Satellite glial cells in sensory ganglia play a wider role in chronic pain via multiple mechanisms

Satellite glial cells are unique glial cells that surround the cell body of primary sensory neurons.An increasing body of evidence suggests that in the presence of inflammation and nerve damage,a significant number of satellite glial cells become activated,thus triggering a series of functional changes.This suggests that satellite glial cells are closely related to the occurrence of chronic pain.In this review,we first summarize the morphological structure,molecular markers,and physiological functions of satellite glial cells.Then,we clarify the multiple key roles of satellite glial cells in chronic pain,including gap junction hemichannel Cx43,membrane channel Pannexin1,K channel subunit 4.1,ATP,purinergic P2 receptors,and a series of additional factors and their receptors,including tumor necrosis factor,glutamate,endothelin,and bradykinin.Finally,we propose that future research should focus on the specific sorting of satellite glial cells,and identify genomic differences between physiological and pathological conditions.This review provides an important perspective for clarifying mechanisms underlying the peripheral regulation of chronic pain and will facilitate the formulation of new treatment plans for chronic pain.

Glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor regulate the interaction between astrocytes and Schwann cells at the trigeminal root entry zone

The trigeminal root entry zone is the zone at which the myelination switches from peripheral Schwann cells to central oligodendrocytes.Its special anatomical and physiological structure renders it susceptible to nerve injury.The etiology of most primary trigeminal neuralgia is closely related to microvascular compression of the trigeminal root entry zone.This study aimed to develop an efficient in vitro model mimicking the glial environment of trigeminal root entry zone as a tool to investigate the effects of glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor on the structural and functional integrity of trigeminal root entry zone and modulation of cellular interactions.Primary astrocytes and Schwann cells isolated from trigeminal root entry zone of postnatal rats were inoculated into a two-well silicon culture insert to mimic the trigeminal root entry zone microenvironment and treated with glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor.In monoculture,glial cell line-derived neurotrophic factor promoted the migration of Schwann cells,but it did not have effects on the migration of astrocytes.In the co-culture system,glial cell line-derived neurotrophic factor promoted the bidirectional migration of astrocytes and Schwann cells.Brain-derived neurotrophic factor markedly promoted the activation and migration of astrocytes.However,in the co-culture system,brain-derived neurotrophic factor inhibited the migration of astrocytes and Schwann cells to a certain degree.These findings suggest that glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor are involved in the regulation of the astrocyte-Schwann cell interaction in the co-culture system derived from the trigeminal root entry zone.This system can be used as a cell model to study the mechanism of glial dysregulation associated with trigeminal nerve injury and possible therapeutic interventions.

Therapeutic potential of glial cell line-derived neurotrophic factor and cell reprogramming for hippocampal-related neurological disorders

Hippocampus serves as a pivotal role in cognitive and emotional processes,as well as in the regulation of the hypothalamus-pituitary axis.It is known to undergo mild neurodegenerative changes during normal aging and severe atrophy in Alzheimer's disease.Furthermore,dysregulation in the hippocampal function leads to epilepsy and mood disorders.In the first section,we summarized the most salient knowledge on the role of glial cell-line-derived neurotrophic factor and its receptors focused on aging,cognition and neurodegenerative and hippocampal-related neurological diseases mentioned above.In the second section,we reviewed the therapeutic approaches,particularly gene therapy,using glial cell-line-derived neurotrophic factor or its gene,as a key molecule in the development of neurological disorders.In the third section,we pointed at the potential of regenerative medicine,as an emerging and less explored strategy for the treatment of hippocampal disorders.We briefly reviewed the use of partial reprogramming to restore brain functions,non-neuronal cell reprogramming to generate neural stem cells,and neural progenitor cells as source-specific neuronal types to be implanted in animal models of specific neurodegenerative disorders.

Ji-Chuan decoction ameliorates slow transit constipation via regulation of intestinal glial cell apoptosis

BACKGROUND Slow transit constipation(STC)is a common intestinal disease with increasing incidence.STC results from various factors,such as the enteric nervous system and metabolic changes.As a classical formula of traditional Chinese medicine,Ji-Chuan decoction(JCD)has been extensively and effectively used in STC treatment,yet its pharmacological mechanism remains unclear.AIM To explore the integrated regulatory pattern of JCD against STC through hyphenated techniques from metabolism,network pharmacology and molecular methods.METHODS STC model mice were generated by intragastric administration of compound diphenoxylate(10 mg/kg/d)for 14 d.The STC mice in the low dose of JCD(3.04 g/kg),middle dose of JCD(6.08 g/kg)and high dose of JCD(12.16 g/kg)groups were orally administered JCD solution once a day for 2 wk.The acetylcholine(ACH)level was examined by enzyme-linked immunosorbent assay.The pathological features of colon tissue were observed by hematoxylin and eosin staining.The differentially expressed metabolites and metabolic pathways were tested by nontargeted metabolomics.The main targets and core ingredients of JCD were identified by network pharmacology,and the expression of AKT was confirmed by immunohistochemistry.Finally,the pathways involved in JCD treatment were predicted using a combination of differentially expressed metabolites and targets,and intestinal glial cell apoptosis was demonstrated by immunofluorescence.RESULTS JCD significantly promoted intestinal motility,increased the levels of the excitatory neurotransmitter ACH and reduced intestinal inflammation in STC mice.Untargeted metabolomics results showed that JCD significantly restored metabolic dysfunction and significantly affected taurine and hypotaurine metabolism.Network pharmacology and molecular experiments showed that JCD regulates AKT protein expression,and the core component is quercetin.Combined analysis demonstrated that apoptosis may be an important mechanism by which JCD relieves constipation.Further experiments showed that JCD reduced enteric glial cell(EGC)apoptosis.CONCLUSION This work demonstrated that reducing EGC apoptosis may be the critical mechanism by which JCD treats STC.These findings call for further molecular research to facilitate the clinical application of JCD.

Stem cell transplantation and/or adenoviral glial cell line-derived neurotrophic factor promote functional recovery in hemiparkinsonian rats

BACKGROUND Parkinson’s disease(PD)is a neurological disorder characterized by the progressive loss of midbrain dopamine(DA)neurons.Bone marrow mesenchymal stem cells(BMSCs)can differentiate into multiple cell types including neurons and glia.Transplantation of BMSCs is regarded as a potential approach for promoting neural regeneration.Glial cell line-derived neurotrophic factor(GDNF)can induce BMSC differentiation into neuron-like cells.This work evaluated the efficacy of nigral grafts of human BMSCs(hMSCs)and/or adenoviral(Ad)GDNF gene transfer in 6-hydroxydopamine(6-OHDA)-lesioned hemiparkinsonian rats.AIM To evaluate the efficacy of nigral grafts of hMSCs and/or Ad-GDNF gene transfer in 6-OHDA-lesioned hemiparkinsonian rats.METHODS We used immortalized hMSCs,which retain their potential for neuronal differentiation.hMSCs,preinduced hMSCs,or Ad-GDNF effectively enhanced neuronal connections in cultured neurons.In vivo,preinduced hMSCs and/or Ad-GDNF were injected into the substantia nigra(SN)after induction of a unilateral 6-OHDA lesion in the nigrostriatal pathway.RESULTS Hemiparkinsonian rats that received preinduced hMSC graft and/or Ad-GDNF showed significant recovery of apomorphine-induced rotational behavior and the number of nigral DA neurons.However,DA levels in the striatum were not restored by these therapeutic treatments.Grafted hMSCs might reconstitute a niche to support tissue repair rather than contribute to the generation of new neurons in the injured SN.CONCLUSION The results suggest that preinduced hMSC grafts exert a regenerative effect and may have the potential to improve clinical outcome.

家蚕glial cell missing(BmGcm)基因鉴定、表达、亚细胞定位和功能

【目的】鉴定、克隆家蚕(Bombyx mori)glial cell missing(Bm Gcm)基因,分析其m RNA表达及亚细胞定位特征。制备多克隆抗体,同时在细胞水平进行过表达,检测Gcm对细胞增殖和周期的影响,为探究Bm Gcm功能打下基础。【方法】利用RACE方法克隆获得Bm Gcm全长c DNA序列,利用ORF Finder和SMART等在线工具对Bm Gcm基本序列特征和结构信息进行分析,运用Clustalx和MEGA 6.0等软件对多物种Gcm蛋白进行同源序列比对和进化分析。采用RT-PCR和q RT-PCR方法检测Bm Gcm的表达情况。利用原核表达系统获得重组蛋白,通过蛋白纯化和免疫小鼠制备多克隆抗体,运用Western blot对抗体进行检测。构建Bm Gcm表达载体,转染家蚕胚胎细胞系,分析其亚细胞定位情况,同时利用EDU细胞增殖标记和流式细胞仪对其功能进行探索。【结果】Bm Gcm(BGIBMGA006182)定位于4号染色体的nscaf2847上,其基因全长4 046 bp,包含4个外显子和3个内含子。其c DNA全长1 734 bp,包含166 bp的5′UTR、227 bp的3′UTR和1 341 bp的完整开放阅读框(ORF)。该基因编码446个氨基酸残基,预测蛋白分子量为50.61 k D,等电点5.557,含有典型的GCM结构域。多重比对结果显示GCM结构域在不同物种间具有高度的保守性,进化分析显示昆虫Gcm蛋白单独聚为一支,其中Bm Gcm蛋白与帝王蝶同源蛋白亲缘关系最为接近。表达分析结果显示Bm Gcm在胚胎发育第4天表达达到峰值,随后表达水平逐渐下调,而在幼虫阶段,Bm Gcm主要表达于中肠、精巢和卵巢。将Bm Gcm完整的开放阅读框序列构建至原核表达系统,经IPTG诱导和亲和层析纯化获得高纯度重组蛋白,通过免疫小鼠获得了多克隆抗体,Western blot检测该抗体可以特异性识别重组蛋白。在家蚕细胞系中过表达Bm Gcm蛋白,结果显示其定位于细胞核。在细胞水平,过表达Bm Gcm会明显抑制细胞增殖,将细胞周期阻滞于G1/S期。【结论】克隆鉴定得到Bmgcm全长序列,获得其表达和亚细胞定位信息。通过原核表达、蛋白纯化和免疫小鼠制备了可用的多克隆抗体。细胞实验发现Bm Gcm可以显著抑制增殖和影响正常的细胞周期进程。

Impact of SARS-CoV-2 infection during pregnancy on postnatal brain development:The potential role of glial cells

Glial cells are crucial for maintaining central nervous system(CNS)homeostasis.They actively participate in immune responses,as well as form functional barriers,such as blood-brain barrier(BBB),which restrict the entry of pathogens and inflammatory mediators into the CNS.In general,viral infections during the gestational period can alter the embryonic and fetal environment,and the related inflammatory response may affect neurodevelopment and lead to behavioral dysfunction during later stage of life,as highlighted by our group for Zika virus infection.Severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)induces a cytokine storm and,during pregnancy,may be related to a more severe form of the coronavirus disease-19(COVID-19)and also to higher preterm birth rates.SARS-CoV-2 can also affect the CNS by inducing neurochemical remodeling in neural cells,which can compromise neuronal plasticity and synaptic function.However,the impact of SARS-CoV-2 infection during pregnancy on postnatal CNS,including brain development during childhood and adulthood,remains undetermined.Our group has recently highlighted the impact of COVID-19 on the expression of molecular markers associated with neuropsychiatric disorders,which are strongly related to the inflammatory response.Thus,based on these relationships,we discussed the impact of SARS-CoV-2 infection either during pregnancy or in critical periods of neurodevelopment as a risk factor for neurological consequences in the offspring later in life,focusing on the potential role of glial cells.Thus,it is important to consider future and long-term public health concerns associated with SARS-CoV-2 infection during pregnancy.

Ginsenoside Rb1 attenuates lipopolysaccharide-induced chronic neuroinflammation in mice by tuning glial cell polarization

Objective:To evaluate whether ginsenoside Rb1(Rb1) can attenuate lipopolysaccharide(LPS)-induced chronic neuroinflammation in mice and to explore its relationship with glial cell polarization.Methods:Intraperitoneal injection with an escalating dose of LPS was used to establish a chronic neuroinflammation model in mice.Once LPS was initiated,10 or 20 mg/kg Rbl,or sterile saline,was administered for 14 consecutive days.Open field test and beam walking test were used to monitor the changes in behavior.The concentration of cytokines in the serum and brain were used to monitor the systemic inflammation and neuroinflammation,respectively.Molecules specific to each glial cell phenotype were used to investigate glial cell polarization.Results:Mice in the LPS group had reduced spontaneous activities and impaired beam walking performance.Rbl obviously eased LPS-induced behavior distu rbances.Regarding the levels of serum cytokines,both tumor necrosis factor-α(TNF-α) and interleukin-1β(IL-1β) were significantly increased,while interleukin-10(IL-10) and transforming growth factor β(TGF-β) remarkably decreased after LPS treatment(all P <.001).Rb1 treatment significantly attenuated LPS-induced serum cytokine changes(all P <.05).The results of quantitative polymerase chain reaction and western blotting showed that the mRNA and protein expression levels of TNF-α and complement component 3(C3) in the brain were significantly increased after LPS treatment(all P<.01).Rbl treatment significantly inhibited LPS-induced inflammation in the brain(all P <.05).Glial cell polarization analysis showed that M1 and M2 microglia,and A1 astrocytes increased following LPS treatment,while A2 astrocytes decreased.Rb1 treatment reduced M1 and M2 microglia,and A1 astrocytes,and significantly increased A2 astrocytes.Conclusion:Rb1 can attenuate chronic neuroinflammation induced by LPS in mice,which may be partially attributable to its fine tuning of microglia and astrocyte polarization.Rb1 has potential value for treating neurodegenerative diseases.

Enteric glial cells and their role in gastrointestinal motor abnormalities: Introducing the neuro-gliopathies

The role of enteric glial cells has somewhat changed from that of mere mechanical support elements, gluing together the various components of the enteric nervous system, to that of active participants in the complex interrelationships of the gut motor and inflammatory events. Due to their multiple functions, spanning from supporting elements in the myenteric plexuses to neurotransmitters, to neuronal homeostasis, to antigen presenting cells, this cell population has probably more intriguing abilities than previously thought. Recently, some evidence has been accumulating that shows how these cells may be involved in the pathophysiological aspects of some diseases. This review will deal with the properties of the enteric glial cells more strictly related to gastrointestinal motor function and the human pathological conditions in which these cells may play a role, suggesting the possibility of enteric neuro- gliopathies.

Electroacupuncture promotes peripheral nerve regeneration after facial nerve crush injury and upregulates the expression of glial cell-derived neurotrophic factor

The efficacy of electroacupuncture in the treatment of peripheral facial paralysis is known, but the specific mechanism has not been clarified. Glial cell-derived neurotrophic factor(GDNF) has been shown to protect neurons by binding to N-cadherin. Our previous results have shown that electroacupuncture could increase the expression of N-cadherin mRNA in facial neurons and promote facial nerve regeneration. In this study, the potential mechanisms by which electroacupuncture promotes nerve regeneration were elucidated through assessing the effects of electroacupuncture on GDNF and N-cadherin expression in facial motoneurons of rabbits with peripheral facial nerve crush injury. New Zealand rabbits were randomly divided into a normal group(normal control, n = 21), injury group(n = 45) and electroacupuncture group(n = 45). Model rabbits underwent facial nerve crush injury only. Rabbits in the electroacupuncture group received facial nerve injury, and then underwent electroacupuncture at Yifeng(TE17), Jiache(ST6), Sibai(ST2), Dicang(ST4), Yangbai(GB14), Quanliao(SI18), and Hegu(LI4; only acupuncture, no electrical stimulation). The results showed that in behavioral assessments, the total scores of blink reflex, vibrissae movement, and position of apex nasi, were markedly lower in the EA group than those in the injury group. Hematoxylin-eosin staining of the right buccinator muscle of each group showed that the cross-sectional area of buccinator was larger in the electroacupuncture group than in the injury group on days 1, 14 and 21 post-surgery. Toluidine blue staining of the right facial nerve tissue of each group revealed that on day 14 post-surgery, there was less axonal demyelination and fewer inflammatory cells in the electroacupuncture group compared with the injury group. Quantitative real time-polymerase chain reaction showed that compared with the injury group, N-cadherin mRNA levels on days 4, 7, 14 and 21 and GDNF mRNA levels on days 4, 7 and 14 were significantly higher in the electroacupuncture group. Western blot assay displayed that compared with the injury group, the expression of GDNF protein levels on days 7, 14 and 21 were significantly upregulated in the electroacupuncture group. The histology with hematoxylin-eosin staining and Nissl staining of brainstem tissues containing facial neurons in the middle and lower part of the pons exhibited that on day 7 post-surgery, there were significantly fewer apoptotic neurons in the electroacupuncture group than in the injury group. By day 21, there was no significantly difference in the number of neurons between the electroacupuncture and normal groups. Taken together, these results have confirmed that electroacupuncture promotes regeneration of peripheral facial nerve injury in rabbits, inhibits neuronal apoptosis, and reduces peripheral inflammatory response, resulting in the recovery of facial muscle function. This is achieved by up-regulating the expression of GDNF and N-cadherin in central facial neurons.

Role of Enteric Glial Cells in Gastric Motility in Diabetic Rats at Different Stages

Diabetes patients tend to have the gastrointestinal motility disorder.Although the relationship between the motility disorder and both the neurons and Cajal cells in the enteric nervous system (ENS) is well established,little is known about the role of enteric glial cells (EGCs) in gastric motility in diabetes.This study aimed to examine the expression of the glial marker S100B and morphology of EGCs in gastric tissues and the relationship between activated EGCs and the damage of gastric emptying in diabetic models.The diabetic model of rat was induced with 1% streptozotocin (STZ).The model rats at 7-14 days and at 56-63 days were defined as early diabetic rats and advanced diabetic rats,respectively,and normal rats at the two time periods served as their corresponding controls.The gastric emptying rate of the rats was tested by using the phenol red solution.The ultrastructure of EGCs in the gastric antrum was observed by the transmission electron microscopy,and the expression of S100B in the myenteric plexus was immunohistochemically detected.The results showed that the gastric emptying rate was significantly increased in the early diabetic rats and decreased in the advanced diabetic rats when compared with their corresponding control rats (P<0.01 for both).The ultrastructure of EGCs was mostly normal in both the early diabetic and control groups.Vacuolization of mitochondria and expansion of endoplasmic reticulum occurred in both the advanced diabetic group and its control group,and even the structure of smooth muscle cells and intestinal neurons was destroyed in the advanced diabetic group.The expression level of S100B in the advanced diabetic group was significantly decreased compared with its control group (P<0.05).It was obviously increased in the early diabetic control group when compared with the advanced diabetic control group (P<0.05).However,there was no significant difference in the S100B expression between the early diabetic group and its control group (P>0.05).The findings suggested that the gastric motility dysfunction in diabetes may be associated with the changes of morphology and number of EGCs in the myenteric plexus.

Stem cell therapy for central nerve system injuries: glial cells hold the key

Mammalian adult central nerve system(CNS) injuries are devastating because of the intrinsic difficulties for effective neuronal regeneration. The greatest problem to be overcome for CNS recovery is the poor regeneration of neurons and myelin-forming cells, oligodendrocytes. Endogenous neural progenitors and transplanted exogenous neuronal stem cells can be the source for neuronal regeneration. However, because of the harsh local microenvironment, they usually have very low efficacy for functional neural regeneration which cannot compensate for the loss of neurons and oligodendrocytes. Glial cells(including astrocytes, microglia, oligodendrocytes and NG2 glia) are the majority of cells in CNS that provide support and protection for neurons. Inside the local microenvironment, glial cells largely influence local and transplanted neural stem cells survival and fates. This review critically analyzes current finding of the roles of glial cells in CNS regeneration, and highlights strategies for regulating glial cells' behavior to create a permissive microenvironment for neuronal stem cells.

Regional brain susceptibility to neurodegeneration: what is the role of glial cells?

The main pathological feature of the neurodegenerative diseases is represented by neuronal death that represents the final step of a cascade of adverse/hostile events.Early in the neurodegenerative process,glial cells (including astrocytes,microglial cells,and oligodendrocytes) activate and trigger an insidious neuroinflammatory reaction,metabolic decay,blood brain barrier dysfunction and energy impairment,boosting neuronal death.How these mechanisms might induce selective neuronal death in specific brain areas are far from being elucidated.The last two decades of neurobiological studies have provided evidence of the main role of glial cells in most of the processes of the central nervous system,from development to synaptogenesis,neuronal homeostasis and integration into,highly specific neuro-glial networks.In this mini-review,we moved from in vitro and in vivo models of neurodegeneration to analyze the putative role of glial cells in the early mechanisms of neurodegeneration.We report changes of transcriptional,genetic,morphological,and metabolic activity in astrocytes and microglial cells in specific brain areas before neuronal degeneration,providing evidence in experimental models of neurodegenerative disorders,including Parkinson’s and Alzheimer’s diseases.Understanding these mechanisms might increase the insight of these processes and pave the way for new specific glia-targeted therapeutic strategies for neurodegenerative disorders.

Intrastriatal glial cell line-derived neurotrophic factors for protecting dopaminergic neurons in the substantia nigra of mice with Parkinson disease

BACKGROUND:Substantia nigra is deep in position and limited in range,the glial cell line-derived neurotrophic factor(GDNF)injection directly into substantia nigra has relatively greater damages with higher difficulty.GDNF injection into striatum,the target area of dopaminergic neuron,may protect the dopaminergic neurons in the compact part of substantia nigra through retrograde transport.OBJECTIVE:To investigate the protective effect of intrastriatal GDNF on dopaminergic neurons in the substantia nigra of mice with Parkinson disease(PD),and analyze the action pathway.DESIGN:A controlled observation.SETTING:Neurobiological Laboratory of Xuzhou Medical College.MATERIALS:Twenty-four male Kunming mice of 7-8 weeks old were used.GDNF,1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)were purchased from Sigma Company(USA);LEICAQWin image processing and analytical system.METHODS:The experiments were carried out in the Neurobiological Laboratory of Xuzhou Medical College from September 2005 to October 2006.The PD models were established in adult KunMing mice by intraperitoneal injection of MPTP.The model mice were were randomly divided into four groups with 6 mice in each group:GDNF 4-day group,phosphate buffer solution(PSB)4-day group,GDNF 6-day group and PSB 6-day group.Mice in the GDNF 4 and 6-day groups were administrated with 1 μL GDNF solution(20 μg/L,dispensed with 0.01 mol/L PBS)injected into right striatum at 4 and 6 days after model establishment.Mice in the PSB 4 and 6-day groups were administrated with 0.01 mol/L PBS of the same volume to the same injection at corresponding time points.② On the 12th day after model establishment,the midbrain tissue section of each mice was divided into 3 areas from rostral to caudal sides.The positive neurons of tyroxine hydroxylase(TH)and calcium binding protein(CB)with obvious nucleolus and clear outline were randomly selected for the measurement,and the number of positive neurons in unit area was counted.MAIN OUTCOME MEASURES:Number of positive neurons of TH and CB in midbrain substantia nigra of mice in each group.RESULTS:All the 24 mice were involved in the analysis of results.The numbers of TH+ and CB+ neurons in the GDNF 4-day group(54.33±6.92,46.33±5.54)were obviously more than those in the PBS 4-day group(27.67±5.01,21.50±5.96,P < 0.01).The numbers of TH+ and CB+ neurons in the GDNF 6-day group(75.67±5.39,69.67±8.69)were obviously more than those in the PBS 6-day group(27.17±4.50,21.33±5.72,P < 0.01)and those in the GDNF 4-day group(P < 0.01).CONCLUSION:Intrastriatal GDNF can protect dopaminergic neurons in substantia nigra of PD mice,and it may be related to the increase of CB expression.

Establishment and expression of recombinant human glial cell linederived neurotrophic factor and TNF α receptor in human neural stem cells

Objective:To investigate the interference and expression of human glial cell line-derived neurotrophic factor(hCDNF) and soluble TNF alpha(sTMFRⅠ) receptor genes in neural stem cells and to evaluate the roles of these proteins in the genetic treatment of spinal cord injury.Methods:Full-length of GDNF cDNA(538 bp) and sTMFRⅠcDNA(504 bp) were inserted into the early 1 region of adenovirus genomic DNA respectively and were immediated by the human cytomegalovirus(gene promoter/enhancer). These adenoviruses were propagated in HEK293 cells via homologous recombination for 7-10 days in vivo,then they were used to infect human neural stem ceils.The infection and expression of gene were tested under immunofluorescence.ELISA and Westem-blot after 48 hours.Results:Almost all the cultured cells showed the nestin immunofluorescence positive staining,which was the characteristics of neural stem cell.A great quantity of EGFP and KFP were observed in neural stem cells,which indicated the expression of GDNF and sTMFRⅠ.After transfection of GDNF and sTMFRⅠgenes,many neural stem cells show GFAP and tubulin immunofluorescence positive staining,which meant that most neural stem cells differentiated into neuron at that condition.Conclusions:The infective efficiency of adenovirus is greatly acceptable to neural stem cell,thus adenovirus provide a useful vector for exogenous GDNF and sTMFRⅠgenes expressing in neural stem cells,which is useful for differentiation of neural stem cell.

Regulatory effects of inhibiting the activation of glial cells on retinal synaptic plasticity

Various retinal injuries induced by ocular hypertension have been shown to induce plastic changes in retinal synapses,but the potential regulatory mechanism of synaptic plasticity after retinal injury was still unclear.A rat model of acute ocular hypertension was established by injecting saline intravitreally for an hour,and elevating the intraocular pressure to 14.63 kPa(110 mmHg).Western blot assay and immunofluorescence results showed that synaptophysin expression had a distinct spatiotemporal change that increased in the inner plexiform layer within 1 day and spread across the outer plexiform layer after 3 days.Glial fibrillary acidic protein expression in retinae was greatly increased after 3 days,and reached a peak at 7 days,which was also consistent with the peak time of synaptophysin expression in the outer plexiform layer following the increased intraocular pressure.Fluorocitrate,a glial metabolic inhibitor,was intravitreally injected to inhibit glial cell activation following high intraocular pressure.This significantly inhibited the enhanced glial fibrillary acidic protein expression induced by high intraocular pressure injury.Synaptophysin expression also decreased in the inner plexiform layer within a day and the widened distribution in the outer plexiform layer had disappeared by 3 days.The results suggested that retinal glial cell activation might play an important role in the process of retinal synaptic plasticity induced by acute high intraocular pressure through affecting the expression and distribution of synaptic functional proteins,such as synaptophysin.

Intraspinal transplantation of motoneuron-like cell combined with delivery of polymer-based glial cell line-derived neurotrophic factor for repair of spinal cord contusion injury

To evaluate the effects of glial cell line-derived neurotrophic factor transplantation combined with adipose-derived stem cells-transdifferentiated motoneuron delivery on spinal cord contusion injury,we developed rat models of spinal cord contusion injury,7 days later,injected adipose-derived stem cells-transdifferentiated motoneurons into the epicenter,rostral and caudal regions of the impact site and simultaneously transplanted glial cell line-derived neurotrophic factor-gelfoam complex into the myelin sheath.Motoneuron-like cell transplantation combined with glial cell line-derived neurotrophic factor delivery reduced cavity formations and increased cell density in the transplantation site.The combined therapy exhibited superior promoting effects on recovery of motor function to transplantation of glial cell line-derived neurotrophic factor,adipose-derived stem cells or motoneurons alone.These findings suggest that motoneuron-like cell transplantation combined with glial cell line-derived neurotrophic factor delivery holds a great promise for repair of spinal cord injury.

Postnatal roles of glial cell line-derived neurotrophic factor family members in nociceptors plasticity

The neurotrophin and glial cell line-derived neurotrophic factor(GDNF) family of growth factors have been extensively studied because of their proven ability to regulate development of the peripheral nervous system.The neurotrophin family,which includes nerve growth factor(NGF),NT-3,NT4/5 and BDNF,is also known for its ability to regulate the function of adult sensory neurons.Until recently,little was known concerning the role of the GNDF-family(that includes GDNF,artemin,neurturin and persephin) in adult sensory neuron function.Here we describe recent data that indicates that the GDNF family can regulate sensory neuron function,that some of its members are elevated in inflammatory pain models and that application of these growth factors produces pain in vivo.Finally we discuss how these two families of growth factors may converge on a single membrane receptor,TRPV1,to produce long-lasting hyperalgesia.

Transfection of the glial cell line-derived neurotrophic factor gene promotes neuronal differentiation

Glial cell line-derived neurotrophic factor recombinant adenovirus vector-transfected bone marrow mesenchymal stem cells were induced to differentiate into neuron-like cells using inductive medium containing retinoic acid and epidermal growth factor.Cell viability,microtubule-associated protein 2-positive cell ratio,and the expression levels of glial cell line-derived neurotrophic factor,nerve growth factor and growth-associated protein-43 protein in the supernatant were significantly higher in glial cell line-derived neurotrophic factor/bone marrow mesenchymal stem cells compared with empty virus plasmid-transfected bone marrow mesenchymal stem cells.Furthermore,microtubule-associated protein 2,glial cell line-derived neurotrophic factor,nerve growth factor and growth-associated protein-43 mRNA levels in cell pellets were statistically higher in glial cell line-derived neurotrophic factor/bone marrow mesenchymal stem cells compared with empty virus plasmid-transfected bone marrow mesenchymal stem cells.These results suggest that glial cell line-derived neurotrophic factor/bone marrow mesenchymal stem cells have a higher rate of induction into neuron-like cells,and this enhanced differentiation into neuron-like cells may be associated with up-regulated expression of glial cell line-derived neurotrophic factor,nerve growth factor and growth-associated protein-43.

A novel primary culture method for high-purity satellite glial cells derived from rat dorsal root ganglion

Satellite glial cells surround neurons within dorsal root ganglia. Previous studies have focused on single-cell suspensions of cultured neurons derived from rat dorsal root ganglia. At present, the primary culture method for satellite glial cells derived from rat dorsal root ganglia requires no digestion skill. Hence, the aim of the present study was to establish a novel primary culture method for satellite glial cells derived from dorsal root ganglia. Neonatal rat spine was collected and an incision made to expose the transverse protrusion and remove dorsal root ganglia. Dorsal root ganglia were freed from nerve fibers, connective tissue, and capsule membranes, then rinsed and transferred to 6-well plates, and cultured in a humidified 5% CO_2 incubator at 37°C. After 3 days in culture, some cells had migrated from dorsal root ganglia. After subculture, cells were identified by immunofluorescence labeling for three satellite glial cell-specific markers: glutamine synthetase, glial fibrillary acidic protein, and S100β. Cultured cells expressed glutamine synthetase, glial fibrillary acidic protein, and S100β, suggesting they are satellite glial cells with a purity of > 95%. Thus, we have successfully established a novel primary culture method for obtaining high-purity satellite glial cells from rat dorsal root ganglia without digestion.