Electroacupuncture Promotes Functional Recovery after Facial Nerve Injury in Rats by Regulating Autophagy via GDNF and PI3K/mTOR Signaling Pathway / 中国结合医学杂志

OBJECTIVE@#To explore the mechanism of electroacupuncture (EA) in promoting recovery of the facial function with the involvement of autophagy, glial cell line-derived neurotrophic factor (GDNF), and phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway.@*METHODS@#Seventy-two male Sprague-Dawley rats were randomly allocated into the control, sham-operated, facial nerve injury (FNI), EA, EA+3-methyladenine (3-MA), and EA+GDNF antagonist groups using a random number table, with 12 rats in each group. An FNI rat model was established with facial nerve crushing method. EA intervention was conducted at Dicang (ST 4), Jiache (ST 6), Yifeng (SJ 17), and Hegu (LI 4) acupoints for 2 weeks. The Simone's 10-Point Scale was utilized to monitor the recovery of facial function. The histopathological evaluation of facial nerves was performed using hematoxylin-eosin (HE) staining. The levels of Beclin-1, light chain 3 (LC3), and P62 were detected by immunohistochemistry (IHC), immunofluorescence, and reverse transcription-polymerase chain reaction, respectively. Additionally, IHC was also used to detect the levels of GDNF, Rai, PI3K, and mTOR.@*RESULTS@#The facial functional scores were significantly increased in the EA group than the FNI group (P<0.05 or P<0.01). HE staining showed nerve axons and myelin sheaths, which were destroyed immediately after the injury, were recovered with EA treatment. The expressions of Beclin-1 and LC3 were significantly elevated and the expression of P62 was markedly reduced in FNI rats (P<0.01); however, EA treatment reversed these abnormal changes (P<0.01). Meanwhile, EA stimulation significantly increased the levels of GDNF, Rai, PI3K, and mTOR (P<0.01). After exogenous administration with autophagy inhibitor 3-MA or GDNF antagonist, the repair effect of EA on facial function was attenuated (P<0.05 or P<0.01).@*CONCLUSIONS@#EA could promote the recovery of facial function and repair the facial nerve damages in a rat model of FNI. EA may exert this neuroreparative effect through mediating the release of GDNF, activating the PI3K/mTOR signaling pathway, and further regulating the autophagy of facial nerves.

Altered Plasma Levels of Glial Cell Line-Derived Neurotrophic Factor in Patients with Internet Gaming Disorder: A Case-Control, Pilot Study

Glial cell line-derived neurotrophic factor (GDNF) has been reported to be involved in negatively regulating the effects of addictive disorders. The objective of this study was to investigate alterations in the levels of GDNF in patients with Internet gaming disorder (IGD) and to assess the relationship between GDNF levels and the severity of IGD indices. Nineteen male patients with IGD and 19 sexmatched control subjects were evaluated for alteration of plasma GDNF levels and for relationship between GDNF levels and clinical characteristics of Internet gaming, including the Young's Internet Addiction Test (Y-IAT). The GDNF levels were found to be significantly low in patients with IGD (103.2±62.0 pg/mL) compared with the levels of controls (245.2±101.6 pg/mL, p<0.001). GDNF levels were negatively correlated with Y-IAT scores (Spearman's rho=-0.645, p=<0.001) and this negative correlation remained even after controlling for multiple variables (r=-0.370, p=0.048). These findings support the assumed role of GDNF in the regulation of IGD.

Glial Cell Line-derived Neurotrophic Factor-overexpressing Human Neural Stem/Progenitor Cells Enhance Therapeutic Efficiency in Rat with Traumatic Spinal Cord Injury

Spinal cord injury (SCI) causes axonal damage and demyelination, neural cell death, and comprehensive tissue loss, resulting in devastating neurological dysfunction. Neural stem/progenitor cell (NSPCs) transplantation provides therapeutic benefits for neural repair in SCI, and glial cell line-derived neurotrophic factor (GDNF) has been uncovered to have capability of stimulating axonal regeneration and remyelination after SCI. In this study, to evaluate whether GDNF would augment therapeutic effects of NSPCs for SCI, GDNF-encoding or mock adenoviral vector-transduced human NSPCs (GDNF-or Mock-hNSPCs) were transplanted into the injured thoracic spinal cords of rats at 7 days after SCI. Grafted GDNF-hNSPCs showed robust engraftment, long-term survival, an extensive distribution, and increased differentiation into neurons and oligodendroglial cells. Compared with Mock-hNSPC- and vehicle-injected groups, transplantation of GDNF-hNSPCs significantly reduced lesion volume and glial scar formation, promoted neurite outgrowth, axonal regeneration and myelination, increased Schwann cell migration that contributed to the myelin repair, and improved locomotor recovery. In addition, tract tracing demonstrated that transplantation of GDNF-hNSPCs reduced significantly axonal dieback of the dorsal corticospinal tract (dCST), and increased the levels of dCST collaterals, propriospinal neurons (PSNs), and contacts between dCST collaterals and PSNs in the cervical enlargement over that of the controls. Finally grafted GDNF-hNSPCs substantially reversed the increased expression of voltage-gated sodium channels and neuropeptide Y, and elevated expression of GABA in the injured spinal cord, which are involved in the attenuation of neuropathic pain after SCI. These findings suggest that implantation of GDNF-hNSPCs enhances therapeutic efficiency of hNSPCs-based cell therapy for SCI.

Effects of cognitive-behavioral therapy on neurotrophic factors in patients with major depressive disorder

Objective: To correlate neurotrophic factors - brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and beta-nerve growth factor (beta-NGF) - and severity of depressive symptoms in patients diagnosed with major depressive disorder (MDD) undergoing cognitive-behavioral therapy (CBT). Methods: In this quasi-experimental study, participants were selected by convenience and received 16 sessions of CBT. The outcomes of interest were severity of depressive symptoms and changes in neurotrophic factor levels after CBT. The differences between variables before and after treatment (deltas) were analyzed. Results: Patients had significant changes in symptom severity after treatment. No significant associations were found between Beck Depression Inventory II (BDI-II) scores and any independent variable. No correlations were observed between BDNF or GDNF levels and BDI scores before or after treatment, although there was a trend toward significant differences in beta-NGF levels. Conclusion: BDNF, beta-NGF, and GDNF were not influenced by the effects of CBT on depressive symptoms.

The differentiation potential of adipose tissue-derived mesenchymal stem cells into cell lineage related to male germ cells / Potencial de diferenciação de células-tronco mesenquimais derivadas do tecido adiposo em células da linhagem germinativa masculina

The adipose tissue is a reliable source of Mesenchymal stem cells (MSCs) showing a higher plasticity and transdifferentiation potential into multilineage cells. In the present study, adipose tissue-derived mesenchymal stem cells (AT-MSCs) were isolated from mice omentum and epididymis fat depots. The AT-MSCs were initially compared based on stem cell surface markers and on the mesodermal trilineage differentiation potential. Additionally, AT-MSCs, from both sources, were cultured with differentiation media containing retinoic acid (RA) and/or testicular cell-conditioned medium (TCC). The AT-MSCs expressed mesenchymal surface markers and differentiated into adipogenic, chondrogenic and osteogenic lineages. Only omentum-derived AT-MSCs expressed one important gene marker related to male germ cell lineages, after the differentiation treatment with RA. These findings reaffirm the importance of adipose tissue as a source of multipotent stromal-stem cells, as well as, MSCs source regarding differentiation purpose.(AU)

O tecido adiposo é uma fonte apropriada de células-tronco mesenquimais (MSCs), as quais demonstram ampla plasticidade com capacidade de transdiferenciar em diversas linhagens. No presente estudo, as células-tronco mesenquimais derivadas do tecido adiposo (AT-MSC) foram isoladas de tecido adiposo localizado nas regiões próximas ao omento e testículos de camundongos. Primeiramente, as AT-MSCs foram comparadas com base na expressão de marcadores antigênicos de superfície e no potencial de diferenciação nas três linhagens mesodérmicas. Além disso, AT-MSC, de ambas as fontes, foram cultivadas com meio de diferenciação contendo ácido retinóico (RA) e / ou meio condicionado testicular (TCC). As AT-MSCs expressaram marcadores de superfície mesenquimais e diferenciaram nas linhagens adipogênica, condrogênica e osteogênica. Após o tratamento com RA, somente as AT-MSCs isoladas do tecido adiposo depositado na região do omento expressaram um único importante marcador relacionado às células da linhagem germinativa masculina. Estes resultados reafirmam a importância do tecido adiposo como fonte de células-tronco estromais-multipotentes, bem como, uma fonte de MSCs para estudos de diferenciação.(AU)

Expression of Glial Cell Line-Derived Neurotrophic Factor (GDNF) and the GDNF Family Receptor Alpha Subunit 1 in the Paravaginal Ganglia of Nulliparous and Primiparous Rabbits / 대한배뇨장애요실금학회지

PURPOSE: To 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. METHODS: Chinchilla-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. RESULTS: Our 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. CONCLUSIONS: The 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.

Alterations in Serum BDNF and GDNF Levels after 12 Weeks of Antidepressant Treatment in Female Outpatients with Major Depressive Disorder

OBJECTIVE: Some clinical studies have found alterations in the levels of serum brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) after applying antidepressant treatment in patients with major depressive disorder (MDD). We evaluated the serum BDNF and GDNF levels before and after 12 weeks of antidepressant treatment in MDD outpatients. METHODS: Serum BDNF and GDNF levels were measured in 23 female MDD outpatients at baseline and after 12 weeks of treatment. The severity of depression was measured with the Hamilton Depression Rating Scale-17 (HAMD-17). Remission of MDD to the treatment was defined as a posttreatment HAMD-17 score of <7. RESULTS: Among MDD patients, 19 (82.6%) subjects were in mild to moderate depression. The whole MDD patients had significantly higher serum BDNF and GDNF levels at baseline than those after 12 weeks of antidepressant treatment. The baseline serum BDNF and GDNF levels did not significantly between the remission and nonremission groups. The significant alteration in both BDNF and GDNF levels after antidepressant treatment were observed in patients with remission. CONCLUSION: The present study suggests that the baseline serum BDNF and GDNF levels are higher than the posttreatment levels in some mild-to-moderate MDD outpatients and the significant alteration in BDNF and GDNF level after treatment were observed in patients with remission.

Serum levels of neurotrophic factors in active toxoplasmic retinochoroiditis

Abstract Toxoplasmic retinochoroiditis (TR) is the most common identifiable cause of posterior uveitis in Brazil. Response to treatment and clinical presentation may vary significantly. We assessed serum levels of brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), nerve growth factor (NGF), neurotrophin (NT)-3, and NT-4/5 in patients with active TR, before and after TR treatment. Methods: Twenty patients with active lesion and 15 healthy controls were enrolled in the study. Serum concentration of neurotrophic factors was determined by enzyme-linked immunosorbent assay. Results: BDNF levels were significantly higher in patients before treatment when compared with controls (p = 0.0015). There was no significant difference in pro-BDNF, NGF, GDNF, NT-3, and NT-4/5 levels between TR patients and controls. Treatment did not affect the levels of these factors. Conclusion: BDNF may be released in the context of the active TR inflammatory response.

Enrichment and In Vitro Culture of Spermatogonial Stem Cells from Pre-Pubertal Monkey Testes

Spermatogonial stem cells (SSCs) are essential for spermatogenesis throughout the lifespan of the male. However, the rarity of SSCs has raised the need for an efficient selection method, but little is known about culture conditions that stimulate monkey SSC proliferation in vitro. In this study, we report the development of effective enrichment techniques and in vitro culturing of germ cells from pre-pubertal monkey testes. Testis cells were analyzed by fluorescence-activated cell sorting techniques and were transplanted into the testes of nude mice to characterize SSCs. Thy-1-positive cells showed a higher number of colonies than the unselected control after xenotransplantation. Extensive colonization of monkey cells in the mouse testes indicated the presence of highly enriched populations of SSCs in the Thy-1-positive sorted cells. Furthermore, monkey testis cells were enriched by differential plating using extracellular matrix, laminin, and gelatin, and then cultured under various conditions. Isolation of monkey testicular germ cells by differential plating increased germ cell purity by 2.7-fold, following the combinational isolation method using gelatin and laminin. These enriched germ cells actively proliferated under culture conditions involving StemPro medium supplemented with bFGF, GDNF, LIF, and EGF at 37 ℃. These results suggest that the enrichment and in vitro culture method proposed in the present study for harvesting a large number of functionally active monkey SSCs can be applied as the basis for efficient in vitro expansion of human SSCs.

Lack of Aberrant Methylation in an Adjacent Area of Left-Sided Colorectal Cancer

PURPOSE: The molecular nature and the rate-limiting step of epigenetic field defects in the evolution of left-sided colorectal cancer (LCA) remain uncertain. MATERIALS AND METHODS: The methylation status of 27 candidate field defect markers, six classic CpG island methylator phenotype (CIMP) markers, and LINE-1 were determined in LCA and adjacent normal mucosas (ADJs) from 33 LCA patients and in left normal colorectal mucosa (LNM) from 33 age- and sex-matched controls. Hotspot mutation analyses in KRAS codons 12 and 13 and BRAF V600E were performed by genomic PCR and pyrosequencing using DNA extracted from endoscopically biopsied tissues. RESULTS: Among the 27 candidate genes tested, we confirmed 15 differentially methylated genes in cancer (15 DMGs; ER, SFRP1, MYOD1, MGMT, CD8a, SPOCK2, ABHD9, BNIP3, IGFBP3, WIF1, MAL, GDNF, ALX4, DOK5, and SLC16A12) in comparison to ADJ samples. We further compared the methylation status of 15 DMGs of ADJs to LNM and found only methylation levels of SLC16A12 in ADJs of LCA patients to be significantly higher than that in LNM (17.3% vs. 11.5%, p=0.002). Based on the CIMP, no significant differences in methylation levels of the 15 DMGs were found between ADJs in CIMP positive LCA cases and those without CIMP. In mutation analyses, no mutation was found in ADJs, while significant KRAS mutations (6/33, 18%) were noted in LCA samples. CONCLUSION: Epigenetic field defect marked by aberrant methylation is uncommon in normal-appearing ADJs of LCA, indicating the critical rate-limiting change of methylation is likely to occur with morphological alterations in the evolution of LCA.

Effects of nerve cells and adhesion molecules on nerve conduit for peripheral nerve regeneration

BACKGROUND: For peripheral nerve regeneration, recent attentions have been paid to the nerve conduits made by tissue-engineering technique. Three major elements of tissue-engineering are cells, molecules, and scaffolds. METHODS: In this study, the attachments of nerve cells, including Schwann cells, on the nerve conduit and the effects of both growth factor and adhesion molecule on these attachments were investigated. RESULTS: The attachment of rapidly-proliferating cells, C6 cells and HS683 cells, on nerve conduit was better than that of slowly-proliferating cells, PC12 cells and Schwann cells, however, the treatment of nerve growth factor improved the attachment of slowly-proliferating cells. In addition, the attachment of Schwann cells on nerve conduit coated with fibronectin was as good as that of Schwann cells treated with glial cell line-derived neurotrophic factor (GDNF). CONCLUSIONS: Growth factor changes nerve cell morphology and affects cell cycle time. And nerve growth factor or fibronectin treatment is indispensable for Schwann cell to be used for implantation in artificial nerve conduits.

Establishment of a HEK293T cell line able to site-specifically integrate and stably express GDNF by rAAV-2 vector

Background: Using recombinant adeno-associated virus 2 (rAAV-2), we attempted to establish a HEK293T cell line that is able to site-specifically integrate and stably express glial cell line-derived neurotrophic factor (GDNF). Results:Recombinant vector with enhanced green fluorescent protein (EGFP) and GDNF (pTR-P5-EGFP-IRES-GDNF), as well as that carrying Rep genes and SV40 promoters (pSVAV2) were constructed and packed. HEK293T cells were co-infected with rAAV-2/EGFP-GDNF and rAAV-2/SVAV2 virus separately at 1 x 10(4),1 x 10(5),and 1x10(6) of multiplicity of infection (MOI). The efficiency of transduction was detected using flow cytometry. Additionally, the infected HEK293T cells were separately validated by touchdown polymerase chain reaction (PCR) and Western-blot. After 72 h of transduction, the rate of EGFP positive cell was 22%, 45% and 49% at the MOIs of 1 x 10(4),1 x 10(5) and 1 x 10(6), respectively. On the 3rd, 6th and 9th day of cell passage, there was no significant difference in the cell viability and proliferation rate between transduction and control groups. Importantly, touchdown PCR showed that there was a specific PCR amplified product band in the lane of infected cells. Furthermore, GDNF expression was detected in the infected cells after 15 and 180 d of cultivation. Conclusions: A HEK293T cell line able to site-specifically integrate and stably express GDNF was established.

Comparsion between Intravenous Delivered Human Fetal Bone Marrow Mesenchymal Stromal Cells and Mononuclear Cells in the Treatment of Rat Cerebral Infarct / 中国医学科学院学报

Objective To compare the effecacy of human mesenchymal stromal cell (hMSC) with human mononuclear cell (hMNC) in treating rat cerebral infarct.Methods The SD rat models of cerebral infarct were established by distal middle cerebral artery occlusion (dMCAO). Rats were divided into four groups: sham,ischemia vehicle,MSC,and MNC transplantation groups. For the transplantation group,1×10hMSCs or hMNCs were intravascularly transplanted into the tail vein 1 hour after the ischemia onset. The ischemia vehicle group received dMCAO surgery and intravascular saline injection 1,3,5,and 7 days after the ischemia onset,and then behavioral tests were performed. At 48 h after the ischemia onset,the abundance of Iba- 1,the symbol of activated microglia,was evaluated in the peri-ischemia striatum area; meanwhile,the neurotrophic factors such as glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) in ipsilateral peri-ischemia striatum area were also measured. Results The relative infarct volume in ischemia vehicle group,hMSC group,and hMNC transplantation group were (37.85±4.40)%,(33.41±3.82)%,and (30.23±3.63)%,respectively. The infarct volumes of MSC group (t=2.100,P=0.034) and MNC group (t=2.109,P=0.0009) were significantly smaller than that of ischemia vehicle group,and that of MNC group was significantly smaller than that of MSC group (t=1.743,P=0.043). One day after transplantation,the score of ischemia vehicle group in limb placing test was (4.32±0.71)%,which was significantly lower than that in sham group (9.73±0.36)% (t=2.178,P=8.61×10). The scores of MSC and MNC group,which were (5.09±0.62)% (t=2.1009,P=0.024) and (5.90±0.68)% (t=2.1008,P=0.0001),respectively,were significantly higher than that of ischemia vehicle group; also,the score of MNC group was significantly higher than that of MSC group(t=2.1009,P=0.0165). The contralateral forelimb scores of MSC and MNC groups in beam walking test were (5.56±0.86)% (t=2.120,P=0.020) and (5.13±0.95)% (t=2.131,P=0.003),were both significantly lower than that of ischemia vehicle group [(6.47±0.61)%]. Three days after the transplantation,the limb placing test score of MNC group [(6.91±1.10)%] was significantly higher than that of ischemia vehicle group (5.80±0.82)% (t=2.110,P=0.027). The score of MSC group [(6.30±0.77)%] showed no statistic difference with that of ischemia vehicle group(t=2.101,P=0.199).The contralateral forelimb scores of MNC group in beam walking test [(4.34±0.58)%] was significantly lower than that of ischemia vehicle group [(5.31±0.65)%] (t=2.100,P=0.006) and MSC group [(4.92±0.53)%] (t=2.100,P=0.041); there was no statistic difference between MSC group and ischemia vehicle group (t=2.109,P=0.139). The relative abundance of Iba- 1 in sham,ischemia vehicle,MSC,and MNC groups was 1.00+0.00,1.72±0.21,1.23±0.08,and 1.48±0.06,respectively. The Iba-1 relative abundance of ischemia vehicle group was significantly higher than that of sham group (t=2.262,P=2.9×10). The Iba-1 relative abundances of both MSC (t=2.178,P=3.91×10)and MNC (t=2.200,P=0.007)groups were significantly lower than that of ischemia vehicle group. It was also significantly lower in MNC group than in MSC group also (t=2.120,P=7.09×10). Three days after transplantation,the BDNF and GDNF levels of MSC group,which were (531.127±73.176)pg/mg (t=2.109,P=0.003)and(127.780±16.733)pg/mg(t=2.100,P=2.76×10),respectively,were significantly higher than those of ischemia vehicle group,which were (401.988±89.006)pg/mg and (86.278±14.832) pg/mg,respectively. The BDNF and GDNF levels of MNC group,which were (627.429±65.646)pg/mg (t=2.144,P=0.017) and (153.117±20.443)pg/mg (t=2.109,P=0.010),respectively,were all significantly higher than that of MSC group. At day 7,the BDNF and GDNF levels of MSC group,which were (504.776±83.282)pg/mg (t=2.101,P=0.005) and (81.641±11.019)pg/mg (t=2.100,P=0.002),respectively,were significantly higher than those of ischemia vehicle group,which were (389.257±70.440)pg/mg and (64.322±9.855) pg/mg,respectively. The BDNF and GDNF levels of MNC group,which were (589.068±63.323)pg/mg (t=2.100,P=0.027) and (102.161±19.932)pg/mg (t=2.144,P=0.017),respectively,were all significantly higher than that of MSC group. Conclusions Both hMSC and hMNC are beneficial to the ischemia-damaged brain when they are intravascularly transplanted within 1 h after the onset of ischemia. The anti-inflammation ability and secretion of neurotrophic factors are the underlying mechanisms of the therapeutic effects. MNC is more effective than MSC in reducing infarct area and improving behaviors,which might be explained by the fact that MNC induces more GDNF and BDNF in brain than MSC.

Neuroprotective effects of electroacupuncture on hypoxic-ischemic encephalopathy in newborn rats are associated with increased expression of GDNF-RET and protein kinase B / 中国结合医学杂志

<p><b>OBJECTIVE</b>To explore the neuroprotective effects of electroacupuncture (EA) on hypoxic-ischemic encephalopathy (HIE) and to further investigate the role of glial cell line-derived neurotrophic factor (GDNF) family receptor member RET (rearranged during transfection) and its key downstream phosphatidylinositol 3 kinase (PI-3K)/protein kinase B (Akt) pathway in the process.</p><p><b>METHODS</b>A total of 220 seven-day-old SD rats (of either sex, from 22 broods) were randomly divided into two groups, one (30 rats) for sham-surgery group and the other (190 rats) for HIE model group. The HIE model was established using the left common carotid artery ligation method in combination with hypoxic treatment. The successfully established rats were randomly divided into five groups, including control model group, EA group, sham-EA group, antagonist group and antagonist plus electroacupuncture group, with 35 rats in each group. Baihui (GV 20), Dazhui (GV 14), Quchi (LI 11) and Yongquan (KI 1) acupoints were chosen for acupuncture. EA was performed at Baihui and Quchi for 10 min once a day for continuous 1, 3, 7 and 21 days, respectively. The rats were then killed after the operation and injured cerebral cortex was taken for the measurement of neurologic damage by hematoxylin-eosin (HE) staining and the degenerative changes of cortical ultrastructure by transmission electron microscopy. RET mRNA level and Akt protein level were detected by real-time reverse-transcription polymerase chain reaction (RT-PCR) and western blot analysis, respectively.</p><p><b>RESULTS</b>EA could ameliorate neurologic damage of the first somatic sensory area (S1Tr) and alleviate the degenerative changes of ultrastructure of cortical neurons in rats subjected to HIE. And the longer acupuncture treatment lasted, the better its therapeutic effect would be. This was accompanied by gradually increased expression of GDNF family receptor RET at the mRNA level and its downstream signaling Akt at the protein level in the ischemic cortex.</p><p><b>CONCLUSION</b>EA has neuroprotective effects on HIE and could be a potential therapeutic strategy for HIE in the neonate. Activation of RET/Akt signaling pathway might be involved in this process.</p>

Therapeutic effect of GDNF gene-modified mesencephalic neural stem cell transplantation in a rat model of Parkinson disease / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the therapeutic effect of transplantation of mesencephalic neural stem cells (mNSCs) genetically modified by glial cell line-derived neurotrophic factor (GDNF) gene in a rat model of Parkinson disease.</p><p><b>METHODS</b>mNSCs isolated from the lateral component of the midbrain of fetal rats at gestational age of 14 or 15 days were cultured for 5 days before genetic modification with GFP or GDNF gene. Rat models of Parkinson disease established by stereotactic injection of 6-hydroxy dopamine in the ventral area of the midbrain and the medial forebrain bundle were randomized into 3 groups to receive PBS injection, GFP gene-modified mNSCs transplantation, or GDNF gene-modified mNSCs transplantation into the right stratum. The behavioral changes of the rats were evaluated by observing rotations induced by intraperitoneal injection of apomorphine after the transplantation, and the survival, migration and differentiation of the transplanted cells were identified by immunohistochemistry.</p><p><b>RESULTS</b>Transplantation with GDNF gene-modified mNSCs significantly improved the behavioral abnormalities of the rat models as compared with PBS injection and GFP gene-modified mNSCs transplantation. At 56 days after the transplantation, a greater number of the transplanted cells survived in the rat brain and more differentiated dopaminergic neurons were detected in GDNF gene-modified mNSCs transplantation group than in GFP gene-modified mNSCs transplantation group.</p><p><b>CONCLUSION</b>GDNF gene-modified mNSCs transplantation can significantly improve dyskinesia in rat models of Parkinson disease, but the molecular mechanism needs further clarification.</p>

The Modulation of Neurotrophin and Epigenetic Regulators: Implication for Astrocyte Proliferation and Neuronal Cell Apoptosis After Spinal Cord Injury

OBJECTIVE: To investigate alterations in the expression of the main regulators of neuronal survival and death related to astrocytes and neuronal cells in the brain in a mouse model of spinal cord injury (SCI). METHODS: Eight-week-old male imprinting control region mice (n=36; 30–35 g) were used in this study and randomly assigned to two groups: the naïve control group (n=18) and SCI group (n=18). The mice in both groups were randomly allocated to the following three time points: 3 days, 1 week, and 2 weeks (n=6 each). The expression levels of regulators such as brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), nerve growth factor (NGF), histone deacetylase 1 (HDAC1), and methyl-CpG-binding protein 2 (MeCP 2) in the brain were evaluated following thoracic contusive SCI. In addition, the number of neuronal cells in the motor cortex (M1 and M2 areas) and the number of astrocytes in the hippocampus were determined by immunohistochemistry. RESULTS: BDNF expression was significantly elevated at 2 weeks after injury (p=0.024). The GDNF level was significantly elevated at 3 days (p=0.042). The expression of HDAC1 was significantly elevated at 1 week (p=0.026). Following SCI, compared with the control the number of NeuN-positive cells in the M1 and M2 areas gradually and consistently decreased at 2 weeks after injury. In contrast, the number of astrocytes was significantly increased at 1 week (p=0.029). CONCLUSION: These results demonstrate that the upregulation of BDNF, GDNF and HDAC1 might play on important role in brain reorganization after SCI.

Effects of adipose-derived mesenchymal stem cells over-expressing glial cell line-derived neurotrophic factor on electrically injured sciatic nerve of rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the effects of adipose-derived mesenchymal stem cells (ADSCs) with continous over-expression of glial cell line-derived neurotrophic factor (GDNF) on the motor function recovery and nerve regeneration of sciatic nerve of rats after electrical injury.</p><p><b>METHODS</b>Five SD rats were collected to prepare ADSCs with over-expression of GDNF. One hundred and fifty SD rats were divided into normal control group (N), GDNF-ADSCs group (GA), ADSCs group (A), GDNF group (G), and physiological saline group (P) according to the random number table, with 30 rats in each group. Rats in group N were routinely fed without treatment, and rats in the other 4 groups were inflicted with electrical injury on sciatic nerve of thigh of the right hind leg. Rats in groups GA, A, G, and P were respectively injected with 100 µL suspension of ADSCs with over-expression of GDNF (1 x 10(7) cells per mL), 100 [µL ADSCs suspension (1 x 10(7) cells per mL), 100 µL GDNF solution (100 mg/L) , and 100 µL physiological saline to the surface of the injured nerves immediately after injury. Six rats of each group were collected for measuring hind limb stride from post injury week (PIW) 1 to 8, and morphology of the sciatic nerves was observed in PIW 8. In PIW 4, the protein expression of GDNF of sciatic nerves of the rest rats in each group was determined with Western blotting. Data were processed with one-way analysis of variance, analysis of variance of repeated measurement, and SNK test.</p><p><b>RESULTS</b>Compared with that of group N, the hind limb stride values in groups GA, A, G, and P were significantly lower at each time point (with P values below 0.05). Compared with those of group P, the hind limb stride values in group GA from PIW 3 to 8, in group A in PIW 3, 5, and 7, and in group G in PIW 3, 5, 7, and 8 were significantly longer (with P values below 0.05). The hind limb stride values in group GA from PIW 4 to 8 were respectively (10.83 ± 0.97), (13.25 ± 1.40), (12.86 ± 1.42), (14.06 ± 1.50), and (15.09 ± 1.17) cm, which were significantly longer than those in group A [(8.90 ± 0.82), (9.03 ± 0.57), (9.27 ± 0.36), (9.86 ± 0.36), and (9.52 ± 0.58) cm] and group G [(8.87 ± 0.69), (8.51 ± 1.18), (9.34 ± 0.87), (9.76 ± 0.67), and (9.50 ± 1.22) cm], with P values below 0.05. Compared with that of group N, the number of myelinated nerve fibers of sciatic nerves was obviously decreased in group P but obviously increased in groups GA, A, and G; the diameter of axons was obviously shorter, and the myelin thickness was obviously increased in groups GA, A, G, and P in PIW 8 (with P values below 0.05). The number of myelinated nerve fibers in group GA was 31.2 ± 0.8, which was significantly higher than that in group A (23.7 ± 2.7), group G (22.3 ± 2.7), or group P (9.3 ± 2.8), with P values below 0.05. The diameter values of axons among groups P, A, G, and GA were similar (with P values above 0.05). The myelin thickness of rats in group GA was (3.41 ± 0.34) µm, which was significantly thicker than that in group A [(2.64 ± 0.37) µm] or group G [(2.41 ± 0.34) µm], with P values below 0.05. In PIW 4, the protein expression of GDNF of sciatic nerves was significantly higher in groups P, A, G, and GA than in group N (with P values below 0.05), and the protein expression of GDNF in group GA was significantly higher than that in group P, A, or G (with P values below 0.05).</p><p><b>CONCLUSIONS</b>ADSCs over-expressing GDNF protein can obviously promote the motor function recovery and nerve regeneration of sciatic nerve of rats after electrical injury.</p>

Effects of angiotensin-(1-7) on hippocampal expressions of GFAP and GDNF and cognitive function in rats with diabetes mellitus / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effects of angiotensin-(1-7) on the learning and memory abilities and the expressions of glial fibrillary acidic protein (GFAP) and glial cell line-derived neurotrophic factor (GDNF) in the hippocampus of diabetic rats.</p><p><b>METHODS</b>Forty male SD rats were randomly assigned into 4 groups, namely the control group, diabetic group, Ang(1-7)-treated diabetic group (DM1 group), and Ang-(1-7)- and Mas receptor antagonist A779-treated diabetic group (DM2 group). Diabetic rat models were established by a single intraperitoneal injection of streptozotocin (60 mg/kg). The cognitive function of the rats was assessed with Morris water maze (MWM) test. The expressions of GDNF in the hippocampus were examined by RT-PCR and Western blot. Nissl staining was performed to evaluate the morphological changes in rat hippocampus. The expressions of glial fibrillary acidic protein (GFAP, a key indicator of astrocytic reactivity) and caspase-3 were measured by immunohistochemistry.</p><p><b>RESULTS</b>Compared with the control group, the diabetic rats exhibited significantly impaired learning and memory abilities (P<0.05) with lowered expression of GDNF and increased caspase-3 expression in the hippocampus (P<0.05) and significant hippocampal neuronal and astrocyte injuries (P<0.05). Treatment with Ang(1-7) obviously improved the learning and memory abilities of the diabetic rats (P<0.05), increased GDNF and GFAP expressions (P<0.05), lowered caspase-3 expression (P<0.05), and increased the number of surviving neurons in the hippocampus (P<0.05). Such effects of Ang(1-7) effect was blocked by treatment with A779 of the diabetic rats.</p><p><b>CONCLUSION</b>Ang(1-7) can alleviate cognitive dysfunction in diabetic rats possibly by up-regulating the expressions of GFAP and GDNF and promoting neuron survival in the hippocampus.</p>

Increased Egr-1 binding to promoter induced by histone hyperacetylation promotes gdnf gene transcription / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the mechanism of high transcription of the glial cell-line derived neurotrophic factor (gdnf) gene induced by hyperacetylation of histone H3 lysine 9 (H3K9) at its promoter region II in rat C6 glioma cells.</p><p><b>METHODS</b>The acetylation level of H3K9 at Egr-1 binding site in gdnf gene promoter region II and the binding capacity of Egr-1 to its binding site in gdnf promoter were examined by ChIP-PCR in C6 astroglioma cells and normal rat astrocytes, and its changes were investigated in C6 astroglioma cells after treatment with histone acetyltransferase inhibitor curcumin or deacetylase inhibitor trichostatin A.</p><p><b>RESULTS</b>Compared normal astrocytes, C6 astroglioma cells showed significantly increased acetylation level of H3K9 at Egr-1 binding site in gdnf gene promoter region II and Egr-1 binding capacity (P<0.01). Curcumin treatment significantly reduced H3K9 acetylation level at Egr-1 binding site and decreased both the binding of Egr-1 to promoter region II and gdnf mRNA levels in C6 astroglioma cells (P<0.05). Conversely, increased H3K9 acetylation at the Egr-1 binding site induced by trichostatin A significantly increased the binding of Egr-1 to promoter region II and gdnf mRNA expression levels (P<0.05).</p><p><b>CONCLUSION</b>H3K9 hyperacetylation induces increased Egr-1 binding to gdnf gene promoter II, which might be the reason for the high transcription level of gdnf gene in rat C6 glioma cells.</p>

Changes in pain threshold and glial cell line-derived neurotrophic factor in rat model of trigeminal neuralgia / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This research aims to study the changes in pain threshold and glial cell line-derived neurotrophic factor (GDNF) in a Sprague Dawley (SD) rat model oftrigeminal neuralgia.</p><p><b>METHODS</b>A total of 36 male SD rats were randomly divided into three groups: operative, sham-operative, and control. In the operative group, a chronic constriction injury (CCI) was caused by placing loose chromic gut ligatures around the right infraorbital nerve (ION). In the sham-operative group, the right ION was subjected to the same procedure, but without ligation. In the control group, the right ION was not subjected to any treatment. The pain thresholds of the three groups were recorded at different times after the operation. The GDNF expression in each group was analyzed via immunohistochemical staining.</p><p><b>RESULTS</b>An allodynia to mechanical stimulation in the region of the ligated ION was observed starting on the 2nd week after operation. Pain thresholds started to increase gradually from the 6th week and returned to the original level at the 10th to 12th week after operation. Cells that expressed the GDNF markedly increased in number in the operative group with changes observed at different times.</p><p><b>CONCLUSION</b>We use chronic constriction injury to the infraorbital nerve (CCI-ION) to establish a trigeminal neuralgia-like animal model in SD rats. GDNF may play a role in regulating pain by promoting the restoration and regeneration of nerve fibers.</p>