Aging Disrupts Circadian Rhythms in Mouse Liver Mitochondria

Area of Science:

• Chronobiology
• Mitochondrial Biology
• Aging Research

Background:

• The circadian clock governs daily physiological rhythms in mammals.
• Aging significantly alters cellular circadian rhythms, particularly in mitochondrial function and oxidative stress.
• Previous findings indicate aging profoundly impacts liver mitochondrial rhythms in mice, despite intact peripheral molecular clocks.

Purpose of the Study:

• To review recent findings on the interplay between the circadian clock and aging.
• To explore the regulation of mitochondrial rhythms and redox homeostasis during aging.
• To investigate the role of chronic inflammation and NADase CD38 in age-related mitochondrial dysfunction.

Main Methods:

• Literature review of recent research findings.
• Analysis of studies on circadian rhythms, aging, and mitochondrial function.
• Examination of the impact of inflammation and specific molecular players like CD38.

Main Results:

• Aging alters gene expression rhythms in peripheral and central tissues.
• Chronic sterile inflammation contributes to mitochondrial dysfunction and oxidative stress in aging.
• Upregulation of NADase CD38 by inflammation during aging is linked to mitochondrial dysregulation.

Conclusions:

• Aging disrupts circadian regulation of mitochondrial function, leading to increased oxidative stress.
• While molecular clocks remain functional, aging alters rhythmic gene expression.
• Inflammation-induced upregulation of CD38 is a key factor in age-related mitochondrial decline.