GDNF plays a crucial role in the stimulation of recovery, neuroplasticity and synaptic reorganization after spinal cord injury providing neuroprotection and neuroregeneration. Plasma GDNF levels are upregulated in cases of spina bifida owing to the intrauterine damage of the exposed spinal cord. Our aim was to compare the plasma GDNF levels in patients of spina bifida with non-spina bifida cases and assess the correlation with neurological impairment at one year of follow up.
Single centre prospective analysis of cases of spina bifida from 2020 to 2022 at presentation and after one year of follow up post-surgery. Cases with hernia and hydrocele without any other disorders were recruited into the control group. Plasma GDNF levels were assessed with immunoassay kits and compared with neurological involvement.
85 cases were included in the study. GDNF levels were elevated in cases compared to controls (mean 6.62 vs 1.76) with significant p value (<0.01). Same was observed for open and closed defects (mean 7.63 vs 4.86: p < 0.01). At follow up of 52 cases post-surgery cases with neurogenic bladder with abnormal urodynamic studies, sphincter involvement and motor impairment had significantly elevated baseline levels of GDNF compared with those who did not have this neurological impairment (p < 0.01).
The neurotrophic factor up-regulation can reflect an endogenous attempt at neuroprotection against the biochemical and molecular cascades triggered by the spinal cord damage. This upregulation can be represented as important biochemical markers of severe spinal cord damage and can be associated with severity of spine injury in MMC patients. Our results are in keeping with these findings, that, there were increased levels of plasma GDNF levels in cases of spinal dysraphism compared to control population. Also, the type of lesion reflecting the severity whether a closed or an open dysraphism, showed significant difference in levels between them suggesting, yet again, more damage in open defect as expected. The levels were higher with involvement of bladder, sphincter and lower limb power.
There is significant elevation of plasma GDNF levels in cases of spina bifida and this elevation is proportional to the degree of spinal damage and hence the neurological impairment. GDNF levels are a good predictor for assessing the severity of the lesion and thus the outcome in these cases. Additional prospective and long-term studies with a larger cohort are needed for a better understanding of neurotrophin pattern modulation in MMC.

Our aim was attempting to find proteins involved in the pain process and correlating with pain but not degree of inflammation in children with juvenile idiopathic arthritis (JIA), using a proteomics panel.
A total of 87 plasma samples were collected from 51 children with JIA (51 at diagnosis in a higher disease activity state, 18 at follow-up in a lower disease activity state) and 18 healthy controls. Relative levels of 92 proteins related to a wide range of biological processes in inflammation were obtained using a proximity extension assay panel. Comparisons between children with and without JIA, in different disease categories, by juvenile disease activity score (JADAS27) and degree of pain on a visual analogue scale (VAS), were performed using parametric and non-parametric statistical methods.
Nineteen proteins involved in arthritic inflammation, such as interleukin 6 (IL-6) and S100 protein A12, were higher in patients with JIA than controls, seven decreased significantly during treatment, and 18 correlated significantly with JADAS27. Three proteins correlated with pain VAS scores in unadjusted analyses: the glial cell line-derived neurotrophic factor (GDNF), transforming growth factor beta, and IL-18R1. Levels of GDNF correlated significantly with pain VAS scores but not with JADAS27.
Plasma levels of 18 of 92 tested proteins correlated with degree of disease activity. Levels of three proteins correlated with pain, and levels of one, GDNF, originating from neural cells, correlated with pain without correlating with inflammatory degree, suggesting that it may play a role in pain in JIA. Further studies in larger cohorts are warranted.

Because of the poor prognosis of lacrimal adenoid cystic carcinoma (LACC), we aimed to investigate the effects of perineural invasion (PNI) and consequent aberrations in GDNF/GFRα-1/RET protein expression on LACC recurrence.
Clinicopathological data for 51 histologically confirmed patients with LACC enrolled between 2001 and 2017 were retrospectively analyzed. Hematoxylin and eosin staining was applied to assess PNI. Tissue-based immunohistochemistry (IHC) detection of GDNF, GFRα-1, and RET proteins was performed on LACC formalin-fixed, paraffin-embedded specimens. We generated semi-quantitative data of the IHC results and compared them with the clinicopathological data for the 51 patients.
Of the 51 patients, 19 (37.3%) were PNI positive. Recurrence was more common for LACC with than without PNI (73.7% vs. 37.5%, P = 0.01). GDNF, GFRα-1, and RET proteins were expressed in 62.7%, 62.7%, and 54.9% of the 51 patients with LACC, respectively. The expression of all 3 proteins was more common in patients with than without PNI. In agreement with previous findings, PNI-associated GFRα-1 and RET positivity, as detected by IHC, remained significantly associated with recurrence, whereas GDNF expression, as detected by IHC, was not correlated with LACC recurrence. Specifically, patients with concurrent GFRα-1 and RET expression may have a high risk of PNI (89.5% positivity rate) and recurrence (84.2% positivity rate).
PNI may contribute to LACC recurrence. The concurrent expression of GFRα-1 and RET proteins, as detected by IHC, may potentially be associated with LACC PNI and recurrence.

Glial cell line-derived neurotrophic factor (GDNF) plays an important role in the protection of dopaminergic neurons, but there are few reports of the relationship between GDNF and its precursors (α-pro-GDNF and β-pro-GDNF) and cognitive impairment in Parkinson\'s disease. This study aimed to investigate the relationship between the serum levels of GDNF and its precursors and cognitive impairment in Parkinson\'s disease, and to assess their potential as a diagnostic marker. Fifty-three primary outpatients and hospitalized patients with Parkinson\'s disease (23 men and 30 women) with an average age of 66.58 years were enrolled from the Affiliated Hospital of Xuzhou Medical University of China in this case-control study. The patients were divided into the Parkinson\'s disease with cognitive impairment group (n = 27) and the Parkinson\'s disease with normal cognitive function group (n = 26) based on their Mini-Mental State Examination, Montreal Cognitive Assessment, and Clinical Dementia Rating scores. In addition, 26 age- and sex-matched healthy subjects were included as the healthy control group. Results demonstrated that serum GDNF levels were significantly higher in the Parkinson\'s disease with normal cognitive function group than in the other two groups. There were no significant differences in GDNF precursor levels among the three groups. Correlation analysis revealed that serum GDNF levels, GDNF/α-pro-GDNF ratios, and GDNF/β-pro-GDNF ratios were moderately or highly correlated with the Mini-Mental State Examination, Montreal Cognitive Assessment, and Clinical Dementia Rating scores. To explore the risk factors for cognitive impairment in patients with Parkinson\'s disease, logistic regression analysis and stepwise linear regression analysis were performed. Both GDNF levels and Hoehn-Yahr stage were risk factors for cognitive impairment in Parkinson\'s disease, and were the common influencing factors for cognitive scale scores. Neither α-pro-GDNF nor β-pro-GDNF was risk factors for cognitive impairment in Parkinson\'s disease. A receiver operating characteristic curve of GDNF was generated to predict cognitive function in Parkinson\'s disease (area under the curve = 0.859). This result indicates that the possibility that serum GDNF can correctly distinguish whether patients with Parkinson\'s disease have cognitive impairment is 0.859. Together, these results suggest that serum GDNF may be an effective diagnostic marker for cognitive impairment in Parkinson\'s disease. However, α-pro-GDNF and β-pro-GDNF are not useful for predicting cognitive impairment in this disease. This study was approved by Ethics Committee of the Affiliated Hospital of Xuzhou Medical University, China (approval No. XYFY2017-KL047-01) on November 30, 2017.

OBJECTIVE: To study the regulation role and mechanism of protein acetylation on the expression of glioblastoma-derived neurotrophic factor (GDNF) in human glioma.
METHODS: Six normal brain tissue samples, six low-grade glioma brain tissue (LG-glioma), and six high-grade glioma brain tissue (HG-glioma) were collected for study. Human glioma U251 cells were treated with histone acetylase inhibitor and histone deacetylase inhibition. The mRNA level of GDNF in glioma and normal controls was detected by Real-time PCR. H3K9 acetylation level of cAMP-response element binding protein (CREB) binding region on GDNF promoter and the ability of CREB combining to GDNF promoter were detected by ChIP-PCR. The effects of histone acetylase and deacetylase inhibitors on transcription factor binding ability and GDNF expression were detected.
RESULTS: The mRNA level of GDNF in HG-glioma was significantly higher than those in normal brain tissue and LG-glioma (P < 0.01). The H3K9 acetylation level of GDNF promoter region in the glioma was increased compared to that in the normal brain tissue (P < 0.01), and the acetylation level in CREB-binding region on the GDNF promoter was higher than that in the non-CREB-binding region (P < 0.01). The binding activity of CREB and GDNF promoter in HG-glioma was higher than those in normal brain tissue and LG-glioma (P < 0.05). After treatment of U251 cells with histone acetyltransferase inhibition, the level of acetylation in CREB-binding region on GDNF promoter, the binding activity of CREB and GDNF promoter was decreased, and GDNF transcription and expression were down-regulated, while histone deacetylase inhibitors had the opposite effect (P < 0.01).
CONCLUSIONS: Histone acetylation promotes the transcription expression of GDNF in glioma by promoting the binding of transcription factor CREB to the promoter region of GDNF gene.

BACKGROUND: Neurotrophins, especially brain-derived neurotrophic factor (BDNF) have gained significant therapeutic interest particularly in neurologic and psychiatric disorders and they have been found in human breast milk of mothers who suffered from adverse outcomes in pregnancy. This study tested the hypothesis that oral administration of BDNF/GDNF (glial cell line-derived neurotrophic factor) can exert a biological effect in a rat model of severe neuropathology induced by olfactory bulbectomy (OBX), which exhibits dysregulation of BDNF signaling and impaired blood-brain barrier.
METHODS: Adult male albino Sprague-Dawley rats underwent the OBX surgery and separate groups of OBX and sham-operated controls received one oral dose of vehicle, BDNF (0.005 mg/kg), GDNF (0.03 mg/kg) or their combination. One week after neurotrophin dosing the rats were sacrificed and BDNF level was assessed by ELISA in the blood serum and cerebrospinal fluid.
RESULTS: A significant decrease of serum BDNF level was found in the OBX model. This alteration was normalized by all types of treatment BDNF, GDNF, or their combination. No influence of sham surgery or treatment was observed in the control rats. BDNF levels in cerebrospinal fluid were below detection limit.
CONCLUSIONS: This study indicates that oral administration of neurotrophins is able to exert a biological effect in the OBX model. There is a number of potential mechanisms, which remain to be elucidated.

To investigate the safety and tolerability of convection-enhanced delivery of an adeno-associated virus, serotype-2 vector carrying glial cell line-derived neurotrophic factor into the bilateral putamina of PD patients.
Thirteen adult patients with advanced PD underwent adeno-associated virus, serotype-2 vector carrying glial cell line-derived neurotrophic factor and gadoteridol (surrogate MRI tracer) coinfusion (450 μL/hemisphere) at escalating doses: 9 × 1010 vg (n = 6); 3 × 1011 vg (n = 6); and 9 × 1011 vg (n = 1). Intraoperative MRI monitored infusion distribution. Patients underwent UPDRS assessment and [18 F]FDOPA-PET scanning preoperatively and 6 and 18 months postoperatively.
Adeno-associated virus, serotype-2 vector carrying glial cell line-derived neurotrophic factor was tolerated without clinical or radiographic toxicity. Average putaminal coverage was 26%. UPDRS scores remained stable. Ten of thirteen and 12 of 13 patients had increased [18 F]FDOPA Kis at 6 and 18 months postinfusion (increase range: 5-274% and 8-130%; median, 36% and 54%), respectively. Ki differences between baseline and 6- and 18-month follow-up were statistically significant (P < 0.0002).
Adeno-associated virus, serotype-2 vector carrying glial cell line-derived neurotrophic factor infusion was safe and well tolerated. Increased [18 F]FDOPA uptake suggests a neurotrophic effect on dopaminergic neurons. © 2019 International Parkinson and Movement Disorder Society.

Brain-derived neurotrophic factor (BDNF) and Glial-derived neurotrophic factor (GDNF) are neurotrophic factors that play key roles in the auditory pathway. While the relationship between serum levels and polymorphisms of BDNF/GDNF and chronic tinnitus is emphasized in the literature, there is no study showing the link between the promoter methylations of these genes and tinnitus. For this purpose, the relationship between chronic tinnitus and peripheral blood derived BDNF/GDNF promoter methylations was investigated to identify their role in the pathophysiology of tinnitus. In this case-control study, we examined the possible effects of BDNF/GDNF methylations in the blood samples of patients with tinnitus complaints for more than 3 months. Sixty tinnitus subjects between the ages of 18-55 and 50 healthy control subjects in the same age group who were free of any otorhinolaryngology and systemic disease were selected for examination. Methylation of total 12 CpG sites in BDNF and GDNF promoter regions were determined by the bisulfite-pyrosequencing method. Statistically significant differences were detected between BDNF CpG6 and GDNF CpG3-5-6 methylation ratios in the comparison of control group and the chronic tinnitus patients (P = 0.002, 0.0005, 0.00003, and 0.0029, respectively). To our knowledge, this is the first study in the literature investigating the relationship between chronic tinnitus and peripheral blood derived BDNF/GDNF promoter methylations. It is believed that the current results might be supported by investigating the relationships between BDNF/GDNF methylations and genotypes in future research using higher sample sizes.

We investigated the effects of glial cell line-derived neurotrophic factor (GDNF) in Parkinson\'s disease, using intermittent intraputamenal convection-enhanced delivery via a skull-mounted transcutaneous port as a novel administration paradigm to potentially afford putamen-wide therapeutic delivery. This was a single-centre, randomized, double-blind, placebo-controlled trial. Patients were 35-75 years old, had motor symptoms for 5 or more years, and presented with moderate disease severity in the OFF state [Hoehn and Yahr stage 2-3 and Unified Parkinson\'s Disease Rating Scale motor score (part III) (UPDRS-III) between 25 and 45] and motor fluctuations. Drug delivery devices were implanted and putamenal volume coverage was required to exceed a predefined threshold at a test infusion prior to randomization. Six pilot stage patients (randomization 2:1) and 35 primary stage patients (randomization 1:1) received bilateral intraputamenal infusions of GDNF (120 µg per putamen) or placebo every 4 weeks for 40 weeks. Efficacy analyses were based on the intention-to-treat principle and included all patients randomized. The primary outcome was the percentage change from baseline to Week 40 in the OFF state (UPDRS-III). The primary analysis was limited to primary stage patients, while further analyses included all patients from both study stages. The mean OFF state UPDRS motor score decreased by 17.3 ± 17.6% in the active group and 11.8 ± 15.8% in the placebo group (least squares mean difference: -4.9%, 95% CI: -16.9, 7.1, P = 0.41). Secondary endpoints did not show significant differences between the groups either. A post hoc analysis found nine (43%) patients in the active group but no placebo patients with a large clinically important motor improvement (≥10 points) in the OFF state (P = 0.0008). 18F-DOPA PET imaging demonstrated a significantly increased uptake throughout the putamen only in the active group, ranging from 25% (left anterior putamen; P = 0.0009) to 100% (both posterior putamina; P < 0.0001). GDNF appeared to be well tolerated and safe, and no drug-related serious adverse events were reported. The study did not meet its primary endpoint. 18F-DOPA imaging, however, suggested that intermittent convection-enhanced delivery of GDNF produced a putamen-wide tissue engagement effect, overcoming prior delivery limitations. Potential reasons for not proving clinical benefit at 40 weeks are discussed.

BACKGROUND: A plethora of reactive cellular responses emerge immediately after a traumatic spinal cord injury (SCI) and may influence the patient\'s outcomes. We investigated whether serum concentrations of neuron-specific enolase, interleukin-6, glial-derived neurotrophic factor, and neurotrophic growth factor reflect the acute-phase responses to different etiologies of SCI and may serve as predictive biomarkers of neurologic and functional outcomes.
METHODS: Fifty-two patients were admitted to the intensive care unit after SCI due to traffic accidents, falls, and firearm wounds and had blood samples collected within 48 hours and 7 days after SCI. Thirty-six healthy subjects with no history of SCI were included as controls. Neurologic and functional status was evaluated on the basis of American Spinal Injury Association and Functional Independence Measure scores over a period of 48 hours and 6 months after SCI.
RESULTS: Serum NSE increased significantly 48 hours and 7 days after SCI compared with controls, while interleukin-6 increased only at 48 hours. In contrast, the neurotrophic growth factor level significantly decreased 48 hours and 7 days after SCI. Serum glial-derived neurotrophic factor level did not differ from control at any time point. Also, there was no significant difference in biomarker concentrations between the etiologies of SCI or the level of spinal injury. There were no correlations between biomarker levels at 48 hours with neurologic or functional outcomes 7 days and 6 months after SCI.
CONCLUSIONS: Our results suggest expansive axonal damage coupled with an acute proinflammatory response after SCI. However, in our study biomarker concentration did not correlate with short- or long-term prognosis, such as survival rate or sensory and motor function.