Anti-colitis effect of Lactobacillus sakei K040706 in the dextran sulfate sodium-induced colitis mice model via inhibition of inflammatory responses

다국어 초록 (Multilingual Abstract)

Lactobacillus sakei K040706 (K040706) has been accepted as the most populous lactic acid bacteria (LAB) in over ripened doenjang, known as traditional Korean food. Recently, we reported the immunostimulatory effects of K040706 in macrophages and in a cyclophosphamide-induced mouse model. In this study, we investigated the ameliorative effects of K040706 in a dextran sulfate sodium (DSS)-induced colitis mice. K040706 significantly attenuated DSS-induced disease activity index (DAI), shortening of colon length, and enlargement of spleen. Histological examinations indicated that K040706 suppressed edema, mucosal damage, and the loss of crypts induced by DSS. These results were well correlated with the restoration of tight junction protein expression, such as, claudin1, zonula occludens-1 (ZO-1) and occludin in K040706-treated group. K040706 significantly reduced immune cell infiltration and the expression of intracellular adhesion molecule intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in colonic tissues. Moreover, K040706 reduced the abnormal secretions and mRNA expressions of pro-inflammatory mediators, such as nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). K040706 suppressed the activation of nuclear factor-κB (NF-κB) and signal transducer and activator of transcription 3 (STAT3) and the expression of toll-like receptor 4 (TLR4). Importantly, K040706 improved the intestinal microbiota composition. These results suggest that K040706 has an anti-colitic effect by suppression of intestinal inflammatory responses in DSS-induced colitic mice.

목차 (Table of Contents)

• 1. INTRODUCTION 1
• 2. MATERIAL AND METHODS 4
• 2-1. Chemicals and reagents 4
• 2-2. Experimental animals 4
• 2-3. Induction of colitis 5
• 2-4. Evaluation of disease activity index (DAI) 6
• 2-5. Histopathology 7
• 2-6. Myeloperoxidase assay 8
• 2-7. Western blot analysis 8
• 2-8. Measurement of NO and cytokines 9
• 2-9. Quantitative real-time reverse-transcriptase polymerase chain reaction (qRT-PCR) 10
• 2-10. DNA extraction and emulsion-based PCR (emPCR) 12
• 2-11. Next Generation Sequencing using Roche 454 GS-FLX plus. 13
• 2-12. Selection of 16S rRNAs and taxonomic assignment 13
• 2-13. Operational taxonomic unit (OTU) analysis for community richness 14
• 2-14. Statistical analysis 14
• 3. RESULTS 15
• 3-1. K040706 attenuated colitis severity, colon shortening, and spleen enlargement in DSS-induced acute colitis model 15
• 3-2. K040706 decreased colon tissue injury and restored epithelial barrier protein expression in mice with DSS-induced colitis 18
• 3-3. K040706 decreased MPO activity and expression of ICAM-1 and VCAM-1 in DSS-induced colon tissue 20
• 3-4. K040706 inhibited nitric oxide (NO) production and iNOS expression in mice with DSS-induced colitis 22
• 3-5. K040706 reduced the production and mRNA expression of inflammatory cytokines in DSS-induced colitis 24
• 3-6. K040706 inhibited the activation of NF-κB and STAT3 and the expression of TLR4 in DSS-induced colitis 26
• 3-7. Effect of K040706 on the microbiota composition in DSS-induced colitis 28
• 4. DISCUSSION 31
• 5. REFERENCES 38