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-methy1-4-pheny1-1,2,3,6-tetrahydropyridine （MPTP） were purchased from Sigma Company （USA）; LEICAQWin image processing and analytical system. METHODS： The experiments were carded 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 μ L GDNF solution （20 μ g/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 12^th 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.

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, micro- tubule-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 su- pernatant were significantly higher in glial cell line-derived neurotrophic factor/bone marrow mesenchymal stem cells compared with empty virus plasmid-transfected bone marrow mes- enchymal stem cells. Furthermore, microtubule-associated protein 2, glial cell line-derived neurotrophic factor, nerve growth factor and growth-associated protein743 mRNA levels in cell pellets were statistically higher in glial cell line-derived neurotrophic factor/bone marrow mesen- chymal 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.

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 con-tusion 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 neuro-trophic 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 ifndings 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.

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.

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.

Secretion of nerve growth factor,brain-derived neurotrophic factor,and glial cell-line derived neurotrophic factor in co-culture of four cell types in cerebrospinal fluid-containing medium

The present study co-cultured human embryonic olfactory ensheathJng cells, human Schwann cells, human amniotic epithelial cells and human vascular endothelial cells in complete culture medium- containing cerebrospinal fluid. Enzyme linked immunosorbent assay was used to detect nerve growth factor, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor secretion in the supernatant of co-cultured cells. Results showed that the number of all cell types reached a peak at 7-10 days, and the expression of nerve growth factor, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor peaked at 9 days. Levels of secreted nerve growth factor were four-fold higher than brain-derived neurotrophic factor, which was three-fold higher than glial cell line-derived neurotrophic factor. Increasing concentrations of cerebrospinal fluid （10%, 20% and 30%） in the growth medium caused a decrease of neurotrophic factor secretion Results indicated co-culture of human embryonic olfactory ensheathing cells, human Schwann cells human amniotic epithelial cells and human vascular endothelial cells improved the expression of nerve growth factor, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor. The reduction of cerebrospinal fluid extravasation at the transplant site after spinal cord injury is beneficial for the survival and secretion of neurotrophic factors from transplanted cells.

Differential expression of glial cell line-derived neurotrophic factor splice variants in the mouse brain

Glial cell line-derived neurotrophic factor(GDNF) plays a critical role in neuronal survival and function. GDNF has two major splice variants in the brain,α-pro-GDNF and β-pro-GDNF, and both isoforms have strong neuroprotective effects on dopamine neurons. However, the expression of the GDNF splice variants in dopaminergic neurons in the brain remains unclear. Therefore, in this study, we investigated the mRNA and protein expression of α-and β-pro-GDNF in the mouse brain by real-time quantitative polymerase chain reaction, using splice variant-specific primers, and western blot analysis. At the mRNA level,β-pro-GDNF expression was significantly greater than that of α-pro-GDNF in the mouse brain. In contrast, at the protein level,α-pro-GDNF expression was markedly greater than that of β-pro-GDNF. To clarify the mechanism underlying this inverse relationship in mRNA and protein expression levels of the GDNF splice variants, we analyzed the expression of sorting protein-related receptor with A-type repeats(SorLA) by real-time quantitative polymerase chain reaction. At the mRNA level, SorLA was positively associated with β-pro-GDNF expression, but not with α-pro-GDNF expression. This suggests that the differential expression of α-and β-pro-GDNF in the mouse brain is related to SorLA expression. As a sorting protein, SorLA could contribute to the inverse relationship among the mRNA and protein levels of the GDNF isoforms. This study was approved by the Animal Ethics Committee of Xuzhou Medical University, China on July 14, 2016.

Use of RNAi silencing to target preconditioned glial cell line-derived neurotrophic factor in neuronal apoptosis

Several studies have suggested that exogenous glial cell line-derived neurotrophic factor may pro-tect neurons from cerebral ischemic injury. However, the mechanisms underlying the neuroprotec-tive effects of endogenous glial cell line-derived neurotrophic factor remain unclear. The present experiments sought to elucidate the influence of various conditioned media on neuronal apoptosis, using a normal culture medium for astrocytes, an astrocyte medium highly expressing glial cell line-derived neurotrophic factor, and an astrocyte medium in which glial cell line-derived neurotro-phic factor expression was silenced using RNAi technology. The results confirmed that the use of RNAi silencing to target pretreated glial cell line-derived neurotrophic factor expression promoted neuronal apoptosis. In addition, oxygen and glucose deprivation preconditioning was found to upregulate glial cell line-derived neurotrophic factor expression, and significantly reduce neuronal apoptosis.

Impact of Pitx3 gene knockdown on glial cell line-derived neurotrophic factor transcriptional activity in dopaminergic neurons

Pitx3 is strongly associated with the phenotype, differentiation, and survival of dopaminergic neurons. The relationship between Pitx3 and glial cell line-derived neurotrophic factor（GDNF） in dopaminergic neurons remains poorly understood. The present investigation sought to construct and screen a lentivirus expression plasmid carrying a rat Pitx3 short hairpin（sh）RNA and to assess the impact of Pitx3 gene knockdown on GDNF transcriptional activity in MES23.5 dopaminergic neurons. Three pairs of interference sequences were designed and separately ligated into GV102 expression vectors. These recombinant plasmids were transfected into MES23.5 cells and western blot assays were performed to detect Pitx3 protein expression. Finally, the most effective Pitx3 sh RNA and a dual-luciferase reporter gene plasmid carrying the GDNF promoter region（GDNF-luciferase） were cotransfected into MES23.5 cells. Sequencing showed that the synthesized sequences were identical to the three Pitx3 interference sequences. Inverted fluorescence microscopy revealed that the lentivirus expression plasmids carrying Pitx3-sh RNA had 40-50% transfection efficiency. Western blot assay confirmed that the corresponding Pitx3 of the third knockdown sequence had the lowest expression level. Dual-luciferase reporter gene results showed that the GDNF transcriptional activity in dopaminergic cells cotransfected with both plasmids was decreased compared with those transfected with GDNF-luciferase alone. Together, the results showed that the designed Pitx3-sh RNA interference sequence decreased Pitx3 protein expression, which decreased GDNF transcriptional activity.

A combination of chondroitinase ABC,glial cell line-derived neurotrophic factor,and Nogo A antibody delayed-release microspheres for the treatment of spinal cord injury

The purpose of this study was to evaluate the effect of poly（lactide-co-glycolic acid） delayed-release microspheres,which were prepared using glial cell line-derived neurotrophic factor（GDNF）,on the delayed-release,controllability,and protection of GDNF activity.The present study is the first to combine chondroitinase ABC,GDNF,and Nogo A antibody delayed-release microspheres for the treatment of spinal cord injury.Results show that the combined therapy of chondroitinase ABC,GDNF,and Nogo A antibody microspheres can increase the immunoreaction of neurofilament 200 in the injured spinal cord,and this therapeutic effect was better than chondroitinase ABC,GDNF,or Nogo A antibody microspheres administered singularly.

Depletion of Glial Cell Line-Derived Neurotrophic Factor by Disuse Muscle Atrophy Exacerbates the Degeneration of Alpha Motor Neurons in Caudal Regions Remote from the Spinal Cord Injury

We have been previously reported that disuse muscle atrophy exacerbates both motor neuron (MN) degeneration in caudal regions remote from a spinal cord injury, and decrease in glial cell line-derived neurotrophic factor (GDNF) protein level in paralyzed muscle. In this study we found that disuse muscle atrophy exacerbated the decrease in GDNF protein level in the L4/5 spinal cord, which was not immunopositive for GDNF. Our results were consistent with the fact that in the lumbar spinal cord of rats with mid-thoracic contusion, GDNF expression was not detected, while expression of GDNF receptors (GFRα1 and RET) was. Our study showed that administration of exogenous recombinant GDNF into the atrophic muscle partially rescued α-MN degeneration in the L4/5 spinal cord. These results suggest that the depletion of GDNF protein by muscle atrophy exacerbates α-MN degeneration in caudal regions remote from the injury.

Sequence analysis and functional study of the Han Nationality glial cell line-derived neurotrophic factor transcript

Objective: To study the sequence and function of the glial cell line-derived neurotrophic factor (GDNF) transcript in subjects of Han nationality. Methods: The Han nationality GDNF transcript was amplified by RT-PCR and expressed by baculovirus expression system. Biological activity of the expressed product was measured by the primary culture of midbrain dopaminergic neurons. Results: There only existed the shorter GDNF transcript of 555 bp in the Han nationality. The secretory expression product of the shorter transcript in insect cells promoted the survival and differentiation of dopaminergic neurons. Conclusion: It is found that there is a 78 bp deletion in the Han nationality GDNF transcript compared with the reported 633 bp GDNF transcript. The 78 bp deletion does not affect the secretory expression and biological activity of GDNF mature protein.

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.

Effects of brain-derived neurotrophic factor on induced differentiation of SH-SY5Y cells in vitro

BACKGROUND： Previous studies have demonstrated that brain-derived neurotrophic factor （BDNF） promotes neural differentiation. However, the mechanisms involved in cell cycle-related protein regulation, which highly correlates to neural proliferation and apoptosis, remain poorly understood. OBJECTIVE： To investigate the effects of various concentrations of BDNF on cycle-related protein mRNA expression in induce-differentiated SH-SY5Y cells in vitro prior to and following G2 phase, and to analyze the neuroprotective effects of BDNF. DESIGN, TIME AND SETTING： A comparison, observational study, based on cell biology, was performed at the Department of Biochemistry, Medical College of Tongji University, from March 2005 to October 2006. MATERIALS： SH-SY5Y cells were provided by Shanghai Institute of Cytology, Chinese Academy of Science; BDNF by Alomone Labs, Israel; all-trans retinoic acid （ATRA） by Sigma-Aldrich, USA. METHODS： SH-SY5Y cells were randomly divided into three groups： blank control [cells were treated in Insulin-Transferrin-Selenium （ITS） solution for 7 days], ATRA （cells were treated with ITS solution containing 10 μmol/L ATRA for 7 days）, and BDNF （cells were treated identical to the ATRA group for 5 days, and then respectively treated in ITS solution containing 1, 10, and 100 μg/L BDNF for 2 days）. The experiment was repeated three times for each group. MAIN OUTCOME MEASURES： mRNA expression levels of cyclin A1, B1, B2, cyclin-dependent kinase 1, and 5 were detected using quantitative real-time RT-PCR; percentage of cells in G1, S, and G2 phases were detected using fluorescence-activated cell sorting. RESULTS： mRNA expression levels of cyclin A1 in the high-dose BDNF group was significantly less than the ATRA group （P 〈 0.05）.mRNA expression levels of cyclin B1 was significantly less in the different BDNF concentration groups compared with the control and ATRA groups （P 〈 0.05 or P 〈 0.01）. mRNA expression levels of cyclin B2 and cyclin-dependent kinase 1 were significantly decreased in the high-dose BDNF group （P 〈 0.05 or P 〈 0.01）. Cyclin-dependent kinase 5 mRNA expression was significantly greater in the low-dose and moderate-dose BDNF groups compared with the ATRA group （P 〈 0.05）. The percentage of cells in G1 phase was significantly greater in the different BDNF concentration groups compared with the ATRA and control groups （P 〈 0.01）. Moreover, the percentage of cells in S phase was significantly less in the three BDNF groups compared with the ATRA group （P 〈 0.01）. However, the percentage of cells in S phase was significantly less in the low-dose and high-dose BDNF groups compared with the control group （P 〈 0.01）. CONCLUSION： BDNF enhanced the percentage of cells in G1 phase, but did not alter mRNA expression of cell cycle-related proteins prior to or following G2 phase. These results suggested that BDNF was not a risk factor for inducing apoptosis.

血清GDNF、S100B、维生素D水平对产后抑郁症的预测价值分析

目的:探讨血清胶质细胞源性神经营养因子(GDNF)、S100钙结合蛋白B(S100B)、维生素D水平联合检测对剖宫产产妇发生产后抑郁的预测价值。方法:选取2021年9月—2023年9月某院产科孕39周以上待产孕妇104例为研究对象,均行剖宫产,根据爱丁堡抑郁量表(EPDS)评估产后抑郁情况,将发生产后抑郁产妇纳入观察组(18例),未发生产后抑郁产妇纳入对照组(86例)。比较2组产前、产后3 d EPDS评分及血清GDNF、S100B、维生素D水平,分析血清各指标水平与EPDS评分之间的相关性,分析血清各指标联合检测对产后抑郁的预测价值。结果:产后3 d,观察组EPDS评分[(18.93±2.24)分]高于对照组[(7.04±0.96)分](P<0.05);产后3 d,观察组血清GDNF、维生素D水平[(5.63±1.28)pg/mL、(22.85±3.26)ng/mL]低于对照组[(12.55±3.07)pg/mL、(32.19±4.02)ng/mL],血清S100B水平[(63.29±5.18)μg/mL]高于对照组[(42.67±3.49)μg/mL],差异均有统计学意义(P<0.05)。产后3 d,血清GDNF、维生素D水平与EPDS评分呈负相关(r=-0.624、-0.549,P均<0.05),S100B水平与EPDS评分呈正相关(r=0.573,P<0.05),且各指标联合预测产后抑郁的AUC为0.938(95%CI:0.873~0.976),最佳诊断敏感度为88.89%,特异度为87.21%,约登指数为0.761。结论:剖宫产产后抑郁患者血清中GDNF、维生素D表达下调,S100B表达上调,各指标水平与EPDS评分均具有一定相关性,联合检测可作为临床评估产后抑郁情况的辅助指标。

Exercise-dependent regulation of glial cell line-derived neurotrophic factor （GDNF） expression in skeletal muscle and its importance for the neuromuscular system

The focus of this review is to highlight the importance of glial cell line-derived neurotrophic factor （GDNF） for the motor nervous system. GDNF is the most potent survival factor for motor neurons, where it enhances maintenance and survival of both developing and mature motor neurons in vivo and in vitro. GDNF aids in neuromuscular junction formation, maintenance, and plasticity, where skeletal muscle-derived GDNF may be responsible for this phenomenon. Increased levels of physical activity can increase GDNF protein levels in skeletal muscle, where alterations in acetylcholine and acetylcholine receptor activation may be involved in regulation of these changes observed. With inactivity and disuse, GDNF expression shows different patterns of regulation in the central and peripheral nervous systems. Due to its potent effects for motor neurons, GDNF is being extensively studied in neuromuscular diseases.

Acupuncture promotes functional recovery after cerebral hemorrhage by upregulating neurotrophic factor expression

Acupuncture is widely used in the treatment of cerebral hemorrhage,and it improves outcomes in experimental animal models and patients.However,the mechanisms underlying the effectiveness of acupuncture treatment for cerebral hemorrhage are still unclear.In this study,a model of intracerebral hemorrhage was produced by injecting 50μL autologous blood into the caudate nucleus in Wistar rats.Acupuncture at Baihui(DU20)and Qubin(GB7)acupoints was performed at a depth of 1.0 inch,12 hours after blood injection,once every 24 hours.The needle was rotated at 200 r/min for 5 minutes,For each 30-minute session,needling at 200 r/min was performed for three sessions,each lasting 5 minutes.For the positive control group,at 6 hours,and 1,2,3 and 7 days after induction of hemorrhage,the rats were intraperitoneally injected with 1 mL aniracetam(0.75 mg/mL),three times a day.The Bederson behavioral test was used to assess palsy in the contralateral limbs.Western blot assay was used to examine the expression levels of Nestin and basic fibroblast growth factor in the basal ganglia.Immunohistochemistry was performed to count the number of Nestin-and glial cell line-derived neurotrophic factor-positive cells in the basal ganglia.Acupuncture effectively reduced hemorrhage and brain edema,elevated the expression levels of Nestin and basic fibroblast growth factor in the basal ganglia,and increased the number of Nestin-and glial cell line-derived neurotrophic factor-positive cells in the basal ganglia.Together,these findings suggest that acupuncture promotes functional recovery after cerebral hemorrhage by increasing the expression of neurotrophic factors.The study was approved by the Committee for Experimental Animals of Heilongjiang Medical Laboratory Animal Center(approval No.2017061001)on June 10,2017.

Transplantation of neural stem cells overexpressing glial cell line-derived neurotrophic factor enhances Akt and Erkl/2 signaling and neurogenesis in rats after stroke

Background Our previous studies have indicated that the beneficial effects of grafting neural stem cells （NSCs） overexpressing glial cell line-derived neurotrophic factor （GDNF） in rats after stroke. However, the underlying mechanisms are highly debatable. In this study, we investigated whether neurogenesis, Akt, and extracellular signal- regulated kinase 1/2 （Erkl/2） signaling were involved in this process. Methods Transient ischemic stroke were induced by occluding middle cerebral artery for 2 hours and reperfusion. At 3 days after reperfusion, GDNF/NSCs, NSCs, and vehicle were administered. Immunohistochemical staining was used to evaluate neurogenesis by nestin antibody; phosphorylation of Akt and Erkl/2 was investigated by Western blotting analysis. Results Transplantation of GDNF/NSCs and NSCs significantly increased nestin-positive cells compared to control group （vehicle） from 1 to 7 weeks after reperfusion, and GDNF/NSCs showed stronger effect than NSCs at 2 and 3 weeks after reperfusion. Meanwhile, enhanced phosphorylation level of Erkl/2 was observed in the GDNF/NSCs and NSCs groups compared with control group, and phosphorylation level of Erkl/2 in GDNF/NSCs group was remarkably higher than that of NSCs group at any given time. In contrast, expression of mitogen-activated protein kinase phosphatase-1 （MKP-1）, known as inhibitor of Erkl/2 signaling, was significantly decreased in the GDNF/NSCs and NSCs groups compared with the control group. Moreover, much enhanced and prolonged phosphorylation level of Akt of GDNF/NSCs group was detected compared with control and NSCs group. Conclusion Grafting GDNF/NSCs enhances neurogenesis and activates Akt and Erkl/2 signaling, that may provide the potential for GDNF/NSCs in stroke treatment.

Neuroprotective effects of BDNF and GDNF in intravitreally transplanted mesenchymal stem cells after optic nerve crush in mice

AIM： To assess the neuro-protective effect of bone marrow mesenchymal stem cells （BMSCs） on retinal ganglion cells （RGCs） following optic nerve crush in mice. METHODS： C56BL/6J mice were treated with intravitreal injection of PBS, BMSCs, BDNF-interference BMSCs （BIM）, and GDNF-interference BMSCs （GIM） following optic nerve crush, respectively. The number of surviving RGCs was determined by whole-mount retinas and frozen sections, while certain mRNA or protein was detected by q-PCR or ELISA, respectively.RESULTS： The density （cell number/mm^2） of RGCs was 410.77±56.70 in the retina 21d after optic nerve crush without any treatment, compared to 1351.39±195.97 in the normal control （P〈0.05）. RGCs in BMSCs treated eyes was 625.07±89.64/mm^2, significantly higher than that of no or PBS treatment （P〈0.05）. While RGCs was even less in the retina with intravitreal injection of BIM （354.07±39.77） and GIM （326.67±33.37） than that without treatment （P〈0.05）. BMSCs injection improved the internal BDNF expression in retinas.CONCLUSION： Optic nerve crush caused rust loss of RGCs and intravitreally transplanted BMSCs at some extent protected RGCs from death. The effect of BMSCs and level of BDNF in retinas are both related to BDNF and GDNF expression in BMSCs.

Neurotrophic factors: from neurodevelopmental regulators to novel therapies for Parkinson's disease

Neuroprotection and neuroregeneration are two of the most promising disease-modifying ther- apies for the incurable and widespread Parkinson＇s disease. In Parkinson＇s disease, progressive degeneration of nigrostriatal dopaminergic neurons causes debilitating motor symptoms. Neurotrophic factors play important regulatory roles in the development, survival and maintenance of specific neuronal populations. These factors have the potential to slow down, halt or reverse the loss of nigrostriatal dopaminergic neurons in Parkinsoffs disease. Several neurotrophic fac- tors have been investigated in this regard. This review article discusses the neurodevelopmental roles and therapeutic potential of three dopaminergic neurotrophic factors： glial cell line-derived neurotrophic factor, neurturin and growth/differentiation factor 5.