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Li M, Hasan AA, Chu C, Hocher JG, Liu Y, Zhang X, Chen X, Yard B, Krämer BK, Hocher B. Only bioactive forms of PTH (n-oxPTH and Met18(ox)-PTH) inhibit synthesis of sclerostin - evidence from in vitro and human studies. Pflugers Arch 2024; 476:889-899. [PMID: 38393416 PMCID: PMC11139748 DOI: 10.1007/s00424-024-02928-x] [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: 09/28/2023] [Revised: 01/30/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024]
Abstract
Sclerostin (SOST) is produced by osteocytes and is known as a negative regulator of bone homeostasis. Parathyroid hormone (PTH) regulates calcium, phosphate as well as vitamin D metabolism, and is a strong inhibitor of SOST synthesis in vitro and in vivo. PTH has two methionine amino acids (positions 8 and 18) which can be oxidized. PTH oxidized at Met18 (Met18(ox)-PTH) continues to be bioactive, whereas PTH oxidized at Met8 (Met8(ox)-PTH) or PTH oxidized at Met8 and Met18 (Met8, Met18(di-ox)-PTH) has minor bioactivity. How non-oxidized PTH (n-oxPTH) and oxidized forms of PTH act on sclerostin synthesis is unknown. The effects of n-oxPTH and oxidized forms of PTH on SOST gene expression were evaluated in UMR106 osteoblast-like cells. Moreover, we analyzed the relationship of SOST with n-oxPTH and all forms of oxPTH in 516 stable kidney transplant recipients using an assay system that can distinguish in clinical samples between n-oxPTH and the sum of all oxidized PTH forms (Met8(ox)-PTH, Met18(ox)-PTH, and Met8, Met18(di-ox)-PTH). We found that both n-oxPTH and Met18(ox)-PTH at doses of 1, 3, 20, and 30 nmol/L significantly inhibit SOST gene expression in vitro, whereas Met8(ox)-PTH and Met8, Met18(di-ox)-PTH only have a weak inhibitory effect on SOST gene expression. In the clinical cohort, multivariate linear regression showed that only n-oxPTH, but not intact PTH (iPTH) nor oxPTH, is independently associated with circulating SOST after adjusting for known confounding factors. In conclusion, only bioactive PTH forms such as n-oxPTH and Met18(ox)-PTH, inhibit SOST synthesis.
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Affiliation(s)
- Mei Li
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Ahmed A Hasan
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Chang Chu
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Johann-Georg Hocher
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Yvonne Liu
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
- Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Xiaoli Zhang
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Xin Chen
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Benito Yard
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Bernhard K Krämer
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Berthold Hocher
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology/Pneumology), University Medical Centre Mannheim, University of Heidelberg, Heidelberg, Germany.
- Reproductive, Genetic Hospital of CITIC-Xiangya, Changsha, China.
- Institute of Medical Diagnostics, IMD Berlin-Potsdam, Berlin, Germany.
- Institute of Reproductive and Stem Cell Engineering, NHC Key Laboratory of Human Stem Cell and Reproductive Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China.
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Koh HB, Ryu JH, Kim SS, Kim MG, Park JB, Kim CD, Kang KP, Ro H, Han SY, Huh KH, Yang J. Association between sclerostin levels and vascular outcomes in kidney transplantation patients. J Nephrol 2023; 36:2091-2109. [PMID: 37751127 DOI: 10.1007/s40620-023-01732-7] [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: 05/06/2023] [Accepted: 07/03/2023] [Indexed: 09/27/2023]
Abstract
BACKGROUND The impact of circulating sclerostin levels on vascular calcification has shown conflicting results depending on the target population and vascular anatomy. This study investigated the associations of sclerostin levels with vascular outcomes in kidney transplant patients. METHODS In a prospective observational study of the Korean Cohort Study for Outcome in Patients with Kidney Transplantation, 591 patients with serum sclerostin level data prior to transplantation were analyzed. The main predictor was the pre-transplant sclerostin level. Vascular outcomes were the abdominal aortic calcification score and brachial-ankle pulse wave velocity measured at pre-transplant screening and three and five years after kidney transplantation. RESULTS In linear regression analysis, sclerostin level positively correlated with changes in abdominal aortic calcification score between baseline and five years after kidney transplantation (coefficient of 0.73 [95% CI, 0.11-1.35] and 0.74 [95% CI, 0.06-1.42] for second and third tertiles, respectively, vs the first tertile). In a longitudinal analysis over five years, using generalized estimating equations, the coefficient of the interaction (sclerostin × time) was significant with a positive value, indicating that higher sclerostin levels were associated with faster increase in post-transplant abdominal aortic calcification score. Linear regression analysis revealed a positive association between pre-transplant sclerostin levels and changes in brachial-ankle pulse wave velocity (coefficient of 126.7 [95% CI, 35.6-217.8], third vs first tertile). Moreover, a significant interaction was identified between sclerostin levels and brachial-ankle pulse wave velocity at five years. CONCLUSIONS Elevated pre-transplant sclerostin levels are associated with the progression of post-transplant aortic calcifications and arterial stiffness.
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Affiliation(s)
- Hee Byung Koh
- Department of Internal Medicine, Catholic Kwandong University International Saint Mary's Hospital, Incheon, Republic of Korea
| | - Jung Hwa Ryu
- Department of Internal Medicine, Ewha Womans University Seoul Hospital, Seoul, Republic of Korea
| | - Seung-Seob Kim
- Department of Radiology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Myung-Gyu Kim
- Department of Internal Medicine, Korea University College of Medicine, Seoul, Republic of Korea
| | - Jae Berm Park
- Department of Surgery, Seoul Samsung Medical Center, Sungkyunkwan University, Seoul, Republic of Korea
| | - Chan Duk Kim
- Department of Internal Medicine, Kyungpook National University Hospital, Daegu, Republic of Korea
| | - Kyung Pyo Kang
- Department of Internal Medicine, Research Institute of Clinical Medicine, Jeonbuk National University Medical School, Jeonju, Republic of Korea
| | - Han Ro
- Department of Internal Medicine, Gil Hospital, Gachon University, Incheon, Republic of Korea
| | - Seung-Yeup Han
- Department of Internal Medicine, Dongsan Medical Center, Keimyung University, Daegu, Republic of Korea
| | - Kyu Ha Huh
- Department of Surgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jaeseok Yang
- Department of Internal Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
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Zuo J, Hasan AA, Hocher CF, Kalk P, Kleuser B, Krämer BK, Hocher B. Inverse correlation of intact PTH, oxidized PTH as well as non-oxidized PTH with 25-hydroxyvitamin D3 in kidney transplant recipients. Front Endocrinol (Lausanne) 2023; 14:1178166. [PMID: 37324252 PMCID: PMC10264784 DOI: 10.3389/fendo.2023.1178166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 05/17/2023] [Indexed: 06/17/2023] Open
Abstract
Background 25-hydroxyvitamin D (25(OH)D) and potentially also 1,25-dihydroxyvitamin D (1,25(OH)2D) inhibits the synthesis of parathyroid hormone (PTH) in the chief cells of the parathyroid gland. Clinical studies showing a negative correlation between (25(OH)D and PTH are in good agreement with these findings in basic science studies. However, PTH was measured in these studies with the currently clinically used 2nd or 3rd generation intact PTH (iPTH) assay systems. iPTH assays cannot distinguish between oxidized forms of PTH and non-oxidized PTH. Oxidized forms of PTH are the by far most abundant form of PTH in the circulation of patients with impaired kidney function. Oxidation of PTH causes a loss of function of PTH. Given that the clinical studies done so far were performed with an PTH assay systems that mainly detect oxidized forms of PTH, the real relationship between bioactive non-oxidized PTH and 25(OH)D as well as 1,25(OH)2D is still unknown. Methods To address this topic, we compared for the first time the relationship between 25(OH)D as well as 1,25(OH)2D and iPTH, oxPTH as well as fully bioactive n-oxPTH in 531 stable kidney transplant recipients in the central clinical laboratories of the Charité. Samples were assessed either directly (iPTH) or after oxPTH (n-oxPTH) was removed using a column that used anti-human oxPTH monoclonal antibodies, a monoclonal rat/mouse parathyroid hormone antibody (MAB) was immobilized onto a column with 500 liters of plasma samples. Spearman correlation analysis and Multivariate linear regression were used to evaluate the correlations between the variables. Results There was an inverse correlation between 25(OH)D and all forms of PTH, including oxPTH (iPTH: r=-0.197, p<0.0001; oxPTH: r=-0.203, p<0.0001; n-oxPTH: r=-0.146, p=0.001). No significant correlation was observed between 1,25(OH)2D and all forms of PTH. Multiple linear regression analysis considering age, PTH (iPTH, oxPTH and n-oxPTH), serum calcium, serum phosphor, serum creatinine, fibroblast growth factor 23 (FGF23), osteoprotegerin (OPG), albumin, and sclerostin as confounding factors confirmed these findings. Subgroup analysis showed that our results are not affected by sex and age. Conclusion In our study, all forms of PTH are inversely correlated with 25-hydroxyvitamin D (25(OH)D). This finding would be in line with an inhibition of the synthesis of all forms of PTH (bioactive n-oxPTH and oxidized forms of PTH with minor or no bioactivity) in the chief cells of the parathyroid glad.
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Affiliation(s)
- Jiao Zuo
- Department of Nephrology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology, Pneumonology), University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
| | - Ahmed A. Hasan
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology, Pneumonology), University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Carl-Friedrich Hocher
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology, Pneumonology), University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
- Klinik für Innere Medizin, Bundeswehrkrankenhaus Berlin, Berlin, Germany
| | - Philipp Kalk
- Department of Nephrology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Diaverum Renal Care Center, Diaverum MVZ Am Neuen Garten Standort Ludwigsfelde, Potsdam, Germany
| | - Burkhard Kleuser
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Bernhard K. Krämer
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology, Pneumonology), University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
- European Center for Angioscience ECAS, Medical Faculty Mannheim of the University of Heidelberg, Mannheim, Germany
| | - Berthold Hocher
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology, Pneumonology), University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany
- Reproductive, Genetic Hospital of CITIC-Xiangya, Changsha, China
- Institute of Medical Diagnostics, IMD, Berlin, Germany
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Cejka D. Cardiovascular Safety of Anti-Sclerostin Therapy in Chronic Kidney Disease. Metabolites 2021; 11:770. [PMID: 34822428 PMCID: PMC8624769 DOI: 10.3390/metabo11110770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 11/05/2021] [Accepted: 11/08/2021] [Indexed: 01/10/2023] Open
Abstract
The significance of sclerostin for bone and cardiovascular health in patients with chronic kidney disease (CKD) is complex and incompletely understood. Experimental evidence suggests that anti-sclerostin therapy shows diminished efficacy on bone in the setting of CKD. Limited clinical evidence suggests that the osteoanabolic and anti-resorptive activity is attenuated, but hypocalcemia is more prevalent in patients with advanced CKD (eGFR < 30 mL/min) treated with anti-sclerostin (romosozumab) therapy as compared to patients without kidney disease. Furthermore, sclerostin is prominently expressed in uremic arteries. Whether the inhibition of sclerostin has adverse effects on cardiovascular health in CKD is currently unknown. This review summarizes the current understanding of the physiology and pathophysiology of sclerostin in CKD, with a focus on the cardiovascular safety of anti-sclerostin therapy in patients with or without CKD.
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Affiliation(s)
- Daniel Cejka
- Department of Medicine III: Nephrology, Transplantation Medicine, Rheumatology, Geriatrics, Ordensklinikum Linz-Elisabethinen Hospital, Fadingerstraße 1, 4020 Linz, Austria
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