Fig. 6

The effects of butyrate on histone acetylation and MCP-1 inhibition were reversible. Cells were given butyrate for 24 hr 14 days after plating. Cells received IL-1β either immediately after butyrate had been removed from the culture media (day 1), or 2 days (day 3) and 6 days later (day 7). MCP-1 mRNA and MCP-1 secretion were measured 2 hr and 24 hr after IL-1β. Results were compared with cells that received no butyrate (control). Histone acetylation was examined at each time point at which IL-1β was given. Butyrate inhibited the expression of MCP-1, as previously shown. However, this effect was reversed by day 3, 2 days after butyrate had been removed. This change was concurrent with the loss of acetylation of histone-4. The effects of butyrate on histone acetylation and MCP-1 production in Caco-2 cells were, therefore, reversible. Bars represent standard deviations of three different wells for each point. The data are representative of three experiments.