Mitochondrial Mistranslation in Brain Provokes a Metabolic Response Which Mitigates the Age-Associated Decline in...

Area of Science:

• Mitochondrial biology
• Neurogenetics
• Molecular mechanisms of disease

Background:

• Mitochondrial dysfunction is implicated in neurological disorders.
• Mitochondrial misreading, caused by mutations in mitochondrial ribosomal proteins, can lead to cellular impairment.
• The specific impact of Mrps5 V338Y mutation on brain mitochondrial function and compensatory responses is not fully understood.

Purpose of the Study:

• To investigate the in-vivo consequences of the Mrps5 V338Y mutation on brain mitochondrial function.
• To elucidate the molecular and metabolic compensatory mechanisms that alleviate impaired oxidative phosphorylation (OXPHOS) in Mrps5 mutant mice.
• To understand how these compensatory strategies affect age-associated mitochondrial decline.

Main Methods:

• Generation of Mrps5 V338Y/V338Y knock-in mutant mice.
• Assessment of brain mitochondrial oxygen consumption and ATP levels.
• Unbiased RNA-sequencing (RNA-Seq) to analyze gene expression changes.
• Untargeted metabolomics to profile metabolic alterations.

Main Results:

• Homozygous Mrps5 V338Y/V338Y mice exhibit reduced brain mitochondrial oxygen consumption and ATP levels.
• A concerted molecular and metabolic response was identified in mutant mice.
• This response involves transcriptional upregulation of OXPHOS components and replenishment of the TCA cycle.
• These adaptations mitigate age-associated decline in mitochondrial gene expression and compensate for impaired respiration.

Conclusions:

• The Mrps5 V338Y mutation induces a subtle neurological phenotype linked to mitochondrial dysfunction.
• Mice mount a significant compensatory response involving OXPHOS upregulation and TCA cycle replenishment.
• These adaptive mechanisms alleviate mitochondrial impairment and mitigate age-related decline in mitochondrial function.