Regulation Of Angiogenesis Research Articles

Immune changes in pregnancy: associations with pre-existing conditions and obstetrical complications at the 20th gestational week—a prospective cohort study

BackgroundPregnancy is a complex biological process and serious complications can arise when the delicate balance between the maternal and semi-allogeneic fetal immune systems is disrupted or challenged. Gestational diabetes mellitus (GDM), pre-eclampsia, preterm birth, and low birth weight pose serious threats to maternal and fetal health. Identification of early biomarkers through an in-depth understanding of molecular mechanisms is critical for early intervention.MethodsWe analyzed the associations between 47 proteins involved in inflammation, chemotaxis, angiogenesis, and immune system regulation, maternal and neonatal health outcomes, and the baseline characteristics and pre-existing conditions of the mother in a prospective cohort of 1049 pregnant women around the 20th gestational week. We used Bayesian linear regression models to examine the impact of risk factors on biomarker levels and Bayesian cause-specific parametric proportional hazards models to analyze the effect of biomarkers on maternal and neonatal outcomes. We evaluated the predictive value of baseline characteristics and 47 proteins using machine-learning models and identified the most predictive biomarkers using Shapley additive explanation scores.ResultsAssociations were identified between specific inflammatory markers and several conditions, including maternal age and pre-pregnancy body mass index, chronic diseases, complications from prior pregnancies, and COVID-19 exposure. Smoking during pregnancy affected GM-CSF and 9 other biomarkers. Distinct biomarker patterns were observed for different ethnicities. Within obstetric complications, IL-6 inversely correlated with pre-eclampsia risk, while birth weight to gestational age ratio was linked to markers including VEGF and PlGF. GDM was associated with IL-1RA, IL-17D, and eotaxin-3. Severe postpartum hemorrhage correlated with CRP, IL-13, and proteins of the IL-17 family. Predictive modeling yielded area under the receiver operating characteristic curve values of 0.708 and 0.672 for GDM and pre-eclampsia, respectively. Significant predictive biomarkers for GDM included IL-1RA and eotaxin-3, while pre-eclampsia prediction yielded the highest predictions when including MIP-1β, IL-1RA, and IL-12p70.ConclusionsOur study provides novel insights into the interplay between preexisting conditions and immune dysregulation in pregnancy. These findings contribute to our understanding of the pathophysiology of obstetric complications and the identification of novel biomarkers for early intervention(s) to improve maternal and fetal health.

DNA Tetrahedron Delivering miR‐21‐5p Promotes Senescent Bone Defects Repair through Synergistic Regulation of Osteogenesis and Angiogenesis (Adv. Healthcare Mater. 30/2024)

DNA Tetrahedron Delivering miR‐21‐5p Promotes Senescent Bone Defects Repair through Synergistic Regulation of Osteogenesis and Angiogenesis (Adv. Healthcare Mater. 30/2024)

Unraveling the role of PBK in glioblastoma: from molecular mechanisms to therapeutic targets.

This study investigates the gene expression characteristics of glioma-initiating cells (GIC), an important subgroup of glioblastoma (GBM), after knockdown of PBK (PDZ-binding kinase). Differentially expressed genes (DEGs) between PBK knockdown GIC and control groups were screened through bioinformatics methods. The authors analyzed the mechanisms and roles of these DEGs in GBM tumorigenesis and patient prognosis. Microarray data (GSE53800) were obtained from the Gene Expression Omnibus (GEO) database, selecting 18 GIC cell line samples with or without PBK knockdown. Each control and knockdown group contained three samples. DEGs were screened using R software. GO enrichment analysis, KEGG pathway analysis, PPI network analysis, and hub gene identification were conducted to explore DEG mechanisms. Western blot analysis was also performed to detect EIF4E protein expression, one of the key hub genes, after PBK knockdown in the HS683 glioma cell line. A total of 175 upregulated and 145 downregulated genes were identified. GO analysis showed that DEGs were mainly enriched in the positive regulation of cell proliferation, cell adhesion, and angiogenesis. KEGG pathway analysis revealed that DEGs were mainly involved in neuroactive ligand-receptor interactions, calcium signaling, and HIF-1 signaling pathways. Western blot results indicated that EIF4E was downregulated after PBK knockdown. A group of genes, such as EIF4E, were closely associated with PBK expression and functions. These findings may provide insight into the molecular mechanism of PBK in GBM.

MiR-142-5p mediated Nrf2 dysregulation in gestational diabetes mellitus and its impact on placental angiogenesis

Gestational diabetes mellitus (GDM) presents significant risks during pregnancy, including adverse perinatal outcomes and placental dysfunction. Impaired angiogenesis, involving crucial factors like Vascular Endothelial Growth Factor (VEGF), contributes to these complications. The Nrf2/Keap1 pathway, crucial for vascular redox homeostasis, has been linked to GDM-associated angiogenesis dysregulation. This study aimed to investigate the molecular mechanisms underlying placental Nrf2 regulation, focusing on angiomiRs, key regulators of angiogenesis in GDM. Computational analysis identified miR-142-5p targeting Nrf2 mRNA. Expression levels of miR-142-5p were assessed in GDM placenta and correlated with Nrf2 expression. Experimental validation utilized human trophoblastic cell lines (BeWo) exposed to hyperglycemic conditions, assessing the effects of anti-miR-142 transfection on Nrf2 expression and angiogenic marker levels. miR-142-5p expression was significantly downregulated in GDM placenta, correlating positively with Nrf2 expression. In BeWo cells exposed to hyperglycemia, anti-miR-142 transfection notably increased Nrf2 expression alongside angiogenic marker levels, confirming the computational predictions. Our findings highlight the pivotal role of miRNAs in GDM-associated impaired angiogenesis by modulating Nrf2 expression. Understanding these molecular mechanisms provides insights into potential therapeutic targets for improving pregnancy outcomes in GDM cases.

Blood Proteome Study to Assess the Regulation of Angiogenesis in Cosmonauts After the End of the Flight

A study of blood samples of 18 cosmonauts who had long flights as members of Russian crews of the International Space Station was performed using the method of quantitative proteomics based on mass spectrometry. The study was focused on elucidation of possible connection of proteome changes under the influence of space flight (SF) factors with the processes of angiogenesis. The analysis was performed with a targeted panel of 125 labeled 13C/15N peptides using chromatography-mass spectrometry with multiple reaction monitoring (LC/MRM-MS). A total of 125 different proteins were quantitatively characterized. Among them, a group of 61 proteins involved in the processes of angiogenesis and its regulation was found. Bioinformatic methods showed that the isolated angiogenesis proteins were participants of 13 biological processes, including lymphangiogenesis. Significant changes of protein level in blood after landing, in relation to preflight samples, were observed in 7 cases. The results have shown that the elimination of gravity (microgravity), space radiation and overloads of the final stage of flight have a combined effect on the processes of angiogenesis, which is manifested by changes in proteomic composition on 1 day after the completion of long-term CP.

Endothelial cell-derived exosomes trigger a positive feedback loop in osteogenesis-angiogenesis coupling via up-regulating zinc finger and BTB domain containing 16 in bone marrow mesenchymal stem cell

The close spatial and temporal connection between osteogenesis and angiogenesis around type H vasculature is referred as “osteogenesis-angiogenesis coupling”, which is one of the basic mechanisms of osteogenesis. Endothelial cells (ECs), bone marrow mesenchymal stem cells (BMSCs), and their specific lineage constitute important cluster that participate in the regulation of osteogenesis and angiogenesis in bone microenvironment. However, the regulatory mechanism of osteogenesis-angiogenesis coupling under the condition of bone healing has not been unveiled. In this study, we demonstrated that the exosome derived from ECs (EC-exo) is an initiator of type H blood vessels formation, and EC-exo acts as a mediator in orchestrating osteogenesis-angiogenesis coupling by enhancing BMSC osteogenic differentiation and EC angiogenesis both in monolayer and stereoscopic co-culture system of primary human cells. The transcriptome array indicated that zinc finger and BTB domain containing 16 (ZBTB16) is a key gene in EC-exo-mediated osteogenesis, and ZBTB16 is indispensable in EC-exo-initiated osteogenesis-angiogenesis coupling. Mechanistically, EC-exo up-regulated the expression of ZBTB16 in BMSCs, thereby promoting osteoprogenitor phenotype transformation; the osteoprogenitors further promote ECs which constitute type H vessel (H-ECs) generation by activating HIF-1α pathway; and the H-ECs conversely promotes osteogenic differentiation of BMSCs. The crosstalk between BMSCs and ECs triggered by EC-exo constitutes a positive feedback loop that enhances osteogenesis-angiogenesis coupling. This study demonstrates that EC-exo can become an effective therapeutic tool to promote bone regeneration and repair.Graphical

Lactylation and Ischemic Stroke: Research Progress and Potential Relationship.

Ischemic stroke is caused by interrupted cerebral blood flow and is a leading cause of mortality and disability worldwide. Significant advancements have been achieved in comprehending the pathophysiology of stroke and the fundamental mechanisms responsible for ischemic damage. Lactylation, as a newly discovered post-translational modification, has been reported to participate in several physiological and pathological processes. However, research on lactylation and ischemic stroke is scarce. This review summarized the current function of protein lactylation in other diseases or normal physiological processes and explored their potential link with the pathophysiological process and the reparative mechanism of ischemic stroke. We proposed that neuroinflammation, regulation of metabolism, regulation of messenger RNA translation, angiogenesis, and neurogenesis might be the bridge linking lactylation and ischemic stroke. Our study provided a novel perspective for comprehending the role of protein lactylation in the pathophysiological processes underlying ischemic stroke. Lactylation might be a promising target in drug development of ischemic stroke.

NSUN2 methylates IRF4 to affect the capacity of macrophages attached to titanium implant on osteogenic differentiation of PDLSCs and angiogenesis of HUVECs in vitro

BackgroundWe aimed to investigate the effect and underlying mechanism of titanium (Ti) implant on the polarization of macrophages and subsequent effects on the osteogenic differentiation of periodontal ligament stem cells (PDLSCs) and angiogenesis of human umbilical vein endothelial cells (HUVECs) affected by macrophages.MethodsFirstly, the regulatory effect of Ti implant on macrophage polarization was investigated. Levels of M1 polarization markers and M2 polarization markers in macrophages were evaluated by immunofluorescence staining method and qPCR analysis. The osteogenic differentiation capacity of PDLSCs cultured with supernatants of macrophages of each group was evaluated by the Alizarin Red S (ARS) staining method and qPCR. Angiogenesis related genes were also evaluated in HUVECs cultured in supernatants of macrophages. To explore whether RNA m5C modification can modulate the effects of Ti implant on macrophage regulation of osteogenic differentiation and angiogenesis, we analyzed the main genes related to m5C in macrophages using RNA m5C dot blotting and qPCR methods. The interaction between NSUN2 and IRF4 was verified by m5C-RIP, RIP, and double-luciferase gene report experiments.ResultsMacrophages were activated as M1 macrophages under the interference of LPS, and macrophages attached to Ti implants were more easily activated as M2 macrophages under the action of LPS. Macrophages activated by Ti implant enhanced osteogenic differentiation of PDLSCs and angiogenesis of HUVECs. NSUN2 level was up-regulated in macrophages treated with LPS and was down-regulated by Ti implant. Over-expression of NSUN2 attenuated the effect of Ti implant on M1 polarization promotion of macrophages and enhanced the M2 polarization promotion of macrophages. Up-regulation of NSUN2 weakened the effects of Ti implant on promotion the capacity of macrophages on osteogenic differentiation of PDLSCs and angiogenesis of HUVECs. The KEGG analysis suggested that IRF4 was enriched in several inflammatory signaling pathways. Moreover, NSUN2 methylates IRF4 to affect the capacity of macrophages on osteogenic differentiation of PDLSCs and angiogenesis of HUVECs.ConclusionsTaken together, macrophages of M1 type can be stimulated by Ti implants in vitro, promoting osteogenic differentiation of PDLSCs and angiogenesis in HUVECs through NSUN2-mediated methylation of IRF4.

Von Willebrand Disease and Angiodysplasia: a wider view of pathogenesis in pursuit of therapy.

Bleeding in the GI tract continues to pose a therapeutic challenge for clinicians in patients with Von Willebrand Disease (VWD). It is associated with significant morbidity and mortality and represents the major unmet need in VWD. Defective angiogenesis in the gut is primarily responsible, resulting in angiodysplastic malformations making bleeding notoriously refractory to standard replacement therapy. A substantial body of evidence now shows that Von Willebrand Factor (VWF) has a role in the regulation of angiogenesis but the mechanisms responsible for the formation of vascular malformations remain incompletely understood. Data from the wider field of vascular malformations may lend insight and point to novel therapeutic approaches. Here we review evidence linking VWF to angiodysplasia, the associated molecular mechanisms and the implications for therapy.

Role of Factor VIII As a Regulator of Angiogenesis and Promoter of Endothelial Barrier Stability

Role of Factor VIII As a Regulator of Angiogenesis and Promoter of Endothelial Barrier Stability

Emerging Mechanisms of Physical Exercise Benefits in Adjuvant and Neoadjuvant Cancer Immunotherapy.

The primary factors that can be modified in one's lifestyle are the most influential determinants and significant preventable causes of various types of cancer. Exercise has demonstrated numerous advantages in preventing cancer and aiding in its treatment. However, the precise mechanisms behind these effects are still not fully understood. To contribute to our comprehension of exercise's impact on cancer immunotherapy and provide recommendations for future research in exercise oncology, we will examine the roles and underlying mechanisms of exercise on immune cells. In addition to reducing the likelihood of developing cancer, exercise can also improve the effectiveness of certain approved anticancer treatments, such as targeted therapy, immunotherapy, and radiotherapy. Exercise is a pivotal modulator of the immune response, and thus, it can play an emerging important role in new immunotherapies. The mechanisms responsible for these effects involve the regulation of intra-tumoral angiogenesis, myokines, adipokines, their associated pathways, cancer metabolism, and anticancer immunity. Our review assesses the potential of physical exercise as an adjuvant/neoadjuvant tool, reducing the burden of cancer relapse, and analyzes emerging molecular mechanisms predicting favorable adjuvanticity effects.

VEGF-Virus Interactions: Pathogenic Mechanisms and Therapeutic Applications.

Many types of viruses directly or indirectly target the vascular endothelial growth factor (VEGF) system, which is a central regulator of vasculogenesis and angiogenesis in physiological homeostasis, causing diverse pathologies. Other viruses have been developed into effective therapeutic tools for VEGF modulation in conditions such as cancer and eye diseases. Some viruses may alter the levels of VEGF in the pathogenesis of respiratory syndromes, or they may encode VEGF-like factors, promoting vascular disruption and angiogenesis to enable viruses' systemic spread. Oncogenic viruses may express interactive factors that perturb VEGF's functional levels or downstream signaling, which increases the neovascularization and metastasis of tumors. Furthermore, many viruses are being developed as therapeutic vectors for vascular pathologies in clinical trials. Major examples are those viral vectors that inhibit the role of VEGF in the neovascularization required for cancer progression; this is achieved through the induction of immune responses, by exposing specific peptides that block signaling or by expressing anti-VEGF and anti-VEGF receptor-neutralizing antibodies. Other viruses have been engineered into effective pro- or anti-angiogenesis multitarget vectors for neovascular eye diseases, paving the way for therapies with improved safety and minimal side effects. This article critically reviews the large body of literature on these issues, highlighting those contributions that describe the molecular mechanisms, thus expanding our understanding of the VEGF-virus interactions in disease and therapy. This could facilitate the clinical use of therapeutic virus vectors in precision medicine for the VEGF system.

COMPARATIVE ANALYSIS OF THE DIAGNOSTIC ACCURACY OF ENDOSTATIN AND VEGF SERUM LEVELS IN PATIENTS WITH BONE SARCOMAS

Introduction. Angiogenesis regulators are of particular interest as new serum markers in cancer patients, since they reflect the intensity of tumor growth and metastasis. Currently, many works are dedicated to the study of vascular endothelial growth factor (VEGF), which activates angiogenesis, and endostatin, which inhibits it. However, a comparative study of the diagnostic accuracy of serum levels of these two markers in patients with bone sarcomas has not been conducted yet. Аim. A comparative analysis of the diagnostic accuracy indicators and prognostic significance of VEGF and endostatin in the blood serum of patients with primary malignant bone tumors. Methods. During the study, the levels of endostatin and VEGF in blood serum samples from 123 patients with a newly diagnosed and morphologically verified bone sarcoma were measured. Patients were examined at the Federal State Budgetary Institution “National Medical Research Center of Oncology named after N.N. Blokhin” of the Russian Ministry of Health from July 2001 to December 2022. Sixty age- and gender-matched healthy donors were included in the control group. Results. Median serum concentrations of endostatin and VEGF in the patient group were statistically significantly increased compared to the control group by 1.3 and 1.4 times, respectively (p < 0.01). Statistically significant differences in the serum concentrations of VEGF and endostatin depending on the T category and the tumor grade and stage were not identified. The cut-off value of VEGF was 279 pg/ml, and the cut-off value of endostatin was 121 ng/ml. With the same sensitivity of 75.6%, endostatin is characterized by higher specificity than VEGF (73.0 and 67.6%, respectively). The proportional hazards model characterizing the effect of serum VEGF and endostatin levels on overall and survival was not statistically significant. Conclusion. Endostatin in the blood serum of patients with bone tumors is more informative compared to VEGF; however, both markers are not predictors of overall and survival.

Angiogenesis and Pancreatic Cancer: Novel Approaches to Overcome Treatment Resistance.

Pancreatic cancer (PCa) is acknowledged as a significant contributor to global cancer- related mortality and is widely recognized as one of the most challenging malignant diseases to treat. Pancreatic ductal adenocarcinoma (PDAC), which is the most common type of PCa, is highly aggressive and is mostly incurable. The poor prognosis of this neoplasm is exacerbated by the prevalence of angiogenic molecules, which contribute to stromal stiffness and immune escape. PDAC overexpresses various proangiogenic proteins, including vascular endothelial growth factor (VEGF)-A, and the levels of these molecules correlate with poor prognosis and treatment resistance. Moreover, VEGF-targeting anti-angiogenesis treatments are associated with the onset of resistance due to the development of hypoxia, which in turn induces the production of angiogenic molecules. Furthermore, excessive angiogenesis is one of the hallmarks of the second most common form of PCa, namely, pancreatic neuroendocrine tumor (PNET). In this review, the role of angiogenesis regulators in promoting disease progression in PCa, and the impact of these molecules on resistance to gemcitabine and various therapies against PCa are discussed. Finally, the use of anti-angiogenic agents in combination with chemotherapy and other targeted therapeutic molecules is discussed as a novel solution to overcome current treatment limitations in PCa.

Co-inhibition of PGF and VEGFA enhances the effectiveness of immunotherapy in bladder cancer.

Background: Anti-angiogenic inhibitors and immune checkpoint blockade combination therapy offers a novel approach to circumvent the challenges associated with limited responsiveness to checkpoint inhibitors in bladder cancer. However, the effective strategies for inhibiting angiogenesis in bladder cancer need further elucidation. Objective: This work aims to identify key targets for the effective inhibition of angiogenesis in bladder cancer and to explore the potential benefits of combining anti-angiogenic therapies with immune checkpoint blockade strategies in the treatment of this disease. Methods: Cell-cell interaction analysis was performed using bladder cancer single-cell transcriptome datasets downloaded from the Gene Expression Omnibus (GEO) database to determine the regulatory network driving angiogenesis in bladder cancer. The bladder cancer cell line MBT2 was orthotopically transplanted into mice to investigate the impact of pro-angiogenic molecules on angiogenesis and tumor growth, and to evaluate the synergistic therapeutic potential of a combination therapy targeting angiogenesis and Programmed Cell Death Protein 1 (PD-1). Proliferation and tube formation assays with Human Umbilical Vein Endothelial Cells (HUVECs) were used to explore the regulatory functions of pro-angiogenic molecules in angiogenesis. Results: Placental growth factor (PGF) is a pro-angiogenic factor in bladder cancer, in addition to vascular endothelial growth factor A (VEGFA). Suppression of PGF reduced the tumor size and angiogenesis in bladder cancer. The expression level of vascular endothelial growth factor receptor 1 (VEGFR1) is higher than that of vascular endothelial growth factor receptor2 (VEGFR2) in the endothelial cells of bladder cancer. The pro-angiogenic activity of PGF is dependent on the expression level of VEGFR1 in endothelial cells. The combined inhibition of PGF and VEGFA exerts a synergistic effect on suppressing tumor growth and angiogenesis. The concurrent inhibition of PGF and VEGFA stands out as the only intervention capable of significantly enhancing the infiltration of CD8+ cytotoxic T cells within the bladder cancer microenvironment. In the bladder cancer mouse model, the introduction of an anti- programmed cell death protein 1 (PD-1) therapeutic regimen combined with the targeted inhibition of PGF and VEGFA, led to a significantly elevated survival rate compared to the outcome observed with anti-PD-1 monotherapy. Conclusion: PGF is a pro-angiogenic molecule in bladder cancer that requires significant expression levels of VEGFR1 in endothelial cells. Notably, the concurrent inhibition of PGF and VEGFA amplifies the therapeutic impact of anti-PD-1 treatment in bladder cancer. These findings provide further insights into the role of PGF in angiogenesis regulation and have conceptual implications for combining anti-angiogenic therapy with immune therapy in bladder cancer treatment.

Aortic valve stenosis augments long noncoding RNA H19 to govern angiogenic responses and phenotypes of valvular endothelial cell through endothelial to mesenchymal transition

Abstract Background Long noncoding RNAs (lncRNAs) have emerged as important regulators of cardiovascular disease, including aortic valve stenosis (AVS). Although several recent studies have reported that lncRNAs are dysregulated and might play a crucial role in (Endothelial to mesenchymal transition) EndMT, no specific role of lncRNA was reported in AVS pathogenesis. Here, we sought to investigate the role of H19 in EndMT during the pathogenesis of AVS. Methods and results High-throughput lncRNA sequencing of human aortic valve tissue explanted from patients with AVS due to severe stenosis during surgical aortic valve replacement (SAVR) demonstrated that certain lncRNAs [H19, AGAP2-AS1 (PUNISHER), GAS5, MALAT1] are significantly dysregulated compared to patients without AVS. To validate the RNA-seq data, 60 patients with AVS (n=30) or without AVS (n=30) were prospectively investigated. Among these, H19 (p=0.002), AGAP2-AS1 (p=0.002), and GAS5 (0.02) were significantly upregulated in patients with AVS, compared to non-AVS patients. Aortic valvular endothelial cells (VECs) were isolated from explanted valve tissue from AVS patients or obtained commercially. In vitro EndMT-promoting stimuli (TNFα or TGFß+IL1ß) were used for VEC stimulation for 5 days. RT-qPCR was used to quantify the expression of EndMT markers (EC markers, vWF, and NOS3, and mesenchymal markers, αSMA, SM22, Vimentin, and SNAI2). Loss of H19 led to dysregulation of the EC gene network and protein expression patterns that were analyzed by qRT-PCR, immunoblotting, and immunofluorescence, respectively. Further experiments show that silencing of H19 affects migration and proliferation, and promotes EndMT in EC. Functional assays suggested that H19 is a critical regulator of angiogenic properties. The molecular signature of angiogenesis was investigated using a RT-qPCR-based angiogenesis array to identify the regulation of angiogenesis with 84-angiogenesis-related genes. Mechanistically, the angiogenesis array revealed that H19 regulates Jagged Canonical Notch Ligand 1 (JAG1) (4.43-fold vs. control EC), an important regulator of NOTCH1 signaling, and pro-angiogenic factor in EC. Accordingly, EndMT marker expressions were dysregulated upon H19 depletion. A high-throughput luciferase reporter array demonstrated STAT3 activation upon H19 knockdown. Depletion of H19 increased the phosphorylation of STAT3 at TYR705 and pharmacological inhibition of STAT3 activation abolished the effects of H19 silencing on EndMT marker expression as well as on angiogenesis. Overexpression of H19 in VEC abrogated the H19-mediated promotion of JAG1- and VEGFA gene- and protein expression. Our data suggest that H19 might play a role in EC angiogenic gene expression and EndMT. The data reveal a pivotal role of H19 in controlling EndMT in AVS via regulation of the JAG1-NOTCH axis, which could potentially be therapeutically targeted to halt EndMT during AVS.

Targeting the VEGFR2 signaling pathway for angiogenesis and fibrosis regulation in neovascular age-related macular degeneration

Neovascular age-related macular degeneration (nAMD) is characterized by abnormal blood vessel growth from the choroid, leading to complications and eventual blindness. Despite anti-VEGF therapy, subretinal fibrosis remains a major concern, as VEGF/VEGF receptor-2 (VEGFR2) signaling can contribute to both angiogenesis and fibrosis. For the identification of the aqueous humor proteome, we performed liquid chromatography with tandem mass spectrometry analysis. To investigate the potential therapeutic effects of targeting the VEGF signaling pathway using apatinib, a highly selective VEGFR2 tyrosine kinase inhibitor, this study employed in vitro (THP-1 conditioned media-treated ARPE-19 cells) and in vivo (laser-induced choroidal neovascularization mouse) models of nAMD. This study revealed elevated VEGFR2 protein levels in the aqueous humor of nAMD patients, suggesting a potential target to mitigate neovascularization and fibrosis in nAMD. Apatinib effectively reduced VEGFA and αSMA levels in both in vitro and in vivo models. Moreover, apatinib showed improvement in laser-induced subretinal hyper-reflective lesions. The action mechanism was linked to the inhibition of VEGFR2 activation, leading to the suppression of both angiogenesis and fibrosis through the downregulation of STAT3 phosphorylation. Therefore, the VEGFR2 signaling pathway appears to play a central role in the development of nAMD by regulating both angiogenesis and fibrosis.

A mathematical model describing the tip-stalk regulation in angiogenesis

Angiogenesis is the process of new blood vessel growth from existing vessels, involving extensive cell signaling. Under normal conditions, new vessels are robust and organized, with a balance among angiogenesis factors. In abnormal conditions, such as tumor development, vessels are stunted and tangled due to an imbalance of these factors. Pathological angiogenesis stimulates rapid vessel growth to feed the oxygen and nutriente starved tumor. Inhibiting angiogenesis can cause side effects like hypertension, thrombosis, and fatigue. To better understand this process, significant effort has gone into studying signaling pathways, contributing to drug development for diseases like cancer. This study presents a mathematical model describing angiogenesis on a microscopic scale, comparing its results with experimental data on vascular network topology. The model, implemented in MatLab®, uses ordinary differential equations to represent cell behavior. Results show that altering VEGF (Vascular Endothelial Growth Factor) disrupts system balance, impacting angiogenesis and possibly explaining differences in network topology seen experimentally.

Hypoxia Reduces Mouse Urine Output via HIF1α-Mediated Upregulation of Renal AQP1

Introduction: Patients with acute mountain sickness (AMS) due to hypoxia at high altitudes often exhibit abnormal water metabolism. Hypoxia-inducible factors (HIFs) are major regulators of adaptive responses to hypoxia. As transcription factors, HIFs are involved in the regulation of erythropoiesis, iron metabolism, angiogenesis, energy metabolism, and cell survival by promoting the transcriptional expression of hundreds of target genes. Roxadustat, a novel drug for the treatment of anemia associated with chronic kidney disease (CKD), acts by inhibiting the degradation of HIFs to increase their protein levels. However, the clinical use of roxadustat is frequently associated with peripheral edema, suggesting the involvement of HIFs in regulating the body’s water balance possibly by modulating water reabsorption in the kidney. Methods: We first evaluated the effect of hypoxia (8% O2) on mouse urine output. We then performed in vitro experiments using hypoxia (1% O2) and roxadustat on mouse primary proximal tubular cells (mPTCs). The quantitative polymerase chain reaction, Western blot, and immunofluorescence were used to assess AQP1 mRNA and protein expression levels. Luciferase, Chromatin immunoprecipitation (ChIP), and electrophoretic mobility shift assay (EMSA) were used to investigate the transcriptional regulation of AQP1 by HIF1α. Results: We found that mice exposed to hypoxia (8% O2) had significantly reduced urine volume compared to mice exposed to normoxia (21% O2). Hypoxia significantly elevated AQP1 expression at both mRNA and protein levels. In vitro experiments using mouse primary cultured proximal tubular cells (mPTCs) revealed that both hypoxia and roxadustat increased AQP1 expression. Mechanistically, overexpression of HIF1α, but not HIF2α, markedly increased AQP1 protein expression. Furthermore, the upregulation of AQP1 by hypoxia and roxadustat can be blocked by the HIF1α inhibitor PX-478 in mPTCs. Finally, we found that the AQP1 gene promoter contains a putative hypoxia response element and confirmed that AQP1 is a target gene of HIF1α using Luciferase reporter, ChIP, and EMSA assays. Conclusion: This study demonstrates that hypoxia can reduce the urine volume of mice via upregulating AQP1 expression by HIF1α in the proximal tubular epithelial cells. Our findings also suggest a potential mechanism involved in water metabolism disorders in patients with AMS and in patients with CKD receiving roxadustat treatment.

A Novel PTPRQ c.3697del Variant Causes Autosomal Dominant Progressive Hearing Loss in Both Humans and Mice.

PTPRQ plays an important role in the development of inner ear hair cell stereocilia. While many autosomal recessive variants in PTPRQ have been identified as the pathogenic cause for nonsyndromic hearing loss (DFNB84A), so far only one autosomal dominant PTPRQ variant, c.6881G>A (p.Trp2294*), has been reported for late-onset, mild-to-severe hearing loss (DFNA73). By using targeted next-generation sequencing, this study identified a novel PTPRQ truncating pathogenic variant, c.3697del (p.Leu1233Phefs*11), from a Chinese Han family that co-segregated with autosomal dominant, postlingual, progressive hearing loss. A Ptprq-3700del knock-in mouse model was generated by CRISPR-Cas9 and characterized for its hearing function and inner ear morphology. While the homozygous knock-in mice exhibit profound hearing loss at all frequencies at the age of 3 weeks, the heterozygous mutant mice resemble the human patients in mild, progressive hearing loss from age 3 to 12 weeks, primarily affecting high frequencies. At this stage, the homozygous knock-in mice have a normal hair cell count but disorganized stereocilia. Cochlear proteosome analysis of the homozygous mutant mice revealed differentially expressed genes and pathways involved in oxidative phosphorylation, regulation of angiogenesis and synaptic vesicle cycling. Our study provides a valuable animal model for further functional studies of the pathogenic mechanisms underlying DFNA73.