Modification of tight junction structure and permeability by nutritional means.

Lankenau Institute for Medical Research, Princeton University, Wynnewood, PA 19096, USA.
Annals of the New York Academy of Sciences (Impact Factor: 4.38). 06/2009; 1165:99-112. DOI: 10.1111/j.1749-6632.2009.04028.x
Source: PubMed

ABSTRACT The relative abundance of various claudin proteins of LLC-PK(1) renal epithelial tight junctions (TJs) is modulated by culturing the cells in a medium that is sharply reduced in the sulfur-containing amino acids, cysteine, cystine, and methionine. The functional result is an epithelial barrier that has a higher transepithelial electrical resistance and a decreased paracellular leak to D-mannitol (i.e., improved barrier function). This is accomplished without affecting the culture's confluent cell density, its short circuit current, or its hallmark differentiated property, Na(+)-dependent sugar transport. The implications of being able to enhance epithelial TJ barrier function by nutritional means are discussed, particularly in light of the ability of methionine-restrictive diets to enhance life span and forestall age-related morbidity.

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