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Opa1 processing is dispensable in mouse development but is protective in mitochondrial cardiomyopathy

Sofia Ahola1, Lilli A Pazurek1, Fiona Mayer1

  • 1Max Planck Institute for Biology of Ageing, Cologne, Germany.

Science Advances
|August 2, 2024
PubMed

Insights

Optic atrophy 1 (Opa1) processing is vital for longevity and preventing heart disease in mice with mitochondrial defects. This mitochondrial dynamics regulation impacts cardiac health and lifespan.

Area of Science:

  • Mitochondrial dynamics and cellular metabolism.
  • Genetics and physiology of mitochondrial proteins.
  • Cardiovascular research and disease mechanisms.

Background:

  • Mitochondrial fusion and fission are crucial for cellular adaptation to stress and metabolic changes.
  • Optic atrophy 1 (Opa1) is essential for inner mitochondrial membrane fusion and cristae structure.
  • Opa1 exists in multiple isoforms and undergoes processing from a long, membrane-bound form to a short, soluble form.

Purpose of the Study:

  • To investigate the physiological roles of different Opa1 isoforms and its processing.
  • To determine the impact of Opa1 processing on mouse development, stress response, and lifespan.
  • To elucidate the role of Opa1 processing in mitochondrial cardiomyopathy in OXPHOS-deficient mice.

Main Methods:

  • Generation of mouse lines expressing single cleavable or non-cleavable Opa1 isoforms.
  • Analysis of embryonic development and adult mouse health under normal and stress conditions (metabolic, thermal).
  • Assessment of mitochondrial cardiomyopathy in Cox10-/- mice with altered Opa1 processing.

Main Results:

  • Expression of a single Opa1 isoform (cleavable or non-cleavable) supports normal embryonic development and adult health.
  • Opa1 processing is not essential for metabolic or thermal stress adaptation but extends lifespan.
  • Loss of Opa1 processing protects against mitochondrial cardiomyopathy in Cox10-/- mice by altering mitochondrial biogenesis and mitophagy balance, suppressing cardiac hypertrophy.

Conclusions:

  • Opa1 processing is dispensable for basic survival and stress adaptation but critically regulates lifespan and cardiac health.
  • The balance between mitochondrial biogenesis and mitophagy, influenced by Opa1 processing, is key to preventing cardiac hypertrophy in mitochondrial disease.
  • Opa1 processing, mitochondrial dynamics, and metabolism are critical regulators of cardiac hypertrophy.

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