Effects of Lipoteichoic Acid from <i>Lactobacillus plantarum</i> on Inflammatory Bowel Disease in Mice and Its Mechanism(植物乳杆菌脂磷壁酸对小鼠肠炎的作用及其机制)
摘要
To clarify the effect of lipoteichoic acid produced by <i>Lactobacillus plantarum</i> on enteritis, lipoteichoic acid from a probiotic <i>Lactobacillus plantarum</i> GSLP-7 was extracted, and gavaged to mice with enteritis. The intestinal tissue damage of mice, level of serum cytokines, activity of myeloperoxidase (MPO) and antioxidants, content of short-chain fatty acids in feces, and protein expression levels related to immune signaling pathways were examined. The results showed that lipoteichoic acid could effectively relieve intestinal inflammation, and its effect was better than that of probiotic <i>Lactobacillus plantarum</i> GSLP-7. Compared with the group of mice with enteritis, the lipoteichoic acid intervention significantly reduced the histopathological damage of colon in mice and reduced colonic atrophy by 12.38%. Lipoteichoic acid decreased the content of cytokines TNF-α, IL-1β, IL-6, and IL-12 in serum by 34.97%, 52.47%, 38.59%, and 34.30%, respectively, and increased the content of anti-inflammatory cytokine IL-10 by 24.78% (<i>P</i><0.05). It decreased the tissue MPO and serum MPO activity, and nitric oxide and malondialdehyde content by 27.93%, 23.84%, 29.60%, 35.32% respectively, and increased total superoxide dismutase and glutathione activities by 56.86% and 39.74%. It also increased the total amount of intestinal short-chain fatty acids by 3.92 times to that of the mice with enteritis. These results indicated that intestinal inflammation was relieved by lipoteichoic acid intervention (<i>P</i><0.05). Results of differentially expressed proteins determined by Western-blot showed that lipoteichoic acid inhibitted the expression of key proteins TLR4, MyD88 and MAPK in intestinal epithelial cells and blocked the TLR4-MyD88-MAPK and NF-κB signal pathyway, which might be the possible mechanism of mitigated effect of lipoteichoic acid on enteritis.(为了明确植物乳杆菌脂磷壁酸对肠炎的作用,提取了益生性植物乳杆菌GSLP-7的脂磷壁酸 (lipoteichoic acid, LTA),灌胃肠炎小鼠,检测小鼠肠道组织损伤、血清炎症因子、髓过氧化物酶(myelo