Changes in redox network expression during Caco-2 cell differentiation into enterocytes

Abstract

Objective: This work characterized fluctuations in cell components involved in the regulation of cell redox homeostasis during Caco-2 cell differentiation into enterocytes. Methods: Caco-2 cells were differentiated for 10 days. Gene expression of NADPH oxidases; enzymes that metabolize superoxide anion and hydrogen peroxide, proteins involved in the production and/or regeneration of glutathione, thioredoxin, and in NADPH production, and NRF2-dependent genes were measured by qPCR at 0, 1, 4, 7, and 10 days post-confluence. Results: NADPH oxidase 1 mRNA levels decreased with Caco-2 cell differentiation, in agreement with its role in regulating cell proliferation. NADPH oxidase 4, DUOX2, superoxide dismutase 1, and catalase mRNA levels increased with differentiation. NRF2 mRNA levels increased with differentiation up to day 4 post-confluence, reaching a plateau until day 10. A similar pattern was observed for the NRF2-regulated genes: NAD(P)H quinone dehydrogenase 1, glutathione reductase 1, and thioredoxin reductase 1. On the contrary, glutamate-cysteine ligase catalytic subunit mRNA levels decreased after reaching a maximum 4 days post-confluence. This and the finding of a correlation between glutathione reductase 1 and thioredoxin reductase 1 mRNA levels suggest that recycling of glutathione and thioredoxin is more relevant than their synthesis during Caco-2 cell differentiation. Conclusion: Results support the relevance of redox homeostasis for cell fate decisions and in preparing enterocytes to interact with their environment. Significance statement Current findings resemble changes in redox components previously characterized in vivo. This stresses the concept that Caco-2 cells are an appropriate model to be used to evaluate redox-regulated mechanisms in human enterocytes.

Keywords

• caco-2 cell differentiation
• intestine
• nadph oxidases
• nrf2
• signaling