Transport of ascorbic acid across Caco-2 cell monolayers and its effects on gene expression by large-scale transcriptional profiling.

摘要

The absorption mechanism of vitamin C (Ascorbic acid, AA) from small intestine and its effects on gene regulation are unknown. An understanding of these mechanisms and effects may facilitate its optimal use in regulating the progression of several disorders including cancer. The objectives of this research are to elucidate the mechanism(s) involved in AA transport across Caco-2 cell monolayers and to determine the important categories of genes affected by AA exposure. The effects of concentration, temperature, pH, glucose, and competitive inhibitors on AA transport (37°C, pH 7.4) were investigated. The changes in gene expression after exposing Caco-2 and RPE monolayers with 1mM AA for 48 hrs were determined by microarray and PCR. AA transport was found to be mediated by SVCT1. An average of 280 of the 8,300 genes analyzed showed altered gene expression profile after ascorbic acid treatment. Majority of these genes were clustered into stress response and metabolism.