Intestinal intraepithelial lymphocyte derived angiotensin converting enzyme modulates epithelial cell apoptosis

Area of Science:

• Gastroenterology
• Immunology
• Cell Biology

Background:

• Short bowel syndrome (SBS) involves increased intestinal epithelial cell (EC) proliferation and apoptosis.
• Previous studies indicated elevated angiotensin converting enzyme (ACE) expression in intraepithelial lymphocytes (IELs) post-SBS.
• ACE is known to induce apoptosis in alveolar ECs.

Purpose of the Study:

• To investigate the role of IEL-derived ACE in intestinal EC apoptosis in SBS.
• To determine if ACE inhibition can mitigate EC apoptosis in SBS.

Main Methods:

• A mouse model of SBS was created via 70% mid-intestinal resection.
• ACE expression and function were assessed, utilizing ACE inhibition (enalaprilat).
• Tumor necrosis factor alpha (TNF-alpha) mRNA expression was measured as a potential mechanism.

Main Results:

• IEL-derived ACE expression was significantly elevated in SBS mice.
• ACE inhibition markedly reduced EC apoptosis in SBS mice.
• ACE inhibition decreased elevated TNF-alpha expression in SBS mice, and this effect was abolished in TNF-alpha knockout mice.

Conclusions:

• This study identifies a novel expression of ACE by IELs.
• SBS is associated with increased IEL-derived ACE, contributing to intestinal EC apoptosis.
• ACE inhibition represents a potential therapeutic strategy for reducing EC apoptosis in SBS.