Pro-angiogenic Vascular Endothelial Growth Factor Research Articles

Vitamin D suppresses proangiogenic factors in patients with ulcerative colitis: A randomized double blind placebo controlled clinical trial

BackgroundAngiogenesis and inflammation are involved in the pathogenesis of ulcerative colitis (UC). This study aimed to assess the effect of vitamin D on serum levels of proangiogenic factors, visfatin and vascular endothelial growth factor (VEGF), in patients with UC. Materials and methodsNinety patients were randomized to receive either a single intramuscular injection of 300,000 IU vitamin D or normal saline. Visfatin, VEGF, and 25-hydroxyvitamin D [25(OH)D] concentrations were assessed before and 90 days after the intervention. ResultsThere were no significant differences in visfatin and VEGF levels between the two groups following supplementation. In patients with vitamin D insufficiency, visfatin increase was significantly lower in the intervention versus placebo group. There was an inverse correlation between serum 25(OH)D and visfatin in the subgroup with vitamin D insufficiency. ConclusionVitamin D might be beneficial in decreasing proangiogenic factors such as visfatin in UC patients with low 25(OH)D levels.

Raman spectroscopy links differentiating osteoblast matrix signatures to pro-angiogenic potential

Mineralization of bone is achieved by the sequential maturation of the immature amorphous calcium phase to mature hydroxyapatite (HA) and is central in the process of bone development and repair. To study normal and dysregulated mineralization in vitro, substrates are often coated with poly-l-lysine (PLL) which facilitates cell attachment. This study has used Raman spectroscopy to investigate the effect of PLL coating on osteoblast (OB) matrix composition during differentiation, with a focus on collagen specific proline and hydroxyproline and precursors of HA. Deconvolution analysis of murine derived long bone OB Raman spectra revealed collagen species were 4.01-fold higher in OBs grown on PLL. Further, an increase of 1.91-fold in immature mineral species (amorphous calcium phosphate) was coupled with a 9.32-fold reduction in mature mineral species (carbonated apatite) on PLL versus controls. These unique low mineral signatures identified in OBs were linked with reduced alkaline phosphatase enzymatic activity, reduced Alizarin Red staining and altered osteogenic gene expression. The promotion of immature mineral species and restriction of mature mineral species of OB grown on PLL were linked to increased cell viability and pro-angiogenic vascular endothelial growth factor (VEGF) production. These results demonstrate the utility of Raman spectroscopy to link distinct matrix signatures with OB maturation and VEGF release. Importantly, Raman spectroscopy could provide a label-free approach to clinically assess the angiogenic potential of bone during fracture repair or degenerative bone loss.

Vascular Endothelial Growth Factor and Cutaneous Scarring.

Significance: The proangiogenic mediator vascular endothelial growth factor (VEGF) plays an important role in cutaneous wound repair. Most of the work on VEGF and wound healing has focused on its role in mediating angiogenesis and how this affects wound closure rates. Less is known about how VEGF affects other phases of wound healing, including scar formation. Recent Advances: Over the last 10 years, mounting evidence suggests that VEGF plays an important role in regulating scar tissue production. Multiple studies have linked high VEGF levels with scar formation in normal, hypertrophic, and keloid scars. In addition, there is experimental evidence that VEGF inhibition can reduce scar tissue deposition. Critical Issues: While there is evidence that VEGF can promote scar formation in the skin, there are several unanswered questions that remain. First, the mechanisms by which VEGF promotes scar formation have not been completely characterized. While both indirect and direct mechanisms could be involved, clear evidence for a specific mechanism is lacking. In addition, despite the availability of anti-VEGF drugs, the potential value in targeting VEGF to attenuate scar formation clinically is not yet known. Future Directions: While there are a significant number of studies examining the effects of VEGF on angiogenesis and wound closure, much less attention has been paid to the contribution of VEGF to scar tissue production. Additional studies are required to learn more about how VEGF regulates scar formation and whether VEGF inhibition could be used clinically to manage scars.

2040P - The potential of a novel antiangiogenic VEGFR1-D2 binding peptide in oncology therapeutics

BackgroundTumor growth depends on pro-angiogenic vascular endothelial growth factors (VEGF-A/-B) via binding to VEGF receptors (VEGFR1 and VEGFR2) that are biomarkers of tumor angiogenesis. Importantly, interfering with this interaction by small molecules impairs tumor growth and angiogenesis. MethodsA novel peptide (known as VGB3) was synthesized using a solid-phase peptide synthesis (SPPS) procedure on 2-chlorotrityl chloride (2-CTC) resin. A disulfide bridge was formed in the peptide and it was purified using RP-HPLC. Recombinant His-tagged VEGFR1D2 obtained from inclusion bodies and purified on a Ni2+-NTA agarose resin. The equilibrium constant for the binding of VGB3 to VEGFR1-D2 molecule was determined by microscale thermophoresis (MST). The accumulation of the peptide in 4T1 mammary carcinoma tumors (MCTs) was assessed using 2D optical imaging. Anti-angiogenic activity of VGB3 were investigated using MTT, scratch assay, and two- as well as three-dimensional angiogenesis assays. Downstream signaling pathways were assessed by quantitative estimation of protein expression using western blotting and immunohistochemistry. (IHC). ResultsWe have indicated that VGB3 is able to block VEGFR1-D2 in human umbilical vein endothelial cells (HUVECs) and 4T1 mammary carcinoma tumor (MCT) cells. This resulted in inhibition in proliferation of HUVEC, 4T1 MCT, and U87 glioblastoma cells and MST results reveals that VGB3 is a high-affinity (Kd=1.96± 0.69 µM, n=3, P<0.0001) binder to VEGFR1-D2. Moreover, fluorescence imaging in Balb/c mice demonstrated that fluorescein isothiocyanate (FITC)-VGB3 accumulated in tumors. VEGFA-stimulated proliferation, migration, and 2 and 3D tube formation in HUVECs were strongly inhibited by VGB3 (n=3, P<0.0001). In a murine 4T1 MCT model, VGB3 strongly inhibited AKT and ERK1/2 phosphorylation and tumor cell downstream signaling pathways associated with proliferation, migration, and angiogenesis, and led to the increased apoptosis index and suppression of systematic spreading of the tumor compared to PBS-treated controls. ConclusionsThese results indicate that VGB3 may be applicable for antiangiogenic and antitumor therapy. Legal entity responsible for the studyS. Mohsen Asghari and Matthew Groves. FundingUniversity of Guilan. DisclosureAll authors have declared no conflicts of interest.

The response of periodontal cells to kaolinite

ObjectivesThe impact of kaolinite on human periodontal cells is yet unknown. The aim of the study was to assess the response of human periodontal cells to kaolinite.MethodsHuman periodontal cells were treated with kaolinite at reducing concentrations from 30 to 0.0015 mg/mL and with conditioned medium, which was depleted of kaolinite. Cell viability was evaluated with a resazurin-based toxicity assay, Live-Dead staining, and MTT assay and staining. The pro-angiogenic factors vascular endothelial growth factor (VEGF) and interleukin (IL)-6 and IL-8 were quantified via ELISA in periodontal fibroblasts. L-929, a standard cell-line used for cytotoxicity studies, served as control cell line. Composition of kaolinite was verified using energy-dispersive X-ray spectroscopy.ResultsKaolinite in suspension but not in conditioned medium impaired cell viability dose-dependently. VEGF, IL-6, and IL-8 production was not substantially modulated by kaolinite or the conditioned medium in periodontal cells.ConclusionOverall, kaolinite can decrease cell viability dose-dependently while conditioned medium showed no toxic effect. No pronounced impact of kaolinite on VEGF, IL-6, and IL-8 production was observed. This study provided first insights into the impact of kaolinite on human periodontal cells thereby inferring to the basis for the evaluation of kaolinite as a carrier in regenerative dentistry.Clinical relevanceKaolinite, a clay mineral, is successfully used in medicine due to its favorable properties. Also, applications in conservative dentistry are described. However, the response of oral cells to kaolinite is still unclear. Here, we assessed the impact of kaolinite on human periodontal cells.

Stimulation of endothelial progenitor cells by microRNA-31a-5p to induce endothelialization in an aneurysm neck after coil embolization by modulating the Axin1-mediated β-catenin/vascular endothelial growth factor pathway.

Emerging evidence shows that frequent recurrence of intracranial aneurysms (IAs) after endovascular coiling is attributable to the lack of endothelialization across the aneurysm neck. Recently, much attention has been given to the role of microRNAs (miRs) in vascular disease, although their contributory role to IA is poorly understood. Adult male Sprague-Dawley rats were subjected to microsurgery to create a coiled embolization aneurysm model, and were injected with miR-31a-5p agomir or a negative control agomir via the tail vein at a dose of 10 mg/kg per week for 4 weeks after IA induction. H & E staining, scanning electron microscopy, and flow cytometry were performed to evaluate the effects of miR-31a-5p agomir on endothelialization and the number of circulating endothelial progenitor cells (EPCs). The effects of miR-31a-5p on the viability and functioning of EPCs were also determined using Cell Counting Kit-8, wound-healing assay, and tube formation assays. The authors tested the ability of miR-31a-5p to promote EPC-induced endothelialization in a model of coiled embolization aneurysm. miR-31a-5p agomir improved endothelialization and elevated the number of circulating EPCs in the peripheral blood compared to a negative control agomir-treated group. In addition, the number of vWF- and KDR-positive cells in the aneurysm neck was increased in the miR-31a-5p agomir-treated group. Furthermore, upregulation of miR-31a-5p promoted EPC proliferation, migration, and tube formation and enhanced the expression of the proangiogenic factor vascular endothelial growth factor in vitro. Mechanistically, miR-31a-5p directly targeted the 3' untranslated region (3'UTR) of Axin1 messenger RNA and repressed its expression. Besides, miR-31a-5p exerted its effect on EPCs by regulating the Axin1-mediated Wnt/β-catenin pathway. Collectively, these results indicate that miR-31a-5p is an important regulator of EPC mobilization and endothelialization and may have a positive effect on aneurysm repair.

S100B Protein Stimulates Proliferation and Angiogenic Mediators Release through RAGE/pAkt/mTOR Pathway in Human Colon Adenocarcinoma Caco-2 Cells

Chronic inflammation and angiogenesis are associated with colonic carcinogenesis. Enteric glia-derived S100B protein has been proposed as an “ideal bridge”, linking colonic inflammation and cancer, given its dual ability to up-regulate nuclear factor-kappaB (NF-κB) transcription via receptor for advanced glycation end products (RAGE) signaling and to sequestrate wild type pro-apoptotic wild type (wt)p53. However, its pro-angiogenic effects on cancer cells are still uninvestigated. To this aim, we evaluated the effect of exogenous S100B (0.05–5 µM) protein alone or in the presence of S100B blocking monoclonal antibody (mAb) (1:105–1:104 v/v diluted) on (1) cultured Caco-2 cells proliferation, migration and invasiveness in vitro, respectively by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT)-formazan, wound healing and matrigel invasion assays and (2) its effect on the release of pro-angiogenic factors, such as vascular endothelial growth factor (VEGF) by ELISA and immunofluorescence analyses. The effect of S100B alone or in the presence of S100BmAb was then investigated on RAGE/pAkt/mammalian target of rapamycin (mTOR) signaling pathway by immunoblot analysis. Our results showed that S100B markedly increases proliferation and invasiveness of Caco-2 cells, through the release of pro-angiogenic VEGF and NO paralleled to a significant decrease of wtp53 expression mediated by RAGE-p38 mitogen-activated protein kinase (MAPK)/pAkt-mTOR and hypoxia-inducible factor 1-alpha (HIF1α) pathways. Such effects were counteracted by S100BmAb, indicating that S100B targeting is a potential approach to inhibit colon carcinoma proliferation and angiogenesis.

The secreted matrix protein mindin increases prostate tumor progression and tumor-bone crosstalk via ERK 1/2 regulation

Advanced prostate cancer cells preferentially metastasize to bone by acquiring a bone phenotype that allows metastatic cells to thrive in the skeletal environment. Identification of factors that promote the expression of ectopic bone genes-process known as osteomimicry-leading to tumor progression is crucial to prevent and treat metastatic prostate cancer and prolong life expectancy for patients. Here, we identify the extracelular matrix protein mindin in the secretome of prostate adenocarcinoma cells and show that mindin overexpression in human and mouse TRAMP-C1-induced prostate tumors correlates with upregulated levels of bone-related genes in the tumorigenic prostate tissues. Moreover, mindin silencing decreased osteomimicry in adenocarcinoma cells and in the prostate tumor mice model, as well as reduced tumor cell proliferation, migration and adhesion to bone cells. Inhibition of the extracellular signal-regulated kinase 1/2 (ERK 1/2) phosphorylation decreased the proliferative, migratory and pro-adhesion actions of mindin on prostate tumor cells. In addition, conditioned media obtained by crosstalk stimulation of either osteocytes or osteoblasts with the secretome of TRAMP-C1 cells promoted osteomimicry in prostate tumor cells; an effect inhibited by mindin silencing of TRAMP-C1 cells. In vivo, tibiae of primary tumor-bearing mice overexpressed the pro-angiogenic and pro-metastattic factor vascular endothelial growth factor receptor 2 (VEGFR2) in a mindin-dependent manner. Our findings indicate that mindin is a novel regulator of osteomimicry in prostate tumors and potentially mediates tumor-bone cell crosstalk, suggesting its promising role as a target to inhibit bone metastases.

PB1940 LEVELS OF VASCULAR ENDOTHELIAL GROWTH FACTOR DURING TREATMENT OF CML PATIENTS WITH IMATINIB – A RETROSPECTIVE ANALYSIS

Background: Role of pro-angiogenic cytokine vascular endothelial growth factor (VEGF) in the course of chronic myelogenous leukemia (CML) and variations of its levels during treatment with interferon alfa and tyrosine kinase inhibitors (TKI) are being discussed in the literature reports. Aims: Aim of this study was to clarify a possibility to use the monitoring of VEGF levels for prognosis of the long-term progression-free survival of the patients with CML. Methods: Retrospective analysis of the VEGF levels at different time-points was performed in 47 patients with different kinds of response and duration of treatment with imatinib (400-800 mg daily) followed from 2000 to 2018 due to chronic phase CML. Treatment response was evaluated by karyotyping and quantitative real-time polymerase chain reaction (PCR). Serum level of VEGF was determined by immunoenzyme analysis using commercial Biosource kits. Results: All the patients were divided according to the duration of their CML treatment into the following groups. Group 1: 20 patients treated with imatinib mesylate (IM) frontline (3 patients) or as a second line therapy (17 patients) after interferon alfa. Median disease duration was 13 years (11-18). Complete cytogenetic response (CCyR) and major molecular response (MMR) was confirmed in 17 (85%) of the patients. After 10 years of IM treatment BCR-ABL was not detectable in 11 of the patients (64%), other 6 had MMR. Group 2: 10 patients treated with IM frontline. Median duration of CML was 8 years (7-10). All of the patients reached CCyR, in 7 of them MMR was detected (4 – MMR; 3 – BCR-ABL was undetectable). Group 3: 17 patients treated with IM administered after 2-3 lines of prior therapy. Among these patients 12 developed progression to the advanced disease stages by 5 years of treatment, the remaining members of this group were switched to nilotinib due to the lack or loss of response. They subsequently achieved cytogenetic and molecular response. Results of serum VEGF levels at different time-points during 60 months of IM treatment are summarized in Fig.1. The baseline parameters were comparable in all 3 groups. However starting from 1,5 months of treatment in patients of group 1 and 2 serum VEGF started reducing and in some cases with slight fluctuations remained comparable to the healthy individuals during all 60 months of therapy. In patients of the third group who either did not reach hematological and cytogenetic response or lost it during treatment serum VEGF level remained almost unchanged as compared to the baseline. The difference between VEGF values of groups 1,2 and group 3 was found to be significant at 3, 12, 48 and 60 months of IM treatment.Summary/Conclusion: We believe that monitoring of the VEGF serum levels during therapy with IM has 2 aspects. First of all rapid reduction of this cytokine during initial months of treatment may be a sign of high sensitivity of leukemic cells to the medication and optimal expected response which was confirmed in patients of groups 1 and 2 by karyotyping and PCR. Secondly patients with low levels of VEGF not achieving molecular response after 12 months of treatment but who continued IM therapy as the best available option reached optimal response after 24 months. Evaluation of VEGF levels as a marker of angiogenesis intensity in CML may be useful for patients who plan to stop treatment with IM as an addition to molecular monitoring of disease. Lack of reduction of VEGF levels in patients treated with IM in our opinion could be a negative prognostic factor.

Pro-Angiogenic Macrophage Phenotype to Promote Myocardial Repair

BackgroundHeart failure following myocardial infarction (MI) remains one of the major causes of death worldwide, and its treatment is a crucial challenge of cardiovascular medicine. An attractive therapeutic strategy is to stimulate endogenous mechanisms of myocardial regeneration. ObjectivesThis study evaluates the potential therapeutic treatment with annexin A1 (AnxA1) to induce cardiac repair after MI. MethodsAnxA1 knockout (AnxA1−/−) and wild-type mice underwent MI induced by ligation of the left anterior descending coronary artery. Cardiac functionality was assessed by longitudinal echocardiographic measurements. Histological, fluorescence-activated cell sorting, dot blot analysis, and in vitro/ex vivo studies were used to assess the myocardial neovascularization, macrophage content, and activity in response to AnxA1. ResultsAnxA1−/− mice showed a reduced cardiac functionality and an expansion of proinflammatory macrophages in the ischemic area. Cardiac macrophages from AnxA1−/− mice exhibited a dramatically reduced ability to release the proangiogenic mediator vascular endothelial growth factor (VEGF)–A. However, AnxA1 treatment enhanced VEGF-A release from cardiac macrophages, and its delivery in vivo markedly improved cardiac performance. The positive effect of AnxA1 treatment on cardiac performance was abolished in wild-type mice transplanted with bone marrow derived from Cx3cr1creERT2Vegfflox/flox or in mice depleted of macrophages. Similarly, cardioprotective effects of AnxA1 were obtained in pigs in which full-length AnxA1 was overexpressed by use of a cardiotropic adeno-associated virus. ConclusionsAnxA1 has a direct action on cardiac macrophage polarization toward a pro-angiogenic, reparative phenotype. AnxA1 stimulated cardiac macrophages to release high amounts of VEGF-A, thus inducing neovascularization and cardiac repair.

Platelet microvesicles promote the recovery of neurological function in mouse model of cerebral infarction by inducing angiogenesis

The aim of this study is to investigate the effect of PMVs on mice with ischemic cerebral infarction and its mechanism. Male C57BL/6 mice were selected, and the right focal cortical infarction model was established via cauterization under a microscope and randomly divided into sham operation (Sham) group, normal saline control (Saline) group and platelet microvesicles intervention (PMVs) group. At 1 h after modeling, 5 μL of PMVs (50 μg/mL) or normal saline was injected into the lateral ventricle. The neurological function of mice in each group was evaluated at 1, 3, 7, 14 and 28 d after modeling. After 28 d, the cerebral infarction area was detected via 2,3,5-triphenyltetrazolium chloride (TTC) staining. At 7 and 28 d after modeling, the blood vessel density, proliferation rate of new vessels and encapsulation rate of pericytes were detected via immunofluorescence staining. Moreover, the changes in cerebral cortical blood flow at the infarction side were detected before modeling and at 7 and 28 d after modeling, respectively. Finally, the expressions of proangiogenic factors vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1) and N-Cadherin were detected via Western blotting at 3, 7 and 28 d after modeling. PMVs could promote the improvement of neurological function and significantly reduce the cerebral infarction volume in mice with cerebral infarction. PMVs promoted proliferation of new vessels and increased blood vessel density at the infarction edge in mice with cerebral infarction. PMVs could increase the encapsulation rate of pericytes at the infarction edge and improve the permeability of blood-brain barrier in mice with cerebral infarction. PMVs could increase the cerebral cortical blood flow perfusion in mice with cerebral infarction. PMVs could increase proangiogenic factors in brain tissues in mice with cerebral infarction. PMVs could significantly improve the recovery of neurological function in mice with cerebral infarction, which is closely related to the ability of PMVs to promote angiogenesis at the infarction edge. The possible mechanism is that PMVs facilitate angiogenesis after cerebral infarction through promoting the expressions of VEGF, Ang-1 and N-Cadherin. More importantly, the new vessels promoted by PMVs have complete structure and perfect function, and can improve the cerebral blood flow perfusion at the infarction side.

Serous Adenocarcinoma of Fallopian Tubes: Histological and Immunohistochemical Aspects.

BackgroundAlthough primary cancer of the fallopian tubes is a relatively rare type of tumor in female reproductive organs, its mortality is quite high. It is important to identify molecular and biological markers of this malignancy that determine its specific phenotype.MethodsThe study was carried out on samples received from 71 female patients with primary cancer of the fallopian tubes. The main molecular and biological properties, including hormone status (estrogen receptor [ER], progesterone receptor [PR]), human epidermal growth factor receptor (HER2)/neu expression, proliferative potential (Ki-67), apoptosis (p53, Bcl-2), and pro-angiogenic (vascular endothelial growth factor) quality of serous tumors were studied in comparison with clinical and morphological characteristics.ResultsER and PR expression is accompanied by low grade neoplasia, early clinical disease stage, and absence of lymphogenic metastasis (p < .001). HER2/neu expression is not typical for primary cancer of the fallopian tubes. Ki-67 expression is characterized by an inverse correlation with ER and PR (p < .05) and is associated with lymphogenic metastasis (p < .01). p53+ status correlates with high grade malignancy, tumor progression, metastasis, negative ER/PR (p < .001), and negative Bcl-2 status (p < .05). Positive Bcl-2 status is positively correlated with ER and PR expression and low grade malignancy.ConclusionsComplex morphologic (histological and immunohistochemical) study of postoperative material allows estimation of the degree of malignancy and tumor spread to enable appropriate treatment for each case.

Sequential Bone-Marrow Cell Delivery of VEGFA/S1P Improves Vascularization and Limits Adverse Cardiac Remodeling After Myocardial Infarction in Mice.

Microvascular dysfunction and resulting tissue hypoxia is a major contributor to the pathogenesis and evolution of cardiovascular diseases (CVD). Diverse gene and cell therapies have been proposed to preserve the microvasculature or boost angiogenesis in CVD, with moderate benefit. This study tested in vivo the impact of sequential delivery by bone-marrow (BM) cells of the pro-angiogenic factors vascular endothelial growth factor (VEGFA) and sphingosine-1-phosphate (S1P) in a myocardial infarction model. For that, mouse BM cells were transduced with lentiviral vectors coding for VEGFA or sphingosine kinase (SPHK1), which catalyzes S1P production, and injected them intravenously 4 and 7 days after cardiac ischemia-reperfusion in mice. Sequential delivery by transduced BM cells of VEGFA and S1P led to increased endothelial cell numbers and shorter extravascular distances in the infarct zone, which support better oxygen diffusion 28 days post myocardial infarction, as shown by automated 3D image analysis of the microvasculature. Milder effects were observed in the remote zone, together with increased proportion of capillaries. BM cells delivering VEGFA and S1P also decreased myofibroblast abundance and restricted adverse cardiac remodeling without major impact on cardiac contractility. The results indicate that BM cells engineered to deliver VEGFA/S1P angiogenic factors sequentially may constitute a promising strategy to improve micro-vascularization and oxygen diffusion, thus limiting the adverse consequences of cardiac ischemia.

PMEPA1/TMEPAI knockout impairs tumour growth and lung metastasis in MDA-MB-231 cells without changing monolayer culture cell growth

Prostate transmembrane protein androgen-induced 1 (PMEPA1)/transmembrane prostate androgen-induced protein (TMEPAI), a direct target and a negative regulator of transforming growth factor beta signalling, has an oncogenic role in many cancers. We observed that knockout (KO) of PMEPA1 in human breast cancer cell line MDA-MB-231 using a CRISPR-Cas9 system resulted in reduction of in vivo tumour growth and lung metastasis but not of in vitro monolayer growth capacity of these KO cell lines. This phenomenon was associated with PMEPA1 KO-mediated downregulation of the key proangiogenic factors vascular endothelial growth factor alpha (VEGFA) and interleukin-8 (IL8) that are essential for in vivo but not in vitro growing cells and are also substantial for initiation of lung metastasis.

Protease-activated receptor 2 protects against VEGF inhibitor-induced glomerular endothelial and podocyte injury

Vascular endothelial growth factor (VEGF) inhibitors cause glomerular injury. We have recently shown that activation of protease-activated receptor 2 (PAR2) by factor Xa exacerbated diabetic kidney disease. However, the role of PAR2 in glomerular injury induced by VEGF blockade is not known. Herein, we investigated the effect of the lack of PAR2 on VEGF inhibitor-induced glomerular injury. Although administering an anti-VEGF antibody by itself did not show renal phenotype in wild type mice, its administration to mice lacking endothelial nitric oxide synthase (eNOS) caused glomerular injury. Different from what we expected, administration of an anti-VEGF antibody in mice lacking PAR2 and eNOS exacerbated albuminuria and reduced the expression levels of CD31, pro-angiogenic VEGF, and angiogenesis-related chemokines in their kidneys. Podocyte injury was also evident in this model of mice lacking PAR2. Our results suggest that PAR2 is protective against VEGF inhibitor-induced glomerular endothelial and podocyte injury.

Cholesterol-Mediated Regulation of Angiogenesis: An Emerging Paradigm

Angiogenesis, the fundamental process that generates new blood vessels from parental vessels, is essential for embryogenesis and pathogenesis. A variety of underlying molecular and cellular mechanisms control angiogenesis. In this review, we focus on a unique mechanism of action – cholesterol-regulated angiogenesis. We will discuss lipoproteins, including low-density lipoprotein and high-density lipoprotein, cholesterol-rich lipid rafts/caveolae, apoA-I-binding protein (AIBP, also known as NAXE)-regulated cholesterol efflux, the effect of the hydroxycholesterol-activated nuclear receptor liver X receptor α/β on the proangiogenic vascular endothelial growth factor receptor 2 and antiangiogenic Notch signaling, and cholesterol-modified sonic hedgehog signaling. These pathways can be exploited, either alone or in conjunction with the currently available regimen for angiogenesis treatment, to control neovascularization in dyslipidemia. A treatment protocol for angiogenesis that takes into consideration cholesterol management might constitute an important component in precision and personalized medicine.

Argon Mitigates Impaired Wound Healing Process and Enhances Wound Healing In Vitro and In Vivo

Diabetic foot ulcers are associated with significant morbidity and mortality, and current treatments are far from optimal. Chronic wounds in diabetes are characterised by impaired angiogenesis, leukocyte function, fibroblast proliferation, and keratinocyte migration and proliferation.Methods: We tested the effect of exposure to argon gas on endothelial cell, fibroblast, macrophage and keratinocyte cell cultures in vitro and in vivo of a streptozotocin-induced diabetic mouse model.Results: Exposure to normobaric argon gas promotes multiple steps of the wound healing process. Argon accelerated angiogenesis, associated with upregulation of pro-angiogenic Angiopoietin-1 and vascular endothelial growth factor (VEGF) signalling in vitro and in vivo. Treatment with argon enhanced expression of transforming growth factor (TGF)-β, early recruitment of macrophages and keratinocyte proliferation. Argon had a pro-survival effect, inducing expression of cytoprotective mediators B-cell lymphoma 2 and heme oxygenase 1. Argon was able to accelerate wound closure in a diabetic mouse model.Conclusion: Together these findings indicate that argon gas may be a promising candidate for clinical use in treatment of diabetic ulcers.

Active Vaccination With EMMPRIN-Derived Multiple Antigenic Peptide (161-MAP) Reduces Angiogenesis in a Dextran Sodium Sulfate (DSS)-Induced Colitis Model.

Ulcerative colitis (UC) is an autoimmune disease that affects the colon and shares many clinical and histological features with the dextran sulfate sodium (DSS)-induced colitis model in mice. Angiogenesis is a critical component in many autoimmune diseases, as well as in the DSS-induced colitis model, and is it partially mediated by EMMPRIN, a multifunctional protein that can induce the expression of both the potent pro-angiogenic vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). We asked whether targeting EMMPRIN by active vaccination, using a novel, specific epitope in the protein, synthesized as a multiple antigenic peptide (MAP), could trigger beneficial effects in the DSS-induced colitic C57BL/6J mice. Mice were vaccinated with four boost injections (50 μg each) of either 161-MAP coding for the EMMPRIN epitope or the scrambled control peptide (Scr-MAP) emulsified in Freund's adjuvant. We show that male mice that were vaccinated with 161-MAP lost less weight, demonstrated improved disease activity indices (DAI), had reduced colitis histological score, and their colons were longer in comparison to mice vaccinated with the Scr-MAP. The 161-MAP vaccination also reduced serum and colon levels of EMMPRIN, colon concentrations of VEGF, MMP-9, and TGFβ, and vessel density assessed by CD31 staining. A similar effect was observed in female mice vaccinated with 161-MAP, including weight loss, colitis histological score, colon length, colon levels of EMMPRIN and colon concentrations of VEGF. However, for female mice, the changes in DAI values, EMMPRIN serum levels, and MMP-9 and TGFβ colon concentrations did not reach significance. We conclude that our strategy of alleviating autoimmunity in this model through targeting angiogenesis by actively vaccinating against EMMPRIN was successful and efficient in reducing angiogenesis.

Molecular determinants of microvascular dysfunction in hypertensive pregnancy and preeclampsia.

Preeclampsia is a pregnancy-related disorder characterized by hypertension and often fetal intrauterine growth restriction, but the underlying mechanisms are unclear. Defective placentation and apoptosis of invasive cytotrophoblasts cause inadequate remodeling of spiral arteries, placental ischemia, and reduced uterine perfusion pressure (RUPP). RUPP causes imbalance between the anti-angiogenic factors soluble fms-like tyrosine kinase-1 and soluble endoglin and the pro-angiogenic vascular endothelial growth factor and placental growth factor, and stimulates the release of proinflammatory cytokines, hypoxia-inducible factor, reactive oxygen species, and angiotensin AT1 receptor agonistic autoantibodies. These circulating factors target the vascular endothelium, smooth muscle and various components of the extracellular matrix. Generalized endotheliosis in systemic, renal, cerebral, and hepatic vessels causes decreases in endothelium-derived vasodilators such as nitric oxide, prostacyclin and hyperpolarization factor, and increases in vasoconstrictors such as endothelin-1 and thromboxane A2. Enhanced mechanisms of vascular smooth muscle contraction, such as intracellular Ca2+ , protein kinase C, and Rho-kinase cause further increases in vasoconstriction. Changes in matrix metalloproteinases and extracellular matrix cause inadequate vascular remodeling and increased arterial stiffening, leading to further increases in vascular resistance and hypertension. Therapeutic options are currently limited, but understanding the molecular determinants of microvascular dysfunction could help in the design of new approaches for the prediction and management of preeclampsia.

Are the Cognitive Alterations Present in Children Born From Preeclamptic Pregnancies the Result of Impaired Angiogenesis? Focus on the Potential Role of the VEGF Family.

Evidence from clinical studies has proposed that children born from preeclamptic women have a higher risk of suffering neurological, psychological, or behavioral alterations. However, to date, the mechanisms behind these outcomes are poorly understood. Here, we speculate that the neurodevelopmental alterations in the children of preeclamptic pregnancies result from impaired angiogenesis. The pro-angiogenic factors vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) are key regulators of both vascular and neurological development, and it has been widely demonstrated that umbilical blood of preeclamptic pregnancies contains high levels of soluble VEGF receptor type 1 (sFlt-1), a decoy receptor of VEGF. As a consequence, this anti-angiogenic state could lead to long-lasting neurological outcomes. In this non-systematic review, we propose that alterations in the circulating concentrations of VEGF, PlGF, and sFlt-1 in preeclamptic pregnancies will affect both fetal cerebrovascular function and neurodevelopment, which in turn may cause cognitive alterations in post-natal life.