Irisin's emerging role in Parkinson's disease research: A review from molecular mechanisms to therapeutic prospects

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.

Intervention strategies for Parkinson's disease: the role of exercise and mitochondria

Parkinson's disease (PD), a progressive neurodegenerative disorder with complex pathogenic mechanisms, exhibiting rising prevalence alongside global population aging. Its pathological hallmarks include substantial loss of dopaminergic neurons in the substantia nigra pars compacta, leading to motor symptoms (e.g., bradykinesia, rigidity) and non-motor manifestations (e.g., cognitive impairment, sleep disorders). Accumulating evidence underscores mitochondrial dysfunction-encompassing reactive oxygen species (ROS) overproduction, defective mitophagy, and impaired biogenesis-as an important contributor to PD pathogenesis. Exercise, endorsed by leading medical and sports authorities as a non-pharmacological therapeutic strategy. While mitochondrial dysfunction impairs cellular energetics in PD patients, exercise can re-establish mitochondrial homeostasis through multiple pathways: stimulating neuroprotective exerkines, regulating mitochondrial ROS balance, modulating mitochondrial biogenesis and mitophagy, and enhancing brain-derived neurotrophic factor production. Many studies demonstrate that aerobic, resistance, and mind-body exercises demonstrably improve gait stability, postural control, and cognitive function in PD patients. However, standardized exercise prescriptions for PD prevention and treatment remain underutilized in clinical practice. This review synthesizes mitochondrial pathophysiology in PD progression, exercise-mediated regulatory mechanisms, and evidence-based exercise protocols, proposing accessible exercise regimens to support PD management. By integrating molecular insights with practical strategies, this work provides foundational evidence for utilizing exercise as a non-medical intervention against PD.

Role and Functions of Irisin: A Perspective on Recent Developments and Neurodegenerative Diseases

Irisin is a peptide derived from fibronectin type III domain-containing protein 5 (FNDC5) and is primarily produced by muscle fibers under the regulation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) during exercise. Irisin has been the subject of extensive research due to its potential as a metabolic regulator and its antioxidant properties. Notably, it has been associated with protective actions within the brain. Despite growing interest, many questions remain regarding the molecular mechanisms underlying its effects. This review summarizes recent findings on irisin, highlighting its pleiotropic functions and the biological processes and molecular cascades involved in its action, with a particular focus on the central nervous system. Irisin plays a crucial role in neuron survival, differentiation, growth, and development, while also promoting mitochondrial homeostasis, regulating apoptosis, and facilitating autophagy-processes essential for normal neuronal function. Emerging evidence suggests that irisin may improve conditions associated with non-communicable neurological diseases, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, frontotemporal dementia, and multiple sclerosis. Given its diverse benefits, irisin holds promise as a novel therapeutic agent for preventing and treating neurological diseases.

Irisin promotes autophagy and attenuates NLRP3 inflammasome activation in Parkinson's disease

Parkinson's disease (PD) is characterized by the aggregation and prion-like propagation of α-synuclein (α-syn). Irisin is an exercise-induced myokine that regulates energy metabolism and exerts protective effects in PD by reducing α-syn pathology. However, the molecular mechanisms underlying the role of irisin are not fully understood. Here, we show that irisin inhibits NLRP3 inflammasome activation and promotes autophagy in cultured cells. Additionally, irisin alleviates oxidative stress and reduces cell apoptosis induced by α-syn fibrils. In a PD mouse model induced by intrastriatal injection of α-syn fibrils, irisin mitigated α-syn aggregation, neuroinflammation and neurodegeneration. These observations suggest that irisin functions as a protective mediator against α-syn pathology in PD and that irisin may serve as a potential therapeutic target for the prevention and treatment of PD.

The centenarian blueprint: lessons in defying Parkinson's disease

Recent advancements in neurology have shifted focus from mere diagnosis to comprehensive management of movement disorders, particularly Parkinson's Disease (PD), which is rapidly increasing in prevalence due to global ageing trends. While age is a key risk factor for PD, centenarians often exhibit a remarkably low prevalence of the disease, presenting an intriguing paradox. This viewpoint explores potential reasons for this low prevalence, drawing on studies from regions with high centenarian populations, known as Blue Zones. The authors highlight the importance of genetic, lifestyle, and environmental factors in promoting healthy ageing and examines how these may contribute to the resilience against PD found in centenarians. By understanding the protective mechanisms in centenarians, particularly the concept of hormesis and factors like diet, exercise, and social connections, we may inform prevention strategies for PD. The study proposes the "EAT, MOVE, SLEEP, PROTECT, and REPEAT" approach as a framework for lifestyle interventions to counteract PD risk factors. Ultimately, centenarians offer valuable insights into delaying neurodegeneration, providing a model for potential preventive trials for PD.