Angiogenesis In Chorioallantoic Membrane Research Articles

HIF1α Counteracts TGFβ1-Driven TSP1 Expression in Endothelial Cells to Stimulate Angiogenesis in the Hypoxic Tumor Microenvironment.

Emerging evidence suggests that transforming growth factor β1 (TGFβ1) can inhibit angiogenesis, contradicting the coexistence of active angiogenesis and high abundance of TGFβ1 in the tumor microenvironment. Here, we investigated how tumors overcome the anti-angiogenic effect of TGFβ1. TGFβ1 treatment suppressed physiological angiogenesis in chick chorioallantoic membrane and zebrafish models but did not affect angiogenesis in mouse hepatoma xenografts. The suppressive effect of TGFβ1 on angiogenesis was recovered in mouse xenografts by a hypoxia-inducible factor 1α (HIF1α) inhibitor. In contrast, a HIF1α stabilizer abrogated angiogenesis in zebrafish, indicating that hypoxia may attenuate the anti-angiogenic role of TGFβ1. Under normoxic conditions, TGFβ1 inhibited angiogenesis by upregulating anti-angiogenic factor thrombospondin 1 (TSP1) in endothelial cells (ECs) via TGFβ type I receptor (TGFβR1)-SMAD2/3 signaling. In a hypoxic microenvironment, HIF1α induced microRNA-145 (miR145) expression; miR145 abolished the inhibitory effect of TGFβ1 on angiogenesis by binding and repressing SMAD2/3 expression and subsequently reducing TSP1 levels in ECs. Primary ECs isolated from human hepatocellular carcinoma (HCC) displayed increased miR145 and decreased SMAD3 and TSP1 compared to ECs from adjacent non-tumor livers. The reduced SMAD3 or TSP1 in ECs was associated with increased angiogenesis in HCC tissues. Collectively, this study identified that TGFβ1-TGFβR1-SMAD2/3-TSP1 signaling in ECs inhibits angiogenesis. This inhibition can be circumvented by a hypoxia-HIF1α-miR145 axis, elucidating a mechanism by which hypoxia promotes angiogenesis.

Effects of neratinib on angiogenesis and the early stage of the embryo using chicken embryo as a model.

Angiogenesis is the process of forming new blood capillaries from pre-existing vessels. Even though it is essential during normal development, it plays a major role in cancer progression. Neratinib is a pan-human epidermal growth factor receptor (HER) inhibitor that has recently been approved for the treatment of HER2-positive breast cancer. However, its effects on angiogenesis and embryogenesis remain unknown. This study examined the antiangiogenic effects of neratinib using the chorioallantoic membrane (CAM) of chicken embryos. We also evaluated neratinib's toxicity during the early stages of normal development using the chicken embryos, primary embryonic fibroblasts (EFBs), and human umbilical vein endothelial cells (HUVEC). Our findings revealed that neratinib significantly inhibited the CAM angiogenesis compared to controls by reducing vessel percentage area and the average vessel length. Furthermore, neratinib downregulated vascular endothelial growth factor (VEGF), a key mediator of angiogenesis. At lower concentrations, neratinib was well-tolerated during early stages of normal development. Additionally, EFBs treated with neratinib showed no morphological or viability changes when compared to controls. However, at the highest concentration tested, neratinib treatment reduced HUVEC cell viability. This effect may be associated with the dysregulation of key apoptotic genes, including caspase-3, caspase-8, caspase-9, and the B-cell lymphoma 2 (Bcl2) gene. Our findings indicate a novel potential application of neratinib as an antiangiogenic agent, exhibiting tolerable toxicity in the early stages of embryogenesis.

Immunometric and functional measurement of endogenous vasoinhibin in human sera.

Circulating levels of the antiangiogenic protein vasoinhibin, a fragment of prolactin, are of interest in vasoproliferative retinopathies, preeclampsia, and peripartum cardiomyopathy; however, it is difficult to determine the circulating levels of vasoinhibin due to the lack of quantitative assays. This study used human serum samples to assess the concentration and bioactivity of vasoinhibin using a novel enzyme-linked immunosorbent assay (ELISA) for human vasoinhibin, which employs an anti-vasoinhibin monoclonal antibody, a human umbilical vein endothelial cell (HUVEC) proliferation assay, and a chick chorioallantoic membrane (CAM) angiogenesis assay. Serum samples from 17 pregnant women without (one group) and with preeclampsia and pregnancy induced hypertension (another group) demonstrated endogenous vasoinhibin concentrations in the range of 5-340 ng/ml. Immunoactive vasoinhibin levels were significantly higher in preeclampsia serum compared to healthy pregnancy serum (mean 63.09 ± 22.15 SD vs. 19.67 ± 13.34 ng/ml, p = 0.0003), as was the bioactive vasoinhibin level as determined by the HUVEC proliferation assay (56.12 ± 19.83 vs. 13.38 ± 4.88 ng/ml, p < 0.0001). There was a correlation between the concentration of vasoinhibin measured by ELISA and the HUVEC proliferation assay (Pearson r = 0.95, p < 0.0001). Healthy serum demonstrated a proangiogenic effect in the CAM assay (p < 0.05, compared to control), while serum from preeclamptic patients demonstrated an antiangiogenic effect (p < 0.05 vs. control), as did recombinant human vasoinhibin and a synthetic circular retro-inverse vasoinhibin analogue (CRIVi45-51). The antiangiogenic effects in the CAM assay and the inhibition of HUVEC proliferation were abolished by addition of the ELISA anti-vasoinhibin monoclonal antibody, but not by mouse IgG. These results demonstrate the first quantitation of endogenous vasoinhibin in human sera and the elevation of it levels and antiangiogenic activity in sera from women with preeclampsia. The development and implementation of a quantitative assay for vasoinhibin overcomes a long-standing barrier and suggests the thorough clinical verification of vasoinhibin as a relevant biomarker.

Alternating Current-Electric Field Inducing Chorio Allantoic Membrane (CAM) Angiogenesis through Exogenous Growth Factor Intervention

Angiogenesis is widely used in various therapies by promoting or inhibiting the formation of new blood vessels. The use of Alternating Current-Electric Fields (AC-EF) in Electro-Capacitive Cancer Therapy (ECCT) showed its potential as an anti-cancer device, and is characterized by its anti-proliferative and pro-apoptotic effects. However, the role of AC-EF in angiogenesis remains unclear. To investigate the effects of AC-EF on CAM angiogenesis, we used the ex ovo culture method of chorioallantoic membrane (CAM). A basic fibroblast growth factor (bFGF) dose of 30 ng/µL was administered as an exogenous growth factor. The ECCT device, generating AC-EF of 150 kHz and 18 Vpp, was exposed to the CAMs. Subsequently, the 24 CAMs of chick embryo were divided into four groups. Two groups were non-bFGF-induced CAM, while the other two were bFGF-induced CAM, and each group was exposed either with or without AC-EF. The vascularization was evaluated through macroscopic observation, while vascular endothelial growth factor A (VEGFA) gene expression was measured using qPCR. The data were statistically analyzed using ANOVA with GraphPad Prism 9.5. The results showed that an AC-EF exposure had no effects on normal CAM angiogenesis (P&gt;0.05). Moreover, VEGFA gene expression did not show significant upregulation (P&gt;0.05) in the bFGF-induced CAM with or without AC-EF exposure. Interestingly, the number of new blood vessels was significantly higher (P&lt;0.05) in the bFGF-induced with AC-EF exposure than in the non-bFGF-induced group. In conclusion, AC-EF of ECCT did not affect normal angiogenesis. AC-EF may trigger CAM angiogenesis with bFGF induction. This observation suggested that AC-EF of intermediate frequency could enhance angiogenesis by administration of external growth factors, offering a potential avenue for addressing obstructive vascular conditions.

Moraea sisyrinchium inhibits proliferation, cell cycle, and migration of cancerous cells, and decreases angiogenesis in chick chorioallantoic membrane.

Experimental studies reported that some plants in the genus of Moraea (Iridaceae family) show anticancer potential. This study aimed to evaluate the effects of Moraea sisyrinchium on U87 glioblastoma multiforme and HepG2 liver cancer cells. The cells were incubated for 24 hr with hydroalcoholic extract of the stem, flower, and bulb of M. sisyrinchium. Then, the cell proliferation (MTT) assay, cell cycle analysis (propidium iodide staining), cell migration test (scratch), Western blotting (Bax and Bcl-2 expression), and gelatin zymography (for matrix metalloproteinases, MMPs) were performed. Oxidative stress was evaluated by determining the levels of reactive oxygen species and lipid peroxidation. Angiogenesis was evaluated on chick embryo chorioallantoic membrane. The extracts of the flower, stem, and bulb significantly decreased the proliferation of HepG2 and U87 cells. This effect was more for U87 than HepG2 and for the bulb and stem than the flower. In U87 cells, the bulb extract increased oxidative stress, cell cycle arrest, and the Bax/Bcl-2 ratio. Also, this extract suppressed the migration ability of HepG2 and U87 cells, which was associated with the inhibition of MMP2 activity. In addition, it significantly reduced the number and diameter of vessels in the chorioallantoic membrane. Liquid chromatography-mass spectrometry revealed the presence of xanthones (bellidifolin and mangiferin), flavonoids (quercetin and luteolin), isoflavones (iridin and tectorigenin), and phytosterols (e.g., stigmasterol) in the bulb. M. sisyrinchium bulb decreased the proliferation and survival of cancer cells by inducing oxidative stress. It also reduced the migration ability of the cells and inhibited angiogenesis.

Pristine gelatin incorporation as a strategy to enhance the biofunctionality of poly(vinyl alcohol)-based hydrogels for tissue engineering applications.

Synthetic polymers, such as poly(vinyl alcohol) (PVA), are popular biomaterials for the fabrication of hydrogels for tissue engineering and regenerative medicine (TERM) applications, as they provide excellent control over the physico-chemical properties of the hydrogel. However, their bioinert nature is known to limit cell-biomaterial interactions by hindering cell infiltration, blood vessel recruitment and potentially limiting their integration with the host tissue. Efforts in the field have therefore focused on increasing the biofunctionality of synthetic hydrogels, without limiting the advantages associated with their tailorability and controlled release capacity. The aim of this study was to investigate the suitability of pristine gelatin to enhance the biofunctionality of tyraminated PVA (PVA-Tyr) hydrogels, by promoting cell infiltration and host blood vessel recruitment for TERM applications. Pure PVA-Tyr hydrogels and PVA-Tyr hydrogels incorporated with vascular endothelial growth factor (VEGF), a well-known pro-angiogenic stimulus, were used for comparison. Incorporating increasing concentrations of VEGF (0.01-10 μg mL-1) or gelatin (0.01-5 wt%) did not influence the physical properties of PVA-Tyr hydrogels. However, their presence within the polymer network (>0.1 μg mL-1 VEGF and >0.1 wt% gelatin) promoted endothelial cell interactions with the hydrogels. The covalent binding of unmodified gelatin or VEGF to the PVA-Tyr network did not hamper their inherent bioactivity, as they both promoted angiogenesis in a chick chorioallantoic membrane (CAM) assay, performing comparably with the unbound VEGF control. When the PVA-Tyr hydrogels were implanted subcutaneously in mice, it was observed that cell infiltration into the hydrogels was possible in the absence of gelatin or VEGF at 1- or 3-weeks post-implantation, highlighting a clear difference between in vitro an in vivo cell-biomaterial interaction. Nevertheless, the presence of gelatin or VEGF was necessary to enhance blood vessel recruitment and infiltration, although no significant difference was observed between these two biological molecules. Overall, this study highlights the potential of gelatin as a standalone pro-angiogenic cue to enhance biofunctionality of synthetic hydrogels and provides promise for their use in a variety of TERM applications.

Bioactive glasses-reinforced human amniotic membrane for tissue engineering applications

In this study, we prepared a biocomposite made of decellularized human amniotic membrane (dHAM) and mesoporous bioactive glasses (MBGs). dHAM was solubilized by using pepsin and acetic acid and then impregnated with copper- and cobalt-doped 13-93B3 MBGs (CuCo-MBGs). The prepared composition was then lyophilized to prepare biocomposite membranes. SEM displayed the homogenous presence of glass particles inside dHAM. The composites showed compatibility with fibroblast cells. dHAM + MBG/CuCo-MBG had higher migratory effects on human umbilical vein endothelial cells (HUVECs) compared to glass-free samples. The angiogenic activity of the samples was further confirmed by the chicken chorioallantoic membrane angiogenesis (CAM) assay. The incorporation of MBG and CuCo-MBG into dHAM resulted in enhancing the antibacterial activity. In conclusion, Cu/Co-doped MBGs could improve the biological functions of dHAM without any adverse significant effects in vitro. In conclusion, this composite could be considered the next generation of wound dressings after performing in vivo experiments.

Jujuboside B suppresses angiogenesis and tumor growth via blocking VEGFR2 signaling pathway

Jujuboside B (JuB), one of the main active triterpenoid saponins from the traditional Chinese medicine Ziziphus jujuba, possesses a wide range of pharmacological activities. However, it is unknown whether JuB can inhibit tumor angiogenesis, a crucial step in solid tumor growth. In this study, we found that JuB significantly inhibited the proliferation, migration, and tube formation of human umbilical vein endothelial cells in a dose-dependent manner. JuB also suppressed angiogenesis in chick embryo chorioallantoic membranes and Matrigel plugs. Moreover, through angiogenesis inhibition, JuB delayed the growth of human HCT-15 colorectal cancer xenograft in mice. Western blot assay demonstrated that JuB inhibited the phosphorylation of VEGFR2 and its key downstream protein kinases, such as Akt, FAK, Src, and PLCγ1. In conclusion, the antiangiogenic potency and molecular mechanism of JuB are revealed for the first time, indicating that this triterpene saponin may be further explored as a potential drug candidate or lead compound for antiangiogenic cancer therapy.

YAP inhibitor verteporfin suppresses tumor angiogenesis and overcomes chemoresistance in esophageal squamous cell carcinoma.

Targeting angiogenesis is an attractive strategy for the effective treatment of cancer. This study aimed to investigate the anti-cancer activities of YAP inhibitor verteporfin (VP) in esophageal squamous cell carcinoma (ESCC) cells through its inhibitory effect on tumor angiogenesis. Cell proliferation, apoptosis, migration and invasion abilities were estimated by MTT, colony formation, DAPI staining, wound healing and transwell assays, respectively. Human umbilical vein endothelial cell (HUVEC) tube formation assay and chick embryo chorioallantoic membrane (CAM) model were used to observe angiogenesis in vitro and in vivo. The interactions between ESCC cells and HUVECs were assessed by cell chemotactic migration and adhesion assays. The expression levels of angiogenesis-related molecules were detected by Western blot. We found that VP was potential to inhibit ESCC cell proliferation, migration, invasion and induce apoptosis in the dose-dependent fashion. VP also significantly suppressed proliferation, migration, and tube formation of HUVECs and promoted apoptosis of HUVECs, and reduced angiogenesis in CAM. Moreover, VP inhibited ESCC cell-induced angiogenesis in vitro by decreasing HUVEC chemotactic migration, adhesion and tube formation, and also reduced ESCC cell-induced neovascularization of the CAM in vivo. In addition, VP suppressed the expression of pro-angiogenic molecules such as VEGFA, MMP-2 and β-catenin in ESCC cells. Furtherly, VP increased the chemosensitivity of ESCC-resistant cells to paclitaxel (PTX). The combination of VP and PTX attenuated the resistant cell-mediated angiogenesis in vitro and in vivo. These results reveal for the first time that VP potently inhibits malignant progression and overcomes chemoresistance of ESCC cells via inhibition of tumor angiogenesis. It provides insight into a new strategy for the treatment of ESCC that VP could be a potential drug candidate for targeting tumor angiogenesis.

Evaluation of the wound-healing potential of the kiwifruit extract by assessing its effects on human gingival fibroblasts and angiogenesis.

Oral surgery and surgical interventions in the field of periodontology require the uneventful wound healing of soft tissues to be successful. However, since the oral cavity is exposed to saliva and is a niche for oral microorganisms, wound healing can be delayed, causing pain and discomfort to the patient. Hence, a great deal of interest has shifted to the study of agents that can enhance wound-healing processes. The aim of the present study was to evaluate the oral wound-healing potential of the Actinidia deliciosa (kiwifruit) extract by assessing its effects on the viability, proliferation and migration of human gingival fibroblasts, and its ability to enhance angiogenesis in the chicken chorioallantoic membrane (CAM). The collection of the A. deliciosa extract and experimentation were carried out in the Maratha Mandal Dental College, Belgavi, India. Human gingival fibroblasts were cultured in a suitable medium and treated with 6.25 μg, 12.5 μg or 25 μg of the ethanolic kiwifruit extract. The MTT cell viability and scratch assays were then carried out in vitro. To determine the angiogenic potential of the extract, solutions of concentrations of 10 μg/mL, 50 μg/mL and 100 μg/mL were transferred to sterile Whatman™ filter paper disks, which were placed on the CAM of 5-day-old Leghorn chicken eggs. The ethanolic extract of A. deliciosa was not cytotoxic to gingival fibroblasts at a dosage of 6.25 μg/mL. In addition, the scratch assay demonstrated the migration of the fibroblasts and the closure of an artificially created wound within 24 h, which is similar to in vivo wound closure. The CAM assay showed that the kiwifruit extract concentrations of 10 μg/mL and 50 μg/mL showed a moderate proangiogenic effect, and a concentration of 100 μg/mL exerted a strong pro-angiogenic effect. The results demonstrate that the kiwifruit extract is safe to use, can enhance the proliferation and migration of human gingival fibroblasts, and promotes angiogenesis, making it a suitable oral wound-healing agent.

Plasmid containing VEGF-165 and ANG-1 dual genes packaged with fibroin-modified PEI to promote the regeneration of vascular network and dermal tissue

Reducing the cytotoxicity of cationic polymers is the major issue to their use as a gene delivery carrier. In this study, plasmids containing encoding vascular endothelial cell growth factor 165 and angiopoietin-1 were packaged with the conjugates of cationic fibroin (CSF) and polyethylenimine (PEI), instead of packaging pDNA with PEI alone, to prepare nanocomplexes (CSF+PEI)/pDNA. The complexes were loaded into a silk fibroin scaffold to enhance its function to induce microvascular network generation and dermal tissue regeneration. The results of transfecting EA.hy926 cells with the complexes in vitro showed that (CSF+PEI)/pDNA had a stronger transfection ability than PEI/pDNA. Importantly, compared with PEI as the gene carrier alone, the cell viability was significantly increased and the cytotoxicity was effectively reduced after the conjugate of CSF and PEI was used as the gene carrier. The results of angiogenesis in chick embryo chorioallantoic membranes showed that compared with scaffolds loaded with PEI/pDNA, the neovascularization ratio in scaffolds loaded with (CSF+PEI)/pDNA was significantly increased. In vivo experimental results of scaffolds implantation for full-thickness skin defects in SD rats showed that, compared with loading PEI/pDNA complex, loading (CSF+PEI)/pDNA complex in the scaffold more effectively promoted the formation of vascular network in the scaffold and accelerated the regeneration of dermal tissue. The gene delivery system established in this study has application potential not only in the regeneration of vascular-containing tissues, but also in tumor gene therapy.

Antiangiogenic Potential of Troxerutin and Chitosan Loaded Troxerutin on Chorioallantoic Membrane Model.

Angiogenesis is crucial to the development of cancer because it allows the transport of oxygen, nutrients, and growth factors as well as the spread of tumors to distant organs. Inhibitors of angiogenesis prevent the formation of blood vessels that allow tumor cells to shrink, rather than promote tumor growth. Chitosan acts as a carrier for many drugs, since the compound has various properties such as biodegradable, less toxicity, more stable, simple, easy to prepare, and biocompatible. The aim of the current study was to evaluate the efficacy of chitosan nanoparticles encapsulated with troxerutin (Chi-Trox NPs) against angiogenesis and cancer in ova chick chorioallantoic membrane (CAM) model. Chi-Trox NPs were synthesized using a nanoprecipitation method and were characterized by various analyses. 24 hours' fertilized eggs (6 eggs/group) were treated with native Trox and Chi-Trox NPs for 5 days. The antiangiogenic activity was evaluated by morphometric, histopathological, immunohistochemical (CD104 and vimentin), and mRNA expression of MMP and FGF2 using RT-PCR. The anticancer activity was evaluated by histopathological, immunohistochmical (CD44), and mRNA expression of FGF2 and MMP. The synthesized chitosan NPs were successfully encapsulated with troxerutin, and the loading efficiency of chitosan NPs was found to be 86.4 ± 0.12% and 13.2 ± 0.16% respectively. Morphometric analysis of Chi-Trox NPs showed a considerable decrease in the number of blood vessels compared with control and native Trox. The histopathological observation of CAM confirmed that Chi-Trox NPs induce a significant reduction in inflammatory cells and the thickness of blood capillaries compared to control and native Trox. The immunohistochemical evaluation of CAM revealed Chi-Trox decreased CD104, vimentin and CD44 protein levels were compared with control and native Trox. Furthermore, the mRNA expression levels of FGF2 and MMP were significantly downregulated compared to their native forms. From the obtained results, Chi-Trox NPs possess significant inhibition of angiogenesis and can be used as therapeutic agents for cancer in the future.

Chick chorioallantoic membrane model to investigate role of migrasome in angiogenensis.

The development of the vascular system is essential for embryonic development, including processes such as angiogenesis. Angiogenesis plays a critical role in many normal physiological and pathological processes. It is driven by a set of angiogenic proteins, including angiogenic growth factors, chemokines, and extracellular matrix proteins. Among various animal model systems, the chorioallantoic membrane (CAM), a specialized and highly vascularized tissue of the avian embryo, has proven to be a valuable tool for analyzing the angiogenic potential of candidate cells or factors. In this protocol, we provide detailed procedures for establishing the CAM model to evaluate the function and mechanism of migrasomes in embryonic angiogenesis. This includes the CAM nylon mesh assay and CAM ex vivo sprouting assay to assess CAM angiogenesis, as well as the observation, purification, and delivery of migrasomes. Additionally, we describe the generation of T4-KO-mCherry-KI embryos using the CRISPR system within the CAM tissue to investigate the role of migrasomes in angiogenesis.

FTIR Characterization of Sulfated Polysaccharides Obtained from Macrocystis integrifolia Algae and Verification of Their Antiangiogenic and Immunomodulatory Potency In Vitro and In Vivo.

The aim of this study was to evaluate the antiangiogenic and immunomodulatory potential of sulfated polysaccharides from the marine algae Macrocystis integrifolia characterized by FTIR. The cytotoxicity of sulfated polysaccharides was evaluated using the 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) assay. Antiangiogenic activity was evaluated using the chicken chorioallantoic membrane (CAM) assay. Immunomodulatory activity was determined on macrophage functionality and allergic response. The results showed that sulfated polysaccharides significantly decreased angiogenesis in chicken chorioallantoic membranes (p &lt; 0.05). Likewise, they inhibited in vivo chemotaxis and in vitro phagocytosis, the transcription process of genes that code the enzymes cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and nitric oxide synthase-2 (NOS-2) and the nuclear factor kappa-light chain enhancer of activated B cells (NF-κB), showing immunomodulatory properties on the allergic response, as well as an in vivo inhibitory effect in the ovalbumin-induced inflammatory allergy model (OVA) and inhibited lymphocyte proliferation specific to the OVA antigen in immunized mice. Finally, these compounds inhibited the histamine-induced skin reaction in rats, the production of immunoglobulin E (IgE) in mice, and the passive response to skin anaphylaxis in rats. Therefore, the results of this research showed the potential of these compounds to be a promising source for the development of antiangiogenic and immunomodulatory drugs.

VEGF-A and FGF4 Engineered C2C12 Myoblasts and Angiogenesis in the Chick Chorioallantoic Membrane.

Angiogenesis is the formation of new blood vessels from pre-existing vessels. Adequate oxygen transport and waste removal are necessary for tissue homeostasis. Restrictions in blood supply can lead to ischaemia which can contribute to disease pathology. Vascular endothelial growth factor (VEGF) is essential in angiogenesis and myogenesis, making it an ideal candidate for angiogenic and myogenic stimulation in muscle. We established C2C12 mouse myoblast cell lines which stably express elevated levels of (i) human VEGF-A and (ii) dual human FGF4-VEGF-A. Both stably transfected cells secreted increased amounts of human VEGF-A compared to non-transfected cells, with the latter greater than the former. In vitro, conditioned media from engineered cells resulted in a significant increase in endothelial cell proliferation, migration, and tube formation. In vivo, this conditioned media produced a 1.5-fold increase in angiogenesis in the chick chorioallantoic membrane (CAM) assay. Delivery of the engineered myoblasts on Matrigel demonstrated continued biological activity by eliciting an almost 2-fold increase in angiogenic response when applied directly to the CAM assay. These studies qualify the use of genetically modified myoblasts in therapeutic angiogenesis for the treatment of muscle diseases associated with vascular defects.

Evaluation of angiogenic and embryotoxic activity of the extract of Anadenanthera peregrina (Angico-do-Cerrado)

The genus Anadenanthera has been reported in the literature with antioxidant, anti-inflammatory, antimicrobial effect and healing action in wound treatment. The study aimed to evaluate, in vivo, the angiogenic and embryotoxic activities of A. peregrina extract. Angiogenesis in chicken embryo egg chorioallantoic membrane and zebrafish embryotoxicity was performed. A. peregrina extract at concentrations 62 mg mL-1 and 124 mg mL-1 were angiogenic. For embryotoxicity, the mortality rate increased with increasing concentration and increased dose and time dependent embryotoxicity was observed. The lethal concentration (LC50) ranged from 0.331mg mL-1 over the 24 hpf period to 0.007 mg mL-1 at 168 hpf (Δ% = -97.9), decreasing with increasing exposure. The heart rate decreased progressively and significantly with increasing concentration at all tested exposure times. In conclusion, it was evidenced that the extract of Anadenanthera peregrina has angiogenic activity. Nonetheless, embryotoxic effects were observed at high concentrations.

Screening of a Library for Factor VIIa Inhibitors

Background:As an alternative to the anticoagulant’s strategy using direct or indirect anti-Xa drugs, considering other targets upstream in the coagulation cascade such as anti-Factor VIIa could represent an effective and safer strategy in coagulation and pathological angiogenesis.Objective:The objective of the study was to assess a high technology methodology composed of virtual screening, anticoagulant, and anti-angiogenesis assays to identify potent small-molecule FVIIa inhibitors.Methods:Chemical databanks were screened to select molecules bearing functional groups that could fit into the active site of FVIIa, which were then tested. Ligands assigned with the lowest scores were retained and then biologically assessed.Results:From the 500 molecules considered, 8 chemical structures revealed to be effective compounds in vitro and to inhibit angiogenesis in the chick chorioallantoic membrane (CAM) model.Conclusion:New potent small-molecule FVIIa inhibitors have been identified; further biochemical and chemical developments would be investigated directly from the selected scaffolds.

The choline acetyltransferase inhibitor BW813U inhibits angiogenesis and tumor growth in human lung adenocarcinoma

Angiogenesis refers to the development of new blood vessels from preexisting blood vessels. The angiogenic pathway is essential for the growth and progression of almost every kind of human cancer. Nicotine, the addictive component of tobacco smoke is known to accelerate the growth of human lung tumors by stimulating tumor angiogenesis. The pro‐angiogenic effects of nicotine are mediated by nicotinic acetylcholine receptors (nAChRs). The endogenous ligand for nicotine is the neurotransmitter acetylcholine (ACh). Published reports show that ACh acts as growth factor for human lung cancers. Almost all lung tissues (including fetal lung) express signaling proteins involved in the synthesis, transport of the ACh‐signaling pathway. These include choline acetyl transferase enzyme (ChAT), vesicular acetylcholine transporter (VAChT), acetylcholine esterase (AChE) and choline transporter (ChT). The primary objective of our studies was to determine if disruption of ChAT could inhibit angiogenesis and suppress the growth of human LACs. We used a small molecule inhibitor of ChAT namely BW813U for our studies. BW813U robustly suppressed angiogenesis in Matrigel assays and chicken chorioallantoic membrane (CAM) assays. The administration of BW813U potenetly decreased the growth rate of H838 tumors xenotransplanted in SCID mice. Immunohistochemical staining experiments revealed that the anti‐tumor activity of BW813U was correlated with decrease of CD31 angiogenic biomarker in H813 tumor sections. The anti‐angiogenic activity of BW813U was mediated by the alpha7‐nAChR pathway and involved the nitric oxide pathway. Taken together, our studies show that ChAT antagonists like BW813U may have applications in the treatment of LAC.

Structural Characterization and Tumor Microvascular Inhibition Activity of Total Polysaccharide from Trametes sanguinea Lloyd.

Trametes sanguinea Lloyd total polysaccharide (TsLTP), was obtained by water extraction and ethanol precipitation from T. sanguinea. The structural characterization of TsLTP was elucidated mutually by TsL1 and TsL2, whose mass ratio is 1: 4. TsL1 is mainly composed of mannose, glucose, galactose, and fucose, and consist of T-Linked-Fucp, T-Linked-Manp, T-Linked-Galp, 1,4-Linked-Manp, 1,4-Linked-Glcp, 1,6-Linked-Manp, 1,6-Linked-Galp, 1,3,4-Linked-Glcp, 1,4,6-Linked-Glcp and 1,3,6-Linked-Glcp, with a molar ratio of 2.1: 1.7: 1.4: 1.0: 3.6: 2.0: 8.6: 1.3: 2.2: 1.2, while TsL2 mainly comprise of glucose and consist of T-Linked-Glcp, 1,3-Linked-Glcp, 1,4-Linked-Glcp and 1,4,6-Linked-Glcp, with a molar ratio of 1.0: 2.1: 7.6: 1.4. TsLTP exhibited strong inhibitory effects on the migration, invasion, and tube formation of human umbilical vein endothelial cells (iHUVECs) and chick embryo chorioallantoic membrane (CAM) angiogenesis, whereas no inhibitory activity on human TNBC cell lines. Taken together, our study suggests that TsLTP possesses a significant inhibition of tumor microvascular activity both in vitro and in vivo. The study of TsLTP with novel monosaccharide composition and tumor microvascular inhibitory activity might be a beneficial attempt for application of polysaccharide from the genus Trametes in tumor therapy.

The Chicken Embryo Chorioallantoic Membrane as an In Vivo Model for Photodynamic Therapy.

For many decades the chicken embryo chorioallantoic membrane (CAM) has been used for research as an in vivo model in a large number of different fields, including toxicology, bioengineering, and cancer research. More specifically, the CAM is also a suitable and convenient model system in the field of photodynamic therapy (PDT), mainly due to the easy access of its membrane and the possibility of grafting or growing tumors on the membrane and, interestingly, to study the PDT effects on its dense vascular network. In addition, the CAM is simple to handle and cheap. Since the CAM is not innervated until later stages of the embryo development, its use in research is simplified compared to other in vivo models as far as ethical and regulatory issues are concerned. In this review different incubation and drug administration protocols of relevance for PDT are presented. Moreover, data regarding the propagation of light at different wavelengths and CAM development stages are provided. Finally, the effects induced by photobiomodulation on the CAM angiogenesis and its impact on PDT treatment outcome are discussed.