their contribution to MB tumorigenesis and angiogenesis and the potential therapeutic targeting of these factors.

Clopidogrel-Induced Gastric Injury in Rats is Attenuated by Stable Gastric Pentadecapeptide BPC 157

Aim

Although Clopidogrel is safe in healthy volunteers, it can induce recurrence of gastric ulcers in high-risk patients. Here, we investigated the protective effect of the natural product, stable gastric pentadecapeptide 157 (BPC 157) on Clopidogrel-induced gastric injury.

Methods

We used acetic acid to induce gastric ulcer in Sprague Dawley rats. Clopidogrel alone or in combination with BPC 157 or L-NAME (nitric oxide system blockade) were administered after healing of acetic acid-induced ulcer. One percent methylcellulose solution was used as control. Ulcer recurrence rate and the ulcer index were compared between these groups. Gastric mucosal apoptosis rate, microscopic inflammation activity and angiogenesis markers vascular endothelial growth factor A (VEGF-A) and CD34 were examined by TUNEL, histological evaluations (HE) and immunohistochemistry (IHC). Pathways involved, expressions of endoplasmic reticulum (ER) stress apoptosis marker CHOP, angiogenic markers VEGF-A and its receptor VEGFR1, and endothelial NO synthase (eNOS) were all analyzed by Western blot.

Results

This study indicated that Clopidogrel significantly induced the gastric ulcers recurrence, severe inflammation and ER stress related apoptosis of the gastric mucosa, suppressed the synthesis of angiogenic markers and eNOS. Furthermore, Clopidrogel intervention resulted in the activation of protein kinase B (AKT) and p38 mitogen-activated protein kinase (p38/MAPK). BPC 157 attenuated the gastric mucosal damage caused by Clopidogrel and reversed these molecular effects. However, NO blockade L-NAME weakened the protective effect and thus the molecular effects of BPC 157 on gastric mucosa.

Conclusion

In conclusion, these results suggest that BPC 157 inhibited Clopidogrel-induced gastric mucosa injury partially by inhibition of gastric mucosa cell ER stress-mediated apoptosis and inflammation, and promoting gastric mucosa angiogenesis via VEGF-A/VEGFR1 mediated-AKT/p38/MAPK signaling pathways.

WDL-RF: predicting bioactivities of ligand molecules acting with G protein-coupled receptors by combining weighted deep learning and random forest

Motivation

Precise assessment of ligand bioactivities (including IC50, EC50, Ki, Kd, etc.) is essential for virtual screening and lead compound identification. However, not all ligands have experimentally determined activities. In particular, many G protein-coupled receptors (GPCRs), which are the largest integral membrane protein family and represent targets of nearly 40% drugs on the market, lack published experimental data about ligand interactions. Computational methods with the ability to accurately predict the bioactivity of ligands can help efficiently address this problem.

Results

We proposed a new method, WDL-RF, using weighted deep learning and random forest, to model the bioactivity of GPCR-associated ligand molecules. The pipeline of our algorithm consists of two consecutive stages: (i) molecular fingerprint generation through a new weighted deep learning method, and (ii) bioactivity calculations with a random forest model; where one uniqueness of the approach is that the model allows end-to-end learning of prediction pipelines with input ligands being of arbitrary size. The method was tested on a set of twenty-six non-redundant GPCRs that have a high number of active ligands, each with 200-4000 ligand associations. The results from our benchmark show that WDL-RF can generate bioactivity predictions with an average root-mean square error 1.33 and correlation coefficient (r2) 0.80 compared to the experimental measurements, which are significantly more accurate than the control predictors with different molecular fingerprints and descriptors. In particular, data-driven molecular fingerprint features, as extracted from the weighted deep learning models, can help solve deficiencies stemming from the use of traditional hand-crafted features and significantly increase the efficiency of short molecular fingerprints in virtual screening.

Availability and implementation

The WDL-RF web server, as well as source codes and datasets of WDL-RF, is freely available at https://zhanglab.ccmb.med.umich.edu/WDL-RF/ for academic purposes.

Supplementary information

Supplementary data are available at Bioinformatics online.

Expression pattern of thaumatin in the selected red varieties of Vitis vinifera, L

Vitis vinifera L. is a specie that is adapted to a very variable range of climates, from cold up to the desert one, but especially it grows in the temperate Mediterranean regions and continental areas of Europe. Grape is a widespread consumed fruit as well as processed to musts, juices or wine. The health beneficial effects of grapes and wine are very well known due to their high nutritional value and unique phytochemical composition. Despite many health protective and beneficial effects of Vitis vinifera, a part of population suffer to allergic reactions to this fruit. Allergens of wine and grapes are: endochitinases, lipid-transfer protein and thaumatin. Thaumatin is a protein having a sweet taste belonging to the PR5-like proteins.  These proteins are very difersified in their functions and were described to be involved in stress responses and fruit ripening, but are expressed in healthy grape fruits in a constitutive manner and needn´t to be expressed only as a answer to the stress. Thaumatin is a minor allergen in grape, but belonging to the suspected panallergens relevant to the food cross-allergy induction, its importance is quite high. Another importance of this protein is a technological one, as reported to aggregate in wine to form a visible haze unless removed prior to bottling. In this study, expression of thaumatin-like allergen was analysed in the grapes of selected varieties. Grapes of four red varieties of Vitis vinifera, L. were obtained in the season 2017 in the Sabo winery  that belongs to the Malokarpatská wine region. Fresh maturated grapes of varieties Alibernet, Cabernet Sauvignon , Frankovka modrá and Dornfelder were analysed. Expression changes of thaumatin was calculated by delta delta Ct method.  Dornfelder was found as to have the lowest activity in thaumatin-like gene activity,  mainly when comparing to the Cabernet Sauvignon and Frankovka modrá. Alibernet, on the other side, has the expression level of thaumatin very similar when comparing to the Cabernet Sauvignon and Frankovka modrá.

The Potential Role of Dietary Platelet-Activating Factor Inhibitors in Cancer Prevention and Treatment

Cancer is the second leading cause of mortality worldwide. The role of unresolved inflammation in cancer progression and metastasis is well established. Platelet-activating factor (PAF) is a key proinflammatory mediator in the initiation and progression of cancer. Evidence suggests that PAF is integral to suppression of the immune system and promotion of metastasis and tumor growth by altering local angiogenic and cytokine networks. Interactions between PAF and its receptor may have a role in various digestive, skin, and hormone-dependent cancers. Diet plays a critical role in the prevention of cancer and its treatment. Research indicates that the Mediterranean diet may reduce the incidence of several cancers in which dietary PAF inhibitors have a role. Dietary PAF inhibitors such as polar lipids have demonstrated inhibitory effects against the physiological actions of PAF in cancer and other chronic inflammatory conditions in vitro and in vivo. In addition, experimental models of radiotherapy and chemotherapy demonstrate that inhibition of PAF as adjuvant therapy may lead to more favorable outcomes. Although promising, there is limited evidence on the potential benefits of dietary PAF inhibitors on cancer prevention or treatment. Therefore, further extensive research is required to assess the effects of various dietary factors and PAF inhibitors and to elucidate the mechanisms in prevention of cancer progression and metastasis at a molecular level.

Review of Natural Product-Derived Compounds as Potent Antiglioblastoma Drugs

Common care for glioblastoma multiforme (GBM) is a surgical resection followed by radiotherapy and temozolomide- (TMZ-) based chemotherapy. Unfortunately, these therapies remain inadequate involving severe mortality and recurrence. Recently, new approaches discovering combinations of multiple inhibitors have been proposed along with the identification of key driver mutations that are specific to each patient. To date, this approach is still limited by the lack of effective therapy. Hopefully, novel compounds derived from natural products are suggested as potential solutions. Inhibitory effects of natural products on angiogenesis and metastasis and cancer suppressive effect of altering miRNA expression are provident discoveries. Angelica sinensis accelerates apoptosis by their key substances influencing factors of apoptosis pathways. Brazilin displays antitumor features by making influence on reactive oxygen species (ROS) intensity. Sargassum serratifolium, flavonoids, and so on have antimetastasis effect. Ficus carica controls miRNA that inhibits translation of certain secretory pathway proteins during the UPR. Serratia marcescens and patupilone (EPO 906) are physically assessed materials through clinical trials related to GBM progression. Consequently, our review puts emphasis on the potential of natural products in GBM treatment by regulating multiple malignant cancer-related pathway solving pending problem such as reducing toxicity and side effect.

Sphingolipids and glycerophospholipids - The "ying and yang" of lipotoxicity in metabolic diseases

Sphingolipids in general and ceramides in particular, contribute to pathophysiological mechanisms by modifying signalling and metabolic pathways. Here, we present the available evidence for a bidirectional homeostatic crosstalk between sphingolipids and glycerophospholipids, whose dysregulation contributes to lipotoxicity induced metabolic stress. The initial evidence for this crosstalk originates from simulated models designed to investigate the biophysical properties of sphingolipids in plasma membrane representations. In this review, we reinterpret some of the original findings and conceptualise them as a sort of "ying/yang" interaction model of opposed/complementary forces, which is consistent with the current knowledge of lipid homeostasis and pathophysiology. We also propose that the dysregulation of the balance between sphingolipids and glycerophospholipids results in a lipotoxic insult relevant in the pathophysiology of common metabolic diseases, typically characterised by their increased ceramide/sphingosine pools.

Red Grape Skin Polyphenols Blunt Matrix Metalloproteinase-2 and -9 Activity and Expression in Cell Models of Vascular Inflammation: Protective Role in Degenerative and Inflammatory Diseases

Matrix metalloproteinases (MMPs) are endopeptidases responsible for the hydrolysis of various components of extracellular matrix. MMPs, namely gelatinases MMP-2 and MMP-9, contribute to the progression of chronic and degenerative diseases. Since gelatinases' activity and expression are regulated by oxidative stress, we sought to evaluate whether supplementation with polyphenol-rich red grape skin extracts modulated the matrix-degrading capacity in cell models of vascular inflammation. Human endothelial and monocytic cells were incubated with increasing concentrations (0.5-25 μg/mL) of Negroamaro and Primitivo red grape skin polyphenolic extracts (NSPE and PSPE, respectively) or their specific components (0.5-25 μmol/L), before stimulation with inflammatory challenge. NSPE and PSPE inhibited, in a concentration-dependent manner, endothelial invasion as well as the MMP-9 and MMP-2 release in stimulated endothelial cells, and MMP-9 production in inflamed monocytes, without affecting tissue inhibitor of metalloproteinases (TIMP)-1 and TIMP-2. The matrix degrading inhibitory capacity was the same for both NSPE and PSPE, despite their different polyphenolic profiles. Among the main polyphenols of grape skin extracts, trans-resveratrol, trans-piceid, kaempferol and quercetin exhibited the most significant inhibitory effects on matrix-degrading enzyme activities. Our findings appreciate the grape skins as rich source of polyphenols able to prevent the dysregulation of vascular remodelling affecting degenerative and inflammatory diseases.

Investigation of anti-asthmatic potential of dried fruits of Vitis vinifera L. in animal model of bronchial asthma

Background

Fruits of Vitis vinifera L., commonly known as grapes, are largely consumed worldwide because of their high nutritional and medicinal benefits.

Context and purpose

The present study investigated effects of V. vinifera fruits in ovalbumin-induced animal model of bronchial asthma.

Methods

Male wistar rats (except group 1) were sensitized with allergen (ovalbumin, 40 mg/rat + aluminum hydroxide, 2 mg/rat). Groups of sensitized animals were treated orally with either vehicle (0.4 mL/kg), standard dexamethasone (2.5 mg/kg) or alcoholic extract of V. vinifera dried fruits (31 and 42.5 mg/kg) from day 1 to 28 (n = 6 for all groups). Inflammatory markers including cell counts, cytokines such as interleukin (IL)-4, IL-5, IL-1β, tumor necrosis factor, immunoglobulin E (IgE), leukotrienes and nitrite levels in both blood/serum and bronchoalveolar fluid were analysed. Breathing rate and tidal volume as lung function parameters were examined by spirometer. Lung tissues were studied for histamine content and histopathology.

Results

Treatment of sensitized animals with dexamethasone or two doses of V. vinifera fruits extract inhibited recruitment of inflammatory cytokines, IgE, nitrites and circulating cells particularly eosinophils in blood/serum and bronchoalveolar fluid (p < 0.001, p < 0.01 and p < 0.05). Dexamethasone and V. vinifera fruits extract treatment also normalized lung functions and histamine levels compared to ovalbumin-sensitized controls (p < 0.05 and p < 0.01). Moreover, both drugs exhibited protection against airway inflammation in lung histology.

Conclusion

Results of study demonstrate the effectiveness of V. vinifera fruits in allergic asthma possibly related to its ability to inhibit cellular response and subsequent production of inflammatory cytokines.

Electronic supplementary material

The online version of this article (doi:10.1186/s13223-016-0145-x) contains supplementary material, which is available to authorized users.

Resveratrol and its oligomers: modulation of sphingolipid metabolism and signaling in disease

Resveratrol, a natural compound endowed with multiple health-promoting effects, has received much attention given its potential for the treatment of cardiovascular, inflammatory, neurodegenerative, metabolic and age-related diseases. However, the translational potential of resveratrol has been limited by its specificity, poor bioavailability and uncertain toxicity. In recent years, there has been an accumulation of evidence demonstrating that resveratrol modulates sphingolipid metabolism. Moreover, resveratrol forms higher order oligomers that exhibit better selectivity and potency in modulating sphingolipid metabolism. This review evaluates the evidence supporting the modulation of sphingolipid metabolism and signaling as a mechanism of action underlying the therapeutic efficacy of resveratrol and oligomers in diseases, such as cancer.

In situ generation of tunable porosity gradients in hydrogel-based scaffolds for microfluidic cell culture

Compared with preformed anisotropic matrices, an anisotropic matrix that allows users to alter its properties and structure in situ after synthesis offers the important advantage of being able to mimic dynamic in vivo microenvironments, such as in tissues undergoing morphogenesis or in wounds undergoing tissue repair. In this study, porous gradients are generated in situ in a hydrogel comprising enzymatically crosslinked gelatin hydroxyphenylpropionic acid (GTN-HPA) conjugate and carboxylmethyl cellulose tyramine (CMC-TYR) conjugate. The GTN-HPA component acts as the backbone of the hydrogel, while CMC-TYR acts as a biocompatible sacrificial polymer. The hydrogel is then used to immobilize HT1080 human fibrosarcoma cells in a microfluidic chamber. After diffusion of a biocompatible cellulase enzyme through the hydrogel in a spatially controlled manner, selective digestion of the CMC component of the hydrogel by the cellulase gives rise to a porosity gradient in situ instead of requiring its formation during hydrogel synthesis as with other methods. The influence of this in situ tunable porosity gradient on the chemotactic response of cancer cells is subsequently studied both in the absence and presence of chemoattractant. This platform illustrates the potential of hydrogel-based microfluidics to mimic the 3D in vivo microenvironment for tissue engineering and diagnostic applications.

Resveratrol dimers are novel sphingosine kinase 1 inhibitors and affect sphingosine kinase 1 expression and cancer cell growth and survival

BACKGROUND AND PURPOSE

Sphingosine kinase 1 catalyses formation of the bioactive lipid, sphingosine 1-phosphate, which protects cancer cells from apoptosis. Therefore, sphingosine kinase 1 is a novel target for intervention with anti-cancer agents. We have assessed the effect of the anti-cancer agent, resveratrol and its dimers (ampelopsin A and balanocarpol) on sphingosine kinase 1 activity and on survival of MCF-7 breast cancer cells.

EXPERIMENTAL APPROACH

Ampelopsin A and balanocarpol were purified from Hopea dryobalanoides and their effect on sphingosine kinase 1 activity and expression, [(3)H] thymidine incorporation, ERK-1/2 phosphorylation and PARP activity assessed in MCF-7 cells.

KEY RESULTS

Resveratrol, ampelopsin A and balanocarpol were novel inhibitors of sphingosine kinase 1 activity. Balanocarpol was a mixed inhibitor (with sphingosine) of sphingosine kinase 1 with a K(ic) = 90 ± 10 µM and a K(iu) of ∼500 µM. Balanocarpol and ampelopsin A also induced down-regulation of sphingosine kinase 1 expression and reduced DNA synthesis, while balanocarpol stimulated PARP cleavage in MCF-7 breast cancer cells. Resveratrol was a competitive inhibitor (with sphingosine) of sphingosine kinase 1 with a K(ic) = 160 ± 40 µM, reduced sphingosine kinase 1 expression and induced PARP cleavage in MCF-7 cells.

CONCLUSIONS AND IMPLICATIONS

Each molecule of balanocarpol may bind at least two sphingosine kinase 1 catalytic molecules to reduce the activity of each simultaneously. These findings suggest that resveratrol, ampelopsin A and balanocarpol could perturb sphingosine kinase 1-mediated signalling and this might explain their activity against MCF-7 breast cancer cells.

Transforming growth factor-beta1 enhanced vascular endothelial growth factor synthesis in mesenchymal stem cells

Angiogenesis is essential for transplantation of mesenchymal stem cells (MSCs). Vascular endothelial growth factor (VEGF) is one of the most potent angiogenic factors identified to date. Elevated VEGF levels in MSCs correlate with the potential of MSCs transplantation. As an indirect angiogenic agent, transforming growth factor-beta1 (TGF-beta1) plays a pivotal role in the regulation of vasculogenesis and angiogenesis. However, the effect of TGF-beta1 on VEGF synthesis in MSCs is still unknown. Besides, the intracellular signaling mechanism by which TGF-beta1 stimulates this process remains poorly understood. In this article, we demonstrated that exposure of MSCs to TGF-beta1 stimulated the synthesis of VEGF. Meanwhile, TGF-beta1 stimulated the phosphorylation of Akt and extracellular signal-regulated kinase 1/2 (ERK1/2). Moreover, Ly 294002, a specific inhibitor of phosphatidylinositol-3-kinase (PI3K)/Akt significantly attenuated the VEGF synthesis stimulated by TGF-beta1. Additionally, U0126, a specific inhibitor of ERK1/2, also significantly attenuated the TGF-beta1-stimulated VEGF synthesis. These results indicated that TGF-beta1 enhanced VEGF synthesis in MSCs, and the Akt and ERK1/2 activation were involved in this process.

Biomarkers for diet and cancer prevention research: potentials and challenges

As cancer incidence is projected to increase for decades there is a need for effective preventive strategies. Fortunately, evidence continues to mount that altering dietary habits is an effective and cost-efficient approach for reducing cancer risk and for modifying the biological behavior of tumors. Predictive, validated and sensitive biomarkers, including those that reliably evaluate "intake" or exposure to a specific food or bioactive component, that assess one or more specific biological "effects" that are linked to cancer, and that effectively predict individual "susceptibility" as a function of nutrient-nutrient interactions and genetics, are fundamental to evaluating who will benefit most from dietary interventions. These biomarkers must be readily accessible, easily and reliably assayed, and predictive of a key process(es) involved in cancer. The response to a food is determined not only by the effective concentration of the bioactive food component(s) reaching the target tissue, but also by the amount of the target requiring modification. Thus, this threshold response to foods and their components will vary from individual to individual. The key to understanding a personalized response is a greater knowledge of nutrigenomics, proteomics and metabolomics.

Effects of red wine polyphenols on postischemic neovascularization model in rats: low doses are proangiogenic, high doses anti-angiogenic

Polyphenols, present in green tea, grapes, or red wine, have paradoxical properties: they protect against cardiac and cerebral ischemia but inhibit angiogenesis in vitro. So we investigated the effects of polyphenols in vivo on postischemic neovascularization. Rats treated with low (0.2 mg x kg(-1) x day(-1)) or high (20 mg x kg(-1) x day(-1)) doses of red wine polyphenolic compounds (RWPC) were submitted to femoral artery ligature on the left leg. Two wks after ligature, high doses of RWPC (i.e., 7 glasses of red wine) reduced arterial, arteriolar, and capillary densities and blood flow in association with an inhibition of a PI3 kinase-Akt-endothelial NO synthase (eNOS) pathway, decreased VEGF expression, and lower metalloproteinase (MMP) activation. Low doses of RWPC (i.e., 1/10th glass of red wine) increased the left/right (L/R) leg ratio to control level in association with an increased blood flow and microvascular density. This angiogenic effect was associated with an overexpression of PI3 kinase-Akt-eNOS pathway and an increased VEGF production without effect on MMP activation. Thus, low and high doses RWPC have respectively pro- and anti-angiogenic properties on postischemic neovascularization in vivo. This unique dual effect of RWPC offers important perspectives for the treatment and prevention of ischemic diseases (low dose) or cancer growth (high dose).