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Saito A, Nikolaidis NM, Amlal H, Uehara Y, Gardner JC, LaSance K, Pitstick LB, Bridges JP, Wikenheiser-Brokamp KA, McGraw DW, Woods JC, Sabbagh Y, Schiavi SC, Altinişik G, Jakopović M, Inoue Y, McCormack FX. Modeling pulmonary alveolar microlithiasis by epithelial deletion of the Npt2b sodium phosphate cotransporter reveals putative biomarkers and strategies for treatment. Sci Transl Med 2016; 7:313ra181. [PMID: 26560359 DOI: 10.1126/scitranslmed.aac8577] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Pulmonary alveolar microlithiasis (PAM) is a rare, autosomal recessive lung disorder associated with progressive accumulation of calcium phosphate microliths. Inactivating mutations in SLC34A2, which encodes the NPT2b sodium-dependent phosphate cotransporter, has been proposed as a cause of PAM. We show that epithelial deletion of Npt2b in mice results in a progressive pulmonary process characterized by diffuse alveolar microlith accumulation, radiographic opacification, restrictive physiology, inflammation, fibrosis, and an unexpected alveolar phospholipidosis. Cytokine and surfactant protein elevations in the alveolar lavage and serum of PAM mice and confirmed in serum from PAM patients identify serum MCP-1 (monocyte chemotactic protein 1) and SP-D (surfactant protein D) as potential biomarkers. Microliths introduced by adoptive transfer into the lungs of wild-type mice produce marked macrophage-rich inflammation and elevation of serum MCP-1 that peaks at 1 week and resolves at 1 month, concomitant with clearance of stones. Microliths isolated by bronchoalveolar lavage readily dissolve in EDTA, and therapeutic whole-lung EDTA lavage reduces the burden of stones in the lungs. A low-phosphate diet prevents microlith formation in young animals and reduces lung injury on the basis of reduction in serum SP-D. The burden of pulmonary calcium deposits in established PAM is also diminished within 4 weeks by a low-phosphate diet challenge. These data support a causative role for Npt2b in the pathogenesis of PAM and the use of the PAM mouse model as a preclinical platform for the development of biomarkers and therapeutic strategies.
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Affiliation(s)
- Atsushi Saito
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, The University of Cincinnati, Cincinnati, OH 45267, USA
| | - Nikolaos M Nikolaidis
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, The University of Cincinnati, Cincinnati, OH 45267, USA
| | - Hassane Amlal
- Department of Internal Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Yasuaki Uehara
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, The University of Cincinnati, Cincinnati, OH 45267, USA
| | - Jason C Gardner
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, The University of Cincinnati, Cincinnati, OH 45267, USA
| | - Kathleen LaSance
- Vontz Core Imaging Laboratory, Vontz Center for Molecular Studies, The University of Cincinnati, Cincinnati, OH 45267, USA
| | - Lori B Pitstick
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, The University of Cincinnati, Cincinnati, OH 45267, USA
| | - James P Bridges
- Perinatal Institute, Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | | | - Dennis W McGraw
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, The University of Cincinnati, Cincinnati, OH 45267, USA
| | - Jason C Woods
- Pulmonary Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Yves Sabbagh
- The Sanofi-Genzyme R&D Center, Genzyme, a Sanofi company, Framingham, MA 01701, USA
| | - Susan C Schiavi
- The Sanofi-Genzyme R&D Center, Genzyme, a Sanofi company, Framingham, MA 01701, USA
| | - Göksel Altinişik
- Department of Chest Diseases, Faculty of Medicine, Pamukkale University, Denizli 20160, Turkey
| | - Marko Jakopović
- Department for Respiratory Diseases, University Hospital Centre Zagreb, University of Zagreb School of Medicine, 10000 Zagreb, Croatia
| | - Yoshikazu Inoue
- Department of Diffuse Lung Diseases and Respiratory Failure, Clinical Research Center, National Hospital Organization Kinki-Chuo Chest Medical Center, Osaka 5918555, Japan
| | - Francis X McCormack
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, The University of Cincinnati, Cincinnati, OH 45267, USA.
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Bover J, Ureña-Torres P, Lloret MJ, Ruiz-García C, DaSilva I, Diaz-Encarnacion MM, Mercado C, Mateu S, Fernández E, Ballarin J. Integral pharmacological management of bone mineral disorders in chronic kidney disease (part I): from treatment of phosphate imbalance to control of PTH and prevention of progression of cardiovascular calcification. Expert Opin Pharmacother 2016; 17:1247-58. [DOI: 10.1080/14656566.2016.1182155] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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Malindretos P, Cozzolino M. Phosphate binders, past - present - future. A critical appraisal. Expert Opin Pharmacother 2016; 17:297-300. [PMID: 26679256 DOI: 10.1517/14656566.2016.1133593] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Pavlos Malindretos
- a Peritoneal Dialysis Unit, Nephrology Department , Achillopouleion General Hospital , Volos , Magnesia , Greece
| | - Mario Cozzolino
- b Chief of Renal Unit San Paolo Hospital , Milan , Italy.,c Nephrology, Chair of School of Nephrology, Chairman ERA-EDTA working group on CKD-MBD, Department of Health Sciences , University of Milan , Milan , Italy
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6
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Katai K, Iwamoto A, Kimura Y, Oshima Y, Arioka S, Morimi Y, Omuro A, Nakasa T. Wakame (Undaria pinnatifida ) modulates hyperphosphatemia in a rat model of chronic renal failure. THE JOURNAL OF MEDICAL INVESTIGATION 2015; 62:68-74. [PMID: 25817287 DOI: 10.2152/jmi.62.68] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
In chronic renal failure, inorganic phosphate (Pi) retention speeds up the progression to end-stage renal disease. The current therapy for hyperphosphatemia in patients with chronic renal failure consists of dietary Pi restriction combined with administration of Pi binders, but each therapy has practical problems. Thus, the discovery of foods or nutrients that inhibit Pi absorption may be useful for the treatment of hyperphosphatemia. In the present study, we investigated whether wakame (Undaria pinnatifida) is a useful food for the prevention of hyperphosphatemia in a rat model of renal failure. Feeding a diet containing 5% wakame significantly decreased plasma and urinary Pi levels and increased the amount of fecal Pi. In addition, wakame significantly reduced plasma blood urea nitrogen and plasma Pi levels in 5/6 nephrectomized rats fed a high-Pi diet. Biochemical analyses showed that the reduction of intestinal Pi absorption is the main reason for the decrease in plasma Pi levels in rats fed a diet containing wakame. In addition, feeding alginic acid and fucoidan, major components of wakame fiber, was effective in reducing plasma Pi levels in normal rats. Finally, we concluded that wakame may be a useful food for the prevention of hyperphosphatemia in rodents.
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Affiliation(s)
- Kanako Katai
- Department of Food science and Nutrition, Faculty of Human Life and Science, Doshisha Women's College of Liberal Arts
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Candeal E, Caldas YA, Guillén N, Levi M, Sorribas V. Na+-independent phosphate transport in Caco2BBE cells. Am J Physiol Cell Physiol 2014; 307:C1113-22. [PMID: 25298422 DOI: 10.1152/ajpcell.00251.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pi transport in epithelia has both Na(+)-dependent and Na(+)-independent components, but so far only Na(+)-dependent transporters have been characterized in detail and molecularly identified. Consequently, in the present study, we initiated the characterization and analysis of intestinal Na(+)-independent Pi transport using an in vitro model, Caco2BBE cells. Only Na(+)-independent Pi uptake was observed in these cells, and Pi uptake was dramatically increased when cells were incubated in high-Pi DMEM (4 mM) from 1 day to several days. No response to low-Pi medium was observed. The increased Pi transport was mainly caused by Vmax changes, and it was prevented by actinomycin D and cycloheximide. Pi transport in cells grown in 1 mM Pi (basal DMEM) decreased at pH > 7.5, and it was inhibited with proton ionophores. Pi transport in cells incubated with 4 mM Pi increased with alkaline pH, suggesting a preference for divalent phosphate. Pi uptake in cells in 1 mM Pi was completely inhibited only by Pi and partially inhibited by phosphonoformate, oxalate, DIDS, SITS, SO4 (2-), HCO3 (-), and arsenate. This inhibition pattern suggests that more than one Pi transporter is active in cells maintained with 1 mM Pi. Phosphate transport from cells maintained at 4 mM Pi was only partially inhibited by phosphonoformate, oxalate, and arsenate. Attempts to identify the responsible transporters showed that multifunctional anion exchangers of the Slc26 family as well as members of Slc17, Slc20, and Slc37 and the Pi exporter xenotropic and polytropic retrovirus receptor 1 are not involved.
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Affiliation(s)
- Eduardo Candeal
- Department of Toxicology, University of Zaragoza, Zaragoza, Spain; and
| | - Yupanqui A Caldas
- Department of Toxicology, University of Zaragoza, Zaragoza, Spain; and Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, Colorado
| | - Natalia Guillén
- Department of Toxicology, University of Zaragoza, Zaragoza, Spain; and
| | - Moshe Levi
- Division of Renal Diseases and Hypertension, Department of Medicine, University of Colorado Denver, Aurora, Colorado
| | - Víctor Sorribas
- Department of Toxicology, University of Zaragoza, Zaragoza, Spain; and
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