Pass the bicarb: the importance of HCO3– for mucin release
Robert C. De Lisle
Robert C. De Lisle
Published August 24, 2009
Citation Information: J Clin Invest. 2009;119(9):2535-2537. https://doi.org/10.1172/JCI40598.
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Commentary

Pass the bicarb: the importance of HCO3– for mucin release

Abstract

Accumulation of thick, sticky mucus is a hallmark of the genetic disease cystic fibrosis (CF) and has a central role in CF pathophysiology. Mutations in the CF transmembrane regulator (CFTR) ion channel are known to result in abnormally thick and sticky mucus; however, why mucus accumulates in CF is still not completely understood. In this issue of the JCI, Garcia and colleagues show that mucin — the heavily glycosylated protein contained within mucus — requires CFTR and bicarbonate in order to be released from mouse intestine (see the related article beginning on page 2613). The authors propose a model whereby CFTR-mediated bicarbonate secretion must be concurrent with mucin exocytosis for proper mucin release.

Authors

Robert C. De Lisle

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Figure 1

Mucus accumulates in the Cftr-knockout mouse (a model of CF) small intestine.

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Mucus accumulates in the Cftr-knockout mouse (a model of CF) small intes...
Intestinal tissue was fixed in Carnoy’s solution, and mucus was stained with PAS base plus Alcian blue, pH 2.5, as described in ref. 5. In contrast with what occurs in wild-type animals, mucus released from goblet cells (arrows) in CF mice accumulates in the crypt lumen and along the villous surfaces (*).