Igf2bp1 is required for full induction of Ptgs2 mRNA in colonic mesenchymal stem cells in mice

NA Manieri, MR Drylewicz, H Miyoshi, TS Stappenbeck - Gastroenterology, 2012 - Elsevier
NA Manieri, MR Drylewicz, H Miyoshi, TS Stappenbeck
Gastroenterology, 2012Elsevier
BACKGROUND & AIMS: Prostaglandin-endoperoxide synthase (Ptgs) 2 is an enzyme
involved in prostaglandin production during the response to mucosal damage. Its
expression is regulated, in part, by messenger RNA (mRNA)-binding proteins that control
the stability of Ptgs2 mRNA. We used a precise system of colonic injury and repair to identify
Ptgs2 mRNA-binding proteins. METHODS: We used endoscopy-guided mucosal excision to
create focal injury sites in colons of mice. Wound beds from wild-type, Ptgs2−/−, Ptgs2+ …
BACKGROUND & AIMS
Prostaglandin-endoperoxide synthase (Ptgs)2 is an enzyme involved in prostaglandin production during the response to mucosal damage. Its expression is regulated, in part, by messenger RNA (mRNA)-binding proteins that control the stability of Ptgs2 mRNA. We used a precise system of colonic injury and repair to identify Ptgs2 mRNA-binding proteins.
METHODS
We used endoscopy-guided mucosal excision to create focal injury sites in colons of mice. Wound beds from wild-type, Ptgs2−/−, Ptgs2+/-, and Myd88−/− mice were analyzed at 2-day intervals after injury for aspects of repair and Ptgs2 expression. We used cultured colonic mesenchymal stem cells (cMSCs) that express Ptgs2 to identify and analyze molecules that regulate Ptgs2 expression.
RESULTS
Ptgs2−/− mice had defects in wound repair, validating the biopsy technique as a system to study the regulation of Ptgs2. Ptgs2+/- mice had similar defects in wound healing, so full induction of Ptgs2 is required for wound repair. In wild-type mice, levels of Ptgs2 mRNA increased significantly in the wound bed 2 and 4 days after injury; the highest levels of Ptgs2 were observed in cMSCs. In a functional short hairpin RNA knockdown screen, we identified Igf2bp1, a VICKZ (Vg1 RNA binding protein, Insulin-like growth factor II mRNA binding protein 1, Coding region determinant-binding protein, KH domain containing protein overexpressed in cancer, and Zipcode-binding protein-1) mRNA-binding protein, as a regulator of Ptgs2 expression in cMSCs. Igf2bp1 also interacted physically with Ptgs2 mRNA. Igf2bp1 expression was induced exclusively in wound-bed cMSCs, and full induction of Ptgs2 and Igf2bp1 during repair required Myd88.
CONCLUSIONS
We identified Igf2bp1 as a regulator of Ptgs2 mRNA in mice. Igf2bp1 is required for full induction of Ptgs2 mRNA in cMSCs.
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