151
|
Shaw PJ, Weidinger C, Vaeth M, Luethy K, Kaech SM, Feske S. CD4⁺ and CD8⁺ T cell-dependent antiviral immunity requires STIM1 and STIM2. J Clin Invest 2014; 124:4549-63. [PMID: 25157823 DOI: 10.1172/jci76602] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 07/10/2014] [Indexed: 02/03/2023] Open
Abstract
Calcium signaling is critical for lymphocyte function, and intracellular Ca2+ concentrations are regulated by store-operated Ca2+ entry (SOCE) through Ca2+ release-activated Ca2+ (CRAC) channels. In patients, loss-of-function mutations in CRAC channel components ORAI1 and STIM1 abolish SOCE and are associated with recurrent and chronic viral infections. Here, using mice with conditional deletion of Stim1 and its homolog Stim2 in T cells, we determined that both components are required for the maintenance of virus-specific memory CD8+ T cells and recall responses following secondary infection. In the absence of STIM1 and STIM2, acute viral infections became chronic. Early during infection, STIM1 and STIM2 were required for the differentiation of naive CD8+ T cells into fully functional cytolytic effector cells and mediated the production of cytokines and prevented cellular exhaustion in viral-specific CD8+ effector T cells. Importantly, memory and recall responses by CD8+ T cells required expression of STIM1 and STIM2 in CD4+ T cells. CD4+ T cells lacking STIM1 and STIM2 were unable to provide "help" to CD8+ T cells due to aberrant regulation of CD40L expression. Together, our data indicate that STIM1, STIM2, and CRAC channel function play distinct but synergistic roles in CD4+ and CD8+ T cells during antiviral immunity.
Collapse
|
152
|
Endoplasmic reticulum stress in insulin resistance and diabetes. Cell Calcium 2014; 56:311-22. [PMID: 25239386 DOI: 10.1016/j.ceca.2014.08.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 08/07/2014] [Indexed: 02/07/2023]
Abstract
The endoplasmic reticulum is the main intracellular Ca(2+) store for Ca(2+) release during cell signaling. There are different strategies to avoid ER Ca(2+) depletion. Release channels utilize first Ca(2+)-bound to proteins and this minimizes the reduction of the free luminal [Ca(2+)]. However, if release channels stay open after exhaustion of Ca(2+)-bound to proteins, then the reduction of the free luminal ER [Ca(2+)] (via STIM proteins) activates Ca(2+) entry at the plasma membrane to restore the ER Ca(2+) load, which will work provided that SERCA pump is active. Nevertheless, there are several noxious conditions that result in decreased activity of the SERCA pump such as oxidative stress, inflammatory cytokines, and saturated fatty acids, among others. These conditions result in a deficient restoration of the ER [Ca(2+)] and lead to the ER stress response that should facilitate recovery of the ER. However, if the stressful condition persists then ER stress ends up triggering cell death and the ensuing degenerative process leads to diverse pathologies; particularly insulin resistance, diabetes and several of the complications associated with diabetes. This scenario suggests that limiting ER stress should decrease the incidence of diabetes and the mobility and mortality associated with this illness.
Collapse
|
153
|
Simmer JP, Richardson AS, Wang SK, Reid BM, Bai Y, Hu Y, Hu JCC. Ameloblast transcriptome changes from secretory to maturation stages. Connect Tissue Res 2014; 55 Suppl 1:29-32. [PMID: 25158176 PMCID: PMC4252044 DOI: 10.3109/03008207.2014.923862] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 12/11/2013] [Accepted: 12/11/2013] [Indexed: 02/03/2023]
Abstract
The purpose of this study was to identify the major molecular components in the secretory and maturation stages of amelogenesis through transcriptome analyses. Ameloblasts (40 sections per age group) were laser micro-dissected from Day 5 (secretory stage) and Days 11-12 (maturation stage) first molars. PolyA+ RNA was isolated from the lysed cells, converted to cDNA, and amplified to generate a cDNA library. DNA sequences were obtained using next generation sequencing and analyzed to identify genes whose expression had increased or decreased at least 1.5-fold in maturation stage relative to secretory stage ameloblasts. Among the 9198 genes that surpassed the quality threshold, 373 showed higher expression in secretory stage, while 614 genes increased in maturation stage ameloblasts. The results were cross-checked against a previously published transcriptome generated from tissues overlying secretory and maturation stage mouse incisor enamel and 34 increasing and 26 decreasing expressers common to the two studies were identified. Expression of F2r, which encodes protease activated receptor 1 (PAR1) that showed 10-fold higher expression during the secretory stage in our transcriptome analysis, was characterized in mouse incisors by immunohistochemistry. PAR1 was detected in secretory, but not maturation stage ameloblasts. We conclude that transcriptome analyses are a good starting point for identifying genes/proteins that are critical for proper dental enamel formation and that PAR1 is specifically expressed by secretory stage ameloblasts.
Collapse
Affiliation(s)
- James P. Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Amelia S. Richardson
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Shih-Kai Wang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Bryan M. Reid
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Yongsheng Bai
- Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, MI, USA
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, WI, USA
| | - Yuanyuan Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Jan C.-C. Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| |
Collapse
|
154
|
Orai1-dependent calcium entry promotes skeletal muscle growth and limits fatigue. Nat Commun 2014; 4:2805. [PMID: 24241282 PMCID: PMC3868675 DOI: 10.1038/ncomms3805] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 10/22/2013] [Indexed: 11/20/2022] Open
Abstract
Store-operated Ca2+ entry (SOCE) in skeletal muscle involves signaling between stromal interaction molecule 1 (STIM1) in the sarcoplasmic reticulum and Ca2+ selective Orai1 channels in the sarcolemma. Here we generate transgenic mice with muscle-specific expression of dominant-negative Orai1 (dnOrai1) and demonstrate that Orai1-dependent SOCE promotes growth and limits fatigue in adult skeletal muscle. dnOrai1 mice lack SOCE specifically in muscle but are fertile and thrive well into adulthood. Although muscle ultrastructure, excitation-contraction coupling fiber type, and expression of other Ca2+ regulatory proteins are unaltered, dnOrai1 mice exhibit reduced body weight, muscle mass, and fiber cross-sectional area. Importantly, during intense repetitive activity, dnOrai1 mice display increased susceptibility to fatigue at the single fibre, excised muscle, and whole animal levels. We further show that STIM1 and Orai1 proteins colocalise within the triad junction but do not exist in a preassembled context. These results show that Orai1-dependent SOCE has an important physiological role in muscles of adult mice.
Collapse
|
155
|
Gaida K, Salimi-Moosavi H, Subramanian R, Almon V, Knize A, Zhang M, Lin FF, Nguyen HQ, Zhou L, Sullivan JK, Wong M, McBride HJ. Inhibition of CRAC with a human anti-ORAI1 monoclonal antibody inhibits T-cell-derived cytokine production but fails to inhibit a T-cell-dependent antibody response in the cynomolgus monkey. J Immunotoxicol 2014; 12:164-73. [PMID: 24990272 DOI: 10.3109/1547691x.2014.915897] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
ORAI1 is the pore-forming component of calcium release-activated calcium (CRAC) channels. CRAC channels are the primary route for calcium ion (Ca(2+)) entry into T-cells following antigen stimulation. This Ca(2+) entry induces proliferation and cytokine production through activation of calcineurin and the nuclear factor of activated T-cells (NFAT) transcription factor along with subsequent cytokine-related genes. It was hypothesized that the in vivo inhibition of T-cell function by blocking ORAI1 or calcineurin would lead to similar functional consequences. To test this hypothesis the activity of 2C1.1, a fully human anti-ORAI1 monoclonal antibody, and cyclosporin A (CsA) were tested in vivo for their suppressive effect on T-cell-derived cytokine production and a T-cell-dependent antibody response (TDAR) using sheep red blood cells (SRBC) in cynomolgus monkeys. Despite showing similar inhibition of ex vivo interleukin (IL)-2 production by stimulated T-cells, both molecules exhibited different pharmacologic effects on the SRBC antibody response. CsA blocked the development of SRBC-specific antibodies, while 2C1.1 failed to inhibit the antigen-specific antibody response. These surprising observations suggest that full inhibition of the CRAC channel is required to inhibit a functional immune response, consistent with findings from human patients with loss of function mutations in ORAI1.
Collapse
|
156
|
Nielsen N, Lindemann O, Schwab A. TRP channels and STIM/ORAI proteins: sensors and effectors of cancer and stroma cell migration. Br J Pharmacol 2014; 171:5524-40. [PMID: 24724725 DOI: 10.1111/bph.12721] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 03/24/2014] [Accepted: 04/03/2014] [Indexed: 01/05/2023] Open
Abstract
UNLABELLED Cancer cells are strongly influenced by host cells within the tumour stroma and vice versa. This leads to the development of a tumour microenvironment with distinct physical and chemical properties that are permissive for tumour progression. The ability to migrate plays a central role in this mutual interaction. Migration of cancer cells is considered as a prerequisite for tumour metastasis and the migration of host stromal cells is required for reaching the tumour site. Increasing evidence suggests that transient receptor potential (TRP) channels and STIM/ORAI proteins affect key calcium-dependent mechanisms implicated in both cancer and stroma cell migration. These include, among others, cytoskeletal remodelling, growth factor/cytokine signalling and production, and adaptation to tumour microenvironmental properties such as hypoxia and oxidative stress. In this review, we will summarize the current knowledge regarding TRP channels and STIM/ORAI proteins in cancer and stroma cell migration. We focus on how TRP channel or STIM/ORAI-mediated Ca(2+) signalling directly or indirectly influences cancer and stroma cell migration by affecting the above listed mechanisms. LINKED ARTICLES This article is part of a themed section on Cytoskeleton, Extracellular Matrix, Cell Migration, Wound Healing and Related Topics. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-24.
Collapse
Affiliation(s)
- N Nielsen
- Institute of Physiology II, University of Münster, Münster, Germany
| | | | | |
Collapse
|
157
|
Wang S, Choi M, Richardson AS, Reid BM, Seymen F, Yildirim M, Tuna E, Gençay K, Simmer JP, Hu JC. STIM1 and SLC24A4 Are Critical for Enamel Maturation. J Dent Res 2014; 93:94S-100S. [PMID: 24621671 PMCID: PMC4107542 DOI: 10.1177/0022034514527971] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Dental enamel formation depends upon the transcellular transport of Ca(2+) by ameloblasts, but little is known about the molecular mechanism, or even if the same process is operative during the secretory and maturation stages of amelogenesis. Identifying mutations in genes involved in Ca(2+) homeostasis that cause inherited enamel defects can provide insights into the molecular participants and potential mechanisms of Ca(2+) handling by ameloblasts. Stromal Interaction Molecule 1 (STIM1) is an ER transmembrane protein that activates membrane-specific Ca(2+) influx in response to the depletion of ER Ca(2+) stores. Solute carrier family 24, member 4 (SLC24A4), is a Na(+)/K(+)/Ca(2+) transporter that exchanges intracellular Ca(2+) and K(+) for extracellular Na(+). We identified a proband with syndromic hypomaturation enamel defects caused by a homozygous C to T transition (g.232598C>T c.1276C>T p.Arg426Cys) in STIM1, and a proband with isolated hypomaturation enamel defects caused by a homozygous C to T transition (g.124552C>T; c.437C>T; p.Ala146Val) in SLC24A4. Immunohistochemistry of developing mouse molars and incisors showed positive STIM1 and SLC24A4 signal specifically in maturation-stage ameloblasts. We conclude that enamel maturation is dependent upon STIM1 and SLC24A4 function, and that there are important differences in the Ca(2+) transcellular transport systems used by secretory- and maturation-stage ameloblasts.
Collapse
Affiliation(s)
- S Wang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1210 Eisenhower Place, Ann Arbor, MI, USA Oral Health Sciences Program, University of Michigan School of Dentistry, 1011 North University, Ann Arbor, MI, USA
| | - M Choi
- Department of Biomedical Sciences, College of Medicine, Seoul National University, 275-1 Yongon-dong, Chongno-gu, Seoul 110-768, Korea Department of Genetics, Howard Hughes Medical Institute, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, USA
| | - A S Richardson
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1210 Eisenhower Place, Ann Arbor, MI, USA
| | - B M Reid
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1210 Eisenhower Place, Ann Arbor, MI, USA
| | - F Seymen
- Department of Pedodontics, Istanbul University, Faculty of Dentistry, Istanbul, Turkey
| | - M Yildirim
- Department of Pedodontics, Istanbul University, Faculty of Dentistry, Istanbul, Turkey
| | - E Tuna
- Department of Pedodontics, Istanbul University, Faculty of Dentistry, Istanbul, Turkey
| | - K Gençay
- Department of Pedodontics, Istanbul University, Faculty of Dentistry, Istanbul, Turkey
| | - J P Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1210 Eisenhower Place, Ann Arbor, MI, USA
| | - J C Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1210 Eisenhower Place, Ann Arbor, MI, USA
| |
Collapse
|
158
|
Cichocki F, Sitnicka E, Bryceson YT. NK cell development and function – Plasticity and redundancy unleashed. Semin Immunol 2014; 26:114-26. [DOI: 10.1016/j.smim.2014.02.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 02/02/2014] [Accepted: 02/04/2014] [Indexed: 01/16/2023]
|
159
|
Enhanced expression of Stim, Orai, and TRPC transcripts and proteins in endothelial progenitor cells isolated from patients with primary myelofibrosis. PLoS One 2014; 9:e91099. [PMID: 24603752 PMCID: PMC3946386 DOI: 10.1371/journal.pone.0091099] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 02/10/2014] [Indexed: 11/22/2022] Open
Abstract
Background An increase in the frequency of circulating endothelial colony forming cells (ECFCs), the only subset of endothelial progenitor cells (EPCs) truly belonging to the endothelial phenotype, occurs in patients affected by primary myelofibrosis (PMF). Herein, they might contribute to the enhanced neovascularisation of fibrotic bone marrow and spleen. Store-operated Ca2+ entry (SOCE) activated by the depletion of the inositol-1,4,5-trisphosphate (InsP3)-sensitive Ca2+ store drives proliferation in ECFCs isolated from both healthy donors (N-ECFCs) and subjects suffering from renal cellular carcinoma (RCC-ECFCs). SOCE is up-regulated in RCC-ECFCs due to the over-expression of its underlying molecular components, namely Stim1, Orai1, and TRPC1. Methodology/Principal Findings We utilized Ca2+ imaging, real-time polymerase chain reaction, western blot analysis and functional assays to evaluate molecular structure and the functional role of SOCE in ECFCs derived from PMF patients (PMF-ECFCs). SOCE, induced by either pharmacological (i.e. cyclopiazonic acid or CPA) or physiological (i.e. ATP) stimulation, was significantly higher in PMF-ECFCs. ATP-induced SOCE was inhibited upon blockade of the phospholipase C/InsP3 signalling pathway with U73111 and 2-APB. The higher amplitude of SOCE was associated to the over-expression of the transcripts encoding for Stim2, Orai2–3, and TRPC1. Conversely, immunoblotting revealed that Stim2 levels remained constant as compared to N-ECFCs, while Stim1, Orai1, Orai3, TRPC1 and TRPC4 proteins were over-expressed in PMF-ECFCs. ATP-induced SOCE was inhibited by BTP-2 and low micromolar La3+ and Gd3+, while CPA-elicited SOCE was insensitive to Gd3+. Finally, BTP-2 and La3+ weakly blocked PMF-ECFC proliferation, while Gd3+ was ineffective. Conclusions Two distinct signalling pathways mediate SOCE in PMF-ECFCs; one is activated by passive store depletion and is Gd3+-resistant, while the other one is regulated by the InsP3-sensitive Ca2+ pool and is inhibited by Gd3+. Unlike N- and RCC-ECFCs, the InsP3-dependent SOCE does not drive PMF-ECFC proliferation.
Collapse
|
160
|
Platelet secretion defect in a patient with stromal interaction molecule 1 deficiency. Blood 2014; 122:3696-8. [PMID: 24263961 DOI: 10.1182/blood-2013-08-522037] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
|
161
|
Rasmussen JE, Sheridan JT, Polk W, Davies CM, Tarran R. Cigarette smoke-induced Ca2+ release leads to cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction. J Biol Chem 2014; 289:7671-81. [PMID: 24448802 DOI: 10.1074/jbc.m113.545137] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chronic obstructive pulmonary disease affects 64 million people and is currently the fourth leading cause of death worldwide. Chronic obstructive pulmonary disease includes both emphysema and chronic bronchitis, and in the case of chronic bronchitis represents an inflammatory response of the airways that is associated with mucus hypersecretion and obstruction of small airways. Recently, it has emerged that exposure to cigarette smoke (CS) leads to an inhibition of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel, causing airway surface liquid dehydration, which may play a role in the development of chronic bronchitis. CS rapidly clears CFTR from the plasma membrane and causes it to be deposited into aggresome-like compartments. However, little is known about the mechanism(s) responsible for the internalization of CFTR following CS exposure. Our studies revealed that CS triggered a rise in cytoplasmic Ca(2+) that may have emanated from lysosomes. Furthermore, chelation of cytoplasmic Ca(2+), but not inhibition of protein kinases/phosphatases, prevented CS-induced CFTR internalization. The macrolide antibiotic bafilomycin A1 inhibited CS-induced Ca(2+) release and prevented CFTR clearance from the plasma membrane, further linking cytoplasmic Ca(2+) and CFTR internalization. We hypothesize that CS-induced Ca(2+) release prevents normal sorting/degradation of CFTR and causes internalized CFTR to reroute to aggresomes. Our data provide mechanistic insight into the potentially deleterious effects of CS on airway epithelia and outline a hitherto unrecognized signaling event triggered by CS that may affect the long term transition of the lung into a hyper-inflammatory/dehydrated environment.
Collapse
|
162
|
Kim KD, Srikanth S, Tan YV, Yee MK, Jew M, Damoiseaux R, Jung ME, Shimizu S, An DS, Ribalet B, Waschek JA, Gwack Y. Calcium signaling via Orai1 is essential for induction of the nuclear orphan receptor pathway to drive Th17 differentiation. THE JOURNAL OF IMMUNOLOGY 2013; 192:110-22. [PMID: 24307733 DOI: 10.4049/jimmunol.1302586] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Orai1 is the pore subunit of Ca(2+) release-activated Ca(2+) (CRAC) channels that stimulate downstream signaling pathways crucial for T cell activation. CRAC channels are an attractive therapeutic target for alleviation of autoimmune diseases. Using high-throughput chemical library screening targeting Orai1, we identified a novel class of small molecules that inhibit CRAC channel activity. One of these molecules, compound 5D, inhibited CRAC channel activity by blocking ion permeation. When included during differentiation, Th17 cells showed higher sensitivity to compound 5D than Th1 and Th2 cells. The selectivity was attributable to high dependence of promoters of retinoic-acid-receptor-related orphan receptors on the Ca(2+)-NFAT pathway. Blocking of CRAC channels drastically decreased recruitment of NFAT and histone modifications within key gene loci involved in Th17 differentiation. The impairment in Th17 differentiation by treatment with CRAC channel blocker was recapitulated in Orai1-deficient T cells, which could be rescued by exogenous expression of retinoic-acid-receptor-related orphan receptors or a constitutive active mutant of NFAT. In vivo administration of CRAC channel blockers effectively reduced the severity of experimental autoimmune encephalomyelitis by suppression of differentiation of inflammatory T cells. These results suggest that CRAC channel blockers can be considered as chemical templates for the development of therapeutic agents to suppress inflammatory responses.
Collapse
Affiliation(s)
- Kyun-Do Kim
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Sonal Srikanth
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Yossan-Var Tan
- The NPI-Semel Institute and Department of Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90024, USA
| | - Ma-Khin Yee
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Marcus Jew
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Robert Damoiseaux
- Molecular Screening Shared Resources, UC CEIN, NanoSystems Institute, University of California, Los Angeles, CA90095, USA
| | - Michael E Jung
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA90095, USA
| | - Saki Shimizu
- Division of Hematology-Oncology, David Geffen School of Medicine at UCLA.,UCLA AIDS Institute, Los Angeles, CA 90095, USA
| | - Dong Sung An
- Division of Hematology-Oncology, David Geffen School of Medicine at UCLA.,UCLA AIDS Institute, Los Angeles, CA 90095, USA.,UCLA School of Nursing, Los Angeles, CA 90095, USA
| | - Bernard Ribalet
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - James A Waschek
- The NPI-Semel Institute and Department of Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA 90024, USA
| | - Yousang Gwack
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| |
Collapse
|
163
|
Saul S, Stanisz H, Backes CS, Schwarz EC, Hoth M. How ORAI and TRP channels interfere with each other: interaction models and examples from the immune system and the skin. Eur J Pharmacol 2013; 739:49-59. [PMID: 24291108 DOI: 10.1016/j.ejphar.2013.10.071] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 10/08/2013] [Accepted: 10/17/2013] [Indexed: 11/16/2022]
Abstract
Four types of Ca(2+) selective ion channels are known, ten voltage gated Ca(2+) (CaV) channels, four CatSper channels, three store operated CRAC channels (ORAI channels) and at least two members of the TRPV subfamily (TRPV5, TRPV6). Some of the other TRP channels also show some Ca(2+) selectivity like certain splice variants of TRPM3. In addition to Ca(2+) selective channels, various cation channels play an important role for Ca(2+) entry and furthermore, they may also regulate Ca(2+) entry through other channels by modulating the membrane potential or other means as outlined in this review. Of the different types of cation channels, TRP channels form one of the most prominent families of non-selective cation channels with functional relevance in electrically non-excitable and electrically excitable cell types. Among these, the seven channels of the TRPC subfamily are rather non-selective with very modest Ca(2+) selectivity, whereas in the other subfamilies, cation selectivity ranges from monovalent selectivity (i.e. TRPM4, TRPM5) to divalent selectivity (i.e. TRPM6, TRPM7) or Ca(2+) selectivity (i.e. TRPV5, TRPV6). Rather than discussing the heavily reviewed individual functions of ORAI or TRP channels, we summarize data and present models how TRP and ORAI may functionally interact to guide cellular functions. We focus on T lymphocytes representing a more ORAI-dominated tissue and skin as model system in which both ORAI and TRP channel have been reported to control relevant functions. We present several interaction models how ORAI and TRP may interfere with each other's function.
Collapse
Affiliation(s)
- Stephanie Saul
- Department of Biophysics, School of Medicine, Saarland University, Homburg, Germany
| | - Hedwig Stanisz
- Department of Dermatology, School of Medicine, Saarland University, Homburg, Germany
| | - Christian S Backes
- Department of Biophysics, School of Medicine, Saarland University, Homburg, Germany
| | - Eva C Schwarz
- Department of Biophysics, School of Medicine, Saarland University, Homburg, Germany
| | - Markus Hoth
- Department of Biophysics, School of Medicine, Saarland University, Homburg, Germany.
| |
Collapse
|
164
|
Schmeitz C, Hernandez-Vargas EA, Fliegert R, Guse AH, Meyer-Hermann M. A mathematical model of T lymphocyte calcium dynamics derived from single transmembrane protein properties. Front Immunol 2013; 4:277. [PMID: 24065966 PMCID: PMC3776162 DOI: 10.3389/fimmu.2013.00277] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 08/29/2013] [Indexed: 11/25/2022] Open
Abstract
Fate decision processes of T lymphocytes are crucial for health and disease. Whether a T lymphocyte is activated, divides, gets anergic, or initiates apoptosis depends on extracellular triggers and intracellular signaling. Free cytosolic calcium dynamics plays an important role in this context. The relative contributions of store-derived calcium entry and calcium entry from extracellular space to T lymphocyte activation are still a matter of debate. Here we develop a quantitative mathematical model of T lymphocyte calcium dynamics in order to establish a tool which allows to disentangle cause-effect relationships between ion fluxes and observed calcium time courses. The model is based on single transmembrane protein characteristics which have been determined in independent experiments. This reduces the number of unknown parameters in the model to a minimum and ensures the predictive power of the model. Simulation results are subsequently used for an analysis of whole cell calcium dynamics measured under various experimental conditions. The model accounts for a variety of these conditions, which supports the suitability of the modeling approach. The simulation results suggest a model in which calcium dynamics dominantly relies on the opening of channels in calcium stores while calcium entry through calcium-release activated channels (CRAC) is more associated with the maintenance of the T lymphocyte calcium levels and prevents the cell from calcium depletion. Our findings indicate that CRAC guarantees a long-term stable calcium level which is required for cell survival and sustained calcium enhancement.
Collapse
Affiliation(s)
- Christine Schmeitz
- Department of Systems Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | | | - Ralf Fliegert
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Andreas H. Guse
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Meyer-Hermann
- Department of Systems Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Department of Life Sciences, Technische Universität Braunschweig, Braunschweig, Germany
| |
Collapse
|
165
|
Waite JC, Vardhana S, Shaw PJ, Jang JE, McCarl CA, Cameron TO, Feske S, Dustin ML. Interference with Ca(2+) release activated Ca(2+) (CRAC) channel function delays T-cell arrest in vivo. Eur J Immunol 2013; 43:3343-54. [PMID: 23939929 DOI: 10.1002/eji.201243255] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 07/20/2013] [Accepted: 08/08/2013] [Indexed: 11/05/2022]
Abstract
Entry of lymphocytes into secondary lymphoid organs (SLOs) involves intravascular arrest and intracellular calcium ion ([Ca(2+)]i) elevation. TCR activation triggers increased [Ca(2+)]i and can arrest T-cell motility in vitro. However, the requirement for [Ca(2+)]i elevation in arresting T cells in vivo has not been tested. Here, we have manipulated the Ca(2+) release-activated Ca(2+) (CRAC) channel pathway required for [Ca(2+)]i elevation in T cells through genetic deletion of stromal interaction molecule (STIM) 1 or by expression of a dominant-negative ORAI1 channel subunit (ORAI1-DN). Interestingly, the absence of CRAC did not interfere with homing of naïve CD4(+) T cells to SLOs and only moderately reduced crawling speeds in vivo. T cells expressing ORAI1-DN lacked TCR activation induced [Ca(2+)]i elevation, yet arrested motility similar to control T cells in vitro. In contrast, antigen-specific ORAI1-DN T cells had a twofold delayed onset of arrest following injection of OVA peptide in vivo. CRAC channel function is not required for homing to SLOs, but enhances spatiotemporal coordination of TCR signaling and motility arrest.
Collapse
Affiliation(s)
- Janelle C Waite
- Program in Molecular Pathogenesis, Helen L. and Martin S. Kimmel Center for Biology and Medicine of the Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY, USA
| | | | | | | | | | | | | | | |
Collapse
|
166
|
Singh K, Rosenberg P. Anti-tumour activity and store operated calcium entry: new roles in immunology. EMBO Mol Med 2013; 5:1297-9. [PMID: 24000152 PMCID: PMC3799486 DOI: 10.1002/emmm.201303129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 08/01/2013] [Accepted: 08/01/2013] [Indexed: 11/05/2022] Open
Affiliation(s)
- Kavisha Singh
- Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | | |
Collapse
|
167
|
Weidinger C, Shaw PJ, Feske S. STIM1 and STIM2-mediated Ca(2+) influx regulates antitumour immunity by CD8(+) T cells. EMBO Mol Med 2013; 5:1311-21. [PMID: 23922331 PMCID: PMC3799488 DOI: 10.1002/emmm.201302989] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 06/11/2013] [Accepted: 06/28/2013] [Indexed: 02/03/2023] Open
Abstract
Store-operated calcium entry (SOCE) through Ca2+ release-activated Ca2+ (CRAC) channels regulates the function of many immune cells. Patients with loss-of-function mutations in the CRAC channel genes ORAI1 or STIM1 are immunodeficient and are prone to develop virus-associated tumours. This and the reported role of Ca2+ signals in cytotoxic lymphocyte function suggest that SOCE may be critical for tumour immune surveillance. Using conditional knock out mice lacking STIM1 and its homologue STIM2, we find that SOCE in CD8+ T cells is required to prevent the engraftment of melanoma and colon carcinoma cells and to control tumour growth. SOCE is essential for the cytotoxic function of CTLs both in vivo and in vitro by regulating the degranulation of CTLs, their expression of Fas ligand and production of TNF-α and IFN-γ. Our results emphasize an important role of SOCE in antitumour immunity, which is significant given recent reports arguing in favour of CRAC channel inhibition for cancer therapy.
Collapse
Affiliation(s)
- Carl Weidinger
- Department of Pathology and Cancer Institute, New York University School of Medicine, New York, NY, USA
| | | | | |
Collapse
|
168
|
Zhou Y, Srinivasan P, Razavi S, Seymour S, Meraner P, Gudlur A, Stathopulos PB, Ikura M, Rao A, Hogan PG. Initial activation of STIM1, the regulator of store-operated calcium entry. Nat Struct Mol Biol 2013; 20:973-81. [PMID: 23851458 PMCID: PMC3784406 DOI: 10.1038/nsmb.2625] [Citation(s) in RCA: 163] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 05/21/2013] [Indexed: 12/11/2022]
Abstract
Physiological Ca2+ signalling in T lymphocytes and other cells depends on the STIM-ORAI pathway of store-operated Ca2+ entry. STIM1 and STIM2 are Ca2+ sensors located in the endoplasmic reticulum (ER) membrane, with ER-luminal domains that monitor cellular Ca2+ stores and cytoplasmic domains that gate ORAI channels in the plasma membrane. The STIM ER-luminal domain dimerizes or oligomerizes upon dissociation of Ca2+, but the mechanism transmitting activation to the STIM cytoplasmic domain has not been defined. Here we demonstrate, using Tb3+–acceptor energy transfer, that dimerization of STIM1 ER-luminal domains can initiate an extensive conformational change in murine STIM1 cytoplasmic domains. The conformational change, triggered by apposition of the predicted coiled-coil 1 (CC1) regions, releases the ORAI-activating domains from their interaction with the CC1 regions and allows physical extension of the STIM1 cytoplasmic domain across the gap between ER and plasma membrane to communicate with ORAI channels.
Collapse
Affiliation(s)
- Yubin Zhou
- La Jolla Institute for Allergy & Immunology, La Jolla, California, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
169
|
Omilusik KD, Nohara LL, Stanwood S, Jefferies WA. Weft, warp, and weave: the intricate tapestry of calcium channels regulating T lymphocyte function. Front Immunol 2013; 4:164. [PMID: 23805141 PMCID: PMC3690356 DOI: 10.3389/fimmu.2013.00164] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 06/11/2013] [Indexed: 12/20/2022] Open
Abstract
Calcium (Ca(2+)) is a universal second messenger important for T lymphocyte homeostasis, activation, proliferation, differentiation, and apoptosis. The events surrounding Ca(2+) mobilization in lymphocytes are tightly regulated and involve the coordination of diverse ion channels, membrane receptors, and signaling molecules. A mechanism termed store-operated Ca(2+) entry (SOCE), causes depletion of endoplasmic reticulum (ER) Ca(2+) stores following T cell receptor (TCR) engagement and triggers a sustained influx of extracellular Ca(2+) through Ca(2+) release-activated Ca(2+) (CRAC) channels in the plasma membrane. The ER Ca(2+) sensing molecule, stromal interaction molecule 1 (STIM1), and a pore-forming plasma membrane protein, ORAI1, have been identified as important mediators of SOCE. Here, we review the role of several additional families of Ca(2+) channels expressed on the plasma membrane of T cells that likely contribute to Ca(2+) influx following TCR engagement, particularly highlighting an important role for voltage-dependent Ca(2+) channels (CaV) in T lymphocyte biology.
Collapse
Affiliation(s)
- Kyla D Omilusik
- Michael Smith Laboratories, University of British Columbia , Vancouver, BC , Canada ; Centre for Blood Research, University of British Columbia , Vancouver, BC , Canada ; The Brain Research Centre, University of British Columbia , Vancouver, BC , Canada ; Department of Microbiology and Immunology, University of British Columbia , Vancouver, BC , Canada ; Department of Medical Genetics, University of British Columbia , Vancouver, BC , Canada ; Department of Zoology, University of British Columbia , Vancouver, BC , Canada
| | | | | | | |
Collapse
|
170
|
Chen YT, Chen YF, Chiu WT, Liu KY, Liu YL, Chang JY, Chang HC, Shen MR. Microtubule-Associated Histone Deacetylase 6 Supports the Calcium Store Sensor STIM1 in Mediating Malignant Cell Behaviors. Cancer Res 2013; 73:4500-9. [DOI: 10.1158/0008-5472.can-12-4127] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
171
|
Félix R, Crottès D, Delalande A, Fauconnier J, Lebranchu Y, Le Guennec JY, Velge-Roussel F. The Orai-1 and STIM-1 complex controls human dendritic cell maturation. PLoS One 2013; 8:e61595. [PMID: 23700407 PMCID: PMC3659124 DOI: 10.1371/journal.pone.0061595] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 03/11/2013] [Indexed: 11/18/2022] Open
Abstract
Ca(2+) signaling plays an important role in the function of dendritic cells (DC), the professional antigen presenting cells. Here, we described the role of Calcium released activated (CRAC) channels in the maturation and cytokine secretion of human DC. Recent works identified STIM1 and Orai1 in human T lymphocytes as essential for CRAC channel activation. We investigated Ca(2+) signaling in human DC maturation by imaging intracellular calcium signaling and pharmalogical inhibitors. The DC response to inflammatory mediators or PAMPs (Pathogen-associated molecular patterns) is due to a depletion of intracellular Ca(2+) stores that results in a store-operated Ca(2+) entry (SOCE). This Ca(2+) influx was inhibited by 2-APB and exhibited a Ca(2+)permeability similar to the CRAC (Calcium-Released Activated Calcium), found in T lymphocytes. Depending on the PAMPs used, SOCE profiles and amplitudes appeared different, suggesting the involvement of different CRAC channels. Using siRNAi, we identified the STIM1 and Orai1 protein complex as one of the main pathways for Ca(2+) entry for LPS- and TNF-α-induced maturation in DC. Cytokine secretions also seemed to be SOCE-dependent with profile differences depending on the maturating agents since IL-12 and IL10 secretions appeared highly sensitive to 2-APB whereas IFN-γ was less affected. Altogether, these results clearly demonstrate that human DC maturation and cytokine secretions depend on SOCE signaling involving STIM1 and Orai1 proteins.
Collapse
Affiliation(s)
- Romain Félix
- EA 4245 Cellules Dendritiques, Immunomodulation et Greffes, Université François Rabelais, IFR-136 Agents Transmissibles et Infectiologie, UFR de Médecine, Tours, France
| | - David Crottès
- EA 4245 Cellules Dendritiques, Immunomodulation et Greffes, Université François Rabelais, IFR-136 Agents Transmissibles et Infectiologie, UFR de Médecine, Tours, France
| | - Anthony Delalande
- Centre de Biophysique Moléculaire CNRS UPR 4301, Orléans, France
- Institut National de la Santé et de la Recherche Médical U930 Imagerie et Cerveau, Equipe 5, Tours, France
| | - Jérémy Fauconnier
- Institut National de la Santé et de la Recherche Médical U637, Physiopathologie Cardiovasculaire, Montpellier, France
| | - Yvon Lebranchu
- EA 4245 Cellules Dendritiques, Immunomodulation et Greffes, Université François Rabelais, IFR-136 Agents Transmissibles et Infectiologie, UFR de Médecine, Tours, France
- Service de Néphrologie et d'Immunologie Clinique, CHRU Tours, Tours, France
| | - Jean-Yves Le Guennec
- Institut National de la Santé et de la Recherche Médical U637, Physiopathologie Cardiovasculaire, Montpellier, France
| | - Florence Velge-Roussel
- EA 4245 Cellules Dendritiques, Immunomodulation et Greffes, Université François Rabelais, IFR-136 Agents Transmissibles et Infectiologie, UFR de Médecine, Tours, France
- UFR des Sciences Pharmaceutiques, Tours, France
- * E-mail:
| |
Collapse
|
172
|
Jin S, Chin J, Kitson C, Woods J, Majmudar R, Carvajal V, Allard J, DeMartino J, Narula S, Thomas-Karyat DA. Natural regulatory T cells are resistant to calcium release-activated calcium (CRAC/ORAI) channel inhibition. Int Immunol 2013; 25:497-506. [DOI: 10.1093/intimm/dxt013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
|
173
|
Miyamoto A, Bannai H, Michikawa T, Mikoshiba K. Optimal microscopic systems for long-term imaging of intracellular calcium using a ratiometric genetically-encoded calcium indicator. Biochem Biophys Res Commun 2013; 434:252-7. [DOI: 10.1016/j.bbrc.2013.02.112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 02/17/2013] [Indexed: 01/11/2023]
|
174
|
McNally BA, Somasundaram A, Jairaman A, Yamashita M, Prakriya M. The C- and N-terminal STIM1 binding sites on Orai1 are required for both trapping and gating CRAC channels. J Physiol 2013; 591:2833-50. [PMID: 23613525 DOI: 10.1113/jphysiol.2012.250456] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Ca(2+) release-activated Ca(2+) (CRAC) channels are activated through a mechanism wherein depletion of intracellular calcium stores results in the aggregation of stromal interaction molecule 1 (STIM1), the endoplasmic reticulum (ER) Ca(2+) sensor, and Orai1, the CRAC channel protein, at overlapping sites in the ER and plasma membranes (PMs). The redistribution of CRAC channels is driven through direct STIM1-Orai1 binding, an important event that not only controls gating, but also regulates Orai1 ion selectivity. Orai1 harbours two STIM1 binding sites, one each on the intracellular C- and N-termini. Previous studies have proposed modular functions for these sites, with the C-terminal site thought to regulate STIM1-Orai1 binding and trapping of Orai1 at the ER-PM junctions, and the N-terminal site mediating gating. However, here we find that a variety of mutations in the N-terminal site impair the binding of Orai1 to STIM1 and to the soluble CRAC activation domain (CAD). Gating could be restored in several N- and C-terminal point mutants by directly tethering the minimal STIM1 activation domain (S) to Orai1 (Orai1-SS channels), indicating that loss of gating in these mutants by full-length STIM1 results from insufficient ligand binding. By contrast, gating could not be restored in mutant Orai1-SS channels carrying more drastic deletions that removed the STIM1 binding sites (1-85, 73-85, or 272-279 Orai1), suggesting that STIM1 binding to both sites is essential for channel activation. Moreover, analysis of ion selectivity indicated that the molecular requirements for gating and modulation of ion selectivity are similar, yet substantively different from those for Orai1 puncta formation, suggesting that ion selectivity and gating are mechanistically coupled in CRAC channels. Our results indicate that the C- and N-terminal STIM1 binding sites are both essential for multiple aspects of Orai1 function including STIM1-Orai1 association, Orai1 trapping, and channel activation.
Collapse
Affiliation(s)
- Beth A McNally
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University School of Medicine, 303 E Chicago Avenue, Ward 8-296, Chicago, IL 60611, USA
| | | | | | | | | |
Collapse
|
175
|
Store-operated calcium entry could prevent continuous spiking of membrane potential to sustain normal intracellular calcium oscillations and normal potential bursting in pancreatic β-cells. Math Biosci 2013; 243:240-50. [PMID: 23541786 DOI: 10.1016/j.mbs.2013.03.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 03/06/2013] [Accepted: 03/12/2013] [Indexed: 12/16/2022]
Abstract
We propose a dynamical store-operated calcium entry (SOCE) model to analyze the complex role of SOCE in modulating calcium oscillations and electrical activity in pancreatic β-cells and provide a new mathematical insight. Using this model, we simulate the SOCE role in a number of cases with different SOCE conductances. When the SOCE conductance is set to 0 or very small (5 pS), our numerical simulation conforms to the experimental observation that endoplasmic reticulum (ER) calcium can sustain normal calcium oscillations and the depletion of ER calcium transforms the normal calcium oscillations into a sustained calcium increase with oscillations of much higher frequency and much smaller amplitude, and transforms the normal membrane potential oscillations to a pattern of continuous spiking. When the SOCE conductance is increased to 20 pS and the ER calcium is depleted, our numerical simulation conforms to the other experimental observation that the normal calcium and potential oscillations are sustained and augmented a little bit. Moreover, the oscillation frequency is increased a very little bit. A further increase of the conductance to 35 pS slows down the oscillation a little bit. This numerical evidence suggests that a sufficiently large SOCE can prevent the continuous spiking of membrane potential to sustain the normal calcium oscillations and the normal membrane potential bursting. A careful examination of our simulated dynamics of the ATP/ADP ratio, the ATP-sensitive outward K(+) current, and the voltage-gated inward Ca(2+) current reveals that intracellular periodic Ca(2+) peaks perhaps resulted from SOCE might play a role in stabilizing the membrane potential at its resting level (avoiding the continuous spiking) for a certain period of time by accelerating ATP consumption, reducing the ratio ATP/ADP, opening the ATP-sensitive potassium channel, and repolarizing the membrane potential.
Collapse
|
176
|
Fujimoto T, Matsuzaki H, Tanaka M, Shirasawa S. Tespa1 protein is phosphorylated in response to store-operated calcium entry. Biochem Biophys Res Commun 2013; 434:162-5. [PMID: 23541577 DOI: 10.1016/j.bbrc.2013.02.128] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 02/27/2013] [Indexed: 10/27/2022]
Abstract
We previously reported that Tespa1 (thymocyte-expressed, positive selection-associated gene 1) protein expressed in lymphocytes physically interacts with IP3R (Inositol 1,4,5-trisphosphate receptor), a Ca(2+) channel protein spanning endoplasmic reticulum (ER) membrane. However, the biochemical characterization of Tespa1 protein remains unknown. In this study, we have found that Tespa1 protein was posttranslationally modified upon intracellular Ca(2+) increase in thymocytes. Through the analyses using various inhibitors, store-operated Ca(2+) entry (SOCE) was found to be an essential factor for the Tespa1 protein modification induced by T cell receptor (TCR)-stimulation. Remarkably, the Ca(2+)-dependent Tespa1 protein modification was restored by in vitro protein phosphatase treatment, indicating that this modification was due to phosphorylation. Moreover, we examined whether Ca(2+)-dependent phosphorylation of Tespa1 protein would affect the physical association between Tespa1 and IP3R proteins, revealing that physical association of these proteins is maintained regardless of the presence or absence of phosphorylation of Tespa1. In addition, KRAP protein which represents substantial amino acid sequence homology to Tespa1 was also posttranslationally phosphorylated by intracellular Ca(2+) increase in HCT116 human colon cancer cells and HEK293 human embryonic kidney cells, suggesting that common signaling mechanism(s) may contribute to the molecular modification of Tespa1 and KRAP in different cellular processes. All these results suggested a novel molecular modification of Tespa1 and the existence of the regulatory pathway that SOCE affects the Tespa1-IP3R molecular complex.
Collapse
Affiliation(s)
- Takahiro Fujimoto
- Department of Cell Biology, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Fukuoka 814-0180, Japan
| | | | | | | |
Collapse
|
177
|
Bergmeier W, Weidinger C, Zee I, Feske S. Emerging roles of store-operated Ca²⁺ entry through STIM and ORAI proteins in immunity, hemostasis and cancer. Channels (Austin) 2013; 7:379-91. [PMID: 23511024 DOI: 10.4161/chan.24302] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Store-operated Ca(2+) entry (SOCE) is an important Ca(2+) influx pathway, which is defined by the fact that depletion of intracellular Ca(2+) stores, mainly the endoplasmic reticulum (ER), triggers the opening of Ca(2+) channels in the plasma membrane. The best characterized SOC channel is the Ca(2+) release-activated Ca(2+) (CRAC) channel, which was first described in cells of the immune system but has since been reported in many different cell types. CRAC channels are multimers of ORAI family proteins, of which ORAI1 is the best characterized. They are activated by stromal interaction molecules (STIM) 1 and 2, which respond to the depletion of intracellular Ca(2+) stores with oligomerization and binding to ORAI proteins. The resulting SOCE is critical for the physiological function of many cell types including immune cells and platelets. Recent studies using cell lines, animal models and primary cells from human patients with defects in SOCE have highlighted the importance of this Ca(2+) entry mechanism in a variety of pathophysiological processes. This review focuses on the role of SOCE in immunity to infection, allergy, hemostasis and cancer.
Collapse
Affiliation(s)
- Wolfgang Bergmeier
- Department of Biochemistry and Biophysics; McAllister Heart Institute; University of North Carolina; Chapel Hill, NC USA
| | - Carl Weidinger
- Department of Pathology; New York University Langone Medical Center; New York, NY USA
| | - Isabelle Zee
- Department of Pathology; New York University Langone Medical Center; New York, NY USA
| | - Stefan Feske
- Department of Pathology; New York University Langone Medical Center; New York, NY USA
| |
Collapse
|
178
|
Zheng H, Zhou MH, Hu C, Kuo E, Peng X, Hu J, Kuo L, Zhang SL. Differential roles of the C and N termini of Orai1 protein in interacting with stromal interaction molecule 1 (STIM1) for Ca2+ release-activated Ca2+ (CRAC) channel activation. J Biol Chem 2013; 288:11263-72. [PMID: 23447534 DOI: 10.1074/jbc.m113.450254] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The entry of extracellular Ca(2+), which is mediated by Ca(2+) release-activated Ca(2+) (CRAC) channels, is essential for T cell activation and the normal functioning of other immune cells. Although the molecular components of CRAC channels, the Orai1 pore-forming subunit and the STIM1-activating subunit have been recently identified, the gating mechanism by which Orai1 channels conduct Ca(2+) entry upon Orai1-STIM1 interaction following Ca(2+) store release remains elusive. Herein, we show that C-terminal truncations or point mutations prevented Orai1 from binding to STIM1 and subsequent channel opening. In contrast, an Orai1 mutant with an N-terminal truncation interacted with but failed to be activated by STIM1. Moreover, Orai1 channels with C-terminal disruption, but not N-terminal truncation, could be gated by fused functional domains of STIM1. Interestingly, the channel activities of Orai1 mutants carrying either an N-terminal or a C-terminal truncation were restored by a methionine mutation at the putative gating hinge, the conserved Gly-98 site in the first transmembrane segment (TM1) of Orai1. Collectively, these results support a stepwise gating mechanism of STIM1-operated Orai1 channels; the initial binding between STIM1 and the C terminus of Orai1 docks STIM1 onto the N terminus of Orai1 to initiate conformational changes of the pore-lining TM1 helix of Orai1, leading to the opening of the channel.
Collapse
Affiliation(s)
- Hongying Zheng
- Department of Medical Physiology, College of Medicine, Texas A&M Health Science Center, Temple, Texas 76504, USA
| | | | | | | | | | | | | | | |
Collapse
|
179
|
Chen YT, Chen YF, Chiu WT, Wang YK, Chang HC, Shen MR. The ER Ca²⁺ sensor STIM1 regulates actomyosin contractility of migratory cells. J Cell Sci 2013; 126:1260-7. [PMID: 23378028 DOI: 10.1242/jcs.121129] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Stromal interaction molecule 1 (STIM1) is an endoplasmic reticulum (ER) Ca(2+) sensor that triggers the store-operated Ca(2+) entry (SOCE). The clinical relevance of STIM1 has been highlighted in breast and cervical cancer, but the molecular mechanism by which STIM1 promotes cancer progression remains unclear. This study explores the regulatory mechanisms by which STIM1-dependent Ca(2+) signaling controls cancer cell migration. Three different SOCE inhibitors, SKF96365, 2-APB and YM-58483, significantly inhibited cervical cancer cell migration to a similar extent to that of STIM1 silencing. In contrast, STIM1 overexpression significantly enhanced cervical cancer cell migration. Live cell confocal images and three-dimensional tomograms showed that STIM1 formed aggregates and translocated towards the plasma membranes of migratory cells, and this was accompanied by increasing cytosolic Ca(2+) spikes. STIM1 silencing also inhibited the recruitment and association of active focal adhesion kinase (pTyr397-FAK) and talin at focal adhesions, indicating the blockade of force transduction from integrin signaling. Epidermal growth factor-induced phosphorylation of myosin II regulatory light chains was abolished by STIM1 knockdown and SOCE inhibition. Dual immunostaining of activated myosin II (pSer19-MLC) and actin revealed that actomyosin formation depended on STIM1-mediated Ca(2+) entry. Most importantly, STIM1 expression levels as well as SOCE activity controlled the generation of cell contractile force, as measured by the microfabricated post-array-detector system. These results highlight the unique role of STIM1-dependent Ca(2+) signaling in controlling cell migration by the regulation of actomyosin reorganization in conjunction with enhanced contractile forces.
Collapse
Affiliation(s)
- Ying-Ting Chen
- Department of Biomedical Engineering, College of Egineering, National Cheng Kung University, Tainan 701, Taiwan
| | | | | | | | | | | |
Collapse
|
180
|
Contribution and regulation of TRPC channels in store-operated Ca2+ entry. CURRENT TOPICS IN MEMBRANES 2013; 71:149-79. [PMID: 23890115 DOI: 10.1016/b978-0-12-407870-3.00007-x] [Citation(s) in RCA: 143] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Store-operated calcium entry (SOCE) is activated in response to depletion of the endoplasmic reticulum-Ca(2+) stores following stimulation of plasma membrane receptors that couple to PIP2 hydrolysis and IP3 generation. Search for the molecular components of SOCE channels led to the identification of mammalian transient receptor potential canonical (TRPC) family of calcium-permeable channels (TRPC1-TRPC7), which are all activated in response to stimuli that result in PIP2 hydrolysis. While several TRPCs, including TRPC1, TRPC3, and TRPC4, have been implicated in SOCE, the data are most consistent for TRPC1. Extensive studies in cell lines and knockout mouse models have established the contribution of TRPC1 to SOCE. Furthermore, there is a critical functional interaction between TRPC1 and the key components of SOCE, STIM1, and Orai1, which determines the activation of TRPC1. Orai1-mediated Ca(2+) entry is required for recruitment of TRPC1 and its insertion into surface membranes while STIM1 gates the channel. Notably, TRPC1 and Orai1 generate distinct patterns of Ca(2+) signals in cells that are decoded for the regulation of specific cellular functions. Thus, SOCE appears to be a complex process that depends on temporal and spatial coordination of several distinct steps mediated by proteins in different cellular compartments. Emerging data suggest that, in many cell types, the net Ca(2+) entry measured in response to store depletion is the result of the coordinated regulation of different calcium-permeable ion channels. Orai1 and STIM1 are central players in this process, and by mediating recruitment or activation of other Ca(2+) channels, Orai1-CRAC function can elicit rapid changes in global and local [Ca(2+)]i signals in cells. It is most likely that the type of channels and the [Ca(2+)]i signature that are generated by this process reflect the physiological function of the cell that is regulated by Ca(2+).
Collapse
|
181
|
Ruhle B, Trebak M. Emerging roles for native Orai Ca2+ channels in cardiovascular disease. CURRENT TOPICS IN MEMBRANES 2013; 71:209-35. [PMID: 23890117 DOI: 10.1016/b978-0-12-407870-3.00009-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Orai proteins form highly calcium (Ca(2+))-selective channels located in the plasma membrane of both nonexcitable and excitable cells, where they make important contributions to many cellular processes. The well-characterized Ca(2+) release-activated Ca(2+) current is mediated by Orai1 multimers and is activated, upon depletion of inositol 1,4,5-trisphosphate-sensitive stores, by direct interaction of Orai1 with the endoplasmic reticulum Ca(2+) sensor, stromal interaction molecule 1 (STIM1). This pathway is known as capacitative Ca(2+) entry or store-operated Ca(2+) entry. While most investigations have focused on STIM1 and Orai1 in their store-dependent mode, emerging evidence suggests that Orai1 and Orai3 heteromultimeric channels can form store-independent Ca(2+)-selective channels. The role of store-dependent and store-independent channels in excitation-transcription coupling and the pathological remodeling of the cardiovascular system are beginning to come forth. Recent evidence suggests that STIM/Orai-generated Ca(2+) signaling couples to gene transcription and subsequent phenotypic changes associated with the processes of cardiac and vascular remodeling. This short review will explore the contributions of native Orai channels to heart and vessel physiology and their role in cardiovascular diseases.
Collapse
Affiliation(s)
- Brian Ruhle
- Nanobioscience Constellation, The College of Nanoscale Science and Engineering, University at Albany-State University of New York, Albany, NY, USA
| | | |
Collapse
|
182
|
Abstract
In many animal cells, store-operated Ca(2+) release-activated Ca(2+) (CRAC) channels function as an essential route for Ca(2+) entry. CRAC channels control many fundamental cellular functions including gene expression, motility, and cell proliferation, are involved in the etiology of several disease processes including a severe combined immunodeficiency syndrome, and have emerged as major targets for drug development. Although little was known of the molecular mechanisms of CRAC channel operation for several decades, the discovery of Orai1 as a prototypic CRAC channel protein and STIM1 as the endoplasmic reticulum (ER) Ca(2+) sensor has led to rapid progress in our understanding of the mechanisms and functions of CRAC channels. It is now known that activation of CRAC channels following ER Ca(2+) store depletion is governed by several events, which include the redistributions and accumulations of STIM1 and Orai1 into overlapping puncta at peripheral cellular sites, resulting in direct protein-protein interactions between the two proteins. In this chapter, I review the molecular features of the STIM and Orai proteins that regulate the gating and ion conduction mechanisms of CRAC channels.
Collapse
Affiliation(s)
- Murali Prakriya
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA.
| |
Collapse
|
183
|
Alternative Forms of the Store-Operated Calcium Entry Mediators, STIM1 and Orai1. CURRENT TOPICS IN MEMBRANES 2013; 71:109-23. [DOI: 10.1016/b978-0-12-407870-3.00005-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
184
|
Robert V, Triffaux E, Savignac M, Pelletier L. Singularities of calcium signaling in effector T-lymphocytes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:1595-602. [PMID: 23266355 DOI: 10.1016/j.bbamcr.2012.12.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 11/30/2012] [Accepted: 12/01/2012] [Indexed: 12/30/2022]
Abstract
CD4(+) helper T (Th) lymphocytes orchestrate the immune response and include several types of effectors such as Th1, Th17 and Th2 cells. They fight against intracellular, extracellular pathogens and parasites respectively. They may also cause distinct immunopathological disorders. Th1 and Th17 are implicated in the development of autoimmune diseases while Th2 cells can initiate allergic diseases. These subsets differ by their TCR-associated signaling. In addition, the regulation of intracellular calcium concentration is not the same in Th1, Th2 and 17 cells. Our group showed that Th2 cells selectively overexpressed voltage-activated calcium (Cav1)-related channels. An increasing number of groups report the presence of Cav1-related products in T-lymphocyte subsets. This is a matter of debate since these calcium channels are classically defined as activated by high cell membrane depolarization in excitable cells. However, the use of mice with ablation of some Cav1 subunits shows undoubtedly an immune phenotype raising the question of how Cav1 channels are regulated in lymphocytes. We showed that knocking down Cav1.2 and/or Cav1.3 subunits impairs the functions of Th2 lymphocytes and is beneficial in experimental models of asthma, while it has no effect on Th1 cell functions. Beyond the role of Cav1 channels in T-lymphocytes, the identification of key components selectively implicated in one or the other T cell subset paves the way for the design of new selective therapeutic targets in the treatment of immune disorders while preserving the other T-cell subsets. This article is part of a Special Issue entitled: 12th European Symposium on Calcium.
Collapse
|
185
|
Xing L, Xiu Y, Boyce BF. Osteoclast fusion and regulation by RANKL-dependent and independent factors. World J Orthop 2012; 3:212-22. [PMID: 23362465 PMCID: PMC3557323 DOI: 10.5312/wjo.v3.i12.212] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 11/21/2012] [Accepted: 12/06/2012] [Indexed: 02/06/2023] Open
Abstract
Osteoclasts are the bone resorbing cells essential for bone remodeling. Osteoclasts are formed from hematopoietic progenitors in the monocyte/macrophage lineage. Osteoclastogenesis is composed of several steps including progenitor survival, differentiation to mono-nuclear pre-osteoclasts, fusion to multi-nuclear mature osteoclasts, and activation to bone resorbing osteoclasts. The regulation of osteoclastogenesis has been extensively studied, in which the receptor activator of NF-κB ligand (RANKL)-mediated signaling pathway and downstream transcription factors play essential roles. However, less is known about osteoclast fusion, which is a property of mature osteoclasts and is required for osteoclasts to resorb bone. Several proteins that affect cell fusion have been identified. Among them, dendritic cell-specific transmembrane protein (DC-STAMP) is directly associated to osteoclast fusion in vivo. Cytokines and factors influence osteoclast fusion through regulation of DC-STAMP. Here we review the recently discovered new factors that regulate osteoclast fusion with specific focus on DC-STAMP. A better understanding of the mechanistic basis of osteoclast fusion will lead to the development of a new therapeutic strategy for bone disorders due to elevated osteoclast bone resorption. Cell-cell fusion is essential for a variety of cellular biological processes. In mammals, there is a limited number of cell types that fuse to form multinucleated cells, such as the fusion of myoblasts for the formation of skeletal muscle and the fusion of cells of the monocyte/macrophage lineage for the formation of multinucleated osteoclasts and giant cells. In most cases, cell-cell fusion is beneficial for cells by enhancing function. Myoblast fusion increases myofiber size and diameter and thereby increases contractile strength. Multinucleated osteoclasts have far more bone resorbing activity than their mono-nuclear counterparts. Multinucleated giant cells are much more efficient in the removal of implanted materials and bacteria due to chronic infection than macrophages. Therefore, they are also called foreign-body giant cells. Cell fusion is a complicated process involving cell migration, chemotaxis, cell-cell recognition and attachment, as well as changes into a fusion-competent status. All of these steps are regulated by multiple factors. In this review, we will discuss osteoclast fusion and regulation.
Collapse
|
186
|
Schäfer C, Rymarczyk G, Ding L, Kirber MT, Bolotina VM. Role of molecular determinants of store-operated Ca(2+) entry (Orai1, phospholipase A2 group 6, and STIM1) in focal adhesion formation and cell migration. J Biol Chem 2012; 287:40745-57. [PMID: 23043102 DOI: 10.1074/jbc.m112.407155] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Store-operated Ca(2+) entry is important for cell migration. RESULTS This study presents characterization of localization and roles of Orai1, STIM1, and PLA2g6 in adhesion dynamics during cell migration. CONCLUSION Orai1 and PLA2g6 are involved in adhesion formation at the front, whereas STIM1 participates in both adhesion formation and disassembly. SIGNIFICANCE Results uncovered new parameters of Orai1, STIM1, and PLA2g6 involvement in cell migration. Store-operated Ca(2+) entry and its major determinants are known to be important for cell migration, but the mechanism of their involvement in this complex process is unknown. This study presents a detailed characterization of distinct roles of Orai1, STIM1, and PLA2g6 in focal adhesion (FA) formation and migration. Using HEK293 cells, we discovered that although molecular knockdown of Orai1, STIM1, or PLA2g6 resulted in a similar reduction in migration velocity, there were profound differences in their effects on number, localization, and lifetime of FAs. Knockdown of STIM1 caused an increase in lifetime and number of FAs, their redistribution toward lamellae region, and an increase in cell tail length. In contrast, the number of FAs in Orai1- or PLA2g6-deficient cells was significantly reduced, and FAs accumulated closer to the leading edge. Assembly rate and Vinculin phosphorylation of FAs was similarly reduced in Orai1, PLA2g6, or STIM1-deficient cells. Although Orai1 and PLA2g6 accumulated and co-localized at the leading edge, STIM1 distribution was more complex. We found STIM1 protrusions in lamellipodia, which co-localized with FAs, whereas major accumulation could be seen in central and retracting parts of the cell. Interestingly, knockdown of Orai1 and PLA2g6 produced similar and non-additive effect on migration, whereas knockdown of STIM1 simultaneously with either Orai1 or PLA2g6 produced additional inhibition. Together these data suggest that although Orai1, PLA2g6, and STIM1 play major roles in formation of new FAs at the leading edge, STIM1 may also be involved in Orai1- and PLA2g6-independent disassembly of FAs in the back of cells.
Collapse
Affiliation(s)
- Claudia Schäfer
- Ion Channel and Calcium Signaling Unit, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | | | | | | | | |
Collapse
|
187
|
Shaw PJ, Qu B, Hoth M, Feske S. Molecular regulation of CRAC channels and their role in lymphocyte function. Cell Mol Life Sci 2012; 70:2637-56. [PMID: 23052215 DOI: 10.1007/s00018-012-1175-2] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Revised: 09/16/2012] [Accepted: 09/17/2012] [Indexed: 12/12/2022]
Abstract
Calcium (Ca(2+)) influx is required for the activation and function of all cells in the immune system. It is mediated mainly by store-operated Ca(2+) entry (SOCE) through Ca(2+) release-activated Ca(2+) (CRAC) channels located in the plasma membrane. CRAC channels are composed of ORAI proteins that form the channel pore and are activated by stromal interaction molecules (STIM) 1 and 2. Located in the membrane of the endoplasmic reticulum, STIM1 and STIM2 have the dual function of sensing the intraluminal Ca(2+) concentration in the ER and to activate CRAC channels. A decrease in the ER's Ca(2+) concentration induces STIM multimerization and translocation into puncta close to the plasma membrane where they bind to and activate ORAI channels. Since the identification of ORAI and STIM genes as the principal mediators of CRAC channel function, substantial advances have been achieved in understanding the molecular regulation and physiological role of CRAC channels in cells of the immune system and other organs. In this review, we discuss the mechanisms that regulate CRAC channel function and SOCE, the role of recently identified proteins and mechanisms that modulate the activation of ORAI/STIM proteins and the consequences of CRAC channel dysregulation for lymphocyte function and immunity.
Collapse
Affiliation(s)
- Patrick J Shaw
- Department of Pathology, New York University Medical Center, 550 First Avenue, SRB 316, New York, NY 10016, USA
| | | | | | | |
Collapse
|
188
|
Nunes P, Cornut D, Bochet V, Hasler U, Oh-Hora M, Waldburger JM, Demaurex N. STIM1 juxtaposes ER to phagosomes, generating Ca²⁺ hotspots that boost phagocytosis. Curr Biol 2012; 22:1990-7. [PMID: 23041196 DOI: 10.1016/j.cub.2012.08.049] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 08/14/2012] [Accepted: 08/23/2012] [Indexed: 11/28/2022]
Abstract
BACKGROUND Endoplasmic reticulum (ER) membranes are recruited to phagosomes, but the mechanism and functional significance of this ER recruitment is not known. Here, we show that the ER Ca(2+) sensor stromal interaction molecule 1 (STIM1) sustains high-efficiency phagocytosis by recruiting thin ER cisternae that interact productively but do not fuse with phagosomes. RESULTS Endogenous STIM1 was recruited to phagosomes upon ER Ca(2+) depletion in mouse neutrophils, and exogenous YFP-STIM1 puncta coincided with localized Ca(2+) elevations around phagosomes in fibroblasts expressing phagocytic receptors. STIM1 ablation decreased phagocytosis, ER-phagosome contacts, and periphagosomal Ca(2+) elevations in both neutrophils and fibroblasts, whereas STIM1 re-expression in Stim1(-/-) fibroblasts rescued these defects, promoted the formation and elongation of tight ER-phagosome contacts upon ER Ca(2+) depletion and increased the shedding of periphagosomal actin rings. Re-expression of a signaling-deficient STIM1 mutant unable to open Ca(2+) channels recruited ER cisternae to the vicinity of phagosomes but failed to rescue phagocytosis, actin shedding, and periphagosomal Ca(2+) elevations. The periphagosomal Ca(2+) hotspots were decreased by extracellular Ca(2+) chelation and by Ca(2+) channels inhibitors, revealing that the Ca(2+) ions originate at least in part from phagosomes. CONCLUSIONS Our findings indicate that STIM1 recruits ER cisternae near phagosomes for signaling purposes and that the opening of phagosomal Ca(2+) channels generates localized Ca(2+) elevations that promote high-efficiency phagocytosis.
Collapse
Affiliation(s)
- Paula Nunes
- Department of Cell Physiology and Metabolism, University of Geneva, 1211 Geneva 4, Switzerland
| | | | | | | | | | | | | |
Collapse
|
189
|
A voltage-gated sodium channel is essential for the positive selection of CD4(+) T cells. Nat Immunol 2012; 13:880-7. [PMID: 22842345 PMCID: PMC3426661 DOI: 10.1038/ni.2379] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 06/26/2012] [Indexed: 12/15/2022]
Abstract
Sustained Ca2+ entry into CD4+CD8+ double-positive thymocytes is required for positive selection. We identified a voltage-gated Na+ channel (VGSC), essential for positive selection of CD4+ T cells. Pharmacological inhibition of VGSC activity inhibitedsustained Ca2+ influx induced by positive-selecting ligands and in vitro positive selection of CD4+ but not CD8+ T cells. In vivo shRNA knockdown of Scn5a specifically inhibited positive selection of CD4+ T cells. Ectopic expression of VGSC in peripheral AND CD4+ T cells bestowed the ability to respond to a positively selecting ligand, directly demonstrating VGSC expression was responsible for increased sensitivity. Thus active VGSCs in thymocytes provide a mechanism by which a weak positive selecting signal can induce sustained Ca2+ signals required for CD4+ T cell development.
Collapse
|
190
|
Moccia F, Berra-Romani R, Tanzi F. Update on vascular endothelial Ca 2+ signalling: A tale of ion channels, pumps and transporters. World J Biol Chem 2012; 3:127-58. [PMID: 22905291 PMCID: PMC3421132 DOI: 10.4331/wjbc.v3.i7.127] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 07/04/2012] [Accepted: 07/11/2012] [Indexed: 02/05/2023] Open
Abstract
A monolayer of endothelial cells (ECs) lines the lumen of blood vessels and forms a multifunctional transducing organ that mediates a plethora of cardiovascular processes. The activation of ECs from as state of quiescence is, therefore, regarded among the early events leading to the onset and progression of potentially lethal diseases, such as hypertension, myocardial infarction, brain stroke, and tumor. Intracellular Ca2+ signals have long been know to play a central role in the complex network of signaling pathways regulating the endothelial functions. Notably, recent work has outlined how any change in the pattern of expression of endothelial channels, transporters and pumps involved in the modulation of intracellular Ca2+ levels may dramatically affect whole body homeostasis. Vascular ECs may react to both mechanical and chemical stimuli by generating a variety of intracellular Ca2+ signals, ranging from brief, localized Ca2+ pulses to prolonged Ca2+ oscillations engulfing the whole cytoplasm. The well-defined spatiotemporal profile of the subcellular Ca2+ signals elicited in ECs by specific extracellular inputs depends on the interaction between Ca2+ releasing channels, which are located both on the plasma membrane and in a number of intracellular organelles, and Ca2+ removing systems. The present article aims to summarize both the past and recent literature in the field to provide a clear-cut picture of our current knowledge on the molecular nature and the role played by the components of the Ca2+ machinery in vascular ECs under both physiological and pathological conditions.
Collapse
Affiliation(s)
- Francesco Moccia
- Francesco Moccia, Franco Tanzi, Department of Biology and Biotechnologies "Lazzaro Spallanzani", Laboratory of Physiology, University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
| | | | | |
Collapse
|
191
|
Dixit N, Simon SI. Chemokines, selectins and intracellular calcium flux: temporal and spatial cues for leukocyte arrest. Front Immunol 2012; 3:188. [PMID: 22787461 PMCID: PMC3392659 DOI: 10.3389/fimmu.2012.00188] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 06/15/2012] [Indexed: 11/13/2022] Open
Abstract
Leukocyte trafficking to acute sites of injury or infection requires spatial and temporal cues that fine tune precise sites of firm adhesion and guide migration to endothelial junctions where they undergo diapedesis to sites of insult. Many detailed studies on the location and gradient of chemokines such as IL-8 and other CXCR ligands reveal that their recognition shortly after selectin-mediated capture and rolling exerts acute effects on integrin activation and subsequent binding to their ligands on the endothelium, which directs firm adhesion, adhesion strengthening, and downstream migration. In this process, G-protein coupled receptor (GPCR) signaling has been found to play an integral role in activating and mobilizing intracellular stores of calcium, GTPases such as Rap-1 and Rho and cytokeletal proteins such as Talin and F-actin to facilitate cell polarity and directional pseudopod formation. A critical question remaining is how intracellular Ca(2+) flux from CRAC channels such as Orai1 synergizes with cytosolic stores to mediate a rapid flux which is critical to the onset of PMN arrest and polarization. Our review will highlight a specific role for calcium as a signaling messenger in activating focal clusters of integrins bound to the cytoskeleton which allows the cell to attain a migratory phenotype. The precise interplay between chemokines, selectins, and integrins binding under the ubiquitous presence of shear stress from blood flow provides an essential cooperative signaling mechanism for effective leukocyte recruitment.
Collapse
Affiliation(s)
- Neha Dixit
- Department of Biomedical Engineering, Graduate Group in Immunology, University of California, Davis CA, USA
| | | |
Collapse
|
192
|
Madsen CP, Klausen TK, Fabian A, Hansen BJ, Pedersen SF, Hoffmann EK. On the role of TRPC1 in control of Ca2+ influx, cell volume, and cell cycle. Am J Physiol Cell Physiol 2012; 303:C625-34. [PMID: 22744003 DOI: 10.1152/ajpcell.00287.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ca(+) signaling plays a crucial role in control of cell cycle progression, but the understanding of the dynamics of Ca(2+) influx and release of Ca(2+) from intracellular stores during the cell cycle is far from complete. The aim of the present study was to investigate the role of the free extracellular Ca(2+) concentration ([Ca(2+)](o)) in cell proliferation, the pattern of changes in the free intracellular Ca(2+) concentration ([Ca(2+)](i)) during cell cycle progression, and the role of the transient receptor potential (TRP)C1 in these changes as well as in cell cycle progression and cell volume regulation. In Ehrlich Lettré Ascites (ELA) cells, [Ca(2+)](i) decreased significantly, and the thapsigargin-releasable Ca(2+) pool in the intracellular stores increased in G(1) as compared with G(0). Store-depletion-operated Ca(2+) entry (SOCE) and TRPC1 protein expression level were both higher in G(1) than in G(0) and S phase, in parallel with a more effective volume regulation after swelling [regulatory volume decrease (RVD)] in G(1) as compared with S phase. Furthermore, reduction of [Ca(2+)](o), as well as two unspecific SOCE inhibitors, 2-APB (2-aminoethyldiphenyl borinate) and SKF96365 (1-(β-[3-(4-methoxy-phenyl)propoxyl-4-methoxyphenethyl)1H-imidazole-hydrochloride), inhibited ELA cell proliferation. Finally, Madin-Darby canine kidney cells in which TRPC1 was stably silenced [TRPC1 knockdown (TRPC1-KD) MDCK] exhibited reduced SOCE, slower RVD, and reduced cell proliferation compared with mock controls. In conclusion, in ELA cells, SOCE and TRPC1 both seem to be upregulated in G(1) as compared with S phase, concomitant with an increased rate of RVD. Furthermore, TRPC1-KD MDCK cells exhibit decreased SOCE, decreased RVD, and decreased proliferation, suggesting that, at least in certain cell types, TRPC1 is regulated during cell cycle progression and is involved in SOCE, RVD, and cell proliferation.
Collapse
Affiliation(s)
- C P Madsen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | | | | | | | | |
Collapse
|
193
|
Abstract
The stromal interaction molecules STIM1 and STIM2 are Ca2+ sensors, mostly located in the endoplasmic reticulum, that detect changes in the intraluminal Ca2+ concentration and communicate this information to plasma membrane store-operated channels, including members of the Orai family, thus mediating store-operated Ca2+ entry (SOCE). Orai and STIM proteins are almost ubiquitously expressed in human cells, where SOCE has been reported to play a relevant functional role. The phenotype of patients bearing mutations in STIM and Orai proteins, together with models of STIM or Orai deficiency in mice, as well as other organisms such as Drosophila melanogaster, have provided compelling evidence on the relevant role of these proteins in cellular physiology and pathology. Orai1-deficient patients suffer from severe immunodeficiency, congenital myopathy, chronic pulmonary disease, anhydrotic ectodermal dysplasia and defective dental enamel calcification. STIM1-deficient patients showed similar abnormalities, as well as autoimmune disorders. This review summarizes the current evidence that identifies and explains diseases induced by disturbances in SOCE due to deficiencies or mutations in Orai and STIM proteins.
Collapse
Affiliation(s)
- A Berna-Erro
- Department of Physiology, University of Extremadura, Cáceres, Spain
| | | | | |
Collapse
|
194
|
Feske S, Skolnik EY, Prakriya M. Ion channels and transporters in lymphocyte function and immunity. Nat Rev Immunol 2012; 12:532-47. [PMID: 22699833 DOI: 10.1038/nri3233] [Citation(s) in RCA: 325] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Lymphocyte function is regulated by a network of ion channels and transporters in the plasma membrane of B and T cells. These proteins modulate the cytoplasmic concentrations of diverse cations, such as calcium, magnesium and zinc ions, which function as second messengers to regulate crucial lymphocyte effector functions, including cytokine production, differentiation and cytotoxicity. The repertoire of ion-conducting proteins includes calcium release-activated calcium (CRAC) channels, P2X receptors, transient receptor potential (TRP) channels, potassium channels, chloride channels and magnesium and zinc transporters. This Review discusses the roles of ion conduction pathways in lymphocyte function and immunity.
Collapse
Affiliation(s)
- Stefan Feske
- Department of Pathology, New York University Langone Medical Center, New York, New York 10016, USA.
| | | | | |
Collapse
|
195
|
Shaw PJ, Feske S. Regulation of lymphocyte function by ORAI and STIM proteins in infection and autoimmunity. J Physiol 2012; 590:4157-67. [PMID: 22615435 DOI: 10.1113/jphysiol.2012.233221] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Store-operated Ca(2+) entry (SOCE) in cells of the immune system is mediated by Ca(2+) release-activated Ca(2+) (CRAC) channels that are formed by ORAI1 and its homologues ORAI2 and ORAI3. They are activated by stromal interaction molecules (STIM) 1 and 2 in response to depletion of endoplasmic reticulum Ca(2+) stores. Loss-of-function mutations in the human ORAI1 and STIM1 genes abolish CRAC channel function and SOCE in a variety of non-excitable cells including lymphocytes and other immune cells, resulting in a unique clinical syndrome termed CRAC channelopathy. It is dominated by severe immunodeficiency and autoimmunity due to impaired SOCE and defects in the function of several lymphocyte subsets. These include CD8(+) T cells, CD4(+) effector and regulatory T cells, natural killer (NK) cells and B cells. This review provides a concise discussion of the role of CRAC channels in these lymphocyte populations and the regulation of adaptive immune responses to infection, in autoimmunity and inflammation.
Collapse
Affiliation(s)
- Patrick J Shaw
- Department of Pathology, New York University Medical Center, 550 First Avenue, SRB 316, New York, NY 10016, USA
| | | |
Collapse
|
196
|
Gwozdz T, Dutko-Gwozdz J, Schafer C, Bolotina VM. Overexpression of Orai1 and STIM1 proteins alters regulation of store-operated Ca2+ entry by endogenous mediators. J Biol Chem 2012; 287:22865-72. [PMID: 22549787 DOI: 10.1074/jbc.m112.356626] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Orai1 and STIM1 have been identified as the main determinants of the store-operated Ca(2+) entry (SOCE). Their specific roles in SOCE and their molecular interactions have been studied extensively following heterologous overexpression or molecular knockdown and extrapolated to the endogenous processes in naïve cells. Using molecular and imaging techniques, we found that variation of expression levels of Orai1 or STIM1 can significantly alter expression and role of some endogenous regulators of SOCE. Although functional inhibition of Ca(2+)-independent phospholipase A(2) β (iPLA(2)β or PLA2g6A), or depletion of plasma membrane cholesterol caused a dramatic loss of endogenous SOCE in HEK293 cells, these effects were attenuated significantly when either Orai1 or STIM1 were overexpressed. Molecular knockdown of iPLA(2)β impaired SOCE in both control cells and cells overexpressing STIM1. We also discovered important cross-talk between expression of Orai1 and a specific plasma membrane variant of iPLA(2)β but not STIM1. These data confirm the role of iPLA(2)β as an essential mediator of endogenous SOCE and demonstrate that its physiological role can be obscured by Orai1 and STIM1 overexpression.
Collapse
Affiliation(s)
- Tomasz Gwozdz
- Ion Channel and Calcium Signaling Unit, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | | | | | | |
Collapse
|
197
|
Willoughby D, Everett KL, Halls ML, Pacheco J, Skroblin P, Vaca L, Klussmann E, Cooper DMF. Direct binding between Orai1 and AC8 mediates dynamic interplay between Ca2+ and cAMP signaling. Sci Signal 2012; 5:ra29. [PMID: 22494970 DOI: 10.1126/scisignal.2002299] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The interplay between calcium ion (Ca(2+)) and cyclic adenosine monophosphate (cAMP) signaling underlies crucial aspects of cell homeostasis. The membrane-bound Ca(2+)-regulated adenylyl cyclases (ACs) are pivotal points of this integration. These enzymes display high selectivity for Ca(2+) entry arising from the activation of store-operated Ca(2+) (SOC) channels, and they have been proposed to functionally colocalize with SOC channels to reinforce crosstalk between the two signaling pathways. Using a multidisciplinary approach, we have identified a direct interaction between the amino termini of Ca(2+)-stimulated AC8 and Orai1, the pore component of SOC channels. High-resolution biosensors targeted to the AC8 and Orai1 microdomains revealed that this protein-protein interaction is responsible for coordinating subcellular changes in both Ca(2+) and cAMP. The demonstration that Orai1 functions as an integral component of a highly organized signaling complex to coordinate Ca(2+) and cAMP signals underscores how SOC channels can be recruited to maximize the efficiency of the interplay between these two ubiquitous signaling pathways.
Collapse
Affiliation(s)
- Debbie Willoughby
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK
| | | | | | | | | | | | | | | |
Collapse
|
198
|
López E, Salido GM, Rosado JA, Berna-Erro A. Unraveling STIM2 function. J Physiol Biochem 2012; 68:619-33. [PMID: 22477146 DOI: 10.1007/s13105-012-0163-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 03/13/2012] [Indexed: 12/11/2022]
Abstract
The discovery of molecular players in capacitative calcium (Ca(2+)) entry, also referred to as store-operated Ca(2+) entry (SOCE), supposed a great advance in the knowledge of cellular mechanisms of Ca(2+) entry, which are essential for a broad range of cellular functions. The identification of STIM1 and STIM2 proteins as the sensors of Ca(2+) stored in the endoplasmic reticulum unraveled the mechanism by which depletion of intracellular Ca(2+) stores is communicated to store-operated Ca(2+) channels located in the plasma membrane, triggering the activation of SOCE and intracellular Ca(2+)-dependent signaling cascades. Initial studies suggested a dominant function of STIM1 in SOCE and SOCE-dependent cellular functions compared to STIM2, especially those that participate in immune responses. Consequently, most of the subsequent studies focused on STIM1. However, during the last years, STIM2 has been demonstrated to play a more relevant and complex function than initially reported, being even important to sustain normal life in mice. These studies have led to reconsider the role of STIM2 in SOCE and its relevance in cellular physiology. This review is intended to summarize and provide an overview of the current data available about this exciting isoform, STIM2, and its actual position together with STIM1 in the mechanism of SOCE.
Collapse
Affiliation(s)
- Esther López
- Department of Physiology (Cellular Physiology Research Group), University of Extremadura, Av. Universidad s/n, 10003, Cáceres, Spain
| | | | | | | |
Collapse
|
199
|
Lacruz RS, Smith CE, Bringas P, Chen YB, Smith SM, Snead ML, Kurtz I, Hacia JG, Hubbard MJ, Paine ML. Identification of novel candidate genes involved in mineralization of dental enamel by genome-wide transcript profiling. J Cell Physiol 2012; 227:2264-75. [PMID: 21809343 DOI: 10.1002/jcp.22965] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The gene repertoire regulating vertebrate biomineralization is poorly understood. Dental enamel, the most highly mineralized tissue in mammals, differs from other calcifying systems in that the formative cells (ameloblasts) lack remodeling activity and largely degrade and resorb the initial extracellular matrix. Enamel mineralization requires that ameloblasts undergo a profound functional switch from matrix-secreting to maturational (calcium transport, protein resorption) roles as mineralization progresses. During the maturation stage, extracellular pH decreases markedly, placing high demands on ameloblasts to regulate acidic environments present around the growing hydroxyapatite crystals. To identify the genetic events driving enamel mineralization, we conducted genome-wide transcript profiling of the developing enamel organ from rat incisors and highlight over 300 genes differentially expressed during maturation. Using multiple bioinformatics analyses, we identified groups of maturation-associated genes whose functions are linked to key mineralization processes including pH regulation, calcium handling, and matrix turnover. Subsequent qPCR and Western blot analyses revealed that a number of solute carrier (SLC) gene family members were up-regulated during maturation, including the novel protein Slc24a4 involved in calcium handling as well as other proteins of similar function (Stim1). By providing the first global overview of the cellular machinery required for enamel maturation, this study provide a strong foundation for improving basic understanding of biomineralization and its practical applications in healthcare.
Collapse
Affiliation(s)
- Rodrigo S Lacruz
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, California, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
200
|
Abstract
Orai1 is the key subunit of the Ca(2+)-release-activated Ca(2+) channel. Our previous report has demonstrated that Orai1 expression in the airway was upregulated in the ovalbumin (OVA)-induced allergic rhinitis (AR) mouse models. To observe whether inhibition of Orai1 expression in the airway could suppress symptoms in a murine model of AR and to assess the impacts of this inhibition on the responses of local and systemic immunocytes, we administered recombinant lentivirus vectors that encoded shRNA against ORAI1 (lenti-ORAI1) into the nostrils of OVA-sensitized mice before the challenges, and analyzed its effect on allergic responses, as compared with the unsensitized mice and untreated AR mice. Administration of lenti-ORAI1 into the nasal cavity successfully infected cells in the epithelial layer of the nasal mucosa, and significantly decreased the frequencies of sneezing and nasal rubbing of the mice. Protein levels of leukotriene C4, OVA-specific IgE, and IL-4 in the nasal lavage fluid and serum and eosinophil cation protein in the serum were also significantly reduced by lenti-ORAI1, as were the mRNA levels of these factors in the nasal mucosa and spleen. These data suggested that administration of lenti-ORAI1 into the nasal cavity effectively decreased Orai1 expression in the nasal mucosa, alleviated AR symptoms, and partially inhibited the hyperresponsiveness of the local and systemic immune cells including T cells, B cells, mast cells and eosinophils that are involved in the pathogenesis of AR.
Collapse
Affiliation(s)
- Yi Wang
- Department of Otorhinolaryngology-Head and Neck Surgery, Eye and ENT Hospital of Fudan University, Shanghai 200031, China
| | | | | |
Collapse
|