Search Results (219)

The application of artificial intelligence through the brain–computer interface (BCI) is proving to be one of the great advances in neuroscience today. The development of surface electrodes over the cortex and very fine electrodes that can be stereotactically implanted in the brain have moved the science forward to the extent that paralyzed people can play chess and blind people can read letters. However, the introduction of foreign bodies into deeper parts of the central nervous system results in foreign body reaction, scarring, apoptosis, and decreased signaling. Implanted electrodes activate microglia, causing the release of inflammatory factors, the recruitment of systemic inflammatory cells to the site of injury, and ultimately glial scarring and the encapsulation of the electrode. Recordings historically fail between 6 months and 1 year; the longest BCI in use has been 7 years. This article proposes a biomolecular strategy provided by angiogenic cell precursors (ACPs) and nerve cell precursors (NCPs), administered intrathecally. This combination of cells is anticipated to sustain and promote learning across the BCI. Together, through the downstream activation of neurotrophic factors, they may exert a salutary immunomodulatory suppression of inflammation, anti-apoptosis, homeostasis, angiogenesis, differentiation, synaptogenesis, neuritogenesis, and learning-associated plasticity. Full article

In familial Alzheimer’s disease (FAD), presenilin 1 (PSEN1) E280A cholinergic-like neurons (ChLNs) induce aberrant secretion of extracellular amyloid beta (eAβ). How PSEN1 E280A ChLNs-eAβ affects microglial activity is still unknown. We obtained induced microglia-like cells (iMG) from human peripheral blood cells (hPBCs) in a 15-day differentiation process to investigate the effect of bolus addition of Aβ42, PSEN1 E280A cholinergic-like neuron (ChLN)-derived culture supernatants, and PSEN1 E280A ChLNs on wild type (WT) iMG, PSEN1 E280A iMG, and sporadic Alzheimer’s disease (SAD) iMG. We found that WT iMG cells, when challenged with non-cellular (e.g., lipopolysaccharide, LPS) or cellular (e.g., Aβ42, PSEN1 E280A ChLN-derived culture supernatants) microenvironments, closely resemble primary human microglia in terms of morphology (resembling an “amoeboid-like phenotype”), expression of surface markers (Ionized calcium-binding adapter molecule 1, IBA-1; transmembrane protein 119, TMEM119), phagocytic ability (high pHrodo™ Red E. coli BioParticles™ phagocytic activity), immune metabolism (i.e., high generation of reactive oxygen species, ROS), increase in mitochondrial membrane potential (ΔΨm), response to ATP-induced transient intracellular Ca²⁺ influx, cell polarization (cluster of differentiation 68 (CD68)/CD206 ratio: M1 phenotype), cell migration activity according to the scratch wound assay, and especially in their inflammatory response (secretion of cytokine interleukin-6, IL-6; Tumor necrosis factor alpha, TNF-α). We also found that PSEN1 E280A and SAD iMG are physiologically unresponsive to ATP-induced Ca²⁺ influx, have reduced phagocytic activity, and diminished expression of Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) protein, but when co-cultured with PSEN1 E280A ChLNs, iMG shows an increase in pro-inflammatory phenotype (M1) and secretes high levels of cytokines IL-6 and TNF-α. As a result, PSEN1 E280A and SAD iMG induce apoptosis in PSEN1 E280A ChLNs as evidenced by abnormal phosphorylation of protein TAU at residue T205 and cleaved caspase 3 (CC3). Taken together, these results suggest that PSEN1 E280A ChLNs initiate a vicious cycle between damaged neurons and M1 phenotype microglia, resulting in excessive ChLN death. Our findings provide a suitable platform for the exploration of novel therapeutic approaches for the fight against FAD. Full article

The developmental processes of microglia follow a general pattern, from immature amoeboid (activated) cells to fully ramified (inactivated) surveilling microglia. However, little is known about the mechanisms controlling the transition of microglia from an activated to an inactivated state during brain development. Due to the complexity of microenvironmentally dynamic changes during neuronal differentiation, interactions between developing nerve cells and microglia might be involved in this process. Extracellular vesicles (EVs) are cell-released particles that serve as mediators of cellular crosstalk and regulation. Using neural progenitor cells (NPCs) and a long-term neuron culture system, we found that EVs derived from NPCs or developing neurons possessed differential capacity on the induction of microglial activation. The exposure of microglia to NPC- or immature neuron (DIV7)-derived EVs resulted in the higher expression of protein and mRNA of multiple inflammatory cytokines (e.g., TNF-α, IL-1β, and IL-6), when compared with mature neuron-derived EVs. Exploration of the intracellular signaling pathways revealed that MAPK signaling, IκBα phosphorylation/degradation, and NF-κB p65 nuclear translocation were strongly induced in microglia treated with NPC- or immature neuron-derived EVs. Using a pharmacological approach, we further demonstrate that Toll-like receptor (TLR) 7-mediated activation of NF-κB and MAPK signaling cascades contribute to EV-elicited microglial activation. Additionally, the application of conditioned media derived from microglia treated with NPC- or immature neuron-derived EVs is found to promote the survival of late-developing dopaminergic neurons. Thus, our results highlight a novel mechanism used by NPCs and developing neurons to modulate the developmental phases and functions of microglia through EV secretion. Full article

Amyotrophic lateral sclerosis (ALS) is characterized by upper and lower motor neuron failure and poor prognosis. This study performed a meta-analysis of gene expression datasets that compared bulk-processed post-mortem spinal cord from ALS and control (CTL) patients. The analysis included 569 samples (454 ALS, 115 CTL) from 348 individuals (262 ALS, 86 CTL). Patterns of differential expression bias, related to mRNA abundance, gene length and GC content, were discernable from individual studies but attenuated by meta-analysis. A total of 213 differentially expressed genes (DEGs) were identified (144 ALS-increased, 69 ALS-decreased). ALS-increased DEGs were most highly expressed by microglia and associated with MHC class II, immune response and leukocyte activation. ALS-decreased DEGs were abundantly expressed by mature oligodendrocytes (e.g., the MOL5 phenotype) and associated with myelin production, plasma membrane and sterol metabolism. Comparison to spatial transcriptomics data showed that DEGs were prominently expressed in white matter, with increased DEG expression strongest in the ventral/lateral white matter. These results highlight white matter as the spinal cord region most strongly associated with the shifts in mRNA abundance observed in bulk-processed tissues. These shifts can be explained by attrition of mature oligodendrocytes and an ALS-emergent microglia phenotype that is partly shared among neurodegenerative conditions. Full article

Neuroinflammation is a key process in Alzheimer’s disease (AD). We aimed to examine the development and evaluation of a comprehensive in vitro model that captures the complex interplay between neurons and immune cell types. Retinoic acid-differentiated SH-SY5Y neuroblastoma cells exposed to LPS-conditioned media (CM) from RAW264.7 macrophages, BV2 microglia, and HL60 promyelocytic cells differentiated into neutrophil- or monocyte-like phenotypes were analyzed. The effects of CM containing inflammatory factors on neuronal viability and function were systematically evaluated. Neuronal oxidative stress, mitochondrial function, autophagy and protein aggregates were analyzed. The involvement of insulin resistance was studied by assaying glucose uptake and determining its IC₅₀ values for cell viability improvement and GSK3β phosphorylation. After short-term exposure (3 h), most inflammatory CMs induced peroxide production in neurons, with the strongest effect observed in media from DMSO- or RA-differentiated HL60 cells. Mitochondrial membrane potential was markedly reduced by LPS-stimulated BV2 and HL60-derived CMs. Prolonged exposure (72 h) revealed partial normalization of oxidative stress and mitochondrial membrane potential. Glucose uptake was significantly impaired in cells treated with LPS-activated RAW264.7, BV2, and DMSO-differentiated HL60 cell media, while insulin partially rescued this effect, except for the CM of BV2 cells. Notably, insulin IC₅₀ increased dramatically under LPS-treated BV2 cells induced inflammation (35 vs. 198 pM), confirming the development of insulin resistance. Immune cell-specific inflammation causes distinct effects on neuronal oxidative stress, mitochondrial function, protein aggregation, insulin signaling and viability. LPS-activated BV2-derived CM best recapitulates AD-related pathology, offering a relevant in vitro model for further studies. Full article

Glioblastoma is a highly aggressive brain tumor with an overall poor prognosis due to its immunosuppressive tumor microenvironment (TME). Microglia and tumor-associated macrophages (TAMs) with pro-tumorigenic properties are dominant populations of immune cells in the glioblastoma TME. To date, several studies targeting TAMs to fight tumor progression in different tumor entities have been initiated. However, the impact of standard therapy schemes of glioblastoma cells on macrophage polarization, activation, and phagocytosis remains controversial. The same applies to the relevance of PD-1/PD-L1 blockade in the interaction between macrophages and tumor cells. Our study, therefore, investigated patient-oriented treatment of GLIOBLASTOMA by examining the phagocytic capacity of polarized M1- and M2-like macrophages using GL261-luc2 tumor cells as a preclinical model system. Additionally, we analyzed the expression of activation and immune checkpoint markers on these macrophage subtypes following contact with tumor cells and their microenvironment. These factors were also determined after PD-1 blockade was initiated. The analyses revealed that the immunoregulatory M2-like macrophages generally exhibited a higher phagocytosis rate than the pro-inflammatory M1-like macrophages; however, this was not influenced by the pretreatment of glioblastoma cells with chemo- or radiotherapy. This could not be improved by blocking the PD-1 receptor. Furthermore, there were no modulations in the expression of differentiation, activation, or immune checkpoint molecules of M1- and M2-like macrophages after cell-to-cell contact with glioblastoma cells. But the medium conditioned by tumor cells strongly altered M1-like macrophages toward a more activated state, whereas M2-like cells were only mildly influenced. This was further enhanced by tumor cell treatment, with the most prominent effect after irradiation. These results suggest that conventional GLIOBLASTOMA tumor cell treatment affects the immunogenic status of macrophage subtypes, which is relevant for enhancing the anti-tumor immune response in brain tumors. Full article

In this study, we investigated the potential of a three-mushroom complex extract (GMK) to inhibit neuronal cell death induced by the activation of AMPA and NMDA receptors following glutamate treatment in NGF-differentiated PC12 neuronal cells. GMK significantly mitigated glutamate-induced excitotoxic neuronal apoptosis by reducing the elevated expression of BAX, a critical regulator of apoptosis, and restoring BCL2 levels. These neuroprotective effects were associated with redox regulation, as evidenced by the upregulation of SOD, CAT, and GSH levels, and the downregulation of MDA levels. Mechanistic studies further revealed that GMK effectively scavenged ROS by downregulating NOX1, NOX2, and NOX4, while upregulating NRF1, P62, NRF2, HO1, and NQO1. Additionally, in the same model, GMK treatment increased acetylcholine, choline acetyltransferase, and GABA levels while reducing acetylcholinesterase activity. These effects were also attributed to the regulation of redox balance. Furthermore, we investigated the antioxidant and anti-inflammatory mechanisms of GMK in LPS-stimulated BV2 microglia. GMK inhibited the activation of IκB and MAPK pathways, positively regulated the BCL2/BAX ratio, suppressed TXNIP activity, and upregulated NQO1 and NOX1. In conclusion, GMK improved neuronal excitotoxicity and microglial inflammation through the positive modulation of the redox regulatory system, demonstrating its potential as a natural resource for pharmaceutical applications and functional health foods. Full article

Apolipoprotein E (APOE) alleles play distinct roles in the pathogenesis of Alzheimer’s disease (AD), with APOEε4 being the strongest genetic risk factor for late-onset AD, while APOEε2 appears protective. Despite extensive research, the precise mechanisms by which APOE alleles contribute to AD pathology remain incompletely understood. Recent advances in multi-omics technologies and single-cell analyses have revealed that APOE alleles shape microglial phenotypes, thereby affecting amyloid clearance, inflammatory responses, tau pathology, and lipid metabolism. In this review, we provide a detailed overview of how APOE alleles differentially regulate microglial activation, inflammatory signaling, phagocytic activity, and lipid metabolism in the context of AD, with a particular focus on the APOEε4-mediated disruption of microglial homeostasis via pathways such as TREM2 signaling, NF-κB/NLRP3 activation, ACSL1 upregulation, and HIF-1α induction. These insights not only advance our understanding of APOE allele-specific contributions to AD pathology, but also highlight novel therapeutic strategies targeting the APOE–microglia axis. Full article

The primary function of microglia is to maintain brain homeostasis. In neurodegenerative diseases like Alzheimer’s, microglia contribute to neurotoxicity and inflammation. In this study, we exposed neonatal murine primary microglial cultures to stimuli mimicking pathogens, injury, or toxins. Treatment with benzoyl ATP (bzATP) and lipopolysaccharide (LPS) triggered a coordinated increase in interleukin and chemokine expression. We analyzed statistically significant differentially expressed microRNAs (DEMs) at 3 and 8 h post-activation, identifying 33 and 57 DEMs, respectively. Notably, miR-155, miR-132, miR-3473e, miR-222, and miR-146b showed strong temporal regulation, while miR-3963 was sharply downregulated by bzATP. These DEMs regulate inflammatory pathways, including TNFα and NFκB signaling. We also examined the effect of ladostigil, a neuroprotective agent known to reduce oxidative stress and inflammation. At 8 h post-activation, ladostigil induced upregulation of anti-inflammatory miRNAs, such as miR-27a, miR-27b, and miR-23b. Our findings suggest that miRNA profiles reflect microglial responses to inflammatory cues and that ladostigil modulates these responses. This model of controlled microglial activation offers a powerful tool with which to study inflammation in the aging brain and the progression of neurodegenerative diseases. Full article

This work reviews the complex interplay between melatonin and nitric oxide (NO) in the central nervous system (CNS), with a detailed focus on its involvement in stroke pathophysiology. Melatonin, a neurohormone with potent antioxidant, anti-inflammatory, and neuroprotective properties, and NO, a gaseous signaling molecule with diverse roles, interact crucially. In the context of ischemic stroke, NO exhibits a dual role: it can be neuroprotective (primarily via endothelial nitric oxide synthase (eNOS)) or neurotoxic (especially through inducible nitric oxide synthase (iNOS) and neuronal nitric oxide synthase (nNOS), contributing to the formation of damaging peroxynitrite (ONOO⁻)). Melatonin has consistently demonstrated neuroprotective effects in animal models of stroke. Its key mechanisms related to NO include (1) differential modulation of nitric oxide synthase isoforms, suppressing detrimental iNOS expression/activity while often preserving or enhancing beneficial eNOS; (2) direct scavenging of NO and, critically, highly reactive peroxynitrite, thereby attenuating nitrosative stress; (3) reduction in neuroinflammation, partly by promoting M2 (anti-inflammatory) microglia polarization; and (4) mitochondrial protection and decreased apoptosis. These multifaceted actions of melatonin contribute to reduced infarct volume and improved functional outcomes, underscoring its considerable therapeutic potential for ischemic stroke through the favorable modulation of the melatonin–NO axis. Full article

Background/Objectives: X-inactive-specific transcript (XIST) is a factor that plays a role in neuroinflammation. This study investigated the role of XIST in neuronal development, neuroinflammation, myelination, and therapeutic responses within cerebral organoids in the context of Multiple Sclerosis (MS) pathogenesis. Methods: Human cerebral organoids with oligodendrocytes were produced from XIST-silenced H9 cells, and the mature organoids were subsequently treated with either FTY720 or DMF. Gene expression related to inflammation and myelination was subsequently analyzed via qRT-PCR. Immunofluorescence staining was used to assess the expression of proteins related to inflammation, myelination, and neuronal differentiation. Alpha-synuclein protein levels were also checked via ELISA. Finally, transcriptome analysis was conducted on the organoid samples. Results: XIST-silenced organoids presented a 2-fold increase in the expression of neuronal stem cells, excitatory neurons, microglia, and mature oligodendrocyte markers. In addition, XIST silencing increased IL-10 mRNA expression by 2-fold and MBP and PLP1 expression by 2.3- and 0.6-fold, respectively. Although XIST silencing tripled IBA1 protein expression, it did not affect organoid MBP expression. FTY720, but not DMF, distinguished MBP and IBA1 expression in XIST-silenced organoids. Furthermore, XIST silencing reduced the concentration of alpha-synuclein from 300 to 100 pg/mL, confirming its anti-inflammatory role. Transcriptomic and gene enrichment analyses revealed that the differentially expressed genes are involved in neural development and immune processes, suggesting the role of XIST in neuroinflammation. The silencing of XIST modified the expression of genes associated with inflammation, myelination, and neuronal growth in cerebral organoids, indicating a potential involvement in the pathogenesis of MS. Conclusions: XIST may contribute to the MS pathogenesis as well as neuroinflammatory diseases such as and Alzheimer’s and Parkinson’s diseases and may be a promising therapeutic target. Full article

Chitinase-3-like protein 1 (CHI3L1) has been implicated in multiple sclerosis (MS) pathology, yet its precise role remains unclear. To elucidate its involvement, we performed proteomic analysis of cerebrospinal fluid (CSF) from relapsing-remitting MS (RRMS) patients using two-dimensional difference gel electrophoresis (2D-DIGE). CHI3L1 emerged as the most upregulated protein in recurrent RRMS. ELISA confirmed significantly elevated CHI3L1 levels in recurrent RRMS and secondary progressive MS (SPMS) patients, with levels decreasing in steroid responders but increasing in non-responders. Immunohistochemistry of MS brain autopsies revealed CHI3L1 expression predominantly in mature oligodendrocytes. In an experimental autoimmune encephalomyelitis (EAE) model, CHI3L1 was highly expressed in the spinal cord, particularly in oligodendrocytes and microglia/macrophages. Functional studies demonstrated that recombinant CHI3L1 (rCHI3L1) protected oligodendrocytes from LPC-induced cell death by attenuating ER stress (GRP78, ORP150). Moreover, rCHI3L1 counteracted IFN-β- and PSL-mediated inhibition of oligodendrocyte differentiation. In microglia, rCHI3L1 suppressed LPS-induced proinflammatory markers (IL-1β, iNOS). In vivo, rCHI3L1 administration significantly mitigated EAE severity by reducing gliosis, demyelination, and axonal degeneration. These findings highlight CHI3L1 as a critical modulator of neuroinflammation and oligodendrocyte survival, positioning it as a promising therapeutic target for MS. Full article

Vitamin A (retinol) and its derivatives (retinoids) assume critical roles in neural development, cellular differentiation, axon elongation, programmed cell apoptosis and various fundamental cellular processes. Retinoids function by binding to specific nuclear receptors, such as retinoic acid receptors (RARs) and retinoid X receptors (RXRs), activating specific signalling pathways in the cells. The disruption of the retinoic acid signalling pathway can result in neuroinflammation, oxidative and ER stress and mitochondrial dysfunction and has been implicated in a wide range of neurodegenerative diseases. The present study explored the potential therapeutic application of our innovative CNS-permeable synthetic retinoid, Ellorarxine, for the treatment of neurodegenerative disorders in vitro. An MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium assay, lactate dehydrogenase (LDH) assay, enzyme-linked immunosorbent assay (ELISA), immunocytochemistry and immunofluorescence staining were performed. Ellorarxine increased Cyp26 and, selectively, RARβ protein expression in neurons, glia and microglia. Ellorarxine significantly reduced cell death (neurons, glia), increased mitochondrial viability (neurons), modulated cytokine release (microglia), and positively regulated cellular autophagy (neurons, glia, microglia). These results suggest that Ellorarxine is a promising drug candidate that should be further investigated in the treatment of neurodegenerative diseases. Full article

In homeostasis, the glial cells support pivotal functions, such as neuronal differentiation, neuroprotection, nutrition, drug metabolism, and immune response in the central nervous system (CNS). Among these cells, astrocytes and microglia have been highlighted due to their role in the pathogenesis of several diseases or due to their role in the defense against several insults (ex., chemicals, and pathogens). In Vitro cytological analysis of astrocytes and microglia has contributed to the understanding of the role of morphological changes in glial cells associated with a neuroprotective or neurotoxic phenotype. Currently, the main tools used for the investigation of glial cell morphology in culture are phase contrast microscopy or immunolabeling/fluorescence microscopy. However, generally, phase contrast microscopy does not generate images with high resolution and therefore does not contribute to visualizing a single cell morphology in confluent cell cultures. On the other hand, immunolabeling requires high-cost consumable antibodies, epifluorescence microscope or confocal microscope, and presents critical steps during the procedure. Therefore, identifying a fast, reproducible, low-cost alternative method that allows the evaluation of glial morphology is essential, especially for neuroscientists from low-income countries. This article aims to revise the use of Rosenfeld’s staining, as an alternative low-cost and easy-to-reproduce method to analyze astrocytic and microglial morphology in culture. Additionally, it shows Rosenfeld’s staining as a valuable tool to analyze changes in neural cell morphology in toxicological studies. Full article

Neuroinflammation is a complex immune response triggered by brain injury or pathological stimuli, and is highly exacerbated in neurodegenerative diseases. It plays a dual role in the central nervous system, promoting repair in acute stages while aggravating disease progression by contributing to neuronal loss, synaptic dysfunction, and glial dysregulation in chronic phases. Inflammatory responses are mainly orchestrated by microglia and infiltrated monocytes, which, when dysregulated, not only harm existing neurons, but also impair the survival and differentiation of neural stem and progenitor cells in the affected brain regions. Modulating neuroinflammation is crucial for harnessing its protective functions while minimizing its detrimental effects. Current therapeutic strategies focus on fine-tuning inflammatory responses through pharmacological agents, bioactive molecules, and stem cell-based therapies. These approaches aim to restore immune homeostasis, support neuroprotection, and promote regeneration in various neurological disorders. However, animal models sometimes fail to reproduce human-specific inflammatory responses in the brain. In this context, stem-cell-derived models provide a powerful tool to study neuroinflammatory mechanisms in a patient-specific and physiologically relevant context. These models facilitate high-throughput screening, personalized medicine, and the development of targeted therapies while addressing the limitations of traditional animal models, paving the way for more targeted and effective treatments. Full article