Neuronal Protection Research Articles

Ginsenoside Rg1 Regulates Immune Microenvironment and Neurological Recovery After Spinal Cord Injury Through MYCBP2 Delivery via Neuronal Cell-Derived Extracellular Vesicles.

Spinal cord injury (SCI) is a severe neurological condition that frequently leads to significant sensory, motor, and autonomic dysfunction. This study sought to delineate the potential mechanistic underpinnings of extracellular vesicles (EVs) derived from ginsenoside Rg1-pretreated neuronal cells (Rg1-EVs) in ameliorating SCI. These results demonstrated that treatment with Rg1-EVs substantially improved motor function in spinal cord-injured mice. Rg1-EVs enhance microglial polarization toward the M2 phenotype and repressed oxidative stress, thereby altering immune responses and decreasing inflammatory cytokine secretion. Moreover, Rg1-EVs substantially diminish reactive oxygen species accumulation and enhanced neural tissue repair by regulating mitochondrial function. Proteomic profiling highlighted a significant enrichment of MYCBP2 in Rg1-EVs, and functional assays confirmed that MYCBP2 knockdown counteracted the beneficial effects of Rg1-EVs in vitro and in vivo. Mechanistically, MYCBP2 is implicated in the ubiquitination and degradation of S100A9, thereby promoting microglial M2-phenotype polarization and reducing oxidative stress. Overall, these findings substantiated the pivotal role of Rg1-EVs in neuronal protection and functional recovery following SCI through MYCBP2-mediated ubiquitination of S100A9. This research offers novel mechanistic insights into therapeutic strategies against SCI and supports the clinical potential of Rg1-EVs.

Psoralen protects neurons and alleviates neuroinflammation by regulating microglial M1/M2 polarization via inhibition of the Fyn-PKCδ pathway

Microglia-mediated neuroinflammation is closely associated with many neurodegenerative diseases. Psoralen has potential for the treatment of many diseases, however, the anti-neuroinflammatory and neuroprotective effects of psoralen have been unclear. This study investigated the anti-neuroinflammatory and neuroprotective effects of psoralen and its regulation of microglial M1/M2 polarization. The LPS-induced mice model was used to test anti-neuroinflammatory effects, regulatory effects on microglia polarization, and neuroprotective effects of psoralen in vivo. The LPS-induced BV2 model was used to test the anti-neuroinflammatory effects and the regulatory effects and mechanisms on microglial M1/M2 polarization of psoralen in vitro. PC12 cell model induced by conditioned medium of BV2 cells was used to validate the protective effects of psoralen against neuroinflammation-induced neuronal damage. These results showed that psoralen inhibited the expression of iNOS, CD86, and TNF-α, and increased the expression of Arg-1, CD206, and IL-10. These results indicated that psoralen inhibited the M1 microglial phenotype and promoted the M2 microglial phenotype. Further studies showed that psoralen inhibited the phosphorylation of Fyn and PKCδ, thereby inhibiting activation of the MAPKs and NF-κB pathways and suppressing the expression of pro-inflammatory cytokines in microglia. Furthermore, psoralen reduced oxidative stress, neuronal damage, and apoptosis via inhibition of neuroinflammation. For the first time, this study showed that psoralen protected neurons and alleviated neuroinflammation by regulating microglial M1/M2 polarization, which may be mediated by inhibition of the Fyn-PKCδ pathway. Thus, psoralen may be a potential agent in the treatment of neuroinflammation-related diseases.

Regional-specific changes in rat brain BDNF in a model of methamphetamine abuse

Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, plays key roles in neuronal protection and synaptic plasticity. Changes in BDNF are associated with various pathological conditions, including methamphetamine (meth) addiction, although the effects of meth on BDNF expression are not always consistent. We have previously demonstrated region-specific effects of a chronic meth regime on BDNF methylation and expression in the rat brain. This study aims to determine the effect of chronic meth administration on the expression of BDNF protein using immunohistochemistry in the rat frontal cortex and hippocampus. Novel object recognition (NOR) as a measure of cognitive function was also determined. Male Sprague Dawley rats were administered a chronic escalating dose (0.1–4 mg/kg over 14 days) (ED) of meth or vehicle; a subgroup of animals receiving meth were also given an acute “binge” (4x6mg) dose on the final day before NOR testing. The results showed that hippocampal CA1 BDNF protein was significantly increased by 72 % above control values in the ED-binge rats, while other hippocampal regions and frontal cortex were not significantly affected. Meth-administered animals also demonstrated deficits in NOR after 24 h delay. No significant effect of the additional binge dose on BDNF protein or NOR findings was apparent. This finding is consistent with our previous results of reduced DNA methylation and increased expression of the BDNF gene in this region. The hippocampal BDNF increase may reflect an initial increase in a protective factor produced in response to elevated glutamate release resulting in neurodegenerative excitotoxicity.

The potential neuroprotective effects of cannabinoids against paclitaxel-induced peripheral neuropathy: in vitro study on neurite outgrowth.

Introduction: Chemotherapy-induced peripheral neuropathy (CIPN) is a shared burden for 68.1% of oncological patients undergoing chemotherapy with Paclitaxel (PTX). The symptoms are intense and troublesome, patients reporting paresthesia, loss of sensation, and dysesthetic pain. While current medications focus on decreasing the symptom intensity, often ineffective, no medication is yet recommended by the guidelines for the prevention of CIPN. Cannabinoids are an attractive option, as their neuroprotective features have already been demonstrated in neuropathies with other etiologies, by offering the peripheral neurons protection against toxic effects, which promotes analgesia. Methods: We aim to screen several new cannabinoids for their potential use as neuroprotective agents for CIPN by investigating the cellular toxicity profile and by assessing the potential neuroprotective features against PTX using a primary dorsal root ganglion neuronal culture. Results: Our study showed that synthetic cannabinoids JWH-007, AM-694 and MAB-CHMINACA and phytocannabinoids Cannabixir® Medium dried flowers (NC1) and Cannabixir® THC full extract (NC2) preserve the viability of fibroblasts and primary cultured neurons, in most of the tested dosages and time-points. The combination between the cannabinoids and PTX conducted to a cell viability of 70%-89% compared to 40% when PTX was administered alone for 48h. When assessing the efficacy for neuroprotection, the combination between cannabinoids and PTX led to better preservation of neurite length at all tested time-points compared to controls, highly drug and exposure-time dependent. By comparison, the combination of the cannabinoids and PTX administered for 24h conducted to axonal shortening between 23% and 44%, as opposed to PTX only, which shortened the axons by 63% compared to their baseline values. Discussion and Conclusion: Cannabinoids could be potential new candidates for the treatment of paclitaxel-induced peripheral neuropathy; however, our findings need to be followed by additional tests to understand the exact mechanism of action, which would support the translation of the cannabinoids in the oncological clinical practice.

Rhein inhibits M1 polarization of BV2 microglia through MAPK/IκB signalling pathway and reduces neurotoxicity caused by neuroinflammation.

Rhein is an anthraquinone compound with anti-inflammatory pharmacological activity. It has been found to play a neuroprotective role in neurological diseases, but the neuroprotective mechanism of rhein remains unclear. SH-SY5Y cells serving as neuron-like cells and BV2 microglia were used. The toxicity of rhein on BV2 microglia and the viability of SH-SY5Y cells were measured by CCK-8 assay. The mRNA expression and secretion of pro-inflammatory cytokines were detected by qPCR and ELISA. Iba1, CD86 and pathway signalling protein in BV2 microglia were assessed by Western blot and immunofluorescence. Apoptosis of SH-SY5Y cells exposed to neuroinflammation was analysed through flow cytometry. Rhein inhibited MAPK/IκB signalling pathways. Further studies revealed that rhein inhibited the production of pro-inflammatory cytokines TNF-α, IL-6, IL-1β and iNOS in BV2 cells and also inhibited the expression of M1 polarization markers Iba1 and CD86 in BV2 cells. Furthermore, rhein reduced the apoptotic rate and restored cell viability of SH-SY5Y cells exposed to neuroinflammation. Our study demonstrated that rhein inhibited microglia M1 polarization via MAPK/IκB signalling pathway and protected nerve cells through suppressing neuroinflammation.

Effects of Chronic Pain Following Unilateral Ureteral Obstruction on Hippocampal CA1 Pyramidal Neurons in Male Wistar Rats

Background: Chronic pain can adversely affect cognitive functions such as learning, memory, and attention. However, the precise mechanisms underlying cognitive impairment in chronic pain remain elusive. Objectives: This study aims to investigate the impact of chronic pain induced by unilateral ureteral obstruction (UUO) on hippocampal neurons. Methods: In the current case-control study, 27 male Wistar rats (230 - 280 g) were randomly assigned to three groups: 1-sham, 2-UUO, and 3-UUO treated with naloxone (i.p.; 1 mg/kg for 5 days). Following transcardial perfusion, the rats' brains were removed, and histological studies were performed to count the number of neurons using an optical microscope. Concurrently, TNF-α and NGF levels were measured in brain tissue homogenate. Results: The mean number of neurons in the CA1 region of the animals in the UUO group was 68.11 ± 1.34, which showed a significant decrease compared to the mean number of neurons in the sham-operated group (114.1 ± 1.77; P < 0.0001). In contrast, the mean number of neurons in the CA1 region of the UUO with naloxone group showed a significant increase compared to the animals in the UUO group (73.44 ± 1.37; P < 0.0001). TNF-α was 264.3 ± 2.6 pg/mL in the UUO animals and decreased significantly in the UUO animals treated with naloxone (P = 0.001). However, NGF was 115.2 ± 2.9 pg/mL in UUO animals and increased significantly in the UUO with naloxone group (P < 0.01). Conclusions: Unilateral ureteral obstruction, through inducing chronic pain and inflammation, resulted in neurodegeneration in the CA1 region of the hippocampus. The use of naloxone, an opioid antagonist, immediately after the surgery was able to provide neuronal protection and an anti-inflammatory effect.

Transplantation of olfactory mucosa mesenchymal stromal cells repairs spinal cord injury by inducing microglial polarization.

Animal studies OBJECTIVES: To evaluate the therapeutic effect of olfactory mucosa mesenchymal stem cell (OM-MSCs) transplantation in mice with spinal cord injury (SCI) and to explore the mechanism by which OM-MSCs inhibit neuroinflammation and improve SCI. Xiangya Hospital, Central South University; Affiliated Hospital of Guangdong Medical University. Mice (C57BL/6, female, 6-week-old) were randomly divided into sham, SCI, and SCI + OM-MSC groups. The SCI mouse model was generated using Allen's method. OM-MSCs were immediately delivered to the lateral ventricle after SCI using stereotaxic brain injections. One day prior to injury and on days 1, 5, 7, 14, 21, and 28 post-injury, the Basso Mouse Scale and Rivlin inclined plate tests were performed. Inflammation and microglial polarization were evaluated using histological staining, immunofluorescence, and qRT-PCR. OM-MSCs originating from the neuroectoderm have great potential in the management of SCI owing to their immunomodulatory effects. OM-MSCs administration improved motor function, alleviated inflammation, promoted the transformation of the M1 phenotype of microglia into the M2 phenotype, facilitated axonal regeneration, and relieved spinal cord injury in SCI mice. OM-MSCs reduced the level of inflammation in the spinal cord tissue, protected neurons, and repaired spinal cord injury by regulating the M1/M2 polarization of microglia.

Biological role of mitochondrial TLR4-mediated NF-κB signaling pathway in central nervous system injury.

Previous studies suggested that central nervous system injury is often accompanied by the activation of Toll-like receptor 4/NF-κB pathway, which leads to the upregulation of proapoptotic gene expression, causes mitochondrial oxidative stress, and further aggravates the inflammatory response to induce cell apoptosis. Subsequent studies have shown that NF-κB and IκBα can directly act on mitochondria. Therefore, elucidation of the specific mechanisms of NF-κB and IκBα in mitochondria may help to discover new therapeutic targets for central nervous system injury. Recent studies have suggested that NF-κB (especially RelA) in mitochondria can inhibit mitochondrial respiration or DNA expression, leading to mitochondrial dysfunction. IκBα silencing will cause reactive oxygen species storm and initiate the mitochondrial apoptosis pathway. Other research results suggest that RelA can regulate mitochondrial respiration and energy metabolism balance by interacting with p53 and STAT3, thus initiating the mitochondrial protection mechanism. IκBα can also inhibit apoptosis in mitochondria by interacting with VDAC1 and other molecules. Regulating the biological role of NF-κB signaling pathway in mitochondria by targeting key proteins such as p53, STAT3, and VDAC1 may help maintain the balance of mitochondrial respiration and energy metabolism, thereby protecting nerve cells and reducing inflammatory storms and death caused by ischemia and hypoxia.

ARMC10 regulates mitochondrial dynamics and affects mitochondrial function via the Wnt/β-catenin signalling pathway involved in ischaemic stroke.

Mitochondrial dynamics has emerged as an important target for neuronal protection after cerebral ischaemia/reperfusion. Therefore, the aim of this study was to investigate the mechanism by which ARMC10 regulation of mitochondrial dynamics affects mitochondrial function involved in ischaemic stroke (IS). Mitochondrial morphology was detected by laser scanning confocal microscopy (LSCM), and mitochondrial ultrastructural alterations were detected by electron microscopy. The expression of mitochondrial dynamics-related genes Drp1, Mfn1, Mfn2, Fis1, OPA1 and ARMC10 and downstream target genes c-Myc, CyclinD1 and AXIN2 was detected by RT-qPCR. Western blot was used to detect the protein expression of β-catenin, GSK-3β, p-GSK-3β, Bcl-2 and Bax. DCFH-DA fluorescent probe was to detect the effect of ARMC10 on mitochondrial ROS level, Annexin V-FITC fluorescent probe was to detect the effect of ARMC10 on apoptosis, and ATP assay kit was to detect the effect of ARMC10 on ATP production. Mitochondrial dynamics was dysregulated in clinical IS samples and in the OGD/R cell model, and the relative expression of ARMC10 gene was significantly decreased in IS group (p < 0.05). Knockdown and overexpression of ARMC10 could affect mitochondrial dynamics, mitochondrial function and neuronal apoptosis. Agonist and inhibitor affected mitochondrial function and neuronal apoptosis by targeting Wnt/β-Catenin signal pathway. In the OGD/R model, ARMC10 affected mitochondrial function and neuronal apoptosis through the mechanism that regulates Wnt/β-catenin signalling pathway. ARMC10 regulates mitochondrial dynamics and protects mitochondrial function by activating Wnt/β-catenin signalling pathway, to exert neuroprotective effects.

Neuroprotective Effects of Sodium-Glucose Cotransporter-2 (SGLT2) Inhibitors (Gliflozins) on Diabetes-Induced Neurodegeneration and Neurotoxicity: A Graphical Review.

Diabetes is a chronic endocrine disorder that negatively affects various body systems, including the nervous system. Diabetes can cause or exacerbate various neurological disorders, and diabetes-induced neurodegeneration can involve several mechanisms such as mitochondrial dysfunction, activation of oxidative stress, neuronal inflammation, and cell death. In recent years, the management of diabetes-induced neurodegeneration has relied on several types of drugs, including sodium-glucose cotransporter-2 (SGLT2) inhibitors, also called gliflozins. In addition to exerting powerful effects in reducing blood glucose, gliflozins have strong anti-neuro-inflammatory characteristics that function by inhibiting oxidative stress and cell death in the nervous system in diabetic subjects. This review presents the molecular pathways involved in diabetes-induced neurodegeneration and evaluates the clinical and laboratory studies investigating the neuroprotective effects of gliflozins against diabetes-induced neurodegeneration, with discussion about the contributing roles of diverse molecular pathways, such as mitochondrial dysfunction, oxidative stress, neuro-inflammation, and cell death. Several databases-including Web of Science, Scopus, PubMed, Google Scholar, and various publishers, such as Springer, Wiley, and Elsevier-were searched for keywords regarding the neuroprotective effects of gliflozins against diabetes-triggered neurodegenerative events. Additionally, anti-neuro-inflammatory, anti-oxidative stress, and anti-cell death keywords were applied to evaluate potential neuronal protection mechanisms of gliflozins in diabetes subjects. The search period considered valid peer-reviewed studies published from January 2000 to July 2023. The current body of literature suggests that gliflozins can exert neuroprotective effects against diabetes-induced neurodegenerative events and neuronal dysfunction, and these effects are mediated via activation of mitochondrial function and prevention of cell death processes, oxidative stress, and inflammation in neurons affected by diabetes. Gliflozins can confer neuroprotective properties in diabetes-triggered neurodegeneration, and these effects are mediated by inhibiting oxidative stress, inflammation, and cell death.

Neuronal cell protective effects of phenolic compounds derived from steam exploded nematode-infected pine

Pine wilt disease is one of the most serious forest diseases that kills pine trees. Most of the nematode-infected pines are fumigated or locally incinerated and are thus not appropriately utilized. This study explored methods to utilize abandoned nematode-infected pines. The chemical compositions of healthy and nematode-infected pines were analyzed, and the neuroprotective effects of phenolic compounds extracted after steam explosion treatment were investigated. In terms of chemical composition, the nematode-infected pine chips suffered more damage from the steam explosion treatment than the healthy pine chips. In addition, the total phenolic compound content showed a clear difference depending on the presence of infection and steam explosion conditions. The maximum total phenolic compound content of extracted ethanol was found when the nematode-infected pine chip was subjected to steam explosion with a severity factor (Ro) of 3.82. The steam exploded pine extract of 10 μg/mL inhibited glutamate-induced early apoptotic cell death compared to cells treated with 10 mM glutamate alone. These results suggested that steam-exploded pine can be used as an effective natural material for neuronal cell protection.

Exploring Dimethylsulfoniopropionate as a potential treatment for Alzheimer's disease: A study using the 3 × Tg-AD mouse model

BackgroundAlzheimer's disease (AD), the most common neurodegenerative disorder, affects a broad spectrum of aging populations. AD is characterized by pathological amyloid-β (Aβ) plaques and neurofibrillary tangles, leading to neural degeneration and cognitive decline. The lack of effective treatments for AD highlights the urgent need for novel therapeutic agents, particularly in the early stages. Dimethylsulfoniopropionate (DMSP) is a natural marine compound with antioxidant and neuroprotective properties. However, studies on the efficacy of DMSP in the treatment of AD and its associated mechanisms are limited. PurposeThis study aimed to explore the therapeutic effects and mechanisms of action of DMSP as an AD treatment using a preclinical 3 × Tg-AD mouse model. MethodsThe research involved administering DMSP (7 μg/mL and 11 μg/mL in drinking water) to four-month-old 3 × Tg-AD mice consecutively for three months. The Y-maze test, novel object recognition test, and Morris water maze test were used to assess memory and learning ability. The relative expression levels and distribution of proteins relevant to Aβ and tau pathology, synapses, and glial cells were analyzed using western blotting and immunofluorescence assays. Additionally, proteomic and bioinformatics approaches were used to explore the potential targets of DMSP treatment. ResultsDMSP-treated AD mice showed significantly enhanced cognitive function, suggesting that DMSP mitigates memory and learning impairments in AD. Moreover, DMSP diminished the abnormal accumulation of Aβ and phosphorylated tau in both the cortex and hippocampus, which are crucial hallmarks of AD pathology. In addition to its neuroprotective properties, DMSP restored synaptic density and the expression of synaptic and neuronal proteins, which are essential for proper brain function. DMSP displayed anti-inflammatory properties, as evidenced by its ability to suppress inflammatory astrocytes and maintain microglial homeostasis. Notably, DMSP facilitated the maturation of oligodendrocytes (OLs) from oligodendrocyte progenitor cells (OPCs), a critical process in the development of the brain myelination architecture. Proteomic analysis revealed that DMSP positively influenced biological processes crucial for oligodendrocyte development, myelination, and axonal ensheathment, which are often compromised in patients with AD. Protein validation and brain tissue staining supported the role of DMSP in preserving myelin enrichment and sheath integrity. These therapeutic effects were largely attributed to the enhanced expression of myelin-associated glycoprotein (Mag) and tetraspanin Cd9. ConclusionOverall, our findings highlight DMSP as a promising novel therapeutic candidate for AD, offering multifaceted benefits in cognitive and memory enhancement, reduction of Aβ and tau pathology, neuronal synapse protection, anti-inflammatory effects, and myelin sheath restoration as an innovative target compared to other studies. In addition to being a potentially effective treatment for AD, DMSP may also have the potential to address other neurodegenerative diseases that are closely associated with myelin impairment.

Varicella zoster virus-induced autophagy in human neuronal and hematopoietic cells exerts antiviral activity.

Autophagy is a degradational pathway with pivotal roles in cellular homeostasis and survival, including protection of neurons in the central nervous system (CNS). The significance of autophagy as antiviral defense mechanism is recognized and some viruses hijack and modulate this process to their advantage in certain cell types. Here, we present data demonstrating that the human neurotropic herpesvirus varicella zoster virus (VZV) induces autophagy in human SH-SY5Y neuronal cells, in which the pathway exerts antiviral activity. Productively VZV-infected SH-SY5Y cells showed increased LC3-I-LC3-II conversion as well as co-localization of the viral glycoprotein E and the autophagy receptor p62. The activation of autophagy was dependent on a functional viral genome. Interestingly, inducers of autophagy reduced viral transcription, whereas inhibition of autophagy increased viral transcript expression. Finally, the genotype of patients with severe ocular and brain VZV infection were analyzed to identify potential autophagy-associated inborn errors of immunity. Two patients expressing genetic variants in the autophagy genes ULK1 and MAP1LC3B2, respectively, were identified. Notably, cells of both patients showed reduced autophagy, alongside enhanced viral replication and death of VZV-infected cells. In conclusion, these results demonstrate a neuro-protective role for autophagy in the context of VZV infection and suggest that failure to mount an autophagy response is a potential predisposing factor for development of severe VZV disease.

Combined Catalpol and Tetramethylpyrazine Promote Axonal Plasticity in Alzheimer's Disease by Inducing Astrocytes to Secrete Exosomes Carrying CDK5 mRNA and Regulating STAT3 Phosphorylation.

Alzheimer's disease (AD) is a common progressive degenerative disease of the central nervous system in aging populations. This study aimed to investigate the effects of combined catalpol and tetramethylpyrazine (CT) in promoting axonal plasticity in AD and the potential underlying mechanism. Astrocytes were treated with different concentrations of compatible CT. Exosomes were collected and subjected to sequencing analysis, which was followed by the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of differentially expressed genes. Amyloid precursor protein/presenilin 1 (APP/PS1) double-transfected male mice were used as the in vivo AD models. Astrocyte-derived exosomes that were transfected with cyclin-dependent kinase 5 (CDK5) or CT treatment were injected into the tail vein of mice. The levels of CDK5, synaptic plasticity marker protein neurofilament 200 (NF200), and growth-associated protein 43 (GAP-43) in the hippocampus of mice were compared in each group. Immunofluorescence staining was used to detect the localization of STAT3 and to visualize synaptic morphology via β-tubulin-III (TUBB3). Astrocyte-derived exosomes transfected with siCDK5 or treated with CT were co-cultured with HT-22 cells, which were untransfected or silenced for signal transducer and activator of transcription 3 (STAT3). Amyloid β-protein (Aβ)1-42 was induced in the in vitro AD models. The viability, apoptosis, and expression levels of NF200 and GAP-43 proteins in the hippocampal neurons of each group were compared. In total, 166 differentially expressed genes in CT-induced astrocyte-derived exosomes were included in the KEGG analysis, and they were found to be enriched in 12 pathways, mainly in axon guidance. CT treatment significantly increased the level of CDK5 mRNA in astrocyte-derived exosomes-these exosomes restored CDK5 mRNA and protein levels in the hippocampus of the in vivo AD model mice and the in vitro AD model; promoted p-STAT3 (Ser727), NF200 and GAP-43 proteins; and promoted the regeneration and extension of neuronal synapses. Silencing of CDK5 blocked both neuronal protection as well as induction of axonal plasticity in AD by CT-treated exosomes in vitro and in vivo. Moreover, silencing of STAT3 blocked both neuronal protection as well as induction of axonal plasticity in AD caused by CDK5 overexpression or CT-treated astrocyte-induced exosomes. CT promotes axonal plasticity in AD by inducing astrocytes to secrete exosomes carrying CDK5 mRNA and regulating STAT3 (Ser727) phosphorylation.

Construction of a Multicellular Communication Network Model for Cell Co-Culture Technology and Evaluation of Its Simulation Capability

Abstract Objective: Cell co-culture technology has been widely used to analyze the effects of drugs on cell proliferation and the expression of some proteins in cells, especially in the field of traditional Chinese medicine (TCM); however, the interactions between cells and the transmission of TCM effects between cells have not been adequately studied. Materials and Methods: Using data on gene transcription regulation, biological response, signal channel, and cell-specific expression protein, we built a network for cell types based on entity grammar. Through the correspondence and location information of signal molecules and receptors, type-specific networks of single cells were connected and a multicellular network of smooth muscle cells, neurons, and vascular endothelial cells was constructed. The mechanism of action of nimodipine was analyzed based on the multicellular communication network and its simulation capability was evaluated. Results: The outputs generated by the model developed in this study showed that nimodipine inhibited smooth muscle contraction, due to the overload of Ca2+ and the toxicity of excitatory amino acids, and protected neurons and vascular endothelial cells by supporting cell proliferation and inhibiting cell apoptosis. These results were consistent with the known mechanism of nimodipine action, thus confirming that the multicellular network can be used to study the transmission of drug effects among cells. Conclusions: This study lays a foundation for the analysis of the transmission of drug effects in multi-cells, tissues, organs, and other spatial scales through multicellular co-culture experiments, based on a multicellular communication network. In addition, it provides a biological network model for the analysis of TCM action mechanisms.

Menthol-Modified Quercetin Liposomes with Brain-Targeting Function for the Treatment of Senescent Alzheimer's Disease.

Oxidative stress and neuroinflammation in the aging brain are correlated with the development of neurodegenerative diseases, such as Alzheimer's disease (AD). The blood-brain barrier (BBB) poses a significant challenge to the effective delivery of therapeutics for AD. Prior research has demonstrated that menthol (Men) can augment the permeability of the BBB. Consequently, in the current study, we modified Men on the surface of liposomes to construct menthol-modified quercetin liposomes (Men-Qu-Lips), designed to cross the BBB and enhance quercetin (Qu) concentration in the brain for improved therapeutic efficacy. The experimental findings indicate that Men-Qu-Lips exhibited good encapsulation efficiency and stability, successfully crossed the BBB, improved oxidative stress and neuroinflammation in the brains of aged mice, protected neurons, and enhanced their learning and memory abilities.

Role of histone deacetylases and sirtuins in the ischaemic stroke: a protocol for a systematic review and meta-analysis of animal studies

BackgroundStroke is a major cause of global mortality and disability. Currently, the treatment of acute ischaemic stroke through reperfusion has posed several challenges, raising the need for complementary options to...

Direct neuronal protection by the protease-activated receptor PAR4 antagonist ML354 after experimental stroke in mice.

Thrombo-inflammation is a key feature of stroke pathophysiology and provides multiple candidate drug targets. Thrombin exerts coagulation-independent actions via protease-activated receptors (PAR), of which PAR1 has been implicated in stroke-associated neuroinflammation. The role of PAR4 in this context is less clear. This study examined if the selective PAR4 antagonist ML354 provides neuroprotection in experimental stroke and explored the underlying mechanisms. Mouse primary cortical neurons were exposed to oxygen-glucose deprivation (OGD) and simulated reperfusion ± ML354. For comparison, functional Ca2+-imaging was performed upon acute stimulation with a PAR4 activating peptide or glutamate. Male mice underwent sham operation or transient middle cerebral artery occlusion (tMCAO), with ML354 or vehicle treatment beginning at recanalization. A subset of mice received a platelet-depleting antibody. Stroke size and functional outcomes were assessed. Abundance of target genes, proteins, and cell markers was determined in cultured cells and tissues by qPCR, immunoblotting, and immunofluorescence. Stroke up-regulated PAR4 expression in cortical neurons in vitro and in vivo. OGD augments spontaneous and PAR4-mediated neuronal activity; ML354 suppresses OGD-induced neuronal excitotoxicity and apoptosis. ML354 applied in vivo after tMCAO reduced infarct size, apoptotic markers, macrophage accumulation, and interleukin-1β expression. Platelet depletion did not affect infarct size in mice with tMCAO ± ML354. Selective PAR4 inhibition during reperfusion improves infarct size and neurological function after experimental stroke by blunting neuronal excitability, apoptosis, and local inflammation. PAR4 antagonists may provide additional neuroprotective benefits in patients with acute stroke beyond their canonical antiplatelet action.

Quercetin Inhibits Neuronal Pyroptosis and Ferroptosis by Modulating Microglial M1/M2 Polarization in Atherosclerosis.

Atherosclerosis (AS) with iron and lipid overload and systemic inflammation is a risk factor for Alzheimer's disease. M1 macrophage/microglia participate in neuronal pyroptosis and recently have been reported to be the ferroptosis-resistant phenotype. Quercetin plays a prominent role in preventing and treating neuroinflammation, but the protective mechanism against neurodegeneration caused by iron deposition is poorly understood. ApoE-/- mice were fed a high-fat diet with or without quercetin treatment. The Morris water maze and novel object recognition tests were conducted to assess spatial learning and memory, and nonspatial recognition memory, respectively. Prussian blue and immunofluorescence staining were performed to assess the iron levels in the whole brain and in microglia, microglia polarization, and the degree of microglia/neuron ferroptosis. In vitro, we further explored the molecular biological alterations associated with microglial polarization, neuronal pyroptosis, and ferroptosis via Western blot, flow cytometry, CCK8, LDH, propidium iodide, and coculture system. We found that quercetin improved brain lesions and spatial learning and memory in AS mice. Iron deposition in the whole brain or microglia was reversed by the quercetin treatment. In the AS group, the colocalization of iNOS with Iba1 was increased, which was reversed by quercetin. However, the colocalization of iNOS with PTGS2/TfR was not increased in the AS group, suggesting a character resisting ferroptosis. Quercetin induced the expression of Arg-1 and decreased the colocalizations of Arg-1 with PTGS2/TfR. In vitro, ox-LDL combined with ferric ammonium citrate treatment (OF) significantly shifted the microglial M1/M2 phenotype balance and increased the levels of free iron, ROS, and lipid peroxides, which was reversed by quercetin. M1 phenotype induced by OF caused neuronal pyroptosis and was promoted to ferroptosis by L-NIL treatment, which contributed to neuronal ferroptosis as well. However, quercetin induced the M1 to M2 phenotype and inhibited M2 macrophages/microglia and neuron pyroptosis or ferroptosis. In summary, quercetin alleviated neuroinflammation by inducing the M1 to M2 phenotype to inhibit neuronal pyroptosis and protected neurons from ferroptosis, which may provide a new idea for neuroinflammation prevention and treatment.

3D hydrogel microfibers promote the differentiation of encapsulated neural stem cells and facilitate neuron protection and axon regrowth after complete transactional spinal cord injury

Spinal cord injury (SCI) can cause permanent impairment to motor or sensory functions. Pre-cultured neural stem cell (NSC) hydrogel scaffolds have emerged as a promising approach to treat SCI by promoting anti-inflammatory effects, axon regrowth, and motor function restoration. Here, in this study, we performed a coaxial extrusion process to fabricate a core-shell hydrogel microfiber with high NSC density in the core portion. Oxidized hyaluronic acid, carboxymethyl chitosan, and matrigel blend were used as a matrix for NSC growth and to facilitate the fabrication process. During the in vitro differentiation culture, it was found that NSC microfibers could differentiate into neurons and astrocytes with higher efficiency compared to NSC cultured in petri dishes. Furthermore, during in vivo transplantation, NSC microfibers were coated with polylactic acid nanosheets by electrospinning for reinforcement. The coated NSC nanofibers exhibited higher anti-inflammatory effect and lesion cavity filling rate compared with the control group. Meanwhile, more neuron- and oligodendrocyte-like cells were visualized at the lesion epicenter. Finally, axon regrowth across the whole lesion site was observed, demonstrating that the microfiber could guide renascent axon regrowth. Experiment results indicate that the NSC microfiber is a promising bioactive treatment for complete SCI treatment with superior outcomes.