eIF5A maintains intestinal epithelial homeostasis by sustaining intestinal stem cells

Area of Science:

• Cell Biology
• Molecular Biology
• Gastroenterology

Background:

• Intestinal homeostasis relies on continuous self-renewal of intestinal stem cells (ISCs).
• The role of eukaryotic translation initiation factor 5A (eIF5A) in intestinal stem cell function is not well understood.
• ISCs generate transit-amplifying (TA) and progenitor cells for epithelial maintenance.

Purpose of the Study:

• To investigate the role of eIF5A in maintaining intestinal epithelial homeostasis.
• To elucidate the molecular mechanisms by which eIF5A influences intestinal stem cell function.
• To determine the impact of eIF5A depletion on mitochondrial function in the intestine.

Main Methods:

• Conditional knockout of Eif5a in adult mouse intestinal epithelium.
• Generation and analysis of Eif5a-deficient intestinal organoids.
• Mass spectrometry to identify protein expression changes.
• Analysis of single-cell RNA sequencing data.
• Assessment of mitochondrial function (ATP levels, ROS).

Main Results:

• Eif5a deletion in mice caused stem cell loss, reduced proliferation, increased apoptosis, and mortality.
• Eif5a deficiency in organoids recapitulated these cellular phenotypes.
• eIF5A depletion led to downregulation of mitochondrial proteins, especially those involved in mitochondrial translation.
• eIF5A-deficient organoids showed impaired mitochondrial function, with decreased ATP and increased ROS.
• Mitochondrial translation-related genes are highly expressed in ISCs, TA, and progenitor cells.

Conclusions:

• eIF5A is critical for maintaining intestinal epithelial homeostasis.
• eIF5A regulates intestinal stem cell renewal by controlling mitochondrial translation.
• Dysregulation of eIF5A impacts mitochondrial function, affecting stem cell maintenance and tissue integrity.