Search Results (86)

Heparan sulfate proteoglycans (HSPGs) within the neuronal niche are expressed during brain development, contributing to multiple aspects of neurogenesis, yet their roles in glial lineage commitment remain elusive. This study utilised three human cell models expanded under basal culture conditions followed by media-induced lineage induction to identify a reproducible and robust model of gliogenesis. SH-SY5Y human neuroblastoma cells (neuronal control), ReNcell CX human neural progenitor cells (astrocyte inductive) and ReNcell VM human neural progenitor (mixed neural induction) models were examined. The cultures were characterised during basal and inductive states via Q-PCR, Western Blotting, immunocytochemistry (ICC) and calcium signalling activity analyses. While the ReNcell lines did not produce fully mature or homogeneous astrocyte cultures, the ReNcell CX cultures most closely resembled an astrocytic phenotype with ReNcell VM cells treated with platelet-derived growth factor (PDGF) biased toward an oligodendrocyte lineage. The glycated variant of surface-bound glypican-2 (GPC2) was found to be associated with lineage commitment, with GPC6 and 6-O HS sulfation upregulated in astrocyte lineage cultures. Syndecan-3 (SDC3) emerged as a lineage-sensitive proteoglycan, with its cytoplasmic domain enriched in progenitor-like states and lost upon differentiation, supporting a role in maintaining neural plasticity. Conversely, the persistence of transmembrane-bound SDC3 in astrocyte cultures suggest continued involvement in extracellular signalling and proteoglycan secretion, demonstrated by increased membrane-bound HS aggregates. This data supports HSPGs and HS GAGs as human neural lineage differentiation and specification markers that may enable better isolation of human neural lineage-specific cell populations and improve our understanding of human neurogenesis. Full article

Glial cells, once considered mere support for neurons, have emerged as key players in brain function across vertebrates. The historical study of glia dates to the 19th century with the identification of ependymal cells and astrocytes, followed by the discovery of oligodendrocytes and microglia. While neurocentric perspectives overlooked glial functions, recent research highlights their essential roles in neurodevelopment, synapse regulation, brain homeostasis, and neuroimmune responses. In teleost fish, a group comprising over 32,000 species, glial cells exhibit unique properties compared to their mammalian counterparts. Thus, the aim of this review is synthesizing the current literature on fish glial cells, emphasizing their evolutionary significance, diversity, and potential as models for understanding vertebrate neurobiology. Microglia originate from both yolk sac cells and hematopoietic stem cells, forming distinct populations with specialized functions in the adult brain. Neural stem cells, including radial glial cells (RGCs) and neuroepithelial cells, remain active throughout life, supporting continuous neuro- and gliogenesis, a phenomenon far more extensive than in mammals. Ependymocytes line brain ventricles and show structural variability, with some resembling quiescent progenitor cells. Astrocytes are largely absent in most fish species. However, zebrafish exhibit astrocyte-like glial cells which show some structural and functional features in common with mammalian astrocytes. Oligodendrocytes share conserved mechanisms with mammals in myelination and axon insulation. 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

Background/Objectives: Autism Spectrum Disorder (ASD) is a complex neurodevelopmental condition marked by challenges in social communication, restricted interests, and repetitive behaviors. Recent studies highlight the crucial roles of neuroglial cells—astrocytes, microglia, and oligodendrocytes—in synaptic function, neural connectivity, and neuroinflammation. These findings offer a fresh perspective on ASD pathophysiology. This review synthesizes current knowledge on neuroglial dysfunction in ASD, emphasizing its role in pathophysiological mechanisms, genetic influences, and potential therapeutic strategies. Methods: We conducted a comprehensive literature review, integrating insights from neuroscience, molecular biology, and clinical studies. Special focus was given to glial-mediated neuroinflammatory mechanisms, synaptic plasticity regulation, and the impact of genetic mutations on neuroglial signaling and homeostasis. Results: Neuroglial dysfunction in ASD is evident in abnormal synaptic pruning by microglia, impaired astrocytic glutamate regulation, and defective oligodendrocyte-driven myelination, which collectively disrupt neuronal architecture. Emerging therapies targeting these pathways, including anti-inflammatory drugs, microglial modulators, and cell-based approaches, show promise in alleviating key ASD symptoms. Additionally, advanced interventions such as gene editing and glial progenitor therapy present opportunities to correct underlying neuroglial dysfunction. Conclusions: This review establishes a comprehensive framework for understanding neuroglial contributions to ASD. By integrating insights from diverse disciplines, it enhances our understanding of ASD pathophysiology and paves the way for novel therapeutic strategies targeting neuroglial pathways. Full article

Our recent study revealed that continuous prenatal low-dose-rate irradiation did not induce cellular changes in the dentate gyrus of the hippocampus in male B6C3F1 mice exposed to gamma rays during prenatal development. However, changes in body weight, body mass index (BMI), locomotor ability, and mRNA and miRNA expressions in the hippocampus and blood were observed. To investigate potential sex differences in the effects of prenatal gamma irradiation, we conducted a parallel study on female B6C3F1 mice. The results showed significant reductions in the weight of the lungs and left kidney in prenatally irradiated female offspring, accompanied by significantly increased fat deposits in the mesentery, retroperitoneal, and left perigonadal areas. Despite these systemic changes, no cellular alterations were observed in the subgranular zone (immature neurons) or the hilus of the dentate gyrus (mature neurons and glial cells, including astrocytes, microglia, and oligodendrocyte progenitor cells). However, significant increases in hippocampal mRNA expression were detected for genes such as H2bc24, Fos, Cd74, Tent5a, Traip, and Sap25. Conversely, downregulation of mRNAs Inpp5j and Gdf3 was observed in whole blood. A Venn diagram highlighted the differential expression of two mRNAs, Ttn and Slc43a3, between the hippocampus and whole blood. Comparisons between prenatally irradiated male and female B6C3F1 mice revealed sex-specific differences. In whole blood, 4 mRNAs (Scd1, Cd59b, Vmn1r58, and Gm42427) and 1 miRNA (mmu-miR-8112) exhibited differential expression. In the hippocampus, 12 mRNAs and 2 novel miRNAs were differentially expressed between the sexes. qRT-PCR analysis validated the upregulation of H2bc24, Fos, Cd74, and Tent5a in the female hippocampus. These gene expression changes may be associated with the increased fat deposition observed following chronic low-dose-rate gamma irradiation exposure. This study underscores the importance of investigating sex-specific biological responses to prenatal gamma irradiation and highlights potential molecular pathways linked to observed physiological changes. Full article

The ultrastructural organization of the nuclei of the tegmental region in juvenile chum salmon (Oncorhynchus keta) was examined using transmission electron microscopy (TEM). The dorsal tegmental nuclei (DTN), the nucleus of fasciculus longitudinalis medialis (NFLM), and the nucleus of the oculomotor nerve (NIII) were studied. The ultrastructural examination provided detailed ultrastructural characteristics of neurons forming the tegmental nuclei and showed neuro–glial relationships in them. Neurons of three size types with a high metabolic rate, characterized by the presence of numerous mitochondria, polyribosomes, Golgi apparatus, and cytoplasmic inclusions (vacuoles, lipid droplets, and dense bodies), were distinguished. It was found that large interneurons of the NFLM formed contacts with protoplasmic astrocytes. Excitatory synaptic structures were identified in the tegmentum and their detailed characteristic are provided for the first time. Microglia-like cells were found in the NIII. The ultrastructural characteristics of neurogenic zones of the tegmentum of juvenile chum salmon were also determined for the first time. In the neurogenic zones of the tegmentum, adult-type neural stem progenitor cells (aNSPCs) corresponding to cells of types III and IVa Danio rerio. In the neurogenic zones of the tegmentum, neuroepithelial-like cells (NECs) corresponding to cells previously described from the zebrafish cerebellum were found and characterized. In the tegmentum of juvenile chum salmon, patterns of paracrine neurosecretion were observed and their ultrastructural characteristics were recorded. Patterns of apoptosis in large neurons of the tegmentum were examined by TEM. Using immunohistochemical (IHC) labeling of the brain lipid-binding protein (BLBP) and aromatase B (AroB), patterns of their expression in the tegmentum of intact animals and in the post-traumatic period after acute injury to the medulla oblongata were characterized. The response to brainstem injury in chum salmon was found to activate multiple signaling pathways, which significantly increases the BLBP and AroB expression in various regions of the tegmentum and valvula cerebelli. However, post-traumatic patterns of BLBP and AroB localizations are not the same. In addition to a general increase in BLBP expression in the tegmental parenchyma, BLBP overexpression was observed in the rostro-lateral tegmental neurogenic zone (RLTNZ), while AroB expression in the RLTNZ was completely absent. Another difference was the peripheral overexpression of AroB and the formation of dense reactive clusters in the ventro-medial zone of the tegmentum. Thus, in the post-traumatic period, various pathways were activated whose components were putative candidates for inducers of the “astrocyte-like” response in the juvenile chum salmon brain that are similar to those present in the mammalian brain. In this case, BLBP acted as a factor enhancing the differentiation of both radial glia and neurons. Estradiol from AroB+ astrocytes exerted paracrine neuroprotective effects through the potential inhibition of inflammatory processes. These results indicate a new role for neuronal aromatization as a mechanism preventing the development of neuroinflammation. Moreover, our findings support the hypothesis that BLBP is a factor enhancing neuronal and glial differentiation in the post-traumatic period in the chum salmon brain. Full article

Amniotic fluid is a complex and dynamic biological matrix that surrounds the fetus during the pregnancy. From this fluid, is possible to isolate various cell types with particular interest directed towards stem cells (AF-SCs). These cells are highly appealing due to their numerous potential applications in the field of regenerative medicine for tissues and organs as well as for treating conditions such as traumatic or ischemic injuries to the nervous system, myocardial infarction, or cancer. AF-SCs, when subcultured in the presence of basic Fibroblast Growth Factor (bFGF), have been shown to survive and migrate when transplanted into the striatum of the rat brain, exhibiting behavior characteristics of neuronal/glial progenitor cells. In this work, we performed an electrophysiological characterization to ascertain the propensity of AF-SCs to differentiate into glial and neuronal cells by bFGF. By using patch clamp technique we characterized a fibroblast-like morphology that display a barium-sensitive inward-rectifying potassium current (Kir) and calcium-activated potassium currents (KCa). The electrophysiological and calcium dynamics of histamine, a marker of undifferentiated neural progenitors, was further studied. Histamine promoted intracellular calcium increase by Fura-2 recording and calcium-activated potassium current activation with a similar temporal profile in AF-SC. The data presented in this paper ultimately confirm the expression in AF-SCs of the Kir and KCa currents, also showing regulation by endogenous stimuli such as histamine for the latter. Full article

Background: Reactive astrogliosis and microgliosis are coordinated responses to CNS insults and are pathological hallmarks of traumatic brain injury (TBI). In these conditions, persistent reactive gliosis can impede tissue repopulation and limit neurogenesis. Thus, modulating this phenomenon has been increasingly recognized as potential therapeutic approach. Methods: In this study, we investigated the potential of the flavonoid agathisflavone to modulate astroglial and microglial injury responses and promote neurogenesis in the subventricular zone (SVZ) neurogenic niche. Agathisflavone, or the vehicle in controls, was administered directly into the lateral ventricles in postnatal day (P)8-10 mice by twice daily intracerebroventricular (ICV) injections for 3 days, and brains were examined at P11. Results: In the controls, ICV injection caused glial reactivity along the needle track, characterised immunohistochemically by increased astrocyte expression of glial fibrillary protein (GFAP) and the number of Iba-1+ microglia at the lesion site. Treatment with agathisflavone decreased GFAP expression, reduced both astrocyte reactivity and the number of Iba-1⁺ microglia at the core of the lesion site and the penumbra, and induced a 2-fold increase on the ratio of anti-inflammatory CD206+ to pro-inflammatory CD16/32+ microglia. Notably, agathisflavone increased the population of neuroblasts (GFAP+ type B cells) in all SVZ microdomains by up to double, without significantly increasing the number of neuronal progenitors (DCX+). Conclusions: Although future studies should investigate the underlying molecular mechanisms driving agathisflavone effects on microglial polarization and neurogenesis at different timepoints, these data indicate that agathisflavone could be a potential adjuvant treatment for TBI or central nervous system disorders that have reactive gliosis as a common feature. Full article

In mice, the fetal brain is dependent upon the placenta for factors that guide its early development. This linkage between the two organs has given rise to the term, the placenta–brain axis. A similar interrelationship between the two organs may exist in humans. We hypothesize that extracellular vesicles (EVs) released from placental trophoblast (TB) cells transport small RNA and other informational biomolecules from the placenta to the brain where their contents have pleiotropic effects. Here, EVs were isolated from the medium in which human trophoblasts (TBs) had been differentiated in vitro from induced pluripotent stem cells (iPSC) and from cultured iPSC themselves, and their small RNA content analyzed by bulk RNA-seq. EVs derived from human TB cells possess unique profiles of miRs, including hsa-miR-0149-3p, hsa-302a-5p, and many long non-coding RNAs (lncRNAs) relative to EVs isolated from parental iPSC. These miRs and their mRNA targets are enriched in neural tissue. Human neural progenitor cells (NPCs), generated from the same iPSC, were exposed to EVs from either TB or iPSC controls. Both sets of EVs were readily internalized. EVs from TB cells upregulate several transcripts in NPCs associated with forebrain formation and neurogenesis; those from control iPSC upregulated a transcriptional phenotype that resembled glial cells more closely than neurons. These results shed light on the possible workings of the placenta–brain axis. Understanding how the contents of small RNA within TB-derived EVs affect NPCs might yield new insights, possible biomarkers, and potential treatment strategies for neurobehavioral disorders that originate in utero, such as autism spectrum disorders (ASDs). Full article

Agathisflavone is a flavonoid that exhibits anti-inflammatory and anti-oxidative properties. Here, we investigated the neuroprotective effects of agathisflavone on central nervous system (CNS) neurons and glia in the cerebellar slice ex vivo model of neonatal ischemia. Cerebellar slices from neonatal mice, in which glial fibrillary acidic protein (GFAP) and SOX10 drive expression of enhanced green fluorescent protein (EGFP), were used to identify astrocytes and oligodendrocytes, respectively. Agathisflavone (10 μM) was administered preventively for 60 min before inducing ischemia by oxygen and glucose deprivation (OGD) for 60 min and compared to controls maintained in normal oxygen and glucose (OGN). The density of SOX-10⁺ oligodendrocyte lineage cells and NG2 immunopositive oligodendrocyte progenitor cells (OPCs) were not altered in OGD, but it resulted in significant oligodendroglial cell atrophy marked by the retraction of their processes, and this was prevented by agathisflavone. OGD caused marked axonal demyelination, determined by myelin basic protein (MBP) and neurofilament (NF70) immunofluorescence, and this was blocked by agathisflavone preventative treatment. OGD also resulted in astrocyte reactivity, exhibited by increased GFAP-EGFP fluorescence and decreased expression of glutamate synthetase (GS), and this was prevented by agathisflavone pretreatment. In addition, agathisflavone protected Purkinje neurons from ischemic damage, assessed by calbindin (CB) immunofluorescence. The results demonstrate that agathisflavone protects neuronal and myelin integrity in ischemia, which is associated with the modulation of glial responses in the face of ischemic damage. Full article

In zebrafish, like in mammals, radial glial cells (RGCs) can act as neural progenitors during development and regeneration in adults. However, the heterogeneity of glia subpopulations entails the need for different specific markers of zebrafish glia. Currently, fluorescent protein expression mediated by a regulatory element from the glial fibrillary acidic protein (gfap) gene is used as a prominent glia reporter. We now expand this tool by demonstrating that a regulatory element from the mouse Fatty acid binding protein 7 (Fabp7) gene drives reliable expression in fabp7-expressing zebrafish glial cells. By using three different Fabp7 regulatory element-mediated fluorescent protein reporter strains, we reveal in double transgenic zebrafish that progenitor cells expressing fluorescent proteins driven by the Fabp7 regulatory element give rise to radial glia, oligodendrocyte progenitors, and some neuronal precursors. Furthermore, Bergmann glia represent the almost only glial population of the zebrafish cerebellum (besides a few oligodendrocytes), and the radial glia also remain in the mature cerebellum. Fabp7 regulatory element-mediated reporter protein expression in Bergmann glia progenitors suggests their origin from the ventral cerebellar proliferation zone, the ventricular zone, but not from the dorsally positioned upper rhombic lip. These new Fabp7 reporters will be valuable for functional studies during development and regeneration. Full article

Zika virus (ZIKV), a mosquito-borne flavivirus, is prominently associated with microcephaly in babies born to infected mothers as well as Guillain-Barré Syndrome in adults. Each cell type infected by ZIKV—neuronal cells (radial glial cells, neuronal progenitor cells, astrocytes, microglia cells, and glioblastoma stem cells) and non-neuronal cells (primary fibroblasts, epidermal keratinocytes, dendritic cells, monocytes, macrophages, and Sertoli cells)—displays its own characteristic changes to their cell physiology and has various impacts on disease. Here, we provide an in-depth review of the ZIKV life cycle and its cellular targets, and discuss the current knowledge of how infections cause neuropathologies, as well as what approaches researchers are currently taking to further advance such knowledge. A key aspect of ZIKV neuropathogenesis is virus-induced neuronal apoptosis via numerous mechanisms including cell cycle dysregulation, mitochondrial fragmentation, ER stress, and the unfolded protein response. These, in turn, result in the activation of p53-mediated intrinsic cell death pathways. A full spectrum of infection models including stem cells and co-cultures, transwells to simulate blood–tissue barriers, brain-region-specific organoids, and animal models have been developed for ZIKV research. Full article

Polyamine (PA) spermidine (SPD) plays a crucial role in aging. Since SPD accumulates in glial cells, particularly in Müller retinal cells (MCs), the expression of the SPD-synthesizing enzyme spermidine synthase (SpdS) in Müller glia and age-dependent SpdS activity are not known. We used immunocytochemistry, Western blot (WB), and image analysis on rat retinae at postnatal days 3, 21, and 120. The anti-glutamine synthetase (GS) antibody was used to identify glial cells. In the neonatal retina (postnatal day 3 (P3)), SpdS was expressed in almost all progenitor cells in the neuroblast. However, by day 21 (P21), the SpdS label was pronouncedly expressed in multiple neurons, while GS labels were observed only in radial Müller glial cells. During early cell adulthood, at postnatal day 120 (P120), SpdS was observed solely in ganglion cells and a few other neurons. Western blot and semi-quantitative analyses of SpdS labeling showed a dramatic decrease in SpdS at P21 and P120 compared to P3. In conclusion, the redistribution of SpdS with aging indicates that SPD is first synthesized in all progenitor cells and then later in neurons, but not in glia. However, MCs take up and accumulate SPD, regardless of the age-associated decrease in SPD synthesis in neurons. Full article

The pathophysiology of nonketotic hyperglycinemia (NKH), a rare neuro-metabolic disorder associated with severe brain malformations and life-threatening neurological manifestations, remains incompletely understood. Therefore, a valid human neural model is essential. We aimed to investigate the impact of GLDC gene variants, which cause NKH, on cellular fitness during the differentiation process of human induced pluripotent stem cells (iPSCs) into iPSC-derived astrocytes and to identify sustainable mechanisms capable of overcoming GLDC deficiency. We developed the GLDC27-FiPS4F-1 line and performed metabolomic, mRNA abundance, and protein analyses. This study showed that although GLDC27-FiPS4F-1 maintained the parental genetic profile, it underwent a metabolic switch to an altered serine–glycine–one-carbon metabolism with a coordinated cell growth and cell cycle proliferation response. We then differentiated the iPSCs into neural progenitor cells (NPCs) and astrocyte-lineage cells. Our analysis showed that GLDC-deficient NPCs had shifted towards a more heterogeneous astrocyte lineage with increased expression of the radial glial markers GFAP and GLAST and the neuronal markers MAP2 and NeuN. In addition, we detected changes in other genes related to serine and glycine metabolism and transport, all consistent with the need to maintain glycine at physiological levels. These findings improve our understanding of the pathology of nonketotic hyperglycinemia and offer new perspectives for therapeutic options. Full article

Internal granular progenitors (IGPs) in the developing cerebellar cortex of ferrets differentiate towards neural and glial lineages. The present study tracked IGPs that proliferated in response to valproic acid (VPA) to determine their fate during cerebellar cortical histogenesis. Ferret kits were used to administer VPA (200 μg/g body weight) on postnatal days 6 and 7. EdU and BrdU were injected on postnatal days 5 and 7, respectively, to label the post-proliferative and proliferating cells when exposed to VPA. At postnatal day 20, when the external granule layer was most expanded, EdU- and BrdU-single-labeled cells were significantly denser in the inner granular layer of VPA-exposed ferrets than in controls. No EdU- or BrdU-labeling was found in Purkinje cells and molecular layer interneurons. Significantly higher percentages of NeuN and Pax6 immunostaining in VPA-exposed ferrets revealed VPA-induced differentiation of IGPs towards granular neurons in BrdU-single-labeled cells. In contrast, both EdU- and BrdU-single-labeled cells exhibited significantly greater percentages of PCNA immunostaining, which appeared in immature Bergman glia, in the internal granular layer of VPA-exposed ferrets. These findings suggest that VPA affects the proliferation of IGPs to induce differentiative division towards granular neurons as well as post-proliferative IGPs toward differentiation into Bergmann glia. Full article