Search Results (1,343)

The sigma-1 receptor (S1R) is an endoplasmic reticulum (ER)-resident protein enriched at the mitochondria-associated ER membranes (MAMs) that supports ER homeostasis, preserves mitochondrial function, and enhances cell survival under stress. Disruptions of MAM integrity and prolonged ER stress are well-recognized pathological features of amyotrophic lateral sclerosis (ALS), contributing to motor neuron dysfunction and degeneration. In this study, we evaluated the protective effects of pridopidine, a highly selective and potent S1R agonist currently in clinical development for Huntington’s disease (HD) and ALS, using neural progenitor cells (NPCs) derived from induced pluripotent stem cells (iPSCs) from a patient with sporadic ALS. Exposure of ALS NPCs to the ER stressor tunicamycin increased the ER stress markers binding immunoglobulin protein (BiP) and C/EBP homologous protein (CHOP), disrupted mitochondrial membrane potential, upregulated expression of the mitochondrial apoptotic marker, BAX, increased caspase-3 activation, and reduced cell viability. Pridopidine significantly attenuated tunicamycin-induced BiP and CHOP expression in a biphasic, dose-dependent manner (with maximal efficacy at 1 µM), consistent with the typical pharmacology of S1R agonists. Pridopidine restored mitochondrial membrane potential, reduced mitochondrial apoptotic signaling, shown by decreased BAX expression and caspase-3 activation, and improved survival of ALS-NPCs under ER stress. Co-treatment with the selective S1R antagonist, NE-100, attenuated these effects, supporting an S1R-mediated mechanism of action for pridopidine. Together, these results demonstrate that S1R activation by pridopidine mitigates ER-stress-induced mitochondrial dysfunction and cell loss in ALS-NPCs, resulting in enhanced survival of NPCs supporting the therapeutic potential of pridopidine in ALS. Full article

Traumatic brain injury (TBI) represents a significant global health challenge with limited effective treatments. The secondary injury phase, characterized by persistent neuroinflammation, is a major contributor to long-term neurological deficits. Conventional therapies face substantial hurdles, including the blood–brain barrier (BBB), short therapeutic windows, and poor neuroregenerative capacity. Innovative biomaterials offer a promising platform to overcome these limitations by providing localized Drug Deliv., immunomodulation, and structural support for neural regeneration. This review outlines the pathological mechanisms of neuroinflammation and repair obstacles following TBI. It then systematically categorizes and discusses the mechanisms of various biomaterials—including natural, synthetic, nano-scale, composite, and intelligent materials—in modulating neuroinflammation. Furthermore, we elaborate on strategies for promoting neural repair, such as constructing regenerative scaffolds, delivering therapeutic agents (e.g., neurotrophic factors, stem cells, and exosomes), and remodeling the regenerative microenvironment. Special emphasis is placed on the emerging application of exosome delivery systems. Finally, we address the challenges in clinical translation and present future perspectives on smart materials, multi-modal systems, and personalized therapies, highlighting the transformative potential of biomaterials in TBI management. Full article

Animal studies have shown that early life exposure to general anesthetics may impair brain development. However, the implications of this phenomenon in human patients remain unclear. In this study, we use an induced pluripotent stem cell (iPSC)-derived human brain microphysiological system (bMPS) to investigate the effects of early sevoflurane (SEV) exposure on human brain development. Human iPSCs were cultured and differentiated into neural progenitor cells (NPCs) and then into bMPS. At week 8, bMPSs were exposed to 2.4% SEV for 4 h. Four weeks after exposure, immunofluorescence (IF), Western blotting (WB), and quantitative real-time polymerase chain reaction (qPCR) were conducted to evaluate the alteration of nerve cells in bMPS. After SEV exposure, the number of apoptotic cells increases, and the level of neural differentiation markers decreases. The ratios of mature neurons over NPCs and mature oligodendrocytes over oligodendrocyte progenitor cells (OPCs) are reduced, which leads to a reduction in myelination. SEV also impedes the development of astrocytes and synaptogenesis, especially the formation of excitatory synapses. Meanwhile, SEV increases the expression of molecules in the mammalian target of rapamycin (mTOR) signal pathway. In conclusion, early SEV exposure substantially disrupts the development of human brain tissue, and the mTOR signal pathway is likely to be involved in this alteration. Full article

Bisphenol A (BPA) has long been used in plastics, resins, and food packaging materials; however, extensive research has demonstrated its reproductive, developmental, and endocrine-disrupting effects. Consequently, BPA has been increasingly restricted and replaced with structural analogues. Among these, tetramethyl bisphenol F (TMBPF) has emerged as one of the most widely used substitutes, particularly in epoxy resins and food-can coatings. Although initially regarded as a safer alternative, accumulating evidence suggests that TMBPF may exert multiple toxicological effects, raising concerns about its potential developmental neurotoxicity. The present study aimed to investigate the neurodevelopmental effects of TMBPF using both in vitro and in vivo approaches. First, a developmental neurotoxicity assay employing Sox1−GFP mouse embryonic stem cells was used to evaluate cytotoxicity using the cell counting kit-8 assay and neural differentiation based on green fluorescent protein (GFP) fluorescence intensity. The results indicated developmental neurotoxic potential according to the established discrimination index. Subsequently, pregnant and lactating mice were exposed to TMBPF daily from gestational day 10.5 to postnatal day 20, and their offspring were assessed for behavioral performance as well as changes in the expression of neurodevelopment-related genes in the brain. Behavioral analyses encompassed multiple domains, including memory and learning, social behavior, anxiety-related responses, and spontaneous locomotor activity, suggesting alterations in these functional outcomes. Molecular analyses further demonstrated changes associated with dopaminergic and cholinergic signaling, synaptic plasticity, neuronal activity markers, neuropeptides, and inflammatory pathways. Collectively, these findings provide the first evidence in a mammalian model that maternal exposure to TMBPF may influence offspring neurodevelopment. These findings suggest potential implications for human exposure to TMBPF, particularly through food-contact materials, and warrant further mechanistic and dose–response studies. Full article

The key challenge in restoring neural function after spinal cord injury stems from a vicious cycle triggered by the collapse of the bioelectrical microenvironment at the injury site: an ‘electrical silence–neuronal degeneration–glial proliferation’ cascade that conventional therapies fail to reverse. This review systematically summarizes the pathological mechanisms of electrical microenvironment imbalance and its critical role in neural regeneration. Furthermore, current intervention strategies based on biomaterials are outlined: evolving from passive reconstruction of electrical pathways using conductive materials to proactive regulation of local electric fields through exogenous electrical stimulation, which activates key signaling pathways, such as voltage-gated calcium channels, and thereby promotes axonal regeneration, stem cell differentiation, and immune modulation. Although existing strategies face challenges in precision and biocompatibility, this review integrates multidisciplinary perspectives from neuroscience and biomaterials to establish a theoretical framework for designing precise, biocompatible electrically modulating biomaterials. Ultimately, we aim to advance spinal cord injury treatment from local electrical environment restoration toward a paradigm shift toward functional neural circuit reconstruction. Full article

Tooth development or odontogenesis is a complex morphogenetic process that requires tightly regulated interactions between the oral epithelium and mesenchyme of neural crest origin. In this narrative review, we compile existing knowledge regarding gene regulatory networks and epigenetic factors throughout tooth development from initiation to eruption. Signaling between the epithelium and mesenchyme is mediated by four conserved pathways—Wnt/β-catenin, bone morphogenetic protein (BMP), fibroblast growth factor (FGF), and Sonic hedgehog (Shh)—which operate iteratively and interact through extensive crosstalk at each developmental stage. Transcription factors, such as PAX9, MSX1, PITX2, and LEF1, interpret these signals to control cell fate decisions and differentiation. Epigenetic modifications, including DNA methylation, histone modifications, and microRNA-mediated regulation, provide additional layers of control that fine-tune gene expression programs. Unlike existing reviews that address these regulatory mechanisms separately, here we integrate signaling pathways, transcription factor networks, epigenetic regulation, human genetic disorders, dental stem cell biology, and recent single-cell transcriptomic insights into a unified framework. We discuss opportunities to apply developmental biology knowledge towards regenerative dentistry goals, including iPSC-derived dental models and spatially resolved multi-omics approaches, while acknowledging the considerable gap between preclinical findings and clinical applications. Full article

Major depressive disorder (MDD) lacks reliable laboratory tests for diagnosis and treatment monitoring, underscoring the need for robust molecular readouts in blood. Beyond symptom-based classification, MDD can also be viewed as a condition involving impaired homeostatic regulation across stress-responsive, immune, metabolic, and neural systems. Consistent with this perspective, altered intron retention (IR) patterns have been observed in peripheral blood in depression-related and treatment-response contexts, supporting the translational relevance of this RNA-processing layer to mood disorders. A key observation underpinning this review is that IR can function as a reversible, intervention-responsive readout of physiological state. In a pre-symptomatic stress-like state in klotho mutant mice (a premature-aging model), widespread IR increases revert toward a healthy pattern upon treatment, suggesting that IR is embedded in a controllable homeostatic layer. Against the backdrop of limited cross-cohort transferability of differential gene expression (DGE) signatures, we propose that IR provides a mechanistically grounded biomarker layer because it reports regulated RNA processing states rather than context-fragile abundance endpoints. We operationalize IR as a post-transcriptional “throttle” on effective gene output, with increased IR/detained intron (DI) states acting as a reversible brake and decreased IR acting as an accelerator that increases translation-competent mRNA supply. Mechanistic exemplars across immune, metabolic, and neuronal systems (e.g., IFNG, OGT, MAT2A, neuronal activity-triggered intron excision, and intron detention-mediated stemness/differentiation switching in adult neural stem cells) show that defined inputs can switch IR/DI states to tune output kinetics. Integrating these findings, we propose an “Intron Retention Homeostat” (IR-Homeostat) model in which cells sense deviations from physiological set points and implement feedback control of gene output through switchable IR/DI regulation. This framework positions IR not only as a robust state readout for stratification, treatment response prediction, and pharmacodynamic profiling, but also as a tractable entry point to identify the molecular sensors and mediators that couple homeostatic signals to RNA processing control. Full article

Background/Objectives: Adult neural stem cells retain the capacity to generate immature neuronal lineages; however, pharmacological approaches that robustly enhance neurogenic activity remain limited. To identify compounds with intrinsic activity under physiologically restrictive conditions, we aimed to screen for small molecules that promote neural stem cell proliferation in the absence of exogenous growth factors and are compatible with central nervous system drug discovery. Methods: We developed a human neural stem cell–based phenotypic screening cascade performed under growth factor–free conditions. Compound activity was evaluated in vitro by ATP-based proliferation assays, BrdU incorporation, and assessment of neurogenic marker analysis. In vivo neurogenic effects were assessed in adult rats by BrdU labeling and immunohistochemical analysis of BrdU/Nestin- and BrdU/DCX-positive cells in the subventricular zone and hippocampal subgranular zone, together with pharmacokinetic analysis to assess brain exposure. Results: Using this platform, we identified Lead-238 as a small-molecule that enhanced neural stem cell proliferation and neurogenic output in vitro. In vivo, Lead-238 increased neurogenic activity in the subventricular zone, as evidenced by elevated numbers of BrdU-positive, BrdU/DCX-positive, and BrdU/Nestin-positive cells, whereas no detectable effects were observed in the hippocampal subgranular zone. Lead-238 achieved sufficient brain exposure, and its neurogenic effects were not readily explained by established neurogenic pathways. Conclusions: These findings demonstrate that growth factor–free phenotypic screening using human neural stem cells is an effective approach for identifying compounds that enhance adult neurogenic activity and identify Lead-238 as a small molecule that increases neurogenic activity in the subventricular zone without detectable effects in the hippocampal subgranular zone. Full article

Glioblastoma (GBM) remains one of the most lethal cancers, and despite advancements in understanding its underlying molecular signature, effective therapeutics are still lacking. The multifaceted challenges of designing treatments for GBM are compounded by the inability to identify a definitive cell of origin, the understanding of which is crucial for developing impactful therapies and ultimately improving patient outcomes. High-resolution technologies, including single-cell and single-nucleus RNA sequencing, spatial transcriptomics, multi-omics, next generation glioma models, bioinformatics, and artificial intelligence are creating an important opportunity to comprehensively map the cellular origin of GBM and its evolutionary dynamics. Accumulating evidence support neural stem cells (NSCs) and oligodendrocyte precursor cells (OPCs) as primary candidates, providing critical insights into the ontogeny of GBM. This comprehensive review synthesizes current knowledge on the cellular origins of GBM and evaluates advanced methodologies, deepening our understanding of its development. Full article

The prevalence of Parkinson’s disease (PD) is projected to rise, stressing the urgency for disease-modifying therapies. Its complex pathophysiology, characterized by α-synuclein aggregation, mitochondrial dysfunction, oxidative stress, and chronic neuroinflammation, continues to complicate therapeutic development. Mounting evidence implicates neuroinflammation as both a driver and consequence of disease progression. This highlights the need to address both neuronal loss and the established dysfunctional microenvironment. Consequently, stem cell-based treatments have generated interest for their immunomodulatory, neuroprotective, and regenerative potential. However, therapeutic outcomes are strongly influenced by stem cell type and route of administration, which together determine whether effects are predominantly regenerative or restorative. In this review, we introduce a conceptual framework that situates stem cell therapies for PD along a regenerative–restorative continuum. Regenerative therapies include fetal ventral mesencephalic, embryonic, and induced pluripotent stem cells. When delivered intracerebrally, they aim to reconstruct dopaminergic circuitry through differentiation and engraftment. In contrast, restorative approaches include mesenchymal stem cells, which exert paracrine and immunomodulatory effects to promote neuroprotection and functional stabilization of the neuronal environment. Multilineage-differentiating stress-enduring cells and neural stem cells exhibit both regenerative and restorative features, to differing extents. This framework integrates mechanistic and clinical evidence that may help clarify distinctions across stem cell approaches and inform future translational development in PD. Full article

The unique ecological gradients of Xinjiang have fostered a rich reservoir of genetic resources in local sheep populations. However, the population genetic structure, adaptive mechanisms to extreme environments, and the genetic basis underlying key economic traits of these breeds remain poorly understood. To address this gap, we performed whole-genome resequencing of 140 individuals from seven indigenous sheep populations—Altay, Bayinbuluke, Kazakh, Kirgiz, Bashibai, Turpan Black, and Yemule White—identifying 18,700,507 high-quality SNPs. Genetic diversity analyses revealed that all populations exhibited comparable levels of genetic diversity, with modest variation across breeds, with Turpan Black sheep exhibiting the highest observed heterozygosity (Ho = 0.3110) and proportion of polymorphic sites, whereas Kirgiz sheep showed comparatively lower values. Population structure analyses consistently indicated that geographic isolation is the primary driver of genetic differentiation, with Kirgiz sheep from the Pamir Plateau in southern Xinjiang displaying the greatest genetic distance relative to northern Xinjiang populations. By integrating multiple selection signature detection methods—including F_ST, π ratio, and XP-CLR—we found that genes under selection in Kirgiz sheep were significantly enriched in biological pathways related to stem cell pluripotency regulation (e.g., BMPR1B), DNA repair (e.g., DDB2), and neural development, thereby elucidating their unique genetic adaptations to high-altitude environments. In contrast, Turpan Black sheep appear to cope with heat stress through mechanisms involving basal transcriptional regulation (e.g., GTF2I), maintenance of protein homeostasis (e.g., DNAJB14), and melanin biosynthesis (e.g., MC1R). Furthermore, comparative analysis of body size identified a suite of candidate genes associated with growth and development (e.g., CUX1, KIT), which are primarily involved in transcriptional regulation, protein kinase activity, and the ubiquitin-mediated proteolytic system, thereby revealing a multi-layered genetic regulatory network governing body conformation. Collectively, this study provides a comprehensive genomic framework for understanding the genetic structure, adaptive evolution, and molecular basis of economically important traits in indigenous sheep breeds from Xinjiang, offering valuable candidate targets for future functional validation and precision breeding programs. Full article

Lipid abnormalities have been observed in brain, cerebrospinal fluid (CSF), and blood in association with late-onset Alzheimer’s disease (LOAD). It is unknown which of these abnormalities are precursors to LOAD and which are concomitants of illness or its treatment. Inherent abnormalities can be identified in induced pluripotent stem cell (iPSC)-derived brain cells. These cells lack markers associated with aging and environmental exposures. The iPSC lines of patients with LOAD or healthy individuals were differentiated to astrocytes. Astrocytes are crucial to neural activity and health, and altered astrocyte functions are associated with LOAD pathology. Lipidomics analyses were performed on whole-cell and mitochondria-enriched fractions. Large reductions in cholesterol esters (CEs) and imbalances in fatty acids (FAs) were observed in LOAD-associated cells or their mitochondria. There were only modest differences in other lipid classes, including membrane structural lipids. The findings identify abnormalities in CEs, as well as in FAs, as inherent abnormalities and likely precursors to LOAD. These differences implicate mechanisms contributing to disease pathogenesis. Further study may lead to early interventions to prevent or delay LOAD. Full article

Dogs represent a promising animal model for analyzing human neurodegenerative diseases, owing to their similarities to humans in nervous system architecture and behavioral phenotypes. Neural stem cells (NSCs) serve as a highly valuable in vitro experimental model for investigating neurogenesis, neurodegenerative disease pathogenesis, and neural molecular biology; however, studies on immortalized canine neural stem cell lines remain scarce. Herein, we successfully established an immortalized canine hippocampal neural stem cell line that can be continuously passaged in vitro via SV40 large T antigen (SV40LT) viral infection and subsequent cellular transformation. Both the immortalized NSCs and their normal parental counterparts differentiated into neuronal and glial lineages under induced differentiation conditions. Normal canine hippocampal NSCs can be passaged for no more than 10 generations, whereas the immortalized line can be passaged indefinitely while maintaining a normal karyotype. This immortalized canine hippocampal NSC line can act as a critical experimental tool for future research into neural differentiation mechanisms and stem cell-derived therapeutic strategies for neurological disorders in dogs. Full article

Glioblastoma (GBM) is an aggressive human malignancy. Recent advances in GBM research have highlighted innovative therapeutic approaches, including the use of small molecules that eliminate GBM in mouse models. However, there are few reports on the restoration of lost neuronal functions in patients. Considering that GBM contains GBM-initiating cells (GICs) with characteristics of both cancer and neural stem cells, we investigated whether GICs could be redirected toward non-tumorigenic neurons to support the preservation of neural function in the brain with GBM. We demonstrated that the neuronal differentiation inducer Isoxazole 9 (ISX9) effectively induced GICs to differentiate into neurons, accompanied by significant changes in their gene expression profiles. The sequential application of ISX9 and the DHODH inhibitor brequinar (BRQ), which successfully eradicated undifferentiated GICs, not only promoted neuronal differentiation but also inhibited GIC tumorigenesis in the mouse brain, leading to prolonged survival and preservation of motor function in tumor-bearing mice. Furthermore, pathological analysis revealed that this combination not only reduced the size of GIC brain tumors but also facilitated the formation of synapse-like structural contacts between GIC-derived cells and host mouse neurons, suggesting remodeling of the tumor–neural interface within the tumor-developed area. Collectively, these findings suggest that the modulation of tumorigenic GIC differentiation may represent a strategy to preserve neural circuit integrity within the tumor-bearing brain. Full article

Mesenchymal stem cells (MSCs) sense biophysical cues from their microenvironment, which regulate cytoskeletal organization and the nuclear–cytoplasmic distribution of the mechanotransducer Yes-associated protein (YAP), thereby shaping cellular behavior. Prolonged ex vivo culture on non-physiologically rigid substrates induces persistent nuclear YAP localization, a phenomenon often referred to as mechanical memory. We therefore examined whether transient epigenetic modulation could modulate YAP subcellular localization in human bone marrow-derived MSCs. Treatment with the DNA methyltransferase inhibitor 5-azacitidine (5-Aza) shifted YAP localization toward the cytoplasm in MSCs, without overt changes in pluripotency marker expression or neural differentiation capacity. RNA sequencing revealed broad down-regulation of extracellular matrix (ECM)-related genes following 5-Aza treatment. Independent suppression of ECM production via TGF-β signaling similarly promoted cytoplasmic YAP localization. When subsequently transferred to soft substrates, 5-Aza–treated MSCs restored YAP relocalization despite prior expansion on stiff surfaces. Together, these findings suggest that transient 5-Aza treatment can partially alleviate mechanically induced YAP regulation associated with mechanical memory. Thus, simple and transient administration of 5-Aza may offer a practical means to improve the quality of MSCs during ex vivo expansion for cell-based therapies. Full article