Astrocytes in Parkinson's disease: Beyond support, toward therapy.

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra. While neuronal dysfunction has traditionally been the focal point of PD research, growing evidence highlights the critical roles of astrocytes - the most abundant glial cells in the central nervous system - in PD pathogenesis and therapy. Targeting astrocytes offers a promising therapeutic avenue through astrocyte-to-neuron reprogramming, inducing A2 phenotypic polarization, suppressing oxidative stress, modulating metal ion deposition, enhancing neurotransmitter homeostasis and promoting α-synuclein clearance. These diverse roles enable astrocytes to act as both protectors and potential contributors to disease progression, depending on the cellular environment. Furthermore, innovative strategies such as gene therapy, nanoparticle-based drug delivery, and astrocyte-derived exosome systems hold potential to overcome barriers like the blood-brain barrier and offer targeted, multifactorial interventions. Collectively, these findings advocate for a paradigm shift from a neuron-centric to a glia-inclusive framework in PD research and treatment, positioning astrocytes as central players in the quest for disease-modifying therapies.