1
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Moya-Alvarado G, Valero-Peña X, Aguirre-Soto A, Bustos FJ, Lazo OM, Bronfman FC. PLC-γ-Ca 2+ pathway regulates axonal TrkB endocytosis and is required for long-distance propagation of BDNF signaling. Front Mol Neurosci 2024; 17:1009404. [PMID: 38660384 PMCID: PMC11040097 DOI: 10.3389/fnmol.2024.1009404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 03/25/2024] [Indexed: 04/26/2024] Open
Abstract
Brain-derived neurotrophic factor (BDNF) and its tropomyosin receptor kinase B (TrkB) are important signaling proteins that regulate dendritic growth and maintenance in the central nervous system (CNS). After binding of BDNF, TrkB is endocytosed into endosomes and continues signaling within the cell soma, dendrites, and axon. In previous studies, we showed that BDNF signaling initiated in axons triggers long-distance signaling, inducing dendritic arborization in a CREB-dependent manner in cell bodies, processes that depend on axonal dynein and TrkB activities. The binding of BDNF to TrkB triggers the activation of different signaling pathways, including the ERK, PLC-γ and PI3K-mTOR pathways, to induce dendritic growth and synaptic plasticity. How TrkB downstream pathways regulate long-distance signaling is unclear. Here, we studied the role of PLC-γ-Ca2+ in BDNF-induced long-distance signaling using compartmentalized microfluidic cultures. We found that dendritic branching and CREB phosphorylation induced by axonal BDNF stimulation require the activation of PLC-γ in the axons of cortical neurons. Locally, in axons, BDNF increases PLC-γ phosphorylation and induces intracellular Ca2+ waves in a PLC-γ-dependent manner. In parallel, we observed that BDNF-containing signaling endosomes transport to the cell body was dependent on PLC-γ activity and intracellular Ca2+ stores. Furthermore, the activity of PLC-γ is required for BDNF-dependent TrkB endocytosis, suggesting a role for the TrkB/PLC-γ signaling pathway in axonal signaling endosome formation.
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Affiliation(s)
- Guillermo Moya-Alvarado
- Faculty of Biological Sciences, Pontificia Universidad Catolica de Chile (UC), Santiago, Chile
| | - Xavier Valero-Peña
- NeuroSignaling Laboratory, Institute of Biomedical Sciences (ICB), Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
| | - Alejandro Aguirre-Soto
- NeuroSignaling Laboratory, Institute of Biomedical Sciences (ICB), Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
| | - Fernando J. Bustos
- Constantin-Paton Research Laboratory, Institute of Biomedical Sciences (ICB), Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
| | - Oscar M. Lazo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Francisca C. Bronfman
- NeuroSignaling Laboratory, Institute of Biomedical Sciences (ICB), Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
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2
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Sushma, Mishra S, Kanchan S, Divakar A, Jha G, Sharma D, Kapoor R, Kumar Rath S. Alcohol induces ER stress and apoptosis by inducing oxidative stress and disruption of calcium homeostasis in glial cells. Food Chem Toxicol 2023; 182:114192. [PMID: 37980976 DOI: 10.1016/j.fct.2023.114192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/08/2023] [Accepted: 11/11/2023] [Indexed: 11/21/2023]
Abstract
Alcohol has teratogenic effects that can cause developmental abnormalities and alter anatomical and functional characteristics of the developed brain and other organs. Glial cells play a crucial role in alcohol metabolism and protect neurons from toxic effects of alcohol. However, chronic alcohol exposure can lead to uncontrollable levels of reactive oxygen species, resulting in the death of glial cells and exposing neuronal cells to the toxic effects of alcohol. The exact molecular mechanism of alcohol-induced glial cell death has not been fully explored. This study reported that different concentrations of alcohol induce different expressions of ER stress markers in glial cells, focusing on the role of endoplasmic reticulum (ER) stress. Alcohol-induced concentration-dependent toxicity in both cells also induced oxidative stress, leading to mitochondrial damage. The expression of p53 and apoptotic proteins was significantly up-regulated after alcohol exposure, while Bcl2 (anti-apoptotic) was down-regulated. The signalling pathway for ER stress was activated and up-regulated marker proteins in a concentration-dependent manner. Cells pre-treated with BAPTA-AM and NAC showed significant resistance against alcohol assault compared to other cells. These in vitro findings will prove valuable for defining the mechanism by which alcohol modulates oxidative stress, mitochondrial and ER damage leading to glial cell death.
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Affiliation(s)
- Sushma
- Genotoxicity Laboratory, Division of Toxicology & Experimental Medicine, CSIR-Central Drug Research Institute, Lucknow, 226001, India
| | - Sakshi Mishra
- Genotoxicity Laboratory, Division of Toxicology & Experimental Medicine, CSIR-Central Drug Research Institute, Lucknow, 226001, India
| | - Sonam Kanchan
- Genotoxicity Laboratory, Division of Toxicology & Experimental Medicine, CSIR-Central Drug Research Institute, Lucknow, 226001, India
| | - Aman Divakar
- Genotoxicity Laboratory, Division of Toxicology & Experimental Medicine, CSIR-Central Drug Research Institute, Lucknow, 226001, India
| | - Gaurav Jha
- Genotoxicity Laboratory, Division of Toxicology & Experimental Medicine, CSIR-Central Drug Research Institute, Lucknow, 226001, India
| | - Divyansh Sharma
- Genotoxicity Laboratory, Division of Toxicology & Experimental Medicine, CSIR-Central Drug Research Institute, Lucknow, 226001, India
| | - Radhika Kapoor
- Genotoxicity Laboratory, Division of Toxicology & Experimental Medicine, CSIR-Central Drug Research Institute, Lucknow, 226001, India
| | - Srikanta Kumar Rath
- Genotoxicity Laboratory, Division of Toxicology & Experimental Medicine, CSIR-Central Drug Research Institute, Lucknow, 226001, India.
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3
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Jaiswal RK, Lei KH, Chastain M, Wang Y, Shiva O, Li S, You Z, Chi P, Chai W. CaMKK2 and CHK1 phosphorylate human STN1 in response to replication stress to protect stalled forks from aberrant resection. Nat Commun 2023; 14:7882. [PMID: 38036565 PMCID: PMC10689503 DOI: 10.1038/s41467-023-43685-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 11/16/2023] [Indexed: 12/02/2023] Open
Abstract
Keeping replication fork stable is essential for safeguarding genome integrity; hence, its protection is highly regulated. The CTC1-STN1-TEN1 (CST) complex protects stalled forks from aberrant MRE11-mediated nascent strand DNA degradation (NSD). However, the activation mechanism for CST at forks is unknown. Here, we report that STN1 is phosphorylated in its intrinsic disordered region. Loss of STN1 phosphorylation reduces the replication stress-induced STN1 localization to stalled forks, elevates NSD, increases MRE11 access to stalled forks, and decreases RAD51 localization at forks, leading to increased genome instability under perturbed DNA replication condition. STN1 is phosphorylated by both the ATR-CHK1 and the calcium-sensing kinase CaMKK2 in response to hydroxyurea/aphidicolin treatment or elevated cytosolic calcium concentration. Cancer-associated STN1 variants impair STN1 phosphorylation, conferring inability of fork protection. Collectively, our study uncovers that CaMKK2 and ATR-CHK1 target STN1 to enable its fork protective function, and suggests an important role of STN1 phosphorylation in cancer development.
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Affiliation(s)
- Rishi Kumar Jaiswal
- Department of Cancer Biology, Cardinal Bernardin Cancer Center, Loyola University Chicago Stritch School of Medicine, Maywood, IL, USA
| | - Kai-Hang Lei
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Megan Chastain
- Office of Research, Washington State University, Spokane, WA, USA
| | - Yuan Wang
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
| | - Olga Shiva
- Office of Research, Washington State University, Spokane, WA, USA
| | - Shan Li
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Zhongsheng You
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Peter Chi
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Weihang Chai
- Department of Cancer Biology, Cardinal Bernardin Cancer Center, Loyola University Chicago Stritch School of Medicine, Maywood, IL, USA.
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4
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Lučić I, Héluin L, Jiang PL, Castro Scalise AG, Wang C, Franz A, Heyd F, Wahl MC, Liu F, Plested AJR. CaMKII autophosphorylation can occur between holoenzymes without subunit exchange. eLife 2023; 12:e86090. [PMID: 37566455 PMCID: PMC10468207 DOI: 10.7554/elife.86090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 08/10/2023] [Indexed: 08/12/2023] Open
Abstract
The dodecameric protein kinase CaMKII is expressed throughout the body. The alpha isoform is responsible for synaptic plasticity and participates in memory through its phosphorylation of synaptic proteins. Its elaborate subunit organization and propensity for autophosphorylation allow it to preserve neuronal plasticity across space and time. The prevailing hypothesis for the spread of CaMKII activity, involving shuffling of subunits between activated and naive holoenzymes, is broadly termed subunit exchange. In contrast to the expectations of previous work, we found little evidence for subunit exchange upon activation, and no effect of restraining subunits to their parent holoenzymes. Rather, mass photometry, crosslinking mass spectrometry, single molecule TIRF microscopy and biochemical assays identify inter-holoenzyme phosphorylation (IHP) as the mechanism for spreading phosphorylation. The transient, activity-dependent formation of groups of holoenzymes is well suited to the speed of neuronal activity. Our results place fundamental limits on the activation mechanism of this kinase.
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Affiliation(s)
- Iva Lučić
- Institute of Biology, Cellular Biophysics, Humboldt Universität zu BerlinBerlinGermany
- Leibniz-Forschungsinstitut für Molekulare PharmakologieBerlinGermany
| | - Léonie Héluin
- Institute of Biology, Cellular Biophysics, Humboldt Universität zu BerlinBerlinGermany
- Leibniz-Forschungsinstitut für Molekulare PharmakologieBerlinGermany
| | - Pin-Lian Jiang
- Leibniz-Forschungsinstitut für Molekulare PharmakologieBerlinGermany
| | - Alejandro G Castro Scalise
- Institute of Biology, Cellular Biophysics, Humboldt Universität zu BerlinBerlinGermany
- Leibniz-Forschungsinstitut für Molekulare PharmakologieBerlinGermany
| | - Cong Wang
- Leibniz-Forschungsinstitut für Molekulare PharmakologieBerlinGermany
| | - Andreas Franz
- Institute of Chemistry and Biochemistry, Freie Universität BerlinBerlinGermany
| | - Florian Heyd
- Institute of Chemistry and Biochemistry, Freie Universität BerlinBerlinGermany
| | - Markus C Wahl
- Institute of Chemistry and Biochemistry, Freie Universität BerlinBerlinGermany
- Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular CrystallographyBerlinGermany
| | - Fan Liu
- Leibniz-Forschungsinstitut für Molekulare PharmakologieBerlinGermany
- Charité-Universitätsmedizin BerlinBerlinGermany
| | - Andrew JR Plested
- Institute of Biology, Cellular Biophysics, Humboldt Universität zu BerlinBerlinGermany
- Leibniz-Forschungsinstitut für Molekulare PharmakologieBerlinGermany
- NeuroCure, Charité UniversitätsmedizinBerlinGermany
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5
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Brandt P, Mirhakkak MH, Wagner L, Driesch D, Möslinger A, Fänder P, Schäuble S, Panagiotou G, Vylkova S. High-Throughput Profiling of Candida auris Isolates Reveals Clade-Specific Metabolic Differences. Microbiol Spectr 2023; 11:e0049823. [PMID: 37097196 PMCID: PMC10269459 DOI: 10.1128/spectrum.00498-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 04/04/2023] [Indexed: 04/26/2023] Open
Abstract
Candida auris, a multidrug-resistant human fungal pathogen that causes outbreaks of invasive infections, emerged as four distinct geographical clades. Previous studies identified genomic and proteomic differences in nutrient utilization on comparison to Candida albicans, suggesting that certain metabolic features may contribute to C. auris emergence. Since no high-throughput clade-specific metabolic characterization has been described yet, we performed a phenotypic screening of C. auris strains from all 4 clades on 664 nutrients, 120 chemicals, and 24 stressors. We identified common and clade- or strain-specific responses, including the preferred utilization of various dipeptides as nitrogen source and the inability of the clade II isolate AR 0381 to withstand chemical stress. Further analysis of the metabolic properties of C. auris isolates showed robust growth on intermediates of the tricarboxylic acid cycle, such as citrate and succinic and malic acids. However, there was reduced or no growth on pyruvate, lactic acid, or acetate, likely due to the lack of the monocarboxylic acid transporter Jen1, which is conserved in most pathogenic Candida species. Comparison of C. auris and C. albicans transcriptomes of cells grown on alternative carbon sources and dipeptides as a nitrogen source revealed common as well as species-unique responses. C. auris induced a significant number of genes with no ortholog in C. albicans, e.g., genes similar to the nicotinic acid transporter TNA1 (alternative carbon sources) and to the oligopeptide transporter (OPT) family (dipeptides). Thus, C. auris possesses unique metabolic features which could have contributed to its emergence as a pathogen. IMPORTANCE Four main clades of the emerging, multidrug-resistant human pathogen Candida auris have been identified, and they differ in their susceptibilities to antifungals and disinfectants. Moreover, clade- and strain-specific metabolic differences have been identified, but a comprehensive overview of nutritional characteristics and resistance to various stressors is missing. Here, we performed high-throughput phenotypic characterization of C. auris on various nutrients, stressors, and chemicals and obtained transcriptomes of cells grown on selected nutrients. The generated data sets identified multiple clade- and strain-specific phenotypes and induction of C. auris-specific metabolic genes, showing unique metabolic properties. The presented work provides a large amount of information for further investigations that could explain the role of metabolism in emergence and pathogenicity of this multidrug-resistant fungus.
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Affiliation(s)
- Philipp Brandt
- Septomics Research Center, Friedrich Schiller University, and Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany
| | - Mohammad H. Mirhakkak
- Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany
| | - Lysett Wagner
- Septomics Research Center, Friedrich Schiller University, and Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany
| | | | - Anna Möslinger
- Septomics Research Center, Friedrich Schiller University, and Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany
- Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany
| | - Pauline Fänder
- Septomics Research Center, Friedrich Schiller University, and Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany
| | - Sascha Schäuble
- Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany
| | - Gianni Panagiotou
- Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany
| | - Slavena Vylkova
- Septomics Research Center, Friedrich Schiller University, and Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute, Jena, Germany
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6
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Lee W, Song G, Bae H. Glucotropaeolin Promotes Apoptosis by Calcium Dysregulation and Attenuates Cell Migration with FOXM1 Suppression in Pancreatic Cancer Cells. Antioxidants (Basel) 2023; 12:antiox12020257. [PMID: 36829815 PMCID: PMC9952507 DOI: 10.3390/antiox12020257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 01/17/2023] [Accepted: 01/21/2023] [Indexed: 01/25/2023] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) has naturally aggressive characteristics including postoperative recurrence, resistance to conventional treatment, and metastasis. Surgical resection with chemotherapeutic agents has been conducted as the major treatment for PDAC. However, surgical treatment is ineffective in the case of advanced cancer, and conventional adjuvant chemotherapy, including gemcitabine and 5-fluorouracil, show low effectiveness due to the high drug resistance of PDAC to this type of treatment. Therefore, the development of innovative therapeutic drugs is crucial to solving the present limitation of conventional drugs. Glucotropaeolin (GT) is a glucosinolate that can be isolated from the Brassicaceae family. GT has exhibited a growth-inhibitory effect against liver and colon cancer cells; however, there is no study regarding the anticancer effect of GT on PDAC. In our study, we determined the antiproliferative effect of GT in PANC-1 and MIA PaCa-2, representative of PDAC. We revealed the intracellular mechanisms underlying the anticancer effect of GT with respect to cell viability, reactive oxygen species (ROS) accumulation, alteration of mitochondrial membrane potential (MMP), calcium dysregulation, cell migration, and the induction of apoptosis. Moreover, GT regulated the signaling pathways related to anticancer in PDAC cells. Finally, the silencing of the forkhead box protein M, a key factor regulating PDAC progression, contributes to the anticancer property of GT in terms of the induction of apoptosis and cell migration. Therefore, GT may be a potential therapeutic drug against PDAC.
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Affiliation(s)
- Woonghee Lee
- Institute of Animal Molecular Biotechnology, Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea
| | - Gwonhwa Song
- Institute of Animal Molecular Biotechnology, Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea
- Correspondence: (G.S.); (H.B.); Tel.: +82-2-3290-3881 (G.S.); +82-31-201-2686 (H.B.)
| | - Hyocheol Bae
- Department of Oriental Medicinal Biotechnology, College of Life Sciences, Kyung Hee University, Yongin 17104, Republic of Korea
- Correspondence: (G.S.); (H.B.); Tel.: +82-2-3290-3881 (G.S.); +82-31-201-2686 (H.B.)
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7
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Kushwaha A, Verma RS, Agarwal V. Pseudomonas aeruginosa quorum-sensing molecule N-(3-oxododecanoyl) homoserine lactone induces calcium signaling-dependent crosstalk between autophagy and apoptosis in human macrophages. Cell Signal 2022; 99:110441. [PMID: 35995303 DOI: 10.1016/j.cellsig.2022.110441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 08/09/2022] [Accepted: 08/15/2022] [Indexed: 01/18/2023]
Abstract
N-(3-oxododecanoyl) homoserine lactone (3oc) is a Pseudomonas aeruginosa secreted quorum-sensing signal molecule playing a crucial role in regulating quorum-sensing (QS) dependent biofilm formation and secretion of virulence factors. In addition to regulating quorum sensing, 3oc also plays an immunomodulatory role in the host by triggering regulated cell death in immune cells. The molecular mechanisms of 3oc in modulating macrophage pathologies are still unclear. In this study, we hypothesized the novel 3oc mediated crosstalk between autophagy and apoptosis at the interphase of calcium signaling in human macrophages. The study showed that 3oc induces mitochondrial dysfunction and apoptosis in macrophages through elevating cytosolic Ca+2 ([Ca+2]cyt) levels. Pre-treatment with the calcium-specific chelator BAPTA-AM effectively abrogated 3oc-induced apoptotic events, like mitochondrial ROS generation (mROS), mitochondrial membrane potential (MMP) drop, and phosphatidylserine (PS) exposure. The study also showed that 3oc induces autophagy, as assessed by the accumulation of autophagic vacuoles, induction of lysosomal biogenesis, upregulation of autophagy genes (LC3, BECLIN 1, STX17, PINK1, and TFEB), autophagosomes formation, and LC3 lipidation. Mechanistically, our study proved that 3oc-induced autophagy was [Ca+2]cyt dependent as BAPTA-AM pre-treatment reduced autophagosome formation. Furthermore, inhibiting autophagy with chloroquine attenuated 3oc-induced apoptosis, while autophagy induction with rapamycin aggravated cell death, suggesting autophagy plays a role in cell death in 3oc-treated macrophages. In conclusion, our findings indicate that 3oc activates a multifaceted death signaling by activating autophagy and apoptosis through Ca+2 signaling, and we propose pharmacological modulation of Ca+2 signaling may act as a combinatorial therapeutic intervention in patients with Pseudomonas aeruginosa-associated infections.
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Affiliation(s)
- Ankit Kushwaha
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, Uttar Pradesh 211004, India
| | - Rama Shanker Verma
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, Uttar Pradesh 211004, India
| | - Vishnu Agarwal
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, Uttar Pradesh 211004, India.
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8
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Maia VSC, Berzaghi R, Arruda DC, Machado FC, Loureiro LL, Melo PMS, Morais AS, Budu A, Travassos LR. PLP2-derived peptide Rb4 triggers PARP-1-mediated necrotic death in murine melanoma cells. Sci Rep 2022; 12:2890. [PMID: 35190586 PMCID: PMC8861012 DOI: 10.1038/s41598-022-06429-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 01/12/2022] [Indexed: 12/28/2022] Open
Abstract
Malignant melanoma is the main cause of death in patients with skin cancer. Overexpression of Proteolipid protein 2 (PLP2) increased tumor metastasis and the knockdown of PLP2 inhibited the growth and metastasis of melanoma cells. In the present work, we studied the antitumor activity of peptide Rb4 derived from protein PLP2. In vitro, Rb4 induced F-actin polymerization, prevented F-actin depolymerization and increased the ER-derived cytosolic calcium. Such effects were associated with necrosis of murine melanoma B16F10-Nex2 cells and with inhibition of the viability of human cancer cell lines. Loss of plasma membrane integrity, dilation of mitochondria, cytoplasm vacuolation and absence of chromatin condensation characterized tumor cell necrosis. Cleavage of PARP-1 and inhibition of RIP1 expression were also observed. In vivo, peptide Rb4 reduced the lung metastasis of tumor cells and delayed the subcutaneous melanoma growth in a syngeneic model. Rb4 induced the expression of two DAMPs molecules, HMGB1 and calreticulin, in B16F10-Nex2. Our results suggest that peptide Rb4 acts directly on tumor cells inducing the expression of DAMPs, which trigger the immunoprotective effect in vivo against melanoma cells. We suggest that peptide Rb4 is a promising compound to be developed as an anticancer drug.
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Affiliation(s)
| | - Rodrigo Berzaghi
- Experimental Oncology Unit, Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo, São Paulo, Brazil
| | - Denise C Arruda
- Integrated Group of Biotechnology, University of Mogi das Cruzes, UMC, Mogi das Cruzes, SP, Brazil
| | - Fabrício C Machado
- Recepta Biopharma, São Paulo, Brazil.,Experimental Oncology Unit, Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo, São Paulo, Brazil
| | - Leticia L Loureiro
- Experimental Oncology Unit, Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo, São Paulo, Brazil
| | - Pollyana M S Melo
- Department of Biophysics, Federal University of São Paulo, São Paulo, Brazil
| | | | - Alexandre Budu
- Department of Biophysics, Federal University of São Paulo, São Paulo, Brazil
| | - Luiz R Travassos
- Recepta Biopharma, São Paulo, Brazil.,Experimental Oncology Unit, Department of Microbiology, Immunology and Parasitology, Federal University of São Paulo, São Paulo, Brazil
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9
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Mansour A, Nagi K, Dallaire P, Lukasheva V, Le Gouill C, Bouvier M, Pineyro G. Comprehensive Signaling Profiles Reveal Unsuspected Functional Selectivity of δ-Opioid Receptor Agonists and Allow the Identification of Ligands with the Greatest Potential for Inducing Cyclase Superactivation. ACS Pharmacol Transl Sci 2021; 4:1483-1498. [PMID: 34661070 PMCID: PMC8506601 DOI: 10.1021/acsptsci.1c00019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Indexed: 11/29/2022]
Abstract
![]()
Prolonged exposure
to opioid receptor agonists triggers adaptations
in the adenylyl cyclase (AC) pathway that lead to enhanced production
of cyclic adenosine monophosphate (cAMP) upon withdrawal. This cellular
phenomenon contributes to withdrawal symptoms, hyperalgesia and analgesic
tolerance that interfere with clinical management of chronic pain
syndromes. Since δ-opioid receptors (DOPrs) are a promising
target for chronic pain management, we were interested in finding
out if cell-based signaling profiles as generated for drug discovery
purposes could inform us of the ligand potential to induce sensitization
of the cyclase path. For this purpose, signaling of DOPr agonists
was monitored at multiple effectors. The resulting signaling profiles
revealed marked functional selectivity, particularly for Met-enkephalin
(Met-ENK) whose signaling bias profile differed from those of synthetic
ligands like SNC-80 and ARM390. Signaling diversity among ligands
was systematized by clustering agonists according to similarities
in Emax and Log(τ) values for the
different responses. The classification process revealed that the
similarity in Gα/Gβγ, but not in β-arrestin
(βarr), responses was correlated with the potential of Met-ENK,
deltorphin II, (d-penicillamine2,5)-enkephalin (DPDPE), ARM390,
and SNC-80 to enhance cAMP production, all of which required Ca2+ mobilization to produce this response. Moreover, superactivation
by Met-ENK, which was the most-effective Ca2+ mobilizing
agonist, required Gαi/o activation, availability of Gβγ
subunits at the membrane, and activation of Ca2+ effectors
such as calmodulin and protein kinase C (PKC). In contrast, superactivation by (N-(l-tyrosyl)-(3S)-1,2,3,4-tetrahydroisoquinoline-3-carbonyl)-l-phenylalanyl-l-phenylalanine (TIPP), which was set
in a distinct category through clustering, required activation of
Gαi/o subunits but was independent of the Gβγ dimer
and Ca2+ mobilization, relying instead on Src and Raf-1
to induce this cellular adaptation.
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Affiliation(s)
- Ahmed Mansour
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada.,CHU Sainte-Justine Research Center, Montréal, Quebec H3T 1C5, Canada
| | - Karim Nagi
- College of Medicine, QU Health, Qatar University, P.O. Box 2713, Doha, Qatar
| | - Paul Dallaire
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada.,CHU Sainte-Justine Research Center, Montréal, Quebec H3T 1C5, Canada
| | - Viktoriya Lukasheva
- Institute for Research in Immunology and Cancer, Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada
| | - Christian Le Gouill
- Institute for Research in Immunology and Cancer, Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada
| | - Michel Bouvier
- Institute for Research in Immunology and Cancer, Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada
| | - Graciela Pineyro
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montréal, Quebec H3T 1J4, Canada.,CHU Sainte-Justine Research Center, Montréal, Quebec H3T 1C5, Canada
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10
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Abu-Odeh M, Zhang Y, Reilly SM, Ebadat N, Keinan O, Valentine JM, Hafezi-Bakhtiari M, Ashayer H, Mamoun L, Zhou X, Zhang J, Yu RT, Dai Y, Liddle C, Downes M, Evans RM, Kliewer SA, Mangelsdorf DJ, Saltiel AR. FGF21 promotes thermogenic gene expression as an autocrine factor in adipocytes. Cell Rep 2021; 35:109331. [PMID: 34192547 PMCID: PMC8293281 DOI: 10.1016/j.celrep.2021.109331] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 03/04/2021] [Accepted: 06/09/2021] [Indexed: 12/14/2022] Open
Abstract
The contribution of adipose-derived FGF21 to energy homeostasis is unclear. Here we show that browning of inguinal white adipose tissue (iWAT) by β-adrenergic agonists requires autocrine FGF21 signaling. Adipose-specific deletion of the FGF21 co-receptor β-Klotho renders mice unresponsive to β-adrenergic stimulation. In contrast, mice with liver-specific ablation of FGF21, which eliminates circulating FGF21, remain sensitive to β-adrenergic browning of iWAT. Concordantly, transgenic overexpression of FGF21 in adipocytes promotes browning in a β-Klotho-dependent manner without increasing circulating FGF21. Mechanistically, we show that β-adrenergic stimulation of thermogenic gene expression requires FGF21 in adipocytes to promote phosphorylation of phospholipase C-γ and mobilization of intracellular calcium. Moreover, we find that the β-adrenergic-dependent increase in circulating FGF21 occurs through an indirect mechanism in which fatty acids released by adipocyte lipolysis subsequently activate hepatic PPARα to increase FGF21 expression. These studies identify FGF21 as a cell-autonomous autocrine regulator of adipose tissue function. Abu-Odeh et al. demonstrate that autocrine action of FGF21 is a required second signal promoting thermogenic gene expression in catecholamine-stimulated adipocytes. Hepatic FGF21 secretions, secondary to catecholamine-stimulated adipocyte lipolysis, are dispensable for adipose tissue browning. These studies identify FGF21 as a cell-autonomous autocrine regulator of adipose tissue function.
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Affiliation(s)
- Mohammad Abu-Odeh
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Yuan Zhang
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Shannon M Reilly
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Nima Ebadat
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Omer Keinan
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Joseph M Valentine
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | | | - Hadeel Ashayer
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Lana Mamoun
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA
| | - Xin Zhou
- Department of Pharmacology, University of California, San Diego, San Diego, CA 92093, USA
| | - Jin Zhang
- Department of Pharmacology, University of California, San Diego, San Diego, CA 92093, USA; Moores Cancer Center at UC San Diego Health, La Jolla, CA 92037, USA; Department of Bioengineering, University of California San Diego, San Diego, CA 92093; Department of Chemistry and Biochemistry, University of California San Diego, San Diego, CA 92093, USA
| | - Ruth T Yu
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Yang Dai
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Christopher Liddle
- Storr Liver Centre, Westmead Institute for Medical Research and Sydney Medical School, University of Sydney, Westmead, NSW, Australia
| | - Michael Downes
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Ronald M Evans
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Steven A Kliewer
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA; Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - David J Mangelsdorf
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA; Howard Hughes Medical Institute
| | - Alan R Saltiel
- Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA; Department of Pharmacology, University of California, San Diego, San Diego, CA 92093, USA.
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11
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Cortisol modulates calcium release-activated calcium channel gating in fish hepatocytes. Sci Rep 2021; 11:9621. [PMID: 33953236 PMCID: PMC8100157 DOI: 10.1038/s41598-021-88957-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 04/12/2021] [Indexed: 02/07/2023] Open
Abstract
Glucocorticoids (GCs) are rapidly released in response to stress and play an important role in the physiological adjustments to re-establish homeostasis. The mode of action of GCs for stress coping is mediated largely by the steroid binding to the glucocorticoid receptor (GR), a ligand-bound transcription factor, and modulating the expression of target genes. However, GCs also exert rapid actions that are independent of transcriptional regulation by modulating second messenger signaling. However, a membrane-specific protein that transduces rapid GCs signal is yet to be characterized. Here, using freshly isolated hepatocytes from rainbow trout (Oncorhynchus mykiss) and fura2 fluorescence microscopy, we report that stressed levels of cortisol rapidly stimulate the rise in cytosolic free calcium ([Ca2+]i). Pharmacological manipulations using specific extra- and intra-cellular calcium chelators, plasma membrane and endoplasmic reticulum channel blockers and receptors, indicated extracellular Ca2+ entry is required for the cortisol-mediated rise in ([Ca2+]i). Particularly, the calcium release-activated calcium (CRAC) channel gating appears to be a key target for the rapid action of cortisol in the ([Ca2+]i) rise in trout hepatocytes. To test this further, we carried out in silico molecular docking studies using the Drosophila CRAC channel modulator 1 (ORAI1) protein, the pore forming subunit of CRAC channel that is highly conserved. The result predicts a putative binding site on CRAC for cortisol to modulate channel gating, suggesting a direct, as well as an indirect regulation (by other membrane receptors) of CRAC channel gating by cortisol. Altogether, CRAC channel may be a novel cortisol-gated Ca2+ channel transducing rapid nongenomic signalling in hepatocytes during acute stress.
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12
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Ros O, Baudet S, Zagar Y, Loulier K, Roche F, Couvet S, Aghaie A, Atkins M, Louail A, Petit C, Metin C, Mechulam Y, Nicol X. SpiCee: A Genetic Tool for Subcellular and Cell-Specific Calcium Manipulation. Cell Rep 2021; 32:107934. [PMID: 32697983 DOI: 10.1016/j.celrep.2020.107934] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 05/21/2020] [Accepted: 06/29/2020] [Indexed: 12/14/2022] Open
Abstract
Calcium is a second messenger crucial to a myriad of cellular processes ranging from regulation of metabolism and cell survival to vesicle release and motility. Current strategies to directly manipulate endogenous calcium signals lack cellular and subcellular specificity. We introduce SpiCee, a versatile and genetically encoded chelator combining low- and high-affinity sites for calcium. This scavenger enables altering endogenous calcium signaling and functions in single cells in vitro and in vivo with biochemically controlled subcellular resolution. SpiCee paves the way to investigate local calcium signaling in vivo and directly manipulate this second messenger for therapeutic use.
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Affiliation(s)
- Oriol Ros
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Sarah Baudet
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Yvrick Zagar
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Karine Loulier
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Fiona Roche
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Sandrine Couvet
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Alain Aghaie
- INSERM, Sorbonne Université, Institut Pasteur, UMR_S 1120, 75012 Paris, France
| | - Melody Atkins
- INSERM, UMR-S839, Sorbonne Université, Institut du Fer à Moulin, 75005 Paris, France
| | - Alice Louail
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Christine Petit
- INSERM, Sorbonne Université, Institut Pasteur, UMR_S 1120, 75012 Paris, France; Collège de France, 75005 Paris, France
| | - Christine Metin
- INSERM, UMR-S839, Sorbonne Université, Institut du Fer à Moulin, 75005 Paris, France
| | - Yves Mechulam
- Laboratoire de Biochimie, Ecole Polytechnique, CNRS UMR 7654, 91128 Palaiseau, France
| | - Xavier Nicol
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, 75012 Paris, France.
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13
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Das C, Faught E, Vijayan MM. Cortisol rapidly stimulates calcium waves in the developing trunk muscle of zebrafish. Mol Cell Endocrinol 2021; 520:111067. [PMID: 33129866 DOI: 10.1016/j.mce.2020.111067] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/09/2020] [Accepted: 10/21/2020] [Indexed: 02/07/2023]
Abstract
Glucocorticoids (GCs) play a role in stress coping by activating the glucocorticoid receptor (GR), a ligand-bound transcription factor. GCs also exert rapid effects that are nongenomic by modulating second messenger signaling, including Ca2+. However, the mechanism of action of GCs in modulating cytoplasmic free calcium level ([Ca2+]i) is unclear. We hypothesized that cortisol increases ([Ca2+]i) in zebrafish (Danio rerio) muscle, and this is independent of GR activation. Indeed, cortisol rapidly stimulated ([Ca2+]i) rise in the developing trunk muscle (DTM), and this response was not abolished in the GR knockout zebrafish. The rapid cortisol-induced ([Ca2+]i) rise was reduced with EGTA, and completely abolished by the pharmacological inhibition of the calcium release-activated calcium channel (CRACC). Also, cortisol stimulation rapidly increased the expression of Orai1, the pore forming protein subunit of CRACC, in the DTM. Altogether, rapid nongenomic action of cortisol on muscle function may involve Ca2+ signaling by CRACC gating in zebrafish.
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Affiliation(s)
- Chinmayee Das
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N1N4, Canada
| | - Erin Faught
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N1N4, Canada
| | - Mathilakath M Vijayan
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, T2N1N4, Canada.
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14
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Eustace NJ, Anderson JC, Warram JM, Widden HN, Pedersen RT, Alrefai H, Patel Z, Hicks PH, Placzek WJ, Gillespie GY, Hjelmeland AB, Willey CD. A cell-penetrating MARCKS mimetic selectively triggers cytolytic death in glioblastoma. Oncogene 2020; 39:6961-6974. [PMID: 33077834 PMCID: PMC7885995 DOI: 10.1038/s41388-020-01511-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 09/22/2020] [Accepted: 10/05/2020] [Indexed: 02/07/2023]
Abstract
Glioblastoma (GBM) is an aggressive malignancy with limited effectiveness of standard of care therapies including surgery, radiation, and temozolomide chemotherapy necessitating novel therapeutics. Unfortunately, GBMs also harbor several signaling alterations that protect them from traditional therapies that rely on apoptotic programmed cell death. Because almost all GBM tumors have dysregulated phosphoinositide signaling as part of that process, we hypothesized that peptide mimetics derived from the phospholipid binding domain of Myristoylated alanine-rich C-kinase substrate (MARCKS) could serve as a novel GBM therapeutic. Using molecularly classified patient-derived xenograft (PDX) lines, cultured in stem-cell conditions, we demonstrate that cell permeable MARCKS effector domain (ED) peptides potently target all GBM molecular classes while sparing normal human astrocytes. Cell death mechanistic testing revealed that these peptides produce rapid cytotoxicity in GBM that overcomes caspase inhibition. Moreover, we identify a GBM-selective cytolytic death mechanism involving plasma membrane targeting and intracellular calcium accumulation. Despite limited relative partitioning to the brain, tail-vein peptide injection revealed tumor targeting in intracranially implanted GBM PDX. These results indicate that MARCKS ED peptide therapeutics may overcome traditional GBM resistance mechanisms, supporting further development of similar agents.
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Affiliation(s)
- Nicholas J Eustace
- Department of Radiation Oncology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Joshua C Anderson
- Department of Radiation Oncology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jason M Warram
- Department of Otolaryngology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hayley N Widden
- Department of Biochemistry and Molecular Genetics, The University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Hasan Alrefai
- Department of Radiation Oncology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Zeel Patel
- Department of Radiation Oncology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Patricia H Hicks
- Department of Radiation Oncology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - William J Placzek
- Department of Biochemistry and Molecular Genetics, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - G Yancey Gillespie
- Department of Neurosurgery, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Anita B Hjelmeland
- Department of Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Christopher D Willey
- Department of Radiation Oncology, The University of Alabama at Birmingham, Birmingham, AL, USA.
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15
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lncRNA-ZFAS1 induces mitochondria-mediated apoptosis by causing cytosolic Ca 2+ overload in myocardial infarction mice model. Cell Death Dis 2019; 10:942. [PMID: 31819041 PMCID: PMC6901475 DOI: 10.1038/s41419-019-2136-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 10/26/2019] [Accepted: 11/11/2019] [Indexed: 12/19/2022]
Abstract
Previously, we have identified ZFAS1 as a potential new long non-coding RNA (lncRNA) biomarker of acute myocardial infarction (MI) and as a sarcoplasmic reticulum Ca2+-ATPase 2a (SERCA2a) inhibitor, causing intracellular Ca2+ overload and contractile dysfunction in a mouse model of MI. In the current study, we aimed to evaluate the effects of ZFAS1 on the apoptosis of cardiomyocytes in the MI mouse model. Knockdown of endogenous ZFAS1 by virus-mediated silencing shRNA or siZFAS1 partially abrogated the ischemia-induced apoptosis of cardiomyocytes. Overexpression of ZFAS1 in normal cardiomyocytes reduced the cell viability, similar to that observed in hypoxia-treated cardiomyocytes. Moreover, ZFAS1 cardiac-specific knock-in mice showed impaired cardiac function, adversely altered Ca2+ homeostasis, repressed expression and activities of SERCA2a, and increased apoptosis. At the subcellular level, ZFAS1 induced mitochondrial swelling and showed a pronounced decrease in mitochondrial membrane potential. At the molecular level, ZFAS1 activated the mitochondria apoptosis pathway, which could be nearly abolished by a calcium chelator. The effects of ZFAS1 were readily reversible upon knockdown of this lncRNA. Notably, ZFAS1-FD (only functional domain) mimicked the effects of full-length ZFAS1 in regulation of cardiomyocyte apoptosis. In conclusion, our study shows that ZFAS1, an endogenous SERCA2a inhibitor, induces mitochondria-mediated apoptosis via cytosolic Ca2+ overload. Therefore, anti-ZFAS1 might be considered a new therapeutic strategy for protecting cardiomyocytes from MI-induced apoptosis.
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16
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Intrinsic attenuation of post-irradiation calcium and ER stress imparts significant radioprotection to lepidopteran insect cells. Biochem Biophys Res Commun 2018. [PMID: 29534965 DOI: 10.1016/j.bbrc.2018.03.078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Sf9 lepidopteran insect cells are 100-200 times more radioresistant than mammalian cells. This distinctive feature thus makes them suitable for studies exploring radioprotective molecular mechanisms. It has been established from previous studies of our group that downstream mitochondrial apoptotic signaling pathways in Sf9 cells are quite similar to mammalian cells, implicating the upstream signaling pathways in their extensive radioresistance. In the present study, intracellular and mitochondrial calcium levels remained unaltered in Sf9 cells in response to radiation, in sharp contrast to human (HEK293T) cells. The isolated mitochondria from Sf9 cells exhibited nearly 1.5 times greater calcium retention capacity than mammalian cells, highlighting their inherent stress resilience. Importantly, UPR/ER stress marker proteins (p-eIF2α, GRP4 and SERCA) remained unaltered by radiation and suggested highly attenuated ER and calcium stress. Lack of SERCA induction further corroborates the lack of radiation-induced calcium mobilization in these cells. The expression of CaMKII, an important effector molecule of calcium signaling, did not alter in response to radiation. Inhibiting CaMKII by KN-93 or suppressing CaM by siRNA failed to alter Sf9 cells response to radiation and suggests CaM-CaMKII independent radiation signaling. Therefore, this study suggests that attenuated calcium signaling/ER stress is an important determinant of lepidopteran cell radioresistance.
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17
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Chai D, Jiang H, Li Q. Isoflurane neurotoxicity involves activation of hypoxia inducible factor-1α via intracellular calcium in neonatal rodents. Brain Res 2016; 1653:39-50. [DOI: 10.1016/j.brainres.2016.10.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 10/08/2016] [Accepted: 10/15/2016] [Indexed: 10/20/2022]
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18
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Meireles M, Moura E, Vieira-Coelho MA, Santos-Buelga C, Gonzalez-Manzano S, Dueñas M, Mateus N, Faria A, Calhau C. Flavonoids as dopaminergic neuromodulators. Mol Nutr Food Res 2016; 60:495-501. [PMID: 26582321 DOI: 10.1002/mnfr.201500557] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 10/28/2015] [Accepted: 10/31/2015] [Indexed: 12/25/2022]
Abstract
SCOPE The present study aimed to characterize and evaluate flavonoids effects on organic cation uptake in neuronal cells. METHODS AND RESULTS Uptake experiments were conducted using radiolabeled methyl-4-phenylpyridinuim ([(3) H]-MPP(+) ), in human neuronal dopaminergic cells, SH-SY5Y. Catechin did not alter [(3) H]-MPP(+) uptake, however its metabolite 4'-methyl-catechin decreased it by almost 50%. Epicatechin and its methylated metabolites also decreased [(3) H]-MPP(+) uptake. Interestingly, the quercetin flavonol and its metabolite conjugated with glucuronic acid, as well as the flavanones naringenin and hesperitin, increased [(3) H]-MPP(+) uptake. CONCLUSION These results showed that different classes of flavonoids, as well as its metabolites, differently influence neuronal organic cation uptake. Several xeno- and endobiotics, including neurotransmitters, are organic cations. Specific food recommendations may be beneficial in pathological conditions where levels of neurotransmitters, as dopamine, are either increased or decreased.
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Affiliation(s)
- Manuela Meireles
- Department of Biochemistry, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Eduardo Moura
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, Porto, Portugal
| | | | - Celestino Santos-Buelga
- Unidad de Nutrición y Bromatología, Facultad de Farmacia, Universidad de Salamanca, Campus Miguel de Unamuno s/n, Salamanca, Espanha
| | - Susana Gonzalez-Manzano
- Unidad de Nutrición y Bromatología, Facultad de Farmacia, Universidad de Salamanca, Campus Miguel de Unamuno s/n, Salamanca, Espanha
| | - Montserrat Dueñas
- Unidad de Nutrición y Bromatología, Facultad de Farmacia, Universidad de Salamanca, Campus Miguel de Unamuno s/n, Salamanca, Espanha
| | - Nuno Mateus
- REQUIMTE/LAQV, Faculty of Sciences, University of Porto, Porto, Portugal
| | - Ana Faria
- Department of Biochemistry, Faculty of Medicine, University of Porto, Porto, Portugal.,REQUIMTE/LAQV, Faculty of Sciences, University of Porto, Porto, Portugal.,Faculty of Nutrition and Food Sciences, University of Porto, Porto, Portugal
| | - Conceição Calhau
- Department of Biochemistry, Faculty of Medicine, University of Porto, Porto, Portugal.,CINTESIS - Center for Research in Health Technologies and Information Systems, Faculty of Medicine, University of Porto, Porto, Portugal
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19
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Targeting TopBP1 at a convergent point of multiple oncogenic pathways for cancer therapy. Nat Commun 2014; 5:5476. [PMID: 25400145 PMCID: PMC4254804 DOI: 10.1038/ncomms6476] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 10/06/2014] [Indexed: 01/12/2023] Open
Abstract
The progression of many solid tumors is driven by de-regulation of multiple common pathways, particularly Rb, PI (3) K/Akt and p53. Prior studies identified TopBP1as a key mediator for the oncogenic gain-of-function activities of mutant p53 (mutp53) in cancer. In Akt-hyperactive cancer, TopBP1 forms oligomers and represses E2F1-dependent apoptosis. Here we perform a molecular docking screening and identify a lead compound, calcein, capable of blocking TopBP1 oligomerization and p53 binding, resulting in re-activation of E2F1-dependent apoptosis and blockade of mutp53 gain-of-function. Calcein AM, the cell permeable derivative of calcein, shows significant anti-tumor activity in a wide-spectrum of cultured cancer cells harboring high TopBP1 levels. These biochemical findings are recapitulated in breast cancer xenograft models. Thus, our study provides proof-of-concept evidence for targeting TopBP1, a convergent point of multiple pathways, as a cancer therapy.
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20
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Tsai JY, Chou CT, Liu SI, Liang WZ, Kuo CC, Liao WC, Lin KL, Hsu SS, Lu YC, Huang JK, Jan CR. Effect of diindolylmethane on Ca2+ homeostasis and viability in PC3 human prostate cancer cells. J Recept Signal Transduct Res 2012; 32:271-8. [PMID: 22845469 DOI: 10.3109/10799893.2012.707212] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The effect of the natural product diindolylmethane on cytosolic Ca(2+) concentrations ([Ca(2+)](i)) and viability in PC3 human prostate cancer cells was explored. The Ca(2+)-sensitive fluorescent dye fura-2 was applied to measure [Ca(2+)](i). Diindolylmethane at concentrations of 20-50 µM induced [Ca(2+)](i) rise in a concentration-dependent manner. The response was reduced partly by removing Ca(2+). Diindolylmethane-evoked Ca(2+) entry was suppressed by nifedipine, econazole, SK&F96365, protein kinase C modulators and aristolochic acid. In the absence of extracellular Ca(2+), incubation with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) inhibited or abolished diindolylmethane-induced [Ca(2+)](i) rise. Incubation with diindolylmethane also 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 50-100 µM, diindolylmethane killed cells in a concentration-dependent manner. This cytotoxic effect was not altered by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). Annexin V/PI staining data implicate that diindolylmethane (50 and 100 µM) induced apoptosis in a concentration-dependent manner. In conclusion, diindolylmethane induced a [Ca(2+)](i) rise in PC3 cells by evoking phospholipase C-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via phospholipase A(2)-sensitive store-operated Ca(2+) channels. Diindolylmethane caused cell death in which apoptosis may participate.
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Affiliation(s)
- Jeng-Yu Tsai
- Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
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21
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Yan JG, Matloub HS, Yan Y, Agresti M, Zhang LL, Jaradeh SS. The correlation between calcium absorption and electrophysiological recovery in crushed rat peripheral nerves. Microsurgery 2010; 30:138-45. [PMID: 19790186 DOI: 10.1002/micr.20709] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The correlation between calcium ion (Ca2+) concentration and electrophysiological recovery in crushed peripheral nerves has not been studied. Observing and quantifying the Ca2+ intensity in live normal and crushed peripheral nerves was performed using a novel microfine tearing technique and Calcium Green-1 Acetoxymethyl ester stain, a fluorescent Ca2+ indicator. Ca2+ was shown to be homogeneously distributed in the myelinated sheaths. After a crush injury, there was significant stasis in the injured zone and the portion distal to the injury. The Ca2+ has been almost completely absorbed after 24 weeks in the injured nerve to be similar to the controls. The process of the calcium absorption was correlated with the Compound Muscle Action Potential recovery process of the injured nerves. This correlation was statistically significant (r = -0.81, P < 0.05). The better understanding of this process will help us to improve nerve regeneration after peripheral nerve injury.
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Affiliation(s)
- Ji-Geng Yan
- Department of Plastic Surgery, Medical College of Wisconsin, Milwaukee, WI, USA.
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22
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Tang Q, Jin MW, Xiang JZ, Dong MQ, Sun HY, Lau CP, Li GR. The membrane permeable calcium chelator BAPTA-AM directly blocks human ether a-go-go-related gene potassium channels stably expressed in HEK 293 cells. Biochem Pharmacol 2007; 74:1596-607. [PMID: 17826747 DOI: 10.1016/j.bcp.2007.07.042] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2007] [Revised: 07/14/2007] [Accepted: 07/30/2007] [Indexed: 11/29/2022]
Abstract
BAPTA-AM is a well-known membrane permeable Ca(2+) chelator. The present study found that BAPTA-AM rapidly and reversibly suppressed human ether a-go-go-related gene (hERG or Kv11.1) K(+) current, human Kv1.3 and human Kv1.5 channel currents stably expressed in HEK 293 cells, and the effects were not related to Ca(2+) chelation. The externally applied BAPTA-AM inhibited hERG channels in a concentration-dependent manner (IC(50): 1.3 microM). Blockade of hERG channels was dependent on channel opening, and tonic block was minimal. Steady-state activation V(0.5) of hERG channels was negatively shifted by 8.5 mV (from -3.7+/-2.8 of control to -12.2+/-3.1 mV, P<0.01), while inactivation V(0.5) was negatively shifted by 6.1 mV (from -37.9+/-2.0 mV of control to -44.0+/-1.6 mV, P<0.05) with application of 3 microM BAPTA-AM. The S6 mutant Y652A and the pore helix mutant S631A significantly attenuated blockade by BAPTA-AM at 10 microM causing profound blockade of wild-type hERG channels. In addition, BAPTA-AM inhibited hKv1.3 and hKv1.5 channels in a concentration-dependent manner (IC(50): 1.45 and 1.23 microM, respectively), and the blockade of these two types of channels was also dependent on channel opening. Moreover, EGTA-AM was found to be an open channel blocker of hERG, hKv1.3, hKv1.5 channels, though its efficacy is weaker than that of BAPTA-AM. These results indicate that the membrane permeable Ca(2+) chelator BAPTA-AM (also EGTA-AM) exerts an open channel blocking effect on hERG, hKv1.3 and hKv1.5 channels.
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Affiliation(s)
- Qiang Tang
- Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, SAR, China
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23
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Powers KA, Szászi K, Khadaroo RG, Tawadros PS, Marshall JC, Kapus A, Rotstein OD. Oxidative stress generated by hemorrhagic shock recruits Toll-like receptor 4 to the plasma membrane in macrophages. ACTA ACUST UNITED AC 2006; 203:1951-61. [PMID: 16847070 PMCID: PMC2118368 DOI: 10.1084/jem.20060943] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Oxidative stress generated by ischemia/reperfusion is known to prime inflammatory cells for increased responsiveness to subsequent stimuli, such as lipopolysaccharide (LPS). The mechanism(s) underlying this effect remains poorly elucidated. These studies show that alveolar macrophages recovered from rodents subjected to hemorrhagic shock/resuscitation expressed increased surface levels of Toll-like receptor 4 (TLR4), an effect inhibited by adding the antioxidant N-acetylcysteine to the resuscitation fluid. Consistent with a role for oxidative stress in this effect, in vitro H2O2 treatment of RAW 264.7 macrophages similarly caused an increase in surface TLR4. The H2O2-induced increase in surface TLR4 was prevented by depleting intracellular calcium or disrupting the cytoskeleton, suggesting the involvement of receptor exocytosis. Further, fluorescent resonance energy transfer between TLR4 and the raft marker GM1 as well as biochemical analysis of the raft components demonstrated that oxidative stress redistributes TLR4 to lipid rafts in the plasma membrane. Preventing the oxidant-induced movement of TLR4 to lipid rafts using methyl-β-cyclodextrin precluded the increased responsiveness of cells to LPS after H2O2 treatment. Collectively, these studies suggest a novel mechanism whereby oxidative stress might prime the responsiveness of cells of the innate immune system.
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Affiliation(s)
- Kinga A Powers
- Department of Surgery, St. Michael's Hospital and University Health Network, Toronto, Ontario, Canada
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24
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Windisch M, Hutter-Paier B, Grygar E, Doppler E, Moessler H. N-PEP-12 – a novel peptide compound that protects cortical neurons in culture against different age and disease associated lesions. J Neural Transm (Vienna) 2005; 112:1331-43. [PMID: 15750682 DOI: 10.1007/s00702-005-0283-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2004] [Accepted: 01/15/2005] [Indexed: 10/25/2022]
Abstract
The neuroprotective potency of N-PEP-12, a novel, proprietary compound consisting of biopeptides and amino acids was investigated. Lesion models have been applied in neuronal cultures of embryonic chicken cortex, pre-treated with N-PEP-12 from the first day onwards. On day 8 in vitro neurons were lesioned and cell viability was measured 24 and 48 hours later. To simulate acute brain ischemia, cytotoxic hypoxia was induced by sodium cyanide or by iodoacetate and excitotoxicity by L-glutamate. Ionomycin for up to 48 hours induced calcium overload. The cytoskeleton was disrupted by addition of colchicine. N-PEP-12 shows dose-dependent neuroprotection in all different models. The effect size depends on the recovery time but also on the extent of the lesion. In cases of mild to moderate lesion pronounced dose-dependent effects could be demonstrated. This indicates that chronic exposure to N-PEP-12 is able to prevent neuronal cell death associated to conditions occurring during normal aging and neurological disorders like ischemic stroke, hypoxia, brain trauma, or AD.
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Affiliation(s)
- M Windisch
- JSW-Research Forschungslabor GmbH, Graz, Austria.
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25
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Veeranna, Kaji T, Boland B, Odrljin T, Mohan P, Basavarajappa BS, Peterhoff C, Cataldo A, Rudnicki A, Amin N, Li BS, Pant HC, Hungund BL, Arancio O, Nixon RA. Calpain mediates calcium-induced activation of the erk1,2 MAPK pathway and cytoskeletal phosphorylation in neurons: relevance to Alzheimer's disease. THE AMERICAN JOURNAL OF PATHOLOGY 2004; 165:795-805. [PMID: 15331404 PMCID: PMC1618589 DOI: 10.1016/s0002-9440(10)63342-1] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/17/2004] [Indexed: 12/31/2022]
Abstract
Aberrant phosphorylation of the neuronal cytoskeleton is an early pathological event in Alzheimer's disease (AD), but the underlying mechanisms are unclear. Here, we demonstrate in the brains of AD patients that neurofilament hyperphosphorylation in neocortical pyramidal neurons is accompanied by activation of both Erk1,2 and calpain. Using immunochemistry, Western blot analysis, and kinase activity measurements, we show in primary hippocampal and cerebellar granule (CG) neurons that calcium influx activates calpain and Erk1,2 and increases neurofilament phosphorylation on carboxy terminal polypeptide sites known to be modulated by Erk1,2 and to be altered in AD. Blocking Erk1,2 activity either with antisense oligonucleotides to Erk1,2 mRNA sequences or by specifically inhibiting its upstream activating kinase MEK1,2 markedly reduced neurofilament phosphorylation. Calpeptin, a cell-permeable calpain inhibitor, blocked both Erk1,2 activation and neurofilament hyperphosphorylation at concentrations that inhibit calpain-mediated cleavage of brain spectrin. By contrast, inhibiting Erk1,2 with U-0126, a specific inhibitor of Mek1,2, had no appreciable effect on ionomycin-induced calpain activation. These findings demonstrate that, under conditions of calcium injury in neurons, calpains are upstream activators of Erk1,2 signaling and are likely to mediate in part the hyperphosphorylation of neurofilaments and tau seen at early stages of AD as well as the neuron survival-related functions of the MAP kinase pathway.
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Affiliation(s)
- Veeranna
- Center for Dementia Research, Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, USA
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26
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Jeong HJ, Hong SH, Lee DJ, Park JH, Kim KS, Kim HM. Role of Ca(2+) on TNF-alpha and IL-6 secretion from RBL-2H3 mast cells. Cell Signal 2002; 14:633-9. [PMID: 11955956 DOI: 10.1016/s0898-6568(02)00005-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Ca2+ acts as an important second messenger in mast cells. However, the mechanisms involved in the secretion of inflammatory cytokines from activated mast cells are unknown. In this study, we examined the signaling pathway involved in calcium-related cytokine secretion in a mast cell line, RBL-2H3 cells. We report that treatment with 1,2-bis (2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA-AM), a chelator of intracellular calcium, can inhibit IgE-stimulated TNF-alpha and IL-6 secretion in a concentration-dependent manner with IC50 values of 0.41 and 0.014 microM, respectively. Maximal inhibition of TNFalpha- and IL-6 secretion was 58.5 +/- 3% and 87 +/- 8% in BAPTA-AM, respectively. BAPTA-AM also completely inhibited the IgE-induced TNF-alpha and IL-6 mRNA levels. In activated RBL-2H3 cells, the expression level of NF-kappaB/Rel A protein increased in the nucleus. However, the level of NF-kappaB/Rel A in nucleus was decreased by treatment of BAPTA-AM. In addition, BAPTA-AM completely inhibited the IgE-induced IkappaB kinase beta (IKKbeta) activation and IkappaBalpha phosphorylation. These observations demonstrate that the intracellular Ca2+ may play an important role in IgE-induced TNF-alpha and IL-6 secretion from mast cells via IKKbeta activation.
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Affiliation(s)
- Hyun-Ja Jeong
- Department of Oriental Pharmacy, College of Pharmacy, and Korea Institute of Oriental Pharmacy, Wonkwang University, Iksan, 570-749, Chonbuk, South Korea
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27
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Grant SK, Bansal A, Mitra A, Feighner SD, Dai G, Kaczorowski GJ, Middleton RE. Delay of intracellular calcium transients using a calcium chelator: application to high-throughput screening of the capsaicin receptor ion channel and G-protein-coupled receptors. Anal Biochem 2001; 294:27-35. [PMID: 11412002 DOI: 10.1006/abio.2001.5157] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Whole-cell functional assays are often used for high-throughput screening (HTS) of molecular targets such as ion channels and G-protein-coupled receptors. A common method for assaying the activity of these membrane proteins is to measure the change in intracellular calcium concentration upon receptor stimulation. These changes in calcium concentration are typically transient and therefore not readily adapted to high-density plate formats used in HTS instruments. We have demonstrated that an intracellular calcium chelator, BAPTA, was able to delay by 5- to 20-fold and extend for several minutes the observed calcium signals initiated by extracellular calcium influx or release of calcium from intracellular stores. As examples, we used cells expressing a calcium-permeable ion channel, vanilloid receptor type 1 (the capsaicin receptor), and two G-protein-coupled receptors. These receptor-mediated increases in intracellular calcium concentration were measured by both fluorescence-based and luminescence-based detection methods. The use of an intracellular calcium chelator to delay calcium signaling should have wide application since it allows the measurement of the functional activity of any cellular receptor that signals through calcium. With this procedure, calcium fluorescence and luminescence whole-cell functional assays may be performed with standard laboratory pipetting and detection systems.
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Affiliation(s)
- S K Grant
- Department of High Throughput Screening and Automation, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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28
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Estradiol-stimulated nitric oxide release in human granulocytes is dependent on intracellular calcium transients: evidence of a cell surface estrogen receptor. Blood 2000. [DOI: 10.1182/blood.v95.12.3951] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractWe tested the hypothesis that estrogen acutely stimulates constitutive nitric oxide synthase activity in human granulocytes by acting on a cell surface estrogen receptor (ER). The release of nitric oxide was measured in real time with an amperometric probe. Exposure of granulocytes to 17β-estradiol stimulated NO release within seconds in a concentration-dependent manner. The NO release was also stimulated by 17β-estradiol conjugated to bovine serum albumin (E2-BSA), which suggests mediation by a cell surface receptor. Tamoxifen, an ER inhibitor, antagonized the action of both 17β-estradiol and E2-BSA, whereas ICI 182,780, an inhibitor of the nuclear ER, had no effect. Using dual emission microfluorometry in a calcium-free medium, the 17β-estradiol–stimulated release of NO from granulocytes was shown to be dependent on intracellular calcium ([Ca2+]i) transients in a tamoxifen-sensitive process. Exposure to BAPTA-AM (1,2bis-(-aminophenoxy)ethans-N,N,N′,N′-tetraacetic acid tetra(acetoxyymethyl) ester), a [Ca2+]i chelator, reduced [Ca2+]i in response to E2-BSA, and depleting [Ca2+]i stores abolished the effect of 17β-estradiol on NO release. Confocal photomicrographs using E2-BSA–FITC (fluorescein isothiocyanate) revealed cell membrane reactivity. Estrogen-stimulated NO release had an immunosuppressive effect, and it initiated granulocyte rounding and loss of adherence in a tamoxifen-sensitive manner. Finally, using reverse transcriptase–polymerase chain reaction, human neutrophil granulocytes expressed ER but not ERβ, suggesting that ER may be the membrane receptor for 17β-estradiol. The study demonstrated that a physiological dose of estrogen down-regulates granulocyte activity by acutely stimulating NO release via the activation of a cell surface ER which is coupled to increases in [Ca2+]i.
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29
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Estradiol-stimulated nitric oxide release in human granulocytes is dependent on intracellular calcium transients: evidence of a cell surface estrogen receptor. Blood 2000. [DOI: 10.1182/blood.v95.12.3951.012k21_3951_3958] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We tested the hypothesis that estrogen acutely stimulates constitutive nitric oxide synthase activity in human granulocytes by acting on a cell surface estrogen receptor (ER). The release of nitric oxide was measured in real time with an amperometric probe. Exposure of granulocytes to 17β-estradiol stimulated NO release within seconds in a concentration-dependent manner. The NO release was also stimulated by 17β-estradiol conjugated to bovine serum albumin (E2-BSA), which suggests mediation by a cell surface receptor. Tamoxifen, an ER inhibitor, antagonized the action of both 17β-estradiol and E2-BSA, whereas ICI 182,780, an inhibitor of the nuclear ER, had no effect. Using dual emission microfluorometry in a calcium-free medium, the 17β-estradiol–stimulated release of NO from granulocytes was shown to be dependent on intracellular calcium ([Ca2+]i) transients in a tamoxifen-sensitive process. Exposure to BAPTA-AM (1,2bis-(-aminophenoxy)ethans-N,N,N′,N′-tetraacetic acid tetra(acetoxyymethyl) ester), a [Ca2+]i chelator, reduced [Ca2+]i in response to E2-BSA, and depleting [Ca2+]i stores abolished the effect of 17β-estradiol on NO release. Confocal photomicrographs using E2-BSA–FITC (fluorescein isothiocyanate) revealed cell membrane reactivity. Estrogen-stimulated NO release had an immunosuppressive effect, and it initiated granulocyte rounding and loss of adherence in a tamoxifen-sensitive manner. Finally, using reverse transcriptase–polymerase chain reaction, human neutrophil granulocytes expressed ER but not ERβ, suggesting that ER may be the membrane receptor for 17β-estradiol. The study demonstrated that a physiological dose of estrogen down-regulates granulocyte activity by acutely stimulating NO release via the activation of a cell surface ER which is coupled to increases in [Ca2+]i.
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30
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Chen LY, Chiang AS, Hung JJ, Hung HI, Lai YK. Thapsigargin-induced grp78 expression is mediated by the increase of cytosolic free calcium in 9L rat brain tumor cells. J Cell Biochem 2000; 78:404-16. [PMID: 10861839 DOI: 10.1002/1097-4644(20000901)78:3<404::aid-jcb6>3.0.co;2-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Exposure of 9L rat brain tumor cells to 300 nM thapsigargin (TG), a sarcoendoplasmic Ca(2+)-ATPases inhibitor, leads to an immediate suppression of general protein synthesis followed by an enhanced synthesis of the 78-kDa glucose-regulated protein, GRP78. Synthesis of GRP78 increases significantly and continues to rise after 4 h of treatment, and this process coincides with the accumulation of grp78 mRNA. TG-induced grp78 expression can be suppressed by the cytosolic free calcium ([Ca(2+)](c)) chelator dibromo-1, 2-bis(aminophenoxy)ethane N,N,N',N'-tetraacetic acid (BAPTA) in a concentration-dependent manner. Induction of grp78 is completely abolished in the presence of 20 microM BAPTA under which the TG-induced increase of [Ca(2+)](c) is also completely prevented. By adding ethyleneglycol bis(beta-aminoethyl)ether-N,N,N',N' tetraacetic acid in the foregoing experiments, in a condition such that endoplasmic reticulum calcium ([Ca(2+)](ER)) is depleted and calcium influx from outside is prevented, TG-induced grp78 expression is also abolished. These data lead us to conclude that increase in [Ca(2+)](c), together with the depletion of [Ca(2+)](ER), are the major causes of TG-induced grp78 expression in 9L rat brain tumor cells. By using electrophoretic mobility shift assays (EMSA), we found that the nuclear extracts prepared from TG-treated cells exhibit an increase in binding activity toward the extended grp78 promoter as well as the individual cis-acting regulatory elements, CRE and CORE. Moreover, this increase in binding activity is also reduced by BAPTA. By competitory assays using the cis-acting regulatory elements as the competitors as well as the EMSA probes, we further show that all of the tested cis elements-CRE, CORE, and C1-are involved in the basal as well as in the TG-induced expression of grp78 and that the protein factor(s) that binds to the C1 region plays an important role in the formation and maintenance of the transcription complex.
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Affiliation(s)
- L Y Chen
- Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
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31
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Chen KD, Lai MT, Cho JH, Chen LY, Lai YK. Activation of p38 mitogen-activated protein kinase and mitochondrial Ca2+-mediated oxidative stress are essential for the enhanced expression ofgrp78 induced by the protein phosphatase inhibitors okadaic acid and calyculin A. J Cell Biochem 2000. [DOI: 10.1002/(sici)1097-4644(20000315)76:4<585::aid-jcb7>3.0.co;2-u] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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32
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Blanquet PR. Identification of two persistently activated neurotrophin-regulated pathways in rat hippocampus. Neuroscience 2000; 95:705-19. [PMID: 10670437 DOI: 10.1016/s0306-4522(99)00489-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Brain-derived neurotrophic factor contributes profoundly to modulate activity-dependent synaptic plasticity in adult brain areas such as the hippocampus, but the mechanisms underlying this important role still remain unclear. Recently, we have shown that two serine/threonine kinases, calcium/calmodulin-dependent protein kinase-2 and casein kinase-2, are capable of mediating brain-derived neurotrophic factor responses in adult rat hippocampus. In the present study, using hippocampal slices from adult rat, we show that phospholipase C-regulated calcium signals couple the brain-derived neurotrophic factor receptor to two distinct pathways: a pathway in which calcium/calmodulin-dependent protein kinase-2 stimulates a signalling module involving the p38 subfamily of mitogen-activated protein kinases and its downstream target, usually named mitogen-activated protein kinase-activated protein kinase-2; and a pathway in which the extracellular signal-regulated kinase subfamily of mitogen-activated protein kinases activates casein kinase-2. Our results suggest that: (i) extracellular signal-regulated kinase is activated by B-Raf in response to a calcium-sensitive adenylate cyclase; and (ii) extracellular signal-regulated kinase activates casein kinase-2 via a protein phosphatase(s) that may be of the PP1 and/or PP2A type. Interestingly, we also show that neurotrophin-induced activation of the two signalling cascades promotes a sustained activation of mitogen-activated protein kinase-activated protein kinase-2 and casein kinase-2 in slices. Considering the ability of these two kinases to be persistently activated, and that most of the protein kinases which lie in these pathways are believed to be important for multiple events underlying neuronal plasticity, it is suggested that the mechanisms described here might contribute both to rapid synaptic changes through local effects and to long-lasting synaptic responses through new gene transcription in the hippocampus.
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Affiliation(s)
- P R Blanquet
- Unité de Recherche de Physiopharmacologie du Système Nerveux, U-161 INSERM, Paris, France
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33
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Buznikov GA, Rakich L. Cholinoreceptors of early (preneural) sea urchin embryos. NEUROSCIENCE AND BEHAVIORAL PHYSIOLOGY 2000; 30:53-62. [PMID: 10768372 DOI: 10.1007/bf02461392] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Agonists of nicotinic cholinoreceptors (n-AChR) and 1-acetyl-4-methylpiperazine (100 microM) had no effect on early embryogenesis in sea urchins, while in the presence of phorbol-12-myristate-13-acetate (PMA) and various other protein kinase C activators, these agents induced rapid lysis of oocytes or early embryos, as a result of calcium shock. Many n-AChR ligands which do not penetrate into the cytoplasm (not being antagonists of muscarinic cholinoreceptors) protected against this cytotoxic effect. In the presence of PMA, acetylcholine and carbachol had actions which were much weaker than those of nicotine, while muscarine was completely inactive in these conditions. Thus, the surfaces of sea urchin oocytes and early embryos bear receptor structures, presumably n-AChR, which are functionally linked with second messengers which are endogenous protein kinase C activators.
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Affiliation(s)
- G A Buznikov
- NK Kol'tsov Institute of Developmental Biology, Russian Academy of Sciences, Moscow
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34
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Beyer C, Karolczak M. Estrogenic stimulation of neurite growth in midbrain dopaminergic neurons depends on cAMP/protein kinase A signalling. J Neurosci Res 2000. [DOI: 10.1002/(sici)1097-4547(20000101)59:1<107::aid-jnr13>3.0.co;2-w] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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35
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Tutdibi O, Brinkmeier H, Rüdel R, Föhr KJ. Increased calcium entry into dystrophin-deficient muscle fibres of MDX and ADR-MDX mice is reduced by ion channel blockers. J Physiol 1999; 515 ( Pt 3):859-68. [PMID: 10066910 PMCID: PMC2269189 DOI: 10.1111/j.1469-7793.1999.859ab.x] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
1. Single fibres were enzymatically isolated from interosseus muscles of dystrophic MDX mice, myotonic-dystrophic double mutant ADR-MDX mice and C57BL/10 controls. The fibres were kept in cell culture for up to 2 weeks for the study of Ca2+ homeostasis and sarcolemmal Ca2+ permeability. 2. Resting levels of intracellular free Ca2+, determined with the fluorescent Ca2+ indicator fura-2, were slightly higher in MDX (63 +/- 20 nM; means +/- s.d.; n = 454 analysed fibres) and ADR-MDX (65 +/- 12 nM; n = 87) fibres than in controls (51 +/- 20 nM; n = 265). 3. The amplitudes of electrically induced Ca2+ transients did not differ between MDX fibres and controls. Decay time constants of Ca2+ transients ranged between 10 and 55 ms in both genotypes. In 50 % of MDX fibres (n = 68), but in only 20 % of controls (n = 54), the decay time constants were > 35 ms. 4. Bath application of Mn2+ resulted in a progressive quench of fura-2 fluorescence emitted from the fibres. The quench rate was about 2 times higher in MDX fibres (3.98 +/- 1.9 % min-1; n = 275) than in controls (2.03 +/- 1.4 % min-1; n = 204). The quench rate in ADR-MDX fibres (2.49 +/- 1.4 % min-1; n = 87) was closer to that of controls. 5. The Mn2+ influx into MDX fibres was reduced to 10 % by Gd3+, to 19 % by La3+ and to 47 % by Ni2+ (all at 50 microM). Bath application of 50 microM amiloride inhibited the Mn2+ influx to 37 %. 6. We conclude that in isolated, resting MDX muscle fibres the membrane permeability for divalent cations is increased. The presumed additional influx of Ca2+ occurs through ion channels, but is well compensated for by effective cellular Ca2+ transport systems. The milder dystrophic phenotype of ADR-MDX mice is correlated with a smaller increase of their sarcolemmal Ca2+ permeability.
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Affiliation(s)
- O Tutdibi
- Department of General Physiology, University of Ulm, D-89069 Ulm, Germany
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