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Dimke H. New insights into renal calcium-sensing receptor activation. Curr Opin Nephrol Hypertens 2024; 33:433-440. [PMID: 38690798 DOI: 10.1097/mnh.0000000000000998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
PURPOSE OF REVIEW Activation of the calcium-sensing receptor (CASR) in the parathyroid gland suppresses the release of parathyroid hormone (PTH). Furthermore, activation of the renal CASR directly increases the urinary excretion of calcium, by inhibiting transepithelial calcium transport in the nephron. Gain-of-function mutations in the CASR gene lead to autosomal dominant hypocalcemia 1 (ADH1), with inappropriately low PTH levels and hypocalcemia, indicative of excessive activation of the parathyroid CASR. However, hypercalciuria is not always observed. The reason why the manifestation of hypercalciuria is not uniform among ADH1 patients is not well understood. RECENT FINDINGS Direct activation of the CASR in the kidney has been cumbersome to study, and an indirect measure to effectively estimate the degree of CASR activation following chronic hypercalcemia or genetic gain-of-function CASR activation has been lacking. Studies have shown that expression of the pore-blocking claudin-14 is strongly stimulated by the CASR in a dose-dependent manner. This stimulatory effect is abolished after renal Casr ablation in hypercalcemic mice, suggesting that claudin-14 abundance may gauge renal CASR activation. Using this marker has led to unexpected discoveries regarding renal CASR activation. SUMMARY These new studies have informed on renal CASR activation thresholds and the downstream CASR-regulated calcium transport mechanisms.
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Affiliation(s)
- Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark
- Department of Nephrology, Odense University Hospital, Odense, Denmark
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Kudryavtseva O, Lyngsø KS, Jensen BL, Dimke H. Nitric oxide, endothelium-derived hyperpolarizing factor, and smooth muscle-dependent mechanisms contribute to magnesium-dependent vascular relaxation in mouse arteries. Acta Physiol (Oxf) 2024; 240:e14096. [PMID: 38258597 DOI: 10.1111/apha.14096] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 09/27/2023] [Accepted: 01/01/2024] [Indexed: 01/24/2024]
Abstract
AIM Magnesium (Mg2+ ) is a vasorelaxant. The underlying physiological mechanisms driving this vasorelaxation remain unclear. Studies were designed to test the hypothesis that multiple signaling pathways including nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF) in endothelial cells as well as Ca2+ antagonization and TRPM7 channels in vascular smooth muscle cells mediate Mg2+ -dependent vessel relaxation. METHODS To uncover these mechanisms, force development was measured ex vivo in aorta rings from mice using isometric wire myography. Concentration responses to Mg2+ were studied in intact and endothelium-denuded aortas. Key findings were confirmed in second-order mesenteric resistance arteries perfused ex vivo using pressure myography. Effects of Mg2+ on NO formation were measured in Chinese Hamster Ovary (CHO) cells, isolated mesenteric vessels, and mouse urine. RESULTS Mg2+ caused a significant concentration-dependent relaxation of aorta rings. This relaxation was attenuated significantly in endothelium-denuded aortas. The endothelium-dependent portion was inhibited by NO and cGMP blockade but not by cyclooxygenase inhibition. Mg2+ stimulated local NO formation in CHO cells and isolated mesenteric vessels without changing urinary NOx levels. High extracellular Mg2+ augmented acetylcholine-induced relaxation. SKCa and IKCa channel blockers apamin and TRAM34 inhibited Mg2+ -dependent relaxation. The endothelium-independent relaxation in aorta rings was inhibited by high extracellular Ca2+ . Combined blockade of NO, SKCa , and IKCa channels significantly reduced Mg2+ -dependent dilatation in mesenteric resistance vessels. CONCLUSIONS In mouse conductance and resistance arteries Mg2+ -induced relaxation is contributed by endothelial NO formation, EDHF pathways, antagonism of Ca2+ in smooth muscle cells, and additional unidentified mechanisms.
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Affiliation(s)
- Olga Kudryavtseva
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
| | - Kristina S Lyngsø
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
| | - Boye L Jensen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
- Department of Nephrology, Odense University Hospital, Odense, Denmark
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Wu F, Bu S, Wang H. Role of TRP Channels in Metabolism-Related Diseases. Int J Mol Sci 2024; 25:692. [PMID: 38255767 PMCID: PMC10815096 DOI: 10.3390/ijms25020692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/27/2023] [Accepted: 12/29/2023] [Indexed: 01/24/2024] Open
Abstract
Metabolic syndrome (MetS), with its high prevalence and significant impact on cardiovascular disease, poses a substantial threat to human health. The early identification of pathological abnormalities related to MetS and prevention of the risk of associated diseases is of paramount importance. Transient Receptor Potential (TRP) channels, a type of nonselective cation channel, are expressed in a variety of tissues and have been implicated in the onset and progression of numerous metabolism-related diseases. This study aims to review and discuss the expression and function of TRP channels in metabolism-related tissues and blood vessels, and to elucidate the interactions and mechanisms between TRP channels and metabolism-related diseases. A comprehensive literature search was conducted using keywords such as TRP channels, metabolic syndrome, pancreas, liver, oxidative stress, diabetes, hypertension, and atherosclerosis across various academic databases including PubMed, Google Scholar, Elsevier, Web of Science, and CNKI. Our review of the current research suggests that TRP channels may be involved in the development of metabolism-related diseases by regulating insulin secretion and release, lipid metabolism, vascular functional activity, oxidative stress, and inflammatory response. TRP channels, as nonselective cation channels, play pivotal roles in sensing various intra- and extracellular stimuli and regulating ion homeostasis by osmosis. They present potential new targets for the diagnosis or treatment of metabolism-related diseases.
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Affiliation(s)
| | | | - Hongmei Wang
- School of Medicine, Southeast University, Nanjing 210009, China; (F.W.); (S.B.)
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Van Beusecum JP, Rianto F, Teakell J, Kon V, Sparks MA, Hoorn EJ, Kirabo A, Ramkumar N. Novel Concepts in Nephron Sodium Transport: A Physiological and Clinical Perspective. ADVANCES IN KIDNEY DISEASE AND HEALTH 2023; 30:124-136. [PMID: 36868728 DOI: 10.1053/j.akdh.2022.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 12/15/2022] [Accepted: 12/15/2022] [Indexed: 04/13/2023]
Abstract
The kidneys play a critical role in maintaining total body sodium (Na+) balance across a wide range of dietary intake, accomplished by a concerted effort involving multiple Na+ transporters along the nephron. Furthermore, nephron Na+ reabsorption and urinary Na+ excretion are closely linked to renal blood flow and glomerular filtration such that perturbations in either of them can modify Na+ transport along the nephron, ultimately resulting in hypertension and other Na+-retentive states. In this article, we provide a brief physiological overview of nephron Na+ transport and illustrate clinical syndromes and therapeutic agents that affect Na+ transporter function. We highlight recent advances in kidney Na+ transport, particularly the role of immune cells, lymphatics, and interstitial Na+ in regulating Na+ reabsorption, the emergence of potassium (K+) as a regulator of Na+ transport, and the evolution of the nephron to modulate Na+ transport.
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Affiliation(s)
- Justin P Van Beusecum
- Ralph H. Johnson VA Medical Center, Charleston, SC; Division of Nephrology, Department of Medicine, Medical University of South Carolina, Charleston, SC
| | - Fitra Rianto
- Division of Nephrology, Department of Medicine, Duke University School of Medicine and Renal Section, Durham VA Health Care System Durham, Durham, NC
| | - Jade Teakell
- Division of Renal Diseases and Hypertension, Department of Medicine, McGovern Medical School, University of Texas Health Science Center, Houston, TX
| | - Valentina Kon
- Division of Nephrology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
| | - Matthew A Sparks
- Division of Nephrology, Department of Medicine, Duke University School of Medicine and Renal Section, Durham VA Health Care System Durham, Durham, NC
| | - Ewout J Hoorn
- Division of Nephrology and Transplantation, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Annet Kirabo
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN; Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Nirupama Ramkumar
- Division of Nephrology and Hypertension, Department of Medicine, University of Utah Health, Salt Lake City, UT.
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Tsai YC, Kuo MC, Hung WW, Wu PH, Chang WA, Wu LY, Lee SC, Hsu YL. Proximal tubule-derived exosomes contribute to mesangial cell injury in diabetic nephropathy via miR-92a-1-5p transfer. Cell Commun Signal 2023; 21:10. [PMID: 36639674 PMCID: PMC9838003 DOI: 10.1186/s12964-022-00997-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 10/21/2022] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Diabetic nephropathy (DN) is an increasing threat to human health and regarded to be the leading cause of end-stage renal disease worldwide. Exosomes delivery may play a key role in cross-talk among kidney cells and the progression of DN. However, the mechanisms underlying exosomes in DN remain unclear. METHODS The cross-disciplinary study, including in vivo, in vitro, and human studies was conducted to explore the cross-talk between proximal tubular epithelial cells (PTECs) and mesangial cells (MCs) in DN. We purified exosome from PTECs treated with high glucose and db/db mice and assessed their influences in the pathologic change of MCs and downstream signal pathway. Healthy individuals and type 2 diabetic patients were enrolled to examine the role of exosomes in clinical applications. RESULTS High glucose stimulated PTECs to secrete exosomal miR-92a-1-5p, which was taken-up by glomerular MCs, inducing myofibroblast transdifferentiation (MFT) in vitro and in vivo. PTEC-released exosomal 92a-1-5p decreased reticulocalbin-3 expression, leading to endoplasmic reticulum (ER) stress by downregulating genes essential for ER homeostasis including calreticulin and mesencephalic astrocyte-derived neurotrophic factor. Treatment with miR-92a-1-5p inhibitor ameliorated kidney damage in db/db mice with DN. Urinary miR-92a-1-5p could predict kidney injury in type 2 diabetic patients. CONCLUSIONS PTEC-derived exosomal miR-92a-1-5p modulated the kidney microenvironment in vivo and in vitro models, which altered ER stress and MFT in MCs resulting in DN progression. Further blocking miR-92a-1-5p epigenetic regulatory network could be a potential therapeutic strategy to prevent the progression of DN. Video Abstract.
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Affiliation(s)
- Yi-Chun Tsai
- grid.412019.f0000 0000 9476 5696School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan ,grid.412019.f0000 0000 9476 5696Division of General Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan ,grid.412019.f0000 0000 9476 5696Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan ,grid.412019.f0000 0000 9476 5696Center for Liquid Biopsy and Cohort Research, Kaohsiung Medical University, Kaohsiung, Taiwan ,grid.412019.f0000 0000 9476 5696Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung, 807 Taiwan
| | - Mei-Chuan Kuo
- grid.412019.f0000 0000 9476 5696Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Wei-Wen Hung
- grid.412019.f0000 0000 9476 5696Division of Endocrinology and Metabolism, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ping-Hsun Wu
- grid.412019.f0000 0000 9476 5696School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan ,grid.412019.f0000 0000 9476 5696Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Wei-An Chang
- grid.412019.f0000 0000 9476 5696Division of Pulmonary and Critical Care Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ling-Yu Wu
- grid.412019.f0000 0000 9476 5696Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Su-Chu Lee
- grid.412019.f0000 0000 9476 5696Division of Nephrology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ya-Ling Hsu
- grid.412019.f0000 0000 9476 5696Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung, 807 Taiwan ,grid.412019.f0000 0000 9476 5696Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, 100 TzYou 1st Road, Kaohsiung, 807 Taiwan
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Alexander RT, Dimke H. Molecular mechanisms underlying paracellular calcium and magnesium reabsorption in the proximal tubule and thick ascending limb. Ann N Y Acad Sci 2022; 1518:69-83. [PMID: 36200584 DOI: 10.1111/nyas.14909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Calcium and magnesium are the most abundant divalent cations in the body. The plasma level is controlled by coordinated interaction between intestinal absorption, reabsorption in the kidney, and, for calcium at least, bone storage and exchange. The kidney adjusts urinary excretion of these ions in response to alterations in their systemic concentration. Free ionized and anion-complexed calcium and magnesium are filtered at the glomerulus. The majority (i.e., >85%) of filtered divalent cations are reabsorbed via paracellular pathways from the proximal tubule and thick ascending limb (TAL) of the loop of Henle. Interestingly, the largest fraction of filtered calcium is reabsorbed from the proximal tubule (65%), while the largest fraction of filtered magnesium is reclaimed from the TAL (60%). The paracellular pathways mediating these fluxes are composed of tight junctional pores formed by claudins. In the proximal tubule, claudin-2 and claudin-12 confer calcium permeability, while the exact identity of the magnesium pore remains to be determined. Claudin-16 and claudin-19 contribute to the calcium and magnesium permeable pathway in the TAL. In this review, we discuss the data supporting these conclusions and speculate as to why there is greater fractional calcium reabsorption from the proximal tubule and greater fractional magnesium reabsorption from the TAL.
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Affiliation(s)
- R Todd Alexander
- Departments of Physiology & Pediatrics, University of Alberta, Edmonton, Alberta, Canada.,Women's and Children's Health Institute, Edmonton, Alberta, Canada
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Demark.,Department of Nephrology, Odense University Hospital, Odense, Denmark
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van Megen WH, Tan RSG, Alexander RT, Dimke H. Differential parathyroid and kidney Ca 2+-sensing receptor activation in autosomal dominant hypocalcemia 1. EBioMedicine 2022; 78:103947. [PMID: 35313217 PMCID: PMC8935519 DOI: 10.1016/j.ebiom.2022.103947] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 02/11/2022] [Accepted: 03/03/2022] [Indexed: 12/04/2022] Open
Abstract
Background Parathyroid Ca2+-sensing receptor (CaSR) activation inhibits parathyroid hormone (PTH) release, while activation of renal CaSRs attenuates Ca2+ transport and increases expression of the pore-blocking claudin-14. Patients with autosomal dominant hypocalcemia 1 (ADH1), due to activating CASR mutations, exhibit hypocalcemia but not always hypercalciuria (elevated Ca2+ in urine). The latter promotes nephrocalcinosis and renal insufficiency. Although CaSRs throughout the body including the kidney harbor activating CASR mutations, it is not understood why only some ADH1 patients display hypercalciuria. Methods Activation of the CaSR was studied in mouse models and a ADH1 patient. In vitro CaSR activation was studied in HEK293 cells. Findings Cldn14 showed blood Ca2+ concentration-dependent regulation, which was absent in mice with kidney-specific Casr deletion, indicating Cldn14 is a suitable marker for chronic CaSR activation in the kidney. Mice with a gain-of-function mutation in the Casr (Nuf) were hypocalcemic with low plasma PTH levels. However, renal CaSRs were not activated at baseline but only after normalizing blood Ca2+ levels. Similarly, significant hypercalciuria was not observed in a ADH1 patient until blood Ca2+ was normalized. In vitro experiments indicate that increased CaSR expression in the parathyroid relative to the kidney could contribute to tissue-specific CaSR activation thresholds. Interpretation Our findings suggest that parathyroid CaSR overactivity can reduce plasma Ca2+ to levels insufficient to activate renal CaSRs, even when an activating mutation is present. These findings identify a conceptually new mechanism of CaSR-dependent Ca2+ balance regulation that aid in explaining the spectrum of hypercalciuria in ADH1 patients. Funding Erasmus+ 2018/E+/4458087, the Canadian Institutes for Health research, the Novo Nordisk Foundation, the Beckett Foundation, the Carlsberg Foundation and Independent Research Fund Denmark.
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Affiliation(s)
- Wouter H van Megen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, J.B. Winsløws Vej 21, 3rd floor, 5000 Odense C, Denmark; Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Rebecca Siu Ga Tan
- Membrane Protein Disease Research Group, Department of Physiology, University of Alberta, Edmonton, Canada; The Women's and Children's Health Research Institute, Edmonton, Alberta, Canada
| | - R Todd Alexander
- Membrane Protein Disease Research Group, Department of Physiology, University of Alberta, Edmonton, Canada; The Women's and Children's Health Research Institute, Edmonton, Alberta, Canada; Department of Pediatrics, 4-585 Edmonton Clinic Health Academy, University of Alberta, 11405 87th Avenue, Edmonton, Alberta T6G 2R7, Canada.
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, J.B. Winsløws Vej 21, 3rd floor, 5000 Odense C, Denmark; Department of Nephrology, Odense University Hospital, Denmark.
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