Oligodendrocyte Transcription Factor Research Articles

Prognostic significance of oligodendrocyte transcription factor 2 expression in glioma patients: A systematic review and meta-analysis.

Gliomas are the most common primary central nervous system neoplasm. Despite recent advances in the diagnosis and treatment of gliomas, patient prognosis remains dismal. Therefore, it is imperative to identify novel diagnostic biomarkers and therapeutic targets of glioma to effectively improve treatment outcomes. To investigate the association between oligodendrocyte transcription factor 2 (Olig2) expression and the outcomes of glioma patients. The PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure databases were searched for studies (published up to October 2023) that investigated the relationship between Olig2 expression and prognosis of glioma patients. The quality of the studies was assessed using the Newcastle Ottawa Scale. Data analyses were performed using Stata Version 12.0 software. A total of 1205 glioma patients from six studies were included in the meta-analysis. High Olig2 expression was associated with better outcomes in glioma patients [hazard ratio (HR): 0.81; 95% (confidence interval) CI: 0.51-1.27; P = 0.000]. Furthermore, the results of subgroup meta-analysis showed that high expression of Olig2 was associated with poor overall survival in European patients (HR: 1.34; 95%CI: 0.79-2.27) and better prognosis in Asian patients (HR: 0.43; 95%CI: 0.22-0.84). The sensitivity analysis showed that no single study had a significant effect on pooled HR, and there was also no indication of publication bias according to the Egger's and Begger's P value test or funnel plot test. High Olig2 expression may have a positive impact on the prognosis of glioma patients, and should be investigated further as a prognostic biomarker and therapeutic target for glioma.

Metformin attenuates white matter injury in neonatal mice through activating NRF2/HO-1/NF-κB pathway

White matter injury (WMI) is a major form of brain injury that occurs in preterm infants and develops into lifelong disabilities, including cerebral palsy, impaired cognitive function, and psychiatric disorders. Metformin (MET) has been reported to have neuroprotective effects. However, whether MET is responsible for neuroprotection against WMI remains unclear. In this study, we established a WMI model in neonatal mice to explore the neuroprotective effects of MET and attempted to elucidate its potential mechanisms. Our results showed that MET increased the expression of myelin basic protein (MBP), oligodendrocyte transcription factor 2 (Olig2), and CC1, improved the thickness and density of the myelin sheath, and reduced oxidative stress and microglial infiltration after chronic hypoxia induction. Moreover, MET improved memory, learning, and motor abilities as well as relieved anxiety-like behaviors in mice with WMI. These protective effects of MET may involve the upregulation of the nuclear factor erythroid 2-related factor 2 (NRF2)/heme oxygenase-1(HO-1)/NF-κB pathway related protein expressions. In addition, the NRF2 inhibitor ML385 could significantly reverse the effects of MET. In conclusion, this study suggested that MET attenuated chronic hypoxia-induced WMI through activating the NRF2/HO-1/NF-κB pathway, indicating that MET might be a promising therapeutic option for WMI.

Targeting the PAC1 receptor mitigates degradation of myelin and synaptic markers and diminishes locomotor deficits in the cuprizone demyelination model.

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system with a strong neuroinflammatory component. Current treatments principally target the immune system but fail to preserve long-term myelin health and do not prevent neurological decline. Studies over the past two decades have shown that the structurally related neuropeptides VIP and PACAP (vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide, respectively) exhibit pronounced anti-inflammatory activities and reduce clinical symptoms in MS disease models, largely via actions on their bivalent VIP receptor type 1 and 2. Here, using the cuprizone demyelination model, we demonstrate that PACAP and VIP, and strikingly the PACAP-selective receptor PAC1 agonist maxadilan, prevented locomotor deficits in the horizontal ladder and open field tests. Moreover, only PACAP and maxadilan were able to prevent myelin deterioration, as assessed by a reduction in the expression of the myelin markers proteolipid protein 1, oligodendrocyte transcription factor 2, quaking-7 (APC) and Luxol Fast Blue staining. Furthermore, PACAP and maxadilan (but not VIP), prevented striatal synaptic loss and diminished astrocyte and microglial activation in the corpus callosum of cuprizone-fed mice. Invitro, PACAP or maxadilan prevented lipopolysaccharide (LPS)-induced polarisation of primary astrocytes at 12-24 h, an effect that was not seen with maxadilan in LPS-stimulated microglia. Taken together, our data demonstrates for the first time that PAC1 agonists provide distinctive protective effects against white matter deterioration, neuroinflammation and consequent locomotor dysfunctions in the cuprizone model. The results indicate that targeting the PAC1 receptor may provide a path to treat myelin-related diseases in humans.

Usp7 Regulates Glial Lineage Cell-Specific Transcription Factors by Modulating Histone H2B Monoubiquitination.

Histone H2B monoubiquitination (H2Bub1) is a dynamic posttranslational modification which are linked to DNA damage and plays a key role in a wide variety of regulatory transcriptional programs. Cancer cells exhibit a variety of epigenetic changes, particularly any aberrant H2Bub1 has frequently been associated with the development of tumors. Nevertheless, our understanding of the mechanisms governing the histone H2B deubiquitination and their associated functions during stem cell differentiation remain only partially understood. In this study, we wished to investigate the role of deubiquitinating enzymes (DUBs) on H2Bub1 regulation during stem cell differentiation. In a search for potential DUBs for H2B monoubiquitination, we identified Usp7, a ubiquitin-specific protease that acts as a negative regulator of H2B ubiquitination during the neuronal differentiation of mouse embryonic carcinoma cells. Loss of function of the Usp7 gene by a CRISPR/Cas9 system during retinoic acid-mediated cell differentiation contributes to the increase in H2Bub1. Furthermore, knockout of the Usp7 gene particularly elevated the expression of neuronal differentiation related genes including astryocyte-specific markers and oligodendrocyte-specific markers. In particular, glial lineage cell-specific transcription factors including oligodendrocyte transcription factor 2, glial fibrillary acidic protein, and SRY-box transcription factor 10 was significantly upregulated during neuronal differentiation. Thus, our findings suggest a novel role of Usp7 in gliogenesis in mouse embryonic carcinoma cells.

Comparative transcriptomic profiling reveals a role for Olig1 in promoting axon regeneration

The regenerative potential of injured axons displays considerable heterogeneity. However, the molecular mechanisms underlying the heterogeneity have not been fully elucidated. Here, we establish a method that can separate spinal motor neurons (spMNs) with low and high regenerative capacities and identify a set of transcripts revealing differential expression between two groups of neurons. Interestingly, oligodendrocyte transcription factor 1 (Olig1), which regulates the differentiation of various neuronal progenitors, exhibits recurrent expression in spMNs with enhanced regenerative capabilities. Furthermore, overexpression of Olig1 (Olig1 OE) facilitates axonal regeneration in various models, and down-regulation or deletion of Olig1 exhibits an opposite effect. By analyzing the overlapped differentially expressed genes after expressing individual Olig factor and functional validation, we find that the role of Olig1 is at least partially through the neurite extension factor 1 (Nrsn1). We therefore identify Olig1 as an intrinsic factor that promotes regenerative capacity of injured axons.

Sepsis-induced inflammatory demyelination in medullary visceral zone and cholinergic anti-inflammatory pathway: Insights from a Rat's model study

BackgroundOur previous studies have demonstrated that the activated Cholinergic Anti-inflammatory Pathway (CAP) effectively suppresses systemic inflammation and immunity in early sepsis. Some parameters of Heart Rate Variability (HRV) could be used to reflect the regulatory activity of CAP. However, in the early stages of severe sepsis of some patients, the inflammatory storm can still result in multiple organs dysfunction and even death, suggesting they lose CAP's modulation ability. Since CAP is part of the vagus nerve and is directly innervated by the Medullary Visceral Zone (MVZ), we can reasonably concluded that pathological changes induced by MVZ's neuroinflammation should be responsible for CAP's dysfunction in modulating systemic inflammation in early sepsis. MethodsWe conducted two independent septic experiments, the sepsis model rats were prepared by cecum ligation and puncture (CLP) method. In the first experiment, A total of 64 adult male Sprague-Dawley rats were included. Under the condition of sepsis and CAP's pharmacological activation or blockade, we investigated the MVZ's pathological changes, the functional state of key neurons including catecholaminergic and cholinergic neurons, key genes' expression such as Oligodendrocyte Transcription Factor 2 (Olig-2) mRNA, glial fibrillary acidic protein (GFAP) mRNA, and matrix metalloprotein (MMP) −9 mRNA, and CAP's activities reflected by HRV. The second experiment involved in 56 rats, through central anti-inflammation by feeding with 10 mg/ml minocycline sucrose solution as the only water source, or right vagus transection excepting for central anti-inflammation as a mean of the CAP's functional cancel, we confirmed that the neuroinflammation in MVZ affected systemic inflammation through CAP in sepsis. ResultsIn the first experiment, cholinergic and catecholaminergic neurons showed significant apoptosis with reduced expressions of TH, but the expression of CHAT remained relatively unaffected in MVZ in sepsis. HRV parameters representing the tone of the vagus nerve, such as SDNN, RMSSD, HF, SD1, and SD2, did not show significant differences among the three Septic Groups, although they all decreased significantly compared to the Control Group. The expressions of GFAP mRNA and MMP-9 mRNA were up-regulated, while the expression of Olig-2 mRNA was down-regulated in the Septic Groups. Intervention of CAP had a significant effect on cholinergic and catecholaminergic neurons' apoptosis, as well as the expressions of TH/CHAT and these key genes, but had little effect on HRV in sepsis. In the second experiment, the levels of TNF-α, IL-6, in serum and MVZ were significantly increased in sepsis. Central anti-inflammatory treatment reversed these changes. However, right vagotomy abolished the central anti-inflammatory effect. ConclusionsOur study uncovered that MVZ's neuroinflammation may play a crucial role in the uncontrolled systemic inflammation through inflammatory demyelination in MVZ, which disrupts CAP's modulation on the systemic inflammation in early sepsis.

Structural characteristics and regenerative potential: Insights from the molly fish spinal cord.

Unlike mammals, species such as fish and amphibians can regenerate damaged spinal cords, offering insights into potential therapeutic targets. This study investigates the structural features of the molly fish spinal cord through light and electron microscopy. The most notable characteristic was the presence of Mauthner cells (M-cells), which exhibited large cell bodies and processes, as well as synaptic connections with astrocytes. These astrocytic connections contained synaptic vesicles, suggesting electrical transmission at the M-cell endings. Astrocytes, which were labeled with glial fibrillary acidic protein (GFAP), contained cytoplasmic glycogen granules, potentially serving as an emergency fuel source. Two types of oligodendrocytes were identified: a small, dark cell and a larger, lighter cell, both of which reacted strongly with oligodendrocyte transcription factor 2 (Olig2). The dark oligodendrocyte resembled human oligodendrocyte precursors, while the light oligodendrocyte was similar to mature human oligodendrocytes. Additionally, proliferative neurons in the substantia grisea centralis expressed myostatin, Nrf2, and Sox9. Collectively, these findings suggest that the molly fish spinal cord has advanced structural features conducive to spinal cord regeneration and could serve as an excellent model for studying central nervous system regeneration. Further studies on the functional aspects of the molly fish spinal cord are recommended. RESEARCH HIGHLIGHTS: Mauthner cells (M-cell), with their typical large cell body and processes, were the most characteristic feature in Molly fish spinal cord, where it presented synaptic connections with astrocytes and their ends contained synaptic vesicles indicating an electrical transmission in the M-cells endings. Two types of oligodendrocytes could be recognized; both reacted intensely with Oligodendrocyte transcription factor 2 (Olig2). The proliferative neurons of the substantia grisea centralis expressed myostatin, Nrf2, and Sox9. The findings of this study suggest that molly fish possess highly developed structural features conducive to spinal cord regeneration. Consequently, they could be deemed an exemplary model for investigating central nervous system regeneration.

Identification and validation of PCDHGA12 and PRRX1 methylation for detecting lung cancer in bronchial washing sample.

Bronchoscopy is a frequently used initial diagnostic procedure for patients with suspected lung cancer (LC). Cytological examinations of bronchial washing (BW) samples obtained during bronchoscopy often yield inconclusive results regarding LC diagnosis. The present study aimed to identify molecular biomarkers as a non-invasive method for LC diagnosis. Aberrant DNA methylation is used as a useful biomarker for LC. Therefore, microarray-based methylation profiling analyses on 13 patient-matched tumor tissues at stages I-III vs. non-tumor tissues were performed, and a group of highly differentially methylated genes was identified. A subsequent analysis using bisulfite-pyrosequencing with additional tissues and cell lines revealed six methylated genes [ADAM metallopeptidase with thrombospondin type 1 motif 20, forkhead box C2 (mesenchyme forkhead 1), NK2 transcription factor related, locus 5 (Drosophila), oligodendrocyte transcription factor 3, protocadherin γ subfamily A 12 (PCDHGA12) and paired related homeobox 1 (PRRX1)] associated with LC. Next, a highly sensitive and accurate detection method, linear target enrichment-quantitative methylation-specific PCR in a single closed tube, was applied for clinical validation using BW samples from patients with LC (n=68) and individuals with benign diseases (n=33). PCDHGA12 and PRRX1 methylation were identified as the best-performing biomarkers to detect LC. The two-marker combination showed a sensitivity of 82.4% and a specificity of 87.9%, with an area under the curve of 0.891. Notably, the sensitivity for small cell LC was 100%. The two-marker combination had a positive predictive value of 93.3% and a negative predictive value of 70.7%. The sensitivity was higher than that of cytology, which only had a sensitivity of 50%. The methylation status of the two-marker combination showed no association with sex, age or stage, but was associated with tumor location and histology. In conclusion, the present study showed that the regulatory regions of PCDHGA12 and PRRX1 are highly methylated in LC and can be used to detect LC in BW specimens as a diagnostic adjunct to cytology in clinical practice.

Abstract 5444: EGFR missense mutation(s) induce OLIG2 expression to regulate glioma stem cells maintenance and therapeutic resistance

Abstract Glioblastoma (GBM) tumors contain a subpopulation of glioma stem cells (GSC) which can escape therapeutic effects through self-renewal and invasion. Epidermal growth factor receptor (EGFR) mutations are the most common alteration in GBM (50%). One example includes extracellular domain missense mutations like G598V, A289V, and R108K (10-15%). These extracellular domain missense mutations increase ligand binding affinity, inducing a highly active receptor. Earlier reports have shown these EGFR missense mutations exhibit therapeutic resistance; however, the molecular mechanism of these missense mutations in GBM remains unknown. In this study, we show high oligodendrocyte transcription factor 2 (OLIG2) expression in GSCs with EGFR-G598V and EGFR-A289V missense mutations. OLIG2 is universally expressed in glioma and essential for reprogramming GBM cells into stem-like tumor cells. Here, we report GSCs with these point mutations display increased self-renewal, growth, invasion, and therapeutic resistance. In addition, EGFR-G598V and EGFR-A289V trigger distinct downstream signaling pathways in GSCs to regulate OLIG2 function. These missense mutation(s) also represent different pathway-based GBM subclassifications, where A289V induces a Neuronal subtype and G598V induces a Glycolytic/Plurimetabolic subtype. We hypothesize that GBM tumors harboring EGFR missense mutations (G598V, A289V) influence stem cell properties via multiple pathways to evade therapeutic effects and inhibiting these different signaling pathways will decrease therapeutic resistance in GBM. Understanding the mechanism of these EGFR mutations may lead to improved therapeutic strategies for GBM patients. Citation Format: Sidney Weaver, Aunay Miller, Mylan Blomquist, James McNamara, Keely Orndorff, Chris Sereduk, Jean Kloss, Joseph Loftus, Shwetal Mehta, Nhan L. Tran. EGFR missense mutation(s) induce OLIG2 expression to regulate glioma stem cells maintenance and therapeutic resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5444.

Dual isolation of primary neurons and oligodendrocytes from guinea pig frontal cortex.

Primary cell culture is a technique that is widely used in neuroscience research to investigate mechanisms that underlie pathologies at a cellular level. Typically, mouse or rat tissue is used for this process; however, altricial rodent species have markedly different neurodevelopmental trajectories comparatively to humans. The use of guinea pig brain tissue presents a novel aspect to this routinely used cell culture method whilst also allowing for dual isolation of two major cell types from a physiologically relevant animal model for studying perinatal neurodevelopment. Primary neuronal and oligodendrocyte cell cultures were derived from fetal guinea pig's frontal cortex brain tissue collected at a gestational age of 62 days (GA62), which is a key time in the neuronal and oligodendrocyte development. The major advantage of this protocol is the ability to acquire both neuronal and oligodendrocyte cellular cultures from the frontal cortex of one fetal brain. Briefly, neuronal cells were grown in 12-well plates initially in a 24-h serum-rich medium to enhance neuronal survival before switching to a serum-free media formulation. Oligodendrocytes were first grown in cell culture flasks using a serum-rich medium that enabled the growth of oligodendrocyte progenitor cells (OPCs) on an astrocyte bed. Following confluency, the shake method of differential adhesion and separation was utilized via horizontally shaking the OPCs off the astrocyte bed overnight. Therefore, OPCs were plated in 12-well plates and were initially expanded in media supplemented with growth hormones, before switching to maturation media to progress the lineage to a mature phenotype. Reverse transcription-polymerase chain reaction (RT-PCR) was performed on both cell culture types to analyze key population markers, and the results were further validated using immunocytochemistry. Primary neurons displayed the mRNA expression of multiple neuronal markers, including those specific to GABAergic populations. These cells also positively stained for microtubule-associated protein 2 (MAP2; a dendritic marker specific to neurons) and NeuN (a marker of neuronal cell bodies). Primary oligodendrocytes expressed all investigated markers of the oligodendrocyte lineage, with a majority of the cells displaying an immature oligodendrocyte phenotype. This finding was further confirmed with positive oligodendrocyte transcription factor (OLIG2) staining, which serves as a marker for the overall oligodendrocyte population. This study demonstrates a novel method for isolating both neurons and oligodendrocytes from the guinea pig brain tissue. These isolated cells display key markers and gene expression that will allow for functional experiments to occur and may be particularly useful in studying neurodevelopmental conditions with perinatal origins.

STEM-20. REGULATION OF GLIOMA STEM CELL MAINTENANCE AND THERAPEUTIC RESISTANCE BY EGFR MISSENSE MUTATIONS

Abstract Glioblastoma (GBM) tumors contain a subpopulation of glioma stem cells (GSC) which can escape therapeutic effects through self-renewal and invasion. Epidermal growth factor receptor (EGFR) mutations are the most common alteration in GBM. EGFRvIII (deletion of exons 2-7) is observed in GBM (20-25%) resulting in a constitutively activated EGFR receptor. In addition, extracellular domain missense point mutations, (e.g. G598V, A289V, R108K) are observed in GBM (14.4%). These missense mutations in the EGFR extracellular domain also induces a highly active receptor by enhancing ligand binding. Earlier reports have shown that these EGFR missense point mutations have exhibited therapeutic resistance; however, the molecular mechanism of these missense point mutations in GBM remains unknown. Previous studies in our lab showed that EGFRvIII promotes GSC maintenance and therapeutic resistance via oligodendrocyte transcription factor 2 (OLIG2) signaling. OLIG2 is universally expressed in glioma and essential for reprogramming GBM cells into stem-like tumor cells. Increased OLIG2 expression promotes invasion, growth, proliferation, and survival. Here we report an increase in OLIG2 protein expression in GSCs harboring EGFR-G598V or EGFR-A289V mutations, suggesting these mutations may support stemness properties in GBM tumors. GSC expressing these point mutations display increased self-renewal, growth, and survival. In addition, EGFR-G598V and EGFR-A289V trigger distinct downstream signaling pathways in GSCs to regulate OLIG2 function. Hence, we hypothesize that GBM tumors harboring EGFR missense mutations (G598V, A289V) influence stem cell properties via multiple pathways to evade therapeutic effects and inhibiting these different signaling pathways will decrease therapeutic resistance in GBM. Understanding the mechanism of these EGFR mutations may lead to improved therapeutic strategies for GBM patients.

Features of neuroglia at the epicenter of spinal cord contusion injury and at distant areas in mini-pigs

Aim. To determine the delayed (after 2 months) effect of spinal cord injury (SCI) in the lower thoracic region in the mini-pigs on the morphologic state of macro- and microglia in nearby and remote caudal areas. Materials and methods. Sexually mature female Vietnamese pot-bellied pigs were randomly divided into two groups: SCI (n = 3) and intact (n = 3). Dosed contusion SCI was modelled at the level of the Th8–Th9 vertebrae, and transverse cryostat sections of the caudal segment adjacent to the epicenter of injury and the lumbar thickening (L4–S2) were examined 2 months later. The expression of astrocyte markers (glial fibrillary acidic protein, GFAP) and microglial markers (ionized calcium-binding adapter molecule 1, Iba1) was assessed as the relative immunopositive area occupied by cells. When counting the number of oligodendroglial cells (oligodendrocyte transcription factor 2, Olig2), the presence of nuclei detectable with 4’,6-diamidino-2-phenylindole (DAPI) was taken into account.Results. After SCI, an increase in the relative areas occupied by GFAP-positive astrocytes and Iba1-positive microglia and a decrease in Olig2-positive oligodendrocytes were detected in both the lesion area and lumbar thickening. In both regions, 2 months after SCI, the proportion of astrocytes was not significantly different in the anterior horns and doubled in the posterior horns. Microglia cells with SCI were 2.5 times more in the anterior horns of both regions and in the posterior horns of the lumbar thickening, while the presence of microglia increased slightly (1.2 times) in the posterior horns in the SCI region. The number of oligodendrocytes decreased in the area of the epicenter of SCI in the anterior and posterior horns by 1.5–1.75 times, and in the lumbar thickening more significantly: the number decreased by 2.5 times in the anterior horn and 5.5 times in the posterior horn. Conclusion. The results of the study revealed a similar pattern of macro- and microglial cell distribution both in the SCI region and in remote areas. The obtained data testify to the necessity to take into account the state of the areas of nervous tissue remote from the epicenter of SCI when stimulating neuroregeneration in such patients

Astrocyte lipocalin-2 modestly effects disease severity in a mouse model of multiple sclerosis while reducing mature oligodendrocyte protein and mRNA expression

Roles for lipocalin-2 (LCN2, also referred to as neutrophil gelatinase associated lipocalin, NGAL) in the progression of disease in multiple sclerosis and its animal models have been reported; however, the importance of astrocyte-derived LCN2, a major source of LCN2, have not been defined. We found that clinical scores in experimental autoimmune encephalomyelitis (EAE) were modestly delayed in mice with conditional knockout of LCN2 from astrocytes, associated with a small decrease in astrocyte GFAP expression. Immunostaining and qPCR of spinal cord samples showed decreased oligodendrocyte proteolipid protein and transcription factor Olig2 expression, but no changes in PDGFRα expression. These results suggest astrocyte LCN2 contributes to early events in EAE and reduces damage to mature oligodendrocytes at later times.

Pyruvate Dehydrogenase-Dependent Metabolic Programming Affects the Oligodendrocyte Maturation and Remyelination.

The metabolic needs of the premature/premyelinating oligodendrocytes (pre-OLs) and mature oligodendrocytes (OLs) are distinct. The metabolic control of oligodendrocyte maturation from the pre-OLs to the OLs is not fully understood. Here, we show that the terminal maturation and higher mitochondrial respiration in the OLs is an integrated process controlled through pyruvate dehydrogenase complex (Pdh). Combined bioenergetics and metabolic studies show that OLs show elevated mitochondrial respiration than the pre-OLs. Our signaling studies show that the increased mitochondrial respiration activity in the OLs is mediated by the activation of Pdh due to inhibition of the pyruvate dehydrogenase kinase-1 (Pdhk1) that phosphorylates and inhibits Pdh activity. Accordingly, when Pdhk1 is directly expressed in the pre-OLs, they fail to mature into the OLs. While Pdh converts pyruvate into the acetyl-CoA by its oxidative decarboxylation, our study shows that Pdh-dependent acetyl-CoA generation from pyruvate contributes to the acetylation of the bHLH family transcription factor, oligodendrocyte transcription factor 1 (Olig1) which is known to be involved in the OL maturation. Pdh inhibition via direct expression of Pdhk1 in the pre-OLs blocks the Olig1-acetylation and OL maturation. Using the cuprizone model of demyelination, we show that Pdh is deactivated during the demyelination phase, which is however reversed in the remyelination phase upon cuprizone withdrawal. In addition, Pdh activity status correlates with the Olig1-acetylation status in the cuprizone model. Hence, the Pdh metabolic node activation allows a robust mitochondrial respiration and activation of a molecular program necessary for the terminal maturation of oligodendrocytes. Our findings open a new dialogue in the developmental biology that links cellular development and metabolism. These findings have far-reaching implications in the development of therapies for a variety of demyelinating disorders including multiple sclerosis.

Oligodendrocyte Transcription Factor 2 as a Potential Prognostic Biomarker of Glioblastoma: Kaplan-Meier Analysis and the Development of a Binary Predictive Model Based on Visually Accessible Rembrandt Image and Magnetic Resonance Imaging Radiomic Features.

Oligodendrocyte transcription factor 2 (OLIG2) is universally expressed in human glioblastoma (GB). Our study explores whether OLIG2 expression impacts GB patients' overall survival and establishes a machine learning model for OLIG2 level prediction in patients with GB based on clinical, semantic, and magnetic resonance imaging radiomic features. Kaplan-Meier analysis was used to determine the optimal cutoff value of the OLIG2 in 168 GB patients. Three hundred thirteen patients enrolled in the OLIG2 prediction model were randomly divided into training and testing sets in a ratio of 7:3. The radiomic, semantic, and clinical features were collected for each patient. Recursive feature elimination (RFE) was used for feature selection. The random forest (RF) model was built and fine-tuned, and the area under the curve was calculated to evaluate the performance. Finally, a new testing set excluding IDH-mutant patients was built and tested in a predictive model using the fifth edition of the central nervous system tumor classification criteria. One hundred nineteen patients were included in the survival analysis. Oligodendrocyte transcription factor 2 was positively associated with GB survival, with an optimal cutoff of 10% (P = 0.00093). One hundred thirty-four patients were eligible for the OLIG2 prediction model. An RFE-RF model based on 2 semantic and 21 radiomic signatures achieved areas under the curve of 0.854 in the training set, 0.819 in the testing set, and 0.825 in the new testing set. Glioblastoma patients with ≤10% OLIG2 expression tended to have worse overall survival. An RFE-RF model integrating 23 features can predict the OLIG2 level of GB patients preoperatively, irrespective of the central nervous system classification criteria, further guiding individualized treatment.

Immunohistochemical analyses of neural stem cell lineage markers in normal feline brains and glial tumors.

Neural stem cell (NSC) lineage cells have not been fully identified in feline brains, and the NSC-like nature of feline glial tumors has not been determined. In this study, 6 normal cat brains (3 newborn and 3 older cats) and 13 feline glial tumors were analyzed using immunohistochemical NSC lineage markers. The feline glial tumors were subjected to immunohistochemical scoring followed by hierarchical cluster analysis. In newborn brains, glial acidic fibrillary protein (GFAP)/nestin/sex-determining region Y-box transcription factor 2 (SOX2)-immunopositive NSCs, SOX2-immunopositive intermediate progenitor cells, oligodendrocyte transcription factor 2 (OLIG2)/platelet-derived growth factor receptor-α (PDGFR-α)-immunopositive oligodendrocyte precursor cells (OPCs), OLIG2/GFAP-immunopositive immature astrocytes, and neuronal nuclear (NeuN)/β-3 tubulin-immunopositive mature neuronal cells were observed. The apical membrane of NSCs was also immunopositive for Na+/H+ exchanger regulatory factor 1 (NHERF1). In mature brains, the NSC lineage cells were similar to those of the newborn brains. A total of 13 glial tumors consisted of 2 oligodendrogliomas, 4 astrocytomas, 3 subependymomas, and 4 ependymomas. Astrocytomas, subependymomas, and ependymomas were immunopositive for GFAP, nestin, and SOX2. Subependymomas and ependymomas showed dot-like or apical membrane immunolabeling for NHERF1, respectively. Astrocytomas were immunopositive for OLIG2. Oligodendrogliomas and subependymomas were immunopositive for OLIG2 and PDGFR-α. Feline glial tumors also showed variable immunolabeling for β-3 tubulin, NeuN, and synaptophysin. Based on these results, feline astrocytomas, subependymomas, and ependymomas appear to have an NSC-like immunophenotype. In addition, astrocytomas, subependymomas, and ependymomas have the characteristics of glial, oligodendrocyte precursor, and ependymal cells, respectively. Feline oligodendrogliomas likely have an OPC-like immunophenotype. In addition, feline glial tumors may have multipotential stemness for differentiation into neuronal cells. These preliminary results should be validated by gene expression analyses in future studies with larger case numbers.

Effect of Carvacrol on histological analysis and expression of genes involved in an animal model of multiple sclerosis.

The most common non-traumatic neurological disease in young- and middle-aged adults is multiple sclerosis (MS), leading to central nervous system (CNS) atrophy and neurological disorders with loss of myelin and axonal degeneration. Due to the inadequate efficiency of common treatments, some natural products with antioxidant properties such as Carvacrol have been considered. the present study aimed to investigate carvacrol's anti-inflammatory and therapeutic effects on MS symptoms in healthy and experimental autoimmune encephalomyelitis (EAE) induced female Lewis rats. The study was performed in three groups of Lewis rats: control group, EAE model, and EAE treated with carvacrol (carvacrol-treated group). The treatment group received 25mg/kg of carvacrol intraperitoneally daily. Histologic examination and expression analysis of pro-inflammatory genes (Interleukin-1 and 17 (IL-1 and IL-17), Nuclear Factor Kappa B Cells (NF-κB) and Tumor Necrosis Factor-α (TNF-α)), myelin repair, and also regeneration genes (Myelin basic protein (MBP), Oligodendrocyte Transcription Factor 2 (OLIG2) and Platelet-Derived Growth Factor Receptor α (PDGFR-α)) were carried out. Gene studies, Hematoxylin and Eosin (H&E), and Luxol fast blue stain were performed in the lumbar region of the spinal cord. The EAE clinical scores in the carvacrol-treated group were lower than in untreated rats (P<0.001). The expression of two genes, IL-17 and MBP, was confirmed using fluorescence immunohistochemistry (FIHC). A significant decrease was observed in NF-κB and IL-17, and IL-1 gene expression. The MBP and OLIG2 gene expression was increased in the carvacrol-treated group (p<0.001). In EAE, PDGFR-α expression increased about four times. However, carvacrol administration did not affect PDGFR-α and TNF-α gene expression. In this treatment, H&E staining of spinal cord regions showed a significant decrease in inflammatory cell infiltration. Moreover, immunostaining analysis demonstrated a considerable increase in MBP and a reduction in IL-17 secretion. The results showed that carvacrol administration reduces the entry of inflammatory cells into the CNS by stimulating myelination-related processes employing increasing the expression of genes involved in myelin repair and reducing the expression of inflammatory genes. Our findings confirm that carvacrol improves the clinical and pathological symptoms of EAE through its therapeutic and modification properties as a potential adjunctive therapy and needs to be studied more.

Baicalin facilitates remyelination and suppresses neuroinflammation in rats with chronic cerebral hypoperfusion by activating Wnt/β-catenin and inhibiting NF-κB signaling

One main factor contributing to the cognitive loss in vascular dementia (VD) is white matter lesions (WMLs) carried on by chronic cerebral hypoperfusion (CCH). A secondary neuroinflammatory response to CCH accelerates the loss and limits the regeneration of oligodendrocytes, leading to progressive demyelination and insufficient remyelination in the white matter. Thus, promoting remyelination and inhibiting neuroinflammation may be an ideal therapeutic strategy. Baicalin (BAI) is known to exhibit protective effects against various inflammatory and demyelinating diseases. However, whether BAI has neuroprotective effects against CCH has not been investigated. To determine whether BAI inhibits CCH-induced demyelination and neuroinflammation, we established a model of CCH in rats by occluding the two common carotid arteries bilaterally. Our results revealed that BAI could remarkably ameliorate cognitive impairment and mitigate CA1 pyramidal neuron damage and myelin loss. BAI exhibited enhancement of remyelination by increasing the expression of myelin basic protein (MBP) and oligodendrocyte transcription factor 2 (Olig2), inhibiting the loss of oligodendrocytes and promoting oligodendrocyte regeneration in the corpus callosum of CCH rats. Furthermore, BAI modified microglia polarization to the anti-inflammatory phenotype and inhibited the release of pro-inflammatory cytokines. Mechanistically, BAI treatment significantly induced phosphorylation of glycogen synthase kinase 3β (GSK3β), enhanced the expression of β-catenin and its nuclear translocation. Simultaneously, BAI reduced the expression of nuclear NF-κB. Collectively, our results suggest that BAI ameliorates cognitive impairment in CCH-induced VD rats through its pro-remyelination and anti-inflammatory capacities, possibly by activating the Wnt/β-catenin and suppressing the NF-κB signaling.

EREG is the core onco-immunological biomarker of cuproptosis and mediates the cross-talk between VEGF and CD99 signaling in glioblastoma

BackgroundGlioma is the most prevalent primary tumor of the central nervous system. Glioblastoma multiforme (GBM) is the most malignant form of glioma with an extremely poor prognosis. A novel, regulated cell death form of copper-induced cell death called “cuproptosis” provides a new prospect for cancer treatment by regulating cuproptosis.MethodsData from bulk RNA sequencing (RNA-seq) analysis (The Cancer Genome Atlas cohort and Chinese Glioma Genome Atlas cohort) and single cell RNA-seq (scRNA-seq) analysis were integrated to reveal their relationships. A scoring system was constructed according to the cuproptosis-related gene expression, and core genes were experimentally verified using real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), Western blot (WB), immunohistochemistry (IHC), and immunofluorescence (IF). Moreover, cell counting kit-8 (CCK8), colony formation, 5-ethynyl-2’-deoxyuridine (EdU) incorporation, transwell, and flow cytometry cell cycle were performed to evaluate cell proliferation, invasion, and migration.ResultsThe Cuproptosis Activation Scoring (CuAS) Model has stable and independent prognostic efficacy, as verified by two CGGA datasets. Epiregulin (EREG), the gene of the model has the most contributions in the principal component analysis (PCA), is an onco-immunological gene that can affect immunity by influencing the expression of programmed death-ligand 1 (PD-L1) and mediate the process of cuproptosis by influencing the expression of ferredoxin 1 (FDX1). Single cell transcriptome analysis revealed that high CuAS GBM cells are found in vascular endothelial growth factor A (VEGFA) + malignant cells. Oligodendrocyte transcription factor 1 (OLIG1) + malignant is the original clone, and VEGF and CD99 are the differential pathways of specific cell communication between the high and low CuAS groups. This was also demonstrated by immunofluorescence in the tissue sections. Furthermore, CuAS has therapeutic potential for immunotherapy, and we predict that many drugs (methotrexate, NU7441, KU -0063794, GDC-0941, cabozantinib, and NVP-BEZ235) may be used in patients with high CuAS.ConclusionEREG is the core onco-immunological biomarker of CuAS and modulates the cross-talk between VEGF and CD99 signaling in glioblastoma, and CuAS may provide support for immunotherapy and chemotherapy.

DDR1 and Its Ligand, Collagen IV, Are Involved in In Vitro Oligodendrocyte Maturation

Discoidin domain receptor 1 (DDR1) is a tyrosine kinase receptor expressed in epithelial cells from different tissues in which collagen binding activates pleiotropic functions. In the brain, DDR1 is mainly expressed in oligodendrocytes (OLs), the function of which is unclear. Whether collagen can activate DDR1 in OLs has not been studied. Here, we assessed the expression of DDR1 during in vitro OL differentiation, including collagen IV incubation, and the capability of collagen IV to induce DDR1 phosphorylation. Experiments were performed using two in vitro models of OL differentiation: OLs derived from adult rat neural stem cells (NSCs) and the HOG16 human oligodendroglial cell line. Immunocytofluorescence, western blotting, and ELISA were performed to analyze these questions. The differentiation of OLs from NSCs was addressed using oligodendrocyte transcription factor 2 (Olig2) and myelin basic protein (MBP). In HOG16 OLs, collagen IV induced DDR1 phosphorylation through slow and sustained kinetics. In NSC-derived OLs, DDR1 was found in a high proportion of differentiating cells (MBP+/Olig2+), but its protein expression was decreased in later stages. The addition of collagen IV did not change the number of DDR1+/MBP+ cells but did accelerate OL branching. Here, we provide the first demonstration that collagen IV mediates the phosphorylation of DDR1 in HOG16 cells and that the in vitro co-expression of DDR1 and MBP is associated with accelerated branching during the differentiation of primary OLs.