51
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Huang H, Hu X, Eno CO, Zhao G, Li C, White C. An interaction between Bcl-xL and the voltage-dependent anion channel (VDAC) promotes mitochondrial Ca2+ uptake. J Biol Chem 2013; 288:19870-81. [PMID: 23720737 DOI: 10.1074/jbc.m112.448290] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The role of the antiapoptotic protein Bcl-xL in regulating mitochondrial Ca(2+) ([Ca(2+)]mito) handling was examined in wild-type (WT) and Bcl-xL knock-out (Bcl-xL-KO) mouse embryonic fibroblast cells. Inositol 1,4,5-trisphosphate-generating agonist evoked cytosolic Ca(2+) transients that produced a larger [Ca(2+)]mito uptake in WT cells compared with Bcl-xL-KO. In permeabilized cells, stepping external [Ca(2+)] from 0 to 3 μm also produced a larger [Ca(2+)]mito uptake in WT; moreover, the [Ca(2+)]mito uptake capacity of Bcl-xL-KO cells was restored by re-expression of mitochondrially targeted Bcl-xL. Bcl-xL enhancement of [Ca(2+)]mito uptake persisted after dissipation of the mitochondrial membrane potential but was absent in mitoplasts lacking an outer mitochondrial membrane. The outer membrane-localized voltage-dependent anion channel (VDAC) is a known Ca(2+) permeability pathway that directly interacts with Bcl-xL. Bcl-xL interacted with VDAC1 and -3 isoforms, and peptides based on the VDAC sequence disrupted Bcl-xL binding. Peptides reduced [Ca(2+)]mito uptake in WT but were without effect in Bcl-xL-KO cells. In addition, peptides reduced [Ca(2+)]mito uptake in VDAC1 and VDAC3 knock-out but not VDAC1 and -3 double knock-out mouse embryonic fibroblast cells, confirming that Bcl-xL interacts functionally with VDAC1 and -3 but not VDAC2. Thus, an interaction between Bcl-xL and VDAC promotes matrix Ca(2+) accumulation by increasing Ca(2+) transfer across the outer mitochondrial membrane.
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Affiliation(s)
- Huiya Huang
- Department of Physiology and Biophysics, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois 60064, USA
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52
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Akl H, Monaco G, La Rovere R, Welkenhuyzen K, Kiviluoto S, Vervliet T, Molgó J, Distelhorst CW, Missiaen L, Mikoshiba K, Parys JB, De Smedt H, Bultynck G. IP3R2 levels dictate the apoptotic sensitivity of diffuse large B-cell lymphoma cells to an IP3R-derived peptide targeting the BH4 domain of Bcl-2. Cell Death Dis 2013; 4:e632. [PMID: 23681227 PMCID: PMC3674349 DOI: 10.1038/cddis.2013.140] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Disrupting inositol 1,4,5-trisphosphate (IP3) receptor (IP3R)/B-cell lymphoma 2 (Bcl-2) complexes using a cell-permeable peptide (stabilized TAT-fused IP3R-derived peptide (TAT-IDPS)) that selectively targets the BH4 domain of Bcl-2 but not that of B-cell lymphoma 2-extra large (Bcl-Xl) potentiated pro-apoptotic Ca2+ signaling in chronic lymphocytic leukemia cells. However, the molecular mechanisms rendering cancer cells but not normal cells particularly sensitive to disrupting IP3R/Bcl-2 complexes are poorly understood. Therefore, we studied the effect of TAT-IDPS in a more heterogeneous Bcl-2-dependent cancer model using a set of ‘primed to death' diffuse large B-cell lymphoma (DL-BCL) cell lines containing elevated Bcl-2 levels. We discovered a large heterogeneity in the apoptotic responses of these cells to TAT-IDPS with SU-DHL-4 being most sensitive and OCI-LY-1 being most resistant. This sensitivity strongly correlated with the ability of TAT-IDPS to promote IP3R-mediated Ca2+ release. Although total IP3R-expression levels were very similar among SU-DHL-4 and OCI-LY-1, we discovered that the IP3R2-protein level was the highest for SU-DHL-4 and the lowest for OCI-LY-1. Strikingly, TAT-IDPS-induced Ca2+ rise and apoptosis in the different DL-BCL cell lines strongly correlated with their IP3R2-protein level, but not with IP3R1-, IP3R3- or total IP3R-expression levels. Inhibiting or knocking down IP3R2 activity in SU-DHL-4-reduced TAT-IDPS-induced apoptosis, which is compatible with its ability to dissociate Bcl-2 from IP3R2 and to promote IP3-induced pro-apoptotic Ca2+ signaling. Thus, certain chronically activated B-cell lymphoma cells are addicted to high Bcl-2 levels for their survival not only to neutralize pro-apoptotic Bcl-2-family members but also to suppress IP3R hyperactivity. In particular, cancer cells expressing high levels of IP3R2 are addicted to IP3R/Bcl-2 complex formation and disruption of these complexes using peptide tools results in pro-apoptotic Ca2+ signaling and cell death.
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Affiliation(s)
- H Akl
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
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53
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Cerella C, Dicato M, Diederich M. Assembling the puzzle of anti-cancer mechanisms triggered by cardiac glycosides. Mitochondrion 2013; 13:225-34. [DOI: 10.1016/j.mito.2012.06.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 06/12/2012] [Accepted: 06/19/2012] [Indexed: 02/04/2023]
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54
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Parra V, Moraga F, Kuzmicic J, López-Crisosto C, Troncoso R, Torrealba N, Criollo A, Díaz-Elizondo J, Rothermel BA, Quest AFG, Lavandero S. Calcium and mitochondrial metabolism in ceramide-induced cardiomyocyte death. Biochim Biophys Acta Mol Basis Dis 2013; 1832:1334-44. [PMID: 23602992 DOI: 10.1016/j.bbadis.2013.04.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 04/04/2013] [Accepted: 04/08/2013] [Indexed: 10/27/2022]
Abstract
Ceramides are important intermediates in the biosynthesis and degradation of sphingolipids that regulate numerous cellular processes, including cell cycle progression, cell growth, differentiation and death. In cardiomyocytes, ceramides induce apoptosis by decreasing mitochondrial membrane potential and promoting cytochrome-c release. Ca(2+) overload is a common feature of all types of cell death. The aim of this study was to determine the effect of ceramides on cytoplasmic Ca(2+) levels, mitochondrial function and cardiomyocyte death. Our data show that C2-ceramide induces apoptosis and necrosis in cultured cardiomyocytes by a mechanism involving increased Ca(2+) influx, mitochondrial network fragmentation and loss of the mitochondrial Ca(2+) buffer capacity. These biochemical events increase cytosolic Ca(2+) levels and trigger cardiomyocyte death via the activation of calpains.
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Affiliation(s)
- Valentina Parra
- Centro de Estudios Moleculares de la Célula, Facultad de Ciencias Químicas y Farmacéuticas & Facultad Medicina, Universidad de Chile, Santiago, Chile
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55
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Dubois C, Vanden Abeele F, Prevarskaya N. Targeting apoptosis by the remodelling of calcium-transporting proteins in cancerogenesis. FEBS J 2013; 280:5500-10. [DOI: 10.1111/febs.12246] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 02/18/2013] [Accepted: 03/12/2013] [Indexed: 12/14/2022]
Affiliation(s)
- Charlotte Dubois
- Inserm; U-1003, Equipe labellisée par la Ligue Nationale contre le cancer. Laboratory of Excellence, Ion Channels Science and Therapeutics, Université des Sciences et Technologies de Lille (USTL); Villeneuve d'Ascq France
| | - Fabien Vanden Abeele
- Inserm; U-1003, Equipe labellisée par la Ligue Nationale contre le cancer. Laboratory of Excellence, Ion Channels Science and Therapeutics, Université des Sciences et Technologies de Lille (USTL); Villeneuve d'Ascq France
| | - Natacha Prevarskaya
- Inserm; U-1003, Equipe labellisée par la Ligue Nationale contre le cancer. Laboratory of Excellence, Ion Channels Science and Therapeutics, Université des Sciences et Technologies de Lille (USTL); Villeneuve d'Ascq France
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56
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Monaco G, Vervliet T, Akl H, Bultynck G. The selective BH4-domain biology of Bcl-2-family members: IP3Rs and beyond. Cell Mol Life Sci 2013; 70:1171-83. [PMID: 22955373 PMCID: PMC11113329 DOI: 10.1007/s00018-012-1118-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 08/01/2012] [Accepted: 08/02/2012] [Indexed: 01/08/2023]
Abstract
Anti-apoptotic Bcl-2-family members not only neutralize pro-apoptotic proteins but also directly regulate intracellular Ca(2+) signaling from the endoplasmic reticulum (ER), critically controlling cellular health, survival, and death initiation. Furthermore, distinct Bcl-2-family members may selectively regulate inositol 1,4,5-trisphosphate receptor (IP3R): Bcl-2 likely acts as an endogenous inhibitor of the IP3R, preventing pro-apoptotic Ca(2+) transients, while Bcl-XL likely acts as an endogenous IP3R-sensitizing protein promoting pro-survival Ca(2+) oscillations. Furthermore, distinct functional domains in Bcl-2 and Bcl-XL may underlie the divergence in IP3R regulation. The Bcl-2 homology (BH) 4 domain, which targets the central modulatory domain of the IP3R, is likely to be Bcl-2's determining factor. In contrast, the hydrophobic cleft targets the C-terminal Ca(2+)-channel tail and might be more crucial for Bcl-XL's function. Furthermore, one amino acid critically different in the sequence of Bcl-2's and Bcl-XL's BH4 domains underpins their selective effect on Ca(2+) signaling and distinct biological properties of Bcl-2 versus Bcl-XL. This difference is evolutionary conserved across five classes of vertebrates and may represent a fundamental divergence in their biological function. Moreover, these insights open novel avenues to selectively suppress malignant Bcl-2 function in cancer cells by targeting its BH4 domain, while maintaining essential Bcl-XL functions in normal cells. Thus, IP3R-derived molecules that mimic the BH4 domain's binding site on the IP3R may function synergistically with BH3-mimetic molecules selectivity suppressing Bcl-2's proto-oncogenic activity. Finally, a more general role for the BH4 domain on IP3Rs, rather than solely anti-apoptotic, may not be excluded as part of a complex network of molecular interactions.
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MESH Headings
- Animals
- Calcium Signaling/genetics
- Calcium Signaling/physiology
- Humans
- Inositol 1,4,5-Trisphosphate Receptors/chemistry
- Inositol 1,4,5-Trisphosphate Receptors/genetics
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Inositol 1,4,5-Trisphosphate Receptors/physiology
- Models, Biological
- Multigene Family/genetics
- Multigene Family/physiology
- Protein Binding/genetics
- Protein Binding/physiology
- Protein Structure, Tertiary/genetics
- Protein Structure, Tertiary/physiology
- Proto-Oncogene Proteins c-bcl-2/chemistry
- Proto-Oncogene Proteins c-bcl-2/genetics
- Proto-Oncogene Proteins c-bcl-2/metabolism
- Proto-Oncogene Proteins c-bcl-2/physiology
- Substrate Specificity
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Affiliation(s)
- Giovanni Monaco
- Laboratory of Molecular and Cellular Signaling, Department Cellular and Molecular Medicine, KU Leuven, Campus Gasthuisberg O/N-1 bus 802, 3000 Leuven, Belgium
| | - Tim Vervliet
- Laboratory of Molecular and Cellular Signaling, Department Cellular and Molecular Medicine, KU Leuven, Campus Gasthuisberg O/N-1 bus 802, 3000 Leuven, Belgium
| | - Haidar Akl
- Laboratory of Molecular and Cellular Signaling, Department Cellular and Molecular Medicine, KU Leuven, Campus Gasthuisberg O/N-1 bus 802, 3000 Leuven, Belgium
| | - Geert Bultynck
- Laboratory of Molecular and Cellular Signaling, Department Cellular and Molecular Medicine, KU Leuven, Campus Gasthuisberg O/N-1 bus 802, 3000 Leuven, Belgium
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57
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Hepatitis C virus-induced mitochondrial dysfunctions. Viruses 2013; 5:954-80. [PMID: 23518579 PMCID: PMC3705306 DOI: 10.3390/v5030954] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 03/15/2013] [Accepted: 03/20/2013] [Indexed: 12/15/2022] Open
Abstract
Chronic hepatitis C is characterized by metabolic disorders and a microenvironment in the liver dominated by oxidative stress, inflammation and regeneration processes that lead in the long term to hepatocellular carcinoma. Many lines of evidence suggest that mitochondrial dysfunctions, including modification of metabolic fluxes, generation and elimination of oxidative stress, Ca2+ signaling and apoptosis, play a central role in these processes. However, how these dysfunctions are induced by the virus and whether they play a role in disease progression and neoplastic transformation remains to be determined. Most in vitro studies performed so far have shown that several of the hepatitis C virus (HCV) proteins localize to mitochondria, but the consequences of these interactions on mitochondrial functions remain contradictory, probably due to the use of artificial expression and replication systems. In vivo studies are hampered by the fact that innate and adaptive immune responses will overlay mitochondrial dysfunctions induced directly in the hepatocyte by HCV. Thus, the molecular aspects underlying HCV-induced mitochondrial dysfunctions and their roles in viral replication and the associated pathology need yet to be confirmed in the context of productively replicating virus and physiologically relevant in vitro and in vivo model systems.
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58
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Functions of BCL-X L at the Interface between Cell Death and Metabolism. Int J Cell Biol 2013; 2013:705294. [PMID: 23533418 PMCID: PMC3603586 DOI: 10.1155/2013/705294] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 01/09/2013] [Accepted: 01/23/2013] [Indexed: 02/07/2023] Open
Abstract
The BCL-2 homolog BCL-XL, one of the two protein products of BCL2L1, has originally been characterized for its prominent prosurvival functions. Similar to BCL-2, BCL-XL binds to its multidomain proapoptotic counterparts BAX and BAK, hence preventing the formation of lethal pores in the mitochondrial outer membrane, as well as to multiple BH3-only proteins, thus interrupting apical proapoptotic signals. In addition, BCL-XL has been suggested to exert cytoprotective functions by sequestering a cytosolic pool of the pro-apoptotic transcription factor p53 and by binding to the voltage-dependent anion channel 1 (VDAC1), thereby inhibiting the so-called mitochondrial permeability transition (MPT). Thus, BCL-XL appears to play a prominent role in the regulation of multiple distinct types of cell death, including apoptosis and regulated necrosis. More recently, great attention has been given to the cell death-unrelated functions of BCL-2-like proteins. In particular, BCL-XL has been shown to modulate a number of pathophysiological processes, including-but not limited to-mitochondrial ATP synthesis, protein acetylation, autophagy and mitosis. In this short review article, we will discuss the functions of BCL-XL at the interface between cell death and metabolism.
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59
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Decrock E, De Bock M, Wang N, Gadicherla AK, Bol M, Delvaeye T, Vandenabeele P, Vinken M, Bultynck G, Krysko DV, Leybaert L. IP3, a small molecule with a powerful message. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1772-86. [PMID: 23291251 DOI: 10.1016/j.bbamcr.2012.12.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 12/18/2012] [Accepted: 12/19/2012] [Indexed: 12/22/2022]
Abstract
Research conducted over the past two decades has provided convincing evidence that cell death, and more specifically apoptosis, can exceed single cell boundaries and can be strongly influenced by intercellular communication networks. We recently reported that gap junctions (i.e. channels directly connecting the cytoplasm of neighboring cells) composed of connexin43 or connexin26 provide a direct pathway to promote and expand cell death, and that inositol 1,4,5-trisphosphate (IP3) diffusion via these channels is crucial to provoke apoptosis in adjacent healthy cells. However, IP3 itself is not sufficient to induce cell death and additional factors appear to be necessary to create conditions in which IP3 will exert proapoptotic effects. Although IP3-evoked Ca(2+) signaling is known to be required for normal cell survival, it is also actively involved in apoptosis induction and progression. As such, it is evident that an accurate fine-tuning of this signaling mechanism is crucial for normal cell physiology, while a malfunction can lead to cell death. Here, we review the role of IP3 as an intracellular and intercellular cell death messenger, focusing on the endoplasmic reticulum-mitochondrial synapse, followed by a discussion of plausible elements that can convert IP3 from a physiological molecule to a killer substance. Finally, we highlight several pathological conditions in which anomalous intercellular IP3/Ca(2+) signaling might play a role. This article is part of a Special Issue entitled:12th European Symposium on Calcium.
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Affiliation(s)
- Elke Decrock
- Department of Basic Medical Sciences, Ghent University, Ghent, Belgium
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60
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Transport and distribution of 45Ca2+ in the perfused rat liver and the influence of adjuvant-induced arthritis. Biochim Biophys Acta Mol Basis Dis 2013; 1832:249-62. [DOI: 10.1016/j.bbadis.2012.10.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 09/30/2012] [Accepted: 10/06/2012] [Indexed: 12/22/2022]
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61
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Shih WL, Kao CF, Chuang LC, Kuo PH. Incorporating Information of microRNAs into Pathway Analysis in a Genome-Wide Association Study of Bipolar Disorder. Front Genet 2012; 3:293. [PMID: 23264780 PMCID: PMC3524550 DOI: 10.3389/fgene.2012.00293] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 11/27/2012] [Indexed: 12/13/2022] Open
Abstract
MicroRNAs (miRNAs) are known to be important post-transcriptional regulators that are involved in the etiology of complex psychiatric traits. The present study aimed to incorporate miRNAs information into pathway analysis using a genome-wide association dataset to identify relevant biological pathways for bipolar disorder (BPD). We selected psychiatric- and neurological-associated miRNAs (N = 157) from PhenomiR database. The miRNA target genes (miTG) predictions were obtained from microRNA.org. Canonical pathways (N = 4,051) were downloaded from the Molecule Signature Database. We employed a novel weighting scheme for miTGs in pathway analysis using methods of gene set enrichment analysis and sum-statistic. Under four statistical scenarios, 38 significantly enriched pathways (P-value < 0.01 after multiple testing correction) were identified for the risk of developing BPD, including pathways of ion channels associated (e.g., gated channel activity, ion transmembrane transporter activity, and ion channel activity) and nervous related biological processes (e.g., nervous system development, cytoskeleton, and neuroactive ligand receptor interaction). Among them, 19 were identified only when the weighting scheme was applied. Many miRNA-targeted genes were functionally related to ion channels, collagen, and axonal growth and guidance that have been suggested to be associated with BPD previously. Some of these genes are linked to the regulation of miRNA machinery in the literature. Our findings provide support for the potential involvement of miRNAs in the psychopathology of BPD. Further investigations to elucidate the functions and mechanisms of identified candidate pathways are needed.
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Affiliation(s)
- Wei-Liang Shih
- Department of Public Health and Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University Taipei, Taiwan ; Infectious Diseases Research and Education Center, Department of Health - Executive Yuan and National Taiwan University Taipei, Taiwan
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62
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Akl H, Bultynck G. Altered Ca(2+) signaling in cancer cells: proto-oncogenes and tumor suppressors targeting IP3 receptors. Biochim Biophys Acta Rev Cancer 2012; 1835:180-93. [PMID: 23232185 DOI: 10.1016/j.bbcan.2012.12.001] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 11/30/2012] [Accepted: 12/01/2012] [Indexed: 01/15/2023]
Abstract
Proto-oncogenes and tumor suppressors critically control cell-fate decisions like cell survival, adaptation and death. These processes are regulated by Ca(2+) signals arising from the endoplasmic reticulum, which at distinct sites is in close proximity to the mitochondria. These organelles are linked by different mechanisms, including Ca(2+)-transport mechanisms involving the inositol 1,4,5-trisphosphate receptor (IP3R) and the voltage-dependent anion channel (VDAC). The amount of Ca(2+) transfer from the endoplasmic reticulum to mitochondria determines the susceptibility of cells to apoptotic stimuli. Suppressing the transfer of Ca(2+) from the endoplasmic reticulum to the mitochondria increases the apoptotic resistance of cells and may decrease the cellular responsiveness to apoptotic signaling in response to cellular damage or alterations. This can result in the survival, growth and proliferation of cells with oncogenic features. Clearly, proper maintenance of endoplasmic reticulum Ca(2+) homeostasis and dynamics including its links with the mitochondrial network is essential to detect and eliminate altered cells with oncogenic features through the apoptotic pathway. Proto-oncogenes and tumor suppressors exploit the central role of Ca(2+) signaling by targeting the IP3R. There are an increasing number of reports showing that activation of proto-oncogenes or inactivation of tumor suppressors directly affects IP3R function and endoplasmic reticulum Ca(2+) homeostasis, thereby decreasing mitochondrial Ca(2+) uptake and mitochondrial outer membrane permeabilization. In this review, we provide an overview of the current knowledge on the proto-oncogenes and tumor suppressors identified as IP3R-regulatory proteins and how they affect endoplasmic reticulum Ca(2+) homeostasis and dynamics.
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Affiliation(s)
- Haidar Akl
- Department Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
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63
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Monaco G, Beckers M, Ivanova H, Missiaen L, Parys JB, De Smedt H, Bultynck G. Profiling of the Bcl-2/Bcl-XL-binding sites on type 1 IP3 receptor. Biochem Biophys Res Commun 2012; 428:31-5. [DOI: 10.1016/j.bbrc.2012.10.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 10/01/2012] [Indexed: 02/04/2023]
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64
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de Bartolomeis A, Tomasetti C. Calcium-Dependent Networks in Dopamine–Glutamate Interaction: The Role of Postsynaptic Scaffolding Proteins. Mol Neurobiol 2012; 46:275-96. [DOI: 10.1007/s12035-012-8293-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 06/21/2012] [Indexed: 01/11/2023]
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65
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Curry MC, Luk NA, Kenny PA, Roberts-Thomson SJ, Monteith GR. Distinct regulation of cytoplasmic calcium signals and cell death pathways by different plasma membrane calcium ATPase isoforms in MDA-MB-231 breast cancer cells. J Biol Chem 2012; 287:28598-608. [PMID: 22733819 DOI: 10.1074/jbc.m112.364737] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Plasma membrane calcium ATPases (PMCAs) actively extrude Ca(2+) from the cell and are essential components in maintaining intracellular Ca(2+) homeostasis. There are four PMCA isoforms (PMCA1-4), and alternative splicing of the PMCA genes creates a suite of calcium efflux pumps. The role of these different PMCA isoforms in the control of calcium-regulated cell death pathways and the significance of the expression of multiple isoforms of PMCA in the same cell type are not well understood. In these studies, we assessed the impact of PMCA1 and PMCA4 silencing on cytoplasmic free Ca(2+) signals and cell viability in MDA-MB-231 breast cancer cells. The PMCA1 isoform was the predominant regulator of global Ca(2+) signals in MDA-MB-231 cells. PMCA4 played only a minor role in the regulation of bulk cytosolic Ca(2+), which was more evident at higher Ca(2+) loads. Although PMCA1 or PMCA4 knockdown alone had no effect on MDA-MB-231 cell viability, silencing of these isoforms had distinct consequences on caspase-independent (ionomycin) and -dependent (ABT-263) cell death. PMCA1 knockdown augmented necrosis mediated by the Ca(2+) ionophore ionomycin, whereas apoptosis mediated by the Bcl-2 inhibitor ABT-263 was enhanced by PMCA4 silencing. PMCA4 silencing was also associated with an inhibition of NFκB nuclear translocation, and an NFκB inhibitor phenocopied the effects of PMCA4 silencing in promoting ABT-263-induced cell death. This study demonstrates distinct roles for PMCA1 and PMCA4 in the regulation of calcium signaling and cell death pathways despite the widespread distribution of these two isoforms. The targeting of some PMCA isoforms may enhance the effectiveness of therapies that act through the promotion of cell death pathways in cancer cells.
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Affiliation(s)
- Merril C Curry
- School of Pharmacy, The University of Queensland, Brisbane, Queensland 4072, Australia
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66
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Bcl2 at the endoplasmic reticulum protects against a Bax/Bak-independent paraptosis-like cell death pathway initiated via p20Bap31. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:335-47. [DOI: 10.1016/j.bbamcr.2011.11.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 11/29/2011] [Accepted: 11/30/2011] [Indexed: 01/20/2023]
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67
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Hirata H, Lopes GS, Jurkiewicz A, Garcez-do-Carmo L, Smaili SS. Bcl-2 Modulates Endoplasmic Reticulum and Mitochondrial Calcium Stores in PC12 Cells. Neurochem Res 2011; 37:238-43. [DOI: 10.1007/s11064-011-0600-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 09/05/2011] [Accepted: 09/09/2011] [Indexed: 11/30/2022]
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68
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Risberg K, Fodstad Ø, Andersson Y. Synergistic anticancer effects of the 9.2.27PE immunotoxin and ABT-737 in melanoma. PLoS One 2011; 6:e24012. [PMID: 21915275 PMCID: PMC3168478 DOI: 10.1371/journal.pone.0024012] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 08/01/2011] [Indexed: 01/01/2023] Open
Abstract
In cancer, combinations of drugs targeting different cellular functions is well accepted to improve tumor control. We studied the effects of a Pseudomonas exotoxin A (PE)-based immunotoxin, the 9.2.27PE, and the BH-3 mimetic compound ABT-737 in a panel of melanoma cell lines. The drug combination resulted in synergistic cytotoxicity, and the cell death observed was associated with apoptosis, as activation of caspase-3, inactivation of Poly (ADP-ribose) polymerase (PARP) and increased DNA fragmentation could be prevented by pre-treatment with caspase and cathepsin inhibitors. We further show that ABT-737 caused endoplasmic reticulum (ER) stress with increased GRP78 and phosphorylated eIF2α protein levels. Moreover, treatment with ABT-737 increased the intracellular calcium levels, an effect which was enhanced by 9.2.27PE, which as a single entity drug had minimal effect on calcium release from the ER. In addition, silencing of Mcl-1 by short hairpin RNA (shRNA) enhanced the intracellular calcium levels and cytotoxicity caused by ABT-737. Notably, the combination of 9.2.27PE and ABT-737 caused growth delay in a human melanoma xenograft mice model, supporting further investigations of this particular drug combination.
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Affiliation(s)
- Karianne Risberg
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital Radiumhospitalet, Montebello, Oslo, Norway.
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69
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ORAI-mediated calcium influx in T cell proliferation, apoptosis and tolerance. Cell Calcium 2011; 50:261-9. [DOI: 10.1016/j.ceca.2011.05.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 05/12/2011] [Accepted: 05/13/2011] [Indexed: 12/25/2022]
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