Coenzyme Q10 ameliorates anxiety and depression‑like behavior associated with chronic opioid use and increases GDNF expression in the hippocampus of morphine‑dependent rats.

Adeno-associated Virus-mediated, Mifepristone-regulated Transgene Expression in the Brain

M27 - Epigenetic Alterations of The Glia Cell-Derived Neurotrophic Factor And Response To Electroconvulsive Stimulation

P.4.017 Epigenetic alterations of the glia cell-derived neurotrophic factor and response to electroconvulsive stimulation

Peripheral nerve injuries commonly occur due to trauma, like a traffic accident. Peripheral nerves get severed, causing motor neuron death and potential muscle atrophy. The current golden standard to treat peripheral nerve lesions, especially lesions with large (≥ 3 cm) nerve gaps, is the use of a nerve autograft or reimplantation in cases where nerve root avulsions occur. If not tended early, degeneration of motor neurons and loss of axon regeneration can occur, leading to loss of function. Although surgical procedures exist, patients often do not fully recover, and quality of life deteriorates. Peripheral nerves have limited regeneration, and it is usually mediated by Schwann cells and neurotrophic factors, like glial cell line-derived neurotrophic factor, as seen in Wallerian degeneration. Glial cell line-derived neurotrophic factor is a neurotrophic factor known to promote motor neuron survival and neurite outgrowth. Glial cell line-derived neurotrophic factor is upregulated in different forms of nerve injuries like axotomy, sciatic nerve crush, and compression, thus creating great interest to explore this protein as a potential treatment for peripheral nerve injuries. Exogenous glial cell line-derived neurotrophic factor has shown positive effects in regeneration and functional recovery when applied in experimental models of peripheral nerve injuries. In this review, we discuss the mechanism of repair provided by Schwann cells and upregulation of glial cell line-derived neurotrophic factor, the latest findings on the effects of glial cell line-derived neurotrophic factor in different types of peripheral nerve injuries, delivery systems, and complementary treatments (electrical muscle stimulation and exercise). Understanding and overcoming the challenges of proper timing and glial cell line-derived neurotrophic factor delivery is paramount to creating novel treatments to tend to peripheral nerve injuries to improve patients’ quality of life.

Glial Cell Line-Derived Neurotrophic Factor Increases β-Cell Mass and Improves Glucose Tolerance

Objective To study the influence of the extrinsic glial cell line-derived neurotrophic factor (GDNF) on the enteric nervous system (ENS) upgrowth in the rectal end of fetal mice.Methods SD pregnant mice were randomly divided into 3 groups,namely ETU group,ETU + GDNF group and control group.On the tenth day of pregnancy,ETU group and ETU+ GDNF group were given 1％ ETU via gavage.On the eleventh day of pregnancy,ETU+ GDNF group was injected with 20 μgGDNF by caudal vein.On the twentieth day of pregnancy,pregnant mice underwent the cesarian sections.The incidence of ARMs and the expression of GDNF in the rectal end of the fetal mice were detected by immunohistochemistry and western-blotting.Results 1.The incidence of ARMs in ETU group and ETU + GDNF group was 51.4％ and 52.5％,respectively,and there was no statistical difference (P＞0.05).2.Results of GDNF:① In the rectal end of the fetal mice with normal anus,there were no significant differences in the expression of GDNF among the three groups [ETU group:(0.051 ± 0.004) ％ ; ETU + GDNF group:(0.058 ± 0.004) ％ ; control group:(0.057 ± 0.004) ％,P ＞0.05].② In the rectal end of the fetal mice with ARMs,the expression of GDNF in ETU+ GDNF group was higher than that in ETU group [(0.043 ± 0.005) ％ vs (0.028 ± 0.005) ％,P =0.0366] ;and the expression in the rectal end of the fetal mice with ARMs in ETU group and ETU + GDNF group was lower than that in the rectal end of fetal mice with normal anus,respectively[ETU group:(0.028 ± 0.005) ％ vs (0.051 ± 0.004) ％,P =0.001 2; ETU + GDNF group:(0.043 ± 0.005) ％ vs (0.058 ± 0.004) ％,P =0.028 5].The expression of GDNF by western-blotting in ETU + GDNF group was significantly higher than that in ETU group (0.019 ± 0.003 vs 0.048 ± 0.003,P＜0.000 1).Conclusions Extrinsic neurotrophic factor (GDNF) may not block the teratogenesis of ARMs induced by ethylenethiourea,but may advance the expression of GDNF gene in the rectal end and promote the development of the dysplastic ENS. Key words: Anus, abnormalities; Rectum, abnormalities; Enteric nervous system; Glial cell line-derived neurotrophic factor

The effect of atypical antipsychotic drugs on the neurotrophic factors gene expression in the MPTP model of Parkinson's disease

Atypical antipsychotics (AAP) are used in the therapy of Parkinson's disease (PD) for elimination of psychotic symptoms. As the brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and cerebral dopamine neurotrophic factor (CDNF) play a crucial role in the PD treatment, the aim of our study was the investigation of the effects of chronic treatment with commonly used AAP, clozapine and quetiapine, on the motor behavior and the BDNF, GDNF and CDNF genes expression in the mouse brain in the PD model produced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Clozapine and quetiapine (1 mg/kg, i.p.) were administered 48 hours after the last MPTP injection, and treatment continued for the following 16 days. Then animals were euthanized, substantia nigra (SN), striatum (St) and hippocampus (Hc) were extracted for RT-PCR and tyrosine hydroxylase (TH) western blot assessment. MPTP treatment led to 50% depletion in the TH protein level in the St. MPTP caused significant decrease in both BDNF and GDNF mRNA level in the Hc and St, respectively. At the same time, increase in the GDNF expression in the MPTP + clozapine group in the SN was found. MPTP caused dramatic decrease in the CDNF mRNA level in the SN with simultaneous increase in the St. Both clozapine and quetiapine decreased it to a normal level in the St. The effect of AAP clozapine and quetiapine on the GDNF and CDNF genes expression in the pharmacological model of PD has been shown for the first time.

Chronic clomipramine treatment restores hippocampal expression of glial cell line-derived neurotrophic factor in a rat model of depression

PurposeTo evaluate the expression of glial cell line-derived neurotrophic factor (GDNF) and its receptor, GDNF family receptor alpha subunit 1 (GFRα-1) in the pelvic (middle third) vagina and, particularly, in the paravaginal ganglia of nulliparous and primiparous rabbits.MethodsChinchilla-breed female rabbits were used. Primiparas were killed on postpartum day 3 and nulliparas upon reaching a similar age. The vaginal tracts were processed for histological analyses or frozen for Western blot assays. We measured the ganglionic area, the Abercrombie-corrected number of paravaginal neurons, the cross-sectional area of the neuronal somata, and the number of satellite glial cells (SGCs) per neuron. The relative expression of both GDNF and GFRα-1 were assessed by Western blotting, and the immunostaining was semiquantitated. Unpaired two-tailed Student t -test or Wilcoxon test was used to identify statistically significant differences (P≤0.05) between the groups.ResultsOur findings demonstrated that the ganglionic area, neuronal soma size, Abercrombie-corrected number of neurons, and number of SGCs per neuron were similar in nulliparas and primiparas. The relative expression of both GDNF and GFRα-1 was similar. Immunostaining for both GDNF and GFRα-1 was observed in several vaginal layers, and no differences were detected regarding GDNF and GFRα-1 immunostaining between the 2 groups. In the paravaginal ganglia, the expression of GDNF was increased in neurons, while that of GFRα-1 was augmented in the SGCs of primiparous rabbits.ConclusionsThe present findings suggest an ongoing regenerative process related to the recovery of neuronal soma size in the paravaginal ganglia, in which GDNF and GFRα-1 could be involved in cross-talk between neurons and SGCs.

Sphingosine 1-phosphate (S1P) is a platelet-derived bioactive sphingolipid that evokes a variety of biological responses. To understand the role of S1P in the central nervous system, we have examined the effect of S1P on the production of glial cell line-derived neurotrophic factor (GDNF) and growth regulation of cortical astrocytes from rat embryo. Moreover, we examined the possibility that the expression of GDNF is regulated differently in cultured astrocytes from the stroke-prone spontaneously hypertensive rat (SHRSP) than in those from Wistar kyoto rats (WKY). The mRNA expression was quantitated by RT-PCR based on the fluorescent TaqMan methodology. A new instrument capable of measuring fluorescence in real time was used to quantify gene amplification in astrocytes. GDNF protein was investigated by enzyme-linked immunosorbent assay. S1P induced the expression of GDNF mRNA and the production of GDNF protein in a dose-dependent manner in WKY astrocytes. Moreover, S1P increased cell numbers and induced the proliferation of astrocytes. In addition, the level of mRNA expression and protein production of GDNF was significantly lower in SHRSP than WKY astrocytes following exposure to S1P. These findings revealed that S1P augments GDNF protein production and cellular growth in astrocytes. Also, our results indicate that production in SHRSP astrocytes was attenuated in response to S1P compared with that observed in WKY. We conclude that S1P specifically triggers a cascade of events that regulate the production of GDNF and cell growth in astrocytes. Our results also suggest that the reduced expression of GDNF caused by S1P is a factor in the stroke proneness of SHRSP.

Glial cell line-derived neurotrophic factor (GDNF) is proposed as a therapeutic tool in Parkinson’s disease, addiction-related disorders, and neurodegenerative conditions affecting motor neurons (MNs). Despite the high amount of work about GDNF therapeutic application, the neuronal circuits requiring GDNF trophic support in the brain and spinal cord (SC) are poorly characterized. Here, we defined GDNF and GDNF family receptor-α 1 (GFRα1) expression pattern in the brain and SC of newborn and adult mice. We performed systematic and simultaneous detection of EGFP and LacZ expressing alleles in reporter mice and asked whether modifications of this signaling pathway lead to a significant central nervous system (CNS) alteration. GFRα1 was predominantly expressed by neurons but also by an unexpected population of non-neuronal cells. GFRα1 expression pattern was wider in neonatal than in adult CNS and GDNF expression was restricted in comparison with GFRα1 at both developmental time points. The use of confocal microscopy to imaging X-gal deposits and EGFP allowed us to identify regions containing cells that expressed both proteins and to discriminate between auto and non-autotrophic signaling. We also suggested long-range GDNF-GFRα1 circuits taking advantage of the ability of the EGFP genetically encoded reporter to label long distance projecting axons. The complete elimination of either the ligand or the receptor during development did not produce major abnormalities, suggesting a preponderant role for GDNF signaling during adulthood. In the SC, our results pointed to local modulatory interneurons as the main target of GDNF produced by Clarke’s column (CC) cells. Our work increases the understanding on how GDNF signals in the CNS and establish a crucial framework for posterior studies addressing either the biological role of GDNF or the optimization of trophic factor-based therapies.

Objective To study the protective function of nimodipine on facial nerve injury and its effect on the expression of glial cell line-derived neurotrophic factor (GDNF). Methods Ninety-six SD rats were randomly divided into sham-operated group, facial nerve injury group, nimodipine pretreatment group, and nimodipine post-treatment group. Rat models of facial nerve injury in thc later 3groups were established. The dynamic changes of expression of GDNF were observed by HE staining and Western blotting in different treatment groups and at different time points (1, 3 and 6 months after the injury). Restdts Compared with the facial nerve injury group, the nimodipine pretreatment and post-treatment groups had significantly less severe nerve damage and significantly up-rcgulated expression of GDNF (P＜0.05). The expression of GDNF in the nimodipine pretreatment group was statistically higher than that in the nimodipine post-treatment group (P＜0.05). However, the expression of GDNF in the nimodipine post-treatment group was not statistically different from that in the facial nerve injury group 3 and 6 months after the injury (P＞0.05). Conclusion Nimodipine has significant facial nerve protective effect, and one of the mechanisms of nimodipine to protect the facial nerve is to regulate the GDNF expression. Key words: Facial nerve; Nimodipine; Glial cell line-derived neurotrophic factor

Objective To explore the expressions and distributions of glial cell line-derived neurotrophic factor (GDNF) and itstyrosine kinase receptor RET in the terminal rectums of fetal rats with congenital anorectal malformations (ARM) at different gestationalage, and to explore their effects on the enteric nervous system in the terminal rectum of ARM fetal rats. Methods Thirty-five SD pregnancy rats were divided into a saline group (n=10) and an ethylenethiourea experiment group (n=25) by simple randomized study.The fetal rats were removed from the pregnant rats at the gestational 16 d, 18 d and 20 d. The fetal rats were divided into the saline control group, the ethylenethiourea control group (fetal rats without ARM) and the ethylenethiourea malformation group (ARM fetal rats) by the naked eye and dissecting microscope.HE staining was used to observe the morphology and the intestinal ganglion cells in the terminal rectum were counted.The immunohistochemical staining and Western blot methods were used to observe the distributions of GDNF and RET in the rectum at the gestational 16 d, 18 d and 20 d. The quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of GDNF mRNA in the fetal rats in the terminal rectum at the gestational 16 d, 18 d and 20 d. Results HE staining: the development of anorectal terminal in 3 groups of fetal rats was unclear at the gestational 16 d. A small amount of scattered nerve plexuses were observed in the muscular layer.The nuclei were small and sparse.The axons and cytoplasms were less.The serosal layer, muscular layer, submucosa, mucosal layer and glands in the terminal rectum were gradually clear in the saline control group and the ethylenethiourea control group at the gestational 18 d and 20 d. The intermuscular submucosal nerve plexuses increased gra-dually (11.400±3.134 and 11.200±3.425 at the gestational 18 d; 66.100±4.954 and 67.600±5.481 at the gestational 20 d). While, the layer was unclear in the ethylenethiourea malformation group and the nerve plexus was less (7.800±1.989 at the gestational 18 d, and 25.200±3.048 at the gestational 20 d), and the difference was statistically significant compared with 2 control groups (F=7.591, 271.833, all P 0.05); the expressions of GDNF and RET protein were 103.624±27.533 and 105.184±19.634 at the gestational 18 d; 151.496±33.622 and 150.738±21.423 at the gestational 20 d in 2 control groups.Compared with the ethylenethiourea malformation group (79.169±11.697 at the gestational 18 d; 94.873±11.309 at the gestational 20 d), and the difference were statistically significant (all P<0.05). Conclusions The expressions of GDNF and its tyrosine kinase receptor RET had a certain temporal correlation in the terminal rectum of normal fetal rats at different gestational ages and ARM.Moreover, the abnormal expressions of GDNF and its tyrosine kinase receptor RET in the distal rectum of ARM fetal rats can affect the development of enteric nervous system. Key words: Glial cell line-derived neurotrophic factor; RET; Signal pathway; Enteric nervous system; Congenital anorectal malformation

GDNF deficit in Hirschsprung's disease