Sargassum polysaccharide inhibits inflammatory response in PCV2 infected-RAW264.7 cells by regulating histone acetylation.

Toxic inflammatory response is frequently introduced upon virus infection. In this study, RAW264.7 cells were infected with porcine circovirus type 2 (PCV2) and treated with Sargassum polysaccharide SP. It was found that PCV2 infection induced increased significant inflammation response represented with increased secretion of inflammatory cytokines, corresponding with promoted HAT activity, inhibited HDAC activity, elevated HDAC1 mRNA levels, and up-regulated acetylation levels of H3 and H4 in RAW264.7 cells. SP treatment significantly inhibited the increase of inflammatory cytokines, HAT activity and the acetylation of histones, but dramatically increased the HDAC activity and the expression of HDAC1. From these results, SP might be able to protect immune cells from virus induced damages through inhibiting the inflammatory responds by maintaining an equilibrium between the activity of HATs and HDACs which contributes to an appropriate level of histone acetylation.