Aberrant Angiogenesis Research Articles

Hypoxic Memory Mediates Prolonged Tumor-Intrinsic Type I Interferon Suppression to Promote Breast Cancer Progression.

Hypoxia is a common feature of many solid tumors due to aberrant proliferation and angiogenesis that is associated with tumor progression and metastasis. Most of the well-known hypoxia effects are mediated through hypoxia-inducible factors (HIF). Identification of the long-lasting effects of hypoxia beyond the immediate HIF-induced alterations could provide a better understanding of hypoxia-driven metastasis and potential strategies to circumvent it. Here, we uncovered a hypoxia-induced mechanism that exerts a prolonged effect to promote metastasis. In breast cancer patient-derived circulating tumor cell lines and common breast cancer cell lines, hypoxia downregulated tumor-intrinsic type I IFN signaling and its downstream antigen presentation (AP) machinery in luminal breast cancer cells, via both HIF-dependent and HIF-independent mechanisms. Hypoxia induced durable IFN/AP suppression in certain cell types that was sustained after returning to normoxic conditions, presenting a "hypoxic memory" phenotype. Hypoxic memory of IFN/AP downregulation was established by specific hypoxic priming, and cells with hypoxic memory had an enhanced ability for tumorigenesis and metastasis. Overexpression of IRF3 enhanced IFN signaling and reduced tumor growth in normoxic, but not hypoxic, conditions. The histone deacetylase inhibitor entinostat upregulated IFN targets and erased the hypoxic memory. These results point to a mechanism by which hypoxia facilitates tumor progression through a long-lasting memory that provides advantages for circulating tumor cells during the metastatic cascade. Significance: Long-term cellular memory of hypoxia leads to sustained suppression of tumor-intrinsic type I IFN signaling and the antigen presentation pathway that facilitates tumorigenesis and metastasis. See related commentary by Purdy and Ford, p. 3125.

Inflammasome activation aggravates choroidal neovascularization.

Inflammasome activation is implicated in diseases of aberrant angiogenesis such as age-related macular degeneration (AMD), though its precise role in choroidal neovascularization (CNV), a characteristic pathology of advanced AMD, is ill-defined. Reports on inhibition of inflammasome constituents on CNV are variable and the precise role of inflammasome in mediating pathological angiogenesis is unclear. Historically, subretinal injection of inflammasome agonists alone has been used to investigate retinal pigmented epithelium (RPE) degeneration, while the laser photocoagulation model has been used to study pathological angiogenesis in a model of CNV. Here, we report that the simultaneous introduction of any of several disease-relevant inflammasome agonists (Alu or B2 RNA, Alu cDNA, or oligomerized amyloid β (1-40)) exacerbates laser-induced CNV. These activities were diminished or abrogated by genetic or pharmacological targeting of inflammasome signaling constituents including P2rx7, Nlrp3, caspase-1, caspase-11, and Myd88, as well as in myeloid-specific caspase-1 knockout mice. Alu RNA treatment induced inflammasome activation in macrophages within the CNV lesion, and increased accumulation of macrophages in an inflammasome-dependent manner. Finally, IL-1β neutralization prevented inflammasome agonist-induced chemotaxis, macrophage trafficking, and angiogenesis. Collectively, these observations support a model wherein inflammasome stimulation promotes and exacerbates CNV and may be a therapeutic target for diseases of angiogenesis such as neovascular AMD.

Unveiling impaired vascular function and cellular heterogeneity in diabetic donor-derived vascular organoids.

Vascular organoids (VOs), derived from induced pluripotent stem cells (iPSCs), hold promise as in vitro disease models and drug screening platforms. However, their ability to faithfully recapitulate human vascular disease and cellular composition remains unclear. In this study, we demonstrate that VOs derived from iPSCs of donors with diabetes (DB-VOs) exhibit impaired vascular function compared to non-diabetic VOs (ND-VOs). DB-VOs display elevated levels of reactive oxygen species (ROS), heightened mitochondrial content and activity, increased proinflammatory cytokines, and reduced blood perfusion recovery in vivo. Through comprehensive single-cell RNA sequencing, we uncover molecular and functional differences, as well as signaling networks, between vascular cell types and clusters within DB-VOs. Our analysis identifies major vascular cell types (endothelial cells [ECs], pericytes, and vascular smooth muscle cells) within VOs, highlighting the dichotomy between ECs and mural cells. We also demonstrate the potential need for additional inductions using organ-specific differentiation factors to promote organ-specific identity in VOs. Furthermore, we observe basal heterogeneity within VOs and significant differences between DB-VOs and ND-VOs. Notably, we identify a subpopulation of ECs specific to DB-VOs, showing overrepresentation in the ROS pathway and underrepresentation in the angiogenesis hallmark, indicating signs of aberrant angiogenesis in diabetes. Our findings underscore the potential of VOs for modeling diabetic vasculopathy, emphasize the importance of investigating cellular heterogeneity within VOs for disease modeling and drug discovery, and provide evidence of GAP43 (neuromodulin) expression in ECs, particularly in DB-VOs, with implications for vascular development and disease.

Eucalyptol Ameliorates Retinal Microvascular Defects through Modulating ER Stress and Angiopoietin-Tie Signaling in Diabetic Eyes.

Loss of the inner blood-retinal barrier (BRB) integrity is a main feature of ocular diseases such as diabetic macular edema. However, there is a lack of clarity on how inner BRB function is modulated within the diabetic retina. The current study examined whether eucalyptol inhibited inner BRB destruction and aberrant retinal angiogenesis in 33 mM glucose-exposed human retinal microvascular endothelial (RVE) cells and db/db mice. This study further examined the molecular mechanisms underlying endothelial dysfunction including retinal endoplasmic reticulum (ER) stress and angiopoietin (Ang)/Tie axis in conjunction with vascular endothelial growth factor (VEGF). Eucalyptol is a naturally occurring monoterpenoid and an achiral aromatic component of many plants including eucalyptus leaves. Nontoxic eucalyptol reduced the production of amyloid-β (Aβ) protein in glucose-loaded RVE cells and in diabetic mice. This natural compound blocked apoptosis of Aβ-exposed RVE cells in diabetic mouse eyes by targeting ER stress via the inhibition of PERK-eIF2α-ATF4-CHOP signaling. Eucalyptol promoted activation of the Ang-1/Tie-2 pathway and dual inhibition of Ang-2/VEGF in Aβ-exposed RVE cells and in diabetic eyes. Supply of eucalyptol reversed the induction of junction proteins in glucose/Aβ-exposed RVE cells within the retina and reduced permeability. In addition, oral administration of eucalyptol reduced vascular leaks in diabetic retinal vessels. Taken together, these findings clearly show that eucalyptol inhibits glucose-induced Aβ-mediated ER stress and manipulates Ang signaling in diabetic retinal vessels, which ultimately blocks abnormal angiogenesis and loss of inner BRB integrity. Therefore, eucalyptol provides new treatment strategies for diabetes-associated RVE defects through modulating diverse therapeutic targets including ER stress, Ang-1/Tie-2 signaling, and Ang-2/VEGF.

Analyzing VEGFA/VEGFR1 Interaction: Application of the Resonant Recognition Model-Stockwell Transform Method to Explore Potential Therapeutics for Angiogenesis-Related Diseases.

The interaction between vascular endothelial growth factor A (VEGFA) and VEGF receptor 1(VEGFR1) is a central focus for drug development in pathological angiogenesis, where aberrant angiogenesis underlies various anomalies necessitating therapeutic intervention. Identifying hotspots of these proteins is crucial for developing new therapeutics. Although machine learning techniques have succeeded significantly in prediction tasks, they struggle to pinpoint hotspots linked to angiogenic activity accurately. This study involves the collection of diverse VEGFA and VEGFR1 protein sequences from various species via the UniProt database. Electron-ion interaction Potential (EIIP) values were assigned to individual amino acids and transformed into frequency-domain representations using discrete Fast Fourier Transform (FFT). A consensus spectrum emerged by consolidating FFT data from multiple sequences, unveiling specific characteristic frequencies. Subsequently, the Stockwell Transform (ST) was employed to yield the hotspots. The Resonant Recognition Model (RRM) identified a characteristic frequency of 0.128007 with an associated wavelength of 1570nm and RRM-ST identified hotspots for VEGFA (Human 36, 46, 48, 67, 71, 74, 82, 86, 89, 93) and VEGFR1 (Human 224, 259, 263, 290, 807, 841, 877, 881, 885, 892, 894, 909, 913, 1018, 1022, 1026, 1043). These findings were cross-validated by Hotspots Wizard 3.0 webserver and Protein Data Bank (PDB). The study proposes using a 1570nm wavelength for photo bio modulation to boost VEGFA/VEGFR1 interaction in the condition that is needed. It also aims to reduce VEGFA/VEGFR2 interaction, limiting harmful angiogenesis in conditions like diabetic retinopathy. Also, the identified hotspots assist in designing agonistic or antagonistic peptides tailored to specific medical requirements with abnormal angiogenesis.

Exploitation of enhanced prime editing for blocking aberrant angiogenesis

IntroductionAberrant angiogenesis plays an important part in the development of a variety of human diseases including proliferative diabetic retinopathy, with which there are still numerous patients remaining a therapeutically challenging condition. Prime editing (PE) is a versatile gene editing approach, which offers a novel opportunity to genetically correct challenging disorders. ObjectivesThe goal of this study was to create a dominant-negative (DN) vascular endothelial growth factor receptor (VEGFR) 2 by editing genomic DNA with an advanced PE system to block aberrant retinal angiogenesis in a mouse model of oxygen-induced retinopathy. MethodsAn advanced PE system (referred to as PE6x) was established within two lentiviral vectors, with one carrying an enhanced PE guide RNA and a canonical Cas9 nickase fused with an optimized reversal transcriptase, and the other conveying a nicking guide RNA and a DN-MLH1 to improve PE efficiency. Dual non-integrating lentiviruses (NILVs) produced with the two lentiviral PE6x vectors were then employed to create a mutation of VEGFR2 T17967A by editing the Mus musculus VEGFR2 locus in vitro and in vivo, leading to generation of a premature stop codon (TAG, K796stop) to produce DN-VEGFR2, to interfere with the wild type VEGFR2 which is essential for angiogenesis. ResultsNILVs targeting VEGFR2 delivered into cultured murine vascular endothelial cells led to 51.06 % VEGFR2 T17967A in the genome analyzed by next generation sequencing and the production of DN-VEGFR2, which was found to hamper VEGF-induced VEGFR2 phosphorylation, as demonstrated by Western blot analysis. Intravitreally injection of the dual NILVs into postnatal day 12 mice in a model of oxygen-induced retinopathy, led to production of retinal DN-VEGFR2 in postnatal day 17 mice which blocked retinal VEGFR2 expression and activation as well as abnormal retinal angiogenesis without interfering with retinal structure and function, as assessed by electroretinography, optical coherence tomography, fundus fluorescein angiography and histology. ConclusionDN-VEGFR2 resulted from editing genomic VEGFR2 using the PE6x system can be harnessed to treat intraocular pathological angiogenesis.

CircHIPK3/miR-124 affects angiogenesis in early-onset preeclampsia via CPT1A-mediated fatty acid oxidation.

Multiple theories have been proposed to explain the pathogenesis of early-onset preeclampsia (EOPE), and angiogenic dysfunction is an important part of this pathogenesis. Carnitine palmitoyltransferase (CPT1A) is a key rate-limiting enzyme in the metabolic process of fatty acid oxidation (FAO). FAO regulates endothelial cell (EC) proliferation during vascular germination and is also essential for ab initio deoxyribonucleotide synthesis, but its role in EOPE needs to be further elucidated. In the present study, we investigated its functional role in EOPE by targeting the circHIPK3/miR-124-3p/CPT1A axis. In our study, reduced expression of circHIPK3 and CPT1A and increased expression of miR-124-3p in placental tissues from patients with EOPE were associated with EC dysfunction. Here, we confirmed that CPT1A regulates fatty acid oxidative activity, cell proliferation, and tube formation in ECs by regulating FAO. Functionally, knockdown of circHIPK3 suppressed EC angiogenesis by inhibiting CPT1A-mediated fatty acid oxidative activity, which was ameliorated by CPT1A overexpression. In addition, circHIPK3 regulates CPT1A expression by sponging miR-124-3p. Hence, circHIPK3 knockdown reduced fatty acid oxidation in ECs by sponging miR-124-3p in a CPT1A-dependent manner and inhibited EC proliferation and tube formation, which may have led to aberrant angiogenesis in EOPE. Thus, strategies targeting CPT1A-driven FAO may be promising approaches for the treatment of EOPE. KEY MESSAGES: Decreased Carnitine palmitoyltransferase (CPT1A) expression in preeclampsia(PE). CPT1A overexpression promotes FAO activity and tube formation in ECs. CircHIPK3 can affect CPT1A expression and impaire angiogenesis of EOPE. CircHIPK3 regulates CPT1A expression by acting as a ceRNA of miR-124-3p in HUVECs. Confirming the effect of circHIPK3/miR-124-3p/CPT1A axis on EOPE.

Enhancing angiogenesis and inhibiting apoptosis: evaluating the therapeutic efficacy of bone marrow mesenchymal stem cell-derived exosomes in a DHEA-induced PCOS mouse model

BackgroundPolycystic Ovary Syndrome (PCOS) is a widespread endocrine disorder among women, characterized by symptoms like ovarian cysts, hormonal imbalance, and metabolic issues. This research evaluates the therapeutic potential of Bone Marrow Mesenchymal Stem Cell-derived exosomes (BMSC-Exo) in treating PCOS symptoms within a mouse model.MethodsBMSC-Exo were isolated from NMRI mice, characterized using Transmission Electron Microscopy (TEM) and Nanoparticle Tracking Analysis (NTA), and administered to a PCOS mouse model induced by dehydroepiandrosterone (DHEA). The efficacy of BMSC-Exo was assessed in three groups of mice: a control group, a PCOS group, and a PCOS group treated with intravenous BMSC-Exo. Morphological changes in ovarian tissue were examined by Hematoxylin and Eosin (H&E) staining, apoptosis was determined using the TUNEL assay, and CD31 expression was analyzed through immunofluorescent staining to assess angiogenic activity.ResultsThe existence of BMSCs-Exo was confirmed via TEM and NTA, revealing their distinct cup-shaped morphology and a size range of 30 to 150 nanometers. H&E staining revealed that BMSCs-Exo treatment improved ovarian morphology in PCOS models, increasing corpora lutea and revitalizing granulosa cell layers, suggesting a reversal of PCOS-induced damage. TUNEL assays showed that BMSCs-Exo treatment significantly reduced apoptosis in PCOS-affected ovarian cells to levels comparable with the control group, highlighting its role in mitigating PCOS-induced cellular apoptosis. Immunofluorescence for CD31 indicated that BMSCs-Exo treatment normalized endothelial marker expression and angiogenic activity in PCOS models, suggesting its effectiveness in modulating the vascular irregularities of PCOS. Collectively, these findings demonstrate the therapeutic potential of BMSCs-Exo in addressing ovarian dysfunction, cellular apoptosis, and aberrant angiogenesis associated with PCOS.ConclusionThe study substantiates the role of BMSC-Exo in mitigating the deleterious effects of PCOS on ovarian tissue, with implications for enhanced follicular development and reduced cellular stress. The modulation of CD31 by BMSC-Exo further highlights their potential in normalizing PCOS-induced vascular anomalies. These findings propel the need for clinical investigations to explore BMSC-Exo as a promising therapeutic avenue for PCOS management.

#1479 Single nucleus RNA-sequencing indicates functional heterogeneity of renal endothelial cells in chronic kidney disease

Abstract Background and Aims The burden of cardiovascular disease (CVD) in patients with chronic kidney disease (CKD) remains very high. Endothelial cell (EC) dysfunction is an important key player in the initiation and progression of both pathologies. More importantly, endothelial dysfunction occurs early in both disease courses and is potentially reversible, making it a promising target for effective preventive strategies. Recently, accumulating single-cell RNA sequencing-based evidence has highlighted EC heterogeneity in different pathophysiological contexts. However, while biological processes such as systemic inflammation, oxidative stress fibrosis are being defined as comm EC in CKD and CVD, a comprehensive understanding of at single-cell resolution is lacking. Here, we characterized renal EC subpopulations by single-nucleus RNA sequencing (snRNA-seq) to investigate alterations in CKD patients healthy controls and identify potential drivers of EC dysfunction in CKD. Method Droplet-based snRNA-seq (10X Genomics Chromium) was performed on cryopreserved kidney biopsy cores from 6 human patients with CKD (eGFR < 45 mL/min/1.73 m2) and 3 healthy controls. CKD patients included 2 patients with primary focal segmental glomerulosclerosis (FSGS) and 4 with secondary/maladaptive FSGS (2 patients with diabetes mellitus, 2 female patients in total); all patients had a Framingham 10-year cardiovascular risk score > 20, but no established CVD. Healthy control samples were pre-perfusion biopsies from patients undergoing living kidney donation (including 2 female patients). EC subclusters were annotated based on the expression of canonical EC marker genes. Differential gene expression analysis for patient samples vs. controls included all ECs and DEGs were filtered for log2FC > 0.25 or < −0.25 and adjusted P-value of < .05. Gene set enrichment analysis (GSEA) on the identified DEGs was performed using GO terms. Results A total of 4 081 ECs were present in the dataset, consisting of 5 EC subtypes in both the patient and control cohorts (Panel A). DEGs in CKD patients vs. controls included upregulated genes related to organogenesis and cell differentiation (MEF2C, MEIS2), vascular development (FLRT2), and angiogenesis regulators (VEGFC, PRCP, HDAC9) (Panel B). Notably, VEGFC and FLRT2, are involved in directing EC motility and vascular patterning. In accordance, GSEA showed enrichment for GO biological processes related to vascular endothelial growth factor signaling pathway, endothelial cell differentiation, endothelial development, regulation of angiogenesis, and endothelial cell migration (Panel C). This suggests a potential link between these genes and aberrant angiogenesis, analogous to previous findings in diabetic nephropathy. Some but not all of these changes were also reported for renal ECs of early diabetic nephropathy patients. Of note, the majority of patients studied in our cohort were non-diabetic, warranting further investigation into renal endothelial cell transcriptional alterations that are general to renal disease or specific to particular renal conditions such as diabetic nephropathy. Differential gene expression and GSEA analysis of the EC subclusters in CKD indicated involvement of the peritubular capillary and ascending vasa recta ECs in EC migration / angiogenesis-related responses, overlapping with the overall analysis described above. Glomerular capillary ECs showed upregulation of immune-related genes and processes, reflecting the inflammatory status of the kidney disease. Conclusion snRNA-seq analysis revealed heterogeneity and subtype-specific gene expression alterations of renal ECs from CKD patients compared to healthy controls. Differential functions include enhanced angiogenic (potentially compensatory) and immune-related responses. These findings suggest that specific biological functions may direct different roles of the renal EC subtypes in CKD and will be further validated for their cluster-specificity and for their therapeutic relevance.

Advances in Anti-Cancer Drug Development: Metformin as Anti-Angiogenic Supplemental Treatment for Glioblastoma.

According to the WHO 2016 classification, glioblastoma is the most prevalent primary tumor in the adult central nervous system (CNS) and is categorized as grade IV. With an average lifespan of about 15 months from diagnosis, glioblastoma has a poor prognosis and presents a significant treatment challenge. Aberrant angiogenesis, which promotes tumor neovascularization and is a prospective target for molecular target treatment, is one of its unique and aggressive characteristics. Recently, the existence of glioma stem cells (GSCs) within the tumor, which are tolerant to chemotherapy and radiation, has been linked to the highly aggressive form of glioblastoma. Anti-angiogenic medications have not significantly improved overall survival (OS), despite various preclinical investigations and clinical trials demonstrating encouraging results. This suggests the need to discover new treatment options. Glioblastoma is one of the numerous cancers for which metformin, an anti-hyperglycemic medication belonging to the Biguanides family, is used as first-line therapy for type 2 diabetes mellitus (T2DM), and it has shown both in vitro and in vivo anti-tumoral activity. Based on these findings, the medication has been repurposed, which has shown the inhibition of many oncopromoter mechanisms and, as a result, identified the molecular pathways involved. Metformin inhibits cancer cell growth by blocking the LKB1/AMPK/mTOR/S6K1 pathway, leading to selective cell death in GSCs and inhibiting the proliferation of CD133+ cells. It has minimal impact on differentiated glioblastoma cells and normal human stem cells. The systematic retrieval of information was performed on PubMed. A total of 106 articles were found in a search on metformin for glioblastoma. Out of these six articles were Meta-analyses, Randomized Controlled Trials, clinical trials, and Systematic Reviews. The rest were Literature review articles. These articles were from the years 2011 to 2024. Appropriate studies were isolated, and important information from each of them was understood and entered into a database from which the information was used in this article. The clinical trials on metformin use in the treatment of glioblastoma were searched on clinicaltrials.gov. In this article, we examine and evaluate metformin's possible anti-tumoral effects on glioblastoma, determining whether or not it may appropriately function as an anti-angiogenic substance and be safely added to the treatment and management of glioblastoma patients.

Ang-1 and VEGF: central regulators of angiogenesis.

Angiopoietin-1 (Ang-1) and Vascular Endothelial Growth Factor (VEGF) are central regulators of angiogenesis and are often inactivated in various cardiovascular diseases. VEGF forms complexes with ETS transcription factor family and exerts its action by downregulating multiple genes. Among the target genes of the VEGF-ETS complex, there are a significant number encoding key angiogenic regulators. Phosphorylation of the VEGF-ETS complex releases transcriptional repression on these angiogenic regulators, thereby promoting their expression. Ang-1 interacts with TEK, and this phosphorylation release can be modulated by the Ang-1-TEK signaling pathway. The Ang-1-TEK pathway participates in the transcriptional activation of VEGF genes. In summary, these elements constitute the Ang-1-TEK-VEGF signaling pathway. Additionally, Ang-1 is activated under hypoxic and inflammatory conditions, leading to an upregulation in the expression of TEK. Elevated TEK levels result in the formation of the VEGF-ETS complex, which, in turn, downregulates the expression of numerous angiogenic genes. Hence, the Ang-1-dependent transcriptional repression is indirect. Reduced expression of many target genes can lead to aberrant angiogenesis. A significant overlap exists between the target genes regulated by Ang-1-TEK-VEGF and those under the control of the Ang-1-TEK-TSP-1 signaling pathway. Mechanistically, this can be explained by the replacement of the VEGF-ETS complex with the TSP-1 transcriptional repression complex at the ETS sites on target gene promoters. Furthermore, VEGF possesses non-classical functions unrelated to ETS and DNA binding. Its supportive role in TSP-1 formation may be exerted through the VEGF-CRL5-VHL-HIF-1α-VH032-TGF-β-TSP-1 axis. This review assesses the regulatory mechanisms of the Ang-1-TEK-VEGF signaling pathway and explores its significant overlap with the Ang-1-TEK-TSP-1 signaling pathway.

400 Brain AVMs-Related MicroRNAs: Machine Learning Algorithm for Expression Profiles of Target Genes

INTRODUCTION: microRNAs (miRNAs) are a class of non-coding RNAs playing a myriad of important roles in regulating gene expression. Of note, recent work demonstrated a critical role of miRNAs in the genesis and progression of brain arteriovenous malformations (bAVMs). METHODS: A PRISMA-based literature review was performed using PubMed/Medline database with the following search terms: "brain arteriovenous malformations", "cerebral arteriovenous malformations", "microRNA", and "miRNA". All preclinical and clinical studies written in English, regardless of date, were selected. For our bioinformatic analyses, miRWalk and miRTarBase machine learning algorithms were employed; the Kyoto Encyclopedia of Genes and Genomes (KEGG) database was quired for associated pathways/functions. RESULTS: 4 studies were ultimately included in the final analyses. Sequencing data consistently revealed the decreased expression of miR-18a in bAVM-endothelial cells, resulting in increased levels of vascular endodermal growth factor (VEGF), Id-1, matrix metalloproteinase, and growth signals. Our analyses also suggest that the downregulation of miR-137 and miR-195* within vascular smooth muscle cells (VSMCs) may foster the activation of inflammation, aberrant angiogenesis, and phenotypic switching. In the peripheral blood, the overexpression of miR-7-5p, miR-629-5p, miR-199a-5p, miR-200b-3p, and let-7b-5p may contribute to endothelial proliferation and nidus development. The machine learning algorithms employed confirmed associations between miRNA-related target networks, vascular rearrangement, and bAVM progression. CONCLUSIONS: miRNAs expression appears to be critical in managing bAVMs' post-transcriptional signals. Targets of microRNAs regulate canonical vascular proliferation and reshaping. Although additional scientific evidence is needed, the identification of bAVM miRNA signatures may facilitate the development of novel prognostic/diagnostic tools and molecular therapies for bAVMs.

Acceleration of moyamoya disease after anti-vascular endothelial growth factor intravitreal injections

Abstract: Moyamoya disease (MMD) is a rare, progressive, irreversible vaso-occlusive disease affecting the cerebral vasculature. The progressive occlusion of blood vessels leads to the development of collateral vessels to compensate for the insufficient blood supply. Some growth factors such as vascular endothelial growth factor (VEGF) may cause excessive and aberrant angiogenesis in MMD. We report a case of a 55-year-old male, following up in retina clinics for diabetic retinopathy and macular edema who received anti-VEGF agents then he presented to the emergency room with left-sided face and body weakness, dysphagia, and dysarthria. Based on his clinical presentation and neuroimaging, he was diagnosed with moyamoya progression. We hypothesize that receiving anti-VEGF agents could have contributed to MMD progression in our patient and interfered with the collateral vessel development in a similar manner to their intended use in regressing neovascularization in diabetic retinopathy.

α-Solanine attenuates chondrocyte pyroptosis to improve osteoarthritis via suppressing NF-κB pathway.

α-Solanine has been shown to exhibit anti-inflammatory and anti-tumour properties; however, its efficacy in treating osteoarthritis (OA) remains ambiguous. The study aimed to evaluate the therapeutic effects of α-solanine on OA development in a mouse OA model. The OA mice were subjected to varying concentrations of α-solanine, and various assessments were implemented to assess OA progression. We found that α-solanine significantly reduced osteophyte formation, subchondral sclerosis and OARSI score. And it decreased proteoglycan loss and calcification in articular cartilage. Specifically, α-solanine inhibited extracellular matrix degradation by downregulating collagen 10, matrix metalloproteinase 3 and 13, and upregulating collagen 2. Importantly, α-solanine reversed chondrocyte pyroptosis phenotype in articular cartilage of OA mice by inhibiting the elevated expressions of Caspase-1, Gsdmd and IL-1β, while also mitigating aberrant angiogenesis and sensory innervation in subchondral bone. Mechanistically, α-solanine notably hindered the early stages of OA progression by reducing I-κB phosphorylation and nuclear translocation of p65, thereby inactivating NF-κB signalling. Our findings demonstrate the capability of α-solanine to disrupt chondrocyte pyroptosis and sensory innervation, thereby improving osteoarthritic pathological progress by inhibiting NF-κB signalling. These results suggest that α-solanine could serve as a promising therapeutic agent for OA treatment.

Tanshinone IIA attenuates osteoarthritis via inhibiting aberrant angiogenesis in subchondral bone

Excessive angiogenesis in subchondral bone is a pathological feature of osteoarthritis (OA). Tanshinone IIA (TIIA), an active compound found in Salvia miltiorrhiza, demonstrates significant anti-angiogenic properties. However, the effect of TIIA on abnormal subchondral angiogenesis in OA is still unclear. This study aims to investigate the mechanism of TIIA in modulating subchondral bone angiogenesis during OA and assess its therapeutic potential in OA. Our findings demonstrate that TIIA attenuated articular cartilage degeneration, normalized subchondral bone remodeling, and effectively suppressed aberrant angiogenesis within subchondral bone in monosodium iodoacetate (MIA)-induced OA mice. Additionally, the angiogenesis capacity of primary CD31hiEmcnhi endothelial cells was observed to be significantly reduced after treatment with TIIA in vitro. Mechanically, TIIA diminished the proportion of hypertrophic chondrocytes, ultimately leading to a substantial reduction in the secretion of vascular endothelial growth factor A (VEGFA). The supernatant of hypertrophic chondrocytes promoted the tube formation of CD31hiEMCNhi endothelial cells, whereas TIIA inhibited this process. Furthermore, TIIA effectively suppressed the expression of vascular endothelial growth factor receptor 2 (VEGFR2) along with its downstream MAPK pathway in CD31hiEmcnhi endothelial cells. In conclusion, our data indicated that TIIA could effectively inhibit the abnormal angiogenesis in subchondral bone during the progression of OA by suppressing the VEGFA/VEFGR2/MAPK pathway. These findings significantly contribute to our understanding of the abnormal angiogenesis in OA and offer a promising therapeutic target for OA treatment.

Maternal exposure to dibutyl phthalate (DBP) impairs angiogenesis and AR signalling pathway through suppression of TGFB1I1 in hypospadias offspring

Early exposure to dibutyl phthalate (DBP) can cause hypospadias in newborn foetuses. However, the underlying molecular mechanism is not well defined. Aberrant angiogenesis is associated with various dysplasias including urogenital deficits. In vivo and in vitro angiogenesis assays showed reduced angiogenesis in the hypospadias group and DBP exposed group. RNA-sequencing analysis of DBP-treated HUVECs revealed decreased expression of transforming growth factor beta 1-induced transcript 1 (TGFB1I1) and a significantly enriched angiogenesis-associated pathway. Further experiments revealed that decreased TGFB1I1 expression was associated with disrupted tube formation and migration, which resulted in decreased angiogenesis. Functional assays revealed that the overexpression of TGFB1I1 promoted tube formation and migration of HUVECs in the DBP-treated group. Moreover, we showed that the transcription factor AR was regulated by TGFB1I1 through inhibiting its translocation from the cytoplasm to the nucleus. Together, our results identified TGFB1I1 as a component of aberrant angiogenesis in hypospadias rats and its interaction with AR might be a potential target for hypospadias development.

From traditional medicine to nanomedicine: potential of Ginkgo biloba extracts in treating inflammatory skin diseases.

The use of plant extracts as a potential cure for various conditions has moved from traditional medicine to evidence-based medicine. Skin diseases have been addressed since time immemorial using plant extracts through observational and traditional knowledge and passed on through generations. With the advent of modern techniques, the molecular mechanisms of action of plant extracts/isolates are being deciphered with more precision, and more nanomedicine-based therapies are being studied to improve their therapeutic efficacy and stability. The leaves and seeds of Ginkgo biloba (G. biloba), an ancient medicinal tree species, have been used in Chinese herbal medicine for thousands of years. G. biloba extracts have been widely studied as a neuroprotective and anti-ischaemic drug for ischaemia-reperfusion injuries in the heart, lungs, brain, kidneys, and other organs. However, the use of G. biloba can be accompanied with side effects and drug interactions. Although, there is now a growing interest for its use in skincare, the mechanisms of action of the extract are not fully understood and vital aspects of G. biloba, such as its neuroprotective and angiogenic properties contributing to the treatment of inflammatory skin diseases and skin ageing, are yet to be investigated. This review critically discusses the mechanisms of action of different constituents of G. biloba extracts linked to their potential interference in the molecular mechanisms underlying the pathogenesis of inflammatory skin diseases. In addition to its ability to act on oxidative stress, G. biloba can regulate angiogenesis through its compounds such as ginkgetin or ginkgolide K, which either inhibit aberrant angiogenesis in eczema/psoriasis or increase microcirculation during skin ageing. G. biloba may also contribute to the control of pruritus in atopic dermatitis via a neuroprotective and anti-inflammatory mechanism by suppressing JAK2/STAT3 signalling pathways. This review also highlights nanomedicine strategies to decrease the side effects and enhance the efficacy of the extracts. Similar strategies have been successfully used for anticancer molecules in targeted chemotherapy and iron delivery in anaemia treatment.

Unlocking Bevacizumab's Potential: rCBVmax as a Predictive Biomarker for Enhanced Survival in Glioblastoma IDH-Wildtype Patients.

Aberrant vascular architecture and angiogenesis are hallmarks of glioblastoma IDH-wildtype, suggesting that these tumors are suitable for antiangiogenic therapy. Bevacizumab was FDA-approved in 2009 following promising results in two clinical trials. However, its use for recurrent glioblastomas remains a subject of debate, as it does not universally improve patient survival. In this study, we aimed to analyze the influence of tumor vascularity on the benefit provided by BVZ and propose preoperative rCBVmax at the high angiogenic tumor habitat as a predictive biomarker to select patients who can benefit the most. Clinical and MRI data from 106 patients with glioblastoma IDH-wildtype have been analyzed. Thirty-nine of them received BVZ, and the remaining sixty-seven did not receive a second-line treatment. The ONCOhabitats method was used to automatically calculate rCBV. We found a median survival from progression of 305 days longer for patients with moderate vascular tumors who received BVZ than those who did not receive any second-line treatment. This contrasts with patients with high-vascular tumors who only presented a median survival of 173 days longer when receiving BVZ. Furthermore, better responses to BVZ were found for the moderate-vascular group with a higher proportion of patients alive at 6, 12, 18, and 24 months after progression. We propose rCBVmax as a potential biomarker to select patients who can benefit more from BVZ after tumor progression. In addition, we propose a threshold of 7.5 to stratify patients into moderate- and high-vascular groups to select the optimal second-line treatment.

TGF-β1 Inhibits Osteoclast Differentiation and Abnormal Angiogenesis in Intervertebral Disc Degeneration: Evidence from RNA Sequencing and Animal Studies.

Mechanisms involved in developing intervertebral disc degeneration (IDD) are poorly understood, thus making developing effective therapies difficult. This study aimed to suggest a possible molecular mechanism, based on transcriptome sequencing-identified transforming growth factor (TGF-β), underlying the effects on bone homeostasis in IDD. A mouse model for IDD was established. Transcriptome sequencing of nucleus pulposus tissue from mice (n = 3) identified differentially expressed mRNAs and key genes impacting bone homeostasis. A protein-protein interaction network pinpointed core genes. GO and KEGG analysis revealed gene functions. Expression levels of TGF-β1, tartrate-resistant acid phosphatase (TRAP), and cathepsin K (CTSK) were measured. Micro-CT evaluated vertebral structures and vascular imaging. Western Blot measured expression levels of Vegf, Opn, MMP3, and MMP13. Safranin O-Fast Green and TRAP staining were performed on intervertebral discs and endplates. Transcriptomic analysis found 1790 differentially expressed mRNAs in IDD mice. Twenty-eight genes related to bone homeostasis in IDD were identified. TGF-β1 was confirmed as the core gene. GO and KEGG showed TGF-β1 regulates osteoclast markers like CTSK and TRAP through pathways including NF-κB and MAPK. Experimental validation revealed lower TGF-β1 expression in IDD mice than controls, and increased TRAP and CTSK expression. Micro-CT showed decreased bone mass and intervertebral disc space in IDD mice. Vascular imaging showed increased vascular volume in IDD cartilaginous endplates. Western blot displayed increased VEGF and OPN levels, but decreased MMP3 and MMP13 in IDD mice. Safranin O-fast green staining revealed severe IDD degeneration. However, TGF-β1 injection improved bone parameters in IDD mice. In vitro experiments confirmed TGF-β1 inhibits bone marrow macrophages differentiation into osteoclasts. From our data, we conclude that TGF-β1 repressed osteoclast differentiation and aberrant bone-associated angiogenesis in cartilage endplates (EPs) to alleviate IDD, which may be instrumental for the therapeutic targeting of IDD.

Liver X receptor alpha ensures blood-brain barrier function by suppressing SNAI2

In Alzheimer’s disease (AD) more than 50% of the patients are affected by capillary cerebral amyloid-angiopathy (capCAA), which is characterized by localized hypoxia, neuro-inflammation and loss of blood-brain barrier (BBB) function. Moreover, AD patients with or without capCAA display increased vessel number, indicating a reactivation of the angiogenic program. The molecular mechanism(s) responsible for BBB dysfunction and angiogenesis in capCAA is still unclear, preventing a full understanding of disease pathophysiology. The Liver X receptor (LXR) family, consisting of LXRα and LXRβ, was reported to inhibit angiogenesis and particularly LXRα was shown to secure BBB stability, suggesting a major role in vascular function. In this study, we unravel the regulatory mechanism exerted by LXRα to preserve BBB integrity in human brain endothelial cells (BECs) and investigate its role during pathological conditions. We report that LXRα ensures BECs identity via constitutive inhibition of the transcription factor SNAI2. Accordingly, deletion of brain endothelial LXRα is associated with impaired DLL4-NOTCH signalling, a critical signalling pathway involved in vessel sprouting. A similar response was observed when BECs were exposed to hypoxia, with concomitant LXRα decrease and SNAI2 increase. In support of our cell-based observations, we report a general increase in vascular SNAI2 in the occipital cortex of AD patients with and without capCAA. Importantly, SNAI2 strongly associated with vascular amyloid-beta deposition and angiopoietin-like 4, a marker for hypoxia. In hypoxic capCAA vessels, the expression of LXRα may decrease leading to an increased expression of SNAI2, and consequently BECs de-differentiation and sprouting. Our findings indicate that LXRα is essential for BECs identity, thereby securing BBB stability and preventing aberrant angiogenesis. These results uncover a novel molecular pathway essential for BBB identity and vascular homeostasis providing new insights on the vascular pathology affecting AD patients.