1
|
Xiong Y, Xu G, Chen M, Ma H. Intestinal Uptake and Tolerance to Food Antigens. Front Immunol 2022; 13:906122. [PMID: 35757706 PMCID: PMC9226482 DOI: 10.3389/fimmu.2022.906122] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/16/2022] [Indexed: 11/24/2022] Open
Abstract
Food allergy is a growing concern due to its increasing world-wide incidence. Strict avoidance of allergens is a passive treatment strategy. Since the mechanisms responsible for the occurrence and development of food allergy have not yet been fully elucidated, effective individualized treatment options are lacking. In this review, we summarize the pathways through which food antigens enter the intestine and review the proposed mechanisms describing how the intestine acquires and tolerates food antigens. When oral tolerance is not established, food allergy occurs. In addition, we also discuss the contribution of commensal bacteria of the gut in shaping tolerance to food antigens in the intestinal tract. Finally, we propose that elucidating the mechanisms of intestinal uptake and tolerance of food antigens will provide additional clues for potential treatment options for food allergy.
Collapse
Affiliation(s)
- Yuhong Xiong
- Department of Pediatrics, The First Affiliated Hospital of University of Science and Technology of China (USTC), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.,Institute of Immunology, The Chinese Academy of Sciences (CAS) Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Guifeng Xu
- Department of Pediatrics, The First Affiliated Hospital of University of Science and Technology of China (USTC), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Mingwu Chen
- Department of Pediatrics, The First Affiliated Hospital of University of Science and Technology of China (USTC), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Hongdi Ma
- Department of Pediatrics, The First Affiliated Hospital of University of Science and Technology of China (USTC), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.,Institute of Immunology, The Chinese Academy of Sciences (CAS) Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| |
Collapse
|
2
|
Behrens JL, Schnepel N, Hansen K, Hustedt K, Burmester M, Klinger S, Breves G, Muscher-Banse AS. Modulation of Intestinal Phosphate Transport in Young Goats Fed a Low Phosphorus Diet. Int J Mol Sci 2021; 22:ijms22020866. [PMID: 33467106 PMCID: PMC7831023 DOI: 10.3390/ijms22020866] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 01/07/2021] [Accepted: 01/13/2021] [Indexed: 12/03/2022] Open
Abstract
The intestinal absorption of phosphate (Pi) takes place transcellularly through the active NaPi-cotransporters type IIb (NaPiIIb) and III (PiT1 and PiT2) and paracellularly by diffusion through tight junction (TJ) proteins. The localisation along the intestines and the regulation of Pi absorption differ between species and are not fully understood. It is known that 1,25-dihydroxy-vitamin D3 (1,25-(OH)2D3) and phosphorus (P) depletion modulate intestinal Pi absorption in vertebrates in different ways. In addition to the apical uptake into the enterocytes, there are uncertainties regarding the basolateral excretion of Pi. Functional ex vivo experiments in Ussing chambers and molecular studies of small intestinal epithelia were carried out on P-deficient goats in order to elucidate the transepithelial Pi route in the intestine as well as the underlying mechanisms of its regulation and the proteins, which may be involved. The dietary P reduction had no effect on the duodenal and ileal Pi transport rate in growing goats. The ileal PiT1 and PiT2 mRNA expressions increased significantly, while the ileal PiT1 protein expression, the mid jejunal claudin-2 mRNA expression and the serum 1,25-(OH)2D3 levels were significantly reduced. These results advance the state of knowledge concerning the complex mechanisms of the Pi homeostasis in vertebrates.
Collapse
|
3
|
Li S, De La Cruz J, Hutchens S, Mukhopadhyay S, Criss ZK, Aita R, Pellon-Cardenas O, Hur J, Soteropoulos P, Husain S, Dhawan P, Verlinden L, Carmeliet G, Fleet JC, Shroyer NF, Verzi MP, Christakos S. Analysis of 1,25-Dihydroxyvitamin D 3 Genomic Action Reveals Calcium-Regulating and Calcium-Independent Effects in Mouse Intestine and Human Enteroids. Mol Cell Biol 2020; 41:e00372-20. [PMID: 33139494 PMCID: PMC7849401 DOI: 10.1128/mcb.00372-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 10/05/2020] [Accepted: 10/24/2020] [Indexed: 01/27/2023] Open
Abstract
Although vitamin D is critical for the function of the intestine, most studies have focused on the duodenum. We show that transgenic expression of the vitamin D receptor (VDR) only in the distal intestine of VDR null mice (KO/TG mice) results in the normalization of serum calcium and rescue of rickets. Although it had been suggested that calcium transport in the distal intestine involves a paracellular process, we found that the 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]-activated genes in the proximal intestine associated with active calcium transport (Trpv6, S100g, and Atp2b1) are also induced by 1,25(OH)2D3 in the distal intestine of KO/TG mice. In addition, Slc30a10, encoding a manganese efflux transporter, was one of the genes most induced by 1,25(OH)2D3 in both proximal and distal intestine. Both villus and crypt were found to express Vdr and VDR target genes. RNA sequence (RNA-seq) analysis of human enteroids indicated that the effects of 1,25(OH)2D3 observed in mice are conserved in humans. Using Slc30a10-/- mice, a loss of cortical bone and a marked decrease in S100g and Trpv6 in the intestine was observed. Our findings suggest an interrelationship between vitamin D and intestinal Mn efflux and indicate the importance of distal intestinal segments to vitamin D action.
Collapse
Affiliation(s)
- Shanshan Li
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
| | - Jessica De La Cruz
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
| | - Steven Hutchens
- Division of Pharmacology and Toxicology, College of Pharmacy, Institute for Cellular and Molecular Biology and Institute for Neuroscience, The University of Texas at Austin, Austin, Texas, USA
| | - Somshuvra Mukhopadhyay
- Division of Pharmacology and Toxicology, College of Pharmacy, Institute for Cellular and Molecular Biology and Institute for Neuroscience, The University of Texas at Austin, Austin, Texas, USA
| | - Zachary K Criss
- Integrative Molecular and Biomedical Sciences Graduate Program, Division of Medicine, Baylor College of Medicine, Houston, Texas, USA
| | - Rohit Aita
- Department of Genetics, Rutgers University, New Brunswick, New Jersey, USA
| | | | - Joseph Hur
- Department of Genetics, Rutgers University, New Brunswick, New Jersey, USA
| | - Patricia Soteropoulos
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
- Genomics Center, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
| | - Seema Husain
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
- Genomics Center, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
| | - Puneet Dhawan
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
- Genomics Center, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
| | - Lieve Verlinden
- Laboratory of Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, Leuven, Belgium
| | - Geert Carmeliet
- Laboratory of Clinical and Experimental Endocrinology, Department of Chronic Diseases and Metabolism, Leuven, Belgium
| | - James C Fleet
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana, USA
| | - Noah F Shroyer
- Integrative Molecular and Biomedical Sciences Graduate Program, Division of Medicine, Baylor College of Medicine, Houston, Texas, USA
| | - Michael P Verzi
- Department of Genetics, Rutgers University, New Brunswick, New Jersey, USA
| | - Sylvia Christakos
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
| |
Collapse
|
4
|
Zanu HK, Keerqin C, Kheravii SK, Morgan N, Wu SB, Bedford MR, Swick RA. Influence of meat and bone meal, phytase, and antibiotics on broiler chickens challenged with subclinical necrotic enteritis: 2. intestinal permeability, organ weights, hematology, intestinal morphology, and jejunal gene expression. Poult Sci 2020; 99:2581-2594. [PMID: 32359594 PMCID: PMC7597457 DOI: 10.1016/j.psj.2019.12.049] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 12/22/2019] [Accepted: 12/29/2019] [Indexed: 12/16/2022] Open
Abstract
Undigested proteins entering the hindgut may favor the proliferation of Clostridium perfringens. Using phytase to eliminate the need for meat and bone meal (MBM) as a P source may reduce potential infection with C. perfringens. A study was conducted to determine the impact of MBM, phytase, and antibiotics (AB) on intestinal permeability and morphology, organ weights, and jejunal gene expression in Ross 308 chickens challenged with subclinical necrotic enteritis (NE). Male Ross 308-day-old chicks (672 each) were randomly allocated to 8 treatments with 6 replicate pens each housing 14 birds. A 2 × 2 × 2 factorial arrangement of treatments was used: MBM (no or yes); AB (no or yes-Zn bacitracin 100 in S and 50 ppm in G/F and salinomycin Na 60 ppm in all phases); phytase (500 or 1,500 FTU/kg, both using 500 FTU matrix values) using wheat-SBM-canola meal diets. Birds were challenged with Eimeria spp on day 9, and C. perfringens strain EHE-NE18 on day 14 and 15. An AB × MBM interaction (P < 0.05) was detected for relative gizzard weight (with contents) being lower in birds fed MBM and AB compared to those fed MBM and no AB. A MBM × AB interaction (P > 0.01) was detected for lymphocyte counts being lower with MBM and AB compared to MBM without AB. A phytase × AB interaction (P < 0.05) was observed for villi length being increased with high phytase and no AB compared to with AB. Inclusion of MBM increased (P < 0.05) blood FICT-d concentration, whereas AB decreased it (P < 0.05). Antibiotics increased RBC (P < 0.05), Hgb (P < 0.05), and PCV (P < 0.05) and expression of Ca-binding protein, CALB1 (P > 0.05). Inclusion of MBM decreased expression of MUC2 (P < 0.05). Results indicate that dietary MBM has a detrimental effect on gut health of broilers but this may be counteracted using AB.
Collapse
Affiliation(s)
- H K Zanu
- School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - C Keerqin
- School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - S K Kheravii
- School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - N Morgan
- School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - S-B Wu
- School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - M R Bedford
- AB Vista, Marlborough, Wiltshire, SN8 4AN, United Kingdom
| | - R A Swick
- School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
| |
Collapse
|
5
|
Dhawan P, Veldurthy V, Yehia G, Hsaio C, Porta A, Kim KI, Patel N, Lieben L, Verlinden L, Carmeliet G, Christakos S. Transgenic Expression of the Vitamin D Receptor Restricted to the Ileum, Cecum, and Colon of Vitamin D Receptor Knockout Mice Rescues Vitamin D Receptor-Dependent Rickets. Endocrinology 2017; 158:3792-3804. [PMID: 28938396 PMCID: PMC5695835 DOI: 10.1210/en.2017-00258] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 09/06/2017] [Indexed: 01/01/2023]
Abstract
Although the intestine plays the major role in 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] action on calcium homeostasis, the mechanisms involved remain incompletely understood. The established model of 1,25(OH)2D3-regulated intestinal calcium absorption postulates a critical role for the duodenum. However, the distal intestine is where 70% to 80% of ingested calcium is absorbed. To test directly the role of 1,25(OH)2D3 and the vitamin D receptor (VDR) in the distal intestine, three independent knockout (KO)/transgenic (TG) lines expressing VDR exclusively in the ileum, cecum, and colon were generated by breeding VDR KO mice with TG mice expressing human VDR (hVDR) under the control of the 9.5-kb caudal type homeobox 2 promoter. Mice from one TG line (KO/TG3) showed low VDR expression in the distal intestine (<50% of the levels observed in KO/TG1, KO/TG2, and wild-type mice). In the KO/TG mice, hVDR was not expressed in the duodenum, jejunum, kidney, or other tissues. Growth arrest, elevated parathyroid hormone level, and hypocalcemia of the VDR KO mice were prevented in mice from KO/TG lines 1 and 2. Microcomputed tomography analysis revealed that the expression of hVDR in the distal intestine of KO/TG1 and KO/TG2 mice rescued the bone defects associated with systemic VDR deficiency, including growth plate abnormalities and altered trabecular and cortical parameters. KO/TG3 mice showed rickets, but less severely than VDR KO mice. These findings show that expression of VDR exclusively in the distal intestine can prevent abnormalities in calcium homeostasis and bone mineralization associated with systemic VDR deficiency.
Collapse
Affiliation(s)
- Puneet Dhawan
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey 07103
| | - Vaishali Veldurthy
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey 07103
| | - Ghassan Yehia
- The Genome Editing Core Facility, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey 07103
| | - Connie Hsaio
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey 07103
| | - Angela Porta
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey 07103
| | - Ki-in Kim
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey 07103
| | - Nishant Patel
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey 07103
| | - Liesbet Lieben
- Clinical and Experimental Medicine and Endocrinology, KU Leuven, Leuven B-3000, Belgium
| | - Lieve Verlinden
- Clinical and Experimental Medicine and Endocrinology, KU Leuven, Leuven B-3000, Belgium
| | - Geert Carmeliet
- Clinical and Experimental Medicine and Endocrinology, KU Leuven, Leuven B-3000, Belgium
| | - Sylvia Christakos
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey 07103
| |
Collapse
|
6
|
Elfers K, Marr I, Wilkens MR, Breves G, Langeheine M, Brehm R, Muscher-Banse AS. Expression of Tight Junction Proteins and Cadherin 17 in the Small Intestine of Young Goats Offered a Reduced N and/or Ca Diet. PLoS One 2016; 11:e0154311. [PMID: 27120348 PMCID: PMC4847856 DOI: 10.1371/journal.pone.0154311] [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: 12/13/2015] [Accepted: 04/12/2016] [Indexed: 12/14/2022] Open
Abstract
Diets fed to ruminants should contain nitrogen (N) as low as possible to reduce feed costs and environmental pollution. Though possessing effective N-recycling mechanisms to maintain the N supply for rumen microbial protein synthesis and hence protein supply for the host, an N reduction caused substantial changes in calcium (Ca) and phosphate homeostasis in young goats including decreased intestinal transepithelial Ca absorption as reported for monogastric species. In contrast to the transcellular component of transepithelial Ca transport, the paracellular route has not been investigated in young goats. Therefore, the aim of the present study was to characterise the effects of dietary N and/or Ca reduction on paracellular transport mechanisms in young goats. Electrophysiological properties of intestinal epithelia were investigated by Ussing chamber experiments. The expression of tight junction (TJ) and adherens junction (AJ) proteins in intestinal epithelia were examined on mRNA level by qPCR and on protein level by western blot analysis. Dietary N reduction led to a segment specific increase in tissue conductances in the proximal jejunum which might be linked to concomitantly decreased expression of cadherin 17 mRNA. Expression of occludin (OCLN) and zonula occludens protein 1 was increased in mid jejunal epithelia of N reduced fed goats on mRNA and partly on protein level. Reduced dietary Ca supply resulted in a segment specific increase in claudin 2 and claudin 12 expression and decreased the expression of OCLN which might have been mediated at least in part by calcitriol. These data show that dietary N as well as Ca reduction affected expression of TJ and AJ proteins in a segment specific manner in young goats and may thus be involved in modulation of paracellular Ca permeability.
Collapse
Affiliation(s)
- Kristin Elfers
- Department of Physiology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15/102, 30173, Hannover, Germany
| | - Isabell Marr
- Department of Physiology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15/102, 30173, Hannover, Germany
| | - Mirja R. Wilkens
- Department of Physiology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15/102, 30173, Hannover, Germany
| | - Gerhard Breves
- Department of Physiology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15/102, 30173, Hannover, Germany
| | - Marion Langeheine
- Institute of Anatomy, University of Veterinary Medicine Hannover, Bischofsholer Damm 15/122, 30173, Hannover, Germany
| | - Ralph Brehm
- Institute of Anatomy, University of Veterinary Medicine Hannover, Bischofsholer Damm 15/122, 30173, Hannover, Germany
| | - Alexandra S. Muscher-Banse
- Department of Physiology, University of Veterinary Medicine Hannover, Bischofsholer Damm 15/102, 30173, Hannover, Germany
- * E-mail:
| |
Collapse
|
7
|
Kopic S, Geibel JP. Gastric acid, calcium absorption, and their impact on bone health. Physiol Rev 2013; 93:189-268. [PMID: 23303909 DOI: 10.1152/physrev.00015.2012] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Calcium balance is essential for a multitude of physiological processes, ranging from cell signaling to maintenance of bone health. Adequate intestinal absorption of calcium is a major factor for maintaining systemic calcium homeostasis. Recent observations indicate that a reduction of gastric acidity may impair effective calcium uptake through the intestine. This article reviews the physiology of gastric acid secretion, intestinal calcium absorption, and their respective neuroendocrine regulation and explores the physiological basis of a potential link between these individual systems.
Collapse
Affiliation(s)
- Sascha Kopic
- Department of Surgery and Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut, USA
| | | |
Collapse
|
8
|
Morgan EL, Mace OJ, Affleck J, Kellett GL. Apical GLUT2 and Cav1.3: regulation of rat intestinal glucose and calcium absorption. J Physiol 2007; 580:593-604. [PMID: 17272350 PMCID: PMC2075547 DOI: 10.1113/jphysiol.2006.124768] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
We have proposed a model of intestinal glucose absorption in which transport by SGLT1 induces rapid insertion and activation of GLUT2 in the apical membrane by a PKC betaII-dependent mechanism. Since PKC betaII requires Ca(2+) and glucose is depolarizing, we have investigated whether glucose absorption is regulated by the entry of dietary Ca(2+) through Ca(v)1.3 in the apical membrane. When rat jejunum was perfused with 75 mM glucose, Ca(2+)-deplete conditions, or perfusion with the L-type antagonists nifedipine and verapamil strongly diminished the phloretin-sensitive apical GLUT2, but not the phloretin-insensitive SGLT1 component of glucose absorption. Western blotting showed that in each case there was a significant decrease in apical GLUT2 level, but no change in SGLT1 level. Inhibition of apical GLUT2 absorption coincided with inhibition of unidirectional (45)Ca(2+) entry by nifedipine and verapamil. At 10 mM luminal Ca(2+), (45)Ca(2+) absorption in the presence of 75 mM glucose was 2- to 3-fold that in the presence of 75 mM mannitol. The glucose-induced component was SGLT1-dependent and nifedipine-sensitive. RT-PCR revealed the presence of Ca(v)beta(3) in jejunal mucosa; Western blotting and immunocytochemistry localized Ca(v)beta(3) to the apical membrane, together with Ca(v)1.3. We conclude that in times of dietary sufficiency Ca(v)1.3 may mediate a significant pathway of glucose-stimulated Ca(2+) entry into the body and that luminal supply of Ca(2+) is necessary for GLUT2-mediated glucose absorption. The integration of glucose and Ca(2+) absorption represents a complex nutrient-sensing system, which allows both absorptive pathways to be regulated rapidly and precisely to match dietary intake.
Collapse
Affiliation(s)
- Emma L Morgan
- Department of Biology, The University of York, York YO10 5YW, UK
| | | | | | | |
Collapse
|
9
|
Fujinaka H, Nakamura J, Kobayashi H, Takizawa M, Murase D, Tokimitsu I, Suda T. Glucose 1-phosphate increases active transport of calcium in intestine. Arch Biochem Biophys 2006; 460:152-60. [PMID: 17320035 DOI: 10.1016/j.abb.2006.09.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Revised: 09/08/2006] [Accepted: 09/08/2006] [Indexed: 11/16/2022]
Abstract
Active calcium transport in intestine is essential for serum calcium homeostasis as well as for bone formation. It is well recognized that vitamin D is a major, if not sole, stimulator of intestinal calcium transport activity in mammals. Besides vitamin D, endogenous glucose 1-phosphate (G1P) affects calcium transport activity in some microorganisms. In this study, we investigated whether G1P affects intestinal calcium transport activity in mammals as well. Of several glycolytic intermediates, G1P was the sole sugar compound in stimulating intestinal calcium uptake in Caco-2 cells. G1P stimulated net calcium influx and expression of calbindin D9K protein in rat intestine, through an active transport mechanism. Calcium uptake in G1P-supplemented rats was greater than that in the control rats fed a diet containing adequate vitamin D3. Bone mineral density (BMD) of aged rat femoral metaphysis and diaphysis was also increased by feeding the G1P diet. G1P did not affect serum levels of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] at all. These results suggest that exogenously applied G1P stimulates active transport of calcium in intestine, independent of vitamin D, leading to an increase of BMD.
Collapse
Affiliation(s)
- Hidetake Fujinaka
- Biological Science Laboratories, Kao Corporation, 2606 Akabane, Ichikaimachi, Haga, Tochigi 321-3497, Japan
| | | | | | | | | | | | | |
Collapse
|