101
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Abstract
Store-operated calcium entry is a process by which the depletion of calcium from the endoplasmic reticulum activates calcium influx across the plasma membrane. In the past few years, the major players in this pathway have been identified. STIM1 and STIM2 function as calcium sensors in the endoplasmic reticulum and can interact with and activate plasma membrane channels comprised of Orai1, Orai2, or Orai3 subunits. This review discusses recent advances in our understanding of this widespread signaling mechanism as well as the mechanisms by which a number of interesting pharmacological agents modify it.
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Affiliation(s)
- James W Putney
- Calcium Regulation Section, National Institute of Environmental Health Sciences - NIH, Department of Health and Human Services, PO Box 12233, Research Triangle Park, NC 27709, USA.
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102
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Wei L, Lu N, Dai Q, Rong J, Chen Y, Li Z, You Q, Guo Q. Different apoptotic effects of wogonin via induction of H2O2 generation and Ca2+ overload in malignant hepatoma and normal hepatic cells. J Cell Biochem 2010; 111:1629-41. [DOI: 10.1002/jcb.22898] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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103
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Zhang Y, Wang QL, Zhan YZ, Duan HJ, Cao YJ, He LC. Role of store-operated calcium entry in imperatorin-induced vasodilatation of rat small mesenteric artery. Eur J Pharmacol 2010; 647:126-31. [PMID: 20813104 DOI: 10.1016/j.ejphar.2010.08.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 06/26/2010] [Accepted: 08/12/2010] [Indexed: 12/28/2022]
Abstract
Store-operated Ca(2+) entry (SOCE) has recently been proposed to contribute to Ca(2+) influx in vascular smooth muscle cells (VSMCs). Imperatorin is known for its potent vasodilatory effects as a dietary furanocoumarin. The study was designed to examine the hypothesis that SOCE have a functional role in imperatorin-induced vasodilation. Small mesenteric resistance arteries and mesenteric VSMCs were obtained from rats. Isometric tensions of isolated artery rings were measured by a sensitive myograph system. Laser scanning confocal microscopy was used to determine the intracellular Ca(2+) concentration of fluo-3-loaded VSMCs. Imperatorin (1-100 μM) relaxed artery rings precontracted by phenylephrine in a concentration-dependent manner. In cultured mesenteric VSMCs, passive store depletion by thapsigargin and active store depletion by phenylephrine both induced Ca(2+) influx due to SOCE. Imperatorin didn't inhibit SOCE-mediated increases in cytosolic Ca(2+) levels evoked by the emptying of the stores. In isolated artery rings, imperatorin didn't inhibit SOCE-induced contractions due to store depletion. Our results exclude SOCE mechanism of vasodilatation by imperatorin. But imperatorin is partly similar with nifedipine in vasorelaxation effect.
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Affiliation(s)
- Yan Zhang
- School of Medicine, Xi'an Jiaotong University, Xi'an, PR China
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104
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Weinbaum S, Duan Y, Satlin LM, Wang T, Weinstein AM. Mechanotransduction in the renal tubule. Am J Physiol Renal Physiol 2010; 299:F1220-36. [PMID: 20810611 DOI: 10.1152/ajprenal.00453.2010] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The role of mechanical forces in the regulation of glomerulotubular balance in the proximal tubule (PT) and Ca(2+) signaling in the distal nephron was first recognized a decade ago, when it was proposed that the microvilli in the PT and the primary cilium in the cortical collecting duct (CCD) acted as sensors of local tubular flow. In this review, we present a summary of the theoretical models and experiments that have been conducted to elucidate the structure and function of these unique apical structures in the modulation of Na(+), HCO(3)(-), and water reabsorption in the PT and Ca(2+) signaling in the CCD. We also contrast the mechanotransduction mechanisms in renal epithelium with those in other cells in which fluid shear stresses have been recognized to play a key role in initiating intracellular signaling, most notably endothelial cells, hair cells in the inner ear, and bone cells. In each case, small hydrodynamic forces need to be greatly amplified before they can be sensed by the cell's intracellular cytoskeleton to enable the cell to regulate its membrane transporters or stretch-activated ion channels in maintaining homeostasis in response to changing flow conditions.
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Affiliation(s)
- Sheldon Weinbaum
- Dept. of Biomedical Engineering, The City College of New York, New York, NY 10031, USA.
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105
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Sun W, Pan L, Ma Z. Hypo-osmotic stress enhances the uptake of polyethylenimine/oligonucleotide complexes in A549 cells via Ca(2+) mobilization from intracellular stores. Oligonucleotides 2010; 20:111-5. [PMID: 20078246 DOI: 10.1089/oli.2009.0203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
To determine the mechanism of osmolarity involved in polyethylenimine (PEI)/oligonucleotide (ON) complex transfection in cells, we measured the fluorescence intensities of fluorescein isothiocyanate-labeled ONs complexed with PEI and the changes in cytosolic Ca(2+) concentration ([Ca(2+)](c)) in A549 cells, and we found that uptake of PEI/ON complexes was improved in the cells along with a rise of [Ca(2+)](c) in A549 cells challenged by 50% hypotonic medium. Further experiments showed that the enhanced uptake efficiency and the rise in [Ca(2+)](c) in A549 cells were almost completely abolished from cells loaded with the intracellular calcium chelator 1,2-bis(2-aminophenoxy)-N,N,N,N-tetraacetic acid-acetoxymethyl ester. 2-Aminoethoxydiphenyl borate or 8-(N,N-diethylamino) octyl-3,4,5-trimethoxybenzoate, two potent antagonists of inositol 1,4,5-trisphosphate-mediated Ca(2+) release that blunt [Ca(2+)](c) elevation via Ca(2+) release from endoplasmic reticulum, inhibited the enhanced uptake of PEI/ON complexes induced by Ca(2+)-free hypo-osmotic stress. In summary, the results strongly suggest that calcium-dependent transfection is responsible for the uptake of PEI/ON complexes into A549 cells under hypotonic conditions.
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Affiliation(s)
- Wenwu Sun
- Department of Respiratory Medicine, The Northern Hospital of ShenYang, Shenyang, China
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106
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Kerem A, Yin J, Kaestle SM, Hoffmann J, Schoene AM, Singh B, Kuppe H, Borst MM, Kuebler WM. Lung Endothelial Dysfunction in Congestive Heart Failure. Circ Res 2010; 106:1103-16. [DOI: 10.1161/circresaha.109.210542] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Rationale
:
Congestive heart failure (CHF) frequently results in remodeling and increased tone of pulmonary resistance vessels. This adaptive response, which aggravates pulmonary hypertension and thus, promotes right ventricular failure, has been attributed to lung endothelial dysfunction.
Objective
:
We applied real-time fluorescence imaging to identify endothelial dysfunction and underlying molecular mechanisms in an experimental model of CHF induced by supracoronary aortic banding in rats.
Methods and Results
:
Endothelial dysfunction was evident in lungs of CHF rats as impaired endothelium-dependent vasodilation and lack of endothelial NO synthesis in response to mechanical stress, acetylcholine, or histamine. This effect was not attributable to downregulation of endothelial NO synthase. Imaging of the cytosolic Ca
2+
concentration ([Ca
2+
]
i
) revealed a singular impairment of endothelial [Ca
2+
]
i
homeostasis and signaling characterized by a lack of [Ca
2+
]
i
oscillations and deficient or attenuated [Ca
2+
]
i
responses to mechanical stress, histamine, acetylcholine, or thapsigargin. Reconstitution of a [Ca
2+
]
i
signal by ionophore treatment restored endothelial NO production, but lack of endothelial responsiveness was not primarily attributable to downregulation of Ca
2+
influx channels in CHF. Rather, we identified a massive remodeling of the endothelial cytoskeleton in the form of an increased expression of β-actin and F-actin formation which contributed critically to endothelial dysfunction in CHF because cytoskeletal disruption by cytochalasin D largely reconstituted endothelial [Ca
2+
]
i
signaling and NO production.
Conclusions
:
Our findings characterize a unique scenario of endothelial dysfunction in CHF that is caused by a singular impairment of [Ca
2+
]
i
signaling, and identify cytoskeletal reorganization as a major regulator of endothelial signaling and function.
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Affiliation(s)
- Alexander Kerem
- From the Institute of Physiology (A.K., J.Y., S.M.K., J.H., W.M.K.), Charité–Universitätsmedizin Berlin, Germany; German Heart Institute Berlin (J.Y., W.M.K., H.K.), Germany; Keenan Research Centre (J.Y., W.M.K.), Li Ka Shing Knowledge Institute, St Michael’s Hospital, Toronto, Ontario, Canada; Department of Cardiology, Angiology and Pneumology (A.M.S., M.M.B.), University of Heidelberg, Germany; Department of Veterinary Biomedical Sciences (B.S.), Western College of Veterinary Medicine,
| | - Jun Yin
- From the Institute of Physiology (A.K., J.Y., S.M.K., J.H., W.M.K.), Charité–Universitätsmedizin Berlin, Germany; German Heart Institute Berlin (J.Y., W.M.K., H.K.), Germany; Keenan Research Centre (J.Y., W.M.K.), Li Ka Shing Knowledge Institute, St Michael’s Hospital, Toronto, Ontario, Canada; Department of Cardiology, Angiology and Pneumology (A.M.S., M.M.B.), University of Heidelberg, Germany; Department of Veterinary Biomedical Sciences (B.S.), Western College of Veterinary Medicine,
| | - Stephanie M. Kaestle
- From the Institute of Physiology (A.K., J.Y., S.M.K., J.H., W.M.K.), Charité–Universitätsmedizin Berlin, Germany; German Heart Institute Berlin (J.Y., W.M.K., H.K.), Germany; Keenan Research Centre (J.Y., W.M.K.), Li Ka Shing Knowledge Institute, St Michael’s Hospital, Toronto, Ontario, Canada; Department of Cardiology, Angiology and Pneumology (A.M.S., M.M.B.), University of Heidelberg, Germany; Department of Veterinary Biomedical Sciences (B.S.), Western College of Veterinary Medicine,
| | - Julia Hoffmann
- From the Institute of Physiology (A.K., J.Y., S.M.K., J.H., W.M.K.), Charité–Universitätsmedizin Berlin, Germany; German Heart Institute Berlin (J.Y., W.M.K., H.K.), Germany; Keenan Research Centre (J.Y., W.M.K.), Li Ka Shing Knowledge Institute, St Michael’s Hospital, Toronto, Ontario, Canada; Department of Cardiology, Angiology and Pneumology (A.M.S., M.M.B.), University of Heidelberg, Germany; Department of Veterinary Biomedical Sciences (B.S.), Western College of Veterinary Medicine,
| | - Axel M. Schoene
- From the Institute of Physiology (A.K., J.Y., S.M.K., J.H., W.M.K.), Charité–Universitätsmedizin Berlin, Germany; German Heart Institute Berlin (J.Y., W.M.K., H.K.), Germany; Keenan Research Centre (J.Y., W.M.K.), Li Ka Shing Knowledge Institute, St Michael’s Hospital, Toronto, Ontario, Canada; Department of Cardiology, Angiology and Pneumology (A.M.S., M.M.B.), University of Heidelberg, Germany; Department of Veterinary Biomedical Sciences (B.S.), Western College of Veterinary Medicine,
| | - Baljit Singh
- From the Institute of Physiology (A.K., J.Y., S.M.K., J.H., W.M.K.), Charité–Universitätsmedizin Berlin, Germany; German Heart Institute Berlin (J.Y., W.M.K., H.K.), Germany; Keenan Research Centre (J.Y., W.M.K.), Li Ka Shing Knowledge Institute, St Michael’s Hospital, Toronto, Ontario, Canada; Department of Cardiology, Angiology and Pneumology (A.M.S., M.M.B.), University of Heidelberg, Germany; Department of Veterinary Biomedical Sciences (B.S.), Western College of Veterinary Medicine,
| | - Hermann Kuppe
- From the Institute of Physiology (A.K., J.Y., S.M.K., J.H., W.M.K.), Charité–Universitätsmedizin Berlin, Germany; German Heart Institute Berlin (J.Y., W.M.K., H.K.), Germany; Keenan Research Centre (J.Y., W.M.K.), Li Ka Shing Knowledge Institute, St Michael’s Hospital, Toronto, Ontario, Canada; Department of Cardiology, Angiology and Pneumology (A.M.S., M.M.B.), University of Heidelberg, Germany; Department of Veterinary Biomedical Sciences (B.S.), Western College of Veterinary Medicine,
| | - Mathias M. Borst
- From the Institute of Physiology (A.K., J.Y., S.M.K., J.H., W.M.K.), Charité–Universitätsmedizin Berlin, Germany; German Heart Institute Berlin (J.Y., W.M.K., H.K.), Germany; Keenan Research Centre (J.Y., W.M.K.), Li Ka Shing Knowledge Institute, St Michael’s Hospital, Toronto, Ontario, Canada; Department of Cardiology, Angiology and Pneumology (A.M.S., M.M.B.), University of Heidelberg, Germany; Department of Veterinary Biomedical Sciences (B.S.), Western College of Veterinary Medicine,
| | - Wolfgang M. Kuebler
- From the Institute of Physiology (A.K., J.Y., S.M.K., J.H., W.M.K.), Charité–Universitätsmedizin Berlin, Germany; German Heart Institute Berlin (J.Y., W.M.K., H.K.), Germany; Keenan Research Centre (J.Y., W.M.K.), Li Ka Shing Knowledge Institute, St Michael’s Hospital, Toronto, Ontario, Canada; Department of Cardiology, Angiology and Pneumology (A.M.S., M.M.B.), University of Heidelberg, Germany; Department of Veterinary Biomedical Sciences (B.S.), Western College of Veterinary Medicine,
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107
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Ritchie MF, Yue C, Zhou Y, Houghton PJ, Soboloff J. Wilms tumor suppressor 1 (WT1) and early growth response 1 (EGR1) are regulators of STIM1 expression. J Biol Chem 2010; 285:10591-6. [PMID: 20123987 PMCID: PMC2856267 DOI: 10.1074/jbc.m109.083493] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Revised: 01/25/2010] [Indexed: 01/12/2023] Open
Abstract
Store-operated calcium entry (SOCE) is a key evolutionarily conserved process whereby decreases in endoplasmic reticulum Ca(2+) content lead to the influx of Ca(2+) across the plasma membrane. How this process is regulated in specific tumor cell types is poorly understood. In an effort to address this concern, we obtained and tested primary Wilms tumor cells, finding no detectable SOCE in this cell type. Analysis of the expression levels of STIM1 and ORAI1 (the molecular mediators of SOC) revealed poor STIM1 expression. Analysis of the STIM1 promoter using the TESS search system (University of Pennsylvania) revealed four putative response elements to the zinc-finger proteins WT1 (Wilms tumor suppressor 1) and EGR1 (early growth response 1). Either overexpression of WT1 or knockdown of EGR1 resulted in loss of STIM1 expression and a resultant decrease in SOCE. Furthermore, examination of Egr1 knock-out animals revealed loss of STIM1 expression in multiple tissues. Finally, using chromatin immunoprecipitation, we reveal direct binding of both WT1 and EGR1 to putative response elements located within 500 bp of the transcriptional start site of STIM1. Considering that WT1 and EGR1 are well described oncogenes and tumor suppressors, these observations may reveal new mechanisms responsible for distinct Ca(2+) signals in cancer cells.
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Affiliation(s)
- Michael F. Ritchie
- From the Department of Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania 19140 and
| | - Chanyu Yue
- From the Department of Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania 19140 and
| | - Yandong Zhou
- From the Department of Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania 19140 and
| | - Peter J. Houghton
- the Children's Cancer Center, Nationwide Children's Hospital, Columbus, Ohio 43205
| | - Jonathan Soboloff
- From the Department of Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania 19140 and
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108
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KIYONAKA S, KATO K, NISHIDA M, MORI Y. Pharmacological Properties of Novel TRPC Channel Inhibitors. YAKUGAKU ZASSHI 2010; 130:303-11. [DOI: 10.1248/yakushi.130.303] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Shigeki KIYONAKA
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University
| | - Kenta KATO
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University
| | - Motohiro NISHIDA
- Department of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Kyushu University
| | - Yasuo MORI
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University
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109
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Hayashi C, Iino K, Oki Y, Matsushita F, Yamashita M, Yogo K, Sasaki S, Kumada T, Nakamura H. Possible contribution of 2-aminoethoxydiphenyl-borate-sensitive Ca2+ mobilization to adrenocorticotropin-induced glucocorticoid synthesis in rat adrenocortical cells. Endocr J 2010; 57:109-17. [PMID: 19851032 DOI: 10.1507/endocrj.k09e-138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Cytoplasmic calcium ([Ca(2+)](i)) provided through voltage-dependent Ca(2+) channels (VDCC) plays an important role in adrenocorticotropin (ACTH)-induced steroidogenesis in adrenocortical cells. To identify alternative mechanisms for [Ca(2+)](i) supply, we investigated the 2-aminoethoxydiphenyl borate (2APB)-sensitive pathway as one of the possible signaling pathways involved in [Ca(2+)](i) supply for ACTH-induced steroidogenesis. In monolayers of cultured rat adrenal fasciculate and reticularis cells, ACTH at 10(-11) M stimulated corticosterone synthesis without increasing intracellular cAMP, and corticosterone synthesis was decreased by 10 microM 2APB by 51.8% (6.71 +/- 0.97 vs. 3.23 +/- 0.05 ng/mL/4 hours; p<0.05). Furthermore, 2APB significantly decreased the 10(-11) M ACTH-stimulated [Ca(2+)](i). ACTH increased the intracellular inositol-1,4,5-trisphosphate (IP3) content with a peak at 10(-13) M ACTH, which illustrates the possibility that ACTH activates IP3/diacylglycerol- dependent protein kinase C signal transduction. However, the difference in ACTH concentrations between that responsible for the IP3 increase and steroidogenesis without elevated cAMP, suggest a hypothesis that IP3 is not required for steroidogenesis, but does involve an unknown messenger, which stimulates the release of Ca(2+) from the ER or the subsequent store-operated Ca(2+) entry (SOCE). The pregnenolone concentration in the culture medium was increased by ACTH, which was significantly suppressed by 2APB, showing that the 2APB-sensitive Ca(2+) supply affects cholesterol transport into the mitochondrial membrane via steroidogenic acute regulatory protein. Therefore, the SOCE may contribute to ACTH-induced steroidogenesis in the mitochondrial region. In conclusion, the [Ca(2+)](i) used for steroidogenesis may be derived from a 2APB-sensitive pathway and via VDCCs, particularly at physiological concentrations of ACTH. We suggest that ACTH receptors activate steroidogenesis via inositol triphosphate, or an unknown downstream messenger, which could be inhibited by 2APB.
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Affiliation(s)
- Chiga Hayashi
- Second Division, Department of Medicine, Hamamatsu University School of Medicine,1-20-1 Handayama, Higashi-ku, Hamamatsu, Japan
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110
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Abstract
The Ca2+release-activated Ca2+ (CRAC) channel is a highly Ca2+-selective store-operated channel expressed in T cells, mast cells, and various other tissues. CRAC channels regulate critical cellular processes such as gene expression, motility, and the secretion of inflammatory mediators. The identification of Orai1, a key subunit of the CRAC channel pore, and STIM1, the endoplasmic reticulum (ER) Ca2+ sensor, have provided the tools to illuminate the mechanisms of regulation and the pore properties of CRAC channels. Recent evidence indicates that the activation of CRAC channels by store depletion involves a coordinated series of steps, which include the redistributions of STIM1 and Orai1, direct physical interactions between these proteins, and conformational changes in Orai1, culminating in channel activation. Additional studies have revealed that the high Ca2+ selectivity of CRAC channels arises from the presence of an intrapore Ca2+ binding site, the properties of which are finely honed to occlude the permeation of the much more prevalent Na+. Structure-function studies have led to the identification of the potential pore-binding sites for Ca2+, providing a firm framework for understanding the mechanisms of selectivity and gating of the CRAC channel. This review summarizes recent progress in understanding the mechanisms of CRAC channel activation, pore properties, and modulation.
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Affiliation(s)
- Murali Prakriya
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University School of Medicine, Chicago, IL 60611, USA.
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111
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Abstract
Rapid to moderately rapid changes in intracellular Ca2+ concentration, or Ca2+ signals, control a variety of critical cellular functions in the immune system. These signals are comprised of Ca2+ release from intracellular stores coordinated with Ca2+ influx across the plasma membrane. The most common mechanisms by which these two modes of signaling occur is through inositol 1,4,5-trisphosphate (IP3)-induced release of Ca2+ from the endoplasmic reticulum (ER) and store-operated Ca2+ entry across the plasma membrane. The latter process was postulated over 20 years ago, and in just the past few years, the key molecular players have been discovered: STIM proteins serve as sensors of Ca2+ within the ER which communicate with and activate plasma membrane store-operated channels composed of Orai subunits. The process of store-operated Ca2+ entry provides support for oscillating Ca2+ signals from the ER and also provides direct activator Ca2+ that signals to a variety of downstream effectors.
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Affiliation(s)
- James W Putney
- Laboratory of Signal Transduction, Department of Health and Human Services, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
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112
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Yehuda-Shnaidman E, Kalderon B, Azazmeh N, Bar-Tana J. Gating of the mitochondrial permeability transition pore by thyroid hormone. FASEB J 2009; 24:93-104. [PMID: 19723706 DOI: 10.1096/fj.09-133538] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The calorigenic-thermogenic activity of thyroid hormone (T3) has long been ascribed to uncoupling of mitochondrial oxidative phosphorylation. However, the mode of action of T3 in promoting mitochondrial proton leak is still unresolved. Mitochondrial uncoupling by T3 is reported here to be transduced in vivo in rats and in cultured Jurkat cells by gating of the mitochondrial permeability transition pore (PTP). T3-induced PTP gating is shown here to be abrogated in inositol 1,4,5-trisphosphate (IP(3)) receptor 1 (IP(3)R1)(-/-) cells, indicating that the endoplasmic reticulum IP(3)R1 may serve as upstream target for the mitochondrial activity of T3. IP(3)R1 gating by T3 is due to its increased expression and truncation into channel-only peptides, resulting in IP(3)-independent Ca(2+) efflux. Increased cytosolic Ca(2+) results in activation of protein phosphatase 2B, dephosphorylation and depletion of mitochondrial Bcl2 (S70), and increase in mitochondrial free Bax leading to low-conductance PTP gating. The T3 transduction pathway integrates genomic and nongenomic activities of T3 in regulating mitochondrial energetics and may offer novel targets for thyromimetics designed to modulate energy expenditure.
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Affiliation(s)
- Einav Yehuda-Shnaidman
- Department of Human Nutrition and Metabolism, Hebrew University Medical School, Jerusalem, Israel
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113
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Bishara NB, Triggle CR, Hill MA. Cytochrome P450 Products and Arachidonic Acid–Induced, Non–Store-Operated, Ca2+Entry in Cultured Bovine Endothelial Cells. ACTA ACUST UNITED AC 2009; 12:153-61. [PMID: 16162437 DOI: 10.1080/10623320500227036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Endothelial cells possess multiple mechanisms for the control of Ca2+ influx during agonist and mechanical stimulation. Increased intracellular Ca2+ during such events is important in the production of vasoactive substances including NO, prostacyclin, and, possibly, endothelium-derived hyperpolarizing factor(s). The present studies examined the effect of arachidonic acid on cellular Ca2+ entry and the underlying mechanisms by which this fatty acid regulates entry. Studies were conducted in cultured bovine aortic endothelial cells (passages 3 to 6) with changes in intracellular Ca2+ determined using the fluorescent Ca2+-sensitive indicator fura 2. Arachidonic acid (1 to 50 microM) stimulated Ca2+ entry from the superfusate without affecting Ca2+ release from intracellular stores. 2-aminoethoxydiphenyl borate (2APB) (100 microM) added at the peak of Ca2+ entry did not inhibit arachidonic acid-induced Ca2+ entry but, in contrast, significantly inhibited entry stimulated by ATP (1 microM). Arachidonic acid-induced Ca2+ entry was inhibited by econazole (1 microM), but not indomethacin (10 microM) or nordihydroguairetic acid (10 microM), suggesting the involvement of cytochrome P450 monooxygenase metabolite of arachidonic acid. Oleic acid (10 microM) was ineffective in inducing Ca2+ entry, whereas linoleic acid (10 microM) stimulated Ca2+ entry but by a mechanism insensitive to econazole. Collectively the data demonstrate that primary cultured aortic endothelial cells possess a Ca2+ entry mechanism modulated by arachidonic acid. This mode of Ca2+ entry appears to operate independently of store depletion-mediated mechanisms.
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Affiliation(s)
- Nour B Bishara
- Microvascular Biology Group, School of Medical Sciences, RMIT University, Melbourne, Victoria, Australia
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114
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Saeedi R, Saran VV, Wu SSY, Kume ES, Paulson K, Chan APK, Parsons HL, Wambolt RB, Dyck JRB, Brownsey RW, Allard MF. AMP-activated protein kinase influences metabolic remodeling in H9c2 cells hypertrophied by arginine vasopressin. Am J Physiol Heart Circ Physiol 2009; 296:H1822-32. [DOI: 10.1152/ajpheart.00396.2008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Substrate use switches from fatty acids toward glucose in pressure overload-induced cardiac hypertrophy with an acceleration of glycolysis being characteristic. The activation of AMP-activated protein kinase (AMPK) observed in hypertrophied hearts provides one potential mechanism for the acceleration of glycolysis. Here, we directly tested the hypothesis that AMPK causes the acceleration of glycolysis in hypertrophied heart muscle cells. The H9c2 cell line, derived from the embryonic rat heart, was treated with arginine vasopressin (AVP; 1 μM) to induce a cellular model of hypertrophy. Rates of glycolysis and oxidation of glucose and palmitate were measured in nonhypertrophied and hypertrophied H9c2 cells, and the effects of inhibition of AMPK were determined. AMPK activity was inhibited by 6-[4-(2-piperidin-1- yl-ethoxy)-phenyl]-3-pyridin-4-yl-pyrrazolo-[1,5-a]pyrimidine (compound C) or by adenovirus-mediated transfer of dominant negative AMPK. Compared with nonhypertrophied cells, glycolysis was accelerated and palmitate oxidation was reduced with no significant alteration in glucose oxidation in hypertrophied cells, a metabolic profile similar to that of intact hypertrophied hearts. Inhibition of AMPK resulted in the partial reduction of glycolysis in AVP-treated hypertrophied H9c2 cells. Acute exposure of H9c2 cells to AVP also activated AMPK and accelerated glycolysis. These elevated rates of glycolysis were not altered by AMPK inhibition but were blocked by agents that interfere with Ca2+ signaling, including extracellular EGTA, dantrolene, and 2-aminoethoxydiphenyl borate. We conclude that the acceleration of glycolysis in AVP-treated hypertrophied heart muscle cells is partially dependent on AMPK, whereas the acute glycolytic effects of AVP are AMPK independent and at least partially Ca2+ dependent.
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115
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Zhou Y, Mancarella S, Wang Y, Yue C, Ritchie M, Gill DL, Soboloff J. The short N-terminal domains of STIM1 and STIM2 control the activation kinetics of Orai1 channels. J Biol Chem 2009; 284:19164-8. [PMID: 19487696 DOI: 10.1074/jbc.c109.010900] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
STIM1 and STIM2 are dynamic transmembrane endoplasmic reticulum Ca(2+) sensors, coupling directly to activate plasma membrane Orai Ca(2+) entry channels. Despite extensive sequence homology, the STIM proteins are functionally distinct. We reveal that the short variable N-terminal random coil sequences of STIM1 and STIM2 confer profoundly different activation properties. Using Orai1-expressing HEK293 cells, chimeric replacement of the 43-amino-acid STIM1 N terminus with that of STIM2 attenuates Orai1-mediated Ca(2+) entry and drastically slows store-induced Orai1 channel activation. Conversely, the 55-amino-acid STIM2 terminus substituted within STIM1 strikingly enhances both Orai1-mediated Ca(2+) entry and constitutive coupling to activate Orai1 channels. Hence, STIM N termini are powerful coupling modifiers, functioning in STIM2 to "brake" the otherwise constitutive activation of Orai1 channels afforded by its high sensitivity to luminal Ca(2+).
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Affiliation(s)
- Yandong Zhou
- Department of Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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116
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Wang S, Zhang Y, Wier WG, Yu X, Zhao M, Hu H, Sun L, He X, Wang Y, Wang B, Zang W. Role of store-operated Ca(2+) entry in adenosine-induced vasodilatation of rat small mesenteric artery. Am J Physiol Heart Circ Physiol 2009; 297:H347-54. [PMID: 19429831 DOI: 10.1152/ajpheart.00060.2009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Store-operated Ca(2+) entry (SOCE) has recently been proposed to contribute to Ca(2+) influx in vascular smooth muscle cells (VSMCs). Adenosine is known for its protective role against hypoxia and ischemia by increasing nutrient and oxygen supply through vasodilation. This study was designed to examine the hypothesis that SOCE have a functional role in adenosine-induced vasodilation. Small mesenteric resistance arteries and mesenteric VSMCs were obtained from rats. Isometric tensions of isolated artery rings were measured by a sensitive myograph system. Laser-scanning confocal microscopy was used to determine the intracellular Ca(2+) concentration of fluo 3-loaded VSMCs. Adenosine (0.1-100 microM) relaxed artery rings that were precontracted by phenylephrine in a concentration-dependent manner. In cultured mesenteric VSMCs, passive store depletion by thapsigargin and active store depletion by phenylephrine both induced Ca(2+) influx due to SOCE. Adenosine inhibited SOCE-mediated increases in cytosolic Ca(2+) levels evoked by the emptying of the stores. In isolated artery rings, adenosine inhibited SOCE-induced contractions due to store depletion. A(2A) receptor antagonism with SCH-58261 and adenylate cyclase inhibition with SQ-22536 largely attenuated adenosine responses. The cAMP analog 8-bromo-cAMP mimicked the effects of adenosine on SOCE. Our results indicate a novel mechanism of vasodilatation by adenosine that involves regulation of SOCE through the cAMP signaling pathway due to activation of adenosine A(2A) receptors.
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Affiliation(s)
- Shengpeng Wang
- Department of Pharmacology, School of Medicine, Xi'an Jiaotong University, Xi'an, PR China
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117
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Wang J, Jiang L, Gao X, Ding H, Wang Q, Cheng J, Gao R, Xiao H. Fenvalerate-induced Ca2+ transients via both intracellular and extracellular way in mouse GC-2spd (ts) cells. Toxicology 2009; 259:122-32. [DOI: 10.1016/j.tox.2009.02.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2008] [Revised: 02/19/2009] [Accepted: 02/19/2009] [Indexed: 11/28/2022]
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118
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Birnbaumer L. The TRPC class of ion channels: a critical review of their roles in slow, sustained increases in intracellular Ca(2+) concentrations. Annu Rev Pharmacol Toxicol 2009; 49:395-426. [PMID: 19281310 DOI: 10.1146/annurev.pharmtox.48.113006.094928] [Citation(s) in RCA: 174] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The realization that there exists a multimembered family of cation channels with structural similarity to Drosophila's Trp channel emerged during the second half of the 1990s. In mammals, depending on the species, the TRP family counts 29 or 30 members which has been subdivided into 6 subfamilies on the basis of sequence similarity. TRP channels are nonselective monovalent cation channels, most of which also allow passage of Ca(2+). Many members of each of these families, but not all, are involved in sensory signal transduction. The C-type (for canonical or classical) subfamily, differs from the other TRP subfamilies in that it fulfills two different types of function: membrane depolarization, resembling sensory transduction TRPs, and mediation of sustained increases in intracellular Ca(2+). The mechanism(s) by which the C-class of TRP channels-the TRPCs-are activated is poorly understood and their role in mediating intracellular Ca(2+) increases is being questioned. Both of these questions-mechanism of activation and participation in Ca(2+) entry-are the topics of this review.
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Affiliation(s)
- Lutz Birnbaumer
- National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina 27709, USA.
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119
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Abstract
STIM proteins are sensors of endoplasmic reticulum (ER) luminal Ca(2+) changes and rapidly translocate into near plasma membrane (PM) junctions to activate Ca(2+) entry through the Orai family of highly Ca(2+)-selective "store-operated" channels (SOCs). Dissecting the STIM-Orai coupling process is restricted by the abstruse nature of the ER-PM junctional domain. To overcome this problem, we studied coupling by using STIM chimera and cytoplasmic C-terminal domains of STIM1 and STIM2 (S1ct and S2ct) and identifying a fundamental action of the powerful SOC modifier, 2-aminoethoxydiphenyl borate (2-APB), the mechanism of which has eluded recent scrutiny. We reveal that 2-APB induces profound, rapid, and direct interactions between S1ct or S2ct and Orai1, effecting full Ca(2+) release-activated Ca(2+) (CRAC) current activation. The short 235-505 S1ct coiled-coil region was sufficient for functional Orai1 coupling. YFP-tagged S1ct or S2ct fragments cleared from the cytosol seconds after 2-APB addition, binding avidly to Orai1-CFP with a rapid increase in FRET and transiently increasing CRAC current 200-fold above basal levels. Functional S1ct-Orai1 coupling occurred in STIM1/STIM2(-/-) DT40 chicken B cells, indicating ct fragments operate independently of native STIM proteins. The 2-APB-induced S1ct-Orai1 and S2-ct-Orai1 complexes undergo rapid reorganization into discrete colocalized PM clusters, which remain stable for >100 s, well beyond CRAC activation and subsequent deactivation. In addition to defining 2-APB's action, the locked STIMct-Orai complex provides a potentially useful probe to structurally examine coupling.
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120
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Evans JF, Lee JH, Ragolia L. Ang-II-induced Ca(2+) influx is mediated by the 1/4/5 subgroup of the transient receptor potential proteins in cultured aortic smooth muscle cells from diabetic Goto-Kakizaki rats. Mol Cell Endocrinol 2009; 302:49-57. [PMID: 19135126 DOI: 10.1016/j.mce.2008.12.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Revised: 12/03/2008] [Accepted: 12/04/2008] [Indexed: 01/04/2023]
Abstract
Angiotensin-II (Ang-II) exerts many of its vascular effects, including the pathophysiological changes associated with type 2 diabetes, through changes in intracellular calcium concentration [Ca(2+)](i). We sought to clarify the mechanism responsible for Ang-II-induced Ca(2+) influx in cultured aortic VSMC using the Goto-Kakizaki (GK) rat model of type 2 diabetes. Ang-II-induced Ca(2+) influx was blocked by neither VDCC nor c-src inhibition but was sensitive to inositol 1,4,5-trisphosphate receptor inhibition, lanthanide and the diacylglycerol analogue, oleoyl-2-acetyl-sn-glycerol. Since transient receptor potential canonical (TRPC)-3 gene expression was undetectable in both WKY and GK VSMCs and TRPC6 gene and protein expression were significantly down-regulated in GK, we believe the 1/4/5 subgroup of TRPC proteins plays a significant role. Furthermore, in GK VSMC the elevated calcium influx observed was not attributable to increased TRPC expression, but rather an alteration of TRPC activity.
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MESH Headings
- Angiotensin II/metabolism
- Angiotensin II/pharmacology
- Animals
- Aorta/drug effects
- Aorta/metabolism
- Blotting, Western
- Calcium/metabolism
- Calcium Signaling/drug effects
- Cells, Cultured
- Diabetes Mellitus, Type 2/metabolism
- Disease Models, Animal
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Polymerase Chain Reaction
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred WKY
- TRPC Cation Channels/genetics
- TRPC Cation Channels/metabolism
- Transient Receptor Potential Channels/genetics
- Transient Receptor Potential Channels/metabolism
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Affiliation(s)
- Jodi F Evans
- Vascular Biology Institute, Department of Medicine, Winthrop University Hospital, Mineola, NY 11501, United States
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121
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Hagenston AM, Rudnick ND, Boone CE, Yeckel MF. 2-Aminoethoxydiphenyl-borate (2-APB) increases excitability in pyramidal neurons. Cell Calcium 2009; 45:310-7. [PMID: 19100621 PMCID: PMC2869079 DOI: 10.1016/j.ceca.2008.11.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 09/09/2008] [Accepted: 11/04/2008] [Indexed: 12/29/2022]
Abstract
Calcium ions (Ca(2+)) released from inositol trisphosphate (IP(3))-sensitive intracellular stores may participate in both the transient and extended regulation of neuronal excitability in neocortical and hippocampal pyramidal neurons. IP(3) receptor (IP(3)R) antagonists represent an important tool for dissociating these consequences of IP(3) generation and IP(3)R-dependent internal Ca(2+) release from the effects of other, concurrently stimulated second messenger signaling cascades and Ca(2+) sources. In this study, we have described the actions of the IP(3)R and store-operated Ca(2+) channel antagonist, 2-aminoethoxydiphenyl-borate (2-APB), on internal Ca(2+) release and plasma membrane excitability in neocortical and hippocampal pyramidal neurons. Specifically, we found that a dose of 2-APB (100 microM) sufficient for attenuating or blocking IP(3)-mediated internal Ca(2+) release also raised pyramidal neuron excitability. The 2-APB-dependent increase in excitability reversed upon washout and was characterized by an increase in input resistance, a decrease in the delay to action potential onset, an increase in the width of action potentials, a decrease in the magnitude of afterhyperpolarizations (AHPs), and an increase in the magnitude of post-spike afterdepolarizations (ADPs). From these observations, we conclude that 2-APB potently and reversibly increases neuronal excitability, likely via the inhibition of voltage- and Ca(2+)-dependent potassium (K(+)) conductances.
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Affiliation(s)
- Anna M Hagenston
- Department of Neurobiology, Yale University School of Medicine, New Haven, CT, USA.
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122
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Hume JR, McAllister CE, Wilson SM. Caffeine inhibits InsP3 responses and capacitative calcium entry in canine pulmonary arterial smooth muscle cells. Vascul Pharmacol 2009; 50:89-97. [PMID: 19084078 PMCID: PMC2667157 DOI: 10.1016/j.vph.2008.11.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2008] [Revised: 10/11/2008] [Accepted: 11/09/2008] [Indexed: 11/24/2022]
Abstract
Caffeine is a well described and characterized ryanodine receptor (RyR) activator. Previous evidence from independent research studies also indicate caffeine inhibits InsP3 receptor functionality, which is important to activation of capacitative Ca2+ entry (CCE) in some cell types. In addition, RyR activation elicits excitatory-coupled Ca2+ entry (ECCE) in skeletal muscle myotubes. Recent studies by our group show that canine pulmonary arterial smooth muscle cells (PASMCs) have functional InsP3 receptors as well as RyRs, and that CCE is dependent on InsP3 receptor activity. The potential for caffeine to activate ECCE as well as inhibit InsP3 receptor function and CCE was examined using fura-2 fluorescent imaging in canine PASMCs. The data show caffeine causes transient as well as sustained cytosolic Ca2+ increases, though this is not due to CCE or ECCE activity as evidenced by a lack of an increase in Mn2+ quench of fura-2. The experiments also show caffeine reversibly inhibits 5-HT elicited-InsP3 mediated Ca2+ responses with an IC50 of 6.87x10(-4) M and 10 mM caffeine fully inhibits CCE. These studies provide the first evidence that caffeine is an inhibitor of InsP3 generated Ca2+ signals and CCE in PASMCs.
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Affiliation(s)
- Joseph R. Hume
- Department of Pharmacology/MS318, University of Nevada School of Medicine, University of Nevada, Reno, NV 89557
| | - Claire E. McAllister
- Department of Pharmacology/MS318, University of Nevada School of Medicine, University of Nevada, Reno, NV 89557
| | - Sean M Wilson
- Department of Pharmacology, University of Mississippi School of Pharmacy, Research Institute of Pharmaceutical Sciences, University of Mississippi Light Microscopy Core, University, MS 38677
- Center for Perinatal Biology, Loma Linda University School of Medicine, Loma, Linda, CA 92350
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123
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Bose DD, Thomas DW. The actin cytoskeleton differentially regulates NG115-401L cell ryanodine receptor and inositol 1,4,5-trisphosphate receptor induced calcium signaling pathways. Biochem Biophys Res Commun 2009; 379:594-9. [PMID: 19126405 PMCID: PMC2660857 DOI: 10.1016/j.bbrc.2008.12.138] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Accepted: 12/22/2008] [Indexed: 11/16/2022]
Abstract
Regulation of bi-directional communication between intracellular Ca(2+) pools and surface Ca(2+) channels remains incompletely characterized. We report Ca(2+) release mediated by inositol 1,4,5-trisphosphate receptor (IP(3)R) and ryanodine receptor (RyR) pathways is diminished under actin cytoskeleton disruption in NG115-401L (401L) neuronal cells, yet despite truncated Ca(2+) release, Ca(2+) influx was not significantly altered in these experiments. However, disruption of cortical actin networks completely abolished IP(3)R induced Ca(2+) release, whereas RyR-mediated Ca(2+) release was preserved, albeit attenuated. Moreover, cortical actin disruption completely abolished IP(3)R and RyR linked Ca(2+) influx even though Ca(2+) pool sensitivities were different. These findings suggest discrete Ca(2+) store/Ca(2+) channel coupling mechanisms in the IP(3)R and RyR pathways as revealed by the differential sensitivity to actin perturbation.
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Affiliation(s)
| | - David W. Thomas
- Department of Physiology and Pharmacology, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA 95211
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124
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Abstract
Calcium signals mediate diverse cellular functions in immunological cells. Early studies with mast cells, then a preeminent model for studying Ca2+-dependent exocytosis, revealed several basic features of calcium signaling in non-electrically excitable cells. Subsequent studies in these and other cells further defined the basic processes such as inositol 1,4,5-trisphosphate-mediated release of Ca2+ from Ca2+ stores in the endoplasmic reticulum (ER); coupling of ER store depletion to influx of external Ca2+ through a calcium-release activated calcium (CRAC) channel now attributed to the interaction of the ER Ca2+ sensor, stromal interacting molecule-1 (STIM1), with a unique Ca2+-channel protein, Orai1/CRACM1, and subsequent uptake of excess Ca2+ into ER and mitochondria through ATP-dependent Ca2+ pumps. In addition, transient receptor potential channels and ion exchangers also contribute to the generation of calcium signals that may be global or have dynamic (e.g., waves and oscillations) and spatial resolution for specific functional readouts. This review discusses past and recent developments in this field of research, the pharmacologic agents that have assisted in these endeavors, and the mast cell as an exemplar for sorting out how calcium signals may regulate multiple outputs in a single cell.
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Affiliation(s)
- Hong-Tao Ma
- Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Michael A. Beaven
- Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
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125
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Ardón F, Rodríguez-Miranda E, Beltrán C, Hernández-Cruz A, Darszon A. Mitochondrial inhibitors activate influx of external Ca2+ in sea urchin sperm. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:15-24. [DOI: 10.1016/j.bbabio.2008.10.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 09/16/2008] [Accepted: 10/09/2008] [Indexed: 01/01/2023]
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126
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van Rossum DB, Oberdick D, Rbaibi Y, Bhardwaj G, Barrow RK, Nikolaidis N, Snyder SH, Kiselyov K, Patterson RL. TRP_2, a lipid/trafficking domain that mediates diacylglycerol-induced vesicle fusion. J Biol Chem 2008; 283:34384-92. [PMID: 19043047 PMCID: PMC2662244 DOI: 10.1074/jbc.m804707200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Revised: 09/17/2008] [Indexed: 11/06/2022] Open
Abstract
We recently modeled transient receptor potential (TRP) channels using the Gestalt Domain Detection Algorithm-Basic Local Alignment Tool (GDDA-BLAST), which derives structural, functional, and evolutionary information from primary amino acid sequences using phylogenetic profiles ( Ko, K. D., Hong, Y., Chang, G. S., Bhardwaj, G., van Rossum, D. B., and Patterson, R. L. (2008) Physics Arch. Quant. Methods arXiv: 0806.2394v1 ). Herein we test our functional predictions for the TRP_2 domain of TRPC3; a domain of unknown function that is conserved in all TRPC channels. Our functional models of this domain identify both lipid binding and trafficking activities. In this study, we reveal: (i) a novel structural determinant of ion channel sensitivity to lipids, (ii) a molecular mechanism for the difference between diacylglycerol (DAG)-sensitive and DAG-insensitive TRPC subfamilies, and (iii) evidence that TRPC3 can comprise part of the vesicle fusion machinery. Indeed, the TRPC3 TRP_2 domain mediates channel trafficking to the plasma membrane and binds to plasma membrane lipids. Further, mutations in TRP_2, which alter lipid binding, also disrupt the DAG-mediated fusion of TRPC3-containing vesicles with the plasma membrane without disrupting SNARE interactions. Importantly, these data agree with the known role of DAG in membrane destabilization, which facilitates SNARE-dependent synaptic vesicle fusion ( Villar, A. V., Goni, F. M., and Alonso, A. (2001) FEBS Lett. 494, 117-120 and Goni, F. M., and Alonso, A. (1999) Prog. Lipid Res. 38, 1-48 ). Taken together, functional models generated by GDDA-BLAST provide a computational platform for deriving domain functionality, which can have in vivo and mechanistic relevance.
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Affiliation(s)
- Damian B. van Rossum
- Center for Computational
Proteomics and Department of Biology,
Pennsylvania State University, University Park, Pennsylvania 16802, the
Department of Biological Sciences,
University of Pittsburgh, Pittsburgh, Pennsylvania 15260, and the
Solomon H. Snyder Department of
Neuroscience, the Department of
Pharmacology and Molecular Science, and the
Department of Psychiatry
and Behavioral Sciences, Johns Hopkins University, Baltimore, Maryland
21205
| | - Daniel Oberdick
- Center for Computational
Proteomics and Department of Biology,
Pennsylvania State University, University Park, Pennsylvania 16802, the
Department of Biological Sciences,
University of Pittsburgh, Pittsburgh, Pennsylvania 15260, and the
Solomon H. Snyder Department of
Neuroscience, the Department of
Pharmacology and Molecular Science, and the
Department of Psychiatry
and Behavioral Sciences, Johns Hopkins University, Baltimore, Maryland
21205
| | - Youssef Rbaibi
- Center for Computational
Proteomics and Department of Biology,
Pennsylvania State University, University Park, Pennsylvania 16802, the
Department of Biological Sciences,
University of Pittsburgh, Pittsburgh, Pennsylvania 15260, and the
Solomon H. Snyder Department of
Neuroscience, the Department of
Pharmacology and Molecular Science, and the
Department of Psychiatry
and Behavioral Sciences, Johns Hopkins University, Baltimore, Maryland
21205
| | - Gaurav Bhardwaj
- Center for Computational
Proteomics and Department of Biology,
Pennsylvania State University, University Park, Pennsylvania 16802, the
Department of Biological Sciences,
University of Pittsburgh, Pittsburgh, Pennsylvania 15260, and the
Solomon H. Snyder Department of
Neuroscience, the Department of
Pharmacology and Molecular Science, and the
Department of Psychiatry
and Behavioral Sciences, Johns Hopkins University, Baltimore, Maryland
21205
| | - Roxanne K. Barrow
- Center for Computational
Proteomics and Department of Biology,
Pennsylvania State University, University Park, Pennsylvania 16802, the
Department of Biological Sciences,
University of Pittsburgh, Pittsburgh, Pennsylvania 15260, and the
Solomon H. Snyder Department of
Neuroscience, the Department of
Pharmacology and Molecular Science, and the
Department of Psychiatry
and Behavioral Sciences, Johns Hopkins University, Baltimore, Maryland
21205
| | - Nikolas Nikolaidis
- Center for Computational
Proteomics and Department of Biology,
Pennsylvania State University, University Park, Pennsylvania 16802, the
Department of Biological Sciences,
University of Pittsburgh, Pittsburgh, Pennsylvania 15260, and the
Solomon H. Snyder Department of
Neuroscience, the Department of
Pharmacology and Molecular Science, and the
Department of Psychiatry
and Behavioral Sciences, Johns Hopkins University, Baltimore, Maryland
21205
| | - Solomon H. Snyder
- Center for Computational
Proteomics and Department of Biology,
Pennsylvania State University, University Park, Pennsylvania 16802, the
Department of Biological Sciences,
University of Pittsburgh, Pittsburgh, Pennsylvania 15260, and the
Solomon H. Snyder Department of
Neuroscience, the Department of
Pharmacology and Molecular Science, and the
Department of Psychiatry
and Behavioral Sciences, Johns Hopkins University, Baltimore, Maryland
21205
| | - Kirill Kiselyov
- Center for Computational
Proteomics and Department of Biology,
Pennsylvania State University, University Park, Pennsylvania 16802, the
Department of Biological Sciences,
University of Pittsburgh, Pittsburgh, Pennsylvania 15260, and the
Solomon H. Snyder Department of
Neuroscience, the Department of
Pharmacology and Molecular Science, and the
Department of Psychiatry
and Behavioral Sciences, Johns Hopkins University, Baltimore, Maryland
21205
| | - Randen L. Patterson
- Center for Computational
Proteomics and Department of Biology,
Pennsylvania State University, University Park, Pennsylvania 16802, the
Department of Biological Sciences,
University of Pittsburgh, Pittsburgh, Pennsylvania 15260, and the
Solomon H. Snyder Department of
Neuroscience, the Department of
Pharmacology and Molecular Science, and the
Department of Psychiatry
and Behavioral Sciences, Johns Hopkins University, Baltimore, Maryland
21205
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127
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Kim BJ, Park EJ, Lee JH, Jeon JH, Kim SJ, So I. Suppression of transient receptor potential melastatin 7 channel induces cell death in gastric cancer. Cancer Sci 2008; 99:2502-2509. [PMID: 19032368 PMCID: PMC11159291 DOI: 10.1111/j.1349-7006.2008.00982.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Revised: 08/11/2008] [Accepted: 08/14/2008] [Indexed: 12/27/2022] Open
Abstract
Ca2+ and Mg2+ have a fundamental role in many cellular processes and ion channels are involved in normal physiologic processes and in the pathology of various diseases. The aim here was to show that the presence and potential role of transient receptor potential melastatin 7 (TRPM7) channels in the growth and survival of AGS cells, the most common human gastric adenocarcinoma cell line. The patch-clamp technique for whole-cell recording was used in AGS cells. TRPM7-specific small interfering RNAs were used for specific inhibition of TRPM7. Whole-cell voltage-clamp recordings revealed the TRPM7-like currents that activated spontaneously following loss of intracellular Mg2+. The current had a non-linear current-voltage relationship with the characteristic steep outward rectification associated with TRPM7 channels. Reverse transcription-polymerase chain reaction, western blotting, and immunoreactivity all showed abundant expression of TRPM7 messenger RNA and protein in AGS cells. Transfection of AGS cells with TRPM7 siRNA significantly reduced the expression of TRPM7 mRNA and protein as well as the amplitude of the TRPM7-like currents. Furthermore, we found that Mg2+ is critical for the growth and survival in AGS cells. Blockade of TRPM7 channels by La3+ and 2-APB or suppression of TRPM7 expression by siRNA inhibited the growth and survival of these cells. Human gastric adenocarcinoma cells express TRPM7 channel whose presence is essential for cell survival. The protein is a likely potential target for the pharmacological treatment of gastric cancer.
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Affiliation(s)
- Byung Joo Kim
- Center for Bio-Artificial Muscle and Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Korea
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128
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Pan L, Zhang X, Song K, Wu X, Xu J. Exogenous nitric oxide-induced release of calcium from intracellular IP3 receptor-sensitive stores via S-nitrosylation in respiratory burst-dependent neutrophils. Biochem Biophys Res Commun 2008; 377:1320-5. [PMID: 19000903 DOI: 10.1016/j.bbrc.2008.11.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Accepted: 11/03/2008] [Indexed: 12/19/2022]
Abstract
PMA-induced respiratory burst neutrophils were exposed to exogenous nitric oxide (NO) donor sodium nitroprusside (SNP) to study the effect of NO on calcium signaling. A sharp rise of cytosolic calcium concentration ([Ca(2+)](c)) was triggered by 1mM SNP with and without external calcium. We found that GF 109203X, a specific inhibitor of protein kinase C, DPI, a putative inhibitor of the respiratory burst-generating NADPH oxidase, and 2-DG, a non-metabolizable analog of glucose, completely inhibited the SNP-induced rise of [Ca(2+)](c) in PMA-activated respiratory burst neutrophils. Meanwhile, 2-APB and TMB-8, two potent IP(3) receptor inhibitors, prevented calcium increase respectively. Furthermore, N-ethylmaleimide (NEM), a specific cysteine alkylating agent, evidently abolished the [Ca(2+)](c) elevation. In contrast, the sGC inhibitor NS2028 had little effect on the rise of [Ca(2+)](c). Taken together, these results indicated that exogenous NO induced the release of calcium from intracellular IP(3) receptor-sensitive stores of neutrophils via S-nitrosylation in a respiratory burst-dependent manner.
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Affiliation(s)
- Leiting Pan
- The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, Institute of Physics and TEDA Applied Physics School, Nankai University, Tianjin 300457, China
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129
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Bird GS, DeHaven WI, Smyth JT, Putney JW. Methods for studying store-operated calcium entry. Methods 2008; 46:204-12. [PMID: 18929662 PMCID: PMC2643845 DOI: 10.1016/j.ymeth.2008.09.009] [Citation(s) in RCA: 156] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Accepted: 09/12/2008] [Indexed: 12/01/2022] Open
Abstract
Activation of surface membrane receptors coupled to phospholipase C results in the generation of cytoplasmic Ca2+ signals comprised of both intracellular Ca2+ release, and enhanced entry of Ca2+ across the plasma membrane. A primary mechanism for this Ca2+ entry process is attributed to store-operated Ca2+ entry, a process that is activated by depletion of Ca2+ ions from an intracellular store by inositol 1,4,5-trisphosphate. Our understanding of the mechanisms underlying both Ca2+ release and store-operated Ca2+ entry have evolved from experimental approaches that include the use of fluorescent Ca2+ indicators and electrophysiological techniques. Pharmacological manipulation of this Ca2+ signaling process has been somewhat limited; but recent identification of key molecular players, STIM and Orai family proteins, has provided new approaches. Here we describe practical methods involving fluorescent Ca2+ indicators and electrophysiological approaches for dissecting the observed intracellular Ca2+ signal to reveal characteristics of store-operated Ca2+ entry, highlighting the advantages, and limitations, of these approaches.
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Affiliation(s)
- Gary S Bird
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, P.O. Box 12233, Research Triangle Park, NC 27709, USA.
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130
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von der Weid PY, Rahman M, Imtiaz MS, van Helden DF. Spontaneous transient depolarizations in lymphatic vessels of the guinea pig mesentery: pharmacology and implication for spontaneous contractility. Am J Physiol Heart Circ Physiol 2008; 295:H1989-2000. [PMID: 18790842 DOI: 10.1152/ajpheart.00007.2008] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Guinea pig mesenteric lymphatic vessels exhibit rhythmic constrictions induced by action potential (AP)-like spikes and initiated by entrainment of spontaneous transient depolarizations (STDs). To characterize STDs and the signaling mechanisms responsible for their occurrence, we used intracellular microelectrodes, Ca2+ imaging, and pharmacological agents. In our investigation of the role of intracellular Ca2+ released from Ca2+ stores, we observed that intracellular Ca2+ transients accompanied some STDs, although there were many exceptions where Ca2+ transients occurred without accompanying STDs. STD frequency and amplitude were markedly affected by activators/inhibitors of inositol 1,4,5-trisphosphate receptors (IP3Rs) but not by treatments known to alter Ca2+ release via ryanodine receptors. A role for Ca2+-activated Cl(-) (Cl(Ca)) channels was indicated, as STDs were dependent on the Cl(-) but not Na+ concentration of the superfusing solution and were inhibited by the Cl(Ca) channel blockers niflumic acid (NFA), anthracene 9-carboxylic acid, and 5-nitro-2-(3-phenylpropylamino)benzoic acid but not by the volume-regulated Cl(-) blocker DIDS. Increases in STD frequency and amplitude induced by agonist stimulation were also inhibited by NFA. Nifedipine, the hyperpolarization-activated inward current blocker ZD-7288, and the nonselective cation/store-operated channel blockers SKF-96365, Gd3+, and Ni2+ had no or marginal effects on STD activity. However, nifedipine, 2-aminoethoxydiphenyl borate, NFA, SKF-96365, Gd3+, and Ni2+ altered the occurrence of spontaneous APs. Our findings support a role for Ca2+ release through IP3Rs and a resultant opening of Cl(Ca) channels in STD generation and confirm the importance of these events in the initiation of lymphatic spontaneous APs and subsequent contractions. The abolition of spontaneous APs by blockers of other excitatory ion channels suggests a contribution of these conductances to lymphatic pacemaking.
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Affiliation(s)
- Pierre-Yves von der Weid
- Inflammation Research Network, Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB, Canada T2N 4N1.
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131
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Guibert C, Ducret T, Savineau JP. Voltage-independent calcium influx in smooth muscle. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2008; 98:10-23. [DOI: 10.1016/j.pbiomolbio.2008.05.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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132
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TRPC channels and diacylglycerol dependent calcium signaling in rat sensory neurons. Histochem Cell Biol 2008; 130:655-67. [DOI: 10.1007/s00418-008-0477-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/03/2008] [Indexed: 10/21/2022]
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133
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Hewavitharana T, Deng X, Wang Y, Ritchie MF, Girish GV, Soboloff J, Gill DL. Location and function of STIM1 in the activation of Ca2+ entry signals. J Biol Chem 2008; 283:26252-62. [PMID: 18635545 DOI: 10.1074/jbc.m802239200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Store-operated channels (SOCs) mediate Ca(2+) entry signals in response to endoplasmic reticulum (ER) Ca(2+) depletion in most cells. STIM1 senses decreased ER luminal Ca(2+) through its EF-hand Ca(2+)-binding motif and aggregates in near-plasma membrane (PM) ER junctions to activate PM Orai1, the functional SOC. STIM1 is also present in the PM, although its role there is unknown. STIM1-mediated coupling was examined using the stable EF20 HEK293 cell line expressing the STIM1-D76A/E87A EF-hand mutant (STIM1(EF)) deficient in Ca(2+) binding. EF20 cells were viable despite constitutive Ca(2+) entry, allowing study of SOC activation without depleting ER Ca(2+). STIM1(EF) was exclusively in stable near-PM junctions, 3.5-fold larger than formed with STIM1(WT). STIM(EF)-expressing cells had normal ER Ca(2+) levels but substantially reduced ER Ca(2+) leak. Expression of antiapoptotic Bcl-2 proteins (BCl-2, MCL-1, BCL-XL) were increased 2-fold in EF20 cells, probably reflecting survival of EF20 cells but not accounting for decreased ER Ca(2+) leak. Surface biotinylation and streptavidin pull-down of cells expressing STIM1(WT) or STIM1(EF) revealed strong PM interactions of both proteins. Although surface expression of STIM1(WT) was clearly detectable, STIM1(EF) was undetectable at the cell surface. Thus, the Ca(2+) binding-defective STIM1(EF) mutant exists exclusively in aggregates within near-PM junctions but, unlike STIM1(WT), is not trafficked to the PM. Although not inserted in the PM, external application of a monoclonal anti-N-terminal STIM1 antibody blocked constitutive STIM(EF)-mediated Ca(2+) entry, but only in cells expressing endogenous STIM1(WT) and not in DT40 STIM1 knock-out cells devoid of STIM(WT). This suggests that PM-STIM1 may play a regulatory role in SOC activation.
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Affiliation(s)
- Thamara Hewavitharana
- Department of Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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134
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Mathew SS, Hablitz JJ. Calcium release via activation of presynaptic IP3 receptors contributes to kainate-induced IPSC facilitation in rat neocortex. Neuropharmacology 2008; 55:106-16. [PMID: 18508095 PMCID: PMC2580077 DOI: 10.1016/j.neuropharm.2008.05.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2008] [Revised: 04/14/2008] [Accepted: 05/05/2008] [Indexed: 10/22/2022]
Abstract
We examined the mechanisms of kainate (KA) induced modulation of GABA release in rat prefrontal cortex. Pharmacologically isolated IPSCs were recorded from visually identified layer II/III pyramidal cells using whole-cell patch clamp techniques. KA produced an increase in evoked IPSC amplitude at low nanomolar concentrations (100-500 nM). The frequency but not the amplitude of miniature (m) IPSCs was also increased. The GluR5 subunit selective agonist (RS)-2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl) propanoic acid (ATPA) caused an increase in mIPSC frequency whereas (3S,4aR,6S,8aR)-6-(4-carboxyphenyl)methyl-1,2,3,4,4a,5,6,7,8,8a-decahydroisoquinoline-3-carboxylic acid (LY382884), a selective GluR5 subunit antagonist, inhibited this facilitation. Philanthotoxin-433 (PhTx) blocked the effect of KA, indicating involvement of Ca(2+)-permeable GluR5 receptors. No IPSC facilitation was seen when Ca(2+) was omitted from the bathing solution. Facilitation was observed when slices were preincubated in ruthenium red or high concentrations of ryanodine, but was inhibited with application of thapsigargin. The IP3 receptor (IP3R) antagonists diphenylboric acid 2-amino-ethyl ester (2-APB) (15 microM) and Xestospongin C (XeC) blocked IPSC facilitation. These results show that activation of KA receptors (KARs) on GABAergic nerve terminals results is linked to intracellular Ca(2+) release via activation of IP3, but not ryanodine, receptors. This represents a new mechanism of presynaptic modulation whereby Ca(2+) entry through Ca(2+)-permeable GluR5 subunit containing KARs activates IP3Rs receptors leading to an increase in GABA release.
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Affiliation(s)
- Seena S Mathew
- Department of Neurobiology and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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135
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Bréchard S, Tschirhart EJ. Regulation of superoxide production in neutrophils: role of calcium influx. J Leukoc Biol 2008; 84:1223-37. [PMID: 18519744 PMCID: PMC2567897 DOI: 10.1189/jlb.0807553] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Upon stimulation, activation of NADPH oxidase complexes in neutrophils produces a burst of superoxide anions contributing to oxidative stress and the development of inflammatory process. Store-operated calcium entry (SOCE), whereby the depletion of intracellular stores induces extracellular calcium influx, is known to be a crucial element of NADPH oxidase regulation. However, the mechanistic basis mediating SOCE is still only partially understood, as is the signal-coupling pathway leading to modulation of store-operated channels. This review emphasizes the role of calcium influx in the control of the NADPH oxidase and summarizes the current knowledge of pathways mediating this extracellular calcium entry in neutrophils. Such investigations into the cross-talk between NADPH oxidase and calcium might allow the identification of novel pharmacological targets with clinical use, particularly in inflammatory diseases.
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Affiliation(s)
- Sabrina Bréchard
- Life Sciences Research Unit, University of Luxembourg, Luxembourg.
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136
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Koslowski M, Sahin U, Dhaene K, Huber C, Türeci O. MS4A12 is a colon-selective store-operated calcium channel promoting malignant cell processes. Cancer Res 2008; 68:3458-66. [PMID: 18451174 DOI: 10.1158/0008-5472.can-07-5768] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Using a data mining approach for the discovery of new targets for antibody therapy of colon cancer, we identified MS4A12, a sequence homologue of CD20. We show that MS4A12 is a cell surface protein. Expression analysis and immunohistochemistry revealed MS4A12 to be a colonic epithelial cell lineage gene confined to the apical membrane of colonocytes with strict transcriptional repression in all other normal tissue types. Expression is maintained upon malignant transformation in 63% of colon cancers. Ca(2+) flux analyses disclosed that MS4A12 is a novel component of store-operated Ca(2+) entry in intestinal cells. Using RNAi-mediated gene silencing, we show that loss of MS4A12 in LoVo colon cancer cells attenuates epidermal growth factor receptor-mediated effects. In particular, proliferation, cell motility, and chemotactic invasion of cells are significantly impaired. Cancer cells expressing MS4A12, in contrast, are sensitized and respond to lower concentrations of epidermal growth factor. In summary, these findings have implications for both the physiology of colonic epithelium as well as for the biology and treatment of colon cancer.
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Affiliation(s)
- Michael Koslowski
- Department of Internal Medicine III, Division of Experimental and Translational Oncology, Johannes Gutenberg University, Mainz, Germany
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137
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Daniels I, Turzanski J, Haynes AP. A requirement for calcium in the caspase-independent killing of Burkitt lymphoma cell lines by Rituximab. Br J Haematol 2008; 142:394-403. [PMID: 18544085 DOI: 10.1111/j.1365-2141.2008.07193.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The therapeutic monoclonal antibody rituximab has previously been shown to kill B cells in a caspase-independent manner. The signalling pathways underpinning this novel death pathway are unknown. The present study showed that rituximab treatment of Burkitt lymphoma cell lines induced a slow rise in intracellular calcium ([Ca(2+)](i)). This rise was only witnessed in cell lines that were killed by antibody, suggesting a critical role for Ca(2+) in mediating rituximab-driven caspase-independent cell death. Inhibition of the two main intracellular store-located Ca(2+) channels, i.e. the ryanodine and inositol-1,4,5-triphosphate receptor channels by dantrolene and xestospongen-c respectively did not prevent the rise in Ca(2+) seen with rituximab or protect cells from subsequent death. In sharp contrast, inhibition of Ca(2+) entry via plasma membrane channels with (2-aminoethoxy) diphenylborate or SKF-96365 or complete chelation of extracellular Ca(2+) with ethyleneglycol bis (aminoethylether) tetra-acetate inhibited the rise in [Ca(2+)](i) and increased cell viability. Together, these data suggest that ligation of the CD20 receptor with rituximab allows a slow sustained influx of Ca(2+) from the external environment that under certain conditions can lead to cell death.
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Affiliation(s)
- Ian Daniels
- David Evans Medical Research Centre, Nottingham University Hospitals Trust, City Hospital Campus, Nottingham, UK.
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138
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Pedersen SF, Owsianik G, Nilius B. TRP channels: an overview. Cell Calcium 2008; 38:233-52. [PMID: 16098585 DOI: 10.1016/j.ceca.2005.06.028] [Citation(s) in RCA: 559] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 06/28/2005] [Indexed: 12/12/2022]
Abstract
The TRP ("transient receptor potential") family of ion channels now comprises more than 30 cation channels, most of which are permeable for Ca2+, and some also for Mg2+. On the basis of sequence homology, the TRP family can be divided in seven main subfamilies: the TRPC ('Canonical') family, the TRPV ('Vanilloid') family, the TRPM ('Melastatin') family, the TRPP ('Polycystin') family, the TRPML ('Mucolipin') family, the TRPA ('Ankyrin') family, and the TRPN ('NOMPC') family. The cloning and characterization of members of this cation channel family has exploded during recent years, leading to a plethora of data on the roles of TRPs in a variety of tissues and species, including mammals, insects, and yeast. The present review summarizes the most pertinent recent evidence regarding the structural and functional properties of TRP channels, focusing on the regulation and physiology of mammalian TRPs.
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Affiliation(s)
- Stine Falsig Pedersen
- Department of Biochemistry, Institute for Molecular Biology and Physiology, University of Copenhagen, Denmark
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139
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DeHaven WI, Smyth JT, Boyles RR, Bird GS, Putney JW. Complex actions of 2-aminoethyldiphenyl borate on store-operated calcium entry. J Biol Chem 2008; 283:19265-73. [PMID: 18487204 DOI: 10.1074/jbc.m801535200] [Citation(s) in RCA: 207] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Store-operated Ca2+ entry (SOCE) is likely the most common mode of regulated influx of Ca2+ into cells. However, only a limited number of pharmacological agents have been shown to modulate this process. 2-Aminoethyldiphenyl borate (2-APB) is a widely used experimental tool that activates and then inhibits SOCE and the underlying calcium release-activated Ca2+ current (I CRAC). The mechanism by which depleted stores activates SOCE involves complex cellular movements of an endoplasmic reticulum Ca2+ sensor, STIM1, which redistributes to puncta near the plasma membrane and, in some manner, activates plasma membrane channels comprising Orai1, -2, and -3 subunits. We show here that 2-APB blocks puncta formation of fluorescently tagged STIM1 in HEK293 cells. Accordingly, 2-APB also inhibited SOCE and I(CRAC)-like currents in cells co-expressing STIM1 with the CRAC channel subunit, Orai1, with similar potency. However, 2-APB inhibited STIM1 puncta formation less well in cells co-expressing Orai1, indicating that the inhibitory effects of 2-APB are not solely dependent upon STIM1 reversal. Further, 2-APB only partially inhibited SOCE and current in cells co-expressing STIM1 and Orai2 and activated sustained currents in HEK293 cells expressing Orai3 and STIM1. Interestingly, the Orai3-dependent currents activated by 2-APB showed large outward currents at potentials greater than +50 mV. Finally, Orai3, and to a lesser extent Orai1, could be directly activated by 2-APB, independently of internal Ca2+ stores and STIM1. These data reveal novel and complex actions of 2-APB effects on SOCE that can be attributed to effects on both STIM1 as well as Orai channel subunits.
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Affiliation(s)
- Wayne I DeHaven
- Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina 27709, USA
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140
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Mellström B, Savignac M, Gomez-Villafuertes R, Naranjo JR. Ca2+-Operated Transcriptional Networks: Molecular Mechanisms and In Vivo Models. Physiol Rev 2008; 88:421-49. [DOI: 10.1152/physrev.00041.2005] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Calcium is the most universal signal used by living organisms to convey information to many different cellular processes. In this review we present well-known and recently identified proteins that sense and decode the calcium signal and are key elements in the nucleus to regulate the activity of various transcriptional networks. When possible, the review also presents in vivo models in which the genes encoding these calcium sensors-transducers have been modified, to emphasize the critical role of these Ca2+-operated mechanisms in many physiological functions.
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141
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Abstract
Phosphoinositide 3-kinase (PI3K), PTEN and localized phosphatidylinositol (3,4,5)-trisphosphate [PtdIns(3,4,5)P3] play key roles in chemotaxis, regulating cell motility by controlling the actin cytoskeleton in Dictyostelium and mammalian cells. PtdIns(3,4,5)P3, produced by PI3K, acts via diverse downstream signaling components, including the GTPase Rac, Arf-GTPases and the kinase Akt (PKB). It has become increasingly apparent, however, that chemotaxis results from an interplay between the PI3K-PTEN pathway and other parallel pathways in Dictyostelium and mammalian cells. In Dictyostelium, the phospholipase PLA2 acts in concert with PI3K to regulate chemotaxis, whereas phospholipase C (PLC) plays a supporting role in modulating PI3K activity. In adenocarcinoma cells, PLC and the actin regulator cofilin seem to provide the direction-sensing machinery, whereas PI3K might regulate motility.
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Affiliation(s)
- Verena Kölsch
- Section of Cell and Developmental Biology, Division of Biological Sciences, Center for Molecular Genetics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0380, USA
| | - Pascale G. Charest
- Section of Cell and Developmental Biology, Division of Biological Sciences, Center for Molecular Genetics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0380, USA
| | - Richard A. Firtel
- Section of Cell and Developmental Biology, Division of Biological Sciences, Center for Molecular Genetics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0380, USA
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142
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Ma HT, Peng Z, Hiragun T, Iwaki S, Gilfillan AM, Beaven MA. Canonical transient receptor potential 5 channel in conjunction with Orai1 and STIM1 allows Sr2+ entry, optimal influx of Ca2+, and degranulation in a rat mast cell line. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 180:2233-9. [PMID: 18250430 PMCID: PMC2681184 DOI: 10.4049/jimmunol.180.4.2233] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Degranulation of mast cells in response to Ag or the calcium mobilizing agent, thapsigargin, is dependent on emptying of intracellular stores of Ca(2+) and the ensuing influx of external Ca(2+), also referred to as store-operated calcium entry. However, it is unlikely that the calcium release-activated calcium channel is the sole mechanism for the entry of Ca(2+) because Sr(2+) and other divalent cations also permeate and support degranulation in stimulated mast cells. In this study we show that influx of Ca(2+) and Sr(2+) as well as degranulation are dependent on the presence of the canonical transient receptor potential (TRPC) channel protein TRPC5, in addition to STIM1 and Orai1, as demonstrated by knock down of each of these proteins by inhibitory RNAs in a rat mast cell (RBL-2H3) line. Overexpression of STIM1 and Orai1, which are known to be essential components of calcium release-activated calcium channel, allows entry of Ca(2+) but not Sr(2+), whereas overexpression of STIM1 and TRPC5 allows entry of both Ca(2+) and Sr(2+). These and other observations suggest that the Sr(2+)-permeable TRPC5 associates with STIM1 and Orai1 in a stoichiometric manner to enhance entry of Ca(2+) to generate a signal for degranulation.
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Affiliation(s)
- Hong-Tao Ma
- Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ze Peng
- Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Takaaki Hiragun
- Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shoko Iwaki
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alasdair M. Gilfillan
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michael A. Beaven
- Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
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143
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Luo D, Yang D, Lan X, Li K, Li X, Chen J, Zhang Y, Xiao RP, Han Q, Cheng H. Nuclear Ca2+ sparks and waves mediated by inositol 1,4,5-trisphosphate receptors in neonatal rat cardiomyocytes. Cell Calcium 2008; 43:165-74. [PMID: 17583790 PMCID: PMC2266086 DOI: 10.1016/j.ceca.2007.04.017] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Revised: 04/16/2007] [Accepted: 04/29/2007] [Indexed: 11/21/2022]
Abstract
Dynamic nuclear Ca(2+) signals play pivotal roles in diverse cellular functions including gene transcription, cell growth, differentiation, and apoptosis. Here we report a novel nuclear Ca(2+) regulatory mechanism mediated by inositol 1,4,5-trisphosphate receptors (IP(3)Rs) around the nucleus in developing cardiac myocytes. Activation of IP(3)Rs by alpha(1)-adrenergic receptor (alpha(1)AR) stimulation or by IP(3) application (in saponin-permeabilized cells) increases Ca(2+) spark frequency preferentially in the region around the nucleus in neonatal rat ventricular myocytes. A nuclear enrichment of IP(3)R distribution supports the higher responsiveness of Ca(2+) release in this particular region. Strikingly, we observed "nuclear Ca(2+)waves" that engulf the entire nucleus without spreading into the bulk cytosol. alpha(1)AR stimulation enhances the occurrence of nuclear Ca(2+) waves and confers them the ability to trigger cytosolic Ca(2+) waves via IP(3)R-dependent pathways. This finding accounts, at least partly, for a profound frequency-dependent modulation of global Ca(2+) oscillations during alpha(1)AR stimulation. Thus, IP(3)R-mediated Ca(2+) waves traveling in the nuclear region provide active, autonomous regulation of nuclear Ca(2+) signaling, which provides for not only the local signal transduction, but also a pacemaker to drive global Ca(2+) transient in the context of alpha(1)AR stimulation in developing cardiac myocytes.
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MESH Headings
- Adrenergic alpha-Agonists/pharmacology
- Animals
- Animals, Newborn
- Calcium Signaling/physiology
- Cell Membrane Permeability
- Inositol 1,4,5-Trisphosphate Receptors/drug effects
- Inositol 1,4,5-Trisphosphate Receptors/physiology
- Microscopy, Confocal
- Myocytes, Cardiac/physiology
- Nuclear Envelope/physiology
- Phenylephrine/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptors, Adrenergic, alpha-1/drug effects
- Receptors, Adrenergic, alpha-1/physiology
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Affiliation(s)
- Dali Luo
- Department of Pharmacology, School of Chemical Biology & Pharmaceutical Sciences, Capital Medical University, Beijing 100069, China.
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144
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Hu G, Place AT, Minshall RD. Regulation of endothelial permeability by Src kinase signaling: vascular leakage versus transcellular transport of drugs and macromolecules. Chem Biol Interact 2008; 171:177-89. [PMID: 17897637 PMCID: PMC3001132 DOI: 10.1016/j.cbi.2007.08.006] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Revised: 06/01/2007] [Accepted: 08/02/2007] [Indexed: 12/17/2022]
Abstract
An important function of the endothelium is to regulate the transport of liquid and solutes across the semi-permeable vascular endothelial barrier. Two cellular pathways have been identified controlling endothelial barrier function. The normally restrictive paracellular pathway, which can become "leaky" during inflammation when gaps are induced between endothelial cells at the level of adherens and tight junctional complexes, and the transcellular pathway, which transports plasma proteins the size of albumin via transcytosis in vesicle carriers originating from cell surface caveolae. During non-inflammatory conditions, caveolae-mediated transport may be the primary mechanism of vascular permeability regulation of fluid phase molecules as well as lipids, hormones, and peptides that bind avidly to albumin. Src family protein tyrosine kinases have been implicated in the upstream signaling pathways that lead to endothelial hyperpermeability through both the paracellular and transcellular pathways. Endothelial barrier dysfunction not only affects vascular homeostasis and cell metabolism, but also governs drug delivery to underlying cells and tissues. In this review of the field, we discuss the current understanding of Src signaling in regulating paracellular and transcellular endothelial permeability pathways and effects on endogenous macromolecule and drug delivery.
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Affiliation(s)
- Guochang Hu
- Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois at Chicago, Chicago, IL 60612, United States.
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145
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Tai K, Hamaide MC, Debaix H, Gailly P, Wibo M, Morel N. Agonist-evoked calcium entry in vascular smooth muscle cells requires IP3 receptor-mediated activation of TRPC1. Eur J Pharmacol 2008; 583:135-47. [PMID: 18289524 DOI: 10.1016/j.ejphar.2008.01.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Revised: 12/17/2007] [Accepted: 01/14/2008] [Indexed: 11/27/2022]
Abstract
Transient receptor potential canonical (TRPC) proteins have been proposed to function as plasma membrane Ca2+ channels activated by store depletion and/or by receptor stimulation. However, their role in the increase in cytosolic Ca2+ activated by contractile agonists in vascular smooth muscle is not yet elucidated. The present study was designed to investigate the functional and molecular properties of the Ca2+ entry pathway activated by endothelin-1 in primary cultured aortic smooth muscle cells. Measurement of the Ca2+ signal in fura-2-loaded cells allowed to characterize endothelin-1-evoked Ca2+ entry, which was resistant to dihydropyridine, and was blocked by 2-aminoethoxydiphenylborate (2-APB) and micromolar concentration of Gd3+. It was not activated by store depletion, but was inhibited by the endothelin ETA receptor antagonist BQ-123, and by heparin. On the opposite, thapsigargin-induced store depletion activated a Ca2+ entry pathway that was not affected by 2-APB, BQ-123 or heparin, and was less sensitive to Gd3+ than was endothelin-1-evoked Ca2+ entry. Investigation of the gene expression of TRPC isoforms by real-time RT-PCR revealed that TRPC1 was the most abundant. In cells transfected with TRPC1 small interfering RNA sequence, TRPC1 mRNA and protein expression were decreased by 72+/-3% and 86+/-2%, respectively, while TRPC6 expression was unaffected. In TRPC1 knockdown cells, both endothelin-1-evoked Ca2+ entry and store-operated Ca2+ entry evoked by thapsigargin were blunted. These results indicate that in aortic smooth muscle cells, TRPC1 is not only involved in Ca2+ entry activated by store depletion but also in receptor-operated Ca2+ entry, which requires inositol (1,4,5) triphosphate receptor activation.
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Affiliation(s)
- Khalid Tai
- Unit of Cellular Physiology, Université Catholique de Louvain, Bruxelles, Belgium
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146
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Inhibition of the transient receptor potential cation channel TRPM2 by 2-aminoethoxydiphenyl borate (2-APB). Br J Pharmacol 2008; 153:1324-30. [PMID: 18204483 DOI: 10.1038/sj.bjp.0707675] [Citation(s) in RCA: 174] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND AND PURPOSE Transient receptor potential melastatin 2 (TRPM2) is a non-selective Ca(2+)-permeable cation channel and is known to be activated by adenosine 5'-diphosphoribose (ADP-ribose) and hydrogen peroxide. TRPM2 current responses are reported to be drastically potentiated by the combination of each of these ligands with heat. Furthermore, the combination of cyclic ADP-ribose with heat also activates TRPM2. Although flufenamic acid, antifungal agents (miconazole and clotrimazole), and a phospholipase A(2) inhibitor (N-(p-amylcinnamoyl)anthranilic acid) inhibit TRPM2, their inhibition was either gradual or irreversible. EXPERIMENTAL APPROACH To facilitate future research on TRPM2, we screened several compounds to investigate their potential to activate or inhibit the TRPM2 channels using the patch-clamp technique in HEK293 cells, transfected with human TRPM2. KEY RESULTS 2-aminoethoxydiphenyl borate (2-APB) exhibited a rapid and reversible inhibition of TRPM2 channels that had been activated by its ADP-ribose or cADP-ribose and heat in a dose-dependent manner (IC(50) about 1 microM). 2-APB also inhibited heat-evoked insulin release from pancreatic islets, isolated from rats. CONCLUSIONS AND IMPLICATIONS 2-APB proved to be a powerful and effective tool for studying the function of TRPM2.
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147
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Johnston L, Carson C, Lyons AD, Davidson RA, McCloskey KD. Cholinergic-induced Ca2+ signaling in interstitial cells of Cajal from the guinea pig bladder. Am J Physiol Renal Physiol 2008; 294:F645-55. [PMID: 18171995 PMCID: PMC2640952 DOI: 10.1152/ajprenal.00526.2007] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Acetylcholine released from parasympathetic excitatory nerves activates contraction in detrusor smooth muscle. Immunohistochemical labeling of guinea pig detrusor with anti-c-Kit and anti-VAChT demonstrated a close structural relationship between interstitial cells of Cajal (ICC) and cholinergic nerves. The ability of guinea pig bladder detrusor ICC to respond to the acetylcholine analog, carbachol, was investigated in enzymatically dissociated cells, loaded with the Ca2+ indicator fluo 4AM. ICC fired Ca2+ transients in response to stimulation by carbachol (1/10 μM). Their pharmacology was consistent with carbachol-induced contractions in strips of detrusor which were inhibited by 4-DAMP (1 μM), an M3 receptor antagonist, but not by the M2 receptor antagonist methoctramine (1 μM). The source of Ca2+ underlying the carbachol transients in isolated ICC was investigated using agents to interfere with influx or release from intracellular stores. Nifedipine (1 μM) or Ni2+ (30–100 μM) to block Ca2+ channels or the removal of external Ca2+ reduced the amplitude of the carbachol transients. Application of ryanodine (30 μM) or tetracaine (100 μM) abolished the transients. The phospholipase C inhibitor, U-73122 (2.5 μM), significantly reduced the responses. 2-Aminoethoxydiethylborate (30 μM) caused a significant reduction and Xestospongin C (1 μM) was more effective, almost abolishing the responses. Intact in situ preparations of guinea pig bladder loaded with a Ca2+ indicator showed distinctively different patterns of spontaneous Ca2+ events in smooth muscle cells and ICC. Both cell types responded to carbachol by an increase in frequency of these events. In conclusion, guinea pig bladder detrusor ICC, both as isolated cells and within whole tissue preparations, respond to cholinergic stimulation by firing Ca2+ transients.
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Affiliation(s)
- Louise Johnston
- Physiology, Division of Basic Medical Sciences, Medical Biology Centre, Belfast, Northern Ireland, UK BT9 7BL
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148
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Löf C, Blom T, Törnquist K. Overexpression of TRPC3 reduces the content of intracellular calcium stores in HEK-293 cells. J Cell Physiol 2008; 216:245-52. [DOI: 10.1002/jcp.21396] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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149
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Medina-Ortiz WE, Gregg EV, Brun-Zinkernagel AM, Koulen P. Identification and functional distribution of intracellular ca channels in mouse lacrimal gland acinar cells. Open Ophthalmol J 2007; 1:8-16. [PMID: 19478858 PMCID: PMC2605693 DOI: 10.2174/1874364100701010008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Revised: 11/14/2007] [Accepted: 11/16/2007] [Indexed: 11/22/2022] Open
Abstract
We have determined the presence and cellular distribution of intracellular calcium channels, inositol 1, 4, 5-trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs) in adult and postnatal (P10) lacrimal gland acinar cells. Western blot analysis of both P10 cultures and adult tissue identified the presence of each IP(3)R and RyR isotypes. The immunocytochemistry analysis showed a differential cellular distribution of these calcium channels where the nuclear envelope, endoplasmic reticulum (ER) and Golgi apparatus membranes represent areas with highest levels of channel expression. This IP(3)R and RyR isotype distribution is confirmed by the immuno-EM results. The findings described in this study are in agreement with published pharmacological data that shows the participation of these channels in the secretion process of the lacrimal gland acinar cells. Furthermore, the differential subcellular distribution between the isoforms could indicate a potential role of these intracellular Ca(2+ )channels on the regulation of specific cellular functions.
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Affiliation(s)
- W E Medina-Ortiz
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
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150
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Yamaga M, Kawai K, Kiyota M, Homma Y, Yagisawa H. Recruitment and activation of phospholipase C (PLC)-delta1 in lipid rafts by muscarinic stimulation of PC12 cells: contribution of p122RhoGAP/DLC1, a tumor-suppressing PLCdelta1 binding protein. ACTA ACUST UNITED AC 2007; 48:41-54. [PMID: 18157946 DOI: 10.1016/j.advenzreg.2007.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Masaki Yamaga
- Laboratory of Biological Signaling, Graduate School of Life Science, University of Hyogo, Harima Science Garden City, Hyogo-ken 978-1297, Japan
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