Oligodendrocyte dysfunction in cerebral ischemia and neurodegenerative disorders:the effect of CysLT receptor antagonists / 中国药理学与毒理学杂志

Ischemic stroke is an acute and serious cerebrovascular accident.Neurodegenerative disorders are characterized by progressive degeneration of neu-rons in the central nervous system(CNS),resulting in severe disability and death.Myelin is essential for the health and function of neuronal axons.Oligodendrocytes,the myelinating cells of CNS,are vulnerable to ischemia and neurodegenerative disorders.G protein-coupled receptor 17(GPR17)is a dual receptor activated by uracil nucleotides/cysteinyl leukotrienes(CysLTs).Abnormal GPR17 activation contributes to oligodendrocyte dysfunc-tion and axonal damage.Gelosa et al.reported that CysLT1 receptor antagonist montelukast increased the recruitment and proliferation of oligodendrocyte precursor cells(OPCs)at the acute phase after ischemic stroke.Similarly,a study showed that montelukast stimulated neural progenitor proliferation and hippocampal neuro-genesis of aged rats through inhibition of GPR17.These results were supported by several studies on neurode-generative diseases.The authors showed that pharmaco-logical blockade of GPR17 with CysLT1 or CysLT2 recep-tor antagonists(montelukast or HAMI3379)improved oli-godendrocyte function and fiber connectivity,highlighting GPR17 as a potential therapeutic target in oligodendro-cyte protection and remyelination.Recently,growing evi-dence has revealed a significant interaction between mi-croglia and oligodendrocytes in CNS injury and disease.It was reported that M2 microglia promoted,while M1 microglia inhibited oligodendrogenesis,OPCs maturation and remyelination.Microglia-mediated neuroinflamma-tion,considered as an important pathological event,neg-atively affected OPCs fate and function in experimental neurological disorders.This was further corroborated by later studies.It was recently reported that montelukast enhanced OPCs differentiation and maturation by upreg-ulating the number of M2 microglia at chronic phase of brain ischemia.In line with the above results,inhibition of microglial inflammation by montelukast was shown to be responsible for neurite outgrowth.Although the exact mechanisms were not fully clarified,these results indi-cate that montelukast may indirectly promote OPCs dif-ferentiation and remyelination by a microglia-dependent manner.It has been widely accepted that CysLT1,CysLT2 and GPR17 receptors are localized in various cell types and their expression are upregulated after brain damage.Therefore,it is likely that CysLT receptor antagonists confer neuroprotection by targeting different receptors and multiple cell functions.Many studies have reported that CysLT receptor antagonists promote protec-tion of oligodendrocytes by inhibiting GPR17.Moreover,they may improve OPCs differentiation and neuronal sur-vival by regulating CysLTs-mediated microglial activation.Altogether,these data open novel perspectives in the treatment of cerebral ischemia and neurodegenerative diseases.

Regulation of Glial Function by Noncoding RNA in Central Nervous System Disease / 神经科学通报·英文版

Non-coding RNAs (ncRNAs) are a class of functional RNAs that play critical roles in different diseases. NcRNAs include microRNAs, long ncRNAs, and circular RNAs. They are highly expressed in the brain and are involved in the regulation of physiological and pathophysiological processes of central nervous system (CNS) diseases. Mounting evidence indicates that ncRNAs play key roles in CNS diseases. Further elucidating the mechanisms of ncRNA underlying the process of regulating glial function that may lead to the identification of novel therapeutic targets for CNS diseases.

Immunological Markers for Central Nervous System Glia / 神经科学通报·英文版

Glial cells in the central nervous system (CNS) are composed of oligodendrocytes, astrocytes and microglia. They contribute more than half of the total cells of the CNS, and are essential for neural development and functioning. Studies on the fate specification, differentiation, and functional diversification of glial cells mainly rely on the proper use of cell- or stage-specific molecular markers. However, as cellular markers often exhibit different specificity and sensitivity, careful consideration must be given prior to their application to avoid possible confusion. Here, we provide an updated overview of a list of well-established immunological markers for the labeling of central glia, and discuss the cell-type specificity and stage dependency of their expression.

Estresse juvenil de curta frequência e intensidade não afeta a substância branca cerebral de ratos / Juvenile stress of short frequency and intensity does not affect rats´ brain white matter

O objetivo deste estudo foi avaliar os efeitos duradouros de dois tipos de estresse sobre o corpo caloso (CC). Foram estudados 42 ratos Wistar machos divididos aleatoriamente em três grupos: Grupo Controle (GC), Estresse Físico (EF, imobilização) e Estresse Psicológico (EP, exposição ao predador). Os procedimentos de estresse ocorreram durante três dias consecutivos na idade juvenil (P25-P27) e foram analisados na idade adulta (P74). Os cérebros foram coletados, processados com a técnica de Klüver-Barrera, e secções foram analisadas por meio de morfometria. Os resultados demonstraram que não houve alterações em aspectos gerais como peso dos animais, e histológicos como espessura do CC e quantidade dos núcleos gliais nesta região. O estudo sugere que os efeitos duradouros de ambos os modelos de estresse juvenil de curta frequência (3 dias) e intensidade (90 minutos/EF e 20 minutos/EP) não foram nem prejudiciais e nem protetores, o que pode ser considerado uma adaptação positiva.

The current study evaluates the lasting effects of two types of stress on the corpus callosum (CC). Forty-two male Wistar rats were randomly divided into three groups: Control Group (CG), Physical Stress (FS, immobilization) and Psychological Stress (PS, exposure to predators). Stress procedures occurred for three consecutive days at the juvenile stage (P25-P27) and analyzed at the adult age (P74); brains were retrieved and processed by Klüver-Barrera technique and sections were analyzed by morphometry. Results showed that there were no changes in the general aspects such as animal weight, and in the histological aspects such as CC thickness and quantity of the region´s glia nuclei. Current research suggests that the lasting effects of both models of juvenile stress of short frequency (3 days) and intensity (90 minutes/FS and 20 minutes/PS) were neither detrimental nor protective, featuring a positive adaptation.

Proportion and morphological characteristics of human oligodendrocyte precursor cells in different cell culture vessels / 中国组织工程研究

BACKGROUND: Oligodendrocyte precursor cell transplantation is one of the keys to the treatment of white matter damage in premature infants. At present, there is a lack of research on the comparison of oligodendrocyte precursor cells induced by neural stem cells derived from human fetal brain cultured in vitro in different vessels worldwide. OBJECTIVE: To observe the morphology of human oligodendrocyte progenitor cells and pre-oligodendrocytes in different cell culture vessels (6-well plates, 24-well plates and T25 flasks). METHODS: The 6-well plates, 24-well plates and T25 flasks were used as culture vessels to culture human oligodendrocyte progenitor cells and pre-oligodendrocytes. The characteristics of human oligodendrocyte progenitor cells were identified by immunofluorescence staining and flow cytometry. The morphology of cells was observed by an ordinary light microscope. Cell counts were performed according to cell morphology and statistical analysis was performed. RESULTS AND CONCLUSION: (1) The oligodendrocyte progenitor cell body was round and the bipolar protrusions were bead-like; the pre-oligodendrocyte protrusions were more than two poles, and did not bifurcate. (2) The ratios of oligodendrocyte progenitor cell morphology in the oligodontia lines were significantly higher in the 6-well plates than those in the 24-well plates and T25 flasks (P < 0.05), followed by T25 flasks and 24-well plates. Morphological ratios of pre-oligodendrocytes were significantly higher in the 24-well plates compared to the 6-well plates and T25 flasks (P < 0.01), followed by T25 flasks and 6-well plates. (3) The cells cultured in the 6-well plate had fewer dregs, and the morphology, vigor and growth were better than those of the other culture vessels. (4) According to morphological view, 6-well plates are more suitable for oligodendrocyte progenitor cell growth, and 24-well plates are more suitable for pre-oligodendrocytes growth.

Pinocembrin Promotes OPC Differentiation and Remyelination via the mTOR Signaling Pathway / 神经科学通报·英文版

The exacerbation of progressive multiple sclerosis (MS) is closely associated with obstruction of the differentiation of oligodendrocyte progenitor cells (OPCs). To discover novel therapeutic compounds for enhancing remyelination by endogenous OPCs, we screened for myelin basic protein expression using cultured rat OPCs and a library of small-molecule compounds. One of the most effective drugs was pinocembrin, which remarkably promoted OPC differentiation and maturation without affecting cell proliferation and survival. Based on these in vitro effects, we further assessed the therapeutic effects of pinocembrin in animal models of demyelinating diseases. We demonstrated that pinocembrin significantly ameliorated the progression of experimental autoimmune encephalomyelitis (EAE) and enhanced the repair of demyelination in lysolectin-induced lesions. Further studies indicated that pinocembrin increased the phosphorylation level of mammalian target of rapamycin (mTOR). Taken together, our results demonstrated that pinocembrin promotes OPC differentiation and remyelination through the phosphorylated mTOR pathway, and suggest a novel therapeutic prospect for this natural flavonoid product in treating demyelinating diseases.

Pinocembrin Promotes OPC Differentiation and Remyelination via the mTOR Signaling Pathway / 神经科学通报·英文版

The exacerbation of progressive multiple sclerosis (MS) is closely associated with obstruction of the differentiation of oligodendrocyte progenitor cells (OPCs). To discover novel therapeutic compounds for enhancing remyelination by endogenous OPCs, we screened for myelin basic protein expression using cultured rat OPCs and a library of small-molecule compounds. One of the most effective drugs was pinocembrin, which remarkably promoted OPC differentiation and maturation without affecting cell proliferation and survival. Based on these in vitro effects, we further assessed the therapeutic effects of pinocembrin in animal models of demyelinating diseases. We demonstrated that pinocembrin significantly ameliorated the progression of experimental autoimmune encephalomyelitis (EAE) and enhanced the repair of demyelination in lysolectin-induced lesions. Further studies indicated that pinocembrin increased the phosphorylation level of mammalian target of rapamycin (mTOR). Taken together, our results demonstrated that pinocembrin promotes OPC differentiation and remyelination through the phosphorylated mTOR pathway, and suggest a novel therapeutic prospect for this natural flavonoid product in treating demyelinating diseases.

Morphological changes in human oligodendrocyte progenitor cells during passage / 中国组织工程研究

BACKGROUND: Oligodendrocyte precursor cells are seed cells for the treatment of white matter injury. The establishment of an efficient and stable in vitro culture method is an important prerequisite for clinical transformation. OBJECTIVE: To investigate the morphological changes of oligodendrocyte precursor cells during passage. METHODS: Four batches of human oligodendrocyte progenitor cells were subcultured from the second generation (P2) to the seventh generation (P7) in vitro. Five pictures of 200-fold field were taken under an optical microscope before each passage. According to the cell morphology, oligodendrocyte precursor cells were divided into three types: bipolar cells (oligodendrocyte precursor cells), multipolar cells (late oligodendrocyte precursor cells) and supra-polar bifurcated cells (immature oligodendrocyte cells). The proportion of oligodendrocyte progenitor cells to the total number of cells was calculated, so as to compare the difference of cell morphology among different generations. RESULTS AND CONCLUSION: In the process of passage from P2 to P7, oligodendrocyte progenitor cells included three types: bipolar cells, multipolar cells and supra-polar bifurcated cells. Among them, bipolar cells and multipolar cells were the main part, and a small number of supra-polar bifurcated cells could be seen in the rest. There were no significant differences in the proportion of bipolar cells, multipolar cells and supra-polar bifurcated cells among P2-P7 (P > 0.05). The cell morphology classification and counting method can be used to preliminarily evaluate that oligodendrocyte progenitor cells have no change in morphology during culture.

Insight into white matter changes in Alzheimer’s disease: A focus on myelin and oligodendrocyte / 中国组织工程研究

BACKGROUND: In previous studies Alzheimer’s disease was considered as a typical disease of the brain gray matter, and most attention has focused on the pathological and neuroimaging changes of gray matter in Alzheimer’s disease. Recently, in addition to neuronal loss, white matter degeneration and demyelination may be important pathophysiological features in the progress of Alzheimer’s disease. To date, much attention has been paid to the changes of white matter in Alzheimer’s disease. OBJECTIVE: To elucidate the evidence for extensive white matter abnormalities in Alzheimer’s disease and its mechanism, and to discuss the relationship between white matter changes and cognitive function. METHODS: A computer-based retrieval was performed by the first author in PubMed and CNKI databases to search related papers published from January 1998 to April 2019 using the keywords of “Alzheimer’s disease, white matter injury, neurodegeneration, oligodendrocyte” in English and Chinese, respectively. Articles related to Alzheimer’s disease, white matter abnormalities, the mechanism of oligodendrocyte death and the relationship between white matter changes and cognitive function were selected. A total of 41 relevant literatures were retrieved. RESULTS AND CONCLUSION: White matter abnormalities widely occur in Alzheimer’s disease patients, which are probably the earliest pathological changes. White matter lesions are of important significance in the pathology and pathogenesis of Alzheimer’s disease. Several mechanisms such Aβ toxicity and tauopathy, oxidative stress, excitotoxicity, and iron overload can affect oligodendrocytes, resulting in myelin loss. Altering axonal conduction by demyelination or axonal damage can directly and/or indirectly affect cognition. In conclusion, white matter changes are closely related to cognitive impairment. Explorations on the relationship between white matter changes and the hallmark of Alzheimer’s disease cannot only provide theoretical evidence for Alzheimer’s disease pathogenesis, but also develop a new therapeutic approach for Alzheimer’s disease.

Progress on the roles of glia in postoperative cognitive dysfunction / 生物医学工程学杂志

Postoperative cognitive dysfunction (POCD) is one of the most common complications after surgery under general anesthesia and usually manifests as newly presented cognitive impairment. However, the mechanism of POCD is still unclear. In addition to neurons, glial cells including microglia, astrocytes and oligodendrocytes, represent a large cell population in the nervous system. The bi-directional communication between neurons and glia provides basis for neural circuit function. Recent studies suggest that glial dysfunctions may contribute to the occurrence and progress of POCD. In this paper, we review the relevant work on POCD, which may provide new insights into the mechanism and therapeutic strategy for POCD.

Electroacupuncture promotes regeneration and repair of myelin sheath of corpus callosum in demyelination mice / 针刺研究

OBJECTIVE: To explore the mechanism of electroacupuncture (EA) in accelerating the aggregation of microglia and promoting the remyelination at the location of demyelination. METHODS: C57BL/6 mice were randomly divided into 4 groups: normal, control, model (LPC) and LPC＋EA. The demyelination model was established by microinjection of Lysolecithin (LPC, 1 µL) into the left corpus callosum. EA (2 Hz/15 Hz, 2－4 mA) was applied to "Baihui"(GV20)and "Zhiyang"(GV9)for 30 min，once daily for 3 days, then, once every other day for 18 days. Immuno-fluorescence staining was used to observe the expression of myelin basic protein (MBP) and Axl tyrosine kinase receptor (Axl), Iba1 and numbers of Olig2-positive oligodendrocytes in the corpus callosum. Western blot was employed to detect the expression of MBP in the corpus callosum, and Oil Red O staining was used to observe changes of number of myelin pieces. RESULTS: Following modeling, the expression levels of MBP on day 5 and 10 after modeling were significantly decreased (P<0.05, P<0.01), Iba1 expression and Olig2-positive oligodendrocyte numbers on day 10 apparently increased (P<0.001, P<0.01). On day 21 after modeling, the levels of the above mentioned indexes returned to normal. After EA intervention, the levels of MBP expression on day 5 and 10, Axl, Iba1 protein expression and Olig2-positive oligodendrocyte numbers on day 5 were markedly increased (P<0.001，P<0.01，P<0.05), while Iba1 expression on day 10 was considerably decreased in comparison with the model group (P<0.01)．Oil Red O staining showed that on day 5 after modeling, the number of red lipid droplets were obviously increased in the corpus callosum tissue on the injection side, and apparently reduced in the EA group, suggesting a clearance of the accumulated myelin fragments by EA. CONCLUSION: EA intervention may reduce myelin debris and promote the aggregation of microglial cells and oligodendrocytes to the injured site, accelerate the myelin regeneration and up-regulate the expression of MBP and Axl of corpus callosum in demyelination mice.

Effect of propofol on myelin basic protein expression and myelination of oligodendrocytes in neonatal SD rats / 南方医科大学学报

OBJECTIVE@#To investigate the effects of different doses of propofol on myelin basic protein (MBP) synthesis and myelination of oligodendrocytes in neonatal SD rats.@*METHODS@#A total of 57 neonatal SD rats (7 days old) were randomly divided into control group (=13), vehicle (fat emulsion) group (=5), and 25, 50 and 100 mg/kg propofol groups (=13 in each group). Eight hours after a single intraperitoneal injection of propofol or the vehicle, the rats were examined for expressions of mRNA, caspase-3 mRNA, cleaved caspase-3 and MBP in the brain tissues using qPCR and Western blotting. Immunofluorescence assay was used to detect the apoptosis of the oligodendrocytes at 8 h after the injection and the myelination of the corpus callosum and internal capsule at 24 h.@*RESULTS@#Compared with the control group, the neonatal rats with propofol injections showed significantly down-regulated expressions of mRNA and MBP protein in the brain tissue ( < 0.05). Propofol dose-dependently increased the transcription level of caspase-3 and the protein levels of cleaved caspase-3 at 8 h after the injection ( < 0.05). Propofol injection significantly increased the apoptosis of the oligodendrocytes, and the effect was significantly stronger in 50 and 100 mg/kg groups than in 25 mg/kg group ( < 0.05). At 24 h after propofol injection, myelin formation was significantly decreased in the corpus callosum of the neonatal rats in 100 mg/kg propofol group and in the internal capsule in 50 and 100 mg/kg groups ( < 0.05).@*CONCLUSIONS@#In neonatal SD rats, propofol can dose-dependently promote oligodendrocyte apoptosis, decrease MBP expressions in the brain, and suppress myelin formation in the corpus callosum and the internal capsule.

Effects of Carpobrotus edulis Extract on Oxidative Stress and 158N Oligodendrocyte Death / 生物医学与环境科学（英文）

OBJECTIVE@#Age-related diseases, including neurodegenerative diseases, are associated with oxidative stress and lipid peroxidation, and increase the levels of cholesterol auto-oxidation products such as 7β-hydroxycholesterol (7β-OHC). Thus, it is imperative to identify agents that can prevent 7β-OHC-induced side-effects.@*METHODS@#We evaluated the potential protective effects of Carpobrotus edulis ethanol-water extract (EWe) on murine oligodendrocytes (158N) cultured in the absence or presence of 7β-OHC (20 μg/mL, 24 h). The cells were incubated with EWe (20-200 µg/mL) 2 h before 7β-OHC treatment. Mitochondrial activity and cell growth were evaluated with the MTT assay. Photometric methods were used to analyze antioxidant enzyme [catalase (CAT) and glutathione peroxidase (GPx)] activities and the generation of lipid and protein oxidation products [malondialdehyde (MDA), conjugated diene (CD), and carbonylated proteins (CPs)].@*RESULTS@#Treatment with 7β-OHC induced cell death and oxidative stress (reflected by alteration in CAT and SOD activities). Overproduction of lipid peroxidation products (MDA and CDs) and CPs was also reported. The cytotoxic effects associated with 7β-OHC were attenuated by 160 μg/mL of EWe of C. edulis. Cell death induced by 7β-OHC treatment was ameliorated, GPx and CAT activities were restored to normal, and MDA, CD, and CP levels were reduced following C. edulis extract treatment.@*CONCLUSION@#These data demonstrate the protective activities of C. edulis EWe against 7β-OHC-induced disequilibrium in the redox status of 158N cells, indicative of the potential role of this plant extract in the prevention of neurodegenerative diseases.

Effects of Xenon on expression of CLIC4 mRNA in neonatal rats brain with white matter damage / 中华实用儿科临床杂志

Objective To investigate the mechanism of white matter damage (WMD) and the neuroprotective effect of Xenon on neonates with WMD.Methods Three-day-old SD rat pups (n =96) were randomly divided into the blank control group (n =24),the WMD control group (n =24),the Xenon intervention group A (n =24) and the Xenon intervention group B (n =24) by random number method according to their birth time.WMD rat models were successfully established by giving intraperitoneal injection of lipopolysaccharide(LPS) 0.05 mg/kg combined with carotid artery ligation and hypoxia for 1 hour in the WMD control group and the Xenon intervention groups.In the control group,only 9 g/L saline (0.05 mg/kg) was injected intraperitoneally,while carotid artery ligation and hypoxia were not administered.Rats in Xenon intervention group A and group B were given inhalation of 500 mL/L Xenon for 3 hours at 0 and 2 hours respectively after establishment of the models.Six rats in each group were randomly selected and decapitated at 0,24,48 and 72 hours after the intervention.The brain white matter on the right was analyzed by using HE staining and myelin basic protein(MBP) immunofluorescence staining,and real-time quantitative polymerase chain reaction was used to detect the expressions level of CLIC4 mRNA.Results (1) Brain tissue pathology:compared with the blank control group,the brain white matter on the right of the WMD control group and the Xenon intervention group A and group B had loose and disordered structure,nuclear pyknosis and cytoplasm loosening.However,the lesions in both Xenon intervention group A and group B were significantly less than those in the WMD control group,and there was no significant difference between the Xenon intervention group A and group B.(2) MBP measurement:the number of MBP-positive cells in the brain white matter on the right of WMD control group was significantly lower than that in the blank control group,while compared with WMD control group,they were significantly higher in Xenon intervention group A and group B.(3) CLIC4 mRNA expression level:compared with blank control group,the expressions levels of CLIC4 mRNA at most time point were higher both in the WMD control group and the Xenon intervention group A and group B (all P ＜ 0.05),except the time point 24 h in the Xenon intervention group A.The expressions of CLIC4 mRNA in group A and group B were significantly decreased compared with those in the WMD control group (all P ＜ 0.05).However,there were no significant differences between Xenon intervention group A and group B (P ＞ 0.05).Conclusions The expressions of CLIC4 mRNA in brain tissues on neonatal rats with WMD significantly increased,indicating that the mitochondrial pathway could be one of the pathological processes of WMD.Early Xenon intervention may reduce neonatal WMD by reducing the expression of CLIC4 mRNA,which plays a neuroprotective role.

Biochemical events related to glial response in spinal cord injury / Eventos bioquímicos de respuesta glial en la fisiopatología de la lesión de médula espinal

Abstract Introduction: Spinal cord injury (SCI) is a devastating event with physical, psychological and socioeconomic implications. Morphophysiological changes are observed in the tissue close to the injury, which allow determining the functional recovery of the medullary segment and the effector organs that depend on the injured axonal tracts. Objective: To describe the most relevant sequential biochemical events of glial cells response after SCI. Materials and methods: A search of scientific publications released in the past 18 years was carried out in PubMed and Science Direct databases, with the terms spinal cord injury (SCI), SCI pathophysiology, SCI inflammation, microglia in SCI, glial scar and chondroitin sulfate proteoglycans (CSPG). Results: The pathophysiological processes resulting from SCI are determinant for the neurological recovery of patients. Activation of glial cells plays an important role in promoting bioactive molecules and the formation of physical barriers that inhibit neural regeneration. Conclusion: Knowledge of neurobiological changes after SCI allows a greater understanding of the pathophysiology and favors the search for new therapeutic alternatives that limit the progression of the primary injury and minimize secondary damage, responsible for neurological dysfunction.

Resumen Introducción. La lesión de la médula espinal (LME) es un evento devastador con implicaciones físicas, psicológicas y socioeconómicas. En el tejido cercano a la lesión se instauran cambios morfofisiológicos que determinan la recuperación funcional del segmento medular y de los órganos efectores dependientes de los tractos axonales lesionados. Objetivo. Describir los eventos bioquímicos secuenciales más relevantes de la respuesta de las células gliales posterior a la LME. Materiales y métodos. Se realizó una búsqueda de publicaciones científicas de los últimos 18 años en las bases de datos PubMed y ScienceDirect, bajo los términos en inglés spinal cord injury (SCI), SCI pathophysiology, SCI inflammation, microglia in SCI, glial scar y chondroitin sulfate proteoglycans (CSPG). Resultados. Los procesos fisiopatológicos que se producen después de la LME determinan la recuperación neurológica de los pacientes. La activación de las células gliales juega un papel importante, ya que promueve la producción de moléculas bioactivas y la formación de barreras físicas que inhiben la regeneración neural. Conclusión. El conocimiento de los cambios neurobiológicos ocurridos tras la LME permite una mayor comprensión de la fisiopatología y favorece la búsqueda de nuevas alternativas terapéuticas que limiten la progresión de la lesión primaria y que minimicen el daño secundario responsable de la disfunción neurológica.

AATYK is a Novel Regulator of Oligodendrocyte Differentiation and Myelination / 神经科学通报·英文版

Oligodendrocytes (OLs) are myelinating glial cells that form myelin sheaths around axons to ensure rapid and focal conduction of action potentials. Here, we found that an axonal outgrowth regulatory molecule, AATYK (apoptosis-associated tyrosine kinase), was up-regulated with OL differentiation and remyelination. We therefore studied its role in OL differentiation. The results showed that AATYK knockdown inhibited OL differentiation and the expression of myelin genes in vitro. Moreover, AATYK-deficiency maintained the proliferation status of OLs but did not affect their survival. Thus, AATYK is essential for the differentiation of OLs.

A clinical analysis of patients with AQP4-IgG and MOG-IgG seropositive / 中国神经精神疾病杂志

Objective To study the seropositive ratio of the antibody to aquporin 4 (AQP4-IgG) and myelin oligodendrocytes glycoprotein antibody(MOG-IgG)in patients with autoimmune-associated central nervous system (CNS) diseases. Meanwhile, epidemiology and clinical manifestation and diagnosis,laboratory examination and magnetic resonance imaging(MRI)of AQP4-IgG seropositive and MOG-IgG seropositive patients are described. Methods 2068 patients serum samples were collected and enrolled in the multi-center research. The methodology of cell-mediated immunofluorescence staining was used to detect serum AQP4-IgG and MOG-IgG. Clinic medical records were collected and characteristics of epidemiology and manifestation were compared. Results 681 patients were AQP4-IgG seropositive and 110 patients were MOG-IgG seropositive. The female/male ratio and age of onset of patients with AQP4-IgG seropositive(616 female and 65 male,female:male=9.50:1.00;Age of onset=41.7±14.9)were significantly higher than that of patients with MOG-IgG (57 female and 53 male, female:male=1.08:1.00, P<0.0001; Age of onset=27.0 ±17.7, P<0.0001). The optic neuritis was significantly higher in patients with AQP4-IgG seropositive and patients with MOG-IgG seropositive (38.4% vs.53.5%, P<0.05).Among patients with AQP4-IgG seropositive, 42.14% conformed the diagnostic criteria of neuromyelitis optica (NMO),which was higher than that of patients with MOG-IgG seropositive (13.64%, P<0.0001). Laboratory examination showed that there was no significant difference in cerebrospinal fluid protein levels between patients with AQP4-IgG seropositive and those with MOG-IgG seropositive.MRI imaging suggested that AQP4-IgG positive patients were more common in cervical thoracic spinal cord lesions, while MOG-IgG positive patients were more involved in thoracolumbar spinal cord. The study also found that these two groups of patients could be comorbid with other autoimmune antibodies. Conclusions This multi-center research has revealed that patients with AQP4-IgG seropositive and those with MOG-IgG seropositive display differences in epidemiology,clinic manifestations and diagnosis,laboratory examination and MRI imaging. AQP4-IgG and MOG IgG auto-antibody detection are necessary for clinic diagnosis and differential diagnosis.

The expression of oligodendrocytes in the emotional disorder-related brain areas of the post-stroke depression model rats / 中华行为医学与脑科学杂志

Objective To explore the expression of the CNPase positive oligodendrocytes in the frontal cortex,hippocampus and amygdala of the post-stroke depression (PSD) model rats,and to understand the role of oligodendrocytes in the pathogenesis of PSD.Methods Healthy adult SD rats were randomly divided into normal group,depression group,stroke group,and PSD group (n =5 in each group).In the stroke group,focal cerebral ischemic rat model was made with thread embolization method.In the depression group,the depression model rats were made by chronic unpredictable mild stress(CUMS) combined with separately breeding.In the PSD group,focal cerebral ischemic rat model was made with thread embolization method firstly,and then PSD rat model was established with comprehensive chronic unpredictable mild stress (CUMS) and separately breeding on this basis.After the procedure,rats were subjected to sucrose preference test (SPT) and open field test (OFT).Immunofluorescence staining was used to detect the expression of the CNPase positive oligodendrocytes in the frontal cortex,hippocampus and amygdala at day 29.Results On the 29th day after CUMS,comparing the sucrose solution consumption,horizontal movement distance of open field test and vertical movement distance of the each group,the depression((26.6± 1.1)％,(63.6±2.3)cm,(26.4±1.1)cm) and the PSD groups((23.8±0.8)％,(63.0± 1.2) cm,(25.0± 1.0) cm) were significantlylower than normal ((31.2± 1.9) ％,(69.8± 2.3) cm,(31.0 ± 1.6) cm) and the stroke groups ((31.0± 1.4) ％,(70.2±2.4) cm,(30.8 ± 1.1) cm) (P＜ 0.05).Comparing the expression of the CNPase positive oligodendrocytes in the frontal cortex,hippocampus and amygdala of the each group,the number of the stroke((16.60± 1.82),(14.60±1.82),(15.00±2.12)),depression((16.40±2.07),(14.80±2.17),(15.80±2.28)) and the PSD groups((12.40± 1.52),(11.20± 1.48),(10.80± 1.92)) were significantly less than that in normal group((20.40±3.51),(18.20±2.59),(19.00±2.55)),and the number of expression CNPase positive oligodendrocytes in the PSD group was significantly less than that in stroke and depression groups(all P＜0.05).Conclusion The number of the CNPase positive oligodendrocytes in PSD group in the emotional disorders related brain areas (the frontal lobe,hippocampus and amygdale) reduced obviously,and the oligodendrocytes may play an important role in the pathogenesis of PSD.

Propentofylline reverses delayed remyelination in streptozotocin-induced diabetic rats

Objective The diabetic state induced by streptozotocin injection is known to impair oligodendroglial remyelination in the rat brainstem following intracisternal injection with the gliotoxic agent ethidium bromide (EB). In such experimental model, propentofylline (PPF) recently showed to improve myelin repair, probably due to its neuroprotective, antiinflammatory and antioxidant effects. The aim of this study was to evaluate the effect of PPF administration in diabetic rats submitted to the EB-demyelinating model. Materials and methods Adult male rats, diabetic or not, received a single injection of 10 microlitres of 0.1% EB solution into the cisterna pontis. For induction of diabetes mellitus the streptozotocin-diabetogenic model was used (50 mg/kg, intraperitoneal route – IP). Some diabetic rats were treated with PPF (12.5 mg/kg/day, IP route) during the experimental period. The animals were anesthetized and perfused from 7 to 31 days after EB injection and brainstem sections were collected for analysis of the lesions by light and transmission electron microscopy. Results Diabetic rats injected with EB showed larger amounts of myelin-derived membranes in the central areas of the lesions and considerable delay in the remyelinating process played by surviving oligodendrocytes and invading Schwann cells after the 15th day. On the other hand, diabetic rats that received PPF presented lesions similar to those of non-diabetic animals, with rapid remyelination at the edges of the lesion site and fast clearance of myelin debris from the central area. Conclusion The administration of PPF apparently reversed the impairment in remyelination induced by the diabetic state. Arch Endocrinol Metab. 2015;59(1):47-53 .

Human intraretinal myelination: Axon diameters and axon/myelin thickness ratios.

Purpose: Human intraretinal myelination of ganglion cell axons occurs in about 1% of the population. We examined myelin thickness and axon diameter in human retinal specimens containing myelinated retinal ganglion cell axons. Materials and Methods: Two eyes containing myelinated patches were prepared for electron microscopy. Two areas were examined in one retina and five in the second retina. Measurements were compared to normal retinal and optic nerve samples and the rabbit retina, which normally contains myelinated axons. Measurements were made using a graphics tablet. Results: Mean axon diameter of myelinated axons at all locations were significantly larger than unmyelinated axons (P ≤ 0.01). Myelinated axons within the patches were significantly larger than axons within the optic nerve (P < 0.01). The relationship between axon diameter/fiber diameter (the G‑ratio) seen in the retinal sites differed from that in the nerve. G‑ratios were higher and myelin thickness was positively correlated to axon diameter (P < 0.01) in the retina but negatively correlated to axon diameter in the nerve (P < 0.001). Conclusion: Intraretinally myelinated axons are larger than non‑myelinated axons from the same population and suggests that glial cells can induce diameter changes in retinal axons that are not normally myelinated. This effect is more dramatic on intraretinal axons compared with the normal transition zone as axons enter the optic nerve and these changes are abnormal. Whether intraretinal myelin alters axonal conduction velocity or blocks axonal conduction remains to be clarified and these issues may have different clinical outcomes.