Altered serum levels of glial cell line-derived neurotrophic factor in male chronic schizophrenia patients with tardive dyskinesia

Lower GDNF Serum Level Is a Possible Risk Factor for Constipation in Patients With Parkinson Disease: A Case–Control Study

Background: Constipation is a significant symptom of Parkinson's disease (PD). Glial-derived neurotrophic factor (GDNF) is important for the morphogenesis of the enteric nervous system and plays a critical role in the preservation of mucosal integrity under enteric glia surveillance. The aim of this work was to evaluate the serum levels of GDNF in patients with PD with and without constipation.

Methods: This work included 128 patients with PD. The patients were classified into three groups: those with PD but no constipation (nCons-PD) (n = 49), those with prodromal stage constipation (Cons-Pro-PD) (n = 48), and those with clinical stage constipation (Cons-Clinic-PD) (n = 31). The association between serum GDNF concentration and constipation was explored using logical regression.

Results: The nCons-PD group's mean GDNF levels were 528.44 pg/ml, which was higher than the Cons-Pro-PD group's 360.72 pg/ml and the Cons-Clinic-PD group's 331.36 pg/ml. The results of binary logistic regression indicated that GDNF was a protective factor in the prevention of constipation. Cons-Clinic-PD group had a higher score of MDS-UPDRS-II, MDS-UPDRS-III, MDS-UPDRS-IV, and a higher H-Y staging as compared with nCons-PD group. Relative to the nCons-PD group, Cons-Clinic-PD had higher NMSS scores, lower MoCA and PDSS scores, and were more likely to have RBD.

Conclusions: GDNF serum levels are lower in patients with PD who are constipated. A low GDNF level is a potential risk factor for constipation in patients with PD.

Elevated endogenous GDNF induces altered dopamine signalling in mice and correlates with clinical severity in schizophrenia

Presynaptic increase in striatal dopamine is the primary dopaminergic abnormality in schizophrenia, but the underlying mechanisms are not understood. Here, we hypothesized that increased expression of endogenous GDNF could induce dopaminergic abnormalities that resemble those seen in schizophrenia. To test the impact of GDNF elevation, without inducing adverse effects caused by ectopic overexpression, we developed a novel in vivo approach to conditionally increase endogenous GDNF expression. We found that a 2-3-fold increase in endogenous GDNF in the brain was sufficient to induce molecular, cellular, and functional changes in dopamine signalling in the striatum and prefrontal cortex, including increased striatal presynaptic dopamine levels and reduction of dopamine in prefrontal cortex. Mechanistically, we identified adenosine A2a receptor (A_2AR), a G-protein coupled receptor that modulates dopaminergic signalling, as a possible mediator of GDNF-driven dopaminergic abnormalities. We further showed that pharmacological inhibition of A_2AR with istradefylline partially normalised striatal GDNF and striatal and cortical dopamine levels in mice. Lastly, we found that GDNF levels are increased in the cerebrospinal fluid of first episode psychosis patients, and in post-mortem striatum of schizophrenia patients. Our results reveal a possible contributor for increased striatal dopamine signalling in a subgroup of schizophrenia patients and suggest that GDNF-A_2AR crosstalk may regulate dopamine function in a therapeutically targetable manner.

BDNF, GDNF, NGF and Klotho levels and neurocognitive functions in acute term of schizophrenia

BACKGROUND

Klotho and its relationship with neurotrophic factors and cognition in schizophrenia has not yet been investigated. In this study, the hypothesis that the blood serum levels of BDNF, GDNF, NGF and Klotho in schizophrenia patients and healthy controls would be related to cognitive functions was investigated.

METHODS

In this study, two groups were assessed: schizophrenia patients (case group) who were hospitalised in the Psychiatry Clinic of Sakarya University Training and Research Hospital and healthy volunteers (control group). The patients were evaluated on the 1st and 20th days of their hospitalisation with the Positive and Negative Syndrome Scale (PANSS), the Brief Psychiatric Rating Scale (BPRS), the General Assessment of Functioning Scale (GAF) and the Clinical Global Impression Scale (CGI). For cognitive assessment, both groups were evaluated with the Wechsler Memory Scale-Visual Production Subtest (Wechsler Memory Scale III-Visual Reproduction Subtest) and the Stroop test.

RESULTS

BDNF, GDNF, NGF and Klotho levels were lower in schizophrenia patients than in healthy controls. In the schizophrenia patients, on the 20th day of treatment, there was a statistically significant increase in BDNF compared to the 1st day of treatment. BDNF, GDNF and Klotho showed positive correlations with some cognitive functions in the healthy controls. BDNF, GDNF, NGF and Klotho levels were intercorrelated and predictive of each other in both groups.

CONCLUSION

This study suggests a relationship between cognitive functions, neurotrophic factors and Klotho. Most of the results are the first of their kind in the extant literature, while other results are either similar to or divergent from those generated in previous studies. Therefore, new, enhanced studies are needed to clarify the role of Klotho and neurotrophic factors in schizophrenia.

Neurotrophic factors in bipolar disorders patients with manic episode

Background/aim

Neurotrophins are one of the most important molecule groups affecting cerebral neuroplasticity. The amount of evidence about the role of changes in neuroplasticity in the pathophysiology of bipolar disease is growing.

Materials and methods

We measured serum levels of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), neurotrophin-3 (NT-3), glial cell-line derived neurotrophic factor (GDNF), vascular endothelial growth factor (VEGF), insulin-like growth factor-1 (IGF-1), fibroblast growth factor (FGF)-2, neuritin 1 (Nrn 1) in bipolar 1 manic episode patients (n = 45) and healthy control group.

Results

When controlled for age, BMI and cortisol, it was found that the serum levels of BDNF, NGF, NT-3, VEGF and FGF-2 of bipolar manic episode patients were not statistically different compared to those of the control group. GDNF level and Nrn 1 levels were significantly lower (P = 0.003 and P = 0.025 respectively) while IGF-1 levels were significantly higher than the control group (P = 0.0001). ROC analysis was performed and the area under the the curve was calculated as 0.737, 0.766 for GDNF, IGF-1 respectively.

Conclusion

The changes in the levels of GDNF, IGF-1 and Nrn 1 might be involved in pathopysiology of bipolar disorder, and GDNF, IGF-1 may be considered as state markers in bipolar manic episode.

Impact of Auditory Integration Therapy (AIT) on the Plasma Levels of Human Glial Cell Line-Derived Neurotrophic Factor (GDNF) in Autism Spectrum Disorder

Neurotrophic factors, including the glial cell line-derived neurotrophic factor (GDNF), are of importance for synaptic plasticity regulation, intended as the synapses' ability to strengthen or weaken their responses to differences in neuronal activity. Such plasticity is essential for sensory processing, which has been shown to be impaired in autism spectrum disorder (ASD). This study is the first to investigate the impact of auditory integration therapy (AIT) of sensory processing abnormalities in autism on plasma GDNF levels. Fifteen ASD children, aged between 5 and 12 years, were enrolled and underwent the present research study. AIT was performed throughout 10 days with a 30-min session twice a day. Before and after AIT, Childhood Autism Rating Scale (CARS), Social Responsiveness Scale (SRS), and Short Sensory Profile (SSP) scores were calculated, and plasma GDNF levels were assayed by an EIA test. A substantial decline in autistic behavior was observed after AIT in the scaling parameters used. Median plasma GDNF level was 52.142 pg/ml before AIT. This level greatly increased immediately after AIT to 242.05 pg/ml (P < 0.001). The levels were depressed to 154.00 pg/ml and 125.594 pg/ml 1 month and 3 months later, respectively, but they were still significantly higher compared with the levels before the treatment (P = 0.001, P = 0.01, respectively). There was an improvement in the measures of autism severity as an effect of AIT which induced the up-regulation of GDNF in plasma. Further research, on a large scale, is needed to evaluate if the cognitive improvement of ASD children after AIT is related or not connected to the up-regulation of GDNF.

Altered serum levels of glial cell line-derived neurotrophic factor in male chronic schizophrenia patients with tardive dyskinesia

OBJECTIVES

Many research indicate that the tardive dyskinesia (TD) is generally linked with long-term antipsychotic therapy for schizophrenia. Glial cell line-derived neurotrophic factor (GDNF) is a critical role in the protection of catecholaminergic, dopaminergic, and cholinergic neurons. Thus, we examined the serum GDNF levels in schizophrenia patients with TD (WTD) and without TD (NTD) and compared with healthy controls (HC), respectively.

METHODS

Totally 75 males with schizophrenia were recruited into this study. All were measured by the Diagnostic and Statistical Manual of Mental Disorders, fifth edition, the Positive and Negative Syndrome Scale, and the Abnormal Involuntary Movement Scale (AIMS). The patient group was divided into two subgroups: WTD (n = 32) and NTD (n = 43) according to the AIMS score. Fifty-three healthy controls matching in age and gender were also enlisted from the region. GDNF levels were examined with sandwich enzyme-linked immunosorbent assay.

RESULTS

Analysis of variance indicated significant differences between the three groups (P = 0.012); GDNF levels in the WTD group were significantly different from those in the NTD (P = 0.030) and HC (P = 0.003) groups.

CONCLUSION

Decreased GDNF levels in TD patients indicated that alterations in neurotrophic factors may be involved in the pathophysiology of TD, but the exact mechanisms need further investigation.