1
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Lorentzen EM, Henriksen S, Rinaldo CH. Modelling BK Polyomavirus dissemination and cytopathology using polarized human renal tubule epithelial cells. PLoS Pathog 2023; 19:e1011622. [PMID: 37639485 PMCID: PMC10491296 DOI: 10.1371/journal.ppat.1011622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/08/2023] [Accepted: 08/17/2023] [Indexed: 08/31/2023] Open
Abstract
Most humans have a lifelong imperceptible BK Polyomavirus (BKPyV) infection in epithelial cells lining the reno-urinary tract. In kidney transplant recipients, unrestricted high-level replication of donor-derived BKPyV in the allograft underlies polyomavirus-associated nephropathy, a condition with massive epithelial cell loss and inflammation causing premature allograft failure. There is limited understanding on how BKPyV disseminates throughout the reno-urinary tract and sometimes causes kidney damage. Tubule epithelial cells are tightly connected and have unique apical and basolateral membrane domains with highly specialized functions but all in vitro BKPyV studies have been performed in non-polarized cells. We therefore generated a polarized cell model of primary renal proximal tubule epithelial cells (RPTECs) and characterized BKPyV entry and release. After 8 days on permeable inserts, RPTECs demonstrated apico-basal polarity. BKPyV entry was most efficient via the apical membrane, that in vivo faces the tubular lumen, and depended on sialic acids. Progeny release started between 48 and 58 hours post-infection (hpi), and was exclusively detected in the apical compartment. From 72 hpi, cell lysis and detachment gradually increased but cells were mainly shed by extrusion and the barrier function was therefore maintained. The decoy-like cells were BKPyV infected and could transmit BKPyV to uninfected cells. By 120 hpi, the epithelial barrier was disrupted by severe cytopathic effects, and BKPyV entered the basolateral compartment mimicking the interstitial space. Addition of BKPyV-specific neutralizing antibodies to this compartment inhibited new infections. Taken together, we propose that during in vivo low-level BKPyV replication, BKPyV disseminates inside the tubular system, thereby causing minimal damage and delaying immune detection. However, in kidney transplant recipients lacking a well-functioning immune system, replication in the allograft will progress and eventually cause denudation of the basement membrane, leading to an increased number of decoy cells, high-level BKPyV-DNAuria and DNAemia, the latter a marker of allograft damage.
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Affiliation(s)
- Elias Myrvoll Lorentzen
- Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway
- Metabolic and Renal Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway
| | - Stian Henriksen
- Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway
- Metabolic and Renal Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway
| | - Christine Hanssen Rinaldo
- Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway
- Metabolic and Renal Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway
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2
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Zhou P, Yang H, Zhang M, Liu J, Yu J, Yu S, Liu Q, Zhang Y, Xie M, Xu X, Liu J, Wang M. CaSR modulates proliferation of the superficial zone cells in temporomandibular joint cartilage via the PTHrP nuclear localization sequence. FASEB J 2023; 37:e23004. [PMID: 37440279 DOI: 10.1096/fj.202300037rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 05/07/2023] [Accepted: 05/16/2023] [Indexed: 07/14/2023]
Abstract
The superficial zone cells in mandibular condylar cartilage are proliferative. The present purpose was to delineate the relation of calcium-sensing receptor (CaSR) and parathyroid hormone-related peptide nuclear localization sequence (PTHrP87-139 ), and their role in the proliferation behaviors of the superficial zone cells. A gain- and loss-of-function strategy were used in an in vitro fluid flow shear stress (FFSS) model and an in vivo bilateral elevation bite model which showed mandibular condylar cartilage thickening. CaSR and PTHrP87-139 were modulated through treating the isolated superficial zone cells with activator/SiRNA and via deleting CaSR or parathyroid hormone-related peptide (PTHrP) gene in mice with the promoter gene of proteoglycan 4 (Prg4-CreERT2 ) in the tamoxifen-inducible pattern with or without additional injection of Cinacalcet, the CaSR agonist, or PTHrP87-139 peptide. FFSS stimulated CaSR and PTHrP expression, and accelerated proliferation of the Prg4-expressing superficial zone cells, in which process CaSR acted as an up-streamer of PTHrP. Proteoglycan 4 specific knockout of CaSR or PTHrP reduced the cartilage thickness, suppressed the proliferation and early differentiation of the superficial zone cells, and inhibited cartilage thickening and matrix production promoted by bilateral elevation bite. Injections of CaSR agonist Cinacalcet could not improve the phenotype caused by PTHrP mutation. Injections of PTHrP87-139 peptide rescued the cartilage from knockout of CaSR gene. CaSR modulates proliferation of the superficial zone cells in mandibular condylar cartilage through activation of PTHrP nuclear localization sequence. Our data support the therapeutic target of CaSR in promoting PTHrP production in superficial zone cartilage.
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Affiliation(s)
- Peng Zhou
- Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
- School of Stomatology, Jiamusi University, Jiamusi, China
| | - Hongxu Yang
- Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Mian Zhang
- Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Jinqiang Liu
- Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Jia Yu
- Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Shibin Yu
- Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Qian Liu
- Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Yuejiao Zhang
- Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
- School of Stomatology, Jiamusi University, Jiamusi, China
- Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Shanghai Stomatological Hospital, Fudan University, Shanghai, China
| | - Mianjiao Xie
- Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Xiaojie Xu
- College of Life Sciences, Northwest University, Xi'an, China
| | - Jiguang Liu
- School of Stomatology, Jiamusi University, Jiamusi, China
| | - Meiqing Wang
- Department of Oral Anatomy and Physiology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
- Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Shanghai Stomatological Hospital, Fudan University, Shanghai, China
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3
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Di Mise A, Wang X, Ye H, Pellegrini L, Torres VE, Valenti G. Pre-clinical evaluation of dual targeting of the GPCRs CaSR and V2R as therapeutic strategy for autosomal dominant polycystic kidney disease. FASEB J 2021; 35:e21874. [PMID: 34486176 PMCID: PMC9290345 DOI: 10.1096/fj.202100774r] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/30/2021] [Accepted: 08/09/2021] [Indexed: 11/30/2022]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD), caused by mutations of PKD1 or PKD2 genes, is characterized by development and growth of cysts causing progressive kidney enlargement. Reduced resting cytosolic calcium and increased cAMP levels associated with the tonic action of vasopressin are two central biochemical defects in ADPKD. Here we show that co‐targeting two GPCRs, the vasopressin V2 receptor (V2R) and the calcium sensing receptor, using the novel V2R antagonist lixivaptan in combination with the calcimimetic R‐568, reduced cyst progression in two animal models of human PKD. Lixivaptan is expected to have a safer liver profile compared to tolvaptan, the only drug approved to delay PKD progression, based on computational model results and initial clinical evidence. PCK rat and Pkd1RC/RC mouse littermates were fed without or with lixivaptan (0.5%) and R‐568 (0.025% for rats and 0.04% for mice), alone or in combination, for 7 (rats) or 13 (mice) weeks. In PCK rats, the combined treatment strongly decreased kidney weight, cyst and fibrosis volumes by 20%, 49%, and 73%, respectively, compared to untreated animals. In Pkd1RC/RC mice, the same parameters were reduced by 20%, 56%, and 69%, respectively. In both cases the combined treatment appeared nominally more effective than the individual drugs used alone. These data point to an intriguing new application for two existing drugs in PKD treatment. The potential for synergy between these two compounds suggested in these animal studies, if confirmed in appropriate clinical investigations, would represent a welcome advancement in the treatment of ADPKD.
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Affiliation(s)
- Annarita Di Mise
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Aldo Moro, Bari, Italy
| | - Xiaofang Wang
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Hong Ye
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Vicente E Torres
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Giovanna Valenti
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari Aldo Moro, Bari, Italy
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4
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Tan RSG, Lee CHL, Dimke H, Todd Alexander R. The role of calcium-sensing receptor signaling in regulating transepithelial calcium transport. Exp Biol Med (Maywood) 2021; 246:2407-2419. [PMID: 33926258 DOI: 10.1177/15353702211010415] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The calcium-sensing receptor (CaSR) plays a critical role in sensing extracellular calcium (Ca2+) and signaling to maintain Ca2+ homeostasis. In the parathyroid, the CaSR regulates secretion of parathyroid hormone, which functions to increase extracellular Ca2+ levels. The CaSR is also located in other organs imperative to Ca2+ homeostasis including the kidney and intestine, where it modulates Ca2+ reabsorption and absorption, respectively. In this review, we describe CaSR expression and its function in transepithelial Ca2+ transport in the kidney and intestine. Activation of the CaSR leads to G protein dependent and independent signaling cascades. The known CaSR signal transduction pathways involved in modulating paracellular and transcellular epithelial Ca2+ transport are discussed. Mutations in the CaSR cause a range of diseases that manifest in altered serum Ca2+ levels. Gain-of-function mutations in the CaSR result in autosomal dominant hypocalcemia type 1, while loss-of-function mutations cause familial hypocalciuric hypercalcemia. Additionally, the putative serine protease, FAM111A, is discussed as a potential regulator of the CaSR because mutations in FAM111A cause Kenny Caffey syndrome type 2, gracile bone dysplasia, and osteocraniostenosis, diseases that are characterized by hypocalcemia, hypoparathyroidism, and bony abnormalities, i.e. share phenotypic features of autosomal dominant hypocalcemia. Recent work has helped to elucidate the effect of CaSR signaling cascades on downstream proteins involved in Ca2+ transport across renal and intestinal epithelia; however, much remains to be discovered.
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Affiliation(s)
- Rebecca Siu Ga Tan
- Department of Physiology, University of Alberta, Edmonton T6G 1C9, Canada.,Membrane Protein Disease Research Group, University of Alberta, Edmonton T6G 1C9, Canada
| | | | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense 5000, Denmark.,Department of Nephrology, Odense University Hospital, Odense 5000, Denmark
| | - R Todd Alexander
- Department of Physiology, University of Alberta, Edmonton T6G 1C9, Canada.,Membrane Protein Disease Research Group, University of Alberta, Edmonton T6G 1C9, Canada.,Department of Pediatrics, University of Alberta, Edmonton T6G 1C9, Canada
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5
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Valdés A, Lucio-Cazaña FJ, Castro-Puyana M, García-Pastor C, Fiehn O, Marina ML. Comprehensive metabolomic study of the response of HK-2 cells to hyperglycemic hypoxic diabetic-like milieu. Sci Rep 2021; 11:5058. [PMID: 33658594 PMCID: PMC7930035 DOI: 10.1038/s41598-021-84590-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/16/2021] [Indexed: 01/31/2023] Open
Abstract
Diabetic nephropathy (DN) is the leading cause of chronic kidney disease. Although hyperglycaemia has been determined as the most important risk factor, hypoxia also plays a relevant role in the development of this disease. In this work, a comprehensive metabolomic study of the response of HK-2 cells, a human cell line derived from normal proximal tubular epithelial cells, to hyperglycemic, hypoxic diabetic-like milieu has been performed. Cells simultaneously exposed to high glucose (25 mM) and hypoxia (1% O2) were compared to cells in control conditions (5.5 mM glucose/18.6% O2) at 48 h. The combination of advanced metabolomic platforms (GC-TOF MS, HILIC- and CSH-QExactive MS/MS), freely available metabolite annotation tools, novel databases and libraries, and stringent cut-off filters allowed the annotation of 733 metabolites intracellularly and 290 compounds in the extracellular medium. Advanced bioinformatics and statistical tools demonstrated that several pathways were significantly altered, including carbohydrate and pentose phosphate pathways, as well as arginine and proline metabolism. Other affected metabolites were found in purine and lipid metabolism, the protection against the osmotic stress and the prevention of the activation of the β-oxidation pathway. Overall, the effects of the combined exposure of HK-cells to high glucose and hypoxia are reasonably compatible with previous in vivo works.
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Affiliation(s)
- Alberto Valdés
- Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, España.
- West Coast Metabolomics Center, UC Davis, Davis, CA, USA.
| | - Francisco J Lucio-Cazaña
- Departamento de Biología de Sistemas, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, España
| | - María Castro-Puyana
- Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, España
- Instituto de Investigación Química Andrés M del Rio, IQAR, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, España
| | - Coral García-Pastor
- Departamento de Biología de Sistemas, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, España
| | - Oliver Fiehn
- West Coast Metabolomics Center, UC Davis, Davis, CA, USA
| | - María Luisa Marina
- Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, España.
- Instituto de Investigación Química Andrés M del Rio, IQAR, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, España.
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6
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Ranieri M, Di Mise A, Centrone M, D'Agostino M, Tingskov SJ, Venneri M, Pellegrino T, Difonzo G, Caponio F, Norregaard R, Valenti G, Tamma G. Olive Leaf Extract (OLE) impaired vasopressin-induced aquaporin-2 trafficking through the activation of the calcium-sensing receptor. Sci Rep 2021; 11:4537. [PMID: 33633156 PMCID: PMC7907100 DOI: 10.1038/s41598-021-83850-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 02/02/2021] [Indexed: 12/14/2022] Open
Abstract
Vasopressin (AVP) increases water permeability in the renal collecting duct through the regulation of aquaporin-2 (AQP2) trafficking. Several disorders, including hypertension and inappropriate antidiuretic hormone secretion (SIADH), are associated with abnormalities in water homeostasis. It has been shown that certain phytocompounds are beneficial to human health. Here, the effects of the Olive Leaf Extract (OLE) have been evaluated using in vitro and in vivo models. Confocal studies showed that OLE prevents the vasopressin induced AQP2 translocation to the plasma membrane in MCD4 cells and rat kidneys. Incubation with OLE decreases the AVP-dependent increase of the osmotic water permeability coefficient (Pf). To elucidate the possible effectors of OLE, intracellular calcium was evaluated. OLE increases the intracellular calcium through the activation of the Calcium Sensing Receptor (CaSR). NPS2143, a selective CaSR inhibitor, abolished the inhibitory effect of OLE on AVP-dependent water permeability. In vivo experiments revealed that treatment with OLE increases the expression of the CaSR mRNA and decreases AQP2 mRNA paralleled by an increase of the AQP2-targeting miRNA-137. Together, these findings suggest that OLE antagonizes vasopressin action through stimulation of the CaSR indicating that this extract may be beneficial to attenuate disorders characterized by abnormal CaSR signaling and affecting renal water reabsorption.
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Affiliation(s)
- Marianna Ranieri
- Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy.
| | - Annarita Di Mise
- Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Mariangela Centrone
- Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Mariagrazia D'Agostino
- Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | | | - Maria Venneri
- Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Tommaso Pellegrino
- Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Graziana Difonzo
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Francesco Caponio
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Rikke Norregaard
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Giovanna Valenti
- Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Grazia Tamma
- Department of Bioscience, Biotechnology and Biopharmaceutics, University of Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy.
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7
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Zhang M, Yang H, Wan X, Lu L, Zhang J, Zhang H, Ye T, Liu Q, Xie M, Liu X, Yu S, Guo S, Chang W, Wang M. Prevention of Injury-Induced Osteoarthritis in Rodent Temporomandibular Joint by Targeting Chondrocyte CaSR. J Bone Miner Res 2019; 34:726-738. [PMID: 30496623 PMCID: PMC6482062 DOI: 10.1002/jbmr.3643] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 11/13/2018] [Accepted: 11/14/2018] [Indexed: 01/21/2023]
Abstract
Traumatic joint injuries produce osteoarthritic cartilage manifesting accelerated chondrocyte terminal differentiation and matrix degradation via unknown cellular and molecular mechanisms. Here we report the ability of biomechanical stress to increase expression of the calcium-sensing receptor (CaSR), a pivotal driver of chondrocyte terminal differentiation, in cultured chondrogenic cells subjected to fluid flow shear stress (FFSS) and in chondrocytes of rodent temporomandibular joint (TMJ) cartilage subjected to unilateral anterior cross-bite (UAC). In cultured ATDC5 cells or TMJ chondrocytes, FFSS induced Ca2+ loading and CaSR localization in endoplasmic reticulum (ER), casually accelerating cell differentiation that could be abrogated by emptying ER Ca2+ stores or CaSR knockdown. Likewise, acute chondrocyte-specific Casr knockout (KO) prevented the UAC-induced acceleration of chondrocyte terminal differentiation and matrix degradation in TMJ cartilage in mice. More importantly, local injections of CaSR antagonist, NPS2143, replicated the effects of Casr KO in preventing the development of osteoarthritic phenotypes in TMJ cartilage of the UAC-treated rats. Our study revealed a novel pathological action of CaSR in development of osteoarthritic cartilage due to aberrant mechanical stimuli and supports a therapeutic potential of calcilytics in preventing osteoarthritis in temporomandibular joints by targeting the CaSR. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Mian Zhang
- State Key Laboratory of Military Stomatology, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, Xi'an, China
| | - Hongxu Yang
- State Key Laboratory of Military Stomatology, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, Xi'an, China
| | - Xianghong Wan
- State Key Laboratory of Military Stomatology, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, Xi'an, China
| | - Lei Lu
- State Key Laboratory of Military Stomatology, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, Xi'an, China
| | - Jing Zhang
- State Key Laboratory of Military Stomatology, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, Xi'an, China
| | - Hongyun Zhang
- State Key Laboratory of Military Stomatology, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, Xi'an, China
| | - Tao Ye
- State Key Laboratory of Military Stomatology, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, Xi'an, China
| | - Qian Liu
- State Key Laboratory of Military Stomatology, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, Xi'an, China
| | - Mianjiao Xie
- State Key Laboratory of Military Stomatology, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, Xi'an, China
| | - Xiaodong Liu
- State Key Laboratory of Military Stomatology, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, Xi'an, China
| | - Shibin Yu
- State Key Laboratory of Military Stomatology, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, Xi'an, China
| | - Shaoxiong Guo
- State Key Laboratory of Military Stomatology, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, Xi'an, China
| | - Wenhan Chang
- Endocrine Research Unit, Department of Veterans Affairs Medical Center and Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Meiqing Wang
- State Key Laboratory of Military Stomatology, Department of Oral Anatomy and Physiology and TMD, School of Stomatology, the Fourth Military Medical University, Xi'an, China
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8
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Wu M, Feng Y, Ye GX, Han YC, Wang SS, Ni HF, Wang FM, Gao M, Lv LL, Liu BC. Calcium-sensing receptor activation attenuates collagen expression in renal proximal tubular epithelial cells. Am J Physiol Renal Physiol 2019; 316:F1006-F1015. [PMID: 30838870 DOI: 10.1152/ajprenal.00413.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
316: F1006-F1015, 2019. First published March 6, 2019; doi: 10.1152/ajprenal.00413.2018 .-Experimental studies have shown that pharmacological activation of calcium-sensing receptor (CaSR) attenuates renal fibrosis in some animal models beyond modification of bone and mineral homeostasis; however, its underlying mechanisms remain largely unknown. Since excessive collagen deposition is the key feature of fibrosis, the present study aimed to examine whether CaSR was involved in the regulation of collagen expression in rats with adenine diet-induced renal fibrosis and in profibrotic transforming growth factor (TGF)-β1-treated renal proximal tubular epithelial cells (PTECs). The results showed that the CaSR agonist cinacalcet significantly attenuated renal collagen accumulation and tubular injury in adenine diet-fed rats. Additionally, the in vitro experiment showed that profibrotic TGF-β1 significantly increased the expression of collagen and decreased CaSR expression at the mRNA and protein levels in a concentration- and time-dependent manner. Furthermore, the CaSR CRISPR activation plasmid and cinacalcet partially abrogated the upregulation of collagen induced by TGF-β1 treatment. Blockade of CaSR by the CRISPR/Cas9 KO plasmid or the pharmacological antagonist Calhex231 further enhanced TGF-β1-induced collagen expression. Mechanistic experiments found that Smad2 phosphorylation and Snail expression were markedly increased in PTECs treated with TGF-β1, whereas the CaSR CRISPR activation plasmid and cinacalcet substantially suppressed this induction. In summary, this study provides evidence for a direct renal tubular epithelial protective effect of CaSR activation in renal fibrosis, possibly through suppression of collagen expression in PTECs.
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Affiliation(s)
- Min Wu
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Ye Feng
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Guo-Xin Ye
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Yu-Chen Han
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Si-Si Wang
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Hai-Feng Ni
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Feng-Mei Wang
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Min Gao
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Lin-Li Lv
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
| | - Bi-Cheng Liu
- Institute of Nephrology, Zhongda Hospital, Southeast University School of Medicine , Nanjing , China
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9
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Di Mise A, Ranieri M, Centrone M, Venneri M, Tamma G, Valenti D, Valenti G. Activation of the Calcium-Sensing Receptor Corrects the Impaired Mitochondrial Energy Status Observed in Renal Polycystin-1 Knockdown Cells Modeling Autosomal Dominant Polycystic Kidney Disease. Front Mol Biosci 2018; 5:77. [PMID: 30197885 PMCID: PMC6117232 DOI: 10.3389/fmolb.2018.00077] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 08/03/2018] [Indexed: 12/19/2022] Open
Abstract
Autosomal Dominant Polycistic kidney Disease (ADPKD) is a renal channelopathy due to loss-of-function mutations in the PKD1 or PKD2 genes, encoding polycystin-1 (PC1) or polycystin-2 (PC2), respectively. PC1 is a large protein found predominantly on the plasma membrane where interacts with different proteins, including PC2. PC2 is a smaller integral membrane protein also expressed in intracellular organelles, acting as a non-selective cation channel permeable to calcium. Both PC1 and PC2 are also localized to the primary cilium of renal epithelial cells serving as mechanosensor that controls calcium influx through the plasma membrane and regulates intracellular calcium release from the endoplasmic reticulum. The mechanisms by which PC1/2 dysfunction leads to ADPKD needs still to be clarified. We have recently reported that selective Calcium-Sensing Receptor (CaSR) activation in human conditionally immortalized Proximal Tubular Epithelial cells deficient for PC1 (ciPTEC-PC1KD), deriving from urine sediments reduces intracellular cAMP and mTOR activity, and increases intracellular calcium reversing the principal ADPKD dysregulations. Reduced cellular free calcium found in ADPKD can, on the other hand, affect mitochondrial function and ATP production and, interestingly, a relationship between mitochondria and renal polycystic diseases have been suggested. By using ciPTEC-PC1KD as experimental tool modeling of ADPKD, we show here that, compared with wild type cells, ciPTEC-PC1KD have significantly lower mitochondrial calcium levels associated with a severe deficit in mitochondrial ATP production, secondary to a multilevel impairment of oxidative phosphorylation. Notably, selective CaSR activation with the calcimimetic NPS-R568 increases mitochondrial calcium content close to the levels found in resting wild type cells, and fully recovers the cell energy deficit associated to the PC1 channel disruption. Treatment of ciPTEC-PC1KD with 2-APB, an IP3R inhibitor, prevented the rescue of bioenergetics deficit induced by CaSR activation supporting a critical role of IP3Rs in driving ER-to-mitochondria Ca2+ shuttle. Together these data indicate that, besides reversing the principal dysregulations considered the most proximal events in ADPKD pathogenesis, selective CaSR activation in PKD1 deficient cells restores altered mitochondrial function that, in ADPKD, is known to facilitate cyst formation. These findings identify CaSR as a potential therapeutic target.
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Affiliation(s)
- Annarita Di Mise
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Marianna Ranieri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Mariangela Centrone
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Maria Venneri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Grazia Tamma
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy.,Istituto Nazionale di Biostrutture e Biosistemi, Rome, Italy
| | - Daniela Valenti
- Institute of Biomembranes Bioenergetics and Molecular Biotechnologies, National Council of Research, Bari, Italy
| | - Giovanna Valenti
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy.,Istituto Nazionale di Biostrutture e Biosistemi, Rome, Italy.,Center of Excellence in Comparative Genomics, University of Bari, Bari, Italy
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10
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Dos Santos PMC, Amaral D, Tararthuch AL, Fernandez R. Calcium-sensing receptor (CaSR) modulates vacuolar H +-ATPase activity in a cell model of proximal tubule. Clin Exp Nephrol 2018; 22:1258-1265. [PMID: 29961155 DOI: 10.1007/s10157-018-1613-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 06/18/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND The calcium-sensing receptor (CaSR) is localized in the apical membrane of proximal tubules in close proximity to the transporters responsible for proton secretion. Therefore, the aim of the present study was to analyze the effects of CaSR stimulation on the biochemical activity of the vacuolar H+-ATPase in a cellular model of proximal tubule cells, OKP cells. METHODS Biochemical activity of H+-ATPase was performed using cell homogenates, and the inorganic phosphate released was determined by a colorimetric method. Changes in cytosolic ionized calcium [Ca2+]i were also determined using Fluo-4. RESULTS A significant increase of vacuolar H+-ATPase activity was observed when the CaSR was stimulated with agonists such as Gd3+ (300 µM) and neomycin (200 µM). This activity was also stimulated in a dose-dependent fashion by changes in extracellular Ca2+ (Ca2+o) between 10-4 and 2 mM. Gd3+ and neomycin produced a sustained rise of [Ca2+]i, an effect that disappears when extracellular calcium was removed in the presence of 0.1 µM thapsigargin. Inhibition of phospholipase C (PLC) activity with U73122 (5 × 10-8 M) reduced the increase in [Ca2+]i induced by neomycin. CONCLUSION CaSR stimulation induces an increase in the vacuolar H+-ATPase activity of OKP cells, an effect that involves an increase in [Ca2+]i and require phospholipase C activity. The consequent decrease in intratubular pH could lead to increase ionization of luminal calcium, potentially enhancing its reabsorption in distal tubule segments and reducing the formation of calcium phosphate stones.
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Affiliation(s)
- Priscilla Marys Costa Dos Santos
- Departamento de Fisiologia, Setor de Ciências Biológicas, UFPR, Centro Politécnico s/n., Jd. das Américas, Postal Box: 19031, Curitiba, PR, 81531-990, Brazil
| | - Deividi Amaral
- Departamento de Fisiologia, Setor de Ciências Biológicas, UFPR, Centro Politécnico s/n., Jd. das Américas, Postal Box: 19031, Curitiba, PR, 81531-990, Brazil
| | - Ana Lucia Tararthuch
- Departamento de Fisiologia, Setor de Ciências Biológicas, UFPR, Centro Politécnico s/n., Jd. das Américas, Postal Box: 19031, Curitiba, PR, 81531-990, Brazil
| | - Ricardo Fernandez
- Departamento de Fisiologia, Setor de Ciências Biológicas, UFPR, Centro Politécnico s/n., Jd. das Américas, Postal Box: 19031, Curitiba, PR, 81531-990, Brazil.
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11
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Di Mise A, Tamma G, Ranieri M, Centrone M, van den Heuvel L, Mekahli D, Levtchenko EN, Valenti G. Activation of Calcium-Sensing Receptor increases intracellular calcium and decreases cAMP and mTOR in PKD1 deficient cells. Sci Rep 2018; 8:5704. [PMID: 29632324 PMCID: PMC5890283 DOI: 10.1038/s41598-018-23732-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 03/13/2018] [Indexed: 12/25/2022] Open
Abstract
Clinical and fundamental research suggest that altered calcium and cAMP signaling might be the most proximal events in ADPKD pathogenesis. Cells from ADPKD cysts have a reduced resting cytosolic calcium [Ca2+]i and increased cAMP levels. CaSR plays an essential role in regulating calcium homeostasis. Its activation is associated with [Ca2+]i increase and cAMP decrease, making CaSR a possible therapeutic target. Human conditionally immortalized Proximal Tubular Epithelial cells (ciPTEC) with stable knockdown of PKD1 (ciPTEC-PC1KD) and ciPTEC generated from an ADPKD1 patient (ciPTEC-PC1Pt) were used as experimental tools. CaSR functional expression was confirmed by studies showing that the calcimimetic NPS-R568 induced a significant increase in [Ca2+]i in ciPTEC-PC1KD and ciPTEC-PC1Pt. Resting [Ca2+]i were significantly lower in ciPTEC-PC1KD with respect to ciPTECwt, confirming calcium dysregulation. As in native cyst cells, significantly higher cAMP levels and mTOR activity were found in ciPTEC-PC1KD compared to ciPTECwt. Of note, NPS-R568 treatment significantly reduced intracellular cAMP and mTOR activity in ciPTEC-PC1KD and ciPTEC-PC1Pt. To conclude, we demonstrated that selective CaSR activation in human ciPTEC carrying PKD1 mutation increases [Ca2+]i, reduces intracellular cAMP and mTOR activity, reversing the principal dysregulations considered the most proximal events in ADPKD pathogenesis, making CaSR a possible candidate as therapeutic target.
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Affiliation(s)
- Annarita Di Mise
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, 70125, Italy.
| | - Grazia Tamma
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, 70125, Italy.,Istituto Nazionale di Biostrutture e Biosistemi, Roma, 00136, Italy
| | - Marianna Ranieri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, 70125, Italy
| | - Mariangela Centrone
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, 70125, Italy
| | - Lambertus van den Heuvel
- Department of Pediatric Nephrology, Radboud University Nijmegen Medical Centre, Nijmegen, 6525 HP, The Netherlands
| | - Djalila Mekahli
- Department of Pediatric Nephrology, University Hospital Gasthuisberg, Leuven, 3000, Belgium.,Department of Development & Regeneration, University of Leuven (KU Leuven), Leuven, 3000, Belgium
| | - Elena N Levtchenko
- Department of Pediatric Nephrology, University Hospital Gasthuisberg, Leuven, 3000, Belgium.,Department of Development & Regeneration, University of Leuven (KU Leuven), Leuven, 3000, Belgium
| | - Giovanna Valenti
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, 70125, Italy. .,Istituto Nazionale di Biostrutture e Biosistemi, Roma, 00136, Italy. .,Center of Excellence in Comparative Genomics (CEGBA), University of Bari, Bari, 70125, Italy.
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12
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Ranieri M, Zahedi K, Tamma G, Centrone M, Di Mise A, Soleimani M, Valenti G. CaSR signaling down-regulates AQP2 expression via a novel microRNA pathway in pendrin and NaCl cotransporter knockout mice. FASEB J 2018; 32:2148-2159. [PMID: 29212817 DOI: 10.1096/fj.201700412rr] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
High concentrations of urinary calcium counteract vasopressin action via the activation of the calcium-sensing receptor (CaSR) that is expressed in the luminal membrane of collecting duct cells, which impairs the trafficking of aquaporin-2 (AQP2). Pendrin/NaCl cotransporter double-knockout (dKO) mice display significant calcium wasting and develop severe volume depletion, despite increased circulating vasopressin levels. We hypothesized that the CaSR-mediated impairment of AQP2 expression/trafficking underlies vasopressin resistance in dKO mice. Compared with wild-type mice, in renal inner medulla, dKO mice had reduced total AQP2 sensitive to proteasome inhibitors, higher levels of AQP2-pS261, ubiquitinated AQP2, and p38-MAPK, an enzyme that is activated by CaSR signaling and known to phosphorylate AQP2 at Ser261. CaSR inhibition with the calcilytic NPS2143 reversed these effects, which indicates that CaSR mediates the up-regulation of AQP2-pS261, ubiquitination, and degradation. Of note, dKO mice demonstrated significantly higher AQP2-targeting miRNA-137 that was reduced upon CaSR inhibition, supporting a critical role for CaSR in the down-regulation of AQP2 expression. Our data indicate that CaSR signaling reduces AQP2 abundance both via AQP2-targeting miRNA-137 and the p38-MAPK/AQP2-pS261/ubiquitination/proteasomal axis. These effects may contribute to the reduced renal concentrating ability that has been observed in dKO mice and underscore a physiologic mechanism of the CaSR-dependent regulation of AQP2 abundance via a novel microRNA pathway.-Ranieri, M., Zahedi, K., Tamma, G., Centrone, M., Di Mise, A., Soleimani, M., Valenti, G. CaSR signaling down-regulates AQP2 expression via a novel microRNA pathway in pendrin and NaCl cotransporter knockout mice.
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Affiliation(s)
- Marianna Ranieri
- Department of Biosciences, Biotechnologies, and Biopharmaceutics University of Bari, Bari, Italy
| | - Kamyar Zahedi
- Research Services, Veterans Affairs Medical Center, Cincinnati, Ohio, USA.,Department of Medicine, University of Cincinnati, Cincinnati, Ohio, USA.,Center on Genetics of Transport and Epithelial Biology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Grazia Tamma
- Department of Biosciences, Biotechnologies, and Biopharmaceutics University of Bari, Bari, Italy.,Istituto Nazionale di Biostrutture e Biosistemi, Rome, Italy
| | - Mariangela Centrone
- Department of Biosciences, Biotechnologies, and Biopharmaceutics University of Bari, Bari, Italy
| | - Annarita Di Mise
- Department of Biosciences, Biotechnologies, and Biopharmaceutics University of Bari, Bari, Italy
| | - Manoocher Soleimani
- Research Services, Veterans Affairs Medical Center, Cincinnati, Ohio, USA.,Department of Medicine, University of Cincinnati, Cincinnati, Ohio, USA.,Center on Genetics of Transport and Epithelial Biology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Giovanna Valenti
- Department of Biosciences, Biotechnologies, and Biopharmaceutics University of Bari, Bari, Italy.,Istituto Nazionale di Biostrutture e Biosistemi, Rome, Italy.,Centre of Excellence in Comparative Genomics, University of Bari, Bari, Italy
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13
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Lee JJ, Plain A, Beggs MR, Dimke H, Alexander RT. Effects of phospho- and calciotropic hormones on electrolyte transport in the proximal tubule. F1000Res 2017; 6:1797. [PMID: 29043081 PMCID: PMC5627579 DOI: 10.12688/f1000research.12097.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/04/2017] [Indexed: 12/17/2022] Open
Abstract
Calcium and phosphate are critical for a myriad of physiological and cellular processes within the organism. Consequently, plasma levels of calcium and phosphate are tightly regulated. This occurs through the combined effects of the phospho- and calciotropic hormones, parathyroid hormone (PTH), active vitamin D
3, and fibroblast growth factor 23 (FGF23). The organs central to this are the kidneys, intestine, and bone. In the kidney, the proximal tubule reabsorbs the majority of filtered calcium and phosphate, which amounts to more than 60% and 90%, respectively. The basic molecular mechanisms responsible for phosphate reclamation are well described, and emerging work is delineating the molecular identity of the paracellular shunt wherein calcium permeates the proximal tubular epithelium. Significant experimental work has delineated the molecular effects of PTH and FGF23 on these processes as well as their regulation of active vitamin D
3 synthesis in this nephron segment. The integrative effects of both phospho- and calciotropic hormones on proximal tubular solute transport and subsequently whole body calcium-phosphate balance thus have been further complicated. Here, we first review the molecular mechanisms of calcium and phosphate reabsorption from the proximal tubule and how they are influenced by the phospho- and calciotropic hormones acting on this segment and then consider the implications on both renal calcium and phosphate handling as well as whole body mineral balance.
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Affiliation(s)
- Justin J Lee
- Department of Physiology, University of Alberta, Edmonton, Canada.,The Women and Children's Health Research Institute, Edmonton, Canada
| | - Allein Plain
- Department of Physiology, University of Alberta, Edmonton, Canada.,The Women and Children's Health Research Institute, Edmonton, Canada
| | - Megan R Beggs
- Department of Physiology, University of Alberta, Edmonton, Canada.,The Women and Children's Health Research Institute, Edmonton, Canada
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - R Todd Alexander
- Department of Physiology, University of Alberta, Edmonton, Canada.,The Women and Children's Health Research Institute, Edmonton, Canada.,Department of Pediatrics, Edmonton Clinic Health Academy, University of Alberta, Edmonton, Canada
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14
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Rak-Raszewska A, Vainio S. Nephrogenesis in organoids to develop novel drugs and progenitor cell based therapies. Eur J Pharmacol 2016; 790:3-11. [DOI: 10.1016/j.ejphar.2016.07.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/21/2016] [Accepted: 07/06/2016] [Indexed: 11/25/2022]
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15
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Mayr B, Glaudo M, Schöfl C. Activating Calcium-Sensing Receptor Mutations: Prospects for Future Treatment with Calcilytics. Trends Endocrinol Metab 2016; 27:643-652. [PMID: 27339034 DOI: 10.1016/j.tem.2016.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 05/17/2016] [Accepted: 05/20/2016] [Indexed: 12/20/2022]
Abstract
Activating mutations of the G protein-coupled receptor, calcium-sensing receptor (CaSR), cause autosomal dominant hypocalcemia and Bartter syndrome type 5. These mutations lower the set-point for extracellular calcium sensing, thereby causing decreased parathyroid hormone secretion and disturbed renal calcium handling with hypercalciuria. Available therapies increase serum calcium levels but raise the risk of complications in affected patients. Symptom relief and the prevention of adverse outcome is currently very difficult to achieve. Calcilytics act as CaSR antagonists that attenuate its activity, thereby correcting the molecular defect of activating CaSR proteins in vitro and elevating serum calcium in mice and humans in vivo, and have emerged as the most promising therapeutics for the treatment of these rare and difficult to treat diseases.
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Affiliation(s)
- Bernhard Mayr
- Division of Endocrinology and Diabetes, Department of Medicine I, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Germany.
| | - Markus Glaudo
- Division of Endocrinology and Diabetes, Department of Medicine I, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Germany
| | - Christof Schöfl
- Division of Endocrinology and Diabetes, Department of Medicine I, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Germany
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16
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Spilanthol from Acmella Oleracea Lowers the Intracellular Levels of cAMP Impairing NKCC2 Phosphorylation and Water Channel AQP2 Membrane Expression in Mouse Kidney. PLoS One 2016; 11:e0156021. [PMID: 27213818 PMCID: PMC4877099 DOI: 10.1371/journal.pone.0156021] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 05/09/2016] [Indexed: 11/19/2022] Open
Abstract
Acmella oleracea is well recognized in Brazilian traditional medicine as diuretic, although few scientific data have been published to support this effect. Aim of this study was to determine the molecular effect of Acmella oleracea extract and its main alkylamide spilanthol on two major processes involved in the urine concentrating mechanism: Na-K-2Cl symporter (NKCC2) activity in the thick ascending limb and water channel aquaporin 2 accumulation at the apical plasma membrane of collecting duct cells. Phosphorylation of NKCC2 was evaluated as index of its activation by Western blotting. Rate of aquaporin 2 apical expression was analyzed by confocal laser microscopy. Spilanthol-induced intracellular signalling events were dissected by video-imaging experiments. Exposure to spilanthol reduced the basal phosphorylation level of NKCC2 both in freshly isolated mouse kidney slices and in NKCC2-expresing HEK293 cells. In addition, exposure to spilanthol strongly reduced both desmopressin and low Cl−-dependent increase in NKCC2 phosphorylation in mouse kidney slices and NKCC2-expressing HEK293 cells, respectively. Similarly, spilanthol reduced both desmopressin- and forskolin-stimulated aquaporin 2 accumulation at the apical plasma membrane of collecting duct in mouse kidney slice and MCD4 cells, respectively. Of note, when orally administered, spilanthol induced a significant increase in both urine output and salt urinary excretion associated with a markedly reduced urine osmolality compared with control mice. Finally, at cellular level, spilanthol rapidly reduced or reversed basal and agonist-increased cAMP levels through a mechanism involving increases in intracellular [Ca2+]. In conclusion, spilanthol-induced inhibition of cAMP production negatively modulates urine-concentrating mechanisms thus holding great promise for its use as diuretic.
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17
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18
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Graca JAZ, Schepelmann M, Brennan SC, Reens J, Chang W, Yan P, Toka H, Riccardi D, Price SA. Comparative expression of the extracellular calcium-sensing receptor in the mouse, rat, and human kidney. Am J Physiol Renal Physiol 2015; 310:F518-33. [PMID: 26661650 DOI: 10.1152/ajprenal.00208.2015] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 11/30/2015] [Indexed: 11/22/2022] Open
Abstract
The calcium-sensing receptor (CaSR) was cloned over 20 years ago and functionally demonstrated to regulate circulating levels of parathyroid hormone by maintaining physiological serum ionized calcium concentration ([Ca(2+)]). The receptor is highly expressed in the kidney; however, intrarenal and intraspecies distribution remains controversial. Recently, additional functions of the CaSR receptor in the kidney have emerged, including parathyroid hormone-independent effects. It is therefore critical to establish unequivocally the localization of the CaSR in the kidney to relate this to its proposed physiological roles. In this study, we determined CaSR expression in mouse, rat, and human kidneys using in situ hybridization, immunohistochemistry (using 8 different commercially available and custom-made antibodies), and proximity ligation assays. Negative results in mice with kidney-specific CaSR ablation confirmed the specificity of the immunohistochemistry signal. Both in situ hybridization and immunohistochemistry showed CaSR expression in the thick ascending limb, distal tubule, and collecting duct of all species, with the thick ascending limb showing the highest levels. Within the collecting ducts, there was significant heterogeneity of expression between cell types. In the proximal tubule, lower levels of immunoreactivity were detected by immunohistochemistry and proximity ligation assays. Proximity ligation assays were the only technique to demonstrate expression within glomeruli. This study demonstrated CaSR expression throughout the kidney with minimal discrepancy between species but with significant variation in the levels of expression between cell and tubule types. These findings clarify the intrarenal distribution of the CaSR and enable elucidation of the full physiological roles of the receptor within this organ.
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Affiliation(s)
- J A Z Graca
- Pathology Sciences, AstraZeneca R&D, Macclesfield, United Kingdom; School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - M Schepelmann
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - S C Brennan
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - J Reens
- Pathology Sciences, AstraZeneca R&D, Macclesfield, United Kingdom
| | - W Chang
- Department of Medicine, UCSF School of Medicine, San Francisco, California
| | - P Yan
- Division of Nephrology, Beth Israel Deaconess Medical Center, Boston, Massachusetts; and
| | - H Toka
- Division of Nephrology and Hyperension, Eastern Virginia Medical School, Norfolk, Virginia
| | - D Riccardi
- School of Biosciences, Cardiff University, Cardiff, United Kingdom;
| | - S A Price
- Pathology Sciences, AstraZeneca R&D, Macclesfield, United Kingdom
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