Catestatin Regulates Epithelial Cell Dynamics to Improve Intestinal Inflammation

Area of Science:

• Gastroenterology
• Immunology
• Cell Biology

Background:

• Ulcerative colitis (UC) involves impaired intestinal barrier function due to dysregulation of tight junctions (TJ), STAT3, and IL-8/18.
• Catestatin (CST), a peptide from enterochromaffin cells, influences immune responses and STAT3 in inflamed intestines.

Purpose of the Study:

• To investigate the role and therapeutic potential of Catestatin (CST) in ulcerative colitis (UC).
• To explore CST's effects on intestinal barrier integrity, inflammation, and STAT3 signaling in UC models.

Main Methods:

• Analysis of CST levels in human UC biopsies and Caco2 cells.
• Utilizing a dextran sulfate sodium (DSS)-induced colitis model in mice.
• Assessing the impact of CST administration on colonic inflammation, TJ proteins, and STAT3 phosphorylation.
• Investigating CST's effects on LPS- and DSS-induced Caco2 cell injury.

Main Results:

• CST levels were significantly reduced in active UC patients and correlated with TJ proteins and STAT3, while inversely correlating with IL-8 and IL-18.
• CST administration reduced experimental colitis severity, decreased IL-18, maintained TJ proteins, and enhanced STAT3 phosphorylation.
• In Caco2 cells, CST improved proliferation, viability, migration, TJ proteins, and p-STAT3, while reducing IL-8 and IL-18; these effects were abrogated by a STAT3 inhibitor.

Conclusions:

• Catestatin (CST) plays a regulatory role in intestinal mucosal dynamics during inflammation, potentially through a STAT3-dependent pathway.
• Targeting CST in intestinal epithelial cells presents a promising therapeutic strategy for conditions like UC where epithelial homeostasis is compromised.