Metabolic orchestration of cell death by AMPK-mediated phosphorylation of RIPK1

Area of Science:

• Cell Biology
• Metabolism
• Molecular Biology

Background:

• Adenosine monophosphate-activated protein kinase (AMPK) regulates metabolic adaptation to energy stress.
• Sustained metabolic stress can lead to cell death, but the role of AMPK in this process is unclear.
• Receptor-interacting protein kinase 1 (RIPK1) activation is implicated in stress-induced cell death.

Purpose of the Study:

• To elucidate the mechanisms by which AMPK influences cell death under metabolic stress.
• To investigate the interplay between AMPK, RIPK1, and cell fate determination.
• To identify potential therapeutic targets for metabolic stress-related conditions.

Main Methods:

• Investigated AMPK and RIPK1 activation in response to metabolic stress.
• Utilized genetic manipulation (Ampk deficiency, RIPK1 S415A mutation) to assess functional consequences.
• Employed mouse models of ischemic injury to evaluate in vivo relevance.

Main Results:

• Metabolic stress activated RIPK1 via TRAIL receptors.
• AMPK inhibited RIPK1 activation by phosphorylating it at Ser415, thereby suppressing cell death.
• Ampk deficiency or RIPK1 S415A mutation promoted RIPK1 activation and cell death.
• Genetic RIPK1 inactivation protected against ischemic injury in Ampkα1-deficient mice.

Conclusions:

• AMPK phosphorylation of RIPK1 is a critical metabolic checkpoint controlling cell fate under stress.
• The AMPK-RIPK1 axis integrates metabolism, cell death, and inflammation.
• This axis represents a novel therapeutic target for conditions involving metabolic stress and cell death.