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Léger C, Pitard I, Sadi M, Carvalho N, Brier S, Mechaly A, Raoux-Barbot D, Davi M, Hoos S, Weber P, Vachette P, Durand D, Haouz A, Guijarro JI, Ladant D, Chenal A. Dynamics and structural changes of calmodulin upon interaction with the antagonist calmidazolium. BMC Biol 2022; 20:176. [PMID: 35945584 PMCID: PMC9361521 DOI: 10.1186/s12915-022-01381-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/29/2022] [Indexed: 11/11/2022] Open
Abstract
Background Calmodulin (CaM) is an evolutionarily conserved eukaryotic multifunctional protein that functions as the major sensor of intracellular calcium signaling. Its calcium-modulated function regulates the activity of numerous effector proteins involved in a variety of physiological processes in diverse organs, from proliferation and apoptosis, to memory and immune responses. Due to the pleiotropic roles of CaM in normal and pathological cell functions, CaM antagonists are needed for fundamental studies as well as for potential therapeutic applications. Calmidazolium (CDZ) is a potent small molecule antagonist of CaM and one the most widely used inhibitors of CaM in cell biology. Yet, CDZ, as all other CaM antagonists described thus far, also affects additional cellular targets and its lack of selectivity hinders its application for dissecting calcium/CaM signaling. A better understanding of CaM:CDZ interaction is key to design analogs with improved selectivity. Here, we report a molecular characterization of CaM:CDZ complexes using an integrative structural biology approach combining SEC-SAXS, X-ray crystallography, HDX-MS, and NMR. Results We provide evidence that binding of a single molecule of CDZ induces an open-to-closed conformational reorientation of the two domains of CaM and results in a strong stabilization of its structural elements associated with a reduction of protein dynamics over a large time range. These CDZ-triggered CaM changes mimic those induced by CaM-binding peptides derived from physiological protein targets, despite their distinct chemical natures. CaM residues in close contact with CDZ and involved in the stabilization of the CaM:CDZ complex have been identified. Conclusion Our results provide molecular insights into CDZ-induced dynamics and structural changes of CaM leading to its inhibition and open the way to the rational design of more selective CaM antagonists. Graphical abstract Calmidazolium is a potent and widely used inhibitor of calmodulin, a major mediator of calcium-signaling in eukaryotic cells. Structural characterization of calmidazolium-binding to calmodulin reveals that it triggers open-to-closed conformational changes similar to those induced by calmodulin-binding peptides derived from enzyme targets. These results provide molecular insights into CDZ-induced dynamics and structural changes of CaM leading to its inhibition and open the way to the rational design of more selective CaM antagonists.![]() Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01381-5.
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Affiliation(s)
- Corentin Léger
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, CNRS UMR3528, Institut Pasteur, Paris, 75015, France
| | - Irène Pitard
- Biological NMR and HDX-MS Technological Platform, CNRS UMR3528, Université Paris Cité, Institut Pasteur, Paris, 75015, France
| | - Mirko Sadi
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, CNRS UMR3528, Institut Pasteur, Paris, 75015, France.,Université Paris Cité, Paris, France
| | - Nicolas Carvalho
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, CNRS UMR3528, Institut Pasteur, Paris, 75015, France.,Université Paris Cité, Paris, France
| | - Sébastien Brier
- Biological NMR and HDX-MS Technological Platform, CNRS UMR3528, Université Paris Cité, Institut Pasteur, Paris, 75015, France
| | - Ariel Mechaly
- Plate-forme de Cristallographie-C2RT, Université Paris Cité, CNRS UMR3528, Institut Pasteur, Paris, France
| | - Dorothée Raoux-Barbot
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, CNRS UMR3528, Institut Pasteur, Paris, 75015, France
| | - Maryline Davi
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, CNRS UMR3528, Institut Pasteur, Paris, 75015, France
| | - Sylviane Hoos
- Plateforme de Biophysique Moléculaire, Université Paris Cité, CNRS UMR3528, Institut Pasteur, Paris, France
| | - Patrick Weber
- Plate-forme de Cristallographie-C2RT, Université Paris Cité, CNRS UMR3528, Institut Pasteur, Paris, France
| | - Patrice Vachette
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Dominique Durand
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Ahmed Haouz
- Plate-forme de Cristallographie-C2RT, Université Paris Cité, CNRS UMR3528, Institut Pasteur, Paris, France
| | - J Iñaki Guijarro
- Biological NMR and HDX-MS Technological Platform, CNRS UMR3528, Université Paris Cité, Institut Pasteur, Paris, 75015, France
| | - Daniel Ladant
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, CNRS UMR3528, Institut Pasteur, Paris, 75015, France.
| | - Alexandre Chenal
- Biochemistry of Macromolecular Interactions Unit, Department of Structural Biology and Chemistry, CNRS UMR3528, Institut Pasteur, Paris, 75015, France.
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Niu L, Wei J, Li X, Jin Y, Shi X. Inhibitory activity of narirutin on RBL-2H3 cells degranulation. Immunopharmacol Immunotoxicol 2020; 43:68-76. [PMID: 33272043 DOI: 10.1080/08923973.2020.1850764] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Context: It is an efficient strategy to apply inhibition of mast cell degranulation for evaluating anti-allergic effects of compounds. Previous works confirmed that narirutin had anti-allergic activity in OVA induced allergic asthma murine model. However, the mechanism is not clear. Objective: Here, inhibitory mechanism of narirutin on RBL-2H3 cells degranulation was investigated. Materials and methods: Cell viability was analyzed by CCK-8 kits, cell degranulation was analyzed by ELISA methods, morphology and ultrastructure of cells was observed by atomic force microscopy, intracellular Ca 2+ concentration was measured by fluorescence microscopre, mRNA expression were measured by PCR, and signaling pathways were measured by WB. Results: The results showed that narirutin have no direct effects on mRNA expression of FcεRI subunit. However, it inhibited Ca2+ influx by suppressing the phosphorylation of Syk, LAT and PLCγ1 signaling pathway transduction. Subsequently, the inhibition of Ca2+ influx directly leads to NF-κB signaling pathway transduction decreased. Narirutin can also suppress the phosphorylation of MAPK signaling pathways by decreasing the expression of P-p38, P-ERK and P-JNK, inhibit the synergistic effect for Ca2+ influx, and then reduce the release of IL-4, TNF-α, histamine and β-HEX. Conclusion: Our study suggested that the inhibitory mechanism of narirutin on RBL-2H3 cells degranulation could be related to regulate MAPK, NF-κB and Tyrosine kinase signaling pathway.
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Affiliation(s)
- Liyan Niu
- College of Food Science and Engineering, Jilin University, Changchun, PR China
| | - Jihao Wei
- College of Food Science and Engineering, Jilin University, Changchun, PR China
| | - Xuwen Li
- College of Chemistry, Jilin University, Changchun, PR China
| | - Yongri Jin
- College of Chemistry, Jilin University, Changchun, PR China
| | - Xiaolei Shi
- College of Food Science and Engineering, Jilin University, Changchun, PR China
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Turovsky EA, Zinchenko VP, Kaimachnikov NP. Attenuation of calmodulin regulation evokes Ca 2+ oscillations: evidence for the involvement of intracellular arachidonate-activated channels and connexons. Mol Cell Biochem 2019; 456:191-204. [PMID: 30756222 DOI: 10.1007/s11010-019-03504-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 02/01/2019] [Indexed: 01/02/2023]
Abstract
Intracellular Са2+ controls its own level by regulation of Ca2+ transport across the plasma and organellar membranes, often acting via calmodulin (CaM). Drugs antagonizing CaM action induce an increase in cytosolic Ca2+ concentration in different cells. We have found persistent Са2+ oscillations in cultured white adipocytes in response to calmidazolium (CMZ). They appeared at [CMZ] > 1 μM as repetitive sharp spikes mainly superimposed on a transient or elevated baseline. Similar oscillations were observed when we used trifluoperazine. Oscillations evoked by 5 μM CMZ resulted from the release of stored Ca2+ and were supported by Са2+ entry. Inhibition of store-operated channels by YM-58483 or 2-APB did not change the responses. Phospholipase A2 inhibited by AACOCF3 was responsible for initial Ca2+ mobilization, but not for subsequent oscillations, whereas inhibition of iPLA2 by BEL had no effect. Phospholipase C was partially involved in both stages as revealed with U73122. Intracellular Са2+ stores engaged by CMZ were entirely dependent on thapsigargin. The oscillations existed in the presence of inhibitors of ryanodine or inositol 1,4,5-trisphosphate receptors, or antagonists of Ca2+ transport by lysosome-like acidic stores. Carbenoxolone or octanol, blockers of hemichannels (connexons), when applied for two hours, prevented oscillations but did not affect the initial Са2+ release. Incubation with La3+ for 2 or 24 h inhibited all responses to CMZ, retaining the thapsigargin-induced Ca2+ rise. These results suggest that Ca2+-CaM regulation suppresses La3+-sensitive channels in non-acidic organelles, of which arachidonate-activated channels initiate Ca2+ oscillations, and connexons are intimately implicated in their generation mechanism.
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Affiliation(s)
- Egor A Turovsky
- Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino, Moscow Region, Russia, 142290
| | - Valery P Zinchenko
- Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino, Moscow Region, Russia, 142290
| | - Nikolai P Kaimachnikov
- Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino, Moscow Region, Russia, 142290.
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Lee J, Kim MS, Kim MA, Jang YK. Calmidazolium chloride inhibits growth of murine embryonal carcinoma cells, a model of cancer stem-like cells. Toxicol In Vitro 2016; 35:86-92. [PMID: 27247146 DOI: 10.1016/j.tiv.2016.05.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 04/07/2016] [Accepted: 05/27/2016] [Indexed: 01/01/2023]
Abstract
Calmidazolium chloride (CMZ) is widely used as a calmodulin (CaM) antagonist, but is also known to induce apoptosis in certain cancer cell lines. However, in spite of the importance of cancer stem cells (CSCs) in cancer therapy, the effects of CMZ on CSCs are not yet well understood. We investigated the effects of CMZ on the F9 embryonal carcinoma cell (ECC) line as a surrogate model of CSCs. To avoid bias due to culture conditions, F9 ECCs and E14 embryonic stem cells (ESCs) were grown in the same culture medium. Results obtained using a cell-counting kit showed that CMZ significantly inhibited growth in F9 ECCs compared with growth in E14 ESCs. CMZ also induced apoptosis of F9 ECCs, but not of E14 ESCs, which was associated with caspase-3 activation and an increased fraction of the sub-G1 cell population. In addition, our data revealed that the expression of stemness-related genes including c-Myc was selectively down regulated in CMZ-treated F9 ECCs. Our results suggest that CMZ can inhibit the growth of ECCs by inducing apoptosis and down regulating stemness-related genes, without causing any harm to normal stem cells. These findings indicate a potential application of CMZ in the development of anti-CSC therapeutics.
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Affiliation(s)
- Jina Lee
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea; Initiative for Biological Function & Systems, Yonsei University, Seoul 120-749, Republic of Korea
| | - Min Seong Kim
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea; Initiative for Biological Function & Systems, Yonsei University, Seoul 120-749, Republic of Korea
| | - Min Aeh Kim
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea; Initiative for Biological Function & Systems, Yonsei University, Seoul 120-749, Republic of Korea
| | - Yeun Kyu Jang
- Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea; Initiative for Biological Function & Systems, Yonsei University, Seoul 120-749, Republic of Korea.
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Wang J, Li M, Wang Y, Liu X. Integrating subpathway analysis to identify candidate agents for hepatocellular carcinoma. Onco Targets Ther 2016; 9:1221-30. [PMID: 27022281 PMCID: PMC4788366 DOI: 10.2147/ott.s97211] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is the second most common cause of cancer-associated death worldwide, characterized by a high invasiveness and resistance to normal anticancer treatments. The need to develop new therapeutic agents for HCC is urgent. Here, we developed a bioinformatics method to identify potential novel drugs for HCC by integrating HCC-related and drug-affected subpathways. By using the RNA-seq data from the TCGA (The Cancer Genome Atlas) database, we first identified 1,763 differentially expressed genes between HCC and normal samples. Next, we identified 104 significant HCC-related subpathways. We also identified the subpathways associated with small molecular drugs in the CMap database. Finally, by integrating HCC-related and drug-affected subpathways, we identified 40 novel small molecular drugs capable of targeting these HCC-involved subpathways. In addition to previously reported agents (ie, calmidazolium), our method also identified potentially novel agents for targeting HCC. We experimentally verified that one of these novel agents, prenylamine, induced HCC cell apoptosis using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, an acridine orange/ethidium bromide stain, and electron microscopy. In addition, we found that prenylamine not only affected several classic apoptosis-related proteins, including Bax, Bcl-2, and cytochrome c, but also increased caspase-3 activity. These candidate small molecular drugs identified by us may provide insights into novel therapeutic approaches for HCC.
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Affiliation(s)
- Jiye Wang
- The Criminal Science and Technology Department, Zhejiang Police College, Hangzhou, Zhejiang Province, People's Republic of China
| | - Mi Li
- Department of Nursing, Shandong College of Traditional Chinese Medicine College, Yantai, Shandong Province, People's Republic of China
| | - Yun Wang
- Office Department of Gastroenterology, The First Affiliated Hospital of Xi'an Jiao Tong University, Xi'an, Shanxi Province, People's Republic of China
| | - Xiaoping Liu
- Key Laboratory of Systems Biology, Shanghai Institutes for Biological Sciences, Shanghai, People's Republic of China
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Budu A, Gomes MM, Melo PM, El Chamy Maluf S, Bagnaresi P, Azevedo MF, Carmona AK, Gazarini ML. Calmidazolium evokes high calcium fluctuations in Plasmodium falciparum. Cell Signal 2015; 28:125-135. [PMID: 26689736 DOI: 10.1016/j.cellsig.2015.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 11/30/2015] [Accepted: 12/07/2015] [Indexed: 10/22/2022]
Abstract
Calcium and calmodulin (CaM) are important players in eukaryote cell signaling. In the present study, by using a knockin approach, we demonstrated the expression and localization of CaM in all erythrocytic stages of Plasmodium falciparum. Under extracellular Ca(2+)-free conditions, calmidazolium (CZ), a potent CaM inhibitor, promoted a transient cytosolic calcium ([Ca(2+)]cyt) increase in isolated trophozoites, indicating that CZ mobilizes intracellular sources of calcium. In the same extracellular Ca(2+)-free conditions, the [Ca(2+)]cyt rise elicited by CZ treatment was ~3.5 fold higher when the endoplasmic reticulum (ER) calcium store was previously depleted ruling out the mobilization of calcium from the ER by CZ. The effects of the Ca(2+)/H(+) ionophore ionomycin (ION) and the Na(+)/H(+) ionophore monensin (MON) suggest that the [Ca(2+)]cyt-increasing effect of CZ is driven by the removal of Ca(2+) from at least one Ca(2+)-CaM-related (CaMR) protein as well as by the mobilization of Ca(2+) from intracellular acidic calcium stores. Moreover, we showed that the mitochondrion participates in the sequestration of the cytosolic Ca(2+) elicited by CZ. Finally, the modulation of membrane Ca(2+) channels by CZ and thapsigargin (THG) was demonstrated. The opened channels were blocked by the unspecific calcium channel blocker Co(2+) but not by 2-APB (capacitative calcium entry inhibitor) or nifedipine (L-type Ca(2+) channel inhibitor). Taken together, the results suggested that one CaMR protein is an important modulator of calcium signaling and homeostasis during the Plasmodium intraerythrocytic cell cycle, working as a relevant intracellular Ca(2+) reservoir in the parasite.
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Affiliation(s)
- Alexandre Budu
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Mayrim M Gomes
- Departamento de Biociências, Universidade Federal de São Paulo, Santos, SP, Brazil
| | - Pollyana M Melo
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Sarah El Chamy Maluf
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Piero Bagnaresi
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Mauro F Azevedo
- Instituto de Ciências Biomédicas, Universidade de São Paulo, SP, Brazil
| | - Adriana K Carmona
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
| | - Marcos L Gazarini
- Departamento de Biociências, Universidade Federal de São Paulo, Santos, SP, Brazil.
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Effects of 39 Compounds on Calmodulin-Regulated Adenylyl Cyclases AC1 and Bacillus anthracis Edema Factor. PLoS One 2015; 10:e0124017. [PMID: 25946093 PMCID: PMC4422518 DOI: 10.1371/journal.pone.0124017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Accepted: 03/09/2015] [Indexed: 12/29/2022] Open
Abstract
Adenylyl cyclases (ACs) catalyze the conversion of ATP into the second messenger cAMP. Membranous AC1 (AC1) is involved in processes of memory and learning and in muscle pain. The AC toxin edema factor (EF) of Bacillus anthracis is involved in the development of anthrax. Both ACs are stimulated by the eukaryotic Ca2+-sensor calmodulin (CaM). The CaM-AC interaction could constitute a potential target to enhance or impair the AC activity of AC1 and EF to intervene in above (patho)physiological mechanisms. Thus, we analyzed the impact of 39 compounds including typical CaM-inhibitors, an anticonvulsant, an anticholinergic, antidepressants, antipsychotics and Ca2+-antagonists on CaM-stimulated catalytic activity of AC1 and EF. Compounds were tested at 10 μM, i.e., a concentration that can be reached therapeutically for certain antidepressants and antipsychotics. Calmidazolium chloride decreased CaM-stimulated AC1 activity moderately by about 30%. In contrast, CaM-stimulated EF activity was abrogated by calmidazolium chloride and additionally decreased by chlorpromazine, felodipine, penfluridol and trifluoperazine by about 20–40%. The activity of both ACs was decreased by calmidazolium chloride in the presence and absence of CaM. Thus, CaM-stimulated AC1 activity is more insensitive to inhibition by small molecules than CaM-stimulated EF activity. Inhibition of AC1 and EF by calmidazolium chloride is largely mediated via a CaM-independent allosteric mechanism.
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Horng CT, Chiang NN, Chen IL, Liang WZ, Chen IS, Kuo DH, Shieh PC, Jan CR. Effect of clotrimazole on cytosolic Ca2+rise and viability in HA59T human hepatoma cells. J Recept Signal Transduct Res 2013; 33:89-95. [DOI: 10.3109/10799893.2013.764321] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Mohanty C, Fayad W, Olofsson MH, Larsson R, De Milito A, Fryknäs M, Linder ST. Massive induction of apoptosis of multicellular tumor spheroids by a novel compound with a calmodulin inhibitor-like mechanism. ACTA ACUST UNITED AC 2013. [DOI: 10.7243/2049-7962-2-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Cheng JS, Shu SS, Kuo CC, Chou CT, Tsai WL, Fang YC, Kuo LN, Yeh JH, Chen WC, Chien JM, Lu T, Pan CC, Cheng HH, Chai KL, Jan CR. Effect of diindolylmethane on Ca(2+) movement and viability in HA59T human hepatoma cells. Arch Toxicol 2011; 85:1257-66. [PMID: 21409406 DOI: 10.1007/s00204-011-0670-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 02/08/2011] [Indexed: 01/15/2023]
Abstract
The effect of diindolylmethane, a natural compound derived from indole-3-carbinol in cruciferous vegetables, on cytosolic Ca(2+) concentrations ([Ca(2+)](i)) and viability in HA59T human hepatoma cells is unclear. This study explored whether diindolylmethane changed [Ca(2+)](i) in HA59T cells. The Ca(2+)-sensitive fluorescent dye fura-2 was applied to measure [Ca(2+)](i). Diindolylmethane at concentrations of 1-50 μM evoked a [Ca(2+)](i) rise in a concentration-dependent manner. The signal was reduced by removing Ca(2+). Diindolylmethane-induced Ca(2+) influx was not inhibited by nifedipine, econazole, SK&F96365, and protein kinase C modulators but was inhibited by aristolochic acid. In Ca(2+)-free medium, treatment with the endoplasmic reticulum Ca(2+) pump inhibitors thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) inhibited or abolished diindolylmethane-induced [Ca(2+)](i) rise. Incubation with diindolylmethane inhibited thapsigargin or BHQ-induced [Ca(2+)](i) rise. Inhibition of phospholipase C with U73122 reduced diindolylmethane-induced [Ca(2+)](i) rise. At concentrations of 10-75 μM, diindolylmethane killed cells in a concentration-dependent manner. The cytotoxic effect of diindolylmethane was not reversed by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid. Propidium iodide staining data suggest that diindolylmethane (25-50 μM) induced apoptosis in a concentration-dependent manner. Collectively, in HA59T cells, diindolylmethane induced a [Ca(2+)](i) rise by causing phospholipase C-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) influx via phospholipase A(2)-sensitive channels. Diindolylmethane induced cell death that may involve apoptosis.
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Affiliation(s)
- Jin-Shiung Cheng
- Department of Medicine, Yongkang Veterans Hospital, Tainan 710, Taiwan
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Kumar S, Kain V, Sitasawad SL. Cardiotoxicity of calmidazolium chloride is attributed to calcium aggravation, oxidative and nitrosative stress, and apoptosis. Free Radic Biol Med 2009; 47:699-709. [PMID: 19497364 DOI: 10.1016/j.freeradbiomed.2009.05.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Revised: 05/05/2009] [Accepted: 05/20/2009] [Indexed: 10/20/2022]
Abstract
The intracellular calcium concentration ([Ca](i)) regulates cell viability and contractility in myocardial cells. Elevation of the [Ca](i) level occurs by entry of calcium ions (Ca(2+)) through voltage-dependent Ca(2+) channels in the plasma membrane and release of Ca(2+) from the sarcoplasmic reticulum. Calmidazolium chloride (CMZ), a subgroup II calmodulin antagonist, blocks L-type calcium channels as well as voltage-dependent Na(+) and K(+) channel currents. This study elaborates on the events that contribute to the cytotoxic effects of CMZ on the heart. We hypothesized that apoptotic cell death occurs in the cardiac cells through calcium accumulation, production of reactive oxygen species, and the cytochrome c-mediated PARP activation pathway. CMZ significantly increased the production of superoxide (O(2)(*-)) and nitric oxide (NO) as detected by FACS and confocal microscopy. CMZ induced mitochondrial damage by increasing the levels of intracellular calcium, lowering the mitochondrial membrane potential, and thereby inducing cytochrome c release. Apoptotic cell death was observed in H9c2 cells exposed to 25 microM CMZ for 24 h. This is the first report that elaborates on the mechanism of CMZ-induced cardiotoxicity. CMZ causes apoptosis by decreasing mitochondrial activity and contractility indices and increasing oxidative and nitrosative stress, ultimately leading to cell death via an intrinsic apoptotic pathway.
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Affiliation(s)
- Sandeep Kumar
- National Centre for Cell Science, NCCS Complex, Pune University Campus, Ganeshkhind, Pune 411007, Maharashtra, India
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