Premature birth is a significant economic and public health burden, and its incidence is rising. Periventricular leukomalacia （PVL） is the predominant form of brain injury in premature infants and the leading cause ...Premature birth is a significant economic and public health burden, and its incidence is rising. Periventricular leukomalacia （PVL） is the predominant form of brain injury in premature infants and the leading cause of cerebral palsy. PVL is characterized by selective white-matter damage with prominent oligodendroglial injury. The maturation-dependent vulnerability of developing and premyelinating oligodendrocytes to excitotoxic, oxidative, and inflammatory forms of injury is a major factor in the pathogenesis of PVL. Recent studies using mouse models of PVL reveal that synapses between axons and developing oligodendrocytes are quickly and profoundly damaged in immature white matter. Axon-glia synapses are highly vulnerable to white-matter injury in the developing brain, and the loss of synapses between axons and premyelinating oligodendrocytes occurs before any cellular loss in the immature white matter. Microglial activation and astrogliosis play important roles in triggering white-matter injury. Impairment of white-matter development and function in the neonatal period contributes critically to functional and behavioral deficits. Preservation of the integrity of the white matter is likely key in the treatment of PVL and subsequent neurological consequences and disabilities.展开更多
Immunoglobulin G against myelin oligodendrocyte glycoprotein(MOG-Ig G) is detectable in neuromyelitis optica spectrum disorder(NMOSD) without aquaporin-4 Ig G(AQP4-Ig G), but its pathogenicity remains unclear.In this ...Immunoglobulin G against myelin oligodendrocyte glycoprotein(MOG-Ig G) is detectable in neuromyelitis optica spectrum disorder(NMOSD) without aquaporin-4 Ig G(AQP4-Ig G), but its pathogenicity remains unclear.In this study, we explored the pathogenic mechanisms of MOG-Ig G in vitro and in vivo and compared them with those of AQP4-Ig G. MOG-Ig G-positive serum induced complement activation and cell death in human embryonic kidney(HEK)-293 T cells transfected with human MOG. In C57 BL/6 mice and Sprague-Dawley rats, MOG-Ig G only caused lesions in the presence of complement. Interestingly, AQP4-Ig G induced astroglial damage, while MOGIg G mainly caused myelin loss. MOG-Ig G also induced astrocyte damage in mouse brains in the presence ofcomplement. Importantly, we also observed ultrastructural changes induced by MOG-Ig G and AQP4-Ig G. These findings suggest that MOG-Ig G directly mediates cell death by activating complement in vitro and producing NMOSDlike lesions in vivo. AQP4-Ig G directly targets astrocytes,while MOG-Ig G mainly damages oligodendrocytes.展开更多
3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-cycloastragenol （astragaloside IV）, the main active component of the traditional Chinese medicine astragalus membranaceus, has been shown to be neuroprotective. Thi...3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-cycloastragenol （astragaloside IV）, the main active component of the traditional Chinese medicine astragalus membranaceus, has been shown to be neuroprotective. This study investigated whether astragaloside IV could promote the repair of injured sciatic nerve. Denervated sciatic nerve of mice was subjected to anastomosis. The mice were intraperitoneally injected with 10, 5, 2.5 mg/kg astragaloside IV per day for 8 consecutive days Western blot assay and real-time PCR results demonstrated that growth-associated protein-43 ex- pression was upregulated in mouse spinal cord segments L4-6 after intervention with 10, 5, 2.5 mg/kg astragaloside IV per day in a dose-dependent manner. Luxol fast blue staining and elec- trophysiological detection suggested that astragaloside IV elevated the number and diameter of myelinated nerve fibers, and simultaneously increased motor nerve conduction velocity and action potential amplitude in the sciatic nerve of mice. These results indicated that astragaloside IV con- tributed to sciatic nerve regeneration and functional recovery in mice. The mechanism underlying this effect may be associated with the upregulation of growth-associated protein-43 expression.展开更多
The development,maturation and regeneration of Schwann cells（SCs）,the main glial cells of the peripheral nervous system,require the coordinate and complementary interaction among several factors,signals and intracel...The development,maturation and regeneration of Schwann cells（SCs）,the main glial cells of the peripheral nervous system,require the coordinate and complementary interaction among several factors,signals and intracellular pathways.These regulatory molecules consist of integrins,neuregulins,growth factors,hormones,neurotransmitters,as well as entire intracellular pathways including protein-kinase A,C,Akt,Erk/MAPK,Hippo,mTOR,etc.For instance,Hippo pathway is overall involved in proliferation,apoptosis,regeneration and organ size control,being crucial in cancer proliferation process.In SCs,Hippo is linked to merlin and YAP/TAZ signaling and it seems to respond to mechanic/physical challenges.Recently,among factors regulating SCs,also the signaling intermediates Src tyrosine kinase and focal adhesion kinase（FAK）proved relevant for SC fate,participating in the regulation of adhesion,motility,migration and in vitro myelination.In SCs,the factors Src and FAK are regulated by the neuroactive steroid allopregnanolone,thus corroborating the importance of this steroid in the control of SC maturation.In this review,we illustrate some old and novel signaling pathways modulating SC biology and functions during the different developmental,mature and regenerative states展开更多
Axonal degeneration is a pivotal feature of many neurodegenerative conditions and substantially accounts for neurological morbidity. A widely used experimental model to study the mechanisms of axonal degeneration is W...Axonal degeneration is a pivotal feature of many neurodegenerative conditions and substantially accounts for neurological morbidity. A widely used experimental model to study the mechanisms of axonal degeneration is Wallerian degeneration （WD）, which occurs after acute axonal injury. In the peripheral nervous system （PNS）, WD is characterized by swift dismantling and clearance of injured axons with their myelin sheaths. This is a prerequisite for successful axonal regeneration. In the central nervous system （CNS）, WD is much slower, which significantly contributes to failed axonal regeneration. Although it is well documented that Schwann cells （SCs） have a critical role in the regenerative potential of the PNS, to date we have only scarce knowledge as to how SCs ＇sense＇ axonal injury and immediately respond to it. In this regard, it remains unknown as to whether SCs play the role of a passive bystander or an active director during the execution of the highly orchestrated disintegration program of axons. Older reports, together with more recent studies, suggest that SCs mount dynamic injury responses minutes after axonal injury, long before axonal breakdown occurs. The swift SC response to axonal injury could play either a pro degenerative role, or alternatively a supportive role, to the integrity of distressed axons that have not yet committed to degenerate. Indeed, supporting the latter concept, recent 昀ndings in a chronic PNS neurodegeneration model indicate that deactivation of a key molecule promoting SC injury responses exacerbates axonal loss. If this holds true in a broader spectrum of conditions, it may provide the grounds for the development of new glia-centric therapeutic approaches to counteract axonal loss.展开更多
Objective： To study the effects of Bushen Yisui Capsule（补肾益髓胶囊, BSYSC） on the oligodendrocyte lineage genes（Olig） 1 and Olig2 in C57BL/6 mice with experimental autoimmune encephalomyelitis（EAE） in order t...Objective： To study the effects of Bushen Yisui Capsule（补肾益髓胶囊, BSYSC） on the oligodendrocyte lineage genes（Olig） 1 and Olig2 in C57BL/6 mice with experimental autoimmune encephalomyelitis（EAE） in order to explore the remyelination effect of BSYSC. Methods： The mice were randomly divided into normal control（NC）, EAE model（EAE-M）, prednisone acetate（PA, 6 mg/kg）, BSYSC high-dose（3.02 g/kg） and BSYSC low-dose（1.51 g/kg） groups. The mice were induced by immunization with myelin oligodendrocyte glycoprotein（MOG） 35-55. The neurological function scores were assessed once daily. The pathological changes in mice brains were observed with hematoxylin-eosin（HE） staining and transmission electron microscope（TEM）. The protein expressions of myelin basic protein（MBP）, Olig1 and Olig2 in brains were measured by immunohistochemistry. The m RNA expressions of Olig1 and Olig 2 was also determined by quantitative real-time polymerase chain reaction. Results： Compared with the EAE-M mice,（1） the neurological function scores were significantly decreased in BSYSC-treated mice on days 22 to 40（P〈0.01）;（2） the inflammatory cells and demyelination in brains were reduced in BSYSC-treated EAE mice;（3） the protein expression of MBP was markedly increased in BSYSC-treated groups on day 18 and 40 respectively（P〈0.05 or P〈0.01）;（4） the protein expression of Olig1 was increased in BSYSC（3.02 g/kg）-treated EAE mice on day 40（P〈0.01）. Protein and m RNA expression of Olig2 was increased in BSYSC-treated EAE mice on day 18 and 40（P〈0.01）. Conclusion： The effects of BSYSC on reducing demyelination and promoting remyelination might be associated with the increase of Olig1 and Olig2.展开更多
Remyelination plays a key role in functional recovery of axons after spinal cord injury.Glial cells are the most abundant cells in the central nervous system.When spinal cord injury occurs,many glial cells at the lesi...Remyelination plays a key role in functional recovery of axons after spinal cord injury.Glial cells are the most abundant cells in the central nervous system.When spinal cord injury occurs,many glial cells at the lesion site are immediately activated,and different cells differentially affect inflammatory reactions after injury.In this review,we aim to discuss the core role of oligodendrocyte precursor cells and crosstalk with the rest of glia and their subcategories in the remyelination process.Activated astrocytes influence proliferation,differentiation,and maturation of oligodendrocyte precursor cells,while activated microglia alter remyelination by regulating the inflammatory reaction after spinal cord injury.Understanding the interaction between oligodendrocyte precursor cells and the rest of glia is necessary when designing a therapeutic plan of remyelination after spinal cord injury.展开更多
Objective: To investigate the therapeutic effect of nerve growth factor (NGF) on changes of myelin basic protein (MBP) and functional repair of sensory and motor nerve following sciatic nerve injury. Methods: The scia...Objective: To investigate the therapeutic effect of nerve growth factor (NGF) on changes of myelin basic protein (MBP) and functional repair of sensory and motor nerve following sciatic nerve injury. Methods: The sciatic nerves of rats were injured by sectioning with shaver,and divided into 3 groups: NGF group (Group A), group of normal saline solution (Group B), untreated group (Group C). The time point of observation was at the 4th week after operation. Sensory evoked potential (SEP) and motor evoked potential (MEP) were detected by Model WD 4000 nerve potential working diagnosis system. Immunohistochemical analysis was used for identification of MBP.Results: The latency of SEP in the Group A at the 4th week after operation was shorter than that in the Group B (P< 0.05 ). The MEP was elicited in 76% of the Group A and was higher than that in the Group B. Results of immunohistochemistry showed that there were less MBP positive cells in the Group A than in the Group B in one and four weeks respectively.Conclusions: NGF can improve the conductive function of injured peripheral nerve and facilitate regeneration of nerve.展开更多
Background Chronic exposure to n-hexane can lead to peripheral neuropathy that no effective treatment regimen could be applied presently. This study investigated whether myelin protein zero （P0） protein and its anti...Background Chronic exposure to n-hexane can lead to peripheral neuropathy that no effective treatment regimen could be applied presently. This study investigated whether myelin protein zero （P0） protein and its antibody could be used to distinguish n-hexane intoxication and protect workers from peripheral neuropathy. Methods We compared P0 protein and its antibody among three levels of n-hexane-exposed groups, which included 18 patients with n-hexane-induced peripheral neuropathy as case group, 120 n-hexane-exposed workers as n-hexane- exposed control group, and 147 non-hexane-exposed participants used as control group. ELISA method was applied to detect P0 protein and its antibody. Results P0 protein in serum was significantly higher in the case group and n-hexane-exposed control group in comparison with the control group （P〈0.01）. Compared with the n-hexane-exposed control group, the case group also had significant increase of P0 protein （P〈0.01）. After 6 months therapy, P0 protein was observed to decrease significantly in the case group （P〈0.01）. The P0 antibody in serum was significantly higher in the n-hexane-exposed control group than in the control group （P〈0.01）, but not significantly different between cases and controls. Conclusions P0 antibodies in serum may be a short-term effect biomarker for n-hexane exposure. P0 protein in serum may be an early effective biomarker for peripheral nerve neuropathy and its biological limit value needs investigation in the future study.展开更多
Human umbilical mesenchymal stem cells from Wharton＇s jelly of the umbilical cord were induced to differentiate into oligodendrocyte precursor-like cells in vitro. Oligodendrocyte precursor cells were transplanted in...Human umbilical mesenchymal stem cells from Wharton＇s jelly of the umbilical cord were induced to differentiate into oligodendrocyte precursor-like cells in vitro. Oligodendrocyte precursor cells were transplanted into contused rat spinal cords. Immunofluorescence double staining indicated that transplanted cells survived in injured spinal cord, and differentiated into mature and immature oligodendrocyte precursor cells. Biotinylated dextran amine tracing results showed that cell transplantation promoted a higher density of the corticospinal tract in the central and caudal parts of the injured spinal cord. Luxol fast blue and toluidine blue staining showed that the volume of residual myelin was significantly increased at 1 and 2 mm rostral and caudal to the lesion epicenter after cell transplantation. Furthermore, immunofluorescence staining verified that the newly regenerated myelin sheath was derived from the central nervous system. Basso, Beattie and Bresnahan testing showed an evident behavioral recovery. These results suggest that human umbilical mesenchymal stem cell-derived oligodendrocyte precursor cells promote the regeneration of spinal axons and myelin sheaths.展开更多
Autism spectrum disorder(ASD) is a neurodevelopmental disorder characterized by deficits in social interaction and communication, along with repetitive and restrictive patterns of behaviors or interests. Normal brain ...Autism spectrum disorder(ASD) is a neurodevelopmental disorder characterized by deficits in social interaction and communication, along with repetitive and restrictive patterns of behaviors or interests. Normal brain development is crucial to behavior and cognition in adulthood. Abnormal brain development, such as synaptic and myelin dysfunction, is involved in the pathogenesis of ASD. Microtubules and microtubule-associated proteins(MAPs) are important in regulating the processes of brain development, including neuron production and synaptic formation, as well as myelination. Increasing evidence suggests that the level of MAPs are changed in autistic patients and mouse models of ASD. Here, we discuss the roles of MAPs.展开更多
The myelin sheath is a lipoprotein-rich,multilayered structure capable of increasing conduction velocity in central and peripheral myelinated nerve fibers.Due to the complex structure and composition of myelin,various...The myelin sheath is a lipoprotein-rich,multilayered structure capable of increasing conduction velocity in central and peripheral myelinated nerve fibers.Due to the complex structure and composition of myelin,various histological techniques have been developed over the centuries to evaluate myelin under normal,pathological or experimental conditions.Today,methods to assess myelin integrity or content are key tools in both clinical diagnosis and neuroscience research.In this review,we provide an updated summary of the composition and structure of the myelin sheath and discuss some histological procedures,from tissue fixation and processing techniques to the most used and practical myelin histological staining methods.Considering the lipoprotein nature of myelin,the main features and technical details of the different available methods that can be used to evaluate the lipid or protein components of myelin are described,as well as the precise ultrastructural techniques.展开更多
Salvianolic acid B,an active pharmaceutical compound present in Salvia miltiorrhiza,exerts a neuroprotective effect in animal models of brain and spinal cord injury.Salvianolic acid B can promote recovery of neurologi...Salvianolic acid B,an active pharmaceutical compound present in Salvia miltiorrhiza,exerts a neuroprotective effect in animal models of brain and spinal cord injury.Salvianolic acid B can promote recovery of neurological function;however,its protective effect on the myelin sheath after spinal cord injury remains poorly understood.Thus,in this study,in vitro tests showed that salvianolic acid B contributed to oligodendrocyte precursor cell differentiation,and the most effective dose was 20 μg/m L.For in vivo investigation,rats with spinal cord injury were intraperitoneally injected with 20 mg/kg salvianolic acid B for 8 weeks.The amount of myelin sheath and the number of regenerating axons increased,neurological function recovered,and caspase-3 expression was decreased in the spinal cord of salvianolic acid B-treated animals compared with untreated control rats.These results indicate that salvianolic acid B can protect axons and the myelin sheath,and can promote the recovery of neurological function.Its mechanism of action is likely to be associated with inhibiting apoptosis and promoting the differentiation and maturation of oligodendrocyte precursor cells.展开更多
Piezo1 is a mechanically-gated calcium channel.Recent studies have shown that Piezo1,a mechanically-gated calcium channel,can attenuate both psychosineand lipopolysaccharide-induced demyelination.Because oligodendrocy...Piezo1 is a mechanically-gated calcium channel.Recent studies have shown that Piezo1,a mechanically-gated calcium channel,can attenuate both psychosineand lipopolysaccharide-induced demyelination.Because oligodendrocyte damage and demyelination occur in intracerebral hemorrhage,in this study,we investigated the role of Piezo1 in intracerebral hemorrhage.We established a mouse model of cerebral hemorrhage by injecting autologous blood into the right basal ganglia and found that Piezo1 was largely expressed soon(within 48 hours)after intracerebral hemorrhage,primarily in oligodendrocytes.Intraperitoneal injection of Dooku1 to inhibit Piezo1 resulted in marked alleviation of brain edema,myelin sheath loss,and degeneration in injured tissue,a substantial reduction in oligodendrocyte apoptosis,and a significant improvement in neurological function.In addition,we found that Dooku1-mediated Piezo1 suppression reduced intracellular endoplasmic reticulum stress and cell apoptosis through the PERK-ATF4-CHOP and inositol-requiring enzyme 1 signaling pathway.These findings suggest that Piezo1 is a potential therapeutic target for intracerebral hemorrhage,as its suppression reduces intracellular endoplasmic reticulum stress and cell apoptosis and protects the myelin sheath,thereby improving neuronal function after intracerebral hemorrhage.展开更多
目的研究三叉神经中枢髓鞘部、周围髓鞘部与移行区的结构特点。方法在15例尸头标本上进行解剖学研究。通过不同的颅底入路,在手术显微镜下观察三叉神经的走行。然后将三叉神经脑池段(三叉神经从脑干端至美克氏腔开口的部分)完整取下,制...目的研究三叉神经中枢髓鞘部、周围髓鞘部与移行区的结构特点。方法在15例尸头标本上进行解剖学研究。通过不同的颅底入路,在手术显微镜下观察三叉神经的走行。然后将三叉神经脑池段(三叉神经从脑干端至美克氏腔开口的部分)完整取下,制作成组织学切片并用Luxol fast blue髓鞘染色,观察三叉神经移行区的结构特点,并测量各项数据。结果三叉神经的中枢髓鞘伴随三叉神经出脑干,前行在脑桥小脑角池内;中枢髓鞘出脑干后(2.34±0.81)mm开始向周围髓鞘部移行,在距脑干(3.78±0.69)mm左右截止。中枢髓鞘占脑池段全长的(30.5±5.6)%,周围髓鞘占脑池段全长的(81.1±8.1)%,移行区出现在脑池段(18.8±6.5)%～(30.5±5.6)%的位置。结论三叉神经的移行区与神经根进出脑干端处于两个不同的位置。三叉神经的中枢髓鞘部和移行区位于脑桥小脑角池内,该区域受到的血管压迫可能是导致三叉神经痛的病因之一。展开更多
Platelet-rich plasma containing various growth factors can promote nerve regeneration. An inside-out vein graft can substitute nerve autograft to repair short nerve defects. It is hypothesized that an inside-out vein ...Platelet-rich plasma containing various growth factors can promote nerve regeneration. An inside-out vein graft can substitute nerve autograft to repair short nerve defects. It is hypothesized that an inside-out vein graft filled with platelet-rich plasma shows better effects in the repair of short sciatic nerve defects. In this study, an inside-out vein autograft filled with platelet-rich plasma was used to bridge a 10 mm-long sciatic nerve defect in rats. The sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better improved than that of rats with a simple inside-out vein autograft. At 6 and 8 weeks, the sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better than that of rats undergoing nerve autografting. Compared with the sciatic nerve repaired with a simple inside-out vein autograft, the number of myelinated axons was higher, axon diameter and myelin sheath were greater in the sciatic nerve repaired with an inside-out vein autograft filled with plateletrich plasma and they were similar to those in the sciatic nerve repaired with nerve autograft. These findings suggest that an inside-out vein graft filled with platelet-rich plasma can substitute nerve autograft to repair short sciatic nerve defects.展开更多
Increasing evidence suggests that white matter disorders based on myelin sheath impairment may underlie the neuropathological changes in schizophrenia.But it is unknown whether enhancing remyelination is a beneficial ...Increasing evidence suggests that white matter disorders based on myelin sheath impairment may underlie the neuropathological changes in schizophrenia.But it is unknown whether enhancing remyelination is a beneficial approach to schizophrenia.To investigate this hypothesis,we used clemastine,an FDA-approved drug with high potency in promoting oligodendroglial differentiation and myelination,on a cuprizone-induced mouse model of demyelination.The mice exposed to cuprizone（0.2%in chow） for 6 weeks displayed schizophrenia-like behavioral changes,including decreased exploration of the center in the open field test and increased entries into the arms of the Y-maze,as well as evident demyelination in the cortex and corpus callosum.Clemastine treatment was initiated upon cuprizone withdrawal at 10 mg/kg per day for3 weeks.As expected,myelin repair was greatly enhanced in the demyelinated regions with increased mature oligodendrocytes（APC-positive） and myelin basic protein.More importantly,the clemastine treatment rescued the schizophrenia-like behavioral changes in the open field test and the Y-maze compared to vehicle,suggesting a beneficial effect via promoting myelin repair.Our findings indicate that enhancing remyelination may be a potential therapy for schizophrenia.展开更多
基金supported by grants to W. D. from the National Institutes of Health (R01 NS059043 and R01 ES015988)the National Multiple Sclerosis Society+1 种基金the Feldstein Medical FoundationShriners Hospitals for Children
文摘Premature birth is a significant economic and public health burden, and its incidence is rising. Periventricular leukomalacia （PVL） is the predominant form of brain injury in premature infants and the leading cause of cerebral palsy. PVL is characterized by selective white-matter damage with prominent oligodendroglial injury. The maturation-dependent vulnerability of developing and premyelinating oligodendrocytes to excitotoxic, oxidative, and inflammatory forms of injury is a major factor in the pathogenesis of PVL. Recent studies using mouse models of PVL reveal that synapses between axons and developing oligodendrocytes are quickly and profoundly damaged in immature white matter. Axon-glia synapses are highly vulnerable to white-matter injury in the developing brain, and the loss of synapses between axons and premyelinating oligodendrocytes occurs before any cellular loss in the immature white matter. Microglial activation and astrogliosis play important roles in triggering white-matter injury. Impairment of white-matter development and function in the neonatal period contributes critically to functional and behavioral deficits. Preservation of the integrity of the white matter is likely key in the treatment of PVL and subsequent neurological consequences and disabilities.
基金supported by grants from the National Natural Science Foundation of China (81471218 and 81771300)the Natural Science Foundation of Guangdong Province, China (2017A030313853)
文摘Immunoglobulin G against myelin oligodendrocyte glycoprotein(MOG-Ig G) is detectable in neuromyelitis optica spectrum disorder(NMOSD) without aquaporin-4 Ig G(AQP4-Ig G), but its pathogenicity remains unclear.In this study, we explored the pathogenic mechanisms of MOG-Ig G in vitro and in vivo and compared them with those of AQP4-Ig G. MOG-Ig G-positive serum induced complement activation and cell death in human embryonic kidney(HEK)-293 T cells transfected with human MOG. In C57 BL/6 mice and Sprague-Dawley rats, MOG-Ig G only caused lesions in the presence of complement. Interestingly, AQP4-Ig G induced astroglial damage, while MOGIg G mainly caused myelin loss. MOG-Ig G also induced astrocyte damage in mouse brains in the presence ofcomplement. Importantly, we also observed ultrastructural changes induced by MOG-Ig G and AQP4-Ig G. These findings suggest that MOG-Ig G directly mediates cell death by activating complement in vitro and producing NMOSDlike lesions in vivo. AQP4-Ig G directly targets astrocytes,while MOG-Ig G mainly damages oligodendrocytes.
文摘3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-cycloastragenol （astragaloside IV）, the main active component of the traditional Chinese medicine astragalus membranaceus, has been shown to be neuroprotective. This study investigated whether astragaloside IV could promote the repair of injured sciatic nerve. Denervated sciatic nerve of mice was subjected to anastomosis. The mice were intraperitoneally injected with 10, 5, 2.5 mg/kg astragaloside IV per day for 8 consecutive days Western blot assay and real-time PCR results demonstrated that growth-associated protein-43 ex- pression was upregulated in mouse spinal cord segments L4-6 after intervention with 10, 5, 2.5 mg/kg astragaloside IV per day in a dose-dependent manner. Luxol fast blue staining and elec- trophysiological detection suggested that astragaloside IV elevated the number and diameter of myelinated nerve fibers, and simultaneously increased motor nerve conduction velocity and action potential amplitude in the sciatic nerve of mice. These results indicated that astragaloside IV con- tributed to sciatic nerve regeneration and functional recovery in mice. The mechanism underlying this effect may be associated with the upregulation of growth-associated protein-43 expression.
基金Financial support by University of Milan,institutional funding "Piano di sostegno per la ricerca 2016-Linea 2 Azione B"
文摘The development,maturation and regeneration of Schwann cells（SCs）,the main glial cells of the peripheral nervous system,require the coordinate and complementary interaction among several factors,signals and intracellular pathways.These regulatory molecules consist of integrins,neuregulins,growth factors,hormones,neurotransmitters,as well as entire intracellular pathways including protein-kinase A,C,Akt,Erk/MAPK,Hippo,mTOR,etc.For instance,Hippo pathway is overall involved in proliferation,apoptosis,regeneration and organ size control,being crucial in cancer proliferation process.In SCs,Hippo is linked to merlin and YAP/TAZ signaling and it seems to respond to mechanic/physical challenges.Recently,among factors regulating SCs,also the signaling intermediates Src tyrosine kinase and focal adhesion kinase（FAK）proved relevant for SC fate,participating in the regulation of adhesion,motility,migration and in vitro myelination.In SCs,the factors Src and FAK are regulated by the neuroactive steroid allopregnanolone,thus corroborating the importance of this steroid in the control of SC maturation.In this review,we illustrate some old and novel signaling pathways modulating SC biology and functions during the different developmental,mature and regenerative states
基金supported by Muscular Dystrophy Association grants#292306 and#236648Empire State Development Corporation for HJKRI Grants W753 and U446+1 种基金Hunter’s Hope FoundationUniversity at Buffalo IMPACT funding
文摘Axonal degeneration is a pivotal feature of many neurodegenerative conditions and substantially accounts for neurological morbidity. A widely used experimental model to study the mechanisms of axonal degeneration is Wallerian degeneration （WD）, which occurs after acute axonal injury. In the peripheral nervous system （PNS）, WD is characterized by swift dismantling and clearance of injured axons with their myelin sheaths. This is a prerequisite for successful axonal regeneration. In the central nervous system （CNS）, WD is much slower, which significantly contributes to failed axonal regeneration. Although it is well documented that Schwann cells （SCs） have a critical role in the regenerative potential of the PNS, to date we have only scarce knowledge as to how SCs ＇sense＇ axonal injury and immediately respond to it. In this regard, it remains unknown as to whether SCs play the role of a passive bystander or an active director during the execution of the highly orchestrated disintegration program of axons. Older reports, together with more recent studies, suggest that SCs mount dynamic injury responses minutes after axonal injury, long before axonal breakdown occurs. The swift SC response to axonal injury could play either a pro degenerative role, or alternatively a supportive role, to the integrity of distressed axons that have not yet committed to degenerate. Indeed, supporting the latter concept, recent 昀ndings in a chronic PNS neurodegeneration model indicate that deactivation of a key molecule promoting SC injury responses exacerbates axonal loss. If this holds true in a broader spectrum of conditions, it may provide the grounds for the development of new glia-centric therapeutic approaches to counteract axonal loss.
基金Supported by the National Natural Science Foundation(Nos.81072765,81173237 and 81273742)Beijing Natural Science Foundation(No.7142053)+2 种基金Scientific Research Key Program of Beijing Municipal Commission of Education(No.KZ201310025023)Program for Changcheng Scholars of the ImportationDevelopment of High-Caliber Talents Project of Beijing Municipal Institutions(No.CIT&TCD20140329)
文摘Objective： To study the effects of Bushen Yisui Capsule（补肾益髓胶囊, BSYSC） on the oligodendrocyte lineage genes（Olig） 1 and Olig2 in C57BL/6 mice with experimental autoimmune encephalomyelitis（EAE） in order to explore the remyelination effect of BSYSC. Methods： The mice were randomly divided into normal control（NC）, EAE model（EAE-M）, prednisone acetate（PA, 6 mg/kg）, BSYSC high-dose（3.02 g/kg） and BSYSC low-dose（1.51 g/kg） groups. The mice were induced by immunization with myelin oligodendrocyte glycoprotein（MOG） 35-55. The neurological function scores were assessed once daily. The pathological changes in mice brains were observed with hematoxylin-eosin（HE） staining and transmission electron microscope（TEM）. The protein expressions of myelin basic protein（MBP）, Olig1 and Olig2 in brains were measured by immunohistochemistry. The m RNA expressions of Olig1 and Olig 2 was also determined by quantitative real-time polymerase chain reaction. Results： Compared with the EAE-M mice,（1） the neurological function scores were significantly decreased in BSYSC-treated mice on days 22 to 40（P〈0.01）;（2） the inflammatory cells and demyelination in brains were reduced in BSYSC-treated EAE mice;（3） the protein expression of MBP was markedly increased in BSYSC-treated groups on day 18 and 40 respectively（P〈0.05 or P〈0.01）;（4） the protein expression of Olig1 was increased in BSYSC（3.02 g/kg）-treated EAE mice on day 40（P〈0.01）. Protein and m RNA expression of Olig2 was increased in BSYSC-treated EAE mice on day 18 and 40（P〈0.01）. Conclusion： The effects of BSYSC on reducing demyelination and promoting remyelination might be associated with the increase of Olig1 and Olig2.
基金supported by the National Natural Science Foundation of China,No.81601957
文摘Remyelination plays a key role in functional recovery of axons after spinal cord injury.Glial cells are the most abundant cells in the central nervous system.When spinal cord injury occurs,many glial cells at the lesion site are immediately activated,and different cells differentially affect inflammatory reactions after injury.In this review,we aim to discuss the core role of oligodendrocyte precursor cells and crosstalk with the rest of glia and their subcategories in the remyelination process.Activated astrocytes influence proliferation,differentiation,and maturation of oligodendrocyte precursor cells,while activated microglia alter remyelination by regulating the inflammatory reaction after spinal cord injury.Understanding the interaction between oligodendrocyte precursor cells and the rest of glia is necessary when designing a therapeutic plan of remyelination after spinal cord injury.
基金ThisworkwassupportedbytheMajorStateBasicResearchDevelopmentProgramofChina (No .G19990 5 42 0 6 )
文摘Objective: To investigate the therapeutic effect of nerve growth factor (NGF) on changes of myelin basic protein (MBP) and functional repair of sensory and motor nerve following sciatic nerve injury. Methods: The sciatic nerves of rats were injured by sectioning with shaver,and divided into 3 groups: NGF group (Group A), group of normal saline solution (Group B), untreated group (Group C). The time point of observation was at the 4th week after operation. Sensory evoked potential (SEP) and motor evoked potential (MEP) were detected by Model WD 4000 nerve potential working diagnosis system. Immunohistochemical analysis was used for identification of MBP.Results: The latency of SEP in the Group A at the 4th week after operation was shorter than that in the Group B (P< 0.05 ). The MEP was elicited in 76% of the Group A and was higher than that in the Group B. Results of immunohistochemistry showed that there were less MBP positive cells in the Group A than in the Group B in one and four weeks respectively.Conclusions: NGF can improve the conductive function of injured peripheral nerve and facilitate regeneration of nerve.
文摘Background Chronic exposure to n-hexane can lead to peripheral neuropathy that no effective treatment regimen could be applied presently. This study investigated whether myelin protein zero （P0） protein and its antibody could be used to distinguish n-hexane intoxication and protect workers from peripheral neuropathy. Methods We compared P0 protein and its antibody among three levels of n-hexane-exposed groups, which included 18 patients with n-hexane-induced peripheral neuropathy as case group, 120 n-hexane-exposed workers as n-hexane- exposed control group, and 147 non-hexane-exposed participants used as control group. ELISA method was applied to detect P0 protein and its antibody. Results P0 protein in serum was significantly higher in the case group and n-hexane-exposed control group in comparison with the control group （P〈0.01）. Compared with the n-hexane-exposed control group, the case group also had significant increase of P0 protein （P〈0.01）. After 6 months therapy, P0 protein was observed to decrease significantly in the case group （P〈0.01）. The P0 antibody in serum was significantly higher in the n-hexane-exposed control group than in the control group （P〈0.01）, but not significantly different between cases and controls. Conclusions P0 antibodies in serum may be a short-term effect biomarker for n-hexane exposure. P0 protein in serum may be an early effective biomarker for peripheral nerve neuropathy and its biological limit value needs investigation in the future study.
基金supported by the National Natural Science Foundation of China, No. 81100916, 30400464,81271316the Postdoctoral Science Foundation of China,No. 201104901907
文摘Human umbilical mesenchymal stem cells from Wharton＇s jelly of the umbilical cord were induced to differentiate into oligodendrocyte precursor-like cells in vitro. Oligodendrocyte precursor cells were transplanted into contused rat spinal cords. Immunofluorescence double staining indicated that transplanted cells survived in injured spinal cord, and differentiated into mature and immature oligodendrocyte precursor cells. Biotinylated dextran amine tracing results showed that cell transplantation promoted a higher density of the corticospinal tract in the central and caudal parts of the injured spinal cord. Luxol fast blue and toluidine blue staining showed that the volume of residual myelin was significantly increased at 1 and 2 mm rostral and caudal to the lesion epicenter after cell transplantation. Furthermore, immunofluorescence staining verified that the newly regenerated myelin sheath was derived from the central nervous system. Basso, Beattie and Bresnahan testing showed an evident behavioral recovery. These results suggest that human umbilical mesenchymal stem cell-derived oligodendrocyte precursor cells promote the regeneration of spinal axons and myelin sheaths.
基金supported by National Natural Science Foundation of China (81671364 and 81201061)a China Postdoctoral Science Foundation Funded Project (2017M611195)the Outstanding Youth Talents Program of Shanxi Province, China (2015009)
文摘Autism spectrum disorder(ASD) is a neurodevelopmental disorder characterized by deficits in social interaction and communication, along with repetitive and restrictive patterns of behaviors or interests. Normal brain development is crucial to behavior and cognition in adulthood. Abnormal brain development, such as synaptic and myelin dysfunction, is involved in the pathogenesis of ASD. Microtubules and microtubule-associated proteins(MAPs) are important in regulating the processes of brain development, including neuron production and synaptic formation, as well as myelination. Increasing evidence suggests that the level of MAPs are changed in autistic patients and mouse models of ASD. Here, we discuss the roles of MAPs.
基金supported by the Spanish“Plan Nacional de Investigación Científica,Desarrollo e Innovación Tecnológica,Ministerio de Economía y Competitividad(Instituto de Salud CarlosⅢ)”,Grant FIS PI20-0318 co-financed by“Fondo Europeo de Desarrollo Regional ERDF-FEDER European Union”Grant P18-RT-5059“Plan Andaluz de Investigación,Desarrollo e Innovación(PAIDI 2020),Consejería de Transformación Económica,Industria,Conocimiento y Universidades,Junta de Andalucía,Espana”(all to VC)Grant PPJIA202219“Ayudas del plan propio UGR 2022,Plan propio de investigación y transferencia,Universidad de Granada,Espana”(to JCA andóDGG)。
文摘The myelin sheath is a lipoprotein-rich,multilayered structure capable of increasing conduction velocity in central and peripheral myelinated nerve fibers.Due to the complex structure and composition of myelin,various histological techniques have been developed over the centuries to evaluate myelin under normal,pathological or experimental conditions.Today,methods to assess myelin integrity or content are key tools in both clinical diagnosis and neuroscience research.In this review,we provide an updated summary of the composition and structure of the myelin sheath and discuss some histological procedures,from tissue fixation and processing techniques to the most used and practical myelin histological staining methods.Considering the lipoprotein nature of myelin,the main features and technical details of the different available methods that can be used to evaluate the lipid or protein components of myelin are described,as well as the precise ultrastructural techniques.
基金supported by a grant of Guangdong Medical University of China,No.XB1380
文摘Salvianolic acid B,an active pharmaceutical compound present in Salvia miltiorrhiza,exerts a neuroprotective effect in animal models of brain and spinal cord injury.Salvianolic acid B can promote recovery of neurological function;however,its protective effect on the myelin sheath after spinal cord injury remains poorly understood.Thus,in this study,in vitro tests showed that salvianolic acid B contributed to oligodendrocyte precursor cell differentiation,and the most effective dose was 20 μg/m L.For in vivo investigation,rats with spinal cord injury were intraperitoneally injected with 20 mg/kg salvianolic acid B for 8 weeks.The amount of myelin sheath and the number of regenerating axons increased,neurological function recovered,and caspase-3 expression was decreased in the spinal cord of salvianolic acid B-treated animals compared with untreated control rats.These results indicate that salvianolic acid B can protect axons and the myelin sheath,and can promote the recovery of neurological function.Its mechanism of action is likely to be associated with inhibiting apoptosis and promoting the differentiation and maturation of oligodendrocyte precursor cells.
基金supported by the National Natural Science Foundation of China,Nos.81901193(to HLZ)and 81901267(to YY)。
文摘Piezo1 is a mechanically-gated calcium channel.Recent studies have shown that Piezo1,a mechanically-gated calcium channel,can attenuate both psychosineand lipopolysaccharide-induced demyelination.Because oligodendrocyte damage and demyelination occur in intracerebral hemorrhage,in this study,we investigated the role of Piezo1 in intracerebral hemorrhage.We established a mouse model of cerebral hemorrhage by injecting autologous blood into the right basal ganglia and found that Piezo1 was largely expressed soon(within 48 hours)after intracerebral hemorrhage,primarily in oligodendrocytes.Intraperitoneal injection of Dooku1 to inhibit Piezo1 resulted in marked alleviation of brain edema,myelin sheath loss,and degeneration in injured tissue,a substantial reduction in oligodendrocyte apoptosis,and a significant improvement in neurological function.In addition,we found that Dooku1-mediated Piezo1 suppression reduced intracellular endoplasmic reticulum stress and cell apoptosis through the PERK-ATF4-CHOP and inositol-requiring enzyme 1 signaling pathway.These findings suggest that Piezo1 is a potential therapeutic target for intracerebral hemorrhage,as its suppression reduces intracellular endoplasmic reticulum stress and cell apoptosis and protects the myelin sheath,thereby improving neuronal function after intracerebral hemorrhage.
文摘目的研究三叉神经中枢髓鞘部、周围髓鞘部与移行区的结构特点。方法在15例尸头标本上进行解剖学研究。通过不同的颅底入路,在手术显微镜下观察三叉神经的走行。然后将三叉神经脑池段(三叉神经从脑干端至美克氏腔开口的部分)完整取下,制作成组织学切片并用Luxol fast blue髓鞘染色,观察三叉神经移行区的结构特点,并测量各项数据。结果三叉神经的中枢髓鞘伴随三叉神经出脑干,前行在脑桥小脑角池内;中枢髓鞘出脑干后(2.34±0.81)mm开始向周围髓鞘部移行,在距脑干(3.78±0.69)mm左右截止。中枢髓鞘占脑池段全长的(30.5±5.6)%,周围髓鞘占脑池段全长的(81.1±8.1)%,移行区出现在脑池段(18.8±6.5)%～(30.5±5.6)%的位置。结论三叉神经的移行区与神经根进出脑干端处于两个不同的位置。三叉神经的中枢髓鞘部和移行区位于脑桥小脑角池内,该区域受到的血管压迫可能是导致三叉神经痛的病因之一。
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology,No.2011-0010429
文摘Platelet-rich plasma containing various growth factors can promote nerve regeneration. An inside-out vein graft can substitute nerve autograft to repair short nerve defects. It is hypothesized that an inside-out vein graft filled with platelet-rich plasma shows better effects in the repair of short sciatic nerve defects. In this study, an inside-out vein autograft filled with platelet-rich plasma was used to bridge a 10 mm-long sciatic nerve defect in rats. The sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better improved than that of rats with a simple inside-out vein autograft. At 6 and 8 weeks, the sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better than that of rats undergoing nerve autografting. Compared with the sciatic nerve repaired with a simple inside-out vein autograft, the number of myelinated axons was higher, axon diameter and myelin sheath were greater in the sciatic nerve repaired with an inside-out vein autograft filled with plateletrich plasma and they were similar to those in the sciatic nerve repaired with nerve autograft. These findings suggest that an inside-out vein graft filled with platelet-rich plasma can substitute nerve autograft to repair short sciatic nerve defects.
基金supported by the National Natural Science Foundation of China ( 81100897 and 81100926 )the Natural Science Foundation of Chongqing Municipality, China (cstc2011jj A0856)
文摘Increasing evidence suggests that white matter disorders based on myelin sheath impairment may underlie the neuropathological changes in schizophrenia.But it is unknown whether enhancing remyelination is a beneficial approach to schizophrenia.To investigate this hypothesis,we used clemastine,an FDA-approved drug with high potency in promoting oligodendroglial differentiation and myelination,on a cuprizone-induced mouse model of demyelination.The mice exposed to cuprizone（0.2%in chow） for 6 weeks displayed schizophrenia-like behavioral changes,including decreased exploration of the center in the open field test and increased entries into the arms of the Y-maze,as well as evident demyelination in the cortex and corpus callosum.Clemastine treatment was initiated upon cuprizone withdrawal at 10 mg/kg per day for3 weeks.As expected,myelin repair was greatly enhanced in the demyelinated regions with increased mature oligodendrocytes（APC-positive） and myelin basic protein.More importantly,the clemastine treatment rescued the schizophrenia-like behavioral changes in the open field test and the Y-maze compared to vehicle,suggesting a beneficial effect via promoting myelin repair.Our findings indicate that enhancing remyelination may be a potential therapy for schizophrenia.
