ILT4 facilitates angiogenesis in non-small cell lung cancer.

Antiangiogenic therapy targeting VEGF-A has become the standard of first-line therapy for non-small cell lung cancer (NSCLC). However, its clinical response rate is still less than 50%, and most patients eventually develop resistance, even when using combination therapy with chemotherapy. The major cause of resistance is the activation of complex bypass signals that induce angiogenesis and tumor progression. Therefore, exploring novel proangiogenic mechanisms and developing promising targets for combination therapy are crucial for improving the efficacy of antiangiogenic therapy. Immunoglobulin-like transcript (ILT) 4 is a classic immunosuppressive molecule that inhibits myeloid cell activation. Recent studies have shown that tumor cell-derived ILT4 drives tumor progression via the induction of malignant biologies and creation of an immunosuppressive microenvironment. However, whether and how ILT4 participates in NSCLC angiogenesis remain elusive. Herein, we found that enriched ILT4 in NSCLC is positively correlated with high microvessel density, advanced disease, and poor overall survival. Tumor cell-derived ILT4 induced angiogenesis both in vitro and in vivo and tumor progression and metastasis in vivo. Mechanistically, ILT4 was upregulated by its ligand angiopoietin-like protein 2 (ANGPTL2). Their interaction subsequently activated the ERK1/2 signaling pathway to increase the secretion of the proangiogenic factors VEGF-A and MMP-9, which are responsible for NSCLC angiogenesis. Our study explored a novel mechanism for ILT4-induced tumor progression and provided a potential target for antiangiogenic therapy in NSCLC.

Prospective Observational Study of Ramucirumab Plus Docetaxel After Combined Chemoimmunotherapy in Patients With Non-Small-Cell Lung Cancer.

BACKGROUND: A history of pre-administration of immune checkpoint inhibitors has been reported to be associated with good outcomes of ramucirumab (RAM) plus docetaxel (DOC) combination therapy for advanced non-small-cell lung cancer (NSCLC). However, existing knowledge on the clinical significance of RAM and DOC following combined chemoimmunotherapy is limited. Therefore, we evaluated the efficacy and safety of RAM plus DOC therapy after combined chemoimmunotherapy and attempted to identify the predictors of its outcomes. PATIENTS AND METHODS: This multicenter, prospective study investigated the efficacy and safety of RAM plus DOC after combined chemoimmunotherapy. The primary endpoint was progression-free survival (PFS). Secondary endpoints were the objective response rate (ORR), disease control rate (DCR), overall survival (OS), and incidence of adverse events. An exploratory analysis measured serum cytokine levels at the start of treatment. RESULTS: Overall, 44 patients were enrolled from 10 Japanese institutions between April 2020 and June 2022. The median PFS and OS were 6.3 and 22.6 months, respectively. Furthermore, the ORR and DCR were 36.4% and 72.7%, respectively. The high vascular endothelial growth factor D (VEGF-D) group had a significantly shorter PFS and OS. A combination of high VEGF-A and low VEGF-D levels was associated with a longer PFS. CONCLUSION: Our results showed that RAM plus DOC after combined chemoimmunotherapy might be an effective and relatively feasible second-line treatment for patients with advanced NSCLC in a real-world setting.

S6K1 deficiency in tumor stroma impairs lung metastasis of melanoma in mice.

Accumulating data suggest that ribosomal protein S6 kinase 1 (S6K1), an effector in the mammalian target of rapamycin (mTOR) pathway, plays pleiotropic roles in tumor progression. However, to date, while the tumorigenic function of S6K1 in tumor cells has been well elucidated, its role in the tumor stroma remains poorly understood. We recently showed that S6K1 mediates vascular endothelial growth factor A (VEGF-A) production in macrophages, thereby supporting tumor angiogenesis and growth. As macrophage-derived VEGF-A is crucial for both tumor cell intravasation and extravasation across the vascular endothelium, our previous findings suggest that stromal S6K1 signaling is required for tumor metastatic spread. Therefore, we aimed to determine the impact of host S6K1 depletion on tumor metastasis using a murine model of pulmonary metastasis (S6k1-/- mice implanted with B16F10 melanoma). The ablation of S6K1 in the host microenvironment significantly reduced the metastasized B16F10 melanoma cells on the lung surface in both spontaneous and intravenous lung metastasis mouse models without affecting the incidence of metastasis to distant lymph nodes. In addition, stromal S6K1 loss decreased the number of tumor cells circulating in the peripheral blood of mice bearing B16F10 xenografts without affecting the vascular leakage induced by VEGF-A in vivo. These observations demonstrate that S6K1 signaling in host cells other than endothelial cells is required to modulate the host microenvironment to facilitate the metastatic spread of tumors via blood circulation, thus revealing its novel role in the tumor stroma during tumor progression.

Serum VEGF-A levels on admission in COVID-19 patients correlate with SP-D and neutrophils, reflecting disease severity: A prospective study.

BACKGROUND AND OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in significant global morbidity and mortality. This study aimed to investigate the clinical significance of serum vascular endothelial growth factor A (VEGF-A) in COVID-19 patients and its association with disease severity and pulmonary injury. METHODS: We prospectively collected data from 71 hospitalized COVID-19 patients between June 2020 and January 2021. Patients were classified as either mild or severe based on their oxygen requirements during hospitalization. Serum VEGF-A levels were measured using an ELISA kit. RESULTS: In comparison to mild cases, significantly elevated serum VEGF-A levels were observed in severe COVID-19 patients. Furthermore, VEGF-A levels exhibited a positive correlation with white blood cell count, neutrophil count, and lymphocyte count. Notably, serum surfactant protein-D (SP-D), an indicator of alveolar epithelial cell damage, was significantly higher in patients with elevated VEGF-A levels. CONCLUSION: These results suggest that elevated serum VEGF-A levels could serve as a prognostic biomarker for COVID-19 as it is indicative of alveolar epithelial cell injury caused by SARS-CoV-2 infection. Additionally, we observed a correlation between VEGF-A and neutrophil activation, which plays a role in the immune response during endothelial cell injury, indicating a potential involvement of angiogenesis in disease progression. Further research is needed to elucidate the underlying mechanisms of VEGF-A elevation in COVID-19.

Umbilical cord mesenchymal stem cells from gestational diabetes show impaired ability to up-regulate paracellular permeability from sub-endothelial niche.

In vitro studies have shown that Wharton's jelly mesenchymal stem cells (WJ-MSCs) can cross umbilical and uterine endothelial barriers and up-regulate endothelial junctional integrity from sub-endothelial niches. This pericytic behaviour may be lost in pregnancies complicated by gestational diabetes (GDM), where increased vascular permeability and junctional disruption are reported. The aim of the present study was to investigate whether WJ-MSCs isolated from GDM pregnancies displayed any changes in morphology, proliferation, VEGF-A secretion, and their ability to influence paracellular junctional composition and permeability. WJ-MSCs were isolated from human umbilical cords from normal pregnancies (nWJ-MSCs, n=13) and those complicated by GDM (gWJ-MSCs), either diet-controlled (d-GDM, n=13) or metformin-treated (m-GDM, n=9). We recorded that 4-fold more WJ-MSCs migrated from m-GDM, and 2.5-fold from d-GDM cord samples compared with the normal pregnancy. gWJ-MSCs showed a less predominance of spindle-shaped morphology and secreted 3.8-fold more VEGF-A compared with nWJ-MSCs. The number of cells expressing CD105 (Endoglin) was higher in gWJ-MSCs compared with nWJ-MSCs (17%) at P-2. The tracer leakage after 24 h across the HUVEC + gWJ-MSCs bilayer was 22.13% and 11.2% higher in the m-GDM and d-GDM, respectively, HUVEC + nWJ-MSCs. Transfection studies with siRNAs that target Endoglin were performed in n-WJ-MSCs; transfected cells were co-cultured with HUVEC followed by permeability studies and VE-cadherin analyses. Loss of Endoglin also led to increased VEGF-A secretion, increased permeability and affected endothelial stabilization. These results reinforce the pericytic role of nWJ-MSCs to promote vascular repair and the deficient ability of gWJ-MSCs to maintain endothelial barrier integrity.

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.

GLUT1 regulates the release of VEGF-A in the alveolar epithelium of lipopolysaccharide-induced acute lung injury.

Acute lung injury (ALI) is a severe disease with high mortality and poor prognosis, characterized by excessive and uncontrolled inflammatory response. Vascular endothelial growth factor A (VEGF-A) contributes to the development and progression of ALI. The aim of this study was to evaluate the role of glucose transporter 1 (GLUT1) in alveolar epithelial VEGF-A production in lipopolysaccharide (LPS)-induced ALI. An ALI mouse model was induced by LPS oropharyngeal instillation. Mice were challenged with LPS and then treated with WZB117, a specific antagonist of GLUT1. For the vitro experiments, cultured A549 cells (airway epithelial cell line) were exposed to LPS, with or without the GLUT1 inhibitors WZB117 or BAY876. LPS significantly upregulated of GLUT1 and VEGF-A both in the lung from ALI mice and in cultured A549. In vivo, treatment with WZB117 not only markedly decreased LPS-induced pulmonary edema, injury, neutrophilia, as well as levels of interleukin (IL)-1ß, IL-6 and tumor necrosis factor-α in bronchoalveolar lavage fluid (BALF), but also reduced VEGF-A production. Yet, the maximum tolerated concentration of WZB117 failed to suppress LPS-induced VEGF-A overexpression in vitro. While administration of BAY876 inhibited gene and protein expression as well as secretion of VEGF-A in response to LPS in A549. These results illustrated that GLUT1 upregulates VEGF-A production in alveolar epithelia from LPS-induced ALI, and inhibition of GLUT1 alleviates ALI.

Does placental VEGF-A protein expression predict early neurological outcome of neonates from FGR complicated pregnancies?

OBJECTIVES: Fetal hypoxia due to placental dysfunction is the hallmark of fetal growth restriction (FGR). Preferential perfusion of the brain (brain-sparing effect), as a part of physiological placental cardiovascular compensatory mechanisms to hypoxia, in FGR was reported. Therefore, the correlation between vascular endothelial growth factor A (VEGF-A) protein expression in the FGR placentas and newborns' early neurological outcome was examined. METHODS: This study included 50 women with FGR complicated pregnancies and 30 uneventful pregnancies. Fetal hemodynamic parameters, neonatal acid-base status after delivery, placental pathohistology and VEGF-A expression were followed. Early neonatal morphological brain evaluation by ultrasound and functional evaluation of neurological status by Amiel - Tison Neurological Assessment at Term (ATNAT) were performed. RESULTS: VEGF-A protein expression level was significantly higher in the FGR placentas than normal term placentas (Fisher-Freeman-Halton's test, p≤0.001). No statistically significant correlation between placental VEGF-A expression and different prenatal and postnatal parameters was noticed. Whereas the alteration of an early neurological status assessed by ATNAT was found in 58 % of FGR newborns, morphological brain changes evaluated by UZV was noticed in 48 % of cases. No association between the level of placental VEGF-A expression and the early neurological deficits was found. CONCLUSIONS: As far as we know this is the first study of a possible connection between VEGF-A protein expression in the FGR placentas and neonates' early neurological outcomes. The lack of correlation between the FGR placental VEGF-A expression and neonates' neurological outcome could indicate that optimal early neurodevelopment may take place due to compensatory mechanism not related to placental VEGF-A expression.

Changes in the Concentrations of Proangiogenic Cytokines in Human Brain Glioma and Acute Lymphoblastic Leukemia.

Acute lymphoblastic leukemia (ALL) and glioma are some of the most common malignancies, with ALL most often affecting children and glioma affecting adult men. Proangiogenic cytokines and growth factors play an important role in the development of both of these tumors. Glioma is characterized by an extremely extensive network of blood vessels, which continues to expand mainly in the process of neoangiogenesis, the direct inducers of which are cytokines from the family of vascular endothelial growth factors, i.e., vascular endothelial growth factor (VEGF-A) and its receptor vascular endothelial growth factor receptor 2 (VEGF-R2), as well as a cytokine from the fibroblast growth factor family, fibroblast growth factor 2 (FGF-2 or bFGF). Growth factors are known primarily for their involvement in the progression and development of solid tumors, but there is evidence that local bone marrow angiogenesis and increased blood vessel density are also present in hematological malignancies, including leukemias. The aim of this study was to examine changes in the concentrations of VEGF-A, VEGF-R2, and FGF-2 (with a molecular weight of 17 kDa) in a group of patients divided into specific grades of malignancy (glioma) and a control group; changes of VEGF-A and FGF-2 concentrations in childhood acute lymphoblastic leukemia and a control group; and to determine correlations between the individual proteins as well as the influence of the patient's age, diet, and other conditions that may place the patient in the risk group. During the statistical analysis, significant differences in concentrations were found between the patient and control groups in samples from people with diagnosed glioma and from children with acute lymphoblastic leukemia, but in general, there are no significant differences in the concentrations of VEGF-A, VEGF-R2, and FGF-2 between different grades of glioma malignancy. Among individuals treated for glioma, there was no significant impact from the patient's gender and age, consumption of food from plastic packaging, frequency of eating vegetables and fruit, smoking of tobacco products, the intensity of physical exercise, or the general condition of the body (Karnofsky score) on the concentrations of the determined cytokines and receptor. The listed factors do not bring about an actual increase in the risk of developing brain glioma.

Thymic Stromal Lymphopoietin (TSLP) Is Cleaved by Human Mast Cell Tryptase and Chymase.

Thymic stromal lymphopoietin (TSLP), mainly expressed by epithelial cells, plays a central role in asthma. In humans, TSLP exists in two variants: the long form TSLP (lfTSLP) and a shorter TSLP isoform (sfTSLP). Macrophages (HLMs) and mast cells (HLMCs) are in close proximity in the human lung and play key roles in asthma. We evaluated the early proteolytic effects of tryptase and chymase released by HLMCs on TSLP by mass spectrometry. We also investigated whether TSLP and its fragments generated by these enzymes induce angiogenic factor release from HLMs. Mass spectrometry (MS) allowed the identification of TSLP cleavage sites caused by tryptase and chymase. Recombinant human TSLP treated with recombinant tryptase showed the production of 1-97 and 98-132 fragments. Recombinant chymase treatment of TSLP generated two peptides, 1-36 and 37-132. lfTSLP induced the release of VEGF-A, the most potent angiogenic factor, from HLMs. By contrast, the four TSLP fragments generated by tryptase and chymase failed to activate HLMs. Long-term TSLP incubation with furin generated two peptides devoid of activating property on HLMs. These results unveil an intricate interplay between mast cell-derived proteases and TSLP. These findings have potential relevance in understanding novel aspects of asthma pathobiology.

Dysregulated VEGF/VEGFR-2 Signaling and Plexogenic Lesions in the Embryonic Lungs of Chickens Predisposed to Pulmonary Arterial Hypertension.

Plexiform lesions are a hallmark of pulmonary arterial hypertension (PAH) in humans and are proposed to stem from dysfunctional angioblasts. Broiler chickens (Gallus gallus) are highly susceptible to PAH, with plexiform-like lesions observed in newly hatched individuals. Here, we reported the emergence of plexiform-like lesions in the embryonic lungs of broiler chickens. Lung samples were collected from broiler chickens at embryonic day 20 (E20), hatch, and one-day-old, with PAH-resistant layer chickens as controls. Plexiform lesions consisting of CD133+/vascular endothelial growth factor receptor type-2 (VEGFR-2)+ angioblasts were exclusively observed in broiler embryos and sporadically in layer embryos. Distinct gene profiles of angiogenic factors were observed between the two strains, with impaired VEGF-A/VEGFR-2 signaling correlating with lesion development and reduced arteriogenesis. Pharmaceutical inhibition of VEGFR-2 resulted in enhanced lesion development in layer embryos. Moreover, broiler embryonic lungs displayed increased activation of HIF-1α and nuclear factor erythroid 2-related factor 2 (Nrf2), indicating a hypoxic state. Remarkably, we found a negative correlation between lung Nrf2 activation and VEGF-A and VEGFR-2 expression. In vitro studies indicated that Nrf2 overactivation restricted VEGF signaling in endothelial progenitor cells. The findings from broiler embryos suggest an association between plexiform lesion development and impaired VEGF system due to aberrant activation of Nrf2.

On Connective Tissue Mast Cells as Protectors of Life, Reproduction, and Progeny.

The connective tissue mast cell (MC), a sentinel tissue-residing secretory immune cell, has been preserved in all vertebrate classes since approximately 500 million years. No physiological role of the MC has yet been established. Considering the power of natural selection of cells during evolution, it is likely that the MCs exert essential yet unidentified life-promoting actions. All vertebrates feature a circulatory system, and the MCs interact readily with the vasculature. It is notable that embryonic MC progenitors are generated from endothelial cells. The MC hosts many surface receptors, enabling its activation via a vast variety of potentially harmful exogenous and endogenous molecules and via reproductive hormones in the female sex organs. Activated MCs release a unique composition of preformed and newly synthesized bioactive molecules, like heparin, histamine, serotonin, proteolytic enzymes, cytokines, chemokines, and growth factors. MCs play important roles in immune responses, tissue remodeling, cell proliferation, angiogenesis, inflammation, wound healing, tissue homeostasis, health, and reproduction. As recently suggested, MCs enable perpetuation of the vertebrates because of key effects-spanning generations-in ovulation and pregnancy, as in life-preserving activities in inflammation and wound healing from birth till reproductive age, thus creating a permanent life-sustaining loop. Here, we present recent advances that further indicate that the MC is a specific life-supporting and progeny-safeguarding cell.

Melatonin and its bioisosteres as potential therapeutic agents for the treatment of retinopathy of prematurity.

We conducted a study on the impact of intraperitoneal injections of melatonin and its three bioisosteres (compounds 1-3) on the development of oxygen-induced retinopathy in newborn rats during a 21-day experiment. It was demonstrated that melatonin and its analogues 1-3 effectively reduce the total protein concentration in the vitreous body of rat pups, decrease concentration of VEGF-A, and lower the level of oxidative stress (as indicated by normalization of antioxidant activity in the vitreous body). Melatonin and its analogues 1-3 equally normalize the level of VEGF-A. Analogues 1 and 2 even exceed melatonin in their ability to reduce protein influx into the vitreous body. However, analogue 2 had no effect on antioxidant activity, while analogues 1 and 3 caused a significant increase in this parameter, with analogue 3 even slightly exceeding melatonin. Thus, it can be concluded that analogues 1-3 are comparable to melatonin and can be utilized as potential therapeutic agents for the treatment of retinopathy of prematurity.

MiR-9-3 hypermethylation is associated with stages of diabetic retinopathy.

Purpose: To investigate the potential relation between methylation of miR-9-3 and stages of diabetic retinopathy (DR). Additionally, we explored whether miR-9-3 methylation impacts the serum levels of Vascular Endothelial Growth Factor (VEGF). Methods: A cross-sectional study was conducted with 170 participants with type 2 diabetes, including a control group (n = 64) and a diabetes retinopathy group (n = 106), which was further divided into NPDR (n = 58) and PDR (n = 48) subgroups. Epidemiological, clinical, anthropometric, biochemical ELISA assay were analysed. DNA extracted from leukocytes was used to profile miR-9-3 methylation using PCR-MSP. Results: MiR-9-3 hypermethylated profile was higher in the DR group (p < 0.001) and PDR subgroup compared to DM2 control group (p < 0.001). The hypermethylated profile in the PDR subgroup was also higher compared to NPDR subgroup (p < 0.001). There was no difference between DM2 control and NPDR group (p = 0.234). Logistic regression showed that miR-9-3 hypermethylation increases the odds of presenting DR (OR: 2.826; p = 0.002) and PDR (OR: 5.472; p < 0.001). In addition, hypermethylation of miR-9-3 in the DR and NPDR subgroup was associated with higher serum VEGF-A levels (p = 0.012 and p = 0.025, respectively). Conclusion: The methylation profile of the miR-9-3 promoter increases the risk of developing PDR. Higher levels of VEGF-A are associated with miR-9-3 hypermethylated profile in patients in the DR and NPDR stages. Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-024-01411-9.

TSLP is localized in and released from human lung macrophages activated by T2-high and T2-low stimuli: relevance in asthma and COPD.

BACKGROUND: Macrophages are the predominant immune cells in the human lung and play a central role in airway inflammation, including asthma and chronic obstructive pulmonary disease (COPD). Thymic stromal lymphopoietin (TSLP), a pleiotropic cytokine mainly expressed by bronchial epithelial cells, plays a key role in asthma and COPD pathobiology. TSLP exists in two variants: the long form (lfTSLP) and a shorter TSLP isoform (sfTSLP). We aimed to localize TSLP in human lung macrophages (HLMs) and investigate the mechanisms of its release from these cells. We also evaluated the effects of the two variants of TSLP on the release of angiogenic factor from HLMs. METHODS: We employed immunofluorescence and Western blot to localize intracellular TSLP in HLMs purified from human lung parenchyma. HLMs were activated by T2-high (IL-4, IL-13) and T2-low (lipopolysaccharide: LPS) immunological stimuli. RESULTS: TSLP was detected in HLMs and subcellularly localized in the cytoplasm. IL-4 and LPS induced TSLP release from HLMs. Preincubation of macrophages with brefeldin A, known to disrupt the Golgi apparatus, inhibited TSLP release induced by LPS and IL-4. lfTSLP concentration-dependently induced the release of vascular endothelial growth factor-A (VEGF-A), the most potent angiogenic factor, from HLMs. sfTSLP neither activated nor interfered with the activating property of lfTSLP on macrophages. CONCLUSIONS: Our results highlight a novel immunologic circuit between HLMs and TSLP. Given the central role of macrophages in airway inflammation, this autocrine loop holds potential translational relevance in understanding innovative aspects of the pathobiology of asthma and chronic inflammatory lung disorders.

Plasma Angiogenic Factors as Predictors of the Efficacy of Second-line Chemotherapy Combined with Angiogenesis Inhibitors in Metastatic Colorectal Cancer: Results From the GI-SCREEN CRC-Ukit Study.

BACKGROUND: The significance of angiogenic factors as predictors of second-line (2L) chemotherapy efficacy when combined with angiogenesis inhibitors for metastatic colorectal cancer (mCRC) remains unestablished. PATIENTS AND METHODS: In this multicenter prospective observational study, 17 angiogenic factors were analyzed in plasma samples collected at pretreatment and progression stages using a Luminex multiplex assay. Patients who received chemotherapy plus bevacizumab (BEV group), FOLFIRI plus ramucirumab (RAM group), or FOLFIRI plus aflibercept (AFL group) as the 2L treatment were included. Interactions between pretreatment and treatment groups for progression-free survival (PFS), overall survival (OS), and response rate (RR) were assessed using the propensity-score weighted Cox proportional hazards model. RESULTS: From February 2018 to September 2020, 283 patients were analyzed in the 2L cohort. A strong interaction was observed for PFS between BEV and RAM with HGF, sNeuropilin-1, sVEGFR-1, and sVEGFR-3. Interactions for RR between the BEV and RAM groups were observed for sNeuropilin-1 and sVEGFR-1. Contrarily, OS, PlGF, sVEGFR-1, and sVEGFR-3 differentiated the treatment effect between BEV and AFL. Plasma samples were evaluable for dynamic analysis in 203 patients. At progression, VEGF-A levels significantly decreased in the BEV group and increased in the RAM and AFL groups. CONCLUSION: The pretreatment plasma sVEGFR-1 and sVEGFR-3 levels could be predictive biomarkers for distinguishing BEV and RAM when combined with chemotherapy in 2L mCRC treatment. Based on the VEGF-A dynamics at progression, selecting RAM or AFL for patients with significantly elevated VEGF-A levels may be a 2L treatment strategy, with BEV considered for the third-line treatment. CLINICAL TRIAL NUMBER: UMIN000028616.

The Combination of Vascular Endothelial Growth Factor A (VEGF-A) and Fibroblast Growth Factor 1 (FGF1) Modified mRNA Improves Wound Healing in Diabetic Mice: An Ex Vivo and In Vivo Investigation.

BACKGROUND: Diabetic foot ulcers (DFU) pose a significant health risk in diabetic patients, with insufficient revascularization during wound healing being the primary cause. This study aimed to assess microvessel sprouting and wound healing capabilities using vascular endothelial growth factor (VEGF-A) and a modified fibroblast growth factor (FGF1). METHODS: An ex vivo aortic ring rodent model and an in vivo wound healing model in diabetic mice were employed to evaluate the microvessel sprouting and wound healing capabilities of VEGF-A and a modified FGF1 both as monotherapies and in combination. RESULTS: The combination of VEGF-A and FGF1 demonstrated increased vascular sprouting in the ex vivo mouse aortic ring model, and topical administration of a combination of VEGF-A and FGF1 mRNAs formulated in lipid nanoparticles (LNPs) in mouse skin wounds promoted faster wound closure and increased neovascularization seven days post-surgical wound creation. RNA-sequencing analysis of skin samples at day three post-wound creation revealed a strong transcriptional response of the wound healing process, with the combined treatment showing significant enrichment of genes linked to skin growth. CONCLUSION: f-LNPs encapsulating VEGF-A and FGF1 mRNAs present a promising approach to improving the scarring process in DFU.

Pharmacological inhibition of PDGF-C/neuropilin-1 interaction: A novel strategy to reduce melanoma metastatic potential.

Activation of neuropilin-1 (NRP-1) by platelet derived growth factor (PDGF)-C sustains melanoma invasiveness. Therefore, in the search of novel agents capable of reducing melanoma spreading, PDGF-C/NRP-1 interaction was investigated as a potential druggable target. Since the PDGF-C region involved in NRP-1 binding is not yet known, based on the sequence and structural homology between PDGF-C and vascular endothelial growth factor-A (VEGF-A), we hypothesized that the NRP-1 b1 domain region involved in the interaction with VEGF-A might also be required for PDGF-C binding. Hence, this region was selected from the protein crystal structure and used as target in the molecular docking procedure. In the following virtual screening, compounds from a DrugBank database were used as query ligands to identify agents potentially capable of disrupting NRP-1/PDGF-C interaction. Among the top 45 candidates with the highest affinity, five drugs were selected based on the safety profile, lack of hormonal effects, and current availability in the market: the antipsychotic pimozide, antidiabetic gliclazide, antiallergic cromolyn sodium, anticancer tyrosine kinase inhibitor entrectinib, and antihistamine azelastine. Analysis of drug influence on PDGF-C in vitro binding to NRP-1 and PDGF-C induced migration of human melanoma cells expressing NRP-1, indicated gliclazide and entrectinib as the most specific agents that were active at clinically achievable and non-toxic concentrations. Both drugs also reverted PDGF-C ability to stimulate extracellular matrix invasion by melanoma cells resistant to BRAF inhibitors. The inhibitory effect on tumor cell motility involved a decrease of p130Cas phosphorylation, a signal transduction pathway activated by PDGF-C-mediated stimulation of NRP-1.

Regulation of VEGF-A expression and VEGF-A-targeted therapy in malignant tumors.

Vascular endothelial growth factor A (VEGF-A), a highly conserved dimeric glycoprotein, is a key regulatory gene and a marker molecule of angiogenesis. The upregulation of VEGF-A facilitates the process of tumor vascularization, thereby fostering the initiation and progression of malignant neoplasms. Many genes can adjust the angiogenesis of tumors by changing the expression of VEGF-A. In addition, VEGF-A also exhibits immune regulatory properties, which directly or indirectly suppresses the antitumor activity of immune cells. The emergence of VEGF-A-targeted therapy alone or in rational combinations has revolutionized the treatment of various cancers. This review discusses how diverse mechanisms in various tumors regulate VEGF-A expression to promote tumor angiogenesis and the role of VEGF-A in tumor immune microenvironment. The application of drugs targeting VEGF-A in tumor therapy is also summarized including antibody molecule drugs and traditional Chinese medicine.

A single dose of VEGF-A circular RNA sustains in situ long-term expression of protein to accelerate diabetic wound healing.

Diabetic foot ulcer (DFU), which is characterised by damage to minute blood vessels or capillaries around wounds, is one of the most serious and dreaded complications of diabetes. It is challenging to repair chronic non-healing DFU wounds. Vascular endothelial growth factor (VEGF) plays an important role in angiogenesis and promotes wound healing in DFU. However, it is difficult to sustainably deliver VEGF to the wound site owing to its poor stability and easy degradation. To overcome this challenge, lipid nanoparticles (LNP) encapsulating circular RNA (circRNA) encoding VEGF-A have been developed to continuously generate and release VEGF-A and accelerate diabetic wound healing. First, VEGF-A circRNA was synthesized using group I intron autocatalysis strategy and confirmed by enzyme digestion, polymerase chain reaction, and sequencing assay. VEGF-A circRNA was encapsulated in ionizable lipid U-105-derived LNP (U-LNP) using microfluidic technology to fabricate U-LNP/VEGF-A circRNA. For comparison, a commercially ionizable lipid ALC-0315-derived LNP (A-LNP) encapsulating circRNA (A-LNP/circRNA) was used. Dynamic light scattering and transmission electron microscopy characterization indicated that U-LNP/circRNA had spherical structure with an average diameter of 108.5 nm, a polydispersity index of 0.22, and a zeta potential of -3.31 mV. The messenger RNA (mRNA) encapsulation efficiency (EE%) of U-LNP was 87.12%. In vitro transfection data confirmed better stability and long-term VEGF-A expression of circRNA compared with linear mRNA. Assessment of cytotoxicity and innate immunity further revealed that U-LNP/circRNA was biocompatible and induced a weak congenital immune response. Cell scratch and angiogenesis tests demonstrated the bioactivity of U-LNP/VEGF-A circRNA owing to its VEGF-A expression. In situ bioluminescence imaging of firefly luciferase (F-Luc) probe and ELISA demonstrated that circRNA had long-term and strong expression of VEGF-A in the first week, and a gradual decrease in the next week at the wound site and surrounding areas. Finally, a diabetic mouse model was used to validate the healing effect of U-LNP/VEGF-A circRNA formulation. The results showed that a single dose of U-LNP/VEGF-A circRNA administered by dripping resulted in almost complete wound recovery on day 12, which was significantly superior to that of U-LNP/VEGF-A linear mRNA, and it also outperformed recombinant human vascular endothelial growth factor (rhVEGF) injection and A-LNP/circRNA dripping. Histological analysis confirmed the healing efficiency and low toxicity of U-LNP/VEGF-A circRNA formulation. Together, VEGF-A circRNA delivered by U-105-derived LNP showed good performance in wound healing, which was ascribed to the long-term expression and continuous release of VEGF-A, and has potential applications for the treatment of diabetic foot ulcer wounds.