Role and therapeutic potential of VEGF in the nervous system

Inhibition of Vascular Endothelial Growth Factor Reduces Photoreceptor Death in Retinal Neovascular Disease via Neurotrophic Modulation in Müller Glia

VEGF is not only the most potent angiogenic factor, but also an important neurotrophic factor. In this study, vitreous expression of six neurotrophic factors were examined in proliferative diabetic retinopathy (PDR) patients with prior anti-VEGF therapy (n = 48) or without anti-VEGF treatment (n = 41) via ELISA. Potential source, variation and impact of these factors were further investigated in a mouse model of oxygen-induced retinopathy (OIR), as well as primary Müller cells and 661W photoreceptor cell line under hypoxic condition. Results showed that vitreous levels of NGF, NT-3, NT-4, BDNF, GDNF and CNTF were significantly higher in eyes undergoing anti-VEGF therapy compared with PDR controls. Statistical correlation between vitreous VEGF and each trophic factor was found. Hypoxia significantly induced the expressions of these neurotrophic factors, whereas application of anti-VEGF agent in OIR model could further upregulate retinal NGF, NT-3, NT-4, together with downregulation of BDNF, GDNF, CNTF, especially in Müller glia. Inhibition of Müller cell-derived VEGF would result in similar neurotrophic changes under hypoxia. With changes of corresponding neurotrophic receptors in the cocultured photoreceptor cells, their synergic effect could protect hypoxic photoreceptor from apoptosis when VEGF inhibition was present. These findings demonstrated that regulation of Müller cell-derived neurotrophic factors might be one of the possible mechanisms by which anti-VEGF therapy produced neuroprotective effects on PDR. These results provided new evidence for the therapeutic strategy of PDR.

In vivo evidence of increased vascular endothelial growth factor in patients with major depressive disorder

BACKGROUND

Vascular endothelial growth factor (VEGF) is a candidate mediator of blood-brain barrier (BBB) disruption in depression. However, previous studies have mainly focused on peripheral blood VEGF levels, and the results are heterogeneous. Here we use astrocyte-derived extracellular vesicles (ADEVs) isolated from plasma to explore the in vivo changes of VEGF levels in patients with major depressive disorder (MDD).

METHODS

Thirty-five unmedicated patients with MDD and 35 healthy controls (HCs) were enrolled, and plasma ADEVs were isolated from each participant. VEGF levels in ADEVs and glial fibrillary acidic protein (GFAP) in plasma were measured. Additionally, Alix and CD81, two established extracellular vesicle markers, were quantified in ADEVs.

RESULTS

At baseline, MDD patients exhibited significantly increased levels of VEGF in ADEVs and GFAP in plasma. Following four weeks of selective serotonin reuptake inhibitor treatment, these target protein levels did not significantly change. ROC curve analysis revealed an AUC of 0.711 for VEGF in ADEVs. In exploratory analysis, VEGF levels in ADEVs were positively correlated with Alix and CD81.

LIMITATIONS

Multiple factors regulate BBB permeability. This study focused solely on VEGF and the sample size for longitudinal analysis was relatively small.

CONCLUSION

Our study is the first to confirm increased ADEV-derived VEGF levels in patients with MDD, thereby providing preliminary evidence supporting the hypothesis that the BBB is disrupted in depression.

FN1 and VEGFA Are Potential Therapeutic Targets in Glioblastoma as Determined by Bioinformatics Analysis

BACKGROUND/AIM

Glioblastoma is the most malignant brain tumor, and despite advances in treatment, survival rates are still dismal. Therefore, a comprehensive understanding of the underlying molecular mechanisms of glioblastoma is needed. This study suggests potential therapeutic targets in glioblastoma that may provide new therapeutic insights.

MATERIALS AND METHODS

To identify hub genes in glioblastoma, three datasets were selected from the GEO database. After screening DEGs using GEO2R, GO and KEGG analyses were performed using DAVID. The PPI network was visualized using Cytoscape and 7 hub genes were extracted. The prognostic potential of 7 hub genes was investigated using the Gliovis and GEPIA2 databases.

RESULTS

In total, 176 up-regulated and 263 down-regulated genes were identified. From the PPI network, 7 hub genes were identified including CAMK2A, DLG4, SNAP25, SYT1, MYC, FN1, and VEGFA. Out of the 7 hub genes identified, FN1 and VEGFA have been associated with a poor prognosis in glioblastoma based on the survival analysis.

CONCLUSION

This study suggests that high levels of FN1 and VEGFA expression are associated with a poor prognosis in glioblastoma and that both genes are promising targets for glioblastoma therapy. Bioinformatics analysis of DEGs revealed putative targets that might reveal the molecular mechanisms underlying glioblastoma.

Angiogenesis in the mature mouse cortex is governed in a regional- and Notch1-dependent manner

Cerebral angiogenesis is well appreciated in development and after injury, but the extent to which it occurs across cortical regions in normal adult mice and the underlying mechanisms are incompletely understood. Using in vivo imaging, we show that angiogenesis in anterior-medial cortical regions (retrosplenial and sensorimotor cortex) was exceptionally rare. By contrast, angiogenesis was significantly elevated in posterior-lateral regions such as visual cortex, primarily within 200 μm of the cortical surface. There was no effect of sex on angiogenesis rates, nor were there regional differences in vessel pruning (for either sex). To understand the mechanisms, we surveyed gene expression and found that Notch-related genes were enriched in ultra-stable retrosplenial cortex. Using endothelial-specific knockdown of Notch1, cerebral angiogenesis was significantly increased along with genes implicated in angiogenesis (Apln, Angpt2, Cdkn1a). Our study shows that angiogenesis is regionally dependent and that manipulations of Notch1 could unlock the angiogenic potential of the mature vasculature.

Association of ten VEGF family genes with Alzheimer's disease endophenotypes at single cell resolution

INTRODUCTION

Using a single-nucleus transcriptome derived from the dorsolateral prefrontal cortex of 424 Religious Orders Study and the Rush Memory and Aging Project (ROS/MAP) participants, we investigated the cell type-specific effect of ten vascular endothelial growth factor (VEGF) genes on Alzheimer's disease (AD) endophenotypes.

METHODS

Negative binomial mixed models were used for differential gene expression and association analysis with AD endophenotypes. VEGF-associated intercellular communication was also profiled.

RESULTS

Higher microglia FLT1, endothelial FLT4, and oligodendrocyte VEGFB are associated with greater amyloid beta (Aβ) load, whereas higher VEGFB expression in inhibitory neurons is associated with lower Aβ load. Higher astrocyte NRP1 is associated with lower tau density. Higher microglia and endothelial FLT1 are associated with worse cognition performance. Endothelial and microglial FLT1 expression was upregulated in clinical AD patients compared to cognitively normal controls. Finally, AD cells showed a significant reduction in VEGF signaling compared to controls.

DISCUSSION

Our results highlight key changes in VEGF receptor expression in endothelial and microglial cells during AD, and the potential protective role of VEGFB in neurons.

HIGHLIGHTS

The prefrontal cortical expression of FLT1 and FLT4 was associated with worse cross-sectional global cognitive function, longitudinal cognitive trajectories, and more Alzheimer's disease (AD) neuropathology. The associations between FLT1 or FLT4 and AD endophenotypes appear to be driven by endothelial and microglial cells. VEGFB expression seems to have opposing effects on the Aβ burden in AD depending on cell types, highlighting its potential protective role in neurons.

flt1 inactivation promotes zebrafish cardiac regeneration by enhancing endothelial activity and limiting the fibrotic response

VEGFA administration has been explored as a pro-angiogenic therapy for cardiovascular diseases including heart failure for several years, but with little success. Here, we investigate a different approach to augment VEGFA bioavailability: by deleting the VEGFA decoy receptor VEGFR1 (also known as FLT1), one can achieve more physiological VEGFA concentrations. We find that after cryoinjury, zebrafish flt1 mutant hearts display enhanced coronary revascularization and endocardial expansion, increased cardiomyocyte dedifferentiation and proliferation, and decreased scarring. Suppressing Vegfa signaling in flt1 mutants abrogates these beneficial effects of flt1 deletion. Transcriptomic analyses of cryoinjured flt1 mutant hearts reveal enhanced endothelial MAPK/ERK signaling and downregulation of the transcription factor gene egr3. Using newly generated genetic tools, we observe egr3 upregulation in the regenerating endocardium, and find that Egr3 promotes myofibroblast differentiation. These data indicate that with enhanced Vegfa bioavailability, the endocardium limits myofibroblast differentiation via egr3 downregulation, thereby providing a more permissive microenvironment for cardiomyocyte replenishment after injury.

Evolution of aberrant brain-wide spatiotemporal dynamics of resting-state networks in a Huntington's disease mouse model

BACKGROUND

Huntington's disease (HD) is marked by irreversible loss of neuronal function for which currently no availability for disease-modifying treatment exists. Advances in the understanding of disease progression can aid biomarker development, which in turn can accelerate therapeutic discovery.

METHODS

We characterised the progression of altered dynamics of whole-brain network states in the zQ175DN mouse model of HD using a dynamic functional connectivity (FC) approach to resting-state fMRI and identified quasi-periodic patterns (QPPs) of brain activity constituting the most prominent resting-state networks.

RESULTS

The occurrence of the normative QPPs, as observed in healthy controls, was reduced in the HD model as the phenotype progressed. This uncovered progressive cessation of synchronous brain activity with phenotypic progression, which is not observed with the conventional static FC approaches. To better understand the potential underlying cause of the observed changes in these brain states, we further assessed how mutant huntingtin (mHTT) protein deposition affects astrocytes and pericytes - one of the most important effectors of neurovascular coupling, along phenotypic progression. Increased cell-type dependent mHTT deposition was observed at the age of onset of motor anomalies, in the caudate putamen, somatosensory and motor cortex, regions that are prominently involved in HD pathology as seen in humans.

CONCLUSION

Our findings provide meaningful insights into the development and progression of altered functional brain dynamics in this HD model and open new avenues in assessing the dynamics of whole brain states, through QPPs, in clinical HD research.

HIGHLIGHTS

Hyperactivity in the LCN-linked regions within short QPPs observed before motor impairment onset. DMLN QPP presents a progressive decrease in DMLN activity and occurrence along HD-like phenotype development. Breakdown of the LCN DMLN state flux at motor onset leads to a subsequent absence of the LCN DMLN QPP at an advanced HD-like stage.

Mesenchymal stem cell therapy for Alzheimer's disease: A novel therapeutic approach for neurodegenerative diseases

Alzheimer's disease (AD) is one of the most progressive and prevalent types of neurodegenerative diseases in the aging population (aged >65 years) and is considered a major factor for dementia, affecting 55 million people worldwide. In the current scenario, drug-based therapies have been employed for the treatment of Alzheimer's disease but are only able to provide symptomatic relief to patients rather than a permanent solution from Alzheimer's. Recent advancements in stem cell research unlock new horizons for developing effective and highly potential therapeutic approaches due to their self-renewal, self-replicating, regenerative, and high differentiation capabilities. Stem cells come in multiple lineages such as embryonic, neural, and induced pluripotent, among others. Among different kinds of stem cells, mesenchymal stem cells are the most investigated for Alzheimer's treatment due to their multipotent nature, low immunogenicity, ability to penetrate the blood-brain barrier, and low risk of tumorigenesis, immune & inflammatory modulation, etc. They have been seen to substantially promote neurogenesis, synaptogenesis by secreting neurotrophic growth factors, as well as in ameliorating the Aβ and tau-mediated toxicity. This review covers the pathophysiology of AD, new medications, and therapies. Further, it will focus on the advancements and benefits of Mesenchymal Stem Cell therapies, their administration methods, clinical trials concerning AD progression, along with their future prospective.

Mapping the cellular expression patterns of vascular endothelial growth factor aa and bb genes and their receptors in the adult zebrafish brain during constitutive and regenerative neurogenesis

The complex interplay between vascular signaling and neurogenesis in the adult brain remains a subject of intense research. By exploiting the unique advantages of the zebrafish model, in particular the persistent activity of neural stem cells (NSCs) and the remarkable ability to repair brain lesions, we investigated the links between NSCs and cerebral blood vessels. In this study, we first examined the gene expression profiles of vascular endothelial growth factors aa and bb (vegfaa and vegfbb), under physiological and regenerative conditions. Employing fluorescence in situ hybridization combined with immunostaining and histology techniques, we demonstrated the widespread expression of vegfaa and vegfbb across the brain, and showed their presence in neurons, microglia/immune cells, endothelial cells and NSCs. At 1 day post-lesion (dpl), both vegfaa and vegfbb were up-regulated in neurons and microglia/peripheral immune cells (macrophages). Analysis of vegf receptors (vegfr) revealed high expression throughout the brain under homeostatic conditions, with vegfr predominantly expressed in neurons and NSCs and to a lower extent in microglia/immune cells and endothelial cells. These findings were further validated by Vegfr3 and Vegfr4 immunostainings, which showed significant expression in neurogenic radial glial cells.Following brain lesion (1 dpl), while vegfr gene expression remained stable, vegfr transcripts were detected in proliferative cells within the injured parenchyma. Collectively, our results provide a first overview of Vegf/Vegfr signaling in the brain and suggest important roles for Vegf in neurogenesis and regenerative processes.

The Janus face of HIF-1α in ischemic stroke and the possible associated pathways

Stroke is the most devastating disease, causing paralysis and eventually death. Many clinical and experimental trials have been done in search of a new safe and efficient medicine; nevertheless, scientists have yet to discover successful remedies that are also free of adverse effects. This is owing to the variability in intensity, localization, medication routes, and each patient's immune system reaction. HIF-1α represents the modern tool employed to treat stroke diseases due to its functions: downstream genes such as glucose metabolism, angiogenesis, erythropoiesis, and cell survival. Its role can be achieved via two downstream EPO and VEGF strongly related to apoptosis and antioxidant processes. Recently, scientists paid more attention to drugs dealing with the HIF-1 pathway. This review focuses on medicines used for ischemia treatment and their potential HIF-1α pathways. Furthermore, we discussed the interaction between HIF-1α and other biological pathways such as oxidative stress; however, a spotlight has been focused on certain potential signalling contributed to the HIF-1α pathway. HIF-1α is an essential regulator of oxygen balance within cells which affects and controls the expression of thousands of genes related to sustaining homeostasis as oxygen levels fluctuate. HIF-1α's role in ischemic stroke strongly depends on the duration and severity of brain damage after onset. HIF-1α remains difficult to investigate, particularly in ischemic stroke, due to alterations in the acute and chronic phases of the disease, as well as discrepancies between the penumbra and ischemic core. This review emphasizes these contrasts and analyzes the future of this intriguing and demanding field.

Platelet-rich plasma attenuates the UPEC-induced cystitis via inhibiting MMP-2,9 activities and downregulation of NGF and VEGF in Canis Lupus Familiaris model

One of the most prevalent disorders of the urinary system is urinary tract infection, which is mostly brought on by uropathogenic Escherichia coli (UPEC). The objective of this study was to evaluate the regenerative therapeutic and antibacterial efficacy of PRP for induced bacterial cystitis in dogs in comparison to conventional antibiotics. 25 healthy male mongrel dogs were divided into 5 groups (n = 5). Control negative group that received neither induced infection nor treatments. 20 dogs were randomized into 4 groups after two weeks of induction of UPEC cystitis into; Group 1 (control positive; G1) received weekly intravesicular instillation of sodium chloride 0.9%. Group 2 (syst/PRP; G2), treated with both systemic intramuscular antibiotic and weekly intravesicular instillation of PRP; Group 3 (PRP; G3), treated with weekly intravesicular instillation of PRP, and Group 4 (syst; G4) treated with an intramuscular systemic antibiotic. Animals were subjected to weekly clinical, ultrasonographic evaluation, urinary microbiological analysis, and redox status biomarkers estimation. Urinary matrix metalloproteinases (MMP-2, MMP-9) and urinary gene expression for platelet-derived growth factor -B (PDGF-B), nerve growth factor (NGF), and vascular endothelial growth factor (VEGF) were measured. At the end of the study, dogs were euthanized, and the bladder tissues were examined macroscopically, histologically, and immunohistochemically for NF-κB P65 and Cox-2. The PRP-treated group showed significant improvement for all the clinical, Doppler parameters, and the urinary redox status (p < 0.05). The urinary MMPs activity was significantly decreased in the PRP-treated group and the expression level of urinary NGF and VEGF were downregulated while PDGFB was significantly upregulated (p < 0.05). Meanwhile, the urinary viable cell count was significantly reduced in all treatments (P < 0.05). Gross examination of bladder tissue showed marked improvement for the PRP-treated group, expressed in the histopathological findings. Immunohistochemical analysis revealed a marked increase in Cox-2 and NF-κB P65 in the PRP-treated group (P < 0.05). autologous CaCl2-activated PRP was able to overcome the bacterial infection, generating an inflammatory environment to overcome the old one and initiate tissue healing. Hence, PRP is a promising alternative therapeutic for UPEC cystitis instead of conventional antibiotics.

Debamestrocel multimodal effects on biomarker pathways in amyotrophic lateral sclerosis are linked to clinical outcomes

INTRODUCTION/AIMS

Biomarkers have shown promise in amyotrophic lateral sclerosis (ALS) research, but the quest for reliable biomarkers remains active. This study evaluates the effect of debamestrocel on cerebrospinal fluid (CSF) biomarkers, an exploratory endpoint.

METHODS

A total of 196 participants randomly received debamestrocel or placebo. Seven CSF samples were to be collected from all participants. Forty-five biomarkers were analyzed in the overall study and by two subgroups characterized by the ALS Functional Rating Scale-Revised (ALSFRS-R). A prespecified model was employed to predict clinical outcomes leveraging biomarkers and disease characteristics. Causal inference was used to analyze relationships between neurofilament light chain (NfL) and ALSFRS-R.

RESULTS

We observed significant changes with debamestrocel in 64% of the biomarkers studied, spanning pathways implicated in ALS pathology (63% neuroinflammation, 50% neurodegeneration, and 89% neuroprotection). Biomarker changes with debamestrocel show biological activity in trial participants, including those with advanced ALS. CSF biomarkers were predictive of clinical outcomes in debamestrocel-treated participants (baseline NfL, baseline latency-associated peptide/transforming growth factor beta1 [LAP/TGFβ1], change galectin-1, all p < .01), with baseline NfL and LAP/TGFβ1 remaining (p < .05) when disease characteristics (p < .005) were incorporated. Change from baseline to the last measurement showed debamestrocel-driven reductions in NfL were associated with less decline in ALSFRS-R. Debamestrocel significantly reduced NfL from baseline compared with placebo (11% vs. 1.6%, p = .037).

DISCUSSION

Following debamestrocel treatment, many biomarkers showed increases (anti-inflammatory/neuroprotective) or decreases (inflammatory/neurodegenerative) suggesting a possible treatment effect. Neuroinflammatory and neuroprotective biomarkers were predictive of clinical response, suggesting a potential multimodal mechanism of action. These results offer preliminary insights that need to be confirmed.

Intranasal Immunotherapy with M2 Macrophage Secretome Ameliorates Language Impairments and Autistic-like Behavior in Children

Background/Objectives: The intranasal delivery of various neurotropic substances is considered a new attractive therapeutic approach for treating neuropathologies associated with neuroinflammation and altered regeneration. Specific language impairment (SLI) that arises as a result of damage to the cortical speech zones during the developmental period is one of the most common problems in preschool children, and it is characterized by persistent difficulties in the acquisition, understanding, and use of language. This study's objective is to evaluate the efficacy and safety of intranasal immunotherapy using the M2 macrophage secretome as a rich source of immunoregulatory and neurotrophic factors for the treatment of severe language impairment in children. Methods: Seventy-one children (54 boys and 17 girls, aged 3 to 13 years) were recruited to participate in a clinical trial (NCT04689282) in two medical centers. The children were examined before, 1 month after, and 6 months after the start of therapy. In the vast majority of children (55/71), language impairment was associated with autistic-like symptoms and attention deficit hyperactivity disorder (ADHD). Results: Daily intranasal inhalations of M2 macrophage-conditioned medium (for 30 days) were well tolerated and led to a decrease in the severity of language impairments, autistic-like behavior, and ADHD symptoms. The clinical effect appeared within a month after the first procedure and persisted or intensified during a 6-month follow-up. Two-thirds of the children showed a clear clinical improvement, while the rest had less pronounced improvement. Conclusions: Thus, the use of the M2 macrophage secretome and its intranasal delivery is safe, well tolerated, and clinically effective in children with severe language impairments.

Association of 10 VEGF Family Genes with Alzheimer's Disease Endophenotypes at Single Cell Resolution

The cell-type specific role of the vascular endothelial growth factors (VEGFs) in the pathogenesis of Alzheimer's disease (AD) is not well characterized. In this study, we utilized a single-nucleus RNA sequencing dataset from Dorsolateral Prefrontal Cortex (DLFPC) of 424 donors from the Religious Orders Study and Memory and Aging Project (ROS/MAP) to investigate the effect of 10 VEGF genes ( VEGFA, VEGFB, VEGFC, VEGFD, PGF, FLT1, FLT4, KDR, NRP1 , and NRP2 ) on AD endophenotypes. Mean age of death was 89 years, among which 68% were females, and 52% has AD dementia. Negative binomial mixed models were used for differential expression analysis and for association analysis with β-amyloid load, PHF tau tangle density, and both cross-sectional and longitudinal global cognitive function. Intercellular VEGF-associated signaling was profiled using CellChat. We discovered prefrontal cortical FLT1 expression was upregulated in AD brains in both endothelial and microglial cells. Higher FLT1 expression was also associated with worse cross-sectional global cognitive function, longitudinal cognitive trajectories, and β-amyloid load. Similarly, higher endothelial FLT4 expression was associated with more β-amyloid load. In contrast to the receptors, VEGFB showed opposing effects on β-amyloid load whereby higher levels in oligodendrocytes was associated with high amyloid burden, while higher levels in inhibitory neurons was associated with lower amyloid burden. Finally, AD cells showed significant reduction in overall VEGF signaling comparing to those from cognitive normal participants. Our results highlight key changes in VEGF receptor expression in endothelial and microglial cells during AD, and the potential protective role of VEGFB in neurons.

AAV-mediated VEGFA overexpression promotes angiogenesis and recovery of locomotor function following spinal cord injury via PI3K/Akt signaling

Spinal cord injury (SCI) is a disorder of the central nervous system resulting from various factors such as trauma, inflammation, tumors, and other etiologies. This condition leads to impairment in motor, sensory, and autonomic functions below the level of injury. Limitations of current therapeutic approaches prompt an investigation into therapeutic angiogenesis through persistent local expression of proangiogenic factors. Here, we investigated whether overexpression of adeno-associated virus (AAV)-mediated vascular endothelial growth factor A (VEGFA) in mouse SCI promoted locomotor function recovery, and whether the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway was mechanistically involved. Three weeks before SCI, AAV-VEGFA was injected at the T10 level to induce VEGFA overexpression. Neurofunctional, histological, and biochemical assessments were done to determine tissue damage and/or recovery of neuromuscular and behavioral impairments. Daily injections of the PI3K/Akt pathway inhibitor LY294002 were made to assess a possible mechanism. AAV-VEGFA overexpression dramatically improved locomotor function and ameliorated pathological injury caused by SCI. Improved motor-evoked potentials in hindlimbs and more spinal CD31-positive microvessels were observed in AAV-VEGFA-overexpressing mice. LY294002 reduced PI3K and Akt phosphorylation levels and attenuated AAV-VEGFA-related improvements. In conclusion, sustained local AAV-mediated VEGFA overexpression in spinal cord can significantly promote angiogenesis and ameliorate locomotor impairment after SCI in a contusion mouse model through activation of the PI3K/Akt signaling pathway.

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.

VEGF expression disparities in brainstem motor neurons of the SOD1G93A ALS model: Correlations with neuronal vulnerability

Amyotrophic lateral sclerosis (ALS) is a rare neuromuscular disease characterized by severe muscle weakness mainly due to degeneration and death of motor neurons. A peculiarity of the neurodegenerative processes is the variable susceptibility among distinct neuronal populations, exemplified by the contrasting resilience of motor neurons innervating the ocular motor system and the more vulnerable facial and hypoglossal motor neurons. The crucial role of vascular endothelial growth factor (VEGF) as a neuroprotective factor in the nervous system is well-established since a deficit of VEGF has been related to motoneuronal degeneration. In this study, we investigated the survival of ocular, facial, and hypoglossal motor neurons utilizing the murine SOD1G93A ALS model at various stages of the disease. Our primary objective was to determine whether the survival of the different brainstem motor neurons was linked to disparate VEGF expression levels in resilient and susceptible motor neurons throughout neurodegeneration. Our findings revealed a selective loss of motor neurons exclusively within the vulnerable nuclei. Furthermore, a significantly higher level of VEGF was detected in the more resistant motor neurons, the extraocular ones. We also examined whether TDP-43 dynamics in the brainstem motor neuron of SOD mice was altered. Our data suggests that the increased VEGF levels observed in extraocular motor neurons may potentially underlie their resistance during the neurodegenerative processes in ALS in a TDP-43-independent manner. Our work might help to better understand the underlying mechanisms of selective vulnerability of motor neurons in ALS.

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.

VEGF and Neuronal Survival

Vascular endothelial growth factor (VEGF) is well known for its angiogenic activity, but recent evidence has revealed a neuroprotective action of this factor on injured or diseased neurons. In the present review, we summarize the most relevant findings that have contributed to establish a link between VEGF deficiency and neuronal degeneration. At issue, 1) mutant mice with reduced levels of VEGF show adult-onset muscle weakness and motoneuron degeneration resembling amyotrophic lateral sclerosis (ALS), 2) administration of VEGF to different animal models of motoneuron degeneration improves motor performance and ameliorates motoneuronal degeneration, and 3) there is an association between low plasmatic levels of VEGF and human ALS. Altogether, the results presented in this review highlight VEGF as an essential motoneuron neurotrophic factor endowed with promising therapeutic potential for the treatment of motoneuron disorders.

Serum biomarkers and disease progression in CT-negative mild traumatic brain injury

Blood proteins are emerging as potential biomarkers for mild traumatic brain injury (mTBI). Molecular pathology of mTBI underscores the critical roles of neuronal injury, neuroinflammation, and vascular health in disease progression. However, the temporal profile of blood biomarkers associated with the aforementioned molecular pathology after CT-negative mTBI, their diagnostic and prognostic potential, and their utility in monitoring white matter integrity and progressive brain atrophy remain unclear. Thus, we investigated serum biomarkers and neuroimaging in a longitudinal cohort, including 103 CT-negative mTBI patients and 66 matched healthy controls (HCs). Angiogenic biomarker vascular endothelial growth factor (VEGF) exhibited the highest area under the curve of 0.88 in identifying patients from HCs. Inflammatory biomarker interleukin-1β and neuronal cell body injury biomarker ubiquitin carboxyl-terminal hydrolase L1 were elevated in acute-stage patients and associated with deterioration of cognitive function from acute-stage to 6-12 mo post-injury period. Notably, axonal injury biomarker neurofilament light (NfL) was elevated in acute-stage patients, with higher levels associated with impaired white matter integrity in acute-stage and progressive gray and white matter atrophy from 3- to 6-12 mo post-injury period. Collectively, our findings emphasized the potential clinical value of serum biomarkers, particularly NfL and VEGF, in diagnosing mTBI and monitoring disease progression.

Analysis of Serum VEGF, IGF-1, and HIF-1α Levels in ADHD

OBJECTIVE

In recent years, it has been emphasized that various growth factors that affect neurogenesis may lead to ADHD. In this study, we aimed to investigate the role of VEGF, IGF-1, and HIF-1α growth factors in the etiopathogenesis of ADHD.

METHOD

Levels of VEGF, IGF-1, and HIF-1α were compared between 40 ADHD children and 40 healthy children, aged 7 to 13 years.

RESULT

VEGF, IGF-1, and HIF-1α levels did not significantly differ between the groups. There was a negative correlation between serum VEGF levels and the parent-rated T-DSM-IV-S (AD) subscale. There was a positive correlation between serum IGF-1 levels and the parent-rated T-DSM-IV-S (AD) subscale, and SDQ (ES) subscale.

CONCLUSION

Given our limitations and the fact that some of our findings differ from those of other studies, it is evident that this area requires additional research with larger samples.

An update on mechanisms of pruritus and their potential treatment in primary cutaneous T-cell lymphoma

Primary cutaneous T-cell lymphomas (CTCL), which include mycosis fungoides (MF) and Sézary syndrome (SS), are a group of lymphoproliferative disorders characterized by clonal accumulation of neoplastic T-lymphocytes in the skin. Severe pruritus, one of the most common and distressing symptoms in primary CTCL, can significantly impair emotional well-being, physical functioning, and interpersonal relationships, thus greatly reducing quality of life. Unfortunately, effectively managing pruritus remains challenging in CTCL patients as the underlying mechanisms are, as of yet, not fully understood. Previous studies investigating the mechanisms of itch in CTCL have identified several mediators and their corresponding antagonists used for treatment. However, a comprehensive overview of the mediators and receptors contributing to pruritus in primary CTCL is lacking in the current literature. Here, we summarize and review the mediators and receptors that may contribute to pruritus in primary CTCL to explore the mechanisms of CTCL pruritus and identify effective therapeutic targets using the PubMed and Web of Science databases. Studies were included if they described itch mediators and receptors in MF and SS. Overall, the available data suggest that proteases (mainly tryptase), and neuropeptides (particularly Substance P) may be of greatest interest. At the receptor level, cytokine receptors, MRGPRs, and TRP channels are most likely important. Future drug development efforts should concentrate on targeting these mediators and receptors for the treatment of CTCL pruritus.

Blocking Hemopexin With Specific Antibodies: A New Strategy for Treating Diabetic Retinopathy

Hemopexin (HPX) is overexpressed in the retina of patients with diabetes and induces the breakdown of the blood-retinal barrier in vitro. The aim of this study was to evaluate whether HPX blockade by specific antibodies (aHPX) could avoid vascular leakage in vivo and microvascular angiogenesis in vitro and ex vivo. For this purpose, the effect of intravitreal (IVT) injections of aHPX on vascular leakage was evaluated in db/db mice and rats with streptozotocin-induced diabetes using the Evans Blue method. Retinal neurodegeneration and inflammation were also evaluated. The antiangiogenic effect of aHPX on human retinal endothelial cells (HRECs) was tested by scratch wound healing and tube formation using standardized methods, as well as by choroidal sprouting assays from retinal explants obtained in rats. We found that IVT injection of aHPX significantly reduced vascular leakage, retinal neurodegeneration, and inflammation. In addition, treatment with aHPX significantly reduced HREC migration and tube formation induced by high glucose concentration and suppressed choroidal sprouting even after vascular endothelial growth factor stimulation, with this effect being higher than obtained with bevacizumab. The antipermeability and antiangiogenic effects of IVT injection of aHPX suggest the blockade or inhibition of HPX as a new strategy for the treatment of advanced stages of diabetic retinopathy.

ARTICLE HIGHLIGHTS

Hemopexin (HPX) is the best-characterized permeability factor in steroid-sensitive nephrotic syndrome. We have previously reported that HPX is overexpressed in the retina of patients with diabetes and induces the breakdown of the blood-retinal barrier in vitro. Here, we report that intravitreal injection of anti-HPX antibodies significantly reduces vascular leakage, retinal neurodegeneration, and inflammation in diabetic murine models and that the immunoneutralization of HPX exerts a significant antiangiogenic effect in vitro and in retinal explants. The blockade of HPX can be considered as a new therapy for advanced stages of diabetic retinopathy.

Ac4C Enhances the Translation Efficiency of Vegfa mRNA and Mediates Central Sensitization in Spinal Dorsal Horn in Neuropathic Pain

N4-Acetylcytidine (ac4C), a highly conserved post-transcriptional machinery with extensive existence for RNA modification, plays versatile roles in various cellular processes and functions. However, the molecular mechanism by which ac4C modification mediates neuropathic pain remains elusive. Here, it is found that the enhanced ac4C modification promotes the recruitment of polysome in Vegfa mRNA and strengthens the translation efficiency following SNI. Nerve injury increases the expression of NAT10 and the interaction between NAT10 and Vegfa mRNA in the dorsal horn neurons, and the gain and loss of NAT10 function further confirm that NAT10 is involved in the ac4C modification in Vegfa mRNA and pain behavior. Moreover, the ac4C-mediated VEGFA upregulation contributes to the central sensitivity and neuropathic pain induced by SNI or AAV-hSyn-NAT10. Finally, SNI promotes the binding of HNRNPK in Vegfa mRNA and subsequently recruits the NAT10. The enhanced interaction between HNRNPK and NAT10 contributes to the ac4C modification of Vegfa mRNA and neuropathic pain. These findings suggest that the enhanced interaction between HNRNPK and Vegfa mRNA upregulates the ac4C level by recruiting NAT10 and contributes to the central sensitivity and neuropathic pain following SNI. Blocking this cascade may be a novel therapeutic approach in patients with neuropathic pain.

White matter hyperintensity volume modifies the association between CSF vascular inflammatory biomarkers and regional FDG-PET along the Alzheimer's disease continuum

In older adults with abnormal levels of Alzheimer's disease neuropathology, lower cerebrospinal fluid (CSF) vascular endothelial growth factor (VEGF) levels are associated with lower [¹⁸F]-fluorodeoxyglucose positron emission tomography (FDG-PET) signal, but whether this association is (1) specific to VEGF or broadly driven by vascular inflammation, or (2) modified by vascular risk (e.g., white matter hyperintensities [WMHs]) remains unknown. To address this and build upon our past work, we evaluated whether 5 CSF vascular inflammation biomarkers (vascular cell adhesion molecule 1, VEGF, C-reactive protein, fibrinogen, and von Willebrand factor)-previously associated with CSF amyloid levels-were related to FDG-PET signal and whether WMH volume modified these associations in 158 Alzheimer's Disease Neuroimaging Initiative participants (55-90 years old, 39 cognitively normal, 80 mild cognitive impairment, 39 Alzheimer's disease). We defined regions both by cortical boundary and by the 3 major vascular territories: anterior, middle, and posterior cerebral arteries. We found that WMH volume had interactive effects with CSF biomarkers (VEGF and C-reactive protein) on FDG-PET throughout the cortex in both vascular territories and conventionally defined regions of interest.

Comparison of the efficacy of human umbilical cord mesenchymal stem cells conditioned medium and platelet-rich plasma on the hippocampus of STZ-induced rat model of Alzheimer's disease: A behavioral and stereological study

Introduction

Alzheimer's disease (AD) is accompanied by progressive cognitive disorders and memory loss. This study aims to determine the combined effects of conditioned medium of human umbilical cord mesenchymal stem cells (CM) and platelet-rich plasma (PRP) on AD model rats.

Methods

Forty-eight male Sprague Dawley rats were classified into 6 groups: Control, Sham, AD, and three treatment groups. AD was induced by streptozotocin(STZ; 3 mg/kg, intracerebroventricular (ICV)) and the treatment groups received injections of CM [(200 µl, intraperitoneally (i.p.), and/or PRP (100 µl, intravenously(i.v)] for 8 days. Behavioral tests (Morris water maze and novel objective recognition) were used to assess learning ability and memory. At the end of the behavioral tests, the rats were sacrificed and their brain was entirely removed, sectioned, and stained with cresyl violet. The hippocampus volume and number of neurons were evaluated by stereological techniques.

Results

In the AD group, the discrimination ratio, time spent in the target zone, volume of Cornu Ammonis1 (CA1) and Dentate Gyrus (DG), and the number of pyramidal and granular cells decreased significantly compared to the Sham group. The mentioned parameters increased in the CM and CM+PRP groups compared to the AD group (p < 0.01). PRP did not have any noticeable effect on the examined parameters.

Conclusions

CM may be beneficial in the treatment of AD as it led to better improvement in STZ-induced learning and memory impairments as well as the structure of the hippocampus.

Reduced Brain Cortex Angiogenesis in the Offspring of the Preeclampsia-Like Syndrome

BACKGROUND

Children from pregnancies affected by preeclampsia have an increased risk of cognitive and behavioral alterations via unknown pathophysiology. We tested the hypothesis that preeclampsia generated reduced brain cortex angiogenesis in the offspring.

METHODS

The preeclampsia-like syndrome (PELS) mouse model was generated by administering the nitric oxide inhibitor NG-nitroarginine methyl ester hydrochloride. Confirmatory experiments were done using 2 additional PELS models. While in vitro analysis used mice and human brain endothelial cells exposed to serum of postnatal day 5 pups or umbilical plasma from preeclamptic pregnancies, respectively.

RESULTS

We report significant reduction in the area occupied by blood vessels in the motor and somatosensory brain cortex of offspring (postnatal day 5) from PELS compared with uncomplicated control offspring. These data were confirmed using 2 additional PELS models. Furthermore, circulating levels of critical proangiogenic factors, VEGF (vascular endothelial growth factor), and PlGF (placental growth factor) were lower in postnatal day 5 PELS. Also we found lower VEGF receptor 2 (KDR [kinase insert domain-containing receptor]) levels in mice and human endothelial cells exposed to the serum of postnatal day 5 PELS or fetal plasma of preeclamptic pregnancies, respectively. These changes were associated with lower in vitro angiogenic capacity, diminished cell migration, larger F-actin filaments, lower number of filopodia, and lower protein levels of F-actin polymerization regulators in brain endothelial cells exposed to serum or fetal plasma of offspring from preeclampsia.

CONCLUSIONS

Offspring from preeclampsia exhibited diminished brain cortex angiogenesis, associated with lower circulating VEGF/PlGF/KDR protein levels, impaired brain endothelial migration, and dysfunctional assembly of F-actin filaments. These alterations may predispose to structural and functional alterations in long-term brain development.

Hepatocyte growth factor pretreatment boosts functional recovery after spinal cord injury through human iPSC-derived neural stem/progenitor cell transplantation

BACKGROUND

Human induced pluripotent stem cell-derived neural stem/progenitor cell (hiPSC-NS/PC)-based cell transplantation has emerged as a groundbreaking method for replacing damaged neural cells and stimulating functional recovery, but its efficacy is strongly influenced by the state of the injured spinal microenvironment. This study evaluates the impact of a dual therapeutic intervention utilizing hepatocyte growth factor (HGF) and hiPSC-NS/PC transplantation on motor function restoration following spinal cord injury (SCI).

METHODS

Severe contusive SCI was induced in immunocompromised rats, followed by continuous administration of recombinant human HGF protein into the subarachnoid space immediately after SCI for two weeks. Acute-phase histological and RNA sequencing analyses were conducted. Nine days after the injury, hiPSC-NS/PCs were transplanted into the lesion epicenter of the injured spinal cord, and the functional and histological outcomes were determined.

RESULTS

The acute-phase HGF-treated group exhibited vascularization, diverse anti-inflammatory effects, and activation of endogenous neural stem cells after SCI, which collectively contributed to tissue preservation. Following cell transplantation into a favorable environment, the transplanted NS/PCs survived well, facilitating remyelination and neuronal regeneration in host tissues. These comprehensive effects led to substantial enhancements in motor function in the dual-therapy group compared to the single-treatment groups.

CONCLUSIONS

We demonstrate that the combined therapeutic approach of HGF preconditioning and hiPSC-NS/PC transplantation enhances locomotor functional recovery post-SCI, highlighting a highly promising therapeutic strategy for acute to subacute SCI.

Pattern detection in the TGFβ cascade controls the induction of long-term synaptic plasticity

Transforming growth factor β (TGFβ) is required for long-term memory (LTM) for sensitization in Aplysia. When LTM is induced using a two-trial training protocol, TGFβ inhibition only blocks LTM when administrated at the second, not the first trial. Here, we show that TGFβ acts as a "repetition detector" during the induction of two-trial LTM. Secretion of the biologically inert TGFβ proligand must coincide with its proteolytic activation by the Bone morphogenetic protein-1 (BMP-1/Tolloid) metalloprotease, which occurs specifically during trial two of our two-trial training paradigm. This paradigm establishes long-term synaptic facilitation (LTF), the cellular correlate of LTM. BMP-1 application paired with a single serotonin (5HT) pulse induced LTF, whereas neither a single 5HT pulse nor BMP-1 alone effectively did so. On the other hand, inhibition of endogenous BMP-1 activity blocked the induction of two-trial LTF. These results suggest a unique role for TGFβ in the interaction of repeated trials: during learning, repeated stimuli engage separate steps of the TGFβ cascade that together are necessary for the induction of long-lasting memories.

Insights into the neurobiology of suicidality: explicating the role of glutamatergic systems through the lens of ketamine

Suicidality is a prevalent mental health condition, and managing suicidal patients is one of the most challenging tasks for health care professionals due to the lack of rapid-acting, effective psychopharmacological treatment options. According to the literature, suicide has neurobiological underpinnings that are not fully understood, and current treatments for suicidal tendencies have considerable limitations. To treat suicidality and prevent suicide, new treatments are required; to achieve this, the neurobiological processes underlying suicidal behavior must be thoroughly investigated. Although multiple neurotransmitter systems, particularly serotonergic systems, have been studied in the past, less has been reported in relation to disruptions in glutamatergic neurotransmission, neuronal plasticity, and neurogenesis that result from stress-related abnormalities of the hypothalamic-pituitary-adrenal system. Informed by the literature, which reports robust antisuicidal and antidepressive properties of subanaesthetic doses of ketamine, this review aims to provide an examination of the neurobiology of suicidality (and relevant mood disorders) with implications of pertinent animal, clinical, and postmortem studies. We discuss dysfunctions in the glutamatergic system, which may play a role in the neuropathology of suicidality and the role of ketamine in restoring synaptic connectivity at the molecular levels.

Effect of chlorpyrifos on VEGF gene expression

Chlorpyrifos (CPF; 0,0-diethyl 0-(3,5,6-trichloro-2-pyridinyl)-phosphorothioate), a cholinesterase inhibitor, compromised the integrity of the blood-brain barrier (BBB) when used at low concentrations during our previous experiments in vitro. To determine if BBB leakage would also occur in vivo, we used FITC-dextrans to evaluate BBB permeability in CPF-dosed mice. Results indicated BBB leakages that were evident at 2 h after treatment with 70 mg/kg CPF ip. Since vascular endothelial growth factor (VEGF), a potent vasopermeability factor, is a signaling protein that promotes the growth of new blood vessels, we investigated the possible involvement of VEGF in BBB disruption by CPF. We found that VEGF serum concentration was significantly increased at 24 h after CPF exposure. To further explore VEGF involving BBB disruption by CPF treatment, the receptor antagonist for VEGF (sFlt-1) was used for pretreatment before CPF exposure. After sFlt-1 pretreatment, gene expressions of the tight junction (TJ) proteins claudin5 and occludin were significantly downregulated at 1, 2, and 3 h, but returned to control levels at 24 h after CPF treatment. These results suggest that VEGF is involved in BBB disruption by CPF through BBB-TJs regulation.

Dexmedetomidine attenuates sleep deprivation-induced inhibition of hippocampal neurogenesis via VEGF-VEGFR2 signaling and inhibits neuroinflammation

Long periods of sleep deprivation (SD) have serious effects on health. While the α2 adrenoceptor agonist dexmedetomidine (DEX) can improve sleep quality for patients who have insomnia, the effect of DEX on cognition and mechanisms after SD remains elusive. C57BL/6 mice were subjected to 20 h SD daily for seven days. DEX (100 μg/kg) was administered intravenously twice daily (at 1:00 p.m. and 3:00 p.m.) during seven days of SD. We found that systemic administration of DEX attenuated cognitive deficits by performing the Y maze and novel object recognition tests and increased DCX+, SOX2+, Ki67+, and BrdU+NeuN+/NeuN+ cell numbers in the dentate gyrus (DG) region of SD mice by using immunofluorescence, western blotting, and BrdU staining. DEX did not reverse the decrease in DCX+, SOX2+, or Ki67+ cell numbers in SD mice after administration of the α2A-adrenoceptor antagonist BRL-44408. Furthermore, the vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor 2 (VEGFR2) expression was upregulated in SD+DEX mice compared with SD mice. Luminex analysis showed that the neurogenic effects of DEX were possibly related to the inhibition of neuroinflammation, including IL-1α, IL-2, CCL5, and CXCL1. Our results suggested that DEX alleviated the impaired learning and memory of SD mice potentially by inducing hippocampal neurogenesis via the VEGF-VEGFR2 signaling pathway and by suppressing neuroinflammation, and α2A adrenoceptors are required for the neurogenic effects of DEX after SD. This novel mechanism may add to our knowledge of DEX in the clinical treatment of impaired memory caused by SD.

A Biosafety Study of Human Umbilical Cord Blood Mononuclear Cells Transduced with Adenoviral Vector Carrying Human Vascular Endothelial Growth Factor cDNA In Vitro

The biosafety of gene therapy remains a crucial issue for both the direct and cell-mediated delivery of recombinant cDNA encoding biologically active molecules for the pathogenetic correction of congenital or acquired disorders. The diversity of vector systems and cell carriers for the delivery of therapeutic genes revealed the difficulty of developing and implementing a safe and effective drug containing artificial genetic material for the treatment of human diseases in practical medicine. Therefore, in this study we assessed changes in the transcriptome and secretome of umbilical cord blood mononuclear cells (UCB-MCs) genetically modified using adenoviral vector (Ad5) carrying cDNA encoding human vascular endothelial growth factor (VEGF165) or reporter green fluorescent protein (GFP). A preliminary analysis of UCB-MCs transduced with Ad5-VEGF165 and Ad5-GFP with MOI of 10 showed efficient transgene expression in gene-modified UCB-MCs at mRNA and protein levels. The whole transcriptome sequencing of native UCB-MCs, UCB-MC+Ad5-VEGF165, and UCB-MC+Ad5-GFP demonstrated individual sample variability rather than the effect of Ad5 or the expression of recombinant vegf165 on UCB-MC transcriptomes. A multiplex secretome analysis indicated that neither the transduction of UCB-MCs with Ad5-GFP nor with Ad5-VEGF165 affects the secretion of the studied cytokines, chemokines, and growth factors by gene-modified cells. Here, we show that UCB-MCs transduced with Ad5 carrying cDNA encoding human VEGF165 efficiently express transgenes and preserve transcriptome and secretome patterns. This data demonstrates the biosafety of using UCB-MCs as cell carriers of therapeutic genes.

Exposure to hand-held vibrating tools and biomarkers of nerve injury in plasma: a population-based, observational study

OBJECTIVES

To analyse potential biomarkers for vibration-induced nerve damage in a population-based, observational study.

DESIGN

Prospective cohort study.

SETTING

Malmö Diet Cancer Study (MDCS), Malmö, Sweden.

PARTICIPANTS

In a subcohort of 3898 individuals (recruited 1991-1996) from MDCS (baseline examination in 28 449 individuals; collection of fasting blood samples in a cardiovascular subcohort of MDCS of 5540 subjects), neuropathy-relevant plasma biomarkers were analysed during follow-up after filling out questionnaires, including a question whether work involved hand-held vibrating tools, graded as 'not at all', 'some' or 'much'.

PRIMARY OUTCOME MEASURES

The neuropathy-relevant plasma biomarkers vascular endothelial growth factor (VEGF)-A, VEGF-D, VEGF receptor 2, galanin, galectin-3, HSP27, ß-nerve growth factor, caspase-3, caspase-8, transforming growth factor-α and tumour necrosis factor were analysed. Data were analysed by conventional statistics (Kruskal-Wallis test; post hoc test Mann-Whitney U test; Bonferroni correction for multiple testing) and in a subanalysis for galanin using two linear regression models (unadjusted and adjusted).

RESULTS

Among participants, 3361 of 3898 (86%) reported no work with hand-held vibrating tools, 351 of 3898 (9%) reported some and 186 of 3898 (5%) much work. There were more men and smokers in vibration-exposed groups. Galanin levels were higher after much vibration exposure (arbitrary units 5.16±0.71) compared with no vibration exposure (5.01±0.76; p=0.015) with no other observed differences.

CONCLUSIONS

Higher plasma levels of galanin, possibly related to magnitude, frequency, acceleration and duration, as well as to severity of symptoms of vibration exposure, may be found in individuals working with hand-held vibrating tools.

Effects of Hydrogen Gas Inhalation on Community-Dwelling Adults of Various Ages: A Single-Arm, Open-Label, Prospective Clinical Trial

Molecular hydrogen (H₂) is a versatile therapeutic agent. H₂ gas inhalation is reportedly safe and has a positive impact on a range of illnesses, including Alzheimer's disease (AD). Herein, we investigated the effects of 4 weeks of H₂ gas inhalation on community-dwelling adults of various ages. Fifty-four participants, including those who dropped out (5%), were screened and enrolled. The selected participants were treated as a single group without randomization. We evaluated the association between total and differential white blood cell (WBC) counts and AD risk at individual levels after 4 weeks of H₂ gas inhalation treatment. The total and differential WBC counts were not adversely affected after H₂ gas inhalation, indicating that it was safe and well tolerated. Investigation of oxidative stress markers such as reactive oxygen species and nitric oxide showed that their levels decreased post-treatment. Furthermore, evaluation of dementia-related biomarkers, such as beta-site APP cleaving enzyme 1 (BACE-1), amyloid beta (Aβ), brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor A (VEGF-A), T-tau, monocyte chemotactic protein-1 (MCP-1), and inflammatory cytokines (interleukin-6), showed that their cognitive condition significantly improved after treatment, in most cases. Collectively, our results indicate that H₂ gas inhalation may be a good candidate for improving AD with cognitive dysfunction in community-dwelling adults of different ages.

Multi-omic characterization of brain changes in the vascular endothelial growth factor family during aging and Alzheimer's disease

The vascular endothelial growth factor (VEGF) signaling family has been implicated in neuroprotection and clinical progression in Alzheimer's disease (AD). Previous work in postmortem human dorsolateral prefrontal cortex demonstrated that higher transcript levels of VEGFB, PGF, FLT1, and FLT4 are associated with AD dementia, worse cognitive outcomes, and higher AD neuropathology. To expand prior work, we leveraged bulk RNA sequencing data, single nucleus RNA (snRNA) sequencing, and both tandem mass tag and selected reaction monitoring mass spectrometry proteomic measures from the post-mortem brain. Outcomes included AD diagnosis, cognition, and AD neuropathology. We replicated previously reported VEGFB and FLT1 results, whereby higher expression was associated with worse outcomes, and snRNA results suggest microglia, oligodendrocytes, and endothelia may play a central role in these associations. Additionally, FLT4 and NRP2 expression were associated with better cognitive outcomes. This study provides a comprehensive molecular picture of the VEGF signaling family in cognitive aging and AD and critical insight towards the biomarker and therapeutic potential of VEGF family members in AD.

Retinal vessels as a window on amyotrophic lateral sclerosis pathophysiology: A systematic review

Amyotrophic lateral sclerosis (ALS) is a rare fatal motor neuron disease. Although many potential mechanisms have been proposed, the pathophysiology of the disease remains unknown. Currently available treatments can only delay the progression of the disease and prolong life expectancy by a few months. There is still no definitive cure for ALS, and the development of new treatments is limited by a lack of understanding of the underlying biological processes that trigger and promote neurodegeneration. Several scientific results suggest a neurovascular impairment in ALS providing perspectives for the development of new biomarkers and treatments. In this article, we performed a systematic review using PRISMA guidelines including PubMed, EmBase, GoogleScholar, and Web of Science Core Collection to analyze the scientific literature published between 2000 and 2021 discussing the neurocardiovascular involvement and ophthalmologic abnormalities in ALS. In total, 122 articles were included to establish this systematic review. Indeed, microvascular pathology seems to be involved in ALS, affecting all the neurovascular unit components. Retinal changes have also been recently highlighted without significant alteration of the visual pathways. Despite the peripheral location of the retina, it is considered as an extension of the central nervous system (CNS) as it displays similarities to the brain, the inner blood-retinal barrier, and the blood-brain barrier. This suggests that the eye could be considered as a 'window' into the brain in many CNS disorders. Thus, studying ocular manifestations of brain pathologies seems very promising in understanding neurodegenerative disorders, mainly ALS. Optical coherence tomography angiography (OCT-A) could therefore be a powerful approach for exploration of retinal microvascularization allowing to obtain new diagnostic and prognostic biomarkers of ALS.

Evaluation of the Autologous Genetically Enriched Leucoconcentrate on the Lumbar Spinal Cord Morpho-Functional Recovery in a Mini Pig with Thoracic Spine Contusion Injury

BACKGROUND

Pathological changes associated with spinal cord injury (SCI) can be observed distant, rostral, or caudal to the epicenter of injury. These remote areas represent important therapeutic targets for post-traumatic spinal cord repair. The present study aimed to investigate the following in relation to SCI: distant changes in the spinal cord, peripheral nerve, and muscles.

METHODS

The changes in the spinal cord, the tibial nerve, and the hind limb muscles were evaluated in control SCI animals and after intravenous infusion of autologous leucoconcentrate enriched with genes encoding neuroprotective factors (VEGF, GDNF, and NCAM), which previously demonstrated a positive effect on post-traumatic restoration.

RESULTS

Two months after thoracic contusion in the treated mini pigs, a positive remodeling of the macro- and microglial cells, expression of PSD95 and Chat in the lumbar spinal cord, and preservation of the number and morphological characteristics of the myelinated fibers in the tibial nerve were observed and were aligned with hind limb motor recovery and reduced soleus muscle atrophy.

CONCLUSION

Here, we show the positive effect of autologous genetically enriched leucoconcentrate-producing recombinant neuroprotective factors on targets distant to the primary lesion site in mini pigs with SCI. These findings open new perspectives for the therapy of SCI.

Exploring the molecular pathways and therapeutic implications of angiogenesis in neuropathic pain

Recently, much attention has been paid to chronic neuro-inflammatory condition underlying neuropathic pain. It is generally linked with thermal hyperalgesia and tactile allodynia. It results due to injury or infection in the nervous system. The neuropathic pain spectrum covers a variety of pathophysiological states, mostly involved are ischemic injury viral infections associated neuropathies, chemotherapy-induced peripheral neuropathies, autoimmune disorders, traumatic origin, hereditary neuropathies, inflammatory disorders, and channelopathies. In CNS, angiogenesis is evident in inflammation of neurons and pain in bone cancer. The role of chemokines and cytokines is dualistic; their aggressive secretion produces detrimental effects, leading to neuropathic pain. However, whether the angiogenesis contributes and exists in neuropathic pain remains doubtful. In the present review, we elucidated summary of diverse mechanisms of neuropathic pain associated with angiogenesis. Moreover, an overview of multiple targets that have provided insights on the VEGF signaling, signaling through Tie-1 and Tie-2 receptor, erythropoietin pathway promoting axonal growth are also discussed. Because angiogenesis as a result of these signaling, results in inflammation, we focused on the mechanisms of neuropathic pain. These factors are mainly responsible for the activation of post-traumatic regeneration of the PNS and CNS. Furthermore, we also reviewed synthetic and herbal treatments targeting angiogenesis in neuropathic pain.

Whole blood transcript and protein abundance of the vascular endothelial growth factor family relate to cognitive performance

The vascular endothelial growth factor (VEGF) family of genes has been implicated in the clinical development of Alzheimer's Disease (AD). A previous study identified associations between gene expression of VEGF family members in the prefrontal cortex and cognitive performance and AD pathology. This study explored if those associations were also observed in the blood. Consistent with previous observations in brain tissue, higher blood gene expression of placental growth factor (PGF) was associated with a faster rate of memory decline (p=0.04). Higher protein abundance of FMS-related receptor tyrosine kinase 4 (FLT4) in blood was associated with biomarker levels indicative of lower amyloid and tau pathology, opposite the direction observed in brain. Also, higher gene expression of VEGFB in blood was associated with better baseline memory (p=0.008). Notably, we observed that higher gene expression of VEGFB in blood was associated with lower expression of VEGFB in the brain (r=-0.19, p=0.02). Together, these results suggest that the VEGFB, FLT4, and PGF alterations in the AD brain may be detectable in the blood compartment.

Recent progress in the manipulation of biochemical and biophysical cues for engineering functional tissues

Tissue engineering (TE) is currently considered a cutting-edge discipline that offers the potential for developing treatments for health conditions that negatively affect the quality of life. This interdisciplinary field typically involves the combination of cells, scaffolds, and appropriate induction factors for the regeneration and repair of damaged tissue. Cell fate decisions, such as survival, proliferation, or differentiation, critically depend on various biochemical and biophysical factors provided by the extracellular environment during developmental, physiological, and pathological processes. Therefore, understanding the mechanisms of action of these factors is critical to accurately mimic the complex architecture of the extracellular environment of living tissues and improve the efficiency of TE approaches. In this review, we recapitulate the effects that biochemical and biophysical induction factors have on various aspects of cell fate. While the role of biochemical factors, such as growth factors, small molecules, extracellular matrix (ECM) components, and cytokines, has been extensively studied in the context of TE applications, it is only recently that we have begun to understand the effects of biophysical signals such as surface topography, mechanical, and electrical signals. These biophysical cues could provide a more robust set of stimuli to manipulate cell signaling pathways during the formation of the engineered tissue. Furthermore, the simultaneous application of different types of signals appears to elicit synergistic responses that are likely to improve functional outcomes, which could help translate results into successful clinical therapies in the future.

Circulating levels of vascular endothelial growth factor in patients with Alzheimer's disease: A case-control study

BACKGROUND

Vascular endothelial growth factor (VEGF) and platelets seem to reflect the Alzheimer's disease (AD) associated either with vascular impairment or disease. This study aimed to compare the circulating levels of VEGF and platelets between AD patients and healthy older adults.

METHODS

Seventy-two older adults, divided in 40 older adults (Clinical Dementia Rating Scale - CDR = 0); and 32 Alzheimer's disease patients (clinically diagnosed - CRD = 1) participated in the present study. The groups were paired by sex, age, comorbidities and educational level. The primary outcomes included circulating plasma VEGF and platelet levels obtained by blood collection.

RESULTS

The VEGF levels were significantly different between the groups (p = 0.03), with having a large effect size ( η² =18.15), in which the AD patients presented lower levels compared to healthy older adults. For platelets, the comparison showed a tendency to difference (p = 0.06), with a large effect size (η² =12.95) between the groups.

CONCLUSION

The VEGF levels and the platelet numbers were reduced in AD patients, suggesting that angiogenic factors could be modified due to AD.

Inhibition of VEGFR-2 by SU5416 increases neonatally glutamate-induced neuronal damage in the cerebral motor cortex and hippocampus

Vascular endothelial growth factor (VEGF) exerts neuroprotective or proinflammatory effects, depending on what VEGF forms (A-E), receptor types (VEGFR1-3), and intracellular signaling pathways are involved. Neonatal monosodium glutamate (MSG) treatment triggers neuronal death by excitotoxicity, which is commonly involved in different neurological disorders, including neurodegenerative diseases. This study was designed to evaluate the effects of VEGFR-2 inhibition on neuronal damage triggered by excitotoxicity in the cerebral motor cortex (CMC) and hippocampus (Hp) after neonatal MSG treatment. MSG was administered at a dose of 4 g/kg of body weight (b.w.) subcutaneously on postnatal days (PD) 1, 3, 5, and 7, whereas the VEGFR-2 inhibitor SU5416 was administered at a dose of 10 mg/kg b.w. subcutaneously on PD 5 and 7, 30 min before the MSG treatment. Neuronal damage was assessed using hematoxylin and eosin staining, fluoro-Jade staining, and TUNEL assay. Additionally, western blot assays for some proteins of the VEGF-A/VEGFR-2 signaling pathway (VEGF-A, VEGFR-2, PI3K, Akt, and iNOS) were carried out. All assays were performed on PD 6, 8, 10, and 14. Inhibition of VEGFR-2 signaling by SU5416 increases the neuronal damage induced by neonatal MSG treatment in both the CMC and Hp. Moreover, neonatal MSG treatment increased the expression levels of the studied VEGF-A/VEGFR-2 signaling pathway proteins, particularly in the CMC. We conclude that VEGF-A/VEGFR-2 signaling pathway activation could be part of the neuroprotective mechanisms that attempt to compensate for neuronal damage induced by neonatal MSG treatment and possibly also in other conditions involving excitotoxicity.

Brain-derived neurotrophic factor, neurofilament light and glial fibrillary acidic protein do not change in response to aerobic training in people with MS-related fatigue - a secondary analysis of a randomized controlled trial

BACKGROUND

Neuroinflammation and neurodegeneration are pathological hallmarks of multiple sclerosis (MS). Brain-derived neurotrophic factor (BDNF), neurofilament light (NfL), and glial fibrillary acidic protein (GFAP) are blood-based biomarkers for neurogenesis, axonal damage and astrocyte reactivity, respectively. We hypothesize that exercise has a neuroprotective effect on MS reflected by normalization of BDNF, NfL and GFAP levels.

OBJECTIVES

To investigate the neuroprotective effect of aerobic training (AT) compared to a control intervention on blood-based biomarkers (i.e. BDNF, NfL, GFAP) in people with MS (pwMS).

METHODS

In the TREFAMS-AT (Treating Fatigue in Multiple Sclerosis - Aerobic Training) study, 89 pwMS were randomly allocated to either a 16-week AT intervention or a control intervention (3 visits to a MS nurse). In this secondary analysis, blood-based biomarker concentrations were measured in 55 patients using Simoa technology. Changes in pre- and post-intervention concentrations were compared and between-group differences were assessed using analysis of covariance (ANCOVA). Confounding effects of age, sex, MS-related disability assessed using the Expanded Disability Status Scale (EDSS), MS duration, use of disease-modifying medication, and Body Mass Index were considered.

RESULTS

Blood samples were available for 30 AT and 25 control group participants (mean age 45.6 years, 71% female, median disease duration 8 years, median EDSS score 2.5). Within-group changes in both study groups were small and non-significant, with the exception of BDNF in the control group (median (interquartile range) -2.1 (-4.7; 0)). No between-group differences were found for any biomarker: BDNF (β = 0.11, 95%CI (-3.78 to 4.00)), NfL (β = -0.04, 95%CI (-0.26 to 0.18)), and GFAP (β = -0.01, 95%CI (-0.16 to 0.15)), adjusted for confounders.

CONCLUSION

Aerobic exercise therapy did not result in statistically significant changes in the tested neuro-specific blood-based biomarkers in people with MS.

TRIAL REGISTRATION

this study is registered under number ISRCTN69520623 (https://www.isrctn.com/ISRCTN695206).

Fruquintinib/HMPL-013 ameliorates cognitive impairments and pathology in a mouse model of cerebral amyloid angiopathy (CAA)

Cerebral amyloid angiopathy (CAA) is characterized by the cerebrovascular amyloid-β (Aβ) accumulation, and always accompanied by Alzheimer's disease (AD). The mechanisms revealing CAA pathogenesis are still unclear, and it is challenging to develop an efficient therapeutic strategy for its treatment. Vascular endothelial growth factor (VEGF) and its receptors including VEGFR-1,-2,-3 activation are involved in Aβ processing, and modulate numerous cellular events associated with central nervous system (CNS) diseases. In the present study, we attempted to explore the regulatory function of fruquintinib (also named as HMPL-013), a highly selective inhibitor of VEGFR-1,-2,-3 tyrosine kinases, on CAA progression in Tg-SwDI mice. Here, we found that HMPL-013-rich diet consumption for 12 months significantly improved the behavioral performances and cerebral blood flow (CBF) of Tg-SwDI mice compared with the vehicle group. Importantly, HMPL-013 administration considerably reduced Aβ_1-40 and Aβ_1-42 burden in cortex and hippocampus of Tg-SwDI mice through regulating Aβ metabolism process. Congo red staining confirmed Aβ deposition in vessel walls, reflecting CAA formation, which was, however, strongly ameliorated after HMPL-013 treatment. Neuron death, aberrant glial activation and pro-inflammatory response in brain tissues of Tg-SwDI mice were dramatically alleviated after HMPL-013 consumption. More studies showed that the protective effects of HMPL-013 against CAA might be partially attributed to its regulation on the expression of genes associated with blood vasculature. Intriguingly, VEGF and phosphorylated VEGFR-1,-2 protein expression levels were remarkably decreased by HMPL-013 in cortex and hippocampus of Tg-SwDI mice, which were validated in HMPL-013-treated brain vascular endothelial cells (BVECs) under hypoxia. Finally, we found that VEGF-induced human umbilical vein endothelial cells (HUVEC) proliferation and tube formation were strongly abolished upon HMPL-013 exposure. Collectively, all these findings demonstrated that oral administration of HMPL-013 had therapeutic potential against CAA by reducing Aβ deposition, inflammation and neuron death via suppressing VEGF/VEGFR-1,-2 signaling.

Aerobic Training and Circulating Neurotrophins in Alzheimer's Disease Patients: A Controlled Trial

OBJECTIVE

to verify the effects of aerobic exercise training in circulating BDNF, VEGF₁₆₅ and IGF-1 plasma levels and cognitive function in Alzheimer's Disease (AD) patients.

METHODS

34 AD patients participated in the study, divided in two groups: Control Group (CG; n = 16) and Training Group (TG; n = 18 - Moderate aerobic training on the treadmill, three times a week, for 12 weeks). BDNF, VEGF_165, and IGF-1 plasma levels were considered as a primary outcome. Secondary outcomes included cognitive functions and aerobic fitness.

RESULTS

After 12 weeks, maintenance of executive functioning in the TG was found, yet no significant changes on circulating neurotrophins levels were identified. For aerobic fitness, there was an increment in TG group.

CONCLUSION

Twelve weeks of aerobic training were neither effective in improving cognitive functioning significantly, nor influential on circulating neurotrophins levels in AD patients.

Changes in adenosine receptors and neurotrophic factors in the SOD1G93A mouse model of amyotrophic lateral sclerosis: Modulation by chronic caffeine

Amyotrophic lateral sclerosis (ALS) is characterized by the progressive degeneration of corticospinal tract motor neurons. Previous studies showed that adenosine-mediated neuromodulation is disturbed in ALS and that vascular endothelial growth factor (VEGF) has a neuroprotective function in ALS mouse models. We evaluated how adenosine (A1R and A2AR) and VEGF (VEGFA, VEGFB, VEGFR-1 and VEGFR-2) system markers are altered in the cortex and spinal cord of pre-symptomatic and symptomatic SOD1G93A mice. We then assessed if/how chronic treatment of SOD1G93A mice with a widely consumed adenosine receptor antagonist, caffeine, modulates VEGF system and/or the levels of Brain-derived Neurotrophic Factor (BDNF), known to be under control of A2AR. We found out decreases in A1R and increases in A2AR levels even before disease onset. Concerning the VEGF system, we detected increases of VEGFB and VEGFR-2 levels in the spinal cord at pre-symptomatic stage, which reverses at the symptomatic stage, and decreases of VEGFA levels in the cortex, in very late disease states. Chronic treatment with caffeine rescued cortical A1R levels in SOD1G93A mice, bringing them to control levels, while rendering VEGF signaling nearly unaffected. In contrast, BDNF levels were significantly affected in SOD1G93A mice treated with caffeine, being decreased in the cortex and increased in spinal the cord. Altogether, these findings suggest an early dysfunction of the adenosinergic system in ALS and highlights the possibility that the negative influence of caffeine previously reported in ALS animal models results from interference with BDNF rather than with the VEGF signaling molecules.

The Association of Biochemical and Genetic Biomarkers in VEGF Pathway with Depression

VEGF is an important neurotrophic and vascular factor involved in mental disorders. The objective of this study was to verify the effect of genetic polymorphisms in the VEGF pathway on the risk for depression, symptom intensity, and suicide attempts. To examine the association between the VEGF pathway and depression, we genotyped polymorphisms and measured the plasma concentrations of VEGF, KDR, and FLT1 proteins. The participants were 160 patients with depression and 114 healthy controls. The questionnaires that assessed the clinical profile of the patients were the MINI-International Neuropsychiatric Interview, GRID-HAMD₂₁, CTQ, BSI, and the number of suicide attempts. Genotyping of participants was performed using the real-time PCR and protein measurements were performed using the enzyme-linked immunosorbent assay (ELISA). VEGF and its inhibitors were reduced in depression. Individuals with depression and displaying the homozygous AA of the rs699947 polymorphism had higher plasma concentrations of VEGF (p-value = 0.006) and were associated with a greater number of suicide attempts (p-value = 0.041). Individuals with depression that were homozygous for the G allele of the FLT1 polymorphism rs7993418 were associated with lower symptom severity (p-value = 0.040). Our results suggest that VEGF pathway polymorphisms are associated with the number of suicide attempts and the severity of depressive symptoms.

Vascular Endothelial Growth Factor and Erythropoietin Show Different Expression Patterns in the Early and Late Hypoxia Preconditioning Phases and May Correlate with DNA Methylation Status in the Mouse Hippocampus

Liu, Na, Yanbo Zhang, Pu Zhang, Kerui Gong, Chunyang Zhang, Kai Sun, and Guo Shao. Vascular endothelial growth factor and erythropoietin show different expression patterns in the early and late hypoxia preconditioning phases and may correlate with DNA methylation status in the mouse hippocampus. High Alt Med Biol. 23:361-368, 2022. Background: Vascular endothelial growth factor (VEGF) and erythropoietin (EPO) have been proven to participate in neuroprotection induced by hypoxia preconditioning (HPC), and they can be regulated by hypoxia-inducible factor 1 (HIF-1). It has been reported that DNA methylation can affect VEGF and EPO expression. This study aimed to explore the expression of VEGF and EPO in the early phase and late phase of HPC and whether their expression was affected by DNA methylation. Method: Acute repeated HPC mice were used as the animal model, and detection of molecular changes was performed immediately (early phase) and 1 day (late phase) after HPC treatment. The mRNA and protein expression levels of VEGF, EPO, and DNA methyltransferases (DNMTs) in the hippocampi were measured by real-time polymerase chain reaction and western blotting, respectively. The activity of DNMTs and global methylation levels were analyzed by enzyme-linked immunosorbent assay. DNA methylation levels of VEGF and EPO promoters, which were catalyzed by DNMTs, were determined by bisulfite-modified DNA sequencing. Results: The expression of VEGF was increased in the early phase and late phase of HPC (p < 0.05), whereas the expression of EPO was unchanged in the early phase (p > 0.05) of HPC and was increased in the late phase (p < 0.05). VEGF and EPO expression were negatively correlated with the DNA methylation levels of their promoters. DNMT3A and DNMT3B were decreased in the early phase and late phase (p < 0.05), whereas DNMT1 was unchanged in the early phase and late phase (p > 0.05). Conclusions: Our data demonstrated that DNMTs affect VEGF and EPO expression by regulating the DNA methylation levels of the promoters of VEGF and EPO.