Intake of semi-refined carrageenan causes low-grade colonic inflammation and alters expression of epithelial-mesenchymal transition markers

Abstract

The aim of this research was to evaluate the effects of semi-refined carrageenan consumed orally on the amount of CD3 and CD68 positive cells residing in the colon and the expression of endothelial-mesenchymal transition (EMT) markers. Materials and methods. To assess colonic expression of CD3+, CD68+, fascin, vimentin and E-cadherin, sections obtained from 8 rats orally exposed to semi-refined carrageenan (E407a) at a dose of 140 mg / kg of weight during 14 consecutive days and 8 control animals were immunostained with the corresponding antibodies. Levels of expression were assessed quantitatively. Results. Oral exposure to semi-refined carrageenan resulted in an increase in CD3 and CD68 positive cells in the colonic lamina propria. Quantitative analysis of fascin, vimentin and E-cadherin immunostaining revealed changes in expression of these EMT markers both in the colonic stroma and epithelial cells. Vimentin and fascin were overexpressed in stromal and epithelial cells, while E-cadherin was upregulated in the stroma and downregulated in epithelia. Conclusions. Our observations suggest that oral intake of semi-refined carrageenan results in the development of low-grade colonic inflammation accompanied by infiltration with CD3 and CD68 positive cells and changes in the expression of EMT markers.