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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

经筋透刺法联合穴位注射治疗顽固性面瘫60例临床观察

目的探讨经筋透刺法联合穴位注射治疗顽固性面瘫的临床疗效。方法选取2020年5月至2021年10月在遂宁市中医院接受治疗的120例顽固性面瘫病人,采用随机数字表法随机分为单一组(60例)和联合组(60例),两组病人均给予常规西药治疗,单一组在此基础上给予穴位注射,联合组在此基础上给予经筋透刺法联合穴位注射,比较两组病人治疗前后面神经功能、神经生长因子(NGF)和胶质细胞源性神经营养因子(GDNF)水平、神经功能分级(H-B)评分、面瘫Portmann评分、Sunnybrook量表、复发率及临床疗效。结果单一组和联合组治疗后面神经功能明显改善,且联合组面神经功能改善情况明显优于单一组(P<0.05);单一组H-B评分治疗后较治疗前降低(2.63±0.54)分比(4.01±0.73)分,联合组(1.67±0.49)分比(4.03±0.71)分(P<0.05),且联合组H-B评分低于单一组(P<0.05),单一组和联合组GDNF(12.16±3.33)mg/L比(8.92±1.35)mg/L、(15.54±3.42)mg/L比(8.89±1.37)mg/L、NGF水平(12.16±3.33)mg/L比(8.92±1.35)mg/L、(15.54±3.42)mg/L比(8.89±1.37)mg/L、面瘫Portmann评分(15.31±1.03)分比(6.69±0.68)分、(17.24±1.16)分比(6.72±0.71)分、Sunnybrook量表评分(69.16±10.67)分比(36.42±10.17)分、(78.64±11.56)分比(36.17±10.13)分治疗后较治疗前升高,且联合组GDNF、NGF水平、面瘫Portmann评分、Sunnybrook量表评分高于单一组(P<0.05);联合组总复发率(3.33%)低于单一组(13.33%)(P<0.05);联合组总有效率(90.00%)明显高于单一组(75.00%)(P<0.05)。结论经筋透刺法联合穴位注射可改善顽固性面瘫病人临床症状及面神经功能,疗效较好且复发率较低。

神经胶质细胞系衍生神经营养因子和雄激素受体在手术诱导隐睾小鼠睾丸管周细胞中的表达

【目的】探讨神经胶质细胞系衍生神经营养因子(GDNF)和雄激素受体(AR)在隐睾症小鼠睾丸管周细胞中的表达水平及对隐睾症导致生精功能障碍的理论意义。【方法】30只5周龄雄性ICR小鼠采用随机数字表法随机分配至6组中,随机抽取3组15只小鼠进行手术诱导隐睾,其余3组为作为对照组进行假手术处理。分别于4 d、7 d、14 d后取各组睾丸组织,然后测量睾丸体积、观察睾丸组织病理,提取各组睾丸管周细胞后利用免疫荧光、Re⁃al-Time PCR和蛋白质印记法检测AR和GDNF的mRNA和蛋白的表达。【结果】对照组4 d、7 d、14 d小鼠的睾丸体积分别为(125.58±19.22)mm^(3)、(123.45±20.12)mm^(3)、(140.09±13.62)mm^(3);睾丸各级生精细胞排列整齐、层次清楚,可见较多精子细胞,生精小管周围管周细胞形态规则,呈梭形围绕小管周围,细胞厚度均一;ARmRNA的表达量分别为1.00±0.05、1.06±0.07、1.19±0.13GDNFmRNA的表达量分别为1.00±0.04、1.09±0.05、1.10±0.07;AR蛋白的表达量分别为1.01±0.01、0.79±0.02、1.01±0.04;GDNF蛋白的浓度分别为(18.68±0.43)pg/mL、(14.39±0.36)pg/mL、(16.88±0.37)pg/mL。隐睾组4 d、7 d、14 d小鼠的睾丸体积分别为(115.64±3.91)mm^(3)、(69.51±14.97)mm^(3)、(44.86±5.56)mm^(3);睾丸各级生精细胞排列紊乱、层次不清、结构破坏,曲细精管周围管周细胞萎缩、弯曲断裂;ARmRNA的表达量分别为0.76±0.06、0.53±0.04、0.29±0.02;GDNFmRNA的表达量分别为0.72±0.05、0.42±0.02、0.30±0.03;AR蛋白的表达量分别为0.54±0.02、0.98±0.04、0.31±0.01;GDNF蛋白的浓度分别为(8.50±0.34)pg/mL、(17.44±0.32)pg/mL、(6.83±0.34)pg/mL。上述指标与对照组相比,除了4 d的睾丸体积差异无统计学意义(P>0.05),其他均有统计学差异(P<0.05)。对照组中3个时间点的睾丸体积、AR和GDNF的mRNA、蛋白表达量的差异无统计学意义(P>0.05),隐睾组3个时间点的睾丸体积、AR和GDNF的mRNA、蛋白表达量呈逐渐下降趋势且各组之间的差异均有统计学意义(P<0.05)。【结论】在手术诱导隐睾小鼠中,睾丸管周细胞的AR和GDNF的表达水平随着诱导时间的延长呈现显著下降。AR和GDNF在隐睾症介导睾丸管周细胞功能的损伤中有重要作用。本研究为阐明隐睾症导致生精功能障碍的机制研究提供理论基础。

骨肉瘤组织中GFRA1、FBN1表达水平及意义

目的探讨胶质细胞系源性神经营养因子受体1(GFRA1)、原纤维蛋白-1(FBN1)在骨肉瘤组织中表达水平及意义。方法收集2017年9月至2019年9月住院手术的66例骨肉瘤患者治疗精细切除骨肉瘤组织标本及癌旁组织标本,同时收集整理其临床分期、肿瘤直径、肿瘤分化程度等临床资料。采用免疫组织化学法检测GFRA1、FBN1蛋白表达;骨肉瘤组织GFRA1、FBN1表达与患者预后的关系采用Kaplan-Meier法分析;多因素Logistic回归分析骨肉瘤患者预后的影响因素。结果与癌旁组织相比,骨肉瘤组织中GFRA1、FBN1阳性表达率明显较高(P<0.05)。GFRA1、FBN1的表达与骨肉瘤患者的临床分期、分化程度、是否发生肺转移、软组织是否浸润有关(P<0.05),与患者性别、年龄、肿瘤直径、肿瘤位置无关(P>0.05);骨肉瘤组织GFRA1、FBN1阳性表达患者3年生存率低于FBN1阴性表达患者(P<0.05)。GFRA1、FBN1阳性表达、肿瘤转移、软组织浸润是骨肉瘤患者预后的独立危险因素(P<0.05)。结论GFRA1、FBN1的表达与骨肉瘤患者的临床病理特征及预后有关,可以作为骨肉瘤患者预后评估的指标。

胶质细胞系源性神经营养因子/胶质细胞系源性神经营养因子受体信号通路在乳鼠先天性巨结肠相关性小肠结肠炎中的作用实验研究

目的:探讨胶质细胞系源性神经营养因子/胶质细胞系源性神经营养因子受体(GDNF/GFRα1)通路在乳鼠先天性巨结肠(HD)相关性小肠结肠炎(HAEC)中的作用研究。方法:21日龄内皮素受体(Ednrb)基因敲除乳鼠为HD模型组(实验组),同日龄野生型乳鼠为对照组,8只/组。取结肠组织,按照形态将实验组乳鼠结肠组织分为狭窄段、扩张段,对照组乳鼠结肠组织分为远段、近段。采用苏木精-伊红(HE)染色法评判两组肠管炎症程度;酶联免疫吸附法(ELISA)法检测两组结肠组织白介素-10(IL-10)、肿瘤坏死因子-α(TNF-α)水平;免疫印迹法(WB)分别检测GDNF/GFRα1信号通路相关基因[GDNF、GFRα1、酪氨酸酶受体(RET)、核转录因子kappaBp65(NF-κBp65)、TNF-α]蛋白水平。结果:HE染色结果显示HAEC主要发生在结肠扩张段;ELISA法结果显示,与实验组乳鼠狭窄段肠管比较,扩张段肠管IL-10水平显著降低、TNF-α水平显著升高(均P<0.05);WB法结果显示,与实验组乳鼠狭窄段肠管比较,扩张段肠管GDNF、GFRα1、RET蛋白水平显著降低,NF-κBp65、TNF-α蛋白水平显著升高(均P<0.05)。结论:HD模型乳鼠结肠扩张段炎症程度较为严重,机制可能与GDNF/GFRα1信号通路受抑制,肠神经免疫调节系统异常有关。

生长分化因子15与胶质源性神经营养因子样受体通路对小鼠动脉粥样硬化进展的影响

目的 探讨生长分化因子15(growth differentiation factor 15,GDF-15)/胶质源性神经营养因子样受体(glial-derived neurotrophic factor receptor alpha-like, GFRAL)通路对载脂蛋白E^(-/-)小鼠动脉粥样硬化进展的影响及可能机制。方法 选择8周龄C57BL/6雄性载脂蛋白E^(-/-)小鼠8只,随机分为对照组和重组GDF-15组,每组4只。对照组:高脂饮食4周后,每周1次尾静脉注射磷酸盐缓冲液;重组GDF-15组:高脂饮食4周后,每周1次尾静脉注射重组GDF-15(0.05 mg/kg)。高脂饮食12周,监测小鼠体质量,处死小鼠。取4只同等周龄(20周龄)正常小鼠作为正常组,比较3组空腹血糖、血脂、皮质醇和醛固酮水平。主动脉冷冻切片油红O染色评估对照组和重组GDF-15组斑块大小。免疫组织化学检测对照组和重组GDF-15组脑组织GDF-15及GFRAL表达。结果 重组GDF-15组血清GDF-15水平较对照组明显升高,差异有统计学意义[(52.59±2.90)ng/ml vs(20.09±1.27)ng/ml,P<0.01]。重组GDF-15组11周和12周体质量较对照组明显减低[(28.60±0.22)g vs(29.47±0.25)g;(28.98±0.22)g vs(30.35±0.13)g,P<0.01]。重组GDF-15组三酰甘油水平较对照组明显降低[(0.22±0.02)mmol/L vs(0.38±0.09)mmol/L,P<0.05]。重组GDF-15组斑块面积明显小于对照组,差异有统计学意义[(22.22±2.58)%vs(31.61±3.51)%,P<0.01]。重组GDF-15组脑组织GDF-15和GFRAL表达较对照组明显增加(0.088±0.007 vs 0.030±0.006,0.031±0.003 vs 0.010±0.001,P<0.01)。对照组及重组GDF-15组皮质醇和醛固酮水平较正常组明显升高,差异有统计学意义(P<0.01)。重组GDF-15组醛固酮水平较对照组明显降低,差异有统计学意义[(22.01±3.67)mg/ml vs(87.29±8.63)mg/ml,P<0.01]。结论 GDF-15可能通过GFRAL调控小鼠体质量、三酰甘油及醛固酮水平影响动脉粥样硬化进展。

靶肌肉注射胶质细胞源性神经营养因子对面神经损伤修复的作用

目的 通过靶肌肉注射胶质细胞源性神经营养因子(GDNF),观察其对面神经压榨损伤后大鼠功能恢复、神经形态学及GDNF在中枢面神经元中表达的影响,探讨经靶肌肉注射GDNF治疗周围性面瘫的可行性及作用机理。方法 SD大鼠随机分为假手术组(只暴露右侧面神经主干)、模型组(面神经主干压榨)、实验对照组(面神经主干压榨+颊肌注射生理盐水)和实验组(面神经主干压榨+颊肌注射GDNF),通过颊肌电生理、面瘫症状评分观察大鼠的神经功能恢复,Masson染色观察颊肌纤维形态学变化、甲苯胺蓝染色观察面神经形态学变化、Western Blot检测面神经元中GDNF的表达。结果 (1)大鼠面瘫症状评分:假手术组无面瘫表现,评分为0分,造模后各组大鼠均出现周围性面瘫表现,评分均为5分;术后第28天,实验组大鼠面瘫症状已基本完全恢复,模型组及实验对照组较前有不同程度改善但未完全恢复,评分均>3分;(2)颊肌电生理:各组造模后与假手术组相比,峰潜伏期有不同程度延长、最大振幅有不同程度下降;随时间的推移,实验组峰潜伏期较模型组及实验对照组明显缩短(P<0.05),最大振幅较其明显上升(P<0.05);(3)甲苯胺蓝染色:模型组、实验对照组、实验组术后均出现神经纤维形态不规则,外膜不连续不清晰,轴突数量减少。术后第28天,实验组面神经形态与假手术无明显差异,较模型组及实验对照组有明显恢复;(4)Masson染色:各组造模后肌纤维数量减少,肌肉组织占比面积减少;实验组肌纤维形态较模型组及实验对照组恢复快,至术后第28天,肌纤维形态接近正常(P<0.05);(5)Western Bolt检测:各组造模后中枢面神经元组织GDNF的蛋白表达下降,观察期内逐渐增强;与模型组及实验对照组相比,术后各时间点,实验组中枢面神经元组织GDNF的蛋白表达显著增强(P<0.01)。结论 靶肌肉注射GDNF可作为改善周围神经损伤的有效给药方式之一,促进神经纤维修复、靶肌肉功能的恢复及中枢神经系统对周围损伤神经的修复。