scholarly journals Biogenic Synthesis of Novel Functionalized Selenium Nanoparticles by Lactobacillus casei ATCC 393 and Its Protective Effects on Intestinal Barrier Dysfunction Caused by Enterotoxigenic Escherichia coli K88

2018 ◽  
Vol 9 ◽  
Author(s):  
Chunlan Xu ◽  
Yu Guo ◽  
Lei Qiao ◽  
Li Ma ◽  
Yiyi Cheng ◽  
...  
2020 ◽  
Vol 11 (4) ◽  
pp. 3020-3031 ◽  
Author(s):  
Lei Qiao ◽  
Xina Dou ◽  
Shuqi Yan ◽  
Baohua Zhang ◽  
Chunlan Xu

Biogenic SeNPs synthesized by Lactobacillus casei ATCC 393 reversed diquat-induced oxidative damage to the epithelium by activating the Nrf2 signaling pathway.


Author(s):  
Yue Chen ◽  
Lei Qiao ◽  
Xiaofan Song ◽  
Li Ma ◽  
Xina Dou ◽  
...  

Composite microecological agents have received widespread attention due to their advantageous properties, including safety, multi-effects, and low cost. This study was conducted to evaluate the protective effects of selenium (Se) nanoparticle-enriched Lactococcus lactis NZ9000 ( L. lactis NZ9000-SeNPs) against enterotoxigenic Escherichia coli K88 (ETEC K88)-induced intestinal barrier damage in C57BL/6 mice. Oral administration of L. lactis NZ9000-SeNPs significantly increased the villi height and the number of goblet cells in the ileum, and reduced the levels of serum and ileal interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ), and increased the activities of thioredoxin reductase (TrxR) and glutathione peroxidase (GSH-Px) compared with the ETEC K88-infected group not treated with L. lactis NZ9000-SeNPs. In addition, L. lactis NZ9000-SeNPs significantly attenuated the reduction of the expression levels of occludin and claudin-1, dysbiosis of the gut microbiome, and the activation of toll-like receptor (TLR)/nuclear factor-kappa (NF-κB)-mediated signaling pathway induced by ETEC K88. These findings suggested that L. lactis NZ9000-SeNPs may be a promising and safe Se supplement for food or feed additives. Importance The beneficial effects of microecological agents have been widely proven. Se, which is nutritionally essential trace element for human and animals, is incorporated into selenoproteins that have a wide range of pleiotropic effects, ranging from antioxidant and anti-inflammatory effects. However, the sodium selenite, a common addition form of Se in feed and food, has disadvantages such as strong toxicity and low bioavailability. We investigated the protective effects of L. lactis NZ9000-SeNPs against ETEC K88-induced intestinal barrier injury in C57BL/6 mice. Our results show that L. lactis NZ9000-SeNPs effectively alleviate ETEC-K88-induced intestinal barrier dysfunction. This study highlights the importance of developing a promising and safe Se supplement for the substation of sodium selenite applied in food, feed and biomedicine.


2018 ◽  
Vol 45 (1) ◽  
pp. 343-355 ◽  
Author(s):  
Zhihua Liu ◽  
Yinghai Tian ◽  
Yanqiong Jiang ◽  
Shihua Chen ◽  
Ting Liu ◽  
...  

Background/Aims: Let-7b was dramatically reduced after a dicer knockout of mice with intestinal barrier function injuries. This paper aims to investigate the molecular mechanism of let-7b by targeting p38 MAPK in preventing intestinal barrier dysfunction. Methods: A total of 186 patients were enrolled, with 93 in the control group and 93 in the PRO group. Only 158 patients completed the entire study, whereas the others either did not meet the inclusion criteria or refused to participate. To further verify the role of let-7b, intestinal epithelial conditional knockout (IKO) mice of mmu-let-7b model were established. Serum let-7b, zonulin, IL-6, and TNF-α concentrations were measured by ELISA or quantitative RT-PCR. Permeability assay was done by ussing chamber. The apoptotic cells were identified using an In Situ Cell Death Detection Kit. Protein was detected by western blot. Results: Probiotics can lower infection-related complications, as well as increase the serum and tissue let-7b levels. P38 MAPK was identified as the target of let-7b, as verified by NCM460 cells. P38 MAPK expression was increased, whereas tight-junction (TJ) proteins were significantly decreased in let-7b IKO mice (both P<0.05). Negative regulation of p38 MAPK molecular signaling pathways was involved in the protective effects of let-7b on intestinal barrier function. Conclusion: Let-7b was identified as a novel diagnosis biomarker or a potential treatment target for preventing intestinal barrier dysfunction.


2020 ◽  
Vol 48 (01) ◽  
pp. 127-142 ◽  
Author(s):  
Jing Wu ◽  
Cheng-Lin Yang ◽  
Yuan-Kun Sha ◽  
Yong Wu ◽  
Zhao-Ying Liu ◽  
...  

Gelsemium elegans Benth. (G. elegans), a traditional Chinese medicine, has great potential as an effective growth promoter in animals, however, the mechanism of its actin remains unclear. Here, we evaluated the protective effects of koumine extract from G. elegans against lipopolysaccharide (LPS)-induced intestinal barrier dysfunction in IPEC-J2 cells through alleviation of inflammation and oxidative stress. MTT and LDH assays revealed that koumine significantly reduced LPS cytotoxicity. Transepithelial electrical resistance (TEER) and cell monolayer permeability assays showed that koumine treatment attenuated the LPS-induced intestinal barrier dysfunction with no particularly different effects in tight junction proteins such as ZO-1, claudin-1, and occludin. LPS-triggered inflammatory response was also suppressed by koumine, as evidenced by the downregulated inflammatory factors, including TNF-[Formula: see text], IL-6, IL-1[Formula: see text], NO, iNOS, and COX-2, which was closely connected with the inhibition of NF-[Formula: see text]B pathway for the decrease of phosphorylation of I[Formula: see text]B[Formula: see text] and NF-[Formula: see text]B and nuclear translocation of p-p65. Amount of reactive oxygen species (ROS) and MDA induced by LPS was also reduced by koumine through activation of Nrf2 pathway, and increased in the levels of Nrf2 and HO-1 degradation of keap-1 to promote anti-oxidants, including superoxide dismutase (SOD) and catalase (CAT). To summarize, koumine-reduced the oxidative stress and inflammatory reaction triggered by LPS through regulation of the Nrf2/NF-[Formula: see text]B signaling pathway and preventing intestinal barrier dysfunction.


2009 ◽  
Vol 297 (3) ◽  
pp. G471-G479 ◽  
Author(s):  
Jessica A. Clark ◽  
Heng Gan ◽  
Alexandr J. Samocha ◽  
Amy C. Fox ◽  
Timothy G. Buchman ◽  
...  

Systemic administration of epidermal growth factor (EGF) decreases mortality in a murine model of septic peritonitis. Although EGF can have direct healing effects on the intestinal mucosa, it is unknown whether the benefits of systemic EGF in peritonitis are mediated through the intestine. Here, we demonstrate that enterocyte-specific overexpression of EGF is sufficient to prevent intestinal barrier dysfunction and improve survival in peritonitis. Transgenic FVB/N mice that overexpress EGF exclusively in enterocytes ( IFABP-EGF) and wild-type (WT) mice were subjected to either sham laparotomy or cecal ligation and puncture (CLP). Intestinal permeability, expression of the tight junction proteins claudins-1, -2, -3, -4, -5, -7, and -8, occludin, and zonula occludens-1; villus length; intestinal epithelial proliferation; and epithelial apoptosis were evaluated. A separate cohort of mice was followed for survival. Peritonitis induced a threefold increase in intestinal permeability in WT mice. This was associated with increased claudin-2 expression and a change in subcellular localization. Permeability decreased to basal levels in IFABP-EGF septic mice, and claudin-2 expression and localization were similar to those of sham animals. Claudin-4 expression was decreased following CLP but was not different between WT septic mice and IFABP-EGF septic mice. Peritonitis-induced decreases in villus length and proliferation and increases in apoptosis seen in WT septic mice did not occur in IFABP-EGF septic mice. IFABP-EGF mice had improved 7-day mortality compared with WT septic mice (6% vs. 64%). Since enterocyte-specific overexpression of EGF is sufficient to prevent peritonitis-induced intestinal barrier dysfunction and confers a survival advantage, the protective effects of systemic EGF in septic peritonitis appear to be mediated in an intestine-specific fashion.


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