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Kahya U, Köseer AS, Dubrovska A. Amino Acid Transporters on the Guard of Cell Genome and Epigenome. Cancers (Basel) 2021; 13:E125. [PMID: 33401748 PMCID: PMC7796306 DOI: 10.3390/cancers13010125] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/26/2020] [Accepted: 12/27/2020] [Indexed: 02/06/2023] Open
Abstract
Tumorigenesis is driven by metabolic reprogramming. Oncogenic mutations and epigenetic alterations that cause metabolic rewiring may also upregulate the reactive oxygen species (ROS). Precise regulation of the intracellular ROS levels is critical for tumor cell growth and survival. High ROS production leads to the damage of vital macromolecules, such as DNA, proteins, and lipids, causing genomic instability and further tumor evolution. One of the hallmarks of cancer metabolism is deregulated amino acid uptake. In fast-growing tumors, amino acids are not only the source of energy and building intermediates but also critical regulators of redox homeostasis. Amino acid uptake regulates the intracellular glutathione (GSH) levels, endoplasmic reticulum stress, unfolded protein response signaling, mTOR-mediated antioxidant defense, and epigenetic adaptations of tumor cells to oxidative stress. This review summarizes the role of amino acid transporters as the defender of tumor antioxidant system and genome integrity and discusses them as promising therapeutic targets and tumor imaging tools.
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Affiliation(s)
- Uğur Kahya
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, 01309 Dresden, Germany; (U.K.); (A.S.K.)
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, 01328 Dresden, Germany
| | - Ayşe Sedef Köseer
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, 01309 Dresden, Germany; (U.K.); (A.S.K.)
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, 01328 Dresden, Germany
- National Center for Tumor Diseases (NCT), Partner Site Dresden and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany
| | - Anna Dubrovska
- OncoRay–National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, 01309 Dresden, Germany; (U.K.); (A.S.K.)
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, 01328 Dresden, Germany
- National Center for Tumor Diseases (NCT), Partner Site Dresden and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany
- German Cancer Consortium (DKTK), Partner Site Dresden and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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Oba J, Okabe M, Yoshida T, Soko C, Fathy M, Amano K, Kobashi D, Wakasugi M, Okudera H. Hyperdry human amniotic membrane application as a wound dressing for a full-thickness skin excision after a third-degree burn injury. BURNS & TRAUMA 2020; 8:tkaa014. [PMID: 32733973 PMCID: PMC7382972 DOI: 10.1093/burnst/tkaa014] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/08/2020] [Indexed: 12/18/2022]
Abstract
Background Severe burn injuries create large skin defects that render the host susceptible to bacterial infections. Burn wound infection often causes systemic sepsis and severe septicemia, resulting in an increase in the mortality of patients with severe burn injuries. Therefore, appropriate wound care is important to prevent infection and improve patient outcomes. However, it is difficult to heal a third-degree burn injury. The aim of this study was to investigate whether hyperdry human amniotic membrane (HD-AM) could promote early granulation tissue formation after full-thickness skin excision in third-degree burn injury sites in mice. Methods After the development of HD-AM and creation of a third-degree burn injury model, the HD-AM was either placed or not placed on the wound area in the HD-AM group or HD-AM group, respectively. The groups were prepared for evaluation on postoperative days 1, 4 and 7. Azan staining was used for granulation tissue evaluation, and estimation of CD163, transforming growth factor beta-1 (TGF-β1), vascular endothelial growth factor (VEGF), CD31, alpha-smooth muscle actin (α-SMA) and Iba1 expression was performed by immunohistochemical staining. Quantitative reverse-transcription polymerase chain reaction (PCR) was used to investigate gene expression of growth factors, cell migration chemokines and angiogenic and inflammatory markers. Results The HD-AM group showed significant early and qualitatively good growth of granulation tissue on the full-thickness skin excision site. HD-AM promoted early-phase inflammatory cell infiltration, fibroblast migration and angiogenesis in the granulation tissue. Additionally, the early infiltration of cells of the immune system was observed. Conclusions HD-AM may be useful as a new wound dressing material for full-thickness skin excision sites after third-degree burn injuries, and may be a new therapeutic technique for improving the survival rate of patients with severe burn injuries.
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Affiliation(s)
- Jiro Oba
- Department of Emergency and Disaster Medicine, University of Toyama, Toyama 930-0194, Japan
| | - Motonori Okabe
- Department of Regenerative Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Toshiko Yoshida
- Department of Regenerative Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Chika Soko
- Department of Regenerative Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Moustafa Fathy
- Department of Regenerative Medicine, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.,Department of Biochemistry, Faculty of Pharmacy, Minia University, Minia 61519, Egypt
| | - Koji Amano
- Department of Emergency Surgery, Sakai City Medical Center, Sakai, Osaka 594-8304, Japan
| | - Daisuke Kobashi
- Department of Emergency and Disaster Medicine, University of Toyama, Toyama 930-0194, Japan
| | - Masahiro Wakasugi
- Department of Emergency and Disaster Medicine, University of Toyama, Toyama 930-0194, Japan
| | - Hiroshi Okudera
- Department of Emergency and Disaster Medicine, University of Toyama, Toyama 930-0194, Japan
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Han MK, Baker M, Zhang Y, Yang C, Zhang M, Garg P, Viennois E, Merlin D. Overexpression of CD98 in intestinal epithelium dysregulates miRNAs and their targeted proteins along the ileal villus-crypt axis. Sci Rep 2018; 8:16220. [PMID: 30385787 PMCID: PMC6212412 DOI: 10.1038/s41598-018-34474-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 10/07/2018] [Indexed: 01/19/2023] Open
Abstract
CD98 has been implicated in the experimental model of inflammatory bowel disease. We have previously shown that IEC-specific overexpression of CD98 mediates intestinal inflammation and intestinal epithelial barrier dysfunction. Mice overexpressing CD98 exhibited severe colitis and a greater susceptibility to CAC. Here we demonstrated CD98 overexpression to dysregulate homeostatic gradient profile of miRNA and protein expression along the ileal villus-crypt axis. Using miRNA-target gene prediction module, we observed differentially expressed miRNAs to target proteins of villus and crypt profoundly affected by CD98 overexpression. We have utilized online bioinformatics as methods to further scrutinize the biological meanings of miRNA-target data. We identified significant interactions among the differentially regulated proteins targeted by altered miRNAs in Tg mice. The biological processes affected by the predicted targets of miRNAs deviate from the homeostatic functions of the miRNA-gene-protein axis of the wildtype mice. Our results emphasize a dynamic perturbation of miRNA and protein expression in villus-crypt axis contributing to potential biological consequences of altering CD98 expression. Our findings also suggest the need for a consideration of arrays of interacting biological entities (i.e. miRNAs-mRNAs, protein-protein interaction) or a combination comparison for a better understanding of the disease pathology which is necessary for an effective therapeutic target development.
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Affiliation(s)
- Moon K Han
- Institute for Biomedical Sciences, Center for Diagnostics and Therapeutics, Center for Inflammation, Immunity and Infection, Digestive Disease Research Group, Georgia State University, Atlanta, 30303, USA.
| | - Mark Baker
- Institute for Biomedical Sciences, Center for Diagnostics and Therapeutics, Center for Inflammation, Immunity and Infection, Digestive Disease Research Group, Georgia State University, Atlanta, 30303, USA
| | - Yuchen Zhang
- Institute for Biomedical Sciences, Center for Diagnostics and Therapeutics, Center for Inflammation, Immunity and Infection, Digestive Disease Research Group, Georgia State University, Atlanta, 30303, USA
| | - Chunhua Yang
- Institute for Biomedical Sciences, Center for Diagnostics and Therapeutics, Center for Inflammation, Immunity and Infection, Digestive Disease Research Group, Georgia State University, Atlanta, 30303, USA
| | - Mingzhen Zhang
- Institute for Biomedical Sciences, Center for Diagnostics and Therapeutics, Center for Inflammation, Immunity and Infection, Digestive Disease Research Group, Georgia State University, Atlanta, 30303, USA
| | - Pallavi Garg
- Institute for Biomedical Sciences, Center for Diagnostics and Therapeutics, Center for Inflammation, Immunity and Infection, Digestive Disease Research Group, Georgia State University, Atlanta, 30303, USA
| | - Emilie Viennois
- Institute for Biomedical Sciences, Center for Diagnostics and Therapeutics, Center for Inflammation, Immunity and Infection, Digestive Disease Research Group, Georgia State University, Atlanta, 30303, USA
| | - Didier Merlin
- Institute for Biomedical Sciences, Center for Diagnostics and Therapeutics, Center for Inflammation, Immunity and Infection, Digestive Disease Research Group, Georgia State University, Atlanta, 30303, USA.,Atlanta Veterans Affairs Medical Center, Decatur, 30033, USA
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Canup BSB, Song H, Le Ngo V, Meng X, Denning TL, Garg P, Laroui H. CD98 siRNA-loaded nanoparticles decrease hepatic steatosis in mice. Dig Liver Dis 2017; 49:188-196. [PMID: 27939923 PMCID: PMC6475075 DOI: 10.1016/j.dld.2016.11.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 11/07/2016] [Accepted: 11/08/2016] [Indexed: 12/11/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is characterized by excessive lipid hepatic accumulation. Here, we investigated whether a reduction of CD98 expression mediated by CD98 siRNA-loaded nanoparticles (NPs) could attenuate liver disease markers in a mouse model of NAFLD. NPs were generated using a double emulsion/solvent evaporation technique. Mice fed a high fat diet for 8 weeks to induce fatty liver were treated with vein tail injections of CD98 siRNA-loaded NPs. In vitro, HepG2 treated with CD98 siRNA-loaded NPs showed significant downregulation of CD98 leading to a significant decrease of major pro-inflammatory cytokines and markers. In vivo, CD98 siRNA-loaded NPs strongly decreased all markers of NAFLD, including the blood levels of ALT and lipids accumulation, fibrosis evidence and pro-inflammatory cytokines. In conclusion, our results indicate that CD98 appears to function as a key actor/inducer in NAFLD, and that our NPs approach may offer a new targeted therapeutic for this disease.
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Affiliation(s)
- Brandon S B Canup
- Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA
| | - Heliang Song
- Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA
| | - Vu Le Ngo
- Department of Biology, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA
| | - Xiangxiao Meng
- Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA
| | - Timothy L Denning
- Department of Biology, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA
| | - Pallavi Garg
- Department of Biology, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA
| | - Hamed Laroui
- Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA; Department of Biology, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, USA.
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Downregulation of LAT1 expression suppresses cholangiocarcinoma cell invasion and migration. Cell Signal 2014; 26:1668-79. [DOI: 10.1016/j.cellsig.2014.04.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 03/26/2014] [Accepted: 04/04/2014] [Indexed: 01/26/2023]
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Ayyadurai S, Charania MA, Xiao B, Viennois E, Zhang Y, Merlin D. Colonic miRNA expression/secretion, regulated by intestinal epithelial PepT1, plays an important role in cell-to-cell communication during colitis. PLoS One 2014; 9:e87614. [PMID: 24586284 PMCID: PMC3929505 DOI: 10.1371/journal.pone.0087614] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 12/23/2013] [Indexed: 12/20/2022] Open
Abstract
PepT1 is a member of the proton-oligopeptide cotransporter family SLC15, which mediates the transport of di/tripeptides from intestinal lumen into epithelial cells. MicroRNAs (miRNAs), a small noncoding RNAs (21–23 nucleotides), post-transcriptionally regulate gene expression by binding to the 3′-untranslated regions (UTRs) of their target mRNAs. Although the role of most miRNAs remains elusive, they have been implicated in vital cellular functions such as intestinal epithelial cells differentiation, proliferation, and apoptosis. In the present study, we investigated the effect of intestinal epithelial PepT1 expression on microRNA (miRNA) expression/secretion in the colons of control mice and in mice with experimentally induced colonic inflammation (colitis). The colonic miRNA expression was deregulated in both colitis and control mice but the deregulation of miRNA expression/secretion was specific to colonic tissue and did not affect other tissues such as spleen and liver. Intestinal epithelial PepT1-dependent deregulation of colonic miRNA expression not only affects epithelial cells but also other cell types, such as intestinal macrophages. Importantly, we found the miRNA 23b which was known to be involved in inflammatory bowel disease was secreted and transported between cells to impose a gene-silencing effect on recipient intestinal macrophages. Based on our data, we may conclude that the expression of a specific protein, PepT1, in the intestine affects local miRNA expression/secretion in the colon on a tissue specific manner and may play an important role during the induction and progression of colitis. Colonic miRNA expression/secretion, regulated by intestinal epithelial PepT1, could play a crucial role in cell-to-cell communication during colitis.
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Affiliation(s)
- Saravanan Ayyadurai
- Department of Biology and Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia, United States of America
- * E-mail:
| | - Moiz A. Charania
- Department of Biology and Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia, United States of America
| | - Bo Xiao
- Department of Biology and Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia, United States of America
| | - Emilie Viennois
- Department of Biology and Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia, United States of America
- Veterans Affairs Medical Center, Decatur, Georgia, United States of America
| | - Yuchen Zhang
- Department of Biology and Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia, United States of America
| | - Didier Merlin
- Department of Biology and Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia, United States of America
- Veterans Affairs Medical Center, Decatur, Georgia, United States of America
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Targeting intestinal inflammation with CD98 siRNA/PEI-loaded nanoparticles. Mol Ther 2013; 22:69-80. [PMID: 24025751 DOI: 10.1038/mt.2013.214] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 09/03/2013] [Indexed: 12/27/2022] Open
Abstract
Intestinal CD98 expression plays a crucial role in controlling homeostatic and innate immune responses in the gut. Modulation of CD98 expression in intestinal cells therefore represents a promising therapeutic strategy for the treatment and prevention of inflammatory intestinal diseases, such as inflammatory bowel disease. Here, the advantages of nanoparticles (NPs) are used, including their ability to easily pass through physiological barriers and evade phagocytosis, high loading concentration, rapid kinetics of mixing and resistance to degradation. Using physical chemistry characterizations techniques, CD98 siRNA/polyethyleneimine (PEI)-loaded NPs was characterized (diameter of ~480 nm and a zeta potential of -5.26 mV). Interestingly, CD98 siRNA can be electrostatically complexed by PEI and thus protected from RNase. In addition, CD98 siRNA/PEI-loaded NPs are nontoxic and biocompatible with intestinal cells. Oral administration of CD98/PEI-loaded NPs encapsulated in a hydrogel reduced CD98 expression in mouse colonic tissues and decreased dextran sodium sulfate-induced colitis in a mouse model. Finally, flow cytometry showed that CD98 was effectively downregulated in the intestinal epithelial cells and intestinal macrophages of treated mice. Finally, the results collectively demonstrated the therapeutic effect of "hierarchical nano-micro particles" with colon-homing capabilities and the ability to directly release "molecularly specific" CD98 siRNA in colonic cells, thereby decreasing colitis.
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Viennois E, Chen F, Laroui H, Baker MT, Merlin D. Dextran sodium sulfate inhibits the activities of both polymerase and reverse transcriptase: lithium chloride purification, a rapid and efficient technique to purify RNA. BMC Res Notes 2013; 6:360. [PMID: 24010775 PMCID: PMC3847706 DOI: 10.1186/1756-0500-6-360] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 09/03/2013] [Indexed: 12/13/2022] Open
Abstract
Background Dextran sodium sulfate (DSS) is commonly used in mouse studies to induce a very reproducible colitis that effectively mimics the clinical and histological features of human inflammatory bowel disease (IBD) patients, especially ulcerative colitis. However, the mechanisms of action of DSS remain poorly understood, and observations by our laboratory and other groups indicate that DSS contamination of colonic tissues from DSS-treated mice potently inhibits the quantitative reverse-transcription polymerase chain reaction (qRT-PCR) amplification of mRNA. Results A prior study used poly-A-mediated mRNA purification to remove DSS from RNA extracts, but we herein report a second efficient and cost-effective approach to counteract this inhibition, using lithium chloride precipitation to entirely remove DSS from RNAs. We also explored how DSS interferes with qRT-PCR process, and we report for the first time that DSS can alter the binding of reverse transcriptase to previously primed RNA and specifically inhibits the enzymatic activities of reverse transcriptase and Taq polymerase in vitro. This likely explains why DSS-treated colonic RNA is not suitable to qRT-PCR amplification without a previous purification step. Conclusion In summary, we provide a simple method to remove DSS from colonic RNAs, and we demonstrate for the first time that DSS can inhibit the activities of both polymerase and reverse transcriptase. In order to reliably analyze gene expression in the colonic mucosa of DSS-treated mice, the efficiency rate of qRT-PCR must be the same between all the different experimental groups, including the water-treated control group, suggesting that whatever the duration and the percentage of the DSS treatment, RNAs must be purified.
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Affiliation(s)
- Emilie Viennois
- Department of Biology, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta GA 30303, USA.
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PepT1 expressed in immune cells has an important role in promoting the immune response during experimentally induced colitis. J Transl Med 2013; 93:888-99. [PMID: 23797361 DOI: 10.1038/labinvest.2013.77] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 05/02/2013] [Accepted: 05/13/2013] [Indexed: 11/08/2022] Open
Abstract
We and others have shown that the dipeptide cotransporter PepT1 is expressed in immune cells, including macrophages that are in close contact with the lamina propria of the small and large intestines. In the present study, we used PepT1-knockout (KO) mice to explore the role played by PepT1 in immune cells during dextran sodium sulfate (DSS)-induced colitis. DSS treatment caused less severe body weight loss, diminished rectal bleeding, and less diarrhea in PepT1-KO mice than in wild-type (WT) animals. A histological examination of colonic sections revealed that the colonic architecture was less disrupted and the extent of immune cell infiltration into the mucosa and submucosa following DSS treatment was reduced in PepT1-KO mice compared with WT animals. Consistent with these results, the DSS-induced colitis increase in colonic myeloperoxidase activity was significantly less in PepT1-KO mice than in WT littermates. The colonic levels of mRNAs encoding the inflammatory cytokines CXCL1, interleukin (IL)-6, monocyte chemotactic protein-1, IL-12, and interferon-γ were significantly lower in DSS-treated PepT1-KO mice than in DSS-treated WT animals. Colonic immune cells from WT had significantly higher level of proinflammatory cytokines then PepT1 KO. In addition, we observed that knocking down the PepT1 expression decreases chemotaxis of immune cells recruited during intestinal inflammation. Antibiotic treatment before DSS-induced colitis eliminated the differential expression of inflammatory cytokines between WT and PepT1-KO mice. In conclusion, PepT1 in immune cells regulates the secretion of proinflammatory cytokines triggered by bacteria and/or bacterial products, and thus has an important role in the induction of colitis. PepT1 may transport small bacterial products, such as muramyl dipeptide and the tripeptide L-Ala-gamma-D-Glu-meso-DAP, into macrophages. These materials may be sensed by members of the nucleotide-binding site-leucine-rich repeat family of intracellular receptors, ultimately resulting in altered homeostasis of the intestinal microbiota.
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Abstract
BACKGROUND MicroRNA-132 (miR-132) targets acetylcholinesterase (AChE) and potentiates the cholinergic blockade of inflammatory reactions in cultured cells and experimental mice, but the implications of this interaction to human inflammatory disease remained unexplored. This study aimed to test whether miR-132 is causally involved in anti-inflammatory reactions of patients with inflammatory bowel disease (IBD) and modulates vagal tone and consequently inflammation in patients with IBD. METHODS We prospectively measured inflammation readouts and the cholinergic status (total capacity for hydrolyzing acetylcholine in one's circulation), and AChE activity in 2 independent cohorts of patients with IBD and quantified miR-132 levels in intestinal tissue biopsies removed at colonoscopy from inflamed and apparently quiescent tissues of tested volunteers. RESULTS MiR-132 levels are higher in inflamed compared with apparently quiescent intestinal biopsies from patients with IBD. Correspondingly, the cholinergic status and AChE activity was significantly lower in patients with IBD suffering from moderate-severe disease as compared with healthy controls or patient with IBD presenting low disease severity. Patients with IBD (n = 16) presented lower AChE activity compared with healthy controls (n = 33; 289 ± 128 AU versus 391 ± 102 AU, P = 0.001), and a negative correlation between AChE activity and C-reactive protein levels (r = -0.47, P = 0.01). Corroborating these observations in an additional cohort of participants, C-reactive protein and AChE activity were negatively correlated in patients with moderate-severe disease (n = 16; r = -0.6, P = 0.04) and positively correlated in healthy controls (n = 74, r = 0.24, P = 0.046). CONCLUSIONS Taken together, these findings support an inflammation-dependent homeostatic role for the regulation by miR-132 of AChE in IBD, opening new venues for therapeutic interference.
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Intestinal epithelial CD98 directly modulates the innate host response to enteric bacterial pathogens. Infect Immun 2013; 81:923-34. [PMID: 23297381 DOI: 10.1128/iai.01388-12] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
CD98 is a type II transmembrane glycoprotein whose expression increases in intestinal epithelial cells (IECs) during intestinal inflammation. Enteropathogenic Escherichia coli (EPEC) is a food-borne human pathogen that attaches to IECs and injects effector proteins directly into the host cells, thus provoking an inflammatory response. In the present study, we investigated CD98 and EPEC interactions in vitro and ex vivo and examined FVB wild-type (WT) and villin-CD98 transgenic mice overexpressing human CD98 in IECs (hCD98 Tg mice) and infected with Citrobacter rodentium as an in vivo model. In vivo studies indicated that CD98 overexpression, localized to the apical domain of colonic cells, increased the attachment of C. rodentium in mouse colons and resulted in increased expression of proinflammatory markers and decreased expression of anti-inflammatory markers. The proliferative markers Ki-67 and cyclin D1 were significantly increased in the colonic tissue of C. rodentium-infected hCD98 Tg mice compared to that of WT mice. Ex vivo studies correlate with the in vivo data. Small interfering RNA (siRNA) studies with Caco2-BBE cells showed a decrease in adherence of EPEC to Caco2 cells in which CD98 expression was knocked down. In vitro surface plasmon resonance (SPR) experiments showed direct binding between recombinant hCD98 and EPEC/C. rodentium proteins. We also demonstrated that the partial extracellular loop of hCD98 was sufficient for direct binding to EPEC/C. rodentium. These findings demonstrate the importance of the extracellular loop of CD98 in the innate host defense response to intestinal infection by attaching and effacing (A/E) pathogens.
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