1
|
Onopiuk M, Eby B, Nesin V, Ngo P, Lerner M, Gorvin CM, Stokes VJ, Thakker RV, Brandi ML, Chang W, Humphrey MB, Tsiokas L, Lau K. Control of PTH secretion by the TRPC1 ion channel. JCI Insight 2020; 5:132496. [PMID: 32213715 PMCID: PMC7205425 DOI: 10.1172/jci.insight.132496] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 03/16/2020] [Indexed: 11/17/2022] Open
Abstract
Familial hypocalciuric hypercalcemia (FHH) is a genetic condition associated with hypocalciuria, hypercalcemia, and, in some cases, inappropriately high levels of circulating parathyroid hormone (PTH). FHH is associated with inactivating mutations in the gene encoding the Ca2+-sensing receptor (CaSR), a GPCR, and GNA11 encoding G protein subunit α 11 (Gα11), implicating defective GPCR signaling as the root pathophysiology for FHH. However, the downstream mechanism by which CaSR activation inhibits PTH production/secretion is incompletely understood. Here, we show that mice lacking the transient receptor potential canonical channel 1 (TRPC1) develop chronic hypercalcemia, hypocalciuria, and elevated PTH levels, mimicking human FHH. Ex vivo and in vitro studies revealed that TRPC1 serves a necessary and sufficient mediator to suppress PTH secretion from parathyroid glands (PTGs) downstream of CaSR in response to high extracellular Ca2+ concentration. Gα11 physically interacted with both the N- and C-termini of TRPC1 and enhanced CaSR-induced TRPC1 activity in transfected cells. These data identify TRPC1-mediated Ca2+ signaling as an essential component of the cellular apparatus controlling PTH secretion in the PTG downstream of CaSR.
Collapse
Affiliation(s)
| | - Bonnie Eby
- Department of Medicine, Division of Nephrology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | | | | | - Megan Lerner
- Department of Surgery, Oklahoma City, Oklahoma, USA
| | - Caroline M Gorvin
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Victoria J Stokes
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Maria Luisa Brandi
- Department of Biomedicals Sperimentals and Clinicals Sciences, Università degli Studi di Firenze and Fondazione FIRMO, Florence, Italy
| | - Wenhan Chang
- Endocrinology and Metabolism, Department of Medicine, UCSF, San Francisco, California, USA
| | - Mary Beth Humphrey
- Department of Medicine, Division of Rheumatology, Immunology, and Allergy, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.,Department of Veterans Affairs, Oklahoma City, Oklahoma, USA
| | | | - Kai Lau
- Department of Medicine, Division of Nephrology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.,Department of Veterans Affairs, Oklahoma City, Oklahoma, USA
| |
Collapse
|
2
|
Zheng W, Cai R, Hofmann L, Nesin V, Hu Q, Long W, Fatehi M, Liu X, Hussein S, Kong T, Li J, Light PE, Tang J, Flockerzi V, Tsiokas L, Chen XZ. Direct Binding between Pre-S1 and TRP-like Domains in TRPP Channels Mediates Gating and Functional Regulation by PIP2. Cell Rep 2019; 22:1560-1573. [PMID: 29425510 PMCID: PMC6483072 DOI: 10.1016/j.celrep.2018.01.042] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 12/08/2017] [Accepted: 01/11/2018] [Indexed: 11/28/2022] Open
Abstract
Transient receptor potential (TRP) channels are regulated by diverse stimuli comprising thermal, chemical, and mechanical modalities. They are also commonly regulated by phosphatidylinositol-4,5-bisphosphate (PIP2), with underlying mechanisms largely unknown. We here revealed an intramolecular interaction of the TRPP3 N and C termini (N-C) that is functionally essential. The interaction was mediated by aromatic Trp81 in pre-S1 domain and cationic Lys568 in TRP-like domain. Structure-function analyses revealed similar N-C interaction in TRPP2 as well as TRPM8/-V1/-C4 via highly conserved tryptophan and lysine/arginine residues. PIP2 bound to cationic residues in TRPP3, including K568, thereby disrupting the N-C interaction and negatively regulating TRPP3. PIP2 had similar negative effects on TRPP2. Interestingly, we found that PIP2 facilitates the N-C interaction in TRPM8/-V1, resulting in channel potentiation. The intramolecular N-C interaction might represent a shared mechanism underlying the gating and PIP2 regulation of TRP channels. Zheng et al. show that an aromatic Trp residue in pre-S1 and a cationic Lys residue in the TRP-like domain of TRP polycystin channels mediate N-C binding, which underlies TRPPs gating and PIP2 regulation. The conservation of these residues suggests that this may be a shared mechanism of TRP channel gating.
Collapse
Affiliation(s)
- Wang Zheng
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, Hubei 430068, China; Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Ruiqi Cai
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Laura Hofmann
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, Homburg 66421, Germany
| | - Vasyl Nesin
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Qiaolin Hu
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Wentong Long
- Alberta Diabetes Institute, Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Mohammad Fatehi
- Alberta Diabetes Institute, Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Xiong Liu
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Shaimaa Hussein
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Tim Kong
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Jingru Li
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Peter E Light
- Alberta Diabetes Institute, Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Jingfeng Tang
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, Hubei 430068, China.
| | - Veit Flockerzi
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, Homburg 66421, Germany
| | - Leonidas Tsiokas
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Xing-Zhen Chen
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, Hubei 430068, China; Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
| |
Collapse
|
3
|
Feng S, Streets AJ, Nesin V, Tran U, Nie H, Onopiuk M, Wessely O, Tsiokas L, Ong ACM. The Sorting Nexin 3 Retromer Pathway Regulates the Cell Surface Localization and Activity of a Wnt-Activated Polycystin Channel Complex. J Am Soc Nephrol 2017; 28:2973-2984. [PMID: 28620080 DOI: 10.1681/asn.2016121349] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 05/07/2017] [Indexed: 02/04/2023] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is caused by inactivating mutations in PKD1 (85%) or PKD2 (15%). The ADPKD proteins encoded by these genes, polycystin-1 (PC1) and polycystin-2 (PC2), form a plasma membrane receptor-ion channel complex. However, the mechanisms controlling the subcellular localization of PC1 and PC2 are poorly understood. Here, we investigated the involvement of the retromer complex, an ancient protein module initially discovered in yeast that regulates the retrieval, sorting, and retrograde transport of membrane receptors. Using yeast two-hybrid, biochemical, and cellular assays, we determined that PC2 binds two isoforms of the retromer-associated protein sorting nexin 3 (SNX3), including a novel isoform that binds PC2 in a direct manner. Knockdown of SNX3 or the core retromer protein VPS35 increased the surface expression of endogenous PC1 and PC2 in vitro and in vivo and increased Wnt-activated PC2-dependent whole-cell currents. These findings indicate that an SNX3-retromer complex regulates the surface expression and function of PC1 and PC2. Molecular targeting of proteins involved in the endosomal sorting of PC1 and PC2 could lead to new therapeutic approaches in ADPKD.
Collapse
Affiliation(s)
- Shuang Feng
- Kidney Genetics Group, Academic Nephrology Unit and the Bateson Centre, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Andrew J Streets
- Kidney Genetics Group, Academic Nephrology Unit and the Bateson Centre, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom
| | - Vasyl Nesin
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; and
| | - Uyen Tran
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Hongguang Nie
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; and
| | - Marta Onopiuk
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; and
| | - Oliver Wessely
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Leonidas Tsiokas
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma; and
| | - Albert C M Ong
- Kidney Genetics Group, Academic Nephrology Unit and the Bateson Centre, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, United Kingdom;
| |
Collapse
|
4
|
Chakraborty PK, Mustafi SB, Xiong X, Dwivedi SKD, Nesin V, Saha S, Zhang M, Dhanasekaran D, Jayaraman M, Mannel R, Moore K, McMeekin S, Yang D, Zuna R, Ding K, Tsiokas L, Bhattacharya R, Mukherjee P. MICU1 drives glycolysis and chemoresistance in ovarian cancer. Nat Commun 2017; 8:14634. [PMID: 28530221 PMCID: PMC5477507 DOI: 10.1038/ncomms14634] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 01/18/2017] [Indexed: 12/18/2022] Open
Abstract
Cancer cells actively promote aerobic glycolysis to sustain their metabolic requirements through mechanisms not always clear. Here, we demonstrate that the gatekeeper of mitochondrial Ca2+ uptake, Mitochondrial Calcium Uptake 1 (MICU1/CBARA1) drives aerobic glycolysis in ovarian cancer. We show that MICU1 is overexpressed in a panel of ovarian cancer cell lines and that MICU1 overexpression correlates with poor overall survival (OS). Silencing MICU1 in vitro increases oxygen consumption, decreases lactate production, inhibits clonal growth, migration and invasion of ovarian cancer cells, whereas silencing in vivo inhibits tumour growth, increases cisplatin efficacy and OS. Mechanistically, silencing MICU1 activates pyruvate dehydrogenase (PDH) by stimulating the PDPhosphatase-phosphoPDH-PDH axis. Forced-expression of MICU1 in normal cells phenocopies the metabolic aberrations of malignant cells. Consistent with the in vitro and in vivo findings we observe a significant correlation between MICU1 and pPDH (inactive form of PDH) expression with poor prognosis. Thus, MICU1 could serve as an important therapeutic target to normalize metabolic aberrations responsible for poor prognosis in ovarian cancer.
Collapse
Affiliation(s)
- Prabir K. Chakraborty
- Department of Pathology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Soumyajit Banerjee Mustafi
- Department of Obstetrics and Gynecology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Xunhao Xiong
- Department of Pathology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Shailendra Kumar Dhar Dwivedi
- Department of Obstetrics and Gynecology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Vasyl Nesin
- Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma 73104, USA
| | - Sounik Saha
- Department of Pathology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Min Zhang
- Department of Pharmaceutical Sciences, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania 15261, USA
| | - Danny Dhanasekaran
- Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma 73104, USA
- Peggy and Charles Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Muralidharan Jayaraman
- Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma 73104, USA
| | - Robert Mannel
- Department of Obstetrics and Gynecology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
- Peggy and Charles Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Kathleen Moore
- Department of Obstetrics and Gynecology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
- Peggy and Charles Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Scott McMeekin
- Department of Obstetrics and Gynecology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
- Peggy and Charles Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Da Yang
- Department of Pharmaceutical Sciences, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania 15261, USA
| | - Rosemary Zuna
- Department of Pathology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
- Peggy and Charles Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Kai Ding
- College of Public Health, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Leonidas Tsiokas
- Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma 73104, USA
| | - Resham Bhattacharya
- Department of Obstetrics and Gynecology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
- Peggy and Charles Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Priyabrata Mukherjee
- Department of Pathology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
- Peggy and Charles Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| |
Collapse
|
5
|
Kim S, Nie H, Nesin V, Tran U, Outeda P, Bai CX, Keeling J, Maskey D, Watnick T, Wessely O, Tsiokas L. The polycystin complex mediates Wnt/Ca(2+) signalling. Nat Cell Biol 2016; 18:752-764. [PMID: 27214281 PMCID: PMC4925210 DOI: 10.1038/ncb3363] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 04/22/2016] [Indexed: 01/22/2023]
Abstract
WNT ligands induce Ca2+ signaling on target cells. PKD1 (Polycystin 1) is considered an orphan, atypical G protein coupled receptor complexed with TRPP2 (Polycystin 2 or PKD2), a Ca2+-permeable ion channel. Inactivating mutations in their genes cause autosomal dominant polycystic kidney disease (ADPKD), one of the most common genetic diseases. Here, we show that WNTs bind to the extracellular domain of PKD1 and induce whole cell currents and Ca2+ influx dependent on TRPP2. Pathogenic PKD1 or PKD2 mutations that abrogate complex formation, compromise cell surface expression of PKD1, or reduce TRPP2 channel activity suppress activation by WNTs. Pkd2−/− fibroblasts lack WNT-induced Ca2+ currents and are unable to polarize during directed cell migration. In Xenopus embryos, PKD1, Dishevelled 2 (DVL2), and WNT9A act within the same pathway to preserve normal tubulogenesis. These data define PKD1 as a WNT (co)receptor and implicate defective WNT/Ca2+ signaling as one of the causes of ADPKD.
Collapse
Affiliation(s)
- Seokho Kim
- Department of Cell Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK 73104, USA
| | - Hongguang Nie
- Department of Cell Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK 73104, USA.,Institute of Metabolic Disease Research and Drug Development, China Medical University, Liaoning Shenyang, 110001 China (H.N)
| | - Vasyl Nesin
- Department of Cell Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK 73104, USA
| | - Uyen Tran
- Department of Cellular and Molecular Medicine, Cleveland Clinic, 9500 Euclid Avenue/NC10, Cleveland, OH 44195, USA
| | - Patricia Outeda
- Division of Nephrology, Baltimore PKD Research and Clinical Core Center, University of Maryland School of Medicine, 655 West Baltimore Street, Baltimore, MD 21201, USA
| | - Chang-Xi Bai
- Department of Cell Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK 73104, USA.,Department of Advanced Research on Mongolian Medicine, Research Institute for Mongolian Medicine, Inner Mongolia Medical University, Hohhot 010110, Inner Mongolia, China (CB)
| | - Jacob Keeling
- Department of Cell Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK 73104, USA
| | - Dipak Maskey
- Department of Cell Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK 73104, USA
| | - Terry Watnick
- Division of Nephrology, Baltimore PKD Research and Clinical Core Center, University of Maryland School of Medicine, 655 West Baltimore Street, Baltimore, MD 21201, USA
| | - Oliver Wessely
- Department of Cellular and Molecular Medicine, Cleveland Clinic, 9500 Euclid Avenue/NC10, Cleveland, OH 44195, USA
| | - Leonidas Tsiokas
- Department of Cell Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK 73104, USA
| |
Collapse
|
6
|
Nesin V, Kim S, Nie H, Tsiokas L. The WNT Proteins Induce Ca2+ Signaling through the Activation of the Polycystin Complex. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
7
|
Abstract
The TRPC1 ion channel was the first mammalian TRP channel to be cloned. In humans, it is encoded by the TRPC1 gene located in chromosome 3. The protein is predicted to consist of six transmembrane segments with the N- and C-termini located in the cytoplasm. The extracellular loop connecting transmembrane segments 5 and 6 participates in the formation of the ionic pore region. Inside the cell, TRPC1 is present in the endoplasmic reticulum, plasma membrane, intracellular vesicles, and primary cilium, an antenna-like sensory organelle functioning as a signaling platform. In human and rodent tissues, it shows an almost ubiquitous expression. TRPC1 interacts with a diverse group of proteins including ion channel subunits, receptors, and cytosolic proteins to mediate its effect on Ca(2+) signaling. It primarily functions as a cation nonselective channel within pathways controlling Ca(2+) entry in response to cell surface receptor activation. Through these pathways, it affects basic cell functions, such as proliferation and survival, differentiation, secretion, and cell migration, as well as cell type-specific functions such as chemotropic turning of neuronal growth cones and myoblast fusion. The biological role of TRPC1 has been studied in genetically engineered mice where the Trpc1 gene has been experimentally ablated. Although these mice live to adulthood, they show defects in several organs and tissues, such as the cardiovascular, central nervous, skeletal and muscular, and immune systems. Genetic and functional studies have implicated TRPC1 in diabetic nephropathy, Parkinson's disease, Huntington's disease, Duchenne muscular dystrophy, cancer, seizures, and Darier-White skin disease.
Collapse
Affiliation(s)
- Vasyl Nesin
- Department of Cell Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK, 73104, USA
| | | |
Collapse
|
8
|
Ong EC, Nesin V, Long CL, Bai CX, Guz JL, Ivanov IP, Abramowitz J, Birnbaumer L, Humphrey MB, Tsiokas L. A TRPC1 protein-dependent pathway regulates osteoclast formation and function. J Biol Chem 2013; 288:22219-32. [PMID: 23770672 DOI: 10.1074/jbc.m113.459826] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Ca(2+) signaling is essential for bone homeostasis and skeletal development. Here, we show that the transient receptor potential canonical 1 (TRPC1) channel and the inhibitor of MyoD family, I-mfa, function antagonistically in the regulation of osteoclastogenesis. I-mfa null mice have an osteopenic phenotype characterized by increased osteoclast numbers and surface, which are normalized in mice lacking both Trpc1 and I-mfa. In vitro differentiation of pre-osteoclasts derived from I-mfa-deficient mice leads to an increased number of mature osteoclasts and higher bone resorption per osteoclast. These parameters return to normal levels in osteoclasts derived from double mutant mice. Consistently, whole cell currents activated in response to the depletion of intracellular Ca(2+) stores are larger in pre-osteoclasts derived from I-mfa knock-out mice compared with currents in wild type mice and normalized in cells derived from double mutant mice, suggesting a cell-autonomous effect of I-mfa on TRPC1 in these cells. A new splice variant of TRPC1 (TRPC1ε) was identified in early pre-osteoclasts. Heterologous expression of TRPC1ε in HEK293 cells revealed that it is unique among all known TRPC1 isoforms in its ability to amplify the activity of the Ca(2+) release-activated Ca(2+) (CRAC) channel, mediating store-operated currents. TRPC1ε physically interacts with Orai1, the pore-forming subunit of the CRAC channel, and I-mfa is recruited to the TRPC1ε-Orai1 complex through TRPC1ε suppressing CRAC channel activity. We propose that the positive and negative modulation of the CRAC channel by TRPC1ε and I-mfa, respectively, fine-tunes the dynamic range of the CRAC channel regulating osteoclastogenesis.
Collapse
Affiliation(s)
- E-Ching Ong
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73014, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Nesin V, Pakhomov AG. Inhibition of voltage-gated Na(+) current by nanosecond pulsed electric field (nsPEF) is not mediated by Na(+) influx or Ca(2+) signaling. Bioelectromagnetics 2012; 33:443-51. [PMID: 22234846 DOI: 10.1002/bem.21703] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2011] [Accepted: 12/12/2011] [Indexed: 11/10/2022]
Abstract
In earlier studies, we found that permeabilization of mammalian cells with nsPEF was accompanied by prolonged inhibition of voltage-gated (VG) currents through the plasma membrane. This study explored if the inhibition of VG Na(+) current (I(Na)) resulted from (i) reduction of the transmembrane Na(+) gradient due to its influx via nsPEF-opened pores, and/or (ii) downregulation of the VG channels by a Ca(2+)-dependent mechanism. We found that a single 300 ns electric pulse at 1.6-5.3 kV/cm triggered sustained Na(+) influx in exposed NG108 cells and in primary chromaffin cells, as detected by increased fluorescence of a Sodium Green Dye. In the whole-cell patch clamp configuration, this influx was efficiently buffered by the pipette solution so that the increase in the intracellular concentration of Na(+) ([Na](i)) did not exceed 2-3 mM. [Na](i) increased uniformly over the cell volume and showed no additional peaks immediately below the plasma membrane. Concurrently, nsPEF reduced VG I(Na) by 30-60% (at 4 and 5.3 kV/cm). In control experiments, even a greater increase of the pipette [Na(+)] (by 5 mM) did not attenuate VG I(Na), thereby indicating that the nsPEF-induced Na(+) influx was not the cause of VG I(Na) inhibition. Similarly, adding 20 mM of a fast Ca(2+) chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) into the pipette solution did not prevent or attenuate the inhibition of the VG I(Na) by nsPEF. These findings point to possible Ca(2+)-independent downregulation of the VG Na(+) channels (e.g., caused by alteration of the lipid bilayer) or the direct effect of nsPEF on the channel.
Collapse
Affiliation(s)
- Vasyl Nesin
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA
| | | |
Collapse
|
10
|
Nesin V, Bowman AM, Xiao S, Pakhomov AG. Cell permeabilization and inhibition of voltage-gated Ca(2+) and Na(+) channel currents by nanosecond pulsed electric field. Bioelectromagnetics 2011; 33:394-404. [PMID: 22213081 DOI: 10.1002/bem.21696] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 10/16/2011] [Indexed: 11/09/2022]
Abstract
Previous studies have found that nanosecond pulsed electric field (nsPEF) exposure causes long-term permeabilization of the cell plasma membrane. In this study, we utilized the whole-cell patch-clamp method to study the nsPEF effect on currents of voltage-gated (VG) Ca(2+) and Na(+) channels (I(Ca) and I(Na)) in cultured GH3 and NG108 cells. We found that a single 300 or 600 ns pulse at or above 1.5-2 kV/cm caused prolonged inhibition of I(Ca) and I(Na). Concurrently, nsPEF increased a non-inactivating "leak" current (I(leak)), presumably due to the formation of nanoelectropores or larger pores in the plasma membrane. The nsPEF effects were similar in cells that were exposed intact and subsequently brought into the whole-cell recording configuration, and in cells that were first brought into the whole-cell configuration and then exposed. Although both I(leak) and the inhibition of VG currents were enhanced at higher E-field levels, these two nsPEF effects showed relatively weak correlation with each other. In some cells, I(leak) increased 10-fold or more while VG currents remained unchanged. At longer time intervals after exposure (5-15 min), I(Ca) and I(Na) could remain inhibited although I(leak) had largely recovered. The causal relation of nsPEF inhibitory effects on VG currents and permeabilization of the plasma membrane is discussed.
Collapse
Affiliation(s)
- Vasyl Nesin
- Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA
| | | | | | | |
Collapse
|
11
|
Shu Xiao, Siqi Guo, Nesin V, Heller R, Schoenbach KH. Subnanosecond Electric Pulses Cause Membrane Permeabilization and Cell Death. IEEE Trans Biomed Eng 2011; 58:1239-45. [DOI: 10.1109/tbme.2011.2112360] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
12
|
Nesin V. The Mechanisms of Decreasing Voltage-Gated Sodium Current by Nanosecond Electric Pulses. Biophys J 2011. [DOI: 10.1016/j.bpj.2010.12.3500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
|