Proangiogenic Effect of Affinin and an Ethanolic Extract from Heliopsis longipes Roots: Ex Vivo and In Vivo Evidence

Angiogenesis, the formation of new blood vessels, underlies tissue development and repair. Some medicinal plant-derived compounds can modulate the angiogenic response. Heliopsis longipes, a Mexican medicinal plant, is widely used because of its effects on pain and inflammation. The main bioactive phytochemicals from H. longipes roots are alkamides, where affinin is the most abundant. Scientific studies show various medical effects of organic extracts of H. longipes roots and affinin that share some molecular pathways with the angiogenesis process, with the vasodilation mechanism of action being the most recent. This study investigates whether pure affinin and the ethanolic extract from Heliopsis longipes roots (HLEE) promote angiogenesis. Using the aortic ring rat assay (ex vivo method) and the direct in vivo angiogenesis assay, where angioreactors were implanted in CD1 female mice, showed that affinin and the HLEE increased vascular growth in a dose-dependent manner in both bioassays. This is the first study showing the proangiogenic effect of H. longipes. Further studies should focus on the mechanism of action and its possible therapeutic use in diseases characterized by insufficient angiogenesis.

LncRNA MALAT1 Promotes Tumor Angiogenesis by Regulating MicroRNA-150-5p/VEGFA Signaling in Osteosarcoma: In-Vitro and In-Vivo Analyses

The present study aims to analyze the expression of long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in human osteosarcoma (OS) cells and to investigate its role in OS-induced angiogenesis. MALAT1 expression in OS cells was significantly higher than in normal osteoblasts. The functional analysis indicated that MALAT1 appears to enhance OS-induced angiogenesis, in vitro and in vivo analyses, endothelial cell proliferation and migration, chick embryo angiogenesis assay, and zebrafish xenograft model. Mechanistically, silencing MALAT1 downregulated vascular endothelial growth factor A (VEGFA) expression and upregulated miR-150-5p expression in OS cells, and MALAT1-mediated angiogenic induction by VEGFA in OS microenvironment. Moreover, MALAT1 directly targeted miR-150-5p and miR-150-5p directly target VEGFA in OS. Overexpression of miR-150-5p downregulates VEGFA expression in OS. More notably, we showed that MALAT1 induced angiogenesis in OS microenvironment by upregulating the expression of VEGFA via targeting miR-150-5p. Overall, our findings suggest that MALAT1 promotes angiogenesis by regulating the miR-150-5p/VEGFA signaling in OS microenvironment. The findings of the molecular mechanisms of MALAT1 in tumor angiogenesis offer a new viewpoint on OS treatment.

Porous tantalum composited gelatin nanoparticles hydrogel integrated with mesenchymal stem cell-derived endothelial cells to construct vascularized tissue in vivo

The ideal scaffold material of angiogenesis should have mechanical strength and provide appropriate physiological microporous structures to mimic the extracellular matrix environment. In this study, we constructed an integrated three-dimensional scaffold material using porous tantalum(pTa), gelatin nanoparticles (GNPs) hydrogel, and seeded with bone marrow mesenchymal stem cells (BMSCs)-derived endothelial cells (ECs) for vascular tissue engineering. The characteristics and biocompatibility of pTa and GNPs hydrogel were evaluated by mechanical testing, scanning electron microscopy, cell counting kit, and live-cell assay. The BMSCs-derived ECs were identified by flow cytometry and angiogenesis assay. BMSCs-derived ECs were seeded on the pTa-GNPs hydrogel scaffold and implanted subcutaneously in nude mice. Four weeks after the operation, the scaffold material was evaluated by histomorphology. The superior biocompatible ability of pTa-GNPs hydrogel scaffold was observed. Our in vivo results suggested that 28 days after implantation, the formation of the stable capillary-like network in scaffold material could be promoted significantly. The novel, integrated pTa-GNPs hydrogel scaffold is biocompatible with the host, and exhibits biomechanical and angiogenic properties. Moreover, combined with BMSCs-derived ECs, it could construct vascular engineered tissue in vivo. This study may provide a basis for applying pTa in bone regeneration and autologous BMSCs in tissue-engineered vascular grafts.

Abstract P429: Aldehyde Dehydrogenase 2 Regulates Angiogenesis Of Coronary Microvascular Endothelial Cells Via A Novel Signaling Pathway

Coronary microvascular endothelial cell (CMECs) damage is implicated in diabetes-mediated heart failure with preserved ejection fraction (HFpEF). 4-hydroxy-2-nonenal (4HNE), a reactive aldehyde that is increased in diabetic heart, decreases angiogenesis in cultured mouse CMECs by decreasing the mRNA and protein levels of vascular endothelial growth factor receptor (VEGFR)2. Nuclear factor-kappa B (NF-kB), a transcription factor, was shown to transcribe VEGFR2. Thus, we presume 4HNE modulates NF-kB-mediated VEGFR2 transcription and regulates angiogenesis in CMECs. Aldehyde dehydrogenase (ALDH) 2, a mitochondrial enzyme that detoxifies 4HNE and confers cryoprotection. However, ALDH2 activity was reduced in the diabetic hearts which results in the augmentation of 4HNE-induced cardiotoxicity. Thus, we hypothesize that ALDH2 in CMECs reduces 4HNE-mediated cell signaling aberrations, and thereby, preserves coronary angiogenesis. We treated the cultured mouse CMECs with disulfiram (DSF) (2.5 μM), an ALDH2 inhibitor, alda1 (10 μM), an ALDH2 activator and prostratin (1 μM), an NF-κB activator prior to challenging the CMECs with 4HNE (75 μM). Our tube-formation angiogenesis assay revealed that pretreatment with DSF exacerbated a 4HNE-induced decrease in CMECs angiogenesis (P<0.0005 vs con and P<0.05 vs both 4HNE & DSF alone) while pretreatments with alda1 and prostratin attenuated a 4HNE-induced decrease in CMEC angiogenesis (P<0.05 vs 4HNE alone). DSF pretreatment exacerbated 4HNE mediated decrease in ALDH2 (P<0.005 vs con), phospho-IKBα (P<0.0005 vs con and P<0.05 vs both 4HNE and DSF alone), NF-κB levels, and nuclear translocation (P<0.0005 vs con and P<0.05 vs both 4HNE & DSF alone) and VEGFR2 (P<0.0005 vs con and P<0.05 vs both 4HNE and DSF alone) levels in cultured CMECs. Pretreatment with both prostratin and alda1 increased ALDH2 (P<0.0005 vs con), VEGFR2 (P<0.05 vs con) and NF-κB (P<0.005 vs con) levels in CMECs. The cardiac tissue samples of db/db mice when they manifest HFpEF showed increased 4HNE adducts, decreased NF-kB and VEGFR2 levels in CD31+ CMECs besides exhibiting low CMEC density. In conclusion, ALDH2 attenuates 4HNE-mediated decrease in coronary angiogenesis by decreasing VEGFR2 levels via low NF-κB mediated transcription.

Evaluation of pro-angiogenic properties of an inorganic silica gel fibre fleece

Hard-to-heal wounds represent an increasing health and economic burden on society. At present, therapy options for hard-to-heal wounds are often unsatisfactory, and the development of more effective wound treatments is urgently needed. We have shown that orthosilicic acid-releasing silica fibre fleece (SIFIB), via its pronounced anti-inflammatory properties, exhibited a significantly enhanced effect on wound closure kinetics in a porcine wound model in vivo. In this present study, we have examined in vitro the impact of the pro-angiogenic potential of SIFIB. Using an in vitro angiogenesis assay we describe for the first time how an inorganic biodegradable silica-based material significantly improved endothelial microvessel-like structure formation. We further demonstrate that the molecular mechanism of this pro-angiogenic activity of SIFIB is based on a significantly increased and tumour necrosis factor (TNF)α-dependent VEGF protein expression. In conclusion, due to its positive effects on angiogenesis, our results further indicate that decomposition products of silica-based biodegradable inorganic materials might represent very relevant therapeutic components of modern wound dressings for the treatment of hard-to-heal wounds.

Selective Apoptosis and Growth Impairment of Cancer Cells Induced by Human Telomerase Reverse Transcriptase (hTERT) Targeting Artificial MicroRNA

Human telomerase reverse transcriptase (hTERT) is a promising cancer target, and amiRNA particle displays the siRNA’s specificity and miRNA’s safety, suggesting that cancers can be treated more effective and safely by hTERT targeting amiRNA particles. Hela, NCI-H446, U2-OS and Huvec cells were transfected by hTERT targeting amiRNA particles. hTERT expression, telomerase activity and cell viability were evaluated by quantitative reverse transcription-PCR (qRT-PCR), western blot (WB), telomeric repeat amplification protocol (TRAP) assays, MTT method, transwell protocol, fluorescence-activated cell sorting (FACS) technologies, angiogenesis assay, and xenograft tumor models. Results: hTERT expression and telomerase activity in Hela and NCIH446 were significantly inhibited by amiRNA. Anti-proliferation and pro-apoptosis effects were only observed in transfected Hela and NCI-H446 cells, but anti-migration and anti-angiogenesis effects were presented in transfected Huvec cells. More interestingly, low to 1.56 nM amiRNA can inhibit the proliferation of Hela cells by 80.99±5.24%. Conclusion: amiRNA selectively and effectively impairs the growth, and assists the apoptosis of telomerase-positive cancer cells.

Three-Dimensional Cell Metabolomics Deciphers the Anti-Angiogenic Properties of the Radioprotectant Amifostine

Aberrant angiogenesis is a hallmark for cancer and inflammation, a key notion in drug repurposing efforts. To delineate the anti-angiogenic properties of amifostine in a human adult angiogenesis model via 3D cell metabolomics and upon a stimulant-specific manner, a 3D cellular angiogenesis assay that recapitulates cell physiology and drug action was coupled to untargeted metabolomics by liquid chromatography–mass spectrometry and nuclear magnetic resonance spectroscopy. The early events of angiogenesis upon its most prominent stimulants (vascular endothelial growth factor-A or deferoxamine) were addressed by cell sprouting measurements. Data analyses consisted of a series of supervised and unsupervised methods as well as univariate and multivariate approaches to shed light on mechanism-specific inhibitory profiles. The 3D untargeted cell metabolomes were found to grasp the early events of angiogenesis. Evident of an initial and sharp response, the metabolites identified primarily span amino acids, sphingolipids, and nucleotides. Profiles were pathway or stimulant specific. The amifostine inhibition profile was rather similar to that of sunitinib, yet distinct, considering that the latter is a kinase inhibitor. Amifostine inhibited both. The 3D cell metabolomics shed light on the anti-angiogenic effects of amifostine against VEGF-A- and deferoxamine-induced angiogenesis. Amifostine may serve as a dual radioprotective and anti-angiogenic agent in radiotherapy patients.

Hypoxic Tubular Epithelial Cells Regulating Angiogenesis by Rab 7

The purpose of our study was to discuss Rab 7 effects in chronic kidney disease (CKD). Methods: Using WT and Rab 7-/- mice as target animal, and HK-2 and HMEC-1 cell co-cultured to make cell model. Measuring kidney tissues were evaluated by Sirius red staining, immunohistochemistry staining to CD 34 protein, Transmission electron microscope (TEM) and gelatin zymography to MMP-2 activities. The cell proliferation were measured by CCK-8 and Ki67 protein expression. Measuring cell invasion and total length were evaluated by transwell and in vitro angiogenesis assay. MMP-2 activities were evaluated by gelatin zymography in cell groups. The relative proteins expression were evaluated by Western blot in kidney tissues and cell groups. Results: Hypoxia promoted the expression of Rab7 in HMEC-1, and the activity of MMP-2 related with regulatory molecules such as reversion-inducing-cysteine-rich protein with kazal motifs (RECK), negative correlation with membrane-type 1 MMP (MT1-MMP or MMP-14) on the membrane of TECs. In addition, the up-regulation of the expression of Rab7 inhibited the activity of MMP-2 and proliferation and cyclization of endothelial cells, and the inhibitor of MMP-2 partially blocked the effects of Rab7 on angiogenesis. Furthermore, the similar data were also obtained in the fibrosis kidney tissues of mice. Conclusion: Rab 7 might be an important role in hypoxic TECs regulated angiogenesis, Rab 7 knockdown could improve hypoxic TECs regulated angiogenesis, the relative mechanisms might be correlation with RECK pathway and MMP-2 activities in vivo and vitro study.

Angiogenic Effect of Pravastatin Alone and with Sera from Healthy and Complicated Pregnancies Studied by in vitro Vasculogenesis/Angiogenesis Assay

<b><i>Objective:</i></b> To determine the direct effect of pravastatin on angiogenesis and to study the interaction between pravastatin and maternal sera from women with early- or late-onset pre-eclampsia (PE), intrauterine growth restriction, or healthy pregnancy. <b><i>Methods:</i></b> We collected 5 maternal serum samples from each group. The effect of pravastatin on angiogenesis was assessed with and without maternal sera by quantifying tubule formation in a human-based in vitro assay. Pravastatin was added at 20, 1,000, and 8,000 ng/mL concentrations. Concentrations of angiogenic and inflammatory biomarkers in serum and in test medium after supplementation of serum alone and with pravastatin (1,000 ng/mL) were measured. <b><i>Results:</i></b> Therapeutic concentration of pravastatin (20 ng/mL) did not have significant direct effect on angiogenesis, but the highest concentrations inhibited angiogenesis. Pravastatin did not change the levels of biomarkers in the test media. There were no changes in angiogenesis when therapeutic dose of pravastatin was added with maternal sera, but there was a trend to wide individual variation towards enhanced angiogenesis, particularly in the early-onset PE group. <b><i>Conclusions:</i></b> At therapeutic concentration, pravastatin alone or with maternal sera has no significant effect on angiogenesis, but at high concentrations the effect seems to be anti-angiogenic estimated by in vitro assay.

RUNX3 Transcript Variants Have Distinct Roles in Ovarian Carcinoma and Differently Influence Platinum Sensitivity and Angiogenesis

The prognosis of late-stage epithelial ovarian cancer (EOC) patients is affected by chemotherapy response and the malignant potential of the tumor cells. In earlier work, we identified hypermethylation of the runt-related transcription factor 3 gene (RUNX3) as a prognostic biomarker and contrary functions of transcript variants (TV1 and TV2) in A2780 and SKOV3 cells. The aim of the study was to further validate these results and to increase the knowledge about RUNX3 function in EOC. New RUNX3 overexpression models of high-grade serous ovarian cancer (HGSOC) were established and analyzed for phenotypic (IC50 determination, migration, proliferation and angiogenesis assay, DNA damage analysis) and transcriptomic consequences (NGS) of RUNX3 TV1 and TV2 overexpression. Platinum sensitivity was affected by a specific transcript variant depending on BRCA background. RUNX3 TV2 induced an increased sensitivity in BRCA1wt cells (OVCAR3), whereas TV1 increased the sensitivity and induced a G2/M arrest under treatment in BRCA1mut cells (A13-2-12). These different phenotypes relate to differences in DNA repair: homologous recombination deficient A13-2-12 cells show less γH2AX foci despite higher levels of Pt-DNA adducts. RNA-Seq analyses prove transcript variant and cell-line-specific RUNX3 effects. Pathway analyses revealed another clinically important function of RUNX3—regulation of angiogenesis. This was confirmed by thrombospondin1 analyses, HUVEC spheroid sprouting assays and proteomic profiling. Importantly, conditioned media (CM) from RUNX3 TV1 overexpressing A13-2-12 cells induced an increased HUVEC sprouting. Altogether, the presented data support the hypothesis of different functions of RUNX3 transcript variants related to the clinically relevant processes—platinum resistance and angiogenesis.