LRRK2-G2019S impairs astrocyte differentiation and triggers a senescence-like phenotype in Parkinson’s disease models

Abstract

Abstract Astrocytes are increasingly recognised as essential contributors to both physiological brain function and neurodegenerative diseases. Here, we describe how the Parkinson’s disease (PD)-associated mutation LRRK2-G2019S affects astrocytes using autoptic brain samples and PD patient-specific 3D midbrain organoids and 2D astrocytes derived from induced pluripotent stem cells. In autoptic midbrain samples from LRRK2-G2019S patients, we observed a reduction in GFAP⁺ astrocytes but increased branching, together with transcriptional signatures consistent with altered astrocyte function. We also observed delayed astrocyte differentiation in PD patient-specific midbrain organoids, accompanied by altered astrocyte transcriptomic profiles revealed by single-cell RNA sequencing. This defective differentiation contributes to the acquisition of a senescent-like phenotype. In 2D cultures, astrocyte differentiation from LRRK2-G2019S precursor cells was associated with early apoptosis and altered Wnt/β-catenin and TGFβ signalling compared to LRRK2-WT cultures. Notably, pharmacological activation of the developmental transcription factor NR2F1, downregulated in LRRK2-G2019S models, reduced astrocyte cell death and senescence-like phenotypes. Together, these data show that LRRK2-G2019S impairs astrocyte specification and predisposes to a senescent phenotype.