Exogenous L-arginine increases intestinal stem cell function through CD90+ stromal cells producing mTORC1-induced...

Area of Science:

• Gastroenterology
• Stem Cell Biology
• Nutritional Science

Background:

• Intestinal epithelium renewal relies on intestinal stem cells (ISCs).
• Exogenous nutrients influence adult stem cell activity.
• The specific role of L-arginine in ISC regulation is largely unknown.

Purpose of the Study:

• To investigate the effect of L-arginine on intestinal stem cells (ISCs) and epithelial differentiation.
• To elucidate the underlying mechanisms of L-arginine's action on ISCs.

Main Methods:

• Utilized mouse models and small intestinal (SI) organoid cultures.
• Performed co-culture experiments with CD90+ intestinal stromal cells.
• Investigated the role of Wnt2b signaling and mTORC1 pathway.

Main Results:

• L-arginine administration increased ISC expansion in mice.
• CD90+ intestinal stromal cells enhanced ISC function upon L-arginine stimulation.
• L-arginine stimulated Wnt2b secretion via mTORC1, which was crucial for ISC expansion.
• L-arginine treatment conferred protection against gut injury.

Conclusions:

• L-arginine plays a significant role in promoting intestinal stem cell (ISC) expansion.
• CD90+ stromal cells mediate L-arginine's effects on ISCs through Wnt2b secretion.
• L-arginine represents a potential therapeutic agent for gut injury and repair.