Angiogenic Signaling Research Articles

Dihydroartemisinin inhibits melanoma migration and metastasis by affecting angiogenesis.

Tumor angiogenesis is critical for tumor metastasis by providing oxygen, nutrients, and metastatic pathways. As a potential anti-angiogenic agent, Dihydroartemisinin (DHA) can effectively inhibit tumor metastasis. However, the mechanism how it regulates angiogenesis to affect tumor metastasis has not been fully clarified. To investigate the mechanisms of how DHA regulates melanoma progression. In this study, bioinformatics methods were used to analyze the correlation between angiogenesis and melanoma metastasis. Then, B16F10, A375, HUVECs and mouse metastasis models were adapted to clarify the inhibition of DHA in melanoma. GESA analysis revealed melanoma metastasis significantly positive correlated with angiogenesis. Meanwhile, DHA significantly decreased melanoma nodules and lung wet weight in metastatic tumor mice, and inhibited the expression of the angiogenic marker CD31 in vitro and in vivo. Similarly, DHA inhibited the expression of the angiogenic signal molecule VEGFR2 in A375 and B16F10 cells, and significantly suppressed the formation of their tubular structures. DHA-treated supernatants significantly inhibited the tubule-forming ability as well as lateral and longitudinal migration ability of HUVECs compared with untreated melanoma cell supernatants. Screening yielded the angiogenic pathways HIF-1α/VEGF, PI3K/ATK/mTOR associated with melanoma metastasis, and DHA may inhibit tumor metastasis by inhibiting these angiogenic pathways in melanoma cells to inhibit tumor metastasis. Further non-targeted metabolomics analysis revealed that DHA-treated model mice produced differential metabolites that were also associated with angiogenic pathways. DHA inhibits melanoma invasion and metastasis by mediating angiogenesis. These results have important implications for the potential use of DHA in treatment of melanoma.

Multi-omic profiling reveals discrepant immunogenic properties and a unique tumor microenvironment among melanoma brain metastases

Melanoma brain metastases (MBM) are clinically challenging to treat and exhibit variable responses to immune checkpoint therapies. Prior research suggests that MBM exhibit poor tumor immune responses and are enriched in oxidative phosphorylation. Here, we report results from a multi-omic analysis of a large, real-world melanoma cohort. MBM exhibited lower interferon-gamma (IFNγ) scores and T cell-inflamed scores compared to primary cutaneous melanoma (PCM) or extracranial metastases (ECM), which was independent of tumor mutational burden. Among MBM, there were fewer computationally inferred immune cell infiltrates, which correlated with lower TNF and IL12B mRNA levels. Ingenuity pathway analysis (IPA) revealed suppression of inflammatory responses and dendritic cell maturation pathways. MBM also demonstrated a higher frequency of pathogenic PTEN mutations and angiogenic signaling. Oxidative phosphorylation (OXPHOS) was enriched in MBM and negatively correlated with NK cell and B cell-associated transcriptomic signatures. Modulating metabolic or angiogenic pathways in MBM may improve responses to immunotherapy in this difficult-to-treat patient subset.

Hyperglycemia-induced miR182-5p drives glycolytic and angiogenic response in Proliferative Diabetic Retinopathy and RPE cells via depleting FoxO1

PurposeDiabetic Retinopathy (DR) is associated with metabolic dysfunction in cells such as retinal pigmented epithelium (RPE). Small molecular weight microRNAs can simultaneously regulate multiple gene products thus having pivotal roles in disease pathogenesis. Since miR182-5p is involved in regulating glycolysis and angiogenesis, two pathologic processes of DR, we investigated its status in DR eyes and in high glucose model in vitro. Methodology: Total RNA was extracted from vitreous humor of PDR (n = 48) and macular hole (n = 22) subjects followed by quantification of miR182-5p and its target genes. ARPE-19 cells, cultured in DMEM under differential glucose conditions (5 mM and 25 mM) were used for metabolic and biochemical assays. Cells were transfected with miRNA182 mimic or antagomir to evaluate the gain and loss of function effects. ResultsPDR patient eyes had high levels of miR182-5p levels (p < 0.05). RPE cells under high glucose stress elevated miR182-5p expression with altered glycolytic pathway drivers such as HK2, PFKP and PKM2 over extended durations. Additionally, RPE cells under high glucose conditions exhibited reduced FoxO1 and enhanced Akt activation. RPE cells transfected with miR182-5p mimic phenocopied the enhanced basal and compensatory glycolytic rates observed under high glucose conditions with increased VEGF secretion. Conversely, inhibiting miR182-5p reduced Akt activation, glycolytic pathway proteins, and VEGF while stabilizing FoxO1. ConclusionGlycolysis-associated proteins downstream of the FoxO1-Akt axis were regulated by miR182-5p. Further, miR182-5p increased expression of VEGFR2 and VEGF levels, likely via inhibition of ZNF24. Thus, the FoxO1-Akt-glycolysis/VEGF pathway driving metabolic dysfunction with concurrent angiogenic signaling in PDR may be potentially targeted for treatment via miR182-5p modulation.

FAM222A, Part of the BET-Regulated Basal Endothelial Transcriptome, Is a Novel Determinant of Endothelial Biology and Angiogenesis-Brief Report.

BETs (bromodomain and extraterminal domain-containing epigenetic reader proteins), including BRD4 (bromodomain-containing protein 4), orchestrate transcriptional programs induced by pathogenic stimuli, as intensively studied in cardiovascular disease and elsewhere. In endothelial cells (ECs), BRD4 directs induced proinflammatory, proatherosclerotic transcriptional responses; BET inhibitors, like JQ1, repress these effects and decrease atherosclerosis. While BET effects in pathogenic conditions have prompted therapeutic BET inhibitor development, BET action under basal conditions, including ECs, has remained understudied. To understand BET action in basal endothelial transcriptional programs, we first analyzed EC RNA-Seq data in the absence versus presence of JQ1 before using BET regulation to identify novel determinants of EC biology and function. RNA-Seq datasets of human umbilical vein ECs without and with JQ1 treatment were analyzed. After identifying C12orf34, also known as FAM222A (family with sequence similarity 222 member A), as a previously unreported, basally expressed, potently JQ1-induced EC gene, FAM222A was studied in endothelial and angiogenic responses in vitro using small-interference RNA silencing and lentiviral overexpression, in vitro, ex vivo and in vivo, including aortic sprouting, matrigel plug assays, and murine neonatal oxygen-induced retinopathy. Resting EC RNA-Seq data indicate BETs direct transcriptional programs underlying core endothelial properties including migration, proliferation, and angiogenesis. BET inhibition in resting ECs also significantly induced a subset of mRNAs, including FAM222A-a unique BRD4-regulated gene with no reported EC role. Silencing endothelial FAM222A significantly decreased cellular proliferation, migration, network formation, aorta sprouting, and Matrigel plug vascularization through coordinated modulation of VEGF (vascular endothelial growth factor) and NOTCH mediator expression in vitro, ex vivo, in vivo; lentiviral FAM222A overexpression had opposite effects. In vivo, siFAM222A significantly repressed retinal revascularization in neonatal murine oxygen-induced retinopathy through similar angiogenic signaling modulation. BET control over the basal endothelial transcriptome includes FAM222A, a novel, BRD4-regulated, key determinant of endothelial biology and angiogenesis.

Abstract 17400: Effects of Concurrent Extracellular Vesicle and Metformin Therapy in Porcine Model of Chronic Myocardial Ischemia and Metabolic Syndrome

Introduction: We previously demonstrated using a swine model of chronic myocardial ischemia (CMI) that extracellular vesicle (EV) therapy improves cardiac function, perfusion, and angiogenic signaling, but these benefits were blunted in the setting of metabolic syndrome (MS). Hypothesis: We hypothesized that concurrent treatment with metformin may augment the cardiac effects of EV therapy in a swine model of CMI and MS. Methods: Twenty-nine Yorkshire swine were fed a high fat diet for four weeks to induce MS, then underwent placement of an ameroid constrictor to the left circumflex artery to induce CMI. Two weeks later, pigs receiving either oral placebo or 500mg metformin (MET) BID underwent intramyocardial injection of either vehicle or mesenchymal stem cell-derived EVs. This resulted in four groups: placebo+vehicle (CON, n=6), placebo+EV (EV, n=8), MET+vehicle (MET, n=7), and MET+EV (METEV, n=8). Five weeks after injection, pigs underwent functional measurements and harvest of ischemic myocardium. Perfusion, capillary density, and protein expression were measured by microspheres, immunofluorescence, and immunoblotting respectively. Results: Cardiac function was improved in EV compared to CON (SV p=0.02, SW p=0.01, CO p=0.03), and in MET compared to CON (SV p=0.03, SW p=0.09, CO p=0.2), though there were no differences between MET and METEV groups (p&gt;0.5 for all). Contractility as measured by slope of PRSW relationship was improved with METEV compared to CON (p=0.04), with a trend towards improvement in MET compared to CON (p=0.21), but not with EV alone. During pacing, there was increased perfusion in MET (p=0.04) and METEV (p=0.04) groups compared to CON. At rest, there was increased perfusion in MET (p=0.05) group, with a trend towards increased perfusion in METEV group (p=0.29) compared to CON, without differences between MET and METEV (p&gt;0.5). Capillary density was unchanged in METEV compared to CON (p&gt;0.5). The MET and METEV groups had decreased expression of p-Akt (p=0.01, p=0.06) and p-ERK (p=0.09, p=0.03) compared to CON, without changes in p-eNOS (p&gt;0.5), and all without differences between MET and METEV (p&gt;0.5). Conclusions: In the setting of CMI and MS, the blunted effects of EVs are not augmented by concurrent metformin therapy.

Abstract 11433: Elevated Vascular Endothelial Growth Factor A is Associated With Disruption of Default Network Connectivity

Introduction: Vascular Endothelial Growth Factor A (VEGF-A) is an angiogenic signaling protein involved in the maintenance of the cerebral vasculature. VEGF-A may play a role in the pathogenesis of Alzheimer’s disease and vascular dementia; however, whether elevated VEGF-A levels indicate a pathophysiolocal response or protective mechanism remains unclear. No prior study has explored whether VEGF-A levels may be associated with changes in functional connectivity among brain regions prior to the development of cognitive decline. Hypothesis: Disruption of the default network often precedes the development of cognitive changes. In a sample of older adults, we hypothesized that VEGF-A levels may be associated with default network connectivity, indicating early involvement of VEGF-A in disease processes. Methods: Forty-six independently living older adults (mean age = 72.0 years; SD = 6.4; 34.8% male) free of dementia or clinical stroke underwent venipuncture and brain MRI. Plasma was assayed for VEGF-A. Using resting state functional MRI, blood-oxygen level dependent (BOLD) time series from all voxels in each region of interest (ROI) was averaged to determine mean ROI activity. Medial prefrontal cortex, lateral parietal cortex and precuneus cortex ROIs comprised the default network. Results: Accounting for age and sex, multiple linear regression analysis revealed a significant negative association between VEGF-A levels and default mode network connectivity (B =-.0007, 95% CI (-.0012, -.0002), p = .0096). This association persisted after adjusting for APOE4 carrier status and Framingham score. A significant association was present in both APOE4 carriers (p = .019) and non-carriers (p = .029). Conclusions: Prior studies evaluating the association between VEGF-A levels and cognition have been conflicted. This study is the first to examine whether VEGF-A may be linked to early changes in brain network connectivity which precede cognitive decline. These findings suggest that VEGF-A may be elevated early in the progression of neurocognitive disorders. Whether higher levels of VEGF-A contribute to the pathogenesis of neurocognitive disorders or play a protective role in persevering cognitive function warrants further investigation.

Deletion of the aryl hydrocarbon receptor in endothelial cells improves ischemic angiogenesis in chronic kidney disease.

Chronic kidney disease (CKD) is a strong risk factor for peripheral artery disease (PAD) that is associated with worsened clinical outcomes. CKD leads to the accumulation of tryptophan metabolites that are associated with adverse limb events in PAD and are ligands of the aryl hydrocarbon receptor (AHR), which may regulate ischemic angiogenesis. To test if endothelial cell-specific deletion of the AHR (AHRecKO) alters ischemic angiogenesis and limb function in mice with CKD subjected to femoral artery ligation. Male AHRecKO mice with CKD displayed better limb perfusion recovery and enhanced ischemic angiogenesis compared with wild-type mice with CKD. However, the improved limb perfusion did not result in better muscle performance. In contrast to male mice, deletion of the AHR in female mice with CKD had no impact on perfusion recovery or angiogenesis. With the use of primary endothelial cells from male and female mice, treatment with indoxyl sulfate uncovered sex-dependent differences in AHR activating potential and RNA sequencing revealed wide-ranging sex differences in angiogenic signaling pathways. Endothelium-specific deletion of the AHR improved ischemic angiogenesis in male, but not female, mice with CKD. There are sex-dependent differences in Ahr activating potential within endothelial cells that are independent of sex hormones.NEW & NOTEWORTHY This study provides novel insights into the mechanisms by which chronic kidney disease worsens ischemic limb outcomes in an experimental model of peripheral artery disease. Deletion of the aryl hydrocarbon receptor (AHR) in the endothelium improved ischemic angiogenesis suggesting that AHR inhibition could be a viable therapeutic target; however, this effect was only observed in male mice. Subsequent analysis in primary endothelial cells reveals sex differences in Ahr activating potential independent of sex hormones.

Angiogenic potential of skeletal muscle derived extracellular vesicles differs between oxidative and glycolytic muscle tissue in mice

Skeletal muscle fibers regulate surrounding endothelial cells (EC) via secretion of numerous angiogenic factors, including extracellular vesicles (SkM-EV). Muscle fibers are broadly classified as oxidative (OXI) or glycolytic (GLY) depending on their metabolic characteristics. OXI fibers secrete more pro-angiogenic factors and have greater capillary densities than GLY fibers. OXI muscle secretes more EV than GLY, however it is unknown whether muscle metabolic characteristics regulate EV contents and signaling potential. EVs were isolated from primarily oxidative or glycolytic muscle tissue from mice. MicroRNA (miR) contents were determined and endothelial cells were treated with OXI- and GLY-EV to investigate angiogenic signaling potential. There were considerable differences in miR contents between OXI- and GLY-EV and pathway analysis identified that OXI-EV miR were predicted to positively regulate multiple endothelial-specific pathways, compared to GLY-EV. OXI-EV improved in vitro angiogenesis, which may have been mediated through nitric oxide synthase (NOS) related pathways, as treatment of endothelial cells with a non-selective NOS inhibitor abolished the angiogenic benefits of OXI-EV. This is the first report to show widespread differences in miR contents between SkM-EV isolated from metabolically different muscle tissue and the first to demonstrate that oxidative muscle tissue secretes EV with greater angiogenic signaling potential than glycolytic muscle tissue.

Extracellular Vesicles Derived from the Serum of Seriola quinqueradiata Induce Human Umbilical Vein Endothelial Cell Proliferation through Angiogenic Signaling.

Daily intake of extracellular vesicles (EVs) derived from fish (f-EVs) may contribute to health maintenance by reducing cardiovascular risk. However, their physicochemical and biological properties remain unclear. In this study, we compared the physical characteristics (size, zeta potential, and free fatty acid composition) and biological characteristics (cell proliferation) of f-EVs with those of EVs derived from mammals (m-EVs). In the physical characteristic analysis, f-EVs derived from Pagrus major (PMS-EVs) and Seriola quinqueradiata (SQS-EVs) had a negatively charged and a positively charged group and higher levels of unsaturated fatty acids, unlike m-EVs. In the biological characteristic analysis for f-EVs, SQS-EV enhanced the human umbilical vein endothelial cell proliferation via vascular endothelial growth factor receptor 2, fibroblast growth factor receptor 1, or platelet-derived growth factor β. These data suggest that SQS-EVs have unique functions compared with other EVs. To the best of our knowledge, this is the first study to show that SQS-EVs act positively on human cells.

Single-Nuclei RNA-Sequencing of the Gastrocnemius Muscle in Peripheral Artery Disease.

Lower extremity peripheral artery disease (PAD) is a growing epidemic with limited effective treatment options. Here, we provide a single-nuclei atlas of PAD limb muscle to facilitate a better understanding of the composition of cells and transcriptional differences that comprise the diseased limb muscle. We obtained gastrocnemius muscle specimens from 20 patients with PAD and 12 non-PAD controls. Nuclei were isolated and single-nuclei RNA-sequencing was performed. The composition of nuclei was characterized by iterative clustering via principal component analysis, differential expression analysis, and the use of known marker genes. Bioinformatics analysis was performed to determine differences in gene expression between PAD and non-PAD nuclei, as well as subsequent analysis of intercellular signaling networks. Additional histological analyses of muscle specimens accompany the single-nuclei RNA-sequencing atlas. Single-nuclei RNA-sequencing analysis indicated a fiber type shift with patients with PAD having fewer type I (slow/oxidative) and more type II (fast/glycolytic) myonuclei compared with non-PAD, which was confirmed using immunostaining of muscle specimens. Myonuclei from PAD displayed global upregulation of genes involved in stress response, autophagy, hypoxia, and atrophy. Subclustering of myonuclei also identified populations that were unique to PAD muscle characterized by metabolic dysregulation. PAD muscles also displayed unique transcriptional profiles and increased diversity of transcriptomes in muscle stem cells, regenerating myonuclei, and fibro-adipogenic progenitor cells. Analysis of intercellular communication networks revealed fibro-adipogenic progenitors as a major signaling hub in PAD muscle, as well as deficiencies in angiogenic and bone morphogenetic protein signaling which may contribute to poor limb function in PAD. This reference single-nuclei RNA-sequencing atlas provides a comprehensive analysis of the cell composition, transcriptional signature, and intercellular communication pathways that are altered in the PAD condition.

Single-cell characterization of neovascularization using hiPSC-derived endothelial cells in a 3D microenvironment.

The formation of vascular structures is fundamental for invitro tissue engineering. Vascularization can enable the nutrient supply within larger structures and increase transplantation efficiency. We differentiated human induced pluripotent stem cells toward endothelial cells in 3D suspension culture. To investigate invitro neovascularization and various 3D microenvironmental approaches, we designed a comprehensive single-cell transcriptomic study. Time-resolved single-cell transcriptomics of the endothelial and co-evolving mural cells gave insights into cell type development, stability, and plasticity. Transfer to a 3D hydrogel microenvironment induced neovascularization and facilitated tracing of migrating, coalescing, and tubulogenic endothelial cell states. During maturation, we monitored two pericyte subtypes evolving mural cells. Profiling cell-cell interactions between pericytes and endothelial cells revealed angiogenic signals during tubulogenesis. In silico discovered ligands were tested for their capability to attract endothelial cells. Our data, analyses, and results provide an invitro roadmap to guide vascularization in future tissue engineering.

Experiment-based computational model predicts that IL-6 classic and trans-signaling exhibit similar potency in inducing downstream signaling in endothelial cells

Inflammatory cytokine mediated responses are important in the development of many diseases that are associated with angiogenesis. Targeting angiogenesis as a prominent strategy has shown limited effects in many contexts such as cardiovascular diseases and cancer. One potential reason for the unsuccessful outcome is the mutual dependent role between inflammation and angiogenesis. Inflammation-based therapies primarily target inflammatory cytokines such as interleukin-6 (IL-6) in T cells, macrophages, cancer cells, and muscle cells, and there is a limited understanding of how these cytokines act on endothelial cells. Thus, we focus on one of the major inflammatory cytokines, IL-6, mediated intracellular signaling in endothelial cells by developing a detailed computational model. Our model quantitatively characterized the effects of IL-6 classic and trans-signaling in activating the signal transducer and activator of transcription 3 (STAT3), phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt), and mitogen-activated protein kinase (MAPK) signaling to phosphorylate STAT3, extracellular regulated kinase (ERK) and Akt, respectively. We applied the trained and validated experiment-based computational model to characterize the dynamics of phosphorylated STAT3 (pSTAT3), Akt (pAkt), and ERK (pERK) in response to IL-6 classic and/or trans-signaling. The model predicts that IL-6 classic and trans-signaling induced responses are IL-6 and soluble IL-6 receptor (sIL-6R) dose-dependent. Also, IL-6 classic and trans-signaling showed similar potency in inducing downstream signaling; however, trans-signaling induces stronger downstream responses and plays a dominant role in the overall effects from IL-6 due to the in vitro experimental setting of abundant sIL-6R. In addition, both IL-6 and sIL-6R levels regulate signaling strength. Moreover, our model identifies the influential species and kinetic parameters that specifically modulate the downstream inflammatory and/or angiogenic signals, pSTAT3, pAkt, and pERK responses. Overall, the model predicts the effects of IL-6 classic and/or trans-signaling stimulation quantitatively and provides a framework for analyzing and integrating experimental data. More broadly, this model can be utilized to identify potential targets that influence IL-6 mediated signaling in endothelial cells and to study their effects quantitatively in modulating STAT3, Akt, and ERK activation.

Case Report: Implication of antiangiogenic therapy (bevacizumab) along with dichloroacetate therapy on endometriosis patient seeking infertility treatment

Endometriosis is a pervasive gynecological ailment which usually results in unease and infertility and is signified by an accumulation of endometrial-like tissue outside the uterus. Current endometriosis medications, which often entail surgical intervention and hormone therapy, are geared around easing discomfort as well as improving fertility. However, alternative approaches targeting angiogenesis have shown promise in managing endometriosis-associated infertility. This case report highlights the implications of combining antiangiogenic therapy (bevacizumab) with dichloroacetate (DCA) therapy in a patient with endometriosis seeking infertility treatment. A 34-year-old woman presented with a five-year history of severe pelvic pain and primary infertility due to stage IV endometriosis. The patient sought other possibilities after repeated unsuccessful attempts using assisted reproductive technology. A revolutionary therapy strategy combining bevacizumab, a vascular endothelial growth factor (VEGF) inhibitor, and DCA, a metabolic modulator, has been proposed considering the potential significance of angiogenesis in endometriosis-related infertility. The patient underwent a six-month treatment regimen consisting of intravenous bevacizumab infusions combined with oral DCA administration. The theory behind this combination was to target the metabolic reprogramming typically associated with the disease in addition to altering the abnormal angiogenic signaling pathways that contribute to the pathogenesis of endometriosis. Given the scores on the visual analogue scale, the patient's pelvic pain substantially decreased during the time frame of treatment. Additionally, a notable improvement in ovarian reserve markers was observed, including an increase in anti-Müllerian hormone levels and the number of antral follicles. This case report suggests that the combination of bevacizumab and DCA may have a synergistic effect in managing endometriosis-associated infertility. This form of therapy may provide patients who have failed typical infertility treatment options with an innovative therapeutic approach since it targets both angiogenesis and metabolic changes.

Phlorotannins: Novel Orally Administrated Bioactive Compounds That Induce Mitochondrial Dysfunction and Oxidative Stress in Cancer.

Mitochondrial dysfunction is an interesting therapeutic target to help reduce cancer deaths, and the use of bioactive compounds has emerged as a novel and safe approach to solve this problem. Here, we discuss the information available related to phlorotannins, a type of polyphenol present in brown seaweeds that reportedly functions as antioxidants/pro-oxidants and anti-inflammatory and anti-tumorigenic agents. Specifically, available evidence indicates that dieckol and phloroglucinol promote mitochondrial membrane depolarization and mitochondria-dependent apoptosis. Phlorotannins also reduce pro-tumorigenic, -inflammatory, and -angiogenic signaling mechanisms involving RAS/MAPK/ERK, PI3K/Akt/mTOR, NF-κB, and VEGF. In doing so, they inhibit pathways that favor cancer development and progression. Unfortunately, these compounds are rather labile and, therefore, this review also summarizes approaches permitting the encapsulation of bioactive compounds, like phlorotannins, and their subsequent oral administration as novel and non-invasive therapeutic alternatives for cancer treatment.

Antiangiogenic Activity of Mangostins Isolated from Thailand Stingless Bee Propolis

Background/Objective Propolis, a resinous substance collected by honeybees from origin plants to protect their beehive, has been reported to have various biological activities and gained popularity as an alternative medicine in recent years. We have previously reported the plant origin, the chemical composition and some biological activities of native Thailand stingless bee propolis. In this study, we further elucidated its active components and their mode of action. Methods/Results Among nine prenylated xanthones isolated from this propolis, α-mangostin and γ-mangostin were shown to strongly inhibit tube formation of human umbilical vein endothelial cells (HUVECs), an indication of antiangiogenic activity in vitro. Further investigation of their effects at a molecular level revealed that both mangostins inactivated extracellular signal-regulated kinase 1/2 (ERK1/2) and activated p38 in tube-forming HUVECs in a concentration-dependent manner. Taken together, the two mangostins were shown to inhibit angiogenesis in vitro by inactivating angiogenic signal ERK1/2 and activating stress signal p38. Detailed comparison revealed that α-mangostin seemed to have a slightly stronger effect than γ-mangostin in these experiments. Combined with the fact that being the most abundant component among the nine prenylated xanthones tested, α-mangostin might be responsible for the antiangiogenic activity of this Thailand stingless bee propolis. Conclusion These results indicate that α-mangostin isolated from Thailand stingless bee propolis may be a good candidate for future applications in the prevention of angiogenesis-related diseases.

Molecular Signatures of Glomerular Neovascularization in a Patient with Diabetic Kidney Disease.

The Kidney Precision Medicine Project (KPMP) aims to create a kidney tissue atlas, define disease subgroups, and identify critical cells, pathways, and targets for novel therapies through molecular investigation of human kidney biopsies obtained from participants with AKI or CKD. We present the case of a 66-year-old woman with diabetic kidney disease who underwent a protocol KPMP kidney biopsy. Her clinical history included diabetes mellitus complicated by neuropathy and eye disease, increased insulin resistance, hypertension, albuminuria, and relatively preserved glomerular filtration rate (early CKD stage 3a). The patient's histopathology was consistent with diabetic nephropathy and arterial and arteriolar sclerosis. Three-dimensional, immunofluorescence imaging of the kidney biopsy specimen revealed extensive periglomerular neovascularization that was underestimated by standard histopathologic approaches. Spatial transcriptomics was performed to obtain gene expression signatures at discrete areas of the kidney biopsy. Gene expression in the areas of glomerular neovascularization revealed increased expression of genes involved in angiogenic signaling, proliferation, and survival of endothelial cells, as well as new vessel maturation and stability. This molecular correlation provides additional insights into the development of kidney disease in patients with diabetes and spotlights how novel molecular techniques used by the KPMP can supplement and enrich the histopathologic diagnosis obtained from a kidney biopsy.

Angiogenesis in Aortic Aneurysm and Dissection: A Literature Review.

Aortic aneurysm and aortic dissection (AA/AD) are critical aortic diseases with a hidden onset and sudden rupture, usually resulting in an inevitable death. Several pro- and anti-angiogenic factors that induce new capillary formation in the existing blood vessels regulate angiogenesis. In addition, aortic disease mainly manifests as the proliferation and migration of endothelial cells of the adventitia vasa vasorum. An increasing number of studies have shown that angiogenesis is a characteristic change that may promote AA/AD occurrence, progression, and rupture. Furthermore, neocapillaries are leaky and highly susceptible to injury by cytotoxic agents, which promote extracellular matrix remodeling, facilitate inflammatory cell infiltration, and release coagulation factors and proteases within the wall. Mechanistically, inflammation, hypoxia, and angiogenic factor signaling play important roles in angiogenesis in AA/AD under the complex interaction of multiple cell types, such as smooth muscle cells, fibroblasts, macrophages, mast cells, and neutrophils. Therefore, based on current evidence, this review aims to discuss the manifestation, pathological role, and underlying mechanisms of angiogenesis involved in AA/AD, providing insights into the prevention and treatment of AA/AD.

MicroRNA-27b Impairs Nrf2-Mediated Angiogenesis in the Progression of Diabetic Foot Ulcer.

Nuclear factor erythroid-2-related factor 2 (Nrf2) is a stress-activated transcription factor regulating antioxidant genes, and a deficiency thereof, slowing lymphangiogenesis, has been reported in diabetic foot ulcer (DFU). The mode of Nrf2 regulation in DFU has been less explored. Emerging studies on miRNA-mediated target regulation show miRNA to be the leading player in the pathogenesis of the disease. In the present study, we demonstrated the role of miR-27b in regulating Nrf2-mediated angiogenesis in DFU. A lower expression of mRNA targets, such as Nrf2, HO-1, SDF-1α, and VEGF, was observed in tissue biopsied from chronic DFU subjects, which was in line with miR-27b, signifying a positive correlation with Nrf2. Similarly, we found significantly reduced expression of miR-27b and target mRNAs Nrf2, HO-1, SDF-1α, and VEGF in endothelial cells under a hyperglycemic microenvironment (HGM). To confirm the association of miR-27b on regulating Nrf2-mediated angiogenesis, we inhibited its expression through RNA interference-mediated knockdown and observed disturbances in angiogenic signaling with reduced endothelial cell migration. In addition, to explore the role of miR-27b and angiogenesis in the activation of Nrf2, we pretreated the endothelial cells with two well-known pharmacological compounds-pterostilbene and resveratrol. We observed that activation of Nrf2 through these compounds ameliorates impaired angiogenesis on HGM-induced endothelial cells. This study suggests a positive role of miR-27b in regulating Nrf2, which seems to be decreased in DFU and improves on treatment with pterostilbene and resveratrol.

PRMT5 facilitates angiogenesis and EMT via HIF-1α/VEGFR/Akt signaling axis in lung cancer.

Abnormal angiogenesis is a critical factor in tumor growth and metastasis, and protein arginine methyltransferase 5 (PRMT5), a prominent type II enzyme, is implicated in various human cancers. However, the precise role of PRMT5 in regulating angiogenesis to promote lung cancer cell metastasis and the underlying molecular mechanisms are not fully understood. Here, we show that PRMT5 is overexpressed in lung cancer cells and tissues, and its expression is triggered by hypoxia. Moreover, inhibiting or silencing PRMT5 disrupts the phosphorylation of the VEGFR/Akt/eNOS angiogenic signaling pathway, NOS activity, and NO production. Additionally, inhibiting PRMT5 activity reduces HIF-1α expression and stability, resulting in the down-regulation of the VEGF/VEGFR signaling pathway. Our findings indicate that PRMT5 promotes lung cancer epithelial-mesenchymal transition (EMT), which might be possibly through controlling the HIF-1α/VEGFR/Akt/eNOS signaling axis. Our study provides compelling evidence of the close association between PRMT5 and angiogenesis/EMT and highlights the potential of targeting PRMT5 activity as a promising therapeutic approach for treating lung cancer with abnormal angiogenesis.

Altered expression of necroptotic, angiogenic and spermatogenic proteins in degenerate testes from aged stallions

We utilized RNA sequencing to compare the testis transcriptomes of fertile, adult stallions to those of adult stallions with age-related testicular degeneration (TD). Large-scale gene ontology analysis identified pathway-wide upregulation of inflammation and alterations in apoptotic pathways that likely play roles in the disease process (Woodward et al., Eq Vet J. 2022; 1-14). In humans and mice, inflammation, together with necroptosis, and alterations in capillary density, all contribute to age-related degenerative changes (Li et. al, ELife. 2017; 6:e27692 DOI: 10.7554/eLife.27692; Das et al, Cell. 2018;(173)74-89). One objective of the current study was to identify differentially expressed genes (DEGs) that may contribute similarly to TD in the horse. We also searched for DEGs that play roles in spermatogenesis. A second objective was to use immunohistochemistry (IHC) to determine if the protein products of these genes are differentially expressed between normal and diseased testes and to determine their patterns of expression. The hypothesis is that aberrations in necroptotic, angiogenic, and spermatogenic signaling pathways contribute to the pathophysiology of TD in stallions. RNA isolation and sequencing were performed on testicular tissue samples from 3 fertile adult stallions and from 3 adult stallions with confirmed TD as previously described (Woodward et al., Eq Vet J. 2022; 1-14). Transcript expression was compared between the 2 populations using either EdgeA or DESeq2, and a minimum of >1.5x fold change and Padj<0.05 asthe cutoffs for significance. Protein expression from selected DEGs was compared between normal adult and TD tissue using IHC. In degenerate testes, significant increases in gene expression were found in testicular-origin growth factors (BMP4 (9x increase), FGF2 (9x increase), and CSF1 (7x increase)). IHC confirmed increased expression of BMP4 and FGF2 proteins in germ cells from degenerate testes. Expression of CSF1R protein also was altered, with loss of expression of the protein in early germ cells, and increased expression in later stages of spermatogenesis. Upregulation of RIPK3 (3x increase) and VEGF (17x increase) transcripts also were confirmed in degenerate testes. These genes are central to necroptotic and angiogenic pathways, respectively. IHC confirmed diffuse upregulation of the RIPK3 protein in germ cells from degenerate testes. IHC for the VEGF protein is pending. In conclusion, alterations in expression of proteins responsible for stimulation of mitosis and meiosis in male germ cells were identified. Additionally, we provide evidence that chronic inflammation, necroptosis and aberrant angiogenesis may cause age-related degenerative changes in equine testes. In mice, inhibitors of the RIPK3 pathway and stimulation of angiogenesis can ameliorate clinical signs of aging in testes and muscle respectively (Li et. al, ELife. 2017; Das et al, Cell. 2018). Financial support: Grayson Jockey Club Research Foundation.