Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 37
Filter
1.
Glia ; 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38829008

ABSTRACT

As one of the top causes of blindness worldwide, glaucoma leads to diverse optic neuropathies such as degeneration of retinal ganglion cells (RGCs). It is widely accepted that the level of intraocular pressure (IOP) is a major risk factor in human glaucoma, and reduction of IOP level is the principally most well-known method to prevent cell death of RGCs. However, clinical studies show that lowering IOP fails to prevent RGC degeneration in the progression of glaucoma. Thus, a comprehensive understanding of glaucoma pathological process is required for developing new therapeutic strategies. In this study, we provide functional and histological evidence showing that optic nerve defects occurred before retina damage in an ocular hypertension glaucoma mouse model, in which oligodendroglial lineage cells were responsible for the subsequent neuropathology. By treatment with clemastine, an Food and Drug Administration (FDA)-approved first-generation antihistamine medicine, we demonstrate that the optic nerve and retina damages were attenuated via promoting oligodendrocyte precursor cell (OPC) differentiation and enhancing remyelination. Taken together, our results reveal the timeline of the optic neuropathies in glaucoma and highlight the potential role of oligodendroglial lineage cells playing in its treatment. Clemastine may be used in future clinical applications for demyelination-associated glaucoma.

2.
Mol Psychiatry ; 27(12): 5154-5166, 2022 12.
Article in English | MEDLINE | ID: mdl-36131044

ABSTRACT

Although the link of white matter to pathophysiology of schizophrenia is documented, loss of myelin is not detected in patients at the early stages of the disease, suggesting that pathological evolution of schizophrenia may occur before significant myelin loss. Disrupted-in-schizophrenia-1 (DISC1) protein is highly expressed in oligodendrocyte precursor cells (OPCs) and regulates their maturation. Recently, DISC1-Δ3, a major DISC1 variant that lacks exon 3, has been identified in schizophrenia patients, although its pathological significance remains unknown. In this study, we detected in schizophrenia patients a previously unidentified pathological phenotype of OPCs exhibiting excessive branching. We replicated this phenotype by generating a mouse strain expressing DISC1-Δ3 gene in OPCs. We further demonstrated that pathological OPCs, rather than myelin defects, drive the onset of schizophrenic phenotype by hyperactivating OPCs' Wnt/ß-catenin pathway, which consequently upregulates Wnt Inhibitory Factor 1 (Wif1), leading to the aberrant synaptic formation and neuronal activity. Suppressing Wif1 in OPCs rescues synaptic loss and behavioral disorders in DISC1-Δ3 mice. Our findings reveal the pathogenetic role of OPC-specific DISC1-Δ3 variant in the onset of schizophrenia and highlight the therapeutic potential of Wif1 as an alternative target for the treatment of this disease.


Subject(s)
Oligodendrocyte Precursor Cells , Schizophrenia , Animals , Humans , Mice , Brain/metabolism , Brain/pathology , Myelin Sheath/metabolism , Nerve Tissue Proteins/genetics , Oligodendrocyte Precursor Cells/metabolism , Oligodendrocyte Precursor Cells/pathology , Oligodendroglia/metabolism , Schizophrenia/metabolism , Schizophrenia/pathology , Disease Models, Animal
3.
Brain ; 145(12): 4474-4488, 2022 12 19.
Article in English | MEDLINE | ID: mdl-35788280

ABSTRACT

Alzheimer's disease is a neurodegenerative disorder that causes age-dependent neurological and cognitive declines. The treatments for Alzheimer's disease pose a significant challenge, because the mechanisms of disease are not being fully understood. Malfunction of the blood-brain barrier is increasingly recognized as a major contributor to the pathophysiology of Alzheimer's disease, especially at the early stages of the disease. However, the underlying mechanisms remain poorly characterized, while few molecules can directly target and improve blood-brain barrier function in the context of Alzheimer's disease. Here, we showed dysfunctional blood-brain barrier in patients with Alzheimer's disease reflected by perivascular accumulation of blood-derived fibrinogen in the hippocampus and cortex, accompanied by decreased tight junction proteins Claudin-5 and glucose transporter Glut-1 in the brain endothelial cells. In the APPswe/PS1dE9 (APP/PS1) mouse model of Alzheimer's disease, blood-brain barrier dysfunction started at 4 months of age and became severe at 9 months of age. In the cerebral microvessels of APP/PS1 mice and amyloid-ß-treated brain endothelial cells, we found suppressed Wnt/ß-catenin signalling triggered by an increase of GSK3ß activation, but not an inhibition of the AKT pathway or switching to the Wnt/planar cell polarity pathway. Furthermore, using our newly developed optogenetic tool for controlled regulation of LRP6 (upstream regulator of the Wnt signalling) to activate Wnt/ß-catenin pathway, blood-brain barrier malfunction was restored by preventing amyloid-ß-induced brain endothelial cells impairments and promoting the barrier repair. In conclusion, targeting LRP6 in the Wnt/ß-catenin pathway in the brain endothelium can alleviate blood-brain barrier malfunction induced by amyloid-ß, which may be a potential treatment strategy for Alzheimer's disease.


Subject(s)
Alzheimer Disease , Mice , Animals , Alzheimer Disease/metabolism , Blood-Brain Barrier/metabolism , Endothelial Cells/metabolism , beta Catenin , Amyloid beta-Peptides/metabolism , Wnt Signaling Pathway , Disease Models, Animal , Mice, Transgenic
4.
Ecotoxicol Environ Saf ; 238: 113589, 2022 Jun 15.
Article in English | MEDLINE | ID: mdl-35525116

ABSTRACT

Air pollution remains one of the major health threats around the world. Compared to adults, foetuses and infants are more vulnerable to the effects of environmental toxins. Maternal exposure to air pollution causes several adverse birth outcomes and may lead to life-long health consequences. Given that a healthy intrauterine environment is a critical factor for supporting normal foetal brain development, there is a need to understand how prenatal exposure to air pollution affects brain health and results in neurological dysfunction. This review summarised the current knowledge on the adverse effects of prenatal air pollution exposure on early life neurodevelopment and subsequent impairment of cognition and behaviour in childhood, as well as the potential of early-onset neurodegeneration. While inflammation, oxidative stress, and endoplasmic reticulum are closely involved in the physiological response, sex differences also occur. In general, males are more susceptible than females to the adverse effect of in-utero air pollution exposure. Considering the evidence provided in this review and the rising concerns of global air pollution, any efforts to reduce pollutant emission or exposure will be protective for the next generation.


Subject(s)
Air Pollutants , Air Pollution , Adult , Air Pollutants/analysis , Air Pollutants/toxicity , Air Pollution/adverse effects , Cognition , Environmental Exposure/adverse effects , Female , Humans , Infant , Male , Maternal Exposure/adverse effects , Particulate Matter/toxicity , Pregnancy
5.
BMC Med Educ ; 22(1): 514, 2022 Jul 01.
Article in English | MEDLINE | ID: mdl-35778724

ABSTRACT

BACKGROUND: Due to insufficient basic medical knowledge and inappropriate learning strategies, students of 8-year medical programme encountered many obstacles in the initial stage of basic medicine learning. This study was to determine whether a prerequisite course can improve basic medicine learning performance and adjust learning strategies to adapt to basic medicine learning. METHODS: A prerequisite course of histology was constructed by a two-round modified Delphi study. Seventy-four students of 8-year medical programme were subjected to two groups: the prerequisite course group (PC group) and non-prerequisite course group (NPC group). The PC group take part in the prerequisite course by student-centred blended learning approach but NPC group not. The PC and NPC group underwent requisite histology teaching activities after prerequisite course. Examination of the prerequisite course and requisite histology course were carried out. Effect of the prerequisite course was evaluated by an empirical method using a questionnaire-based approach. RESULTS: The results of examinations showed students' scores of the PC group were significantly higher than those of students of NPC group in both prerequisite course and requisite histology examinations (P < 0.05). The results of questionnaires showed that students were satisfied with the prerequisite course, which was beneficial for uptake in medical knowledge, cultivation of clinical thinking and scientific research ability and adaptation in learning strategies (P < 0.01). Furthermore, our prerequisite course is conducive to subsequent courses learning, especially for pathology (P < 0.01). CONCLUSION: Our prerequisite course could effectively supplement knowledge of basic medicine, improve clinical thinking and scientific research ability and adapt their learning strategies. These findings suggest that the prerequisite course is useful and should be introduced in medical curriculum reform at the early stages of basic medical training.


Subject(s)
Learning , Students , China , Humans , Surveys and Questionnaires
6.
Glia ; 69(7): 1709-1722, 2021 07.
Article in English | MEDLINE | ID: mdl-33660902

ABSTRACT

Oligodendroglial lineage cells go through a series of morphological changes before myelination. Prior to myelination, cell processes and membrane structures enlarge by approximately 7,000 times, which is required to support axonal wrapping and myelin segment formation. Failure of these processes leads to maldevelopment and impaired myelination. Quetiapine, an atypical antipsychotic drug, was proved to promote oligodendroglial differentiation and (re)myelination, pending detailed effects and regulatory mechanism. In this study, we showed that quetiapine promotes morphological maturation of oligodendroglial lineage cells and myelin segment formation, and a short-term quetiapine treatment is sufficient to induce these changes. To uncover the underlying mechanism, we examined the effect of quetiapine on the Oligodendrocyte transcription factor 1 (Olig1). We found that quetiapine upregulates Olig1 expression level and promotes nuclear Olig1 translocation to the cytosol, where it functions not as a transcription modulator, but in a way that highly correlates with oligodendrocyte morphological transformation. In addition, quetiapine treatment reverses the negative regulatory effect of the Olig1-regulated G protein-coupled receptor 17 (GPR17) on oligodendroglial morphological maturation. Our results demonstrate that quetiapine enhances oligodendroglial differentiation and myelination by promoting cell morphological transformation. This would shed light on the orchestration of oligodendroglia developmental mechanisms, and provides new targets for further therapeutic research.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors , Oligodendroglia , Axons/metabolism , Basic Helix-Loop-Helix Transcription Factors/metabolism , Cell Differentiation/physiology , Myelin Sheath/metabolism , Oligodendroglia/metabolism , Quetiapine Fumarate/metabolism , Quetiapine Fumarate/pharmacology
7.
Glia ; 68(6): 1201-1212, 2020 06.
Article in English | MEDLINE | ID: mdl-31868275

ABSTRACT

As the most abundant gap junction protein in the central nervous system (CNS), astrocytic connexin 43 (Cx43) maintains astrocyte network homeostasis, affects oligodendroglial development and participates in CNS pathologies as well as injury progression. However, its role in remyelination is not yet fully understood. To address this issue, we used astrocyte-specific Cx43 conditional knockout (Cx43 cKO) mice generated through the use of a hGFAP-cre promoter, in combination with mice carrying a floxed Cx43 allele that were subjected to lysolecithin so as to induce demyelination. We found no significant difference in the demyelination of the corpus callosum between Cx43 cKO mice and their non-cre littermate controls, while the remyelination process in Cx43 cKO mice was accelerated. Moreover, an increased number of mature oligodendrocytes and an unaltered number of oligodendroglial lineage cells were found in Cx43 cKO mouse lesions. This indicates that oligodendrocyte precursor cell (OPC) differentiation was facilitated by astroglial Cx43 depletion as remyelination progressed. Underlying the latter, there was a down-regulated glial activation and modulated local inflammation as well as a reduction of myelin debris in Cx43 cKO mice. Importantly, 2 weeks of orally administrating boldine, a natural alkaloid that blocks Cx hemichannel activity in astrocytes without affecting gap junctional communication, obviously modulated local inflammation and promoted remyelination. Together, the data suggest that the astrocytic Cx43 hemichannel is negatively involved in the remyelination process by favoring local inflammation. Consequently, inhibiting Cx43 hemichannel functionality may be a potential therapeutic approach for demyelinating diseases in the CNS.


Subject(s)
Astrocytes/metabolism , Connexin 43/metabolism , Inflammation/metabolism , Remyelination/physiology , Animals , Cell Differentiation/physiology , Central Nervous System/metabolism , Demyelinating Diseases/pathology , Gap Junctions/metabolism , Mice , Myelin Sheath/metabolism , Oligodendrocyte Precursor Cells/metabolism , Oligodendroglia/metabolism
8.
Biochem Biophys Res Commun ; 520(3): 651-656, 2019 12 10.
Article in English | MEDLINE | ID: mdl-31629472

ABSTRACT

Melanocortin 4 receptor (MC4R)-deficient mice had been used for several years to study human nonalcoholic steatohepatitis (NASH). However, although liver pathologic and biochemical indicators have been examined, mice models do not always faithfully display the phenotype of the human disease. In this study, we investigated the MC4R knockout phenotype in miniature pigs. We found that pigs lacking MC4R exhibited hyperorexia, insulin resistance, hyperinsulinemia, disordered lipid metabolism and their livers accumulated significant amounts of fat. We have shown that deletion of MC4R results in hyperphagia and increased body fat, ultimately leading to hepatic steatosis without atherogenic diet.


Subject(s)
Hyperphagia/etiology , Non-alcoholic Fatty Liver Disease/etiology , Receptor, Melanocortin, Type 4/deficiency , Adipocytes/pathology , Adipose Tissue/pathology , Animals , Animals, Genetically Modified , Cell Enlargement , Diet, High-Fat , Disease Models, Animal , Eating/genetics , Eating/physiology , Female , Gene Knockout Techniques , Humans , Hyperphagia/genetics , Hyperphagia/metabolism , Insulin Resistance/genetics , Insulin Resistance/physiology , Male , Mice , Non-alcoholic Fatty Liver Disease/genetics , Non-alcoholic Fatty Liver Disease/metabolism , Pregnancy , Receptor, Melanocortin, Type 4/genetics , Swine , Swine, Miniature
9.
Brain ; 141(1): 85-98, 2018 01 01.
Article in English | MEDLINE | ID: mdl-29244098

ABSTRACT

Hypoxia can injure brain white matter tracts, comprised of axons and myelinating oligodendrocytes, leading to cerebral palsy in neonates and delayed post-hypoxic leukoencephalopathy (DPHL) in adults. In these conditions, white matter injury can be followed by myelin regeneration, but myelination often fails and is a significant contributor to fixed demyelinated lesions, with ensuing permanent neurological injury. Non-myelinating oligodendrocyte precursor cells are often found in lesions in plentiful numbers, but fail to mature, suggesting oligodendrocyte precursor cell differentiation arrest as a critical contributor to failed myelination in hypoxia. We report a case of an adult patient who developed the rare condition DPHL and made a nearly complete recovery in the setting of treatment with clemastine, a widely available antihistamine that in preclinical models promotes oligodendrocyte precursor cell differentiation. This suggested possible therapeutic benefit in the more clinically prevalent hypoxic injury of newborns, and we demonstrate in murine neonatal hypoxic injury that clemastine dramatically promotes oligodendrocyte precursor cell differentiation, myelination, and improves functional recovery. We show that its effect in hypoxia is oligodendroglial specific via an effect on the M1 muscarinic receptor on oligodendrocyte precursor cells. We propose clemastine as a potential therapy for hypoxic brain injuries associated with white matter injury and oligodendrocyte precursor cell maturation arrest.


Subject(s)
Clemastine/therapeutic use , Demyelinating Diseases/drug therapy , Demyelinating Diseases/etiology , Histamine H1 Antagonists/therapeutic use , Hypoxia, Brain/complications , Recovery of Function/drug effects , Action Potentials/drug effects , Animals , Animals, Newborn , Cell Differentiation/drug effects , Cells, Cultured , Cerebellum/drug effects , Cerebellum/metabolism , Cerebellum/ultrastructure , Demyelinating Diseases/diagnostic imaging , Demyelinating Diseases/pathology , Disease Models, Animal , Gene Expression Regulation, Developmental/drug effects , Humans , Hypoxia, Brain/diagnostic imaging , Male , Mice , Mice, Knockout , Middle Aged , Myelin Sheath/drug effects , Myelin Sheath/ultrastructure , Oligodendrocyte Precursor Cells/drug effects , Optic Nerve/physiopathology , Oxygen/pharmacology , Receptor, Muscarinic M1/genetics , Receptor, Muscarinic M1/metabolism
10.
Glia ; 66(9): 1960-1971, 2018 09.
Article in English | MEDLINE | ID: mdl-29726608

ABSTRACT

Myelinating glial cells (MGCs), oligodendrocytes (OLs) in the central nervous system (CNS) and Schwann cells (SCs) in the peripheral nervous system (PNS), generate myelin sheaths that insulate axons. After myelination is completed in adulthood, MGC functions independent from myelin are required to support axon survival, but the underlying mechanisms are still unclear. Dicer is a key enzyme that is responsible for generating functional micro-RNAs (miRNAs). Despite the importance of Dicer in initiating myelination, the role of Dicer in mature MGCs is still unclear. Here, Dicer was specifically deleted in mature MGCs in 2-month old mice (PLP-CreERT; Dicer fl/fl) by tamoxifen administration. Progressive motor dysfunction was observed in the Dicer conditional knockout mice, which displayed hind limb ataxia at 3 months post recombination that deteriorated into paralysis within 5 months. Massive axonal degeneration/atrophy in peripheral nerves was responsible for this phenomenon, but overt demyelination was not observed in either the CNS or PNS. In contrast to the PNS, signs of axonal degeneration were not observed in the CNS of these animals. We induced a Dicer deletion in oligodendroglia at postnatal day 5 in NG2-CreERT; Dicer fl/fl mice to evaluate whether Dicer expression in OLs is essential for axonal survival. Dicer deletion in oligodendroglia did not cause motor dysfunction at the age of 7 months. Neither axonal atrophy nor demyelination was observed in the CNS. Based on our results, Dicer expression in SCs is required to maintain axon integrity in adult PNS, and Dicer is dispensable for maintaining myelin sheaths in MGCs.


Subject(s)
Axons/enzymology , DEAD-box RNA Helicases/deficiency , Myelin Sheath/enzymology , Nerve Degeneration/enzymology , Ribonuclease III/deficiency , Animals , Ataxia/enzymology , Ataxia/pathology , Atrophy , Axons/pathology , DEAD-box RNA Helicases/genetics , Disease Progression , Female , Male , Mice, Inbred C57BL , Mice, Transgenic , Motor Activity/physiology , Myelin Sheath/pathology , Nerve Degeneration/pathology , Optic Nerve/enzymology , Optic Nerve/pathology , Paralysis/enzymology , Paralysis/pathology , Ribonuclease III/genetics , Sciatic Nerve/enzymology , Sciatic Nerve/pathology , Spinal Cord/enzymology , Spinal Cord/pathology , White Matter/enzymology , White Matter/pathology
11.
J Cell Sci ; 129(9): 1902-14, 2016 05 01.
Article in English | MEDLINE | ID: mdl-27006115

ABSTRACT

Oligodendrocyte precursor cells (OPCs) undergo a series of energy-consuming developmental events; however, the uptake and trafficking pathways for their energy metabolites remain unknown. In the present study, we found that 2-NBDG, a fluorescent glucose analog, can be delivered between astrocytes and oligodendrocytes through connexin-based gap junction channels but cannot be transferred between astrocytes and OPCs. Instead, connexin hemichannel-mediated glucose uptake supports OPC proliferation, and ethidium bromide uptake or increase of 2-NBDG uptake rate is correlated with intracellular Ca(2+) elevation in OPCs, indicating a Ca(2+)-dependent activation of connexin hemichannels. Interestingly, deletion of connexin 43 (Cx43, also known as GJA1) in astrocytes inhibits OPC proliferation by decreasing matrix glucose levels without impacting on OPC hemichannel properties, a process that also occurs in corpus callosum from acute brain slices. Thus, dual functions of connexin-based channels contribute to glucose supply in oligodendroglial lineage, which might pave a new way for energy-metabolism-directed oligodendroglial-targeted therapies.


Subject(s)
Astrocytes/metabolism , Calcium Signaling/physiology , Calcium/metabolism , Connexin 43/metabolism , Corpus Callosum/metabolism , Oligodendroglia/metabolism , Animals , Astrocytes/cytology , Connexin 43/genetics , Corpus Callosum/cytology , Glucose/genetics , Glucose/metabolism , Mice , Mice, Knockout , Oligodendroglia/cytology
12.
J Neurosci ; 33(19): 8454-62, 2013 May 08.
Article in English | MEDLINE | ID: mdl-23658182

ABSTRACT

The temporal and spatial patterning involved in the specification, differentiation, and myelination by oligodendroglia is coordinated in part by the activation and repression of various transcriptional programs. Olig2 is a basic helix-loop-helix transcription factor necessary for oligodendroglial development and expressed continuously throughout the lineage. Despite evidence for the critical role of Olig2 in oligodendroglial specification and differentiation, the function for Olig2 during later stages of oligodendroglial development, namely, the transition into mature oligodendrocytes (OLs) and the formation of the myelin sheath, remains unclear. To address the possibility for a stage-specific role, we deleted Olig2 in oligodendrocyte precursor cells (OPCs) under the control of the CNPase-promoter or in immature OLs under the inducible proteolipid protein promoter. As expected, ablation of Olig2 in OPCs significantly inhibits differentiation, resulting in hypomyelination. However, deletion of the Olig2 gene in immature OLs significantly enhances the maturation process and accelerates the kinetics of myelination/remyelination. Underlying the stage-specific roles for Olig2 is the compensatory expression and function of Olig1, a transcription factor that promotes OL maturation and (re)myelination. Olig1 expression is significantly reduced upon Olig2 deletion in OPCs but is dramatically increased by nearly threefold when deleted in immature OLs. By enforcing expression of Olig1 into OPCs in a null Olig2 background, we demonstrate that overexpression of Olig1 is sufficient to rescue the differentiation phenotype and partially compensates for the Olig2 deletion in vitro. Our results suggest a stage-specific regulatory role for Olig2, mediated by Olig1 that conveys opposing functions on the differentiation and maturation of oligodendrocytes.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/deficiency , Cell Differentiation/physiology , Nerve Tissue Proteins/deficiency , Oligodendroglia/physiology , 2',3'-Cyclic-Nucleotide Phosphodiesterases/genetics , 2',3'-Cyclic-Nucleotide Phosphodiesterases/metabolism , Animals , Animals, Newborn , Arabidopsis Proteins/metabolism , Autophagy-Related Proteins , Basic Helix-Loop-Helix Transcription Factors/genetics , Basic Helix-Loop-Helix Transcription Factors/metabolism , Basic Helix-Loop-Helix Transcription Factors/ultrastructure , Bromodeoxyuridine/metabolism , Cell Differentiation/drug effects , Cuprizone/toxicity , Demyelinating Diseases/chemically induced , Demyelinating Diseases/metabolism , Gene Expression Regulation, Developmental/drug effects , Gene Expression Regulation, Developmental/genetics , Green Fluorescent Proteins/genetics , In Situ Nick-End Labeling , Intracellular Signaling Peptides and Proteins/metabolism , Intramolecular Transferases/metabolism , Male , Mice , Mice, Transgenic , Microscopy, Electron, Transmission , Monoamine Oxidase Inhibitors/toxicity , Myelin Basic Protein/metabolism , Myelin Proteolipid Protein/genetics , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Nerve Tissue Proteins/ultrastructure , Oligodendrocyte Transcription Factor 2 , Oligodendroglia/drug effects , Transfection , ran GTP-Binding Protein/metabolism
13.
Sci Adv ; 10(6): eadk3931, 2024 Feb 09.
Article in English | MEDLINE | ID: mdl-38324685

ABSTRACT

Maldevelopment of oligodendroglia underlies neural developmental disorders such as leukodystrophy. Precise regulation of the activity of specific transcription factors (TFs) by various posttranslational modifications (PTMs) is required to ensure proper oligodendroglial development and myelination. However, the role of ubiquitination of these TFs during oligodendroglial development is yet unexplored. Here, we find that RNF220, a known leukodystrophy-related E3 ubiquitin ligase, is required for oligodendroglial development. RNF220 depletion in oligodendrocyte lineage cells impedes oligodendrocyte progenitor cell proliferation, differentiation, and (re)myelination, which consequently leads to learning and memory defects. Mechanistically, RNF220 targets Olig1/2 for K63-linked polyubiquitination and stabilization during oligodendroglial development. Furthermore, in a knock-in mouse model of leukodystrophy-related RNF220R365Q mutation, the ubiquitination and stabilization of Olig proteins are deregulated in oligodendroglial cells. This results in pathomimetic oligodendroglial developmental defects, impaired myelination, and abnormal behaviors. Together, our evidence provides an alternative insight into PTMs of oligodendroglial TFs and how this essential process may be implicated in the etiology of leukodystrophy.


Subject(s)
Demyelinating Diseases , Neurogenesis , Mice , Animals , Cell Differentiation/genetics , Ubiquitination , Oligodendroglia/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Demyelinating Diseases/metabolism , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/metabolism
14.
J Neurochem ; 127(3): 426-33, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23692407

ABSTRACT

Developing oligodendrocytes, collectively termed 'pre-myelinating oligodendrocytes' (preOLs), are vulnerable to hypoxic or ischemic insults. The underlying mechanism of this vulnerability remains unclear. Previously, we showed that Bcl-2/E1B-19K-interacting protein 3 (BNIP3), a proapoptotic member of the Bcl-2 family proteins, induced neuronal death in a caspase-independent manner in stroke. In this study, we investigated the role of BNIP3 in preOL cell death induced by hypoxia or ischemia. In primary oligodendrocyte progenitor cell (OPC) cultures exposed to oxygen-glucose deprivation, we found that BNIP3 was upregulated and levels of BNIP3 expression correlated with the death of OPCs. Up-regulation of BNIP3 was observed in preOLs in the white matter in a neonatal rat model of stroke. Knockout of BNIP3 significantly reduced death of preOLs in the middle cerebral artery occlusion model in mice. Our results demonstrate a role of BNIP3 in mediating preOLs cell death induced by hypoxia or ischemia, and suggest that BNIP3 may be a new target for protecting oligodendrocytes from death after stroke. Pre-myelinating oligodendrocytes (preOLs) are known to be highly vulnerable to ischemic insults. It remains unclear, however, how preOLs die. This study shows that BNIP3, a proapoptotic member of the Bcl-2 family proteins, is a mediator of hypoxia/ischemia-induced preOLs death. The BNIP3 cell death pathway may therefore be a new target for protecting oligodendrocytes from death after stroke.


Subject(s)
Brain Ischemia/pathology , Cell Death/physiology , Hypoxia, Brain/pathology , Membrane Proteins/physiology , Mitochondrial Proteins/physiology , Oligodendroglia/pathology , Oligodendroglia/physiology , Proto-Oncogene Proteins/physiology , Animals , Blotting, Western , Cell Survival/physiology , Cells, Cultured , Female , Immunohistochemistry , In Situ Nick-End Labeling , Infarction, Middle Cerebral Artery/pathology , Male , Mice , Mice, Knockout , Myelin Sheath/physiology , Rats
15.
Trends Neurosci ; 46(7): 581-596, 2023 07.
Article in English | MEDLINE | ID: mdl-37183154

ABSTRACT

Adult oligodendrocyte precursor cells (aOPCs), transformed from fetal OPCs, are idiosyncratic neuroglia of the central nervous system (CNS) that are distinct in many ways from other glial cells. OPCs have been classically studied in the context of their remyelinating capacity. Recent studies, however, revealed that aOPCs not only contribute to post-lesional remyelination but also play diverse crucial roles in multiple neurological diseases. In this review we briefly present the physiology of aOPCs and summarize current knowledge of the beneficial and detrimental roles of aOPCs in different CNS diseases. We discuss unique features of aOPC death, reactivity, and changes during senescence, as well as aOPC interactions with other glial cells and pathological remodeling during disease. Finally, we outline future perspectives for the study of aOPCs in brain pathologies which may instigate the development of aOPC-targeting therapeutic strategies.


Subject(s)
Oligodendrocyte Precursor Cells , Remyelination , Oligodendrocyte Precursor Cells/physiology , Central Nervous System , Neuroglia , Remyelination/physiology , Oligodendroglia/physiology , Cell Differentiation/physiology , Myelin Sheath/physiology
16.
Neuron ; 111(2): 190-201.e8, 2023 01 18.
Article in English | MEDLINE | ID: mdl-36384142

ABSTRACT

Oligodendrocyte precursor cells (OPCs) undergo an extensive and coordinated migration in the developing CNS, using the pre-formed scaffold of developed blood vessels as their physical substrate for migration. While OPC association with vasculature is critical for dispersal, equally important for permitting differentiation and proper myelination of target axons is their appropriate and timely detachment, but regulation of this process remains unclear. Here we demonstrate a correlation between the developmental formation of astrocytic endfeet on vessels and the termination of OPC perivascular migration. Ex vivo and in vivo live imaging shows that astrocyte endfeet physically displace OPCs from vasculature, and genetic abrogation of endfoot formation hinders both OPC detachment from vessels and subsequent differentiation. Astrocyte-derived semaphorins 3a and 6a act to repel OPCs from blood vessels at the cessation of their perivascular migration and, in so doing, permit subsequent OPC differentiation by insulating them from a maturation inhibitory endothelial niche.


Subject(s)
Oligodendrocyte Precursor Cells , Astrocytes , Oligodendroglia/physiology , Cell Differentiation/physiology , Cell Movement/physiology
17.
Glia ; 60(9): 1427-36, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22639060

ABSTRACT

Oligodendroglial cells undergo rapid transcriptional and dynamic morphological transformation in order to effectively myelinate neuronal axons. Olig1, a basic helix-loop-helix transcription factor, functions to promote the transcription of myelin-specific genes and promotes differentiation and (re)myelination. While the role for nuclear Olig1 is well established, the function for cytoplasmic Olig1 remains uncertain. We observe that translocation of Olig1 into the cytosol highly correlates with differentiation of oligodendrocytes both invivo and invitro. By enforcing expression of a nuclear-specific form of Olig1 into OPCs in a null-Olig1 background, we demonstrate that nuclear Olig1 is sufficient to facilitate MBP expression, but with greatly diminished membrane volume and area. We demonstrate that serine 138 in the helix-loop-helix domain of Olig1 is phosphorylated and that this form resides in the cytosol. Mutating serine 138 to alanine restricts Olig1 to the nucleus, facilitating MBP expression but limiting membrane expansion. However, a serine to aspartic acid mutation results in the cytoplasmic localization of Olig1 enhancing membrane expansion. Our results suggest a novel role for a phosphorylated cytosolic Olig1 in membrane expansion and maturation of oligodendrocytes.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/metabolism , Brain/metabolism , Cell Membrane/metabolism , Cytosol/metabolism , Oligodendroglia/metabolism , Animals , Cell Count , Cell Differentiation/physiology , Mice , Mice, Inbred C57BL , Neural Stem Cells/metabolism , Phosphorylation , Protein Transport/physiology , Rats , Rats, Sprague-Dawley
18.
J Biomed Res ; 36(5): 343-352, 2022 Apr 28.
Article in English | MEDLINE | ID: mdl-35578762

ABSTRACT

Oligodendrocyte lineage cells (OL-lineage cells) are a cell population that are crucial for mammalian central nervous system (CNS) myelination. OL-lineage cells go through developmental stages, initially differentiating into oligodendrocyte precursor cells (OPCs), before becoming immature oligodendrocytes, then mature oligodendrocytes (OLs). While the main function of cell lineage is in myelin formation, and increasing number of studies have turned to explore the immunological characteristics of these cells. Initially, these studies focused on discovering how OPCs and OLs are affected by the immune system, and then, how these immunological changes influence the myelination process. However, recent studies have uncovered another feature of OL-lineage cells in our immune systems. It would appear that OL-lineage cells also express immunological factors such as cytokines and chemokines in response to immune activation, and the expression of these factors changes under various pathologic conditions. Evidence suggests that OL-lineage cells actually modulate immune functions. Indeed, OL-lineage cells appear to play both "victim" and "agent" in the CNS which raises a number of questions. Here, we summarize immunologic changes in OL-lineage cells and their effects, as well as consider OL-lineage cell changes which influence immune cells under pathological conditions. We also describe some of the underlying mechanisms of these changes and their effects. Finally, we describe several studies which use OL-lineage cells as immunotherapeutic targets for demyelination diseases.

19.
J Vis Exp ; (178)2021 12 17.
Article in English | MEDLINE | ID: mdl-34978294

ABSTRACT

Demyelination has been identified in not only multiple sclerosis (MS), but also other central nervous system diseases such as Alzheimer's disease and autism. As evidence suggests that remyelination can effectively ameliorate the disease symptoms, there is an increasing focus on drug development to promote the myelin regeneration process. Thus, a region-selectable and result-reliable drug delivery technique is required to test the efficiency and specificity of these drugs in vivo. This protocol introduces the osmotic pump implant as a new drug delivery approach in the lysolecithin-induced demyelination mouse model. The osmotic pump is a small implantable device that can bypass the blood-brain barrier (BBB) and deliver drugs steadily and directly to specific areas of the mouse brain. It can also effectively improve the bioavailability of drugs such as peptides and proteins with a short half-life. Therefore, this method is of great value to the field of central nervous system myelin regeneration research.


Subject(s)
Multiple Sclerosis , Remyelination , Animals , Blood-Brain Barrier/metabolism , Disease Models, Animal , Lysophosphatidylcholines/metabolism , Lysophosphatidylcholines/pharmacology , Mice , Myelin Sheath/metabolism , Oligodendroglia/metabolism
20.
Viruses ; 13(3)2021 03 12.
Article in English | MEDLINE | ID: mdl-33809239

ABSTRACT

Porcine epidemic diarrhea virus (PEDV) is a highly infectious and pathogenic virus causing high morbidity and mortality, especially in newborn piglets. There remain problems with contemporary PEDV vaccines, in part because of the rapid variation of PEDV, poor conferred immunity, and numerous side effects. The ability to produce PEDV-neutralizing antibodies suggests that we may be able to increase the success rate of PEDV prevention in piglets using these antibodies. In this study, we produced an anti-PEDV S protein monoclonal antibody (anti-PEDV mAb-2) that neutralized PEDV-CV777 (a G1 strain), PEDV-SDSX16 and PEDV-Aj1102 (two G2 strains). In vivo challenge experiments demonstrated that anti-PEDV mAb-2 inhibited the PEDV infection in piglets. We also produced three HEK293 cell lines that expressed anti-PEDV mAb-2. Overall, our study showed that anti-PEDV mAb-2 produced from hybridoma supernatants effectively inhibited PEDV infection in piglets, and the recombinant HEK293 cell lines expressed anti-PEDV mAb-2 genes.


Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/isolation & purification , Antibodies, Viral/isolation & purification , Coronavirus Infections , Porcine epidemic diarrhea virus/immunology , Swine Diseases , Animals , Chlorocebus aethiops , Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Coronavirus Infections/veterinary , HEK293 Cells , Humans , Swine , Swine Diseases/immunology , Swine Diseases/prevention & control , Vero Cells
SELECTION OF CITATIONS
SEARCH DETAIL