The Mitochondrial-Astrocyte-Neuron Triad Hypothesis in Parkinson's Disease: A Toxic Feedback Loop of Metabolism, Aggregation, and Oxidative Stress.

The medical field has spent many years investigating Parkinson's disease (PD), primarily focusing on its main pathogenic feature, dopaminergic neuronal degeneration. Recent studies indicate that PD develops through a complex pathogenic model that links mitochondria to astrocytes and neurons, creating a destructive metabolic loop, a protein aggregation cycle, and oxidative stress. This review examines how mitochondria integrate with astrocytes and neurons in the "triad hypothesis," offering a multifaceted perspective on PD progression. Despite being previously overlooked, we have observed that astrocytic mitochondria play a central role in maintaining neuroprotection and homeostasis. Given that, dysfunctional mitochondria in astrocytes and neurons lead to metabolic failure, compromised glutamate regulation, while also enhancing α-synuclein aggregation, amplifying neuroinflammation, ferroptotic vulnerability and oxidative stress. Henceforth, this report discusses current insights into astrocyte-neuron metabolic coupling, mitochondrial quality control, and lipid redox imbalance, highlighting the role of astrocytic mitochondria as a strong therapeutic strategy. We discuss experimental and translational approaches that aim to restore triad integrity, including mitophagy enhancement, metabolic reprogramming, mitochondrial transfer, and astrocyte-to-neuron reprogramming. By positioning astrocytic mitochondria at the core of PD pathogenesis, this review advocates novel interventions focused on glial metabolic resilience. This integrated approach addresses three major pathogenic axes. It offers promising potential for disease modification and developing effective therapeutics beyond symptomatic dopamine replacement to correct neurodegenerative conditions.