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Okyar A, Ozturk Civelek D, Akyel YK, Surme S, Pala Kara Z, Kavakli IH. The role of the circadian timing system on drug metabolism and detoxification: an update. Expert Opin Drug Metab Toxicol 2024; 20:503-517. [PMID: 38753451 DOI: 10.1080/17425255.2024.2356167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 05/13/2024] [Indexed: 05/18/2024]
Abstract
INTRODUCTION The 24-hour variations in drug absorption, distribution, metabolism, and elimination, collectively known as pharmacokinetics, are fundamentally influenced by rhythmic physiological processes regulated by the molecular clock. Recent advances have elucidated the intricacies of the circadian timing system and the molecular interplay between biological clocks, enzymes and transporters in preclinical level. AREA COVERED Circadian rhythm of the drug metabolizing enzymes and carrier efflux functions possess a major role for drug metabolism and detoxification. The efflux and metabolism function of intestines and liver seems important. The investigations revealed that the ABC and SLC transporter families, along with cytochrome p-450 systems in the intestine, liver, and kidney, play a dominant role in the circadian detoxification of drugs. Additionally, the circadian control of efflux by the blood-brain barrier is also discussed. EXPERT OPINION The influence of the circadian timing system on drug pharmacokinetics significantly impacts the efficacy, adverse effects, and toxicity profiles of various drugs. Moreover, the emergence of sex-related circadian changes in the metabolism and detoxification processes has underscored the importance of considering gender-specific differences in drug tolerability and pharmacology. A better understanding of coupling between central clock and circadian metabolism/transport contributes to the development of more rational drug utilization and the implementation of chronotherapy applications.
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Affiliation(s)
- Alper Okyar
- Department of Pharmacology, Istanbul University Faculty of Pharmacy, Istanbul, Turkiye
| | - Dilek Ozturk Civelek
- Department of Pharmacology, Faculty of Pharmacy, Bezmialem Vakif University, Istanbul, Turkiye
| | - Yasemin Kubra Akyel
- Department of Medical Pharmacology, School of Medicine, Istanbul Medipol University, Istanbul, Turkey
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Saliha Surme
- Molecular Biology and Genetics, Koc University, Istanbul, Türkiye
- Chemical and Biological Engineering, Koc University, Istanbul, Türkiye
| | - Zeliha Pala Kara
- Department of Pharmacology, Istanbul University Faculty of Pharmacy, Istanbul, Turkiye
| | - I Halil Kavakli
- Molecular Biology and Genetics, Koc University, Istanbul, Türkiye
- Chemical and Biological Engineering, Koc University, Istanbul, Türkiye
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Benjamin JI, Pollock DM. Current perspective on circadian function of the kidney. Am J Physiol Renal Physiol 2024; 326:F438-F459. [PMID: 38134232 PMCID: PMC11207578 DOI: 10.1152/ajprenal.00247.2023] [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: 08/17/2023] [Revised: 11/28/2023] [Accepted: 12/18/2023] [Indexed: 12/24/2023] Open
Abstract
Behavior and function of living systems are synchronized by the 24-h rotation of the Earth that guides physiology according to time of day. However, when behavior becomes misaligned from the light-dark cycle, such as in rotating shift work, jet lag, and even unusual eating patterns, adverse health consequences such as cardiovascular or cardiometabolic disease can arise. The discovery of cell-autonomous molecular clocks expanded interest in regulatory systems that control circadian physiology including within the kidney, where function varies along a 24-h cycle. Our understanding of the mechanisms for circadian control of physiology is in the early stages, and so the present review provides an overview of what is known and the many gaps in our current understanding. We include a particular focus on the impact of eating behaviors, especially meal timing. A better understanding of the mechanisms guiding circadian function of the kidney is expected to reveal new insights into causes and consequences of a wide range of disorders involving the kidney, including hypertension, obesity, and chronic kidney disease.
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Affiliation(s)
- Jazmine I Benjamin
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - David M Pollock
- Section of Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
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Abstract
Inorganic phosphate (Pi) is an essential component of many biologically important molecules such as DNA, RNA, ATP, phospholipids, or apatite. It is required for intracellular phosphorylation signaling events and acts as pH buffer in intra- and extracellular compartments. Intestinal absorption, uptake into cells, and renal reabsorption depend on a set of different phosphate transporters from the SLC20 (PiT transporters) and SLC34 (NaPi transporters) gene families. The physiological relevance of these transporters is evident from rare monogenic disorders in humans affecting SLC20A2 (Fahr's disease, basal ganglia calcification), SLC34A1 (idiopathic infantile hypercalcemia), SLC34A2 (pulmonary alveolar microlithiasis), and SLC34A3 (hereditary hypophosphatemic rickets with hypercalciuria). SLC34 transporters are inhibited by millimolar concentrations of phosphonoformic acid or arsenate while SLC20 are relatively resistant to these compounds. More recently, a series of more specific and potent drugs have been developed to target SLC34A2 to reduce intestinal Pi absorption and to inhibit SLC34A1 and/or SLC34A3 to increase renal Pi excretion in patients with renal disease and incipient hyperphosphatemia. Also, SLC20 inhibitors have been developed with the same intention. Some of these substances are currently undergoing preclinical and clinical testing. Tenapanor, a non-absorbable Na+/H+-exchanger isoform 3 inhibitor, reduces intestinal Pi absorption likely by indirectly acting on the paracellular pathway for Pi and has been tested in several phase III trials for reducing Pi overload in patients with renal insufficiency and dialysis.
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Affiliation(s)
- Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland.
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Gan L, Xing L, Xu Y, Zhou L, Jiang H, Sun X, Guan T, Luo P, Wang J, Sun F, Guo Z, Guo M, Gao J, Wei G, Zhong W, Zhou Y, Zuo L. Tenapanor in Chinese ESRD patients with hyperphosphatemia on haemodialysis: a randomised, phase 3 trial. Clin Kidney J 2024; 17:sfad216. [PMID: 38186905 PMCID: PMC10768776 DOI: 10.1093/ckj/sfad216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Indexed: 01/09/2024] Open
Abstract
Background The efficacy and safety of tenapanor has not been confirmed in Chinese end-stage renal disease (ESRD) patients with hyperphosphatemia on haemodialysis (HD). Methods This was a randomised, double blind, phase 3 trial conducted at 26 dialysis facilities in China (https://www.chictr.org.cn/index.aspx; CTR20202588). After a 3-week washout, adults with ESRD on HD with hyperphosphatemia were randomised (1:1) using an interactive web response system to oral tenapanor 30 mg twice a day or placebo for 4 weeks. The primary endpoint was the change in mean serum phosphorous level from baseline to the endpoint visit (day 29 or last serum phosphorus measurement). Efficacy was analysed in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of the study drug. Results Between 5 March 2021 and 8 June 2022, 77 patients received tenapanor and 73 received placebo. Tenapanor treatment (n = 75) resulted in a significantly greater least squares (LS) mean reduction in serum phosphate at the endpoint visit versus placebo (n = 72): LS mean difference -1.17 mg/dl (95% CI -1.694 to -0.654, P < .001). More patients receiving tenapanor achieved a serum phosphorous level <5.5 mg/dl at the endpoint visit (44.6% versus 10.1%). The most common treatment-related adverse event was diarrhoea [tenapanor 28.6% (22/77), placebo 2.7% (2/73)], which was mostly mild and led to treatment discontinuation in two patients receiving tenapanor. Conclusions Tenapanor significantly reduced the serum phosphorous level versus placebo in Chinese ESRD patients on HD and was generally well tolerated.
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Affiliation(s)
- Liangying Gan
- Department of Nephrology, Peking University People's Hospital, Beijing, China
| | - Li Xing
- Hemodialysis Room, People's Hospital of Zhengzhou, Zhengzhou, China
| | - Yan Xu
- Department of Nephrology, Affiliated Hospital of Qingdao University, Qingdao, China
| | - Linghui Zhou
- Department of Nephrology, First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Hong Jiang
- Division of Nephrology, Department of Internal Medicine, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | - Xiuli Sun
- Department of Nephrology, Baotou Central Hospital, Baotou, China
| | - Tianjun Guan
- Department of Nephrology, Zhongshan Hospital Xiamen University, Xiamen, China
| | - Ping Luo
- Department of Nephrology, Second Hospital of Jilin University, Changchun, China
| | - Junxia Wang
- Blood Purifying Center, First Affiliated Hospital of Henan University of Science and Technology, Luoyang, China
| | - Fuyun Sun
- Department of Nephrology, Cangzhou Center Hospital, Cangzhou, China
| | - Zhiyong Guo
- Department of Nephrology, Shanghai Changhai Hospital, Shanghai, China
| | - Minghao Guo
- Department of Nephrology, First Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Ju Gao
- Panjin Liaohe Oilfield Baoshihua Hospital, Panjin, China
| | - Gang Wei
- R&D Center, Fosun Pharma, Shanghai, China
| | - Wen Zhong
- R&D Center, Fosun Pharma, Shanghai, China
| | | | - Li Zuo
- Department of Nephrology, Peking University People's Hospital, Beijing, China
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Lucea S, Chopo-Escuin G, Guillén N, Sosa C, Sorribas V. Intestinal and Renal Adaptations to Changes of Dietary Phosphate Concentrations in Rat. FUNCTION 2023; 5:zqad063. [PMID: 38033458 PMCID: PMC10686248 DOI: 10.1093/function/zqad063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 11/05/2023] [Accepted: 11/07/2023] [Indexed: 12/02/2023] Open
Abstract
We have studied the role of the intestine, kidney, and several hormones when adapting to changes in dietary P concentration. Normal and parathyroidectomized (PTX) rats were fed pH-matched diets containing 0.1%, 0.6%, and 1.2% P concentrations. 32Pi uptake was determined in the jejunum and kidney cortex brush border membrane vesicles. Several hormone and ion concentrations were determined in the blood and urine of rats. Both jejunum and kidney cortex Pi transport was regulated with 5 d of chronic feeding of P diets in normal rats. Acute adaptation was determined by switching foods on day 6, which was only clearly observed in the kidney cortex of normal rats, with more statistical variability in the jejunum. However, no paradoxical increase of Pi uptake in the jejunum was reproduced after the acute switch to the 1.2% P diet. Pi uptake in the jejunum was parathyroid hormone (PTH)-independent, but in the kidney, the chronic adaptation was reduced, and no acute dietary adaptations were observed. The NaPi2a protein was more abundant in the PTX than the sham kidneys, but contrary to the modest or absent changes in Pi uptake adaptation, the transporter was similarly regulated by dietary P, as in the sham rats. PTH and fibroblast growth factor 23 (FGF23) were the only hormones regulated by all diet changes, even in fasting animals, which exhibited regulated Pi transport despite similar phosphatemia. Evidence of Pi appetite effects was also observed. In brief, our results show new characteristics of Pi adaptations, including a lack of correlation between Pi transport, NaPi2a expression, and PTH/FGF23 concentrations.
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Affiliation(s)
- Susana Lucea
- Laboratory of Molecular Toxicology, Department of Biochemistry and Cell and Molecular Biology, University of Zaragoza, E50013 Zaragoza, Spain
| | - Gema Chopo-Escuin
- Laboratory of Molecular Toxicology, Department of Biochemistry and Cell and Molecular Biology, University of Zaragoza, E50013 Zaragoza, Spain
| | - Natalia Guillén
- Laboratory of Molecular Toxicology, Department of Biochemistry and Cell and Molecular Biology, University of Zaragoza, E50013 Zaragoza, Spain
| | - Cecilia Sosa
- Laboratory of Molecular Toxicology, Department of Biochemistry and Cell and Molecular Biology, University of Zaragoza, E50013 Zaragoza, Spain
| | - Víctor Sorribas
- Laboratory of Molecular Toxicology, Department of Biochemistry and Cell and Molecular Biology, University of Zaragoza, E50013 Zaragoza, Spain
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6
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Ginsberg C, Miller LM, Ofsthun N, Dalrymple LS, Ix JH. Differences in Phosphate and Parathyroid Hormone Concentrations over the Day among Patients on Hemodialysis. J Am Soc Nephrol 2022; 33:2087-2093. [PMID: 36316091 PMCID: PMC9678027 DOI: 10.1681/asn.2021111493] [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: 11/19/2021] [Accepted: 06/22/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Elevated serum phosphate and parathyroid hormone (PTH) concentrations are associated with cardiovascular events, bone disease, and mortality in patients on maintenance hemodialysis. Although circadian changes are known in people with CKD, it is unknown whether differences occur in these parameters over the course of a day in people receiving hemodialysis. METHODS We used clinical data from Fresenius Medical Care US dialysis clinics to determine how the time of day when measurements were collected (hemodialysis treatment start time) may be associated with serum phosphate and PTH concentrations. We used harmonic regression to assess these associations while accounting for demographic data and treatment parameters. RESULTS A total of 96,319 patients receiving maintenance hemodialysis were included in this analysis. Patients had a mean age of 64±14 years, 43% were women, and dialysis start times ranged from 3:00 am to 7:59 pm. The mean serum phosphate concentration was 5.2±1.5 mg/dl, and the median PTH was 351 pg/ml (interquartile range [IQR], 214-547). In fully adjusted models, serum phosphate had a nadir at 11:00 am of 4.97 (IQR, 4.94-5.01) mg/dl and a peak at 7:00 pm of 5.56 (IQR, 5.50-5.62) mg/dl. Serum PTH had a nadir at 9:00 am of 385 (IQR, 375-395) pg/ml and a peak at 7:00 pm of 530 (IQR, 516-547) pg/ml. CONCLUSIONS Among patients receiving maintenance hemodialysis, concentrations of PTH and phosphate before a dialysis session vary with the time of day that these values are measured. Consideration of whether these values were obtained at peak or nadir times of the day may be important in treatment decisions.
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Affiliation(s)
- Charles Ginsberg
- Division of Nephrology-Hypertension, University of California San Diego, La Jolla, California
| | - Lindsay M. Miller
- Division of Nephrology-Hypertension, University of California San Diego, La Jolla, California
| | - Norma Ofsthun
- Global Medical Office, Fresenius Medical Care, Waltham, Massachusetts
| | | | - Joachim H. Ix
- Division of Nephrology-Hypertension, University of California San Diego, La Jolla, California
- Nephrology Section, Veterans Affairs San Diego Healthcare System, San Diego, California
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7
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Costello HM, Johnston JG, Juffre A, Crislip GR, Gumz ML. Circadian clocks of the kidney: function, mechanism, and regulation. Physiol Rev 2022; 102:1669-1701. [PMID: 35575250 PMCID: PMC9273266 DOI: 10.1152/physrev.00045.2021] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 05/03/2022] [Accepted: 05/07/2022] [Indexed: 11/22/2022] Open
Abstract
An intrinsic cellular circadian clock is located in nearly every cell of the body. The peripheral circadian clocks within the cells of the kidney contribute to the regulation of a variety of renal processes. In this review, we summarize what is currently known regarding the function, mechanism, and regulation of kidney clocks. Additionally, the effect of extrarenal physiological processes, such as endocrine and neuronal signals, on kidney function is also reviewed. Circadian rhythms in renal function are an integral part of kidney physiology, underscoring the importance of considering time of day as a key biological variable. The field of circadian renal physiology is of tremendous relevance, but with limited physiological and mechanistic information on the kidney clocks this is an area in need of extensive investigation.
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Affiliation(s)
- Hannah M Costello
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
| | - Jermaine G Johnston
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
- North Florida/South Georgia Malcom Randall Department of Veterans Affairs Medical Center, Gainesville, Florida
| | - Alexandria Juffre
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida
| | - G Ryan Crislip
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
| | - Michelle L Gumz
- Department of Physiology and Functional Genomics, University of Florida, Gainesville, Florida
- Division of Nephrology, Hypertension, and Renal Transplantation, Department of Medicine, University of Florida, Gainesville, Florida
- North Florida/South Georgia Malcom Randall Department of Veterans Affairs Medical Center, Gainesville, Florida
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, Florida
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Lucea S, Guillén N, Sosa C, Sorribas V. Inhibition of epithelial phosphate transport by NAD +/NADH. Am J Physiol Cell Physiol 2022; 322:C803-C813. [PMID: 35264014 DOI: 10.1152/ajpcell.00404.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nicotinamide is an important regulator of Pi homeostasis after conversion into NAD+/NADH. In this work, we have studied the classical inhibition of Pi transport by these compounds in the brush border membrane vesicles (BBMV) of rat kidney and rat intestine, and we examined the effects in Opossum Kidney (OK) cells and in phosphate transporter-expressing Xenopus laevis oocytes. In BBMV, NAD+ required preincubation at either room temperature or on ice to inhibit Pi uptake in BBMV. However, no effects were observed in the known Slc34 or Slc20 Pi transporters expressed in Xenopus oocytes, in OK cells, or in isolated rat cortical nephron segments. In BBMV from jejunum or kidney cortex, the inhibition of Pi transport was specific, dose-related, and followed a competitive inhibition pattern, as shown by linear transformation and non-linear regression analyses. A Ki value of 538 µM NAD+ in kidney BBMV was obtained. Ribosylation inhibitors and ribosylation assays revealed no evidence that this reaction was responsible for inhibiting Pi transport. An analysis of the persistence of NAD+/NADH revealed a half-life of just 2 minutes during preincubation. Out of several metabolites of NAD degradation, only ADP-ribose was able to inhibit Pi uptake. Pi concentration also increased during 30 minutes of preincubation, up to 0.67mM, most likely as a metabolic end-product. In conclusion, the classical inhibition of Pi transport by NAD+/NADH in BBMV seems to be caused by the degradation metabolites of these compounds during the preincubation time.
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Affiliation(s)
- Susana Lucea
- Group of Molecular Toxicology, Department of Biochemistry and Molecular and Cell Biology, University of Zaragoza, Veterinary Faculty, Zaragoza, Spain
| | - Natalia Guillén
- Group of Molecular Toxicology, Department of Biochemistry and Molecular and Cell Biology, University of Zaragoza, Veterinary Faculty, Zaragoza, Spain
| | - Cecilia Sosa
- Group of Molecular Toxicology, Department of Biochemistry and Molecular and Cell Biology, University of Zaragoza, Veterinary Faculty, Zaragoza, Spain
| | - Victor Sorribas
- Group of Molecular Toxicology, Department of Biochemistry and Molecular and Cell Biology, University of Zaragoza, Veterinary Faculty, Zaragoza, Spain
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Block GA, Bleyer AJ, Silva AL, Weiner DE, Lynn RI, Yang Y, Rosenbaum DP, Chertow GM. Safety and Efficacy of Tenapanor for Long-term Serum Phosphate Control in Maintenance Dialysis: A 52-Week Randomized Phase 3 Trial (PHREEDOM). KIDNEY360 2021; 2:1600-1610. [PMID: 35372979 PMCID: PMC8785778 DOI: 10.34067/kid.0002002021] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 08/25/2021] [Indexed: 12/17/2022]
Abstract
Background Treating hyperphosphatemia is a tenet of dialysis care. This trial assessed the safety and efficacy of tenapanor for the management of hyperphosphatemia. Methods In this 52-week phase 3 study (NCT03427125), participants receiving maintenance dialysis with both hyperphosphatemia (serum phosphate 6.0-10.0 mg/dl) and a 1.5 mg/dl increase after phosphate binder washout were randomized (3:1) to tenapanor 30 mg twice daily for 26 weeks (randomized treatment period) or sevelamer carbonate (52-week safety control). Participants completing 26 weeks of treatment with tenapanor were rerandomized (1:1) to tenapanor or placebo for 12 weeks (randomized withdrawal period), and were eligible to enter the 14-week safety extension period. With input from the US Food and Drug Administration, the primary efficacy end point was the difference in the change in serum phosphate from the end of the randomized treatment period to the end of the randomized withdrawal period, among participants who achieved ≥1.2 mg/dl decrease in serum phosphate during the randomized treatment period (efficacy analysis set). Efficacy was also evaluated in the intention-to-treat (ITT) analysis set. Results Of 564 eligible participants randomized to receive tenapanor (n=423) or sevelamer carbonate (n=141) during the randomized treatment period, 255 (60%) in the tenapanor group subsequently were rerandomized to tenapanor (n=128) or placebo (n=127) during the randomized withdrawal period. In the efficacy analysis set (n=131), the difference in estimated mean change in serum phosphate level between tenapanor and placebo from the beginning to the end of the randomized withdrawal period was -1.4 mg/dl (P<0.0001); in the ITT analysis set (n=243), the estimated mean difference was -0.7 mg/dl (P=0.002). Loosened stools were the most frequently reported adverse event (53% during the randomized treatment period). Serious adverse events were reported more frequently for participants treated with sevelamer carbonate (16%-23% across the three study periods) compared with tenapanor (11%-17%). Conclusions Tenapanor reduced serum phosphate concentrations and maintained control of serum phosphate in participants receiving maintenance dialysis, with an acceptable safety and tolerability profile.
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Affiliation(s)
- Geoffrey A Block
- Clinical Research and Medical Affairs, US Renal Care, Inc., Plano, Texas
| | - Anthony J Bleyer
- Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Arnold L Silva
- Boise Kidney and Hypertension Institute, Meridian, Idaho
| | - Daniel E Weiner
- Division of Nephrology, Tufts Medical Center, Boston, Massachusetts
| | - Robert I Lynn
- Department of Medicine, Albert Einstein College of Medicine, New York, New York.,Kidney Medical Associates, New York, New York
| | - Yang Yang
- Biometrics, Ardelyx, Inc., Fremont, California
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Wei W, Guo X, Gu L, Jia J, Yang M, Yuan W, Rong S. Bone marrow mesenchymal stem cell exosomes suppress phosphate-induced aortic calcification via SIRT6-HMGB1 deacetylation. Stem Cell Res Ther 2021; 12:235. [PMID: 33849640 PMCID: PMC8042866 DOI: 10.1186/s13287-021-02307-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 03/22/2021] [Indexed: 02/06/2023] Open
Abstract
Background Vascular calcification associated with chronic kidney disease (CKD) can increase the risk of mortality. Elevated serum levels of high mobility group box 1 (HMGB1) promotes vascular calcification in CKD via the Wnt/β-catenin pathway. Sirtuin 6 (SIRT6) prevents fibrosis in CKD by blocking the expression of β-catenin target genes through deacetylation. This study aimed to investigate whether the inhibition of vascular calcification by bone marrow mesenchymal stem cell (BMSC)-derived exosomes is related to SIRT6 activity and assess the regulatory relationship between HMGB1 and SIRT6. Methods CKD characteristics, osteogenic markers, calcium deposition, and the differential expression of HMGB1 and SIRT6 have been measured in a 5/6 nephrectomized mouse CKD model fed a high-phosphate diet to induce aortic calcification. In vitro assays were also performed to validate the in vivo findings. Results High phosphate promotes the translocation of HMGB1 from the nucleus to the cytosol and induces the expression of Runx2, osteopontin, and Msx2. However, BMSC-derived exosomes were found to alleviate CKD-related fibrosis and the induction of osteogenic genes although less significantly when SIRT6 expression is suppressed. SIRT6 was found to modulate the cytosol translocation of HMGB1 by deacetylation in vascular smooth muscle cells. Conclusion Our results indicate that BMSC-derived exosomes inhibit high phosphate-induced aortic calcification and ameliorate renal function via the SIRT6–HMGB1 deacetylation pathway.
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Affiliation(s)
- Wenqian Wei
- Department of Nephrology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, No. 100, Haining Rd, Hongkou District, Shanghai, 200080, China
| | - Xiaodong Guo
- Department of Oncology, Yueyang Hospital of Traditional Chinese and Western Medicine Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 200437, China
| | - Lijie Gu
- Department of Nephrology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, No. 100, Haining Rd, Hongkou District, Shanghai, 200080, China
| | - Jieshuang Jia
- Department of Nephrology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, No. 100, Haining Rd, Hongkou District, Shanghai, 200080, China
| | - Man Yang
- Department of Nephrology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, No. 100, Haining Rd, Hongkou District, Shanghai, 200080, China
| | - Weijie Yuan
- Department of Nephrology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, No. 100, Haining Rd, Hongkou District, Shanghai, 200080, China
| | - Shu Rong
- Department of Nephrology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, No. 100, Haining Rd, Hongkou District, Shanghai, 200080, China.
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11
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McKenna MJ, Crowley RK, Twomey PJ, Kilbane MT. Renal Phosphate Handling: Independent Effects of Circulating FGF23, PTH, and Calcium. JBMR Plus 2021; 5:e10437. [PMID: 33615106 PMCID: PMC7872336 DOI: 10.1002/jbm4.10437] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 11/13/2020] [Indexed: 12/25/2022] Open
Abstract
Excess fibroblast growth factor 23 (FGF23), excess PTH, and an increase in extracellular calcium cause hypophosphatemia by lowering the maximum renal phosphate reabsorption threshold (TmP/GFR). We recently reported two cases of X-linked hypophosphatemia (XLH) with severe tertiary hyperparathyroidism who had normalization of TmP/GFR upon being rendered hypoparathyroid following total parathyroidectomy, despite marked excess in both C-terminal FGF23 (cFGF23) and intact FGF23 (iFGF23). We explored the effects of FGF23, PTH, and calcium on TmP/GFR in a cross-sectional study (n = 74) across a spectrum of clinical cases with abnormalities in TmP/GFR, PTH, and FGF23. This comprised three groups: FGF23-dependent hypophosphatemia (n = 27), hypoparathyroidism (HOPT; n = 17), and chronic kidney disease (n = 30). Measurements included TmP/GFR, cFGF23, PTH, ionized calcium, vitamin D metabolites, and bone turnover markers. The combined effect of cFGF23, PTH, and ionized calcium on TmP/GFR was modeled using hierarchical multiple regression and was probed by moderation analysis with PROCESS. Modeling analysis showed independent effects on TmP/GFR by cFGF23, PTH, and ionized calcium in conjunction with a weak but significant effect of the interaction term for PTH and FGF23; probing showed that the effect was most prominent during PTH deficiency. Teriparatide 20 μg daily was self-administered for 28 days by one case of X-linked hypophosphatemia with hypoparathyroidism (XLH-HOPT) to assess the response of TmP/GFR, cFGF23, iFGF23, nephrogenous cyclic adenosine monophosphate (NcAMP), vitamin D metabolites, and bone turnover markers. After 28 days, TmP/GFR was lowered from 1.10 mmol/L to 0.48 mmol/L; this was accompanied by increases in NcAMP, ionized calcium, and bone turnover markers. In conclusion, the effect of FGF23 excess on TmP/GFR is altered by PTH such that the effect is ameliorated by hypoparathyroidism and the effect is augmented by hyperparathyroidism. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Malachi J McKenna
- UCD School of MedicineUniversity College DublinDublinIreland
- Department of Clinical ChemistrySt. Vincent's University HospitalDublinIreland
- Department of EndocrinologySt. Vincent's University HospitalDublinIreland
| | - Rachel K Crowley
- UCD School of MedicineUniversity College DublinDublinIreland
- Department of Clinical ChemistrySt. Vincent's University HospitalDublinIreland
- Department of EndocrinologySt. Vincent's University HospitalDublinIreland
| | - Patrick J Twomey
- UCD School of MedicineUniversity College DublinDublinIreland
- Department of Clinical ChemistrySt. Vincent's University HospitalDublinIreland
| | - Mark T Kilbane
- UCD School of MedicineUniversity College DublinDublinIreland
- Department of Clinical ChemistrySt. Vincent's University HospitalDublinIreland
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12
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Tani M, Tanaka S, Takamiya K, Kato Y, Harata G, He F, Sakaue M, Ito M. Effects of dietary fiber on vascular calcification by repetitive diet-induced fluctuations in plasma phosphorus in early-stage chronic kidney disease rats. J Clin Biochem Nutr 2020; 67:283-289. [PMID: 33293769 PMCID: PMC7705083 DOI: 10.3164/jcbn.20-46] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 04/12/2020] [Indexed: 12/12/2022] Open
Abstract
Vascular calcification progresses under hyperphosphatemia, and represents a risk factor for cardiovascular disease in chronic kidney disease (CKD) patients. We recently indicated that phosphorus (P) fluctuations also exacerbated vascular calcification in early-stage CKD rats. Dietary fiber intake is reportedly associated with cardiovascular risk. This study investigated the effects of dietary fiber on vascular calcification by repeated P fluctuations in early-stage CKD rats. Unilateral nephrectomy rats were used as an early-stage CKD model. For 36 days, a P fluctuation (LH) group was fed low-P (0.02% P) and high-P (1.2% P) diets alternating every 2 days, and a P fluctuation with dietary fiber intake (LH + F) group was fed low-P and high-P diets containing dietary fiber alternating every 2 days. The effect on vascular calcification was measured calcium content. Effects on uremic toxin were measured levels of indoxyl sulfate (IS) and investigated gut microbiota. The LH + F group showed significantly reduced vessel calcium content compared to the LH group. Further, dietary fiber inhibited increases in blood levels of IS after intake of high-P diet, and decreased uremic toxin-producing intestinal bacteria. Dietary fiber may help suppress progression of vascular calcification due to repeated P fluctuations in early-stage CKD rats by decreasing uremic toxin-producing intestinal bacteria.
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Affiliation(s)
- Mariko Tani
- Graduate School of Human Science and Environment, University of Hyogo, 1-1-12 Shinzaike-Honcho, Himeji, Hyogo 670-0092, Japan
| | - Sarasa Tanaka
- Graduate School of Human Science and Environment, University of Hyogo, 1-1-12 Shinzaike-Honcho, Himeji, Hyogo 670-0092, Japan
| | - Kana Takamiya
- School of Human Science and Environment, University of Hyogo, 1-1-12 Shinzaike-Honcho, Himeji, Hyogo 670-0092, Japan
| | - Yoji Kato
- Graduate School of Human Science and Environment, University of Hyogo, 1-1-12 Shinzaike-Honcho, Himeji, Hyogo 670-0092, Japan
| | - Gaku Harata
- Technical Research Laboratory, Takanashi Milk Products Co., Ltd., Yokohama, Kanagawa 241-0023, Japan
| | - Fang He
- Technical Research Laboratory, Takanashi Milk Products Co., Ltd., Yokohama, Kanagawa 241-0023, Japan
| | - Motoyoshi Sakaue
- Graduate School of Human Science and Environment, University of Hyogo, 1-1-12 Shinzaike-Honcho, Himeji, Hyogo 670-0092, Japan
| | - Mikiko Ito
- Graduate School of Human Science and Environment, University of Hyogo, 1-1-12 Shinzaike-Honcho, Himeji, Hyogo 670-0092, Japan
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13
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Svajger BA, Riddoch JLH, Pruss CM, Laverty KJ, Ward E, Holden RM, Adams MA. Development of experimental chronic kidney disease and vascular calcification alters diurnal variation of phosphate and its hormonal regulators. Physiol Rep 2020; 8:e14626. [PMID: 33190417 PMCID: PMC7666773 DOI: 10.14814/phy2.14626] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 10/04/2020] [Indexed: 11/25/2022] Open
Abstract
The mineral-bone axis is tightly regulated and dependent on renal function. In chronic kidney disease (CKD) progressive loss of renal capacity disrupts this axis over-time, with marked changes in circulating calcium, phosphate, PTH, and fibroblast growth factor-23 (FGF-23). These changes contribute to the development of cardiovascular disease, like vascular calcification (VC), which worsens morbidity and mortality in CKD. Although the chronic changes in these circulating factors and their relationships are well known, no experimental studies have examined how the progressive development of CKD and VC alter the circadian rhythms of these factors. An adenine-induced experimental model of CKD in rats was used to establish (i) general circulating trends, (ii) if renal dysfunction affects these observed trends, and (iii) identify potential changes in these trends caused by VC. This study clearly discerned patterns of daily variations in circulating minerals and hormones, finding that both phosphate and PTH follow modelable diurnal variations whereas calcium and FGF-23 maintain relative stability over 24-hr. Surprisingly, the development of CKD was not sufficient to disrupt these patterns of diurnal variation and only altered the magnitude of change; however, it was found that the diurnal rhythms of circulating phosphate and daily stability of calcium were only significantly altered in the setting of CKD with established VC.
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Affiliation(s)
- Bruno A. Svajger
- Department of Biomedical and Molecular SciencesQueen's UniversityKingstonONCanada
| | - Justin L. H. Riddoch
- Department of Biomedical and Molecular SciencesQueen's UniversityKingstonONCanada
| | - Cynthia M. Pruss
- Department of Biomedical and Molecular SciencesQueen's UniversityKingstonONCanada
| | - Kimberly J. Laverty
- Department of Biomedical and Molecular SciencesQueen's UniversityKingstonONCanada
| | - Emilie Ward
- Department of Biomedical and Molecular SciencesQueen's UniversityKingstonONCanada
| | | | - Michael A. Adams
- Department of Biomedical and Molecular SciencesQueen's UniversityKingstonONCanada
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14
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Khan K, Yu B, Kiwan C, Shalal Y, Filimon S, Cipro M, Shum-Tim D, Cecere R, Schwertani A. The Role of Wnt/β-Catenin Pathway Mediators in Aortic Valve Stenosis. Front Cell Dev Biol 2020; 8:862. [PMID: 33015048 PMCID: PMC7513845 DOI: 10.3389/fcell.2020.00862] [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: 04/29/2020] [Accepted: 08/10/2020] [Indexed: 02/06/2023] Open
Abstract
Aortic valve stenosis (AVS) is a prevailing and life-threatening cardiovascular disease in adults over 75 years of age. However, the molecular mechanisms governing the pathogenesis of AVS are yet to be fully unraveled. With accumulating evidence that Wnt signaling plays a key role in the development of AVS, the involvement of Wnt molecules has become an integral study target in AVS pathogenesis. Thus, we hypothesized that the Wnt/β-catenin pathway mediators, SFRP2, DVL2, GSK3β and β-catenin are dysregulated in patients with AVS. Using immunohistochemistry, Real-Time qPCR and Western blotting, we investigated the presence of SFRP2, GSK-3β, DVL2, and β-catenin in normal and stenotic human aortic valves. Markedly higher mRNA and protein expression of GSK-3β, DVL2, β-catenin and SFRP2 were found in stenotic aortic valves. This was further corroborated by observation of their abundant immunostaining, which displayed strong immunoreactivity in diseased aortic valves. Proteomic analyses of selective GSK3b inhibition in calcifying human aortic valve interstitial cells (HAVICs) revealed enrichment of proteins involved organophosphate metabolism, while reducing the activation of pathogenic biomolecular processes. Lastly, use of the potent calcification inhibitor, Fetuin A, in calcifying HAVICs significantly reduced the expression of Wnt signaling genes Wnt3a, Wnt5a, Wnt5b, and Wnt11. The current findings of altered expression of canonical Wnt signaling in AVS suggest a possible role for regulatory Wnts in AVS. Hence, future studies focused on targeting these molecules are warranted to underline their role in the pathogenesis of the disease.
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Affiliation(s)
- Kashif Khan
- Division of Cardiology and Cardiac Surgery, McGill University Health Centre, Montreal, QC, Canada
| | - Bin Yu
- Division of Cardiology and Cardiac Surgery, McGill University Health Centre, Montreal, QC, Canada
| | - Chrystina Kiwan
- Division of Cardiology and Cardiac Surgery, McGill University Health Centre, Montreal, QC, Canada
| | - Yousif Shalal
- Division of Cardiology and Cardiac Surgery, McGill University Health Centre, Montreal, QC, Canada
| | - Sabin Filimon
- Division of Cardiology and Cardiac Surgery, McGill University Health Centre, Montreal, QC, Canada
| | - Megan Cipro
- Division of Cardiology and Cardiac Surgery, McGill University Health Centre, Montreal, QC, Canada
| | - Dominique Shum-Tim
- Division of Cardiology and Cardiac Surgery, McGill University Health Centre, Montreal, QC, Canada
| | - Renzo Cecere
- Division of Cardiology and Cardiac Surgery, McGill University Health Centre, Montreal, QC, Canada
| | - Adel Schwertani
- Division of Cardiology and Cardiac Surgery, McGill University Health Centre, Montreal, QC, Canada
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15
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Fan HX, Gou BD, Gao YX, Wu G, Liu SH, Li F, Zhang TL. Protein-bound calcium phosphate in uremic rat serum: a quantitative study. J Biol Inorg Chem 2020; 25:1051-1063. [PMID: 32839886 DOI: 10.1007/s00775-020-01807-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 08/04/2020] [Indexed: 10/23/2022]
Abstract
Protein-bound calcium (prCa) constitutes about 40% of serum total calcium, in which albumin is the most dominant protein. Given the chemical interaction between calcium and phosphate (Pi), the increased serum Pi in chronic kidney disease may cause changes in the composition and structure of the prCa fraction. Here, we report the phosphate binding on the protein-bound calcium in uremic rat serum. Using adenine-fed rats as a uremic model, we separated the calcium and phosphate fractions in rat serum by ultrafiltration, and found that the level of protein-bound phosphate (prPi) in the uremic serum was markedly higher than in control. The elevated prPi level was comparable to the prCa level, consistent with the presence of protein-bound calcium phosphate pr(Ca)j-m(CaPi)m. We then confirmed its presence by ex vivo X-ray absorption near-edge structure spectroscopy, revealing the discrete state of the calcium phosphate clusters associated with protein. Finally, in a quantitative investigation using Ca- and Pi-boosted serum, we discovered the threshold concentration for the Pi binding on prCa, and determined the binding constant. The threshold, while preventing Pi from binding to prCa in normal condition, allows the reaction to take place in hyperphosphatemia conditions. The protein-bound calcium phosphate could act as a link between the metabolism of serum proteins and the homeostasis of phosphate and calcium, and it deserves further investigation whether the molar ratio of (prPi/prCa)⋅100% may serve as a serum index of the vascular calcification status in chronic kidney disease.
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Affiliation(s)
- Hong-Xing Fan
- Department of Preclinical and Forensic Medicine, Baotou Medical College, Inner Mongolia University of Science & Technology, Baotou, 014010, People's Republic of China.,CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Road, Beijing, 100049, People's Republic of China
| | - Bao-Di Gou
- Department of Chemical Biology, Peking University School of Pharmaceutical Sciences, 38 Xueyuan Road, Beijing, 100191, People's Republic of China
| | - Yu-Xi Gao
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Road, Beijing, 100049, People's Republic of China
| | - Gang Wu
- Department of Preclinical and Forensic Medicine, Baotou Medical College, Inner Mongolia University of Science & Technology, Baotou, 014010, People's Republic of China.
| | - Shu-Hu Liu
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Road, Beijing, 100049, People's Republic of China
| | - Fan Li
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Road, Beijing, 100049, People's Republic of China
| | - Tian-Lan Zhang
- Department of Chemical Biology, Peking University School of Pharmaceutical Sciences, 38 Xueyuan Road, Beijing, 100191, People's Republic of China.
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16
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Jung JY, Ro H, Chang JH, Kim AJ, Lee HH, Han SH, Yoo TH, Lee KB, Kim YH, Kim SW, Park SK, Chae DW, Oh KH, Ahn C, Chung W. Mediation of the relationship between proteinuria and serum phosphate: Insight from the KNOW-CKD study. PLoS One 2020; 15:e0235077. [PMID: 32569271 PMCID: PMC7307748 DOI: 10.1371/journal.pone.0235077] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 06/07/2020] [Indexed: 12/31/2022] Open
Abstract
Proteinuria and hyperphosphatemia are risk factors for cardiovascular disease in patients with chronic kidney disease (CKD). Although the interaction between proteinuria and the serum phosphate level is well established, the mechanistic link between the two, particularly the extent to which this interaction is mediated by phosphate-regulating factors, remains poorly understood. In this study, we examined the association between proteinuria and the serum phosphate level, as well as potential mediators, including circulating fibroblast growth factor (FGF23)/klotho, the 24-h urinary phosphate excretion rate to glomerular filtration rate ratio (EP/GFR), and the 24-h tubular phosphate reabsorption rate to GFR ratio (TRP/GFR). The analyses were performed with data from 1793 patients in whom 24-h urine protein and phosphate, serum phosphate, FGF23, and klotho levels were measured simultaneously, obtained from the KoreaN cohort study for Outcome in patients With Chronic Kidney Disease (KNOW-CKD). Multivariable linear regression and mediation analyses were performed. Total, direct, and indirect effects were also estimated. Patients with high serum phosphate levels were found to be more likely to exhibit greater proteinuria, higher FGF23 levels, and lower klotho levels. The 24-h EP/GFR increased and the 24-h TRP/GFR decreased with increasing proteinuria and CKD progression. Simple mediation analyses showed that 15.4% and 67.9% of the relationship between proteinuria and the serum phosphate level were mediated by the FGF23/klotho ratio and 24-h EP/GFR, respectively. Together, these two factors accounted for 73.1% of the relationship between serum markers. These findings suggest that proteinuria increases the 24-h EP/GFR via the FGF23/klotho axis as a compensatory mechanism for the increased phosphate burden well before the reduction in renal function is first seen.
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Affiliation(s)
- Ji Yong Jung
- Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Republic of Korea
- Gachon University College of Medicine, Incheon, Republic of Korea
- * E-mail:
| | - Han Ro
- Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Republic of Korea
- Gachon University College of Medicine, Incheon, Republic of Korea
| | - Jae Hyun Chang
- Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Republic of Korea
- Gachon University College of Medicine, Incheon, Republic of Korea
| | - Ae Jin Kim
- Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Republic of Korea
- Gachon University College of Medicine, Incheon, Republic of Korea
| | - Hyun Hee Lee
- Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Republic of Korea
- Gachon University College of Medicine, Incheon, Republic of Korea
| | - Seung Hyeok Han
- Department of Internal Medicine, College of Medicine, Institute of Kidney Disease Research, Yonsei University, Seoul, Republic of Korea
| | - Tae-Hyun Yoo
- Department of Internal Medicine, College of Medicine, Institute of Kidney Disease Research, Yonsei University, Seoul, Republic of Korea
| | - Kyu-Beck Lee
- Department of Internal Medicine, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Korea
| | - Yeong Hoon Kim
- Department of Internal Medicine, Busan Paik Hospital, College of Medicine, Inje University, Busan, Republic of Korea
| | - Soo Wan Kim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Sue Kyung Park
- Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Dong-Wan Chae
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul, Republic of Korea
| | - Kook-Hwan Oh
- Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Curie Ahn
- Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Wookyung Chung
- Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Republic of Korea
- Gachon University College of Medicine, Incheon, Republic of Korea
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17
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Abstract
Phosphate is an essential nutrient for life and is a critical component of bone formation, a major signaling molecule, and structural component of cell walls. Phosphate is also a component of high-energy compounds (i.e., AMP, ADP, and ATP) and essential for nucleic acid helical structure (i.e., RNA and DNA). Phosphate plays a central role in the process of mineralization, normal serum levels being associated with appropriate bone mineralization, while high and low serum levels are associated with soft tissue calcification. The serum concentration of phosphate and the total body content of phosphate are highly regulated, a process that is accomplished by the coordinated effort of two families of sodium-dependent transporter proteins. The three isoforms of the SLC34 family (SLC34A1-A3) show very restricted tissue expression and regulate intestinal absorption and renal excretion of phosphate. SLC34A2 also regulates the phosphate concentration in multiple lumen fluids including milk, saliva, pancreatic fluid, and surfactant. Both isoforms of the SLC20 family exhibit ubiquitous expression (with some variation as to which one or both are expressed), are regulated by ambient phosphate, and likely serve the phosphate needs of the individual cell. These proteins exhibit similarities to phosphate transporters in nonmammalian organisms. The proteins are nonredundant as mutations in each yield unique clinical presentations. Further research is essential to understand the function, regulation, and coordination of the various phosphate transporters, both the ones described in this review and the phosphate transporters involved in intracellular transport.
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Affiliation(s)
- Nati Hernando
- University of Zurich-Irchel, Institute of Physiology, Zurich, Switzerland; Department of Medicine, University of Louisville School of Medicine, Louisville, Kentucky; and Robley Rex VA Medical Center, Louisville, Kentucky
| | - Kenneth Gagnon
- University of Zurich-Irchel, Institute of Physiology, Zurich, Switzerland; Department of Medicine, University of Louisville School of Medicine, Louisville, Kentucky; and Robley Rex VA Medical Center, Louisville, Kentucky
| | - Eleanor Lederer
- University of Zurich-Irchel, Institute of Physiology, Zurich, Switzerland; Department of Medicine, University of Louisville School of Medicine, Louisville, Kentucky; and Robley Rex VA Medical Center, Louisville, Kentucky
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18
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Drüeke TB, Massy ZA. Vascular calcification-any place left for nicotinamide? Nephrol Dial Transplant 2020; 35:18-22. [PMID: 31071218 DOI: 10.1093/ndt/gfz057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 03/06/2019] [Indexed: 12/12/2022] Open
Affiliation(s)
- Tilman B Drüeke
- Inserm U-1018, Team 5, CESP, Versailles Saint-Quentin-en-Yvelines University (Paris-Ile-de-France-Ouest University, UVSQ), Paris-Sud University (UPS), and Paris Saclay University, Villejuif, France
| | - Ziad A Massy
- Inserm U-1018, Team 5, CESP, Versailles Saint-Quentin-en-Yvelines University (Paris-Ile-de-France-Ouest University, UVSQ), Paris-Sud University (UPS), and Paris Saclay University, Villejuif, France.,Division of Nephrology, Ambroise Paré Hospital, APHP, Boulogne-Billancourt, Paris, France
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19
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Abstract
Over the past 25 years, successive cloning of SLC34A1, SLC34A2 and SLC34A3, which encode the sodium-dependent inorganic phosphate (Pi) cotransport proteins 2a-2c, has facilitated the identification of molecular mechanisms that underlie the regulation of renal and intestinal Pi transport. Pi and various hormones, including parathyroid hormone and phosphatonins, such as fibroblast growth factor 23, regulate the activity of these Pi transporters through transcriptional, translational and post-translational mechanisms involving interactions with PDZ domain-containing proteins, lipid microdomains and acute trafficking of the transporters via endocytosis and exocytosis. In humans and rodents, mutations in any of the three transporters lead to dysregulation of epithelial Pi transport with effects on serum Pi levels and can cause cardiovascular and musculoskeletal damage, illustrating the importance of these transporters in the maintenance of local and systemic Pi homeostasis. Functional and structural studies have provided insights into the mechanism by which these proteins transport Pi, whereas in vivo and ex vivo cell culture studies have identified several small molecules that can modify their transport function. These small molecules represent potential new drugs to help maintain Pi homeostasis in patients with chronic kidney disease - a condition that is associated with hyperphosphataemia and severe cardiovascular and skeletal consequences.
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20
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Tani M, Tanaka S, Takamiya K, Sakaue M, Ito M. Effects of repetitive diet-induced fluctuations in plasma phosphorus on vascular calcification and inflammation in rats with early-stage chronic kidney disease. J Clin Biochem Nutr 2020; 66:139-145. [PMID: 32231410 DOI: 10.3164/jcbn.19-93] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 11/21/2019] [Indexed: 12/16/2022] Open
Abstract
Cardiovascular disease is a major cause of death among hemodialysis patients. Hyperphosphatemia induces cardiovascular disease through vascular endothelial dysfunction and calcification. Repetition of a short-term excessive-phosphorus (P) diet causes transient elevations in plasma P and subsequent vascular endothelial dysfunction in normal rats. The purpose of this study was to investigate the effects of the P fluctuation on vascular calcification and inflammation in rats after unilateral nephrectomy as an early-stage chronic kidney disease (CKD) model. Rats were bred for 36 days; CP group, fed a control P (0.6%) diet; HP group, fed a high-P (1.2%) diet; and P fluctuation group, fed low-P (0.02%) and high-P diets alternately every 2 days. Influences on vascular calcification were analyzed using Von Kossa staining and measurement of vessel Ca content. The influence on inflammation was measured as urinary levels of 8-hydroxy-2'-deoxyguanosine. We demonstrated that the P fluctuation group showed similar vascular calcification and inflammation to the HP group, despite having the same total P intake as the CP group. A diet avoiding P fluctuations may be important for patients with early-stage CKD.
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Affiliation(s)
- Mariko Tani
- Graduate School of Human Science and Environment, University of Hyogo, 1-1-12 Shinzaike-Honcho, Himeji, Hyogo 670-0092, Japan
| | - Sarasa Tanaka
- Graduate School of Human Science and Environment, University of Hyogo, 1-1-12 Shinzaike-Honcho, Himeji, Hyogo 670-0092, Japan
| | - Kana Takamiya
- School of Human Science and Environment, University of Hyogo, 1-1-12 Shinzaike-Honcho, Himeji, Hyogo 670-0092, Japan
| | - Motoyoshi Sakaue
- Graduate School of Human Science and Environment, University of Hyogo, 1-1-12 Shinzaike-Honcho, Himeji, Hyogo 670-0092, Japan
| | - Mikiko Ito
- Graduate School of Human Science and Environment, University of Hyogo, 1-1-12 Shinzaike-Honcho, Himeji, Hyogo 670-0092, Japan
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21
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Barreto FC, Barreto DV, Massy ZA, Drüeke TB. Strategies for Phosphate Control in Patients With CKD. Kidney Int Rep 2019; 4:1043-1056. [PMID: 31440695 PMCID: PMC6698320 DOI: 10.1016/j.ekir.2019.06.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 05/27/2019] [Accepted: 06/03/2019] [Indexed: 02/08/2023] Open
Abstract
Hyperphosphatemia is a common complication in patients with chronic kidney disease (CKD), particularly in those requiring renal replacement therapy. The importance of controlling serum phosphate has long been recognized based on observational epidemiological studies that linked increased phosphate levels to adverse outcomes and higher mortality risk. Experimental data further supported the role of phosphate in the development of bone and cardiovascular diseases. Recent advances in our understanding of the mechanisms involved in phosphate homeostasis have made it clear that the serum phosphate concentration depends on a complex interplay among the kidneys, intestinal tract, and bone, and is tightly regulated by a complex endocrine system. Moreover, the source of dietary phosphate and the use of phosphate-based additives in industrialized foods are additional factors that are of particular importance in CKD. Not surprisingly, the management of hyperphosphatemia is difficult, and, despite a multifaceted approach, it remains unsuccessful in many patients. An additional issue is the fact that the supposedly beneficial effect of phosphate lowering on hard clinical outcomes in interventional trials is a matter of ongoing debate. In this review, we discuss currently available treatment approaches for controlling hyperphosphatemia, including dietary phosphate restriction, reduction of intestinal phosphate absorption, phosphate removal by dialysis, and management of renal osteodystrophy, with particular focus on practical challenges and limitations, and on potential benefits and harms.
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Affiliation(s)
- Fellype Carvalho Barreto
- Service of Nephrology, Department of Internal Medicine, Federal University of Paraná, Curitiba, Paraná, Brazil
| | - Daniela Veit Barreto
- Service of Nephrology, Department of Internal Medicine, Federal University of Paraná, Curitiba, Paraná, Brazil
| | - Ziad A. Massy
- Institut National de la Santé et de la Recherche Médicale U-1018, Team 5, Centre de Recherche en Epidémiologie et Santé des Populations, Versailles Saint-Quentin-en-Yvelines University (Paris-Ile-de-France-Ouest University), Paris-Sud University and Paris Saclay University, Villejuif, France
- Division of Nephrology, Ambroise Paré Hospital, Assistance Publique-Hôpitaux de Paris, Boulogne Billancourt/Paris, France
| | - Tilman B. Drüeke
- Institut National de la Santé et de la Recherche Médicale U-1018, Team 5, Centre de Recherche en Epidémiologie et Santé des Populations, Versailles Saint-Quentin-en-Yvelines University (Paris-Ile-de-France-Ouest University), Paris-Sud University and Paris Saclay University, Villejuif, France
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Block GA, Block MS, Smits G, Mehta R, Isakova T, Wolf M, Chertow GM. A Pilot Randomized Trial of Ferric Citrate Coordination Complex for the Treatment of Advanced CKD. J Am Soc Nephrol 2019; 30:1495-1504. [PMID: 31278194 PMCID: PMC6683712 DOI: 10.1681/asn.2018101016] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 05/03/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Researchers have yet to determine the optimal care of patients with advanced CKD. Evidence suggests that anemia and CKD-related disordered mineral metabolism (including abnormalities in phosphate and fibroblast growth factor 23 [FGF23]) contribute to adverse outcomes in this population. METHODS To investigate whether fixed-dose ferric citrate coordination complex favorably affects multiple biochemical parameters in patients with advanced CKD, we randomly assigned 203 patients with eGFR≤20 ml/min per 1.73 m2 2:1 to receive a fixed dose of ferric citrate coordination complex (two tablets per meal, 210 mg ferric iron per tablet) or usual care for 9 months or until 3 months after starting dialysis. No single biochemical end point was designated as primary; sample size was determined empirically. RESULTS The two groups had generally similar baseline characteristics, although diabetes and peripheral vascular disease were more common in the usual-care group. Ferric citrate coordination complex significantly increased hemoglobin, transferrin saturation, and serum ferritin, and it significantly reduced serum phosphate and intact FGF23 (P<0.001 for all). Of the 133 patients randomized to ferric citrate coordination complex, 31 (23%) initiated dialysis during the study period, as did 32 of 66 (48%) patients randomized to usual care (P=0.001). Compared with usual care, ferric citrate coordination complex treatment resulted in significantly fewer annualized hospital admissions, fewer days in hospital, and a lower incidence of the composite end point of death, provision of dialysis, or transplantation (P=0.002). CONCLUSIONS The beneficial effects of fixed-dose ferric citrate coordination complex on biochemical parameters, as well as the exploratory results regarding the composite end point and hospitalization, suggest that fixed-dose ferric citrate coordination complex has an excellent safety profile in an unselected population with advanced CKD and merits further study.
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Affiliation(s)
| | | | | | - Rupal Mehta
- Division of Nephrology and Hypertension, Department of Medicine and Center for Translational Metabolism and Health, Institute of Public Health and Medicine, Feinberg School of Medicine, Jesse Brown Veterans Administration Medical Center
| | - Tamara Isakova
- Division of Nephrology and Hypertension, Department of Medicine and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Myles Wolf
- Division of Nephrology, Department of Medicine, and Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina; and
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23
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Nordholm A, Egstrand S, Gravesen E, Mace ML, Morevati M, Olgaard K, Lewin E. Circadian rhythm of activin A and related parameters of mineral metabolism in normal and uremic rats. Pflugers Arch 2019; 471:1079-1094. [PMID: 31236663 PMCID: PMC6614158 DOI: 10.1007/s00424-019-02291-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 12/11/2022]
Abstract
Activin A is a new fascinating player in chronic kidney disease-mineral and bone disorder (CKD-MBD), which is implicated in progressive renal disease, vascular calcification, and osteodystrophy. Plasma activin A rises early in the progression of renal disease. Disruption of circadian rhythms is related to increased risk of several diseases and circadian rhythms are observed in mineral homeostasis, bone parameters, and plasma levels of phosphate and PTH. Therefore, we examined the circadian rhythm of activin A and CKD-MBD-related parameters (phosphate, PTH, FGF23, and klotho) in healthy controls and CKD rats (5/6 nephrectomy) on high-, standard- and low-dietary phosphate contents as well as during fasting conditions. Plasma activin A exhibited circadian rhythmicity in healthy control rats with fourfold higher values at acrophase compared with nadir. The rhythm was obliterated in CKD. Activin A was higher in CKD rats compared with controls when measured at daytime but not significantly when measured at evening/nighttime, stressing the importance of time-specific reference intervals when interpreting plasma values. Plasma phosphate, PTH, and FGF23 all showed circadian rhythms in control rats, which were abolished or disrupted in CKD. Plasma klotho did not show circadian rhythm. Thus, the present investigation shows, for the first time, circadian rhythm of plasma activin A. The rhythmicity is severely disturbed by CKD and is associated with disturbed rhythms of phosphate and phosphate-regulating hormones PTH and FGF23, indicating that disturbed circadian rhythmicity is an important feature of CKD-MBD.
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Affiliation(s)
- Anders Nordholm
- Nephrological Department, Herlev Hospital, University of Copenhagen, 2730, Herlev, Denmark.,Nephrological Department, Rigshospitalet, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Søren Egstrand
- Nephrological Department, Herlev Hospital, University of Copenhagen, 2730, Herlev, Denmark.,Nephrological Department, Rigshospitalet, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Eva Gravesen
- Nephrological Department, Rigshospitalet, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Maria L Mace
- Nephrological Department, Herlev Hospital, University of Copenhagen, 2730, Herlev, Denmark.,Nephrological Department, Rigshospitalet, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Marya Morevati
- Nephrological Department, Rigshospitalet, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Klaus Olgaard
- Nephrological Department, Rigshospitalet, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Ewa Lewin
- Nephrological Department, Herlev Hospital, University of Copenhagen, 2730, Herlev, Denmark. .,Nephrological Department, Rigshospitalet, University of Copenhagen, 2100, Copenhagen, Denmark.
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24
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Block GA, Rosenbaum DP, Yan A, Chertow GM. Efficacy and Safety of Tenapanor in Patients with Hyperphosphatemia Receiving Maintenance Hemodialysis: A Randomized Phase 3 Trial. J Am Soc Nephrol 2019; 30:641-652. [PMID: 30846557 DOI: 10.1681/asn.2018080832] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 01/24/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Guidelines recommend reducing elevated serum phosphate in patients with CKD. Tenapanor, a minimally absorbed inhibitor of gastrointestinal sodium/hydrogen exchanger 3 (NHE3), reduces paracellular phosphate transport. METHODS In this phase 3 randomized, double-blind trial, we randomly assigned patients with hyperphosphatemia receiving maintenance hemodialysis to receive twice-daily oral tenapanor (3, 10, or 30 mg [the latter down-titrated, if needed]) for 8 weeks. Patients were then rerandomized 1:1 to receive either their previously assigned dose or placebo for a 4-week 'withdrawal' period. We measured serum phosphate levels over the course of the trial. The primary end point was mean change in serum phosphate over the 4-week withdrawal period for the tenapanor group (using pooled data) versus the placebo group. RESULTS Of 219 patients randomized, 152 completed both study phases. During the initial 8-week treatment period, all three treatment groups experienced significant decreases in mean serum phosphate (reductions of 1.00, 1.02, and 1.19 mg/dl, corresponding to the 3, 10, and 30 mg [down-titrated] dose groups, respectively). Tenapanor also showed a significant benefit over placebo during the withdrawal period, with a mean increase of 0.85 mg/dl in the placebo group versus a mean increase of 0.02 mg/dl in the pooled tenapanor group. Adverse events were largely limited to softened stool and a modest increase in bowel movement frequency, resulting from increased stool sodium and water content, stemming from tenapanor's mechanism of action. CONCLUSIONS Tenapanor significantly reduced elevated serum phosphate in patients with hyperphosphatemia receiving maintenance hemodialysis. Adverse effects were limited to those induced by its known mechanism of action, which increases stool sodium and water content.
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Affiliation(s)
- Geoffrey A Block
- Denver Nephrology Research Division, Denver Nephrology, Denver, Colorado;
| | | | | | - Glenn M Chertow
- Division of Nephrology, Stanford University School of Medicine, Stanford, California
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25
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Lioufas N, Toussaint ND, Pedagogos E, Elder G, Badve SV, Pascoe E, Valks A, Hawley C. Can we IMPROVE cardiovascular outcomes through phosphate lowering in CKD? Rationale and protocol for the IMpact of Phosphate Reduction On Vascular End-points in Chronic Kidney Disease (IMPROVE-CKD) study. BMJ Open 2019; 9:e024382. [PMID: 30796122 PMCID: PMC6398689 DOI: 10.1136/bmjopen-2018-024382] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 10/09/2018] [Accepted: 01/08/2019] [Indexed: 12/25/2022] Open
Abstract
INTRODUCTION Patients with chronic kidney disease (CKD) are at heightened cardiovascular risk, which has been associated with abnormalities of bone and mineral metabolism. A deeper understanding of these abnormalities should facilitate improved treatment strategies and patient-level outcomes, but at present there are few large, randomised controlled clinical trials to guide management. Positive associations between serum phosphate and fibroblast growth factor 23 (FGF-23) and cardiovascular morbidity and mortality in both the general and CKD populations have resulted in clinical guidelines suggesting that serum phosphate be targeted towards the normal range, although few randomised and placebo-controlled studies have addressed clinical outcomes using interventions to improve phosphate control. Early preventive measures to reduce the development and progression of vascular calcification, left ventricular hypertrophy and arterial stiffness are crucial in patients with CKD. METHODS AND ANALYSIS We outline the rationale and protocol for an international, multicentre, randomised parallel-group trial assessing the impact of the non-calcium-based phosphate binder, lanthanum carbonate, compared with placebo on surrogate markers of cardiovascular disease in a predialysis CKD population-the IM pact of P hosphate R eduction O n V ascular E nd-points (IMPROVE)-CKD study. The primary objective of the IMPROVE-CKD study is to determine if the use of lanthanum carbonate reduces the burden of cardiovascular disease in patients with CKD stages 3b and 4 when compared with placebo. The primary end-point of the study is change in arterial compliance measured by pulse wave velocity over a 96-week period. Secondary outcomes include change in aortic calcification and biochemical parameters of serum phosphate, parathyroid hormone and FGF-23 levels. ETHICS AND DISSEMINATION Ethical approval for the IMPROVE-CKD trial was obtained by each local Institutional Ethics Committee for all 17 participating sites in Australia, New Zealand and Malaysia prior to study commencement. Results of this clinical trial will be published in peer-reviewed journals and presented at conferences. TRIAL REGISTRATION NUMBER ACTRN12610000650099.
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Affiliation(s)
- Nicole Lioufas
- Department of Nephrology, Royal Melbourne Hospital, Melbourne, Victoria, Australia
- Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
| | - Nigel D Toussaint
- Department of Nephrology, Royal Melbourne Hospital, Melbourne, Victoria, Australia
- Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
| | | | - Grahame Elder
- Department of Renal Medicine, Westmead Hospital, Sydney, New South Wales, Australia
| | - Sunil V Badve
- Department of Nephrology, St. George Hospital, Sydney, New South Wales, Australia
| | - Elaine Pascoe
- Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
- Australasian Kidney Trials Network, Brisbane, Queensland, Australia
| | - Andrea Valks
- University of Queensland, Australasian Kidney Trials Network, Brisbane, Queensland, Australia
| | - Carmel Hawley
- Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
- Australasian Kidney Trials Network, Brisbane, Queensland, Australia
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26
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Saurette M, Alexander RT. Intestinal phosphate absorption: The paracellular pathway predominates? Exp Biol Med (Maywood) 2019; 244:646-654. [PMID: 30764666 DOI: 10.1177/1535370219831220] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
IMPACT STATEMENT This review summarizes the work on transcellular intestinal phosphate absorption, arguing why this pathway is not the predominant pathway in humans consuming a "Western" diet. We then highlight the recent evidence which is strongly consistent with paracellular intestinal phosphate absorption mediating the bulk of intestinal phosphate absorption in humans.
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Affiliation(s)
- Matthew Saurette
- 1 Department of Physiology, University of Alberta, Edmonton, Alberta T6G 2R7, Canada.,2 The Women's & Children's Health Research Institute, Edmonton, Alberta T6G 1C9, Canada
| | - R Todd Alexander
- 1 Department of Physiology, University of Alberta, Edmonton, Alberta T6G 2R7, Canada.,2 The Women's & Children's Health Research Institute, Edmonton, Alberta T6G 1C9, Canada.,3 Department of Pediatrics, University of Alberta, Edmonton, Alberta T6G 2R7, Canada
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27
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Bartoli-Leonard F, Wilkinson FL, Langford-Smith AWW, Alexander MY, Weston R. The Interplay of SIRT1 and Wnt Signaling in Vascular Calcification. Front Cardiovasc Med 2018; 5:183. [PMID: 30619890 PMCID: PMC6305318 DOI: 10.3389/fcvm.2018.00183] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 12/04/2018] [Indexed: 12/24/2022] Open
Abstract
Vascular calcification is a major health risk and is highly correlated with atherosclerosis, diabetes, and chronic kidney disease. The development of vascular calcification is an active and complex process linked with a multitude of signaling pathways, which regulate promoters and inhibitors of osteogenesis, the balance of which become deregulated in disease conditions. SIRT1, a protein deacetylase, known to be protective in inhibiting oxidative stress and inflammation within the vessel wall, has been shown as a possible key player in modulating the cell-fate determining canonical Wnt signaling pathways. Suppression of SIRT1 has been reported in patients suffering with cardiovascular pathologies, suggesting that the sustained acetylation of osteogenic factors could contribute to their activation and in turn, lead to the progression of calcification. There is clear evidence of the synergy between β-Catenin and elevated Runx2, and with Wnt signaling being β-Catenin dependent, further understanding is needed as to how these molecular pathways converge and interact, in order to provide novel insight into the mechanism by which smooth muscle cells switch to an osteogenic differentiation programme. Therefore, this review will describe the current concepts of pathological soft tissue mineralization, with a focus on the contribution of SIRT1 as a regulator of Wnt signaling and its targets, discussing SIRT1 as a potential target for manipulation and therapy.
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Affiliation(s)
- Francesca Bartoli-Leonard
- Translational Cardiovascular Science, Centre for Bioscience, Manchester Metropolitan University, Manchester, United Kingdom
| | - Fiona L Wilkinson
- Translational Cardiovascular Science, Centre for Bioscience, Manchester Metropolitan University, Manchester, United Kingdom
| | - Alex W W Langford-Smith
- Translational Cardiovascular Science, Centre for Bioscience, Manchester Metropolitan University, Manchester, United Kingdom
| | - M Y Alexander
- Translational Cardiovascular Science, Centre for Bioscience, Manchester Metropolitan University, Manchester, United Kingdom
| | - Ria Weston
- Translational Cardiovascular Science, Centre for Bioscience, Manchester Metropolitan University, Manchester, United Kingdom
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28
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de Jong MA, Petrykiv SI, Laverman GD, van Herwaarden AE, de Zeeuw D, Bakker SJL, Heerspink HJL, de Borst MH. Effects of Dapagliflozin on Circulating Markers of Phosphate Homeostasis. Clin J Am Soc Nephrol 2018; 14:66-73. [PMID: 30559106 PMCID: PMC6364523 DOI: 10.2215/cjn.04530418] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 10/20/2018] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND OBJECTIVES The sodium glucose cotransporter 2 (SGLT-2) inhibitor dapagliflozin is a novel drug for the treatment of diabetes mellitus. Recent studies suggest that SGLT-2 inhibitors affect phosphate homeostasis, but their effects on phosphate-regulating hormones in patients with diabetic kidney disease are still unclear. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We performed a post-hoc analysis of a double-blind, randomized, crossover trial in patients with type 2 diabetes with early-stage diabetic kidney disease on stable renin-angiotensin-aldosterone system blockade, with an albumin-to-creatinine ratio between 100 and 3500 mg/g, eGFR≥45 ml/min per 1.73 m2, and glycosylated hemoglobin≥7.2% and <11.4%. Patients were randomized to dapagliflozin 10 mg/d or placebo during consecutive 6-week study periods, separated by a 6-week wash-out. We investigated effects on circulating phosphate, calcium, parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), 25-hydroxyvitamin D (25[OH]D), and 1,25-dihydroxyvitamin D (1,25[OH]2D) levels. RESULTS Thirty-one patients (age 62 years; 23% female) were analyzed. Compared with placebo, dapagliflozin increased serum phosphate by 9% (95% confidence interval, 4% to 15%; P=0.002), PTH increased by 16% (3% to 30%; P=0.01), FGF23 increased by 19% (0.3% to 42%; P=0.05), and serum 1,25(OH)2D decreased by -12% (-25% to 4%; P=0.12). Calcium and 25(OH)D were unaffected. We found no correlation between changes in markers of phosphate homeostasis and changes in eGFR or 24-hour albumin excretion during dapagliflozin treatment. CONCLUSIONS Dapagliflozin increases serum phosphate, plasma PTH, and FGF23. This effect was independent of concomitant changes in eGFR or 24-hour albumin excretion.
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Affiliation(s)
| | - Sergei I Petrykiv
- Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Gozewijn D Laverman
- Department of Nephrology, Zorggroep Twente, Almelo and Hengelo, The Netherlands; and
| | | | - Dick de Zeeuw
- Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | | | - Hiddo J L Heerspink
- Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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29
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Lederer E, Wagner CA. Clinical aspects of the phosphate transporters NaPi-IIa and NaPi-IIb: mutations and disease associations. Pflugers Arch 2018; 471:137-148. [DOI: 10.1007/s00424-018-2246-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 12/05/2018] [Indexed: 12/12/2022]
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30
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Sorribas V, Guillén N, Sosa C. Substrates and inhibitors of phosphate transporters: from experimental tools to pathophysiological relevance. Pflugers Arch 2018; 471:53-65. [DOI: 10.1007/s00424-018-2241-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 11/21/2018] [Accepted: 11/25/2018] [Indexed: 12/26/2022]
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31
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Vorland CJ, Lachcik PJ, Aromeh LO, Moe SM, Chen NX, Hill Gallant KM. Effect of dietary phosphorus intake and age on intestinal phosphorus absorption efficiency and phosphorus balance in male rats. PLoS One 2018; 13:e0207601. [PMID: 30452474 PMCID: PMC6242370 DOI: 10.1371/journal.pone.0207601] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 10/26/2018] [Indexed: 12/31/2022] Open
Abstract
Intestinal phosphorus absorption is an important component of whole-body phosphorus metabolism, and limiting dietary phosphorus absorption is particularly of interest as a therapeutic target in patients with chronic kidney disease to manage mineral bone disorders. Yet, mechanisms and regulation of intestinal phosphorus absorption have not been adequately studied and discrepancies in findings exist based on the absorption assessment technique used. In vitro techniques show rather consistent effects of dietary phosphorus intake level and age on intestinal sodium-dependent phosphate transport. But, the few studies that have used in vivo techniques conflict with these in vitro studies. Therefore, we aimed to investigate the effects of dietary phosphorus intake level on phosphorus absorption using the in situ ligated loop technique in three different aged rats. Male Sprague-Dawley rats (n = 72), were studied at 10-, 20-, and 30-weeks-of-age on a low (0.1%), normal (0.6%), or high (1.2%) phosphorus diet in a 3x3 factorial design (n = 8/group). Rats were fed their assigned diet for 2-weeks prior to absorption testing by jejunal ligated loop as a non-survival procedure, utilizing 33P radioisotope. Metabolic cages were used for determination of calcium and phosphorus balance over the final four days prior to sacrifice, and blood was collected at the time of sacrifice for biochemistries. Our results show that phosphorus absorption was higher in 10-week-old rats compared with 20- and 30-week-olds and this corresponded to higher gene expression of the major phosphate transporter, NaPi-2b, as well as higher whole-body phosphorus balance and net phosphorus absorption. Dietary phosphorus intake level did not affect jejunal phosphorus absorption or NaPi-2b gene expression. Our results contrast with studies utilizing in vitro techniques, but corroborate results of other rodent studies utilizing in situ or in vivo methods. Thus, there is need for additional studies that employ more physiological methods of phosphorus absorption assessment.
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Affiliation(s)
- Colby J. Vorland
- Department of Nutrition Science, Purdue University, West Lafayette, IN, United States of America
| | - Pamela J. Lachcik
- Department of Nutrition Science, Purdue University, West Lafayette, IN, United States of America
| | - Loretta O. Aromeh
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Sharon M. Moe
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, United States of America
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, United States of America
- Department of Medicine, Roudebush Veterans Affairs Medicine Center, Indianapolis, IN, United States of America
| | - Neal X. Chen
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Kathleen M. Hill Gallant
- Department of Nutrition Science, Purdue University, West Lafayette, IN, United States of America
- * E-mail:
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32
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Isakova T, Block G. The phosphate bucket list. Kidney Int 2018; 93:1033-1035. [PMID: 29680017 DOI: 10.1016/j.kint.2018.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 01/10/2018] [Accepted: 01/12/2018] [Indexed: 10/17/2022]
Abstract
As our understanding of phosphate homeostasis has expanded over the last 20 years, additional quandaries have surfaced. Though the phosphate bucket list remains full, we are confident that the next 20 years will lead to major fundamental discoveries. In this commentary, we provide an example of how findings from a basic study that examined the mechanisms for circadian rhythms of plasma and urinary phosphate sheds light on important pathways that can be harnessed for novel therapeutic approaches in the future.
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Affiliation(s)
- Tamara Isakova
- Division of Nephrology and Hypertension, Department of Medicine and Center for Translational Metabolism and Health, Institute for Public Health and Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
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33
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Tatsumi S, Katai K, Kaneko I, Segawa H, Miyamoto KI. NAD metabolism and the SLC34 family: evidence for a liver-kidney axis regulating inorganic phosphate. Pflugers Arch 2018; 471:109-122. [PMID: 30218374 DOI: 10.1007/s00424-018-2204-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 08/29/2018] [Accepted: 09/06/2018] [Indexed: 12/18/2022]
Abstract
The solute carrier 34 (SLC34) family of membrane transporters is a major contributor to Pi homeostasis. Many factors are involved in regulating the SLC34 family. The roles of the bone mineral metabolism factors parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) in Pi homeostasis are well studied. Intracellular Pi is thought to be involved in energy metabolism, such as ATP production. Under certain conditions of altered energy metabolism, plasma Pi concentrations are affected by the regulation of a Pi shift into cells or release from the tissues. We recently investigated the mechanism of hepatectomy-related hypophosphatemia, which is thought to involve an unknown phosphaturic factor. Hepatectomy-related hypophosphatemia is due to impaired nicotinamide adenine dinucleotide (NAD) metabolism through its effects on the SLC34 family in the liver-kidney axis. The oxidized form of NAD, NAD+, is an essential cofactor in various cellular biochemical reactions. Levels of NAD+ and its reduced form NADH vary with the availability of dietary energy and nutrients. Nicotinamide phosphoribosyltransferase (Nampt) generates a key NAD+ intermediate, nicotinamide mononucleotide, from nicotinamide and 5-phosphoribosyl 1-pyrophosphate. The liver, an important organ of NAD metabolism, is thought to release metabolic products such as nicotinamide and may control NAD metabolism in other organs. Moreover, NAD is an important regulator of the circadian rhythm. Liver-specific Nampt-deficient mice and heterozygous Nampt mice have abnormal daily plasma Pi concentration oscillations. These data indicate that NAD metabolism in the intestine, liver, and kidney is closely related to Pi metabolism through the SLC34 family. Here, we review the relationship between the SLC34 family and NAD metabolism based on our recent studies.
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Affiliation(s)
- Sawako Tatsumi
- Department of Molecular Nutrition, Institution of Biomedical Science, Tokushima University Graduate School, 3-18-15 Kuramoto, Tokushima, 770-8503, Japan.,Department of Food Science and Nutrition, School of Human Cultures, The University of Shiga Prefecture, Hikone, Japan
| | - Kanako Katai
- Faculty of Human Life and Science, Department of Food Science and Nutrition, Doshisha Women's College of Liberal Arts, Kyoto, Japan
| | - Ichiro Kaneko
- Department of Molecular Nutrition, Institution of Biomedical Science, Tokushima University Graduate School, 3-18-15 Kuramoto, Tokushima, 770-8503, Japan
| | - Hiroko Segawa
- Department of Molecular Nutrition, Institution of Biomedical Science, Tokushima University Graduate School, 3-18-15 Kuramoto, Tokushima, 770-8503, Japan
| | - Ken-Ichi Miyamoto
- Department of Molecular Nutrition, Institution of Biomedical Science, Tokushima University Graduate School, 3-18-15 Kuramoto, Tokushima, 770-8503, Japan.
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