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Xia K, Ma Z, Shen J, Li M, Hou B, Gao M, Zhang S, Wu J. The 2-aminoethoxydiphenyl borate analog, DPB161 blocks store-operated Ca 2+ entry in acutely dissociated rat submandibular cells. Oncotarget 2017; 8:61551-61560. [PMID: 28977884 PMCID: PMC5617444 DOI: 10.18632/oncotarget.18623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 05/06/2017] [Indexed: 02/05/2023] Open
Abstract
Cellular Ca2+ signals play a critical role in cell physiology and pathology. In most non-excitable cells, store-operated Ca2+ entry (SOCE) is an important mechanism by which intracellular Ca2+ signaling is regulated. However, few drugs can selectively modulate SOCE. 2-Aminoethoxydiphenyl borate (2APB) and its analogs (DPB162 and DPB163) have been reported to inhibit SOCE. Here, we examined the effects of another 2-APB analog, DPB161 on SOCE in acutely-isolated rat submandibular cells. Both patch-clamp recordings and Ca2+ imaging showed that upon removal of extracellular Ca2+ ([Ca2+]o=0), rat submandibular cells were unable to maintain ACh-induced Ca2+ oscillations, but restoration of [Ca2+]o to refill Ca2+ stores enable recovery of these Ca2+ oscillations. However, addition of 50 μM DPB161 with [Ca2+]o to extracellular solution prevented the refilling of Ca2+ store. Fura-2 Ca2+ imaging showed that DPB161 inhibited SOCE in a concentration-dependent manner. After depleting Ca2+ stores by thapsigargin treatment, bath perfusion of 1 mM Ca2+ induced [Ca2+]i elevation in a manner that was prevented by DPB161. Collectively, these results show that the 2-APB analog DPB161 blocks SOCE in rat submandibular cells, suggesting that this compound can be developed as a pharmacological tool for the study of SOCE function and as a new therapeutic agent for treating SOCE-associated disorders.
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Affiliation(s)
- Kunkun Xia
- Department of Hepatobiliary and Pancreatic Surgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Department of Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA
| | - Zegang Ma
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders and State Key Disciplines, Physiology, Medical College of Qingdao University, Qingdao, China.,Department of Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA
| | - Jianxin Shen
- Department of Physiology, Shantou University Medical College, Shantou, China
| | - Menghan Li
- Department of Physiology, Shantou University Medical College, Shantou, China
| | - Baoke Hou
- Department of Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA
| | - Ming Gao
- Department of Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA
| | - Shuijun Zhang
- Department of Hepatobiliary and Pancreatic Surgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Jie Wu
- Department of Hepatobiliary and Pancreatic Surgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Department of Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA.,Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders and State Key Disciplines, Physiology, Medical College of Qingdao University, Qingdao, China.,Department of Physiology, Shantou University Medical College, Shantou, China
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Tatsumi H, Toyota M, Furuichi T, Sokabe M. Calcium mobilizations in response to changes in the gravity vector in Arabidopsis seedlings: possible cellular mechanisms. PLANT SIGNALING & BEHAVIOR 2014; 9:e29099. [PMID: 25763612 PMCID: PMC4203510 DOI: 10.4161/psb.29099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 05/02/2014] [Accepted: 05/02/2014] [Indexed: 05/11/2023]
Abstract
Gravity influences the growth direction of higher plants. Changes in the gravity vector (gravistimulation) immediately promote the increase in the cytoplasmic free calcium ion concentration ([Ca(2+)]c) in Arabidopsis (Arabidopsis thaliana) seedlings. When the seedlings are gravistimulated by reorientation at 180°, a transient two peaked (biphasic) [Ca(2+)]c-increase arises in their hypocotyl and petioles. Parabolic flights (PFs) can generate a variety of gravity-stimuli, and enables us to measure gravity-induced [Ca(2+)]c-increases without specimen rotation, which demonstrate that Arabidopsis seedlings possess a rapid gravity-sensing mechanism linearly transducing a wide range of gravitational changes into Ca(2+) signals on a sub-second timescale. Hypergravity by centrifugation (20 g or 300 g) also induces similar transient [Ca(2+)]c-increases. In this review, we propose models for possible cellular processes of the garavi-stimulus-induced [Ca(2+)]c-increase, and evaluate those by examining whether the model fits well with the kinetic parameters derived from the [Ca(2+)]c-increases obtained by applying gravistimulus with different amplitudes and time sequences.
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Affiliation(s)
- Hitoshi Tatsumi
- Nagoya University Graduate School of Medicine; Nagoya, Japan
| | - Masatsugu Toyota
- Department of Botany; University of Wisconsin; Madison, WI USA
- Precursory Research for Embryonic Science and Technology (PRESTO); Japan Science and Technology Agency (JST); Kawaguchi, Saitama, Japan
| | - Takuya Furuichi
- Department of Health and Nutrition; Gifu Women’s University; Gifu, Japan
| | - Masahiro Sokabe
- Nagoya University Graduate School of Medicine; Nagoya, Japan
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Larina O, Thorn P. Ca2+ dynamics in salivary acinar cells: distinct morphology of the acinar lumen underlies near-synchronous global Ca2+ responses. J Cell Sci 2005; 118:4131-9. [PMID: 16118245 DOI: 10.1242/jcs.02533] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In salivary acinar cells, the pattern of the Ca2+ signals that regulates fluid and enzyme secretion has yet to be resolved, as there are conflicting reports in the literature. We have used a two-photon technique to directly visualize the acinar cell lumen in living fragments of exocrine tissue and simultaneously recorded agonist-induced changes in intracellular Ca2+. We show near-synchronous global Ca2+ responses in submandibular acinar cells, distinct from the typical apical to basal Ca2+ wave usually seen in rodent pancreatic acinar cells. In an effort to explain the basis of these near-synchronous global Ca2+ responses we used immunocytochemical experiments to localize luminal proteins and inositol trisphosphate receptors (InsP3Rs) in tissue fragments. Zona occludens 1 (ZO-1), a tight junction protein, shows that individual submandibular acinar cells are often nearly completely encircled by a narrow luminal structure. By contrast, in pancreatic fragments, ZO-1 staining shows short luminal branches terminating abruptly at the apical pole of single acinar cells. Co-immunostaining of InsP3Rs type 2 and type 3 showed them in the same region as ZO-1 in both exocrine tissues. Functional experiments showed that the near-synchronous global Ca2+ responses were still observed in the absence of extracellular Ca2+ and also in the presence of ryanodine. We conclude that the elaborate luminal region of submandibular cells leads to a hitherto unrecognized extensive distribution of InsP3Rs in a band around the cell and that this underlies the near-synchronous global Ca2+ response to agonists. We suggest that this may be a structural adaptation in submandibular cells to support the copious amounts of fluid secreted.
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Affiliation(s)
- Olga Larina
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
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Wu J, Kamimura N, Takeo T, Suga S, Wakui M, Maruyama T, Mikoshiba K. 2-Aminoethoxydiphenyl borate modulates kinetics of intracellular Ca(2+) signals mediated by inositol 1,4,5-trisphosphate-sensitive Ca(2+) stores in single pancreatic acinar cells of mouse. Mol Pharmacol 2000; 58:1368-74. [PMID: 11093775 DOI: 10.1124/mol.58.6.1368] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Regulation of the kinetics of intracellular Ca(2+) signals with a novel, membrane-penetrable, inositol 1,4,5-trisphosphate (InsP(3)) receptor/Ca(2+) channel modulator, 2-amino-ethoxydiphenyl borate (2APB), has been investigated using patch-clamp, whole-cell recording to monitor Ca(2+)-activated Cl(-) currents in single isolated pancreatic acinar cells. 2APB itself fails to evoke a detectable current response but it dramatically changes the kinetics of agonist-induced Ca(2+) release from pulsatile spikes to long-lasting, huge Ca(2+) waves, suggesting that 2APB coordinates local Ca(2+) release to generate global Ca(2+) signals. The regulation by 2APB can be elicited by internal perfusion of InsP(3) in a concentration-dependent manner, indicating that this regulation is not mediated through membrane receptors or G protein signal transduction. The InsP(3) receptor blocker heparin, but not the ryanodine-sensitive receptor blockers ruthenium red or ryanodine, abolishes 2APB-mediated regulation of Ca(2+) release. This results also suggest that 2APB effects are mediated through InsP(3) receptors. 2APB substantially modifies single inward Cl(-) current pulse evoked by the photolytic release of caged InsP(3) but not by caged Ca(2+). These data indicate that 2APB-induced regulation is mediated neither by Ca(2+)-induced Ca(2+) release nor by affecting Cl(-) channel activity directly. We conclude that 2APB regulates the kinetics of intracellular Ca(2+) signals, represented as the change in the Ca(2+) oscillation patterns from brief pulsatile spikes to huge, long-lasting Ca(2+) waves. Moreover, this regulation seems to be mediated through InsP(3)-sensitive Ca(2+) pools. 2APB may act as a novel, useful pharmacological tool to study the genesis of intracellular Ca(2+) signals.
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Affiliation(s)
- J Wu
- Department of Physiology, Hirosaki University School of Medicine, Hirosaki, Japan.
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