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Ilani T, Reznik N, Yeshaya N, Feldman T, Vilela P, Lansky Z, Javitt G, Shemesh M, Brenner O, Elkis Y, Varsano N, Jaramillo AM, Evans CM, Fass D. The disulfide catalyst QSOX1 maintains the colon mucosal barrier by regulating Golgi glycosyltransferases. EMBO J 2023; 42:e111869. [PMID: 36245281 PMCID: PMC9841341 DOI: 10.15252/embj.2022111869] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 09/25/2022] [Accepted: 09/29/2022] [Indexed: 01/27/2023] Open
Abstract
Mucus is made of enormous mucin glycoproteins that polymerize by disulfide crosslinking in the Golgi apparatus. QSOX1 is a catalyst of disulfide bond formation localized to the Golgi. Both QSOX1 and mucins are highly expressed in goblet cells of mucosal tissues, leading to the hypothesis that QSOX1 catalyzes disulfide-mediated mucin polymerization. We found that knockout mice lacking QSOX1 had impaired mucus barrier function due to production of defective mucus. However, an investigation on the molecular level revealed normal disulfide-mediated polymerization of mucins and related glycoproteins. Instead, we detected a drastic decrease in sialic acid in the gut mucus glycome of the QSOX1 knockout mice, leading to the discovery that QSOX1 forms regulatory disulfides in Golgi glycosyltransferases. Sialylation defects in the colon are known to cause colitis in humans. Here we show that QSOX1 redox control of sialylation is essential for maintaining mucosal function.
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Affiliation(s)
- Tal Ilani
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Nava Reznik
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Noa Yeshaya
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Tal Feldman
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Patrick Vilela
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Zipora Lansky
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Gabriel Javitt
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Michal Shemesh
- Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Ori Brenner
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel
| | | | - Neta Varsano
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Ana M Jaramillo
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Aurora, CO, USA
| | - Christopher M Evans
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Aurora, CO, USA.,Department of Medicine, School of Medicine, University of Colorado, Aurora, CO, USA
| | - Deborah Fass
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
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Rahimi R, Malek I, Lerrer-Goldshtein T, Elkis Y, Shoval I, Jacob A, Shpungin S, Nir U. TMF1 is upregulated by insulin and is required for a sustained glucose homeostasis. FASEB J 2021; 35:e21295. [PMID: 33475194 DOI: 10.1096/fj.202001995r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 11/20/2020] [Accepted: 12/07/2020] [Indexed: 01/14/2023]
Abstract
Insulin-regulated glucose homeostasis is a critical and intricate physiological process, of which not all regulatory components have been deciphered. One of the key players in modulating glucose uptake by cells is the glucose transporter-GLUT4. In this study, we aimed to explore the regulatory role of the trans-Golgi-associated protein-TATA Element Modulatory Factor (TMF1) in the GLUT4 mediated, insulin-directed glucose uptake. By establishing and using TMF1-/- myoblasts and mice, we examined the effect of TMF1 absence on the insulin driven functioning of GLUT4. We show that TMF1 is upregulated by insulin in myoblasts, and is essential for the formation of insulin responsive, glucose transporter GLUT4-containing vesicles. Absence of TMF1 leads to the retention of GLUT4 in perinuclear compartments, and to severe impairment of insulin-stimulated GLUT4 trafficking throughout the cytoplasm and to the cell plasma membrane. Accordingly, glucose uptake is impaired in TMF1-/- cells, and TMF1-/- mice are hyperglycemic. This is reflected by the mice impaired blood glucose clearance and increased blood glucose level. Correspondingly, TMF1-/- animals are leaner than their normal littermates. Thus, TMF1 is a novel effector of insulin-regulated glucose homeostasis, and dys-functioning of this protein may contribute to the onset of a diabetes-like disorder.
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Affiliation(s)
- Roni Rahimi
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Israel Malek
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Tali Lerrer-Goldshtein
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Yoav Elkis
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Irit Shoval
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Avi Jacob
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Sally Shpungin
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Uri Nir
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
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Feldman T, Grossman-Haham I, Elkis Y, Vilela P, Moskovits N, Barshack I, Salame TM, Fass D, Ilani T. Correction: Inhibition of fibroblast secreted QSOX1 perturbs extracellular matrix in the tumor microenvironment and decreases tumor growth and metastasis in murine cancer models. Oncotarget 2020; 11:3687. [PMID: 33088428 PMCID: PMC7546759 DOI: 10.18632/oncotarget.27764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Affiliation(s)
- Tal Feldman
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Iris Grossman-Haham
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yoav Elkis
- Almog Diagnostic, Shoham 6081513, Israel
| | - Patrick Vilela
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Neta Moskovits
- Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Iris Barshack
- Institute of Pathology, Sheba Medical Center Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Tomer M Salame
- Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Deborah Fass
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Tal Ilani
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
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Feldman T, Grossman-Haham I, Elkis Y, Vilela P, Moskovits N, Barshack I, Salame TM, Fass D, Ilani T. Inhibition of fibroblast secreted QSOX1 perturbs extracellular matrix in the tumor microenvironment and decreases tumor growth and metastasis in murine cancer models. Oncotarget 2020; 11:386-398. [PMID: 32064042 PMCID: PMC6996906 DOI: 10.18632/oncotarget.27438] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 12/29/2019] [Indexed: 12/20/2022] Open
Abstract
Extracellular matrix (ECM) plays an important role in tumor development and dissemination, but few points of therapeutic intervention targeting ECM of the tumor microenvironment have been exploited to date. Recent observations suggest that the enzymatic introduction of disulfide bond cross-links into the ECM may be modulated to affect cancer progression. Specifically, the disulfide bond-forming activity of the enzyme Quiescin sulfhydryl oxidase 1 (QSOX1) is required by fibroblasts to assemble ECM components for adhesion and migration of cancer cells. Based on this finding and the increased QSOX1 expression in the stroma of aggressive breast carcinomas, we developed monoclonal antibody inhibitors with the aim of preventing QSOX1 from participating in pro-metastatic ECM remodeling. Here we show that QSOX1 inhibitory antibodies decreased tumor growth and metastasis in murine cancer models and had added benefits when provided together with chemotherapy. Mechanistically, the inhibitors dampened stromal participation in tumor development, as the tumors of treated animals showed fewer myofibroblasts and poorer ECM organization. Thus, our findings demonstrate that specifically targeting excess stromal QSOX1 secreted in response to tumor-cell signaling provides a means to modulate the tumor microenvironment and may complement other therapeutic approaches in cancer.
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Affiliation(s)
- Tal Feldman
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Iris Grossman-Haham
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yoav Elkis
- Almog Diagnostic, Shoham 6081513, Israel
| | - Patrick Vilela
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Neta Moskovits
- Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Iris Barshack
- Institute of Pathology, Sheba Medical Center Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Tomer M Salame
- Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Deborah Fass
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Tal Ilani
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
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Elkis Y, Cohen M, Yaffe E, Satmary-Tusk S, Feldman T, Hikri E, Nyska A, Feiglin A, Ofran Y, Shpungin S, Nir U. A novel Fer/FerT targeting compound selectively evokes metabolic stress and necrotic death in malignant cells. Nat Commun 2017; 8:940. [PMID: 29038547 PMCID: PMC5643328 DOI: 10.1038/s41467-017-00832-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 07/28/2017] [Indexed: 12/31/2022] Open
Abstract
Disruption of the reprogrammed energy management system of malignant cells is a prioritized goal of targeted cancer therapy. Two regulators of this system are the Fer kinase, and its cancer cell specific variant, FerT, both residing in subcellular compartments including the mitochondrial electron transport chain. Here, we show that a newly developed inhibitor of Fer and FerT, E260, selectively evokes metabolic stress in cancer cells by imposing mitochondrial dysfunction and deformation, and onset of energy-consuming autophagy which decreases the cellular ATP level. Notably, Fer was also found to associate with PARP-1 and E260 disrupted this association thereby leading to PARP-1 activation. The cooperative intervention with these metabolic pathways leads to energy crisis and necrotic death in malignant, but not in normal human cells, and to the suppression of tumors growth in vivo. Thus, E260 is a new anti-cancer agent which imposes metabolic stress and cellular death in cancer cells. The tyrosine-kinases Fer/FerT associate with the mitochondrial electron transport chain in cancer cells supporting their metabolic reprogramming. Here the authors discover a compound that disrupts Fer /FerT activity and selectively induces cell death of cancer cell lines displaying anti-tumor activity in vivo.
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Affiliation(s)
- Yoav Elkis
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Moshe Cohen
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Etai Yaffe
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Shirly Satmary-Tusk
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Tal Feldman
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Elad Hikri
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Abraham Nyska
- Consultant in Toxicological Pathology, Timrat, and Sackler School of Medicine, Tel Aviv University, Tel Aviv, 36576, Israel
| | - Ariel Feiglin
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Yanay Ofran
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Sally Shpungin
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Uri Nir
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel.
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Elkis Y, Bel S, Rahimi R, Lerer-Goldstein T, Levin-Zaidman S, Babushkin T, Shpungin S, Nir U. TMF/ARA160 Governs the Dynamic Spatial Orientation of the Golgi Apparatus during Sperm Development. PLoS One 2015; 10:e0145277. [PMID: 26701263 PMCID: PMC4689540 DOI: 10.1371/journal.pone.0145277] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 12/02/2015] [Indexed: 12/20/2022] Open
Abstract
TMF/ARA160 is known to be a TATA element Modulatory Factor (TMF). It was initially identified as a DNA-binding factor and a coactivator of the Androgen receptor. It was also characterized as a Golgi-associated protein, which is essential for acrosome formation during functional sperm development. However, the molecular roles of TMF in this intricate process have not been revealed. Here, we show that during spermiogenesis, TMF undergoes a dynamic change of localization throughout the Golgi apparatus. Specifically, TMF translocates from the cis-Golgi to the trans-Golgi network and to the emerging vesicles surface, as the round spermatids develop. Notably, lack of TMF led to an abnormal spatial orientation of the Golgi and to the deviation of the trans-Golgi surface away from the nucleus of the developing round spermatids. Concomitantly, pro-acrosomal vesicles derived from the TMF-/- Golgi lacked targeting properties and did not tether to the spermatid nuclear membrane thereby failing to form the acrosome anchoring scaffold, the acroplaxome, around the cell-nucleus. Absence of TMF also perturbed the positioning of microtubules, which normally lie in proximity to the Golgi and are important for maintaining Golgi spatial orientation and dynamics and for chromatoid body formation, which is impaired in TMF-/- spermatids. In-silico evaluation combined with molecular and electron microscopic analyses revealed the presence of a microtubule interacting domain (MIT) in TMF, and confirmed the association of TMF with microtubules in spermatogenic cells. Furthermore, the MIT domain in TMF, along with microtubules integrity, are required for stable association of TMF with the Golgi apparatus. Collectively, we show here for the first time that a Golgi and microtubules associated protein is crucial for maintaining proper Golgi orientation during a cell developmental process.
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Affiliation(s)
- Yoav Elkis
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Shai Bel
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Roni Rahimi
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Tali Lerer-Goldstein
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Smadar Levin-Zaidman
- Electron Microscopy Unit, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Tatiana Babushkin
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Sally Shpungin
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Uri Nir
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
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Yaffe E, Hikri E, Elkis Y, Cohen O, Segal A, Makovski A, Varvak A, Shpungin S, Nir U. Oncogenic properties of a spermatogenic meiotic variant of fer kinase expressed in somatic cells. Cancer Res 2014; 74:6474-85. [PMID: 25237066 DOI: 10.1158/0008-5472.can-14-0058] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The kinase Fer and its spermatogenic meiotic variant, FerT, are coexpressed in normal testes and cancerous tumors, but whether they exert related roles in spermatogenic or malignant cells has not been known. Here, we show that Fer and FerT reside in the mitochondria of spermatogenic cells and are harnessed to the reprogrammed mitochondria of colon carcinoma cells. Both kinases bound complex I of the mitochondrial electron transport chain (ETC) in spermatogenic and in colon carcinoma cells, and silencing of either Fer or FerT was sufficient to impair the activity of this complex. Directed mitochondrial accumulation of FerT in nonmalignant NIH3T3 cells increased their ETC complex I activity, ATP production, and survival, contingent upon stress conditions caused by nutrient and oxygen deprivation. Strikingly, directed mitochondrial accumulation of FerT endowed nonmalignant cells with tumor-forming ability. Thus, recruitment of a meiotic mitochondrial component to cancer cell mitochondria highlights a pivotal role for reprogrammed mitochondria in tumorigenesis.
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Affiliation(s)
- Etai Yaffe
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Elad Hikri
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Yoav Elkis
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Ortal Cohen
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Ariela Segal
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Adar Makovski
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Alexander Varvak
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Sally Shpungin
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Uri Nir
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
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Elkis Y, Bel S, Lerer-Goldstein T, Nyska A, Creasy DM, Shpungin S, Nir U. Testosterone deficiency accompanied by testicular and epididymal abnormalities in TMF(-/-) mice. Mol Cell Endocrinol 2013; 365:52-63. [PMID: 23000399 DOI: 10.1016/j.mce.2012.09.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 08/01/2012] [Accepted: 09/06/2012] [Indexed: 10/27/2022]
Abstract
TMF/ARA160 is a Golgi-associated protein, which is essential for spermiogenesis. In this study, we show that lack of TMF/ARA160 leads to defects in both the testis and the epididymis. In the testis, spermatid retention and extensive proliferation of Leydig cells were observed. Concomitantly, the serum levels of luteinizing hormone (LH), a stimulator of Leydig cell proliferation, were significantly increased in TMF(-/-) mice. Structural and functional defects were also seen in the epididymis. These included apoptosis of epithelial epididymal cells and sperm stasis in the cauda. Notably, the serum testosterone levels of TMF(-/-) mice were significantly lower than those of wt mice, and external testosterone administration decreased the number of apoptotic epithelial epididymal cells in TMF(-/-) animals. In summary, we show here for the first time that TMF/ARA160 participates in the control of serum testosterone levels in males, and its absence results in major testicular and epididymal defects.
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Affiliation(s)
- Yoav Elkis
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
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Bel S, Elkis Y, Lerer-Goldstein T, Nyska A, Shpungin S, Nir U. Loss of TMF/ARA160 protein renders colonic mucus refractory to bacterial colonization and diminishes intestinal susceptibility to acute colitis. J Biol Chem 2012; 287:25631-9. [PMID: 22553199 DOI: 10.1074/jbc.m112.364786] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
TMF/ARA160 is a Golgi-associated protein with several cellular functions, among them direction of the NF-κB subunit, p65 RelA, to ubiquitination and proteasomal degradation in stressed cells. We sought to investigate the role of TMF/ARA160 under imposed stress conditions in vivo. TMF(-/-) and wild-type (WT) mice were treated with the ulcerative agent dextran sulfate sodium (DSS), and the severity of the inflicted acute colitis was determined. TMF(-/-) mice were found to be significantly less susceptible to DSS-induced colitis, with profoundly less bacterial penetration into the colonic epithelia. Surprisingly, unlike in WT mice, no bacterial colonies were visualized in colons of healthy untreated TMF(-/-) mice, indicating the constitutive resistance of TMF(-/-) colonic mucus to bacterial retention and penetration. Gene expression analysis of colon tissues from unchallenged TMF(-/-) mice revealed 5-fold elevated transcription of the muc2 gene, which encodes the major component of the colonic mucus gel, the MUC2 mucin. Accordingly, the morphology of the colonic mucus in TMF(-/-) mice was found to differ from the mucus structure in WT colons. The NF-κB subunit, p65, a well known transcription inducer of muc2, was up-regulated significantly in TMF(-/-) intestinal epithelial cells. However, this did not cause spontaneous inflammation or increased colonic crypt cell proliferation. Collectively, our findings demonstrate that absence of TMF/ARA160 renders the colonic mucus refractory to bacterial colonization and the large intestine less susceptible to the onset of colitis.
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Affiliation(s)
- Shai Bel
- The Mina and Everard Goodman Faculty of Life-Science, Bar-Ilan University, Ramat-Gan 52900, Israel
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