scholarly journals Beneficial effect of probiotics on Pseudomonas aeruginosa–infected intestinal epithelial cells through inflammatory IL-8 and antimicrobial peptide human beta-defensin-2 modulation

2020 ◽  
Vol 26 (7) ◽  
pp. 592-600
Author(s):  
Fu-Chen Huang ◽  
Yi-Ting Lu ◽  
Yu-Hsuan Liao
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Epithelial Cells ◽  
Protein Expression ◽  
Intestinal Epithelial Cells ◽  
Receptor Protein ◽  
Supporting Evidence ◽  
Clinical Effects ◽  
Intestinal Epithelial ◽  
Antibiotic Overuse ◽  
Probiotic Treatment

The human pathogen Pseudomonas aeruginosa can rapidly induce fatal sepsis, even in previously healthy infants or children treated with appropriate antibiotics. To reduce antibiotic overuse, exploring novel complementary therapies, such as probiotics that reportedly protect patients against P. aeruginosa infection, would be particularly beneficial. However, the major mechanism underlying the clinical effects is not completely understood. We thus aimed to investigate how probiotics affect IL-8 and human beta-defensin 2 (hBD-2) in P. aeruginosa–infected intestinal epithelial cells (IECs). We infected SW480 IECs with wild type PAO1 P. aeruginosa following probiotic treatment with Lactobacillus rhamnosus GG or Bifidobacterium longum spp. infantis S12, and analysed the mRNA expression and secreted protein of IL-8 and hBD-2, Akt signalling and NOD1 receptor protein expression. We observed that probiotics enhanced hBD-2 expression but suppressed IL-8 responses when administered before infection. They also enhanced P. aeruginosa–induced membranous NOD1 protein expression and Akt activation. The siRNA-mediated Akt or NOD1 knockdown counteracted P. aeruginosa–induced IL-8 or hBD-2 expression, indicating regulatory effects of these probiotics. In conclusion, these data suggest that probiotics exert reciprocal regulation of inflammation and antimicrobial peptides in P. aeruginosa–infected IECs and provide supporting evidence for applying probiotics to reduce antibiotic overuse.

scholarly journals Interferon-γ inhibits sirtuin 6 gene expression in intestinal epithelial cells through a microRNA-92b-dependent mechanism

2020 ◽  
Vol 318 (4) ◽  
pp. C732-C739
Author(s):  
Fangyi Liu ◽  
Xiao Wang ◽  
Hua Geng ◽  
Heng-Fu Bu ◽  
Peng Wang ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Protein Expression ◽  
Intestinal Epithelial Cells ◽  
Specific Inhibitor ◽  
In Silico Analysis ◽  
Interferon Γ ◽  
Luciferase Assay ◽  
Epithelial Cell Line ◽  
Dependent Manner ◽  
Intestinal Epithelial

Sirtuin 6 (Sirt6) is predominantly expressed in epithelial cells in intestinal crypts. It plays an important role in protecting intestinal epithelial cells against inflammatory injury. Previously, we found that colitis is associated with the downregulation of Sirt6 protein in the intestines. Here, we report that murine interferon-γ (Ifnγ) inhibits Sirt6 protein but not mRNA expression in young adult mouse colonocytes (YAMC, a mouse colonic epithelial cell line) in a dose- and time-dependent manner. Using microRNA array analysis, we showed that Ifnγ induces expression of miR-92b in YAMC cells. With in silico analysis, we found that the Sirt6 3′-untranslated region (UTR) contains a putative binding site for miR-92b. Luciferase assay showed that Ifnγ inhibited Sirt6 3′-UTR activity and this effect was mimicked by miR-92b via directly targeting the miR-92b seed site in the 3′-UTR of Sirt6 mRNA. Furthermore, Western blot demonstrated that miR-92b downregulated Sirt6 protein expression in YAMC cells. Blocking miR-92b with a specific inhibitor attenuated the inhibitory effect of Ifnγ on Sirt6 protein expression in the cells. Collectively, our data suggest that Ifnγ inhibits Sirt6 protein expression in intestinal epithelial cells via a miR-92b-mediated mechanism. miR-92b may be a novel therapeutic target for rescuing Sirt6 protein levels in intestinal epithelial cells, thereby protecting against intestinal mucosal injury caused by inflammation.

LPA protects intestinal epithelial cells from apoptosis by inhibiting the mitochondrial pathway

2003 ◽  
Vol 284 (5) ◽  
pp. G821-G829 ◽  
Author(s):  
Wenlin Deng ◽  
De-An Wang ◽  
Elvira Gosmanova ◽  
Leonard R. Johnson ◽  
Gabor Tigyi
Keyword(s):  
Epithelial Cells ◽  
Cytochrome C ◽  
Protein Expression ◽  
Caspase 3 ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Apoptotic Pathway ◽  
Antiapoptotic Activity

We previously showed ( Gastroenterology 123: 206–216, 2002) that lysophosphatidic acid (LPA) protects and rescues rat intestinal epithelial cells (IEC-6) from apoptosis. Here, we provide evidence for the LPA-elicited inhibition of the mitochondrial apoptotic pathway leading to attenuation of caspase-3 activation. Pretreatment of IEC-6 cells with LPA inhibited campothecin-induced caspase-9 and caspase-3 activation and DNA fragmentation. A caspase-9 inhibitor peptide mimicked the LPA-elicited antiapoptotic activity. LPA elicited ERK1/ERK2 and PKB/Akt phosphorylation. The LPA-elicited antiapoptotic activity and inhibition of caspase-9 activity were abrogated by pertussis toxin, PD 98059, wortmannin, and LY 294002. LPA reduced cytochrome c release from mitochondria and prevented activation of caspase-9. LPA prevented translocation of Bax from cytosol to mitochondria and increased the expression of the antiapoptotic Bcl-2 mRNA and protein. LPA had no effect on Bcl-xl, Bad, and Bak mRNA or protein expression. These data indicate that LPA protects IEC-6 cells from camptothecin-induced apoptosis through Gi-coupled inhibition of caspase-3 activation mediated by the attenuation of caspase-9 activation due to diminished cytochrome c release, involving upregulation of Bcl-2 protein expression and prevention of Bax translocation.

Soluble factors fromLactobacillus GGactivate MAPKs and induce cytoprotective heat shock proteins in intestinal epithelial cells

2006 ◽  
Vol 290 (4) ◽  
pp. C1018-C1030 ◽  
Author(s):  
Yun Tao ◽  
Kenneth A. Drabik ◽  
Tonya S. Waypa ◽  
Mark W. Musch ◽  
John C. Alverdy ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Heat Shock ◽  
Epithelial Cells ◽  
Map Kinases ◽  
Intestinal Epithelial Cells ◽  
Oxidant Stress ◽  
Signal Transduction Pathways ◽  
Clinical Effects ◽  
Dependent Manner ◽  
Intestinal Epithelial

Conditioned media from the probiotic Lactobacillus GG (LGG-CM) induce heat shock protein (Hsp) expression in intestinal epithelial cells. LGG-CM induces both Hsp25 and Hsp72 in a time- and concentration-dependent manner. These effects are mediated by a low-molecular-weight peptide that is acid and heat stable. DNA microarray experiments demonstrate that Hsp72 is one of the most highly upregulated genes in response to LGG-CM treatment. Real-time PCR and electrophoretic mobility shift assay confirm that regulation of Hsp induction is at least in part transcriptional in nature, involving heat shock factor-1. Although Hsps are not induced for hours after exposure, transient exposure to LGG-CM is sufficient to initiate the signal for Hsp induction, suggesting that signal transduction pathways may be involved. Experiments confirm that LGG-CM modulates the activity of certain signaling pathways in intestinal epithelial cells by activating MAP kinases. Inhibitors of p38 and JNK block the expression of Hsp72 normally induced by LGG-CM. Functional studies indicate that LGG-CM treatment of gut epithelial cells protects them from oxidant stress, perhaps by preserving cytoskeletal integrity. By inducing the expression of cytoprotective Hsps in gut epithelial cells, and by activating signal transduction pathways, the peptide product(s) secreted by LGG may contribute to the beneficial clinical effects attributed to this probiotic.

Probiotics exert reciprocal effects on autophagy and interleukin-1β expression in Salmonella-infected intestinal epithelial cells via autophagy-related 16L1 protein

2019 ◽  
Vol 10 (8) ◽  
pp. 913-922 ◽  
Author(s):  
W.-T. Lai ◽  
F.-C. Huang
Keyword(s):  
Epithelial Cells ◽  
Protein Expression ◽  
Western Blot ◽  
Inflammatory Responses ◽  
Intestinal Epithelial Cells ◽  
Bifidobacterium Longum ◽  
Lactobacillus Rhamnosus ◽  
Interleukin 1Β ◽  
Intestinal Epithelial ◽  
Serovar Typhimurium

This study aimed to examine how probiotics affect autophagy and interleukin-1β (IL-1β) expression in Salmonella-infected intestinal epithelial cells (IECs). The original Caco-2 cells and ATG16L1 siRNA-transfected Caco-2 cells were pretreated or left untreated with probiotics, including Lactobacillus rhamnosus GG (LGG; ATCC 53103) and Bifidobacterium longum (BL; ATCC15697), and these cells were infected with wild-type Salmonella enterica serovar Typhimurium (S. Typhimurium strain, SL1344). Western blot analysis was used to detect the conversion of microtubule-associated proteins 1A/1B light chain 3B (LC3)-I to LC3-II. Immunofluorescence was used to analyse LC3+ autophagosomes. Membrane proteins were analysed by western blot for protein (ATG16L1, NOD2), and total RNA by RT-PCR for mRNA expression [ATG16L1, vitamin D receptor (VDR)]. We demonstrated that probiotics enhanced both VDR mRNA, and nucleotide-binding oligomerisation domain-containing protein 2 (NOD2) and autophagy-related protein 16-like 1 (ATG16L1) protein expression. The enhanced expression resulted in autophagic LC3-II protein expression and formation of LC3 punctae in Salmonella-infected Caco-2 cells. It was observed that ATG16L1 siRNA could attenuate this mechanism, and ATG16L1-mediated IL-1β expression was suppressed by probiotics. These results suggest that probiotics enhance autophagy and also suppress inflammatory IL-1β expression in Salmonella-infected IECs via membrane ATG16L1 protein expression. Probiotics may enhance autophagic clearance of Salmonella infection and modulate inflammatory responses to protect the hosts. Hence, we can assume that probiotics could treat infectious and autoimmune diseases through mechanisms involving ATG16L1.

Protective effects of baicalin on LPS-induced injury in intestinal epithelial cells and intercellular tight junctions

2015 ◽  
Vol 93 (4) ◽  
pp. 233-237 ◽  
Author(s):  
Jian Chen ◽  
Ren Zhang ◽  
Jian Wang ◽  
Peng Yu ◽  
Quan Liu ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Protein Expression ◽  
Tight Junctions ◽  
Inflammatory Cytokines ◽  
Intestinal Epithelial Cells ◽  
Expression Level ◽  
Protective Effects ◽  
Intestinal Epithelial ◽  
Tnf Α ◽  
Mrna And Protein Expression

Aims: To investigate the protective effects and mechanisms of baicalin on lipopolysaccharide (LPS)-induced injury in intestinal epithelial cells and intercellular tight junctions. Methods: IEC-6 cells were stimulated with LPS (1.0 μg/mL), with or without baicalin, for 24 h. The levels of the inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α were determined using ELISA. Quantitative real-time PCR was used for determining the mRNA expression level of claudin-3, occludin, and ZO-1; Western blot and immunofluorescence analysis were used for analyzing the expression level and the distribution patterns of ZO-1 protein. Results: Pretreatment with baicalin (10.0 μg/mL) improved LPS-stimulated cell viability and repressed IL-6 and TNF-α levels. In addition, pretreatment with baicalin up-regulated mRNA and protein expression levels of ZO-1 and kept the protein intact in IEC-6 cells injured with LPS. Conclusion: Baicalin has the capacity to protect IEC-6 cells and the intercellular tight junctions from LPS-induced injury. The mechanisms may be associated with inhibiting the production of inflammatory cytokines, and up-regulating the mRNA and protein expression of ZO-1.

Effects of preinflammatory cytokines on cell cycle regulatory protein expression in intestinal epithelial cells

2001 ◽  
Vol 120 (5) ◽  
pp. A191
Author(s):  
Gary E. Wild ◽  
Line Dufresne ◽  
Chantal Cossette ◽  
Kevin A. Waschke ◽  
Alan B.R. Thomson
Keyword(s):  
Cell Cycle ◽  
Epithelial Cells ◽  
Protein Expression ◽  
Intestinal Epithelial Cells ◽  
Regulatory Protein ◽  
Intestinal Epithelial ◽  
Cell Cycle Regulatory Protein
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