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Sheikh IA, Midura‐Kiela MT, Herchuelz A, Sokolow S, Kiela PR, Ghishan FK. The Na +/Ca 2+ exchanger NCX3 mediates Ca 2+ entry into matrix vesicles to facilitate initial steps of mineralization in osteoblasts. J Extracell Vesicles 2024; 13:e12450. [PMID: 38859730 PMCID: PMC11165172 DOI: 10.1002/jev2.12450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 02/23/2024] [Accepted: 04/24/2024] [Indexed: 06/12/2024] Open
Abstract
Matrix vesicles (MVs) provide the initial site for amorphous hydroxyapatite (HA) formation within mineralizing osteoblasts. Although Na+/Ca2+ exchanger isoform-3 (NCX3, SLC8A3) was presumed to function as major Ca2+ transporter responsible for Ca2+ extrusion out of osteoblast into the calcifying bone matrix, its presence and functional role in MVs have not been investigated. In this study, we investigated the involvement of NCX3 in MV-mediated mineralization process and its impact on bone formation. Using differentiated MC3T3-E1 cells, we demonstrated that NCX3 knockout in these cells resulted in a significant reduction of Ca2+ deposition due to reduced Ca2+ entry within the MVs, leading to impaired mineralization. Consequently, the capacity of MVs to promote extracellular HA formation was diminished. Moreover, primary osteoblast isolated from NCX3 deficient mice (NCX3-/-) exhibits reduced mineralization efficacy without any effect on osteoclast activity. To validate this in vitro finding, μCT analysis revealed a substantial decrease in trabecular bone mineral density in both genders of NCX3-/- mice, thus supporting the critical role of NCX3 in facilitating Ca2+ uptake into the MVs to initiate osteoblast-mediated mineralization. NCX3 expression was also found to be the target of downregulation by inflammatory mediators in vitro and in vivo. This newfound understanding of NCX3's functional role in MVs opens new avenues for therapeutic interventions aimed at enhancing bone mineralization and treating mineralization-related disorders.
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Affiliation(s)
- Irshad A. Sheikh
- Daniel Cracchiolo Institute for Pediatric Autoimmune Disease Research, Steele Children’s Research Center, Department of PediatricsUniversity of ArizonaTucsonArizonaUSA
| | - Monica T. Midura‐Kiela
- Daniel Cracchiolo Institute for Pediatric Autoimmune Disease Research, Steele Children’s Research Center, Department of PediatricsUniversity of ArizonaTucsonArizonaUSA
| | - André Herchuelz
- Laboratoire de Pharmacodynamie et de Thérapeutique, Faculté de MédecineUniversité Libre de BruxellesBruxellesBelgium
| | - Sophie Sokolow
- School of NursingUniversity of California, Los Angeles (UCLA)Los AngelesCaliforniaUSA
| | - Pawel R. Kiela
- Daniel Cracchiolo Institute for Pediatric Autoimmune Disease Research, Steele Children’s Research Center, Department of PediatricsUniversity of ArizonaTucsonArizonaUSA
- Department of ImmunobiologyUniversity of ArizonaTucsonArizonaUSA
| | - Fayez K. Ghishan
- Daniel Cracchiolo Institute for Pediatric Autoimmune Disease Research, Steele Children’s Research Center, Department of PediatricsUniversity of ArizonaTucsonArizonaUSA
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2
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Neuberger A, Sobolevsky AI. Molecular pharmacology of the onco-TRP channel TRPV6. Channels (Austin) 2023; 17:2266669. [PMID: 37838981 PMCID: PMC10578198 DOI: 10.1080/19336950.2023.2266669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 09/29/2023] [Indexed: 10/17/2023] Open
Abstract
TRPV6, a representative of the vanilloid subfamily of TRP channels, serves as the principal calcium uptake channel in the gut. Dysregulation of TRPV6 results in disturbed calcium homeostasis leading to a variety of human diseases, including many forms of cancer. Inhibitors of this oncochannel are therefore particularly needed. In this review, we provide an overview of recent advances in structural pharmacology that uncovered the molecular mechanisms of TRPV6 inhibition by a variety of small molecules, including synthetic and natural, plant-derived compounds as well as some prospective and clinically approved drugs.
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Affiliation(s)
- Arthur Neuberger
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
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3
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Neuberger A, Trofimov YA, Yelshanskaya MV, Khau J, Nadezhdin KD, Khosrof LS, Krylov NA, Efremov RG, Sobolevsky AI. Molecular pathway and structural mechanism of human oncochannel TRPV6 inhibition by the phytocannabinoid tetrahydrocannabivarin. Nat Commun 2023; 14:4630. [PMID: 37532722 PMCID: PMC10397291 DOI: 10.1038/s41467-023-40362-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 07/25/2023] [Indexed: 08/04/2023] Open
Abstract
The calcium-selective oncochannel TRPV6 is an important driver of cell proliferation in human cancers. Despite increasing interest of pharmacological research in developing synthetic inhibitors of TRPV6, natural compounds acting at this channel have been largely neglected. On the other hand, pharmacokinetics of natural small-molecule antagonists optimized by nature throughout evolution endows these compounds with a medicinal potential to serve as potent and safe next-generation anti-cancer drugs. Here we report the structure of human TRPV6 in complex with tetrahydrocannabivarin (THCV), a natural cannabinoid inhibitor extracted from Cannabis sativa. We use cryo-electron microscopy combined with electrophysiology, calcium imaging, mutagenesis, and molecular dynamics simulations to identify THCV binding sites in the portals that connect the membrane environment surrounding the protein to the central cavity of the channel pore and to characterize the allosteric mechanism of TRPV6 inhibition. We also propose the molecular pathway taken by THCV to reach its binding site. Our study provides a foundation for the development of new TRPV6-targeting drugs.
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Affiliation(s)
- Arthur Neuberger
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Yury A Trofimov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Maria V Yelshanskaya
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Jeffrey Khau
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Kirill D Nadezhdin
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Lena S Khosrof
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Nikolay A Krylov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Roman G Efremov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
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4
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Neuberger A, Trofimov YA, Yelshanskaya MV, Nadezhdin KD, Krylov NA, Efremov RG, Sobolevsky AI. Structural mechanism of human oncochannel TRPV6 inhibition by the natural phytoestrogen genistein. Nat Commun 2023; 14:2659. [PMID: 37160865 PMCID: PMC10169861 DOI: 10.1038/s41467-023-38352-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 04/27/2023] [Indexed: 05/11/2023] Open
Abstract
Calcium-selective oncochannel TRPV6 is the major driver of cell proliferation in human cancers. While significant effort has been invested in the development of synthetic TRPV6 inhibitors, natural channel blockers have been largely neglected. Here we report the structure of human TRPV6 in complex with the plant-derived phytoestrogen genistein, extracted from Styphnolobium japonicum, that was shown to inhibit cell invasion and metastasis in cancer clinical trials. Despite the pharmacological value, the molecular mechanism of TRPV6 inhibition by genistein has remained enigmatic. We use cryo-EM combined with electrophysiology, calcium imaging, mutagenesis, and molecular dynamics simulations to show that genistein binds in the intracellular half of the TRPV6 pore and acts as an ion channel blocker and gating modifier. Genistein binding to the open channel causes pore closure and a two-fold symmetrical conformational rearrangement in the S4-S5 and S6-TRP helix regions. The unprecedented mechanism of TRPV6 inhibition by genistein uncovers new possibilities in structure-based drug design.
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Affiliation(s)
- Arthur Neuberger
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Yury A Trofimov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Maria V Yelshanskaya
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Kirill D Nadezhdin
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Nikolay A Krylov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Roman G Efremov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
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Szymczak-Tomczak A, Ratajczak AE, Kaczmarek-Ryś M, Hryhorowicz S, Rychter AM, Zawada A, Słomski R, Dobrowolska A, Krela-Kaźmierczak I. Pleiotropic Effects of Vitamin D in Patients with Inflammatory Bowel Diseases. J Clin Med 2022; 11:jcm11195715. [PMID: 36233580 PMCID: PMC9573215 DOI: 10.3390/jcm11195715] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/18/2022] [Accepted: 09/21/2022] [Indexed: 12/07/2022] Open
Abstract
The multifaceted activity of vitamin D in patients with inflammatory bowel disease (IBD) presents a challenge for further research in this area. Vitamin D is involved in the regulation of bone mineral metabolism, it participates in the regulation of the immune system, and it is an underlying factor in the pathogenesis of IBD. Additionally, vitamin D affects Th1 and Th2 lymphocytes, influencing the release of cytokines and inhibiting tumor necrosis factor (TNF) expression and the wnt/β-catenin pathway. As far as IBDs are concerned, they are associated with microbiota dysbiosis, abnormal inflammatory response, and micronutrient deficiency, including vitamin D hypovitaminosis. In turn, the biological activity of active vitamin D is regulated by the vitamin D receptor (VDR) which is associated with several processes related to IBD. Therefore, in terms of research on vitamin D supplementation in IBD patients, it is essential to understand the metabolic pathways and genetic determinants of vitamin D, as well as to identify the environmental factors they are subject to, not only in view of osteoporosis prevention and therapy, but primarily concerning modulating the course and supplementation of IBD pharmacotherapy.
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Affiliation(s)
- Aleksandra Szymczak-Tomczak
- Department of Gastroenterology, Dietetics and Internal Diseases, Poznan University of Medical Sciences, 61-701 Poznan, Poland
- Correspondence: (A.S.-T.); (A.E.R.); Tel.: +48-8691-343 (A.S.-T.); +48-667-385-996 (A.E.R.); Fax: +48-8691-686 (A.E.R.)
| | - Alicja Ewa Ratajczak
- Department of Gastroenterology, Dietetics and Internal Diseases, Poznan University of Medical Sciences, 61-701 Poznan, Poland
- Correspondence: (A.S.-T.); (A.E.R.); Tel.: +48-8691-343 (A.S.-T.); +48-667-385-996 (A.E.R.); Fax: +48-8691-686 (A.E.R.)
| | - Marta Kaczmarek-Ryś
- Institute of Human Genetics, Polish Academy of Sciences, 60-479 Poznan, Poland
| | - Szymon Hryhorowicz
- Institute of Human Genetics, Polish Academy of Sciences, 60-479 Poznan, Poland
| | - Anna Maria Rychter
- Department of Gastroenterology, Dietetics and Internal Diseases, Poznan University of Medical Sciences, 61-701 Poznan, Poland
| | - Agnieszka Zawada
- Department of Gastroenterology, Dietetics and Internal Diseases, Poznan University of Medical Sciences, 61-701 Poznan, Poland
| | - Ryszard Słomski
- Institute of Human Genetics, Polish Academy of Sciences, 60-479 Poznan, Poland
| | - Agnieszka Dobrowolska
- Department of Gastroenterology, Dietetics and Internal Diseases, Poznan University of Medical Sciences, 61-701 Poznan, Poland
| | - Iwona Krela-Kaźmierczak
- Department of Gastroenterology, Dietetics and Internal Diseases, Poznan University of Medical Sciences, 61-701 Poznan, Poland
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Edwards V, Smith DL, Meylan F, Tiffany L, Poncet S, Wu WW, Phue JN, Santana-Quintero L, Clouse KA, Gabay O. Analyzing the Role of Gut Microbiota on the Onset of Autoimmune Diseases Using TNF ΔARE Murine Model. Microorganisms 2021; 10:73. [PMID: 35056521 PMCID: PMC8779571 DOI: 10.3390/microorganisms10010073] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/13/2021] [Accepted: 12/21/2021] [Indexed: 12/24/2022] Open
Abstract
Very little is known about disease transmission via the gut microbiome. We hypothesized that certain inflammatory features could be transmitted via the gut microbiome and tested this hypothesis using an animal model of inflammatory diseases. Twelve-week-old healthy C57 Bl/6 and Germ-Free (GF) female and male mice were fecal matter transplanted (FMT) under anaerobic conditions with TNFΔARE-/+ donors exhibiting spontaneous Rheumatoid Arthritis (RA) and Inflammatory Bowel Disease (IBD) or with conventional healthy mice control donors. The gut microbiome analysis was performed using 16S rRNA sequencing amplification and bioinformatics analysis with the HIVE bioinformatics platform. Histology, immunohistochemistry, ELISA Multiplex analysis, and flow cytometry were conducted to confirm the inflammatory transmission status. We observed RA and IBD features transmitted in the GF mice cohort, with gut tissue disruption, cartilage alteration, elevated inflammatory mediators in the tissues, activation of CD4/CD8+ T cells, and colonization and transmission of the gut microbiome similar to the donors' profile. We did not observe a change or transmission when conventional healthy mice were FMT with TNFΔARE-/+ donors, suggesting that a healthy microbiome might withstand an unhealthy transplant. These findings show the potential involvement of the gut microbiome in inflammatory diseases. We identified a cluster of bacteria playing a role in this mechanism.
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Affiliation(s)
- Vivienne Edwards
- Division of Biotechnology Review and Research I, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Office of Biotechnology Products, Office of Pharmaceutical Quality, Silver Spring, MD 20993, USA; (V.E.); (D.L.S.); (L.T.); (S.P.); (K.A.C.)
| | - Dylan L. Smith
- Division of Biotechnology Review and Research I, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Office of Biotechnology Products, Office of Pharmaceutical Quality, Silver Spring, MD 20993, USA; (V.E.); (D.L.S.); (L.T.); (S.P.); (K.A.C.)
| | - Francoise Meylan
- Translational Immunology Section, NIH, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA;
| | - Linda Tiffany
- Division of Biotechnology Review and Research I, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Office of Biotechnology Products, Office of Pharmaceutical Quality, Silver Spring, MD 20993, USA; (V.E.); (D.L.S.); (L.T.); (S.P.); (K.A.C.)
| | - Sarah Poncet
- Division of Biotechnology Review and Research I, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Office of Biotechnology Products, Office of Pharmaceutical Quality, Silver Spring, MD 20993, USA; (V.E.); (D.L.S.); (L.T.); (S.P.); (K.A.C.)
| | - Wells W. Wu
- Facility for Biotechnology Resources, Center for Biologicals Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (W.W.W.); (J.-N.P.)
| | - Je-Nie Phue
- Facility for Biotechnology Resources, Center for Biologicals Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD 20993, USA; (W.W.W.); (J.-N.P.)
| | - Luis Santana-Quintero
- U.S. Food and Drug Administration, Center for Biologics Evaluation & Research, Office of Biostatistics and Epidemiology, HIVE, Silver Spring, MD 20993, USA;
- U.S. Food and Drug Administration, Center for Drug Evaluation and Research, Office of New Drugs, Office of Hematology and Oncology Products, Silver Spring, MD 20993, USA
| | - Kathleen A. Clouse
- Division of Biotechnology Review and Research I, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Office of Biotechnology Products, Office of Pharmaceutical Quality, Silver Spring, MD 20993, USA; (V.E.); (D.L.S.); (L.T.); (S.P.); (K.A.C.)
| | - Odile Gabay
- Division of Biotechnology Review and Research I, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Office of Biotechnology Products, Office of Pharmaceutical Quality, Silver Spring, MD 20993, USA; (V.E.); (D.L.S.); (L.T.); (S.P.); (K.A.C.)
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7
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Structural mechanisms of TRPV6 inhibition by ruthenium red and econazole. Nat Commun 2021; 12:6284. [PMID: 34725357 PMCID: PMC8560856 DOI: 10.1038/s41467-021-26608-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 10/14/2021] [Indexed: 11/26/2022] Open
Abstract
TRPV6 is a calcium-selective ion channel implicated in epithelial Ca2+ uptake. TRPV6 inhibitors are needed for the treatment of a broad range of diseases associated with disturbed calcium homeostasis, including cancers. Here we combine cryo-EM, calcium imaging, and mutagenesis to explore molecular bases of human TRPV6 inhibition by the antifungal drug econazole and the universal ion channel blocker ruthenium red (RR). Econazole binds to an allosteric site at the channel’s periphery, where it replaces a lipid. In contrast, RR inhibits TRPV6 by binding in the middle of the ion channel’s selectivity filter and plugging its pore like a bottle cork. Despite different binding site locations, both inhibitors induce similar conformational changes in the channel resulting in closure of the gate formed by S6 helices bundle crossing. The uncovered molecular mechanisms of TRPV6 inhibition can guide the design of a new generation of clinically useful inhibitors. TRPV6 is a calcium-selective ion channel that is involved in numerous calcium-dependent physiological processes and it is of interest as a potential drug target. Here, the authors present the cryo-EM structures of human TRPV6 with the bound inhibitors ruthenium red and the antifungal drug econazole and discuss their inhibition mechanisms.
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Gîlcă-Blanariu GE, Coroabă A, Ciocoiu M, Trifan A, Dimofte G, Diaconescu S, Afrăsânie VA, Balan GG, Pinteală T, Ștefănescu G. Hair EDX Analysis-A Promising Tool for Micronutrient Status Evaluation of Patients with IBD? Nutrients 2021; 13:nu13082572. [PMID: 34444730 PMCID: PMC8399661 DOI: 10.3390/nu13082572] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 02/05/2023] Open
Abstract
Micronutrient deficiencies can arise in various conditions, including inflammatory bowel diseases (IBD), and diagnosing these deficiencies can be challenging in the absence of specific clinical signs. The aim of this study was to evaluate the status of various trace elements hair concentration in IBD patients compared to a healthy control group and to identify potential correlations between the micronutrient status and relevant parameters related to disease activity. The concentrations of iron, magnesium, calcium, zinc, copper, manganese, selenium and sulfur in the hair of 37 IBD patients with prior diagnosed IBD (12 Crohn's disease and 25 ulcerative colitis) and 31 healthy controls were evaluated by Energy Dispersive X-Ray spectroscopy (EDX). Significant differences in hair concentration profile of studied trace elements were identified for IBD patients compared to healthy controls. A significantly decreased hair concentration of iron, magnesium, calcium and selenium and a significantly increased sulfur hair concentration were observed in IBD patients at the time of evaluation. A decreased hair calcium concentration (r = -0.772, p = 0.003) and an increased sulfur concentration (r = 0.585, p = 0.046) were significantly correlated with disease activity. Conclusion: Hair mineral and trace elements evaluation may contribute to a proper evaluation of their status in IBD patients and improving the management of nutritional status of IBD patients.
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Affiliation(s)
- Georgiana-Emmanuela Gîlcă-Blanariu
- Faculty of Medicine, Grigore T Popa University of Medicine and Pharmacy, 700115 Iași, Romania; (G.-E.G.-B.); (M.C.); (A.T.); (G.D.); (V.-A.A.); (G.G.B.); (G.Ș.)
| | - Adina Coroabă
- Petru Poni Institute of Macromolecular Chemistry, 700487 Iași, Romania;
| | - Manuela Ciocoiu
- Faculty of Medicine, Grigore T Popa University of Medicine and Pharmacy, 700115 Iași, Romania; (G.-E.G.-B.); (M.C.); (A.T.); (G.D.); (V.-A.A.); (G.G.B.); (G.Ș.)
| | - Anca Trifan
- Faculty of Medicine, Grigore T Popa University of Medicine and Pharmacy, 700115 Iași, Romania; (G.-E.G.-B.); (M.C.); (A.T.); (G.D.); (V.-A.A.); (G.G.B.); (G.Ș.)
- Sf Spiridon County Clinical Emergency Hospital, 700111 Iași, Romania;
| | - Gabriel Dimofte
- Faculty of Medicine, Grigore T Popa University of Medicine and Pharmacy, 700115 Iași, Romania; (G.-E.G.-B.); (M.C.); (A.T.); (G.D.); (V.-A.A.); (G.G.B.); (G.Ș.)
| | - Smaranda Diaconescu
- Faculty of Medicine, Grigore T Popa University of Medicine and Pharmacy, 700115 Iași, Romania; (G.-E.G.-B.); (M.C.); (A.T.); (G.D.); (V.-A.A.); (G.G.B.); (G.Ș.)
- Correspondence:
| | - Vlad-Adrian Afrăsânie
- Faculty of Medicine, Grigore T Popa University of Medicine and Pharmacy, 700115 Iași, Romania; (G.-E.G.-B.); (M.C.); (A.T.); (G.D.); (V.-A.A.); (G.G.B.); (G.Ș.)
| | - Gheorghe G. Balan
- Faculty of Medicine, Grigore T Popa University of Medicine and Pharmacy, 700115 Iași, Romania; (G.-E.G.-B.); (M.C.); (A.T.); (G.D.); (V.-A.A.); (G.G.B.); (G.Ș.)
- Sf Spiridon County Clinical Emergency Hospital, 700111 Iași, Romania;
| | - Tudor Pinteală
- Sf Spiridon County Clinical Emergency Hospital, 700111 Iași, Romania;
| | - Gabriela Ștefănescu
- Faculty of Medicine, Grigore T Popa University of Medicine and Pharmacy, 700115 Iași, Romania; (G.-E.G.-B.); (M.C.); (A.T.); (G.D.); (V.-A.A.); (G.G.B.); (G.Ș.)
- Sf Spiridon County Clinical Emergency Hospital, 700111 Iași, Romania;
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Calcium physiology, metabolism and supplementation: a glance at patients with ankylosing spondylitis. Reumatologia 2020; 58:297-311. [PMID: 33227082 PMCID: PMC7667943 DOI: 10.5114/reum.2020.100112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 09/29/2020] [Indexed: 12/17/2022] Open
Abstract
The aim of this review is to describe the metabolism of calcium in ankylosing spondylitis compared to physiologic conditions, and to present the current evidence on the benefits and disadvantages of calcium supplementation in these patients. A narrative review of the literature was conducted using the PubMed database and a total of 65 articles were selected. Calcium is involved in many physiopathological processes, including inflammation, bone loss and bone formation, all of which occur in ankylosing spondylitis. Many ankylosing spondylitis patients suffer from concomitant osteopenia or osteoporosis, which represent indications for calcium supplementation. Conversely, there are still concerns about the use of calcium salts for the prevention of bone fragility in non-osteoporotic or non-osteopenic patients. In these cases, biologic agents may indirectly normalize calcium dysmetabolism by rebalancing the cytokine milieu, in turn associated with bone remodeling. Calcium supplements may be disadvantageous for entheseal calcifications, but so far there are no clear data confirming that such an association exists.
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10
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Yelshanskaya MV, Nadezhdin KD, Kurnikova MG, Sobolevsky AI. Structure and function of the calcium-selective TRP channel TRPV6. J Physiol 2020; 599:2673-2697. [PMID: 32073143 DOI: 10.1113/jp279024] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 02/03/2020] [Indexed: 12/23/2022] Open
Abstract
Epithelial calcium channel TRPV6 is a member of the vanilloid subfamily of TRP channels that is permeable to cations and highly selective to Ca2+ ; it shows constitutive activity regulated negatively by Ca2+ and positively by phosphoinositol and cholesterol lipids. In this review, we describe the molecular structure of TRPV6 and discuss how its structural elements define its unique functional properties. High Ca2+ selectivity of TRPV6 originates from the narrow selectivity filter, where Ca2+ ions are directly coordinated by a ring of anionic aspartate side chains. Divalent cations Ca2+ and Ba2+ permeate TRPV6 pore according to the knock-off mechanism, while tight binding of Gd3+ to the aspartate ring blocks the channel and prevents Na+ from permeating the pore. The iris-like channel opening is accompanied by an α-to-π helical transition in the pore-lining transmembrane helix S6. As a result of this transition, the intracellular halves of the S6 helices bend and rotate by about 100 deg, exposing different residues to the channel pore in the open and closed states. Channel opening is also associated with changes in occupancy of the transmembrane domain lipid binding sites. The inhibitor 2-aminoethoxydiphenyl borate (2-APB) binds to TRPV6 in a pocket formed by the cytoplasmic half of the S1-S4 transmembrane helical bundle and shifts open-closed channel equilibrium towards the closed state by outcompeting lipids critical for activation. Ca2+ inhibits TRPV6 via binding to calmodulin (CaM), which mediates Ca2+ -dependent inactivation. The TRPV6-CaM complex exhibits 1:1 stoichiometry; one TRPV6 tetramer binds both CaM lobes, which adopt a distinct head-to-tail arrangement. The CaM C-terminal lobe plugs the channel through a unique cation-π interaction by inserting the side chain of lysine K115 into a tetra-tryptophan cage at the ion channel pore intracellular entrance. Recent studies of TRPV6 structure and function described in this review advance our understanding of the role of this channel in physiology and pathophysiology and inform new therapeutic design.
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Affiliation(s)
- Maria V Yelshanskaya
- Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168th Street, New York, NY, 10032, USA
| | - Kirill D Nadezhdin
- Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168th Street, New York, NY, 10032, USA
| | - Maria G Kurnikova
- Chemistry Department, Carnegie Mellon University, 4400 Fifth Ave, Pittsburgh, PA, 15213, USA
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168th Street, New York, NY, 10032, USA
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11
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TNF-α-driven inflammation and mitochondrial dysfunction define the platelet hyperreactivity of aging. Blood 2019; 134:727-740. [PMID: 31311815 DOI: 10.1182/blood.2019000200] [Citation(s) in RCA: 174] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 07/02/2019] [Indexed: 12/11/2022] Open
Abstract
Aging and chronic inflammation are independent risk factors for the development of atherothrombosis and cardiovascular disease. We hypothesized that aging-associated inflammation promotes the development of platelet hyperreactivity and increases thrombotic risk during aging. Functional platelet studies in aged-frail adults and old mice demonstrated that their platelets are hyperreactive and form larger thrombi. We identified tumor necrosis factor α (TNF-α) as the key aging-associated proinflammatory cytokine responsible for platelet hyperreactivity. We further showed that platelet hyperreactivity is neutralized by abrogating signaling through TNF-α receptors in vivo in a mouse model of aging. Analysis of the bone marrow compartments showed significant platelet-biased hematopoiesis in old mice reflected by increased megakaryocyte-committed progenitor cells, megakaryocyte ploidy status, and thrombocytosis. Single-cell RNA-sequencing analysis of native mouse megakaryocytes showed significant reprogramming of inflammatory, metabolic, and mitochondrial gene pathways in old mice that appeared to play a significant role in determining platelet hyperreactivity. Platelets from old mice (where TNF-α was endogenously increased) and from young mice exposed to exogenous TNF-α exhibited significant mitochondrial changes characterized by elevated mitochondrial mass and increased oxygen consumption during activation. These mitochondrial changes were mitigated upon TNF-α blockade. Similar increases in platelet mitochondrial mass were seen in platelets from patients with myeloproliferative neoplasms, where TNF-α levels are also increased. Furthermore, metabolomics studies of platelets from young and old mice demonstrated age-dependent metabolic profiles that may differentially poise platelets for activation. Altogether, we present previously unrecognized evidence that TNF-α critically regulates megakaryocytes resident in the bone marrow niche and aging-associated platelet hyperreactivity and thrombosis.
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12
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Kilby K, Mathias H, Boisvenue L, Heisler C, Jones JL. Micronutrient Absorption and Related Outcomes in People with Inflammatory Bowel Disease: A Review. Nutrients 2019; 11:E1388. [PMID: 31226828 PMCID: PMC6627381 DOI: 10.3390/nu11061388] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/31/2019] [Accepted: 06/08/2019] [Indexed: 12/14/2022] Open
Abstract
Inflammatory Bowel Disease (IBD) is a chronic disorder associated with immune dysregulation and chronic inflammation of the digestive tract. While it is poorly understood, the role of nutrition and nutrient status in the etiology of IBD and its associated outcomes has led to increased research relating to micronutrient deficiency. This review offers an overview of recent literature related to micronutrient absorption and outcomes in adults with IBD. Although the absorption and IBD-related outcomes of some micronutrients (e.g., vitamin D and iron) are well understood, other micronutrients (e.g., vitamin A) require further research. Increased research and clinician knowledge of the relationship between micronutrients and IBD may manifest in improved nutrient screening, monitoring, treatment, and outcomes for people living with IBD.
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Affiliation(s)
- Kyle Kilby
- Faculty of Medicine, Dalhousie University, 1459 Oxford Street, Halifax, NS B3J 4R2, Canada.
| | - Holly Mathias
- School of Health and Human Performance, Dalhousie University, 6230 South Street, Halifax, NS B3H 1T8, Canada.
| | - Lindsay Boisvenue
- Seaway Valley Community Health Care, 353 Pitt Street, Cornwall, ON K6J 3R1, Canada.
| | - Courtney Heisler
- Nova Scotia Collaborative Inflammatory Bowel Disease Program, Division of Digestive Care and Endoscopy, QEII Health Science Centre, Room 932, Victoria Building, 1276 South Park Street, Halifax, NS B3H 2Y9, Canada.
| | - Jennifer L Jones
- Nova Scotia Collaborative Inflammatory Bowel Disease Program, Division of Digestive Care and Endoscopy, QEII Health Science Centre, Room 932, Victoria Building, 1276 South Park Street, Halifax, NS B3H 2Y9, Canada.
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13
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Smyth A, Gogarty M, Crean D, Murphy EP. Subcellular Localization of NR4A2 Orphan Nuclear Receptor Expression in Human and Mouse Synovial Joint Tissue. Methods Mol Biol 2019; 1966:17-26. [PMID: 31041736 DOI: 10.1007/978-1-4939-9195-2_3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
NR4A1-3 receptors are required in inflammatory disease initiation and progression, where they function as early response regulators, controlling the extent of the inflammatory response and promoting inflammatory resolution. NR4A receptor activity controls inflammatory processes in several diseases characterized by chronic inflammation including rheumatoid arthritis (RA) and atherosclerosis. Studies indicate that cell-type and cellular microenvironment can alter NR4A1-3 receptor activity and influence their biological roles. Thus, the study of appropriate in vivo models of inflammatory disease is important to ascertain their cell- and tissue-specific functional roles. Here we describe immunohistochemical approaches optimized to study the expression patterns of NR4A nuclear receptors in inflamed synovium tissues obtained from patients diagnosed with RA and mouse models of inflammatory joint disease.
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Affiliation(s)
- Aisling Smyth
- School of Veterinary Medicine, University College Dublin, Dublin 4, Ireland
| | - Martina Gogarty
- School of Veterinary Medicine, University College Dublin, Dublin 4, Ireland
| | - Daniel Crean
- School of Veterinary Medicine, University College Dublin, Dublin 4, Ireland
| | - Evelyn P Murphy
- School of Veterinary Medicine, University College Dublin, Dublin 4, Ireland.
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14
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Fecher-Trost C, Wissenbach U, Weissgerber P. TRPV6: From identification to function. Cell Calcium 2017; 67:116-122. [PMID: 28501141 DOI: 10.1016/j.ceca.2017.04.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 04/26/2017] [Accepted: 04/26/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Claudia Fecher-Trost
- Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Building 46, 66421 Homburg, Germany.
| | - Ulrich Wissenbach
- Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Building 46, 66421 Homburg, Germany
| | - Petra Weissgerber
- Institute of Experimental and Clinical Pharmacology and Toxicology, Saarland University, Building 46, 66421 Homburg, Germany.
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15
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Radhakrishnan VM, Gilpatrick MM, Parsa NA, Kiela PR, Ghishan FK. Expression of Cav1.3 calcium channel in the human and mouse colon: posttranscriptional inhibition by IFNγ. Am J Physiol Gastrointest Liver Physiol 2017; 312:G77-G84. [PMID: 27932504 PMCID: PMC5283901 DOI: 10.1152/ajpgi.00394.2016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 12/05/2016] [Accepted: 12/06/2016] [Indexed: 01/31/2023]
Abstract
It has been hypothesized that apically expressed L-type Ca2+ channel Cav1.3 (encoded by CACNA1D gene) contributes toward an alternative TRPV6-independent route of intestinal epithelial Ca2+ absorption, especially during digestion when high luminal concentration of Ca2+ and other nutrients limit TRPV6 contribution. We and others have implicated altered expression and activity of key mediators of intestinal and renal Ca2+ (re)absorption as contributors to negative systemic Ca2+ balance and bone loss in intestinal inflammation. Here, we investigated the effects of experimental colitis and related inflammatory mediators on colonic Cav1.3 expression. We confirmed Cav1.3 expression within the segments of the mouse and human gastrointestinal tract. Consistent with available microarray data (GEO database) from inflammatory bowel disease (IBD) patients, mouse colonic expression of Cav1.3 was significantly reduced in trinitrobenzene sulfonic acid (TNBS) colitis. In vitro, IFNγ most potently reduced Cav1.3 expression. We reproduced these findings in vivo with wild-type and Stat1-/- mice injected with IFNγ. The observed effect in Stat1-/- suggested a noncanonical transcriptional repression or a posttranscriptional mechanism. In support of the latter, we observed no effect on the cloned Cav1.3 gene promoter activity and accelerated Cav1.3 mRNA decay rate in IFNγ-treated HCT116 cells. While the relative contribution of Cav1.3 to intestinal Ca2+ absorption and its value as a therapeutic target remain to be established, we postulate that Cav1.3 downregulation in IBD may contribute to the negative systemic Ca2+ balance, to increased bone resorption, and to reduced bone mineral density in IBD patients.
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Affiliation(s)
| | | | - Nour Alhoda Parsa
- 1Department of Pediatrics, The University of Arizona, Tucson, Arizona; and
| | - Pawel R. Kiela
- 1Department of Pediatrics, The University of Arizona, Tucson, Arizona; and ,2Department of Immunobiology, The University of Arizona, Tucson, Arizona
| | - Fayez K. Ghishan
- 1Department of Pediatrics, The University of Arizona, Tucson, Arizona; and
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van Goor MKC, Hoenderop JGJ, van der Wijst J. TRP channels in calcium homeostasis: from hormonal control to structure-function relationship of TRPV5 and TRPV6. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:883-893. [PMID: 27913205 DOI: 10.1016/j.bbamcr.2016.11.027] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 11/23/2016] [Indexed: 12/16/2022]
Abstract
Maintaining plasma calcium levels within a narrow range is of vital importance for many physiological functions. Therefore, calcium transport processes in the intestine, bone and kidney are tightly regulated to fine-tune the rate of absorption, storage and excretion. The TRPV5 and TRPV6 calcium channels are viewed as the gatekeepers of epithelial calcium transport. Several calciotropic hormones control the channels at the level of transcription, membrane expression, and function. Recent technological advances have provided the first near-atomic resolution structural models of several TRPV channels, allowing insight into their architecture. While this field is still in its infancy, it has increased our understanding of molecular channel regulation and holds great promise for future structure-function studies of these ion channels. This review will summarize the mechanisms that control the systemic calcium balance, as well as extrapolate structural views to the molecular functioning of TRPV5/6 channels in epithelial calcium transport.
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Affiliation(s)
- Mark K C van Goor
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Joost G J Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands.
| | - Jenny van der Wijst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands.
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17
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Allais L, De Smet R, Verschuere S, Talavera K, Cuvelier CA, Maes T. Transient Receptor Potential Channels in Intestinal Inflammation: What Is the Impact of Cigarette Smoking? Pathobiology 2016; 84:1-15. [DOI: 10.1159/000446568] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 05/02/2016] [Indexed: 11/19/2022] Open
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18
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van Loon EPM, Little R, Prehar S, Bindels RJM, Cartwright EJ, Hoenderop JGJ. Calcium Extrusion Pump PMCA4: A New Player in Renal Calcium Handling? PLoS One 2016; 11:e0153483. [PMID: 27101128 PMCID: PMC4839660 DOI: 10.1371/journal.pone.0153483] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/17/2016] [Indexed: 11/19/2022] Open
Abstract
Calcium (Ca2+) is vital for multiple processes in the body, and maintenance of the electrolyte concentration is required for everyday physiological function. In the kidney, and more specifically, in the late distal convoluted tubule and connecting tubule, the fine-tuning of Ca2+ reabsorption from the pro-urine takes place. Here, Ca2+ enters the epithelial cell via the transient receptor potential vanilloid receptor type 5 (TRPV5) channel, diffuses to the basolateral side bound to calbindin-D28k and is extruded to the blood compartment via the Na+/Ca2+ exchanger 1 (NCX1) and the plasma membrane Ca2+ ATPase (PMCA). Traditionally, PMCA1 was considered to be the primary Ca2+ pump in this process. However, in recent studies TRPV5-expressing tubules were shown to highly express PMCA4. Therefore, PMCA4 may have a predominant role in renal Ca2+ handling. This study aimed to elucidate the role of PMCA4 in Ca2+ homeostasis by characterizing the Ca2+ balance, and renal and duodenal Ca2+-related gene expression in PMCA4 knockout mice. The daily water intake of PMCA4 knockout mice was significantly lower compared to wild type littermates. There was no significant difference in serum Ca2+ level or urinary Ca2+ excretion between groups. In addition, renal and duodenal mRNA expression levels of Ca2+-related genes, including TRPV5, TRPV6, calbindin-D28k, calbindin-D9k, NCX1 and PMCA1 were similar in wild type and knockout mice. Serum FGF23 levels were significantly increased in PMCA4 knockout mice. In conclusion, PMCA4 has no discernible role in normal renal Ca2+ handling as no urinary Ca2+ wasting was observed. Further investigation of the exact role of PMCA4 in the distal convoluted tubule and connecting tubule is required.
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Affiliation(s)
- Ellen P. M. van Loon
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Robert Little
- Institute of Cardiovascular Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
| | - Sukhpal Prehar
- Institute of Cardiovascular Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
| | - René J. M. Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Elizabeth J. Cartwright
- Institute of Cardiovascular Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom
| | - Joost G. J. Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
- * E-mail:
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19
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van Loon EPM, Pulskens WP, van der Hagen EAE, Lavrijsen M, Vervloet MG, van Goor H, Bindels RJM, Hoenderop JGJ. Shedding of klotho by ADAMs in the kidney. Am J Physiol Renal Physiol 2015; 309:F359-68. [PMID: 26155844 DOI: 10.1152/ajprenal.00240.2014] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/01/2015] [Indexed: 11/22/2022] Open
Abstract
The anti-aging gene klotho plays an important role in Ca(2+) and phosphate homeostasis. Membrane-bound klotho is an essential coreceptor for fibroblast growth factor-23 and can be cleaved by proteases, including a disintegrin and metalloproteinase (ADAM)10 and ADAM17. Cleavage of klotho occurs at a site directly above the plasma membrane (α-cut) or between the KL1 and KL2 domain (β-cut), resulting in soluble full-length klotho or KL1 and KL2 fragments, respectively. The aim of the present study was to gain insights into the mechanisms behind klotho cleavage processes in the kidney. Klotho shedding was demonstrated using a Madin-Darby canine kidney cell line stably expressing klotho and human embryonic kidney-293 cells transiently transfected with klotho. Here, we report klotho expression on both the basolateral and apical membrane, with a higher abundance of klotho at the apical membrane and in the apical media. mRNA expression of ADAM17 and klotho were enriched in mouse distal convoluted and connecting tubules. In vitro ADAM/matrix metalloproteinase inhibition by TNF484 resulted in a concentration-dependent inhibition of the α-cut, with a less specific effect on β-cut shedding. In vivo TNF484 treatment in wild-type mice did not change urinary klotho levels. However, ADAM/matrix metalloproteinase inhibition did increase renal and duodenal mRNA expression of phosphate transporters, whereas serum phosphate levels were significantly decreased. In conclusion, our data show that renal cells preferentially secrete klotho to the apical side and suggest that ADAMs are responsible for α-cut cleavage.
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Affiliation(s)
- Ellen P M van Loon
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Wilco P Pulskens
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Eline A E van der Hagen
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marla Lavrijsen
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marc G Vervloet
- Department of Nephrology, VU University Medical Center, Amsterdam, The Netherlands; and
| | - Harry van Goor
- Department of Pathology and Medical Biology, University Medical Center Groningen, Groningen, The Netherlands
| | - René J M Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joost G J Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands;
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20
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Patel C, Douard V, Yu S, Tharabenjasin P, Gao N, Ferraris RP. Fructose-induced increases in expression of intestinal fructolytic and gluconeogenic genes are regulated by GLUT5 and KHK. Am J Physiol Regul Integr Comp Physiol 2015; 309:R499-509. [PMID: 26084694 DOI: 10.1152/ajpregu.00128.2015] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 06/16/2015] [Indexed: 01/09/2023]
Abstract
Marked increases in fructose consumption have been tightly linked to metabolic diseases. One-third of ingested fructose is metabolized in the small intestine, but the underlying mechanisms regulating expression of fructose-metabolizing enzymes are not known. We used genetic mouse models to test the hypothesis that fructose absorption via glucose transporter protein, member 5 (GLUT5), metabolism via ketohexokinase (KHK), as well as GLUT5 trafficking to the apical membrane via the Ras-related protein in brain 11a (Rab11a)-dependent endosomes are required for the regulation of intestinal fructolytic and gluconeogenic enzymes. Fructose feeding increased the intestinal mRNA and protein expression of these enzymes in the small intestine of adult wild-type (WT) mice compared with those gavage fed with lysine or glucose. Fructose did not increase expression of these enzymes in the GLUT5 knockout (KO) mice. Blocking intracellular fructose metabolism by KHK ablation also prevented fructose-induced upregulation. Glycolytic hexokinase I expression was similar between WT and GLUT5- or KHK-KO mice and did not vary with feeding solution. Gavage feeding with the fructose-specific metabolite glyceraldehyde did not increase enzyme expression, suggesting that signaling occurs before the hydrolysis of fructose to three-carbon compounds. Impeding GLUT5 trafficking to the apical membrane using intestinal epithelial cell-specific Rab11a-KO mice impaired fructose-induced upregulation. KHK expression was uniformly distributed along the villus but was localized mainly in the basal region of the cytosol of enterocytes. The feedforward upregulation of fructolytic and gluconeogenic enzymes specifically requires GLUT5 and KHK and may proactively enhance the intestine's ability to process anticipated increases in dietary fructose concentrations.
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Affiliation(s)
- Chirag Patel
- Department of Pharmacology and Physiology, New Jersey Medical School, Rutgers University, Newark, New Jersey; and
| | - Veronique Douard
- Department of Pharmacology and Physiology, New Jersey Medical School, Rutgers University, Newark, New Jersey; and
| | - Shiyan Yu
- Department of Biological Sciences, School of Arts and Sciences, Rutgers University, Newark, New Jersey
| | - Phuntila Tharabenjasin
- Department of Pharmacology and Physiology, New Jersey Medical School, Rutgers University, Newark, New Jersey; and
| | - Nan Gao
- Department of Biological Sciences, School of Arts and Sciences, Rutgers University, Newark, New Jersey
| | - Ronaldo P Ferraris
- Department of Pharmacology and Physiology, New Jersey Medical School, Rutgers University, Newark, New Jersey; and
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21
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Caplazi P, Baca M, Barck K, Carano RAD, DeVoss J, Lee WP, Bolon B, Diehl L. Mouse Models of Rheumatoid Arthritis. Vet Pathol 2015; 52:819-26. [DOI: 10.1177/0300985815588612] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Rheumatoid arthritis (RA) is a chronic debilitating autoimmune disorder characterized by synovitis that leads to cartilage and bone erosion by invading fibrovascular tissue. Mouse models of RA recapitulate many features of the human disease. Despite the availability of medicines that are highly effective in many patient populations, autoimmune diseases (including RA) remain an area of active biomedical research, and consequently mouse models of RA are still extensively used for mechanistic studies and validation of therapeutic targets. This review aims to integrate morphologic features with model biology and cover the key characteristics of the most commonly used induced and spontaneous mouse models of RA. Induced models emphasized in this review include collagen-induced arthritis and antibody-induced arthritis. Collagen-induced arthritis is an example of an active immunization strategy, whereas antibody- induced arthritis models, such as collagen antibody–induced arthritis and K/BxN antibody transfer arthritis, represent examples of passive immunization strategies. The coverage of spontaneous models in this review is focused on the TNFΔ ARE mouse, in which arthritis results from overexpression of TNF-α, a master proinflammatory cytokine that drives disease in many patients.
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Affiliation(s)
- P. Caplazi
- Departments of Research Pathology, Genentech Inc, South San Francisco, CA, USA
| | - M. Baca
- Departments of Research Pathology, Genentech Inc, South San Francisco, CA, USA
| | - K. Barck
- Biomedical Imaging, Genentech Inc, South San Francisco, CA, USA
| | - R. A. D. Carano
- Biomedical Imaging, Genentech Inc, South San Francisco, CA, USA
| | - J. DeVoss
- Translational Immunology, Genentech Inc, South San Francisco, CA, USA
| | - W. P. Lee
- Translational Immunology, Genentech Inc, South San Francisco, CA, USA
| | - B. Bolon
- Department of Veterinary Biosciences and the Comparative Pathology and Mouse Phenotyping Shared Resource, The Ohio State University, Columbus, OH, USA
| | - L. Diehl
- Departments of Research Pathology, Genentech Inc, South San Francisco, CA, USA
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22
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Radhakrishnan VM, Kojs P, Ramalingam R, Midura-Kiela MT, Angeli P, Kiela PR, Ghishan FK. Experimental colitis is associated with transcriptional inhibition of Na+/Ca2+ exchanger isoform 1 (NCX1) expression by interferon γ in the renal distal convoluted tubules. J Biol Chem 2015; 290:8964-74. [PMID: 25648899 DOI: 10.1074/jbc.m114.616516] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Indexed: 01/20/2023] Open
Abstract
NCX1 is a Na(+)/Ca(2+) exchanger, which is believed to provide a key route for basolateral Ca(2+) efflux in the renal epithelia, thus contributing to renal Ca(2+) reabsorption. Altered mineral homeostasis, including intestinal and renal Ca(2+) transport may represent a significant component of the pathophysiology of the bone mineral density loss associated with Inflammatory Bowel Diseases (IBD). The objective of our research was to investigate the effects of TNBS and DSS colitis and related inflammatory mediators on renal Ncx1 expression. Colitis was associated with decreased renal Ncx1 expression, as examined by real-time RT-PCR, Western blotting, and immunofluorescence. In mIMCD3 cells, IFNγ significantly reduced Ncx1 mRNA and protein expression. Similar effects were observed in cells transiently transfected with a reporter construct bearing the promoter region of the kidney-specific Ncx1 gene. This inhibitory effect of IFNγ is mediated by STAT1 recruitment to the proximal promoter region of Ncx1. Further in vivo study with Stat1(-/-) mice confirmed that STAT1 is indeed required for the IFNγ mediated Ncx1 gene regulation. These results strongly support the hypothesis that impaired renal Ca(2+) handling occurs in experimental colitis. Negative regulation of NCX1- mediated renal Ca(2+) absorption by IFNγ may significantly contribute to the altered Ca(2+) homeostasis in IBD patients and to IBD-associated loss of bone mineral density.
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Affiliation(s)
| | - Pawel Kojs
- From the Departments of Pediatrics, Steele Children's Research Center and
| | | | | | - Peter Angeli
- Zanvyl Krieger School of Arts and Sciences Johns Hopkins University, Baltimore, Maryland 21218
| | - Pawel R Kiela
- From the Departments of Pediatrics, Steele Children's Research Center and Immunobiology, University of Arizona Health Sciences Center, Tucson, Arizona 85724, and
| | - Fayez K Ghishan
- From the Departments of Pediatrics, Steele Children's Research Center and
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23
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Van Acker A, Filtjens J, Van Welden S, Taveirne S, Van Ammel E, Vanhees M, Devisscher L, Kerre T, Taghon T, Vandekerckhove B, Plum J, Leclercq G. Ly49E expression on CD8αα-expressing intestinal intraepithelial lymphocytes plays no detectable role in the development and progression of experimentally induced inflammatory bowel diseases. PLoS One 2014; 9:e110015. [PMID: 25310588 PMCID: PMC4195694 DOI: 10.1371/journal.pone.0110015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 09/06/2014] [Indexed: 12/14/2022] Open
Abstract
The Ly49E NK receptor is a unique inhibitory receptor, presenting with a high degree of conservation among mouse strains and expression on both NK cells and intraepithelial-localised T cells. Amongst intraepithelial-localised T cells, the Ly49E receptor is abundantly expressed on CD8αα-expressing innate-like intestinal intraepithelial lymphocytes (iIELs), which contribute to front-line defense at the mucosal barrier. Inflammatory bowel diseases (IBDs), encompassing Crohn's disease and ulcerative colitis, have previously been suggested to have an autoreactive origin and to evolve from a dysbalance between regulatory and effector functions in the intestinal immune system. Here, we made use of Ly49E-deficient mice to characterize the role of Ly49E receptor expression on CD8αα-expressing iIELs in the development and progression of IBD. For this purpose we used the dextran sodium sulphate (DSS)- and trinitrobenzenesulfonic-acid (TNBS)-induced colitis models, and the TNFΔARE ileitis model. We show that Ly49E is expressed on a high proportion of CD8αα-positive iIELs, with higher expression in the colon as compared to the small intestine. However, Ly49E expression on small intestinal and colonic iIELs does not influence the development or progression of inflammatory bowel diseases.
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Affiliation(s)
- Aline Van Acker
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium
| | - Jessica Filtjens
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium
| | | | - Sylvie Taveirne
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium
| | - Els Van Ammel
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium
| | - Mandy Vanhees
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium
| | | | - Tessa Kerre
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium
| | - Tom Taghon
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium
| | - Bart Vandekerckhove
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium
| | - Jean Plum
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium
| | - Georges Leclercq
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium
- * E-mail:
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Hummel DM, Fetahu IS, Gröschel C, Manhardt T, Kállay E. Role of proinflammatory cytokines on expression of vitamin D metabolism and target genes in colon cancer cells. J Steroid Biochem Mol Biol 2014; 144 Pt A:91-5. [PMID: 24120915 PMCID: PMC4138205 DOI: 10.1016/j.jsbmb.2013.09.017] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 09/20/2013] [Accepted: 09/30/2013] [Indexed: 12/28/2022]
Abstract
Interleukin 6 (IL-6) and tumor necrosis factor alpha (TNFα) are proinflammatory cytokines that play a critical role in inflammatory bowel disease, as well as in colorectal tumorigenesis. We hypothesize that these cytokines modulate the expression and thus activity of the vitamin D system in colonic epithelial cells. We treated the colon cancer cell line COGA-1A for 6, 12, and 24h with 1,25-dihydroxyvitamin D3 (1,25-D3), IL-6, TNFα, and with combinations of these compounds. Using quantitative RT-PCR, we analyzed mRNA expression of genes activating and catabolizing 1,25-D3 (1α-hydroxylase (CYP27B1), 24-hydroxylase (CYP24A1)), expression of several vitamin D target genes, as well as expression of cyclooxygenase 2 (COX-2) and 15-hydroxyprostaglandin dehydrogenase. As expected, treatment with 1,25-D3 resulted in an upregulation of CYP24A1, whereas expression of CYP27B1 was not affected. Treatment with TNFα and IL-6 led to decreased expression of the vitamin D activating enzyme CYP27B1. The strong inflammatory property of TNFα was mirrored by its activation of COX-2 and inhibition of prostaglandin E2 (PGE2) catabolism. Interestingly, expression of the calcium ion channel TRPV6 was markedly decreased by TNFα. We conclude from these results that the presence of proinflammatory cytokines might impair activation of 1,25-D3, limiting its anti-inflammatory action. This article is part of a Special Issue entitled '16th Vitamin D Workshop'.
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Affiliation(s)
- Doris M Hummel
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
| | - Irfete S Fetahu
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
| | - Charlotte Gröschel
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
| | - Teresa Manhardt
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
| | - Enikő Kállay
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
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Abstract
The epithelium of the gastrointestinal tract is one of the most versatile tissues in the organism, responsible for providing a tight barrier between dietary and bacterial antigens and the mucosal and systemic immune system while maintaining efficient digestive and absorptive processes to ensure adequate nutrient and energy supply. Inflammatory bowel diseases (Crohn's disease and ulcerative colitis) are associated with a breakdown of both functions, which in some cases are clearly interrelated. In this updated literature review, we focus on the effects of intestinal inflammation and the associated immune mediators on selected aspects of the transepithelial transport of macronutrients and micronutrients. The mechanisms responsible for nutritional deficiencies are not always clear and could be related to decreased intake, malabsorption, and excess losses. We summarize the known causes of nutrient deficiencies and the mechanism of inflammatory bowel disease-associated diarrhea. We also overview the consequences of impaired epithelial transport, which infrequently transcend its primary purpose to affect the gut microbial ecology and epithelial integrity. Although some of those regulatory mechanisms are relatively well established, more work needs to be done to determine how inflammatory cytokines can alter the transport process of nutrients across the gastrointestinal and renal epithelia.
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Abstract
TRPV6 (former synonyms ECAC2, CaT1, CaT-like) displays several specific features which makes it unique among the members of the mammalian Trp gene family (1) TRPV6 (and its closest relative, TRPV5) are the only highly Ca(2+)-selective channels of the entire TRP superfamily (Peng et al. 1999; Wissenbach et al. 2001; Voets et al. 2004). (2) Translation of Trpv6 initiates at a non-AUG codon, at ACG, located upstream of the annotated AUG, which is not used for initiation (Fecher-Trost et al. 2013). The ACG codon is nevertheless decoded by methionine. Not only a very rare event in eukaryotic biology, the full-length TRPV6 protein existing in vivo comprises an amino terminus extended by 40 amino acid residues compared to the annotated truncated TRPV6 protein which has been used in most studies on TRPV6 channel activity so far. (In the following numbering occurs according to this full-length protein, with the numbers of the so far annotated truncated protein in brackets). (3) Only in humans a coupled polymorphism of Trpv6 exists causing three amino acid exchanges and resulting in an ancestral Trpv6 haplotype and a so-called derived Trpv6 haplotype (Wissenbach et al. 2001). The ancestral allele encodes the amino acid residues C197(157), M418(378) and M721(681) and the derived alleles R197(157), V418(378) and T721(681). The ancestral haplotype is found in all species, the derived Trpv6 haplotype has only been identified in humans, and its frequency increases with the distance to the African continent. Apparently the Trpv6 gene has been a strong target for selection in humans, and its derived variant is one of the few examples showing consistently differences to the orthologues genes of other primates (Akey et al. 2004, 2006; Stajich and Hahn 2005; Hughes et al. 2008). (4) The Trpv6 gene expression is significantly upregulated in several human malignancies including the most common cancers, prostate and breast cancer (Wissenbach et al. 2001; Zhuang et al. 2002; Fixemer et al. 2003; Bolanz et al. 2008). (5) Male mice lacking functional TRPV6 channels are hypo-/infertile making TRPV6 one of the very few channels essential for male fertility (Weissgerber et al. 2011, 2012).
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Affiliation(s)
- Claudia Fecher-Trost
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421, Homburg, Germany
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Role of proinflammatory cytokines on expression of vitamin D metabolism and target genes in colon cancer cells. J Steroid Biochem Mol Biol 2013. [PMID: 24120915 DOI: 10.1016/j.jsmb.2013.09.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Interleukin 6 (IL-6) and tumor necrosis factor alpha (TNFα) are proinflammatory cytokines that play a critical role in inflammatory bowel disease, as well as in colorectal tumorigenesis. We hypothesize that these cytokines modulate the expression and thus activity of the vitamin D system in colonic epithelial cells. We treated the colon cancer cell line COGA-1A for 6, 12, and 24h with 1,25-dihydroxyvitamin D3 (1,25-D3), IL-6, TNFα, and with combinations of these compounds. Using quantitative RT-PCR, we analyzed mRNA expression of genes activating and catabolizing 1,25-D3 (1α-hydroxylase (CYP27B1), 24-hydroxylase (CYP24A1)), expression of several vitamin D target genes, as well as expression of cyclooxygenase 2 (COX-2) and 15-hydroxyprostaglandin dehydrogenase. As expected, treatment with 1,25-D3 resulted in an upregulation of CYP24A1, whereas expression of CYP27B1 was not affected. Treatment with TNFα and IL-6 led to decreased expression of the vitamin D activating enzyme CYP27B1. The strong inflammatory property of TNFα was mirrored by its activation of COX-2 and inhibition of prostaglandin E2 (PGE2) catabolism. Interestingly, expression of the calcium ion channel TRPV6 was markedly decreased by TNFα. We conclude from these results that the presence of proinflammatory cytokines might impair activation of 1,25-D3, limiting its anti-inflammatory action. This article is part of a Special Issue entitled '16th Vitamin D Workshop'.
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Radhakrishnan VM, Ramalingam R, Larmonier CB, Thurston RD, Laubitz D, Midura-Kiela MT, McFadden RMT, Kuro-O M, Kiela PR, Ghishan FK. Post-translational loss of renal TRPV5 calcium channel expression, Ca(2+) wasting, and bone loss in experimental colitis. Gastroenterology 2013; 145:613-24. [PMID: 23747339 PMCID: PMC3755094 DOI: 10.1053/j.gastro.2013.06.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Revised: 05/30/2013] [Accepted: 06/01/2013] [Indexed: 01/21/2023]
Abstract
BACKGROUND & AIMS Dysregulated Ca(2+) homeostasis likely contributes to the etiology of inflammatory bowel disease-associated loss of bone mineral density. Experimental colitis leads to decreased expression of Klotho, a protein that supports renal Ca(2+) reabsorption by stabilizing the transient receptor potential vanilloid 5 (TRPV5) channel on the apical membrane of distal tubule epithelial cells. METHODS Colitis was induced in mice via administration of 2,4,6-trinitrobenzenesulfonic acid (TNBS) or transfer of CD4(+)interleukin-10(-/-) and CD4(+), CD45RB(hi) T cells. We investigated changes in bone metabolism, renal processing of Ca(2+), and expression of TRPV5. RESULTS Mice with colitis had normal serum levels of Ca(2+) and parathormone. Computed tomography analysis showed a decreased density of cortical and trabecular bone, and there was biochemical evidence for reduced bone formation and increased bone resorption. Increased fractional urinary excretion of Ca(2+) was accompanied by reduced levels of TRPV5 protein in distal convoluted tubules, with a concomitant increase in TRPV5 sialylation. In mouse renal intermedullary collecting duct epithelial (mIMCD3) cells transduced with TRPV5 adenovirus, the inflammatory cytokines tumor necrosis factor, interferon-γ, and interleukin-1β reduced levels of TRPV5 on the cell surface, leading to its degradation. Cytomix induced interaction between TRPV5 and UBR4 (Ubiquitin recoginition 4), an E3 ubiquitin ligase; knockdown of UBR4 with small interfering RNAs prevented cytomix-induced degradation of TRPV5. The effects of cytokines on TRPV5 were not observed in cells stably transfected with membrane-bound Klotho; TRPV5 expression was preserved when colitis was induced with TNBS in transgenic mice that overexpressed Klotho or in mice with T-cell transfer colitis injected with soluble recombinant Klotho. CONCLUSIONS After induction of colitis in mice via TNBS administration or T-cell transfer, tumor necrosis factor and interferon-γ reduced the expression and activity of Klotho, which otherwise would protect TRPV5 from hypersialylation and cytokine-induced TRPV5 endocytosis, UBR4-dependent ubiquitination, degradation, and urinary wasting of Ca(2+).
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Dashdorj A, Jyothi KR, Lim S, Jo A, Nguyen MN, Ha J, Yoon KS, Kim HJ, Park JH, Murphy MP, Kim SS. Mitochondria-targeted antioxidant MitoQ ameliorates experimental mouse colitis by suppressing NLRP3 inflammasome-mediated inflammatory cytokines. BMC Med 2013. [PMID: 23915129 DOI: 10.1186/17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
BACKGROUND MitoQ is a mitochondria-targeted derivative of the antioxidant ubiquinone, with antioxidant and anti-apoptotic functions. Reactive oxygen species are involved in many inflammatory diseases including inflammatory bowel disease. In this study, we assessed the therapeutic effects of MitoQ in a mouse model of experimental colitis and investigated the possible mechanisms underlying its effects on intestinal inflammation. METHODS Reactive oxygen species levels and mitochondrial function were measured in blood mononuclear cells of patients with inflammatory bowel disease. The effects of MitoQ were evaluated in a dextran sulfate sodium-induced colitis mouse model. Clinical and pathological markers of disease severity and oxidative injury, and levels of inflammatory cytokines in mouse colonic tissue were measured. The effect of MitoQ on inflammatory cytokines released in the human macrophage-like cell line THP-1 was also analyzed. RESULTS Cellular and mitochondrial reactive oxygen species levels in mononuclear cells were significantly higher in patients with inflammatory bowel disease (P <0.003, cellular reactive oxygen species; P <0.001, mitochondrial reactive oxygen species). MitoQ significantly ameliorated colitis in the dextran sulfate sodium-induced mouse model in vivo, reduced the increased oxidative stress response (malondialdehyde and 3-nitrotyrosine formation), and suppressed mitochondrial and histopathological injury by decreasing levels of inflammatory cytokines IL-1 beta and IL-18 (P <0.001 and P <0.01 respectively). By decreasing mitochondrial reactive oxygen species, MitoQ also suppressed activation of the NLRP3 inflammasome that was responsible for maturation of IL-1 beta and IL-18. In vitro studies demonstrated that MitoQ decreases IL-1 beta and IL-18 production in human THP-1 cells. CONCLUSION Taken together, our results suggest that MitoQ may have potential as a novel therapeutic agent for the treatment of acute phases of inflammatory bowel disease.
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Affiliation(s)
- Amarjargal Dashdorj
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea
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30
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Dashdorj A, Jyothi KR, Lim S, Jo A, Nguyen MN, Ha J, Yoon KS, Kim HJ, Park JH, Murphy MP, Kim SS. Mitochondria-targeted antioxidant MitoQ ameliorates experimental mouse colitis by suppressing NLRP3 inflammasome-mediated inflammatory cytokines. BMC Med 2013; 11:178. [PMID: 23915129 PMCID: PMC3750576 DOI: 10.1186/1741-7015-11-178] [Citation(s) in RCA: 147] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 07/08/2013] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND MitoQ is a mitochondria-targeted derivative of the antioxidant ubiquinone, with antioxidant and anti-apoptotic functions. Reactive oxygen species are involved in many inflammatory diseases including inflammatory bowel disease. In this study, we assessed the therapeutic effects of MitoQ in a mouse model of experimental colitis and investigated the possible mechanisms underlying its effects on intestinal inflammation. METHODS Reactive oxygen species levels and mitochondrial function were measured in blood mononuclear cells of patients with inflammatory bowel disease. The effects of MitoQ were evaluated in a dextran sulfate sodium-induced colitis mouse model. Clinical and pathological markers of disease severity and oxidative injury, and levels of inflammatory cytokines in mouse colonic tissue were measured. The effect of MitoQ on inflammatory cytokines released in the human macrophage-like cell line THP-1 was also analyzed. RESULTS Cellular and mitochondrial reactive oxygen species levels in mononuclear cells were significantly higher in patients with inflammatory bowel disease (P <0.003, cellular reactive oxygen species; P <0.001, mitochondrial reactive oxygen species). MitoQ significantly ameliorated colitis in the dextran sulfate sodium-induced mouse model in vivo, reduced the increased oxidative stress response (malondialdehyde and 3-nitrotyrosine formation), and suppressed mitochondrial and histopathological injury by decreasing levels of inflammatory cytokines IL-1 beta and IL-18 (P <0.001 and P <0.01 respectively). By decreasing mitochondrial reactive oxygen species, MitoQ also suppressed activation of the NLRP3 inflammasome that was responsible for maturation of IL-1 beta and IL-18. In vitro studies demonstrated that MitoQ decreases IL-1 beta and IL-18 production in human THP-1 cells. CONCLUSION Taken together, our results suggest that MitoQ may have potential as a novel therapeutic agent for the treatment of acute phases of inflammatory bowel disease.
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Affiliation(s)
- Amarjargal Dashdorj
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea
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Woudenberg-Vrenken TE, van der Eerden BCJ, van der Kemp AWCM, van Leeuwen JPTM, Bindels RJM, Hoenderop JGJ. Characterization of vitamin D-deficient klotho-/- mice: do increased levels of serum 1,25(OH)2D3 cause disturbed calcium and phosphate homeostasis in klotho-/- mice? Nephrol Dial Transplant 2012; 27:4061-8. [DOI: 10.1093/ndt/gfs177] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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Kann PH, Bartsch D, Langer P, Waldmann J, Hadji P, Pfützner A, Klüsener J. Peripheral bone mineral density in correlation to disease-related predisposing conditions in patients with multiple endocrine neoplasia type 1. J Endocrinol Invest 2012; 35:573-9. [PMID: 21791969 DOI: 10.3275/7880] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND AND AIM Patients with multiple endocrine neoplasia type 1 (MEN1) often have low bone mineral density (BMD) attributed to primary hyperparathyroidism (pHPT). However, in MEN1 patients, other endocrine dysfunctions and conditions such as hypercortisolism, hypogonadism, and GH deficiency due to pituitary manifestation, and surgery on the upper gastrointestinal tract may affect BMD. SUBJECTS AND METHODS In 23 patients with MEN1 (10 females, 13 males; 46±12 yr), BMD was determined by quantitative computed tomography at the forearm (pqCT), compared to a reference population and related to different conditions suspected to affect bone metabolism in MEN1. RESULTS In this cohort, Z-score for trabecular BMD was -0.85±1.18 and for total BMD -1.16±1.04. There was a similar trend towards lower BMD in uncontrolled hyperparathyroidism, hypercortisolism, hypogonadism/GH deficiency and the state after surgery at the upper gastrointestinal tract. CONCLUSIONS These data while confirming previous observations on reduced BMD in patients with MEN1, however, challenge its only or even predominant association with pHPT. Other conditions such as hypercortisolism, somatotrophic/ gonadotrophic pituitary insufficiency, and previous upper gastrointestinal surgery seem to be factors contributing to the risk of developing osteoporosis.
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Affiliation(s)
- P H Kann
- Division of Endocrinology and Diabetology, Faculty of Medicine and University Hospital, Philipp's University, Marburg, Germany.
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Abstract
A considerable part of the difficulty of determining nutrient requirements in pathologic states is the failure to understand the physiology unique to the specific condition. Here we take the specific example of burns in childhood and discuss the roles of the inflammatory and stress responses to the burn and the consequent transient increased bone resorption followed by osteoblast apoptosis and adynamic bone. This condition leads to a failure of the bone to take up and thus conserve the increased calcium liberated by the acutely increased bone resorption. On top of this mechanism, there is a cytokine-mediated upregulation in the parathyroid gland calcium-sensing receptor that results in hypocalcemic hypoparathyroidism and consequent urinary calcium wasting. As if that were not sufficient, the skin of the burned patient, both scarred area and normal-appearing adjacent skin, convert 7 dehydrocholesterol to pre-vitamin D(3) at a rate that is 20-25% of normal skin and circulating levels of 25-hydroxyvitamin D are chronically low. Thus, burn injury gives rise to calcium wasting, failure of bone to take up excessive calcium, and vitamin D insufficiency to frank deficiency. These and other areas must be addressed before it can be determined how much vitamin D and calcium should be given to a patient with severe burn injury.
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Baur P, Martin FP, Gruber L, Bosco N, Brahmbhatt V, Collino S, Guy P, Montoliu I, Rozman J, Klingenspor M, Tavazzi I, Thorimbert A, Rezzi S, Kochhar S, Benyacoub J, Kollias G, Haller D. Metabolic phenotyping of the Crohn's disease-like IBD etiopathology in the TNF(ΔARE/WT) mouse model. J Proteome Res 2011; 10:5523-35. [PMID: 22029571 DOI: 10.1021/pr2007973] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The underlying biochemical consequences of inflammatory bowel disease (IBD) on the systemic and gastrointestinal metabolism have not yet been fully elucidated but could help to better understand the disease pathogenesis and to identify tissue-specific markers associated with the different disease stages. Here, we applied a metabonomic approach to monitor metabolic events associated with the gradual development of Crohn's disease (CD)-like ileitis in the TNF(ΔARE/WT) mouse model. Metabolic profiles of different intestinal compartments from the age of 4 up to 24 weeks were generated by combining proton nuclear magnetic resonance ((1)H NMR) spectroscopy and liquid chromatography-mass spectrometry (LC-MS). From 8 weeks onward, mice developed CD similar to the immune and tissue-related phenotype of human CD with ileal involvement, including ileal histological abnormalities, reduced fat mass and body weight, as well as hallmarks of malabsorption with higher energy wasting. The metabonomic approach highlighted shifts in the intestinal lipid metabolism concomitant to the histological onset of inflammation. Moreover, the advanced disease status was characterized by a significantly altered metabolism of cholesterol, triglycerides, phospholipids, plasmalogens, and sphingomyelins in the inflamed tissue (ileum) and the adjacent intestinal parts (proximal colon). These results describe different biological processes associated with the disease onset, including modifications of the general cell membrane composition, alteration of energy homeostasis, and finally the generation of inflammatory lipid mediators. Taken together, this provides novel insights into IBD-related alterations of specific lipid-dependant processes during inflammatory states.
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Affiliation(s)
- Pia Baur
- ZIEL-Research Center for Nutrition and Food Science, CDD-Center for Diet and Disease, Technische Universität München, Gregor-Mendel-Strasse 2, 85350 Freising-Weihenstephan, Germany
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Gut-bone interactions and implications for the child with chronic gastrointestinal disease. J Pediatr Gastroenterol Nutr 2011; 53:250-4. [PMID: 21613962 DOI: 10.1097/mpg.0b013e3182254828] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Bone is not simply a framework on which to hang viscera and connective tissue; it is also a dynamic interactive organ system with roles in immunoregulation, adipogenesis, and vascular calcification, among others. Bone is intimately affected by chronic disease, including gastrointestinal disease. The mechanisms for bone loss in conditions such as inflammatory bowel disease, celiac disease, and cystic fibrosis are discussed with regard to the role of the inflammatory response. Furthermore, we raise the issue of effects of inflammation on both intestinal and renal calcium and phosphate transport, although the ways in which these actions affect bone are not explained and require further research. The stress response, a prominent feature following burn injury, is also elucidated and its relation to gastrointestinal disease is examined. We then discuss the importance of knowing the mechanism of bone loss to determine proper prevention and treatment for the bone loss in specific gastrointestinal conditions.
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Centeno V, Picotto G, Pérez A, Alisio A, Tolosa de Talamoni N. Intestinal Na(+)/Ca(2+) exchanger protein and gene expression are regulated by 1,25(OH)(2)D(3) in vitamin D-deficient chicks. Arch Biochem Biophys 2011; 509:191-6. [PMID: 21458410 DOI: 10.1016/j.abb.2011.03.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 03/21/2011] [Accepted: 03/25/2011] [Indexed: 12/14/2022]
Abstract
The role of 1,25(OH)(2)D(3) on the intestinal NCX activity was studied in vitamin D-deficient chicks (-D) as well as the hormone effect on NCX1 protein and gene expression and the potential molecular mechanisms underlying the responses. Normal, -D and -D chicks treated with cholecalciferol or 1,25(OH)(2)D(3) were employed. In some experiments, -D chicks were injected with cycloheximide or with cycloheximide and 1,25(OH)(2)D(3) simultaneously. NCX activity was decreased by -D diet, returning to normal values after 50 IU daily of cholecalciferol/10 days or a dose of 1μg calcitriol/kg of b.w. for 15 h. Cycloheximide blocked NCX activity enhancement produced by 1,25(OH)(2)D(3). NCX1 protein and gene expression were diminished by -D diet and enhanced by 1,25(OH)(2)D(3). Vitamin D receptor expression was decreased by -D diet, effect that disappeared after 1,25(OH)(2)D(3) treatment. Rapid effects of 1,25(OH)(2)D(3) on intestinal NCX activity were also demonstrated. The abolition of the rapid effects through addition of Rp-cAMPS and staurosporine suggests that non genomic effects of 1,25(OH)(2)D(3) on NCX activity are mediated by activation of PKA and PKC pathways. In conclusion, 1,25(OH)(2)D(3) enhances the intestinal NCX activity in -D chicks through genomic and non genomic mechanisms.
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Affiliation(s)
- Viviana Centeno
- Laboratorio Dr. Fernando Cañas, Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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Holzer P. Transient receptor potential (TRP) channels as drug targets for diseases of the digestive system. Pharmacol Ther 2011; 131:142-70. [PMID: 21420431 PMCID: PMC3107431 DOI: 10.1016/j.pharmthera.2011.03.006] [Citation(s) in RCA: 172] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 03/01/2011] [Indexed: 12/12/2022]
Abstract
Approximately 20 of the 30 mammalian transient receptor potential (TRP) channel subunits are expressed by specific neurons and cells within the alimentary canal. They subserve important roles in taste, chemesthesis, mechanosensation, pain and hyperalgesia and contribute to the regulation of gastrointestinal motility, absorptive and secretory processes, blood flow, and mucosal homeostasis. In a cellular perspective, TRP channels operate either as primary detectors of chemical and physical stimuli, as secondary transducers of ionotropic or metabotropic receptors, or as ion transport channels. The polymodal sensory function of TRPA1, TRPM5, TRPM8, TRPP2, TRPV1, TRPV3 and TRPV4 enables the digestive system to survey its physical and chemical environment, which is relevant to all processes of digestion. TRPV5 and TRPV6 as well as TRPM6 and TRPM7 contribute to the absorption of Ca²⁺ and Mg²⁺, respectively. TRPM7 participates in intestinal pacemaker activity, and TRPC4 transduces muscarinic acetylcholine receptor activation to smooth muscle contraction. Changes in TRP channel expression or function are associated with a variety of diseases/disorders of the digestive system, notably gastro-esophageal reflux disease, inflammatory bowel disease, pain and hyperalgesia in heartburn, functional dyspepsia and irritable bowel syndrome, cholera, hypomagnesemia with secondary hypocalcemia, infantile hypertrophic pyloric stenosis, esophageal, gastrointestinal and pancreatic cancer, and polycystic liver disease. These implications identify TRP channels as promising drug targets for the management of a number of gastrointestinal pathologies. As a result, major efforts are put into the development of selective TRP channel agonists and antagonists and the assessment of their therapeutic potential.
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Affiliation(s)
- Peter Holzer
- Research Unit of Translational Neurogastroenterology, Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Universitätsplatz 4, A-8010 Graz, Austria.
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Ghishan FK, Kiela PR. Advances in the understanding of mineral and bone metabolism in inflammatory bowel diseases. Am J Physiol Gastrointest Liver Physiol 2011; 300:G191-201. [PMID: 21088237 PMCID: PMC3043650 DOI: 10.1152/ajpgi.00496.2010] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Accepted: 11/11/2010] [Indexed: 02/08/2023]
Abstract
Chronic inflammatory disorders such as inflammatory bowel diseases (IBDs) affect bone metabolism and are frequently associated with the presence of osteopenia, osteoporosis, and increased risk of fractures. Although several mechanisms may contribute to skeletal abnormalities in IBD patients, inflammation and inflammatory mediators such as TNF, IL-1β, and IL-6 may be the most critical. It is not clear whether the changes in bone metabolism leading to decreased mineral density are the result of decreased bone formation, increased bone resorption, or both, with varying results reported in experimental models of IBD and in pediatric and adult IBD patients. New data, including our own, challenge the conventional views, and contributes to the unraveling of an increasingly complex network of interactions leading to the inflammation-associated bone loss. Since nutritional interventions (dietary calcium and vitamin D supplementation) are of limited efficacy in IBD patients, understanding the pathophysiology of osteopenia and osteoporosis in Crohn's disease and ulcerative colitis is critical for the correct choice of available treatments or the development of new targeted therapies. In this review, we discuss current concepts explaining the effects of inflammation, inflammatory mediators and their signaling effectors on calcium and phosphate homeostasis, osteoblast and osteoclast function, and the potential limitations of vitamin D used as an immunomodulator and anabolic hormone in IBD.
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Affiliation(s)
- Fayez K Ghishan
- Dept. of Pediatrics, Steele Children's Research Center, Univ. of Arizona Health Sciences Center; 1501 N. Campbell Ave., Tucson, AZ 85724, USA
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Peng JB. TRPV5 and TRPV6 in transcellular Ca(2+) transport: regulation, gene duplication, and polymorphisms in African populations. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 704:239-75. [PMID: 21290300 DOI: 10.1007/978-94-007-0265-3_14] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
TRPV5 and TRPV6 are unique members of the TRP super family. They are highly selective for Ca(2+) ions with multiple layers of Ca(2+)-dependent inactivation mechanisms, expressed at the apical membrane of Ca(2+) transporting epithelia, and robustly responsive to 1,25-dihydroxivitamin D(3). These features are well suited for their roles as Ca(2+) entry channels in the first step of transcellular Ca(2+) transport pathways, which are involved in intestinal absorption, renal reabsorption of Ca(2+), placental transfer of Ca(2+) to fetus, and many other processes. While TRPV6 is more broadly expressed in a variety of tissues such as esophagus, stomach, small intestine, colon, kidney, placenta, pancreas, prostate, uterus, salivary gland, and sweat gland, TRPV5 expression is relatively restricted to the distal convoluted tubule and connecting tubule of the kidney. There is only one TRPV6-like gene in fish and birds in comparison to both TRPV5 and TRPV6 genes in mammals, indicating TRPV5 gene was likely generated from duplication of TRPV6 gene during the evolution of mammals to meet the needs of complex renal function. TRPV5 and TRPV6 are subjected to vigorous regulations under physiological, pathological, and therapeutic conditions. The elevated TRPV6 level in malignant tumors such as prostate and breast cancers makes it a potential therapeutic target. TRPV6, and to a lesser extent TRPV5, exhibit unusually high levels of single nucleotide polymorphisms (SNPs) in African populations as compared to other populations, indicating TRPV6 gene was under selective pressure during or after humans migrated out of Africa. The SNPs of TRPV6 and TRPV5 likely contribute to the Ca(2+) conservation mechanisms in African populations.
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Affiliation(s)
- Ji-Bin Peng
- Division of Nephrology, Department of Medicine, Nephrology Research and Training Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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Kumari M, Khazai NB, Ziegler TR, Nanes MS, Abrams SA, Tangpricha V. Vitamin D-mediated calcium absorption in patients with clinically stable Crohn's disease: a pilot study. Mol Nutr Food Res 2010; 54:1085-91. [PMID: 20306476 DOI: 10.1002/mnfr.200900351] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Vitamin D is the critical hormone for intestinal absorption of calcium. Optimal calcium absorption is important for proper mineralization of bone in the prevention of osteoporosis and osteoporotic fractures, among other important functions. Diseases associated with gut inflammation, such as Crohn's disease (CD), may impair calcium absorption. This pilot study evaluated vitamin D- dependent calcium absorption in subjects with CD. Male subjects with CD (n=4) and healthy age-matched controls (n=5) were studied. All subjects had fractional calcium absorption (FCA; by the dual calcium isotope method), serum 25-hydroxyvitamin D, serum calcium and 24 h urinary calcium excretion measurements at baseline. The FCA in response to vitamin D therapy was re-assessed following administration of oral calcitriol 0.25 mcg twice daily for 1 wk, followed by oral calcitriol 0.50 mcg twice daily for 1 wk. Serum calcium and 24 h urinary calcium determinations were re-assessed after each increasing dose of calcitriol as safety measures. There was no significant difference in calcium FCA at baseline or after increasing doses of calcitriol between the CD and controls. FCA in the control and CD group was approximately 35% at baseline, which increased to 60% after calcitriol therapy. No subject developed hypercalcemia or hypercalciuria. Our results suggest that CD patients have a normal response to vitamin D in enhancing the efficacy of calcium absorption. This suggests that stable CD patients can follow calcium and vitamin D guidelines of non-CD adults. Other factors independent of vitamin D status may impair intestinal calcium absorption in CD, including the degree and location of inflammation, presence of surgical resection and/or use of glucocorticoids.
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Affiliation(s)
- Meena Kumari
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
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Thurston RD, Larmonier CB, Majewski PM, Ramalingam R, Midura-Kiela M, Laubitz D, Vandewalle A, Besselsen DG, Mühlbauer M, Jobin C, Kiela PR, Ghishan FK. Tumor necrosis factor and interferon-gamma down-regulate Klotho in mice with colitis. Gastroenterology 2010; 138:1384-94, 1394.e1-2. [PMID: 20004202 PMCID: PMC3454518 DOI: 10.1053/j.gastro.2009.12.002] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Revised: 11/13/2009] [Accepted: 06/11/2009] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Klotho (KL) is an anti-inflammatory protein that protects the endothelium from nitric oxide (NO)-induced dysfunction, reduces the expression of endothelial adhesion molecules, and potentially regulates T-cell functions. KL deficiency leads to premature senescence and impaired Ca2+/Pi homeostasis, which can lead to inflammatory bowel disease (IBD)-associated osteopenia/osteoporosis. We investigated the changes in renal expression of Kl as a consequence of colitis. METHODS We studied 3 mouse models of IBD: colitis induced by trinitrobenzene sulfonic acid, colitis induced by microflora (in gnotobiotic interleukin-10(-/-)), and colitis induced by adoptive transfer of CD4(+)CD45RB(high) T cells. Effects of the tumor necrosis factor (TNF) and interferon (IFN)-gamma on Kl expression and the activity of its promoter were examined in renal epithelial cells (mpkDCT4 and mIMCD3). RESULTS Renal expression of Kl messenger RNA (mRNA) and protein was reduced in all 3 models of IBD. Reduced level of KL correlated with the severity of colitis; the effect was reversed by neutralizing antibodies against TNF. In vitro, TNF inhibited Kl expression, an effect potentiated by IFN-gamma. The combination of TNF and IFN-gamma increased expression of inducible nitric oxide synthase (iNOS) and increased NO production. The effect of IFN-gamma was reproduced by exposure to an NO donor and reversed by the iNOS inhibitor. In cells incubated with TNF and/or IFN-gamma, Kl mRNA stability was unaffected, whereas Kl promoter activity was reduced, indicating that these cytokines regulate Kl at the transcriptional level. CONCLUSIONS The down-regulation of KL that occurs during inflammation might account for the extraintestinal complications such as abnormalities in bone homeostasis that occur in patients with IBD.
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Affiliation(s)
- Robert D. Thurston
- Department of Pediatrics, Steele Children’s Research Center, Tucson, Arizona
| | - Claire B. Larmonier
- Department of Pediatrics, Steele Children’s Research Center, Tucson, Arizona
| | - Pawel M. Majewski
- Department of Pediatrics, Steele Children’s Research Center, Tucson, Arizona
| | | | - Monica Midura-Kiela
- Department of Pediatrics, Steele Children’s Research Center, Tucson, Arizona
| | - Daniel Laubitz
- Department of Pediatrics, Steele Children’s Research Center, Tucson, Arizona
| | - Alain Vandewalle
- Center for Gastrointestinal Biology and Disease, University of North Carolina, Chapel Hill, North Carolina, INSERM U773
| | - David G. Besselsen
- Departments of University Animal Care and Veterinary Science, University of Arizona, Tucson, Arizona
| | - Marcus Mühlbauer
- Centre de Recherche Biomédicale Bichat Beaujon - Université Paris 7 Denis Diderot, Paris France
| | - Christian Jobin
- Centre de Recherche Biomédicale Bichat Beaujon - Université Paris 7 Denis Diderot, Paris France
| | - Pawel R. Kiela
- Department of Pediatrics, Steele Children’s Research Center, Tucson, Arizona,Department of Immunobiology, University of Arizona Health Sciences Center, Tucson, Arizona
| | - Fayez K. Ghishan
- Department of Pediatrics, Steele Children’s Research Center, Tucson, Arizona
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Alexander RT, Woudenberg-Vrenken TE, Buurman J, Dijkman H, van der Eerden BCJ, van Leeuwen JPTM, Bindels RJ, Hoenderop JG. Klotho prevents renal calcium loss. J Am Soc Nephrol 2009; 20:2371-9. [PMID: 19713312 DOI: 10.1681/asn.2008121273] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Disturbed calcium (Ca(2+)) homeostasis, which is implicit to the aging phenotype of klotho-deficient mice, has been attributed to altered vitamin D metabolism, but alternative possibilities exist. We hypothesized that failed tubular Ca(2+) absorption is primary, which causes increased urinary Ca(2+) excretion, leading to elevated 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] and its sequelae. Here, we assessed intestinal Ca(2+) absorption, bone densitometry, renal Ca(2+) excretion, and renal morphology via energy-dispersive x-ray microanalysis in wild-type and klotho(-/-) mice. We observed elevated serum Ca(2+) and fractional excretion of Ca(2+) (FE(Ca)) in klotho(-/-) mice. Klotho(-/-) mice also showed intestinal Ca(2+) hyperabsorption, osteopenia, and renal precipitation of calcium-phosphate. Duodenal mRNA levels of transient receptor potential vanilloid 6 (TRPV6) and calbindin-D(9K) increased. In the kidney, klotho(-/-) mice exhibited increased expression of TRPV5 and decreased expression of the sodium/calcium exchanger (NCX1) and calbindin-D(28K), implying a failure to absorb Ca(2+) through the distal convoluted tubule/connecting tubule (DCT/CNT) via TRPV5. Gene and protein expression of the vitamin D receptor (VDR), 25-hydroxyvitamin D-1-alpha-hydroxylase (1alphaOHase), and calbindin-D(9K) excluded renal vitamin D resistance. By modulating the diet, we showed that the renal Ca(2+) wasting was not secondary to hypercalcemia and/or hypervitaminosis D. In summary, these findings illustrate a primary defect in tubular Ca(2+) handling that contributes to the precipitation of calcium-phosphate in DCT/CNT. This highlights the importance of klotho to the prevention of renal Ca(2+) loss, secondary hypervitaminosis D, osteopenia, and nephrocalcinosis.
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Affiliation(s)
- R Todd Alexander
- Department of Physiology, Nijmegen Centre for Molecular Life Sciences, , 6500 HB Nijmegen, The Netherlands
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