Astrocyte-specific mitochondrial dysfunctions and calcium dysregulation are identified as key features of LRRK2- and PRKN-related pathology, providing new insights into how glial metabolic alterations contribute to neurodegeneration in PD.
Abstract
Parkinson’s disease (PD) is the second most common neurodegenerative disorder worldwide, and mutations in the LRRK2 and PRKN genes are among the most common familial causes of the disease. In neurodegenerative diseases such as PD, disturbances in Ca²⁺ homeostasis and cellular bioenergetics impair the function of neurons and glial cells, contributing to disease progression. These changes are not limited to neurons; mitochondrial dysfunction and disrupted Ca2+ homeostasis in astrocytes are increasingly recognized as key contributors to PD, impairing bioenergetics, redox balance, neuroinflammatory responses, and metabolic support essential for dopaminergic neuron survival. In this study, we investigated mitochondrial calcium homeostasis, mitochondrial oxidative phosphorylation, morphology and distribution in human induced pluripotent stem cell (hiPSC)-derived astrocytes with mutations in the PD genes LRRK2 (G2019S) and PRKN (c.155delA; Ex3-4del) and wild-type controls. Intracellular calcium dynamics were assessed using Fura-2 AM. Compared with control astrocytes, LRRK2-related PD patient-derived mutant astrocytes exhibited lower intracellular calcium levels, and slower calcium extrusion following stimulation with ATP. Mitochondrial morphology was analyzed using MitoTracker Deep Red, revealing increased mitochondrial fragmentation and redistribution of mitochondria toward the cell periphery in both PD mutant cell types. Because oxidative phosphorylation is tightly regulated by mitochondrial morphology and calcium homeostasis, we next assessed oxygen consumption rates using a continuous metabolic monitoring system (Resipher) and quantified the expression of genes (RT-qPCR) and proteins (capillary electrophoresis-based western detection) involved in mitochondrial calcium transport and bioenergetics. These analyses showed that PRKN mutant astrocytes exhibit a more oxidative bioenergetic phenotype than LRRK2 mutant astrocytes, while both mutant lines displayed altered phosphorylation of mitochondrial morphology regulator DRP1 as well as decreased levels of respiratory complexes relative to control astrocytes. In summary, this study identifies astrocyte-specific mitochondrial dysfunctions and calcium dysregulation as key features of LRRK2- and PRKN-related pathology, providing new insights into how glial metabolic alterations contribute to neurodegeneration in PD.
This integrated framework reframes PD as a disorder of impaired cellular maintenance rather than solely a consequence of late-stage degenerative processes, and provides a translational shift from mechanism-based biomarkers to early detection of mitochondrial failure and supports therapeutic strategies aimed at restoring mitochondrial function and resilience.
Oscar Arias-Carrión, Magdalena Guerra-Crespo, L. O. Soto-Rojas et al.· Frontiers in Pharmacology· 0 citations
This work generates human induced pluripotent stem cell-derived midbrain dopaminergic neurons using both a 2D differentiation protocol and a recently developed 3D method based on the microencapsulation of hiPSCs in small alginate/fibronectin beads.
A. Zanon, E. Kerschbamer, D. Riekschnitz et al.· Communications Biology· 0 citations
This review focuses on the potential molecular mechanism underlying KLF4-mediated neuroinflammation, oxidative stress, mitochondrial dysfunction, and apoptosis and targeting them appears to be a viable therapeutic strategy for treating PD.
Anjali Kumari, K. Aran· Current Medical Science· 0 citations
BACKGROUND
Mitochondrial dysfunction and oxidative stress are central to the pathogenesis of Parkinson's disease (PD), particularly affecting substantia nigra pars compacta (SNc) dopamine (DA) neurons. Here, we investigate how the R1441G mutation in leucine-rich repeat kinase 2 (LRRK2), a key genetic contributor to familial and sporadic PD, impacts mitochondrial function in midbrain DA neurons.
METHODS
We employed a BAC transgenic mouse model overexpressing human LRRK2-R1441G (BAC-hR1441G) and crossed it with TH-mito-roGFP mice to enable mitochondria-targeted redox imaging specifically in DA neurons. Acute midbrain slices from 3-, 6-, and 10-month-old mice were imaged using two-photon microscopy to assess mitochondrial oxidative stress. In parallel, mitochondrial respiratory function, membrane potential flickering events, and expression of uncoupling proteins (UCP4/UCP5) were analyzed. Spatial transcriptomic profiling was performed using the GeoMx® Digital Spatial Profiler to uncover associated molecular alterations.
RESULTS
We observed a progressive increase in mitochondrial oxidative stress in SNc DA neurons of BAC-hR1441G mice at 3, 6, and 10 months of age. This was accompanied by reduced respiratory complex activity, attenuated mitochondrial membrane potential flickering, and diminished expression of UCP4 and UCP5. Spatial transcriptomic analysis revealed dysregulation of genes linked to mitochondrial uncoupling, calcium signaling, and redox regulation in BAC-hR1441G SNc DA neurons.
CONCLUSIONS
These findings reveal an age-dependent progression of mitochondrial dysfunction in BAC-hR1441G SNc DA neurons. Dysregulation of calcium channels and uncoupling proteins emerges as a key mechanism contributing to bioenergetic failure, suggesting potential therapeutic targets to mitigate PD progression.
Yuanxin Chen, Lianteng Zhi, Shiquan Cui et al.· Molecular Neurodegeneration· 1 citation
Mitochondria are central regulators of cellular metabolism, redox balance, calcium signaling, and cell survival, making them essential for neuronal function. Because neurons rely heavily on mitochondrial oxidative phosphorylation to meet their high energetic demands, mitochondrial dysfunction has emerged as a key pathogenic driver in major neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and amyotrophic lateral sclerosis. Defects in mitochondrial bioenergetics, excessive reactive oxygen species production, impaired mitochondrial dynamics, disrupted mitophagy, and dysregulated calcium handling collectively contribute to neuronal damage, synaptic dysfunction, and neuroinflammation. These insights have prompted growing interest in therapeutic strategies that directly target mitochondria to restore organelle homeostasis. Recent advances in chemical biology and nanomedicine have enabled the development of mitochondria-targeted ligands, peptide-based targeting systems, and carrier or nanotechnology-enabled delivery platforms designed to overcome biological barriers and selectively deliver therapeutic cargos to mitochondria within the central nervous system. In this Review, we summarize mitochondrial pathological mechanisms in neurodegenerative diseases and discuss emerging mitochondria-targeted therapeutic strategies, highlighting delivery technologies, therapeutic modalities, and translational challenges. Although most strategies remain at the preclinical or proof-of-principle stage, these advances are beginning to shape a conceptual framework for precision mitochondrial medicine, with the longer-term goal of developing disease-modifying interventions for neurodegenerative disorders.
Qian Li, Ming You· Frontiers in Neuroscience· 0 citations