101
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Shi CX, Zhao MX, Shu XD, Xiong XQ, Wang JJ, Gao XY, Chen Q, Li YH, Kang YM, Zhu GQ. β-aminoisobutyric acid attenuates hepatic endoplasmic reticulum stress and glucose/lipid metabolic disturbance in mice with type 2 diabetes. Sci Rep 2016; 6:21924. [PMID: 26907958 PMCID: PMC4764829 DOI: 10.1038/srep21924] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 02/02/2016] [Indexed: 02/06/2023] Open
Abstract
β-aminoisobutyric acid (BAIBA) is a nature thymine catabolite, and contributes to exercise-induced protection from metabolic diseases. Here we show the therapeutical effects of BAIBA on hepatic endoplasmic reticulum (ER) stress and glucose/lipid metabolic disturbance in diabetes. Type 2 diabetes was induced by combined streptozotocin (STZ) and high-fat diet (HFD) in mice. Oral administration of BAIBA for 4 weeks reduced blood glucose and lipids levels, hepatic key enzymes of gluconeogenesis and lipogenesis expressions, attenuated hepatic insulin resistance and lipid accumulation, and improved insulin signaling in type 2 diabetic mice. BAIBA reduced hepatic ER stress and apoptosis in type 2 diabetic mice. Furthermore, BAIBA alleviated ER stress in human hepatocellular carcinoma (HepG2) cells with glucosamine-induced insulin resistance. Hepatic AMPK phosphorylation was reduced in STZ/HFD mice and glucosamine-treated HepG2 cells, which were restored by BAIBA treatment. The suppressive effects of BAIBA on glucosamine-induced ER stress were reversed by knockdown of AMPK with siRNA. In addition, BAIBA prevented thapsigargin- or tunicamycin-induced ER stress, and tunicamycin–induced apoptosis in HepG2 cells. These results indicate that BAIBA attenuates hepatic ER stress, apoptosis and glucose/lipid metabolic disturbance in mice with type 2 diabetes. AMPK signaling is involved to the role of BAIBA in attenuating ER stress.
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Affiliation(s)
- Chang-Xiang Shi
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Ming-Xia Zhao
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Xiao-Dong Shu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Xiao-Qing Xiong
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Jue-Jin Wang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Xing-Ya Gao
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Qi Chen
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Yue-Hua Li
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Yu-Ming Kang
- Department of Physiology and Pathophysiology, Cardiovascular Research Center, Xi'an Jiaotong University School of Medicine, Xi'an 710061, China
| | - Guo-Qing Zhu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China.,Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu 210029, China
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102
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Lee KFH, Soares C, Thivierge JP, Béïque JC. Correlated Synaptic Inputs Drive Dendritic Calcium Amplification and Cooperative Plasticity during Clustered Synapse Development. Neuron 2016; 89:784-99. [PMID: 26853305 DOI: 10.1016/j.neuron.2016.01.012] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 09/21/2015] [Accepted: 12/21/2015] [Indexed: 11/29/2022]
Abstract
The mechanisms that instruct the assembly of fine-scale features of synaptic connectivity in neural circuits are only beginning to be understood. Using whole-cell electrophysiology, two-photon calcium imaging, and glutamate uncaging in hippocampal slices, we discovered a functional coupling between NMDA receptor activation and ryanodine-sensitive intracellular calcium release that dominates the spatiotemporal dynamics of activity-dependent calcium signals during synaptogenesis. This developmentally regulated calcium amplification mechanism was tuned to detect and bind spatially clustered and temporally correlated synaptic inputs and enacted a local cooperative plasticity rule between coactive neighboring synapses. Consistent with the hypothesis that synapse maturation is spatially regulated, we observed clustering of synaptic weights in developing dendritic arbors. These results reveal developmental features of NMDA receptor-dependent calcium dynamics and local plasticity rules that are suited to spatially guide synaptic connectivity patterns in emerging neural networks.
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Affiliation(s)
- Kevin F H Lee
- Neuroscience Graduate Program, University of Ottawa, Ottawa, ON K1H 8M5, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Cary Soares
- Neuroscience Graduate Program, University of Ottawa, Ottawa, ON K1H 8M5, Canada; Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jean-Philippe Thivierge
- Centre for Neural Dynamics, University of Ottawa, Ottawa, ON K1H 8M5, Canada; School of Psychology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jean-Claude Béïque
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada; Brain and Mind Research Institute, University of Ottawa, Ottawa, ON K1H 8M5, Canada; Centre for Neural Dynamics, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
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103
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Foufelle F, Fromenty B. Role of endoplasmic reticulum stress in drug-induced toxicity. Pharmacol Res Perspect 2016; 4:e00211. [PMID: 26977301 PMCID: PMC4777263 DOI: 10.1002/prp2.211] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 12/14/2015] [Indexed: 12/13/2022] Open
Abstract
Drug‐induced toxicity is a key issue for public health because some side effects can be severe and life‐threatening. These adverse effects can also be a major concern for the pharmaceutical companies since significant toxicity can lead to the interruption of clinical trials, or the withdrawal of the incriminated drugs from the market. Recent studies suggested that endoplasmic reticulum (ER) stress could be an important event involved in drug liability, in addition to other key mechanisms such as mitochondrial dysfunction and oxidative stress. Indeed, drug‐induced ER stress could lead to several deleterious effects within cells and tissues including accumulation of lipids, cell death, cytolysis, and inflammation. After recalling important information regarding drug‐induced adverse reactions and ER stress in diverse pathophysiological situations, this review summarizes the main data pertaining to drug‐induced ER stress and its potential involvement in different adverse effects. Drugs presented in this review are for instance acetaminophen (APAP), arsenic trioxide and other anticancer drugs, diclofenac, and different antiretroviral compounds. We also included data on tunicamycin (an antibiotic not used in human medicine because of its toxicity) and thapsigargin (a toxic compound of the Mediterranean plant Thapsia garganica) since both molecules are commonly used as prototypical toxins to induce ER stress in cellular and animal models.
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104
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Vasconcelos TB, Ribeiro-Filho HV, Lucetti LT, Magalhães PJC. β-Citronellol, an alcoholic monoterpene with inhibitory properties on the contractility of rat trachea. Braz J Med Biol Res 2016; 49:e4800. [PMID: 26648088 PMCID: PMC4712486 DOI: 10.1590/1414-431x20154800] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 09/18/2015] [Indexed: 11/21/2022] Open
Abstract
β-Citronellol is an alcoholic monoterpene found in essential oils such Cymbopogon citratus (a plant with antihypertensive properties). β-Citronellol can act against pathogenic microorganisms that affect airways and, in virtue of the popular use of β-citronellol-enriched essential oils in aromatherapy, we assessed its pharmacologic effects on the contractility of rat trachea. Contractions of isolated tracheal rings were recorded isometrically through a force transducer connected to a data-acquisition device. β-Citronellol relaxed sustained contractions induced by acetylcholine or high extracellular potassium, but half-maximal inhibitory concentrations (IC50) for K(+)-elicited stimuli were smaller than those for cholinergic contractions. It also inhibited contractions induced by electrical field stimulation or sodium orthovanadate with pharmacologic potency equivalent to that seen against acetylcholine-induced contractions. When contractions were evoked by selective recruitment of Ca2+ from the extracellular medium, β-citronellol preferentially inhibited contractions that involved voltage-operated (but not receptor-operated) pathways. β-Citronellol (but not verapamil) inhibited contractions induced by restoration of external Ca2+ levels after depleting internal Ca2+ stores with the concomitant presence of thapsigargin and recurrent challenge with acetylcholine. Treatment of tracheal rings with L-NAME, indomethacin or tetraethylammonium did not change the relaxing effects of β-citronellol. Inhibition of transient receptor potential vanilloid subtype 1 (TRPV1) or transient receptor potential ankyrin 1 (TRPA1) receptors with selective antagonists caused no change in the effects of β-citronellol. In conclusion, β-citronellol exerted inhibitory effects on rat tracheal rings, with predominant effects on contractions that recruit Ca2+ inflow towards the cytosol by voltage-gated pathways, whereas it appears less active against contractions elicited by receptor-operated Ca2+ channels.
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Affiliation(s)
- T B Vasconcelos
- Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - H V Ribeiro-Filho
- Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - L T Lucetti
- Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - P J C Magalhães
- Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, Fortaleza, CE, Brasil
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105
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Li Y, Lian X, Wan Y, Wang D, Chen W, Di F, Wu W, Li Z. Modulation of the Ca(2+) signaling pathway by celangulin I in the central neurons of Spodoptera exigua. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2016; 127:76-81. [PMID: 26821661 DOI: 10.1016/j.pestbp.2015.09.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 08/31/2015] [Accepted: 09/21/2015] [Indexed: 06/05/2023]
Abstract
Celangulin I is an insecticidal component isolated from Chinese bittersweet Celastrus angulatus. The present study explored the possible effects of celangulin I on the calcium signaling pathway, especially on the L-type Ca(2+) channel and the calcium channels in the endoplasmic reticulum in the central neurons isolated from the third instar larvae of Spodoptera exigua using whole-cell patch-clamp and calcium imaging technique. The results showed that celangulin I could activate the high voltage-gated calcium channel at the concentration of 150μM. The peak currents were increased by 17% of the initial value at the end of the 10-min recording after treated with celangulin I. The rises of intracellular calcium ion concentration ([Ca(2+)]i) in neurons treated by celangulin I showed that the effects of celangulin I were concentration-dependent. Activation of the RyRs by ryanodine decreased the calcium release induced by celangulin I, indicating that celangulin I exerts effect on insect RyRs. Furthermore, we also provided evidence for the first time that celangulin I activates inositol 1,4,5-trisphosphate (IP3) sensitive intracellular calcium release channels in the endoplasmic reticulum third instar larvae neurons of S. exigua. Plausibly, these experimental results can explain the characteristic symptoms of anesthesia and paralysis in celangulin I treated insects.
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Affiliation(s)
- Yuxin Li
- State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin 300071, China.
| | - Xihong Lian
- Institute of Pesticide Science, Key Laboratory of Applied Entomology, Northwest A&F University, Box 61, Xinong Road 22, Yangling, Shanxi 712100, China
| | - Yinging Wan
- State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin 300071, China
| | - Duoyi Wang
- State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin 300071, China
| | - Wei Chen
- State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin 300071, China
| | - Fengjuan Di
- State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin 300071, China
| | - Wenjun Wu
- Institute of Pesticide Science, Key Laboratory of Applied Entomology, Northwest A&F University, Box 61, Xinong Road 22, Yangling, Shanxi 712100, China
| | - Zhengming Li
- State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin 300071, China.
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106
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Hertel F, Mo GCH, Duwé S, Dedecker P, Zhang J. RefSOFI for Mapping Nanoscale Organization of Protein-Protein Interactions in Living Cells. Cell Rep 2015; 14:390-400. [PMID: 26748717 DOI: 10.1016/j.celrep.2015.12.036] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 09/04/2015] [Accepted: 12/06/2015] [Indexed: 11/27/2022] Open
Abstract
It has become increasingly clear that protein-protein interactions (PPIs) are compartmentalized in nanoscale domains that define the biochemical architecture of the cell. Despite tremendous advances in super-resolution imaging, strategies to observe PPIs at sufficient resolution to discern their organization are just emerging. Here we describe a strategy in which PPIs induce reconstitution of fluorescent proteins (FPs) that are capable of exhibiting single-molecule fluctuations suitable for stochastic optical fluctuation imaging (SOFI). Subsequently, spatial maps of these interactions can be resolved in super-resolution in living cells. Using this strategy, termed reconstituted fluorescence-based SOFI (refSOFI), we investigated the interaction between the endoplasmic reticulum (ER) Ca(2+) sensor STIM1 and the pore-forming channel subunit ORAI1, a crucial process in store-operated Ca(2+) entry (SOCE). Stimulating SOCE does not appear to change the size of existing STIM1/ORAI1 interaction puncta at the ER-plasma membrane junctions, but results in an apparent increase in the number of interaction puncta.
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Affiliation(s)
- Fabian Hertel
- Department of Pharmacology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Gary C H Mo
- Department of Pharmacology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Sam Duwé
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, 3001 Heverlee, Belgium
| | - Peter Dedecker
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, 3001 Heverlee, Belgium
| | - Jin Zhang
- Department of Pharmacology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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107
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Integration of high-content screening and untargeted metabolomics for comprehensive functional annotation of natural product libraries. Proc Natl Acad Sci U S A 2015; 112:11999-2004. [PMID: 26371303 DOI: 10.1073/pnas.1507743112] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Traditional natural products discovery using a combination of live/dead screening followed by iterative bioassay-guided fractionation affords no information about compound structure or mode of action until late in the discovery process. This leads to high rates of rediscovery and low probabilities of finding compounds with unique biological and/or chemical properties. By integrating image-based phenotypic screening in HeLa cells with high-resolution untargeted metabolomics analysis, we have developed a new platform, termed Compound Activity Mapping, that is capable of directly predicting the identities and modes of action of bioactive constituents for any complex natural product extract library. This new tool can be used to rapidly identify novel bioactive constituents and provide predictions of compound modes of action directly from primary screening data. This approach inverts the natural products discovery process from the existing "grind and find" model to a targeted, hypothesis-driven discovery model where the chemical features and biological function of bioactive metabolites are known early in the screening workflow, and lead compounds can be rationally selected based on biological and/or chemical novelty. We demonstrate the utility of the Compound Activity Mapping platform by combining 10,977 mass spectral features and 58,032 biological measurements from a library of 234 natural products extracts and integrating these two datasets to identify 13 clusters of fractions containing 11 known compound families and four new compounds. Using Compound Activity Mapping we discovered the quinocinnolinomycins, a new family of natural products with a unique carbon skeleton that cause endoplasmic reticulum stress.
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108
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Efficient entry of cell-penetrating peptide nona-arginine into adherent cells involves a transient increase in intracellular calcium. Biochem J 2015; 471:221-30. [PMID: 26272944 PMCID: PMC4613506 DOI: 10.1042/bj20150272] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 08/13/2015] [Indexed: 01/20/2023]
Abstract
Mechanisms by which drug-delivery vehicles based on cationic peptides cross cell membranes remain unknown. We report that an increase in intracellular calcium triggered by temperature drop or high peptide concentrations transiently permeabilizes the plasma membrane for nona-arginine (R9) and delivers it to the cytosol. Understanding the mechanism of entry of cationic peptides such as nona-arginine (R9) into cells remains an important challenge to their use as efficient drug-delivery vehicles. At nanomolar to low micromolar R9 concentrations and at physiological temperature, peptide entry involves endocytosis. In contrast, at a concentration ≥10 μM, R9 induces a very effective non-endocytic entry pathway specific for cationic peptides. We found that a similar entry pathway is induced at 1–2 μM concentrations of R9 if peptide application is accompanied by a rapid temperature drop to 15°C. Both at physiological and at sub-physiological temperatures, this entry mechanism was inhibited by depletion of the intracellular ATP pool. Intriguingly, we found that R9 at 10–20 μM and 37°C induces repetitive spikes in intracellular Ca2+ concentration. This Ca2+ signalling correlated with the efficiency of the peptide entry. Pre-loading cells with the Ca2+ chelator BAPTA (1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid) inhibited both Ca2+ spikes and peptide entry, suggesting that an increase in intracellular Ca2+ precedes and is required for peptide entry. One of the hallmarks of Ca2+ signalling is a transient cell-surface exposure of phosphatidylserine (PS), a lipid normally residing only in the inner leaflet of the plasma membrane. Blocking the accessible PS with the PS-binding domain of lactadherin strongly inhibited non-endocytic R9 entry, suggesting the importance of PS externalization in this process. To conclude, we uncovered a novel mechanistic link between calcium signalling and entry of cationic peptides. This finding will enhance our understanding of the properties of plasma membrane and guide development of future drug-delivery vehicles.
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109
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Ventosa-Andrés P, La-Venia A, Ripoll CAB, Hradilová L, Krchňák V. Synthesis of Nature-Inspired Medium-Sized Fused Heterocycles from Amino Acids. Chemistry 2015. [DOI: 10.1002/chem.201501746] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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110
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Doan NTQ, Crestey F, Olsen CE, Christensen SB. Chemo- and Regioselective Functionalization of Nortrilobolide: Application for Semisynthesis of the Natural Product 2-Acetoxytrilobolide. JOURNAL OF NATURAL PRODUCTS 2015; 78:1406-1414. [PMID: 26078214 DOI: 10.1021/acs.jnatprod.5b00333] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The difference in reactivity of the hexaoxygenated natural product thapsigargin (1) and the pentaoxygenated nortrilobolide (3) was compared in order to develop a chemo- and regioselective method for the conversion of nortrilobolide (3) into the natural product 2-acetoxytrilobolide (4). For the first time, a stereoselective synthesis of 2-acetoxytrilobolide (4) is described, which involves two key reactions: the first chemical step was a one-pot substitution-oxidation reaction of an allylic ester into its corresponding α,β-unsaturated ketone. The second process consisted of a stereoselective α'-acyloxylation of the key intermediate α,β-unsaturated ketone to afford its corresponding acetoxyketone, which was converted into 2-acetoxytrilobolide (4) in a few steps. This innovative approach would allow the synthesis of a broad library of novel and valuable penta- and hexaoxygenated guaianolides as potential anticancer agents.
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Affiliation(s)
- Nhu Thi Quynh Doan
- †Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen Ø, Denmark
| | - François Crestey
- †Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen Ø, Denmark
| | - Carl Erik Olsen
- ‡Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Søren Brøgger Christensen
- †Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen Ø, Denmark
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111
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Wang C, Zhang L, Jaeger LA, Machaty Z. Store-Operated Ca2+ Entry Sustains the Fertilization Ca2+ Signal in Pig Eggs. Biol Reprod 2015; 93:25. [PMID: 26063872 DOI: 10.1095/biolreprod.114.126151] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 06/01/2015] [Indexed: 11/01/2022] Open
Abstract
The role of store-operated Ca(2+) entry (SOCE) in the maintenance of sperm-induced Ca(2+) oscillations was investigated in porcine eggs. We found that 10 μM gadolinium (Gd(3+)), which is known to inhibit SOCE, blocked Ca(2+) entry that was triggered by thapsigargin-induced store depletion and also caused an abrupt cessation of the fertilization Ca(2+) signal. In a similar manner 3,5-bis(trifluoromethyl)pyrazole 2 (20 μM), and tetrapandin-2 (10 μM), potent SOCE inhibitors, also blocked thapsigargin-stimulated Ca(2+) entry and disrupted the Ca(2+) oscillations after sperm-egg fusion. The downregulation of Stim1 or Orai1 in the eggs did not alter the Ca(2+) content of the intracellular stores, whereas co-overexpression of these proteins led to the generation of irregular Ca(2+) transients after fertilization that stopped prematurely. We also found that thapsigargin completely emptied the endoplasmic reticulum, and that the series of Ca(2+) transients stopped abruptly after the addition of thapsigargin to the fertilized eggs, indicating that the proper reloading of the intracellular stores is a prerequisite for the maintenance of the Ca(2+) oscillations. These data strengthen our previous findings that in porcine eggs SOCE is a major signaling cascade that is responsible for sustaining the repetitive Ca(2+) signal at fertilization.
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Affiliation(s)
- Chunmin Wang
- Department of Animal Sciences, Purdue University, West Lafayette, Indiana
| | - Lu Zhang
- Department of Animal Sciences, Purdue University, West Lafayette, Indiana
| | - Laurie A Jaeger
- Department of Basic Medical Sciences, Purdue University, West Lafayette, Indiana
| | - Zoltan Machaty
- Department of Animal Sciences, Purdue University, West Lafayette, Indiana
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112
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Doan NTQ, Paulsen ES, Sehgal P, Møller JV, Nissen P, Denmeade SR, Isaacs JT, Dionne CA, Christensen SB. Targeting thapsigargin towards tumors. Steroids 2015; 97:2-7. [PMID: 25065587 PMCID: PMC4696022 DOI: 10.1016/j.steroids.2014.07.009] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 07/04/2014] [Accepted: 07/09/2014] [Indexed: 11/16/2022]
Abstract
The skin irritating principle from Thapsia garganica was isolated, named thapsigargin and the structure elucidated. By inhibiting the sarco/endoplasmic reticulum Ca(2+) ATPase (SERCA) thapsigargin provokes apoptosis in almost all cells. By conjugating thapsigargin to peptides, which are only substrates for either prostate specific antigen (PSA) or prostate specific membrane antigen (PSMA) prodrugs were created, which selectively affect prostate cancer cells or neovascular tissue in tumors. One of the prodrug is currently tested in clinical phase II. The prodrug under clinical trial has been named mipsagargin.
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Affiliation(s)
- Nhu Thi Quynh Doan
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen Ø, Denmark
| | - Eleonora Sandholdt Paulsen
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen Ø, Denmark
| | - Pankaj Sehgal
- Department of Biomedicine, Ole Worms Allé 6, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Jesper Vuust Møller
- Department of Biomedicine, Ole Worms Allé 6, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Poul Nissen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, DK-8000 Aarhus C, Denmark
| | - Samuel R Denmeade
- The Bunting-Blaustein Cancer Research Building, 1650 Orleans Street, Baltimore, MD 21231, USA
| | - John T Isaacs
- The Bunting-Blaustein Cancer Research Building, 1650 Orleans Street, Baltimore, MD 21231, USA
| | - Craig A Dionne
- GenSpera, 2511 N Loop 1604 W, Suite 204, San Antonio, TX 78258, USA
| | - Søren Brøgger Christensen
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen Ø, Denmark.
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113
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Zhang Y, Wang Y, Taylor JL, Jiang Z, Zhang S, Mei F, Wu Y, Wu P, Ni J. Aequorin-based luminescence imaging reveals differential calcium signalling responses to salt and reactive oxygen species in rice roots. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:2535-45. [PMID: 25754405 PMCID: PMC4986864 DOI: 10.1093/jxb/erv043] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
It is well established that both salt and reactive oxygen species (ROS) stresses are able to increase the concentration of cytosolic free Ca(2+) ([Ca(2+)]i), which is caused by the flux of calcium (Ca(2+)). However, the differences between these two processes are largely unknown. Here, we introduced recombinant aequorin into rice (Oryza sativa) and examined the change in [Ca(2+)]i in response to salt and ROS stresses. The transgenic rice harbouring aequorin showed strong luminescence in roots when treated with exogenous Ca(2+). Considering the histological differences in roots between rice and Arabidopsis, we reappraised the discharging solution, and suggested that the percentage of ethanol should be 25%. Different concentrations of NaCl induced immediate [Ca(2+)]i spikes with the same durations and phases. In contrast, H₂O₂ induced delayed [Ca(2+)]i spikes with different peaks according to the concentrations of H₂O₂. According to the Ca(2+) inhibitor research, we also showed that the sources of Ca(2+) induced by NaCl and H₂O₂ are different. Furthermore, we evaluated the contribution of [Ca(2+)]i responses in the NaCl- and H₂O₂-induced gene expressions respectively, and present a Ca(2+)- and H₂O₂-mediated molecular signalling model for the initial response to NaCl in rice.
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Affiliation(s)
- Yanyan Zhang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Yifeng Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Science, Zhejiang University, Hangzhou 310058, China
| | - Jemma L Taylor
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Zhonghao Jiang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Shu Zhang
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Fengling Mei
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Yunrong Wu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Science, Zhejiang University, Hangzhou 310058, China
| | - Ping Wu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Science, Zhejiang University, Hangzhou 310058, China
| | - Jun Ni
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
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114
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Bardy G, Virsolvy A, Quignard JF, Ravier MA, Bertrand G, Dalle S, Cros G, Magous R, Richard S, Oiry C. Quercetin induces insulin secretion by direct activation of L-type calcium channels in pancreatic beta cells. Br J Pharmacol 2015; 169:1102-13. [PMID: 23530660 DOI: 10.1111/bph.12194] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 03/01/2013] [Accepted: 03/21/2013] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Quercetin is a natural polyphenolic flavonoid that displays anti-diabetic properties in vivo. Its mechanism of action on insulin-secreting beta cells is poorly documented. In this work, we have analysed the effects of quercetin both on insulin secretion and on the intracellular calcium concentration ([Ca(2+)]i) in beta cells, in the absence of any co-stimulating factor. EXPERIMENTAL APPROACH Experiments were performed on both INS-1 cell line and rat isolated pancreatic islets. Insulin release was quantified by the homogeneous time-resolved fluorescence method. Variations in [Ca(2+)]i were measured using the ratiometric fluorescent Ca(2+) indicator Fura-2. Ca(2+) channel currents were recorded with the whole-cell patch-clamp technique. KEY RESULTS Quercetin concentration-dependently increased insulin secretion and elevated [Ca(2+)]i. These effects were not modified by the SERCA inhibitor thapsigargin (1 μmol·L(-1)), but were nearly abolished by the L-type Ca(2+) channel antagonist nifedipine (1 μmol·L(-1)). Similar to the L-type Ca(2+) channel agonist Bay K 8644, quercetin enhanced the L-type Ca(2+) current by shifting its voltage-dependent activation towards negative potentials, leading to the increase in [Ca(2+)]i and insulin secretion. The effects of quercetin were not inhibited in the presence of a maximally active concentration of Bay K 8644 (1 μmol·L(-1)), with the two drugs having cumulative effects on [Ca(2+)]i. CONCLUSIONS AND IMPLICATIONS Taken together, our results show that quercetin stimulates insulin secretion by increasing Ca(2+) influx through an interaction with L-type Ca(2+) channels at a site different from that of Bay K 8644. These data contribute to a better understanding of quercetin's mechanism of action on insulin secretion.
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Affiliation(s)
- G Bardy
- Département de Pharmacologie Médicale et Toxicologie, Hôpital Lapeyronie, CHRU de Montpellier, Montpellier, France
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115
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Ohno Y, Otaki JM. Spontaneous long-range calcium waves in developing butterfly wings. BMC DEVELOPMENTAL BIOLOGY 2015; 15:17. [PMID: 25888365 PMCID: PMC4445562 DOI: 10.1186/s12861-015-0067-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 01/15/2015] [Indexed: 11/11/2022]
Abstract
Background Butterfly wing color patterns emerge as the result of a regular arrangement of scales produced by epithelial scale cells at the pupal stage. These color patterns and scale arrangements are coordinated throughout the wing. However, the mechanism by which the development of scale cells is controlled across the entire wing remains elusive. In the present study, we used pupal wings of the blue pansy butterfly, Junonia orithya, which has distinct eyespots, to examine the possible involvement of Ca2+ waves in wing development. Results Here, we demonstrate that the developing pupal wing tissue of the blue pansy butterfly displayed spontaneous low-frequency Ca2+ waves in vivo that propagated slowly over long distances. Some waves appeared to be released from the immediate peripheries of the prospective eyespot and discal spot, though it was often difficult to identify the specific origins of these waves. Physical damage, which is known to induce ectopic eyespots, led to the radiation of Ca2+ waves from the immediate periphery of the damaged site. Thapsigargin, which is a specific inhibitor of Ca2+-ATPases in the endoplasmic reticulum, induced an acute increase in cytoplasmic Ca2+ levels and halted the spontaneous Ca2+ waves. Additionally, thapsigargin-treated wings showed incomplete scale development as well as other scale and color pattern abnormalities. Conclusions We identified a novel form of Ca2+ waves, spontaneous low-frequency slow waves, which travel over exceptionally long distances. Our results suggest that spontaneous Ca2+ waves play a critical role in the coordinated development of scale arrangements and possibly in color pattern formation in butterflies. Electronic supplementary material The online version of this article (doi:10.1186/s12861-015-0067-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yoshikazu Ohno
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa, 903-0213, Japan.
| | - Joji M Otaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa, 903-0213, Japan.
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116
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Liu Y, Neely E, Simmons Z, Connor JR. Adaptive endoplasmic reticulum stress alters cellular responses to the extracellular milieu. J Neurosci Res 2015; 93:766-76. [DOI: 10.1002/jnr.23541] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 11/12/2014] [Accepted: 11/13/2014] [Indexed: 12/11/2022]
Affiliation(s)
- Yiting Liu
- Department of Neurosurgery; Pennsylvania State University, M.S. Hershey Medical Center; Hershey Pennsylvania
| | - Elizabeth Neely
- Department of Neurosurgery; Pennsylvania State University, M.S. Hershey Medical Center; Hershey Pennsylvania
| | - Zachary Simmons
- Department of Neurology; Pennsylvania State University, M.S. Hershey Medical Center; Hershey Pennsylvania
| | - James R. Connor
- Department of Neurosurgery; Pennsylvania State University, M.S. Hershey Medical Center; Hershey Pennsylvania
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117
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Glanowska KM, Moenter SM. Differential regulation of GnRH secretion in the preoptic area (POA) and the median eminence (ME) in male mice. Endocrinology 2015; 156:231-41. [PMID: 25314270 PMCID: PMC4272400 DOI: 10.1210/en.2014-1458] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
GnRH release in the median eminence (ME) is the central output for control of reproduction. GnRH processes in the preoptic area (POA) also release GnRH. We examined region-specific regulation of GnRH secretion using fast-scan cyclic voltammetry to detect GnRH release in brain slices from adult male mice. Blocking endoplasmic reticulum calcium reuptake to elevate intracellular calcium evokes GnRH release in both the ME and POA. This release is action potential dependent in the ME but not the POA. Locally applied kisspeptin induced GnRH secretion in both the ME and POA. Local blockade of inositol triphospate-mediated calcium release inhibited kisspeptin-induced GnRH release in the ME, but broad blockade was required in the POA. In contrast, kisspeptin-evoked secretion in the POA was blocked by local gonadotropin-inhibitory hormone, but broad gonadotropin-inhibitory hormone application was required in the ME. Although action potentials are required for GnRH release induced by pharmacologically-increased intracellular calcium in the ME and kisspeptin-evoked release requires inositol triphosphate-mediated calcium release, blocking action potentials did not inhibit kisspeptin-induced GnRH release in the ME. Kisspeptin-induced GnRH release was suppressed after blocking both action potentials and plasma membrane Ca(2+) channels. This suggests that kisspeptin action in the ME requires both increased intracellular calcium and influx from the outside of the cell but not action potentials. Local interactions among kisspeptin and GnRH processes in the ME could thus stimulate GnRH release without involving perisomatic regions of GnRH neurons. Coupling between action potential generation and hormone release in GnRH neurons is thus likely physiologically labile and may vary with region.
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Affiliation(s)
- Katarzyna M Glanowska
- Neuroscience Graduate Program (K.M.G.), University of Virginia, Charlottesville, Virginia 22908; and Departments of Molecular and Integrative Physiology (S.M.M.), Internal Medicine, and Obstetrics and Gynecology, University of Michigan, Ann Arbor, Michigan 48109
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118
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Wang J, Hou T, Wei L, Shi L, He J, Zhou N, Sun G, Zhang X, Liang X. Discovery of new targets of phenolic acids in danshen using a label-free cell phenotypic assay. RSC Adv 2015. [DOI: 10.1039/c4ra16102e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Pharmacological profiling of 10 known phenolic acids in danshen using a label-free cell phenotypic assay in HT-29 and A431 cells revealed that lithospermic acid, salvianolic acid A, B, C and danshensu all displayed agonistic activity towards GPR35.
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Affiliation(s)
- Jixia Wang
- Key Lab of Separation Science for Analytical Chemistry
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Tao Hou
- Institute of Materia Medica
- Dalian University
- Dalian
- China
| | - Lai Wei
- Key Lab of Separation Science for Analytical Chemistry
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Liying Shi
- Institute of Materia Medica
- Dalian University
- Dalian
- China
| | - Jian He
- Key Lab of Separation Science for Analytical Chemistry
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Nan Zhou
- Department of Oral Pathology
- College of Stomatology
- Dalian Medical University
- Dalian
- China
| | - Guangwei Sun
- Key Lab of Separation Science for Analytical Chemistry
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Xiuli Zhang
- Key Lab of Separation Science for Analytical Chemistry
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
| | - Xinmiao Liang
- Key Lab of Separation Science for Analytical Chemistry
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
- China
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119
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Yu Z, Taylor JL, He Y, Ni J. Enlightenment on the aequorin-based platform for screening Arabidopsis stress sensory channels related to calcium signaling. PLANT SIGNALING & BEHAVIOR 2015; 10:e1057366. [PMID: 26336841 PMCID: PMC4883862 DOI: 10.1080/15592324.2015.1057366] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 05/23/2015] [Accepted: 05/27/2015] [Indexed: 06/05/2023]
Abstract
Free calcium ions (Ca(2+)) are an important signal molecule in response to a large array of external stimuli encountered by plants. Using the aequorin-based Ca(2+) recording system, tremendous progress has been made in understanding the Ca(2+) responses to biotic or abiotic stresses in dicotyledonous Arabidopsis. However, due to the lack of a similar detection system, little information has been obtained from the monocotyledonous rice (Oryza sativa). Recombinant aequorin has been introduced into rice, and the Ca(2+) responses to NaCl and H2O2 in rice roots were characterized. Although rice calcium signal sensor research has just started, the transgenic rice expressing aequorin provides a good platform to study rice adapted to different environmental conditions.
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Affiliation(s)
- Zhiming Yu
- College of Life and Environmental Sciences; Hangzhou Normal University; Hangzhou, China
| | - Jemma L Taylor
- School of Life Sciences; Gibbet Hill Campus; University of Warwick; Coventry, United Kingdom
| | - Yue He
- College of Life and Environmental Sciences; Hangzhou Normal University; Hangzhou, China
| | - Jun Ni
- College of Life and Environmental Sciences; Hangzhou Normal University; Hangzhou, China
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120
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Pónya Z, Corsi I, Hoffmann R, Kovács M, Dobosy A, Kovács AZ, Cresti M, Barnabás B. When isolated at full receptivity, in vitro fertilized wheat (Triticum aestivum, L.) egg cells reveal [Ca2+]cyt oscillation of intracellular origin. Int J Mol Sci 2014; 15:23766-91. [PMID: 25535074 PMCID: PMC4284791 DOI: 10.3390/ijms151223766] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 08/19/2014] [Accepted: 09/25/2014] [Indexed: 11/28/2022] Open
Abstract
During in vitro fertilization of wheat (Triticum aestivum, L.) in egg cells isolated at various developmental stages, changes in cytosolic free calcium ([Ca2+]cyt) were observed. The dynamics of [Ca2+]cyt elevation varied, reflecting the difference in the developmental stage of the eggs used. [Ca2+]cyt oscillation was exclusively observed in fertile, mature egg cells fused with the sperm cell. To determine how [Ca2+]cyt oscillation in mature egg cells is generated, egg cells were incubated in thapsigargin, which proved to be a specific inhibitor of the endoplasmic reticulum (ER) Ca2+-ATPase in wheat egg cells. In unfertilized egg cells, the addition of thapsigargin caused an abrupt transient increase in [Ca2+]cyt in the absence of extracellular Ca2+, suggesting that an influx pathway for Ca2+ is activated by thapsigargin. The [Ca2+]cyt oscillation seemed to require the filling of an intracellular calcium store for the onset of which, calcium influx through the plasma membrane appeared essential. This was demonstrated by omitting extracellular calcium from (or adding GdCl3 to) the fusion medium, which prevented [Ca2+]cyt oscillation in mature egg cells fused with the sperm. Combined, these data permit the hypothesis that the first sperm-induced transient increase in [Ca2+]cyt depletes an intracellular Ca2+ store, triggering an increase in plasma membrane Ca2+ permeability, and this enhanced Ca2+ influx results in [Ca2+]cyt oscillation.
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Affiliation(s)
- Zsolt Pónya
- Department of Plant Production and Plant Protection, Institute of Plant Science, Faculty of Agricultural and Environmental Sciences, Kaposvár University, Kaposvár H-7400, Hungary.
| | - Ilaria Corsi
- Dipartimento di Scienze Ambientali "G. Sarfatti", University of Siena, Siena 53100, Italy.
| | - Richárd Hoffmann
- Department of Plant Production and Plant Protection, Institute of Plant Science, Faculty of Agricultural and Environmental Sciences, Kaposvár University, Kaposvár H-7400, Hungary.
| | - Melinda Kovács
- Institute of Physiology, Biochemistry and Animal Health, Faculty of Agricultural and Environmental Sciences, Kaposvár University, Kaposvár H-7400, Hungary.
| | - Anikó Dobosy
- Department of Plant Production and Plant Protection, Institute of Plant Science, Faculty of Agricultural and Environmental Sciences, Kaposvár University, Kaposvár H-7400, Hungary.
| | - Attila Zoltán Kovács
- Department of Technology of Animal Breeding and Management, Faculty of Agricultural and Environmental Sciences Kaposvár University, Kaposvár H-7400, Hungary.
| | - Mauro Cresti
- Dipartimento di Scienze Ambientali "G. Sarfatti", University of Siena, Siena 53100, Italy.
| | - Beáta Barnabás
- Department of Plant Cell Biology, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Martonvàsàr H-2462, Hungary.
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121
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Tiribuzi R, Tartacca F, Aisa MC, Cerulli GG, Palmerini CA. The impact of nitric oxide on calcium homeostasis in PE/CA-PJ15 cells. Arch Oral Biol 2014; 59:1377-83. [DOI: 10.1016/j.archoralbio.2014.07.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 07/29/2014] [Accepted: 07/30/2014] [Indexed: 11/27/2022]
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122
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Luo FL, Yang N, He C, Li HL, Li C, Chen F, Xiong JX, Hu ZA, Zhang J. Exposure to extremely low frequency electromagnetic fields alters the calcium dynamics of cultured entorhinal cortex neurons. ENVIRONMENTAL RESEARCH 2014; 135:236-246. [PMID: 25462671 DOI: 10.1016/j.envres.2014.09.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 08/25/2014] [Accepted: 09/13/2014] [Indexed: 06/04/2023]
Abstract
Previous studies have revealed that extremely low frequency electromagnetic field (ELF-EMF) exposure affects neuronal dendritic spine density and NMDAR and AMPAR subunit expressions in the entorhinal cortex (EC). Although calcium signaling has a critical role in control of EC neuronal functions, however, it is still unclear whether the ELF-EMF exposure affects the EC neuronal calcium homeostasis. In the present study, using whole-cell recording and calcium imaging, we record the whole-cell inward currents that contain the voltage-gated calcium currents and show that ELF-EMF (50Hz, 1mT or 3mT, lasting 24h) exposure does not influence these currents. Next, we specifically isolate the high-voltage activated (HVA) and low-voltage activated (LVA) calcium channels-induced currents. Similarly, the activation and inactivation characteristics of these membrane calcium channels are also not influenced by ELF-EMF. Importantly, ELF-EMF exposure reduces the maximum amplitude of the high-K(+)-evoked calcium elevation in EC neurons, which is abolished by thapsigargin, a Ca(2+) ATPase inhibitor, to empty the intracellular calcium stores of EC neurons. Together, these findings indicate that ELF-EMF exposure specifically influences the intracellular calcium dynamics of cultural EC neurons via a calcium channel-independent mechanism.
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Affiliation(s)
- Fen-Lan Luo
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China
| | - Nian Yang
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China
| | - Chao He
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China
| | - Hong-Li Li
- Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, PR China
| | - Chao Li
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China
| | - Fang Chen
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China
| | - Jia-Xiang Xiong
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China
| | - Zhi-An Hu
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China.
| | - Jun Zhang
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China.
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123
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Ermakova YG, Bilan DS, Matlashov ME, Mishina NM, Markvicheva KN, Subach OM, Subach FV, Bogeski I, Hoth M, Enikolopov G, Belousov VV. Red fluorescent genetically encoded indicator for intracellular hydrogen peroxide. Nat Commun 2014; 5:5222. [PMID: 25330925 PMCID: PMC4553041 DOI: 10.1038/ncomms6222] [Citation(s) in RCA: 191] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 09/09/2014] [Indexed: 01/10/2023] Open
Abstract
Reactive oxygen species (ROS) are conserved regulators of numerous cellular functions, and overproduction of ROS is a hallmark of various pathological processes. Genetically encoded fluorescent probes are unique tools to study ROS production in living systems of different scale and complexity. However, the currently available recombinant redox sensors have green emission, which overlaps with the spectra of many other probes. Expanding the spectral range of recombinant in vivo ROS probes would enable multiparametric in vivo ROS detection. Here we present the first genetically encoded red fluorescent sensor for hydrogen peroxide detection, HyPerRed. The performance of this sensor is similar to its green analogues. We demonstrate the utility of the sensor by tracing low concentrations of H2O2 produced in the cytoplasm of cultured cells upon growth factor stimulation. Moreover, using HyPerRed we detect local and transient H2O2 production in the mitochondrial matrix upon inhibition of the endoplasmic reticulum Ca(2+) uptake.
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Affiliation(s)
- Yulia G Ermakova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
| | - Dmitry S Bilan
- 1] Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia [2] NBIC, Moscow Institute of Physics and Technology, 123182 Moscow, Russia
| | - Mikhail E Matlashov
- 1] Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia [2] NBIC, Moscow Institute of Physics and Technology, 123182 Moscow, Russia
| | - Natalia M Mishina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
| | | | - Oksana M Subach
- NBIC, Moscow Institute of Physics and Technology, 123182 Moscow, Russia
| | - Fedor V Subach
- NBIC, Moscow Institute of Physics and Technology, 123182 Moscow, Russia
| | - Ivan Bogeski
- Department of Biophysics, School of Medicine, Saarland University, Homburg 66421, Germany
| | - Markus Hoth
- Department of Biophysics, School of Medicine, Saarland University, Homburg 66421, Germany
| | - Grigori Enikolopov
- 1] NBIC, Moscow Institute of Physics and Technology, 123182 Moscow, Russia [2] Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Vsevolod V Belousov
- 1] Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia [2] NBIC, Moscow Institute of Physics and Technology, 123182 Moscow, Russia
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124
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Wu Y, Yang M, Fan J, Peng Y, Deng L, Ding Y, Yang R, Zhou J, Miao D, Fu Q. Deficiency of osteoblastic Arl6ip5 impaired osteoblast differentiation and enhanced osteoclastogenesis via disturbance of ER calcium homeostasis and induction of ER stress-mediated apoptosis. Cell Death Dis 2014; 5:e1464. [PMID: 25321471 PMCID: PMC4237252 DOI: 10.1038/cddis.2014.427] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 08/29/2014] [Accepted: 09/04/2014] [Indexed: 12/15/2022]
Abstract
ADP-ribosylation-like factor 6 interacting protein 5 (Arl6ip5), which belongs to the prenylated rab-acceptor-family, has an important role in exocytic protein trafficking, glutathione metabolism and involves in cancer progression. However, its expression pattern and functional role in bone are unknown. Here we demonstrate that Arl6ip5 knock-out mice (Arl6ip5 (Δ2/Δ2)) show marked decrease of bone mineral density, trabecular bone volume and trabecular thickness. Histomorphometric studies reveal that bone formation parameters are decreased but bone resorption parameters and mRNA level of osteoclast-specific markers are increased in Arl6ip5(Δ2/Δ2) mice. In osteoblast, we demonstrate that Arl6ip5 abundantly expresses in osteoblastic cells and is regulated by bone metabolism-related hormones and growth factors. In vitro analysis reveals that osteoblast proliferation and differentiation are impaired in Arl6ip5 knocked-down and deficient primary osteoblast. Arl6ip5 is also found to function as an ER calcium regulator and control calmodulin signaling for osteoblast proliferation. Moreover, Arl6ip5 insufficiency in osteoblast induces ER stress and enhances ER stress-mediated apoptosis. CCAAT/enhancer-binding protein homologous protein (Chop) is involved in the regulation of apoptosis and differentiation in Arl6ip5 knocked-down osteoblasts. For osteoclastogenesis, Arl6ip5 insufficiency in osteoclast precursors has no effect on osteoclast formation. However, knocked-down osteoblastic Arl6ip5 induces receptor activator of nuclear factor-κB ligand (RANKL) expression and enhances osteoclastogenesis. In addition, ER stress and Chop are involved in the RANKL expression in Arl6ip5 knocked-down osteoblasts. In conclusion, we demonstrate that Arl6ip5 is a novel regulator of bone formation in osteoblasts.
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Affiliation(s)
- Y Wu
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, China
| | - M Yang
- Department of Radiotherapy, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - J Fan
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, China
| | - Y Peng
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, China
| | - L Deng
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, China
| | - Y Ding
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, China
| | - R Yang
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, China
| | - J Zhou
- Department of Molecular Cell Biology and Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
| | - D Miao
- State Key Laboratory of Reproductive Medicine, The Research Center for Bone and Stem Cells, Department of Anatomy, Histology, and Embryology, Nanjing, China
| | - Q Fu
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, China
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125
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Gordon JR, Nelson HM, Virgil SC, Stoltz BM. The total syntheses of basiliolide C, epi-basiliolide C, and protecting-group-free total syntheses of transtaganolides C and D. J Org Chem 2014; 79:9740-7. [PMID: 25244187 DOI: 10.1021/jo501924u] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The total syntheses of basiliolide C and previously unreported epi-basiliolide C are achieved by an Ireland-Claisen/Diels-Alder cascade. The development of a palladium catalyzed cross-coupling of methoxy alkynyl zinc reagents allows for the protecting-group-free syntheses of transtaganolides C and D. Syntheses of transtaganolides C and D are accomplished in a single operation to generate three rings, two all-carbon quaternary centers, and four tertiary stereocenters from a monocyclic, achiral precursor.
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Affiliation(s)
- Jonny R Gordon
- Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, MC 101-20, Pasadena, California 91125, United States
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126
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García-Cabeza AL, Ray LP, Marín-Barrios R, Ortega MJ, Moreno-Dorado FJ, Guerra FM, Massanet GM. Optimization by Response Surface Methodology (RSM) of the Kharasch–Sosnovsky Oxidation of Valencene. Org Process Res Dev 2014. [DOI: 10.1021/op5002462] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ana Leticia García-Cabeza
- Departamento
de Química
Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - Lindsey P. Ray
- Departamento
de Química
Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - Rubén Marín-Barrios
- Departamento
de Química
Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - María J. Ortega
- Departamento
de Química
Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - F. Javier Moreno-Dorado
- Departamento
de Química
Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - Francisco M. Guerra
- Departamento
de Química
Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - Guillermo M. Massanet
- Departamento
de Química
Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
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Park EC, Kim SI, Hong Y, Hwang JW, Cho GS, Cha HN, Han JK, Yun CH, Park SY, Jang IS, Lee ZW, Choi JS, Kim S, Kim GH. Inhibition of CYP4A reduces hepatic endoplasmic reticulum stress and features of diabetes in mice. Gastroenterology 2014; 147:860-9. [PMID: 24983671 DOI: 10.1053/j.gastro.2014.06.039] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 06/20/2014] [Accepted: 06/24/2014] [Indexed: 01/12/2023]
Abstract
BACKGROUND & AIMS Endoplasmic reticulum (ER) stress is implicated in the development of type 2 diabetes mellitus. ER stress activates the unfolded protein response pathway, which contributes to apoptosis and insulin resistance. We investigated the roles of cytochrome P450 4A (CYP4A) in the regulation of hepatic ER stress, insulin resistance, and the development of diabetes in mice. METHODS We used mass spectrometry to compare levels of CYP450 proteins in livers from C57BL/6J and C57BL/KsJ-db/db (db/db) mice; findings were confirmed by immunoblot and real-time PCR analyses. To create a model of diet-induced diabetes, C57BL/6J mice were placed on high-fat diets. Mice were given intraperitoneal injections of an inhibitor (HET0016) or an inducer (clofibrate) of CYP4A, or tail injections of small hairpin RNAs against CYP4A messenger RNA; liver tissues were collected and analyzed for ER stress, insulin resistance, and apoptosis. The effect of HET0016 and CYP4A knockdown also were analyzed in HepG2 cells. RESULTS Levels of the CYP4A isoforms were highly up-regulated in livers of db/db mice compared with C57BL/6J mice. Inhibition of CYP4A in db/db and mice on high-fat diets reduced features of diabetes such as insulin hypersecretion, hepatic steatosis, and increased glucose tolerance. CYP4A inhibition reduced levels of ER stress, insulin resistance, and apoptosis in the livers of diabetic mice; it also restored hepatic functions. Inversely, induction of CYP4A accelerated ER stress, insulin resistance, and apoptosis in livers of db/db mice. CONCLUSIONS CYP4A proteins are up-regulated in livers of mice with genetically induced and diet-induced diabetes. Inhibition of CYP4A in mice reduces hepatic ER stress, apoptosis, insulin resistance, and steatosis. Strategies to reduce levels or activity of CYP4A proteins in liver might be developed for treatment of patients with type 2 diabetes.
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Affiliation(s)
| | - Seung Il Kim
- Division of Life Science, Korea Basic Science Institute, Daejeon, Republic of Korea
| | - Yeonhee Hong
- Division of Life Science, Korea Basic Science Institute, Daejeon, Republic of Korea
| | - Jeong Won Hwang
- Division of Life Science, Korea Basic Science Institute, Daejeon, Republic of Korea
| | - Gun-Sik Cho
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, Kyungbuk, Republic of Korea
| | - Hye-Na Cha
- Department of Physiology, College of Medicine, Yeungnam University, Daegu, Republic of Korea
| | - Jin-Kwan Han
- Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, Kyungbuk, Republic of Korea
| | - Chul-Ho Yun
- School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - So-Young Park
- Department of Physiology, College of Medicine, Yeungnam University, Daegu, Republic of Korea
| | - Ik-Soon Jang
- Division of Life Science, Korea Basic Science Institute, Daejeon, Republic of Korea
| | - Zee-Won Lee
- Division of Life Science, Korea Basic Science Institute, Daejeon, Republic of Korea
| | - Jong-Soon Choi
- Division of Life Science, Korea Basic Science Institute, Daejeon, Republic of Korea; Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, Republic of Korea
| | | | - Gun-Hwa Kim
- Division of Life Science, Korea Basic Science Institute, Daejeon, Republic of Korea; Department of Functional Genomics, University of Science and Technology, Daejeon, Republic of Korea.
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128
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Treinys R, Kaselis A, Jover E, Bagnard D, Šatkauskas S. R-type calcium channels are crucial for semaphorin 3A-induced DRG axon growth cone collapse. PLoS One 2014; 9:e102357. [PMID: 25032951 PMCID: PMC4102519 DOI: 10.1371/journal.pone.0102357] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 06/18/2014] [Indexed: 12/20/2022] Open
Abstract
Semaphorin 3A (Sema3A) is a secreted protein involved in axon path-finding during nervous system development. Calcium signaling plays an important role during axonal growth in response to different guidance cues; however it remains unclear whether this is also the case for Sema3A. In this study we used intracellular calcium imaging to figure out whether Sema3A-induced growth cone collapse is a Ca2+ dependent process. Intracellular Ca2+ imaging results using Fura-2 AM showed Ca2+ increase in E15 mice dorsal root ganglia neurons upon Sema3A treatment. Consequently we analyzed Sema3A effect on growth cones after blocking or modifying intracellular and extracellular Ca2+ channels that are expressed in E15 mouse embryos. Our results demonstrate that Sema3A increased growth cone collapse rate is blocked by the non-selective R- and T- type Ca2+ channel blocker NiCl2 and by the selective R-type Ca2+ channel blocker SNX482. These Ca2+ channel blockers consistently decreased the Sema3A-induced intracellular Ca2+ concentration elevation. Overall, our results demonstrate that Sema3A-induced growth cone collapses are intimately related with increase in intracellular calcium concentration mediated by R-type calcium channels.
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Affiliation(s)
- Rimantas Treinys
- Biophysical Research Group, Biology department, Vytautas Magnus University, Kaunas, Lithuania
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Andrius Kaselis
- Biophysical Research Group, Biology department, Vytautas Magnus University, Kaunas, Lithuania
| | - Emmanuel Jover
- INCI – UPR-CNRS 3212, Neurotransmission et sécrétion neuroendocrine, Strasbourg, France
| | - Dominique Bagnard
- INSERM U1109, MN3t lab, Labex Medalis, University of Strasbourg, Strasbourg, France
| | - Saulius Šatkauskas
- Biophysical Research Group, Biology department, Vytautas Magnus University, Kaunas, Lithuania
- * E-mail:
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129
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Villalta PC, Townsley MI. Transient receptor potential channels and regulation of lung endothelial permeability. Pulm Circ 2014; 3:802-15. [PMID: 25006396 DOI: 10.1086/674765] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 08/22/2013] [Indexed: 12/19/2022] Open
Abstract
This review highlights our current knowledge regarding expression of transient receptor potential (TRP) cation channels in lung endothelium and evidence for their involvement in regulation of lung endothelial permeability. Six mammalian TRP families have been identified and organized on the basis of sequence homology: TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPML (mucolipin), TRPP (polycystin), and TRPA (ankyrin). To date, only TRPC1/4, TRPC6, TRPV4, and TRPM2 have been extensively studied in lung endothelium. Calcium influx through each of these channels has been documented to increase lung endothelial permeability, although their channel-gating mechanisms, downstream signaling mechanisms, and impact on endothelial structure and barrier integrity differ. While other members of the TRPC, TRPV, and TRPM families may be expressed in lung endothelium, we have little or no evidence linking these to regulation of lung endothelial permeability. Further, neither the expression nor functional role(s) of any TRPML, TRPP, and TRPA family members has been studied in lung endothelium. In addition to this assessment organized by TRP channel family, we also discuss TRP channels and lung endothelial permeability from the perspective of lung endothelial heterogeneity, using outcomes of studies focused on TRPC1/4 and TRPV4 channels. The diversity within the TRP channel family and the relative paucity of information regarding roles of a number of these channels in lung endothelium make this field ripe for continued investigation.
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Affiliation(s)
- Patricia C Villalta
- Departments of Physiology and Medicine, Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA
| | - Mary I Townsley
- Departments of Physiology and Medicine, Center for Lung Biology, University of South Alabama, Mobile, Alabama, USA
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130
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Marín-Barrios R, García-Cabeza AL, Moreno-Dorado FJ, Guerra FM, Massanet GM. Acyloxylation of Cyclic Enones: Synthesis of Densely Oxygenated Guaianolides. J Org Chem 2014; 79:6501-9. [DOI: 10.1021/jo500915r] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rubén Marín-Barrios
- Departamento de Química
Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - Ana Leticia García-Cabeza
- Departamento de Química
Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - F. Javier Moreno-Dorado
- Departamento de Química
Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - Francisco M. Guerra
- Departamento de Química
Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - Guillermo M. Massanet
- Departamento de Química
Orgánica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain
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131
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Park HK, Lee JE, Lim J, Kang BH. Mitochondrial Hsp90s suppress calcium-mediated stress signals propagating from mitochondria to the ER in cancer cells. Mol Cancer 2014; 13:148. [PMID: 24924916 PMCID: PMC4070406 DOI: 10.1186/1476-4598-13-148] [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: 03/19/2014] [Accepted: 06/05/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Resistance to cell death in the presence of stressful stimuli is one of the hallmarks of cancer cells acquired during multistep tumorigenesis, and knowledge of the molecular mechanism of stress adaptation can be exploited to develop cancer-selective therapeutics. Mitochondria and the endoplasmic reticulum (ER) are physically interconnected organelles that can sense and exchange various stress signals. Although there have been many studies on stress propagation from the ER to mitochondria, reverse stress signals originating from mitochondria have not been well reported. METHODS After inactivation of the proteins by pharmacologic and genetic methods, the signal pathways were analyzed by fluorescence microscopy, flow cytometry, MTT assay, and western blotting. A mouse xenograft model was used to examine synergistic anticancer activity and the action mechanism of drugs in vivo. RESULTS We show in this study that mitochondrial heat shock protein 90 (Hsp90) suppresses mitochondria-initiated calcium-mediated stress signals propagating into the ER in cancer cells. Mitochondrial Hsp90 inhibition triggers the calcium signal by opening the mitochondrial permeability transition pore and, in turn, the ER ryanodine receptor, via calcium-induced calcium release. Subsequent depletion of ER calcium activates unfolded protein responses in the ER lumen, thereby increasing the expression of a pro-apoptotic transcription factor, CEBP homologous protein (CHOP). Combined treatment with the ER stressor thapsigargin and the mitochondrial Hsp90 inhibitor gamitrinib augmented interorganelle stress signaling by elevating CHOP expression, and showed synergistic cytotoxic activity exclusively in cancer cells in vitro and in vivo. CONCLUSIONS Collectively, mitochondrial Hsp90s confer cell death resistance to cancer cells by suppressing the mitochondria-initiated calcium-mediated interorganelle stress response.
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Affiliation(s)
| | | | | | - Byoung Heon Kang
- Department of Biological Sciences, School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST St,, Ulsan 689-798, South Korea.
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132
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Abstract
Synaptic dysfunction is widely thought to play a key role in the pathogenesis of Alzheimer's disease (AD). Presenilins, the major gene products involved in familial AD, are essential for short- and long-term synaptic plasticity in mature neurons as well as for the survival of cortical neurons during aging. Presenilin and nicastrin are both indispensable components of the γ-secretase complex, but it remains unknown whether presenilin regulates synaptic function in a γ-secretase-dependent or γ-secretase-independent manner and whether nicastrin plays similar roles in central synapses. In the current study, we address these questions using an electrophysiological approach to analyze nicastrin conditional knockout (cKO) mice in the hippocampal Schaffer collateral pathway. In these mice, we found that, even at 2 mo of age, deletion of nicastrin in excitatory neurons of the postnatal forebrain using Cre recombinase expressed under the control of the αCaMKII promoter led to deficits in presynaptic short-term plasticity including paired-pulse facilitation and frequency facilitation. Depletion of Ca(2+) in the endoplasmic reticulum mimics and occludes the presynaptic facilitation deficits in nicastrin cKO mice, suggesting that disrupted intracellular Ca(2+) homeostasis underlies the presynaptic deficits. In addition, NMDA receptor-mediated responses and long-term potentiation induced by theta-burst stimulation were decreased in nicastrin cKO mice at 3 mo but not at 2 mo of age. Together, these findings show that, similar to presenilins, nicastrin plays essential roles in the regulation of short- and long-term synaptic plasticity, highlighting the importance of γ-secretase in the function of mature synapses.
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133
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Ha JH, Shil PK, Zhu P, Gu L, Li Q, Chung S. Ocular inflammation and endoplasmic reticulum stress are attenuated by supplementation with grape polyphenols in human retinal pigmented epithelium cells and in C57BL/6 mice. J Nutr 2014; 144:799-806. [PMID: 24699803 PMCID: PMC6611528 DOI: 10.3945/jn.113.186957] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Inflammation and endoplasmic reticulum (ER) stress are common denominators for vision-threatening diseases such as diabetic retinopathy and age-related macular degeneration. Based on our previous study, supplementation with muscadine grape polyphenols (MGPs) alleviated systemic insulin resistance and proinflammatory responses. In this study, we hypothesized that MGPs would also be effective in attenuating ocular inflammation and ER stress. We tested this hypothesis using the human retinal pigmented epithelium (ARPE-19) cells and C57BL/6 mice. In ARPE-19 cells, tumor necrosis factor-α-induced proinflammatory gene expression of interleukin (IL)-1β, IL-6, and monocyte chemotactic protein-1 was decreased by 35.0%, 68.8%, and 62.5%, respectively, with MGP pretreatment, which was primarily due to the diminished mitogen-activated protein kinase activation and subsequent reduction of nuclear factor κ-B activation. Consistently, acute ocular inflammation and leukocyte infiltration were almost completely dampened (>95%) by MGP supplementation (100-200 mg/kg body weight) in C57BL/6 mice. Moreover, MGPs reduced inflammation-mediated loss of tight junctions and retinal permeability. To further investigate the protective roles of MGPs against ER stress, ARPE-19 cells were stimulated with thapsigargin. Pretreatment with MGPs significantly decreased the following: 1) ER stress-mediated vascular endothelial growth factor secretion (3.47 ± 0.06 vs. 1.58 ± 0.02 μg/L, P < 0.0001), 2) unfolded protein response, and 3) early apoptotic cell death (64.4 ± 6.85 vs. 33.7 ± 4.32%, P = 0.0003). Collectively, we have demonstrated that MGP is effective in attenuating ocular inflammation and ER stress. Our work also suggests that MGP may provide a novel dietary strategy to prevent vision-threatening retinal diseases.
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Affiliation(s)
- Jung-Heun Ha
- Department of Food Science and Human Nutrition, University of Florida,
Gainesville, FL
| | | | - Ping Zhu
- Department of Ophthalmology, University of Florida, Gainesville, FL
| | - Liwei Gu
- Department of Food Science and Human Nutrition, University of Florida,
Gainesville, FL
| | - Qiuhong Li
- Department of Ophthalmology, University of Florida, Gainesville, FL
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134
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Moon SY, Kim HS, Nho KW, Jang YJ, Lee SK. Endoplasmic reticulum stress induces epithelial-mesenchymal transition through autophagy via activation of c-Src kinase. Nephron Clin Pract 2014; 126:127-40. [PMID: 24863135 DOI: 10.1159/000362457] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 03/20/2014] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Endoplasmic reticulum (ER) stress has been implicated in inducing epithelial-mesenchymal transition (EMT). ER stress is also known to induce autophagy. However, it is unclear whether ER stress-induced autophagy contributes to EMT. We hypothesized that ER stress might induce EMT through autophagy via activation of c-Src kinase in tubular epithelial cells. METHOD All experiments were performed using HK-2 cells. Protein expression was measured by Western blot analysis. Immunofluorescence and small interfering RNA (siRNA) experiments were performed. RESULTS Chemical ER stress inducers such as tunicamycin (TM, 0.2 μM) and thapsigargin (TG, 0.2 μM) induced EMT, as shown by upregulation of α-smooth muscle actin and downregulation of E-cadherin. ER stress inhibitors such as 4-PBA and salubrinal suppressed both TM- and TG-induced EMT. TM and TG also induced autophagy, as evidenced by upregulation of LC3-II and beclin-1, which were abolished by pretreatment with ER stress inhibitors. Transfection with siRNA targeting ER stress protein (IRE-1) blocked the TM- or TG-induced EMT and autophagy. Autophagy inhibitors such as 3-methyladenine and bafilomycin inhibited the TM- or TG-induced EMT. Transfection with siRNA targeting autophagy protein (beclin-1) also blocked the TM- or TG-induced EMT. Both TM and TG induced activation of c-Src kinase. Inhibitor of c-Src kinase (PP2) suppressed the TM- or TG-induced autophagy and EMT. CONCLUSION ER stress by TM or TG induced EMT through autophagy via activation of c-Src kinase in tubular epithelial cells.
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Affiliation(s)
- Soo Young Moon
- Department of Internal Medicine, Asan Medical Center, University of Ulsan, Seoul, Korea
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135
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Angelovski G, Gottschalk S, Milošević M, Engelmann J, Hagberg GE, Kadjane P, Andjus P, Logothetis NK. Investigation of a calcium-responsive contrast agent in cellular model systems: feasibility for use as a smart molecular probe in functional MRI. ACS Chem Neurosci 2014; 5:360-9. [PMID: 24712900 DOI: 10.1021/cn500049n] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Responsive or smart contrast agents (SCAs) represent a promising direction for development of novel functional MRI (fMRI) methods for the eventual noninvasive assessment of brain function. In particular, SCAs that respond to Ca(2+) may allow tracking neuronal activity independent of brain vasculature, thus avoiding the characteristic limitations of current fMRI techniques. Here we report an in vitro proof-of-principle study with a Ca(2+)-sensitive, Gd(3+)-based SCA in an attempt to validate its potential use as a functional in vivo marker. First, we quantified its relaxometric response in a complex 3D cell culture model. Subsequently, we examined potential changes in the functionality of primary glial cells following administration of this SCA. Monitoring intracellular Ca(2+) showed that, despite a reduction in the Ca(2+) level, transport of Ca(2+) through the plasma membrane remained unaffected, while stimulation with ATP induced Ca(2+)-transients suggested normal cellular signaling in the presence of low millimolar SCA concentrations. SCAs merely lowered the intracellular Ca(2+) level. Finally, we estimated the longitudinal relaxation times (T1) for an idealized in vivo fMRI experiment with SCA, for extracellular Ca(2+) concentration level changes expected during intense neuronal activity which takes place upon repetitive stimulation. The values we obtained indicate changes in T1 of around 1-6%, sufficient to be robustly detectable using modern MRI methods in high field scanners. Our results encourage further attempts to develop even more potent SCAs and appropriate fMRI protocols. This would result in novel methods that allow monitoring of essential physiological processes at the cellular and molecular level.
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Affiliation(s)
| | | | - Milena Milošević
- Institute
for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Beograd 11000, Serbia
| | | | - Gisela E. Hagberg
- Biomedical
Magnetic Resonance, Department of Radiology, Tübingen University Hospital, 72076 Tübingen, Germany
| | | | - Pavle Andjus
- Institute
for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Beograd 11000, Serbia
| | - Nikos K. Logothetis
- Division
of Imaging Science and Biomedical Engineering, University of Manchester, Manchester M13 9PL, United Kingdom
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136
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Label-free cell phenotypic profiling decodes the composition and signaling of an endogenous ATP-sensitive potassium channel. Sci Rep 2014; 4:4934. [PMID: 24816792 PMCID: PMC4017216 DOI: 10.1038/srep04934] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 04/24/2014] [Indexed: 11/27/2022] Open
Abstract
Current technologies for studying ion channels are fundamentally limited because of their inability to functionally link ion channel activity to cellular pathways. Herein, we report the use of label-free cell phenotypic profiling to decode the composition and signaling of an endogenous ATP-sensitive potassium ion channel (KATP) in HepG2C3A, a hepatocellular carcinoma cell line. Label-free cell phenotypic agonist profiling showed that pinacidil triggered characteristically similar dynamic mass redistribution (DMR) signals in A431, A549, HT29 and HepG2C3A, but not in HepG2 cells. Reverse transcriptase PCR, RNAi knockdown, and KATP blocker profiling showed that the pinacidil DMR is due to the activation of SUR2/Kir6.2 KATP channels in HepG2C3A cells. Kinase inhibition and RNAi knockdown showed that the pinacidil activated KATP channels trigger signaling through Rho kinase and Janus kinase-3, and cause actin remodeling. The results are the first demonstration of a label-free methodology to characterize the composition and signaling of an endogenous ATP-sensitive potassium ion channel.
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137
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The Caenorhabditis elegans HP1 family protein HPL-2 maintains ER homeostasis through the UPR and hormesis. Proc Natl Acad Sci U S A 2014; 111:5956-61. [PMID: 24715729 DOI: 10.1073/pnas.1321698111] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Cellular adaptation to environmental changes and stress relies on a wide range of regulatory mechanisms that are tightly controlled at several levels, including transcription. Chromatin structure and chromatin binding proteins are important factors contributing to the transcriptional response to stress. However, it remains largely unknown to what extent specific chromatin factors influence the response to distinct forms of stress in a developmental context. One of the best characterized stress response pathways is the unfolded protein response (UPR), which is activated by accumulation of misfolded proteins in the endoplasmic reticulum (ER). Here, we show that Caenorhabditis elegans heterochromatin protein like-2 (HPL-2), the homolog of heterochromatin protein 1 (HP1), down-regulates the UPR in the intestine. Inactivation of HPL-2 results in an enhanced resistance to ER stress dependent on the X-box binding protein 1 (XBP-1)/inositol requiring enzyme 1 branch of the UPR and the closely related process of autophagy. Increased resistance to ER stress in animals lacking HPL-2 is associated with increased basal levels of XBP-1 activation and ER chaperone expression under physiological conditions, which may in turn activate an adaptive response known as ER hormesis. HPL-2 expression in intestinal cells is sufficient to rescue stress resistance, whereas expression in neuronal cells negatively influenced the ER stress response through a cell-nonautonomous mechanism. We further show that the retinoblastoma protein homolog LIN-35 and the LIN-13 zinc finger protein act in the same pathway as HPL-2 to limit the ER stress response. Altogether, our results point to multiple functions for HP1 in different cell types to maintain ER homeostasis.
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138
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Abstract
Layer 1 neocortical GABAergic interneurons control the excitability of pyramidal neurons through cell-class-specific direct inhibitory and disynaptic disinhibitory circuitry. The engagement of layer 1 inhibitory circuits during behavior is powerfully controlled by the cholinergic neuromodulatory system. Here we report that acetylcholine (ACh) influences the excitability of layer 1 interneurons in a cell-class and activity-dependent manner. Whole-cell recordings from identified layer 1 interneurons of the rat somatosensory neocortex revealed that brief perisomatic application of ACh excited both neurogliaform cells (NGFCs) and classical-accommodating cells (c-ACs) at rest by the activation of nicotinic receptors. In contrast, under active, action potential firing states, ACh excited c-ACs, but inhibited NGFCs through muscarinic receptor-mediated, IP3 receptor-dependent elevations of intracellular calcium that gated surface-membrane calcium-activated potassium channels. These excitatory and inhibitory actions of ACh could be switched between by brief periods of NGFC action potential firing. Paired recordings demonstrated that cholinergic inhibition of NGFCs disinhibited the apical dendrites of layer 2/3 pyramidal neurons by silencing widespread, GABA(B) receptor-mediated, monosynaptic inhibition. Together, these data suggest that the cholinergic system modulates layer 1 inhibitory circuits in an activity-dependent manner to dynamically control dendritic synaptic inhibition of pyramidal neurons.
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139
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Mehlitz A, Karunakaran K, Herweg JA, Krohne G, van de Linde S, Rieck E, Sauer M, Rudel T. The chlamydial organism Simkania negevensis forms ER vacuole contact sites and inhibits ER-stress. Cell Microbiol 2014; 16:1224-43. [PMID: 24528559 DOI: 10.1111/cmi.12278] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 01/28/2014] [Accepted: 02/05/2014] [Indexed: 01/01/2023]
Abstract
Most intracellular bacterial pathogens reside within membrane-surrounded host-derived vacuoles. Few of these bacteria exploit membranes from the host's endoplasmic reticulum (ER) to form a replicative vacuole. Here, we describe the formation of ER-vacuole contact sites as part of the replicative niche of the chlamydial organism Simkania negevensis. Formation of ER-vacuole contact sites is evolutionary conserved in the distantly related protozoan host Acanthamoeba castellanii. Simkania growth is accompanied by mitochondria associating with the Simkania-containing vacuole (SCV). Super-resolution microscopy as well as 3D reconstruction from electron micrographs of serial ultra-thin sections revealed a single vacuolar system forming extensive ER-SCV contact sites on the Simkania vacuolar surface. Simkania infection induced an ER-stress response, which was later downregulated. Induction of ER-stress with Thapsigargin or Tunicamycin was strongly inhibited in cells infected with Simkania. Inhibition of ER-stress was required for inclusion formation and efficient growth, demonstrating a role of ER-stress in the control of Simkania infection. Thus, Simkania forms extensive ER-SCV contact sites in host species evolutionary as diverse as human and amoeba. Moreover, Simkania is the first bacterial pathogen described to interfere with ER-stress induced signalling to promote infection.
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Affiliation(s)
- Adrian Mehlitz
- University of Wuerzburg, Biocenter, Department of Microbiology, Am Hubland, D-97074, Wuerzburg, Germany
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140
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Influence of external calcium and thapsigargin on the uptake of polystyrene beads by the macrophage-like cell lines U937 and MH-S. BMC Pharmacol Toxicol 2014; 15:16. [PMID: 24646666 PMCID: PMC3994969 DOI: 10.1186/2050-6511-15-16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 03/10/2014] [Indexed: 11/10/2022] Open
Abstract
Background Macrophages are equipped with several receptors for the recognition of foreign particles and pathogens. Upon binding to these receptors, particles become internalized. An interaction of particles with macrophage surface receptors is accompanied by an increase in cytosolic calcium concentration. This calcium is provided by intracellular stores and also by an influx of external calcium upon activation of the calcium channels. Nevertheless, the role of calcium in phagocytosis remains controversial. Some researchers postulate the necessity of calcium in Fc-receptor-mediated phagocytosis and a calcium-independent phagocytosis of complement opsonized particles. Others refute the need for calcium in Fc-receptor-mediated phagocytosis by macrophages. Methods In this study, the influence of external calcium concentrations and thapsigargin on the phagocytosis of polystyrene latex beads by the macrophage-like cell lines MH-S (murine) and differentiated U937 (human) was analyzed. The phagocytosis efficiency was determined by flow cytometry and was evaluated statistically by ANOVA test and Dunett’s significance test, or ANOVA and Bonferroni’s Multiple Comparison. Results Acquired data revealed an external calcium-independent way of internalization of non-functionalized polystyrene latex beads at free calcium concentrations ranging from 0 mM to 3 mM. The phagocytosis efficiency of the cells is not significantly decreased by a complete lack of external calcium. Furthermore, the presence of thapsigargin, known to lead to an increase of cytosolic calcium levels, did not have a significant enhancing influence on bead uptake by MH-S cells and only an enhancing effect on bead uptake by macrophage-like U937 cells at an external calcium concentration of 4 mM. Conclusion The calcium-independent phagocytosis process and the decrease of phagocytosis efficiency in the presence of complement receptor inhibitor staurosporine lead to the assumption that besides other calcium independent receptors, complement receptors are also involved in the uptake of polystyrene beads. The comparison of the phagocytosis efficiencies of both cell types in bivalent cation-free HBSS buffer and in cell medium, leads to the conclusion that it is more likely that other media ingredients such as magnesium are of greater importance for phagocytosis of non-functionalized polystyrene beads than calcium.
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141
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Shintani SA, Oyama K, Kobirumaki-Shimozawa F, Ohki T, Ishiwata S, Fukuda N. Sarcomere length nanometry in rat neonatal cardiomyocytes expressed with α-actinin-AcGFP in Z discs. ACTA ACUST UNITED AC 2014; 143:513-24. [PMID: 24638993 PMCID: PMC3971663 DOI: 10.1085/jgp.201311118] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Nanometry is widely used in biological sciences to analyze the movement of molecules or molecular assemblies in cells and in vivo. In cardiac muscle, a change in sarcomere length (SL) by a mere ∼100 nm causes a substantial change in contractility, indicating the need for the simultaneous measurement of SL and intracellular Ca(2+) concentration ([Ca(2+)]i) in cardiomyocytes at high spatial and temporal resolution. To accurately analyze the motion of individual sarcomeres with nanometer precision during excitation-contraction coupling, we applied nanometry techniques to primary-cultured rat neonatal cardiomyocytes. First, we developed an experimental system for simultaneous nanoscale analysis of single sarcomere dynamics and [Ca(2+)]i changes via the expression of AcGFP in Z discs. We found that the averaging of the lengths of sarcomeres along the myocyte, a method generally used in today's myocardial research, caused marked underestimation of sarcomere lengthening speed because of the superpositioning of different timings for lengthening between sequentially connected sarcomeres. Then, we found that after treatment with ionomycin, neonatal myocytes exhibited spontaneous sarcomeric oscillations (cell-SPOCs) at partial activation with blockage of sarcoplasmic reticulum functions, and the waveform properties were indistinguishable from those obtained in electric field stimulation. The myosin activator omecamtiv mecarbil markedly enhanced Z-disc displacement during cell-SPOC. Finally, we interpreted the present experimental findings in the framework of our mathematical model of SPOCs. The present experimental system has a broad range of application possibilities for unveiling single sarcomere dynamics during excitation-contraction coupling in cardiomyocytes under various settings.
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Affiliation(s)
- Seine A Shintani
- Department of Pure and Applied Physics, Faculty of Science and Engineering, Waseda University, Shinjuku-ku, Tokyo 169-8555, Japan
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142
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Pan Z, Avila A, Gollahon L. Paclitaxel induces apoptosis in breast cancer cells through different calcium--regulating mechanisms depending on external calcium conditions. Int J Mol Sci 2014; 15:2672-94. [PMID: 24549172 PMCID: PMC3958875 DOI: 10.3390/ijms15022672] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 02/10/2014] [Accepted: 02/11/2014] [Indexed: 12/19/2022] Open
Abstract
Previously, we reported that endoplasmic reticulum calcium stores were a direct target for paclitaxel initiation of apoptosis. Furthermore, the actions of paclitaxel attenuated Bcl-2 resistance to apoptosis through endoplasmic reticulum-mediated calcium release. To better understand the calcium-regulated mechanisms of paclitaxel-induced apoptosis in breast cancer cells, we investigated the role of extracellular calcium, specifically; whether influx of extracellular calcium contributed to and/or was necessary for paclitaxel-induced apoptosis. Our results demonstrated that paclitaxel induced extracellular calcium influx. This mobilization of extracellular calcium contributed to subsequent cytosolic calcium elevation differently, depending on dosage. Under normal extracellular calcium conditions, high dose paclitaxel induced apoptosis-promoting calcium influx, which did not occur in calcium-free conditions. In the absence of extracellular calcium an “Enhanced Calcium Efflux” mechanism in which high dose paclitaxel stimulated calcium efflux immediately, leading to dramatic cytosolic calcium decrease, was observed. In the absence of extracellular calcium, high dose paclitaxel’s stimulatory effects on capacitative calcium entry and apoptosis could not be completely restored. Thus, normal extracellular calcium concentrations are critical for high dose paclitaxel-induced apoptosis. In contrast, low dose paclitaxel mirrored controls, indicating that it occurs independent of extracellular calcium. Thus, extracellular calcium conditions only affect efficacy of high dose paclitaxel-induced apoptosis.
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Affiliation(s)
- Zhi Pan
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA.
| | - Andrew Avila
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA.
| | - Lauren Gollahon
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA.
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143
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Paula S, Hofmann E, Burden J, Stanton DT. Novel phenolic inhibitors of the sarco/endoplasmic reticulum calcium ATPase: identification and characterization by quantitative structure–activity relationship modeling and virtual screening. J Enzyme Inhib Med Chem 2014; 30:1-8. [DOI: 10.3109/14756366.2013.866659] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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144
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Nakajima A, Tsuji M, Inagaki M, Tamura Y, Kato M, Niiya A, Usui Y, Oguchi K. Neuroprotective effects of propofol on ER stress-mediated apoptosis in neuroblastoma SH-SY5Y cells. Eur J Pharmacol 2014; 725:47-54. [DOI: 10.1016/j.ejphar.2014.01.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 12/20/2013] [Accepted: 01/07/2014] [Indexed: 11/27/2022]
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145
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Zhang X, Li Y, Ma J, Zhu H, Wang B, Mao M, Xiong L, Li Y, Li Z. Synthesis and insecticidal evaluation of novel anthranilic diamides containing N-substitued nitrophenylpyrazole. Bioorg Med Chem 2014; 22:186-93. [DOI: 10.1016/j.bmc.2013.11.038] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 11/18/2013] [Accepted: 11/19/2013] [Indexed: 11/16/2022]
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146
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Nishiyama K, Azuma YT, Shintaku K, Yoshida N, Nakajima H, Takeuchi T. Evidence that Nitric Oxide Is a Non-Adrenergic Non-Cholinergic Inhibitory Neurotransmitter in the Circular Muscle of the Mouse Distal Colon: A Study on the Mechanism of Nitric Oxide-Induced Relaxation. Pharmacology 2014; 94:99-108. [DOI: 10.1159/000363191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 04/25/2014] [Indexed: 11/19/2022]
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147
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Wang SQ, Niu XL, Liu ZW, Zhu YH, Gao DF. Selenium deficiency is associated with endoplasmic reticulum stress in a rat model of cardiac malfunction. Biol Trace Elem Res 2013; 156:196-201. [PMID: 24081780 DOI: 10.1007/s12011-013-9834-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Accepted: 09/23/2013] [Indexed: 01/02/2023]
Abstract
The relationship between selenium (Se) deficiency-induced cardiac malfunction and endoplasmic reticulum (ER) stress is poorly understood. In the present study, 18 weaning Sprague Dawley rats were randomly fed with three different Se diets, and myocardial glutathione peroxidase (GPx) activity was measured by an enzyme activity assay. Cardiac function was evaluated by hemodynamic parameters. ER stress markers immunoglobulin-binding protein (BiP)/glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) were detected by western blotting. Our data showed that myocardial GPx activity and cardiac function were conspicuously impaired in Se-deficient rats. Expression of GRP78 and CHOP was significantly upregulated by treatment of Se deficiency. Improvements in myocardial GPx activity and cardiac function, as well as decreases in expression of GRP78 and CHOP, were observed after Se supplementation. Consequently, our data show that ER stress was involved in Se deficiency-induced cardiac dysfunction.
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Affiliation(s)
- Su-Qin Wang
- Department of Cardiology, Second Affiliated Hospital, Xi'an Jiaotong University, 157 Road Xiwu, Xi'an, Shaanxi, 710004, People's Republic of China
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Schmeits PCJ, Katika MR, Peijnenburg AACM, van Loveren H, Hendriksen PJM. DON shares a similar mode of action as the ribotoxic stress inducer anisomycin while TBTO shares ER stress patterns with the ER stress inducer thapsigargin based on comparative gene expression profiling in Jurkat T cells. Toxicol Lett 2013; 224:395-406. [PMID: 24247028 DOI: 10.1016/j.toxlet.2013.11.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 11/06/2013] [Accepted: 11/06/2013] [Indexed: 11/17/2022]
Abstract
Previously, we studied the effects of deoxynivalenol (DON) and tributyltin oxide (TBTO) on whole genome mRNA expression profiles of human T lymphocyte Jurkat cells. These studies indicated that DON induces ribotoxic stress and both DON and TBTO induced ER stress which resulted into T-cell activation and apoptosis. The first goal of the present study was to provide final proof for these mode of actions by comparing the effects of 6 h exposure to DON and TBTO on mRNA expression to those of positive controls of ribotoxic stress (anisomycin), ER stress (thapsigargin) and T cell activation (ionomycin). Genes affected by anisomycin and the majority of genes affected by thapsigargin were affected in the same direction by DON and TBTO, respectively, confirming the expected modes of action. Pathway analysis further sustained that DON induces ribotoxic stress and both DON and TBTO induce unfolded protein response (UPR), ER stress, T cell activation and apoptosis. The second goal was to assess whether DON and/or TBTO affect other pathways above those detected before. TBTO induced groups of genes that are involved in DNA packaging and heat shock response that were not affected by thapsigargin. DON did not affect other genes than anisomycin indicating the effect of DON to be restricted to ribotoxic stress. This study also demonstrates that comparative gene expression analysis is a very promising tool for the identification of modes of action of immunotoxic compounds.
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Affiliation(s)
- Peter C J Schmeits
- RIKILT-Institute of Food Safety, Wageningen University and Research Centre, P.O. Box 230, 6700 AE Wageningen, The Netherlands; Department of Toxicogenomics, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
| | - Madhumohan R Katika
- RIKILT-Institute of Food Safety, Wageningen University and Research Centre, P.O. Box 230, 6700 AE Wageningen, The Netherlands; Department of Toxicogenomics, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
| | - Ad A C M Peijnenburg
- RIKILT-Institute of Food Safety, Wageningen University and Research Centre, P.O. Box 230, 6700 AE Wageningen, The Netherlands.
| | - Henk van Loveren
- Department of Toxicogenomics, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands; National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720 BA Bilthoven, The Netherlands.
| | - Peter J M Hendriksen
- RIKILT-Institute of Food Safety, Wageningen University and Research Centre, P.O. Box 230, 6700 AE Wageningen, The Netherlands.
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149
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Jothi M, Mal M, Keller C, Mal AK. Small molecule inhibition of PAX3-FOXO1 through AKT activation suppresses malignant phenotypes of alveolar rhabdomyosarcoma. Mol Cancer Ther 2013; 12:2663-74. [PMID: 24107448 DOI: 10.1158/1535-7163.mct-13-0277] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Alveolar rhabdomyosarcoma comprises a rare highly malignant tumor presumed to be associated with skeletal muscle lineage in children. The hallmark of the majority of alveolar rhabdomyosarcoma is a chromosomal translocation that generates the PAX3-FOXO1 fusion protein, which is an oncogenic transcription factor responsible for the development of the malignant phenotype of this tumor. Alveolar rhabdomyosarcoma cells are dependent on the oncogenic activity of PAX3-FOXO1, and its expression status in alveolar rhabdomyosarcoma tumors correlates with worst patient outcome, suggesting that blocking this activity of PAX3-FOXO1 may be an attractive therapeutic strategy against this fusion-positive disease. In this study, we screened small molecule chemical libraries for inhibitors of PAX3-FOXO1 transcriptional activity using a cell-based readout system. We identified the Sarco/endoplasmic reticulum Ca(2+)-ATPases (SERCA) inhibitor thapsigargin as an effective inhibitor of PAX3-FOXO1. Subsequent experiments in alveolar rhabdomyosarcoma cells showed that activation of AKT by thapsigargin inhibited PAX3-FOXO1 activity via phosphorylation. Moreover, this AKT activation appears to be associated with the effects of thapsigargin on intracellular calcium levels. Furthermore, thapsigargin inhibited the binding of PAX3-FOXO1 to target genes and subsequently promoted its proteasomal degradation. In addition, thapsigargin treatment decreases the growth and invasive capacity of alveolar rhabdomyosarcoma cells while inducing apoptosis in vitro. Finally, thapsigargin can suppress the growth of an alveolar rhabdomyosarcoma xenograft tumor in vivo. These data reveal that thapsigargin-induced activation of AKT is an effective mechanism to inhibit PAX3-FOXO1 and a potential agent for targeted therapy against alveolar rhabdomyosarcoma.
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Affiliation(s)
- Mathivanan Jothi
- Corresponding Author: Asoke K. Mal, Department of Cell Stress Biology, BLSC-L3-319 Roswell Park Cancer Institute Elm and Carlton Streets, Buffalo, NY 14263.
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150
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Bleeker NP, Cornea RL, Thomas DD, Xing C. A novel SERCA inhibitor demonstrates synergy with classic SERCA inhibitors and targets multidrug-resistant AML. Mol Pharm 2013; 10:4358-66. [PMID: 24079514 DOI: 10.1021/mp400458u] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Drug resistance exists as a major obstacle in the treatment of cancer, and drug molecules that retain effectiveness against resistant cancers are a high clinical priority. Ethyl 2-amino-6-(3,5-dimethoxyphenyl)-4-(2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (CXL017) was recently identified as a promising lead for the treatment of multidrug-resistant leukemia, which elicits its cytotoxic effect, in part, through inhibition of the sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA). Herein initial experiments with SERCA1a and CXL017 demonstrated no significant effect on calcium affinity, competed with ATP, and induced a dose-dependent decrease in ATPase activity. Among all CXLs tested, (-)-CXL017 exhibited the greatest SERCA inhibition with an IC50 = 13.5 ± 0.5 μM. Inhibitor combination studies were used to assess potential interactions between (-)-CXL017 and well-known SERCA inhibitors: thapsigargin, cyclopiazonic acid, and 2,5-di-tert-butylhydroquinone. Surprisingly, (-)-CXL017 exhibited marked synergy with each of the known SERCA inhibitors, whereas all combinations of the known inhibitors yielded additive effects, indicating that (-)-CXL017 may bind at a unique allosteric site. Treatment of parental (HL60) and multidrug-resistant (HL60/MX2) acute myeloid leukemia cells with the known SERCA inhibitors revealed that all of these inhibitors demonstrate selective cytotoxicity (7.7-400-fold) for the resistant cell line. Within the CXL series, a positive correlation exists between SERCA inhibition and cytotoxicity in HL60/MX2 but not HL60. (-)-CXL017 was also shown to enhance the cytotoxicity of thapsigargin in HL60/MX2 cells. Given the elevated SERCA levels and ER calcium content in HL60/MX2, SERCA likely plays a significant role in the collateral sensitivity of this multidrug-resistance cell line to CXL molecules as well as known SERCA inhibitors.
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Affiliation(s)
- Nicholas P Bleeker
- Department of Medicinal Chemistry, University of Minnesota , 2231 Sixth St. SE, Minneapolis, Minnesota 55455, United States
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