Molecular Pharmacology of VEGF-A Isoforms: Binding and Signalling at VEGFR2

Targeting the interaction of pleiotrophin and VEGFA165 with protein tyrosine phosphatase receptor zeta 1 inhibits endothelial cell activation and angiogenesis

Protein tyrosine phosphatase receptor zeta 1 (PTPRZ1) is a transmembrane tyrosine phosphatase (TP) that serves as a receptor for pleiotrophin (PTN) and vascular endothelial growth factor A 165 (VEGFA165) to regulate endothelial cell migration. In the present work, we identify a PTN peptide fragment (PTN97-110) that inhibits the interaction of PTN and VEGFA165 with PTPRZ1 but not VEGF receptor 2. This peptide abolishes the stimulatory effect of PTN and VEGFA165 on endothelial cell migration, tube formation on Matrigel, and Akt activation in vitro. It also partially inhibits VEGFA165-induced VEGF receptor 2 activation but does not affect ERK1/2 activation and cell proliferation. In vivo, PTN97-110 inhibits or dysregulates angiogenesis in the chick embryo chorioallantoic membrane and the zebrafish assays, respectively. In glioblastoma cells in vitro, PTN97-110 abolishes the stimulatory effect of VEGFA165 on cell migration and inhibits their anchorage-independent growth, suggesting that this peptide might also be exploited in glioblastoma therapy. Finally, in silico and experimental evidence indicates that PTN and VEGFA165 bind to the extracellular fibronectin type-III (FNIII) domain to stimulate cell migration. Collectively, our data highlight novel aspects of the interaction of PTN and VEGFA165 with PTPRZ1, strengthen the notion that PTPRZ1 is required for VEGFA165-induced signaling, and identify a peptide that targets this interaction and can be exploited for the design of novel anti-angiogenic and anti-glioblastoma therapeutic approaches.

Endothelial ELABELA improves post-ischemic angiogenesis by upregulating VEGFR2 expression

BACKGROUND

Post-ischemic angiogenesis is critical for perfusion recovery and tissue repair. ELABELA (ELA) plays an essential role in embryonic heart development and vasculogenesis. However, the mechanism of ELA on post-ischemic angiogenesis is poorly characterized.

METHODS

We first assessed ELA expression after hind limb ischemia (HLI) in mice. We then established a HLI model in tamoxifen-inducible endothelial-ELA-specific knockout mice (ELAECKO) and assessed the rate of perfusion recovery, capillary density, and VEGFR2 pathway. Knockdown of ELA with lentivirus or siRNA and exogenous addition of ELA peptides were employed to analyze the effects of ELA on angiogenic capacity and VEGFR2 pathway in endothelial cells in vitro. The serum levels of ELA in healthy people and patients with type 2 diabetes mellitus (T2DM) and diabetic foot ulcer (DFU) were detected by a commercial ELISA kit.

RESULTS

In murine HLI models, ELA was significantly up-regulated in the ischemic hindlimb. Endothelial-specific deletion of ELA impaired perfusion recovery and angiogenesis. In physiologic conditions, no significant difference in VEGFR2 expression was found between ELAECKO mice and ELAWT mice. After ischemia, the expression of VEGFR2, p-VEGFR2, and p-AKT was significantly lower in ELAECKO mice than in ELAWT mice. In cellular experiments, the knockdown of ELA inhibited endothelial cell proliferation and tube formation, and the addition of ELA peptides promoted proliferation and tube formation. Mechanistically, ELA upregulated the expression of VEGFR2, p-VEGFR2, and p-AKT in endothelial cells under hypoxic conditions. In clinical investigations, DFU patients had significantly lower serum levels of ELA compared to T2DM patients.

CONCLUSION

Our results indicated that endothelial ELA is a positive regulator of post-ischemic angiogenesis via upregulating VEGFR2 expression. Targeting ELA may be a potential therapeutic option for peripheral arterial diseases.

Adaptive resistance of tumor cells to anti-vascular endothelial growth factor therapy: A reversible phenomenon

Vascular endothelial growth factor (VEGF) inhibition is an essential targeted strategy for malignant tumors, but its efficacy is severely constrained by drug resistance. The traditional view holds that the target of VEGF inhibition is endothelial cells, and thus compensatory angiogenesis is considered the main mechanism of drug resistance. In this study, we found that tumor cells themselves could develop acquired resistance to VEGF therapy, indicating an independent resistance mechanism apart from angiogenesis. Notably, this acquired resistance was temporary, disappearing completely four days after discontinuing exposure to the drug in vitro. Our findings suggest that tumor cells may also be targets of VEGF inhibition, and their response to treatment should not be overlooked in contributing to drug resistance.

Protective effect and mechanism of Lycium ruthenicum Murray anthocyanins against retinal damage induced by blue light exposure

Lycium ruthenicum Murray (LR) is a medicine and edible plant in Northwest China, and L. ruthenicum Murray anthocyanins (LRA) are green antioxidants with various pharmacological activities, such as antioxidant and anti-inflammatory activities. However, the protective effect and mechanism of LRA against retinal damage induced by blue light exposure are poorly understood. This study explored the protective effects and potential mechanisms of LRA on retinal damage induced by blue light exposure in vitro and in vivo. The results showed that LRA could ameliorate oxidative stress injury by activating the antioxidant stress nuclear factor-related factor 2 pathway, promoting the expression of phase II detoxification enzymes (HO-1, NQO1) and endogenous antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase), and reducing reactive oxygen species and malondialdehyde levels. Additionally, LRA could inhibit inflammatory response by decreasing the expression of blue light exposure-induced nuclear factor-κB (NF-κB) pathway-related proteins (NF-κB and p-IκBα), as well as interleukin (IL)-6, tumor necrosis factor-α, IL-1β pro-inflammatory factors and pro-inflammatory chemokine VEGF, and increasing the expression of anti-inflammatory factor IL-10. Furthermore, LRA could ameliorate oxidative stress-induced apoptosis by upregulating Bcl-2 and downregulating Bax and Caspase-3 protein expression. All these results indicate that LRA can be used as an antioxidant dietary supplement for the treatment or prevention of retinal diseases.

Elevated VEGF-A Levels in the Aqueous Humor of Patients With Primary Open Angle Glaucoma

BACKGROUND/AIM

The purpose of the current study was to compare the vascular endothelial growth factor-A (VEGF-A) levels in the aqueous humor of patients with primary open angle glaucoma (POAG) and non-glaucomatous eyes and reveal any potential statistically significant correlations.

PATIENTS AND METHODS

This was an observational cross-sectional study. Aqueous humor samples (50-100 μl) were collected under aseptic conditions, from the anterior chamber at the start of glaucoma or cataract surgery. The levels of VEGF-A were measured using a multiplex bead-based immunoassay.

RESULTS

Aqueous humor samples were obtained from 76 participants: 39 with POAG and 36 with age-related cataracts as controls. VEGF-A levels were significantly elevated in the POAG group (166.37±110.04 pg/ml, p=0.011) compared to the control group (119.02±49.09 pg/ml). The receiver operating characteristic (ROC) analysis showed that VEGF-A had significant prognostic ability for POAG (AUC=0.67; p=0.006). An optimal cut-off for VEGF-A was found to be 148.5 pg/ml with a sensitivity of 54%, specificity of 81.1%, positive prognostic value (PPV) of 75% and negative prognostic value (NPV) of 62.5%. Logistic regression analysis showed that after adjusting for sex and age, patients with VEGF-A higher than 148.5 pg/ml had almost 10 times greater likelihood for POAG.

CONCLUSION

VEGF-A is elevated in patients with POAG and can potentially have a prognostic ability for these patients.

A method for rapid and reliable quantification of VEGF-cell binding activity

Vascular endothelial growth factor (VEGF) is a pleiotropic growth factor that binds a broad spectrum of cell types and regulates diverse cellular processes, including angiogenesis, growth and survival. However, it is technically difficult to quantify VEGF-cell binding activity because of reversible nature of ligand-receptor interactions. Here we used T7 bacteriophage display to quantify and compare binding activity of three human VEGF-A (hVEGF) isoforms, including hVEGF111, 165 and 206. All three isoforms bound equally well to immobilized aflibercept, a decoy VEGF receptor. hVEGF111-Phage exhibited minimal binding to immobilized heparan sulfate, whereas hVEGF206-Phage and hVEGF165-Phage had the highest and intermediate binding to heparan, respectively. In vitro studies revealed that all three isoforms bound to human umbilical vein endothelial cells (HUVECs), HEK293 epithelial and SK-N-AS neuronal cells. hVEGF111-Phage has the lowest binding activity, while hVEGF206-Phage has the highest binding. hVEGF206-Phage was the most sensitive to detect VEGF-cell binding, albeit with the highest background binding to SK-N-AS cells. These results suggest that hVEGF206-Phage is the best-suited isoform to quantify VEGF-cell binding even though VEGF165 is the most biologically active. Furthermore, this study demonstrates the utility of T7 phage display as a platform for rapid and convenient ligand-cell binding quantification with pros and cons discussed.

A Review of Advances in Molecular Imaging of Rheumatoid Arthritis: From In Vitro to Clinic Applications Using Radiolabeled Targeting Vectors with Technetium-99m

Rheumatoid arthritis (RA) is a systemic autoimmune disorder caused by inflammation of cartilaginous diarthrodial joints that destroys joints and cartilage, resulting in synovitis and pannus formation. Timely detection and effective management of RA are pivotal for mitigating inflammatory arthritis consequences, potentially influencing disease progression. Nuclear medicine using radiolabeled targeted vectors presents a promising avenue for RA diagnosis and response to treatment assessment. Radiopharmaceutical such as technetium-99m (99mTc), combined with single photon emission computed tomography (SPECT) combined with CT (SPECT/CT), introduces a more refined diagnostic approach, enhancing accuracy through precise anatomical localization, representing a notable advancement in hybrid molecular imaging for RA evaluation. This comprehensive review discusses existing research, encompassing in vitro, in vivo, and clinical studies to explore the application of 99mTc radiolabeled targeting vectors with SPECT imaging for RA diagnosis. The purpose of this review is to highlight the potential of this strategy to enhance patient outcomes by improving the early detection and management of RA.

Recent advances and future directions on small molecule VEGFR inhibitors in oncological conditions

"A journey of mixed emotions" is a quote that best describes the progress chart of vascular endothelial growth factor receptor (VEGFR) inhibitors as cancer therapeutics in the last decade. Exhilarated with the Food and Drug Administration (FDA) approvals of numerous VEGFR inhibitors coupled with the annoyance of encountering the complications associated with their use, drug discovery enthusiasts are on their toes with an unswerving determination to enhance the rate of translation of VEGFR inhibitors from preclinical to clinical stage. The recently crafted armory of VEGFR inhibitors is a testament to their growing dominance over other antiangiogenic therapies for cancer treatment. This review perspicuously underscores the earnest attempts of the researchers to extract the antiproliferative potential of VEGFR inhibitors through the design of mechanistically diverse structural assemblages. Moreover, this review encompasses sections on structural/molecular properties and physiological functions of VEGFR, FDA-approved VEGFR inhibitors, and hurdles restricting the activity range/clinical applicability of VEGFR targeting antitumor agents. In addition, tactics to overcome the limitations of VEGFR inhibitors are discussed. A clear-cut viewpoint transmitted through this compilation can provide practical directions to push the cart of VEGFR inhibitors to advanced-stage clinical investigations in diverse malignancies.

Integrating network pharmacology, experimental validation and molecular docking to reveal the alleviation of Yinhuang granule on idiopathic pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic disease characterized by the abnormal proliferation of fibroblast and excessive deposition of extracellular matrix (ECM), accompanied by inflammation and ultimately respiratory failure. Yinhuang granule (YHG), with clinical properties of clearing heat, detoxifying and anti-inflammation, is commonly used to heal upper respiratory diseases in China for decades.

PURPOSE

To explore the improvement of YHG on bleomycin (BLM)-induced IPF in mice and its possible engaged mechanism.

METHODS

The mortality rate was recorded, lung function was determined and hematoxylin-eosin (H&E) staining was carried out to explore the alleviation of YHG on BLM-caused IPF in mice. Hydroxyproline, collagen I and collagen III contents were detected, and Sirius red and Masson staining were conducted to evaluate YHG's alleviation on lung fibrosis. The underlying mechanism was predicted by network pharmacology, and confirmed by Real-time polymerase chain reaction (RT-PCR), Western-blot (WB) and enzyme linked immunosorbent assay (ELISA). The binding affinity between related key proteins and active compounds in YHG was calculated by using molecular docking, and further validated by cellular thermal shift assay (CESTA).

RESULTS

YHG (400, 800 mg/kg) weakened lung damage and pulmonary fibrosis in mice induced by BLM. Network pharmacology and experimental validation displayed that inflammation and angiogenesis participated in the YHG-provided improvement on IPF, and key involved molecules included tumor necrosis factor-α (TNFα), vascular endothelial growth factor-A (VEGFA), interleukine-6 (IL-6), etc. The data of molecular docking presented that some main active compounds from YHG had a high binding affinity with TNFR1 or VEGFR2, and some of them were further validated by CESTA.

CONCLUSION

YHG effectively improved the BLM-induced IPF in mice via reducing inflammation and angiogenesis.

Framework Nucleic Acids-Based VEGF Signaling Activating System for Angiogenesis: A Dual Stimulation Strategy

Angiogenesis is crucial for tissue engineering, wound healing, and regenerative medicine. Nanomaterials constructed based on specific goals can be employed to activate endogenous growth factor-related signaling. In this study, based on the conventional single-stranded DNA self-assembly into tetrahedral framework nucleic acids (tFNAs), the Apt02 nucleic acid aptamer and dimethyloxallyl glycine (DMOG) small molecule are integrated into a complex via a template-based click chemistry reaction and toehold-mediated strand displacement reaction. Thus, being able to simulate the VEGF (vascular endothelial growth factor) function and stabilize HIF (hypoxia-inducible factor), a functional whole is constructed and applied to angiogenesis. Cellular studies demonstrate that the tFNAs-Apt02 complex (TAC) has a conspicuous affinity to human umbilical vein endothelial cells (HUVECs). Further incubation with DMOG yields the tFNAs-Apt02-DMOG complex (TACD), which promotes VEGF secretion, in vitro blood vessel formation, sprouting, and migration of HUVECs. Additionally, TACD enhances angiogenesis by upregulating the VEGF/VEGFR and HIF signaling pathways. Moreover, in a diabetic mouse skin defect repair process, TACD increases blood vessel formation and collagen deposition, therefore accelerating wound healing. The novel strategy simulating VEGF and stabilizing HIF promotes blood-vessel formation in vivo and in vitro and has the potential for broad applications in the vascularization field.

Role of miRNA-regulated type H vessel formation in osteoporosis

Osteoporosis (OP) is a chronic systemic bone metabolism disease characterized by decreased bone mass, microarchitectural deterioration, and fragility fractures. With the demographic change caused by long lifespans and population aging, OP is a growing health problem. The role of miRNA in the pathogenesis of OP has also attracted widespread attention from scholars in recent years. Type H vessels are unique microvessels of the bone and have become a new focus in the pathogenesis of OP because they play an essential role in osteogenesis-angiogenesis coupling. Previous studies found some miRNAs regulate type H vessel formation through the regulatory factors, including platelet-derived growth factor-BB (PDGF-BB), hypoxia-inducible factor 1α (HIF-1α), vascular endothelial growth factor (VEGF), and so on. These findings help us gain a more in-depth understanding of the relationship among miRNAs, type H vessels, and OP to find a new perspective on treating OP. In the present mini-review, we will introduce the role of type H vessels in the pathogenesis of OP and the regulation of miRNAs on type H vessel formation by affecting regulatory factors to provide some valuable insights for future studies of OP treatment.

Role of mRNA-binding proteins in retinal neovascularization

Retinal neovascularization (RNV) is a pathological process that primarily occurs in diabetic retinopathy, retinopathy of prematurity, and retinal vein occlusion. It is a common yet debilitating clinical condition that culminates in blindness. Urgent efforts are required to explore more efficient and less limiting therapeutic strategies. Key RNA-binding proteins (RBPs), crucial for post-transcriptional regulation of gene expression by binding to RNAs, are closely correlated with RNV development. RBP-RNA interactions are altered during RNV. Here, we briefly review the characteristics and functions of RBPs, and the mechanism of RNV. Then, we present insights into the role of the regulatory network of RBPs in RNV. HuR, eIF4E, LIN28B, SRSF1, METTL3, YTHDF1, Gal-1, HIWI1, and ZFR accelerate RNV progression, whereas YTHDF2 and hnRNPA2B1 hinder it. The mechanisms elucidated in this review provide a reference to guide the design of therapeutic strategies to reverse abnormal processes.

2-Desaza-annomontine (C81) impedes angiogenesis through reduced VEGFR2 expression derived from inhibition of CDC2-like kinases

Angiogenesis is a crucial process in the progression of various pathologies, like solid tumors, wet age-related macular degeneration, and chronic inflammation. Current anti-angiogenic treatments still have major drawbacks like limited efficacy in diseases that also rely on inflammation. Therefore, new anti-angiogenic approaches are sorely needed, and simultaneous inhibition of angiogenesis and inflammation is desirable. Here, we show that 2-desaza-annomontine (C81), a derivative of the plant alkaloid annomontine previously shown to inhibit endothelial inflammation, impedes angiogenesis by inhibiting CDC2-like kinases (CLKs) and WNT/β-catenin signaling. C81 reduced choroidal neovascularization in a laser-induced murine in vivo model, inhibited sprouting from vascular endothelial growth factor A (VEGF-A)-activated murine aortic rings ex vivo, and reduced angiogenesis-related activities of endothelial cells in multiple functional assays. This was largely phenocopied by CLK inhibitors and knockdowns, but not by inhibitors of the other known targets of C81. Mechanistically, CLK inhibition reduced VEGF receptor 2 (VEGFR2) mRNA and protein expression as well as downstream signaling. This was partly caused by a reduction of WNT/β-catenin pathway activity, as activating the pathway induced, while β-catenin knockdown impeded VEGFR2 expression. Surprisingly, alternative splicing of VEGFR2 was not detected. In summary, C81 and other CLK inhibitors could be promising compounds in the treatment of diseases that depend on angiogenesis and inflammation due to their impairment of both processes.

Angiogenic Gene Therapy for Refractory Angina: Results of the EXACT Phase 2 Trial

BACKGROUND

XC001 is a novel adenoviral-5 vector designed to express multiple isoforms of VEGF (vascular endothelial growth factor) and more safely and potently induce angiogenesis. The EXACT trial (Epicardial Delivery of XC001 Gene Therapy for Refractory Angina Coronary Treatment) assessed the safety and preliminary efficacy of XC001 in patients with no option refractory angina.

METHODS

In this single-arm, multicenter, open-label trial, 32 patients with no option refractory angina received a single treatment of XC001 (1×1011 viral particles) via transepicardial delivery.

RESULTS

There were no severe adverse events attributed to the study drug. Twenty expected severe adverse events in 13 patients were related to the surgical procedure. Total exercise duration increased from a mean±SD of 359.9±105.55 seconds at baseline to 448.2±168.45 (3 months), 449.2±175.9 (6 months), and 477.6±174.7 (12 months; +88.3 [95% CI, 37.1-139.5], +84.5 [95% CI, 34.1-134.9], and +115.5 [95% CI, 59.1-171.9]). Total myocardial perfusion deficit on positron emission tomography imaging decreased by 10.2% (95% CI, -3.1% to 23.5%), 14.3% (95% CI, 2.8%-25.7%), and 10.2% (95% CI, -0.8% to -21.2%). Angina frequency decreased from a mean±SD 12.2±12.5 episodes to 5.2±7.2 (3 months), 5.1±7.8 (6 months), and 2.7±4.8 (12 months), with an average decrease of 7.7 (95% CI, 4.1-11.3), 6.6 (95% CI, 3.5-9.7), and 8.8 (4.6-13.0) episodes at 3, 6, and 12 months. Angina class improved in 81% of participants at 6 months.

CONCLUSIONS

XC001 administered via transepicardial delivery is safe and generally well tolerated. Exploratory improvements in total exercise duration, ischemic burden, and subjective measures support a biologic effect sustained to 12 months, warranting further investigation.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04125732.

Potent anti-angiogenic component in Kaempferia galanga L. and its mechanism of action

ETHNOPHARMACOLOGICAL RELEVANCE

Traditionally, the roots of Kaempferia galanga has been used to treat high blood pressure, chest pain, headache, toothache, rheumatism, indigestion, cough, inflammation and cancer in Asia. Nevertheless, most of its pharmacological studies were focused on ethanolic extracts and volatile oils. The exact active chemical constituents and their underlying mechanisms are still poorly understood, especially towards its anti-cancer treatment. Inhibition of angiogenesis is an important atrategy to inhibit tumor growth. It has been reported that the low polar component of the plant possessed anti-angiogenic activity. Yet, the potent compound which is responsible for the effect and its molecular mechanism has not been reported.

AIM OF THE STUDY

To determine the potent anti-angiogenic component in K.galanga and its mechanism of action.

MATERIAL AND METHODS

The low polar components of the plant were concentrated using the methods of supercritical fluid extraction (SFE), subcritical extraction (SCE) and steam distillation (SD). The anti-angiogenic activity of the three extracts was evaluated using a zebrafish model. The content of the active compound in those extracts was determined with HPLC analysis. The in-vitro and in-vivo activity of the isolated compound was evaluated using human umbilical vein endothelial cells (HUVECs) model, the aortic ring assay and the matrigel plug assay, respectively. Its molecular mechanism was further studied by the western blotting assay and computer-docking experiments. Besides, its cytotoxicity on cancer and normal cell lines was evaluated using the cell-counting kit.

RESULTS

HPLC results showed that trans-ethyl p-methoxycinnamate (TEM) was the major component of the extracts. The extract of SFE showed the best effect as it has the highest content of TEM. TEM could inhibit vascular endothelial growth factor (VEGF)-induced viability, migration, invasion and tube formation in human umbilical vein endothelial cells (HUVECs) in vitro. Moreover, it inhibited VEGF-induced sprout formation ex vivo and vessel formation in vivo. Mechanistic study showed that it could suppress tyrosine kinase activity of the receptor of VEGF (VEGFR2) and alter its downstream signaling pathways. In addition, the molecular docking showed that the binding of TEM and VEGFR2 is stable, which mainly attributed to the non-covalent binding interaction. Beside, TEM possessed little toxicity to both cancer and normal cells.

CONCLUSION

TEM is the major anti-angiogenic component present in K. galanga and its anti-angiogenic property rather than toxicity provides scientific basis for the traditional use of K. galanga in cancer treatment.

SERPINB5 promotes colorectal cancer invasion and migration by promoting EMT and angiogenesis via the TNF-α/NF-κB pathway

This study aimed to investigate the role of SERPINB5 in colorectal cancer (CRC). We established knockdown and overexpression models of SERPINB5 in CRC cells and conducted bioinformatics analysis to assess the clinicopathological significance of SERPINB5 expression in CRC patients. Human CRC cells were transfected with LV-SERPINB5 and sh-SERPINB5 lentivirus for subsequent functional and mechanistic studies. Results showed that high SERPINB5 expression correlated positively with CEA levels, N stage and lymphatic infiltration, while displaying a negative correlation with progression-free survival. Overexpression of SERPINB5 in CRC cells upregulated the expression of TNF-α, p-NF-κB/p65, N-cadherin, MMP2 and MMP9, accompanied by decreased E-cadherin expression. In addition, SERPINB5 overexpression enhanced the migration, invasion, and proliferation of CRC cells. Furthermore, overexpression of SERPINB5 in CRC cells increased VEGFA expression, and the conditioned medium from SERPINB5-overexpressing CRC cells promoted tube formation of HUVECs. Conversely, overexpression of SERPINB5 in HUVECs decreased VEGFA expression and inhibited tube formation. Notably, these changes in CRC cells were reversed by QNZ, a specific inhibitor of the TNF-α/NF-κB pathway. In summary, our findings revealed that high SERPINB5 expression correlated with poor progression-free survival in CRC patients. Moreover, SERPINB5 could induce EMT and angiogenesis by activating the TNF-α/NF-κB pathway, thereby promoting the invasion and migration of CRC cells.

Hydrogen Sulfide Exerted a Pro-Angiogenic Role by Promoting the Phosphorylation of VEGFR2 at Tyr797 and Ser799 Sites in Hypoxia-Reoxygenation Injury

The protective effects of hydrogen sulfide (H2S) against ischemic brain injury and its role in promoting angiogenesis have been established. However, the specific mechanism underlying these effects remains unclear. This study is designed to investigate the regulatory impact and mechanism of H2S on VEGFR2 phosphorylation. Following expression and purification, the recombinant His-VEGFR2 protein was subjected to LC-PRM/MS analysis to identify the phosphorylation sites of VEGFR2 upon NaHS treatment. Adenovirus infection was used to transfect primary rat brain artery endothelial cells (BAECs) with the Ad-VEGFR2WT, Ad-VEGFR2Y797F, and Ad-VEGFR2S799A plasmids. The expression of VEGFR2 and recombinant Flag-VEGFR2, along with Akt phosphorylation, cell proliferation, and LDH levels, was assessed. The migratory capacity and tube-forming potential of BAECs were assessed using wound healing, transwell, and tube formation assays. NaHS notably enhanced the phosphorylation of VEGFR2 at Tyr797 and Ser799 sites. These phosphorylation sites were identified as crucial for mediating the protective effects of NaHS against hypoxia-reoxygenation (H/R) injury. NaHS significantly enhanced the Akt phosphorylation, migratory capacity, and tube formation of BAECs and upregulated the expression of VEGFR2 and recombinant proteins. These findings suggest that Tyr797 and Ser799 sites of VEGFR2 serve as crucial mediators of H2S-induced pro-angiogenic effects and protection against H/R injury.

Metabolic Syndrome and Cardiac Vessel Remodeling Associated with Vessel Rarefaction: A Possible Underlying Mechanism May Result from a Poor Angiogenic Response to Altered VEGF Signaling Pathways

BACKGROUND

Elevated mortality rates in patients with metabolic syndrome (MetS) are partly due to adverse remodeling of multiple organs, which may lead to cardiovascular disease, nonalcoholic fatty liver disease, kidney failure, or other conditions. MetS symptoms, such as obesity, hypertension, hyperglycemia, dyslipidemia, associated with insulin and leptin resistance, are recognized as major cardiovascular risk factors that adversely affect the heart.

SUMMARY

Pathological cardiac remodeling is accompanied by endothelial cell dysfunction which may result in diminished coronary flow, dysregulated oxygen demand/supply balance, as well as vessel rarefaction. The reduced number of vessels and delayed or inhibited formation of collaterals after myocardial infarction in MetS heart may be due to unfavorable changes in endothelial cell metabolism but also to altered expression of vascular endothelial growth factor molecules, their receptors, and changes in signal transduction from the cell membrane, which severely affect angiogenesis.

KEY MESSAGES

Given the established role of cardiac vessel endothelial cells in maintaining tissue homeostasis, defining the molecular background underlying vessel dysfunction associated with impaired angiogenesis is of great importance for future therapeutic purposes. Therefore, the aim of this paper was to present current information regarding vascular endothelial growth factor signaling in the myocardium of MetS individuals.

Decoding Tumor Angiogenesis for Therapeutic Advancements: Mechanistic Insights

Tumor angiogenesis, the formation of new blood vessels within the tumor microenvironment, is considered a hallmark of cancer progression and represents a crucial target for therapeutic intervention. The tumor microenvironment is characterized by a complex interplay between proangiogenic and antiangiogenic factors, regulating the vascularization necessary for tumor growth and metastasis. The study of angiogenesis involves a spectrum of techniques, spanning from biomarker assessment to advanced imaging modalities. This comprehensive review aims to provide insights into the molecular intricacies, regulatory dynamics, and clinical implications of tumor angiogenesis. By delving into these aspects, we gain a deeper understanding of the processes driving vascularization in tumors, paving the way for the development of novel and effective antiangiogenic therapies in the fight against cancer.

Proteomic studies of VEGFR2 in human placentas reveal protein associations with preeclampsia, diabetes, gravidity, and labor

VEGFR2 (Vascular endothelial growth factor receptor 2) is a central regulator of placental angiogenesis. The study of the VEGFR2 proteome of chorionic villi at term revealed its partners MDMX (Double minute 4 protein) and PICALM (Phosphatidylinositol-binding clathrin assembly protein). Subsequently, the oxytocin receptor (OT-R) and vasopressin V1aR receptor were detected in MDMX and PICALM immunoprecipitations. Immunogold electron microscopy showed VEGFR2 on endothelial cell (EC) nuclei, mitochondria, and Hofbauer cells (HC), tissue-resident macrophages of the placenta. MDMX, PICALM, and V1aR were located on EC plasma membranes, nuclei, and HC nuclei. Unexpectedly, PICALM and OT-R were detected on EC projections into the fetal lumen and OT-R on 20-150 nm clusters therein, prompting the hypothesis that placental exosomes transport OT-R to the fetus and across the blood-brain barrier. Insights on gestational complications were gained by univariable and multivariable regression analyses associating preeclampsia with lower MDMX protein levels in membrane extracts of chorionic villi, and lower MDMX, PICALM, OT-R, and V1aR with spontaneous vaginal deliveries compared to cesarean deliveries before the onset of labor. We found select associations between higher MDMX, PICALM, OT-R protein levels and either gravidity, diabetes, BMI, maternal age, or neonatal weight, and correlations only between PICALM-OT-R (p < 2.7 × 10-8), PICALM-V1aR (p < 0.006), and OT-R-V1aR (p < 0.001). These results offer for exploration new partnerships in metabolic networks, tissue-resident immunity, and labor, notably for HC that predominantly express MDMX.

Clinical Outcomes of Faricimab in Patients with Previously Treated Neovascular Age-Related Macular Degeneration

PURPOSE

To assess the anatomic and functional outcomes in eyes with neovascular age-related macular degeneration (nAMD) previously treated with anti-VEGF therapy in response to intravitreal faricimab.

DESIGN

Retrospective, interventional, consecutive case series.

SUBJECTS

Patients with previously treated nAMD who received ≥ 4 consecutive injections of faricimab were included. The study period was from March through November 2022.

METHODS

Clinical and imaging data were extracted from the electronic medical record. Central foveal thickness (CFT), maximum fibrovascular pigment epithelial detachment (fvPED) height, and Snellen visual acuity (VA) were obtained. Generalized estimating equations were used to analyze the change in CFT, maximum fvPED height, and logarithm of the minimum angle of resolution VA.

MAIN OUTCOME MEASURES

Change in CFT, maximum fvPED height, and Snellen VA before faricimab and after ≥ 4 faricimab intravitreal injections.

RESULTS

During the study period, 218 eyes of 191 patients met inclusion criteria. Mean age was 79.9 (range, 70.6-89.2) years. The mean number of intravitreal anti-VEGF injections received before faricimab was 34.2 (range, 6.4-62). The following results were found after ≥ 4 faricimab injections. Mean logarithm of the minimum angle of resolution VA before switching to faricimab was 0.58 (Snellen VA ∼20/76; range, 20/22-20/264) and was 0.55 (Snellen VA ∼20/71; range, 20/21-20/235; P = 0.20) after switching. Mean maximum fvPED height was 195.0 (range, 50.2-339.8) μm before switching to faricimab and improved to 165.0 (range, 33.6-296.4; P < 0.001) μm after switching. Mean CFT was 354.8 (range, 184.7-524.9) μm before switching to faricimab and improved to 306.6 (range, 144.4-468.8; P < 0.001) after switching. The proportion of eyes with intraretinal fluid was 36.7% (80/218 eyes) before switching, and decreased to 24.8% (54/218 eyes, P < 0.001) after switching. The proportion of eyes with subretinal fluid was 53.2% (116/218 eyes) before switching and decreased to 26.6% (58/218 eyes, P < 0.001) after switching.

CONCLUSIONS

Intravitreal faricimab may improve anatomic outcomes in patients with previously treated nAMD, while maintaining VA in the short-term.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Idiopathic and connective tissue disease-associated pulmonary arterial hypertension (PAH): Similarities, differences and the role of autoimmunity

Pre-capillary pulmonary arterial hypertension (PAH) is hemodynamically characterized by a mean pulmonary arterial pressure (mPAP) ≥ 20 mmHg, pulmonary capillary wedge pressure (PAWP) ≤15 mmHg and pulmonary vascular resistance (PVR) > 2. PAH is classified in six clinical subgroups, including idiopathic PAH (IPAH) and PAH associated to connective tissue diseases (CTD-PAH), that will be the main object of this review. The aim is to compare these two PAH subgroups in terms of epidemiology, histological and pathogenic findings in an attempt to define disease-specific features, including autoimmunity, that may explain the heterogeneity of response to therapy between IPAH and CTD-PAH.

Emodin suppresses alkali burn-induced corneal inflammation and neovascularization by the vascular endothelial growth factor receptor 2 signaling pathway

OBJECTIVE

To investigate the effects of emodin on alkali burn-induced corneal inflammation and neovascularization.

METHODS

The ability of emodin to target vascular endothelial growth factor receptor 2 (VEGFR2) was predicted by molecular docking. The effects of emodin on the invasion, migration, and proliferation of human umbilical vein endothelial cells (HUVEC) were determined by cell counting kit-8, Transwell, and tube formation assays. Analysis of apoptosis was performed by flow cytometry. CD31 levels were examined by immunofluorescence. The abundance and phosphorylation state of VEGFR2, protein kinase B (Akt), signal transducer and activator of transcription 3 (STAT3), and P38 were examined by immunoblot analysis. Corneal alkali burn was performed on 40 mice. Animals were divided randomly into two groups, and the alkali-burned eyes were then treated with drops of either 10 μM emodin or phosphate buffered saline (PBS) four times a day. Slit-lamp microscopy was used to evaluate inflammation and corneal neovascularization (CNV) in all eyes on Days 0, 7, 10, and 14. The mice were killed humanely 14 d after the alkali burn, and their corneas were removed and preserved at －80 ℃ until histological study or protein extraction.

RESULTS

Molecular docking confirmed that emodin was able to target VEGFR2. The findings revealed that emodin decreased the invasion, migration, angiogenesis, and proliferation of HUVEC in a dose-dependent manner. In mice, emodin suppressed corneal inflammatory cell infiltration and inhibited the development of corneal neovascularization induced by alkali burn. Compared to those of the PBS-treated group, lower VEGFR2 expression and CD31 levels were found in the emodin-treated group. Emodin dramatically decreased the expression of VEGFR2, p-VEGFR2, p-Akt, p-STAT3, and p-P38 in VEGF-treated HUVEC.

CONCLUSION

This study provides a new avenue for evaluating the molecular mechanisms underlying corneal inflammation and neovascularization. Emodin might be a promising new therapeutic option for corneal alkali burns.

Mechanisms of vascular invasion after cartilage injury and potential engineering cartilage treatment strategies

Articular cartilage injury is one of the most common diseases in orthopedic clinics. Following an articular cartilage injury, an inability to resist vascular invasion can result in cartilage calcification by newly formed blood vessels. This process ultimately leads to the loss of joint function, significantly impacting the patient's quality of life. As a result, developing anti-angiogenic methods to repair damaged cartilage has become a popular research topic. Despite this, tissue engineering, as an anti-angiogenic strategy in cartilage injury repair, has not yet been adequately investigated. This exhaustive literature review mainly focused on the process and mechanism of vascular invasion in articular cartilage injury repair and summarized the major regulatory factors and signaling pathways affecting angiogenesis in the process of cartilage injury. We aimed to discuss several potential methods for engineering cartilage repair with anti-angiogenic strategies. Three anti-angiogenic tissue engineering methods were identified, including administering angiogenesis inhibitors, applying scaffolds to manage angiogenesis, and utilizing in vitro bioreactors to enhance the therapeutic properties of cultured chondrocytes. The advantages and disadvantages of each strategy were also analyzed. By exploring these anti-angiogenic tissue engineering methods, we hope to provide guidance for researchers in related fields for future research and development in cartilage repair.

Research progress on the antitumor effects of harmine

Harmine is a naturally occurring β-carboline alkaloid originally isolated from Peganum harmala. As a major active component, harmine exhibits a broad spectrum of pharmacological properties, particularly remarkable antitumor effects. Recent mechanistic studies have shown that harmine can inhibit cancer cell proliferation and metastasis through epithelial-to-mesenchymal transition, cell cycle regulation, angiogenesis, and the induction of tumor cell apoptosis. Furthermore, harmine reduces drug resistance when used in combination with chemotherapeutic drugs. Despite its remarkable antitumor activity, the application of harmine is limited by its poor solubility and toxic side effects, particularly neurotoxicity. Novel harmine derivatives have demonstrated strong clinical application prospects, but further validation based on drug activity, acute toxicity, and other aspects is necessary. Here, we present a review of recent research on the action mechanism of harmine in cancer treatment and the development of its derivatives, providing new insights into its potential clinical applications and strategies for mitigating its toxicity while enhancing its efficacy.

FBXO22 promotes glioblastoma malignant progression by mediating VHL ubiquitination and degradation

Glioblastoma (GBM) is the most common malignant primary brain tumor. Despite comprehensive treatment with traditional surgery, radiotherapy, and chemotherapy, the median survival rate is <14.6% and the 5-year survival rate is only 5%. FBXO22, a substrate receptor of the SCF ubiquitin ligases, has been reported to play a promoting role in melanoma, liver cancer, cervical cancer, and other cancers. However, the function of FBXO22 in GBM has not been reported. In the present study, we demonstrate that FBXO22 is highly expressed in glioma and is positively correlated with worse pathological features and shorter survival of GBM patients. We revealed that FBXO22 promotes GBM cell proliferation, angiogenesis, migration, and tumorigenesis in vitro and in vivo. In terms of mechanism, we reveal that FBXO22 decreases VHL expression by directly mediating VHL ubiquitination degradation, which ultimately increases HIF-1α and VEGFA expression. In addition, our data confirm that there are positive correlations among FBXO22, HIF-1α, and VEGFA expression, and there is a negative correlation between FBXO22 and VHL protein expression in glioma patients. Our study strongly indicates that FBXO22 is a promising diagnostic marker and therapeutic target for glioma patients.

Aflibercept Off-Target Effects in Diabetic Macular Edema: An In Silico Modeling Approach

Intravitreal aflibercept injection (IAI) is a treatment for diabetic macular edema (DME), but its mechanism of action (MoA) has not been completely elucidated. Here, we aimed to explore IAI's MoA and its multi-target nature in DME pathophysiology with an in silico (computer simulation) disease model. We used the Therapeutic Performance Mapping System (Anaxomics Biotech property) to generate mathematical models based on the available scientific knowledge at the time of the study, describing the relationship between the modulation of vascular endothelial growth factor receptors (VEGFRs) by IAI and DME pathophysiological processes. We also undertook an enrichment analysis to explore the processes modulated by IAI, visualized the effectors' predicted protein activity, and specifically evaluated the role of VEGFR1 pathway inhibition on DME treatment. The models simulated the potential pathophysiology of DME and the likely IAI's MoA by inhibiting VEGFR1 and VEGFR2 signaling. The action of IAI through both signaling pathways modulated the identified pathophysiological processes associated with DME, with the strongest effects in angiogenesis, blood-retinal barrier alteration and permeability, and inflammation. VEGFR1 inhibition was essential to modulate inflammatory protein effectors. Given the role of VEGFR1 signaling on the modulation of inflammatory-related pathways, IAI may offer therapeutic advantages for DME through sustained VEGFR1 pathway inhibition.

CXCL17 is an allosteric inhibitor of CXCR4 through a mechanism of action involving glycosaminoglycans

CXCL17 is a chemokine principally expressed by mucosal tissues, where it facilitates chemotaxis of monocytes, dendritic cells, and macrophages and has antimicrobial properties. CXCL17 is also implicated in the pathology of inflammatory disorders and progression of several cancers, and its expression is increased during viral infections of the lung. However, the exact role of CXCL17 in health and disease requires further investigation, and there is a need for confirmed molecular targets mediating CXCL17 functional responses. Using a range of bioluminescence resonance energy transfer (BRET)-based assays, here we demonstrated that CXCL17 inhibited CXCR4-mediated signaling and ligand binding. Moreover, CXCL17 interacted with neuropillin-1, a VEGFR2 coreceptor. In addition, we found that CXCL17 only inhibited CXCR4 ligand binding in intact cells and demonstrated that this effect was mimicked by known glycosaminoglycan binders, surfen and protamine sulfate. Disruption of putative GAG binding domains in CXCL17 prevented CXCR4 binding. This indicated that CXCL17 inhibited CXCR4 by a mechanism of action that potentially required the presence of a glycosaminoglycan-containing accessory protein. Together, our results revealed that CXCL17 is an endogenous inhibitor of CXCR4 and represents the next step in our understanding of the function of CXCL17 and regulation of CXCR4 signaling.

The VEGFs/VEGFRs system in Alzheimer's and Parkinson's diseases: Pathophysiological roles and therapeutic implications

The vascular endothelial growth factors (VEGFs) and their cognate receptors (VEGFRs), besides their well-known involvement in physiological angiogenesis/lymphangiogenesis and in diseases associated to pathological vessel formation, play multifaceted functions in the central nervous system (CNS). In addition to shaping brain development, by controlling cerebral vasculogenesis and regulating neurogenesis as well as astrocyte differentiation, the VEGFs/VEGFRs axis exerts essential functions in the adult brain both in physiological and pathological contexts. In this article, after describing the physiological VEGFs/VEGFRs functions in the CNS, we focus on the VEGFs/VEGFRs involvement in neurodegenerative diseases by reviewing the current literature on the rather complex VEGFs/VEGFRs contribution to the pathogenic mechanisms of Alzheimer's (AD) and Parkinson's (PD) diseases. Thereafter, based on the outcome of VEGFs/VEGFRs targeting in animal models of AD and PD, we discuss the factual relevance of pharmacological VEGFs/VEGFRs modulation as a novel and potential disease-modifying approach for these neurodegenerative pathologies. Specific VEGFRs targeting, aimed at selective VEGFR-1 inhibition, while preserving VEGFR-2 signal transduction, appears as a promising strategy to hit the molecular mechanisms underlying AD pathology. Moreover, therapeutic VEGFs-based approaches can be proposed for PD treatment, with the aim of fine-tuning their brain levels to amplify neurotrophic/neuroprotective effects while limiting an excessive impact on vascular permeability.

Potential oral VEGFR2 inhibitors: Treatment of wet age-related macular degeneration

Wet age-related macular degeneration (w-AMD) is one of the leading causes of vision loss in industrialized countries. A large body of evidence suggests that inhibitors targeting VEGFR2 may be effective in the treatment of w-AMD. The identification of an oral VEGFR2 inhibitor for the treatment of w-AMD provides an opportunity for a route of administration other than intravitreal injection. While screening potent VEGFR2 inhibitors at the enzyme and cellular levels, ensuring the safety of the compounds was our primary strategy for screening optimal compounds. Finally, compound 16 was identified, exhibiting enhanced inhibition of VEGFR2 enzyme and proliferation of BaF3-TEL-VEGFR2 cells compared to Vorolanib. Compound 16 had a weak inhibitory effect on human Ether-a-go-go-related gene (hERG) channel currents, showing a cardiac safety profile similar to Vorolanib. Compound 16 showed no significant toxicity to human liver cell LX-2, indicating a liver safety profile similar to Vorolanib. The water solubility of compound 16 was found to be higher than that of Vorolanib when tested at pH = 7.4. In addition, compound 16 was found to inhibit VEGFR2 phosphorylation in human umbilical vein endothelial cells (HUVECs) in a dose-dependent manner by WB assay. Furthermore, the in vitro preliminary evaluation of the drug-like properties of compound 16 showed remarkable plasma stability and moderate liver microsomal stability. Based on in vivo pharmacokinetic studies in ICR mice, compound 16 exhibited acceptable oral bioavailability (F = 20.2 %). Overall, these findings provide evidence that compound 16 is a leading potential oral drug candidate for w-AMD.

Small molecule agents for triple negative breast cancer: Current status and future prospects

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with poor prognosis. The number of cases increased by 2.26 million in 2020, making it the most commonly diagnosed cancer type in the world. TNBCs lack hormone receptor (HR) and human epidermal growth factor 2 (HER2), which limits treatment options. Currently, paclitaxel-based drugs combined with other chemotherapeutics remain the main treatment for TNBC. There is currently no consensus on the best therapeutic regimen for TNBC. However, there have been successful clinical trials exploring large-molecule monoclonal antibodies, small-molecule targeted drugs, and novel antibody-drug conjugate (ADC). Although monoclonal antibodies have produced clinical success, their large molecular weight can limit therapeutic benefits. It is worth noting that in the past 30 years, the FDA has approved small molecule drugs for HER2-positive breast cancers. The lack of effective targets and the occurrence of drug resistance pose significant challenges in the treatment of TNBC. To improve the prognosis of TNBC, it is crucial to search for effective targets and to overcome drug resistance. This review examines the clinical efficacy, adverse effects, resistance mechanisms, and potential solutions of targeted small molecule drugs in both monotherapies and combination therapies. New therapeutic targets, including nuclear export protein 1 (XPO1) and hedgehog (Hh), are emerging as potential options for researchers and become integrated into clinical trials for TNBC. Additionally, there is growing interest in the potential of targeted protein degradation chimeras (PROTACs), degraders of rogue proteins, as a future therapy direction. This review provides potentially valuable insights with clinical implications.

Comprehensive structural and functional analysis of hVEGFR1: Insights into phosphorylation, molecular interactions, and potential inhibitors through docking and dynamics simulations

Vascular Endothelial Growth Factor Receptor 1 (VEGFR1), is an enzyme with tyrosine kinase activity that plays a pivotal role in angiogenesis, the process of new blood vessel formation. This receptor is of significant clinical importance as it is implicated in various cancers, particularly non-small cell lung cancer (NSCLC), where its dysregulation leads to uncontrolled cell growth through ligand-induced phosphorylation. While commercially available drugs target VEGFR1, their prolonged use often leads to drug resistance and the emergence of mutations in cancer patients. To address these challenges, researchers have identified the human tyrosine kinase (hTK) domain of VEGFR1 as a potential therapeutic marker for lung malignancies. The 3D crystal structure of the hTK domain, obtained from Protein Data Bank (PDB ID: 3HNG), has provided vital structural insights of hVEGFR1. This study has revealed variations within the hVEGFR1 tyrosine kinase domain, distinguishing between regions associated with phosphorylase kinase and transferase activities. We identified numerous potential phosphorylation sites within the TK domain, shedding light on the protein's regulation and signaling possible. Detailed molecular interaction analyses have elucidated the binding forces between lead molecules and hVEGFR1, including hydrogen bonds, electrostatic, hydrophobic, and π-sigma interactions. The stability observed during molecular dynamics simulations further underscores the biological relevance of these interactions. Furthermore, docked complexes has highlighted localized structural fluctuations, offering insight into potential allosteric effects and dynamic conformational changes induced by lead molecules. These findings not only provide a comprehensive characterization of hVEGFR1 but also pave the way for the development of targeted therapies. Eventually, this study has the potential in identifying drug to combat diseases associated with hVEGFR1 dysregulation, including cancer and angiogenesis-related disorders, contributing to effective treatment strategies.

Hydrogel-Based Therapy for Age-Related Macular Degeneration: Current Innovations, Impediments, and Future Perspectives

Age-related macular degeneration (AMD) is an ocular disease that leads to progressive photoreceptor death and visual impairment. Currently, the most common therapeutic strategy is to deliver anti-vascular endothelial growth factor (anti-VEGF) agents into the eyes of patients with wet AMD. However, this treatment method requires repeated injections, which potentially results in surgical complications and unwanted side effects for patients. An effective therapeutic approach for dry AMD also remains elusive. Therefore, there is a surge of enthusiasm for the developing the biodegradable drug delivery systems with sustained release capability and develop a promising therapeutic strategy. Notably, the strides made in hydrogels which possess intricate three-dimensional polymer networks have profoundly facilitated the treatments of AMD. Researchers have established diverse hydrogel-based delivery systems with marvelous biocompatibility and efficacy. Advantageously, these hydrogel-based transplantation therapies provide promising opportunities for vision restoration. Herein, we provide an overview of the properties and potential of hydrogels for ocular delivery. We introduce recent advances in the utilization of hydrogels for the delivery of anti-VEGF and in cell implantation. Further refinements of these findings would lay the basis for developing more rational and curative therapies for AMD.

Isoimperatorin Inhibits Angiogenesis by Suppressing VEGFR2 Signaling Pathway

PURPOSE

Angiogenesis involves in many pathological processes, including tumor metastasis, diabetic retinopathy, and rheumatoid arthritis. Therefore, identifying therapeutic drugs that target angiogenesis may be a promising strategy for disease treatment. Isoimperatorin is a furanocoumarin with anti-inflammatory and anti-microbial effects. However, the impacts of isoimperatorin on angiogenesis and its underlying mechanisms remain unclear. This study aimed to verify its effects on vascular endothelial growth factor (VEGF)-induced endothelial angiogenesis.

METHODS

We employed various assays including 5-ethynyl-2'-deoxyuridine incorporation assay, transwell migration assay, wound healing assay, tube formation assay, and Western blot to evaluate the effects of isoimperatorin on angiogenesis in vitro. Additionally, we utilized Western blot and immunofluorescence analysis to examine the activation of vascular endothelial growth factor receptor (VEGFR) 2 and its downstream signaling pathways following isoimperatorin treatment. To further validate the anti-angiogenic effects of isoimperatorin in vivo, we conducted a matrigel plug assay and established an orthotopic tumor model.

RESULTS

We demonstrated that pretreatment with isoimperatorin inhibited VEGF-induced endothelial cell proliferation, migration, and tube formation. Isoimperatorin also suppressed angiogenesis in vivo in a matrigel plug assay and in an orthotopic tumor model. Our results revealed that isoimperatorin exhibited anti-angiogenic effects via inhibiting VEGFR2 and its downstream signaling pathways activation.

CONCLUSIONS

Our study showed that isoimperatorin suppressed angiogenesis by targeting the VEGFR2 signaling pathway and could be a potential therapeutic agent for targeting angiogenesis.

Effects of HMGB1/TLR4 on secretion IL-10 and VEGF in human jaw bone-marrow mesenchymal stem cells

OBJECTIVE

We aimed to investigate the regulatory effects of HMGB1/TLR4 signaling pathway on the expression of IL-10 and VEGF in human bone marrow mesenchymal stem cells.

METHODOLOGY

Human JBMSCs were isolated and cultured. Then, HMGB1 was added into the JBMSCs culture medium, and the protein and mRNA expression levels of IL-10 and VEGF were assessed. Moreover, cells were pretreated with a specific TLR4 inhibitor (TAK-242), and the expression changes of IL-10 and VEGF were compared.

RESULTS

Compared with the control group, exposure to HMGB1 in human JBMSCs up-regulated TLR4, IL-10, and VEGF secretion at both protein and mRNA levels (P<0. 05). In addition, the increased expression of IL-10 and VEGF could be restrained in TAK-242 group compared with the HMGB1 group (P<0.05).

CONCLUSIONS

The results indicated that HMGB1 activate TLR4 signaling pathway in Human JBMSCs, which plays a regulatory role in cytokines expression.

Challenging the anticolorectal cancer capacity of quinoxaline-based scaffold via triazole ligation unveiled new efficient dual VEGFR-2/MAO-B inhibitors

Monoamine oxidases (MAOs) and vascular endothelial growth factor receptor-2 (VEGFR-2) are promoters of colorectal cancer (CRC) and central signaling nodes in epithelial-mesenchymal transition (EMT) induced by activating hypoxia-inducible factors (HIFs). Herein, a novel series of rationally designed triazole-tethered quinoxalines were synthesized and evaluated against HCT-116 CRC cells. The tailored scaffolds combine the pharmacophoric themes of both VEGFR-2 inhibitors and MAO inhibitors. All the synthesized derivatives were screened utilizing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay for their possible cytotoxic effects on normal human colonocytes, then evaluated for their anticancer activities against HCT-116 cells overexpressing MAOs. The hit derivatives 11 and 14 exhibited IC50 = 18.04 and 7.850 µM, respectively, against HCT-116cells within their EC100 doses on normal human colonocytes. Wound healing assay revealed their efficient CRC antimetastatic activities recording HCT-116 cell migration inhibition exceeding 75 %. In vitro enzymatic assays demonstrated that both 11 and 14 efficiently inhibited VEGFR-2 (IC50 = 88.79 and 9.910 nM), MAO-A (IC50 = 0.763 and 629.1 nM) and MAO-B (IC50 = 0.488 and 209.6 nM) with observed MAO-B over MAO-A selectivity (SI = 1.546 and 3.001), respectively. Enzyme kinetics studies were performed for both compounds to identify their mode of MAO-B inhibition. Furthermore, qRT-PCR analysis showed that the hits efficiently downregulated HIF-1α in HCT-116cells by 3.420 and 16.96 folds relative to untreated cells. Docking studies simulated their possible binding modes within the active sites of VEGFR-2 and MAO-B to highlight their essential structural determinants of activities. Finally, they recorded in silico drug-like absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiles as well as ligand efficiency metrics.

Nonsynonymous mutations in VEGF receptor binding domain alter the efficacy of bevacizumab treatment

Vascular endothelial growth factor (VEGF) mediated angiogenesis is crucial for tumor progression. Isoforms of VEGF bind to different VEGF receptors (VEGFRs) to initiate angiogenesis specific cellular signaling. Inhibitors that target both the receptors and ligands are in clinical use to impede angiogenesis. Bevacizumab, a monoclonal antibody (mAb) approved by the Food and Drug Administration (FDA), binds in the VEGF receptor binding domain (RBD) of all soluble isoforms of VEGF and inhibits the VEGF-VEGFR interaction. Bevacizumab is also used in combination with other chemotherapeutic agents for a better therapeutic outcome. Understanding the intricate polymorphic character of VEGFA gene and the influence of missense or nonsynonymous mutations in the form of nonsynonymous polymorphisms (nsSNPs) on RBD of VEGF may aid in increasing the efficacy of this drug. This study has identified 18 potential nsSNPs in VEGFA gene that affect the VEGF RBD structure and alter its binding pattern to bevacizumab. The mutated RBDs, modeled using trRosetta, in addition to the changed pattern of secondary structure, post translational modification and stability compared to the wild type, have shown contrasting binding affinity and molecular interaction pattern with bevacizumab. Molecular docking analysis by ClusPro and visualization using PyMol and PDBsum tools have detected 17 nsSNPs with decreased binding affinity to bevacizumab and therefore may impact the treatment efficacy. Whereas VEGF RBD expressed due to rs1267535717 (R229H) nsSNP of VEGFA has increased affinity to the mAb. This study suggests that genetic characterization of VEGFA before bevacizumab mediated cancer treatment is essential in predicting the appropriate efficacy of the drug, as the treatment efficiency may vary at individual level.

NRP1 interacts with endoglin and VEGFR2 to modulate VEGF signaling and endothelial cell sprouting

Endothelial cells express neuropilin 1 (NRP1), endoglin (ENG) and vascular endothelial growth factor receptor 2 (VEGFR2), which regulate VEGF-A-mediated vascular development and angiogenesis. However, the link between complex formation among these receptors with VEGF-A-induced signaling and biology is yet unclear. Here, we quantify surface receptor interactions by IgG-mediated immobilization of one receptor, and fluorescence recovery after photobleaching (FRAP) measurements of the mobility of another coexpressed receptor. We observe stable ENG/NRP1, ENG/VEGFR2, and NRP1/VEGFR2 complexes, which are enhanced by VEGF-A. ENG augments NRP1/VEGFR2 interactions, suggesting formation of tripartite complexes bridged by ENG. Effects on signaling are measured in murine embryonic endothelial cells expressing (MEEC+/+) or lacking (MEEC-/-) ENG, along with NRP1 and/or ENG overexpression or knockdown. We find that optimal VEGF-A-mediated phosphorylation of VEGFR2 and Erk1/2 requires ENG and NRP1. ENG or NRP1 increase VEGF-A-induced sprouting, becoming optimal in cells expressing all three receptors, and both processes are inhibited by a MEK1/2 inhibitor. We propose a model where the maximal potency of VEGF-A involves a tripartite complex where ENG bridges VEGFR2 and NRP1, providing an attractive therapeutic target for modulation of VEGF-A signaling and biological responses.

Epsin Endocytic Adaptor Proteins in Angiogenic and Lymphangiogenic Signaling

Circulating vascular endothelial growth factor (VEGF) ligands and receptors are central regulators of vasculogenesis, angiogenesis, and lymphangiogenesis. In response to VEGF ligand binding, VEGF receptor tyrosine kinases initiate the chain of events that transduce extracellular signals into endothelial cell responses such as survival, proliferation, and migration. These events are controlled by intricate cellular processes that include the regulation of gene expression at multiple levels, interactions of numerous proteins, and intracellular trafficking of receptor-ligand complexes. Endocytic uptake and transport of macromolecular complexes through the endosome-lysosome system helps fine-tune endothelial cell responses to VEGF signals. Clathrin-dependent endocytosis remains the best understood means of macromolecular entry into cells, although the importance of non-clathrin-dependent pathways is increasingly recognized. Many of these endocytic events rely on adaptor proteins that coordinate internalization of activated cell-surface receptors. In the endothelium of both blood and lymphatic vessels, epsins 1 and 2 are functionally redundant adaptors involved in receptor endocytosis and intracellular sorting. These proteins are capable of binding both lipids and proteins and are important for promoting curvature of the plasma membrane as well as binding ubiquitinated cargo. Here, we discuss the role of epsin proteins and other endocytic adaptors in governing VEGF signaling in angiogenesis and lymphangiogenesis and discuss their therapeutic potential as molecular targets.

Zeolite imidazolate framework-8 in bone regeneration: A systematic review

Zeolite imidazolate framework-8 (ZIF-8) is a biomaterial that has been increasingly studied in recent years. It has several applications such as bone regeneration, promotion of angiogenesis, drug loading, and antibacterial activity, and exerts multiple effects to deal with various problems in the process of bone regeneration. This systematic review aims to provide an overview of the applications and effectiveness of ZIF-8 in bone regeneration. A search of papers published in the PubMed, Web of Science, Embase, and Cochrane Library databases revealed 532 relevant studies. Title, abstract, and full-text screening resulted in 39 papers being included in the review, including 39 in vitro and 22 animal studies. Appropriate concentrations of nano ZIF-8 can promote cell proliferation and osteogenic differentiation by releasing Zn2+ and entering the cell, whereas high doses of ZIF-8 are cytotoxic and inhibit osteogenic differentiation. In addition, five studies confirmed that ZIF-8 exhibits good vasogenic activity. In all in vivo experiments, nano ZIF-8 promoted bone formation. These results indicate that, at appropriate concentrations, materials containing ZIF-8 promote bone regeneration more than materials without ZIF-8, and with characteristics such as promoting angiogenesis, drug loading, and antibacterial activity, it is expected to show promising applications in the field of bone regeneration. STATEMENT OF SIGNIFICANCE: This manuscript reviewed the use of ZIF-8 in bone regeneration, clarified the biocompatibility and effectiveness in promoting bone regeneration of ZIF-8 materials, and discussed the possible mechanisms and factors affecting its promotion of bone regeneration. Overall, this study provides a better understanding of the latest advances in the field of bone regeneration of ZIF-8, serves as a design guide, and contributes to the design of future experimental studies.

HIF-1α signaling: Essential roles in tumorigenesis and implications in targeted therapies

The hypoxic microenvironment is an essential characteristic of most malignant tumors. Notably, hypoxia-inducible factor-1 alpha (HIF-1α) is a key regulatory factor of cellular adaptation to hypoxia, and many critical pathways are correlated with the biological activity of organisms via HIF-1α. In the intra-tumoral hypoxic environment, HIF-1α is highly expressed and contributes to the malignant progression of tumors, which in turn results in a poor prognosis in patients. Recently, it has been indicated that HIF-1α involves in various critical processes of life events and tumor development via regulating the expression of HIF-1α target genes, such as cell proliferation and apoptosis, angiogenesis, glucose metabolism, immune response, therapeutic resistance, etc. Apart from solid tumors, accumulating evidence has revealed that HIF-1α is also closely associated with the development and progression of hematological malignancies, such as leukemia, lymphoma, and multiple myeloma. Targeted inhibition of HIF-1α can facilitate an increased sensitivity of patients with malignancies to relevant therapeutic agents. In the review, we elaborated on the basic structure and biological functions of HIF-1α and summarized their current role in various malignancies. It is expected that they will have future potential for targeted therapy.

Thalidomide suppresses migration and invasion of colorectal cancer cells by inhibiting HOXB7-mediated activation of the Wnt/β-catenin signaling pathway

Heaps of studies have verified the effects of thalidomide (THA) on colorectal cancer (CRC). Howbeit, the corresponding mechanism awaits illustration, which is the foothold of this study. Following the treatment of 0, 1.94, 7.75, or 19.36 μM THA, CRC cell viability, apoptosis, migration, and invasion were evaluated by methyl tetrazolium, flow cytometry, wound-healing, and transwell assays. Homeobox B7 (HOXB7) expression in CRC was analyzed and detected by bioinformatics analysis, quantitative real-time PCR or western blot. After the corresponding transfection or treatment with inhibitor of catenin-responsive transcription-3 (iCRT-3), abovementioned CRC cell biological behaviors as well as expression levels of HOXB7 and β-catenin were evaluated. 7.75 and 19.36 μM THA dwindled CRC cell viability, migration, and invasion, and facilitated apoptosis. HOXB7 upregulation was detected in CRC cells, which promoted the viability, migration, invasion, and β-catenin expression, and weakened the apoptosis of CRC cells. Also, HOXB7 upregulation counteracted the effects of THA on CRC cells. iCRT-3 restrained β-catenin expression, viability, migration, and invasion, whereas promoting the apoptosis of CRC cells. In addition, iCRT-3 antagonized the effects of overexpressed HOXB7 on CRC cells. THA inhibits the migration and invasion of CRC cells, which is achieved by suppressing HOXB7-mediated activation of Wnt/β-catenin signaling pathway.

Dual targeting of DR5 and VEGFR2 molecular pathways by multivalent fusion protein significantly suppresses tumor growth and angiogenesis

Destroying tumor vasculature is a relevant therapeutic strategy due to its involvement in tumor progression. However, adaptive resistance to approved antiangiogenic drugs targeting VEGF/VEGFR pathway requires the recruitment of additional targets. In this aspect, targeting TRAIL pathway is promising as it is an important component of the immune system involved in tumor immunosurveillance. For dual targeting of malignant cells and tumor vascular microenvironment, we designed a multivalent fusion protein SRH-DR5-B-iRGD with antiangiogenic VEGFR2-specific peptide SRH at the N-terminus and a tumor-targeting and -penetrating peptide iRGD at the C-terminus of receptor-selective TRAIL variant DR5-B. SRH-DR5-B-iRGD obtained high affinity for DR5, VEGFR2 and αvβ3 integrin in nanomolar range. Fusion of DR5-B with effector peptides accelerated DR5 receptor internalization rate upon ligand binding. Antitumor efficacy was evaluated in vitro in human tumor cell lines and primary patient-derived glioblastoma neurospheres, and in vivo in xenograft mouse model of human glioblastoma. Multivalent binding of SRH-DR5-B-iRGD fusion efficiently stimulated DR5-mediated tumor cell death via caspase-dependent mechanism, suppressed xenograft tumor growth by >80 %, doubled the lifespan of xenograft animals, and inhibited tumor vascularization. Therefore, targeting DR5 and VEGFR2 molecular pathways with SRH-DR5-B-iRGD protein may provide a novel therapeutic approach for treatment of solid tumors.

Role of endothelin ETA receptors in the hypertension induced by the VEGFR-2 kinase inhibitors axitinib and lenvatinib in conscious freely-moving rats

Receptor tyrosine kinase inhibitors (RTKIs) suppress tumour growth by targeting vascular endothelial growth factor receptor 2 (VEGFR-2) which is an important mediator of angiogenesis. Here, we demonstrate that two potent RTKIs, axitinib and lenvatinib, are associated with hypertensive side effects. Doppler flowmetry was used to evaluate regional haemodynamic profiles of axitinib and lenvatinib. Male Sprague Dawley rats (350-500 g) were instrumented with Doppler flow probes (renal and mesenteric arteries and descending abdominal aorta) and catheters (jugular vein and distal abdominal aorta, via the caudal artery). Rats were dosed daily with axitinib (3 or 6 mg.kg-1) or lenvatinib (1 or 3 mg.kg-1) and regional haemodynamics were recorded over a maximum of 4 days. Both RTKIs caused significant (p < 0.05) increases in mean arterial pressure (MAP), which was accompanied by significant (p < 0.05) vasoconstriction in both the mesenteric and hindquarters vascular beds. To gain insight into the involvement of endothelin-1 (ET-1) in RTKI-mediated hypertension, we also monitored heart rate (HR) and MAP in response to axitinib or lenvatinib in animals treated with the ETA receptor selective antagonist sitaxentan (5 mg.kg-1) or the mixed ETA/ETB receptor antagonist bosentan (15 mg.kg-1) over two days. Co-treatment with bosentan or sitaxentan markedly reduced the MAP effects mediated by both RTKIs (p < 0.05). Bosentan, but not sitaxentan, also attenuated ET-1 mediated increases in HR. These data suggest that selective antagonists of ETA receptors may be appropriate to alleviate the hypertensive effects of axitinib and lenvatinib.

Association analysis of Vascular Endothelial Growth Factor-A (VEGF-A) polymorphism in rheumatoid arthritis using computational approaches

Rheumatoid arthritis (RA), is marked by joint inflammation leading to pannus formation which results in cartilage destruction promoting bone erosion. The pathological hallmark of RA includes synovial hyperplasia and synovial angiogenesis. Active tissue neovascularization is observed in RA. Vascular endothelial Growth factor A (VEGFA), an endothelial cell-specific proangiogenic molecule is triggered by hypoxic cells and its levels are upregulated in RA. The aim of this study was to investigate functional and pathogenic VEGFA variants and to identify the impact of point mutation in VEGFA's interaction with VEGFR2 and how these polymorphisms affect the susceptibility and severity of RA. We investigated impact of these point mutations on the stability of VEGFA using various computational tools. These mutations were further identified by conservational profile as they are highly involved as structural and functional mutations. Furthermore, these selected variants were modelled and docked against targeted domain regions IGD2 and IGD3 of VEGFR2. Further molecular dynamic simulations were performed using Gromacs. Out of 168 nsSNPS, 19 were highlighted as highly pathogenic using insilico prediction tools. InterPro and ConSurf revealed domains and conserved variants respectively. After stability analysis, we concluded that almost all the mutations were responsible for decreasing the protein stability. HOPE predicted that all the selected damaging nsSNPs were present in the domain which is essential for the functioning of VEGFA protein. Constructed Ramachandran plot and ERRAT validated the quality of all the models. Based on the interactions predicted by STRING database, we performed Protein-Protein docking between VEGFA and VEGFR2. We found few conserved interactions and new polar contacts among wild-type and mutants with VEGFR2. From the simulations, we concluded that mutant R108Q was the most stabilizing mutant among all others whereas R82Q, C86Y, and R108W complexed with VEGFR2 were comparatively less stabilizing as compared to the wild type. This study provides insight into pathogenic nsSNPs that can affect VEGFA protein structure and function. These high-risk variants must be taken into consideration for genetic screening of patients suffering from RA.

Synergic effects of EP2 and FP receptors co-activation on Blood-Retinal Barrier and Microglia

Macular edema (ME) is caused with disruption of the blood-retinal barrier (BRB) followed by fluid accumulation in the subretinal space. Main components of the outer and inner BRB are retinal pigment epithelial (RPE) cells and retinal microvascular endothelial cells, respectively. In addition, glial cells also participate in the functional regulation of the BRB as the member of 'neurovascular unit'. Under various stresses, cells in neurovascular units secrete inflammatory cytokines. Neuroinflammation induced by these cytokines can cause BRB dysfunction by degrading barrier-related proteins and contribute to the pathophysiology of ME. Prostaglandins (PGs) are crucial lipid mediators involved in neuroinflammation. Among PGs, a novel EP2 agonist, omidenepag (OMD) acts on not only the uveoscleral pathway but also the conventional pathway, unlike F prostanoid (FP) receptor agonists. Moreover, the combination use of the EP and the FP agonist is not recommended because of the risk of inflammation. In this study, we investigated effects of OMD and latanoprost acid (LTA), a FP agonist, on BRB and microglia in vitro and in vivo. To investigate the function of outer/inner BRB and microglia, in vitro, ARPE-19 cells, human retinal microvascular endothelial cells (HRMECs), and MG5 cells were used. Cell viability, inflammatory cytokines mRNA and protein levels, barrier morphology/function, and microglial activation were evaluated using proliferation assays, qRT-PCR, ELISA, immunocytochemistry, trans-epithelial electrical resistance, and permeability assay. Moreover, after vitreous injection into the mouse, outer BRB morphology, glial activation, and cytokine expression were assessed. Each OMD and LTA alone did not affect the viability or cytokines expression of the three types of cells. In ARPE-19 cells, the co-stimulation of OMD and LTA increased the mRNA and protein levels of inflammatory cytokines (IL-6, TNF-α, and VEGF-A) and decreased the barrier function and the junction-related protein (ZO-1 and β-catenin). By contrast in HRMECs, the co-stimulation affected significant differences in the mRNA levels of some cytokine (IL-6 and TNF-α) but enhanced the barrier function. In MG5 cells, the cytokines mRNA and size of Iba1-expressed cell were increased. A non-steroidal anti-inflammatory inhibited the barrier dysfunction and the junction-related protein downregulation in ARPE-19 cells and activation of MG5 cells. Also in vivo, the co-stimulation induced outer BRB disruption, cytokine increase, and retinal glial activation. Therefore, the co-stimulation of EP2 and FP induced the inflammatory cytokine-mediated outer BRB disruption, the enhanced inner BRB function, and the microglial activation. The BRB imbalance and the intrinsic prostaglandin production may be involved in OMD-related inflammation.

Zinc regulates a specific subpopulation of VEGFA + microglia to improve the hypoxic microenvironment for functional recovery after spinal cord injury

INTRODUCTION

Spinal cord injury (SCI) is a central nervous system injury that is primarily traumatic and manifests as autonomic dysfunction below the level of injury. Our previous studies have found that zinc ions have important effects on the nervous system and nerve repair, promoting autophagy and reducing inflammatory responses. However, the role of zinc ions in vascular regeneration is unclear.

AIMS

We investigated the effect of zinc ions after spinal cord injury from the perspective of a hypoxic microenvironment, and elucidated the role of VEGF-A secreted by microglia for vascular regeneration after spinal cord injury, providing new ideas for the treatment of spinal cord injury.

RESULTS

Zinc promotes functional recovery after spinal cord injury by regulating VEGF-A secretion from microglia. On the one hand, VEGF-A secreted by microglia promotes angiogenesis through the PI3K/AKT/Bcl-2 pathway and improves the hypoxic microenvironment after spinal cord injury. On the other hand, VEGF-A secreted by microglia was positively correlated with platelet endothelial cell adhesion molecule-1 (CD31), and zinc could increase the association between microglia and blood vessels.

CONCLUSION

Zinc promoted microglia secretion of VEGF-A, increased vascular endothelial cell proliferation and migration through the PI3K/AKT/Bcl-2 pathway, and inhibited microglia apoptosis.

Extensive preclinical evaluation of combined mangiferin and glycyrrhizic acid for restricting synovial neovascularization in rheumatoid arthritis

BACKGROUND

Synovial neovascularization promotes rheumatoid arthritis (RA) progression. Baihu guizhi decoction (BHGZD) has a potential in restricting this pathological change of RA.

PURPOSE

To identify bioactive compounds (BACs) of BHGZD and to elucidate the underlying mechanisms in restricting synovial neovascularization of RA.

METHOD

Through transcriptomic profiling, the chemical profiling of BHGZD and its effective transcriptomic profiling against RA were identified. Then, candidate targets and the corresponding BACs against synovial neovascularization were screened by "disease gene-drug target" interaction network analysis and in silico molecular docking. The binding affinities of candidate BAC-target pairs were verified using surface plasmon resonance, and the pharmacokinetic characteristics of BACs in vivo after BHGZD administration at different time points were detected by Ultra Performance Liquid Chromatography-Mass spectrum/Mass spectrum. After that, in vivo experiments based on adjuvant-induced arthritis (AIA-M) rats, and in vitro experiments based on human umbilical vein endothelial cells (HUVEC) and arthritic synovial fibroblasts (MH7A) were carried out to evaluate the pharmacological effects of BHGZD and the two-BACs-combination, and to verify the associated mechanisms.

RESULT

VEGFA/VEGFR2/SRC/PI3K/AKT signal axis was screened as one of the key network targets of BHGZD against synovial neovascularization in RA. Mangiferin (MG) and glycyrrhizic acid (GA) were identified as the representative BACs of BHGZD for their strong binding affinities with components of the VEGFA/VEGFR2/SRC/PI3K/AKT signal axis, and their high exposed quantity in vivo. Both BHGZD and the two-BAC combination of MG and GA were demonstrated to be effective in restricting disease severity, reducing synovial inflammation and decreasing the formation of vascular opacities in AIA-M rats, and also reducing the migrative and invasive activities of HUVEC and MH7A cells and attenuating the lumen formation ability of HUVEC cells significantly. Mechanically, both BHGZD and the two-BAC combination markedly reduced the expression of VEGFA in synovial tissues, the serum levels of VEGF and NO, and the enzymatic activity of eNOS, increased the content of endostatin, and also reversed the abnormal alterations in the VEGFA/VEGFR2/SRC/PI3K/AKT signal axis in vivo and in vitro.

CONCLUSION

MG and GA may be the representative BACs of BHGZD for restricting excessive synovial vascularization in RA via regulating VEGFA/VEGFR2/SRC/PI3K/AKT signal axis.

Photothermal-Ionic-Pharmacotherapy of Myocardial Infarction with Enhanced Angiogenesis and Antiapoptosis

Promoting angiogenesis is an effective therapeutic strategy to repair damaged hearts after myocardial infarction (MI). Copper ions and mild heat (41-42 °C) have been shown to promote angiogenesis, but their efficacy in MI is unknown. Here, a multicomponent hydrogel (EDR@PHCuS HG) is developed by encapsulating edaravone (EDR, a free radical scavenger) loaded porous hollow copper sulfide nanoparticles (PHCuS NPs) in a hyaluronic acid hydrogel (HG). Exposed to 808 nm near-infrared (NIR) light irradiation, the EDR@PHCuS HG exhibits controlled copper-ion release and mild photothermal effect to synergistically promote angiogenesis. In addition, released EDR inhibits cardiomyocyte apoptosis to further repair hearts. In the mouse model of MI, treatment with the EDR@PHCuS HG under an 808 nm laser significantly recovers the cardiac function and inhibits ventricular remodeling. This platform elucidates the cardioprotective effects of copper ions and mild heat and will provide a highly efficient treatment for MI.

Mechanisms of resveratrol against diabetic wound by network pharmacology and experimental validation

BACKGROUND

Resveratrol (RSV) that possesses anti-oxidative, anti-inflammatory, and pro-angiogenic effects is an effective drug for diabetic wound (DW), while its pharmacological mechanism remains to be elucidated. In this study, we apply network pharmacology and experimental validation approach to reveal the potential mechanism of RSV against DW.

METHODS

We obtained potential targets for RSV and DW from the publicly available database. Using interaction networks and conducting GO and KEGG pathway enrichment analyses, we constructed target-pathway networks to explore the relationship between RSV and DW. To validate the pharmacological mechanism of RSV, we induced the DW model.

RESULTS

Ninety overlapped targets between RSV and DW were obtained, and the hub genes of the PPI network included TNF, IL-6, CASP3, MAPK3, VEGFA, IL-1β, AKT1, and JUN. Based on target-pathway networks, the AGE-RAGE signalling pathway was involved in the RSV treatment of DW. Furthermore, in vivo experiments revealed that RSV significantly promoted wound healing in diabetic mice and attenuated the expression of pro-inflammatory cytokines in wound tissue. Meanwhile, RSV could inhibit the AGE-RAGE signalling pathway and thus reduce the activation of NF-κB.

CONCLUSION

This study initially revealed the biological mechanism of RSV for treating DW through multi-target and multi-pathway. AGE-RAGE, FoxO, MAPK, PI3K-AKT and other signalling pathways may be the main pathways of RSV in treating DW. RSV reduces the inflammatory response by inhibiting the AGE-RAGE signalling pathway, which in turn promotes DW healing.