Investigating the effect of food on the gene expression of intestinal cells

07 Feb 2011

A team from The Netherlands have validated a set of normalization genes for quantitative RT-PCR in differentiated Caco-2 cells and used them to detect changes in gene expression upon exposure to apple, tomato, broccoli and mushroom.

Fruit and vegetables are considered a healthy food choice and many potential health promoting compounds have been identified. However, fruit and vegetables are complex products with a wide variety of compounds; therefore, a tool is required which analyses the potential bioactivity of whole foods or food products rather than the mechanisms of a single bioactive compound. This paper describes the development of such a tool by Robert Vreeburg and co-workers from the Wageningen University and Research centre.

Intestinal cells are exposed to food we consume and it has been shown that their functions can be modulated by food compounds. Furthermore, in vitro cell lines (such as the human, colon derived Caco-2 culture) can mimic these responses. The most versatile readout for detecting responses of cells is to measure changes in mRNA abundance; this gives a snapshot of the gene expression of a cell. Changes in mRNA are detected using a technique called quantitative reverse transcriptase polymerase chain reaction (RT-qPCR) which requires a set of normalisation genes whose expression will not change upon exposure to food.

This study identifies a set of reference genes suitable for RT-qPCR use in food exposure studies with the intestinal-like Caco-2 cell line. The reference genes are validated by exposing the Caco-2 cell line to homogenates of apple, tomato, broccoli and mushroom. These food homogenates provoked gene expression changes in the cell line thus showing that natural food homogenates can exert effects in Caco-2 cells, and that the stability in expression of the reference genes is not due to a lack of response of the Caco-2 cells.

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