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Patacsil D, Tran AT, Cho YS, Suy S, Saenz F, Malyukova I, Ressom H, Collins SP, Clarke R, Kumar D. Gamma-tocotrienol induced apoptosis is associated with unfolded protein response in human breast cancer cells. J Nutr Biochem 2011; 23:93-100. [PMID: 21429729 DOI: 10.1016/j.jnutbio.2010.11.012] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 11/04/2010] [Accepted: 11/09/2010] [Indexed: 12/01/2022]
Abstract
Gamma-tocotrienol (γ-T3) is a member of the vitamin E family. Tocotrienols (T3s) are powerful antioxidants and possess anticancer, neuroprotective and cholesterol-lowering properties. Tocotrienols inhibit the growth of various cancer cell lines without affecting normal cells. Less is known about the exact mechanisms of action of T3s on cell death and other growth inhibitory pathways. In the present study, we demonstrate that γ-T3 induces apoptosis in MDA-MB 231 and MCF-7 breast cancer cells as evident by PARP cleavage and caspase-7 activation. Gene expression analysis of MCF-7 cells treated with γ-T3 revealed alterations in the expression of multiple genes involved in cell growth and proliferation, cell death, cell cycle, cellular development, cellular movement and gene expression. Further analysis of differentially modulated genes using Ingenuity Pathway Analysis software suggested modulation of canonical signal transduction or metabolic pathways such as NRF-2-mediated oxidative stress response, TGF-β signaling and endoplasmic reticulum (ER) stress response. Analysis of ER-stress-related proteins in MCF-7 and MDA-MB 231 cells treated with γ-T3 demonstrated activation of PERK and pIRE1α pathway to induce ER stress. Activating transcription factor 3 (ATF3) was identified as the most up-regulated gene (16.8-fold) in response to γ-T3. Activating transcription factor 3 knockdown using siRNA suggested an essential role of ATF3 in γ-T3-induced apoptosis. In summary, we demonstrate that γ-T3 modulates ER stress signaling and have identified ATF3 as a molecular target for γ-T3 in breast cancer cells.
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Affiliation(s)
- Dorrelyn Patacsil
- Cancer Research Laboratory, Department of Biological and Environmental Sciences, University of the District of Columbia, Washington, DC 20008, USA
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Laiko M, Murtazina R, Malyukova I, Zhu C, Boedeker EC, Gutsal O, O'Malley R, Cole RN, Tarr PI, Murray KF, Kane A, Donowitz M, Kovbasnjuk O. Shiga toxin 1 interaction with enterocytes causes apical protein mistargeting through the depletion of intracellular galectin-3. Exp Cell Res 2009; 316:657-66. [PMID: 19744479 DOI: 10.1016/j.yexcr.2009.09.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 09/01/2009] [Accepted: 09/02/2009] [Indexed: 01/09/2023]
Abstract
Shiga toxins (Stx) 1 and 2 are responsible for intestinal and systemic sequelae of infection by enterohemorrhagic Escherichia coli (EHEC). However, the mechanisms through which enterocytes are damaged remain unclear. While secondary damage from ischemia and inflammation are postulated mechanisms for all intestinal effects, little evidence excludes roles for more primary toxin effects on intestinal epithelial cells. We now document direct pathologic effects of Stx on intestinal epithelial cells. We study a well-characterized rabbit model of EHEC infection, intestinal tissue and stool samples from EHEC-infected patients, and T84 intestinal epithelial cells treated with Stx1. Toxin uptake by intestinal epithelial cells in vitro and in vivo causes galectin-3 depletion from enterocytes by increasing the apical galectin-3 secretion. This Shiga toxin-mediated galectin-3 depletion impairs trafficking of several brush border structural proteins and transporters, including villin, dipeptidyl peptidase IV, and the sodium-proton exchanger 2, a major colonic sodium absorptive protein. The mistargeting of proteins responsible for the absorptive function might be a key event in Stx1-induced diarrhea. These observations provide new evidence that human enterocytes are directly damaged by Stx1. Conceivably, depletion of galectin-3 from enterocytes and subsequent apical protein mistargeting might even provide a means whereby other pathogens might alter intestinal epithelial absorption and produce diarrhea.
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Affiliation(s)
- Marina Laiko
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Malyukova I, Murray KF, Zhu C, Boedeker E, Kane A, Patterson K, Peterson JR, Donowitz M, Kovbasnjuk O. Macropinocytosis in Shiga toxin 1 uptake by human intestinal epithelial cells and transcellular transcytosis. Am J Physiol Gastrointest Liver Physiol 2009; 296:G78-92. [PMID: 18974311 PMCID: PMC2636932 DOI: 10.1152/ajpgi.90347.2008] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Shiga toxin 1 and 2 production is a cardinal virulence trait of enterohemorrhagic Escherichia coli infection that causes a spectrum of intestinal and systemic pathology. However, intestinal sites of enterohemorrhagic E. coli colonization during the human infection and how the Shiga toxins are taken up and cross the globotriaosylceramide (Gb3) receptor-negative intestinal epithelial cells remain largely uncharacterized. We used samples of human intestinal tissue from patients with E. coli O157:H7 infection to detect the intestinal sites of bacterial colonization and characterize the distribution of Shiga toxins. We further used a model of largely Gb3-negative T84 intestinal epithelial monolayers treated with B-subunit of Shiga toxin 1 to determine the mechanisms of non-receptor-mediated toxin uptake. We now report that E. coli O157:H7 were found at the apical surface of epithelial cells only in the ileocecal valve area and that both toxins were present in large amounts inside surface and crypt epithelial cells in all tested intestinal samples. Our in vitro data suggest that macropinocytosis mediated through Src activation significantly increases toxin endocytosis by intestinal epithelial cells and also stimulates toxin transcellular transcytosis. We conclude that Shiga toxin is taken up by human intestinal epithelial cells during E. coli O157:H7 infection regardless of the presence of bacterial colonies. Macropinocytosis might be responsible for toxin uptake by Gb3-free intestinal epithelial cells and transcytosis. These observations provide new insights into the understanding of Shiga toxin contribution to enterohemorrhagic E. coli-related intestinal and systemic diseases.
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Affiliation(s)
- Irina Malyukova
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Karen F. Murray
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Chengru Zhu
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Edgar Boedeker
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Anne Kane
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Kathleen Patterson
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Jeffrey R. Peterson
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Mark Donowitz
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
| | - Olga Kovbasnjuk
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Pediatrics, Division of Gastroenterology and Nutrition, Children's Hospital and Regional Medical Center, Seattle, Washington; Department of Medicine, Division of Gastroenterology, University of New Mexico School of Medicine, Albuquerque, New Mexico; Division of Geographic Medicine/Infectious Diseases, Tufts Medical Center, Boston, Massachusetts; Department of Pathology, Children's Hospital and Regional Medical Center, Seattle, Washington; and Fox Chase Cancer Center, Philadelphia, Pennsylvania
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Senatorov V, Malyukova I, Fariss R, Wawrousek EF, Swaminathan S, Sharan SK, Tomarev S. Expression of mutated mouse myocilin induces open-angle glaucoma in transgenic mice. J Neurosci 2006; 26:11903-14. [PMID: 17108164 PMCID: PMC6674879 DOI: 10.1523/jneurosci.3020-06.2006] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We developed a genetic mouse model of open-angle glaucoma by expression of mutated mouse myocilin (Myoc) in transgenic (Tg) mice. The Tyr423His point mutation, corresponding to the severe glaucoma-causing Tyr437His mutation in the human MYOC gene, was introduced into bacterial artificial chromosome DNA encoding the full-length mouse Myoc gene and long flanking regions. Both wild-type (Wt) and Tg animals expressed Myoc in tissues of the irido-corneal angle and the sclera. Expression of mutated Myoc induced the accumulation of Myoc in cell cytoplasm and prevented its secretion into the extracellular space. The levels of ATPase-1 were reduced in the irido-corneal angle of Tg mice compared with Wt animals. Tg mice demonstrated a moderate elevation of intraocular pressure, the loss of approximately 20% of the retinal ganglion cells (RGCs) in the peripheral retina, and axonal degeneration in the optic nerve. RGC depletion was associated with the shrinkage of their nuclei and DNA fragmentation in the peripheral retina. Pathological changes observed in the eyes of Tg mice are similar to those observed in glaucoma patients.
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Affiliation(s)
- Vladimir Senatorov
- Section of Molecular Mechanisms of Glaucoma, Laboratory of Molecular and Developmental Biology, and
| | - Irina Malyukova
- Section of Molecular Mechanisms of Glaucoma, Laboratory of Molecular and Developmental Biology, and
| | - Robert Fariss
- Biological Imaging Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, and
| | - Eric F. Wawrousek
- Section of Molecular Mechanisms of Glaucoma, Laboratory of Molecular and Developmental Biology, and
| | - Srividya Swaminathan
- Mouse Cancer Genetics Program, National Cancer Institute, Frederick, Maryland 21702
| | - Shyam K. Sharan
- Mouse Cancer Genetics Program, National Cancer Institute, Frederick, Maryland 21702
| | - Stanislav Tomarev
- Section of Molecular Mechanisms of Glaucoma, Laboratory of Molecular and Developmental Biology, and
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Tomarev SI, Wistow G, Raymond V, Dubois S, Malyukova I. Gene expression profile of the human trabecular meshwork: NEIBank sequence tag analysis. Invest Ophthalmol Vis Sci 2003; 44:2588-96. [PMID: 12766061 DOI: 10.1167/iovs.02-1099] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To characterize the gene expression pattern in the human trabecular meshwork (TM) and identify candidate genes for glaucoma by expressed sequence tag (EST) analysis as part of the NEIBank project. METHODS RNA was extracted from dissected human TM and used to construct unamplified, un-normalized cDNA libraries in the pSPORT1 vector. More than 4000 clones were sequenced from the 5' end. Clones were clustered and identified using GRIST software. In addition, the expression patterns of genes encoding olfactomedin-domain proteins were analyzed by RT-PCR. RESULTS After non-mRNA contaminants were removed, 3459 independent TM-expressed clones were obtained. These were grouped in 1888 clusters, potentially representing individual expressed genes. Transcripts for the myocilin gene, a locus for inherited glaucoma, formed the third most abundant cluster in the TM collection, and several other genes implicated in glaucoma (PITX2, CYP1B1, and optineurin) were also represented. One abundant TM transcript was from the gene for the angiopoietin-like factor CTD6, which is located at on the long arm of chromosome 1, area 36.2-36.1 in the region of the glaucoma locus GLC3B, whereas other transcripts were from genes close to known glaucoma loci. The TM collection contains cDNAs for genes that are preferentially expressed in the lymphatic endothelium (matrix Gla protein, apolipoprotein D precursor, and selenoprotein P precursor). In addition to EST profiling, RT- PCR was used to detect transcripts of the olfactomedin-domain proteins latrotoxin receptor Lec3 and optimedin in the TM. CONCLUSIONS The TM libraries are a good source of molecular markers for TM and candidate genes for glaucoma. The abundance of myocilin cDNAs corresponds to the critical role of this gene in glaucoma and contrasts with libraries derived from cultured tissue. The expression profile raises the possibility that cells of the TM and Schlemm's canal may be more similar to lymphatic, rather than blood vascular endothelium.
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Affiliation(s)
- Stanislav I Tomarev
- Laboratory of Molecular and Developmental Biology, National Institutes of Health, Bethesda, Maryland 20892-2730, USA.
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