LBP gene methylation involved in mRNA expression and resistance to E. coli F18 in weaned piglets

Lipopolysaccharide binding protein (LBP) plays an important role in recognizing and regulating endotoxin. In this study, we aimed at clarifying the relationship between the methylation of LBP gene and it's expression, to identify mechanisms involved in resistance to E. coli F18 in Sutai weaned piglets. LBP expression was detected by real-time PCR in duodenum and jejunum tissues from E. coli F18-sensitive or -resistant piglets. The LBP methylation status of the regions with many CG sites upstream of the transcription start site was analyzed by Bbisulfite Sequencing PCR (BSP) +Miseq in jejunum and duodenum tissue. The results showed that LBP expression was significantly higher in the sensitive group than the resistant group in duodenum tissue (p<0.05). There was a negative correlation between the methylation of CpG islands upstream of the LBP transcription start site and its expression; the methylation at two CpG sites in particular was significantly correlated with reduced LBP expression (CpG-1 and CpG-2; p<0.05 and p<0.01, respectively). These indicated that the methylation of CpG-1 and CpG-2 sites in the LBP region is involved in the regulation of LBP expression, and may provide key contributions to resisting E. coli F18 in Sutai weaned piglets.