Netrin-1 in Post-stroke Neuroprotection: Beyond Axon Guidance Cue

Netrin-1 signaling pathway mechanisms in neurodegenerative diseases

Netrin-1 and its receptors play crucial roles in inducing axonal growth and neuronal migration during neuronal development. Their profound impacts then extend into adulthood to encompass the maintenance of neuronal survival and synaptic function. Increasing amounts of evidence highlight several key points: (1) Diminished Netrin-1 levels exacerbate pathological progression in animal models of Alzheimer's disease and Parkinson's disease, and potentially, similar alterations occur in humans. (2) Genetic mutations of Netrin-1 receptors increase an individuals' susceptibility to neurodegenerative disorders. (3) Therapeutic approaches targeting Netrin-1 and its receptors offer the benefits of enhancing memory and motor function. (4) Netrin-1 and its receptors show genetic and epigenetic alterations in a variety of cancers. These findings provide compelling evidence that Netrin-1 and its receptors are crucial targets in neurodegenerative diseases. Through a comprehensive review of Netrin-1 signaling pathways, our objective is to uncover potential therapeutic avenues for neurodegenerative disorders.

Bioinformatics analysis of electroacupuncture treatment for ischemic stroke: exploring transcriptional regulatory mechanisms mediated by super-enhancers

Background

Ischemic stroke is a leading cause of disability and mortality, imposing substantial physical, emotional, and economic burdens on patients and society. This study aimed to explore the regulatory effects of super-enhancers (SEs) on gene expression in the context of ischemic stroke and their potential transcriptional regulatory mechanisms.

Methods

Super-enhancers were identified via H3K27ac chromatin immunoprecipitation sequencing (ChIP-seq) and ROSE software. RNA-sequencing (RNA-seq) was employed to screen for differentially expressed genes. A comparative analysis of ChIP-seq and RNA-seq data initially identified SE target genes, followed by further screening of key core differentially expressed SE target genes via the random forest method. The identified core SE target genes were initially validated through immunofluorescence and immunoblotting techniques. Additionally, potential core transcriptional regulatory circuits were preliminarily screened via the Coltron algorithm.

Results

We identified SE-associated genes in the ischemic stroke model and electroacupuncture-treated groups, revealing 41 genes uniquely regulated by SEs in the electroacupuncture group compared with 367 in the model group. Enrichment analyses revealed that pathways involved in axon guidance, regulation of lipolysis in adipocytes and sphingolipid signaling pathway were significantly enriched in the SE target genes, suggesting that these pathways may be involved in the therapeutic effects of electroacupuncture. Notably, HDAC7 emerged as a key SE-driven gene; its expression was significantly reduced following electroacupuncture treatment, indicating its potential as a therapeutic target. Protein expression analyses confirmed elevated levels of HDAC7 in the model group, which were reduced by electroacupuncture intervention (p < 0.05). Furthermore, core transcriptional regulatory circuitries involving SOX8, FOXK1, and KLF13 were identified, highlighting their roles in the modulation of SE-mediated gene regulation by acupuncture in the ischemic stroke context.

Conclusion

Overall, our findings provide novel insights into the molecular mechanisms by which acupuncture may treat ischemic stroke, identifying key SE target genes and transcriptional circuits as promising targets for future therapeutic strategies. Further research is warranted to validate these findings in clinical settings and explore the translational potential of acupuncture in ischemic stroke treatment.

Predictive Value of Netrin-1 Expression and Ultrasonic Blood Flow in Cervical Intraepithelial Neoplasia Severity

Objective

To analyze the relationship and predictive value of Netrin-1 expression and ultrasonic blood flow parameters with the severity of cervical intraepithelial neoplasia (CIN).

Methods

A retrospective analysis was performed on 115 patients diagnosed with CIN and 37 patients with chronic cervicitis, all of whom underwent surgical intervention. The expression levels of Netrin-1 were evaluated through immunohistochemical staining and quantitative fluorescence PCR. Doppler ultrasound was employed to quantify flow index (FI), vascularization index (VI), and vascularization flow index (VFI) using VOCAL software. Statistical analyses, including correlation analysis, logistic regression, and receiver operating characteristic (ROC) curve analysis, were conducted to assess the predictive value of Netrin-1 expression and ultrasound-derived blood flow parameters.

Results

FI, VI, and VFI increased with CIN grade, showing significant differences between CIN II, CIN III, and the control group (P < 0.05). Netrin-1 levels were negatively correlated with FI, VI, and VFI (correlation coefficients of -0.287, -0.309, and -0.298; P < 0.05). Logistic regression indicated that Netrin-1 positivity was a protective factor against CIN III, while FI, VI, and VFI were risk factors. The AUC for Netrin-1 was 0.712, with sensitivity and specificity of 76.4% and 79.5% (P < 0.05).

Conclusion

Netrin-1 expression is significantly reduced in CIN patients, whereas Doppler ultrasound-derived blood flow parameters-FI, VI, and VFI-are markedly elevated. Both Netrin-1 levels and these ultrasound parameters exhibit a strong correlation with the severity of cervical lesions. Notably, Netrin-1 is negatively correlated with FI, VI, and VFI. Furthermore, Netrin-1 positivity serves as a protective factor against CIN III lesions, while elevated levels of FI, VI, and VFI are associated with increased risk for these lesions. The expression levels of both Netrin-1 and ultrasound parameters provide valuable predictive insights for the early screening, diagnosis, and prevention of cervical cancer.

Small Molecule Drug C381 Attenuates Brain Vascular Damage Following Repetitive Mild Traumatic Injury

Traumatic brain injury (TBI) remains a significant public health concern, with no effective therapeutic interventions to ameliorate the enduring consequences. The prevailing understanding of TBI pathophysiology indicates a central role for vascular dysfunction. Transforming growth factor-β (TGF-β) is a multifunctional cytokine crucial for vascular development. Aberrant TGF-β signaling is implicated in vascular pathologies associated with various neurological conditions. We recently developed a novel small molecule drug, C381, a TGF-β activator with the ability to restore lysosomal function. Here we used a mouse model of repetitive mild TBI (mTBI) to examine whether C381 would attenuate vascular injury. We first employed RNA-seq analysis to investigate the gene expression patterns associated with mTBI and evaluated the therapeutic potential of C381 in mitigating these changes. Our results demonstrate distinct mTBI-related gene expression signatures, prominently implicating pathways related to vascular integrity and endothelial function. Notably, treatment with C381 reversed these mTBI-induced gene expression changes. Immunohistochemical analysis further corroborated these findings, revealing that C381 treatment attenuated vascular damage in mTBI-affected brain tissue. These findings strongly support the potential clinical usefulness of C381 as a novel therapeutic intervention for mTBI.

Association between plasma Netrin-1 levels and motor and nonmotor symptoms in Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a prevalent neurodegenerative disorder characterized by dopaminergic neuron degeneration and diverse motor and nonmotor symptoms. Early diagnosis and intervention are crucial but challenging due to reliance on clinical presentation. Recent research suggests potential biomarkers for early detection, including plasma netrin-1 (NTN-1), a protein implicated in neuronal survival.

METHODS

This cross-sectional study recruited 105 PD patients and 65 healthy controls, assessing plasma NTN-1 levels and correlating them with clinical characteristics. Statistical analyses explored associations between NTN-1 levels and PD symptoms, considering demographic factors.

RESULTS

PD patients exhibited significantly lower plasma NTN-1 levels compared to controls. NTN-1 demonstrated moderate potential as a PD biomarker. Positive correlations were found between NTN-1 levels and motor, depression, and cognitive symptoms. Multiple regression analysis revealed disease duration and NTN-1 levels as key factors influencing symptom severity. Gender also impacted symptom scores.

CONCLUSION

Reduced plasma NTN-1 levels correlate with PD severity, suggesting its potential as a biomarker. However, further research is needed to elucidate the roles of NTN-1 in PD pathophysiology and validate its diagnostic and therapeutic implications. Understanding the involvement of NTN-1 may lead to personalized management strategies for PD.

Netrin-1 mitigates acute lung injury by preventing the activation of the Toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) signaling

Acute lung injury (ALI) is one of the most common high-risk diseases associated with a high mortality rate and is still a challenge to treat effectively. Netrin-1 (NT-1) is a novel peptide with a wide range of biological functions, however, its effects on ALI have not been reported before. In this study, an ALI model was constructed using lipopolysaccharide (LPS) and treated with NT-1. Pulmonary function and lung wet to dry weight ratio (W/D) were detected. The expressions of pro-inflammatory cytokines and chemokines interleukin-8 (IL-8), interleukin-1β (IL-1β), and chemokine (C-X-C motif) ligand 2 (CXCL2) were measured using real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). We found that the levels of NT-1 were reduced in the LPS-induced ALI mice model. Administration of NT-1 improved histopathological changes of lung tissues and lung function in LPS-challenged ALI mice. We also report that NT-1 decreased Myeloperoxidase (MPO) activity and ameliorated pulmonary edema. Additionally, treatment with NT-1 reduced the levels of pro-inflammatory cytokines and chemokines such as IL-8, IL-1β, and CXCL2 in lung tissues of LPS-challenged ALI mice. Importantly, NT-1 reduced cell count in BALF and mitigated oxidative stress (OS) by reducing the levels of MDA and increasing the levels of GSH. Mechanistically, it is shown that NT-1 reduced the levels of Toll-like receptor 4 (TLR4) and prevented nuclear translocation of nuclear factor-κB (NF-κB) p65. Our findings indicate that NT-1 is a promising agent for the treatment of ALI through inhibiting TLR4/NF-κB signaling.

Ginkgolide B promotes spontaneous recovery and enhances endogenous netrin-1 after neonatal hypoxic-ischemic brain damage

OBJECTIVES

Perinatal hypoxic-ischemic encephalopathy (HIE) is a condition that can lead to long-term cognitive, motor, and behavioral impairments in newborns. Although brain hypothermia therapy is currently the standard treatment for HIE, it does not provide complete neuroprotection. As a result, there is a need to explore additional therapies to enhance treatment outcomes. This study aims to investigate the potential role of Ginkgolide B (GB) in promoting neuroplasticity and facilitating spontaneous recovery after HIE.

METHODS

In this study, we employed a neonatal rat model of HIE to investigate the effects of GB on spontaneous recovery. GB treatment was initiated 24 h after hypoxia and administered continuously for a duration of 14 days. We evaluated several outcome measures after the treatment period, including spontaneous behavioral recovery and brain repair. Additionally, we quantified the levels of netrin-1 in both plasma and the peri-ischemic zone after the occurrence of HIE.

RESULTS

We found that GB treatment significantly facilitated spontaneous behavioral recovery in the HIE pups. Furthermore, cognitive function was restored, and brain tissue repair had a noticeable acceleration. We observed increased cell proliferation in the subventricular, stratum, and subgranular zones. Of particular interest, we observed elevated levels of netrin-1 in both plasma and the ischemic penumbra following GB treatment.

CONCLUSION

Our findings suggest that GB promotes neuroplasticity and enhances spontaneous recovery in newborns affected by HIE. The observed upregulation of netrin-1 may be crucial in mediating these effects. These results highlight the promising potential of GB as a post-HIE therapy, particularly in enhancing spontaneous recovery and improving long-term outcomes.

HIF-1, an important regulator in potential new therapeutic approaches to ischemic stroke

Ischemic stroke is a leading cause of disability and mortality worldwide due to the narrow therapeutic window of the only approved therapies like intravenous thrombolysis and thrombectomy. Hypoxia inducible factor-1α (HIF-1α) is a sensitive regulator of oxygen homeostasis, and its expression is rapidly induced after hypoxia/ischemia. It plays an extensive role in the pathophysiology of stroke by regulating multiple pathways including glucose metabolism, angiogenesis, neuronal survival, neuroinflammation and blood brain barrier regulation. Here, we give a brief overview of the HIF-1α-targeting strategies currently under investigation and summarise recent research on how HIF-1α is regulated in various brain cells, including neurons and microglia, at various stages in ischemic stroke. The roles of HIF-1 in stroke varies with ischemic time and degree of ischemia, are still up for debate. More focus has been placed on prospective HIF-1α targeting drugs, such as HIF-1α activator, HIF-1α stabilizers, and natural compounds. In this review, we have highlighted the regulation of HIF-1α in the novel therapeutic approaches for treatment of stroke.

Netrin-1: A Serum Marker Predicting Cognitive Impairment after Spinal Cord Injury

Objective

Although cognitive impairment has received more attention in recent years as a result of spinal cord injury (SCI), the pathogenic process that causes it is still unknown. The neuroprotective effects of Netrin as a family of laminin-related secreted proteins were discovered. The purpose of this study was to determine the changes of serum Netrin-1 after SCI and its relationship with cognitive impairment.

Methods

96 SCI patients and 60 controls were included in our study. We collected baseline data from all participants, measured their serum Netrin-1 levels, and followed up their cognitive levels 3 months later.

Results

The clinical baseline values between the control and SCI groups were not significantly different (p > 0.05). However, the serum Netrin-1 level in the SCI group was significantly lower than that in the control group (528.4 ± 88.3 pg/ml vs. 673.5 ± 97.2 pg/ml, p < 0.05). According to the quartile level of serum Netrin-1 level in the SCI group, we found that with the increase of serum Netrin-1 level, the MoCA score also increased significantly (p < 0.001), indicating that the serum Netrin-1 level was positively correlated with the MoCA score after SCI. After controlling for baseline data, multiple regression analysis revealed that Netrin-1 remained an independent risk factor for cognitive impairment after SCI (=0.274, p = 0.036).

Conclusions

Netrin-1 may be a neuroprotective factor for cognitive impairment, which may serve as a serum marker to predict cognitive impairment after SCI.