IL-22 promotes the formation of a MUC17 glycocalyx barrier in the postnatal small intestine during weaning.

Layunta E, Jäverfelt S, Dolan B, Arike L, Pelaseyed T

Cell Rep 34 (7) 108757 [2021-02-16; online 2021-02-18]

The intestine is under constant exposure to chemicals, antigens, and microorganisms from the external environment. Apical aspects of transporting epithelial cells (enterocytes) form a brush-border membrane (BBM), shaped by packed microvilli coated with a dense glycocalyx. We present evidence showing that the glycocalyx forms an epithelial barrier that prevents exogenous molecules and live bacteria from gaining access to BBM. We use a multi-omics approach to investigate the function and regulation of membrane mucins exposed on the BBM during postnatal development of the mouse small intestine. Muc17 is identified as a major membrane mucin in the glycocalyx that is specifically upregulated by IL-22 as part of an epithelial defense repertoire during weaning. High levels of IL-22 at time of weaning reprogram neonatal postmitotic progenitor enterocytes to differentiate into Muc17-expressing enterocytes, as found in the adult intestine during homeostasis. Our findings propose a role for Muc17 in epithelial barrier function in the small intestine.

Integrated Microscopy Technologies Gothenburg [Service]

PubMed 33596425

DOI 10.1016/j.celrep.2021.108757

Crossref 10.1016/j.celrep.2021.108757

pii: S2211-1247(21)00070-X