Developmental mitochondrial complex I activity determines lifespan.

Area of Science:

• Mitochondrial biology
• Developmental biology
• Aging research

Background:

• Aberrant mitochondrial function is linked to numerous human diseases.
• Maladaptations to mitochondrial dysfunction may drive disease pathology.
• System plasticity influences the severity of maladaptation to mitochondrial dysfunction.

Purpose of the Study:

• To investigate how the timing of mitochondrial dysfunction impacts organismal health and stress resistance.
• To determine if developmental timing of mitochondrial complex I (CI) dysfunction affects survival and stress resilience.
• To characterize the molecular responses to CI dysfunction initiated at different life stages.

Main Methods:

• Utilized inducible fly models to disrupt mitochondrial complex I (CI) activity.
• Induced CI dysfunction during early development and post-adult eclosion.
• Performed transcriptomic, proteomic, and metabolomic analyses on affected fly populations.
• Assessed survival and stress resistance in fly models with varying CI dysfunction timing.

Main Results:

• Developmental CI dysfunction led to significantly reduced adult survival and stress resistance.
• Adult-onset CI dysfunction resulted in long lifespan and stress resistance despite substantial CI activity reduction (up to 75%).
• Short-lived flies exhibited distinct molecular profiles (transcriptomic, proteomic, metabolomic) compared to long-lived ones.

Conclusions:

• Early-life mitochondrial dysfunction induces a maladaptive response, severely impairing survival.
• Mitochondrial CI depletion initiated in adulthood does not compromise survival or stress resistance.
• The timing of mitochondrial dysfunction is a critical determinant of organismal health outcomes and disease adaptation.