Angiogenic Process Research Articles

Exosome-Integrated Hydrogels for Bone Tissue Engineering

Exosome-integrated hydrogels represent a promising frontier in bone tissue engineering, leveraging the unique biological properties of exosomes to enhance the regenerative capabilities of hydrogels. Exosomes, as naturally occurring extracellular vesicles, carry a diverse array of bioactive molecules that play critical roles in intercellular communication and tissue regeneration. When combined with hydrogels, these exosomes can be spatiotemporally delivered to target sites, offering a controlled and sustained release of therapeutic agents. This review aims to provide a comprehensive overview of the recent advancements in the development, engineering, and application of exosome-integrated hydrogels for bone tissue engineering, highlighting their potential to overcome current challenges in tissue regeneration. Furthermore, the review explores the mechanistic pathways by which exosomes embedded within hydrogels facilitate bone repair, encompassing the regulation of inflammatory pathways, enhancement of angiogenic processes, and induction of osteogenic differentiation. Finally, the review addresses the existing challenges, such as scalability, reproducibility, and regulatory considerations, while also suggesting future directions for research in this rapidly evolving field. Thus, we hope this review contributes to advancing the development of next-generation biomaterials that synergistically integrate exosome and hydrogel technologies, thereby enhancing the efficacy of bone tissue regeneration.

DDEL-09. AS1411 APTAMER-CONJUGATED NANOSPHERES FOR TARGETING GLIOBLASTOMA THERAPY

Abstract Postoperative chemotherapy remains essential for treating glioblastoma (GBM), with nanocarrier-based drug delivery emerging as the most efficient method. However, non-specific delivery across the blood-brain barrier (BBB) can limit drug accumulation in tumors and cause damage to nearby tissues. As cancer progresses, angiogenic processes lead to the formation of an irregular blood-tumor barrier (BTB), necessitating nanodrug platforms for precise targeting and efficient drug delivery to cancer cells. In this study, we aimed to demonstrate targeted cancer therapy by selectively identifying tumor cells overexpressing nucleolin (NCL) protein using Dox-loaded AS1411 aptamer-conjugated nanospheres. Drug nanocarriers were synthesized from small molecules with sizes ranging from 100 to 300 nm to facilitate drug delivery. Selective drug delivery and cellular uptake were demonstrated for NCL-positive GBM cells (U87 and U251) compared to NCL-negative normal human astrocyte (NHA) cells. Flow cytometric analysis using FAM dye-labeled AS1411 aptamer-conjugated nanospheres confirmed that drug delivery to GBM U87 and U251 cells was actively targeted by specific AS1411-NCL interactions. Confocal laser scanning microscopy and cytotoxicity analysis confirmed that inoculation of Dox-loaded AS1411 aptamer-conjugated nanospheres induced selective internalization in GBM U87 and U251 cells. Moreover, to evaluate cytotoxicity and anti-tumor effects after treatment with PBS, Apt-Nanospheres, Free Dox, and Dox-Apt-Nanospheres, the results were analyzed through cell counting kit (CCK-8) analysis, evaluation of differences in 3D tumor sphere radii, and an in vivo GBM xenograft tumor model. The AS1411 aptamer-conjugated nanosphere drug delivery system was developed for dual-target treatment of GBM. AS1411-mediated specific recognition and drug accumulation significantly enhanced binding to NCL-positive U87 and U251 cells and improved cytotoxicity efficiency compared to Free Dox. Additionally, this study demonstrated that the active targeting model using aptamer-mediated drug delivery was more effective in improving drug penetration and retention in tumor cells than non-specific enhanced permeability and retention (EPR)-mediated delivery and passive drug delivery.

AIP1 Regulates Ocular Angiogenesis Via NLRP12-ASC-Caspase-8 Inflammasome-Mediated Endothelial Pyroptosis.

Pathological ocular angiogenesis is a significant cause of irreversible vision loss and blindness worldwide. Currently, most studies have focused on the angiogenesis factors in ocular vascular diseases, and very few endogenous anti-angiogenic compounds have been found. Moreover, although inflammation is closely related to the predominant processes involved in angiogenesis, the mechanisms by which inflammation regulates pathological ocular angiogenesis remain obscure. In this study, a vascular endothelial cells (VECs)-specific anti-angiogenic factor is identified, apoptosis signal-regulating kinase 1(ASK1)-interacting protein-1 (AIP1) as a key pathogenic regulator in a typical ocular angiogenesis model, oxygen-induced retinopathy (OIR), using single-cell RNA sequencing. It is demonstrated that AIP1 inhibited pathological angiogenesis by preventing a particular inflammatory death pathway, namely pyroptosis, in retinal VECs. The assembly of a noncanonical inflammasome is further uncovered, the NLRP12-ASC-caspase-8 inflammasome, which is promoted by decreased AIP1 in OIR. This inflammasome elicited gasdermin D (GSDMD)-dependent endothelial pyroptosis, which in turn promoted the release of vascular endothelial growth factor (VEGF) and interleukin (IL)-1β. Suppression of NLRP12-CASP8-GSDMD axis and AIP1 upregulation reduced VEGF signaling, limiting new vessel formation. These findings reveal a previously uncharacterized inflammatory angiogenic process involving VECs pyroptosis-inducing retinal neovascularization, paving the way for promising therapeutic avenues targeting angiogenesis via AIP1 or pyroptosis.

Genetically Engineered Filamentous Bacteriophages Displaying TGF-β1 Promote Angiogenesis in 3D Microenvironments.

Combined 3D cell culture in vitro assays with microenvironment-mimicking systems are effective for cell-based screening tests of drug and chemical toxicity. Filamentous bacteriophages have diverse applications in material science, drug delivery, tissue engineering, energy, and biosensor development. Specifically, genetically modified bacteriophages have the potential to deliver therapeutic molecules or genes to targeted tumor tissues. The engineered bacteriophages in this study significantly enhanced endothelial cell migration and tube formation within the extracellular matrix (ECM). Compared to TGF-β1 alone and non-modified phages, the presence of TGF-β1 on the bacteriophages demonstrated superior performance as a continuous stimulant in the microenvironment, effectively promoting these angiogenic processes. Assays, including RT-qPCR, ELISA, and fluorescence microscopy, confirmed the expression of angiogenic markers such as CD31, validating the formation of 3D angiogenic structures. Our findings indicate that the TGF-β1 displayed by bacteriophages likely acted as a chemotactic factor, promoting the migration, proliferation, and tube formation of endothelial cells (ECs) within the ECM. Although direct contact between ECs and bacteriophages was not explicitly confirmed, the observed effects strongly suggest that TGF-β1-RGD bacteriophages contributed to the stimulation of angiogenic processes. The formation of angiogenic structures by ECs in the ECM was confirmed as three-dimensional and regulated by the surface treatment of microfluidic channels. These results suggest that biocompatible TGF-β1-displaying bacteriophages could continuously stimulate the microenvironment in vitro for angiogenesis models. Furthermore, we demonstrated that these functionalized bacteriophages have the potential to be utilized as versatile biomaterials in the field of biomedical engineering. Similar strategies could be applied to develop angiogenic matrices for tissue engineering in in vitro assays.

Polydopamine-functionalized calcium-deficient hydroxyapatite 3D-printed scaffold with sustained doxorubicin release for synergistic chemo-photothermal therapy of osteosarcoma and accelerated bone regeneration

Interior bone-tissue regeneration and rapid tumor recurrence post-resection are critical challenges in osteosarcoma and other bone cancers. Conventional bone tissue engineering scaffolds lack inhibitory effects on bone tumor recurrence. Herein, multifunctional scaffolds (named DOX/PDA@CDHA) were designed through the spontaneous polymerization of Dopamine (PDA) on the surface of Calcium Deficient Hydroxyapatite (CDHA) scaffolds, followed by in situ loading of the chemotherapeutic drug Doxorubicin (DOX). The PDA coating endowed the scaffolds with significant photothermal properties, while the gradual release of DOX provided an effective chemotherapeutic effect. The on-demand release of DOX at tumor sites, triggered by dual stimulation (near-infrared (NIR) light and the acidic pH typical of tumor microenvironments), specifically targets cancer cells, thereby mitigating systemic side effects. These unique characteristics facilitated effective osteosarcoma eradication both in vitro and in vivo. Moreover, the scaffold's composition, which mimics the mineral phase of natural bone and is enhanced by PDA's biocompatibility, promotes critical osteogenic and angiogenic processes. This facilitates not only tumor eradication but also the regeneration of healthy bone tissue. Collectively, this study presents a potent candidate for the regeneration of bone defects induced by osteosarcoma.

14K prolactin derived 14-mer antiangiogenic peptide targets bradykinin-/nitric oxide-cGMP-dependent angiogenesis.

Over the past few decades, VEGF-targeted antiangiogenic therapy for cancers has gained increasing attention. Nevertheless, there are still several limitations such as the potential resistance mechanisms arising in cancer cells against these therapies and their potential adverse effects. These limitations highlight the need for novel anti-angiogenesis molecules and better understanding of the mechanisms of tumor angiogenesis. In the present study, we investigated the antiangiogenic properties of a novel 14-mer antiangiogenic peptide (14-MAP) derived from N-terminal 14 kDa buffalo prolactin and characterized its mode of action. 14-MAP at the picomolar concentration inhibited VEGF- and bradykinin (an autacoid peptide expressed in vascular tissues in pathophysiology, BK)-stimulated endothelial nitric oxide (eNO) production, cell migration, and proliferation in endothelial cells and vessel development in the chick embryo. Although this peptide inhibited both VEGF- and BK-dependent angiogenic processes, its action was more pronounced in the latter. Moreover, the interference of 14-MAP with the eNO synthase (eNOS)-cyclic GMP pathway was also identified. A combination of a low dose of Avastin, a widely used drug targeting VEGF-dependent angiogenesis, and 14-MAP significantly reduced tumor size in an in vivo model of human colon cancer. Taken together, our results suggest that 14-MAP, a BK- and eNOS-dependent antiangiogenic peptide, might be useful for overcoming the limitation of VEGF-targeted antiangiogenic therapy in cancer patients. However, further studies will be required to further characterize its mode of action and therapeutic potential.

Abstract A035: Protein quantitative trait loci analysis in diverse prostate cancer patients: A focus on angiogenesis

Abstract Prostate cancer exhibits notable disparities in mortality rates between African American (AA) and European American (EA) populations, with genetic ancestry and the social environment influencing both disease risk and lethality. Angiogenesis, the process of new blood vessel formation, plays a critical role in tumor progression and metastasis. However, the germline genetic contribution to the physiological variation in levels of circulating angiogenic markers, and the angiogenic process, is largely unknown. This study aims to explore the genetic underpinnings of angiogenesis in prostate cancer patients through a protein quantitative trait loci (pQTL) analysis. We analyzed 30 blood-based angiogenesis-related immuno-oncology markers in a cohort of 2,437 men from Ghana and the United States, comprising 1,330 controls and 1,107 prostate cancer cases. A comprehensive evaluation of 4,301,332 single nucleotide polymorphisms (SNPs) was conducted to investigate their associations with these markers across 3 population groups (Ghanaian, African American, and European American men). In this genome-wide pQTL we identified loci that associated with the levels of 13 markers (p <1.2 x 10-9). Our findings reveal that germline genetic variants may contribute to the variability in circulating angiogenic marker levels, or the systemic angiogenesis-inducing potential, with specific loci showing population-specific associations. We further link these circulating angiogenic markers to prostate cancer disease characteristics. Thus, our results suggest that germline genetic factors influence circulating levels of circulating angiogenesis-related proteins and thereby systemic angiogenesis, with a relationship to prostate cancer. Citation Format: Ashlie Santaliz Casiano, Hunter Schaumloffel, Huaitian Liu, Brittany Jenkins-Lord, Tsion Minas, Tiffany Dorsey, Stefan Ambs. Protein quantitative trait loci analysis in diverse prostate cancer patients: A focus on angiogenesis [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A035.

The Impact of Potent Addictive Substances on Angiogenic Behavior: A Comprehensive Review.

Angiogenesis, the formation of new vasculature from preexisting vasculature, is involved in the development of several diseases as well as various physiological processes. Strict cooperation of proangiogenic and antiangiogenic factors mediates the control of angiogenesis. The fundamental steps in angiogenesis include endothelial cell proliferation, migration, and invasion. Addictive substances, which are considered therapeutic candidates in research and medicine, are classified as natural substances, such as nicotine, or synthetic substances, such as synthetic cannabinoids. Addictive substances have been shown to either enhance or suppress angiogenesis. This review article provides an overview of recent studies concerning the effects of several addictive substances on the process of angiogenesis. Google Scholar and PubMed were used to collect the scientific literature used in this review. The addictive substances addressed in this review are nicotine, opioids such as morphine and heroin, alcohol, cocaine, methamphetamine, and cannabinoids. An accurate assessment of the influence of these substances on the angiogenic process may help to construct a potentially effective therapeutic protocol to control and treat several angiogenesis-related diseases.

Telencephalic stab wound injury induces regenerative angiogenesis and neurogenesis in zebrafish: unveiling the role of vascular endothelial growth factor signaling and microglia.

After brain damage, regenerative angiogenesis and neurogenesis have been shown to occur simultaneously in mammals, suggesting a close link between these processes. However, the mechanisms by which these processes interact are not well understood. In this work, we aimed to study the correlation between angiogenesis and neurogenesis after a telencephalic stab wound injury. To this end, we used zebrafish as a relevant model of neuroplasticity and brain repair mechanisms. First, using the Tg(fli1:EGFP × mpeg1.1:mCherry) zebrafish line, which enables visualization of blood vessels and microglia respectively, we analyzed regenerative angiogenesis from 1 to 21 days post-lesion. In parallel, we monitored brain cell proliferation in neurogenic niches localized in the ventricular zone by using immunohistochemistry. We found that after brain damage, the blood vessel area and width as well as expression of the fli1 transgene and vascular endothelial growth factor (vegfaa and vegfbb) were increased. At the same time, neural stem cell proliferation was also increased, peaking between 3 and 5 days post-lesion in a manner similar to angiogenesis, along with the recruitment of microglia. Then, through pharmacological manipulation by injecting an anti-angiogenic drug (Tivozanib) or Vegf at the lesion site, we demonstrated that blocking or activating Vegf signaling modulated both angiogenic and neurogenic processes, as well as microglial recruitment. Finally, we showed that inhibition of microglia by clodronate-containing liposome injection or dexamethasone treatment impairs regenerative neurogenesis, as previously described, as well as injury-induced angiogenesis. In conclusion, we have described regenerative angiogenesis in zebrafish for the first time and have highlighted the role of inflammation in this process. In addition, we have shown that both angiogenesis and neurogenesis are involved in brain repair and that microglia and inflammation-dependent mechanisms activated by Vegf signaling are important contributors to these processes. This study paves the way for a better understanding of the effect of Vegf on microglia and for studies aimed at promoting angiogenesis to improve brain plasticity after brain injury.

VEGFA gene variants are associated with breast cancer progression.

Angiogenesis is recognized as a hallmark of cancer, and vascular endothelial growth factor (VEGF) is a key regulator of the angiogenic process and is related to cancer progression. Anti-VEGF therapy has been tried but with limited success and without useful stratification for angiogenesis markers. Further, the landscape of VEGF single nucleotide polymorphisms (SNPs) in breast cancer and their clinical relevance is not well studied, and their relation to tissue-based angiogenesis markers has not been explored. Here, we studied a selection of VEGFA SNPs in nontumor lymph nodes from a population-based breast cancer cohort (n = 544), and their relation to clinicopathologic variables, vascular tissue metrics, and breast cancer-specific survival. Two of the SNP candidates (rs833068GA genotype and rs25648CC genotype) showed associations with angiogenesis tissue markers, and the VEGFA rs833068GA genotype was associated with breast cancer-specific survival among ER-negative cases. We also found trends of association between the rs699947CA genotype and large tumor diameter and ER-negative tumors, and between the rs3025039CC genotype and large tumor diameter. Our findings indicate some associations between certain VEGF SNPs, in particular the rs833068GA genotype, and both vascular metrics and patient survival. These findings and their potential implications need to be validated by independent studies.

Characterization of the Secretome from Spheroids of Adipose-Derived Stem Cells (SASCs) and Its Potential for Tissue Regeneration.

Spheroids are spherical aggregates of cells that mimic the three-dimensional (3D) architecture of tissues more closely than traditional two dimensional (2D) cultures. Spheroids of adipose stem cells (SASCs) show special features such as high multilineage differentiation potential and immunomodulatory activity. These properties have been attributed to their secreted factors, such as cytokines and growth factors. Moreover, a key role is played by the extracellular vesicles (EVs), which lead a heterogeneous cargo of proteins, mRNAs, and small RNAs that interfere with the pathways of the recipient cells. The aim of this work was to characterize the composition of the secretome and exosome from SASCs and evaluate their regenerative potential. SASCs were extracted from adipose samples of healthy individuals after signing informed consent. The exosomes were isolated and characterized by Dinamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), and Western blotting analyses. The expression of mRNAs and miRNAs were evaluated through real-time PCR. Lastly, a wound-healing assay was performed to investigate their regenerative potential on different cell cultures. The SASCs' exosomes showed an up-regulation of NANOG and SOX2 mRNAs, typical of stemness maintenance, as well as miR126 and miR146a, related to angiogenic and osteogenic processes. Moreover, the exosomes showed a regenerative effect. The SASCs' secretome carried paracrine signals involved in stemness maintenance, pro-angiogenic and pro-osteogenic differentiation, immune system regulation, and regeneration.

Synthesis and biological evaluation of novel 3,6- amide and thioamide substituted- 2,3,4,9-tetrahydro-1H-carbazoles for anti-cancer activity

Herein, we report the synthesis of new compounds with demonstrated anticancer properties based on the 2,3,4,9-tetrahydro-1H-carbazole scaffold. The Fischer indolization method was used to close the heterocyclic motif. The synthesis method's scope and limitations were thoroughly assessed through a series of experiments. Biological assays revealed that two thioamide compounds exhibited significant anticancer activity against MCF-7, HTC116, and A596 cell lines. Comprehensive in vitro profiling included evaluation of cell cytotoxicity, morphological alterations, colony formation and cell adhesion in 3D cultures, cell cycle analysis, DNA damage induction, impact on mitochondria, and apoptosis. Ex ovo studies further demonstrated these compounds' potential to inhibit angiogenic processes. Our results indicate that the newly developed compounds activate processes leading to DNA damage and disruption of mitochondrial function.

Mn2+ vs Co2+ substitution into β-TCP: Structural details and bone cells response

This work investigated the range of substitution of two biologically relevant ions, namely Mn2+ and Co2+, into the structure of β-tricalcium phosphate, as well as their influence on bone cells response. To this aim, β-TCP was synthesized by solid state reaction in the presence of increasing amount of the substituent ions. The results of the X-ray diffraction analysis reveal that just limited amounts of these ions can enter into the β-TCP structure: 15 at% and 20 at% for cobalt and manganese, respectively. Substitution provokes aggregation of the micrometric particles and reduction of the lattice constants. In particular, the dimension of the c-parameter exhibits a discontinuity at about 10 at% for both cations, although with different trend. Moreover, Rietveld refinement demonstrates a clear preference of both manganese and cobalt for the octahedral site (V). The influence of these ions on cell response was tested on osteoblast, osteoclast and endothelial cells. The results indicate that the presence of manganese promotes a good osteoblast viability, significantly enhances the expression of osteoblast key genes and the angiogenic process of endothelial cells, while inhibiting osteoclast resorption. At variance, osteoblast viability appears reduced in the presence of Co samples, on which osteoblast genes reach higher expression than on β-TCP just in a few cases. On the other hand, the results clearly show that cobalt significantly stimulates the angiogenic process and inhibits osteoclast resorption.

Exploring the Nexus of Steroidal Hormone Receptor, Uterine VEGF Expression and NADPH-d Interaction in Buffalo Uterus During Oestrous Cycle With Seasonal Variation.

The reproductive efficiency in buffalo is highly influenced by seasonal variability. Angiogenesis in the reproductive cycle is important for optimal physiological functioning of uterus. Estrogen receptor-α (ERα), vascular endothelial growth factor (VEGF) and reduced nicotinamide adenine dinucleotide phosphatase diaphorase (NADPH-d) are vital indicators for the uterine angiogenic process. This study was conducted to see the effect of season on the expression of different uterine angiogenic factors. Season wise (winter and summer) and phase wise (follicular and luteal), immune staining intensity of buffalo uterus was measured by calculating the optical density value (OD) for ERα and VEGF. Percentage of immuno-positive cell count for ERα was done. Histoenzymic NADPH-d expression was analysed. Expression of all these factors increased during follicular phase of oestrous cycle in order to support the angiogenesis; however, the expression was significantly lower (p ≤ 0.05) in term of OD value as well as percentage count of immuno-positive cells during summer season indicating lower angiogenic activity that subsequently affected reproduction in buffalo.

Spatial Transcriptome Mapping of the Desmoplastic Growth Pattern of Colorectal Liver Metastases by In Situ Sequencing Reveals a Biologically Relevant Zonation of the Desmoplastic Rim.

We describe the fibrotic rim formed in the desmoplastic histopathologic growth pattern (DHGP) of colorectal cancer liver metastasis (CLM) using in situ sequencing (ISS). The origin of the desmoplastic rim is still a matter of debate, and the detailed cellular organization has not yet been fully elucidated. Understanding the biology of the DHGP in CLM can lead to targeted treatment and improve survival. We used ISS, targeting 150 genes, to characterize the desmoplastic rim by unsupervised clustering of gene coexpression patterns. The cohort comprised 10 chemo-naïve liver metastasis resection samples with a DHGP. Unsupervised clustering of spatially mapped genes revealed molecular and cellular diversity within the desmoplastic rim. We confirmed the presence of the ductular reaction and cancer-associated fibroblasts. Importantly, we discovered angiogenesis and outer and inner zonation in the rim, characterized by nerve growth factor receptor and periostin expression. ISS enabled the analysis of the cellular organization of the fibrous rim surrounding CLM with a DHGP and suggests a transition from the outer part of the rim, with nonspecific liver injury response, into the inner part, with gene expression indicating collagen synthesis and extracellular matrix remodeling influenced by the interaction with cancer cells, creating a cancer cell-supportive environment. Moreover, we found angiogenic processes in the rim. Our results provide a potential explanation of the origin of the rim in DHGP and lead to exploring novel targeted treatments for patients with CLM to improve survival.

Multiomics unveils extracellular vesicle-driven mechanisms of endothelial communication in human carotid atherosclerosis.

Background: Carotid atherosclerosis is orchestrated by cell-cell communication that drives progression along a clinical continuum (asymptomatic to symptomatic). Extracellular vesicles (EVs) are cell-derived nanoparticles representing a new paradigm in cellular communication. Little is known about their biological cargo, cellular origin/destination, and functional roles in human atherosclerotic plaque. Methods: EVs were enriched via size exclusion chromatography from human carotid endarterectomy samples dissected into paired plaque and marginal zones (symptomatic n=16, asymptomatic n=13). EV cargos were assessed via whole transcriptome miRNA sequencing and mass spectrometry-based proteomics. EV multi-omics were integrated with bulk and single cell RNA-sequencing (scRNA-seq) datasets to predict EV cellular origin and ligand-receptor interactions, and multi-modal biological network integration of EV-cargo was completed. EV functional impact was assessed with endothelial angiogenesis assays. Results: Carotid plaques contained more EVs than adjacent marginal zones, with differential enrichment for EV-miRNAs and EV-proteins in key atherogenic pathways. EV cellular origin analysis suggested that tissue EV signatures originated from endothelial cells (EC), smooth muscle cells (SMC), and immune cells. Integrated tissue vesiculomics and scRNA-seq indicated complex EV-vascular cell communication that changed with disease progression and plaque vulnerability (i.e., symptomatic disease). Plaques from symptomatic patients, but not asymptomatic patients, were characterized by increased involvement of endothelial pathways and more complex ligand-receptor interactions, relative to their marginal zones. Plaque-EVs were predicted to mediate communication with ECs. Pathway enrichment analysis delineated an endothelial signature with roles in angiogenesis and neovascularization - well-known indices of plaque instability. This was validated functionally, wherein human carotid symptomatic plaque EVs induced sprouting angiogenesis in comparison to their matched marginal zones. Conclusion: Our findings indicate that EVs may drive dynamic changes in plaques through EV- vascular cell communication and effector functions that typify vulnerability to rupture, precipitating symptomatic disease. The discovery of endothelial-directed angiogenic processes mediated by EVs creates new therapeutic avenues for atherosclerosis.

TMEM16F scramblase regulates angiogenesis via endothelial intracellular signaling.

TMEM16F (also known as ANO6), a Ca2+-activated lipid scramblase (CaPLSase) that dynamically disrupts lipid asymmetry, plays a crucial role in various physiological and pathological processes, such as blood coagulation, neurodegeneration, cell-cell fusion and viral infection. However, the mechanisms through which it regulates these processes remain largely elusive. Using endothelial cell-mediated angiogenesis as a model, here we report a previously unknown intracellular signaling function of TMEM16F. We demonstrate that TMEM16F deficiency impairs developmental retinal angiogenesis in mice and disrupts angiogenic processes in vitro. Biochemical analyses indicate that the absence of TMEM16F enhances the plasma membrane association of activated Src kinase. This in turn increases VE-cadherin phosphorylation and downregulation, accompanied by suppressed angiogenesis. Our findings not only highlight the role of intracellular signaling by TMEM16F in endothelial cells but also open new avenues for exploring the regulatory mechanisms for membrane lipid asymmetry and their implications in disease pathogenesis.

Synthesis, Radiolabeling, and Biodistribution Study of a Novel DOTA-Peptide for Targeting Vascular Endothelial Growth Factor Receptors in the Molecular Imaging of Breast Cancer.

As angiogenesis plays a pivotal role in tumor progression and metastasis, leading to more cancer-related deaths, the angiogenic process can be considered as a target for diagnostic and therapeutic applications. The vascular endothelial growth factor receptor-1 (VEGR-1) and VEGFR-2 have high expression on breast cancer cells and contribute to angiogenesis and tumor development. Thus, early diagnosis through VEGFR-1/2 detection is an excellent strategy that can significantly increase a patient's chance of survival. In this study, the VEGFR1/2-targeting peptide VGB3 was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), using 6-aminohexanoic acid (Ahx) as a spacer to prevent steric hindrance in binding. DOTA-Ahx-VGB3 was radiolabeled with Gallium-68 (68Ga) efficiently. An in vitro cell binding assay was assessed in the 4T1 cell line. The tumor-targeting potential of [68Ga]Ga-DOTA-Ahx-VGB3 was conducted for 4T1 tumor-bearing mice. Consequently, high radiochemical purity [68Ga]Ga-DOTA-Ahx-VGB3 (RCP = 98%) was prepared and stabilized in different buffer systems. Approximately 17% of the radiopeptide was internalized after 2 h incubation and receptor binding as characterized by the IC50 value being about 867 nM. The biodistribution and PET/CT studies revealed that [68Ga]Ga-DOTA-Ahx-VGB3 reached the tumor site and was excreted rapidly by the renal system. These features convey [68Ga]Ga-DOTA-Ahx-VGB3 as a suitable agent for the noninvasive visualization of VEGFR-1/2 expression.

Recent Insights into Cellular and Molecular Mechanisms of Defective Angiogenesis in Systemic Sclerosis.

In systemic sclerosis (SSc, or scleroderma), defective angiogenesis, clinically manifesting with abnormal capillary architecture and severe capillary reduction, represents a hallmark of early-stage disease, usually preceding the onset of tissue fibrosis, and is caused by several cellular and molecular mechanisms affecting microvascular endothelial cells with different outcomes. Indeed, once damaged, endothelial cells can be dysfunctionally activated, thus becoming unable to undergo angiogenesis and promoting perivascular inflammation. They can also undergo apoptosis, transdifferentiate into profibrotic myofibroblasts, or acquire a senescence-associated secretory phenotype characterized by the release of exosomes and several profibrotic and proinflammatory mediators. In this narrative review, we aimed to give a comprehensive overview of recent studies dealing with the cellular and molecular mechanisms underlying SSc defective angiogenesis and the related endothelial cell dysfunctions, mainly the endothelial-to-mesenchymal transition process. We also discussed potential novel vascular treatment strategies able to restore the angiogenic process and reduce the endothelial-to-mesenchymal transition in this complex disease.

FDI-6 inhibits VEGF-B expression in metastatic breast cancer: a combined in vitro and in silico study

AbstractAngiogenesis is the process by which new blood vessels are formed to meet the oxygen and nutrient needs of tissues. This process is vitally important in many physiological and pathological conditions such as tumor growth, metastasis, and chronic inflammation. Although the relationship of FDI-6 compound with FOXM1 protein is well known in the literature, its relationship with angiogenesis is not adequately elucidated. This study investigates the relationship of FDI-6 with angiogenesis and vascular endothelial growth factor B (VEGF-B) protein expression alterations. Furthermore, the study aims to elucidate the in silico interaction of FDI-6 with the VEGFR1 protein, a key player in initiating the angiogenic process, which is activated through its binding with VEGF-B. Our results demonstrate a significant effect of FDI-6 on cell viability. Specifically, we determined that the IC50 value of FDI-6 in HUVEC cells after 24 h of treatment is 24.2 μM, and in MDA-MB-231 cells after 24 h of application, it is 10.8 μM. These findings suggest that the cytotoxic effect of FDI-6 varies depending on the cell type. In wound healing experiments, FDI-6 significantly suppressed wound closure in MDA-MB-231 cells but did not show a similar effect in HUVEC cells. This finding suggests FDI-6 may have potential cell-type-specific effects. Molecular docking studies reveal that FDI-6 exhibits a stronger interaction with the VEGFR1 protein compared to its inhibitor, a novel interaction not previously reported in the literature. Molecular dynamic simulation results demonstrate a stable interaction between FDI-6 and VEGFR1. This interaction suggests that FDI-6 might modulate mechanisms associated with angiogenesis. Our Western blot analysis results show regulatory effects of FDI-6 on the expression of the VEGF-B protein. We encourage exploration of FDI-6 as a potential therapeutic agent in pathological processes related to angiogenesis. In conclusion, this study provides a detailed examination of the relationship between FDI-6 and both the molecular interactions and protein expressions of VEGF-B. Our findings support FDI-6 as a potential therapeutic agent in pathological processes associated with angiogenesis.