Changes of brain-derived neurotrophic factor (BDNF) levels after different exercise protocols: a systematic review of clinical studies in Parkinson's disease

Therapeutic Mechanisms of Exercise in Parkinson's Disease

Despite being the second-most common neurodegenerative disease, the etiology of Parkinson's disease (PD) remains uncertain with current knowledge suggestive of multiple risk factors. Furthermore, curative treatment does not yet exist, and treatment is primarily symptomatic in nature. For this reason, supportive therapies such as exercise are a crucial tool in PD management. It is useful to better understand how exercise affects the brain and body in the context of PD to guide clinical decision-making and determine the optimal exercise intensity and modality for PD patients. This review outlines the various mechanisms by which exercise can be beneficial as a therapeutic option in PD.

Effect of an adapted physical activity program in Parkinson's disease: A randomized controlled study (APA-Park)

CONTEXT

Previous studies assessing adapted physical activity (APA) in Parkinson's disease (PD) have been very heterogeneous regarding methodology and intervention, and have generally not addressed the question of combining various types of physical activity with a long-term evaluation.

OBJECTIVES

To evaluate the immediate and long-term effect of a 3-month APA program, combining endurance, resistance training and stretching on motor symptoms, body composition, cardiorespiratory function and metabolic profile in PD patients.

METHODS

In this controlled trial, we randomly assigned forty-four PD patients in a 1:1 ratio to receive a 3-month APA program (APA + group, n = 22), or freely practice physical activity (APA- group, n = 22). The patients were evaluated for parkinsonian symptoms (UPDRS-III), body composition, cardiorespiratory function and metabolic profile at baseline, immediately after the end of the program (M3) and six months later (M9).

RESULTS

Between baseline and M3, the mean UPDRS-III score decreased in PD patients from the APA + group whereas it increased in the APA- group (-1.2 ± 6.6 vs. +1.9 ± 8.9; p = 0.04), regardless of age, sex, disease duration, dopaminergic treatment, UPDRS-III and axial score at baseline, but these between group differences waned at M9. No between group difference was observed regarding the evolution of body composition, metabolic profile or cardiorespiratory function between baseline, M3 and M9.

CONCLUSION

A 3-month APA program combining endurance and resistance training plus stretching is more efficient for improving motor symptoms in PD compared to an unstructured engagement in non-specific physical activities. However, the benefits fade away six months after discontinuation of the program.

STATISTICAL ANALYSIS CONDUCTED BY

LAMBERT Céline, CHU Clermont-Ferrand, DRCI, Biostatistics Unit, Clermont-Ferrand, FRANCE.

REGISTRATION NUMBER

clinicaltrials.gov number NCT02816619.

From Synaptic Plasticity to Neurodegeneration: BDNF as a Transformative Target in Medicine

The brain-derived neurotrophic factor (BDNF) has become one of the cornerstones of neuropathology, influencing synaptic plasticity, cognitive resilience, and neuronal survival. Apart from its molecular biology, BDNF is a powerful target for transformative benefit in precision medicine, leading to innovative therapeutic approaches for neurodegenerative and psychiatric diseases like Alzheimer's disease (AD), Parkinson's disease (PD), major depressive disorder (MDD), and post-traumatic stress disorder (PTSD). Nevertheless, clinical applicability is obstructed by hurdles in delivery, patient-specific diversity, and pleiotropic signaling. Here, we summarize findings in BDNF research, including its regulatory pathways and diagnostic/prognostic biomarkers and integrative therapeutic approaches. We describe innovative delivery systems, such as lipid nanoparticle-based mRNA therapies and CRISPR-dCas9-based epigenetic editing that bypass obstacles such as BBB (blood-brain barrier) and enzymatic degradation. The recent implementation of multiplex panels combining BDNF biodynamic indicators with tau and amyloid-β signaling markers showcases novel levels of specificity for both early detection and potential therapeutic monitoring. Humanized preclinical models like iPSC-derived neurons and organoids point to the key role of BDNF in neurodeveloping and neurodegenerative processes, paralleling advances in bridging preclinical observation and clinical environments. Moreover, novel therapeutic tools delivering TrkB activators or the implementation of AI-based dynamic care platforms enable tailored and scalable treatments. This review also aims to extend a framework used in the understanding of BDNF's relevance to traditional neurodegenerative models by situating more recent work detailing BDNF's actions in ischemic tissues and the gut-brain axis in the context of systemic health. Finally, we outline a roadmap for the incorporation of BDNF-centered therapies into worldwide healthcare, highlighting ethical issues, equity, and interdisciplinary decomposition. The therapeutic potential of BDNF heralds a new era in neuroscience and medicine, revolutionizing brain health and paving the way for the advancement of precision medicine.

Changes in proBDNF and Mature BDNF Levels After Medium-Intensity Functional Motor Rehabilitation Program in Patients with Parkinson's Disease

Physical rehabilitation complements the treatment of Parkinson's disease (PD). The applied physical exercises are effective in PD by promoting activity-dependent neuroplasticity. The main aim of this study was to assess the effect of a 16-week moderate-intensity functional physical rehabilitation program (FPR) on the concentration of mature brain-derived neurotrophic factor (BDNF) and its precursor (proBDNF) in blood serum and the severity of symptoms and quality of life in people with PD. People with PD (Hoehn and Yahr stage 3) were randomly assigned to the experimental (FPR) and control (CG) groups. FPR participated in movement training to improve functional mobility, motor coordination, and balance. Pre- and post-intervention assessments included serum levels of proBDNF, mature BDNF, MDS-UPDRS sub-scales, and the PDQ-39 quality of life measured. In the FPR group, a statistically significant increase in serum proBDNF levels by 39.42% (p = 0.006) was observed, as well as an improvement in motor and non-motor aspects of daily functioning, motor complications, and overall quality of life. No statistically significant changes in BDNF levels were observed. The results indicate that moderately intensive FPR enhances neurotrophic mechanisms, primarily through regulating proBDNF and improving motor functions and quality of life in patients with PD. The results underline the potential of targeted rehabilitation programs to increase neuroplasticity and improve clinical outcomes in PD.

Brain-Derived Neurotrophic Factor (BDNF) as a Marker of Physical Exercise or Activity Effectiveness in Fatigue, Pain, Depression, and Sleep Disturbances: A Scoping Review

Background/Objectives: Brain-derived neurotrophic factor (BDNF) has been investigated as a potential mechanistic marker or therapeutic target to manage symptoms such as fatigue, pain, depression, and sleep disturbances. However, the variability in BDNF response to exercise or physical activity (exercise/PA) and its clinical relevance in symptom management remains unclear. This scoping review assesses existing studies exploring the relationships between exercise/PA, symptoms, and BDNF levels, specifically focusing on fatigue, pain, depression, and sleep disturbances in adults. Methods: Relevant studies indexed in PubMed and CINAHL were identified. Using systematic review software, two reviewers independently screened and evaluated full texts, based on the following criteria: human studies reporting BDNF levels in adults, using exercise/PA interventions, assessing symptoms (pain, fatigue, depression, and/or sleep disturbance) as outcomes, and published in English. Results: Of 950 records, 35 records met the inclusion criteria. While exercise/PA is broadly supported for managing symptoms, 74.3% (n = 26) of studies reported increased BDNF levels, and only 40% (n = 14) showed significant increases following exercise/PA. Only 14% (n = 5) of studies demonstrated a significant relationship between changes in BDNF and symptoms. No significant differences in BDNF levels and symptoms were observed between different types of exercise (e.g., aerobic vs. strength vs. flexibility/stretching) and PA. Conclusions: The current literature provides insufficient evidence to confirm BDNF as a marker for exercise/PA effectiveness on symptoms. Further clinical investigations are needed to validate its potential as a therapeutic target.

The Optimal Type and Dose of Exercise for Elevating Brain-Derived Neurotrophic Factor Levels in Patients With Depression: A Systematic Review With Pairwise, Network, and Dose-Response Meta-Analyses

Background: Reduced brain-derived neurotrophic factor (BDNF) levels have been linked to increased depression risk. While physical exercise is known to alleviate depressive symptoms and elevate BDNF levels, the effects of different exercise modalities and doses, along with their dose-response relationships, remain unclear. Objective: This study aims to systematically evaluate the effects of various exercise types and doses on BDNF levels in patients with depression through pairwise meta-analysis, network meta-analysis (NMA), and dose-response NMA and to provide personalized exercise prescription recommendations. Methods: A comprehensive search identified randomized controlled trials (RCTs) examining exercise's impact on BDNF levels in depression. Pairwise and NMA compared six exercise modalities: continuous aerobic exercise (CAE), resistance exercise (RE), combined aerobic and resistance exercise (AERE), yoga, Qigong, and mindfulness. Dose-response NMA was used to assess the relationships between exercise dose and BDNF levels. Results: Thirty-six RCTs with 2515 participants were included. The pairwise meta-analysis indicated that all exercise interventions significantly elevated BDNF levels in patients with depression, with AERE, RE, and yoga demonstrating the most substantial effects. NMA rankings suggested that AERE was the most effective intervention, followed by RE, yoga, Qigong, mindfulness, and CAE. Dose-response NMA revealed a positive nonlinear dose-response relationship between total exercise volume and BDNF levels, with an optimal effective dose identified at ~610 METs-min/week. Beyond 1000 metabolic equivalent of tasks (METs)-min/week, increases in BDNF levels appeared to plateau. Moreover, each exercise type had distinct dose-response patterns, with RE and AERE having relatively higher optimal effective dose ranges, while CAE, yoga, Qigong, and mindfulness exhibited lower optimal ranges. Conclusions: AERE, RE, and yoga are effective interventions for enhancing BDNF levels in patients with depression, with Qigong, mindfulness, and CAE being comparatively less effective. A positive nonlinear dose-response relationship between exercise volume and BDNF levels was observed. Further research is needed to refine dose-response relationships in this population.

Filbertone-Induced Nrf2 Activation Ameliorates Neuronal Damage via Increasing BDNF Expression

Neurotrophic factors are endogenous proteins that promote the survival of various neuronal cells. Increasing evidence has suggested a key role for brain-derived neurotrophic factor (BDNF) in the dopaminergic neurotoxicity associated with Parkinson's Disease (PD). This study explores the therapeutic potential of filbertone, a bioactive compound found in hazelnuts, in neurodegeneration, focusing on its effects on neurotrophic factors and the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. In our study, filbertone markedly elevated the expression of neurotrophic factors, including BDNF, Glial cell line-Derived Neurotrophic Factor (GDNF), and Nerve Growth Factor (NGF), in human neuroblastoma SH-SY5Y cells, mouse astrocyte C8-D1A cells, and mouse hypothalamus mHypoE-N1 cells. Moreover, filbertone effectively countered neuroinflammation and reversed the decline in neurotrophic factors and Nrf2 activation induced by a high-fat diet (HFD) in neurodegeneration models. The neuroprotective effects of filbertone were further validated in models of neurotoxicity induced by palmitic acid (PA) and the neurotoxin MPTP/MPP+, where it was observed to counteract PA and MPTP/MPP+-induced decreases in cell viability and neuroinflammation, primarily through the activation of Nrf2 and the subsequent upregulation of BDNF and heme oxygenase-1 expression. Nrf2 deficiency negated the neuroprotective effects of filbertone in MPTP-treated mice. Consequently, our finding suggests that filbertone is a novel therapeutic agent for neurodegenerative diseases, enhancing neuronal resilience through the Nrf2 signaling pathway and upregulation of neurotrophic factors.

Neuroprotective properties of zinc oxide nanoparticles: therapeutic implications for Parkinson's disease

Parkinson's disease (PD) significantly affects millions of people worldwide due to the progressive degeneration of dopamine-producing neurons in the substantia nigra pars compacta. Despite extensive research efforts, effective treatments that can halt or reverse the progression of PD remain elusive. In recent years, nanotechnology has emerged as a promising new avenue for addressing this challenge, with zinc oxide nanoparticles (ZnO-NPs) standing out for their extensive therapeutic potential. ZnO-NPs have shown remarkable promise in neuroprotection through several key mechanisms. The multifaceted properties of ZnO-NPs suggest that they could play a crucial role in intervening across various fundamental mechanisms implicated in PD. By targeting these mechanisms, ZnO-NPs offer new insights and potential strategies for managing and treating PD. This review aims to provide a thorough examination of the molecular mechanisms through which ZnO-NPs exert their neuroprotective effects. It highlights their potential as innovative therapeutic agents for PD and outlines directions for future research to explore and harness their full capabilities.

Neuroplasticity in Parkinson's disease

Parkinson's disease (PD) is the second most frequent neurodegenerative disorder, affecting millions of people and rapidly increasing over the last decades. Even though there is no intervention yet to stop the neurodegenerative pathology, many efficient treatment methods are available, including for patients with advanced PD. Neuroplasticity is a fundamental property of the human brain to adapt both to external changes and internal insults and pathological processes. In this paper we examine the current knowledge and concepts concerning changes at network level, cellular level and molecular level as parts of the neuroplastic response to protein aggregation pathology, synapse loss and neuronal loss in PD. We analyse the beneficial, compensatory effects, such as augmentation of nigral neurons efficacy, as well as negative, maladaptive effects, such as levodopa-induced dyskinesia. Effects of physical activity and different treatments on neuroplasticity are considered and the opportunity of biomarkers identification and use is discussed.

Exercise, Neuroprotective Exerkines, and Parkinson's Disease: A Narrative Review

Parkinson's disease (PD) is a prevalent neurodegenerative disease in which treatment often includes an exercise regimen. Exercise is neuroprotective in animal models of PD, and, more recently, human clinical studies have verified exercise's disease-modifying effect. Aerobic exercise and resistance training improve many of PD's motor and non-motor symptoms, while neuromotor therapy and stretching/flexibility exercises positively contribute to the quality of life in people with PD. Therefore, understanding the role of exercise in managing this complex disorder is crucial. Exerkines are bioactive substances that are synthesized and released during exercise and have been implicated in several positive health outcomes, including neuroprotection. Exerkines protect neuronal cells in vitro and rodent PD models in vivo. Aerobic exercise and resistance training both increase exerkine levels in the blood, suggesting a role for exerkines in the neuroprotective theory. Many exerkines demonstrate the potential for protecting the brain against pathological missteps caused by PD. Every person (people) with Parkinson's (PwP) needs a comprehensive exercise plan tailored to their unique needs and abilities. Here, we provide an exercise template to help PwP understand the importance of exercise for treating PD, describe barriers confronting many PwP in their attempt to exercise, provide suggestions for overcoming these barriers, and explore the role of exerkines in managing PD. In conclusion, exercise and exerkines together create a powerful neuroprotective system that should contribute to slowing the chronic progression of PD.

BDNF-Regulated Modulation of Striatal Circuits and Implications for Parkinson's Disease and Dystonia

Neurotrophins, particularly brain-derived neurotrophic factor (BDNF), act as key regulators of neuronal development, survival, and plasticity. BDNF is necessary for neuronal and functional maintenance in the striatum and the substantia nigra, both structures involved in the pathogenesis of Parkinson's Disease (PD). Depletion of BDNF leads to striatal degeneration and defects in the dendritic arborization of striatal neurons. Activation of tropomyosin receptor kinase B (TrkB) by BDNF is necessary for the induction of long-term potentiation (LTP), a form of synaptic plasticity, in the hippocampus and striatum. PD is characterized by the degeneration of nigrostriatal neurons and altered striatal plasticity has been implicated in the pathophysiology of PD motor symptoms, leading to imbalances in the basal ganglia motor pathways. Given its essential role in promoting neuronal survival and meditating synaptic plasticity in the motor system, BDNF might have an important impact on the pathophysiology of neurodegenerative diseases, such as PD. In this review, we focus on the role of BDNF in corticostriatal plasticity in movement disorders, including PD and dystonia. We discuss the mechanisms of how dopaminergic input modulates BDNF/TrkB signaling at corticostriatal synapses and the involvement of these mechanisms in neuronal function and synaptic plasticity. Evidence for alterations of BDNF and TrkB in PD patients and animal models are reviewed, and the potential of BDNF to act as a therapeutic agent is highlighted. Advancing our understanding of these mechanisms could pave the way toward innovative therapeutic strategies aiming at restoring neuroplasticity and enhancing motor function in these diseases.