Impaired Solute Transporters and Aquaporins May Trigger Malabsorption in Celiac Disease

Celiac.com 05/12/2010 - Diarrhea, weight loss and malabsorption represent the major clinical presentation of celiac disease, but the exact mechanisms of these symptoms are not fully understood.

A team of researchers recently set out to determine whether celiac disease impairs the function of solute transporters and aquaporins. The research team included U. Laforenza, E. Miceli, G. Gastaldi, M. F. Scaffino, U. Ventura, J. M. Fontana, M. N. Orsenigo, and G. R. Corazza.

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The team looked for possible alteration in the expression and localization of water channels, known as aquaporins, and certain solute transporters in duodenal mucosa of celiac disease patients.

To do this, the team evaluated duodenal biopsies from untreated celiacs, treated celiacs, healthy controls and disease controls.  The team used semi-quantitative RT-PCR and real time RT-PCR to determine the expression of some aquaporins and transporters mRNA in the duodenal biopsies. They relied on immunohistochemistry to evaluate the localization of aquaporin 3, 7 and 10, and of Na+/glucose cotransporter, H+/oligopeptide transporter and Na+/H+ exchanger.

They found that the duodenal biopsies of healthy controls, treated celiac patients and disease controls expressed aquaporin 3, 7, 10, 11, Na+/glucose cotransporter, H+/oligopeptide transporter and Na+/H+ exchanger, cystic fibrosis transmembrane conductance regulator and Na-K-2Cl cotransporter mRNAs.

Transcript expression was largely absent in the duodenal biopsies of untreated celiac disease patients, except for cystic fibrosis transmembrane conductance regulator and Na-K-2Cl cotransporter.

Immunohistochemistry of healthy control subjects showed a labeling in the apical membrane of surface epithelial cells of duodenum. Immunolabeling was heavily reduced or absent in untreated celiac patients, but normal patients who had followed a gluten free diet for at least 1 year.

The results of the study show that people with celiac disease have defects in their primary pathways for water and solute absorption that may play a role in the onset of malabsorption symptoms.

Source:

• Open Original Shared Link 2010 Apr 26.