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Neuropilin-1 (NRP-1) is a major co-receptor of vascular endothelial growth factor receptor-2 (VEGFR-2). It may also stimulate tumour growth and metastasis independently of VEGF-A165. ...These functions make VEGF-A165/NRP-1 complex formation and its inhibition of great interest, where NRP-1 is the target for which effective ligands are sought. Design of peptide-like inhibitors represent a strategy with great potential in the treatment of NRP-1-related disorders. Here, we present the synthesis, molecular modelling, structure-activity relationship studies as well as biological evaluation of peptides with the branched sequences H2N-X-Lys(hArg)-Dab-Oic-Arg-OH and H2N-Lys(X-hArg)-Dab-Oic-Arg-OH. Two of the designed peptides, in which Cys was inserted in X position, expressed high affinity (∼40 nM value) for NRP-1 and were resistant to enzymatic digestion in human serum. Moreover, peptide/NRP-1 complex promoted fast intracytoplasmic protein trafficking towards the plasma membrane in breast cancer cells. Our results suggest that these compounds might be good candidates for further development of VEGF-A165/NRP-1 inhibitors.
In the recent years, there was an important improvement in the understanding of the pathogenesis of hereditary angioedema (HAE). Notwithstanding, in a large portion of patients with unknown mutation ...(HAE-UNK) the genetic cause remains to be identified.
To identify new genetic targets associated with HAE, a large Argentine family with HAE-UNK spanning 3 generations was studied.
Whole exome sequencing was performed on affected family members to identify potential genetic variants associated with HAE-UNK. In silico analyses and experimental studies were applied to assess the role of the identified gene variant.
A missense variant (p.D239N) in DAB2IP was identified. The variant occurred in the C2-domain, the region interacting with vascular endothelial growth factor receptor 2 (VEGFR2). It was found to be rare, and predicted to have a detrimental effect on the functionality of DAB2IP. Protein structure modeling predicted changes in the mutant p.D239N protein structure, impacting protein stability. The p.D239N variant affected the subcellular localization of VEGFR2. Cells transfected with the DAB2IP-239N transcript exhibited an intracellular distribution, and VEGFR2 remained associated with the cell membrane. The altered localization pattern indicated reduced colocalization of the mutant protein with VEGFR2, suggesting a diminished ability of VEGFR2 binding.
The study identified a novel missense variant (p.D239N) in DAB2IP in a family with HAE-UNK and highlighted the role of dysregulated VEGF-mediated signaling in altered endothelial permeability. DAB2IP loss-of-function pathogenic variants lead to the impairment of the endothelial VEGF/VEGFR2 ligand system and represent a new pathophysiologic cause of HAE-UNK.
The angiogenic process in the central nervous system (CNS) is basically regulated by typical angiogenic signaling systems such as vascular endothelial growth factor (VEGF)-VEGF receptors and ...angiopoietin-Tie receptors. In addition to regular endothelial-pericyte interaction, the CNS vasculature has a unique system of cell to cell communication between endothelial cells and astrocytes which is known as the blood-brain barrier. Among the pathological conditions of the CNS vascular network, stroke is a major disease in which the supply of blood is decreased. Pro-angiogenic therapy using natural VEGF-A has so far been unsuccessful, indicating the possible need for a new approach related to upstream or downstream regulators involved in the VEGF-signaling pathway, or alternate VEGF family members. By contrast, a pathological increase in the blood supply in the CNS is seen in brain tumors, in particular malignant gliomas. In phase II clinical trials, anti-VEGF therapies have been shown to suppress tumor growth and improve survival rates to some extent. However, tumor invasion and the distant metastasis of gliomas can occur following anti-angiogenic therapy. Further studies are needed to obtain safer clinical outcomes by developing new strategies with combination therapy using known anti-angiogenic drugs or by developing unique medicines specifically targeting the blood vessels in brain tumors.
Clinical trials investigating the potential of mesenchymal stromal cells (MSCs) for the treatment of inflammatory diseases, such as acute respiratory distress syndrome (ARDS), have been ...disappointing, with less than 50% of patients responding to treatment. Licensed MSCs show enhanced therapeutic efficacy in response to cytokine-mediated activation signals. There are two distinct sub-phenotypes of ARDS: hypo- and hyper-inflammatory. We hypothesized that pre-licensing MSCs in a hyper-inflammatory ARDS environment would enhance their therapeutic efficacy in acute lung inflammation (ALI). Serum samples from patients with ARDS were segregated into hypo- and hyper-inflammatory categories based on interleukin (IL)-6 levels. MSCs were licensed with pooled serum from patients with hypo- or hyper-inflammatory ARDS or healthy serum controls. Our findings show that hyper-inflammatory ARDS pre-licensed MSC conditioned medium (MSC-CMHyper) led to a significant enrichment in tight junction expression and enhanced barrier integrity in lung epithelial cells in vitro and in vivo in a vascular endothelial growth factor (VEGF)-dependent manner. Importantly, while both MSC-CMHypo and MSC-CMHyper significantly reduced IL-6 and tumor necrosis factor alpha (TNF-α) levels in the bronchoalveolar lavage fluid (BALF) of lipopolysaccharide (LPS)-induced ALI mice, only MSC-CMHyper significantly reduced lung permeability and overall clinical outcomes including weight loss and clinical score. Thus, the hypo- and hyper-inflammatory ARDS environments may differentially influence MSC cytoprotective and immunomodulatory functions.
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English and colleagues investigated the differential impact of the hypo- and hyper-inflammatory ARDS patient microenvironment on human bone marrow-derived mesenchymal stromal cells (MSCs). While both hypo- and hyper-inflammatory ARDS licensing enhanced MSC immunomodulatory function, only the hyper-licensed MSC secretome promoted lung barrier reparation post-endotoxin challenge in a VEGF-dependent manner.
To investigate the changes in the retinal microvasculature during the course of anti-VEGF therapy in eyes with macular edema due to retinal vein occlusion (RVO) and their association with visual ...outcomes.
The vessel density (VD) and foveal avascular zone (FAZ) area in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were quantitatively measured by optical coherence tomography angiography (OCTA) in 48 consecutive eyes with RVO before and 1, 3, 6, 9, and 12 months after anti-VEGF therapy. Anti-VEGF therapy was performed either with ranibizumab or aflibercept following a pro re nata (PRN) regimen. The correlation between post-treatment best-corrected visual acuity (BCVA) and changes in the retinal microvasculature evaluated by OCTA were assessed.
The BCVA improved significantly at 12 months (P < 0.001). Better BCVA at 12 months was significantly associated with a better VD in the SCP and DCP both at baseline (R2 = 0.524, P < 0.001 and R2 = 0.457, P < 0.001, respectively) and at 12 months (R2 = 0.521, P < 0.001 and R2 = 0.662, P < 0.001, respectively). Overall, both VD and FAZ did not change significantly during the 12 months. However, the progression of nonperfusion was observed in the SCP in 6 (13%) eyes and in the DCP in 10 (21%) eyes. The number of macular edema recurrence was significantly associated with a decrease in the VD (P = 0.006 SCP and P < 0.001 DCP) and less visual gain (P = 0.02) after treatment.
Anti-VEGF therapy maintains retinal perfusion in most patients with RVO. Preserving retinal perfusion is crucial for better visual outcomes.
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.
Oxaliplatin therapy of colorectal cancer induces a dose-dependent neuropathic syndrome in 50% of patients. Pharmacological treatments may offer limited relief; scientific efforts are needed for new ...therapeutic approaches. Therefore we evaluated in a preclinical setting the pain relieving properties of mesenchymal stem cells and its secretome. Rat adipose stem cells (rASCs) were administered in a rat model of oxaliplatin-induced neuropathy.
A single intravenous injection of rASCs reduced oxaliplatin-dependent mechanical hypersensitivity to noxious and non-noxious stimuli taking effect 1 h after administration, peaking 6 h thereafter and lasting 5 days. Cell-conditioned medium was ineffective. Repeated rASCs injections every 5 days relieved pain each time with a comparable effect. Labeled rASCs were detected in the bloodstream 1 and 3 h after administration and found in the liver 24 h thereafter. In oxaliplatin-treated rats, the plasma concentration of vascular endothelial growth factor (pan VEGF-A) was increased while the isoform VEGF165b was upregulated in the spinal cord. Both alterations were reverted by rASCs. The anti-VEGF-A monoclonal antibody bevacizumab (intraperitoneally) reduced oxaliplatin-dependent pain. Studying the peripheral and central role of VEGF165b in pain, we determined that the intraplantar and intrathecal injection of the growth factor induced a pro-algesic effect. In the oxaliplatin neuropathy model, the intrathecal infusion of bevacizumab, anti-rat VEGF165b antibody and rASCs reduced pain.
Adult adipose mesenchymal stem cells could represent a novel approach in the treatment of neuropathic pain. The regulation of VEGF-A is suggested as an effective mechanism in the complex response orchestrated by stem cells against neuropathy.
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•Adipose stem cells relieve neuropathic pain induced by chemotherapy.•The pain killer effect has a rapid onset and lasts until 5 days.•High levels of VEGF are related to oxaliplatin-dependent neuropathic pain.•The pain relieving effects of stem cells are related to a decrease of VEGF levels.
We developed a novel “signal-off” photoelectrochemical (PEC) aptasensor based on an aptamer bridged DNA network structure for the sensitive detection of vascular endothelial growth factor (VEGF165), ...using g-C3N4 as photoactive material. The DNA network provides an excellent platform for the immobilization of methylene blue (MB), which can facilitate the electron transport through the DNA helix structure and suppress the recombination of electron-hole pairs generated by g-C3N4. In the presence of the target VEGF165, the DNA network can be destroyed adequately by the recognition between VEGF165 and the aptamer, resulting in the release of MB. Therefore, the originally enhanced electron transfer process could be inhibited, leading to a remarkable decrease of the photocurrent. A good linear relationship between the PEC signal and the logarithm of VEGF165 concentration over the range of 100fM to 10nM with a detection limit of 30 fM can be obtained. Our concept can be easily extended to develop aptasensors for the sensitive detection of different targets by triggering the release of the payloads from their corresponding aptamer bridged DNA networks.
•A novel PEC biosensor was fabricated by disassembly of aptamer bridged DNA networks.•This aptasensor can be utilized for the detection of VEGF165 with a detection limit of 30 fM.•This strategy can be easily extended to develop aptasensors for the sensitive detection of different targets.A novel PEC biosensor was fabricated by disassembly of aptamer bridged DNA networks.
Recurrent pregnancy loss (RPL) is defined as the spontaneous loss of two or more consecutive pregnancies before 20 weeks of gestation, and affects 7.46 % of the Indian population. About 40–50 % of ...RPL cases are idiopathic making it a therapeutic challenge for clinicians. This study focuses on elucidating the role of hypoxia-associated placental angiogenesis in these idiopathic RPL cases.
Whole blood and product of conception (POCs) were collected from RPL patients (N = 87) and cases of voluntary abortions (medically terminated pregnancy, MTP; n = 110) as controls with informed consent. Serum separated from whole blood was used to study the ROS-antioxidant status in the cases and controls through colorimetric assays and ELISA. The mRNA extracted from placental tissue samples were used to determine the hypoxic and angiogenic status in cases and controls through real time PCR. Statistical analysis was also carried out to correlate the differential hypoxic status between RPL and MTP cohorts with the expression of angiogenic factors (VEGFA, VEGFR1 and VEGFR2).
HIF1α mRNA expression was found to be upregulated in the RPL cases. While the serum levels of H2O2 (p = 0.012), guanine oxides and lipid hydroperoxides (LPO) were increased in the RPL cases, reduced glutathione (GSH) was found to be significantly decreased (p = 0.012). Additionally, AUROC analysis also shows an excellent discriminatory ability of 0.850 for serum H2O2 levels. VEGF-A and VEGF-R1 mRNA expression was also found to be downregulated in the RPL cases compared to MTP.
This study indicates that increased oxidative stress may lead to aberrations in the VEGF pathway resulting in improper placentation in RPL cases, and subsequently, pregnancy loss.
•Moderately increased hypoxia observed in the RPL cases.•Elevated oxidative stress due to increased H2O2 and decreased GSH levels.•Transcriptional deregulation of VEGF and its receptor genes in RPL.•Aberrations in placental angiogenesis; possible cause of pregnancy loss.
Proangiogenesis is generally regarded as an effective approach for treating ischemic heart disease. Vascular endothelial growth factor (VEGF)‐A is a strong and essential proangiogenic factor. ...Reactive oxygen species (ROS), endoplasmic reticulum (ER) stress, and autophagy are implicated in the process of angiogenesis. This study is designed to clarify the regulatory mechanisms underlying VEGF‐A, ROS, ER stress, autophagy, and angiogenesis in acute myocardial infarction (AMI). A mouse model of AMI was successfully established by occluding the left anterior descending coronary artery. Compared with the sham‐operated mice, the microvessel density, VEGF‐A content, ROS production, expression of vascular endothelial cadherin, positive expression of 78 kDa glucose‐regulated protein/binding immunoglobulin protein (GRP78/Bip), and LC3 puncta in CD31‐positive endothelial cells of the ischemic myocardium were overtly elevated. Moreover, VEGF‐A exposure predominantly increased the expression of beclin‐1, autophagy‐related gene (ATG) 4, ATG5, inositol‐requiring enzyme‐1 (IRE‐1), GRP78/Bip, and LC3‐II/LC3‐I as well as ROS production in the human umbilical vein endothelial cells (HUVECs) in a dose and time‐dependent manner. Both beclin‐1 small interfering RNA and 3‐methyladenine treatment predominantly mitigated VEGF‐A‐induced tube formation and migration of HUVECs, but they failed to elicit any notable effect on VEGF‐A‐increased expression of GRP78/Bip. Tauroursodeoxycholic acid not only obviously abolished VEGF‐A‐induced increase of IRE‐1, GRP78/Bip, beclin‐1 expression, and LC3‐II/LC3‐I, but also negated VEGF‐A‐induced tube formation and migration of HUVECs. Furthermore,
N‐acetyl‐
l‐cysteine markedly abrogated VEGF‐A‐increased ROS production, IRE‐1, GRP78/Bip, beclin‐1 expression, and LC3‐II/LC3‐I in the HUVECs. Taken together, our data demonstrated that increased spontaneous production of VEGF‐A may induce angiogenesis after AMI through initiating ROS–ER stress‐autophagy axis in the vascular endothelial cells.
Our data demonstrated that increased spontaneous production of vascular endothelial growth factor‐A may induce angiogenesis after acute myocardial infarction through initiating reactive oxygen species–endoplasmic reticulum stress‐autophagy axis in the vascular endothelial cells.
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