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Hakimi S, Dutta P, Layton AT. Renal calcium and magnesium handling during pregnancy: modeling and analysis. Am J Physiol Renal Physiol 2024; 327:F77-F90. [PMID: 38721663 DOI: 10.1152/ajprenal.00001.2024] [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: 01/09/2024] [Revised: 04/15/2024] [Accepted: 05/05/2024] [Indexed: 06/21/2024] Open
Abstract
Pregnancy is associated with elevated demand of most nutrients, with many trace elements and minerals critical for the development of fetus. In particular, calcium (Ca2+) and magnesium (Mg2+) are essential for cellular function, and their deficiency can lead to impaired fetal growth. A key contributor to the homeostasis of these ions is the kidney, which in a pregnant rat undergoes major changes in morphology, hemodynamics, and molecular structure. The goal of this study is to unravel the functional implications of these pregnancy-induced changes in renal handling of Ca2+ and Mg2+, two cations that are essential in a healthy pregnancy. To achieve that goal, we developed computational models of electrolyte and water transport along the nephrons of a rat in mid and late pregnancy. Model simulations reveal a substantial increase in the reabsorption of Mg2+ along the proximal tubules and thick ascending limbs. In contrast, the reabsorption of Ca2+ is increased in the proximal tubules but decreased in the thick ascending limbs, due to the lower transepithelial concentration gradient of Ca2+ along the latter. Despite the enhanced transport capacity, the marked increase in glomerular filtration rate results in elevated urinary excretions of Ca2+ and Mg2+ in pregnancy. Furthermore, we conducted simulations of hypocalcemia and hypomagnesemia. We found that hypocalcemia lowers Ca2+ excretion substantially more than Mg2+ excretion, with this effect being more pronounced in virgin rats than in pregnant ones. Conversely, hypomagnesemia reduces the excretion of Mg2+ and Ca2+ to more similar degrees. These differences can be explained by the greater sensitivity of the calcium-sensing receptor (CaSR) to Ca2+ compared with Mg2+.NEW & NOTEWORTHY A growing fetus' demands of minerals, notably calcium and magnesium, necessitate adaptations in pregnancy. In particular, the kidney undergoes major changes in morphology, hemodynamics, and molecular structure. This computational modeling study provides insights into how these pregnancy-induced renal adaptation impact calcium and magnesium transport along different nephron segments. Model simulations indicate that, despite the enhanced transport capacity, the marked increase in glomerular filtration rate results in elevated urinary excretions of calcium and magnesium in pregnancy.
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Affiliation(s)
- Shervin Hakimi
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
| | - Pritha Dutta
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
| | - Anita T Layton
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, Canada
- Department of Biology, Cheriton School of Computer Science, and School of Pharmacology, University of Waterloo, Waterloo, Ontario, Canada
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2
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Florance JA, Schollum JBW, Pomeranc A, Endre ZH, Walker RJ. Autosomal dominant hypercalciuric hypocalcaemia: the calcium-sensing receptor in renal calcium homeostasis and the impact of renal transplantation. Intern Med J 2024; 54:852-860. [PMID: 38665051 DOI: 10.1111/imj.16403] [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: 01/15/2024] [Accepted: 03/28/2024] [Indexed: 06/18/2024]
Abstract
Calcium-sensing receptors (CaSRs) are G protein-coupled receptors that help maintain Ca2+ concentrations, modulating calciotropic hormone release (parathyroid hormone (PTH), calcitonin and 1,25-dihydroxyvitamin D) by direct actions in the kidneys, gastrointestinal tract and bone. Variability in population calcium levels has been attributed to single nucleotide polymorphisms in CaSR genes, and several conditions affecting calcium and phosphate homeostasis have been attributed to gain- or loss-of-function mutations. An example is autosomal dominant hypercalciuric hypocalcaemia, because of a missense mutation at codon 128 of chromosome 3, as reported in our specific case and her family. As a consequence of treating symptomatic hypocalcaemia as a child, this female subject slowly developed progressive end-stage kidney failure because of nephrocalcinosis and nephrolithiasis. After kidney transplantation, she remains asymptomatic, with decreased vitamin D and elemental calcium requirements, stable fluid and electrolyte homeostasis during intercurrent illnesses and has normalised urinary calcium and phosphate excretion, reducing the likelihood of hypercalciuria-induced graft impairment. We review the actions of the CaSR, its role in regulating renal Ca2+ homeostasis along with the impact of a proven gain-of-function mutation in the CaSR gene resulting in autosomal dominant hypercalciuric hypocalcaemia before and after kidney transplantation.
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Affiliation(s)
- James A Florance
- Department of Nephrology, Dunedin Hospital, Dunedin, Otago, New Zealand
| | - John B W Schollum
- Department of Nephrology, Dunedin Hospital, Dunedin, Otago, New Zealand
| | - Abigail Pomeranc
- Department of Nephrology, Dunedin Hospital, Dunedin, Otago, New Zealand
| | - Zoltan H Endre
- Department of Nephrology, Prince of Wales Clinical School, UNSW Medicine, Sydney, New South Wales, Australia
| | - Robert J Walker
- Department of Nephrology, Dunedin Hospital, Dunedin, Otago, New Zealand
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3
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Flores-Espinoza E, Thomsen ARB. Beneath the surface: endosomal GPCR signaling. Trends Biochem Sci 2024; 49:520-531. [PMID: 38643023 PMCID: PMC11162320 DOI: 10.1016/j.tibs.2024.03.006] [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: 01/03/2024] [Revised: 03/02/2024] [Accepted: 03/15/2024] [Indexed: 04/22/2024]
Abstract
G protein-coupled receptors (GPCRs) located at the cell surface bind extracellular ligands and convey intracellular signals via activation of heterotrimeric G proteins. Traditionally, G protein signaling was viewed to occur exclusively at this subcellular region followed by rapid desensitization facilitated by β-arrestin (βarr)-mediated G protein uncoupling and receptor internalization. However, emerging evidence over the past 15 years suggests that these βarr-mediated events do not necessarily terminate receptor signaling and that some GPCRs continue to activate G proteins after having been internalized into endosomes. Here, we review the recently elucidated mechanistic basis underlying endosomal GPCR signaling and discuss physiological implications and pharmacological targeting of this newly appreciated signaling mode.
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Affiliation(s)
- Emmanuel Flores-Espinoza
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY 10010, USA; NYU Pain Research Center, New York University College of Dentistry, New York, NY 10010, USA
| | - Alex R B Thomsen
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY 10010, USA; NYU Pain Research Center, New York University College of Dentistry, New York, NY 10010, USA.
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4
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Vieira-Neto A, Lean IJ, Santos JEP. Periparturient Mineral Metabolism: Implications to Health and Productivity. Animals (Basel) 2024; 14:1232. [PMID: 38672379 PMCID: PMC11047658 DOI: 10.3390/ani14081232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 04/02/2024] [Accepted: 04/08/2024] [Indexed: 04/28/2024] Open
Abstract
Mineral metabolism, in particular Ca, and to a lesser extent phosphorus (P) and magnesium (Mg), is altered with the onset of lactation because of extensive irreversible loss to synthesize colostrum and milk. The transient reduction in the concentration of Ca in blood, particularly when it lasts days, increases the risk of mineral-related disorders such as hypocalcemia and, to a lesser extent, hypophosphatemia. Although the incidence of clinical hypocalcemia can be reduced by prepartum dietary interventions, subclinical hypocalcemia remains prevalent, affecting up to 60% of the dairy cows in the first 3 d postpartum. More importantly, strong associations exist between hypocalcemia and increased susceptibility to other peripartum diseases and impaired reproductive performance. Mechanistic experiments have demonstrated the role of Ca on innate immune response in dairy cows, which presumably predisposes them to other diseases. Hypocalcemia is not related to inadequate Ca intake as prepartum diets marginal to deficient in Ca reduce the risk of the disease. Therefore, the understanding of how Ca homeostasis is regulated, in particular how calciotropic hormones such as parathyroid hormone and 1,25-dihydroxyvitamin D3, affect blood Ca concentrations, gastrointestinal Ca absorption, bone remodeling, and renal excretion of Ca become critical to develop novel strategies to prevent mineral imbalances either by nutritional or pharmacological interventions. A common method to reduce the risk of hypocalcemia is the manipulation of the prepartum dietary cation-anion difference. Feeding acidogenic diets not only improves Ca homeostasis and reduces hypocalcemia, but also reduces the risk of uterine diseases and improves productive performance. Feeding diets that induce a negative Ca balance in the last weeks of gestation also reduce the risk of clinical hypocalcemia, and recent work shows that the incorporation of mineral sequestering agents, presumably by reducing the absorption of P and Ca prepartum, increases blood Ca at calving, although benefits to production and health remain to be shown. Alternative strategies to minimize subclinical hypocalcemia with the use of vitamin D metabolites either fed prepartum or as a pharmacological agent administered immediately after calving have shown promising results in reducing hypocalcemia and altering immune cell function, which might prove efficacious to prevent diseases in early lactation. This review summarizes the current understanding of Ca homeostasis around parturition, the limited knowledge of the exact mechanisms for gastrointestinal Ca absorption in bovine, the implications of hypocalcemia on the health of dairy cows, and discusses the methods to minimize the risk of hypocalcemia and their impacts on productive performance and health in dairy cows.
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Affiliation(s)
- Achilles Vieira-Neto
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611, USA;
| | - Ian J. Lean
- Scibus, Camden, NSW 2570, Australia;
- Faculty of Veterinary Science, The University of Sydney, Camden, NSW 2570, Australia
| | - José Eduardo P. Santos
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611, USA;
- DH Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville, FL 32611, USA
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5
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Peña KA, Savransky S, Lewis B. Endosomal signaling via cAMP in parathyroid hormone (PTH) type 1 receptor biology. Mol Cell Endocrinol 2024; 581:112107. [PMID: 37981188 DOI: 10.1016/j.mce.2023.112107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 10/25/2023] [Accepted: 11/06/2023] [Indexed: 11/21/2023]
Abstract
Compartmentalization of GPCR signaling is an emerging topic that highlights the physiological relevance of spatial bias in signaling. The parathyroid hormone (PTH) type 1 receptor (PTH1R) was the first GPCR described to signal via heterotrimeric G-protein and cAMP from endosomes after β-arrestin mediated internalization, challenging the canonical GPCR signaling model which established that signaling is terminated by receptor internalization. More than a decade later, many other GPCRs have been shown to signal from endosomes via cAMP, and recent studies have proposed that location of cAMP generation impacts physiological outcomes of GPCR signaling. Here, we review the extensive literature regarding PTH1R endosomal signaling via cAMP, the mechanisms that regulate endosomal generation of cAMP, and the implications of spatial bias in PTH1R physiological functions.
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Affiliation(s)
- Karina A Peña
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Sofya Savransky
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Graduate Program in Molecular Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Breanna Lewis
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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6
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Vilardaga JP, Clark LJ, White AD, Sutkeviciute I, Lee JY, Bahar I. Molecular Mechanisms of PTH/PTHrP Class B GPCR Signaling and Pharmacological Implications. Endocr Rev 2023; 44:474-491. [PMID: 36503956 PMCID: PMC10461325 DOI: 10.1210/endrev/bnac032] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 11/14/2022] [Accepted: 12/05/2022] [Indexed: 12/14/2022]
Abstract
The classical paradigm of G protein-coupled receptor (GPCR) signaling via G proteins is grounded in a view that downstream responses are relatively transient and confined to the cell surface, but this notion has been revised in recent years following the identification of several receptors that engage in sustained signaling responses from subcellular compartments following internalization of the ligand-receptor complex. This phenomenon was initially discovered for the parathyroid hormone (PTH) type 1 receptor (PTH1R), a vital GPCR for maintaining normal calcium and phosphate levels in the body with the paradoxical ability to build or break down bone in response to PTH binding. The diverse biological processes regulated by this receptor are thought to depend on its capacity to mediate diverse modes of cyclic adenosine monophosphate (cAMP) signaling. These include transient signaling at the plasma membrane and sustained signaling from internalized PTH1R within early endosomes mediated by PTH. Here we discuss recent structural, cell signaling, and in vivo studies that unveil potential pharmacological outputs of the spatial versus temporal dimension of PTH1R signaling via cAMP. Notably, the combination of molecular dynamics simulations and elastic network model-based methods revealed how precise modulation of PTH signaling responses is achieved through structure-encoded allosteric coupling within the receptor and between the peptide hormone binding site and the G protein coupling interface. The implications of recent findings are now being explored for addressing key questions on how location bias in receptor signaling contributes to pharmacological functions, and how to drug a difficult target such as the PTH1R toward discovering nonpeptidic small molecule candidates for the treatment of metabolic bone and mineral diseases.
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Affiliation(s)
- Jean-Pierre Vilardaga
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Lisa J Clark
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Alex D White
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Ieva Sutkeviciute
- Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Ji Young Lee
- Department of Computational and Systems Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Ivet Bahar
- Department of Computational and Systems Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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7
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Agarwal S, McMahon DJ, Chen J, Brossfield A, Fernando J, Bilezikian JP, Cusano NE, Rubin MR. The Clinical and Skeletal Effects of Long-Term Therapy of Hypoparathyroidism With rhPTH(1-84). J Bone Miner Res 2023; 38:480-492. [PMID: 36726204 PMCID: PMC10101915 DOI: 10.1002/jbmr.4780] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 01/16/2023] [Accepted: 01/25/2023] [Indexed: 02/03/2023]
Abstract
Hypoparathyroidism (HypoPT) is a disorder characterized by hypocalcemia, low or absent parathyroid hormone (PTH) levels, reduced bone remodeling, and high areal bone mineral density (aBMD). PTH is a therapeutic option, yet data on the prolonged clinical and skeletal effects of PTH treatment are limited. We tracked annual daily doses of calcium and active vitamin D supplements, calciotropic biochemistries, estimated glomerular filtration rate (eGFR), and aBMD measurements in 27 HypoPT patients (16 postsurgical, 11 nonsurgical) who were treated with recombinant human PTH(1-84) [rhPTH(1-84)] for at least 8 (n = 27) and up to 12 (n = 14) years. We also performed high-resolution-peripheral quantitative computed tomography (HRpQCT) imaging and report results at baseline, 5, 8, and 12 years of rhPTH(1-84) treatment. With prolonged use of rhPTH, reductions in the need for supplemental calcium and active vitamin D were maintained. The eGFR did not decline. Serum calcium was maintained within the lower limit of the normal range. aBMD by dual-energy X-ray absorptiometry (DXA) showed an increase at the lumbar spine and a decrease at the distal 1/3 radius. By HRpQCT, cortical volumetric BMD (vBMD) at the tibia decreased at year 5: -20.0% ± 1.5%. The magnitude of this reduction was mitigated in year 8: -8.5% ± 1.6% and in year 12: -10.3% ± 2.2% but all were significantly below the mean baseline value (p < 0.001). A similar pattern of decline was observed at the radius. Cortical porosity progressively increased at the tibia in year 5: 17.4% ± 10% (p < 0.05), year 8: 55.2% ± 11% (p < 0.001), and year 12: 83.5% ± 14% (p < 0.001). A similar pattern of increase was observed at the radius. Failure load, which was higher than normal at baseline, decreased but remained above normal at year 12. This is the longest experience, to date, with PTH therapy in HypoPT. These results demonstrate sustained biochemical stability but overall decreases in bone mass. © 2023 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Sanchita Agarwal
- Metabolic Bone Disease Unit, Department of Medicine, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY
| | - Donald J. McMahon
- Metabolic Bone Disease Unit, Department of Medicine, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY
| | - Juliet Chen
- Sophie Davis Program for Biomedical Education, CUNY School of Medicine, New York, NY
| | - Aiden Brossfield
- Metabolic Bone Disease Unit, Department of Medicine, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY
| | - Jason Fernando
- Metabolic Bone Disease Unit, Department of Medicine, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY
| | - John P. Bilezikian
- Metabolic Bone Disease Unit, Department of Medicine, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY
| | | | - Mishaela R. Rubin
- Metabolic Bone Disease Unit, Department of Medicine, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY
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8
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The importance of kidney calcium handling in the homeostasis of extracellular fluid calcium. Pflugers Arch 2022; 474:885-900. [PMID: 35842482 DOI: 10.1007/s00424-022-02725-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/09/2022] [Accepted: 06/30/2022] [Indexed: 12/13/2022]
Abstract
Extracellular fluid calcium concentration must be maintained within a narrow range in order to sustain many biological functions, encompassing muscle contraction, blood coagulation, and bone and tooth mineralization. Blood calcium value is critically dependent on the ability of the renal tubule to reabsorb the adequate amount of filtered calcium. Tubular calcium reabsorption is carried out by various and complex mechanisms in 3 distinct segments: the proximal tubule, the cortical thick ascending limb of the loop of Henle, and the late distal convoluted/connecting tubule. In addition, calcium reabsorption is tightly controlled by many endocrine, paracrine, and autocrine factors, as well as by non-hormonal factors, in order to adapt the tubular handling of calcium to the metabolic requirements. The present review summarizes the current knowledge of the mechanisms and factors involved in calcium handling by the kidney and, ultimately, in extracellular calcium homeostasis. The review also highlights some of our gaps in understanding that need to be addressed in the future.
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9
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Yoon SH, Tang CC, Wein MN. Salt inducible kinases and PTH1R action. VITAMINS AND HORMONES 2022; 120:23-45. [PMID: 35953111 DOI: 10.1016/bs.vh.2022.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Parathyroid hormone is a central regulator of calcium homeostasis. PTH protects the organism from hypocalcemia through its actions in bone and kidney. Recent physiologic studies have revealed key target genes for PTH receptor (PTH1R) signaling in these target organs. However, the complete signal transduction cascade used by PTH1R to accomplish these physiologic actions has remained poorly defined. Here we will review recent studies that have defined an important role for salt inducible kinases downstream of PTH1R in bone, cartilage, and kidney. PTH1R signaling inhibits the activity of salt inducible kinases. Therefore, direct SIK inhibitors represent a promising novel strategy to mimic PTH actions using small molecules. Moreover, a detailed understanding of the molecular circuitry used by PTH1R to exert its biologic effects will afford powerful new models to better understand the diverse actions of this important G protein coupled receptor in health and disease.
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Affiliation(s)
- Sung-Hee Yoon
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Cheng-Chia Tang
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Marc N Wein
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.
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10
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Fluck EC, Yazici AT, Rohacs T, Moiseenkova-Bell VY. Structural basis of TRPV5 regulation by physiological and pathophysiological modulators. Cell Rep 2022; 39:110737. [PMID: 35476976 PMCID: PMC9088182 DOI: 10.1016/j.celrep.2022.110737] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 03/02/2022] [Accepted: 04/05/2022] [Indexed: 12/11/2022] Open
Abstract
Transient receptor potential vanilloid 5 (TRPV5) is a kidney-specific Ca2+-selective ion channel that plays a key role in Ca2+ homeostasis. The basal activity of TRPV5 is balanced through activation by phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and inhibition by Ca2+-bound calmodulin (CaM). Parathyroid hormone (PTH), the key extrinsic regulator of Ca2+ homeostasis, increases the activity of TRPV5 via protein kinase A (PKA)-mediated phosphorylation. Metabolic acidosis leads to reduced TRPV5 activity independent of PTH, causing hypercalciuria. Using cryoelectron microscopy (cryo-EM), we show that low pH inhibits TRPV5 by precluding PI(4,5)P2 activation. We capture intermediate conformations at low pH, revealing a transition from open to closed state. In addition, we demonstrate that PI(4,5)P2 is the primary modulator of channel gating, yet PKA controls TRPV5 activity by preventing CaM binding and channel inactivation. Our data provide detailed molecular mechanisms for regulation of TRPV5 by two key extrinsic modulators, low pH and PKA.
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Affiliation(s)
- Edwin C Fluck
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Aysenur Torun Yazici
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ 07103, USA
| | - Tibor Rohacs
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ 07103, USA
| | - Vera Y Moiseenkova-Bell
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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11
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George B, Szilagyi JT, Joy MS, Aleksunes LM. Regulation of renal calbindin expression during cisplatin‐induced kidney injury. J Biochem Mol Toxicol 2022; 36:e23068. [DOI: 10.1002/jbt.23068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 11/20/2021] [Accepted: 01/04/2022] [Indexed: 11/10/2022]
Affiliation(s)
- Blessy George
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy Rutgers University Piscataway New Jersey USA
| | - John T. Szilagyi
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy Rutgers University Piscataway New Jersey USA
| | - Melanie S. Joy
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences University of Colorado Aurora Colorado USA
- Division of Developmental Therapeutics, Cancer Center University of Colorado Aurora Colorado USA
- Division of Renal Diseases and Hypertension University of Colorado School of Medicine Aurora Colorado USA
| | - Lauren M. Aleksunes
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy Rutgers University Piscataway New Jersey USA
- Division of Toxicology, Environmental and Occupational Health Sciences Institute Rutgers University Piscataway New Jersey USA
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12
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Chen N, Wang NN, Du C, Zhang JL, Guo YX, Zhang Y. Amelioration of Fructus Ligustri Lucidi and its phenol glycosides on hypercalciuria via stimulating PTH1R/PKA/TRPV5 signaling. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2022; 98:153982. [PMID: 35168092 DOI: 10.1016/j.phymed.2022.153982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/22/2022] [Accepted: 02/06/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Our early studies performed on aged rats, ovariectomized (OVX) rats and diabetic mice, indicated the calciotropic role of Fructus Ligustri Lucidi (FLL), the fruit of Ligustrum lucidum Ait., in mediating calcium homeostasis which was partially attributed to its stimulation on renal calcium reabsorption. PURPOSE This study aimed to explicate the underlying molecular mechanism and explore the potential bioactive ingredients in FLL. STUDY DESIGN AND METHODS The OVX C57BL/6 J mice were orally administered with low (FL, 75 mg/kg), middle (FM, 225 mg/kg) or high (FH, 675 mg/kg) dose of extract of Fructus Ligustri Lucidi for 10 weeks. The biological properties of trabecular bone were measured by micro-CT and H&E staining. The molecular expression was assessed by immunoblotting and immunostaining. The potential active components were identified by cell membrane chromatography (CMC) and explored in renal tubular cells with Fluo-3/AM fluorescent staining to indicate intracellular calcium level. The male mice fed with high calcium diet (1.2% Ca) and orally treated with active components for 3 weeks. RESULTS Treatment of OVX mice with FLL extract suppressed the elevation in urinary calcium level (FH, 0.081 ± 0.012, vs. OVX, 0.189 ± 0.038 mg/mg), and increased bone mineral density (FH, 62.41 ± 2.57, vs. OVX, 43.72 ± 8.43 mg/ccm) and percentage of trabecular bone area. It also decreased circulating PTH level (FH, 66.69 ± 10.94, vs. OVX, 303.50 ± 26.56 pg/ml) and up-regulated TRPV5 expression in renal cortex of OVX mice as well as enhanced the expression of PTH receptor (PTH1R) and the ratio of p-PKA/PKA. The PKA inhibitor H89 abolished the induction of serum, prepared from rats treated with FLL extract, on PKA/TRPV5 signaling in renal tubular cells. The CMC identified phenol glycosides, including salidroside and oleuropein, which increased intracellular calcium content, promoted expression of PTH1R and TRPV5 and ratio of p-PKA/PKA as well as decreased calcium excretion in urine of mice fed with high calcium diet. CONCLUSION Salidroside and oleuropein are major ingredients contributing to the anti-hypercalciuria effects of FLL via acting on PTH1R/PKA/TRPV5 signaling in kidney. Further translational research would be required.
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Affiliation(s)
- Nan Chen
- Spine Disease Research Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China; Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai 200032, China
| | - Na-Ni Wang
- Department of Medicine, Zhejiang Academy of Traditional Chinese Medicine, Hangzhou 310007, China
| | - Chen Du
- Department of Gynecology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China
| | - Jia-Li Zhang
- Spine Disease Research Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China; Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai 200032, China
| | - Yi-Xun Guo
- Spine Disease Research Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China; Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai 200032, China
| | - Yan Zhang
- Spine Disease Research Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China; Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai 200032, China.
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13
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Molecular mechanisms altering tubular calcium reabsorption. Pediatr Nephrol 2022; 37:707-718. [PMID: 33796889 DOI: 10.1007/s00467-021-05049-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 02/12/2021] [Accepted: 03/09/2021] [Indexed: 12/09/2022]
Abstract
The majority of calcium filtered by the glomerulus is reabsorbed along the nephron. Most is reabsorbed from the proximal tubule (> 60%) via a paracellular pathway composed of the tight junction proteins claudins-2 and -12, a process driven by sodium and consequently water reabsorption. The thick ascending limb reabsorbs the next greatest amount of calcium (20-25%), also by a paracellular pathway composed of claudins-16 and -19. This pathway is regulated by the CaSR, whose activity increases the expression of claudin-14, a protein that blocks paracellular calcium reabsorption. The fine tuning of urinary calcium excretion occurs in the distal convoluted and connecting tubule by a transcellular pathway composed of the apical calcium channel TRPV5, the calcium shuttling protein calbindin-D28K and the basolateral proteins PMCA1b and the sodium calcium exchanger, NCX. Not surprisingly, mutations in a subset of these genes cause monogenic disorders with hypercalciuria as a part of the phenotype. More commonly, "idiopathic" hypercalciuria is encountered clinically with genetic variations in CLDN14, the CASR and TRPV5 associating with kidney stones and increased urinary calcium excretion. An understanding of the molecular pathways conferring kidney tubular calcium reabsorption is employed in this review to help explain how dietary and medical interventions for this disorder lower urinary calcium excretion.
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14
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Liu J, Tio MC, Verma A, Schmidt IM, Ilori TO, Knauf F, Mc Causland FR, Waikar SS. Determinants and Outcomes Associated With Urinary Calcium Excretion in Chronic Kidney Disease. J Clin Endocrinol Metab 2022; 107:e281-e292. [PMID: 34390334 PMCID: PMC8684460 DOI: 10.1210/clinem/dgab574] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Indexed: 02/08/2023]
Abstract
CONTEXT Abnormalities in calcium metabolism are common in chronic kidney disease (CKD). Diminished urinary calcium excretion may promote vascular calcification and increased urinary calcium excretion may lead to nephrolithiasis and nephrocalcinosis, conditions associated with CKD. OBJECTIVE To study predictors of urinary calcium excretion and its association with adverse clinical outcomes in CKD. DESIGN, SETTING AND PATIENTS This study assessed 3768 nondialysis participants in the Chronic Renal Insufficiency Cohort study from April 2003 to September 2008. Participants were followed up to October 2018. EXPOSURE Clinically plausible predictors of urinary calcium excretion and 24-h urinary calcium excretion at baseline. MAIN OUTCOME MEASURES Urinary calcium excretion; incident end stage kidney disease (ESKD), CKD progression [50% estimated glomerular filtration rate (eGFR) decline or incident ESKD], all-cause mortality, and atherosclerotic cardiovascular disease events. RESULTS eGFR was positive correlated with 24-h urinary calcium excretion. The variables most strongly associated with 24-h urinary calcium excretion in males and females were 24-h urinary sodium (β = 0.19 and 0.28, respectively), serum parathyroid hormone (β = -0.22 and -0.20, respectively), loop diuretics (β = 0.36 and 0.26, respectively), thiazide diuretics (β = -0.49 and -0.53, respectively), and self-identified black race (β = -0.23 and -0.27, respectively). Lower urinary calcium excretion was associated with greater risks of adverse outcomes, but these associations were greatly attenuated or nullified after adjustment for baseline eGFR. CONCLUSION Urinary calcium excretion is markedly lower in individuals with CKD compared to the general population. Determinants of urinary calcium excretion differed between sexes and levels of CKD. Associations between urinary calcium excretion and adverse clinical events were substantially confounded by eGFR.
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Affiliation(s)
- Jing Liu
- Renal Division, Kidney Research Institute, West China Hospital of Sichuan University, Chengdu, China
- Section of Nephrology, Department of Medicine, Boston University School of Medicine and Boston Medical Center, Boston, MA, USA
| | - Maria Clarissa Tio
- Renal Division, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Ashish Verma
- Renal Division, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Insa M Schmidt
- Section of Nephrology, Department of Medicine, Boston University School of Medicine and Boston Medical Center, Boston, MA, USA
- Renal Division, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Titilayo O Ilori
- Section of Nephrology, Department of Medicine, Boston University School of Medicine and Boston Medical Center, Boston, MA, USA
| | - Felix Knauf
- Department of Nephrology and Medical Intensive Care, Charité Universitätsmedizin Berlin, Berlin, Germany
| | | | - Sushrut S Waikar
- Section of Nephrology, Department of Medicine, Boston University School of Medicine and Boston Medical Center, Boston, MA, USA
- Correspondence: Sushrut S. Waikar, MD, MPH, Boston Medical Center, Renal Section, Evans Biomedical Research Center, 650 Albany Street, X504, Boston, MA 02118, USA.
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15
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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: 33] [Impact Index Per Article: 11.0] [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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16
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Pou Casellas C, Rookmaaker MB, Verhaar MC. Controlling cellular plasticity to improve in vitro models for kidney regeneration. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2021. [DOI: 10.1016/j.cobme.2021.100345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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17
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Abstract
Nephrolithiasis is a worldwide problem with increasing prevalence, enormous costs, and significant morbidity. Calcium-containing kidney stones are by far the most common kidney stones encountered in clinical practice. Consequently, hypercalciuria is the greatest risk factor for kidney stone formation. Hypercalciuria can result from enhanced intestinal absorption, increased bone resorption, or altered renal tubular transport. Kidney stone formation is complex and driven by high concentrations of calcium-oxalate or calcium-phosphate in the urine. After discussing the mechanism mediating renal calcium salt precipitation, we review recent discoveries in renal tubular calcium transport from the proximal tubule, thick ascending limb, and distal convolution. Furthermore, we address how calcium is absorbed from the intestine and mobilized from bone. The effect of acidosis on bone calcium resorption and urinary calcium excretion is also considered. Although recent discoveries provide insight into these processes, much remains to be understood in order to provide improved therapies for hypercalciuria and prevent kidney stone formation. Expected final online publication date for the Annual Review of Physiology, Volume 84 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- R T Alexander
- Departments of Physiology and Pediatrics, University of Alberta, Edmonton, Canada; .,Membrane Protein Disease Research Group, University of Alberta, Edmonton, Canada
| | - D G Fuster
- Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - H Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.,Department of Nephrology, Odense University Hospital, Odense, Denmark
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18
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Yuan M, Shah A, Zeng L, Wang Z, Wang L, Xue B, Yu P, Peng Q. Effects of dietary cation-anion differences at the early stage of transitional period on dry matter intake and plasma Ca metabolism in beef cows. Anim Feed Sci Technol 2021. [DOI: 10.1016/j.anifeedsci.2021.114982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Magnesium and Calcium Homeostasis Depend on KCTD1 Function in the Distal Nephron. Cell Rep 2021; 34:108616. [PMID: 33440155 PMCID: PMC7869691 DOI: 10.1016/j.celrep.2020.108616] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 10/31/2020] [Accepted: 12/17/2020] [Indexed: 11/20/2022] Open
Abstract
Magnesium (Mg2+) homeostasis depends on active transcellular Mg2+ reuptake from urine in distal convoluted tubules (DCTs) via the Mg2+ channel TRPM6, whose activity has been proposed to be regulated by EGF. Calcium (Ca2+) homeostasis depends on paracellular reabsorption in the thick ascending limbs of Henle (TALs). KCTD1 promotes terminal differentiation of TALs/DCTs, but how its deficiency affects urinary Mg2+ and Ca2+ reabsorption is unknown. Here, this study shows that DCT1-specific KCTD1 inactivation leads to hypomagnesemia despite normal TRPM6 levels because of reduced levels of the sodium chloride co-transporter NCC, whereas Mg2+ homeostasis does not depend on EGF. Moreover, KCTD1 deficiency impairs paracellular urinary Ca2+ and Mg2+ reabsorption in TALs because of reduced NKCC2/claudin-16/-19 and increased claudin-14 expression, leading to hypocalcemia and consequently to secondary hyperparathyroidism and progressive metabolic bone disease. Thus, KCTD1 regulates urinary reabsorption of Mg2+ and Ca2+ by inducing expression of NCC in DCTs and NKCC2/claudin-16/-19 in TALs.
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20
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Vieira-Neto A, Leão IMR, Prim JG, Silva ACM, Nehme Marinho M, Zimpel R, Etheve S, Nelson CD, Santos JEP. Effect of duration of exposure to diets differing in dietary cation-anion difference on Ca metabolism after a parathyroid hormone challenge in dairy cows. J Dairy Sci 2020; 104:1018-1038. [PMID: 33162070 DOI: 10.3168/jds.2020-19127] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 07/29/2020] [Indexed: 11/19/2022]
Abstract
Objectives of the experiment were to determine the length of exposure to an acidogenic diet that would elicit changes in acid-base balance, mineral digestion, and response to parathyroid hormone (PTH)-induced changes in blood Ca and vitamin D3 in prepartum dairy cows. Nonlactating parous Holstein cows (n = 20) at 242 d of gestation were blocked by lactation (1 or >1) and pretreatment dry matter (DM) intake and, within block, they were randomly assigned to a diet with a dietary cation-anion difference (DCAD) of +200 mEq/kg of DM (DCAD +200) or an acidogenic diet with -150 mEq/kg of DM (DCAD -150). Water and DM intake were measured and blood was sampled daily. Urine was sampled every 3 h for 36 h, and then daily. During PTH challenges on d 3, 8, and 13, cows received i.v. PTH 1-34 fragment at 0.05 µg/kg of body weight every 20 min for 9 h to mimic the pulsatile release of endogenous PTH. Blood was sampled at 0 h, and hourly thereafter until 10 h, and at 12, 18, 24, 36, and 48 h relative to each challenge. Acid-base measures and concentrations of ionized Ca (iCa) in whole blood, and total Ca, Mg, P, and vitamin D metabolites in plasma were evaluated. On d 2 and 7, Ca, Mg, and P balances were evaluated. Cows fed DCAD -150 had smaller blood pH (7.431 vs. 7.389) and HCO3- (27.4 vs. 22.8 mM) compared with DCAD +200, and metabolic acidosis in DCAD -150 was observed 24 h after dietary treatments started. Concentrations of iCa begin to increase 24 h after feeding the acidogenic diet, and it was greater in DCAD -150 compared with DCAD +200 by 3 d in the experiment (1.23 vs. 1.26 mM). During the PTH challenges, cows fed DCAD -150 had greater concentration of iCa and area under the curve for iCa than those fed DCAD +200 (48.2 vs. 50.7 mmol/L × hour), and there was no interaction between treatment and challenge day. Concentration of 1,25-dihydroxyvitamin D3 in plasma did not differ during the PTH challenge, but change in 1,25-dihydroxyvitamin D3 relative to h 0 of the challenge was smaller in cows fed DCAD -150 than cows fed DCAD +200 (44.1 vs. 32.9 pg/mL). Urinary loss of Ca was greater in cows fed DCAD -150 compared with DCAD +200 (1.8 vs. 10.8 g/d); however, because digestibility of Ca increased in cows fed DCAD -150 (19.7 vs. 36.6%), the amount of Ca retained did not differ between treatments. Diet-induced metabolic acidosis was observed by 24 h after dietary treatment started, resulting in increases in concentration of iCa in blood observed between 1 and 3 d. Collectively, present results indicate that tissue responsiveness to PTH and changes in blood concentrations of iCa and digestibility of Ca are elicited within 3 d of exposure to an acidogenic diet. The increased apparent digestibility of Ca compensated for the increased urinary loss of Ca resulting in similar Ca retention.
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Affiliation(s)
- A Vieira-Neto
- Department of Animal Sciences, University of Florida, Gainesville 32611; DH Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32611
| | - I M R Leão
- Department of Animal Sciences, University of Florida, Gainesville 32611
| | - J G Prim
- Department of Animal Sciences, University of Florida, Gainesville 32611
| | - A C M Silva
- Department of Animal Sciences, University of Florida, Gainesville 32611
| | - M Nehme Marinho
- Department of Animal Sciences, University of Florida, Gainesville 32611
| | - R Zimpel
- Department of Animal Sciences, University of Florida, Gainesville 32611; DH Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32611
| | - S Etheve
- DSM Nutritional Products Ltd., Basel, 4002 Switzerland
| | - C D Nelson
- Department of Animal Sciences, University of Florida, Gainesville 32611
| | - J E P Santos
- Department of Animal Sciences, University of Florida, Gainesville 32611; DH Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32611.
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21
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Sun M, Wu X, Yu Y, Wang L, Xie D, Zhang Z, Chen L, Lu A, Zhang G, Li F. Disorders of Calcium and Phosphorus Metabolism and the Proteomics/Metabolomics-Based Research. Front Cell Dev Biol 2020; 8:576110. [PMID: 33015068 PMCID: PMC7511772 DOI: 10.3389/fcell.2020.576110] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 08/20/2020] [Indexed: 12/19/2022] Open
Abstract
Since calcium and phosphorus play vital roles in a multitude of physiologic systems, disorders of calcium and phosphorus metabolism always lead to severe consequences such as skeletal-related and cardiovascular morbidity, or even life-threatening. Physiologically, the maintenance of calcium and phosphorus homeostasis is achieved via a variety of concerted actions of hormones such as parathyroid hormone (PTH), vitamin D, and fibroblast growth factor (FGF23), which could be regulated mainly at three organs, the intestine, kidney, and bone. Disruption of any organ or factor might lead to disorders of calcium and phosphorus metabolism. Currently, lacking of accurate diagnostic approaches and unknown molecular basis of pathophysiology will result in patients being unable to receive a precise diagnosis and personalized treatment timely. Therefore, it is urgent to identify early diagnostic biomarkers and develop therapeutic strategies. Fortunately, proteomics and metabolomics offer promising tools to discover novel indicators and further understanding of pathological mechanisms. Therefore, in this review, we will give a systematic introduction on PTH-1,25(OH)2D-FGF23 axis in the disorders of calcium and phosphorus metabolism, diagnostic biomarkers identified, and potential altered metabolic pathways involved.
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Affiliation(s)
- Meiheng Sun
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Integrated Bioinfomedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Precision Medicine and Innovative Drug Discovery, HKBU Institute for Research and Continuing Education, Shenzhen, China.,Jiangsu Key Laboratory of Xenotransplantation, School of Basic Medical Science, Nanjing Medical University, Nanjing, China
| | - Xiaoqiu Wu
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Integrated Bioinfomedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Precision Medicine and Innovative Drug Discovery, HKBU Institute for Research and Continuing Education, Shenzhen, China
| | - Yuanyuan Yu
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Integrated Bioinfomedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Precision Medicine and Innovative Drug Discovery, HKBU Institute for Research and Continuing Education, Shenzhen, China
| | - Luyao Wang
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Integrated Bioinfomedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Precision Medicine and Innovative Drug Discovery, HKBU Institute for Research and Continuing Education, Shenzhen, China
| | - Duoli Xie
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Integrated Bioinfomedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong
| | - Zhenlin Zhang
- Shanghai Clinical Research Center of Bone Disease, Department of Osteoporosis and Bone Disease, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Lin Chen
- Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China
| | - Aiping Lu
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Integrated Bioinfomedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Precision Medicine and Innovative Drug Discovery, HKBU Institute for Research and Continuing Education, Shenzhen, China.,Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Beijing, China.,Institute of Arthritis Research, Shanghai Academy of Chinese Medical Sciences, Shanghai, China
| | - Ge Zhang
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Integrated Bioinfomedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Precision Medicine and Innovative Drug Discovery, HKBU Institute for Research and Continuing Education, Shenzhen, China
| | - Fangfei Li
- Law Sau Fai Institute for Advancing Translational Medicine in Bone and Joint Diseases, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Integrated Bioinfomedicine and Translational Science, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tsai, Hong Kong.,Institute of Precision Medicine and Innovative Drug Discovery, HKBU Institute for Research and Continuing Education, Shenzhen, China
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22
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Physical Activity-Dependent Regulation of Parathyroid Hormone and Calcium-Phosphorous Metabolism. Int J Mol Sci 2020; 21:ijms21155388. [PMID: 32751307 PMCID: PMC7432834 DOI: 10.3390/ijms21155388] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 07/09/2020] [Accepted: 07/23/2020] [Indexed: 12/14/2022] Open
Abstract
Exercise perturbs homeostasis, alters the levels of circulating mediators and hormones, and increases the demand by skeletal muscles and other vital organs for energy substrates. Exercise also affects bone and mineral metabolism, particularly calcium and phosphate, both of which are essential for muscle contraction, neuromuscular signaling, biosynthesis of adenosine triphosphate (ATP), and other energy substrates. Parathyroid hormone (PTH) is involved in the regulation of calcium and phosphate homeostasis. Understanding the effects of exercise on PTH secretion is fundamental for appreciating how the body adapts to exercise. Altered PTH metabolism underlies hyperparathyroidism and hypoparathyroidism, the complications of which affect the organs involved in calcium and phosphorous metabolism (bone and kidney) and other body systems as well. Exercise affects PTH expression and secretion by altering the circulating levels of calcium and phosphate. In turn, PTH responds directly to exercise and exercise-induced myokines. Here, we review the main concepts of the regulation of PTH expression and secretion under physiological conditions, in acute and chronic exercise, and in relation to PTH-related disorders.
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23
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Abstract
Parathyroid hormone is an essential regulator of extracellular calcium and phosphate. PTH enhances calcium reabsorption while inhibiting phosphate reabsorption in the kidneys, increases the synthesis of 1,25-dihydroxyvitamin D, which then increases gastrointestinal absorption of calcium, and increases bone resorption to increase calcium and phosphate. Parathyroid disease can be an isolated endocrine disorder or part of a complex syndrome. Genetic mutations can account for diseases of parathyroid gland formulation, dysregulation of parathyroid hormone synthesis or secretion, and destruction of the parathyroid glands. Over the years, a number of different options are available for the treatment of different types of parathyroid disease. Therapeutic options include surgical removal of hypersecreting parathyroid tissue, administration of parathyroid hormone, vitamin D, activated vitamin D, calcium, phosphate binders, calcium-sensing receptor, and vitamin D receptor activators to name a few. The accurate assessment of parathyroid hormone also provides essential biochemical information to properly diagnose parathyroid disease. Currently available immunoassays may overestimate or underestimate bioactive parathyroid hormone because of interferences from truncated parathyroid hormone fragments, phosphorylation of parathyroid hormone, and oxidation of amino acids of parathyroid hormone.
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Affiliation(s)
- Edward Ki Yun Leung
- Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, Los Angeles, CA, United States; Department of Pathology, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States.
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24
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Lawenius L, Scheffler JM, Gustafsson KL, Henning P, Nilsson KH, Colldén H, Islander U, Plovier H, Cani PD, de Vos WM, Ohlsson C, Sjögren K. Pasteurized Akkermansia muciniphila protects from fat mass gain but not from bone loss. Am J Physiol Endocrinol Metab 2020; 318:E480-E491. [PMID: 31961709 PMCID: PMC7191407 DOI: 10.1152/ajpendo.00425.2019] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 01/14/2020] [Accepted: 01/15/2020] [Indexed: 02/07/2023]
Abstract
Probiotic bacteria can protect from ovariectomy (ovx)-induced bone loss in mice. Akkermansia muciniphila is considered to have probiotic potential due to its beneficial effect on obesity and insulin resistance. The purpose of the present study was to determine if treatment with pasteurized Akkermansia muciniphila (pAkk) could prevent ovx-induced bone loss. Mice were treated with vehicle or pAkk for 4 wk, starting 3 days before ovx or sham surgery. Treatment with pAkk reduced fat mass accumulation confirming earlier findings. However, treatment with pAkk decreased trabecular and cortical bone mass in femur and vertebra of gonadal intact mice and did not protect from ovx-induced bone loss. Treatment with pAkk increased serum parathyroid hormone (PTH) levels and increased expression of the calcium transporter Trpv5 in kidney suggesting increased reabsorption of calcium in the kidneys. Serum amyloid A 3 (SAA3) can suppress bone formation and mediate the effects of PTH on bone resorption and bone loss in mice and treatment with pAkk increased serum levels of SAA3 and gene expression of Saa3 in colon. Moreover, regulatory T cells can be protective of bone and pAkk-treated mice had decreased number of regulatory T cells in mesenteric lymph nodes and bone marrow. In conclusion, treatment with pAkk protected from ovx-induced fat mass gain but not from bone loss and reduced bone mass in gonadal intact mice. Our findings with pAkk differ from some probiotics that have been shown to protect bone mass, demonstrating that not all prebiotic and probiotic factors have the same effect on bone.
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Affiliation(s)
- Lina Lawenius
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Julia M Scheffler
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Karin L Gustafsson
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Petra Henning
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Karin H Nilsson
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Hannah Colldén
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Ulrika Islander
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
- Department of Rheumatology and Inflammation Research, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Hubert Plovier
- Université Catholique de Louvain, Louvain Drug Research Institute, WELBIO (Walloon Excellence in Life Sciences and BIOtechnology), Metabolism and Nutrition Research Group, Brussels, Belgium
| | - Patrice D Cani
- Université Catholique de Louvain, Louvain Drug Research Institute, WELBIO (Walloon Excellence in Life Sciences and BIOtechnology), Metabolism and Nutrition Research Group, Brussels, Belgium
| | - Willem M de Vos
- Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands
- Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Claes Ohlsson
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Klara Sjögren
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
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25
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Guo Y, Wang Q, Lu C, Fan P, Li J, Luo X, Chen D. New parathyroid function index for the differentiation of primary and secondary hyperparathyroidism: a case-control study. BMC Endocr Disord 2020; 20:5. [PMID: 31914999 PMCID: PMC6950802 DOI: 10.1186/s12902-019-0487-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 12/30/2019] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Patients with primary hyperparathyroidism (PHPT) may be asymptomatic, and some may present with normocalcemic PHPT (NPHPT). Patients with vitamin D deficiency may also be asymptomatic, with normal calcium and elevated PTH concentrations. These latter patients are usually diagnosed with vitamin D deficiency-induced secondary hyperparathyroidism (VD-SHPT). Therefore, it is very difficult to distinguish PHPT and NPHPT from VD-SHPT based on calcium or PTH concentrations in clinical settings. In this case-control study, we aimed to verify the diagnostic power of a new parathyroid function index (PFindex = Ca*PTH/P). METHODS This study enrolled 128 patients with surgically and pathologically confirmed PHPT, including 36 with NPHPT, at a hospital in West China between January 2009 and September 2017. Thirty-seven patients with VD-SHPT and 45 healthy controls were selected from the population of a cross-sectional epidemiological study as the SHPT and healthy groups, respectively. We used the PFindex to describe the characteristics of PHPT, NPHPT, and VD-SHPT.. Differences between the four groups were compared, and a receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic power of PFindex. RESULTS The PHPT group had the highest PFindex (454 ± 430), compared to the other three groups (NPHPT: 101 ± 111; SHPT: 21.7 ± 6.38; healthy: 12.2 ± 2.98, all p < 0.001). A PFindex cut-off value of 34 yielded sensitivity and specificity rates of 96.9 and 97.6% and of 94.4 and 94.6% for the diagnoses of PHPT and NPHPT, respectively. The use of a PFindex > 34 to differentiate NPHPT from VD-SHPT yielded the highest positive likelihood ratio and lowest negative likelihood ratio. CONCLUSION The PFindex provided excellent diagnostic power for the differentiation of NPHPT from VD-SHPT. This simple tool may be useful for guiding timely decision-making processes regarding the initiation of vitamin D treatment or surgery for PHPT.
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Affiliation(s)
- Yanhong Guo
- Endocrinology Department of West China Hospital, Sichuan University, Chengdu, China
- Endocrinology Department, Hospital of Chengdu Office of People's Government of Tibetan autonomous Region, Chengdu, China
| | - Qin Wang
- Endocrinology Department of West China Hospital, Sichuan University, Chengdu, China
| | - Chunyan Lu
- Endocrinology Department of West China Hospital, Sichuan University, Chengdu, China
| | - Pianpian Fan
- Endocrinology Department of West China Hospital, Sichuan University, Chengdu, China
| | - Jing Li
- Endocrinology Department of West China Hospital, Sichuan University, Chengdu, China
| | - Ximing Luo
- Endocrinology Department of West China Hospital, Sichuan University, Chengdu, China
| | - Decai Chen
- Endocrinology Department of West China Hospital, Sichuan University, Chengdu, China.
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Karst NA, Sidler X, Liesegang A. Influence of mastitis metritis agalactia (MMA) on bone and fat metabolism. J Anim Physiol Anim Nutr (Berl) 2019; 105 Suppl 2:138-146. [PMID: 31637783 DOI: 10.1111/jpn.13201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 07/03/2019] [Accepted: 08/02/2019] [Indexed: 11/30/2022]
Abstract
Mastitis metritis agalactia (MMA) is a common disease in post-partum sows and has a negative effect on sows' longevity as well as on sows' and piglets' health. MMA leads to an inflammatory state. The aim was to investigate the impact of MMA on bone and fat metabolism. The hypothesis was that it is possible to predict MMA by measuring ketone bodies and bone markers. Blood samples from 175 sows were taken within 72 hr after farrowing. Serum was analysed for 25-hydroxyvitamin D (25-(OH)-D), serum crosslaps (CTX-I), osteocalcin (OC), alkaline phosphatase (ALP), calcium (Ca), magnesium (Mg), phosphorus (P), parathyroid hormone (PTH), triglycerides (TG), beta-hydroxybutyric acid (BHB), tumour necrosis factor-alpha (TNF-α) and haptoglobin. Spontaneous urine was collected, and pH value was measured in addition to Ca and P. A proximate analysis of the sows' diets was performed. Age, litter size, body condition score (BCS) and clinical signs of MMA were recorded for each sow. A multivariable logistic regression was undertaken with disease status (MMA or healthy) as the dependent variable. Significance was accepted at p < .05. MMA sows had a poorer BCS (p < .001) in relation to healthy sows. Age and number of piglets did not differ. MMA sows showed increased serum CTX-I (p = .004) and decreased serum OC (p < .001). Concentrations of P (p = .007), activity of ALP (p = .002) and BHB (p = .019) as well as TNF-α (p < .001) and haptoglobin (p = .048) concentrations were increased in MMA sows. No difference in urinary pH value between MMA and healthy sows was found. Our results are in accordance with the known fact that sows are in an extreme catabolic state peripartum. Bone metabolism in MMA sows is much more negatively affected than in healthy sows post-partum, due to inflammatory processes shown by higher concentrations of pro-inflammatory cytokines.
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Affiliation(s)
- Niklas A Karst
- Vetsuisse-Faculty, Institute of Animal Nutrition, University of Zurich, Zurich, Switzerland.,Vetsuisse-Faculty, Centre for Clinical Studies, University of Zurich, Zurich, Switzerland
| | - Xaver Sidler
- Division of Swine Medicine, Department of Farm Animals, Vetsuisse-Faculty, University of Zurich, Zurich, Switzerland
| | - Annette Liesegang
- Vetsuisse-Faculty, Institute of Animal Nutrition, University of Zurich, Zurich, Switzerland.,Vetsuisse-Faculty, Centre for Clinical Studies, University of Zurich, Zurich, Switzerland.,Centre for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland
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Gu J, Tong X, Chen Y, Zhang C, Ma T, Li S, Min W, Yuan Y, Liu X, Bian J, Liu Z. Vitamin D Inhibition of TRPV5 Expression During Osteoclast Differentiation. Int J Endocrinol Metab 2019; 17:e91583. [PMID: 31998380 PMCID: PMC6948119 DOI: 10.5812/ijem.91583] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 07/15/2019] [Accepted: 09/08/2019] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Vitamin D is an important steroid that can regulate bone metabolism including osteoclast (OC) differentiation. Transient receptor potential cation channel subfamily V member 5 (TRPV5), is a calcium channel protein involved in OC differentiation. However, the impact of vitamin D on TRPV5 expression during OC differentiation is not clear. OBJECTIVES To determine if 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) regulates the expression of TRPV5 during OC differentiation. METHODS Bone marrow mononuclear macrophage (BMMs) were induced to differentiate into OC with or without treatment with 10 nM 1,25(OH)2D3. The expression levels of vitamin D receptor (VDR) and TRPV5 were examined. The expression of several OC markers, including tartrate resistant acid phosphatase (TRAP), carbonic anhydrase II (Ca II), cathepsin K (CTSK), and vacuolar-type H+-ATPase (V-ATPase) were also detected. RESULTS We found that the VDR was expressed in murine bone marrow-derived macrophages at the early stage of OC differentiation. TRPV5 expression was increased during OC differentiation, which was down-regulated by 1,25(OH)2D3 after a prolonged exposure. The 1,25(OH)2D3 and TRPV5 inhibitors inhibited OC differentiation. CONCLUSIONS 1,25(OH)2D3 can inhibit TRPV5 expression as well as TRPV5 inhibitors during OC differentiation. This suggests that 1,25(OH)2D3 may suppress OC differentiation by inhibiting TRPV5 expression.
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Affiliation(s)
- Jianhong Gu
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China
| | - Xishuai Tong
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Yang Chen
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Chuang Zhang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Tianhong Ma
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Saihui Li
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Wenyan Min
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Yan Yuan
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Xuezhong Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Jianchun Bian
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
| | - Zongping Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China
- Corresponding Author: College of Veterinary Medicine, Yangzhou University, Wenhui East Road 48#, Yangzhou, China. Tel: +86-51487991448,
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Abstract
Parathyroid hormone (PTH) exerts both anabolic and catabolic actions on bone,depending on the duration and periodicity of exposure. Hypoparathyroidism is defined by inadequate production of PTH in the presence oflow serum calcium. In hypoparathyroidism it has been reported an increase in corticaland trabecular bone mass, but it is still unknown if these quantitative variations maybe accompanied by qualitative ones and increased bone strength. Despite the extensive data available on the effects of hypoparathyroidism on bone, itseffect on the hard end point in this area which is the risk of fractures still remainsunresolved and highly debated. As a matter of fact no previous review has focused onthis relevant clinical topic. This review will deal with the various aspects of bone metabolism (turn-over,density, quality) in hypoparathyroidism, focusing on the few data available on therisk of fracture and in particular of morphometric vertebral fractures, the emerging way to assess actual skeletal fragility particularly in secondary forms of osteoporosis.
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Affiliation(s)
| | | | | | - Andrea Giustina
- San Raffaele Vita-Salute University Via Olgettina, Milano, Italy.
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Capolongo G, Suzumoto Y, D'Acierno M, Simeoni M, Capasso G, Zacchia M. ERK1,2 Signalling Pathway along the Nephron and Its Role in Acid-base and Electrolytes Balance. Int J Mol Sci 2019; 20:E4153. [PMID: 31450703 PMCID: PMC6747339 DOI: 10.3390/ijms20174153] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/14/2019] [Accepted: 08/22/2019] [Indexed: 12/17/2022] Open
Abstract
Mitogen-activated protein kinases (MAPKs) are intracellular molecules regulating a wide range of cellular functions, including proliferation, differentiation, apoptosis, cytoskeleton remodeling and cytokine production. MAPK activity has been shown in normal kidney, and its over-activation has been demonstrated in several renal diseases. The extracellular signal-regulated protein kinases (ERK 1,2) signalling pathway is the first described MAPK signaling. Intensive investigations have demonstrated that it participates in the regulation of ureteric bud branching, a fundamental process in establishing final nephron number; in addition, it is also involved in the differentiation of the nephrogenic mesenchyme, indicating a key role in mammalian kidney embryonic development. In the present manuscript, we show that ERK1,2 signalling mediates several cellular functions also in mature kidney, describing its role along the nephron and demonstrating whether it contributes to the regulation of ion channels and transporters implicated in acid-base and electrolytes homeostasis.
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Affiliation(s)
- Giovanna Capolongo
- Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli", 80131 Naples, Italy
| | | | | | - Mariadelina Simeoni
- Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli", 80131 Naples, Italy
| | - Giovambattista Capasso
- Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli", 80131 Naples, Italy
- Biogem Scarl, 83031 Ariano Irpino, Italy
| | - Miriam Zacchia
- Department of Translational Medical Sciences, University of Campania "Luigi Vanvitelli", 80131 Naples, Italy.
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Calcitriol and FGF-23, but neither PTH nor sclerostin, are associated with calciuria in CKD. Int Urol Nephrol 2019; 51:1823-1829. [PMID: 31368056 DOI: 10.1007/s11255-019-02215-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 06/18/2019] [Indexed: 02/07/2023]
Abstract
PURPOSE The recent observation that urinary calcium excretion (UCE) drops considerably with CKD and that this effect may occur beyond compensation for reduced intestinal calcium absorption suggests that CKD per se is a state of sustained positive calcium balance, a mechanism likely to contribute to vascular calcification and CVD in CKD. However, the determinants of UCE reduction in CKD are not well understood and there is a lack of clinical studies, particularly in the CKD population. Therefore, in this study, we aimed to evaluate variables associated with UCE in a CKD cohort. METHODS Baseline data on 356 participants of the Progredir Study, Sao Paulo, Brazil, essentially composed of CKD G3a-G4, were analyzed according to UCE (24 h urine collection). RESULTS Median 24 h UCE was 38 mg/day (IQR 21-68 mg/day) and 0.48 mg/kg/day (IQR 0.28-0.82 mg/kg/day). In univariate analysis, UCE was inversely related to age, phosphorus, 1-84 PTH, FGF-23 and sclerostin, and positively associated with eGFR, DBP, 1,25(OH)2-vitamin D, calcium, bicarbonate, total calorie intake and spironolactone use. After adjustments for age, sex and eGFR, only 1,25(OH)2-vitamin D, calcium, FGF-23, bicarbonate and total calorie intake remained associated with it, but not PTH nor sclerostin. Lastly, in a multivariable model, eGFR, serum 1,25(OH)2-vitamin D, calcium, and FGF-23 remained associated with UCE. Similar results were observed when calcium fractional excretion was used instead of UCE, with eGFR, 1-25-vitamin D and FGF-23 remaining as independent associations. CONCLUSION Our results showed that CKD is associated with very low levels of UCE and that 1,25(OH)2-vitamin D, serum calcium and FGF-23 were independently associated with UCE in this population, raising the question whether these factors are modulators of the tubular handling of calcium in CKD.
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Pawlak D, Domaniewski T, Znorko B, Pawlak K. The use of LP533401 as a therapeutic option for renal osteodystrophy affects, renal calcium handling, vitamin D metabolism, and bone health in uremic rats. Expert Opin Ther Targets 2019; 23:353-364. [PMID: 30801205 DOI: 10.1080/14728222.2019.1586883] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Klotho is a key regulator of phosphate and Ca2+-transport in the kidney. Recently, we showed that treatment with LP533401 improved bone health in rats with chronic kidney disease (CKD) via the normalization of serum phosphate resulting from the reduced renal expression of phosphate cotransporters, including Klotho. METHODS We evaluated the effect of LP533401 therapy on Klotho-expression-dependent Ca2+-transporters, renal calcium handling, and the potential consequences for the bone of uremic rats. RESULTS Treatment with LP533401 and its vehicle resulted in the inhibition of transient receptor potential vanilloid receptor subtypes 5 and 6 (TRPV5, TRPV6) and calbindin (CaBP-28k, CaBP-9k) expression. The compensatory acceleration in renal expression of Na+/Ca2+-exchanger, 25-hydroxyvitamin d-1α-hydroxylase (CYP27B1), the intensification of vitamin D metabolism, and disruption of sophisticated balance between 1,25-dihydroxyvitamin D-serotonin was observed, especially in rats treated with LP533401. The imbalance between 1,25-dihydroxyvitamin D-serotonin levels led to intensified bone remodeling and improvement in bone geometry, mineral status, and strength in animals treated with LP533401. CONCLUSION The modulation of circulating serotonin and its relation to other regulators of calcium handling can play an important role in calcium homeostasis and bone integrity in CKD rats treated with LP533401.
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Affiliation(s)
- Dariusz Pawlak
- a Department of Pharmacodynamics , Medical University of Bialystok , Bialystok , Poland
| | - Tomasz Domaniewski
- b Department of Monitored Pharmacotherapy , Medical University of Bialystok , Bialystok , Poland
| | - Beata Znorko
- b Department of Monitored Pharmacotherapy , Medical University of Bialystok , Bialystok , Poland
| | - Krystyna Pawlak
- b Department of Monitored Pharmacotherapy , Medical University of Bialystok , Bialystok , Poland
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Abstract
Calcium kidney stones are common worldwide. Most are idiopathic and composed of calcium oxalate. Calcium phosphate is present in around 80% and may initiate stone formation. Stone production is multifactorial with a polygenic genetic contribution. Phosphaturia is found frequently among stone formers but until recently received scant attention. This review examines possible mechanisms for the phosphaturia and its relevance to stone formation from a wide angle. There is a striking lack of clinical data. Phosphaturia is associated, but not correlated, with hypercalciuria, increased 1,25 dihydroxy-vitamin D [1,25 (OH)2D], and sometimes evidence of disturbances in proximal renal tubular function. Phosphate reabsorption in the proximal renal tubules requires tightly regulated interaction of many proteins. Paracellular flow through intercellular tight junctions is the major route of phosphate absorption from the intestine and can be reduced therapeutically in hyperphosphatemic patients. In monogenic defects stones develop when phosphaturia is associated with hypercalciuria, generally explained by increased 1,25 (OH)2D production in response to hypophosphatemia. Calcification does not occur in disorders with increased FGF23 when phosphaturia occurs in isolation and 1,25 (OH)2D is suppressed. Candidate gene studies have identified mutations in the phosphate transporters, but in few individuals. One genome-wide study identified a polymorphism of the phosphate transporter gene SLC34A4 associated with stones. Others did not find mutations obviously linked to phosphate reabsorption. Future genetic studies should have a wide trawl and should focus initially on groups of patients with clearly defined phenotypes. The global data should be pooled.
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Affiliation(s)
- Valerie Walker
- Department of Clinical Biochemistry, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
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34
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Systemic Changes Affecting the Morphology of Calvarial Bone. J Craniofac Surg 2018; 30:e65-e75. [PMID: 30516566 DOI: 10.1097/scs.0000000000004991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Plastic surgeons are frequently consulted to evaluate concerns about a patient's skull. Imaging studies often reveal abnormalities in bone morphology, from increased porosity to sclerotic changes. While focal findings imply a benign or malignant neoplasm, the etiology of more diffuse findings can be more varied, making the correct diagnosis challenging. The present review summarizes the differential diagnosis of osseous lesions of the calvarium that affect the bone and contribute to changes seen on imaging studies.
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Abstract
Parathyroid hormone (PTH) is the major secretory product of the parathyroid glands, and in hypocalcemic conditions, can enhance renal calcium reabsorption, increase active vitamin D production to increase intestinal calcium absorption, and mobilize calcium from bone by increasing turnover, mainly but not exclusively in cortical bone. PTH has therefore found clinical use as replacement therapy in hypoparathyroidism. PTH also may have a physiologic role in augmenting bone formation, particularly in trabecular and to some extent in cortical bone. This action has been applied to the clinic to provide anabolic therapy for osteoporosis.
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Affiliation(s)
- David Goltzman
- Department of Medicine and Research Institute of the McGill University Health Centre, 1001 Decarie Boulevard, Montreal, Quebec H4A 3J1, Canada; Departments of Medicine and of Physiology, McGill University, 845 Sherbrooke St West, Montreal, Quebec H3A 0B9, Canada.
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Pouresmaeili F, Kamalidehghan B, Kamarehei M, Goh YM. A comprehensive overview on osteoporosis and its risk factors. Ther Clin Risk Manag 2018; 14:2029-2049. [PMID: 30464484 PMCID: PMC6225907 DOI: 10.2147/tcrm.s138000] [Citation(s) in RCA: 205] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Osteoporosis is a bone disorder with remarkable changes in bone biologic material and consequent bone structural distraction, affecting millions of people around the world from different ethnic groups. Bone fragility is the worse outcome of the disease, which needs long term therapy and medical management, especially in the elderly. Many involved genes including environmental factors have been introduced as the disease risk factors so far, of which genes should be considered as effective early diagnosis biomarkers, especially for the individuals from high-risk families. In this review, a number of important criteria involved in osteoporosis are addressed and discussed.
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Affiliation(s)
- Farkhondeh Pouresmaeili
- Infertility and Reproductive Health Research Center (IRHRC), Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Medical Genetics Department, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran,
| | - Behnam Kamalidehghan
- Medical Genetics Department, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran,
- Medical Genetics Center, National Institute of Genetics Engineering and Biotechnology (NIGEB), Tehran, Iran,
| | - Maryam Kamarehei
- Department of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran,
| | - Yong Meng Goh
- Department of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, Universiti Putra Malaysia (UPM), Serdang, Malaysia
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Ide N, Ye R, Courbebaisse M, Olauson H, Densmore MJ, Larsson TE, Hanai JI, Lanske B. In vivo evidence for an interplay of FGF23/Klotho/PTH axis on the phosphate handling in renal proximal tubules. Am J Physiol Renal Physiol 2018; 315:F1261-F1270. [PMID: 29993278 DOI: 10.1152/ajprenal.00650.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Phosphate homeostasis is primarily maintained in the renal proximal tubules, where the expression of sodium/phosphate cotransporters (Npt2a and Npt2c) is modified by the endocrine actions of both fibroblast growth factor 23 (FGF23) and parathyroid hormone (PTH). However, the specific contribution of each regulatory pathway in the proximal tubules has not been fully elucidated in vivo. We have previously demonstrated that proximal tubule-specific deletion of the FGF23 coreceptor Klotho results in mild hyperphosphatemia with little to no change in serum levels of FGF23, 1,25(OH)2D3, and PTH. In the present study, we characterized mice in which the PTH receptor PTH1R was specifically deleted from the proximal tubules, either alone or in combination with Klotho ( PT-PTH1R-/- and PT-PTH1R/KL-/-, respectively). PT-PTH1R-/- mice showed significant increases in serum FGF23 and PTH levels, whereas serum phosphate levels were maintained in the normal range, and Npt2a and Npt2c expression in brush border membrane (BBM) did not change compared with control mice. In contrast, PT-PTH1R/KL-/- mice displayed hyperphosphatemia and an increased abundance of Npt2a and Npt2c in the renal BBM, along with increased circulating FGF23 levels. While serum calcium was normal, 1,25(OH)2D3 levels were significantly decreased, leading to extremely high levels of PTH. Collectively, mice with a deletion of PTH1R alone in proximal tubules results in only minor changes in phosphate regulation, whereas deletion of both PTH1R and Klotho leads to a severe disturbance, including hyperphosphatemia with increased sodium/phosphate cotransporter expression in BBM. These results suggest an important interplay between the PTH/PTH1R and FGF23/Klotho pathways to affect renal phosphate handling in the proximal tubules.
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Affiliation(s)
- Noriko Ide
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine , Boston, Massachusetts
| | - Rui Ye
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine , Boston, Massachusetts.,State Key Laboratory of Oral Disease, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University , Chengdu , China
| | - Marie Courbebaisse
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine , Boston, Massachusetts.,Paris Descartes University , Paris , France
| | - Hannes Olauson
- Division of Renal Medicine, Department of Clinical Science, Intervention, and Technology, Karolinska Institutet , Stockholm , Sweden
| | - Michael J Densmore
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine , Boston, Massachusetts
| | - Tobias E Larsson
- Division of Renal Medicine, Department of Clinical Science, Intervention, and Technology, Karolinska Institutet , Stockholm , Sweden
| | - Jun-Ichi Hanai
- Division of Nephrology, Division of Interdisciplinary Medicine and Biotechnology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School , Boston, Massachusetts
| | - Beate Lanske
- Division of Bone and Mineral Research, Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine , Boston, Massachusetts
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Association between Urinary Calcium Excretion and Estimated Glomerular Filtration Rate Decline in Patients with Type 2 Diabetes Mellitus: A Retrospective Single-center Observational Study. J Clin Med 2018; 7:jcm7070171. [PMID: 29996526 PMCID: PMC6069054 DOI: 10.3390/jcm7070171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 07/07/2018] [Accepted: 07/08/2018] [Indexed: 12/20/2022] Open
Abstract
Urinary calcium excretion is not known to predict progression of renal dysfunction in patients with type 2 diabetes mellitus. This study aimed to investigate associations between urinary calcium excretion and progression of estimated glomerular filtration rate (eGFR) in type 2 diabetic patients. This study was a retrospective, single-center, observational cohort study. We enrolled a total of 89 patients with type 2 diabetes mellitus and the average follow-up period was 7.2 ± 1.0 years. We divided patients into two groups based on the median of annual decline in the slope of eGFR, then defined the over-median population as the progressed group and under-median population as the non-progressed group. Median of annual decline in the slope of eGFR was −1.1 mL/min/1.73 m²/year. Correlation coefficient analysis showed positive correlation of urinary calcium excretion with eGFR (r = 0.39, p < 0.001). Multivariate logistic analysis showed that baseline eGFR and urinary calcium excretion were independent variables for progression of eGFR decline. Urinary calcium excretion could be a useful metabolic parameter for predicting decline in slope of eGFR in patients with type 2 diabetes mellitus.
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Reduced secretion of parathyroid hormone and hypocalcemia in systemic heterozygous ATP2B1-null hypertensive mice. Hypertens Res 2018; 41:699-707. [PMID: 29950683 PMCID: PMC8076045 DOI: 10.1038/s41440-018-0067-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 01/20/2018] [Accepted: 01/22/2018] [Indexed: 01/11/2023]
Abstract
The ATP2B1 gene is associated with hypertension. We previously reported that systemic heterozygous ATP2B1-null (ATP2B1+/−) mice exhibited hypertension due to impaired endothelial nitric oxide synthase (eNOS) activity and decreased nitric oxide (NO) production. The ATP2B1 gene encodes plasma membrane calcium ATPase 1 (PMCA1), which has been thought to regulate only intracellular Ca2+ concentration. However, recently, it has been suggested that ATP2B1 works not only at cellular levels, but also throughout the entire body, including in the calcium metabolism, using small intestine-specific ATP2B1 knockout mice. To clarify the roles of ATP2B1 in the entire body and the effects of ATP2B1 on blood pressure, we examined the alterations of calcium related factors in ATP2B1+/− mice. ATP2B1+/− mice exhibited hypocalcemia. The expression of ATP2B1 in the kidney and small intestine decreased, and hypercalciuria was confirmed in ATP2B1+/− mice. The intact-PTH levels were lower, and bone mineral density was increased in these mice. These results suggest that hypocalcemia is mainly a result of inhibited bone resorption without compensation by PTH secretion in the case of ATP2B1 knockout. Moreover, NO production may be affected by reduced PTH secretion, which may cause the increase in vascular contractility in these mice. The ATP2B1 gene is important for not only intra-cellular calcium regulation but also for calcium homeostasis and blood pressure control.
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Kolp E, Wilkens MR, Pendl W, Eichenberger B, Liesegang A. Vitamin D metabolism in growing pigs: influence of UVB irradiation and dietary vitamin D supply on calcium homeostasis, its regulation and bone metabolism. J Anim Physiol Anim Nutr (Berl) 2018. [PMID: 28627057 DOI: 10.1111/jpn.12707] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The aim of this study was to prove whether pigs are able to synthesize vitamin D (vitD) in the skin and to investigate the influence of ultraviolet irradiation (UVB) on vitD status and calcium (Ca) homeostasis of growing pigs. Thirty-two 11-week-old pigs were kept without access to sunlight and divided into four groups receiving the following treatment in a 2 × 2 factorial design: (i) UVB irradiation or not and (ii) vitD in feed or not. Blood, urine and faeces were sampled every third week. In serum, vitD metabolites, Ca, phosphorus (P), magnesium (Mg) and bone markers were analysed. Digestibility of Ca, P and Mg as well as urinary excretion of these minerals was analysed. After 14 weeks, the animals were slaughtered, and samples of skin, intestines, kidneys and bones (metatarsus) were taken for further analyses: sterols of vitD synthesis in the skin, Ca flux rates in the intestines, expression of genes involved in Ca transport in the intestines and kidneys, bone mineral density (BMD) with the aid of peripheral quantitative computer tomography and bone mineral content by ashing the metatarsus. Irradiated animals showed higher levels of 7-dehydrocholesterol and tachysterol in the skin, higher levels of 25-hydroxycholecalciferol and 1,25-dihydroxycholecalciferol in the serum and higher Ca net flux rates were determined in Ussing chambers. In contrast, the expression of genes involved in Ca transport in the intestines and kidneys was not altered. Similarly, the digestibility of Ca and P as well as the urinary excretion was not affected. With respect to the metatarsus, no differences in mineral contents and BMD were found between groups. At the end of the study, some subclinical signs of beginning vitD 'insufficiency' were observed in the group without access to vitD (represented by higher expression of 1α-hydroxylase in the kidney and increased parathyroid hormone in serum).
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Affiliation(s)
- E Kolp
- Institute of Animal Nutrition, Vetsuisse-Faculty, University of Zurich, Zurich, Switzerland.,Centre for Clinical Studies, Vetsuisse-Faculty, University of Zurich, Zurich, Switzerland
| | - M R Wilkens
- Department of Physiology, University of Veterinary Medicine, Foundation Hannover, Germany
| | - W Pendl
- Department of Farm Animals, Section of Swine Medicine, Vetsuisse-Faculty, University of Zurich, Zurich, Switzerland
| | | | - A Liesegang
- Institute of Animal Nutrition, Vetsuisse-Faculty, University of Zurich, Zurich, Switzerland.,Centre for Clinical Studies, Vetsuisse-Faculty, University of Zurich, Zurich, Switzerland.,Centre for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland
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41
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Rodenbeck SD, Zarse CA, McKenney-Drake ML, Bruning RS, Sturek M, Chen NX, Moe SM. Intracellular calcium increases in vascular smooth muscle cells with progression of chronic kidney disease in a rat model. Nephrol Dial Transplant 2017; 32:450-458. [PMID: 27510531 DOI: 10.1093/ndt/gfw274] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 06/08/2016] [Indexed: 01/12/2023] Open
Abstract
Background Vascular smooth muscle cells (VSMCs) exhibit phenotypic plasticity, promoting vascular calcification and increasing cardiovascular risk. Changes in VSMC intracellular calcium ([Ca 2+ ] i ) are a major determinant of plasticity, but little is known about changes in [Ca 2+ ] i in chronic kidney disease (CKD). We have previously demonstrated such plasticity in aortas from our rat model of CKD and therefore sought to examine changes in [Ca 2+ ] i during CKD progression. Materials and Methods We examined freshly isolated VSMCs from aortas of normal rats, Cy/+ rats (CKD) with early and advanced CKD, and advanced CKD rats treated without and with 3% calcium gluconate (CKD + Ca 2+ ) to lower parathyroid hormone (PTH) levels. [Ca 2+ ] i was measured with fura-2. Results Cy/+ rats developed progressive CKD, as assessed by plasma levels of blood urea nitrogen, calcium, phosphorus, parathyroid hormone and fibroblast growth factor 23. VSMCs isolated from rats with CKD demonstrated biphasic alterations in resting [Ca 2+ ] i : VSMCs from rats with early CKD exhibited reduced resting [Ca 2+ ] i , while VSMCs from rats with advanced CKD exhibited elevated resting [Ca 2+ ] i . Caffeine-induced sarcoplasmic reticulum (SR) Ca 2+ store release was modestly increased in early CKD and was more drastically increased in advanced CKD. The advanced CKD elevation in SR Ca 2+ store release was associated with a significant increase in the activity of the sarco-endoplasmic reticulum Ca 2+ ATPase (SERCA); however, SERCA2a protein expression was decreased in advanced CKD. Following SR Ca 2+ store release, recovery of [Ca 2+ ] i in the presence of caffeine and extracellular Ca 2+ was attenuated in VSMCs from rats with advanced CKD. This impairment, together with reductions in expression of the Na + /Ca 2+ exchanger, suggest a reduction in Ca 2+ extrusion capability. Finally, store-operated Ca 2+ entry (SOCE) was assessed following SR Ca 2+ store depletion. Ca 2+ entry during recovery from caffeine-induced SR Ca 2+ store release was elevated in advanced CKD, suggesting a role for exacerbated SOCE with progressing CKD. Conclusions With progressive CKD in the Cy/+ rat there is increased resting [Ca 2+ ] i in VSMCs due, in part, to increased SOCE and impaired calcium extrusion from the cell. Such changes may predispose VSMCs to phenotypic changes that are a prerequisite to calcification.
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Affiliation(s)
- Stacey Dineen Rodenbeck
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Chad A Zarse
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Mikaela L McKenney-Drake
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Rebecca S Bruning
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Michael Sturek
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Neal X Chen
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Sharon M Moe
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA.,Department of Medicine, Roudebush Veterans Affairs Medical Center, Indianapolis, IN, USA
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42
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Lee JJ, Plain A, Beggs MR, Dimke H, Alexander RT. Effects of phospho- and calciotropic hormones on electrolyte transport in the proximal tubule. F1000Res 2017; 6:1797. [PMID: 29043081 PMCID: PMC5627579 DOI: 10.12688/f1000research.12097.1] [Citation(s) in RCA: 9] [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] [Accepted: 10/04/2017] [Indexed: 12/17/2022] Open
Abstract
Calcium and phosphate are critical for a myriad of physiological and cellular processes within the organism. Consequently, plasma levels of calcium and phosphate are tightly regulated. This occurs through the combined effects of the phospho- and calciotropic hormones, parathyroid hormone (PTH), active vitamin D
3, and fibroblast growth factor 23 (FGF23). The organs central to this are the kidneys, intestine, and bone. In the kidney, the proximal tubule reabsorbs the majority of filtered calcium and phosphate, which amounts to more than 60% and 90%, respectively. The basic molecular mechanisms responsible for phosphate reclamation are well described, and emerging work is delineating the molecular identity of the paracellular shunt wherein calcium permeates the proximal tubular epithelium. Significant experimental work has delineated the molecular effects of PTH and FGF23 on these processes as well as their regulation of active vitamin D
3 synthesis in this nephron segment. The integrative effects of both phospho- and calciotropic hormones on proximal tubular solute transport and subsequently whole body calcium-phosphate balance thus have been further complicated. Here, we first review the molecular mechanisms of calcium and phosphate reabsorption from the proximal tubule and how they are influenced by the phospho- and calciotropic hormones acting on this segment and then consider the implications on both renal calcium and phosphate handling as well as whole body mineral balance.
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Affiliation(s)
- Justin J Lee
- Department of Physiology, University of Alberta, Edmonton, Canada.,The Women and Children's Health Research Institute, Edmonton, Canada
| | - Allein Plain
- Department of Physiology, University of Alberta, Edmonton, Canada.,The Women and Children's Health Research Institute, Edmonton, Canada
| | - Megan R Beggs
- Department of Physiology, University of Alberta, Edmonton, Canada.,The Women and Children's Health Research Institute, Edmonton, Canada
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - R Todd Alexander
- Department of Physiology, University of Alberta, Edmonton, Canada.,The Women and Children's Health Research Institute, Edmonton, Canada.,Department of Pediatrics, Edmonton Clinic Health Academy, University of Alberta, Edmonton, Canada
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43
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Parathyroid hormone and the regulation of renal tubular calcium transport. Curr Opin Nephrol Hypertens 2017; 26:405-410. [DOI: 10.1097/mnh.0000000000000347] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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44
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Granjon D, Bonny O, Edwards A. Coupling between phosphate and calcium homeostasis: a mathematical model. Am J Physiol Renal Physiol 2017; 313:F1181-F1199. [PMID: 28747359 DOI: 10.1152/ajprenal.00271.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/19/2017] [Accepted: 07/19/2017] [Indexed: 12/18/2022] Open
Abstract
We developed a mathematical model of calcium (Ca) and phosphate (PO4) homeostasis in the rat to elucidate the hormonal mechanisms that underlie the regulation of Ca and PO4 balance. The model represents the exchanges of Ca and PO4 between the intestine, plasma, kidneys, bone, and the intracellular compartment, and the formation of Ca-PO4-fetuin-A complexes. It accounts for the regulation of these fluxes by parathyroid hormone (PTH), vitamin D3, fibroblast growth factor 23, and Ca2+-sensing receptors. Our results suggest that the Ca and PO4 homeostatic systems are robust enough to handle small perturbations in the production rate of either PTH or vitamin D3 The model predicts that large perturbations in PTH or vitamin D3 synthesis have a greater impact on the plasma concentration of Ca2+ ([Ca2+]p) than on that of PO4 ([PO4]p); due to negative feedback loops, [PO4]p does not consistently increase when the production rate of PTH or vitamin D3 is decreased. Our results also suggest that, following a large PO4 infusion, the rapidly exchangeable pool in bone acts as a fast, transient storage PO4 compartment (on the order of minutes), whereas the intracellular pool is able to store greater amounts of PO4 over several hours. Moreover, a large PO4 infusion rapidly lowers [Ca2+]p owing to the formation of CaPO4 complexes. A large Ca infusion, however, has a small impact on [PO4]p, since a significant fraction of Ca binds to albumin. This mathematical model is the first to include all major regulatory factors of Ca and PO4 homeostasis.
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Affiliation(s)
- David Granjon
- Sorbonne Universités, UPMC University of Paris 06, Université Paris Descartes, Sorbonne Paris Cité, INSERM UMRS 1138, CNRS ERL 8228, Centre de Recherche des Cordeliers, Paris, France.,Department of Pharmacology and Toxicology, University of Lausanne, and Service of Nephrology, Lausanne University Hospital, Lausanne, Switzerland; and
| | - Olivier Bonny
- Department of Pharmacology and Toxicology, University of Lausanne, and Service of Nephrology, Lausanne University Hospital, Lausanne, Switzerland; and
| | - Aurélie Edwards
- Sorbonne Universités, UPMC University of Paris 06, Université Paris Descartes, Sorbonne Paris Cité, INSERM UMRS 1138, CNRS ERL 8228, Centre de Recherche des Cordeliers, Paris, France; .,Department of Biomedical Engineering, Boston University, Boston, Massachusetts
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45
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Parathyroid hormone controls paracellular Ca 2+ transport in the thick ascending limb by regulating the tight-junction protein Claudin14. Proc Natl Acad Sci U S A 2017; 114:E3344-E3353. [PMID: 28373577 DOI: 10.1073/pnas.1616733114] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Renal Ca2+ reabsorption is essential for maintaining systemic Ca2+ homeostasis and is tightly regulated through the parathyroid hormone (PTH)/PTHrP receptor (PTH1R) signaling pathway. We investigated the role of PTH1R in the kidney by generating a mouse model with targeted deletion of PTH1R in the thick ascending limb of Henle (TAL) and in distal convoluted tubules (DCTs): Ksp-cre;Pth1rfl/fl Mutant mice exhibited hypercalciuria and had lower serum calcium and markedly increased serum PTH levels. Unexpectedly, proteins involved in transcellular Ca2+ reabsorption in DCTs were not decreased. However, claudin14 (Cldn14), an inhibitory factor of the paracellular Ca2+ transport in the TAL, was significantly increased. Analyses by flow cytometry as well as the use of Cldn14-lacZ knock-in reporter mice confirmed increased Cldn14 expression and promoter activity in the TAL of Ksp-cre;Pth1rfl/fl mice. Moreover, PTH treatment of HEK293 cells stably transfected with CLDN14-GFP, together with PTH1R, induced cytosolic translocation of CLDN14 from the tight junction. Furthermore, mice with high serum PTH levels, regardless of high or low serum calcium, demonstrated that PTH/PTH1R signaling exerts a suppressive effect on Cldn14. We therefore conclude that PTH1R signaling directly and indirectly regulates the paracellular Ca2+ transport pathway by modulating Cldn14 expression in the TAL. Finally, systemic deletion of Cldn14 completely rescued the hypercalciuric and lower serum calcium phenotype in Ksp-cre;Pth1rfl/fl mice, emphasizing the importance of PTH in inhibiting Cldn14. Consequently, suppressing CLDN14 could provide a potential treatment to correct urinary Ca2+ loss, particularly in patients with hypoparathyroidism.
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46
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Bi R, Fan Y, Luo E, Yuan Q, Mannstadt M. Two Techniques to Create Hypoparathyroid Mice: Parathyroidectomy Using GFP Glands and Diphtheria-Toxin-Mediated Parathyroid Ablation. J Vis Exp 2017. [PMID: 28362393 PMCID: PMC5408591 DOI: 10.3791/55010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Hypoparathyroidism (HP) is a disorder characterized by low levels of PTH which lead to hypocalcemia, hyperphosphatemia, and low bone turnover. The most common cause of the disease is accidental removal of the parathyroid glands during thyroid surgery. Novel therapies for HP are needed, but testing them requires reliable animal models of acquired HP. Here, we demonstrate the generation of two mouse models of acquired HP. In the GFP-PTX model, mice with green fluorescent protein (GFP) expressed specifically in the parathyroids (PTHcre-mTmG) were created by crossing PTHcre+ mice with Rosa-mTmGfl/fl mice. Green fluorescing parathyroid glands are easily identified under a fluorescence dissecting microscope and parathyroidectomy is performed in less than 20 min. After fluorescence-guided surgery, mice are profoundly hypocalcemic. Contrary to the traditional thyro-parathyroidectomy, this precise surgical approach leaves thyroid glands and thyroid function intact. The second model, which does not require surgery, is based on a diphtheria-toxin approach. PTHcre-iDTR mice, which express the diphtheria toxin (DT) receptor specifically in the parathyroids, were generated by crossing the inducible DTR mouse with the PTHcre mouse. Parathyroid cells are thus rendered sensitive to diphtheria toxin (DT) and can be selectively destroyed by systemically injecting mice with DT. The resulting hypocalcemic phenotype is stable.
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Affiliation(s)
- Ruiye Bi
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School; West China School of Stomatology, Sichuan University
| | - Yi Fan
- West China School of Stomatology, Sichuan University; Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine
| | - En Luo
- West China School of Stomatology, Sichuan University; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University
| | - Quan Yuan
- West China School of Stomatology, Sichuan University; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University
| | - Michael Mannstadt
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School;
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Verdelli C, Corbetta S. MECHANISMS IN ENDOCRINOLOGY: Kidney involvement in patients with primary hyperparathyroidism: an update on clinical and molecular aspects. Eur J Endocrinol 2017; 176:R39-R52. [PMID: 27601015 DOI: 10.1530/eje-16-0430] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 08/12/2016] [Accepted: 09/02/2016] [Indexed: 12/27/2022]
Abstract
Primary hyperparathyroidism (PHPT) is the third most common endocrine disease. Kidney is a target of both chronic elevated PTH and calcium in PHPT. The classic PHPT complications of symptomatic kidney stones and nephrocalcinosis have become rare and the PHPT current presentation is asymptomatic with uncertain and long-lasting progression. Nonetheless, the routine use of imaging and of biochemical determinations have revealed the frequent occurrence of asymptomatic kidney stones, hypercalciuria and reduced kidney function in asymptomatic PHPT patients. Though the pathogenesis is far from being elucidated, PHPT is associated with reduced renal function, in terms of estimated glomerular filtration rate, and related increased morbidity and mortality. In the last decade, the effort of the Kidney Disease: Improving Global Outcomes (KDIGO) panel of experts highlighted that even mild reduction of kidney function is associated with increased risk of cardiovascular disease. These considerations provided the basis for the Fourth Workshop recommendations of a more extensive diagnostic workout about kidney features and of wider criteria for parathyroid surgery including asymptomatic kidney disease. Moreover, kidney involvement in PHPT is likely to be affected by variants of genes coding the key molecules regulating the calcium and ions renal handling; these features might have clinical relevance and should be considered both during diagnostic workout and follow-up. Finally, the effects of parathyroid surgery and of medical treatment on kidney involvement of PHPT are reviewed.
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Affiliation(s)
- C Verdelli
- Laboratory of Experimental EndocrinologyIRCCS Istituto Ortopedico Galeazzi, Milan, Italy
| | - S Corbetta
- Laboratory of Experimental EndocrinologyIRCCS Istituto Ortopedico Galeazzi, Milan, Italy
- Endocrinology ServiceDepartment of Biomedical Sciences for Health, University of Milan, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
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48
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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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Thévenod F, Wolff NA. Iron transport in the kidney: implications for physiology and cadmium nephrotoxicity. Metallomics 2016; 8:17-42. [PMID: 26485516 DOI: 10.1039/c5mt00215j] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The kidney has recently emerged as an organ with a significant role in systemic iron (Fe) homeostasis. Substantial amounts of Fe are filtered by the kidney, which have to be reabsorbed to prevent Fe deficiency. Accordingly Fe transporters and receptors for protein-bound Fe are expressed in the nephron that may also function as entry pathways for toxic metals, such as cadmium (Cd), by way of "ionic and molecular mimicry". Similarities, but also differences in handling of Cd by these transport routes offer rationales for the propensity of the kidney to develop Cd toxicity. This critical review provides a comprehensive update on Fe transport by the kidney and its relevance for physiology and Cd nephrotoxicity. Based on quantitative considerations, we have also estimated the in vivo relevance of the described transport pathways for physiology and toxicology. Under physiological conditions all segments of the kidney tubules are likely to utilize Fe for cellular Fe requiring processes for metabolic purposes and also to contribute to reabsorption of free and bound forms of Fe into the circulation. But Cd entering tubule cells disrupts metabolic pathways and is unable to exit. Furthermore, our quantitative analyses contest established models linking chronic Cd nephrotoxicity to proximal tubular uptake of metallothionein-bound Cd. Hence, Fe transport by the kidney may be beneficial by preventing losses from the body. But increased uptake of Fe or Cd that cannot exit tubule cells may lead to kidney injury, and Fe deficiency may facilitate renal Cd uptake.
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Affiliation(s)
- Frank Thévenod
- Institute of Physiology, Pathophysiology & Toxicology, Center for Biomedical Training and Research (ZBAF), University of Witten/Herdecke, Stockumer Str. 12, 58453 Witten, Germany.
| | - Natascha A Wolff
- Institute of Physiology, Pathophysiology & Toxicology, Center for Biomedical Training and Research (ZBAF), University of Witten/Herdecke, Stockumer Str. 12, 58453 Witten, Germany.
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50
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Granjon D, Bonny O, Edwards A. A model of calcium homeostasis in the rat. Am J Physiol Renal Physiol 2016; 311:F1047-F1062. [PMID: 27358053 DOI: 10.1152/ajprenal.00230.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 06/27/2016] [Indexed: 12/14/2022] Open
Abstract
We developed a model of calcium homeostasis in the rat to better understand the impact of dysfunctions such as primary hyperparathyroidism and vitamin D deficiency on calcium balance. The model accounts for the regulation of calcium intestinal uptake, bone resorption, and renal reabsorption by parathyroid hormone (PTH), vitamin D3, and Ca2+ itself. It is the first such model to incorporate recent findings regarding the role of the calcium-sensing receptor (CaSR) in the kidney, the presence of a rapidly exchangeable pool in bone, and the delayed response of vitamin D3 synthesis. Accounting for two (fast and slow) calcium storage compartments in bone allows the model to properly predict the effects of bisphophonates on the plasma levels of Ca2+ ([Ca2+]p), PTH, and vitamin D3 Our model also suggests that Ca2+ exchange rates between plasma and the fast pool vary with both sex and age, allowing [Ca2+]p to remain constant in spite of sex- and age-based hormonal and other differences. Our results suggest that the inconstant hypercalciuria that is observed in primary hyperparathyroidism can be attributed in part to counterbalancing effects of PTH and CaSR in the kidney. Our model also correctly predicts that calcimimetic agents such as cinacalcet bring down [Ca2+]p to within its normal range in primary hyperparathyroidism. In addition, the model provides a simulation of CYP24A1 inactivation that leads to a situation reminiscent of infantile hypercalcemia. In summary, our model of calcium handling can be used to decipher the complex regulation of calcium homeostasis.
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Affiliation(s)
- David Granjon
- Sorbonne Universités, UPMC Univ Paris 06, Université Paris Descartes, Sorbonne Paris Cité, INSERM UMRS 1138, CNRS ERL 8228, Centre de Recherche des Cordeliers, Paris, France; and.,Department of Pharmacology and Toxicology, University of Lausanne, and Service of Nephrology, Lausanne University Hospital, Lausanne, Switzerland
| | - Olivier Bonny
- Department of Pharmacology and Toxicology, University of Lausanne, and Service of Nephrology, Lausanne University Hospital, Lausanne, Switzerland
| | - Aurélie Edwards
- Sorbonne Universités, UPMC Univ Paris 06, Université Paris Descartes, Sorbonne Paris Cité, INSERM UMRS 1138, CNRS ERL 8228, Centre de Recherche des Cordeliers, Paris, France; and
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