MRP2 by oxidative stress in caco-2 cells: im pact on their barrier function and prevention by adenosine.

LAURA RICARDI; FELIPE ZECCHINATI; MAITE ROCÍO ARANA; VIRGINIA GABRIELA PERDOMO; ALDO DOMINGO MOTTINO; FABIANA GARCÍA; SILVINA STELLA MARIS VILLANUEVA

Mar del Plata

Congreso; REUNIÓN CONJUNTA SAIC SAI&FAIC SAFIS 2022; 2022

Oxidative stress (OS) produced by continuous exposure to dietarycontaminants, is a key factor in the development of gastrointestinaldisorders, in which the intestinal barrier is altered. Its effect onMRP2, an essential component of the intestinal transcellular barrierin the detoxification and disposition of environmental and food toxicants,and therapeutic drugs, has been recently evaluated. Longtermexposure to OS of Caco-2 cells, a model of human intestinal epithelium, by treatment with tert-butyl hydroperoxide (TBH) for 24h, showed proteosomal degradation of the MRP2 protein. In turn,adenosine plays an important physiological role in the CNS and inperipheral tissues, and its activity is related to the effect of variousdrugs. We previously demonstrated a positive acute effect of adenosineon MRP2, consisting of an increase in its apical localization,associated with greater activity barrier. The aim of this workwas to evaluate the impact of post-translational down-regulation ofMRP2 by TBH 250 μM on the efflux MRP2 activity and its potentialprevention by co-treatment of Caco-2 cells with adenosine 50 μM,for 24 h. MRP2 activity was determined by quantifying the efflux ofDNP-SG into the incubation medium by HPLC, using CDNB 100 μMas precursor substrate. Statistical analyses were performed usingone-way ANOVA followed by the post hoc Tukey-test for multiplecomparisons and results expressed as a % difference with respectto control (C). We first confirmed that TBH 250 generated OS asindicated by increased lipid peroxidation end products (+140%) andreduced SOD activity (-29%) (p