Female Mice Reaching Exceptionally High Old Age Have Preserved 20S Proteasome Activities

Area of Science:

• Aging research
• Cellular biology
• Biochemistry

Background:

• Oxidized, damaged, and misfolded proteins accumulate with age, impairing cellular function and tissue homeostasis.
• Cellular clearance mechanisms, such as the 20S proteasome, degrade damaged proteins.
• Previous studies show conflicting results regarding 20S proteasome function decline with age, with limited data on exceptionally old individuals.

Purpose of the Study:

• To investigate age-related changes in 20S proteasome activity (caspase-like and chymotrypsin-like) in various tissues and cells.
• To determine if 20S proteasome function declines universally with age in female mice.
• To explore the association between 20S proteasome function and successful aging in exceptionally old mice.

Main Methods:

• Assessed caspase-like and chymotrypsin-like proteasome activities.
• Examined tissues: lung, heart, axillary lymph nodes, liver, and kidney.
• Analyzed peritoneal leukocytes from adult, old, and exceptionally old female BALB/c mice.

Main Results:

• Age-related changes in 20S proteasome activity varied significantly across different tissues and between the two measured activities.
• No universal decline in proteasome function was observed with aging in female mice.
• Exceptionally old mice exhibited better-maintained proteasome activities compared to younger age groups.

Conclusions:

• 20S proteasome function does not uniformly decrease with age in female mice.
• Preserved 20S proteasome activity is linked to successful aging.
• These findings highlight the importance of cellular protein degradation in the aging process and longevity.