1
|
Bover J, Trinidad P, Jara A, Soler-Majoral J, Martín-Malo A, Torres A, Frazão J, Ureña P, Dusso A, Arana C, Graterol F, Romero-González G, Troya M, Samaniego D, D'Marco L, Valdivielso JM, Fernández E, Arenas MD, Torregrosa V, Navarro-González JF, Lloret MJ, Ballarín JA, Bosch RJ, Górriz JL, de Francisco A, Gutiérrez O, Ara J, Felsenfeld A, Canalejo A, Almadén Y. Silver jubilee: 25 years of the first demonstration of the direct effect of phosphate on the parathyroid cell. Nefrologia 2022; 42:645-655. [PMID: 36925324 DOI: 10.1016/j.nefroe.2023.02.008] [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: 12/27/2021] [Accepted: 12/30/2021] [Indexed: 06/18/2023] Open
Abstract
Although phosphorus is an essential element for life, it is not found in nature in its native state but rather combined in the form of inorganic phosphates (PO43-), with tightly regulated plasma levels that are associated with deleterious effects and mortality when these are out of bounds. The growing interest in the accumulation of PO43- in human pathophysiology originated in its attributed role in the pathogenesis of secondary hyperparathyroidism (SHPT) in chronic kidney disease. In this article, we review the mechanisms by which this effect was justified and we commemorate the important contribution of a Spanish group led by Dr. M. Rodríguez, just 25 years ago, when they first demonstrated the direct effect of PO43- on the regulation of the synthesis and secretion of parathyroid hormone by maintaining the structural integrity of the parathyroid glands in their original experimental model. In addition to demonstrating the importance of arachidonic acid (AA) and the phospholipase A2-AA pathway as a mediator of parathyroid gland response, these findings were predecessors of the recent description of the important role of PO43- on the activity of the calcium sensor-receptor, and also fueled various lines of research on the importance of PO43- overload not only for the pathophysiology of SHPT but also in its systemic pathogenic role.
Collapse
Affiliation(s)
- Jordi Bover
- Servicio de Nefrología, Hospital Universitario Germans Trias i Pujol, RICORS, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Universitat Autònoma de Barcelona, Badalona (Barcelona), Spain.
| | - Pedro Trinidad
- Departamento de Nefrología, HECMN siglo XXI, IMSS, Ciudad de México, México
| | - Aquiles Jara
- Departamento de Nefrología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jordi Soler-Majoral
- Servicio de Nefrología, Hospital Universitario Germans Trias i Pujol, RICORS, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Universitat Autònoma de Barcelona, Badalona (Barcelona), Spain
| | - Alejandro Martín-Malo
- Unidad de Gestión Clinica Nefrología, Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofía, Universidad de Córdoba, España. Red Nacional de Investigación en Nefrología (REDinREN), Instituto de Salud Carlos III, Spain
| | - Armando Torres
- Servicio de Nefrología, Hospital Universitario de Canarias, Instituto de Tecnologías Biomédicas, Universidad de La Laguna, Tenerife, Spain
| | - João Frazão
- Department of Nephrology, Centro Hospitalar Universitário São João, Institute for Innovation and Health Research (I3S), Institute of Biomedical Engineering (INEB), Nephrology and Infectious Diseases Research Group, University of Porto, Porto, Portugal
| | - Pablo Ureña
- AURA Nord Saint Ouen Dialysis Service. Saint Ouen, France and Service d'Explorations Fonctionnelles Rénales, Hôpital Necker, Université Paris V, René Descartes, Paris, France
| | - Adriana Dusso
- Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, St Louis, MO, USA
| | - Carolt Arana
- Departamento de Nefrología y Trasplante Renal, Hospital Clínic, Barcelona, España
| | - Fredzzia Graterol
- Servicio de Nefrología, Hospital Universitario Germans Trias i Pujol, RICORS, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Universitat Autònoma de Barcelona, Badalona (Barcelona), Spain
| | - Gregorio Romero-González
- Servicio de Nefrología, Hospital Universitario Germans Trias i Pujol, RICORS, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Universitat Autònoma de Barcelona, Badalona (Barcelona), Spain
| | - Maribel Troya
- Servicio de Nefrología, Hospital Universitario Germans Trias i Pujol, RICORS, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Universitat Autònoma de Barcelona, Badalona (Barcelona), Spain
| | - Diana Samaniego
- Servicio de Nefrología, Hospital Universitario Germans Trias i Pujol, RICORS, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Universitat Autònoma de Barcelona, Badalona (Barcelona), Spain
| | - Luis D'Marco
- CEU Cardenal Herrera University, Valencia, Spain
| | - José Manuel Valdivielso
- Vascular and Renal Translational Research Group, Biomedical Research Institute, IRBLLEIDA, Lleida, España. Red Nacional de Investigación en Nefrología (REDinREN, RETIC), Instituto de Salud Carlos III, Spain
| | - Elvira Fernández
- Vascular and Renal Translational Research Group, Biomedical Research Institute, IRBLLEIDA, Lleida, España. Red Nacional de Investigación en Nefrología (REDinREN, RETIC), Instituto de Salud Carlos III, Spain; Grupo de Investigación Traslacional Vascular y Renal, Fundación Renal Jaume Arnó, Lleida, Spain
| | | | - Vicente Torregrosa
- Departamento de Nefrología y Trasplante Renal, Hospital Clínic, Barcelona, España
| | - Juan F Navarro-González
- Unidad de Investigación y Servicio de Nefrología, Hospital Universitario Nuestra Señora de la Candelaria, Instituto Universitario de Tecnologías Biomédicas, Universidad de la Laguna, Santa Cruz de Tenerife, España. Red Nacional de Investigación en Nefrología (REDinREN, RICORS), Instituto de Salud Carlos III, Spain
| | - María Jesús Lloret
- Servicio de Nefrología, Fundació Puigvert, IIB Sant Pau, Barcelona, Spain
| | - J A Ballarín
- Servicio de Nefrología, Fundació Puigvert, IIB Sant Pau, Barcelona, Spain
| | - Ricardo J Bosch
- Unidad de Fisiología, Departamento de Biología de Sistemas, Facultad de Medicina, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain
| | - José L Górriz
- Servicio de Nefrología, Hospital Clínico Universitario, INCLIVA, Universidad de Valencia, Valencia, Spain
| | | | - Orlando Gutiérrez
- Division of Nephrology, Department of Medicine, Universidad de Alabama en Birmingham, Birmingham USA
| | - Jordi Ara
- Servicio de Nefrología, Hospital Universitario Germans Trias i Pujol, RICORS, Institut d'Investigació en Ciències de la Salut Germans Trias i Pujol (IGTP), Universitat Autònoma de Barcelona, Badalona (Barcelona), Spain
| | - Arnold Felsenfeld
- Department of Medicine, Veterans Affairs Greater Los Angeles Healthcare System and David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Antonio Canalejo
- Departamento de Ciencias Integradas/Centro de Investigación RENSMA, Facultad de Ciencias Experimentales, Universidad de Huelva. Huelva, Spain
| | - Yolanda Almadén
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Hospital Universitario Reina Sofía, Universidad de Córdoba, Córdoba, Spain
| |
Collapse
|
2
|
Xiang Z, Wang M, Miao C, Jin D, Wang H. Mechanism of calcitriol regulating parathyroid cells in secondary hyperparathyroidism. Front Pharmacol 2022; 13:1020858. [PMID: 36267284 PMCID: PMC9577402 DOI: 10.3389/fphar.2022.1020858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 09/15/2022] [Indexed: 12/03/2022] Open
Abstract
A common consequence of chronic renal disease is secondary hyperparathyroidism (SHPT) and is closely related to the mortality and morbidity of uremia patients. Secondary hyperparathyroidism (SHPT) is caused by excessive PTH production and release, as well as parathyroid enlargement. At present, the mechanism of cell proliferation in secondary hyperparathyroidism (SHPT) is not completely clear. Decreased expression of the vitamin D receptor (VDR) and calcium-sensing receptor (CaSR), and 1,25(OH)2D3 insufficiency all lead to a decrease in cell proliferation suppression, and activation of multiple pathways is also involved in cell proliferation in renal hyperparathyroidism. The interaction between the parathormone (PTH) and parathyroid hyperplasia and 1,25(OH)2D3 has received considerable attention. 1,25(OH)2D3 is commonly applied in the therapy of renal hyperparathyroidism. It regulates the production of parathormone (PTH) and parathyroid cell proliferation through transcription and post-transcription mechanisms. This article reviews the role of 1,25(OH)2D3 in parathyroid cells in secondary hyperparathyroidism and its current understanding and potential molecular mechanism.
Collapse
|
3
|
Hou YC, Zheng CM, Chiu HW, Liu WC, Lu KC, Lu CL. Role of Calcimimetics in Treating Bone and Mineral Disorders Related to Chronic Kidney Disease. Pharmaceuticals (Basel) 2022; 15:ph15080952. [PMID: 36015101 PMCID: PMC9415417 DOI: 10.3390/ph15080952] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/25/2022] [Accepted: 07/27/2022] [Indexed: 12/17/2022] Open
Abstract
Renal osteodystrophy is common in patients with chronic kidney disease and end-stage renal disease and leads to the risks of fracture and extraosseous vascular calcification. Secondary hyperparathyroidism (SHPT) is characterized by a compensatory increase in parathyroid hormone (PTH) secretion in response to decreased renal phosphate excretion, resulting in potentiating bone resorption and decreased bone quantity and quality. Calcium-sensing receptors (CaSRs) are group C G-proteins and negatively regulate the parathyroid glands through (1) increasing CaSR insertion within the plasma membrane, (2) increasing 1,25-dihydroxy vitamin D3 within the kidney and parathyroid glands, (3) inhibiting fibroblast growth factor 23 (FGF23) in osteocytes, and (4) attenuating intestinal calcium absorption through Transient Receptor Potential Vanilloid subfamily member 6 (TRPV6). Calcimimetics (CaMs) decrease PTH concentrations without elevating the serum calcium levels or extraosseous calcification through direct interaction with cell membrane CaSRs. CaMs reduce osteoclast activity by reducing stress-induced oxidative autophagy and improving Wnt-10b release, which promotes the growth of osteoblasts and subsequent mineralization. CaMs also directly promote osteoblast proliferation and survival. Consequently, bone quality may improve due to decreased bone resorption and improved bone formation. CaMs modulate cardiovascular fibrosis, calcification, and renal fibrosis through different mechanisms. Therefore, CaMs assist in treating SHPT. This narrative review focuses on the role of CaMs in renal osteodystrophy, including their mechanisms and clinical efficacy.
Collapse
Affiliation(s)
- Yi-Chou Hou
- Division of Nephrology, Department of Medicine, Cardinal-Tien Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City 24205, Taiwan;
| | - Cai-Mei Zheng
- Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, School of Medicine, College of Medicine, Taipei Medical University, New Taipei City 11031, Taiwan;
- TMU Research Centre of Urology and Kidney, Taipei Medical University, New Taipei City 11031, Taiwan;
| | - Hui-Wen Chiu
- TMU Research Centre of Urology and Kidney, Taipei Medical University, New Taipei City 11031, Taiwan;
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, New Taipei City 11031, Taiwan
- Department of Medical Research, Shuang Ho Hospital, Taipei Medical University, New Taipei City 11031, Taiwan
| | - Wen-Chih Liu
- Department of Biology and Anatomy, National Defense Medical Center, Taipei 11490, Taiwan;
- Section of Nephrology, Department of Medicine, Antai Medical Care Corporation, Anti Tian-Sheng Memorial Hospital, Pingtung 92842, Taiwan
| | - Kuo-Cheng Lu
- Division of Nephrology, Department of Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, School of Medicine, Buddhist Tzu Chi University, Hualien 97004, Taiwan
- Division of Nephrology, Department of Medicine, Fu-Jen Catholic University Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City 24205, Taiwan;
- Correspondence:
| | - Chien-Lin Lu
- Division of Nephrology, Department of Medicine, Fu-Jen Catholic University Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City 24205, Taiwan;
| |
Collapse
|
4
|
Hassan A, Khalaily N, Kilav-Levin R, Nechama M, Volovelsky O, Silver J, Naveh-Many T. Molecular Mechanisms of Parathyroid Disorders in Chronic Kidney Disease. Metabolites 2022; 12:metabo12020111. [PMID: 35208186 PMCID: PMC8878033 DOI: 10.3390/metabo12020111] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/17/2022] [Accepted: 01/20/2022] [Indexed: 01/27/2023] Open
Abstract
Secondary hyperparathyroidism (SHP) is a common complication of chronic kidney disease (CKD) that induces morbidity and mortality in patients. How CKD stimulates the parathyroid to increase parathyroid hormone (PTH) secretion, gene expression and cell proliferation remains an open question. In experimental SHP, the increased PTH gene expression is post-transcriptional and mediated by PTH mRNA–protein interactions that promote PTH mRNA stability. These interactions are orchestrated by the isomerase Pin1. Pin1 participates in conformational change-based regulation of target proteins, including mRNA-binding proteins. In SHP, Pin1 isomerase activity is decreased, and thus, the Pin1 target and PTH mRNA destabilizing protein KSRP fails to bind PTH mRNA, increasing PTH mRNA stability and levels. An additional level of post-transcriptional regulation is mediated by microRNA (miRNA). Mice with parathyroid-specific knockout of Dicer, which facilitates the final step in miRNA maturation, lack parathyroid miRNAs but have normal PTH and calcium levels. Surprisingly, these mice fail to increase serum PTH in response to hypocalcemia or uremia, indicating a role for miRNAs in parathyroid stimulation. SHP often leads to parathyroid hyperplasia. Reduced expressions of parathyroid regulating receptors, activation of transforming growth factor α-epidermal growth factor receptor, cyclooxygenase 2-prostaglandin E2 and mTOR signaling all contribute to the enhanced parathyroid cell proliferation. Inhibition of mTOR by rapamycin prevents and corrects the increased parathyroid cell proliferation of SHP. This review summarizes the current knowledge on the mechanisms that stimulate the parathyroid cell at multiple levels in SHP.
Collapse
Affiliation(s)
- Alia Hassan
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel; (A.H.); (N.K.); (R.K.-L.); (J.S.)
| | - Nareman Khalaily
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel; (A.H.); (N.K.); (R.K.-L.); (J.S.)
| | - Rachel Kilav-Levin
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel; (A.H.); (N.K.); (R.K.-L.); (J.S.)
- Nursing, Jerusalem College of Technology, Jerusalem 91160, Israel
| | - Morris Nechama
- Pediatric Nephrology, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel; (M.N.); (O.V.)
- The Wohl Institute for Translational Medicine, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Oded Volovelsky
- Pediatric Nephrology, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel; (M.N.); (O.V.)
- The Wohl Institute for Translational Medicine, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Justin Silver
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel; (A.H.); (N.K.); (R.K.-L.); (J.S.)
| | - Tally Naveh-Many
- Minerva Center for Bone and Mineral Research, Nephrology Services, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel; (A.H.); (N.K.); (R.K.-L.); (J.S.)
- The Wohl Institute for Translational Medicine, Hadassah—Hebrew University Medical Center, Jerusalem 91120, Israel
- Correspondence:
| |
Collapse
|
5
|
Bodas de plata: 25 años de la primera demostración del efecto directo del fósforo en la célula paratiroidea. Nefrologia 2022. [DOI: 10.1016/j.nefro.2021.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
|
6
|
Dusso AS, Bauerle KT, Bernal-Mizrachi C. Non-classical Vitamin D Actions for Renal Protection. Front Med (Lausanne) 2021; 8:790513. [PMID: 34950686 PMCID: PMC8688743 DOI: 10.3389/fmed.2021.790513] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022] Open
Abstract
Chronic Kidney Disease (CKD), a disorder that affects 11% of the world's population, is characterized by an acceleration in skeletal, immune, renal, and cardiovascular aging that increases the risk of cardiovascular mortality by 10- to 20-fold, compared to that in individuals with normal renal function. For more than two decades, the progressive impairment in renal capacity to maintain normal circulating levels of the hormonal form of vitamin D (1,25-dihydroxyvitamin D or calcitriol) was considered the main contributor to the reduced survival of CKD patients. Accordingly, calcitriol administration was the treatment of choice to attenuate the progression of secondary hyperparathyroidism (SHPT) and its adverse impact on bone health and vascular calcification. The development of calcitriol analogs, designed to mitigate the resistance to calcitriol suppression of PTH associated with CKD progression, demonstrated survival benefits unrelated to the control of SHPT or skeletal health. The exhaustive search for the pathophysiology behind survival benefits associated with active vitamin D analogs has identified novel anti-inflammatory, anti-hypertensive, anti-aging actions of the vitamin D endocrine system. A major paradigm shift regarding the use of calcitriol or active vitamin D analogs to improve survival in CKD patients emerged upon demonstration of a high prevalence of vitamin D (not calcitriol) deficiency at all stages of CKD and, more significantly, that maintaining serum levels of the calcitriol precursor, 25(OH)vitamin D, above 23 ng/ml delayed CKD progression. The cause of vitamin D deficiency in CKD, however, is unclear since vitamin D bioactivation to 25(OH)D occurs mostly at the liver. Importantly, neither calcitriol nor its analogs can correct vitamin D deficiency. The goals of this chapter are to present our current understanding of the pathogenesis of vitamin D deficiency in CKD and of the causal link between defective vitamin D bioactivation to calcitriol and the onset of molecular pathways that promote CKD progression independently of the degree of SHPT. An understanding of these mechanisms will highlight the need for identification of novel sensitive biomarkers to assess the efficacy of interventions with vitamin D and/or calcitriol(analogs) to ameliorate CKD progression in a PTH-independent manner.
Collapse
Affiliation(s)
- Adriana S. Dusso
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Kevin T. Bauerle
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
- Department of Medicine, VA Medical Center, St. Louis, MO, United States
| | - Carlos Bernal-Mizrachi
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
- Department of Medicine, VA Medical Center, St. Louis, MO, United States
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, United States
| |
Collapse
|
7
|
Svajger BA, Pruss CM, Laverty KJ, Zelt JGE, Jones G, Kaufmann M, Petkovich M, Holden RM, Adams MA. PTH suppression by calcitriol does not predict off-target actions in experimental CKD. Pharmacol Res Perspect 2021; 8:e00605. [PMID: 32519465 PMCID: PMC7283992 DOI: 10.1002/prp2.605] [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: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 12/28/2022] Open
Abstract
Vitamin D receptor agonist (VDRA) therapy for PTH suppression is a mainstay for patients with severe CKD. Calcitriol (1,25‐(OH)2D3) is a former first‐line VDRA in CKD treatment. However, a consequence of its use in CKD is accelerated vascular calcification (VC). An experimental CKD model was used to determine whether altering the calcitriol delivery profile to obtain different PTH suppression levels could improve vascular health outcomes. High adenine diet (0.25%) was used to generate experimental CKD in rats. CKD rats were treated using different calcitriol dosing strategies: (a) 20 ng/kg SD (n = 8), (b) 80 ng/kg SD (n = 8), (c) 5 ng/kg QID (n = 9), or (d) 20 ng/kg QID (n = 9). Multiple targets of calcitriol were assessed which include arterial calcium and phosphate as well as circulating calcium, phosphate, PTH, FGF‐23, VWF, and vitamin D metabolome. PTH suppression occurred dose‐dependently after 1‐week calcitriol treatment (P < .01), but the suppressive effect was lost over time. Both VC and circulating FGF‐23 increased > 10× in all calcitriol‐treated rats (P < .05 and P < .001, respectively); similarly, circulating VWF increased at all time points (P < .05). Ad‐hoc analysis of CKD morbidities in treated rats indicated no differences in negative outcomes based on PTH suppression level (minimal‐, target‐, and over‐). Comparing different calcitriol dosing strategies revealed the following: (a) despite initial calcitriol‐influenced PTH suppression across all treatments, the ability to continually suppress PTH was markedly reduced by study conclusion and (b) PTH suppression level is not an adequate proxy for improvements in overall CKD morbidity. These findings show (a) a more holistic approach to evaluate CKD treatment efficacy aside from PTH suppression is needed and (b) that other VDRA therapies should be examined in CKD treatment.
Collapse
Affiliation(s)
- Bruno A Svajger
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Cynthia M Pruss
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Kimberly J Laverty
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Jason G E Zelt
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Molecular Function and Imaging Program, The National Cardiac PET Centre, and the Advanced Heart Disease Program, Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute and University of Ottawa, Ottawa, Ontario, Canada
| | - Glenville Jones
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Martin Kaufmann
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Martin Petkovich
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Rachel M Holden
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada.,Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Michael A Adams
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| |
Collapse
|
8
|
Carrillo-López N, Martínez-Arias L, Alonso-Montes C, Martín-Carro B, Martín-Vírgala J, Ruiz-Ortega M, Fernández-Martín JL, Dusso AS, Rodriguez-García M, Naves-Díaz M, Cannata-Andía JB, Panizo S. The receptor activator of nuclear factor κΒ ligand receptor leucine-rich repeat-containing G-protein-coupled receptor 4 contributes to parathyroid hormone-induced vascular calcification. Nephrol Dial Transplant 2021; 36:618-631. [PMID: 33367746 DOI: 10.1093/ndt/gfaa290] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/12/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND In chronic kidney disease, serum phosphorus (P) elevations stimulate parathyroid hormone (PTH) production, causing severe alterations in the bone-vasculature axis. PTH is the main regulator of the receptor activator of nuclear factor κB (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) system, which is essential for bone maintenance and also plays an important role in vascular smooth muscle cell (VSMC) calcification. The discovery of a new RANKL receptor, leucine-rich repeat-containing G-protein-coupled receptor 4 (LGR4), which is important for osteoblast differentiation but with an unknown role in vascular calcification (VC), led us to examine the contribution of LGR4 in high P/high PTH-driven VC. METHODS In vivo studies were conducted in subtotally nephrectomized rats fed a normal or high P diet, with and without parathyroidectomy (PTX). PTX rats were supplemented with PTH(1-34) to achieve physiological serum PTH levels. In vitro studies were performed in rat aortic VSMCs cultured in control medium, calcifying medium (CM) or CM plus 10-7 versus 10-9 M PTH. RESULTS Rats fed a high P diet had a significantly increased aortic calcium (Ca) content. Similarly, Ca deposition was higher in VSMCs exposed to CM. Both conditions were associated with increased RANKL and LGR4 and decreased OPG aorta expression and were exacerbated by high PTH. Silencing of LGR4 or parathyroid hormone receptor 1 (PTH1R) attenuated the high PTH-driven increases in Ca deposition. Furthermore, PTH1R silencing and pharmacological inhibition of protein kinase A (PKA), but not protein kinase C, prevented the increases in RANKL and LGR4 and decreased OPG. Treatment with PKA agonist corroborated that LGR4 regulation is a PTH/PKA-driven process. CONCLUSIONS High PTH increases LGR4 and RANKL and decreases OPG expression in the aorta, thereby favouring VC. The hormone's direct pro-calcifying actions involve PTH1R binding and PKA activation.
Collapse
Affiliation(s)
- Natalia Carrillo-López
- Bone and Mineral Research Unit, Hospital Universitario Central de Asturias, Instituto de Investigación Sanitaria del Principado de Asturias, REDinREN-ISCIII, Oviedo, Spain
| | - Laura Martínez-Arias
- Bone and Mineral Research Unit, Hospital Universitario Central de Asturias, Instituto de Investigación Sanitaria del Principado de Asturias, REDinREN-ISCIII, Oviedo, Spain
| | - Cristina Alonso-Montes
- Bone and Mineral Research Unit, Hospital Universitario Central de Asturias, Instituto de Investigación Sanitaria del Principado de Asturias, REDinREN-ISCIII, Oviedo, Spain
| | - Beatriz Martín-Carro
- Bone and Mineral Research Unit, Hospital Universitario Central de Asturias, Instituto de Investigación Sanitaria del Principado de Asturias, REDinREN-ISCIII, Oviedo, Spain
| | - Julia Martín-Vírgala
- Bone and Mineral Research Unit, Hospital Universitario Central de Asturias, Instituto de Investigación Sanitaria del Principado de Asturias, REDinREN-ISCIII, Oviedo, Spain
| | - Marta Ruiz-Ortega
- Vascular and Renal Laboratory Fundación Jimenez Díaz, Universidad Autónoma Madrid, REDinREN-ISCIII, Madrid, Spain
| | - José Luis Fernández-Martín
- Bone and Mineral Research Unit, Hospital Universitario Central de Asturias, Instituto de Investigación Sanitaria del Principado de Asturias, REDinREN-ISCIII, Oviedo, Spain
| | - Adriana S Dusso
- Bone and Mineral Research Unit, Hospital Universitario Central de Asturias, Instituto de Investigación Sanitaria del Principado de Asturias, REDinREN-ISCIII, Oviedo, Spain
| | - Minerva Rodriguez-García
- Bone and Mineral Research Unit, Hospital Universitario Central de Asturias, Instituto de Investigación Sanitaria del Principado de Asturias, REDinREN-ISCIII, Oviedo, Spain.,Departamento de Medicina, Universidad de Oviedo, Oviedo, Spain
| | - Manuel Naves-Díaz
- Bone and Mineral Research Unit, Hospital Universitario Central de Asturias, Instituto de Investigación Sanitaria del Principado de Asturias, REDinREN-ISCIII, Oviedo, Spain
| | - Jorge B Cannata-Andía
- Bone and Mineral Research Unit, Hospital Universitario Central de Asturias, Instituto de Investigación Sanitaria del Principado de Asturias, REDinREN-ISCIII, Oviedo, Spain.,Departamento de Medicina, Universidad de Oviedo, Oviedo, Spain
| | - Sara Panizo
- Bone and Mineral Research Unit, Hospital Universitario Central de Asturias, Instituto de Investigación Sanitaria del Principado de Asturias, REDinREN-ISCIII, Oviedo, Spain
| |
Collapse
|
9
|
Gonçalves JG, Canale D, de Bragança AC, Seguro AC, Shimizu MHM, Volpini RA. The Blockade of TACE-Dependent EGF Receptor Activation by Losartan-Erlotinib Combination Attenuates Renal Fibrosis Formation in 5/6-Nephrectomized Rats Under Vitamin D Deficiency. Front Med (Lausanne) 2021; 7:609158. [PMID: 33469545 PMCID: PMC7813781 DOI: 10.3389/fmed.2020.609158] [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: 09/22/2020] [Accepted: 12/03/2020] [Indexed: 11/23/2022] Open
Abstract
Chronic kidney disease (CKD) has been considered a major public health issue. In addition to cardiovascular diseases and infections, hypovitaminosis D has been considered a non-traditional aggravating factor for CKD progression. Interstitial fibrosis is a hallmark of CKD strongly correlated with deterioration of renal function. Transforming growth factor β (TGF-β) is the major regulatory profibrotic cytokine in CKD. Many injurious stimuli converge on the TGF-β pathway, which has context-dependent pleiotropic effects and interacts with several related renal fibrosis formation (RFF) pathways. Epidermal growth factor receptor (EGFR) is critically involved in CKD progression, exerting a pathogenic role in RFF associated with TGF-β-related fibrogenesis. Among others, EGFR pathway can be activated by a disintegrin and a metalloproteinase known as tumor necrosis factor α-converting enzyme (TACE). Currently no effective therapy is available to completely arrest RFF and slow the progression of CKD. Therefore, we investigated the effects of a double treatment with losartan potassium (L), an AT1R antagonist, and the tyrosine kinase inhibitor erlotinib (E) on the alternative pathway of RFF related to TACE-dependent EGFR activation in 5/6-nephrectomized rats under vitamin D deficiency (D). During the 90-day protocol, male Wistar rats under D, were submitted to 5/6 nephrectomy (N) on day 30 and randomized into four groups: N+D, no treatment; N+D+L, received losartan (50 mg/kg/day); N+D+E, received erlotinib (6 mg/kg/day); N+D+L+E received losartan+erlotinib treatment. N+D+L+E data demonstrated that the double treatment with losartan+erlotinib not only blocked the TACE-dependent EGF receptor activation but also prevented the expression of TGF-β, protecting against RFF. This renoprotection by losartan+erlotinib was corroborated by a lower expression of ECM proteins and markers of phenotypic alteration as well as a lesser inflammatory cell infiltrate. Although erlotinib alone has been emerging as a renoprotective drug, its association with losartan should be considered as a potential therapeutic strategy on the modulation of RFF.
Collapse
Affiliation(s)
- Janaína Garcia Gonçalves
- Laboratorio de Investigacao Medica 12, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Daniele Canale
- Laboratorio de Investigacao Medica 12, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Ana Carolina de Bragança
- Laboratorio de Investigacao Medica 12, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Antonio Carlos Seguro
- Laboratorio de Investigacao Medica 12, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | | | - Rildo Aparecido Volpini
- Laboratorio de Investigacao Medica 12, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| |
Collapse
|
10
|
Li X, Li J, Li Y, Wang H, Yang J, Mou S, Zhou M, Jiang C, Ning C. The role of preoperative ultrasound, contrast-enhanced ultrasound, and 99mTc-MIBI scanning with single-photon emission computed tomography/X-ray computed tomography localization in refractory secondary hyperparathyroidism. Clin Hemorheol Microcirc 2020; 75:35-46. [PMID: 31868660 DOI: 10.3233/ch-190723] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE The aim of our study was to evaluate the role of preoperative US, CEUS, and 99mTc-MIBI scanning with SPECT/CT in localizing diseased parathyroid glands in cases of refractory secondary hyperparathyroidism (SHPT). MATERIAL AND METHODS Using pathological results as the gold standard, we compared the operative findings with the preoperative localization of each modality in 73 nodules and evaluated the accuracy, and sensitivity of each modality and combinations of the four modalities. RESULTS The sensitivity of US, CEUS, 99mTc-MIBI and SPECT/CT was 98.59%, 94.37%, 50.70% and 78.87%, respectively. US had the highest sensitivity of the four imaging methods and the diagnostic sensitivity of US and CEUS was superior to that of 99mTc-MIBI (p < 0.001 and p < 0.001) and SPECT/CT (p = 0.001 and p = 0.012). In addition, we found that the sensitivity of the combination of US with CEUS, US with 99mTc-MIBI and/or SPECT/CT, CEUS with 99mTc-MIBI and/or SPECT/CT, US with CEUS and two other imaging modalities (99mTc-MIBI and/or SPECT/CT) was 98.59%, 100%, 95.77%, and 100%, respectively. CONCLUSIONS The combination of US with SPECT/CT is the best choice for the comprehensive preoperative localization of glands in refractory SHPT. CEUS can elevate the accuracy of US in differential diagnosis via the interpretation of dynamic microvascular features.
Collapse
Affiliation(s)
- XiuMei Li
- The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - Jun Li
- The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - Yong Li
- The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - HongQiao Wang
- The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - JingRu Yang
- The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - Shuang Mou
- The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - MaoPing Zhou
- The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - CaiYun Jiang
- The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - ChunPing Ning
- The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| |
Collapse
|
11
|
Naveh-Many T, Volovelsky O. Parathyroid Cell Proliferation in Secondary Hyperparathyroidism of Chronic Kidney Disease. Int J Mol Sci 2020; 21:ijms21124332. [PMID: 32570711 PMCID: PMC7352987 DOI: 10.3390/ijms21124332] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 06/14/2020] [Accepted: 06/15/2020] [Indexed: 12/12/2022] Open
Abstract
Secondary hyperparathyroidism (SHP) is a common complication of chronic kidney disease (CKD) that correlates with morbidity and mortality in uremic patients. It is characterized by high serum parathyroid hormone (PTH) levels and impaired bone and mineral metabolism. The main mechanisms underlying SHP are increased PTH biosynthesis and secretion as well as increased glandular mass. The mechanisms leading to parathyroid cell proliferation in SHP are not fully understood. Reduced expressions of the receptors for calcium and vitamin D contribute to the disinhibition of parathyroid cell proliferation. Activation of transforming growth factor-α-epidermal growth factor receptor (TGF-α-EGFR), nuclear factor kappa B (NF-kB), and cyclooxygenase 2- prostaglandin E2 (Cox2-PGE2) signaling all correlate with parathyroid cell proliferation, underlining their roles in the development of SHP. In addition, the mammalian target of rapamycin (mTOR) pathway is activated in parathyroid glands of experimental SHP rats. Inhibition of mTOR by rapamycin prevents and corrects the increased parathyroid cell proliferation of SHP. Mice with parathyroid-specific deletion of all miRNAs have a muted increase in serum PTH and fail to increase parathyroid cell proliferation when challenged by CKD, suggesting that miRNA is also necessary for the development of SHP. This review summarizes the current knowledge on the mechanisms of parathyroid cell proliferation in SHP.
Collapse
Affiliation(s)
- Tally Naveh-Many
- Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah Hebrew University Medical Center, Jerusalem 91120, Israel;
- The Wohl Institute for Translational Medicine, Hadassah Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Oded Volovelsky
- The Wohl Institute for Translational Medicine, Hadassah Hebrew University Medical Center, Jerusalem 91120, Israel
- Pediatric Nephrology Unit and Research Lab, Hadassah Hebrew University Medical Center, Jerusalem 91120, Israel
- Correspondence: ; Tel.: +972-26777213
| |
Collapse
|
12
|
Zhang Q, Li S, Ye G, Wang M, Ni L, Kan S, Zhang M, Chen J. Prostaglandin E2 receptor EP2 mediates the effect of cyclooxygenase 2 on secondary parathyroid hyperplasia in end-stage renal disease. Nephrol Dial Transplant 2020; 34:606-617. [PMID: 29982796 DOI: 10.1093/ndt/gfy194] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Secondary hyperparathyroidism (SHPT) in patients with end-stage renal disease (ESRD) is characterized by hyperplasia of the parathyroid glands (PTGs), while the underlying mechanism is not completely understood. Previously we demonstrated a relationship between cyclooxygenase 2 (COX2) overexpression and parathyroid hyperplasia and here we investigate the role of COX2 downstream metabolic product prostaglandin E2 (PGE2) and its receptor EP2 in the pathogenesis of SHPT. METHODS PTGs isolated from ESRD patients with advanced SHPT were used to test the expression of COX2-microsomal prostaglandin E synthase-1 (mPGES-1)-EP2 pathway. A diffuse proliferative section of the PTGs was used for tissue culture and treated with high phosphate (HPi) medium, COX2-PGE2-EP2 pathway inhibitors or agonists. EP2 short hairpin RNA (shRNA) lentivirus was locally applied to treat an SHPT rat model. RESULTS In PTGs isolated from ESRD patients, enhanced immunoactivities of COX2, mPGES-1 and EP2 were observed. In primary cultured PTG tissues, HPi induced intact parathyroid hormone (iPTH) secretion, proliferating cell nuclear antigen (PCNA) expression and COX2 activity, while COX2 and EP2 inhibitors attenuated hyperparathyroidism promoted by HPi. Furthermore, PGE2 or EP2 agonist (butaprost) directly stimulated hyperparathyroidism, whereas EP2 receptor antagonist or cyclic adenosine monophosphate inhibitor attenuated the hyperparathyroidism promoted by PGE2 or butaprost. EP2 shRNA treatment significantly reduced excessive expressions of EP2 and PCNA in the PTGs of nephrectomy rats fed an HPi diet, diminished the size of PTGs and downregulated serum iPTH levels. CONCLUSIONS The COX2 downstream PGE2 and its receptor EP2 may play an important role in HPi-induced parathyroid hyperplasia and may serve as a potential therapeutic target for SHPT in ESRD.
Collapse
Affiliation(s)
- Qian Zhang
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Shensen Li
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Guoxin Ye
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Mengjing Wang
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Li Ni
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Sen Kan
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Minmin Zhang
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jing Chen
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| |
Collapse
|
13
|
Singh A, Mia MM, Cibi DM, Arya AK, Bhadada SK, Singh MK. Deficiency in the secreted protein Semaphorin3d causes abnormal parathyroid development in mice. J Biol Chem 2019; 294:8336-8347. [PMID: 30979723 DOI: 10.1074/jbc.ra118.007063] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 04/09/2019] [Indexed: 12/31/2022] Open
Abstract
Primary hyperparathyroidism (PHPT) is a common endocrinopathy characterized by hypercalcemia and elevated levels of parathyroid hormone. The primary cause of PHPT is a benign overgrowth of parathyroid tissue causing excessive secretion of parathyroid hormone. However, the molecular etiology of PHPT is incompletely defined. Here, we demonstrate that semaphorin3d (Sema3d), a secreted glycoprotein, is expressed in the developing parathyroid gland in mice. We also observed that genetic deletion of Sema3d leads to parathyroid hyperplasia, causing PHPT. In vivo and in vitro experiments using histology, immunohistochemistry, biochemical, RT-qPCR, and immunoblotting assays revealed that Sema3d inhibits parathyroid cell proliferation by decreasing the epidermal growth factor receptor (EGFR)/Erb-B2 receptor tyrosine kinase (ERBB) signaling pathway. We further demonstrate that EGFR signaling is elevated in Sema3d -/- parathyroid glands and that pharmacological inhibition of EGFR signaling can partially rescue the parathyroid hyperplasia phenotype. We propose that because Sema3d is a secreted protein, it may be possible to use recombinant Sema3d or derived peptides to inhibit parathyroid cell proliferation causing hyperplasia and hyperparathyroidism. Collectively, these findings identify Sema3d as a negative regulator of parathyroid growth.
Collapse
Affiliation(s)
- Anamika Singh
- Program in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore 169857
| | - Masum M Mia
- Program in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore 169857
| | - Dasan Mary Cibi
- Program in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore 169857
| | - Ashutosh Kumar Arya
- Department of Endocrinology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh 160012, India
| | - Sanjay Kumar Bhadada
- Department of Endocrinology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh 160012, India
| | - Manvendra K Singh
- Program in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore 169857; National Heart Research Institute Singapore, National Heart Center Singapore, Singapore 169609.
| |
Collapse
|
14
|
Mizobuchi M, Ogata H, Koiwa F. Secondary Hyperparathyroidism: Pathogenesis and Latest Treatment. Ther Apher Dial 2018; 23:309-318. [PMID: 30411503 DOI: 10.1111/1744-9987.12772] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/23/2018] [Accepted: 11/02/2018] [Indexed: 01/02/2023]
Abstract
The classic pathogenesis of secondary hyperparathyroidism (SHPT) began with the trade-off hypothesis based on parathyroid hormone hypersecretion brought about by renal failure resulting from a physiological response to correct metabolic disorder of calcium, phosphorus, and vitamin D. In dialysis patients with failed renal function, physiological mineral balance control by parathyroid hormone through the kidney fails and hyperparathyroidism progresses. In this process, many significant genetic findings have been established. Abnormalities of Ca-sensing receptor and vitamin D receptor are associated with the pathogenesis of SHPT, and fibroblast growth factor 23 has also been shown to be involved in the pathogenesis. Vitamin D receptor activators (VDRAs) are widely used for treatment of SHPT. However, VDRAs have calcemic and phosphatemic effects that limit their use to a subset of patients, and calcimimetics have been developed as alternative drugs for SHPT. Hyperphosphatemia also affects progression of SHPT, and control of hyperphosphatemia is, therefore, thought to be fundamental for control of SHPT. Currently, a combination of a VDRA and a calcimimetic is recognized as the optimal strategy for SHPT, and for other outcomes such as reduced cardiovascular disease and improved survival. The latest findings on the pathogenesis and treatment of SHPT are summarized in this review.
Collapse
Affiliation(s)
- Masahide Mizobuchi
- Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan
| | - Hiroaki Ogata
- Department of Medicine, Showa University Northern Yokohama Hospital, Yokohama, Japan
| | - Fumihiko Koiwa
- Division of Nephrology, Department of Medicine, Showa University Fujigaoka Hospital, Yokohama, Japan
| |
Collapse
|
15
|
Kan S, Zhang W, Mao J, Wang M, Ni L, Zhang M, Zhang Q, Chen J. NF-κB activation contributes to parathyroid cell proliferation in chronic kidney disease. J Nephrol 2018; 31:941-951. [DOI: 10.1007/s40620-018-0530-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 05/26/2018] [Indexed: 12/20/2022]
|
16
|
Cozzolino M, Pasho S, Fallabrino G, Olivi L, Gallieni M, Brancaccio D. Pathogenesis of Secondary Hyperparathyroidism. Int J Artif Organs 2018; 32:75-80. [DOI: 10.1177/039139880903200203] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Chronic renal failure is the primary cause of secondary hyperparathyroidism (SHPT). Patients with mineral metabolism disorders commonly present with low serum calcium levels, hyperphosphatemia, and calcitriol deficiency. In normal renal function subjects, parathyroid cells have a low turnover and rarely undergo mitoses. In uremic conditions, however, parathyroid glands become hyperplasic and leave quiescence. During the last ten years, new molecular mechanisms have been investigated to better understand the pathogenesis of SHPT: the emerging role of the Calcium Sensing Receptor (CaSR); the importance of the parathyroid expression of the Vitamin D receptor (VDR); the growing evidence on the central role of the Fibroblast Growth Factor 23 (FGF-23). In contrast, the discovery of a parathyroid phosphate sensor or receptor has yet to be made.
Collapse
Affiliation(s)
- Mario Cozzolino
- Renal Division, San Paolo Hospital, University of Milan, Milan - Italy
| | - Sabina Pasho
- Renal Division, San Paolo Hospital, University of Milan, Milan - Italy
| | | | - Laura Olivi
- Renal Division, San Paolo Hospital, University of Milan, Milan - Italy
| | - Maurizio Gallieni
- Renal Division, San Paolo Hospital, University of Milan, Milan - Italy
| | - Diego Brancaccio
- Renal Division, San Paolo Hospital, University of Milan, Milan - Italy
| |
Collapse
|
17
|
Týcová I, Sulková SD, Štěpánková J, Krejčík Z, Merkerová MD, Stránecký V, Hrubá P, Girmanová E, Černoch M, Lipár K, Marada T, Povýšil C, Viklický O. Molecular patterns of diffuse and nodular parathyroid hyperplasia in long-term hemodialysis. Am J Physiol Endocrinol Metab 2016; 311:E720-E729. [PMID: 27600827 DOI: 10.1152/ajpendo.00517.2015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 08/21/2016] [Indexed: 01/08/2023]
Abstract
Secondary hyperparathyroidism is a well-known complication of end-stage renal disease (ESRD). Both nodular and diffuse parathyroid hyperplasia occur in ESRD patients. However, their distinct molecular mechanisms remain poorly understood. Parathyroid tissue obtained from ESRD patients who had undergone parathyroidectomy was used for Illumina transcriptome screening and subsequently for discriminatory gene analysis, pathway mapping, and gene annotation enrichment analysis. Results were further validated using quantitative RT-PCR on the independent larger cohort. Microarray screening proved homogeneity of gene transcripts in hemodialysis patients compared with the transplant cohort and primary hyperparathyroidism; therefore, further experiments were performed in hemodialysis patients only. Enrichment analysis conducted on 485 differentially expressed genes between nodular and diffuse parathyroid hyperplasia revealed highly significant differences in Gene Ontology terms and the Kyoto Encyclopedia of Genes and Genomes database in ribosome structure (P = 3.70 × 10-18). Next, quantitative RT-PCR validation of the top differently expressed genes from microarray analysis proved higher expression of RAN guanine nucleotide release factor (RANGRF; P < 0.001), calcyclin-binding protein (CACYBP; P < 0.05), and exocyst complex component 8 (EXOC8; P < 0.05) and lower expression of peptidylprolyl cis/trans-isomerase and NIMA-interacting 1 (PIN1; P < 0.01) mRNA in nodular hyperplasia. Multivariate analysis revealed higher RANGRF and lower PIN1 expression along with parathyroid weight to be associated with nodular hyperplasia. In conclusion, our study suggests the RANGRF transcript, which controls RNA metabolism, to be likely involved in pathways associated with the switch to nodular parathyroid growth. This transcript, along with PIN1 transcript, which influences parathyroid hormone secretion, may represent new therapeutical targets to cure secondary hyperparathyroidism.
Collapse
Affiliation(s)
- Irena Týcová
- Transplant Laboratory, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Sylvie Dusilová Sulková
- Department of Nephrology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic; Hemodialysis Centre, University Hospital, Hradec Králové, Czech Republic
| | - Jitka Štěpánková
- Department of Nephrology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Zdeněk Krejčík
- Institute of Hematology and Blood Transfusion, Prague, Czech Republic
| | | | - Viktor Stránecký
- Institute of Inherited Metabolic Disorders, Charles University and 1st School of Medicine and General University Hospital, Prague, Czech Republic
| | - Petra Hrubá
- Transplant Laboratory, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Eva Girmanová
- Transplant Laboratory, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Marek Černoch
- Transplant Laboratory, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Květoslav Lipár
- Transplant Surgery Department, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Tomáš Marada
- Transplant Surgery Department, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Ctibor Povýšil
- Department of Pathology, Charles University and 1st School of Medicine and General University Hospital, Prague, Czech Republic; and
| | - Ondřej Viklický
- Transplant Laboratory, Institute for Clinical and Experimental Medicine, Prague, Czech Republic; Department of Nephrology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic;
| |
Collapse
|
18
|
Selagea L, Mishra A, Anand M, Ross J, Tucker-Burden C, Kong J, Brat DJ. EGFR and C/EBP-β oncogenic signaling is bidirectional in human glioma and varies with the C/EBP-β isoform. FASEB J 2016; 30:4098-4108. [PMID: 27572958 DOI: 10.1096/fj.201600550r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/15/2016] [Indexed: 01/06/2023]
Abstract
We investigated the intersection of epidermal growth factor receptor (EGFR) and CCAAT enhancer binding protein (C/EBP)-β signaling in glioblastoma (GBM), given that both gene products strongly influence neoplastic behavior. C/EBP-β is known to drive the mesenchymal transcriptional signature in GBM, likely through strong microenvironmental influences, whereas the genetic contributions to its up-regulation in this disease are not well described. We demonstrated that stable overexpression and activation of WT EGFR (U87MG-WT) led to elevated C/EBP-β expression, as well as enhanced nuclear translocation and DNA-binding activity, leading to up-regulation of C/EBP-β transcription and translation. Deeper investigation identified bidirectional regulation, with C/EBP-β also causing up-regulation of EGFR that was at least partially dependent on the STAT3. Based on ChIP-based studies, we also found that that the translational isoforms of C/EBP-β [liver-enriched transcription-activating protein (LAP)-1/2 and liver inhibitory protein (LIP)] have differential occupancy on STAT3 promoter and opposing roles in transcriptional regulation of STAT3 and EGFR. We further demonstrated that the shorter C/EBP-β isoform, LIP, promoted proliferation and migration of U87MG glioma cells, potentially via induction of cytokine IL-6. Our molecular dissection of EGFR and C/EBP-β pathway interactions uncovered a complex signaling network in which increased activity of either EGFR or C/EBP-β leads to the up-regulation of the other, enhancing oncogenic signaling. Disrupting the EGFR-C/EBP-β signaling axis could attenuate malignant behavior of glioblastoma.-Selagea, L., Mishra, A., Anand, M., Ross, J., Tucker-Burden, C., Kong, J., Brat, D. J. EGFR and C/EBP-β oncogenic signaling is bidirectional in human glioma and varies with the C/EBP-β isoform.
Collapse
Affiliation(s)
- Ligia Selagea
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia.,Department of Biology, Agnes Scott College, Decatur, Georgia
| | - Alok Mishra
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia
| | - Monika Anand
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia
| | - James Ross
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia.,Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, Georgia; and
| | - Carol Tucker-Burden
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia
| | - Jun Kong
- Department of Biomedical Informatics, Winship Cancer Institute, Emory University, Atlanta, Georgia
| | - Daniel J Brat
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia; .,Department of Biomedical Informatics, Winship Cancer Institute, Emory University, Atlanta, Georgia
| |
Collapse
|
19
|
Zand L, Kumar R. Serum Parathyroid Hormone Concentrations and Clinical Outcomes in ESRD: A Call for Targeted Clinical Trials. Semin Dial 2015; 29:184-8. [PMID: 26676210 DOI: 10.1111/sdi.12457] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Secondary hyperparathyroidism almost universally accompanies end-stage renal disease (ESRD). In some, but not all studies, elevated serum parathyroid hormone (PTH) concentrations are associated with increased fracture rates, cardiovascular disease, and mortality in ESRD. The serum concentration of PTH required for optimal bone health and reduced cardiovascular risk in such patients remains elusive. Recent clinical trials have failed to show substantial changes in morbidity and mortality following reductions of elevated serum PTH concentrations. In this review, we will assess some of the difficulties in evaluating elevated serum PTH concentrations, and their association with skeletal fractures and mortality in ESRD patients. We are of the opinion that in the context of ESRD, elevated PTH concentrations occur in conjunction with other comorbid conditions such as diabetes mellitus, malnutrition, hypertension, volume excess, preexisting heart disease, all of which have prevented establishing a precise association between elevated serum PTH concentrations and global or skeletal outcomes. Age, gender, and racial variability among groups make interpretation exceptionally difficult. Analysis of prevalent ESRD populations with secondary hyperparathyroidism should take all these factors into account. We suggest that future clinical trials which examine the usefulness of reductions in serum PTH concentrations be conducted in age, sex, and racially balanced groups, without or with minimal coexisting confounding disease. Furthermore, trials in such populations should have as their primary outcome a reduction in fractures rather than an alteration in mortality.
Collapse
Affiliation(s)
- Ladan Zand
- Division of Nephrology and Hypertension, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota
| | - Rajiv Kumar
- Division of Nephrology and Hypertension, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota.,Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota
| |
Collapse
|
20
|
Volovelsky O, Cohen G, Kenig A, Wasserman G, Dreazen A, Meyuhas O, Silver J, Naveh-Many T. Phosphorylation of Ribosomal Protein S6 Mediates Mammalian Target of Rapamycin Complex 1-Induced Parathyroid Cell Proliferation in Secondary Hyperparathyroidism. J Am Soc Nephrol 2015; 27:1091-101. [PMID: 26283674 DOI: 10.1681/asn.2015040339] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 06/30/2015] [Indexed: 01/03/2023] Open
Abstract
Secondary hyperparathyroidism is characterized by increased serum parathyroid hormone (PTH) level and parathyroid cell proliferation. However, the molecular pathways mediating the increased parathyroid cell proliferation remain undefined. Here, we found that the mTOR pathway was activated in the parathyroid of rats with secondary hyperparathyroidism induced by either chronic hypocalcemia or uremia, which was measured by increased phosphorylation of ribosomal protein S6 (rpS6), a downstream target of the mTOR pathway. This activation correlated with increased parathyroid cell proliferation. Inhibition of mTOR complex 1 by rapamycin decreased or prevented parathyroid cell proliferation in secondary hyperparathyroidism rats and in vitro in uremic rat parathyroid glands in organ culture. Knockin rpS6(p-/-) mice, in which rpS6 cannot be phosphorylated because of substitution of all five phosphorylatable serines with alanines, had impaired PTH secretion after experimental uremia- or folic acid-induced AKI. Uremic rpS6(p-/-) mice had no increase in parathyroid cell proliferation compared with a marked increase in uremic wild-type mice. These results underscore the importance of mTOR activation and rpS6 phosphorylation for the pathogenesis of secondary hyperparathyroidism and indicate that mTORC1 is a significant regulator of parathyroid cell proliferation through rpS6.
Collapse
Affiliation(s)
- Oded Volovelsky
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Gili Cohen
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Ariel Kenig
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Gilad Wasserman
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Avigail Dreazen
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Oded Meyuhas
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Justin Silver
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Tally Naveh-Many
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| |
Collapse
|
21
|
Goto S, Komaba H, Fukagawa M. Pathophysiology of parathyroid hyperplasia in chronic kidney disease: preclinical and clinical basis for parathyroid intervention. NDT Plus 2015; 1:iii2-iii8. [PMID: 25983967 PMCID: PMC4421132 DOI: 10.1093/ndtplus/sfn079] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2008] [Accepted: 03/14/2008] [Indexed: 01/15/2023] Open
Abstract
Secondary hyperparathyroidism is characterised by excessive secretion of parathyroid hormone and parathyroid hyperplasia, resulting in both skeletal and extraskeletal consequences. Recent basic and clinical studies have brought considerable advances in our understanding of the pathophysiology of parathyroid hyperplasia and have also provided practical therapeutic approaches, especially with regard to indications for parathyroid intervention. In this context, it is quite important to recognize the development of nodular hyperplasia, because the cells in nodular hyperplasia are usually resistant to calcitriol treatment. Patients with nodular hyperplasia should undergo parathyroid intervention including percutaneous ethanol injection therapy (PEIT). Selective PEIT of the parathyroid gland is an effective approach in which the enlarged parathyroid gland with nodular hyperplasia is 'selectively' destroyed by ethanol injection, and other glands with diffuse hyperplasia are then managed by medical therapy. With a more focused attention to applying parathyroid intervention, we can expect significant improvement in the management of secondary hyperparathyroidism in dialysis patients.
Collapse
Affiliation(s)
- Shunsuke Goto
- Division of Nephrology and Kidney Center , Kobe University School of Medicine , Kobe 650-0017 , Japan
| | - Hirotaka Komaba
- Division of Nephrology and Kidney Center , Kobe University School of Medicine , Kobe 650-0017 , Japan
| | - Masafumi Fukagawa
- Division of Nephrology and Kidney Center , Kobe University School of Medicine , Kobe 650-0017 , Japan
| |
Collapse
|
22
|
Paydas S, Acikalim A, Kaya B, Bicer BH, Ulker M, Demircan O, Uguz A, Balal M, Sakman G, Sertdemir Y, Karaer R, Altun E. Expression of p53, Ki67, epidermal growth factor receptor, transforming growth-factorα, and p21 in primary and secondary hyperparathyroidism. Indian J Endocrinol Metab 2014; 18:826-830. [PMID: 25364678 PMCID: PMC4192989 DOI: 10.4103/2230-8210.140265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Secondary hyperparathyroidism (SH) is major problem in chronic renal failure. There are studies to examine proliferation and apoptosis associated biomarkers expressions in parathyroid lesions to reveal specific features. In this study, we evaluated the expression of some growth factors and their receptors in parathyroid gland of patients with SH or primary hyperparathyroidism (PH). MATERIALS AND METHODS A total of 49 patients had been operated for PH and 26 for SH. Parathyroid tissue samples were evaluated histopathologically and immunohistochemically using antibodies to human p53, Kİ-67, anti-human p21, antitransforming growth factor (TGF) α, CPP32 (caspase 3), and epidermal growth factor receptor (EGFR). RESULTS Adenoma was higher in PH compared with SH as 48/49 and 3/26, respectively (P = 0.000). Parathyroid hyperplasia was found in 23/26 patients with SH and 1/49 patient with PH. In parathyroid tissue there were no difference between PH and SH for p53, Ki-67, caspase, EGFR expressions; while there were significantly difference for TGFα (P = 0.047) and borderline significant difference for p21 (P = 0.06) expressions. CONCLUSION Adenoma was priority present in PH patients, hyperplasia was present in SH. There were no differences between primary and SH or adenoma and hyperplasia for expressions of cycline-dependent kinase inhibitor p21, p53, EGFR, Ki67, caspase; while TGFα expression was found to be different.
Collapse
Affiliation(s)
- Saime Paydas
- Department of Nephrology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Arbil Acikalim
- Department of Pathology and General Surgery, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Bulent Kaya
- Department of Nephrology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Bermal Hasbay Bicer
- Department of Pathology and General Surgery, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Mehmet Ulker
- Department of Nephrology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Orhan Demircan
- Department of Nephrology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Aysun Uguz
- Department of Pathology and General Surgery, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Mustafa Balal
- Department of Nephrology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Gurhan Sakman
- Department of Nephrology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Yasar Sertdemir
- Department of Biostatistics, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Refika Karaer
- Department of Nephrology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Eda Altun
- Department of Nephrology, Faculty of Medicine, Cukurova University, Adana, Turkey
| |
Collapse
|
23
|
Arcidiacono MV, Yang J, Fernandez E, Dusso A. Parathyroid-specific epidermal growth factor-receptor inactivation prevents uremia-induced parathyroid hyperplasia in mice. Nephrol Dial Transplant 2014; 30:434-40. [PMID: 25324357 DOI: 10.1093/ndt/gfu318] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND In chronic kidney disease (CKD), parathyroid hyperplasia contributes to high serum parathyroid hormone (PTH) and also to an impaired suppression of secondary hyperparathyroidism by calcium, vitamin D and fibroblast growth factor 23 (FGF23). In rats, systemic inhibition of epidermal growth factor receptor (EGFR) activation markedly attenuated uremia-induced parathyroid hyperplasia and vitamin D receptor (VDR) loss, hence restoring the response to vitamin D. Therefore, we propose that parathyroid-specific EGFR inactivation should prevent CKD-induced parathyroid hyperplasia. METHODS A dominant-negative human EGFR mutant, which forms non-functional heterodimers with full-length endogenous EGFR, was successfully targeted to the parathyroid glands (PTGs) of FVB/N mice, using the 5' regulatory sequence of the PTH promoter. The parathyroid phenotype and serum chemistries of wild-type (WT) and transgenic mice were examined after 14 weeks of either sham operation or 75% renal mass reduction (NX). RESULTS Both genotypes had similar morphology and body weight, and NX-induction enhanced similarly serum blood urea nitrogen compared with sham-operated controls. However, despite similar serum calcium, phosphate and FGF23 levels in NX mice of both genotypes, parathyroid EGFR inactivation sufficed to completely prevent the marked increases in PTG enlargement, serum PTH and in parathyroid levels of transforming growth factor-α, a powerful EGFR-activator, and the VDR reductions observed in WT mice. CONCLUSION In CKD, parathyroid EGFR activation is essential for parathyroid hyperplasia and VDR loss, rendering this transgenic mouse a unique tool to scrutinize the pathogenesis of parathyroid and multiple organ dysfunction of CKD progression unrelated to parathyroid hyperplasia.
Collapse
Affiliation(s)
- Maria Vittoria Arcidiacono
- Renal Division, Washington University School of Medicine, St. Louis, MO, USA Division of Experimental Nephrology, IRB Lleida, Lleida, Spain Renal Division, Hospital Universitari Arnau de Vilanova, Universidad de Lleida, Lleida, Spain
| | - Jing Yang
- Renal Division, Washington University School of Medicine, St. Louis, MO, USA
| | - Elvira Fernandez
- Division of Experimental Nephrology, IRB Lleida, Lleida, Spain Renal Division, Hospital Universitari Arnau de Vilanova, Universidad de Lleida, Lleida, Spain
| | - Adriana Dusso
- Renal Division, Washington University School of Medicine, St. Louis, MO, USA Division of Experimental Nephrology, IRB Lleida, Lleida, Spain Renal Division, Hospital Universitari Arnau de Vilanova, Universidad de Lleida, Lleida, Spain
| |
Collapse
|
24
|
Arcidiacono MV, Yang J, Fernandez E, Dusso A. The induction of C/EBPβ contributes to vitamin D inhibition of ADAM17 expression and parathyroid hyperplasia in kidney disease. Nephrol Dial Transplant 2014; 30:423-33. [PMID: 25294851 DOI: 10.1093/ndt/gfu311] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND In secondary hyperparathyroidism (SHPT), enhanced parathyroid levels of transforming growth factor-α (TGFα) increase EGF receptor (EGFR) activation causing parathyroid hyperplasia, high parathyroid hormone (PTH) and also reductions in vitamin D receptor (VDR) that limit vitamin D suppression of SHPT. Since anti-EGFR therapy is not an option in human SHPT, we evaluated ADAM17 as a therapeutic target to suppress parathyroid hyperplasia because ADAM17 is required to release mature TGFα, the most potent EGFR-activating ligand. METHODS Computer analysis of the ADAM17 promoter identified TGFα and C/EBPβ as potential regulators of the ADAM17 gene. Their regulation of ADAM17 expression, TGFα/EGFR-driven growth and parathyroid gland (PTG) enlargement were assessed in promoter-reporter assays in A431 cells and corroborated in rat and human SHPT, using erlotinib as anti-EGFR therapy to suppress TGFα signals, active vitamin D to induce C/EBPβ or the combination. RESULTS While TGFα induced ADAM17-promoter activity by 2.2-fold exacerbating TGFα/EGFR-driven growth, ectopic C/EBPβ expression completely prevented this vicious synergy. Accordingly, in advanced human SHPT, parathyroid ADAM17 levels correlated directly with TGFα and inversely with C/EBPβ. Furthermore, combined erlotinib + calcitriol treatment suppressed TGFα/EGFR-cell growth and PTG enlargement more potently than erlotinib in part through calcitriol induction of C/EBPβ to inhibit ADAM17-promoter activity, mRNA and protein. Importantly, in rat SHPT, the correction of vitamin D deficiency effectively reversed the resistance to paricalcitol induction of C/EBPβ to suppress ADAM17 expression and PTG enlargement, reducing PTH by 50%. CONCLUSION In SHPT, correction of vitamin D and calcitriol deficiency induces parathyroid C/EBPβ to efficaciously attenuate the severe ADAM17/TGFα synergy, which drives PTG enlargement and high PTH.
Collapse
Affiliation(s)
- Maria Vittoria Arcidiacono
- Renal Division, Washington University School of Medicine, St. Louis, MO, USA Division of Experimental Nephrology, IRB Lleida, Lleida, Spain
| | - Jing Yang
- Renal Division, Washington University School of Medicine, St. Louis, MO, USA
| | - Elvira Fernandez
- Division of Experimental Nephrology, IRB Lleida, Lleida, Spain Renal Division, Hospital Universitari Arnau de Vilanova, Universidad de Lleida, Lleida, Spain
| | - Adriana Dusso
- Renal Division, Washington University School of Medicine, St. Louis, MO, USA Division of Experimental Nephrology, IRB Lleida, Lleida, Spain
| |
Collapse
|
25
|
The parathyroid glands. Mol Oncol 2013. [DOI: 10.1017/cbo9781139046947.066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
26
|
de Brito Galvao JF, Nagode LA, Schenck PA, Chew DJ. Calcitriol, calcidiol, parathyroid hormone, and fibroblast growth factor-23 interactions in chronic kidney disease. J Vet Emerg Crit Care (San Antonio) 2013; 23:134-62. [PMID: 23566108 PMCID: PMC3677418 DOI: 10.1111/vec.12036] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2012] [Accepted: 02/05/2013] [Indexed: 12/13/2022]
Abstract
Objective To review the inter-relationships between calcium, phosphorus, parathyroid hormone (PTH), parent and activated vitamin D metabolites (vitamin D, 25(OH)-vitamin D, 1,25(OH)2-vitamin D, 24,25(OH)2-vitamin D), and fibroblast growth factor-23 (FGF-23) during chronic kidney disease (CKD) in dogs and cats. Data Sources Human and veterinary literature. Human Data Synthesis Beneficial effects of calcitriol treatment during CKD have traditionally been attributed to regulation of PTH but new perspectives emphasize direct renoprotective actions independent of PTH and calcium. It is now apparent that calcitriol exerts an important effect on renal tubular reclamation of filtered 25(OH)-vitamin D, which may be important in maintaining adequate circulating 25(OH)-vitamin D. This in turn may be vital for important pleiotropic actions in peripheral tissues through autocrine/paracrine mechanisms that impact the health of those local tissues. Veterinary Data Synthesis Limited information is available reporting the benefit of calcitriol treatment in dogs and cats with CKD. Conclusions A survival benefit has been shown for dogs with CKD treated with calcitriol compared to placebo. The concentrations of circulating 25(OH)-vitamin D have recently been shown to be low in people and dogs with CKD and are related to survival in people with CKD. Combination therapy for people with CKD using both parental and activated vitamin D compounds is common in human nephrology and there is a developing emphasis using combination treatment with activated vitamin D and renin-angiotensin-aldosterone-system (RAAS) inhibitors.
Collapse
|
27
|
Drüeke TB, Olgaard K. Report on 2012 ISN Nexus Symposium: ‘Bone and the Kidney’. Kidney Int 2013; 83:557-62. [DOI: 10.1038/ki.2012.453] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
28
|
Zhao Y, Natarajan V. Lysophosphatidic acid (LPA) and its receptors: role in airway inflammation and remodeling. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1831:86-92. [PMID: 22809994 DOI: 10.1016/j.bbalip.2012.06.014] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 06/27/2012] [Accepted: 06/29/2012] [Indexed: 12/14/2022]
Abstract
Lysophosphatidic acid (LPA), a simple bioactive phospholipid, is present in biological fluids such as plasma and bronchoalveolar lavage (BAL). It appears to have both pro- and anti-inflammatory roles in inflammatory lung diseases. Exogenous LPA promotes inflammatory responses by regulating the expression of chemokines, cytokines, and cytokine receptors in lung epithelial cells. In addition to the modulation of inflammatory responses, LPA regulates cytoskeleton rearrangement and confers protection against lung injury by enhancing lung epithelial cell barrier integrity and remodeling. The biological effects of LPA are mediated through its cell surface G-protein coupled LPA(1-7) receptors. The roles of LPA receptors in lung fibrosis, asthma, and acute lung injury have been investigated using genetically engineered LPA receptor deficient mice and there appears to be a definitive role for endogenous LPA and its receptors in the pathogenesis of pulmonary inflammatory diseases. This review summarizes recent reports on the role of LPA and its receptors in the regulation of lung epithelial inflammatory responses and remodeling. This article is part of a Special Issue entitled: Advances in Lysophospholipid Research.
Collapse
Affiliation(s)
- Yutong Zhao
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | | |
Collapse
|
29
|
Komaba H, Kakuta T, Fukagawa M. Diseases of the parathyroid gland in chronic kidney disease. Clin Exp Nephrol 2011; 15:797-809. [DOI: 10.1007/s10157-011-0502-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2011] [Accepted: 07/08/2011] [Indexed: 12/31/2022]
|
30
|
Lisse TS, Hewison M, Adams JS. Hormone response element binding proteins: novel regulators of vitamin D and estrogen signaling. Steroids 2011; 76:331-9. [PMID: 21236284 PMCID: PMC3042887 DOI: 10.1016/j.steroids.2011.01.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 01/04/2011] [Accepted: 01/05/2011] [Indexed: 01/11/2023]
Abstract
Insights from vitamin D-resistant New World primates and their human homologues as models of natural and pathological insensitivity to sterol/steroid action have uncovered a family of novel intracellular vitamin D and estrogen regulatory proteins involved in hormone action. The proteins, known as "vitamin D or estrogen response element-binding proteins", behave as potent cis-acting, transdominant regulators to inhibit steroid receptor binding to DNA response elements and is responsible for vitamin D and estrogen resistances. This set of interactors belongs to the heterogeneous nuclear ribonucleoprotein (hnRNP) family of previously known pre-mRNA-interacting proteins. This review provides new insights into the mechanism by which these novel regulators of signaling and metabolism can act to regulate responses to vitamin D and estrogen. In addition the review also describes other molecules that are known to influence nuclear receptor signaling through interaction with hormone response elements.
Collapse
Affiliation(s)
- Thomas S Lisse
- Department of Orthopaedic Surgery and Molecular Biology Institute, David Geffen School of Medicine at UCLA, 615 Charles E. Young Drive South, Los Angeles, CA 90095, USA.
| | | | | |
Collapse
|
31
|
Zhang Q, Qiu J, Li H, Lu Y, Wang X, Yang J, Wang S, Zhang L, Gu Y, Hao CM, Chen J. Cyclooxygenase 2 promotes parathyroid hyperplasia in ESRD. J Am Soc Nephrol 2011; 22:664-72. [PMID: 21335517 DOI: 10.1681/asn.2010060594] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Hyperplasia of the PTG underlies the secondary hyperparathyroidism (SHPT) observed in CKD, but the mechanism underlying this hyperplasia is incompletely understood. Because aberrant cyclooxygenase 2 (COX2) expression promotes epithelial cell proliferation, we examined the effects of COX2 on the parathyroid gland in uremia. In patients with ESRD who underwent parathyroidectomy, clusters of cells within the parathyroid glands had increased COX2 expression. Some COX2-positive cells exhibited two nuclei, consistent with proliferation. Furthermore, nearly 78% of COX2-positive cells expressed proliferating cell nuclear antigen (PCNA). In the 5/6-nephrectomy rat model, rats fed a high-phosphate diet had significantly higher serum PTH levels and larger parathyroid glands than sham-operated rats. Compared with controls, the parathyroid glands of uremic rats exhibited more PCNA-positive cells and greater COX2 expression in the chief cells. Treatment with COX2 inhibitor celecoxib significantly reduced PCNA expression, attenuated serum PTH levels, and reduced the size of the glands. In conclusion, COX2 promotes the pathogenesis of hyperparathyroidism in ESRD, suggesting that inhibiting the COX2 pathway could be a potential therapeutic target.
Collapse
Affiliation(s)
- Qian Zhang
- Division of Nephrology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200040, People's Republic of China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Defective renal maintenance of the vitamin D endocrine system impairs vitamin D renoprotection: a downward spiral in kidney disease. Kidney Int 2011; 79:715-29. [PMID: 21270766 DOI: 10.1038/ki.2010.543] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In kidney disease, the progressive loss of renal capacity to produce calcitriol, the vitamin D hormone, is a key contributor to elevations in parathyroid hormone (PTH) and mineral and skeletal disorders predisposing to renal and cardiovascular damage, ectopic calcifications, and high mortality rates. Thus, the safe correction of calcitriol deficiency to suppress PTH has been the treatment of choice for decades. However, recent epidemiological and experimental data suggest that calcitriol replacement may improve outcomes through renal and cardioprotective actions unrelated to PTH suppression. Furthermore, a striking incidence of vitamin D deficiency occurs in kidney disease and associates more strongly than calcitriol deficiency with a higher risk for kidney disease progression and death. Despite the translational relevance of these findings, no prospective trials are currently available in support of the efficacy of vitamin D supplementation and/or calcitriol replacement to safely halt/moderate renal disease progression. This review updates the pathophysiology behind the vicious cycle by which kidney injury impairs the maintenance of normal vitamin D and calcitriol levels, which in turn impedes vitamin D/calcitriol renoprotective actions, a requirement for the design of prospective trials to improve current recommendations for vitamin D interventions at all stages of kidney disease.
Collapse
|
33
|
Komaba H, Shiizaki K, Fukagawa M. Pharmacotherapy and interventional treatments for secondary hyperparathyroidism: current therapy and future challenges. Expert Opin Biol Ther 2010; 10:1729-42. [DOI: 10.1517/14712598.2010.518614] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
34
|
Dusso A, Arcidiacono MV, Yang J, Tokumoto M. Vitamin D inhibition of TACE and prevention of renal osteodystrophy and cardiovascular mortality. J Steroid Biochem Mol Biol 2010; 121:193-8. [PMID: 20359533 PMCID: PMC2906659 DOI: 10.1016/j.jsbmb.2010.03.064] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 03/18/2010] [Accepted: 03/22/2010] [Indexed: 11/28/2022]
Abstract
In the course of kidney disease, the progressive loss of renal capacity to maintain normal serum levels of 1,25-dihydroxyvitamin D (1,25(OH)2D) is a main contributor to parathyroid hyperplasia and high serum PTH. High PTH causes mineral and skeletal abnormalities predisposing to ectopic calcifications and increased mortality. Intriguingly, replacement therapy with 1,25(OH)2D or its less calcemic analogs was recently shown to improve survival in kidney disease patients through renal and cardiovascular protective actions that are independent of PTH suppression. This work presents preliminary evidence that 1,25(OH)2D inhibition of TACE (Tumor necrosis factor Alpha Converting Enzyme) is a potential common mechanism underlying the efficacy of therapy with 1,25(OH)2D or its analogs to improve outcomes in chronic kidney disease. 1,25(OH)2D prevents/moderates not only the onset and progression of parathyroid TACE/TGFalpha-driven secondary hyperparathyroidism, but, more significantly, renal TACE/TGFalpha-driven fibrotic and inflammatory lesions to the renal parenchyma, and TACE/TNFalpha-driven systemic inflammation, which is known to aggravate renal and cardiovascular lesions and enhance the risk of vascular calcification and cardiovascular mortality.
Collapse
Affiliation(s)
- Adriana Dusso
- Renal Division, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | | | | | | |
Collapse
|
35
|
Carrillo-López N, Román-García P, Fernández-Martín JL, Cannata-Andía JB. Parathyroid gland regulation: contribution of thein vivoandin vitromodels. Expert Opin Drug Discov 2010; 5:265-75. [DOI: 10.1517/17460441003615170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Natalia Carrillo-López
- Hospital Universitario Central de Asturias, Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Universidad de Oviedo, C/Julián Clavería s/n, Oviedo 33006, Asturias, Spain +34 985106137 ; +34 985106142 ;
| | | | | | | |
Collapse
|
36
|
Zella LA, Meyer MB, Nerenz RD, Lee SM, Martowicz ML, Pike JW. Multifunctional enhancers regulate mouse and human vitamin D receptor gene transcription. Mol Endocrinol 2009; 24:128-47. [PMID: 19897601 DOI: 10.1210/me.2009-0140] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The vitamin D receptor (VDR) mediates the endocrine actions of 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] and autoregulates the expression of its own gene in target cells. In studies herein, we used chromatin immunoprecipitation-chip analyses to examine further the activities of 1,25(OH)(2)D(3) and to assess the consequences of VDR/retinoid X receptor heterodimer binding at the VDR gene locus. We also explored mechanisms underlying the ability of retinoic acid, dexamethasone, and the protein kinase A activator forskolin to induce VDR up-regulation as well. We confirmed two previously identified intronic 1,25(OH)(2)D(3)-inducible enhancers and discovered two additional regions, one located 6 kb upstream of the VDR transcription start site. Although RNA polymerase II was present at the transcription start site in the absence of 1,25(OH)(2)D(3), it was strikingly up-regulated at both this site and at individual enhancers in its presence. 1,25(OH)(2)D(3) also increased basal levels of H4 acetylation at these enhancers as well. Surprisingly, many of these enhancers were targets for CCAAT enhancer-binding protein-beta and runt-related transcription factor 2; a subset also bound cAMP response element binding protein, retinoic acid receptor, and glucocorticoid receptor. Unexpectedly, many of these factors were resident at the Vdr gene locus in the absence of inducer, suggesting that they might contribute to basal Vdr gene expression. Indeed, small interfering RNA down-regulation of CCAAT enhancer-binding protein-beta suppressed basal VDR expression. These regulatory activities of 1,25(OH)(2)D(3), forskolin, and dexamethasone were recapitulated in MC3T3-E1 cells stably transfected with a full-length VDR bacterial artificial chromosome (BAC) clone-luciferase reporter gene. Finally, 1,25(OH)(2)D(3) also induced accumulation of VDR and up-regulated H4 acetylation at conserved regions in the human VDR gene. These data provide important new insights into VDR gene regulation in bone cells.
Collapse
Affiliation(s)
- Lee A Zella
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | | | | | | | | | | |
Collapse
|
37
|
Depressed expression of Klotho and FGF receptor 1 in hyperplastic parathyroid glands from uremic patients. Kidney Int 2009; 77:232-8. [PMID: 19890272 DOI: 10.1038/ki.2009.414] [Citation(s) in RCA: 222] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Fibroblast growth factor 23 (FGF23) exerts its effect by binding to its cognate FGF receptor 1 (FGFR1) in the presence of its co-receptor Klotho. Parathyroid glands express both FGFR1 and Klotho, and FGF23 decreases parathyroid hormone gene expression and hormone secretion directly. In uremic patients with secondary hyperparathyroidism (SHPT), however, parathyroid hormone secretion remains elevated despite extremely high FGF23 levels. To determine the mechanism of this resistance, we measured the expression of Klotho, FGFR1, and the proliferative marker Ki67 in 7 normal and 80 hyperplastic parathyroid glands from uremic patients by immunohistochemistry. All uremic patients had severe SHPT along with markedly high FGF23 levels. Quantitative real-time reverse transcription PCR showed that the mRNA levels for Klotho and FGFR1correlated significantly with their semi-quantitative immunohistochemical intensity. Compared with normal tissue, the immunohistochemical expression of Klotho and FGFR1 decreased, but Ki67 expression increased significantly in hyperplastic parathyroid glands, particularly in glands with nodular hyperplasia. These results suggest that the depressed expression of the Klotho-FGFR1 complex in hyperplastic glands underlies the pathogenesis of SHPT and its resistance to extremely high FGF23 levels in uremic patients.
Collapse
|
38
|
Valdivielso JM, Cannata-Andía J, Coll B, Fernández E. A new role for vitamin D receptor activation in chronic kidney disease. Am J Physiol Renal Physiol 2009; 297:F1502-9. [PMID: 19625376 DOI: 10.1152/ajprenal.00130.2009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Vitamin D has proven to be much more than a simple "calcium hormone." The fact that the vitamin D receptor has been found in cells not related to mineral metabolism supports that statement. The interest of nephrologists in vitamin D and its effects beyond mineral metabolism has increased over the last few years, evidencing the importance of this so-called "sunshine hormone." In the present review, we highlight the most recent developments in the traditional use of vitamin D in chronic kidney disease (CKD) patients, namely, the control of secondary hyperparathyroidism (sHPT). Furthermore, we also explore the data available regarding the new possible therapeutic uses of vitamin D for the treatment of other complications present in CKD patients, such as vascular calcification, left ventricular hypertrophy, or proteinuria. Finally, some still scarce but very promising data regarding a possible role of vitamin D in kidney transplant patients also are reviewed. The available data point to a potential beneficial effect of vitamin D in CKD patients beyond the control of mineral metabolism.
Collapse
Affiliation(s)
- José M Valdivielso
- Laboratorio de Nefrología Experimental, IRBLLEIDA, Hospital Universitari Arnau de Vilanova, Rovira Roure 80, 25198 Lleida, Spain.
| | | | | | | |
Collapse
|
39
|
CCAAT/enhancer-binding protein beta: its role in breast cancer and associations with receptor tyrosine kinases. Expert Rev Mol Med 2009; 11:e12. [PMID: 19351437 DOI: 10.1017/s1462399409001033] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The CCAAT/enhancer-binding proteins (C/EBPs) are a family of leucine-zipper transcription factors that regulate gene expression to control cellular proliferation, differentiation, inflammation and metabolism. Encoded by an intronless gene, C/EBPbeta is expressed as several distinct protein isoforms (LAP1, LAP2, LIP) whose expression is regulated by the differential use of several in-frame translation start sites. LAP1 and LAP2 are transcriptional activators and are associated with differentiation, whereas LIP is frequently elevated in proliferative tissue and acts as a dominant-negative inhibitor of transcription. However, emerging evidence suggests that LIP can serve as a transcriptional activator in some cellular contexts, and that LAP1 and LAP2 might also have unique actions. The LIP:LAP ratio is crucial for the maintenance of normal growth and development, and increases in this ratio lead to aggressive forms of breast cancer. This review discusses the regulation of C/EBPbeta activity by post-translational modification, the individual actions of LAP1, LAP2 and LIP, and the functions and downstream targets that are unique to each isoform. The role of the C/EBPbeta isoforms in breast cancer is discussed and emphasis is placed on their interactions with receptor tyrosine kinases.
Collapse
|
40
|
|
41
|
Abstract
Decline in renal function is related directly to cardiovascular mortality. However, traditional risk factors do not fully account for the high mortality in these patients. Activated vitamin D, a hormone produced by the proximal convoluted tubule of the kidney, appears to have beneficial effects beyond suppressing parathyroid hormone (PTH). However, activated vitamin D also can cause hypercalcemia and hyperphosphatemia in chronic kidney disease. Newer agents such as vitamin D receptor activators (eg, paricalcitol) suppress PTH with reduced risk of hypercalcemia and hyperphosphatemia. Recent evidence from animal and preliminary human studies supports an association between vitamin D receptor activators and reduced risk of cardiovascular disease deaths, irrespective of PTH levels. New pathways of vitamin D regulation also have been discovered, involving fibroblast growth factor-23 and klotho. Although considerable work has been performed to advance our understanding of the effects of vitamin D in health and chronic kidney disease, more investigations and randomized trials need to be performed to elucidate the mechanistic underpinnings of these effects.
Collapse
Affiliation(s)
- Tejas V Patel
- Renal Division, Brigham and Women's Hospital, Boston, MA 02115, USA.
| | | |
Collapse
|
42
|
Fretz MM, Dolman MEEM, Lacombe M, Prakash J, Nguyen TQ, Goldschmeding R, Pato J, Storm G, Hennink WE, Kok RJ. Intervention in growth factor activated signaling pathways by renally targeted kinase inhibitors. J Control Release 2008; 132:200-7. [PMID: 18793687 DOI: 10.1016/j.jconrel.2008.08.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Revised: 08/04/2008] [Accepted: 08/16/2008] [Indexed: 12/21/2022]
Abstract
Cell-specific targeting to renal tubular cells is an interesting approach to enhance the accumulation of drugs in the kidney. Low molecular weight proteins are rapidly filtered and extensively accumulate in proximal tubular cells. We therefore have used lysozyme (LZM, 14 kDa) as a tubular cell-specific carrier for the delivery of kinase inhibitors. Two different kinase inhibitors (LY364947 and erlotinib, directed to either the TGF-beta receptor kinase or the EGF receptor) were individually conjugated to LZM via a novel platinum-based linker (Universal Linkage System; ULS). The cellular handling and pharmacological efficacy of the conjugates were evaluated in cultured proximal tubular cells (HK-2 cells). Both conjugates were efficiently internalized via endocytosis. TGF-beta or EGF activated HK-2 cells showed a strong activation of the studied kinases and the conjugates inhibited these events, as was demonstrated by Western blotting of phosphorylated downstream mediators and quantitative gene expression analysis. In conclusion, we have developed tubular cell-specific kinase inhibitor-LZM conjugates via a novel linker strategy, which both showed to be effective in vitro. Future in vivo studies should show their potential for the treatment of renal diseases.
Collapse
Affiliation(s)
- Marjan M Fretz
- Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands
| | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Arcidiacono MV, Cozzolino M, Spiegel N, Tokumoto M, Yang J, Lu Y, Sato T, Lomonte C, Basile C, Slatopolsky E, Dusso AS. Activator protein 2alpha mediates parathyroid TGF-alpha self-induction in secondary hyperparathyroidism. J Am Soc Nephrol 2008; 19:1919-28. [PMID: 18579641 DOI: 10.1681/asn.2007111216] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
In secondary hyperparathyroidism, enhanced expression of TGF-alpha in the parathyroid leads to its own upregulation, generating a feed-forward loop for TGF-alpha activation of its receptor, EGFR receptor (EGFR), which promotes parathyroid hyperplasia. These studies examined the role of activator protein 2alpha (AP2), an inducer of TGF-alpha gene transcription, in the upregulation of parathyroid TGF-alpha in secondary hyperparathyroidism. In rat and human secondary hyperparathyroidism, parathyroid AP2 expression strongly correlated with TGF-alpha levels and with the rate of parathyroid growth, as expected. Furthermore, the increases in rat parathyroid content of AP2 and its binding to a consensus AP2 DNA sequence preceded the increase in TGF-alpha induced by high dietary phosphate. More significant, in A431 cells, which provide a model of enhanced TGF-alpha and TGF-alpha self-induction, mutating the core AP2 site of the human TGF-alpha promoter markedly impaired promoter activity induced by endogenous or exogenous TGF-alpha. Important for therapy, in five-sixths nephrectomized rats fed high-phosphate diets, inhibition of parathyroid TGF-alpha self-induction using erlotinib, a highly specific inhibitor of TGF-alpha/EGFR-driven signals, reduced AP2 expression dosage dependently. This suggests that the increases in parathyroid AP2 occur downstream of EGFR activation by TGF-alpha and are required for TGF-alpha self-induction. Indeed, in A431 cells, erlotinib inhibition of TGF-alpha self-induction caused parallel reductions in AP2 expression and nuclear localization, as well as TGF-alpha mRNA and protein levels. In summary, increased AP2 expression and transcriptional activity at the TGF-alpha promoter determine the severity of the hyperplasia driven by parathyroid TGF-alpha self-upregulation in secondary hyperparathyroidism.
Collapse
Affiliation(s)
- Maria Vittoria Arcidiacono
- Renal Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|