Mitochondrial Quality Control in Neurodegenerative Diseases

Mitochondrial quality control encompasses multiple surveillance pathways that preserve organelle function, distribution and proteostasis within neurons characterised by high energy consumption and elaborate architecture. Core mechanisms include the ubiquitin-mediated removal of damaged mitochondria by mitophagy, chaperone-assisted clearance of misfolded proteins, dynamic regulation of mitochondrial morphology through fission and fusion, formation of mitochondrial-derived vesicles for targeted export of oxidised cargo, and activation of the mitochondrial unfolded protein response to restore proteome integrity. PTEN-induced kinase 1 (PINK1) functions as a stress sensor, accumulating on depolarised mitochondria to recruit the E3 ubiquitin ligase Parkin, which tags outer membrane proteins for degradation. Deubiquitinases such as USP30 fine-tune this process, preventing excessive clearance and maintaining homeostasis. Impairment of these pathways leads to the accumulation of dysfunctional mitochondria, heightened production of reactive oxygen species and bioenergetic compromise, all hallmarks of neurodegenerative diseases including Parkinson’s disease, Alzheimer’s disease and amyotrophic lateral sclerosis. Genetic mutations in core quality-control components and age-related declines in autophagic efficiency converge to drive selective neuronal vulnerability. Understanding these interconnected systems holds global significance for ageing populations and offers concrete targets for therapies aimed at restoring mitochondrial health.

Research from Nature Portfolio

Recent studies have shown that genetic ablation or pharmacological inhibition of a key mitochondrial deubiquitinase in murine models significantly enhances mitophagy and confers robust neuroprotection in Parkinsonian pathology. Loss of this enzyme increases ubiquitylation of damaged mitochondria, accelerates clearance of α-synuclein aggregates and preserves dopaminergic neurons, resulting in improved motor function. Crucially, a potent, brain-penetrant small-molecule inhibitor recapitulates these protective effects, reducing behavioural deficits and demonstrating favourable pharmacokinetic properties. These findings validate targeted deubiquitinase blockade as a promising disease-modifying strategy.

Mitochondrial Quality Control in Neurodegenerative Diseases publication trend

The graph below shows the total number of articles in mitochondrial quality control in neurodegenerative diseases across all publications each year (not limited to Nature Index journals).

Technical terms

Mitophagy: The selective autophagic degradation of damaged or superfluous mitochondria to maintain cellular homeostasis.

E3 ubiquitin ligase: An enzyme that catalyses the transfer of ubiquitin to substrate proteins, marking them for degradation or signalling.

Deubiquitinase: An enzyme that removes ubiquitin moieties from proteins, counteracting ubiquitylation and regulating protein fate.

PTEN-induced kinase 1 (PINK1): A mitochondrial kinase that accumulates on depolarised mitochondria and recruits Parkin to initiate mitophagy.

Parkin: A cytosolic E3 ubiquitin ligase activated by PINK1 that ubiquitylates outer mitochondrial membrane proteins to signal their removal.

References

1. PINK1 Is Selectively Stabilized on Impaired Mitochondria to Activate Parkin. PLOS Biology (2010).
2. Knockout or inhibition of USP30 protects dopaminergic neurons in a Parkinson’s disease mouse model. Nature Communications (2023).
3. Mitochondrial CISD1/Cisd accumulation blocks mitophagy and genetic or pharmacological inhibition rescues neurodegenerative phenotypes in Pink1/parkin models. Molecular Neurodegeneration (2024).
4. Activation of Ca2+ phosphatase Calcineurin regulates Parkin translocation to mitochondria and mitophagy in flies. Cell Death & Differentiation (2024).
5. PINK1 and Parkin mitochondrial quality control: a source of regional vulnerability in Parkinson’s disease. Molecular Neurodegeneration (2020).