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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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2
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Dewaker V, Sharma AR, Debnath U, Park ST, Kim HS. Insights from molecular dynamics simulations of TRPV1 channel modulators in pain. Drug Discov Today 2023; 28:103798. [PMID: 37838068 DOI: 10.1016/j.drudis.2023.103798] [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: 07/28/2023] [Revised: 09/28/2023] [Accepted: 10/09/2023] [Indexed: 10/16/2023]
Abstract
TRPV1 is a nonselective cation channel vital for detecting noxious stimuli (heat, acid, capsaicin). Its role in pain makes it a potential drug target for chronic pain management, migraines, and related disorders. This review updates molecular dynamics (MD) simulation studies on the TRPV1 channel, focusing on its gating mechanism, ligand-binding sites, and implications for drug design. The article also explores challenges in developing modulators, SAR optimization, and clinical trial studies. Efforts have been undertaken to concisely present MD simulation findings, with a focus on their relevance to drug discovery.
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Affiliation(s)
- Varun Dewaker
- Institute of New Frontier Research Team, Hallym University, Chuncheon-si 24252, Gangwon-do, Republic of Korea
| | - Ashish R Sharma
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon-si 24252, Gangwon-do, Republic of Korea
| | - Utsab Debnath
- School of Health Sciences & Technology, UPES, Dehradun, Uttarakhand 248007, India
| | - Sung Taek Park
- Institute of New Frontier Research Team, Hallym University, Chuncheon-si 24252, Gangwon-do, Republic of Korea; Department of Obstetrics and Gynecology, Kangnam Sacred-Heart Hospital, Hallym University Medical Center, Hallym University College of Medicine, Seoul 07441, Republic of Korea; EIONCELL Inc., Chuncheon 24252, Republic of Korea
| | - Hyeong Su Kim
- Institute of New Frontier Research Team, Hallym University, Chuncheon-si 24252, Gangwon-do, Republic of Korea; Division of Hemato-Oncology, Department of Internal Medicine, Kangnam Sacred-Heart Hospital, Hallym University Medical Center, Hallym University College of Medicine, Seoul 07441, Republic of Korea; EIONCELL Inc., Chuncheon 24252, Republic of Korea.
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3
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Fischer PR, Johnson CR, Leopold KN, Thacher TD. Treatment of vitamin D deficiency in children. Expert Rev Endocrinol Metab 2023; 18:489-502. [PMID: 37861060 DOI: 10.1080/17446651.2023.2270053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 10/09/2023] [Indexed: 10/21/2023]
Abstract
INTRODUCTION Vitamin D deficiency affects from 10% to 50% in various pediatric population groups and causes life-threatening hypocalcemia in infants, crippling rickets in infants and children, and increased risk of subsequent adult metabolic and neurologic problems. AREAS COVERED An English language literature search of PubMed was performed since 1940 as were the authors' personal literature collections. References identified in the reviewed literature are considered. DIAGNOSIS The diagnosis of vitamin D deficiency is based on serum 25-hydroxyvitamin D levels. Clinical features of rickets include bone deformities and elevated alkaline phosphatase. Most children and adolescents who are biochemically vitamin D deficient do not have specific symptoms or signs of deficiency. PREVENTION Prevention of vitamin D deficiency is via exposure to sunshine, food and beverage fortification, and dietary supplementation. TREATMENT Effective treatment of vitamin D deficiency is via oral or injectable administration of vitamin D. Dosing and duration of vitamin D therapy have been described for healthy children and for children with underlying medical conditions, but recommendations vary. EXPERT OPINION Further investigation is needed to determine long-term non-skeletal effects of childhood vitamin D deficiency, benefits of supplementation in asymptomatic individuals with biochemical vitamin D deficiency, and appropriate screening for vitamin D deficiency in asymptomatic children and adolescents.
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Affiliation(s)
- Philip R Fischer
- Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN USA
- Sheikh Shakhbout Medical City, Abu Dhabi, UAE
- Khalifa University College of Health and Medical Science, Abu Dhabi, UAE
| | - Casey R Johnson
- Pediatric Gastroenterology and Nutrition, Boston Children's Hospital, Boston, MN, USA
| | - Kaitlin N Leopold
- Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN USA
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4
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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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5
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Wang L, Cai R, Chen XZ, Peng JB. Molecular insights into the structural and dynamical changes of calcium channel TRPV6 induced by its interaction with phosphatidylinositol 4,5-bisphosphate. J Biomol Struct Dyn 2023; 41:6559-6568. [PMID: 35950523 PMCID: PMC9918602 DOI: 10.1080/07391102.2022.2109752] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 07/30/2022] [Indexed: 10/15/2022]
Abstract
Transient receptor potential vanilloid subfamily member 6 (TRPV6) is an epithelial calcium channel that regulates the initial step of the transcellular calcium transport pathway. TRPV6 is expressed in the kidney, intestine, placenta, and other tissues, and the dysregulation of the channel is implicated in several human cancers. It has been reported that phosphatidylinositol 4,5-bisphosphate (PIP2) activates TRPV6 and its close homologue TRPV5; however, the underlying molecular mechanism is less clear. Recently, a structure of rabbit TRPV5 in complex with dioctanoyl (diC8) PIP2, a soluble form of PIP2, was determined by cryo-electron microscopy. Based on this structure, the structural model of human TRPV6 with PIP2 was set up, and then molecular dynamics simulations were performed for TRPV6 with and without PIP2. Simulation results show that the positively charged residues responsible for TRPV5 binding of diC8 PIP2 are conserved in the interactions between TRPV6 and PIP2. The binding of PIP2 to TRPV6 increases the distance between the diagonally opposed residues D542 in the selectivity filter and that between the diagonally opposed M578 residues in the lower gate of TRPV6. A secondary structural analysis reveals that residues M578 in TRPV6 undergo structural and position changes during the binding of PIP2 with TRPV6. In addition, principal component analysis indicates that the binding of PIP2 increases the dynamical motions of both the selectivity filter and the lower gate of TRPV6. These changes induced by PIP2 favor the channel opening. Thus, this study provides a basis for understanding the mechanism underlying the PIP2-induced TRPV6 channel activation.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Lingyun Wang
- Division of Nephrology, Department of Medicine, Nephrology Research and Training Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Ruiqi Cai
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, T6G 2H7 Edmonton, AB, Canada
| | - Xing-Zhen Chen
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, T6G 2H7 Edmonton, AB, Canada
| | - Ji-Bin Peng
- Division of Nephrology, Department of Medicine, Nephrology Research and Training Center, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294
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6
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Zhang M, Ma Y, Ye X, Zhang N, Pan L, Wang B. TRP (transient receptor potential) ion channel family: structures, biological functions and therapeutic interventions for diseases. Signal Transduct Target Ther 2023; 8:261. [PMID: 37402746 DOI: 10.1038/s41392-023-01464-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 59.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 03/26/2023] [Accepted: 04/25/2023] [Indexed: 07/06/2023] Open
Abstract
Transient receptor potential (TRP) channels are sensors for a variety of cellular and environmental signals. Mammals express a total of 28 different TRP channel proteins, which can be divided into seven subfamilies based on amino acid sequence homology: TRPA (Ankyrin), TRPC (Canonical), TRPM (Melastatin), TRPML (Mucolipin), TRPN (NO-mechano-potential, NOMP), TRPP (Polycystin), TRPV (Vanilloid). They are a class of ion channels found in numerous tissues and cell types and are permeable to a wide range of cations such as Ca2+, Mg2+, Na+, K+, and others. TRP channels are responsible for various sensory responses including heat, cold, pain, stress, vision and taste and can be activated by a number of stimuli. Their predominantly location on the cell surface, their interaction with numerous physiological signaling pathways, and the unique crystal structure of TRP channels make TRPs attractive drug targets and implicate them in the treatment of a wide range of diseases. Here, we review the history of TRP channel discovery, summarize the structures and functions of the TRP ion channel family, and highlight the current understanding of the role of TRP channels in the pathogenesis of human disease. Most importantly, we describe TRP channel-related drug discovery, therapeutic interventions for diseases and the limitations of targeting TRP channels in potential clinical applications.
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Affiliation(s)
- Miao Zhang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
- Experiment Center for Science and Technology, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
- The Center for Microbes, Development and Health; Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Yueming Ma
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Xianglu Ye
- Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Ning Zhang
- Experiment Center for Science and Technology, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
| | - Lei Pan
- The Center for Microbes, Development and Health; Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, 200031, China.
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Bing Wang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
- Center for Pharmaceutics Research, Shanghai Institute of Materia Medica Chinese Academy of Sciences, Shanghai, 201203, China.
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7
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Neves RC. Relationship between calcium dynamics and inflammatory status in the transition period of dairy cows. JDS COMMUNICATIONS 2023; 4:225-229. [PMID: 37360125 PMCID: PMC10285257 DOI: 10.3168/jdsc.2022-0348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 12/20/2022] [Indexed: 06/28/2023]
Abstract
Improvements in nutrition, management, and genetics of dairy cows over the last several decades have shifted research focus from clinical diseases to subclinical disorders, to which transition cows are particularly vulnerable. Recent studies on the characterization of subclinical hypocalcemia (SCH) indicate that the combined analysis of the degree, timing of suboptimal blood Ca concentration, and duration are most reflective of the disorder. Therefore, the understanding of blood Ca dynamics in early postpartum cows has emerged as an avenue to investigate the paths leading to a successful metabolic adaptation to lactation or not. The conundrum has been in defining whether SCH is the cause or a reflection of a greater underlying disorder. Immune activation and systemic inflammation have been proposed to be the root cause of SCH. However, there is a paucity of data investigating the mechanisms of how systemic inflammation can lead to reduced blood Ca concentration in dairy cows. The objective of this review is to discuss the links between systemic inflammation and reduced blood Ca concentration, and studies needed to advance knowledge on the interface between systemic inflammation and Ca metabolism for the transition dairy cow.
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8
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Walker V, Vuister GW. Biochemistry and pathophysiology of the Transient Potential Receptor Vanilloid 6 (TRPV6) calcium channel. Adv Clin Chem 2023; 113:43-100. [PMID: 36858649 DOI: 10.1016/bs.acc.2022.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
TRPV6 is a Transient Receptor Potential Vanilloid (TRPV) cation channel with high selectivity for Ca2+ ions. First identified in 1999 in a search for the gene which mediates intestinal Ca2+ absorption, its far more extensive repertoire as a guardian of intracellular Ca2+ has since become apparent. Studies on TRPV6-deficient mice demonstrated additional important roles in placental Ca2+ transport, fetal bone development and male fertility. The first reports of inherited deficiency in newborn babies appeared in 2018, revealing its physiological importance in humans. There is currently strong evidence that TRPV6 also contributes to the pathogenesis of some common cancers. The recently reported association of TRPV6 deficiency with non-alcoholic chronic pancreatitis suggests a role in normal pancreatic function. Over time and with greater awareness of TRPV6, other disease-associations are likely to emerge. Powerful analytical tools have provided invaluable insights into the structure and operation of TRPV6. Its roles in Ca2+ signaling and carcinogenesis, and the use of channel inhibitors in cancer treatment are being intensively investigated. This review first briefly describes the biochemistry and physiology of the channel, and analytical methods used to investigate these. The focus subsequently shifts to the clinical disorders associated with abnormal expression and the underlying pathophysiology. The aims of this review are to increase awareness of this channel, and to draw together findings from a wide range of sources which may help to formulate new ideas for further studies.
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Affiliation(s)
- Valerie Walker
- Department of Clinical Biochemistry, University Hospital Southampton NHS Foundation Trust, Southampton General Hospital, Southampton, United Kingdom.
| | - Geerten W Vuister
- Department of Molecular and Cell Biology, Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester, United Kingdom
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9
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Effects of Dietary Phosphorus Levels on Growth Performance, Phosphorus Utilization and Intestinal Calcium and Phosphorus Transport-Related Genes Expression of Juvenile Chinese Soft-Shelled Turtle ( Pelodiscus sinensis). Animals (Basel) 2022; 12:ani12223101. [PMID: 36428331 PMCID: PMC9687074 DOI: 10.3390/ani12223101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/03/2022] [Accepted: 11/08/2022] [Indexed: 11/12/2022] Open
Abstract
A 60-day feeding trial was performed to assess the effects of dietary phosphorus levels on growth performance, body composition, phosphorus utilization, plasma physiological parameters and intestinal Ca and P transport-related gene expression of juvenile Chinese soft-shelled turtle (P. sinensis). Four diets containing available P at graded levels of 0.88%, 1.00%, 1.18% and 1.63% (termed as D0.88, D1.00, D1.18 and D1.63, respectively) were formulated and each diet was fed to turtles (5.39 ± 0.02 g) in sextuplicate. The turtles were randomly distributed to 24 tanks with 8 turtles per tank. The results indicated that final body weight, specific growth rate, feed conversion ratio and protein efficiency ratio performed best in turtles fed 1.00% available P diet. The crude lipids of the whole body exhibited a decreasing trend with the dietary available P, whereas the calcium and phosphorus of the whole body and bone phosphorus showed an opposite tendency. The apparent digestibility coefficient of phosphorus declined with the dietary available P. Turtles fed 1.00% available phosphorus had the highest phosphorus retention ratio compared with other treatments. Simultaneously they had significantly lower phosphorus loss than turtles fed D1.18 and D1.63 and had no differences in this respect from turtles fed a low-phosphorus diet. It was noteworthy that the lowest plasma calcium concentrations, and alkaline phosphatase activities in plasma and liver, were discovered in turtles fed the diet containing 1.63% available phosphorus. In addition, the high-phosphorus diet resulted in significantly down-regulated expression of intestinal phosphorus and calcium transport-related key genes. In conclusion, the available phosphorus requirement of juvenile P. sinensis was determined at 1.041% (total phosphorus was 1.80%) based on quadratic regression of weight gain rate, and excessive dietary phosphorus stunted turtle growth possibly via inhibiting intestinal calcium absorption.
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10
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Beggs MR, Bhullar H, Dimke H, Alexander RT. The contribution of regulated colonic calcium absorption to the maintenance of calcium homeostasis. J Steroid Biochem Mol Biol 2022; 220:106098. [PMID: 35339651 DOI: 10.1016/j.jsbmb.2022.106098] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 03/05/2022] [Accepted: 03/20/2022] [Indexed: 11/20/2022]
Abstract
Calcium absorption and secretion can occur along the length of the small and large intestine. To date, the focus of research into intestinal calcium absorption has been the small intestine, the site contributing the majority of intestinal calcium absorption. However, evidence that the colon contributes as much as 10% of enteral calcium transport has been available for decades. Transcellular calcium absorption and bidirectional paracellular calcium flux contributing to either net absorption or secretion have been observed in the colon, depending on the physiological state. Moreover, the calcium transport pathways contributing to colonic absorption or secretion are regulated by a variety of hormones, including calcitriol, plasma calcium and dietary factors, including prebiotics. Herein we review historical and recent research highlighting the role of colonic calcium transport in overall maintenance of calcium balance, and suggest these data are consistent with the colon being a site of significant regulated transepithelial calcium transport.
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Affiliation(s)
- Megan R Beggs
- Department of Physiology, University of Alberta, Canada; Women's and Children's Health Institute, Alberta, Canada
| | | | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Demark; Department of Nephrology, Odense University Hospital, Denmark
| | - R Todd Alexander
- Department of Physiology, University of Alberta, Canada; Women's and Children's Health Institute, Alberta, Canada; Department of Paediatrics, University of Alberta, Canada.
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11
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Khattar V, Wang L, Peng JB. Calcium selective channel TRPV6: Structure, function, and implications in health and disease. Gene 2022; 817:146192. [PMID: 35031425 PMCID: PMC8950124 DOI: 10.1016/j.gene.2022.146192] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 12/20/2021] [Accepted: 01/07/2022] [Indexed: 12/14/2022]
Abstract
Calcium-selective channel TRPV6 (Transient Receptor Potential channel family, Vanilloid subfamily member 6) belongs to the TRP family of cation channels and plays critical roles in transcellular calcium (Ca2+) transport, reuptake of Ca2+ into cells, and maintaining a local low Ca2+ environment for certain biological processes. Recent crystal and cryo-electron microscopy-based structures of TRPV6 have revealed mechanistic insights on how the protein achieves Ca2+ selectivity, permeation, and inactivation by calmodulin. The TRPV6 protein is expressed in a range of epithelial tissues such as the intestine, kidney, placenta, epididymis, and exocrine glands such as the pancreas, prostate and salivary, sweat, and mammary glands. The TRPV6 gene is a direct transcriptional target of the active form of vitamin D and is efficiently regulated to meet the body's need for Ca2+ demand. In addition, TRPV6 is also regulated by the level of dietary Ca2+ and under physiological conditions such as pregnancy and lactation. Genetic models of loss of function in TRPV6 display hypercalciuria, decreased bone marrow density, deficient weight gain, reduced fertility, and in some cases alopecia. The models also reveal that the channel plays an indispensable role in maintaining maternal-fetal Ca2+ transport and low Ca2+ environment in the epididymal lumen that is critical for male fertility. Most recently, loss of function mutations in TRPV6 gene is linked to transient neonatal hyperparathyroidism and early onset chronic pancreatitis. TRPV6 is overexpressed in a wide range of human malignancies and its upregulation is strongly correlated to tumor aggressiveness, metastasis, and poor survival in selected cancers. This review summarizes the current state of knowledge on the expression, structure, biophysical properties, function, polymorphisms, and regulation of TRPV6. The aberrant expression, polymorphisms, and dysfunction of this protein linked to human diseases are also discussed.
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Affiliation(s)
- Vinayak Khattar
- Division of Nephrology, Department of Medicine, Nephrology Research and Training Center, Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Lingyun Wang
- Division of Nephrology, Department of Medicine, Nephrology Research and Training Center, Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Ji-Bin Peng
- Division of Nephrology, Department of Medicine, Nephrology Research and Training Center, Department of Urology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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Abstract
Extracellular calcium is normally tightly regulated by parathyroid hormone (PTH), 1,25-dihydroxyvitamin D, as well as by calcium ion (Ca++) itself. Dysregulated PTH production leading to hypercalcemia occurs most commonly in sporadic primary hyperparathryoidism (PHPT) but may also result from select genetic mutations in familial disorders. Parathyroid hormone-related protein shares molecular mechanisms of action with PTH and is the most common cause of hypercalcemia of malignancy. Other cytokines and mediators may also cause resorptive hypercalcemia once bone metastases have occurred. Less commonly, extrarenal production of calcitriol can occur in malignancies and in infectious and noninfectious inflammatory conditions and can cause hypercalcemia.
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Affiliation(s)
- David Goltzman
- Calcium Research Laboratory, Department of Medicine and Physiology, McGill University, Research Institute of the McGill University Health Centre, Glen Site, 1001 Decarie Boulevard, Room EM1.3220, Montreal, Quebec H4A 3J1, Canada.
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13
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Matikainen N, Pekkarinen T, Ryhänen EM, Schalin-Jäntti C. Physiology of Calcium Homeostasis: An Overview. Endocrinol Metab Clin North Am 2021; 50:575-590. [PMID: 34774235 DOI: 10.1016/j.ecl.2021.07.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Calcium plays a key role in skeletal mineralization and several intracellular and extracellular homeostatic networks. It is an essential element that is only available to the body through dietary sources. Daily acquisition of calcium depends, in addition to the actual intake, on the hormonally regulated state of calcium homeostasis through three main mechanisms: bone turnover, intestinal absorption, and renal reabsorption. These procedures are regulated by a group of interacting circulating hormones and their key receptors. This includes parathyroid hormone (PTH), PTH-related peptide, 1,25-dihydroxyvitamin D, calcitonin, fibroblast growth factor 23, the prevailing calcium concentration itself, the calcium-sensing receptor, as well as local processes in the bones, gut, and kidneys.
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Affiliation(s)
- Niina Matikainen
- Endocrinology, Abdominal Center, Helsinki University Hospital and University of Helsinki, PB 340, 00029 HUS, Helsinki, Finland
| | - Tuula Pekkarinen
- Endocrinology, Abdominal Center, Helsinki University Hospital and University of Helsinki, PB 340, 00029 HUS, Helsinki, Finland
| | - Eeva M Ryhänen
- Endocrinology, Abdominal Center, Helsinki University Hospital and University of Helsinki, PB 340, 00029 HUS, Helsinki, Finland
| | - Camilla Schalin-Jäntti
- Endocrinology, Abdominal Center, Helsinki University Hospital and University of Helsinki, PB 340, 00029 HUS, Helsinki, Finland.
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14
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TRPV6 is a potential regulator of bone resorption in bone loss induced by estrogen deficiency. iScience 2021; 24:103261. [PMID: 34778726 PMCID: PMC8577076 DOI: 10.1016/j.isci.2021.103261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 05/20/2021] [Accepted: 10/11/2021] [Indexed: 11/29/2022] Open
Abstract
The precise effect of estrogen (E2) on osteoclast function is still poorly understood. The aim of this study was to investigate the potential role of transient receptor potential vanilloid 6 (TRPV6) in E2-mediated osteoclast function and to characterize the relevant underlying mechanisms. Here, we found that Trpv6 is drastically decreased in ovariectomy operation animals and the administration of E2 results in an increased expression of Trpv6 in osteoclasts. In contrast, Trpv6 depletion significantly blocked the inhibitory effects of E2 on bone resorption activity, and silencing Trpv6 alleviated E2-induced osteoclast apoptosis. In addition, we found that E2 regulates the transcription of Trpv6 through ERα, by interacting with C/EBPβ and NF-κB. Chip assay analysis indicated that C/EBPβ regulates Trpv6 transcription by binding to Trpv6 promoter fragments −1,866 nt to −1,761 nt and −2,685 nt to −2,580 nt, whereas NF-κB binds to the −953 nt to −851 nt region. We conclude that TRPV6 has a significant effect on E2-mediated osteoclast function. E2 induces Trpv6 expression in osteoclasts TRPV6 was involved in the effect of E2-mediated osteoclast function E2 regulates the transcription of Trpv6 through Erα in osteoclasts
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15
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Neuberger A, Nadezhdin KD, Sobolevsky AI. 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: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [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.
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Affiliation(s)
- Arthur Neuberger
- 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
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
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16
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Sharma A, Sharma L, Goyal R. Molecular Signaling Pathways and Essential Metabolic Elements in Bone Remodeling: An Implication of Therapeutic Targets for Bone Diseases. Curr Drug Targets 2020; 22:77-104. [PMID: 32914712 DOI: 10.2174/1389450121666200910160404] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 06/28/2020] [Accepted: 07/15/2020] [Indexed: 01/01/2023]
Abstract
Bone is one of the dynamic tissues in the human body that undergoes continuous remodelling through subsequent actions of bone cells, osteoclasts, and osteoblasts. Several signal transduction pathways are involved in the transition of mesenchymal stem cells into osteoblasts. These primarily include Runx2, ATF4, Wnt signaling and sympathetic signalling. The differentiation of osteoclasts is controlled by M-CSF, RANKL, and costimulatory signalling. It is well known that bone remodelling is regulated through receptor activator of nuclear factor-kappa B ligand followed by binding to RANK, which eventually induces the differentiation of osteoclasts. The resorbing osteoclasts secrete TRAP, cathepsin K, MMP-9 and gelatinase to digest the proteinaceous matrix of type I collagen and form a saucer-shaped lacuna along with resorption tunnels in the trabecular bone. Osteoblasts secrete a soluble decoy receptor, osteoprotegerin that prevents the binding of RANK/RANKL and thus moderating osteoclastogenesis. Moreover, bone homeostasis is also regulated by several growth factors like, cytokines, calciotropic hormones, parathyroid hormone and sex steroids. The current review presents a correlation of the probable molecular targets underlying the regulation of bone mass and the role of essential metabolic elements in bone remodelling. Targeting these signaling pathways may help to design newer therapies for treating bone diseases.
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Affiliation(s)
- Aditi Sharma
- School of Pharmaceutical Sciences, Shoolini University, Solan, Himachal Pradesh, 173212, India
| | - Lalit Sharma
- School of Pharmaceutical Sciences, Shoolini University, Solan, Himachal Pradesh, 173212, India
| | - Rohit Goyal
- School of Pharmaceutical Sciences, Shoolini University, Solan, Himachal Pradesh, 173212, India
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17
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Lisi G, Ribolsi M, Siracusano A, Niolu C. Maternal Vitamin D and its Role in Determining Fetal Origins of Mental Health. Curr Pharm Des 2020; 26:2497-2509. [PMID: 32370709 DOI: 10.2174/1381612826666200506093858] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 04/26/2020] [Indexed: 12/21/2022]
Abstract
There is evidence that mental health disorders may have roots in fetal life and are associated with deficiencies in various micronutrients, including vitamin D. During pregnancy, vitamin D balance is influenced by an increase in maternal calcitriol and a substantial increase in maternal Vitamin D Binding Protein concentrations. In the early stages of life, vitamin D is necessary to mediate numerous brain processes such as proliferation, apoptosis, and neurotransmission. Furthermore, Vitamin D has a recognized anti-inflammatory activity that normally suppresses inflammation. Increased activation of hypothalamo-pituitary-adrenal axis (HPA) and inflammation during gestation may influence maternal health and fetal neurodevelopment during and beyond pregnancy. A deficit of Vitamin D and maternal stressful events during gestation, such as perinatal depression, could influence the efficacy of the immune system altering its activity. Vitamin D deficiency during gestation associated with a reduction in fetal brain development has been widely described and correlated with alteration in the production of the brain-derived neurotrophic factor. To this regard, many studies highlights that low maternal vitamin D dosage during gestation has been related to a significantly greater risk to develop schizophrenia and other severe mental illnesses in later life. The objective of this paper is a comprehensive overview of maternal vitamin D balance in determining the fetal origins of mental health with some references to the link between vitamin D levels, inflammatory responses to stress and mental disorders in adult life.
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Affiliation(s)
- Giulia Lisi
- Chair of Psychiatry, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.,Department of Mental Health, ASL ROMA 1, Rome, Italy
| | - Michele Ribolsi
- Chair of Psychiatry, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.,Policlinico Tor Vergata Foundation, Rome, Italy
| | - Alberto Siracusano
- Chair of Psychiatry, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.,Policlinico Tor Vergata Foundation, Rome, Italy
| | - Cinzia Niolu
- Chair of Psychiatry, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.,Policlinico Tor Vergata Foundation, Rome, Italy
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18
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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.
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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
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19
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Schlesinger PH, Braddock DT, Larrouture QC, Ray EC, Riazanski V, Nelson DJ, Tourkova IL, Blair HC. Phylogeny and chemistry of biological mineral transport. Bone 2020; 141:115621. [PMID: 32858255 PMCID: PMC7771281 DOI: 10.1016/j.bone.2020.115621] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/24/2020] [Accepted: 08/24/2020] [Indexed: 02/08/2023]
Abstract
Three physiologically mineralizing tissues - teeth, cartilage and bone - have critical common elements and important evolutionary relationships. Phylogenetically the most ancient densely mineralized tissue is teeth. In jawless fishes without skeletons, tooth formation included epithelial transport of phosphates, a process echoed later in bone physiology. Cartilage and mineralized cartilage are skeletal elements separate from bone, but with metabolic features common to bone. Cartilage mineralization is coordinated with high expression of tissue nonspecific alkaline phosphatase and PHOSPHO1 to harvest available phosphate esters and support mineralization of collagen secreted locally. Mineralization in true bone results from stochastic nucleation of hydroxyapatite crystals within the cross-linked collagen fibrils. Mineral accumulation in dense collagen is, at least in major part, mediated by amorphous aggregates - often called Posner clusters - of calcium and phosphate that are small enough to diffuse into collagen fibrils. Mineral accumulation in membrane vesicles is widely suggested, but does not correlate with a definitive stage of mineralization. Conversely mineral deposition at non-physiologic sites where calcium and phosphate are adequate has been shown to be regulated in large part by pyrophosphate. All of these elements are present in vertebrate bone metabolism. A key biological element of bone formation is an epithelial-like cellular organization which allows control of phosphate, calcium and pH during mineralization.
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Affiliation(s)
- Paul H Schlesinger
- Dept of Cell Biology, Washington University, Saint Louis, MO, United States of America
| | - Demetrios T Braddock
- Dept. of Pathology, Yale New Haven Hospital, 310 Cedar Street, New Haven, CT, United States of America
| | - Quitterie C Larrouture
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, Windmill Road, Oxford OX3 7LD, UK
| | - Evan C Ray
- Renal Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Vladimir Riazanski
- Dept of Neurobiology, Pharmacology & Physiology, University of Chicago, Chicago, IL, United States of America
| | - Deborah J Nelson
- Dept of Neurobiology, Pharmacology & Physiology, University of Chicago, Chicago, IL, United States of America
| | - Irina L Tourkova
- Veteran's Affairs Medical Center, Pittsburgh PA and Department of Pathology, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Harry C Blair
- Veteran's Affairs Medical Center, Pittsburgh PA and Department of Pathology, University of Pittsburgh, Pittsburgh, PA, United States of America.
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20
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Ma J, Zhu L, Zhou Z, Song T, Yang L, Yan X, Chen A, Ye TW. The calcium channel TRPV6 is a novel regulator of RANKL-induced osteoclastic differentiation and bone absorption activity through the IGF-PI3K-AKT pathway. Cell Prolif 2020; 54:e12955. [PMID: 33159483 PMCID: PMC7791174 DOI: 10.1111/cpr.12955] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/01/2020] [Accepted: 10/20/2020] [Indexed: 12/18/2022] Open
Abstract
Objectives Calcium ion signals are important for osteoclast differentiation. Transient receptor potential vanilloid 6 (TRPV6) is a regulator of bone homeostasis. However, it was unclear whether TRPV6 was involved in osteoclast formation. Therefore, the aim of this study was to evaluate the role of TPRV6 in bone metabolism and to clarify its regulatory role in osteoclasts at the cellular level. Materials and methods Bone structure and histological changes in Trpv6 knockout mice were examined using micro‐computed tomography and histological analyses. To investigate the effects of Trpv6 on osteoclast function, we silenced or overexpressed Trpv6 in osteoclasts via lentivirus transfection, respectively. Osteoclast differentiation and bone resorption viability were measured by tartrate‐resistant acid phosphatase (TRAP) staining and pit formation assays. The expression of osteoclast marker genes, including cathepsin k, DC‐STAMP, Atp6v0d2 and TRAP, was measured by qRT‐PCR. Cell immunofluorescence and Western blotting were applied to explore the mechanisms by which the IGF‐PI3K‐AKT pathway was involved in the regulation of osteoclast formation and bone resorption by Trpv6. Results We found that knockout of Trpv6 induced osteoporosis and enhanced bone resorption in mice, but did not affect bone formation. Further studies showed that Trpv6, which was distributed on the cell membrane of osteoclasts, acted as a negative regulator for osteoclast differentiation and function. Mechanistically, Trpv6 suppressed osteoclastogenesis by decreasing the ratios of phosphoprotein/total protein in the IGF–PI3K–AKT signalling pathway. Blocking of the IGF–PI3K–AKT pathway significantly alleviated the inhibitory effect of Trpv6 on osteoclasts formation. Conclusions Our study confirmed the important role of Trpv6 in bone metabolism and clarified its regulatory role in osteoclasts at the cellular level. Taken together, this study may inspire a new strategy for the treatment of osteoporosis.
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Affiliation(s)
- Jun Ma
- Department of Orthopedic Trauma Surgery, Changzheng Hospital, The Second Military Medical University, Shanghai, China.,Department of Health Statistics, The Second Military Medical University, Shanghai, China
| | - Lei Zhu
- Department of Orthopedic Trauma Surgery, Changzheng Hospital, The Second Military Medical University, Shanghai, China
| | - Zhibin Zhou
- Department of Orthopedic Surgery, General Hospital of Northern Theater Command, Shenyang, China
| | - Tengfei Song
- Department of Orthopedic Trauma Surgery, Changzheng Hospital, The Second Military Medical University, Shanghai, China
| | - Lei Yang
- Department of Orthopedic Surgery, The 2nd affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xu Yan
- Department of Orthopedic Surgery, Naval Characteristic Medical Center, The Second Military Medical University, Shanghai, China
| | - Aimin Chen
- Department of Orthopedic Trauma Surgery, Changzheng Hospital, The Second Military Medical University, Shanghai, China
| | - Tian Wen Ye
- Department of Orthopedic Trauma Surgery, Changzheng Hospital, The Second Military Medical University, Shanghai, China
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21
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Bhardwaj R, Lindinger S, Neuberger A, Nadezhdin KD, Singh AK, Cunha MR, Derler I, Gyimesi G, Reymond JL, Hediger MA, Romanin C, Sobolevsky AI. Inactivation-mimicking block of the epithelial calcium channel TRPV6. SCIENCE ADVANCES 2020; 6:eabe1508. [PMID: 33246965 PMCID: PMC7695471 DOI: 10.1126/sciadv.abe1508] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/14/2020] [Indexed: 05/25/2023]
Abstract
Epithelial calcium channel TRPV6 plays vital roles in calcium homeostasis, and its dysregulation is implicated in multifactorial diseases, including cancers. Here, we study the molecular mechanism of selective nanomolar-affinity TRPV6 inhibition by (4-phenylcyclohexyl)piperazine derivatives (PCHPDs). We use x-ray crystallography and cryo-electron microscopy to solve the inhibitor-bound structures of TRPV6 and identify two types of inhibitor binding sites in the transmembrane region: (i) modulatory sites between the S1-S4 and pore domains normally occupied by lipids and (ii) the main site in the ion channel pore. Our structural data combined with mutagenesis, functional and computational approaches suggest that PCHPDs plug the open pore of TRPV6 and convert the channel into a nonconducting state, mimicking the action of calmodulin, which causes inactivation of TRPV6 channels under physiological conditions. This mechanism of inhibition explains the high selectivity and potency of PCHPDs and opens up unexplored avenues for the design of future-generation biomimetic drugs.
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Affiliation(s)
- Rajesh Bhardwaj
- Department of Nephrology and Hypertension and Department of Biomedical Research, University of Bern, Inselspital, Freiburgstrasse 15, CH-3010 Bern, Switzerland
| | - Sonja Lindinger
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Arthur Neuberger
- 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
| | - Appu K Singh
- Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168th Street, New York, NY 10032, USA
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Micael R Cunha
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Isabella Derler
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Gergely Gyimesi
- Department of Nephrology and Hypertension and Department of Biomedical Research, University of Bern, Inselspital, Freiburgstrasse 15, CH-3010 Bern, Switzerland
| | - Jean-Louis Reymond
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland
| | - Matthias A Hediger
- Department of Nephrology and Hypertension and Department of Biomedical Research, University of Bern, Inselspital, Freiburgstrasse 15, CH-3010 Bern, Switzerland.
| | - Christoph Romanin
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria.
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168th Street, New York, NY 10032, USA.
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22
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Cai R, Liu X, Zhang R, Hofmann L, Zheng W, Amin MR, Wang L, Hu Q, Peng JB, Michalak M, Flockerzi V, Ali DW, Chen XZ, Tang J. Autoinhibition of TRPV6 Channel and Regulation by PIP2. iScience 2020; 23:101444. [PMID: 32829285 PMCID: PMC7452202 DOI: 10.1016/j.isci.2020.101444] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 07/07/2020] [Accepted: 08/04/2020] [Indexed: 12/30/2022] Open
Abstract
Transient receptor potential vanilloid 6 (TRPV6), a calcium-selective channel possessing six transmembrane domains (S1-S6) and intracellular N and C termini, plays crucial roles in calcium absorption in epithelia and bone and is involved in human diseases including vitamin-D deficiency, osteoporosis, and cancer. The TRPV6 function and regulation remain poorly understood. Here we show that the TRPV6 intramolecular S4-S5 linker to C-terminal TRP helix (L/C) and N-terminal pre-S1 helix to TRP helix (N/C) interactions, mediated by Arg470:Trp593 and Trp321:Ile597 bonding, respectively, are autoinhibitory and are required for maintaining TRPV6 at basal states. Disruption of either interaction by mutations or blocking peptides activates TRPV6. The N/C interaction depends on the L/C interaction but not reversely. Three cationic residues in S5 or C terminus are involved in binding PIP2 to suppress both interactions thereby activating TRPV6. This study reveals "PIP2 - intramolecular interactions" regulatory mechanism of TRPV6 activation-autoinhibition, which will help elucidating the corresponding mechanisms in other TRP channels.
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Affiliation(s)
- Ruiqi Cai
- National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, Hubei 430068, China
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Xiong Liu
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Rui Zhang
- National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, Hubei 430068, China
| | - Laura Hofmann
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421 Homburg, Germany
| | - Wang Zheng
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Md Ruhul Amin
- Department of Biological Sciences, Biological Sciences Building, University of Alberta, T6G 2E9 Edmonton, AB, Canada
| | - Lingyun Wang
- Division of Nephrology, Department of Medicine, Nephrology Research and Training Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Qiaolin Hu
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Ji-Bin Peng
- Division of Nephrology, Department of Medicine, Nephrology Research and Training Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Marek Michalak
- Membrane Protein Disease Research Group, Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Veit Flockerzi
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421 Homburg, Germany
| | - Declan W. Ali
- Department of Biological Sciences, Biological Sciences Building, University of Alberta, T6G 2E9 Edmonton, AB, Canada
| | - Xing-Zhen Chen
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Jingfeng Tang
- National “111” Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, Hubei 430068, China
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23
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Evolutionary analyses reveal independent origins of gene repertoires and structural motifs associated to fast inactivation in calcium-selective TRPV channels. Sci Rep 2020; 10:8684. [PMID: 32457384 PMCID: PMC7250927 DOI: 10.1038/s41598-020-65679-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 04/23/2020] [Indexed: 01/14/2023] Open
Abstract
Essential for calcium homeostasis, TRPV5 and TRPV6 are calcium-selective channels belonging to the transient receptor potential (TRP) gene family. In this study, we investigated the evolutionary history of these channels to add an evolutionary context to the already available physiological information. Phylogenetic analyses revealed that paralogs found in mammals, sauropsids, amphibians, and chondrichthyes, are the product of independent duplication events in the ancestor of each group. Within amniotes, we identified a traceable signature of three amino acids located at the amino-terminal intracellular region. The signature correlates with both the duplication events and the phenotype of fast inactivation observed in mammalian TRPV6 channels. Electrophysiological recordings and mutagenesis revealed that the signature sequence modulates the phenotype of fast inactivation in all clades of vertebrates but reptiles. A transcriptome analysis showed a change in tissue expression from gills, in marine vertebrates, to kidneys in terrestrial vertebrates. Our results highlight a cytoplasmatic structural triad composed by the Helix-Loop-Helix domain, the S2-S3 linker, and the TRP domain helix that is important on modulating the activity of calcium-selective TRPV channels.
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24
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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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Giustina A, Adler RA, Binkley N, Bollerslev J, Bouillon R, Dawson-Hughes B, Ebeling PR, Feldman D, Formenti AM, Lazaretti-Castro M, Marcocci C, Rizzoli R, Sempos CT, Bilezikian JP. Consensus statement from 2 nd International Conference on Controversies in Vitamin D. Rev Endocr Metab Disord 2020; 21:89-116. [PMID: 32180081 PMCID: PMC7113202 DOI: 10.1007/s11154-019-09532-w] [Citation(s) in RCA: 158] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The 2nd International Conference on Controversies in Vitamin D was held in Monteriggioni (Siena), Italy, September 11-14, 2018. The aim of this meeting was to address ongoing controversies and timely topics in vitamin D research, to review available data related to these topics and controversies, to promote discussion to help resolve lingering issues and ultimately to suggest a research agenda to clarify areas of uncertainty. Several issues from the first conference, held in 2017, were revisited, such as assays used to determine serum 25-hydroxyvitamin D [25(OH)D] concentration, which remains a critical and controversial issue for defining vitamin D status. Definitions of vitamin D nutritional status (i.e. sufficiency, insufficiency and deficiency) were also revisited. New areas were reviewed, including vitamin D threshold values and how they should be defined in the context of specific diseases, sources of vitamin D and risk factors associated with vitamin D deficiency. Non-skeletal aspects related to vitamin D were also discussed, including the reproductive system, neurology, chronic kidney disease and falls. The therapeutic role of vitamin D and findings from recent clinical trials were also addressed. The topics were considered by 3 focus groups and divided into three main areas: 1) "Laboratory": assays and threshold values to define vitamin D status; 2) "Clinical": sources of vitamin D and risk factors and role of vitamin D in non-skeletal disease and 3) "Therapeutics": controversial issues on observational studies and recent randomized controlled trials. In this report, we present a summary of our findings.
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Affiliation(s)
- A Giustina
- Chair of Endocrinology, School of Medicine, Vita-Salute San Raffaele University, Milan, Italy
- Division of Endocrinology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - R A Adler
- McGuire Veterans Affairs Medical Center and Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - N Binkley
- Osteoporosis Clinical Research Program and Institute on Aging, University of Wisconsin-Madison, Madison, WI, USA
| | - J Bollerslev
- Section of Specialized Endocrinology, Department of Endocrinology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
- Faculty of Medicine, University of Oslo, Oslo, Norway
| | - R Bouillon
- Laboratory of Clinical and Experimental Endocrinology, Department of Chronic Diseases, Metabolism and Ageing, Leuven, KU, Belgium
| | - B Dawson-Hughes
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA
| | - P R Ebeling
- Department of Medicine, School of Clinical Sciences, Monash University, Clayton, VIC, Australia
| | - D Feldman
- Department of Medicine, Endocrinology Division, Stanford University School of Medicine, Stanford, CA, USA
| | - A M Formenti
- Chair of Endocrinology, School of Medicine, Vita-Salute San Raffaele University, Milan, Italy
- Division of Endocrinology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - M Lazaretti-Castro
- Division of Endocrinology, Escola Paulista de Medicina - Universidade Federal de Sao Paulo (EPM-UNIFESP), Sao Paulo, Brazil
| | - C Marcocci
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - R Rizzoli
- Divison of Bone Diseases, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - C T Sempos
- Vitamin D Standardization Program LLC, Havre de Grace, MD, USA
| | - J P Bilezikian
- Department of Medicine, Endocrinology Division, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
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Munson S, Wang Y, Chang W, Bikle DD. Myosin 1a Regulates Osteoblast Differentiation Independent of Intestinal Calcium Transport. J Endocr Soc 2019; 3:1993-2011. [PMID: 31620669 PMCID: PMC6789431 DOI: 10.1210/js.2019-00171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 08/06/2019] [Indexed: 01/01/2023] Open
Abstract
Myosin 1A (Myo1a) is a mechanoenzyme previously thought to be located exclusively in the intestinal epithelium. It is the principle calmodulin-binding protein of the brush border. Based on earlier studies in chickens, we hypothesized that Myo1a facilitates calcium transport across the brush border membrane of the intestinal epithelium, perhaps in association with the calcium channel Trpv6. Working with C2Bbe1 cells, a human intestinal epithelial cell line, we observed that overexpression of Myo1a increased, whereas the antisense construct blocked calcium transport. To further test this hypothesis, we examined mice in which either or both Myo1a and Trpv6 had been deleted. Although the Trpv6-null mice had decreased intestinal calcium transport, the Myo1a-null mouse did not, disproving our original hypothesis, at least in mice. Expecting that a reduction in intestinal calcium transport would result in decreased bone, we examined the skeletons of these mice. To our surprise, we found no decrease in bone in the Trpv6-null mouse, but a substantial decrease in the Myo1a-null mouse. Double deletions were comparable to the Myo1a null. Moreover, Myo1a but not Trpv6 was expressed in osteoblasts. In vitro, the bone marrow stromal cells from the Myo1a-null mice showed normal numbers of colony-forming units but marked decrements in the formation of alkaline phosphatase-positive colonies and mineralized nodules. We conclude that Myo1a regulates osteoblast differentiation independent of its role, if any, in intestinal calcium transport, whereas Trpv6 functions primarily to promote intestinal calcium transport with little influence in osteoblast function.
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Affiliation(s)
- Scott Munson
- Department of Medicine and Endocrine Research Unit, Veterans Affairs Medical Center and University of California San Francisco, San Francisco, California
| | - Yongmei Wang
- Department of Medicine and Endocrine Research Unit, Veterans Affairs Medical Center and University of California San Francisco, San Francisco, California
| | - Wenhan Chang
- Department of Medicine and Endocrine Research Unit, Veterans Affairs Medical Center and University of California San Francisco, San Francisco, California
| | - Daniel D Bikle
- Department of Medicine and Endocrine Research Unit, Veterans Affairs Medical Center and University of California San Francisco, San Francisco, California
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Effect of Chlorella Pyrenoidosa Protein Hydrolysate-Calcium Chelate on Calcium Absorption Metabolism and Gut Microbiota Composition in Low-Calcium Diet-Fed Rats. Mar Drugs 2019; 17:md17060348. [PMID: 31212630 PMCID: PMC6628084 DOI: 10.3390/md17060348] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 05/22/2019] [Accepted: 06/03/2019] [Indexed: 12/20/2022] Open
Abstract
In our current investigation, we evaluated the effect of Chlorella pyrenoidosa protein hydrolysate (CPPH) and Chlorella pyrenoidosa protein hydrolysate-calcium chelate (CPPH-Ca) on calcium absorption and gut microbiota composition, as well as their in vivo regulatory mechanism in SD rats fed low-calcium diets. Potent major compounds in CPPH were characterized by HPLC-MS/MS, and the calcium-binding mechanism was investigated through ultraviolet and infrared spectroscopy. Using high-throughput next-generation 16S rRNA gene sequencing, we analyzed the composition of gut microbiota in rats. Our study showed that HCPPH-Ca increased the levels of body weight gain, serum Ca, bone activity, bone mineral density (BMD) and bone mineral content (BMC), while decreased serum alkaline phosphatase (ALP) and inhibited the morphological changes of bone. HCPPH-Ca up-regulated the gene expressions of transient receptor potential cation V5 (TRPV5), TRPV6, calcium-binding protein-D9k (CaBP-D9k) and a calcium pump (plasma membrane Ca-ATPase, PMCA1b). It also improved the abundances of Firmicutes and Lactobacillus. Bifidobacterium and Sutterella were both positively correlated with calcium absorption. Collectively, these findings illustrate the potential of HCPPH-Ca as an effective calcium supplement.
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Fecher-Trost C, Lux F, Busch KM, Raza A, Winter M, Hielscher F, Belkacemi T, van der Eerden B, Boehm U, Freichel M, Weissgerber P. Maternal Transient Receptor Potential Vanilloid 6 (Trpv6) Is Involved In Offspring Bone Development. J Bone Miner Res 2019; 34:699-710. [PMID: 30786075 DOI: 10.1002/jbmr.3646] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 11/16/2018] [Accepted: 11/18/2018] [Indexed: 12/29/2022]
Abstract
Embryonic growth and bone development depend on placental Ca2+ transport across the feto-maternal barrier to supply minerals to the fetus. The individual factors and cellular mechanisms that regulate placental Ca2+ transfer, however, are only beginning to emerge. We find that the Ca2+ -selective transient receptor potential vanilloid 6 (TRPV6) channel is expressed in trophoblasts of the fetal labyrinth, in the yolk sac, and in the maternal part of the placenta. Lack of functional TRPV6 channels in the mother leads to a reduced Ca2+ content in both placenta and embryo. Ca2+ uptake in trophoblasts is impaired in the absence of Trpv6. Trpv6-deficient embryos are smaller, have a lower body weight, and shorter and less calcified femurs. The altered cortical bone microarchitecture persists in adulthood. We show that TRPV6's Ca2+ -conducting property causes this embryonic and bone phenotype. Our results show that TRPV6 is necessary for the Ca2+ uptake in trophoblasts and that TRPV6 deficiency in the placenta leads to reduced embryo growth, minor bone calcification, and impaired bone development. © 2019 American Society for Bone and Mineral Research.
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Affiliation(s)
- Claudia Fecher-Trost
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Femke Lux
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Kai-Markus Busch
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Ahsan Raza
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Manuel Winter
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Franziska Hielscher
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Thabet Belkacemi
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Bram van der Eerden
- Department of Internal Medicine, Laboratory for Calcium and Bone Metabolism, Erasmus MC, Rotterdam, Netherlands
| | - Ulrich Boehm
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Marc Freichel
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Petra Weissgerber
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany.,Transgenic Technologies, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
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Hassanin WF, Ibrahim NS, El-Barkouky EE, Abu-Taleb AM. Assessment of 47Ca Distribution and Biological Half-Life in Japanese Quail Chicks. BRAZILIAN JOURNAL OF POULTRY SCIENCE 2019. [DOI: 10.1590/1806-9061-2019-1028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Karras SN, Wagner CL, Castracane VD. Understanding vitamin D metabolism in pregnancy: From physiology to pathophysiology and clinical outcomes. Metabolism 2018; 86:112-123. [PMID: 29066285 DOI: 10.1016/j.metabol.2017.10.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 09/14/2017] [Indexed: 12/21/2022]
Abstract
This critical time frame of intrauterine life development is considered of major importance on the metabolic imprinting of overall health of the offspring, in later life. This requires a delicate immune balance that nurtures the allogeneic fetus, while maintaining reactivity against pathogens. Dysregulation of these tightly controlled biophenomena at a systemic and placental level, have been considered as a potential mechanism mediating pathogenesis of preeclampsia and spontaneous birth. In this context, vitamin D has been considered as a significant regulator of both innate and adaptive immunity by regulating cell proliferation, differentiation and apoptosis. Vitamin D metabolism during pregnancy manifests striking differences as compared to the non-pregnant state. Calcitriol is increasing >2-3 fold in the first weeks of pregnancy whereas maternal 25-hydroxyvitamin D crosses the placental barrier and represents the main pool of vitamin D in the fetus. Moreover, during pregnancy, vitamin D receptor and regulatory metabolic enzymes are expressed in the placenta and decidua, indicating a potential critical point in the immunomodulation at the maternal-fetal interface. Considering these effects, maternal hypovitaminosis D during pregnancy has been associated with pregnancy related disorders. This review focuses on the mechanistic basis of these adaptive changes, as a background for the development of pregnancy related disorders, with a discourse on the pathophysiology relating hypovitaminosis D and clinical outcomes.
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Affiliation(s)
- Spyridon N Karras
- Division of Endocrinology and Metabolism, First Department of Internal Medicine, Medical School, Aristotle University of Thessaloniki, AHEPA Hospital, Thessaloniki, Greece.
| | - Carol L Wagner
- Division of Neonatology, Department of Pediatrics, Medical University of South Carolina, Charleston, SC, USA
| | - V Daniel Castracane
- Department of Obstetrics and Gynecology, Texas Tech University School of Medicine, Odessa, TX, United States
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Bone development in growing female mice fed calcium and vitamin D at lower levels than is present in the AIN-93G reference diet. Bone Rep 2018; 8:229-238. [PMID: 29955642 PMCID: PMC6020397 DOI: 10.1016/j.bonr.2018.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 05/09/2018] [Accepted: 05/17/2018] [Indexed: 12/31/2022] Open
Abstract
Background The AIN-93G reference (REF) diet is used to allow the comparison within and between studies of different research groups but its levels of vitamin D (vit D) and calcium (Ca) may be higher than required for healthy bone structure and bone mineral density (BMD). Objective To determine if lower dietary levels of Ca (3.5, 3 or 2.5 g Ca/kg diet) at 1 of 2 levels of vit D (100 or 400 IU/kg diet) supports similar development of bone structure and BMD compared to AIN-93G reference (REF) diet in female CD-1 mice at 2 and 4 months of age. Methods Within a trial, weanling female mice (n = 12–15/group) were randomized to 1 of 4 diets until necropsy at 4 months of age: Trial 1: 100 IU vit D/kg + 3.5, 3 or 2.5 g Ca/kg diet or 1000 IU vit D/kg + 5 g Ca/kg diet (REF); and Trial 2: 400 IU vit D/kg + 3.5, 3 or 2.5 g Ca/kg diet or 1000 IU vit D/kg + 5 g/kg diet (REF). At age 2 and 4 months, in vivo bone structure and BMD were assessed using micro-computed tomography (μCT) at the proximal and midpoint tibia. At age 4 months, lumbar vertebra 4 (L4) and mandible structure were analyzed ex vivo, femur strength at midpoint and neck was assessed and serum 25(OH)D3 and PTH were quantified. Results For Trial 1 (100 IU vit D/kg), there were no differences in tibia structure at age 2 and 4 months nor L4 or mandible structure or femur strength at the midpoint or neck at 4 months of age despite lower serum 25(OH)D3 among all groups compared to REF. For Trial 2 (400 IU vit D/kg), mice fed 2.5 g Ca/kg diet had lower (p < 0.05) Ct.Ar/Tt.Ar and Ct.Th at the tibia midpoint compared to REF. Furthermore, Ct.Th. was greater in REF and 3.5 g Ca/kg diet compared to 2.5 g Ca/kg diet at age 2 but not 4 months of age. At L4, BV/TV was lower (p < 0.05) in the 3 g Ca/kg diet group compared to REF at age 4 months. There were no differences among groups for serum 25(OH)D3 or femur strength at the midpoint or neck. Serum PTH was not elevated compared to REF in either Trial. Conclusion Lowering both dietary vit D (100 IU/kg) and Ca (2.5 g/kg) in AIN-93G diet did not result in differences in bone development of female CD-1 mice at early adulthood. Translational relevance of bone studies conducted using the AIN-93G diet may be affected by its high vit D and Ca content.
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Key Words
- AIN93G
- ANOVA, analysis of variance
- BMC, bone mineral content
- BMD, bone mineral density
- BV/TV, percent bone volume
- Bone mineral density
- Bone structure
- Ca, calcium
- Calcium
- Conn.Dn, connectivity density
- Ct.Ar/Tt.Ar, cortical area fraction
- Ct.Th, cortical thickness
- DA, degree anisotropy
- Ec.Pm, endocortical perimeter
- Ecc, mean eccentricity
- ISO, isoflavones
- L4, lumbar vertebrae 4
- Ma.Ar, medullary area
- Micro-computed tomography
- P, phosphorus
- PBM, peak bone mass
- PTH, parathyroid hormone
- Ps.Pm, periosteum perimeter
- REF, AIN-93G reference diet
- ROI, region of interest
- SEM, standard error mean
- Tb.N, trabecular number
- Tb.Sp, trabecular separation
- Tb.Th, trabecular thickness
- Vitamin D
- vit D, vitamin D
- μCT, micro computed tomography
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Lotinun S, Suwanwela J, Poolthong S, Baron R. Kit W-sh Mutation Prevents Cancellous Bone Loss during Calcium Deprivation. Calcif Tissue Int 2018; 102:93-104. [PMID: 29032463 DOI: 10.1007/s00223-017-0334-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 09/25/2017] [Indexed: 12/25/2022]
Abstract
Calcium is essential for normal bone growth and development. Inadequate calcium intake increases the risk of osteoporosis and fractures. Kit ligand/c-Kit signaling plays an important role in regulating bone homeostasis. Mice with c-Kit mutations are osteopenic. The present study aimed to investigate whether impairment of or reduction in c-Kit signaling affects bone turnover during calcium deprivation. Three-week-old male WBB6F1/J-Kit W /Kit W-v /J (W/W v ) mice with c-Kit point mutation, Kit W-sh /HNihrJaeBsmJ (W sh /W sh ) mice with an inversion mutation in the regulatory elements upstream of the c-Kit promoter region, and their wild-type controls (WT) were fed either a normal (0.6% calcium) or a low calcium diet (0.02% calcium) for 3 weeks. μCT analysis indicated that both mutants fed normal calcium diet had significantly decreased cortical thickness and cancellous bone volume compared to WT. The low calcium diet resulted in a comparable reduction in cortical bone volume and cortical thickness in the W/W v and W sh /W sh mice, and their corresponding controls. As expected, the low calcium diet induced cancellous bone loss in the W/W v mice. In contrast, W sh /W sh cancellous bone did not respond to this diet. This c-Kit mutation prevented cancellous bone loss by antagonizing the low calcium diet-induced increase in osteoblast and osteoclast numbers in the W sh /W sh mice. Gene expression profiling showed that calcium deficiency increased Osx, Ocn, Alp, type I collagen, c-Fms, M-CSF, and RANKL/OPG mRNA expression in controls; however, the W sh mutation suppressed these effects. Our findings indicate that although calcium restriction increased bone turnover, leading to osteopenia, the decreased c-Kit expression levels in the W sh /W sh mice prevented the low calcium diet-induced increase in cancellous bone turnover and bone loss but not the cortical bone loss.
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Affiliation(s)
- Sutada Lotinun
- Department of Physiology and Craniofacial and Skeletal Disorders Research Group, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA.
| | - Jaijam Suwanwela
- Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Suchit Poolthong
- Department of Operative Dentistry, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Roland Baron
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
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Zand L, Kumar R. The Use of Vitamin D Metabolites and Analogues in the Treatment of Chronic Kidney Disease. Endocrinol Metab Clin North Am 2017; 46:983-1007. [PMID: 29080646 PMCID: PMC5977979 DOI: 10.1016/j.ecl.2017.07.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chronic kidney disease (CKD) and end-stage renal disease (ESRD) are associated with abnormalities in bone and mineral metabolism, known as CKD-bone mineral disorder. CKD and ESRD cause skeletal abnormalities characterized by hyperparathyroidism, mixed uremic osteodystrophy, osteomalacia, adynamic bone disease, and frequently enhanced vascular and ectopic calcification. Hyperparathyroidism and mixed uremic osteodystrophy are the most common manifestations due to phosphate retention, reduced concentrations of 1,25-dihydroxyvitamin D, intestinal calcium absorption, and negative calcium balance. Treatment with 1-hydroxylated vitamin D analogues is useful.
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Affiliation(s)
- Ladan Zand
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55901, USA.
| | - Rajiv Kumar
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55901, USA; Department of Biochemistry and Molecular Biology, Mayo Clinic, 200 First Street SW, Rochester, MN 55901, USA.
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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.
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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
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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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Vitamin D, calcium homeostasis and aging. Bone Res 2016; 4:16041. [PMID: 27790378 PMCID: PMC5068478 DOI: 10.1038/boneres.2016.41] [Citation(s) in RCA: 198] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 08/31/2016] [Accepted: 09/04/2016] [Indexed: 12/15/2022] Open
Abstract
Osteoporosis is characterized by low bone mass and microarchitecture deterioration of bone tissue, leading to enhanced bone fragility and consequent increase in fracture risk. Evidence is accumulating for an important role of calcium deficiency as the process of aging is associated with disturbed calcium balance. Vitamin D is the principal factor that maintains calcium homeostasis. Increasing evidence indicates that the reason for disturbed calcium balance with age is inadequate vitamin D levels in the elderly. In this article, an overview of our current understanding of vitamin D, its metabolism, and mechanisms involved in vitamin D-mediated maintenance of calcium homeostasis is presented. In addition, mechanisms involved in age-related dysregulation of 1,25(OH)2D3 action, recommended daily doses of vitamin D and calcium, and the use of vitamin D analogs for the treatment of osteoporosis (which remains controversial) are reviewed. Elucidation of the molecular pathways of vitamin D action and modifications that occur with aging will be an active area of future research that has the potential to reveal new therapeutic strategies to maintain calcium balance.
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Abstract
Hypercalcemia occurs in up to 4% of the population in association with malignancy, primary hyperparathyroidism, ingestion of excessive calcium and/or vitamin D, ectopic production of 1,25-dihydroxyvitamin D [1,25(OH)2D], and impaired degradation of 1,25(OH)2D. The ingestion of excessive amounts of vitamin D3 (or vitamin D2) results in hypercalcemia and hypercalciuria due to the formation of supraphysiological amounts of 25-hydroxyvitamin D [25(OH)D] that bind to the vitamin D receptor, albeit with lower affinity than the active form of the vitamin, 1,25(OH)2D, and the formation of 5,6-trans 25(OH)D, which binds to the vitamin D receptor more tightly than 25(OH)D. In patients with granulomatous disease such as sarcoidosis or tuberculosis and tumors such as lymphomas, hypercalcemia occurs as a result of the activity of ectopic 25(OH)D-1-hydroxylase (CYP27B1) expressed in macrophages or tumor cells and the formation of excessive amounts of 1,25(OH)2D. Recent work has identified a novel cause of non-PTH-mediated hypercalcemia that occurs when the degradation of 1,25(OH)2D is impaired as a result of mutations of the 1,25(OH)2D-24-hydroxylase cytochrome P450 (CYP24A1). Patients with biallelic and, in some instances, monoallelic mutations of the CYP24A1 gene have elevated serum calcium concentrations associated with elevated serum 1,25(OH)2D, suppressed PTH concentrations, hypercalciuria, nephrocalcinosis, nephrolithiasis, and on occasion, reduced bone density. Of interest, first-time calcium renal stone formers have elevated 1,25(OH)2D and evidence of impaired 24-hydroxylase-mediated 1,25(OH)2D degradation. We will describe the biochemical processes associated with the synthesis and degradation of various vitamin D metabolites, the clinical features of the vitamin D-mediated hypercalcemia, their biochemical diagnosis, and treatment.
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Affiliation(s)
- Peter J Tebben
- Divisions of Endocrinology (P.J.T., R.K.) and Nephrology and Hypertension (R.K.), and Departments of Pediatric and Adolescent Medicine (P.J.T.), Internal Medicine (P.J.T., R.K.), Laboratory Medicine and Pathology (R.J.S.), and Biochemistry in Molecular Biology (R.K.), Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Ravinder J Singh
- Divisions of Endocrinology (P.J.T., R.K.) and Nephrology and Hypertension (R.K.), and Departments of Pediatric and Adolescent Medicine (P.J.T.), Internal Medicine (P.J.T., R.K.), Laboratory Medicine and Pathology (R.J.S.), and Biochemistry in Molecular Biology (R.K.), Mayo Clinic College of Medicine, Rochester, Minnesota 55905
| | - Rajiv Kumar
- Divisions of Endocrinology (P.J.T., R.K.) and Nephrology and Hypertension (R.K.), and Departments of Pediatric and Adolescent Medicine (P.J.T.), Internal Medicine (P.J.T., R.K.), Laboratory Medicine and Pathology (R.J.S.), and Biochemistry in Molecular Biology (R.K.), Mayo Clinic College of Medicine, Rochester, Minnesota 55905
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Abstract
Calcium is an important ion in cell signaling, hormone regulation, and bone health. Its regulation is complex and intimately connected to that of phosphate homeostasis. Both ions are maintained at appropriate levels to maintain the extracellular to intracellular gradients, allow for mineralization of bone, and to prevent extra skeletal and urinary calcification. The homeostasis involves the target organs intestine, parathyroid glands, kidney, and bone. Multiple hormones converge to regulate the extracellular calcium level: parathyroid hormone, vitamin D (principally 25(OH)D or 1,25(OH)2D), fibroblast growth factor 23, and α-klotho. Fine regulation of calcium homeostasis occurs in the thick ascending limb and collecting tubule segments via actions of the calcium sensing receptor and several channels/transporters. The kidney participates in homeostatic loops with bone, intestine, and parathyroid glands. Initially in the course of progressive kidney disease, the homeostatic response maintains serum levels of calcium and phosphorus in the desired range, and maintains neutral balance. However, once the kidneys are no longer able to appropriately respond to hormones and excrete calcium and phosphate, positive balance ensues leading to adverse cardiac and skeletal abnormalities. © 2016 American Physiological Society. Compr Physiol 6:1781-1800, 2016.
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Affiliation(s)
- Sharon M Moe
- Division of Nephrology, Indiana University School of Medicine, Roudebush Veterans Administration Medical Center, Indianapolis, Indiana.,Section of Nephrology, Roudebush Veterans Administration Medical Center, Indianapolis, Indiana
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Pu F, Chen N, Xue S. Calcium intake, calcium homeostasis and health. FOOD SCIENCE AND HUMAN WELLNESS 2016. [DOI: 10.1016/j.fshw.2016.01.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Christakos S, Dhawan P, Verstuyf A, Verlinden L, Carmeliet G. Vitamin D: Metabolism, Molecular Mechanism of Action, and Pleiotropic Effects. Physiol Rev 2016; 96:365-408. [PMID: 26681795 PMCID: PMC4839493 DOI: 10.1152/physrev.00014.2015] [Citation(s) in RCA: 1081] [Impact Index Per Article: 135.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
1,25-Dihydroxvitamin D3 [1,25(OH)2D3] is the hormonally active form of vitamin D. The genomic mechanism of 1,25(OH)2D3 action involves the direct binding of the 1,25(OH)2D3 activated vitamin D receptor/retinoic X receptor (VDR/RXR) heterodimeric complex to specific DNA sequences. Numerous VDR co-regulatory proteins have been identified, and genome-wide studies have shown that the actions of 1,25(OH)2D3 involve regulation of gene activity at a range of locations many kilobases from the transcription start site. The structure of the liganded VDR/RXR complex was recently characterized using cryoelectron microscopy, X-ray scattering, and hydrogen deuterium exchange. These recent technological advances will result in a more complete understanding of VDR coactivator interactions, thus facilitating cell and gene specific clinical applications. Although the identification of mechanisms mediating VDR-regulated transcription has been one focus of recent research in the field, other topics of fundamental importance include the identification and functional significance of proteins involved in the metabolism of vitamin D. CYP2R1 has been identified as the most important 25-hydroxylase, and a critical role for CYP24A1 in humans was noted in studies showing that inactivating mutations in CYP24A1 are a probable cause of idiopathic infantile hypercalcemia. In addition, studies using knockout and transgenic mice have provided new insight on the physiological role of vitamin D in classical target tissues as well as evidence of extraskeletal effects of 1,25(OH)2D3 including inhibition of cancer progression, effects on the cardiovascular system, and immunomodulatory effects in certain autoimmune diseases. Some of the mechanistic findings in mouse models have also been observed in humans. The identification of similar pathways in humans could lead to the development of new therapies to prevent and treat disease.
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Affiliation(s)
- Sylvia Christakos
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey; and Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Puneet Dhawan
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey; and Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Annemieke Verstuyf
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey; and Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Lieve Verlinden
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey; and Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Geert Carmeliet
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey; and Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
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Lieben L, Verlinden L, Masuyama R, Torrekens S, Moermans K, Schoonjans L, Carmeliet P, Carmeliet G. Extra-intestinal calcium handling contributes to normal serum calcium levels when intestinal calcium absorption is suboptimal. Bone 2015; 81:502-512. [PMID: 26319498 DOI: 10.1016/j.bone.2015.08.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 08/18/2015] [Accepted: 08/20/2015] [Indexed: 01/01/2023]
Abstract
The active form of vitamin D, 1,25(OH)2D, is a crucial regulator of calcium homeostasis, especially through stimulation of intestinal calcium transport. Lack of intestinal vitamin D receptor (VDR) signaling does however not result in hypocalcemia, because the increased 1,25(OH)2D levels stimulate calcium handling in extra-intestinal tissues. Systemic VDR deficiency, on the other hand, results in hypocalcemia because calcium handling is impaired not only in the intestine, but also in kidney and bone. It remains however unclear whether low intestinal VDR activity, as observed during aging, is sufficient for intestinal calcium transport and for mineral and bone homeostasis. To this end, we generated mice that expressed the Vdr exclusively in the gut, but at reduced levels. We found that ~15% of intestinal VDR expression greatly prevented the Vdr null phenotype in young-adult mice, including the severe hypocalcemia. Serum calcium levels were, however, in the low-normal range, which may be due to the suboptimal intestinal calcium absorption, renal calcium loss, insufficient increase in bone resorption and normal calcium incorporation in the bone matrix. In conclusion, our results indicate that low intestinal VDR levels improve intestinal calcium absorption compared to Vdr null mice, but also show that 1,25(OH)2D-mediated fine-tuning of renal calcium reabsorption and bone mineralization and resorption is required to maintain fully normal serum calcium levels.
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Affiliation(s)
- Liesbet Lieben
- Laboratory of Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
| | - Lieve Verlinden
- Laboratory of Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
| | - Ritsuko Masuyama
- Laboratory of Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
| | - Sophie Torrekens
- Laboratory of Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
| | - Karen Moermans
- Laboratory of Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
| | - Luc Schoonjans
- Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, Department of Oncology, KU Leuven, Leuven, Belgium; Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, VIB, KU Leuven, Leuven, Belgium
| | - Peter Carmeliet
- Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, Department of Oncology, KU Leuven, Leuven, Belgium; Laboratory of Angiogenesis and Neurovascular link, Vesalius Research Center, VIB, KU Leuven, Leuven, Belgium
| | - Geert Carmeliet
- Laboratory of Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium.
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Fluid shear triggers microvilli formation via mechanosensitive activation of TRPV6. Nat Commun 2015; 6:8871. [PMID: 26563429 PMCID: PMC4660203 DOI: 10.1038/ncomms9871] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Accepted: 10/12/2015] [Indexed: 12/15/2022] Open
Abstract
Microvilli are cellular membrane protrusions present on differentiated epithelial cells, which can sense and interact with the surrounding fluid environment. Biochemical and genetic approaches have identified a set of factors involved in microvilli formation; however, the underlying extrinsic regulatory mechanism of microvilli formation remains largely unknown. Here we demonstrate that fluid shear stress (FSS), an external mechanical cue, serves as a trigger for microvilli formation in human placental trophoblastic cells. We further reveal that the transient receptor potential, vanilloid family type-6 (TRPV6) calcium ion channel plays a critical role in flow-induced Ca2+ influx and microvilli formation. TRPV6 regulates phosphorylation of Ezrin via a Ca2+-dependent phosphorylation of Akt; this molecular event is necessary for microvillar localization of Ezrin in response to FSS. Our findings provide molecular insight into the microvilli-mediated mechanoresponsive cellular functions, such as epithelial absorption, signal perception and mechanotransduction. Microvilli on epithelial cells can sense the surrounding fluid environment, but the regulatory mechanism behind their formation is mostly unknown. Here Miura et al. show that fluid shear stress serves as a trigger for microvilli formation via activation of the calcium ion channel TRPV6.
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Ryan ZC, Craig TA, Filoteo AG, Westendorf JJ, Cartwright EJ, Neyses L, Strehler EE, Kumar R. Deletion of the intestinal plasma membrane calcium pump, isoform 1, Atp2b1, in mice is associated with decreased bone mineral density and impaired responsiveness to 1, 25-dihydroxyvitamin D3. Biochem Biophys Res Commun 2015; 467:152-6. [PMID: 26392310 DOI: 10.1016/j.bbrc.2015.09.087] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 09/16/2015] [Indexed: 01/01/2023]
Abstract
The physiological importance of the intestinal plasma membrane calcium pump, isoform 1, (Pmca1, Atp2b1), in calcium absorption and homeostasis has not been previously demonstrated in vivo. Since global germ-line deletion of the Pmca1 in mice is associated with embryonic lethality, we selectively deleted the Pmca1 in intestinal absorptive cells. Mice with loxP sites flanking exon 2 of the Pmca1 gene (Pmca1(fl/fl)) were crossed with mice expressing Cre recombinase in the intestine under control of the villin promoter to give mice in which the Pmca1 had been deleted in the intestine (Pmca1(EKO) mice). Pmca1(EKO) mice were born at a reduced frequency and were small at the time of birth when compared to wild-type (Wt) littermates. At two months of age, Pmca1(EKO) mice fed a 0.81% calcium, 0.34% phosphorus, normal vitamin D diet had reduced whole body bone mineral density (P < 0.037), and reduced femoral bone mineral density (P < 0.015). There was a trend towards lower serum calcium and higher serum parathyroid hormone (PTH) and 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) concentrations in Pmca1(EKO) mice compared to Wt mice but the changes were not statistically significant. The urinary phosphorus/creatinine ratio was increased in Pmca1(EKO) mice (P < 0.004). Following the administration of 200 ng of 1α,25(OH)2D3 intraperitoneally to Wt mice, active intestinal calcium transport increased ∼2-fold, whereas Pmca1(EKO) mice administered an equal amount of 1α,25(OH)2D3 failed to show an increase in active calcium transport. Deletion of the Pmca1 in the intestine is associated with reduced growth and bone mineralization, and a failure to up-regulate calcium absorption in response to 1α,25(OH)2D3.
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Affiliation(s)
- Zachary C Ryan
- Nephrology Research, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
| | - Theodore A Craig
- Nephrology Research, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
| | - Adelaida G Filoteo
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
| | - Jennifer J Westendorf
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA; Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA
| | | | - Ludwig Neyses
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, M13 9PT, UK; University of Luxembourg, L-4365, Esch-sur-Alzette, Luxembourg
| | - Emanuel E Strehler
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA.
| | - Rajiv Kumar
- Nephrology Research, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA; Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA.
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Carmeliet G, Dermauw V, Bouillon R. Vitamin D signaling in calcium and bone homeostasis: a delicate balance. Best Pract Res Clin Endocrinol Metab 2015; 29:621-31. [PMID: 26303088 DOI: 10.1016/j.beem.2015.06.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Loss-of-function mutations in genes involved in the vitamin D/vitamin D receptor system have clearly evidenced its critical role for mineral and skeletal homeostasis. Adequate levels of 1,25-dihydroxyvitamin D [1,25(OH)2D], the active form of vitamin D are therefore required and depend on sufficient sunlight exposure or dietary intake. Intestinal calcium absorption is a primary target of 1,25(OH)2D action and this pathway indirectly promotes calcium incorporation in bone. Severe vitamin D deficiency may thus decrease bone quality and leads to osteomalacia, whereas less severe deficiency increases the risk of osteoporosis and bone fractures. On the other hand, high vitamin D levels together with low dietary calcium intake will increase bone resorption and decrease bone mineralization in order to maintain normal serum calcium levels. Appropriate dietary calcium intake and sufficient serum vitamin D levels are thus important for skeletal health. Dosing of calcium and vitamin D supplements is still debated and requires further investigation.
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Affiliation(s)
- Geert Carmeliet
- Laboratory of Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Veronique Dermauw
- Laboratory of Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Roger Bouillon
- Laboratory of Clinical and Experimental Endocrinology, Department of Clinical and Experimental Medicine, KU Leuven, 3000 Leuven, Belgium.
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Schlegel RN, Cuffe JSM, Moritz KM, Paravicini TM. Maternal hypomagnesemia causes placental abnormalities and fetal and postnatal mortality. Placenta 2015; 36:750-8. [PMID: 25924939 DOI: 10.1016/j.placenta.2015.03.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/24/2015] [Accepted: 03/31/2015] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Magnesium (Mg(2+)) is essential for cellular growth and the maintenance of normal cellular processes. However, little is known about how maternal hypomagnesemia during pregnancy affects fetal growth and development. This study investigated the effects of maternal hypomagnesemia on the late gestation placenta and fetus, and postnatal outcomes until weaning. METHODS Female CD1 mice consumed a control (0.2% w/w Mg(2+)), moderately Mg(2+) deficient (MMD; 0.02% w/w Mg(2+)) or severely Mg(2+) deficient (SMD; 0.005% w/w Mg(2+)) diet for 4 weeks prior to mating and throughout pregnancy. Dams were killed at E18.5 for embryonic studies or allowed to litter naturally and the offspring studied up to postnatal day 21. RESULTS At E18.5, both Mg(2+) deficient diets decreased maternal plasma and bone Mg(2+) but only the SMD diet decreased fetal plasma Mg(2+). Maternal hypomagnesemia led to fetal loss and fetal growth restriction. Maternal Mg(2+) deficiency increased placental glycogen cell area and decreased spongiotrophoblast cell area while upregulating mRNA expression of the MagT1 Mg(2+) transporter in spongiotrophoblast cells. The SMD animals also displayed instances of gross placental abnormalities. After birth, pups in the SMD group had increased early postnatal mortality and failed to thrive. Pups in the MMD group underwent catch-up growth but remained shorter than controls at PN21 and were hypomagnesemic and hypoglycemic. CONCLUSIONS These changes suggest that maternal Mg(2+) deficiency during pregnancy impairs placental development and fetal growth, which may have long-term health consequences for offspring. Collectively, these results have important implications for women who are Mg(2+) deficient during pregnancy.
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Affiliation(s)
- R N Schlegel
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - J S M Cuffe
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - K M Moritz
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - T M Paravicini
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia.
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Zhang J, Deng Y, Ma H, Hou J, Zhou Z. Effect of transient receptor potential vanilloid 6 gene silencing on the expression of calcium transport genes in chicken osteoblasts. Poult Sci 2015; 94:395-401. [DOI: 10.3382/ps/peu071] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Yang H, Ahn C, Jeung EB. Differential expression of calcium transport genes caused by COMT inhibition in the duodenum, kidney and placenta of pregnant mice. Mol Cell Endocrinol 2015; 401:45-55. [PMID: 25486511 DOI: 10.1016/j.mce.2014.11.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 11/24/2014] [Accepted: 11/24/2014] [Indexed: 12/11/2022]
Abstract
Preeclampsia is a pregnancy-specific disease characterized by concurrent development of hypertension, proteinuria, and oxidative stress in the placenta. Preeclampsia-like genetic models were also developed by modification of preeclampsia-related genes, such as catechol-O-methyltranferase (COMT). In this study, we induced COMT inhibition in mice during pregnancy in order to reproduce physiological conditions associated with preeclampsia. Expression of the gene known as hypoxia biomarker, HIF-1α, was highly induced in the placenta of this model. The over-expression of HIF-1α demonstrates that our experimental conditions were similar to those of preeclampsia. We measured the expression of several calcium transport genes (CTGs; TRPV5, TRPV6, PMCA1 and CaBP-9k) in the placenta, duodenum and kidney after COMT inhibition on gestation day 17.5 (GD 17.5). In addition, we evaluated the calcium transporters in the kidney, duodenum of non-pregnant female mice. Placental TRPV5, TRPV6 and PMCA1 expressions were down-regulated by COMT inhibitor (ro41-0960). In addition, the reduced PMCA1 expression in the placenta was reversed by calcium supplementation. Duodenal expressions of TRPV5, TRPV6, and PMCA1 were decreased in COMT-inhibited mice, and recovered slightly after calcium supplementation. Renal expression of TRPV5, TRPV6, and PMCA1 was also decreased by COMT inhibition, while it was reversed by calcium supplementation to the level of control. Duodenal- and renal calcium transporting genes, TRPV5, TPRV6, PMCA1 and CaBP-9k, were down-regulated by COMT treatment in female mice. Taken together, these results indicate that physiological changes observed in COMT inhibition were similar to symptoms of preeclampsia, which may be related to disturbance of calcium metabolism during pregnancy.
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Affiliation(s)
- Hyun Yang
- Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea
| | - Changhwan Ahn
- Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea
| | - Eui-Bae Jeung
- Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea.
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48
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Elias E, Casselbrant A, Werling M, Abegg K, Vincent RP, Alaghband-Zadeh J, Olbers T, le Roux CW, Fändriks L, Wallenius V. Bone mineral density and expression of vitamin D receptor-dependent calcium uptake mechanisms in the proximal small intestine after bariatric surgery. Br J Surg 2014; 101:1566-75. [PMID: 25209438 DOI: 10.1002/bjs.9626] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 12/17/2013] [Accepted: 07/08/2014] [Indexed: 11/09/2022]
Abstract
BACKGROUND Roux-en-Y gastric bypass may lead to impaired calcium uptake. Therefore, operation-specific effects of gastric bypass and vertical banded gastroplasty on bone mineral density (BMD) were examined in a randomized clinical trial. Bone resorption markers and mechanisms of decreased calcium uptake after gastric bypass were investigated using blood and endoscopic samples from two additional patient cohorts. METHODS Total BMD and non-weight-bearing skull BMD were measured by dual-energy X-ray absorptiometry at baseline, and 1 and 6 years after gastric bypass or vertical banded gastroplasty in patients who were not receiving calcium supplements. Bone resorption markers in serum and calcium uptake mechanisms in jejunal mucosa biopsies were analysed after gastric bypass by proteomics including radioimmunoassay, gel electrophoresis and mass spectrometry. RESULTS One year after surgery, weight loss was similar after gastric bypass and vertical banded gastroplasty. There was a moderate decrease in skull BMD after gastric bypass, but not after vertical banded gastroplasty (P < 0·001). Between 1 and 6 years after gastric bypass, skull BMD and total BMD continued to decrease (P = 0·001). C-terminal telopeptide levels in serum had increased twofold by 18 months after gastric bypass. Proteomic analysis of the jejunal mucosa revealed decreased levels of heat-shock protein 90β, a co-activator of the vitamin D receptor, after gastric bypass. Despite increased vitamin D receptor levels, expression of the vitamin D receptor-regulated calcium transporter protein TRPV6 decreased. CONCLUSION BMD decreases independently of weight after gastric bypass. Bone loss might be attributed to impaired calcium absorption caused by decreased activation of vitamin D-dependent calcium absorption mechanisms mediated by heat-shock protein 90β and TRPV6.
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Affiliation(s)
- E Elias
- Departments of Gastrosurgical Research and Education, University of Gothenburg, Gothenburg, Sweden
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Krupa-Kozak U. Pathologic bone alterations in celiac disease: etiology, epidemiology, and treatment. Nutrition 2014; 30:16-24. [PMID: 24290593 DOI: 10.1016/j.nut.2013.05.027] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 05/29/2013] [Accepted: 05/31/2013] [Indexed: 12/13/2022]
Abstract
Low bone mineral density (BMD), osteopenia, and osteoporosis are frequent complications of celiac disease (CD). The etiology of pathologic bone alterations in CD is multifactorial; however, two main mechanisms are involved: intestinal malabsorption and chronic inflammation. A strict gluten-free diet (GFD) is thought to be the only effective treatment for CD; but treating bone complications related to CD remains complex. The objective of this review is to elucidate the bones problems related to CD and to increase awareness of osteoporosis development, considered as a sign of atypical CD presentation. Currently, a question of whether GFD alone is an effective treatment to correct the bone alterations in patients with CD is under debate. This review presents factors contributing to pathologic bone derangement, recent research on the epidemiology of low BMD, osteoporosis, and fractures, and the treatment of bone problems in patients with CD. The roles of calcium and transport mechanisms are additionally presented.
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Affiliation(s)
- Urszula Krupa-Kozak
- Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Department of Chemistry and Biodynamics of Food, Olsztyn, Poland.
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Chen J, Wang L, Shen Y, Yu J, Ye T, Zhuang C, Zhang W. Key genes associated with osteoporosis revealed by genome wide gene expression analysis. Mol Biol Rep 2014; 41:5971-7. [PMID: 24993113 DOI: 10.1007/s11033-014-3474-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 06/14/2014] [Indexed: 11/29/2022]
Abstract
Gene expression profiles of circulating monocytes were analyzed to identify key genes associated with osteoporosis. Raw microarray data were downloaded from gene expression omnibus under accession number GSE7158, including 8 microarray dataset for patients with high peak bone mass (PBM) and 8 for low PBM. Package linear models for microarray data of R was adopted to screen out differentially expressed genes (DEGs). Gene ontology enrichment analysis and Kyoto encyclopedia of genes and genomes pathway analysis were performed with plug-ins of cytoscape. Protein-protein interaction network was constructed using FunCoup. A total of 283 DEGs were identified in low-PBM group, including 135 up- and 148 down-regulated genes. A considerable part of DEGs were localized in plasma membrane. Several ion transport-related pathways were revealed, such as mineral absorption and carbohydrate digestion and absorption. A range of DEGs were identified and some of them were related to calcium transport as well as osteoporosis. These findings are helpful in disclosing the pathogenetic mechanisms of osteoporosis.
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Affiliation(s)
- Jie Chen
- Department of Orthopedics, Shanghai Institute of Traumatology and Orthopedics, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Er Rd, Shanghai, 200025, People's Republic of China
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