Matrix metalloproteinase-9 regulates MUC-2 expression through its effect on goblet cell differentiation

Area of Science:

• Gastroenterology
• Molecular Biology
• Immunology

Background:

• Epithelial-derived matrix metalloproteinase (MMP)-9 is upregulated during inflammatory bowel disease and contributes to tissue damage.
• MMP-9 null mice exhibit reduced inflammatory responses and an intact epithelial barrier during colitis.

Purpose of the Study:

• To investigate the role and mechanism of MMP-9 in regulating intestinal epithelial barrier protective function.
• To determine how MMP-9 influences goblet cell differentiation and mucosal defense.

Main Methods:

• In vivo studies using wild-type and MMP-9 null mice.
• In vitro studies using goblet cell line HT29-cl.16E and enterocyte cell line Caco2-BBE.
• Analysis of goblet cell differentiation markers, transcription factors (KLF-4, Elf-3), and signaling pathways (Notch).

Main Results:

• MMP-9 null mice showed increased goblet cell numbers and MUC-2 expression, with altered transcription factor activity.
• MMP-9 overexpression inhibited goblet cell differentiation in vitro, while gene silencing promoted a goblet cell phenotype.
• MMP-9 levels inversely correlated with MUC-2 expression during goblet cell maturation.
• MMP-9 affected Salmonella typhimurium adherence to goblet cells.

Conclusions:

• MMP-9 plays a regulatory role in colon goblet cell differentiation.
• Altered MMP-9 function can impact mucosal defense and contribute to inflammation.
• This study reveals a novel function of MMP-9 in intestinal epithelial cells related to barrier integrity.