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Legros N, Pohlentz G, Steil D, Müthing J. Shiga toxin-glycosphingolipid interaction: Status quo of research with focus on primary human brain and kidney endothelial cells. Int J Med Microbiol 2018; 308:1073-1084. [PMID: 30224239 DOI: 10.1016/j.ijmm.2018.09.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 08/28/2018] [Accepted: 09/06/2018] [Indexed: 12/21/2022] Open
Abstract
Shiga toxin (Stx)-mediated injury of the kidneys and the brain represent the major extraintestinal complications in humans upon infection by enterohemorrhagic Escherichia coli (EHEC). Damage of renal and cerebral endothelial cells is the key event in the pathogenesis of the life-threatening hemolytic uremic syndrome (HUS). Stxs are AB5 toxins and the B-pentamers of the two clinically important Stx subtypes Stx1a and Stx2a preferentially bind to the glycosphingolipid globotriaosylceramide (Gb3Cer, Galα4Galβ4Glcβ1Cer) and to less extent to globotetraosylceramide (Gb4Cer, GalNAcβ3Galα4Galβ4Glcβ1), which are expected to reside in lipid rafts in the plasma membrane of the human endothelium. This review summarizes the current knowledge on the Stx glycosphingolipid receptors and their lipid membrane ensemble in primary human brain microvascular endothelial cells (pHBMECs) and primary human renal glomerular endothelial cells (pHRGECs). Increasing knowledge on the precise initial molecular mechanisms by which Stxs interact with cellular targets will help to develop specific therapeutics and/or preventive measures to combat EHEC-caused diseases.
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Affiliation(s)
- Nadine Legros
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany
| | | | - Daniel Steil
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany
| | - Johannes Müthing
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany; Interdisciplinary Center for Clinical Research (IZKF), University of Münster, D-48149 Münster, Germany.
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Legros N, Pohlentz G, Steil D, Kouzel IU, Liashkovich I, Mellmann A, Karch H, Müthing J. Membrane assembly of Shiga toxin glycosphingolipid receptors and toxin refractiveness of MDCK II epithelial cells. J Lipid Res 2018; 59:1383-1401. [PMID: 29866658 DOI: 10.1194/jlr.m083048] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 05/22/2018] [Indexed: 12/16/2022] Open
Abstract
Shiga toxins (Stxs) are the major virulence factors of Stx-producing Escherichia coli (STEC), which cause hemorrhagic colitis and severe extraintestinal complications due to injury of renal endothelial cells, resulting in kidney failure. Since kidney epithelial cells are suggested additional targets for Stxs, we analyzed Madin-Darby canine kidney (MDCK) II epithelial cells for presence of Stx-binding glycosphingolipids (GSLs), determined their distribution to detergent-resistant membranes (DRMs), and ascertained the lipid composition of DRM and non-DRM preparations. Globotriaosylceramide and globotetraosylceramide, known as receptors for Stx1a, Stx2a, and Stx2e, and Forssman GSL as a specific receptor for Stx2e, were found to cooccur with SM and cholesterol in DRMs of MDCK II cells, which was shown using TLC overlay assay detection combined with mass spectrometry. The various lipoforms of GSLs were found to mainly harbor ceramide moieties composed of sphingosine (d18:1) and C24:1/C24:0 or C16:0 FA. The cells were highly refractory toward Stx1a, Stx2a, and Stx2e, most likely due to the absence of Stx-binding GSLs in the apical plasma membrane determined by immunofluorescence confocal laser scanning microscopy. The results suggest that the cellular content of Stx receptor GSLs and their biochemical detection in DRM preparations alone are inadequate to predict cellular sensitivity toward Stxs.
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Affiliation(s)
- Nadine Legros
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany
| | | | - Daniel Steil
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany
| | - Ivan U Kouzel
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany.,Interdisciplinary Center for Clinical Research, University of Münster, D-48149 Münster, Germany
| | - Ivan Liashkovich
- Institute of Physiology II, University of Münster, D-48149 Münster, Germany
| | - Alexander Mellmann
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany.,Interdisciplinary Center for Clinical Research, University of Münster, D-48149 Münster, Germany
| | - Helge Karch
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany.,Interdisciplinary Center for Clinical Research, University of Münster, D-48149 Münster, Germany
| | - Johannes Müthing
- Institute for Hygiene, University of Münster, D-48149 Münster, Germany .,Interdisciplinary Center for Clinical Research, University of Münster, D-48149 Münster, Germany
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Shiga Toxin Glycosphingolipid Receptors in Human Caco-2 and HCT-8 Colon Epithelial Cell Lines. Toxins (Basel) 2017; 9:toxins9110338. [PMID: 29068380 PMCID: PMC5705953 DOI: 10.3390/toxins9110338] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 10/11/2017] [Accepted: 10/19/2017] [Indexed: 12/21/2022] Open
Abstract
Shiga toxins (Stxs) released by enterohemorrhagic Escherichia coli (EHEC) into the human colon are the causative agents for fatal outcome of EHEC infections. Colon epithelial Caco-2 and HCT-8 cells are widely used for investigating Stx-mediated intestinal cytotoxicity. Only limited data are available regarding precise structures of their Stx receptor glycosphingolipids (GSLs) globotriaosylceramide (Gb3Cer) and globotetraosylceramide (Gb4Cer), and lipid raft association. In this study we identified Gb3Cer and Gb4Cer lipoforms of serum-free cultivated Caco-2 and HCT-8 cells, chiefly harboring ceramide moieties composed of sphingosine (d18:1) and C16:0, C22:0 or C24:0/C24:1 fatty acid. The most significant difference between the two cell lines was the prevalence of Gb3Cer with C16 fatty acid in HCT-8 and Gb4Cer with C22–C24 fatty acids in Caco-2 cells. Lipid compositional analysis of detergent-resistant membranes (DRMs), which were used as lipid raft-equivalents, indicated slightly higher relative content of Stx receptor Gb3Cer in DRMs of HCT-8 cells when compared to Caco-2 cells. Cytotoxicity assays revealed substantial sensitivity towards Stx2a for both cell lines, evidencing little higher susceptibility of Caco-2 cells versus HCT-8 cells. Collectively, Caco-2 and HCT-8 cells express a plethora of different receptor lipoforms and are susceptible towards Stx2a exhibiting somewhat lower sensitivity when compared to Vero cells.
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Sestili P, Calcabrini C, Diaz AR, Fimognari C, Stocchi V. The Fast-Halo Assay for the Detection of DNA Damage. Methods Mol Biol 2017; 1644:75-93. [PMID: 28710754 DOI: 10.1007/978-1-4939-7187-9_6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The need for express screening of the DNA damaging potential of chemicals has progressively increased over the past 20 years due to the wide number of new synthetic molecules to be evaluated, as well as the adoption of more stringent chemical regulations such as the EU REACH and risk reduction politics. In this regard, DNA diffusion assays such as the microelectrophoretic comet assay paved the way for rapid genotoxicity testing. A more significant simplification and speeding up of the experimental processes was achieved with the fast halo assay (FHA) described in the present chapter. FHA operates at the single cell level and relies on radial dispersion of the fragments of damaged DNA from intact nuclear DNA. The fragmented DNA is separated by diffusion in an alkaline solvent and is stained, visualized, and finally quantified using computer-assisted image analysis programs. This permits the rapid assessment of the extent of DNA breakage caused by different types of DNA lesions. FHA has proven to be sensitive, reliable, and flexible. This is currently one of the simplest, cheapest, and quickest assays for studying DNA damage and repair in living cells. It does not need expensive reagents or electrophoretic equipment and requires only 40 min to prepare samples for computer-based quantification. This technique can be particularly useful in rapid genotoxicity assessments and in high-throughput genotoxicity screenings.
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Affiliation(s)
- Piero Sestili
- Dipartimento di Scienze Biomolecolari, Università degli Studi di Urbino "Carlo Bo", Via Saffi, 2, 61029, Urbino, Italy.
| | - Cinzia Calcabrini
- Dipartimento di Scienze Biomolecolari, Università degli Studi di Urbino "Carlo Bo", Via Saffi, 2, 61029, Urbino, Italy
- Dipartimento di Scienze per la Qualità della Vita, Alma Mater Studiorum - Università di Bologna, Corso D'Augusto 237, 47921, Rimini, Italy
| | - Anna Rita Diaz
- Dipartimento di Scienze Biomolecolari, Università degli Studi di Urbino "Carlo Bo", Via Saffi, 2, 61029, Urbino, Italy
| | - Carmela Fimognari
- Dipartimento di Scienze per la Qualità della Vita, Alma Mater Studiorum - Università di Bologna, Corso D'Augusto 237, 47921, Rimini, Italy
| | - Vilberto Stocchi
- Dipartimento di Scienze Biomolecolari, Università degli Studi di Urbino "Carlo Bo", Via Saffi, 2, 61029, Urbino, Italy
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Akbari A, Farahnejad Z, Akhtari J, Abastabar M, Mobini GR, Mehbod ASA. Staphylococcus aureus Enterotoxin B Down-Regulates the Expression of Transforming Growth Factor-Beta (TGF-β) Signaling Transducers in Human Glioblastoma. Jundishapur J Microbiol 2016; 9:e27297. [PMID: 27540448 PMCID: PMC4976063 DOI: 10.5812/jjm.27297] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 08/08/2015] [Accepted: 10/19/2015] [Indexed: 11/30/2022] Open
Abstract
Background It has been revealed that Staphylococcus aureus enterotoxin B (SEB) may feature anti-cancer and anti-metastatic advantages due to its ability to modify cell immunity processes and signaling pathways. Glioblastoma is one of the most aggressive human cancers; it has a high mortality nature, which makes it an attractive area for the development of novel therapies. Objectives We examined whether the SEB could exert its growth inhibitory effects on glioblastoma cells partially through the manipulation of a key tumor growth factor termed transforming growth factor-beta (TGF-β). Materials and Methods A human primary glioblastoma cell line, U87, was treated with different concentrations of SEB. The cell quantity was measured by the MTT assay at different exposure times. For molecular assessments, total ribonucleic acid (RNA) was extracted from either non-treated or SEB-treated cells. Subsequently, the gene expression of TGF-β transducers, smad2/3, at the messenger RNA (mRNA) level, was analyzed via a quantitative real-time polymerase chain reaction (qPCR) using the SYBR Green method. Significant differences between cell viability and gene expression levels were determined (Prism 5.0 software) using one-way analyses of variance (ANOVA) test. Results We reported that SEB could effectively down-regulate smad2/3 expression in glioblastoma cells at concentrations as quantity as 1 μg/mL and 2 μg/mL (P < 0.05 and P < 0.01, respectively). The SEB concentrations effective at regulating smad2/3 expression were correlated with those used to inhibit the proliferation of glioblastoma cells. Our results also showed that SEB was able to decrease smad2/3 expression at the mRNA level in a concentration- and time-dependent manner. Conclusions We suggested that SEB could represent an agent that can significantly decrease smad2/3 expression in glioblastoma cells, leading to moderate TGF-β growth signaling and the reduction of tumor cell proliferation.
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Affiliation(s)
- Abolfazl Akbari
- Colorectal Research Center, Iran University of Medical Sciences, Tehran, IR Iran
| | - Zohreh Farahnejad
- Department of Medical Mycology, AJA University of Medical Sciences, Tehran, IR Iran
| | - Javad Akhtari
- Immunogenetic Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, IR Iran
| | - Mahdi Abastabar
- Department of Medical Mycology and Parasitology, Invasive Fungi Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, IR Iran
| | - Gholam Reza Mobini
- Medical Plants Research Center, Shahrekord University of Medical Sciences, Shahrekord, IR Iran
| | - Amir Seied Ali Mehbod
- Department of Medical Mycology, AJA University of Medical Sciences, Tehran, IR Iran
- Corresponding author: Amir Seied Ali Mehbod, Department of Medical Mycology, AJA University of Medical Sciences, Tehran, IR Iran. Tel: +98-2188028350, Fax: +98-2188028350, E-mail:
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Akbari A, Mobini GR, Maghsoudi R, Akhtari J, Faghihloo E, Farahnejad Z. Modulation of transforming growth factor‑β signaling transducers in colon adenocarcinoma cells induced by staphylococcal enterotoxin B. Mol Med Rep 2015; 13:909-14. [PMID: 26647993 DOI: 10.3892/mmr.2015.4596] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 09/09/2015] [Indexed: 11/06/2022] Open
Abstract
Colorectal cancer (CRC) is a notable cause of cancer‑associated mortality worldwide, making it a pertinent topic for the study of cancer and its treatment. Staphylococcal enterotoxin B (SEB), an enterotoxin produced by Staphylococcus aureus, has been demonstrated to exert anticancer and antimetastatic effects due to its ability to modify cell immunity and cellular signaling pathways. In the current study, SEB was investigated, including whether it exerts its growth inhibitory effects on colon adenocarcinoma cells. This may occur through the manipulation of a key tumor growth factor, termed transforming growth factor‑β (TGF‑β), and its signaling pathway transducer, Smad2/3. The human colon adenocarcinoma HCT116 cell line was treated with different concentrations of SEB, and cell number was measured using MTT assay at different treatment times. Smad2/3 RNA expression level was analyzed in untreated or SEB‑treated cells using quantitative polymerase chain reaction, which indicated significant differences between cell viability and Smad2/3 expression levels. SEB effectively downregulated Smad2/3 expression in the HCT116 cells at concentrations of 1 and 2 µg/ml (P=0.0021 and P=0.0017, respectively). SEB concentrations that were effective at inhibiting Smad2/3 expression were correlated with those able to inhibit the proliferation of the cancer cells. SEB inhibited Smad2/3 expression at the mRNA level in a concentration‑ and time‑dependent manner. The present study thus proposed SEB as an agent able to significantly reduce Smad2/3 expression in colon cancer cells, provoking moderate TGF‑β growth signaling and the reduction of tumor cell proliferation.
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Affiliation(s)
- Abolfazl Akbari
- Colorectal Research Center, Iran University of Medical Sciences, Tehran 1313114456, Iran
| | - Gholam Reza Mobini
- Medical Plants Research Center, Shahrekord University of Medical Sciences, Shahrekord 8815713471, Iran
| | - Reza Maghsoudi
- Department of Microbiology and Immunology, Shahrekord University of Medical Sciences, Shahrekord 8815713471, Iran
| | - Javad Akhtari
- Immunogenetic Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari 48175866, Iran
| | - Ebrahim Faghihloo
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran 1313114456, Iran
| | - Zohreh Farahnejad
- Department of Medical Mycology, AJA University of Medical Sciences, Tehran 1917793164, Iran
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A rapid and sensitive method to measure the functional activity of Shiga toxins in human serum. Toxins (Basel) 2015; 7:4564-76. [PMID: 26556372 PMCID: PMC4663520 DOI: 10.3390/toxins7114564] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 10/26/2015] [Accepted: 10/26/2015] [Indexed: 11/17/2022] Open
Abstract
Shiga toxins (Stx) have a definite role in the development of hemolytic uremic syndrome in children with hemorrhagic colitis caused by pathogenic Stx-producing Escherichia coli (STEC) strains. The dramatic effects of these toxins on the microvasculature of different organs, particularly of the kidney, are well known, whereas there is no consensus on the mechanism by which Stx reach the endothelia of target organs and/or indirectly injure these body sites. We hereby describe a quick (4 h), radioactive, Raji cell-based method designed for the detection of Stx in human sera. The assay monitors the translation impairment induced by these powerful inhibitors of protein synthesis, which are identified properly by neutralizing their activity with specific monoclonal antibodies. By this method, we detected for the first time the functional activity of Stx in sera of STEC-infected patients during hemorrhagic colitis. Recent research has pointed to a dynamic process of Stx-induced renal intoxication in which concurrent and interactive steps are involved. Our rapid and specific method could be useful for studying the kinetics of Stx during the natural course of STEC infection and the interplay between Stx activity in serum and Stx presence in different blood fractions (neutrophils, monocytes, platelets, leukocyte-platelet aggregates, microvesicles, lipoproteins).
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Liu CC, Yang H, Zhang LL, Zhang Q, Chen B, Wang Y. Biotoxins for cancer therapy. Asian Pac J Cancer Prev 2015; 15:4753-8. [PMID: 24998537 DOI: 10.7314/apjcp.2014.15.12.4753] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
In recent times, a number of studies have provided evidence that biotoxins present great potential as antitumor agents, such as snake venom, bee venom, some bacteria toxins and plant toxins, and thus could be used as chemotherapeutic agents against tumors. The biodiversity of venoms and toxins make them a unique source from which novel anticancer agent may be developed. Biotoxins, also known as natural toxins, include toxic substances produced by plants, animals and microorganisms. Here, we systematically list representative biological toxins that have antitumor properties, involving animal toxins, plant toxins, mycotoxins as well as bacterial toxins. In this review, we summarize the current knowledge involving biotoxins and the active compounds that have anti-cancer activity to induce cytotoxic, antitumor, immunomodulatory, and apoptotic effects in different tumor cells in vivo or in vitro. We also show insights into the molecular and functional evolution of biotoxins.
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Affiliation(s)
- Cui-Cui Liu
- Department of Scientific Research, Hong Hui Hospital, Xi'an Jiaotong University College of Medicine, Xi'an, China E-mail :
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