Lactobacillus rhamnosus CY12 Enhances Intestinal Barrier Function by Regulating Tight Junction Protein Expression, Oxidative Stress, and Inflammation Response in Lipopolysaccharide-Induced Caco-2 Cells

Abstract

The intestinal barrier is vital for preventing inflammatory bowel disease (IBD). The objectives of this study were to assess whether the Lactobacillus rhamnosus CY12 could alleviate oxidative stress, inflammation, and the disruption of tight junction (TJ) barrier functions induced by lipopolysaccharide (LPS), and therefore to explore the potential underlying molecular mechanisms. Our results showed that LPS-induced Cancer coli-2 (Caco-2) cells significantly increased the levels of reactive oxygen species (ROS), lactate dehydrogenase, inflammatory cytokines interleukin-1β, interleukin-6, interleukin-8, and tumor necrosis factor-α (IL-1β, IL-6, IL-8, and TNF-α), and the cell apoptosis rate while decreasing the levels of TJ proteins occludin, zonula occludens-1 (ZO-1), and claudin and antioxidant enzymes, such as catalase, superoxide dismutase, and glutathione peroxidase(CAT, SOD, and GSH-Px) (p < 0.05). However, Lactobacillus rhamnosus CY12 could relieve cytotoxicity, apoptosis, oxidative stress, and pro-inflammatory cytokine expressions, and also inhibit the Toll-like receptor 4/ nuclear factor kappa-B(TLR4/NF-κB) signaling pathway. Furthermore, the gene expression of antioxidant enzymes, as well as the mRNA and protein expressions of TJ proteins, was improved. Particularly, the concentration of 108 cfu/mL significantly prevented the inflammatory injury induced by LPS in Caco-2 cells (p < 0.05). These findings support a potential application of Lactobacillus rhamnosus CY12 as a probiotic to prevent LPS-induced intestinal injury and treat intestinal barrier dysfunction.

Exposure to Polypropylene Microplastics via Oral Ingestion Induces Colonic Apoptosis and Intestinal Barrier Damage through Oxidative Stress and Inflammation in Mice

“…Therefore, our results show that PP-MP exposure affects ion transport in the intestinal tract of mice. This is suggestive of damage to the intestinal barrier and mucus layer, which may cause pathogens and other harmful substances to enter blood circulation through the intestinal wall [ 103 , 104 , 105 ]. PP particles likely enter intestinal epithelial cells through the damaged intestinal barrier and deposit in the cells.…”

Orally Administered Lactobacillus rhamnosus CY12 Alleviates DSS-Induced Colitis in Mice by Restoring the Intestinal Barrier and Inhibiting the TLR4-MyD88-NF-κB Pathway via Intestinal Microbiota Modulation

“…This was achieved by increasing the expression of TJ proteins, reducing the accumulation of ROS, and inhibiting the excessive production of inflammatory cytokines that activate the TLR4/NF-κB pathway. 24 These outcomes suggest that LCY12 administration may block the TLR4/MyD88/NF-κB pathway by lowering the levels of TLR4 and MyD88, deactivating phosphorylated IκBα, and hindering the translocation of NF-κB p65 from the cytoplasm to the nucleus. LCY12 Administration Enhanced Microbial Diversity in DSS-Induced Mice.…”

“…The extraction, integrity detection, cDNA synthesis, and qPCR analysis of total RNA in colon were based on our previous study. 24 The expression levels of the candidate gene was calculated using 2 −ΔΔCT method that involved normalizing with β-actin. 27 The specific PCR primers used for amplifying the target genes are detailed in Table S2.…”

“…The protein expression analysis was conducted as previous described. 28−30 The GAPDH, ZO-1, occludin, claudin, p65, and TLR4 were diluted following our previous study, 24 and other antibodies used were listed as follows: β-actin (Cat# ab8226, abcam, 1:100), IkB-α (Cat# ab32518, abcam, 1:50), and Myeloid differentiation factor 88 (MyD88, Cat# ab276131, abcam, 1:25).…”

“…The LCY12 strain was isolated from cattle-yak milk and inoculated in MRS at 37 °C overnight. The cells was centrifuged and washed similar to our previous study, 24 Based on our previous study, for the animal test, the pellet was diluted with sterile PBS to a concentration of 1 × 10 8 , 1 × 10 9 , and 1 × 10 10 cfu/mL, before being administered to mice through oral gavage. 24 Animals and Experimental Design.…”