Aberrant mTOR activation in senescence and aging: A mitochondrial stress response?

Area of Science:

• Gerontology
• Molecular Biology
• Cellular Biology

Background:

• Elevated mechanistic target of rapamycin (mTOR) signaling, evidenced by ribosomal S6 phosphorylation or ribosomal S6 kinase (p70S6K) activity, is increasingly reported in aging contexts.
• This heightened mTOR activity has been documented in cardiac and muscle tissues of aged mice and humans, as well as in progeria mouse models and senescent human fibroblasts.

Purpose of the Study:

• To investigate the potential link between mTOR/p70S6K pathway activation and reactive oxygen species (ROS)-mediated mitochondrial stress in aging.
• To explore whether this pathway activation contributes to the development of cellular senescence, a key feature of aged tissues.

Main Methods:

• Review and synthesis of existing literature on mTOR signaling in aging.
• Analysis of evidence linking mTOR activation to mitochondrial dysfunction and ROS production.
• Exploration of the role of the mTOR/p70S6K pathway in the induction of senescence.

Main Results:

• The study highlights consistent reports of increased mTOR signaling in various aging models.
• It proposes a model where mitochondrial stress and ROS may trigger mTOR/p70S6K activation.
• This activation is suggested to be a significant factor in the onset of cellular senescence.

Conclusions:

• The mTOR/p70S6K pathway may be activated by ROS-induced mitochondrial stress during aging.
• Activation of this pathway is a potential driver of cellular senescence in aged tissues and cells.
• Further research is warranted to elucidate the precise mechanisms and therapeutic implications.