Plasma glial cell line-derived neurotrophic factor in patients with major depressive disorder: a preliminary study

Altered blood parameters in "major depression" patients receiving repetitive transcranial magnetic stimulation (rTMS) therapy: a randomized case-control study

Major depressive disorder (MDD) is a debilitating illness that includes depressive mood. Repetitive Transcranial Magnetic Stimulation (rTMS) is a therapy method used in the treatment of MDD. The purpose of this study was to assess neurotrophic factors, and oxidative stress levels in MDD patients and evaluate the changes in these parameters as a result of rTMS therapy. Twenty-five patients with MDD and twenty-six healthy volunteers with the same demographic characteristics were included in the study. Brain-derived neurotrophic factors were measured photometrically with commercial kits. Oxidative stress parameters were measured by the photometric method. Oxidative stress index (OSI) and disulfide (DIS) levels were calculated with mathematical formulas. In this study, total antioxidant status (TAS), total thiol (TT), and native thiol (NT) antioxidant parameters and brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and allopregnanolone (ALLO) levels were reduced in pre-rTMS with regard to the healthy control group; TOS, OSI, DIS, and S100 calcium-binding protein B (S100B) levels were increased statistically significantly (p < 0.01). Moreover, owing to TMS treatment; TAS, TT, NT, BDNF, GDNF, and ALLO levels were increased compared to pre-rTMS, while DIS, TOS, OSI, and S100B levels were decreased significantly (p < 0.01). The rTMS treatment reduces oxidative stress and restores thiol-disulfide balance in MDD patients. Additionally, rTMS modulates neurotrophic factors and neuroactive steroids, suggesting its potential as an antidepressant therapy. The changes in the biomarkers evaluated may help determine a more specific approach to treating MDD with rTMS therapy.

Gender differences in plasma glial cell line-derived neurotrophic factor levels of patients with bipolar disorder

BACKGROUND

The glial cell line-derived neurotrophic factor (GDNF) has an important role in neurons and is closely associated with psychiatric disorders. The development of bipolar disorder (BD) may differ between genders. Existing studies have shown that plasma GDNF levels are altered in patients with BD. In this study, we investigate whether the GDNF levels in patients with BD differ in terms of gender.

METHODS

Participants were divided into the BD group (n = 76, with 26 males and 50 females) and healthy control (HC) group (n = 89, with 35 males and 54 females). Plasma GDNF levels were detected via multifactor assay. Clinical symptoms of patients with BD were collected and assessed using the Hamilton Depression-17 Inventory, Hamilton Anxiety-17 Inventory, Young's Mania Rating Scale, and Brief Psychiatric Rating Scale.

RESULTS

The GDNF levels were significantly higher in all participants in the HC group (F = 4.262, p < 0.05) compared with those in the BD group. In the HC group, the males (t = 4.814, p < 0.001) presented significantly higher levels than the females. The plasma GDNF levels in males in the BD group (t = 3.022, p < 0.05) were significantly lower than those in males in the HC group.

CONCLUSION

Differences in plasma GDNF levels are associated with the gender of patients with BD.

Glial cell line-derived neurotrophic factor (GDNF) in blood serum and lacrimal fluid of patients with a current depressive episode

BACKGROUND

Many studies indicate a significant role of GDNF in the pathogenesis of the mood disorders, including bipolar disorder (BD) and major depressive disorder (MDD). Potentially, neurotrophic factors in lacrimal fluid (LF) could become biomarkers of various specific disorders. The aim of this study was to assess GDNF levels in LF and blood serum (BS) of patients with a current depressive episode (cDE).

METHODS

We studied the glial cell line-derived neurotrophic factor (GDNF) concentration in the LF and BS of 39 healthy controls and 137 patients with a current depressive episode (cDE) (both subgroups members were 20-49 years): BD - 46 patients, MDD - 91 patients.

RESULTS

GDNF concentration in BS of women with MDD was significantly lower than in men. In BD patients, univariate linear regression analysis revealed significant correlations between GDNF concentration in the LF and the use of anxiolytics or antidepressants. These correlations were confirmed by the multivariate linear regression analysis. A significant correlation between GDNF concentrations in the LF and BS was found in controls.

LIMITATIONS

The unequal proportion of men in the BD group did not permit adjusting GDNF concentrations for sex. The collected LF was stimulated, which could influence GDNF levels. It should also be noted that the patients included in the study were not treatment- naïve.

CONCLUSIONS

Our findings suggest that GDNF concentration in LF could be a biomarker of the cDE (both unipolar and bipolar), though the sensitivity of this potential biomarker may be lower in depressive patients with anxiety symptoms.

Serum brain-derived neurotrophic factor and glial cell-derived neurotrophic factor in patients with first-episode depression at different ages

OBJECTIVES

We investigated the differences in serum brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) levels and clinical symptoms with first-episode depression at different ages.

METHODS

Ninety patients (15-60 years old) diagnosed with first-episode depression were enrolled as the study group, and they were divided into early-onset, adult and late-onset groups. The age-matched control groups were healthy volunteers. Serum BDNF and GDNF concentrations were determined by enzyme-linked immunosorbent assay (ELISA). GraphPad Prism 9 was used for t tests, one-way ANOVAs, chi-square tests, and correlation analyses. p < 0.05 indicated significant differences.

RESULTS

Serum BDNF and GDNF levels were lower in the whole study group and the three subgroups than in the healthy groups. Illness severity, anxiety and education were higher in the early-onset than late-onset patients. Serum BDNF levels were lower in the adult than late-onset patients. Serum BDNF levels were negatively correlated with patient CGI-SI scores. After the LSD test for multiple comparisons, the results were also significant.

CONCLUSIONS

Low serum BDNF and GDNF levels may be involved in the pathophysiology of first-episode depression, and there were differences in serum BDNF levels at different ages, verifying that serum BDNF and GDNF could serve as potential biomarkers of depression. KEY POINTSDepression is often conceptualised as a systemic illness with different biological mechanisms, but satisfactory explanations have not been provided thus far.The aim of our study was to investigate differences in serum BDNF and GDNF levels and their relationships with clinical symptoms in patients with first-episode depression at different ages.The potential of the neurotrophic factor hypothesis to advance the diagnosis and treatment of depression will be a very exciting new strategy for future research.

Value of peripheral neurotrophin levels for the diagnosis of depression and response to treatment: A systematic review and meta-analysis

The neurotrophin hypothesis indicates that neurotrophic factors are important for the pathophysiology of major depressive disorder (MDD), with alterations in peripheral neurotrophin levels having potential clinical application for MDD. The present meta-analysis aimed to investigate the diagnostic value for MDD of peripheral neurotrophin levels in cross-sectional studies and the association between peripheral neurotrophin levels and the response to antidepressant treatment in longitudinal studies. Published studies in the PubMed and Web of Science databases were systematically searched up to February 2020. The search terms included depressive disorder, neurotrophic factor, serum/plasma and their synonyms. Human studies reporting on BDNF, GDNF, IGF-2, VEGF, NGF, FGF-2, and S100B levels in MDD patients were included. Data comparing MDD patients and healthy controls, and/or between responders and non-responders before and after antidepressant treatment were extracted. A random effects model was used to calculate standardized mean differences. A total of 177 original studies were identified, including 139 cross-sectional and 38 longitudinal studies. Significantly reduced BDNF and NGF levels and significantly elevated IGF-1, VEGF, and S100B levels were reported in MDD patients compared with healthy controls, while GDNF and FGF-2 levels were not significantly different. Furthermore, compared with non-responders, S100B levels at baseline and BDNF levels following treatment were significantly elevated in responders. In addition, there was a significantly elevated level of VEGF after treatment in responders only. In conclusions, alterations in peripheral neurotrophins levels were strongly associated with the biology and the treatment response of MDD. Further investigations are required to examine potential sources of heterogeneity.

Evaluation of Serum Glial Cell Line-derived Neurotrophic Factor in Bangladeshi Major Depressive Disorder Patients

Background

Major depressive disorder (MDD) is a global health burden in the 21^st century because of its high rate of prevalence linked with disability, morbidity, and mortality. The actual etiology behind the development of MDD is not understood yet. Various genetic, physiological, biological and environmental factors have been predicted to be involved. As there is currently no sufficient laboratory test for the diagnosis of MDD, it is expected that this investigation can assist in better diagnosis and management of MDD. The present study aimed to evaluate glial cell line-derived neurotrophic factor (GDNF) in MDD patients compared to healthy controls (HCs).

Materials and methods

This case-control study was conducted with 167 participants including 85 MDD patients and 82 age- and sex-matched HCs. A qualified psychiatrist evaluated all the study participants according to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5). The severity of depression was measured by the Hamilton depression rating scale (Ham-D) and the participants with Ham-D score ≥ 7 were considered as cases. Serum GDNF levels were determined by enzyme-linked immunosorbent assay (ELISA) kits (Boster Bio, Pleasanton, CA, USA).

Results

MDD patients and HCs were similar in terms of their socio-demographic profiles. Serum GDNF was found to have no significant alterations in MDD patients when compared to HCs (p > 0.05). Moreover, no significant positive or negative correlation was found between serum levels of GDNF and Ham-D scores in MDD patients.

Conclusions

It can be predicted from the above findings that there is no significant relation between serum GDNF levels and the pathophysiology of depression. This study should be treated as preliminary and further studies with a more homogeneous and larger study population are required to establish these findings.

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.

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 &lt;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.

Glial Cell Line-Derived Neurotrophic Factor (GDNF) serum level in women with schizophrenia and depression, correlation with clinical and metabolic parameters

AIM

Neurotrophic factors have been implicated in neuropsychiatric disorders, including schizophrenia and depression. Glial Cell Line-Derived Neurotrophic Factor (GDNF) promotes development, differentiation, and protection of dopaminergic, serotonergic, GABAergic and noradrenergic neurons as well as glial cells in different brain regions. This study examined serum levels of GDNF in schizophrenia and depression and its correlation with metabolic parameters during 8 weeks of treatment.

METHODS

Serum GDNF level, fasting serum glucose and lipid profile were measured at baseline and week 8 in 133 women: 55 with schizophrenia, 30 with a first episode depression and 48 healthy controls. The severity of the symptoms was evaluated using Positive and Negative Syndrome Scale (PANSS), 17-item Hamilton Depression Rating Scale (HDRS) and Beck Depression Inventory (BDI).

RESULTS

There was statistically significant higher GDNF level in schizophrenia at baseline when compared with week 8. Correlations of GDNF with PANSS in schizophrenia and cholesterol level in depression have also been detected.

CONCLUSIONS

To our knowledge, this is the first study which correlates GDNF levels with metabolic parameters. Our results show no differences in GDNF serum level between schizophrenia, a first depressive episode, and healthy controls. GDNF serum level did not correlate with metabolic parameters except for total cholesterol in depression.

The protein and mRNA expression levels of glial cell line-derived neurotrophic factor in post stroke depression and major depressive disorder

Previous studies have indicated that the level of glial cell line-derived neurotrophic factor (GDNF) may be correlated with stroke and depression. Here, we investigated whether GDNF can be a discriminant indicator for post stroke depression (PSD). 159 participants were divided into four groups: PSD, stroke without depression (Non-PSD), major depressive disorder (MDD) and normal control (NC) group, and the protein and mRNA expression levels of GDNF in serum were measured. The results showed that only MDD group had statistical difference in protein and mRNA levels compared with the other three groups (Bonferroni test, P < 0.05). The results of receiver operating curve (ROC) analysis supported GDNF as general distinguishing models in PSD and MDD groups with the area under the curve (AUC) at 0.797 (P < 0.001) and 0.831 (P < 0.001) respectively. In addition, the Spearman analysis demonstrated that the GDNF protein level negatively correlated with the value of Hamilton depression rating scale (HAMD) in PSD patients (correlation coefficient = -0.328, P = 0.047). Together, these findings suggest the protein and mRNA expression levels of GDNF decreased in patients with depression. GDNF may serve as a potential biomarker for differential diagnosis of PSD from MDD patients.

Role of glial cell line-derived neurotrophic factor in the pathogenesis and treatment of mood disorders

Glial cell line-derived neurotrophic factor (GDNF) is widely recognized as a survival factor for dopaminergic neurons, but GDNF has also been shown to promote development, differentiation, and protection of other central nervous system neurons and was thought to play an important role in various neuropsychiatric disorders. Severe mood disorders, such as primarily major depressive disorder and bipolar affective disorder, attract particular attention. These psychopathologies are characterized by structural alterations accompanied by the dysregulation of neuroprotective and neurotrophic signaling mechanisms required for the maturation, growth, and survival of neurons and glia. The main objective of this review is to summarize the recent findings and evaluate the potential role of GDNF in the pathogenesis and treatment of mood disorders. Specifically, it describes (1) the implication of GDNF in the mechanism of depression and in the effect of antidepressant drugs and mood stabilizers and (2) the interrelation between GDNF and brain neurotransmitters, playing a key role in the pathogenesis of depression. This review provides converging lines of evidence that (1) brain GDNF contributes to the mechanism underlying depressive disorders and the effect of antidepressants and mood stabilizers and (2) there is a cross-talk between GDNF and neurotransmitters representing a feedback system: GDNF-neurotransmitters and neurotransmitters-GDNF.