scholarly journals Initial events in the breakthrough of the epithelial barrier of the small intestine by Angiostrongylus cantonensis

2016 ◽  
Vol 68 (2) ◽  
pp. 375-383
Author(s):  
Ying Long ◽  
Xuri Zhang ◽  
Binbin Cao ◽  
YU. Liang ◽  
Meks Tukayo ◽  
...  

Although the third-stage larvae of Angiostrongylus cantonensis (AcL3) are thought to initiate infection by penetrating the epithelium of the small intestine, the mode of intestinal invasion remains obscure. Considering the inaccessibility of the gut tract and the need to sacrifice animals for this type of study, we devised an in vitro cell-parasite co-culture system to examine the initial cellular and molecular events between AcL3 and host epithelia. No apoptosis augmentation was detected in enterocytes after introduction of larvae. A significant increase in dead cells was detected in IEC-6, NCM460 and 293T after incubating for 4 h, with AcL3 wounding rat small intestinal epithelial cells IEC-6 more rapidly. Under a scanning electron microscope (SEM), cell gap opening was visualized in the IEC-6 monolayer treated with AcL3. Loosening of the extracellular matrix (ECM) of the monolayer was found to be involved in the parasite-cell interactions. Pretreating the AcL3 with a protease inhibitor attenuated its penetration ability of the artificial intestine barrier. In conclusion, AcL3 broke through the intestinal barrier of the host with the assistance of mechanical injury and the opening of a cell gap, but without causing apoptosis. The interaction platform presented here may provide direct insight into the cellular and molecular events during worm invasion of host enterocytes.

2021 ◽  
Vol 14 (3) ◽  
pp. 691-702
Author(s):  
Alzbeta Krausova ◽  
Petra Buresova ◽  
Lenka Sarnova ◽  
Gizem Oyman-Eyrilmez ◽  
Jozef Skarda ◽  
...  

AbstractPlectin, a highly versatile cytolinker protein, provides tissues with mechanical stability through the integration of intermediate filaments (IFs) with cell junctions. Here, we hypothesize that plectin-controlled cytoarchitecture is a critical determinant of the intestinal barrier function and homeostasis. Mice lacking plectin in an intestinal epithelial cell (IEC; PleΔIEC) spontaneously developed colitis characterized by extensive detachment of IECs from the basement membrane (BM), increased intestinal permeability, and inflammatory lesions. Moreover, plectin expression was reduced in the colons of ulcerative colitis (UC) patients and negatively correlated with the severity of colitis. Mechanistically, plectin deficiency in IECs led to aberrant keratin filament (KF) network organization and the formation of dysfunctional hemidesmosomes (HDs) and intercellular junctions. In addition, the hemidesmosomal α6β4 integrin (Itg) receptor showed attenuated association with KFs, and protein profiling revealed prominent downregulation of junctional constituents. Consistent with the effects of plectin loss in the intestinal epithelium, plectin-deficient IECs exhibited remarkably reduced mechanical stability and limited adhesion capacity in vitro. Feeding mice with a low-residue liquid diet that reduced mechanical stress and antibiotic treatment successfully mitigated epithelial damage in the PleΔIEC colon.


PLoS ONE ◽  
2013 ◽  
Vol 8 (8) ◽  
pp. e72084 ◽  
Author(s):  
Rong-Jyh Lin ◽  
Jie-Wen He ◽  
Li-Yu Chung ◽  
June-Der Lee ◽  
Jiun-Jye Wang ◽  
...  

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2284
Author(s):  
Constantin Cerbu ◽  
Vlad Alexandru Ilaș ◽  
Michał Czopowicz ◽  
Adrian Valentin Potârniche ◽  
Elisa-Paz Bodart-Nieva ◽  
...  

Today, zeolite appears as an interesting alternative for the symptomatic treatment of acute diarrhea. Therefore, this study aimed to investigate the properties of activated micronized (5 microns) zeolite clinoptilolite (MZC) from Transylvania, Romania, first by testing it in vitro and then in vivo on calves with diarrhea. To assess the toxic potential of the MZC, we performed a cell cytotoxicity assay using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) technique on primary bovine intestinal epithelial cells (BIECs). The antimicrobial activity of MZC was investigated by measuring the minimal inhibitory concentration (MIC) on Escherichia coli (ATCC 25922). The uncontrolled in vivo study was carried out over 8 days on a fattening farm, with some 650 calves. Selected calves were randomly assigned to four groups of 20 individuals. Several combinations between MZC, chestnut extract, and oxytetracycline were tested. At the beginning of the study, all calves had diarrhea, while at the end of the study, the prevalence of diarrhea was significantly lower in all four groups (p < 0.001), including the ones treated with MZC. Due to its low cytotoxicity on the intestinal cells and with regards to the results we obtained in vivo, MZC may be considered an alternative for the symptomatic treatment of undifferentiated diarrhea in calves.


2018 ◽  
Vol 315 (2) ◽  
pp. G259-G271 ◽  
Author(s):  
Jamie M. Golden ◽  
Oswaldo H. Escobar ◽  
Michelle V. L. Nguyen ◽  
Michael U. Mallicote ◽  
Patil Kavarian ◽  
...  

The intestinal barrier is often disrupted in disease states, and intestinal barrier failure leads to sepsis. Ursodeoxycholic acid (UDCA) is a bile acid that may protect the intestinal barrier. We hypothesized that UDCA would protect the intestinal epithelium in injury models. To test this hypothesis, we utilized an in vitro wound-healing assay and a mouse model of intestinal barrier injury. We found that UDCA stimulates intestinal epithelial cell migration in vitro, and this migration was blocked by inhibition of cyclooxygenase 2 (COX-2), epidermal growth factor receptor (EGFR), or ERK. Furthermore, UDCA stimulated both COX-2 induction and EGFR phosphorylation. In vivo UDCA protected the intestinal barrier from LPS-induced injury as measured by FITC dextran leakage into the serum. Using 5-bromo-2′-deoxyuridine and 5-ethynyl-2′-deoxyuridine injections, we found that UDCA stimulated intestinal epithelial cell migration in these animals. These effects were blocked with either administration of Rofecoxib, a COX-2 inhibitor, or in EGFR-dominant negative Velvet mice, wherein UDCA had no effect on LPS-induced injury. Finally, we found increased COX-2 and phosphorylated ERK levels in LPS animals also treated with UDCA. Taken together, these data suggest that UDCA can stimulate intestinal epithelial cell migration and protect against acute intestinal injury via an EGFR- and COX-2-dependent mechanism. UDCA may be an effective treatment to prevent the early onset of gut-origin sepsis. NEW & NOTEWORTHY In this study, we show that the secondary bile acid ursodeoxycholic acid stimulates intestinal epithelial cell migration after cellular injury and also protects the intestinal barrier in an acute rodent injury model, neither of which has been previously reported. These effects are dependent on epidermal growth factor receptor activation and downstream cyclooxygenase 2 upregulation in the small intestine. This provides a potential treatment for acute, gut-origin sepsis as seen in diseases such as necrotizing enterocolitis.


2004 ◽  
Vol 379 (3) ◽  
pp. 687-695 ◽  
Author(s):  
Fumio OMAE ◽  
Masao MIYAZAKI ◽  
Ayako ENOMOTO ◽  
Minoru SUZUKI ◽  
Yusuke SUZUKI ◽  
...  

The C-4 hydroxylation of sphinganine and dihydroceramide is a rate-limiting reaction in the biosynthesis of phytosphingolipids. Mouse DES1 (MDES1) cDNA homologous to the Drosophila melanogaster degenerative spermatocyte gene-1 (des-1) cDNA leads to sphingosine Δ4-desaturase activity, and another mouse homologue, MDES2, has bifunctional activity, producing C-4 hydroxysphinganine and Δ4-sphingenine in yeast [Ternes, Franke, Zahringer, Sperling and Heinz (2002) J. Biol. Chem. 277, 25512–25518]. Here, we report the characterization of mouse DES2 (MDES2) using an in vitro assay with a homogenate of COS-7 cells transfected with MDES2 cDNA and N-octanoyl-sphinganine and sphinganine as substrates. MDES2 protein prefers dihydroceramide as a substrate to sphinganine, and exhibits dihydroceramide Δ4-desaturase and C-4 hydroxylase activities. MDES2 mRNA content was high in the small intestine and abundant in the kidney. In situ hybridization detected signals of MDES2 mRNA in the crypt cells. Immunohistochemistry using an anti-MDES2 peptide antibody stained the crypt cells and the adjacent epithelial cells. These results suggest that MDES2 is the dihydroceramide C-4 hydroxylase responsible for the biosynthesis of enriched phytosphingoglycolipids in the microvillous membranes of intestinal epithelial cells.


2018 ◽  
Author(s):  
Chong Zhang ◽  
Andong He ◽  
Shuai Liu ◽  
Qiaoling He ◽  
Yiqin Luo ◽  
...  

AbstractNecroptosis of intestinal epithelial cells has been indicated to play an important role in the pathogenesis of inflammatory bowel disease (IBD). The identification of dysregulated proteins that can regulate necroptosis in dextran sulfate sodium (DSS)-induced colitis is the key to the rational design of therapeutic strategies for colitis. Through Tandem Mass Tag (TMT)-based quantitative proteomics, HtrA2 was found to be downregulated in the colon of DSS-treated mice. UCF-101, a specific serine protease inhibitor of HtrA2, significantly alleviated DSS-induced colitis as indicated by prevention of body weight loss and decreased mortality. UCF-101 decreased DSS-induced colonic inflammation, prevented intestinal barrier function loss and inhibited necroptosis of intestinal epithelial cells. In vitro, UCF-101 or silencing of HtrA2 decreased necroptosis of HT-29 and L929 cells. UCF-101 decreased phosphorylation of RIPK1 and subsequent phosphorylation of RIPK3 and MLKL during necroptosis. HtrA2 directly interacted with RIPK1 and promoted its degradation during a specific time phase of necroptosis. Our findings highlight the importance of HtrA2 in regulating colitis by modulation of necroptosis and suggest HtrA2 as an attractive target for anti-colitis treatment.


Author(s):  
María A. Duque-Correa ◽  
Fernanda Schreiber ◽  
Faye H. Rodgers ◽  
David Goulding ◽  
Sally Forrest ◽  
...  

ABSTRACTThe caecum, an intestinal appendage in the junction of the small and large intestines, displays a unique epithelium that serves as an exclusive niche for a range of pathogens including whipworms (Trichuris spp). While protocols to grow organoids from small intestine (enteroids) and colon (colonoids) exist, the conditions to culture organoids from the caecum have yet to be described. Here, we report methods to grow, differentiate and characterise mouse adult stem cell-derived caecal organoids, termed caecaloids. We compare the cellular composition of caecaloids to that of enteroids identifying differences in intestinal epithelial cell (IEC) populations that mimic those found in the caecum and small intestine. The remarkable similarity in the IECs composition and spatial conformation of caecaloids and their tissue of origin enables their use as an in vitro model to study host interactions with important caecal pathogens. Thus, exploiting this system we investigated the responses of caecal IECs to extracellular vesicles (EVs) secreted/excreted by the intracellular helminth Trichuris muris. Our findings reveal novel immunoregulatory effects of whipworm EVs on the caecal epithelium, including the downregulation of responses to nucleic acid recognition and type-I interferon (IFN) signalling.


Inflammation ◽  
2021 ◽  
Author(s):  
Yan Cao ◽  
Maiying Fan ◽  
Yanfang Pei ◽  
Lei Su ◽  
Weiwei Xiao ◽  
...  

Abstract The intestine is one of the main target organs involved in the pathological process of heatstroke. CCAAT/enhancer-binding protein homologous protein (CHOP) is involved in endoplasmic reticulum (ER) stress-induced apoptosis. This study aimed to explore the role of CHOP in heatstroke-induced intestinal injury and potential therapy. An in vitro heat stress (HS) model using Caco-2 cells was employed. We observed the role of CHOP in apoptosis-mediated intestinal epithelial cell injury secondary to HS by evaluating cell viability, lactate dehydrogenase release, apoptosis levels, and GRP78, PERK, ATF4, CHOP, Bcl-2, and BAX mRNA and protein expression. To further study the role of CHOP in HS-induced intestinal barrier dysfunction, we assessed transepithelial electrical resistance, paracellular tracer flux, ultrastructure of tight junctions, and protein expression of ZO-1 and occludin. Male wild-type mice and CHOP knockout mice were used for in vivo experiments. We evaluated serum d-lactate and diamine oxidase levels, histopathological changes, intestinal ultrastructure, and ZO-1 and occludin protein expression. HS activated the PERK-CHOP pathway and promoted apoptosis by upregulating BAX and downregulating Bcl-2; these effects were prevented by CHOP silencing. Intestinal epithelial barrier function was disrupted by HS in vitro and in vivo. CHOP silencing prevented intestinal barrier dysfunction in Caco-2 cells, whereas CHOP knockout mice exhibited decreased intestinal mucosal injury. The ER stress inhibitor 4-phenylbutyrate (4-PBA) prevented HS-induced intestinal injury in vitro and in vivo. This study indicated that CHOP deficiency attenuates heatstroke-induced intestinal injury and may contribute to the identification of a novel therapy against heatstroke associated with the ER stress pathway.


2017 ◽  
Vol 42 (2) ◽  
pp. 848-858 ◽  
Author(s):  
Bin Zhang ◽  
Yinghai Tian ◽  
Ping Jiang ◽  
Yanqiong Jiang ◽  
Chao Li ◽  
...  

Background/Aims: This study aimed to investigate the role of microRNA (miR)-122a in regulating zonulin during the modulation of intestinal barrier. Methods: Zonulin proteins and their target gene expression were analyzed in miR-122a-overexpressing cell lines and in the target gene of epidermal growth factor receptor (EGFR). An mmu-miR-122a intestinal epithelial conditional transgenic (miR-122a-TG) mouse model was established to investigate EGFR and zonulin expression. MiR-122a was also detected in the clinical specimens of inflammatory bowel disease. Results: EGFR was identified as a target gene of miR-122a. The expression level of miR-122a was positively correlated with that of zonulin. The expression level of zonulin was significantly increased, whereas the expression level of EGFR was significantly decreased in the miR-122a-TG mice and in the corresponding primary epithelial culture (P < 0.05). These results were consistent with the data of the clinical specimens. Conclusions: miR-122a could be a positive factor of zonulin by targeting EGFR, which increased the intestinal epithelial permeability in vivo and in vitro.


2007 ◽  
Vol 292 (1) ◽  
pp. G231-G241 ◽  
Author(s):  
M. Neunlist ◽  
P. Aubert ◽  
S. Bonnaud ◽  
L. Van Landeghem ◽  
E. Coron ◽  
...  

Although recent studies have shown that enteric neurons control intestinal barrier function, the role of enteric glial cells (EGCs) in this control remains unknown. Therefore, our goal was to characterize the role of EGCs in the control of intestinal epithelial cell proliferation using an in vivo transgenic and an in vitro coculture model. Assessment of intestinal epithelial cell proliferation after ablation of EGCs in transgenic mice demonstrated a significant increase in crypt cell hyperplasia. Furthermore, mucosal glial network (assessed by immunohistochemical detection of S-100β) is altered in colon adenocarcinoma compared with control tissue. In an in vitro coculture model of subconfluent Caco-2 cells seeded onto Transwell filters with EGCs, Caco-2 cell density and [3H]thymidine incorporation were significantly lower than in control (Caco-2 cultured alone). Flow cytometry analysis showed that EGCs had no effect on Caco-2 cell viability. EGCs induced a significant increase in Caco-2 cell surface area without any sign of cellular hypertrophy. These effects by EGCs were also seen in various transformed or nontransformed intestinal epithelial cell lines. Furthermore, TGF-β1 mRNA was expressed, and TGF-β1 was secreted by EGCs. Exogenously added TGF-β1 reproduced partly the EGC-mediated effects on cell density and surface area. In addition, EGC effects on Caco-2 cell density were significantly reduced by a neutralizing TGF-β antibody. In conclusion, EGCs have profound antiproliferative effects on intestinal epithelial cells. Functional alterations in EGCs may therefore modify intestinal barrier functions and be involved in pathologies such as cancer or inflammatory bowel diseases.


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