VEGF Receptor Research Articles

Approaches to Treating High Risk and Advanced Renal Cell Carcinoma (RCC): Key Trial Data That Impacts Treatment Decisions in the Clinic.

The treatment paradigm for high risk localized and advanced kidney cancer has been characterized by ongoing changes, with the introduction of vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR TKIs) and later with immune checkpoint blockade. In this article, we review how current evidence informs our decision-making on post-checkpoint inhibitor systemic therapies, the role of adjuvant and/or neoadjuvant therapies, and the role of cytoreductive nephrectomy in the evolving systemic therapy landscape. While some studies support a post-checkpoint inhibitor benefit from the VEGFR TKIs cabozantinib or axitinib, the benefit of doublet therapies including a VEGF receptor inhibitor and a checkpoint inhibitor remains an area of active investigation, with the combination of lenvatinib plus pembrolizumab showing promise but with a Phase III trial of the combination of atezolizumab plus cabozantinib showing no benefit over cabozantinib alone. The role of adjuvant therapy in patients with high-risk disease who have undergone cytoreductive nephrectomy and potentially metastasectomy is also an area of continuing interest. While the S-TRAC study demonstrated a disease-free survival benefit for adjuvant sunitinib, no overall survival benefit was shown, and multiple other studies of adjuvant VEGFR TKI therapy have been negative. Subsequently, adjuvant pembrolizumab has shown a benefit in overall survival, whereas trials of neoadjuvant and adjuvant nivolumab, adjuvant atezolizumab, and adjuvant ipilimumab plus nivolumab have all been negative. Finally, the role for cytoreductive nephrectomy continues to be an area of active debate. The CARMENA study raised important questions about the role of cytoreductive nephrectomy given the advances in VEGFR TKI therapy but was characterized by accrual difficulties and a significant number of patients not receiving treatment according to the study protocol. Two ongoing studies (NORDIC-SUN and PROBE) seek to further address the role of cytoreductive nephrectomy in the doublet therapy era.

Pneumonia promotes pulmonary metastasis of HCC after transplantation via VEGF regulated PI3K/AKT/Cas-9 signaling and angiogenesis

Aim: Pneumonia is the most frequent early postoperative complication in liver transplantation (LT) recipients. Inflammation may provide a favorable environment for tumor implantation, so we aimed to evaluate the impact of pneumonia on pulmonary metastasis of hepatocellular carcinoma (HCC) and reveal its underlying mechanism. Methods: A training cohort with 234 LT recipients were recorded and analyzed. Using the propensity-score method, we matched covariates between patients with and without pneumonia. A model for predicting pulmonary metastasis was built and validated in an independent validating cohort containing 179 subjects. A mouse model was built to mimic HCC pulmonary metastasis. The potential pathway was revealed by cytokine array analysis and validated in vitro . Results: Pneumonia was an independent risk factor for pulmonary metastasis in liver transplant recipients. It promoted pulmonary metastasis in both the clinical setting and the mouse model. In vitro , LPS-stimulated VEGF secretion from macrophages in the lung significantly reduced cell apoptosis and activated PI3K/AKT/cas-9 signaling. Administration of VEGF receptor2 inhibitor Vatalanib could reduce metastasis and improve prognosis in pneumonia mice. Conclusion: Pneumonia promotes HCC pulmonary metastasis by activating PI3K/AKT/Cas-9 signaling in HCC cells via macrophage-originated VEGF. Vatalanib might be efficient in reducing HCC pulmonary metastasis in liver transplant recipients with pneumonia.

Identification of naturally occurring flavonoids as anticancer agents: In silico studies

It is recognized that flavonoids have a variety of functions in nature, including anti-inflammatory, antibacterial, antioxidant, anticancer, anti-HIV and neuroprotective properties. In the present study, molecular docking experiment was performed on 15 naturally occurring flavonoids as anticancer agents. The analysis of results was performed on the basis of docking score, glide energy and interaction with amino acids. Each flavonoid showed a specific interaction with target protein. Naringin showed interactions with amino acids GLN131, ASP145, PHE80, VAL83, GLU8, ILE10, THR89 (docking score −12.48) involved with the protein PDB ID: 1gij (inhibitor of cyclin-dependent kinase 4). Naringin further showed interactions with THR887, THR886, LYS833, ASP836 amino acids (docking score −15.078) involved with PDB ID: 5jhb (inhibitor of PI3K and tubulin). Orientin showed interactions with amino acids ASN150, ASP163, LYS43, VAL101 (docking score −13.89) with PDB ID: 2euf as inhibitor of cyclin-dependent kinase 6. Quercetin showed interactions with amino acids PHE1047, LEU840, CYS919, GLU917 (docking score −11.7) with PDB ID: 4agd as inhibitor of VEGF receptor tyrosine kinase inhibitor. Epigallocatechin gallate showed interactions with amino acids LYS868, GLU885, THR916, ASP1046 using protein PDB ID: 3ewh (docking score −10.004) as inhibitor of Tie-2 kinase. The given flavonoid drugs interaction with cancer targets shows their possible potential against various forms of cancer. Epigallocatechin gallate when docked with 3ewh showed best docking score with important interaction required for anticancer activity. In molecular dynamic study, Epigallocatechin gallate in complex with VEGFR2 kinase protein (PDB ID: 3ewh) with RMSD indicates the protein remained stable through the simulation of 100ns with fluctuation in the range of 1.5–3.5 Å. The provided docking results may be useful for the development of novel drug candidate for anticancer targets.

Anti-PD-1/L1 antibody plus anti-VEGF antibody vs. plus VEGFR-targeted TKI as first-line therapy for unresectable hepatocellular carcinoma: a network meta-analysis.

This article is based on our previous research, which was presented at the 2023 ASCO Annual Meeting I and published in Journal of Clinical Oncology as Conference Abstract (JCO. 2023;41:e16148. doi: 10.1200/JCO.2023.41.16_suppl.e16148). Both anti-programmed death 1/ligand-1 (PD-1/L1) antibody + anti-vascular endothelial growth factor (VEGF) antibody (A + A) and anti-PD-1/L1 antibody + VEGF receptor (VEGFR)-targeted tyrosine kinase inhibitor (A + T) are effective first-line therapies for unresectable hepatocellular carcinoma. However, there lacks evidence from head-to-head comparisons between these two treatments. We conducted a network meta-analysis on the efficacy and safety of them. After a rigorous literature research, 6 phase III trials were identified for the final analysis, including IMbrave150, ORIENT-32, COSMIC-312, CARES-310, LEAP-002, and REFLECT. The experiments were classified into three groups: A + A, A + T, and intermediate reference group. The primary endpoint was overall survival (OS), and secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and incidence of treatment-related adverse events (TRAEs). Hazard ratio (HR) with 95% confidence intervals (CI) for OS and PFS, odds ratio (OR) for ORR, and relative risk (RR) for all grade and grade ≥3 TRAEs were calculated. Under Bayesian framework, the meta-analysis was conducted using sorafenib as intermediate reference. With the rank probability of 96%, A + A showed the greatest reduction in the risk of death, without significant difference from A + T (HR: 0.82, 95% CI: 0.65-1.04). A + T showed the greatest effect in prolonging PFS and improving ORR with the rank probability of 77%, but there were no statistical differences with A + A. A + A was safer than A + T in terms of all grade of TRAEs (RR: 0.91, 95% CI: 0.82-1.00) and particularly in those grade ≥3 (RR: 0.65, 95% CI: 0.54-0.77). A + A had the greatest probability of delivering the longest OS, while A + T was correlated with larger PFS benefits at the cost of a lower safety rate.

Latrophilin-2 mediates fluid shear stress mechanotransduction at endothelial junctions

Endothelial cell responses to fluid shear stress from blood flow are crucial for vascular development, function, and disease. A complex of PECAM-1, VE-cadherin, VEGF receptors (VEGFRs), and Plexin D1 located at cell–cell junctions mediates many of these events. However, available evidence suggests that another mechanosensor upstream of PECAM-1 initiates signaling. Hypothesizing that GPCR and Gα proteins may serve this role, we performed siRNA screening of Gα subunits and found that Gαi2 and Gαq/11 are required for activation of the junctional complex. We then developed a new activation assay, which showed that these G proteins are activated by flow. We next mapped the Gα residues required for activation and developed an affinity purification method that used this information to identify latrophilin-2 (Lphn2/ADGRL2) as the upstream GPCR. Latrophilin-2 is required for all PECAM-1 downstream events tested. In both mice and zebrafish, latrophilin-2 is required for flow-dependent angiogenesis and artery remodeling. Furthermore, endothelial-specific knockout demonstrates that latrophilin plays a role in flow-dependent artery remodeling. Human genetic data reveal a correlation between the latrophilin-2-encoding Adgrl2 gene and cardiovascular disease. Together, these results define a pathway that connects latrophilin-dependent G protein activation to subsequent endothelial signaling, vascular physiology, and disease.

The matricellular protein CCN5 prevents anti-VEGF drug-induced epithelial-mesenchymal transition of retinal pigment epithelium

Age-related macular degeneration (AMD) is one of the major causes of blindness in the elderly worldwide. Anti-vascular endothelial growth factor (VEGF) drugs have been widely used to treat the neovascular type of AMD (nAMD). However, VEGF acts not only as a pro-angiogenic factor but also as an anti-apoptotic factor in the eyes. In this study, we found that anti-VEGF drugs, including bevacizumab (Bev), ranibizumab (Ran), and aflibercept (Afl), induced epithelial-mesenchymal transition (EMT) in ARPE-19 cells in vitro, accompanied by the induction of CCN2, a potent pro-fibrotic factor. Similarly, intravitreal injection of Afl into mouse eyes resulted in EMT in the retinal pigmented epithelium (RPE). Co-treatment with CCN5, an anti-fibrotic factor that down-regulates CCN2 expression, significantly attenuated the adverse effects of the anti-VEGF drugs both in vitro and in vivo. Inhibition of the VEGF signaling pathway with antagonists of VEGF receptors, SU5416 and ZM323881, induced EMT and up-regulated CCN2 in ARPE-19 cells. Additionally, knock-down of CCN2 with siRNA abolished the adverse effects of the anti-VEGF drugs in ARPE-19 cells. Collectively, these results suggest that anti-VEGF drugs induce EMT in RPE through the induction of CCN2 and that co-treatment with CCN5 attenuates the adverse effects of anti-VEGF drugs in mouse eyes.

Anti-angiogenic Potential of Trans-chalcone in an In Vivo Chick Chorioallantoic Membrane Model: An ATP Antagonist to VEGFR with Predicted Blood-brain Barrier Permeability.

Glioblastoma multiforme (GBM) is characterized by massive tumorinduced angiogenesis aiding tumorigenesis. Vascular endothelial growth factor A (VEGF-A) via VEGF receptor 2 (VEGFR-2) constitutes majorly to drive this process. Putting a halt to tumordriven angiogenesis is a major clinical challenge, and the blood-brain barrier (BBB) is the prime bottleneck in GBM treatment. Several phytochemicals show promising antiangiogenic activity across different models, but their ability to cross BBB remains unexplored. We screened over 99 phytochemicals having anti-angiogenic properties reported in the literature and evaluated them for their BBB permeability, molecular interaction with VEGFR-2 domains, ECD2-3 (extracellular domains 2-3) and TKD (tyrosine kinase domain) at VEGF-A and ATP binding site, cell membrane permeability, and hepatotoxicity using in silico tools. Furthermore, the anti-angiogenic activity of predicted lead Trans-Chalcone (TC) was evaluated in the chick chorioallantoic membrane. Out of 99 phytochemicals, 35 showed an efficient ability to cross BBB with a probability score of > 0.8. Docking studies revealed 30 phytochemicals crossing benchmark binding affinity < -6.4 kcal/mol of TKD with the native ligand ATP alone. Out of 30 phytochemicals, 12 showed moderate to low hepatotoxicity, and 5 showed a violation of Lipinski's rule of five. Our in silico analysis predicted TC as a BBB permeable anti-angiogenic compound for use in GBM therapy. TC reduced vascularization in the CAM model, which was associated with the downregulation of VEGFR-2 transcript expression. The present study showed TC to possess anti-angiogenic potential via the inhibition of VEGFR-2. In addition, the study predicted TC to cross BBB as well as a safe alternative for GBM therapy, which needs further investigation.

Advanced renal cell cancer combination immunotherapy clinical trial (ARCITECT; HCRN GU 22-587).

TPS4614 Background: First-line treatment for patients with metastatic clear cell renal cell carcinoma (mccRCC) often includes an anti-PD1 inhibitor in combination with either an anti-CTLA inhibitor (IO/IO) or a VEGF receptor tyrosine kinase inhibitor (TKI) (IO/TKI). Although some patients treated with nivolumab/ipilimumab (Nivo/Ipi) (IO/IO) experience durable responses leading to treatment free intervals, over two-thirds experience disease progression. Resistance to Nivo (anti-PD1) monotherapy has been associated with increased presence of a subpopulation of Tregs in the tumor microenvironment. Botensilimab (Bot) is an IO agent that leverages novel FcyR-associated mechanisms of action to enhance T cell priming, deplete intratumoral Tregs and enhance myeloid activation. Combination botensilimab/balstilimab (Bot/Bal) (anti-CTLA/anti-PD1) has shown impressive anti-tumor activity in diseases where Nivo/Ipi has shown little to no efficacy. Methods: ARCITECT is a phase II, multicenter investigator initiated trial evaluating the efficacy and safety of Bot/Bal relative to Nivo/Ipi. Patients with mccRCC (favorable, intermediate, or poor risk), no prior systemic therapy (including adjuvant or neoadjuvant), and at least one measurable lesion as defined by RECIST 1.1 are eligible for enrollment. 120 patients will be randomized in a 2:1 fashion to Arm A (Bot/Bal induction followed by Bal maintenance) or Arm B (Nivo/Ipi induction followed by Nivo maintenance) each for a maximum of 2 years. Stratification factors include IMDC risk groups and sarcomatoid histology. The primary endpoint is overall response rate (ORR) per RECIST 1.1. We hypothesize that Bot/Bal will lead to a superior ORR (55%) relative to Nivo/Ipi (40%). This trial has &gt; 90% power to detect the alternative hypothesis while maintaining a one-sided significance level of not more than 0.10 using the exact binomial. The study will be monitored for early stopping in favor of the null hypothesis based on a Simon’s two stage design. In the first stage, 69 patients will be enrolled (Arm A:46 and Arm B:23). If at the end of the first stage, Arm A has either at least 18/42 (42.8%) of eligible patients responding or an ORR at least numerically equivalent to that for eligible patients in Arm B, then the trial will progress to the second stage. The primary endpoint will be met if there are 38/80 responders (ORR &gt; 47.5%) in Arm A. Key secondary endpoints include landmark progression-free survival, treatment-free survival and rates of immune-related adverse events. Correlative studies will explore immune and molecular predictors of response and resistance to IO/IO in tumor and blood. Clinical trial information: NCT05928806 .

Equine Endothelial Cells Show Pro-Angiogenic Behaviours in Response to Fibroblast Growth Factor 2 but Not Vascular Endothelial Growth Factor A.

Understanding the factors which control endothelial cell (EC) function and angiogenesis is crucial for developing the horse as a disease model, but equine ECs remain poorly studied. In this study, we have optimised methods for the isolation and culture of equine aortic endothelial cells (EAoECs) and characterised their angiogenic functions in vitro. Mechanical dissociation, followed by magnetic purification using an anti-VE-cadherin antibody, resulted in EC-enriched cultures suitable for further study. Fibroblast growth factor 2 (FGF2) increased the EAoEC proliferation rate and stimulated scratch wound closure and tube formation by EAoECs on the extracellular matrix. Pharmacological inhibitors of FGF receptor 1 (FGFR1) (SU5402) or mitogen-activated protein kinase (MEK) (PD184352) blocked FGF2-induced extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and functional responses, suggesting that these are dependent on FGFR1/MEK-ERK signalling. In marked contrast, vascular endothelial growth factor-A (VEGF-A) had no effect on EAoEC proliferation, migration, or tubulogenesis and did not promote ERK1/2 phosphorylation, indicating a lack of sensitivity to this classical pro-angiogenic growth factor. Gene expression analysis showed that unlike human ECs, FGFR1 is expressed by EAoECs at a much higher level than both VEGF receptor (VEGFR)1 and VEGFR2. These results suggest a predominant role for FGF2 versus VEGF-A in controlling the angiogenic functions of equine ECs. Collectively, our novel data provide a sound basis for studying angiogenic processes in horses and lay the foundations for comparative studies of EC biology in horses versus humans.

Causal roles and clinical utility of cardiovascular proteins in colorectal cancer risk: a multi-modal study integrating mendelian randomization, expression profiling, and survival analysis.

This comprehensive investigation delved into the intricate causal interplay existing between cardiovascular-related plasma proteins and the susceptibility to colorectal cancer, leveraging the robust framework of Mendelian randomization, and employed expression profiling and survival analysis to unravel the latent clinical worth embedded within pertinent gene expressions. Protein quantitative trait loci (pQTLs) of 85 cardiovascular proteins were employed as instrumental variables to investigate the causal relationship between proteins and CRC risk using a Mendelian randomization approach. Causal inferences were graded as strong, intermediate or weak based on statistical checks. Drug-target MR examined VEGF receptors for their potential as therapeutic targets for colorectal cancer. Differential expression analysis, diagnostic ROC curves, and survival analyses were performed for identified proteins using RNA-seq data from The Cancer Genome Atlas (TCGA) colorectal cancer cohort. Using cis-pQTLs, LOX-1, VEGF-A and OPG were associated with increased CRC risk (strong evidence), while PTX3, TNF-R2 and MMP-7 were protective (strong evidence). Pan-pQTL analysis found MMP-10 increased risk (intermediate evidence) and ADM increased risk (weak evidence). Drug-target MR found VEGF R1 may be promising therapeutic targets. Differential expression analysis revealed seven genes encoding the identified proteins were dysregulated in tumors. ROC analysis showed five gene expression had high diagnostic accuracy. KM analysis showed four genes had prognostic value. This large-scale MR study implicates several cardiovascular proteins in CRC susceptibility and progression. Findings highlight roles for VEGF signaling and extracellular matrix regulation. Results nominate specific proteins as potential diagnostic biomarkers or therapeutic targets warranting further investigation.

VEGF-R2/CAV-1 Interaction Induced by Resveratrol/Eicosapentaenoic Acid/Docosahexaenoic Acid-Enriched Formulation through Functional Detergent-Resistant Membranes Is Associated with Decreased VEGF-A Release in ARPE-19 Cells.

Omega-3 fatty acids (O3FAs) and resveratrol (RSV) are known to be beneficial for certain eye diseases, such as age-related macular degeneration (AMD). Neovascular AMD is characterized by abnormal blood vessel formation due to the excessive synthesis of vascular endothelial growth factor (VEGF) by retinal pigment epithelium (RPE) cells. The study investigates whether a formulation based on eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and RSV is capable of counteracting VEGF-A secretion, and elucidates the molecular mechanism. The study finds, using ELISA, that O3FAs/RSV reduces VEGF-A secretion in human RPE cells. This phenomenon is related to the increased interaction between VEGF-receptor 2 (VEGF-R2) and caveolin-1 (CAV-1), a protein of detergent-resistant membranes (DRMs), as determined by co-immunoprecipitation and proximity ligation assay. Using microscale thermophoresis, the study confirms that O3FAs/RSV causes a high-affinity interaction. Isolation and analysis of DRMs reveal that this interaction is concomitant with VEGF-R2 relocalization in DRMs. The depletion of DRMs by a cholesterol-chelating agent blocks the VEGF-R2/CAV-1 interaction and EPA/DHA/RSV-mediated impairment of VEGF production. This specific interaction can provide a new strategy for countering VEGF-A production in human RPE cells and, consequently, reducing neovascularization in AMD. Further preclinical studies involving O3FAs and polyphenols are warranted.

Duloxetine protected indomethacin-induced gastric mucosal injury by increasing serotonin-dependent RANTES expression and activating PI3K-AKT-VEGF pathway

Antidepressant duloxetine has been shown protective effect on indomethacin-induced gastric ulcer, which was escorted by inflammation in the gastric mucosa. Cytokines are the principal mediators of inflammation. Thus, by screening the differential expression of cytokines in the gastric mucosa using cytokine array at 3 h after indomethacin exposure, when the gastric ulcer began to format, we found that indomethacin increased cytokines which promoted inflammation responses, whereas duloxetine decreased pro-inflammatory cytokines increased by indomethacin and increased RANTES expression. RANTES was consistently increased by pretreated with both 5 mg/kg and 20 mg/kg duloxetine at 3 h and 6 h after indomethacin exposure in male rats. Selective blockade of RANTES-CCR5 axis by a functional antagonist Met-RANTES or a CCR5 antagonist maraviroc suppressed the protection of duloxetine. Considering the pharmacologic action of duloxetine on reuptake of monoamine neurotransmitters, we examined the serotonin (5-HT), norepinephrine and dopamine contents in the blood and discovered 20 mg/kg duloxetine increased 5-HT levels in platelet-poor plasma, while treatment with 5-HT promoted expression of RANTES in the gastric mucosa and alleviated the indomethacin-induced gastric injury. Furthermore, duloxetine activated PI3K-AKT-VEGF signaling pathway, which was regulated by RANTES-CCR5, and selective inhibitor of VEGF receptor axitinib blocked the prophylactic effect of duloxetine. Furthermore, duloxetine also protected gastric mucosa from indomethacin in female rats, and RANTES was increased by duloxetine after 6 h after indomethacin exposure too. Together, our results identified the role of cytokines, particularly RANTES, and the underlying mechanisms in gastroprotective effect of duloxetine against indomethacin, which advanced our understanding in inflammatory modulation by monoamine-based antidepressants.

Abstract 2109: Nox1-mediated Endothelial Ros Propagates Hypoxia-induced Pulmonary Hypertension Via The Unfolded Protein Response.

Pulmonary arterial hypertension (PAH) is a devastating disease in which reactive oxygen species (ROS) play an important role. The disease is characterized by lung arterial cell proliferation (inward remodeling) leading to right ventricle (RV) failure. We postulated that NADPH oxidase 1 (NOX1)-derived ROS mediate endothelial cell (EC) proliferation and hemodynamic changes in PAH. Indeed, we found increased NOX1 (1.6±0.10-fold; n=7-9, p&lt;0.01) in human pulmonary artery ECs (HPAECs) exposed to 24 hr hypoxia (Hx) vs. normoxia (Nx) (1% v. 21% O 2 , in vitro PAH phenotype). To test an in vivo NOX1 role, C57BL/6J (WT), mice were implanted with pumps delivering a NOX1-selective peptidic inhibitor (NoxA1ds) or scrambled control (Scr) and exposed to Nx (21% O 2 ) or Hx (10% O 2 ) for 3 wks plus vehicle or VEGF receptor antagonist Sugen 5416. Sugen/Hx (Su/Hx) increased RV max pressure (RVMP) 2-fold ± 0.20-fold (n=7-9, p&lt;0.001) along with elevated mean pulmonary artery pressure (mPAP, 2-fold 0.25-fold, n=7-9, p&lt;0.001), pulmonary vascular resistance (PVR, 2-fold±0.2-fold, n=7-9, p&lt;0.001), and right ventricular max dP/dt (RVM dP/dt, 2-fold±0.2-fold, n=7-9, p&lt;0.001) vs. Nx. NoxA1ds infusion significantly attenuated these rises. In parallel, RNA-Seq of HPAECs treated with NOX1 siRNA and exposed to Nx or Hx revealed the protein kinase R-like ER kinase (PERK) branch of the unfolded protein response (UPR) as NOX1-mediated. UPR promotes tumor growth in cancer due to positive effects on cell survival and proliferation. Indeed, phospho-PERK expression measured via WB increased by 1.5-fold ± 0.3-fold (n=9, p&lt;0.01) in HPAECs exposed to Hx, which was completely reversed by siNOX1. Further, downstream members of the PERK-UPR pathway followed similar trends including phospho-eukaryotic translation initiation factor 2A (eIF2α, 3-fold ± 0.6-fold, n=9, p&lt;0.05), activating transcription factor 4 (ATF4, 2.1-fold ± 0.4-fold, n=9, p&lt;0.01), and protein disulfide-isomerase (PDI, 2.3-fold ± 0.65-fold, n=9, p&lt;0.01). We corroborated these findings in cross-sections of Su/Hx mouse lungs and in autopsied iPAH patient lungs. The findings are consistent with NOX1 mediating activation of the UPR through PERK, which, in turn, induces EC hyperproliferation in PAH.

Effcacy of a chimeric PlGF derived protein for the management of preeclampsia

Preeclampsia (PE) is one of the most common complications of pregnancy, affecting ~5-7% of pregnancies. Hallmarked by new onset hypertension and maternal endothelial dysfunction, PE is believed to be caused by insuffcient blood flow to the placenta. This causes the release of factors into the maternal circulation; notably the soluble VEGF receptor sFlt-1, which antagonizes the effects of VEGF in the endothelium. Placental growth factor (PlGF) is a VEGF family member produced by the placenta that only binds to the Flt-1 receptor and has little inherent angiogenic activity. We hypothesized that administration of a stabilized chimeric PlGF-derived protein (ELP-PlGF) would antagonize sFlt-1 in a rodent model of PE, and help resolve the maternal symptoms. We therefore utilized the reduced uterine perfusion pressure (RUPP) model of placental ischemia. RUPP animals exhibited a significant increase in blood presssure (99 vs 118 mmHg p&lt;005), while RUPP animals treated with ELP-PlGF demonstrated significantly attenuated hypertension (105mmHg, p&lt;0.05). Likewise, RUPP animals treated with ELP-PlGF showed decreased placental sFlt-1 (512 vs 308 pg/mg, p&lt;0.05), and plasma sFlt-1 by western blot (13877 vs 6860 AU, p&lt;0.05). Further, vascular preproendothelin expression from the aorta decreased 60% between RUPP and RUPP treated animals. Taken together, these results suggest that PlGF-based therapeutics could be a viable approach to the management of PE, and this formulation demonstrates significant effcacy in vivo in a relevant animal model. This work was partially supported by NIH grants P01HL51971, P20GM104357, and R01HL137791. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Establishment of a placental lncRNA-mRNA expression network for early-onset preeclampsia

BackgroundThis study aimed to establish a placental long non-coding RNA (lncRNA)-mRNA expression network for early-onset preeclampsia (early-onset PE).MethodsThe RNA sequencing data of the GSE14821 dataset were acquired. Several crucial lncRNAs and mRNAs were exerted based on the differential expression analysis of lncRNA and mRNA. By analyzing the differentially expressed lncRNA and mRNA, we constructed a regulatory network to explore the mechanism of the lncRNA in early onset preeclampsia.Results A total of 4436 differentially expressed lncRNAs (DElncRNAs) were identified in early-onset PE placenta samples compared with control placenta samples. Pearson correlation analysis revealed significant correlations between 3659 DElncRNAs and 372 DEmRNAs. KEGG analysis showed that the DEmRNAs were enriched in cytokine-cytokine receptor and hypoxia-inducible factor (HIF)-1 pathways. Several well-known early-onset PE-related mRNAs, such as vascular endothelial growth factor A (VEGFA) and VEGF receptor 1 (FLT1), were involved in the two pathways. Weighted gene co-expression network analysis and cis-regulatory analysis further suggested the involvement of the two pathways and potential DElncRNA-DEmRNA interactions in early-onset PE. Moreover, the upregulation of representative DElncRNAs, such as RP11-211G3.3 and RP11-65J21.3, and DEmRNAs, such as VEGFA and FLT1, were validated in clinical placenta samples from patients with early-onset PE by quantitative reverse transcription PCR. Importantly, overexpression of RP11-65J21.3 significantly promoted the proliferation of HTR-8 trophoblast cells at 72 h after transfection.ConclusionsIn conclusion, we identified placental DElncRNAs of early-onset PE and established a DElncRNA-DEmRNA network that was closely related to the cytokine-cytokine receptor and HIF-1 pathways. Our results provide potential diagnostic markers and therapeutic targets for early-onset PE management.

Single-cell insights: pioneering an integrated atlas of chromatin accessibility and transcriptomic landscapes in diabetic cardiomyopathy

BackgroundDiabetic cardiomyopathy (DCM) poses a growing health threat, elevating heart failure risk in diabetic individuals. Understanding DCM is crucial, with fibroblasts and endothelial cells playing pivotal roles in driving myocardial fibrosis and contributing to cardiac dysfunction. Advances in Multimodal single-cell profiling, such as scRNA-seq and scATAC-seq, provide deeper insights into DCM’s unique cell states and molecular landscape for targeted therapeutic interventions.MethodsSingle-cell RNA and ATAC data from 10x Multiome libraries were processed using Cell Ranger ARC v2.0.1. Gene expression and ATAC data underwent Seurat and Signac filtration. Differential gene expression and accessible chromatin regions were identified. Transcription factor activity was estimated with chromVAR, and Cis-coaccessibility networks were calculated using Cicero. Coaccessibility connections were compared to the GeneHancer database. Gene Ontology analysis, biological process scoring, cell-cell communication analysis, and gene-motif correlation was performed to reveal intricate molecular changes. Immunofluorescent staining utilized various antibodies on paraffin-embedded tissues to verify the findings.ResultsThis study integrated scRNA-seq and scATAC-seq data obtained from hearts of WT and DCM mice, elucidating molecular changes at the single-cell level throughout the diabetic cardiomyopathy progression. Robust and accurate clustering analysis of the integrated data revealed altered cell proportions, showcasing decreased endothelial cells and macrophages, coupled with increased fibroblasts and myocardial cells in the DCM group, indicating enhanced fibrosis and endothelial damage. Chromatin accessibility analysis unveiled unique patterns in cell types, with heightened transcriptional activity in myocardial cells. Subpopulation analysis highlighted distinct changes in cardiomyocytes and fibroblasts, emphasizing pathways related to fatty acid metabolism and cardiac contraction. Fibroblast-centered communication analysis identified interactions with endothelial cells, implicating VEGF receptors. Endothelial cell subpopulations exhibited altered gene expressions, emphasizing contraction and growth-related pathways. Candidate regulators, including Tcf21, Arnt, Stat5a, and Stat5b, were identified, suggesting their pivotal roles in DCM development. Immunofluorescence staining validated marker genes of cell subpopulations, confirming PDK4, PPARγ and Tpm1 as markers for metabolic pattern-altered cardiomyocytes, activated fibroblasts and endothelial cells with compromised proliferation.ConclusionOur integrated scRNA-seq and scATAC-seq analysis unveils intricate cell states and molecular alterations in diabetic cardiomyopathy. Identified cell type-specific changes, transcription factors, and marker genes offer valuable insights. The study sheds light on potential therapeutic targets for DCM.

Short Term Effect of Pre-Operative Anti-VEGF on Angiogenic and Fibrotic Profile of Fibrovascular Membranes of Proliferative Diabetic Retinopathy.

Adjuvant, pre-operative intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections have been used to reduce peri-operative bleeding in eyes undergoing pars-plana vitrectomy for complications of proliferative diabetic retinopathy (PDR). To address the concern over their potential off-target effects of progressive fibrous contraction, we sought to dissect the transcriptional changes in the surgically extracted fibrovascular membranes (FVMs). We analyzed surgically extracted FVMs from 10 eyes: 4 eyes pretreated with intravitreal bevacizumab (IVB) and 6 untreated eyes. FVMs were digested into single cells, mRNA was extracted from endothelial cell-enriched (microbead selection with CD31) and non-endothelial cell compartments, followed by RT-qPCR quantification. We then compared the relative expression of genes involved in angiogenesis, endothelial cell integrity, and myofibroblastic processes between treated and untreated FVMs. Endothelial cells from IVB pretreated FVMs showed significant reduction of VEGFA, VEGF receptors (FLT1 and KDR), and angiopoietin 2 expression as well as increased vascular endothelial cadherin and endothelin, suggesting reduced angiogenesis and enhanced vascular integrity. The non-endothelial cell fraction showed decreased expression of VEGFA and fibronectin, without significant difference in the expression of other profibrotic factors. Our findings confirm that adjuvant pre-operative IVB decreased fibronectin and increase endothelin-1 expression without affecting other profibrotic gene expression, uncovering an important interaction between IVB and endothelin-1 that deserves further study.

Autocrine VEGF drives neural stem cell proximity to the adult hippocampus vascular niche.

The vasculature is a key component of adult brain neural stem cell (NSC) niches. In the adult mammalian hippocampus, NSCs reside in close contact with a dense capillary network. How this niche is maintained is unclear. We recently found that adult hippocampal NSCs express VEGF, a soluble factor with chemoattractive properties for vascular endothelia. Here, we show that global and NSC-specific VEGF loss led to dissociation of NSCs and their intermediate progenitor daughter cells from local vasculature. Surprisingly, though, we found no changes in local vascular density. Instead, we found that NSC-derived VEGF supports maintenance of gene expression programs in NSCs and their progeny related to cell migration and adhesion. In vitro assays revealed that blockade of VEGF receptor 2 impaired NSC motility and adhesion. Our findings suggest that NSCs maintain their own proximity to vasculature via self-stimulated VEGF signaling that supports their motility towards and/or adhesion to local blood vessels.

Endomucin selectively regulates vascular endothelial growth factor receptor-2 endocytosis through its interaction with AP2

The endothelial glycocalyx, located at the luminal surface of the endothelium, plays an important role in the regulation of leukocyte adhesion, vascular permeability, and vascular homeostasis. Endomucin (EMCN), a component of the endothelial glycocalyx, is a mucin-like transmembrane glycoprotein selectively expressed by venous and capillary endothelium. We have previously shown that knockdown of EMCN impairs retinal vascular development in vivo and vascular endothelial growth factor 165 isoform (VEGF165)-induced cell migration, proliferation, and tube formation by human retinal endothelial cells in vitro and that EMCN is essential for VEGF165-stimulated clathrin-mediated endocytosis and signaling of VEGF receptor 2 (VEGFR2). Clathrin-mediated endocytosis is an essential step in receptor signaling and is of paramount importance for a number of receptors for growth factors involved in angiogenesis. In this study, we further investigated the molecular mechanism underlying EMCN’s involvement in the regulation of VEGF-induced endocytosis. In addition, we examined the specificity of EMCN's role in angiogenesis-related cell surface receptor tyrosine kinase endocytosis and signaling. We identified that EMCN interacts with AP2 complex, which is essential for clathrin-mediated endocytosis. Lack of EMCN did not affect clathrin recruitment to the AP2 complex following VEGF stimulation, but it is necessary for the interaction between VEGFR2 and the AP2 complex during endocytosis. EMCN does not inhibit VEGFR1 and FGFR1 internalization or their downstream activities since EMCN interacts with VEGFR2 but not VEGFR1 or FGFR1. Additionally, EMCN also regulates VEGF121-induced VEGFR2 phosphorylation and internalization.Graphical

Abstract 2126: Efficacy and underlying mechanisms of surufatinib in non-small cell lung cancer treatment

Abstract Background: The prevalence and fatality of lung cancer, especially non-small cell lung cancer (NSCLC), highlight the urgency for efficacious therapies. Surufatinib, an inhibitor of tyrosine kinases like VEGF receptors (VEGFR) 1, 2, and 3, Fibroblast growth factor receptor 1 (FGFR1), and CSF-1R, shows potential in augmenting chemotherapy efficacy and reducing adverse effects. Preliminary clinical studies (NCT04922658) have indicated survival benefits for NSCLC patients treated with surufatinib. This investigation seeks to delineate the therapeutic efficacy of surufatinib, correlating clinical benefits with mechanistic insights. Methods: To elucidate mechanisms, proliferation assays (CCK8), migration (scratch assay), and apoptosis (flow cytometry) were conducted in A549 and H1299 cell lines. Angiogenesis and macrophage polarization were examined via vascular junction points and mRNA expression profiling. In nude mice, subcutaneous tumors were induced and treated with the study drugs, with tumor growth and angiogenic markers assessed. Results: In vitro, surufatinib potently inhibited angiogenesis and exerted a dose-dependent suppression of proliferation and colony formation in lung cancer A549 and PC9 cell lines. It also enhanced apoptosis and cell migration. Additionally, surufatinib shifted macrophage polarization towards an M1 phenotype while diminishing M2 macrophages, thereby, contributing to a more robust anti-tumor immune milieu. In vivo studies corroborated these findings, with surufatinib and vinorelbine combination therapy significantly curtailing tumor growth and reducing CD31 expression in tumor tissues, highlighting its potential for substantial therapeutic gains in NSCLC management. Conclusion: Surufatinib achieved notable antitumor effect consistent with clinical findings in NSCLC, effectively inhibiting cellular proliferation and migration, attenuating angiogenesis, and enhancing apoptosis. Significantly, it also modulated macrophage polarization to favor an M1/M2 balance, thus activating the immune response. Therapeutic strategies with surufatinib have underscored augmented antineoplastic efficacy, meriting additional clinical investigations. Citation Format: Yanfang Zheng, Binjie Shan, Meng Wang, Xiaoran Wu, Rui Cai, Feiyu Niu, Yan Yuan, Lu Liu, Xiongjie Zhu. Efficacy and underlying mechanisms of surufatinib in non-small cell lung cancer treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2126.