scholarly journals Characterization of increased mucus production of HT29-MTX-E12 cells grown under Semi-Wet interface with Mechanical Stimulation

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261191
Author(s):  
Janneke Elzinga ◽  
Benthe van der Lugt ◽  
Clara Belzer ◽  
Wilma T. Steegenga

The intestinal mucus layer plays a crucial role in human health. To study intestinal mucus function and structure in vitro, the mucus-producing intestinal cell line HT29-MTX-E12 has been commonly used. However, this cell line produces only low amounts of the intestine-specific MUC2. It has been shown previously that HT29-MTX-E12 cells cultured under Semi-Wet interface with Mechanical Stimulation (SWMS) produced higher amounts of MUC2, concomitant with a thicker mucus layer, compared to cells cultured conventionally. However, it remains unknown which underlying pathways are involved. Therefore, we aimed to further explore the cellular processes underlying the increased MUC2 production by HT29-MTX-E12 cells grown under SWMS conditions. Cells grown on Transwell membranes for 14 days under static and SWMS conditions (after cell seeding and attachment) were subjected to transcriptome analysis to investigate underlying molecular pathways at gene expression level. Caco-2 and LS174T cell lines were included as references. We characterized how SWMS conditions affected HT29-MTX-E12 cells in terms of epithelial barrier integrity, by measuring transepithelial electrical resistance, and cell metabolism, by monitoring pH and lactate production per molecule glucose of the conditioned medium. We confirmed higher MUC2 production under SWMS conditions at gene and protein level and demonstrated that this culturing method primarily stimulated cell growth. In addition, we also found evidence for a more aerobic cell metabolism under SWMS, as shown previously for similar models. In summary, we suggest different mechanisms by which MUC2 production is enhanced under SWMS and propose potential applications of this model in future studies.

2017 ◽  
Author(s):  
Daniel M. Czyż ◽  
Jonathan Willett ◽  
Sean Crosson

ABSTRACTIntracellular bacterial pathogens exploit host cell resources to replicate and survive inside the host. Targeting these host systems is one promising approach to developing novel antimicrobials to treat intracellular infections. We show that human macrophage-like cells infected withBrucella abortusundergo a metabolic shift characterized by attenuated tricarboxylic acid cycle metabolism, reduced amino acid consumption, altered mitochondrial localization, and increased lactate production. This shift to an aerobic glycolytic state resembles the Warburg effect, a change in energy production that is well-described in cancer cells, and also occurs in activated inflammatory cells.B. abortusefficiently uses lactic acid as its sole carbon and energy source and requires the ability to metabolize lactate for normal survival in human macrophage-like cells. We demonstrate that chemical inhibitors of host glycolysis and lactate production do not affectin vitrogrowth ofB. abortusin axenic culture, but decrease its survival in the intracellular niche. Our data support a model in which infection shifts host metabolism to a Warburg-like state, andB. abortususes this change in metabolism to promote intracellular survival. Pharmacological perturbation of these features of host cell metabolism may be a useful strategy to inhibit infection by intracellular pathogens.IMPORTANCEBrucellaspp. are intracellular bacterial pathogens that cause disease in a range of mammals, including livestock. Transmission from livestock to humans is common and can lead to chronic human disease. Human macrophage-like cells infected withBrucella abortusundergo a Warburg-like metabolic shift to an aerobic glycolytic state where the host cells produce lactic acid and have reduced amino acid catabolism. We provide evidence that the pathogen can exploit this change in host metabolism to support growth and survival in the intracellular niche. Drugs that inhibit this shift in host cell metabolism inhibit intracellular replication and decrease the survival ofB. abortusin anin vitroinfection model; these drugs may be broadly useful therapeutics for intracellular infections.


2020 ◽  
Vol 3 (5) ◽  
pp. 2897-2909 ◽  
Author(s):  
Abhinav Sharma ◽  
Jun-Goo Kwak ◽  
Kristopher W. Kolewe ◽  
Jessica D. Schiffman ◽  
Neil S. Forbes ◽  
...  

1991 ◽  
Vol 260 (2) ◽  
pp. G207-G212 ◽  
Author(s):  
A. R. Giuliano ◽  
R. J. Wood

The human colon adenocarcinoma cell line Caco-2 is the only intestinal cell line to differentiate spontaneously in culture exhibiting structural and biochemical characteristics of mature enterocytes and to possess a vitamin D receptor in the fully differentiated state. Transepithelial calcium transport was characterized in differentiated Caco-2 cells grown on permeable filters supports to assess the potential utility of this cell line as an in vitro model to study 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]-induced calcium transport. Calcium transport was increased in a dose-dependent manner by 1,25(OH)2D3. Total calcium transport at different calcium concentrations could be fitted to a modified Michaelis-Menten equation containing a linear transport component. The maximum rate of saturable calcium transport was increased by 4.3-fold (P less than 0.005) in cells treated with 10(-8) M 1,25(OH)2D3. This treatment also increased the apparent buffer calcium concentration that results in half-maximal velocity from 0.4 to 1.3 mM but had no significant effect on nonsaturable calcium transport. Caco-2 cells grown on permeable filter supports provide a unique in vitro human cell culture model to study the mechanism of vitamin D-regulated transepithelial intestinal calcium transport.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3145-3145
Author(s):  
Narjis Rizwan ◽  
Yandong Shen ◽  
Edwin Iwanowicz ◽  
Stephen P. Mulligan ◽  
Kyle R Crassini ◽  
...  

Abstract Introduction Despite the revolution in the treatment of chronic lymphocytic leukemia (CLL) over the past decade with the introduction of novel inhibitors targeting the B-cell receptor (BCR) signaling pathway and the Bcl-2 family of proteins, relapse is still common. Recent studies suggest that imipridones, a novel class of small molecule agents that attenuate mitochondrial respiration and modulate an immune response against cancer cells, may be an effective treatment option for several difficult to treat cancers. We investigated the effects of the imipridone, ONC-212 (I-39, first published by Nanjing Gator Meditech), as a potential therapeutic strategy for CLL using the OSU-CLL cell line and a modified OSU-CLL line in which TP53 was stably knocked out and primary CLL cells cultured under conditions that mimic the tumour microenvironment (TME). Methodology Primary CLL cells were co-cultured with CD40L-expressing fibroblasts to mimic aspects of the TME. The cytotoxicity of ONC-212 was assessed using the mitochondrial dye DiIC1(5), propidium iodide and flow cytometry. The effects of the drug on the adhesive and migratory capacity of primary CLL cells were evaluated using antibodies against CD49d, CXCR4 and an in vitro migration assay using stroma-derived factor 1a (SDF1-α). Changes in protein expression were assessed by immuno-blotting. The effects of ONC-212 on the cell cycle and proliferation were assessed using the OSU-CLL cell line. OSU-CLL cells were modified using the CRISPr-Cas9 technology to be TP53 deficient (OSU-TP53ko). The proportion of cells in each cycle phase was determined using propidium iodide and flow cytometry. Cell proliferation rates were determined using carboxyfluorescein succinimidyl ester (CFSE) and flow cytometry. Results ONC-212 induced apoptosis in a dose-dependent manner in primary CLL cells cultured in medium alone or in contact with CD40L-fibroblasts (Figure 1); the IC50 values were 72.97 nm +/- 1.45 nM and 472 +/- 2.04 nM, respectively. OSU-CLL and OSU-TP53ko cells were also sensitive to ONC-212, although the TP53 deficient line was less sensitive than OSU-CLL(Figure 1). IC50 values for the cell lines were 22 +/- 1.37 nM (OSU-CLL) and 48 +/- 3.25 nM (OSU-TP53ko). ONC-212 induced cell cycle arrest of the OSU-CLL and OSU-TP53ko lines at the G1/S phase transition. This effect was concomitant with a significant reduction in the proliferation of both lines. ONC-212 significantly down-regulated expression of the adhesion molecule CD49d and the G-coupled protein receptor CXCR4 on primary CLL cells. Down-regulation of CXCR4 translated into a decrease in the migratory capacity of CLL cells along an SDF1-α gradient. Immunoblotting suggested the mechanisms of action of ONC-212 include inhibition of ERK1/2-MAPK, a decrease in the Bcl-2/Bax ratio and upregulation of the pro-apoptotic Puma and Bak proteins. Conclusions ONC-212 is highly effective against CLL cells at nanomolar concentrations, against cells cultured under conditions that mimic aspects of the TME and against TP53-deficient cells. ONC-212 has cytotoxic effects, induces cell cycle arrest, slows proliferation and inhibits the mechanisms by which CLL cells migrate to and are retained within the TME. ONC-212 inhibited signaling downstream of the BCR and induced a pro-apoptotic 'tipping' of the balance in expression of BCl-2 family proteins. These data suggest ONC-212 may represent an effective treatment for CLL, particularly for patients who have high risk, relapsed/refractory disease associated with loss or mutation of TP53. Disclosures No relevant conflicts of interest to declare.


2021 ◽  
Vol 91 (1) ◽  
pp. 31-39
Author(s):  
Yasmin Ranjous ◽  
Dóra Kósa ◽  
Zoltán Ujhelyi ◽  
Géza Regdon ◽  
Krisztina Anita Nagy ◽  
...  

Titanate nanotubes (TNTs) are promising vectors for drug delivery due to their unique physicochemical properties such as biocompatibility, mechanical strength, and chemical resistivity. However, considering their strong hydrophilicity, pristine TNTs exert very limited permeability through the intestinal cell layer. The aim of this study was to turn the surface characteristics and thus enhance the permeability of TNTs by functionalization. TNTs were functionalized with trichloro(octyl)silane (TCOS) and magnesium stearate (MgSt). Carbon content and surface free energy of the functionalized TNTs were detected to evaluate the effectiveness of functionalization, by using CHNS analytical and optical contact angle (OCA) measurements, respectively. Caco-2 cell line was applied to test the permeability and the cytotoxicity of the samples. Cytotoxicity was evaluated by using MTT assay. The results revealed that the surface characteristics of TNTs may be adjusted in a wider range with TCOS-TNT than with St, but the samples show higher toxicity. Silane functionalized TNTs may be safe up to 1 mg/ml, while St functionalized TNTs up to 2 mg/ml concentration. The preparation method of MgSt-TNT was also superior from the aspect of environmental safety. The permeability was suitable for samples with moderate hydrophobicity (aqueous contact angle 60-90°).


mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Melinda A. Engevik ◽  
Berkley Luk ◽  
Alexandra L. Chang-Graham ◽  
Anne Hall ◽  
Beatrice Herrmann ◽  
...  

ABSTRACTMuch remains unknown about how the intestinal microbiome interfaces with the protective intestinal mucus layer.Bifidobacteriumspecies colonize the intestinal mucus layer and can modulate mucus production by goblet cells. However, selectBifidobacteriumstrains can also degrade protective glycans on mucin proteins. We hypothesized that the human-derived speciesBifidobacterium dentiumwould increase intestinal mucus synthesis and expulsion, without extensive degradation of mucin glycans.In silicodata revealed thatB. dentiumlacked the enzymes necessary to extensively degrade mucin glycans. This finding was confirmed by demonstrating thatB. dentiumcould not use naive mucin glycans as primary carbon sourcesin vitro. To examineB. dentiummucus modulationin vivo, Swiss Webster germfree mice were monoassociated with live or heat-killedB. dentium. LiveB. dentium-monoassociated mice exhibited increased colonic expression of goblet cell markersKrüppel-like factor 4(Klf4),Trefoil factor 3(Tff3),Relm-β,Muc2, and several glycosyltransferases compared to both heat-killedB. dentiumand germfree counterparts. Likewise, liveB. dentium-monoassociated colon had increased acidic mucin-filled goblet cells, as denoted by Periodic Acid-Schiff-Alcian Blue (PAS-AB) staining and MUC2 immunostaining.In vitro,B. dentium-secreted products, including acetate, were able to increase MUC2 levels in T84 cells. We also identified thatB. dentium-secreted products, such as γ-aminobutyric acid (GABA), stimulated autophagy-mediated calcium signaling and MUC2 release. This work illustrates thatB. dentiumis capable of enhancing the intestinal mucus layer and goblet cell function via upregulation of gene expression and autophagy signaling pathways, with a net increase in mucin production.IMPORTANCEMicrobe-host interactions in the intestine occur along the mucus-covered epithelium. In the gastrointestinal tract, mucus is composed of glycan-covered proteins, or mucins, which are secreted by goblet cells to form a protective gel-like structure above the epithelium. Low levels of mucin or alterations in mucin glycans are associated with inflammation and colitis in mice and humans. Although current literature links microbes to the modulation of goblet cells and mucins, the molecular pathways involved are not yet fully understood. Using a combination of gnotobiotic mice and mucus-secreting cell lines, we have identified a human-derived microbe,Bifidobacterium dentium, which adheres to intestinal mucus and secretes metabolites that upregulate the major mucin MUC2 and modulate goblet cell function. Unlike otherBifidobacteriumspecies,B. dentiumdoes not extensively degrade mucin glycans and cannot grow on mucin alone. This work points to the potential of usingB. dentiumand similar mucin-friendly microbes as therapeutic agents for intestinal disorders with disruptions in the mucus barrier.


2010 ◽  
Vol 78 (6) ◽  
pp. 2812-2822 ◽  
Author(s):  
Abofu Alemka ◽  
Marguerite Clyne ◽  
Fergus Shanahan ◽  
Thomas Tompkins ◽  
Nicolae Corcionivoschi ◽  
...  

ABSTRACT The HT29MTXE12 (E12) cell line harbors an adherent mucus layer, providing a novel technique to model mucosal infection in vitro. In this study, we have characterized the interaction of Campylobacter jejuni with the E12 cell line and exploited its unique mucus layer to examine the potential efficacy of probiotic treatment to attenuate C. jejuni virulence properties. C. jejuni 81-176 colonized and reproduced in E12 mucus. Adhesion to and internalization of C. jejuni were enhanced in E12 cells harboring mucus compared to parental cells without mucus. Translocation of C. jejuni occurred at early time points following infection. C. jejuni aligned with tight junctions and colocalized with the tight junction protein occludin, suggesting a paracellular route of translocation. Probiotic strains Lactobacillus rhamnosus R0011, Lactobacillus helveticus R0052, Lactobacillus salivarius AH102, Bifidobacterium longum AH1205, a commercial combination of L. rhamnosus R0011 and L. helveticus R0052 (Lacidofil), and a cocktail consisting of L. rhamnosus, L. helveticus, and L. salivarius (RhHeSa) colonized E12 mucus and bound to underlying cells. Probiotics attenuated C. jejuni association with and internalization into E12 cells and translocation to the basolateral medium of transwells. Live bacteria and prolonged precolonization of E12 cells with probiotics were necessary for probiotic action. These results demonstrate the potential for E12 cells as a model of mucosal pathogenesis and provide a rationale for the further investigation of probiotics as prophylaxis against human campylobacteriosis.


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