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Pontisso I, Ornelas-Guevara R, Chevet E, Combettes L, Dupont G. Gradual ER calcium depletion induces a progressive and reversible UPR signaling. PNAS NEXUS 2024; 3:pgae229. [PMID: 38933930 PMCID: PMC11200134 DOI: 10.1093/pnasnexus/pgae229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 05/29/2024] [Indexed: 06/28/2024]
Abstract
The unfolded protein response (UPR) is a widespread signal transduction pathway triggered by endoplasmic reticulum (ER) stress. Because calcium (Ca2+) is a key factor in the maintenance of ER homeostasis, massive Ca2+ depletion of the ER is a potent inducer of ER stress. Although moderate changes in ER Ca2+ drive the ubiquitous Ca2+ signaling pathways, a possible incremental relationship between UPR activation and Ca2+ changes has yet to be described. Here, we determine the sensitivity and time-dependency of activation of the three ER stress sensors, inositol-requiring protein 1 alpha (IRE1α), protein kinase R-like ER kinase (PERK), and activating transcription factor 6 alpha (ATF6α) in response to controlled changes in the concentration of ER Ca2+ in human cultured cells. Combining Ca2+ imaging, fluorescence recovery after photobleaching experiments, biochemical analyses, and mathematical modeling, we uncover a nonlinear rate of activation of the IRE1α branch of UPR, as compared to the PERK and ATF6α branches that become activated gradually with time and are sensitive to more important ER Ca2+ depletions. However, the three arms are all activated within a 1 h timescale. The model predicted the deactivation of PERK and IRE1α upon refilling the ER with Ca2+. Accordingly, we showed that ER Ca2+ replenishment leads to the complete reversion of IRE1α and PERK phosphorylation in less than 15 min, thus revealing the highly plastic character of the activation of the upstream UPR sensors. In conclusion, our results reveal a dynamic and dose-sensitive Ca2+-dependent activation/deactivation cycle of UPR induction, which could tightly control cell fate upon acute and/or chronic stress.
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Affiliation(s)
- Ilaria Pontisso
- U1282 “Calcium Signaling and Microbial Infections”, Institut de Biologie Intégrative de la Cellule (I2BC)—Université Paris-Saclay, Gif-Sur-Yvette 91190, France
| | - Roberto Ornelas-Guevara
- Unit of Theoretical Chronobiology, Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium
| | - Eric Chevet
- Inserm U1242 Université de Rennes, 35000 Rennes, France
- Centre de Lutte Contre le Cancer Eugène Marquis, 35042 Rennes, France
| | - Laurent Combettes
- U1282 “Calcium Signaling and Microbial Infections”, Institut de Biologie Intégrative de la Cellule (I2BC)—Université Paris-Saclay, Gif-Sur-Yvette 91190, France
| | - Geneviève Dupont
- Unit of Theoretical Chronobiology, Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium
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Xi G, Lamba SA, Mysh M, Poulton JS. Oxidative Stress Contributes to Slit Diaphragm Defects Caused by Disruption of Endocytosis. Kidney Int Rep 2024; 9:451-463. [PMID: 38344712 PMCID: PMC10851022 DOI: 10.1016/j.ekir.2023.11.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 10/27/2023] [Accepted: 11/20/2023] [Indexed: 03/04/2024] Open
Abstract
Introduction Podocyte slit diaphragms are an important component of the glomerular filtration barrier. Podocyte injury frequently includes defects in slit diaphragms, and various mechanisms for these defects have been described, including altered endocytic trafficking of slit diaphragm proteins or oxidative stress. However, the potential relationship between endocytosis and oxidative stress in the context of slit diaphragm integrity has not been extensively considered. Methods To examine the potential relationships between endocytosis, oxidative stress, and slit diaphragm integrity, we induced genetic or pharmacological disruption of endocytosis in Drosophila nephrocytes (the insect orthologue of podocytes) and cultured human podocytes. We then employed immunofluorescence microscopy to analyze protein localization and levels, and to quantify signal from reactive oxygen species (ROS) dyes. Immunoprecipitation from podocyte cell lysates was used to examine effects on slit diaphragm protein complex formation (i.e., nephrin/podocin and nephrin/ZO-1). Results Disruption of endocytosis in nephrocytes and podocytes led to slit diaphragm defects, elevated levels of ROS (oxidative stress), and activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant pathway. In nephrocytes with defective endocytosis, perturbation of Nrf2 signaling exacerbated slit diaphragm defects. Conversely, overexpression of Nrf2 target genes catalase or glucose-6-phosphate dehydrogenase (G6PD) significantly ameliorated slit diaphragm defects caused by disruption of endocytosis. Conclusion Oxidative stress is an important consequence of defective endocytosis and contributes to the defects in slit diaphragm integrity associated with disruption of endocytic trafficking.
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Affiliation(s)
- Gang Xi
- UNC Kidney Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Sajan A. Lamba
- UNC Kidney Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Michael Mysh
- UNC Kidney Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - John S. Poulton
- UNC Kidney Center, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Liu J, Yan G, Chen Q, Zeng Q, Wang X. Modified 5-aminolevulinic acid photodynamic therapy (M-PDT) inhibits cutaneous squamous cell carcinoma cell proliferation via targeting PP2A/PP5-mediated MAPK signaling pathway. Int J Biochem Cell Biol 2021; 137:106036. [PMID: 34217813 DOI: 10.1016/j.biocel.2021.106036] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/15/2021] [Accepted: 06/29/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND We previously demonstrated that M-PDT is painless and effective in precancerous skin diseases treatment. However, whether M-PDT is effective in cSCC and the underlying inhibitory mechanism remains enigmatic. OBJECTIVE We aims to unveil the effect of M-PDT on cSCC cell proliferation and the regulatory effect of M-PDT on MAPK signaling. METHODS The proliferation and migration of cSCC cells were revealed by CCK8 assay, tumor sphere formation assay and scratch assay respectively. The expression of MAPKs was examined by western blot. The activity of PP2A and PP5 was regulated by inhibitor and recombinant adenoviruses. RESULTS Here, we show that M-PDT inhibits cSCC cell proliferation by activating p-JNK, p-p38 and inhibiting p-Erk1/2, as well as activation of PP2A and inactivation of PP5. Furthermore, pharmacological inhibition of PP2A conferred resistance to M-PDT's suppression on p-Erk1/2 and attenuated inhibitory effects of M-PDT on cell proliferation whereas overexpression of wild-type PP2A showed the contrary results. Pharmacological inhibition of PP5 potentiated M-PDT's elevation on p-JNK and strengthened inhibitory effects of M-PDT on cell proliferation whereas overexpression of wild-type PP5 exhibited the contrary results. CONCLUSION Our findings indicate that M-PDT inhibits cSCC cell proliferation via targeting PP2A/PP5-mediated MAPK signaling pathway.
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Affiliation(s)
- Jia Liu
- Institute of Photomedicine, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai 200092, China
| | - Guorong Yan
- Institute of Photomedicine, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai 200092, China
| | - Qi Chen
- Institute of Photomedicine, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai 200092, China
| | - Qingyu Zeng
- Institute of Photomedicine, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai 200092, China.
| | - Xiuli Wang
- Institute of Photomedicine, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai 200092, China.
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Gibhardt CS, Cappello S, Bhardwaj R, Schober R, Kirsch SA, Bonilla Del Rio Z, Gahbauer S, Bochicchio A, Sumanska M, Ickes C, Stejerean-Todoran I, Mitkovski M, Alansary D, Zhang X, Revazian A, Fahrner M, Lunz V, Frischauf I, Luo T, Ezerina D, Messens J, Belousov VV, Hoth M, Böckmann RA, Hediger MA, Schindl R, Bogeski I. Oxidative Stress-Induced STIM2 Cysteine Modifications Suppress Store-Operated Calcium Entry. Cell Rep 2020; 33:108292. [PMID: 33086068 DOI: 10.1016/j.celrep.2020.108292] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 08/28/2020] [Accepted: 09/29/2020] [Indexed: 12/12/2022] Open
Abstract
Store-operated calcium entry (SOCE) through STIM-gated ORAI channels governs vital cellular functions. In this context, SOCE controls cellular redox signaling and is itself regulated by redox modifications. However, the molecular mechanisms underlying this calcium-redox interplay and the functional outcomes are not fully understood. Here, we examine the role of STIM2 in SOCE redox regulation. Redox proteomics identify cysteine 313 as the main redox sensor of STIM2 in vitro and in vivo. Oxidative stress suppresses SOCE and calcium currents in cells overexpressing STIM2 and ORAI1, an effect that is abolished by mutation of cysteine 313. FLIM and FRET microscopy, together with MD simulations, indicate that oxidative modifications of cysteine 313 alter STIM2 activation dynamics and thereby hinder STIM2-mediated gating of ORAI1. In summary, this study establishes STIM2-controlled redox regulation of SOCE as a mechanism that affects several calcium-regulated physiological processes, as well as stress-induced pathologies.
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Affiliation(s)
- Christine Silvia Gibhardt
- Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Sabrina Cappello
- Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Rajesh Bhardwaj
- Department of Nephrology and Hypertension, Inselspital, University of Bern, Bern, Switzerland
| | - Romana Schober
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria; Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Sonja Agnes Kirsch
- Computational Biology, Department of Biology, Friedrich-Alexander University of Erlangen-Nürnberg, Germany
| | - Zuriñe Bonilla Del Rio
- Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Stefan Gahbauer
- Computational Biology, Department of Biology, Friedrich-Alexander University of Erlangen-Nürnberg, Germany
| | - Anna Bochicchio
- Computational Biology, Department of Biology, Friedrich-Alexander University of Erlangen-Nürnberg, Germany
| | - Magdalena Sumanska
- Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Christian Ickes
- Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Ioana Stejerean-Todoran
- Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Miso Mitkovski
- Light Microscopy Facility, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Dalia Alansary
- Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Xin Zhang
- Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Aram Revazian
- Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Marc Fahrner
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Victoria Lunz
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Irene Frischauf
- Institute of Biophysics, JKU Life Science Center, Johannes Kepler University Linz, Linz, Austria
| | - Ting Luo
- VIB-VUB Center for Structural Biology, Brussels Center for Redox Biology, Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Daria Ezerina
- VIB-VUB Center for Structural Biology, Brussels Center for Redox Biology, Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Joris Messens
- VIB-VUB Center for Structural Biology, Brussels Center for Redox Biology, Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Vsevolod Vadimovich Belousov
- Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany; Pirogov Russian National Research Medical University, Moscow, Russia; Federal Center of Brain Research and Neurotechnologies of the Federal Medical Biological Agency, Moscow, Russia
| | - Markus Hoth
- Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Rainer Arnold Böckmann
- Computational Biology, Department of Biology, Friedrich-Alexander University of Erlangen-Nürnberg, Germany
| | | | - Rainer Schindl
- Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria.
| | - Ivan Bogeski
- Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany.
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Chamorro ME, Maltaneri R, Schiappacasse A, Nesse A, Vittori D. Role of protein tyrosine phosphatase 1B (PTP1B) in the increased sensitivity of endothelial cells to a promigratory effect of erythropoietin in an inflammatory environment. Biol Chem 2020; 401:1167-1180. [PMID: 32386183 DOI: 10.1515/hsz-2020-0136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 05/04/2020] [Indexed: 11/15/2022]
Abstract
The proliferation and migration of endothelial cells are vascular events of inflammation, a process which can also potentiate the effects of promigratory factors. With the aim of investigating possible modifications in the activity of erythropoietin (Epo) in an inflammatory environment, we found that Epo at a non-promigratory concentration was capable of stimulating EA.hy926 endothelial cell migration when TNF-α was present. VCAM-1 and ICAM-1 expression, as well as adhesion of monocytic THP-1 cells to endothelial layers were also increased. Structurally modified Epo (carbamylation or N-homocysteinylation) did not exhibit these effects. The sensitizing effect of TNF-α on Epo activity was mediated by the Epo receptor. Inhibition assays targeting the PI3K/mTOR/NF-κB pathway, shared by Epo and TNF-α, show a cross-talk between both cytokines. As observed in assays using antioxidants, cell migration elicited by TNF-α + Epo depended on TNF-α-generated reactive oxygen species (ROS). ROS-mediated inactivation of protein tyrosine phosphatase 1B (PTP1B), involved in Epo signaling termination, could explain the synergistic effect of these cytokines. Our results suggest that ROS generated by inflammation inactivate PTP1B, causing the Epo signal to last longer. This mechanism, along with the cross-talk between both cytokines, could explain the sensitizing action of TNF-α on the migratory effect of Epo.
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Affiliation(s)
- María Eugenia Chamorro
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto del Departamento de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Ciudad Autónoma de Buenos Aires, C1428EHA, Argentina
| | - Romina Maltaneri
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto del Departamento de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Ciudad Autónoma de Buenos Aires, C1428EHA, Argentina
| | - Agustina Schiappacasse
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto del Departamento de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Ciudad Autónoma de Buenos Aires, C1428EHA, Argentina
| | - Alcira Nesse
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto del Departamento de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Ciudad Autónoma de Buenos Aires, C1428EHA, Argentina
| | - Daniela Vittori
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto del Departamento de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Ciudad Autónoma de Buenos Aires, C1428EHA, Argentina
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Palma FR, He C, Danes JM, Paviani V, Coelho DR, Gantner BN, Bonini MG. Mitochondrial Superoxide Dismutase: What the Established, the Intriguing, and the Novel Reveal About a Key Cellular Redox Switch. Antioxid Redox Signal 2020; 32:701-714. [PMID: 31968997 PMCID: PMC7047081 DOI: 10.1089/ars.2019.7962] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Significance: Reactive oxygen species (ROS) are now widely recognized as central mediators of cell signaling. Mitochondria are major sources of ROS. Recent Advances: It is now clear that mitochondrial ROS are essential to activate responses to cellular microenvironmental stressors. Mediators of these responses reside in large part in the cytosol. Critical Issues: The primary form of ROS produced by mitochondria is the superoxide radical anion. As a charged radical anion, superoxide is restricted in its capacity to diffuse and convey redox messages outside of mitochondria. In addition, superoxide is a reductant and not particularly efficient at oxidizing targets. Because there are many opportunities for superoxide to be neutralized in mitochondria, it is not completely clear how redox cues generated in mitochondria are converted into diffusible signals that produce transient oxidative modifications in the cytosol or nucleus. Future Directions: To efficiently intervene at the level of cellular redox signaling, it seems that understanding how the generation of superoxide radicals in mitochondria is coupled with the propagation of redox messages is essential. We propose that mitochondrial superoxide dismutase (SOD2) is a major system converting diffusion-restricted superoxide radicals derived from the electron transport chain into highly diffusible hydrogen peroxide (H2O2). This enables the coupling of metabolic changes resulting in increased superoxide to the production of H2O2, a diffusible secondary messenger. As such, to determine whether there are other systems coupling metabolic changes to redox messaging in mitochondria as well as how these systems are regulated is essential.
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Affiliation(s)
- Flavio R Palma
- Division of Endocrinology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Chenxia He
- Division of Endocrinology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Jeanne M Danes
- Division of Endocrinology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Veronica Paviani
- Division of Endocrinology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Diego R Coelho
- Division of Endocrinology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Benjamin N Gantner
- Division of Endocrinology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Marcelo G Bonini
- Division of Endocrinology, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin.,Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin
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The Effects of Ibogaine on Uterine Smooth Muscle Contractions: Relation to the Activity of Antioxidant Enzymes. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:5969486. [PMID: 29599898 PMCID: PMC5828116 DOI: 10.1155/2018/5969486] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 12/28/2017] [Indexed: 11/21/2022]
Abstract
Ibogaine is an indole alkaloid originally extracted from the root bark of the African rainforest shrub Tabernanthe iboga. It has been explored as a treatment for substance abuse because it interrupts drug addiction and relieves withdrawal symptoms. However, it has been shown that ibogaine treatment leads to a sharp and transient fall in cellular ATP level followed by an increase of cellular respiration and ROS production. Since contractile tissues are sensitive to changes in the levels of ATP and ROS, here we investigated an ibogaine-mediated link between altered redox homeostasis and uterine contractile activity. We found that low concentrations of ibogaine stimulated contractile activity in spontaneously active uteri, but incremental increase of doses inhibited it. Inhibitory concentrations of ibogaine led to decreased SOD1 and elevated GSH-Px activity, but doses that completely inhibited contractions increased CAT activity. Western blot analyses showed that changes in enzyme activities were not due to elevated enzyme protein concentrations but posttranslational modifications. Changes in antioxidant enzyme activities point to a vast concentration-dependent increase in H2O2 level. Knowing that extracellular ATP stimulates isolated uterus contractility, while H2O2 has an inhibitory effect, this concentration-dependent stimulation/inhibition could be linked to ibogaine-related alterations in ATP level and redox homeostasis.
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8
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Jung HJ, Im SS, Song DK, Bae JH. Effects of chlorogenic acid on intracellular calcium regulation in lysophosphatidylcholine-treated endothelial cells. BMB Rep 2018; 50:323-328. [PMID: 28088946 PMCID: PMC5498143 DOI: 10.5483/bmbrep.2017.50.6.182] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Indexed: 12/31/2022] Open
Abstract
Lysophosphatidylcholine (LPC) is a major phospholipid component of oxidized low-density lipoprotein (ox-LDL) and is implicated in its atherogenic activity. This study investigated the effects of LPC on cell viability, intracellular calcium homeostasis, and the protective mechanisms of chlorogenic acid (CGA) in human umbilical vein endothelial cells (HUVECs). LPC increased intracellular calcium ([Ca2+]i) by releasing Ca2+ from intracellular stores and via Ca2+ influx through store-operated channels (SOCs). LPC also increased the generation of reactive oxygen species (ROS) and decreased cell viability. The mRNA expression of Transient receptor potential canonical (TRPC) channel 1 was increased significantly by LPC treatment and suppressed by CGA. CGA inhibited LPC-induced Ca2+ influx and ROS generation, and restored cell viability. These results suggested that CGA inhibits SOC-mediated Ca2+ influx and ROS generation by attenuating TRPC1 expression in LPC-treated HUVECs. Therefore, CGA might protect endothelial cells against LPC injury, thereby inhibiting atherosclerosis.
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Affiliation(s)
- Hye-Jin Jung
- Department of Physiology, Keimyung University School of Medicine, Daegu 42601, Korea
| | - Seung-Soon Im
- Department of Physiology, Keimyung University School of Medicine, Daegu 42601, Korea
| | - Dae-Kyu Song
- Department of Physiology, Keimyung University School of Medicine, Daegu 42601, Korea
| | - Jae-Hoon Bae
- Department of Physiology, Keimyung University School of Medicine, Daegu 42601, Korea
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9
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The interplay between p16 serine phosphorylation and arginine methylation determines its function in modulating cellular apoptosis and senescence. Sci Rep 2017; 7:41390. [PMID: 28120917 PMCID: PMC5264599 DOI: 10.1038/srep41390] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 12/20/2016] [Indexed: 01/09/2023] Open
Abstract
Cyclin-dependent kinase inhibitor p16INK4a (p16) primarily functions as a negative regulator of the retinoblastoma protein (Rb) -E2F pathway, thus plays critical role in cell cycle progression, cellular senescence and apoptosis. In this study, we showed that the methylation of Arg 138 and the phosphorylation of Ser 140 on p16 were critical for the control of cell proliferation and apoptosis. Compared to wild type p16, mutant p16R138K possessed improved function in preventing cell proliferation and inducing apoptosis, while the Ser 140 mutation (p16S140A) exhibited the opposite alteration. We also demonstrated that H2O2 was able to induce the phosphorylation of p16, which facilitated the interaction between CDK4 (Cyclin-dependent protein kinase) and p16, in 293T (human emborynic kidney) cells. Furthermore, the elevated arginine methylation in p16S140A mutant and increased serine phosphorylation in p16R138K mutant suggest that a antagonizing mechanism coordinating Arg 138 methylation and Ser 140 phosphorylation to regulates p16 function as well as cellular apoptosis and senescence. These findings will therefore contribute to therapeutic treatment for p16-related gene therapy by providing theoretical and experimental evidence.
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10
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Anguita E, Villalobo A. Src-family tyrosine kinases and the Ca 2+ signal. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:915-932. [PMID: 27818271 DOI: 10.1016/j.bbamcr.2016.10.022] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/25/2016] [Accepted: 10/30/2016] [Indexed: 01/08/2023]
Abstract
In this review, we shall describe the rich crosstalk between non-receptor Src-family kinases (SFKs) and the Ca2+ transient generated in activated cells by a variety of extracellular and intracellular stimuli, resulting in diverse signaling events. The exchange of information between SFKs and Ca2+ is reciprocal, as it flows in both directions. These kinases are main actors in pathways leading to the generation of the Ca2+ signal, and reciprocally, the Ca2+ signal modulates SFKs activity and functions. We will cover how SFKs participate in the generation of the cytosolic Ca2+ rise upon activation of a series of receptors and the mechanism of clearance of this Ca2+ signal. The role of SFKs modulating Ca2+-translocating channels participating in these events will be amply discussed. Finally, the role of the Ca2+ sensor protein calmodulin on the activity of c-Src, and potentially on other SFKs, will be outlined as well. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech.
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Affiliation(s)
- Estefanía Anguita
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, c/ Arturo Duperier 4, E-28029 Madrid, Spain
| | - Antonio Villalobo
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, c/ Arturo Duperier 4, E-28029 Madrid, Spain.
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11
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Sato T, Kaneko YK, Sawatani T, Noguchi A, Ishikawa T. Obligatory Role of Early Ca(2+) Responses in H2O2-Induced β-Cell Apoptosis. Biol Pharm Bull 2016; 38:1599-605. [PMID: 26424020 DOI: 10.1248/bpb.b15-00396] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Our previous study using apoptosis analysis suggested that Ca(2+) release through inositol 1,4,5-trisphosphate (IP3) receptors and the subsequent Ca(2+) influx through store-operated channels (SOCs) constitute a triggering signal for H2O2-induced β-cell apoptosis. In the present study, we further examined the obligatory role of early Ca(2+) responses in β-cell apoptosis induction. H2O2 induced elevation of the cytosolic Ca(2+) concentration ([Ca(2+)]c) consisting of two phases: an initial transient [Ca(2+)]c elevation within 30 min and a slowly developing one thereafter. The first phase was almost abolished by 2-aminoethoxydiphenylborate (2-APB), which blocks IP3 receptors and cation channels including SOCs, while the second phase was only partially inhibited by 2-APB. The inhibition by 2-APB of the second phase was not observed when 2-APB was added 30 min after the treatment with H2O2. 2-APB also largely inhibited elevation of the mitochondrial Ca(2+) concentration ([Ca(2+)]m) induced by H2O2 when 2-APB was applied simultaneously with H2O2, but not when applied 30 min after H2O2 application. In addition, 2-APB inhibited the release of mitochondrial cytochrome c to the cytosol induced by H2O2 when 2-APB was applied simultaneously with H2O2 but not 30 min post-treatment. H2O2-induced [Ca(2+)]m elevation and cell death were not inhibited by Ru360, an inhibitor of the mitochondrial calcium uniporter (MCU). These results suggest that the H2O2-induced initial [Ca(2+)]c elevation, occurring within 30 min and mediated by Ca(2+) release through IP3 receptors and subsequent Ca(2+) influx through SOCs, leads to [Ca(2+)]m elevation, possibly through a mechanism independent of MCU, thereby inducing cytochrome c release and consequent apoptosis.
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Affiliation(s)
- Taiji Sato
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, University of Shizuoka
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Gibhardt CS, Zimmermann KM, Zhang X, Belousov VV, Bogeski I. Imaging calcium and redox signals using genetically encoded fluorescent indicators. Cell Calcium 2016; 60:55-64. [PMID: 27142890 DOI: 10.1016/j.ceca.2016.04.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 04/23/2016] [Accepted: 04/25/2016] [Indexed: 12/30/2022]
Abstract
Calcium and redox signals are presently established as essential regulators of many cellular processes. Nevertheless, we are still far from fully understanding the physiological and pathological importance of these universal second messengers. It is becoming increasingly apparent that many cellular functions are not regulated by global changes in the abundance of Ca(2+) ions and/or reactive oxygen and nitrogen species (ROS and RNS), but by the formation of transient local micro-domains or by signaling limited to a particular cellular compartment. Therefore, it is essential to identify and quantify Ca(2+) and redox signals in single cells with a high spatial and temporal resolution. The best tools for this purpose are the genetically encoded fluorescent indicators (GEFI). These protein sensors can be targeted into different cellular compartments, feature different colors, can be used to establish transgenic animal models, and are relatively inert to the cellular environment. Based on the chemical properties of Ca(2+) and ROS/RNS, currently more sensors exist for the detection of Ca(2+)- than for redox signals. Here, we shortly describe the most popular genetically encoded fluorescent Ca(2+) and redox indicators, discuss advantages and disadvantages based on our experience, show examples of different applications, and thus provide a brief guide that will help scientists choose the right combination of Ca(2+) and redox sensors to answer specific scientific questions.
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Affiliation(s)
- Christine S Gibhardt
- Department of Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany
| | - Katharina M Zimmermann
- Department of Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany
| | - Xin Zhang
- Department of Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany
| | | | - Ivan Bogeski
- Department of Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany.
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13
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Majewski L, Kuznicki J. SOCE in neurons: Signaling or just refilling? BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1940-52. [DOI: 10.1016/j.bbamcr.2015.01.019] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 01/22/2015] [Accepted: 01/26/2015] [Indexed: 01/14/2023]
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14
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Redox regulation of T-cell receptor signaling. Biol Chem 2015; 396:555-68. [DOI: 10.1515/hsz-2014-0312] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 02/27/2015] [Indexed: 11/15/2022]
Abstract
Abstract
T-cell receptor (TCR) triggering by antigens activates a sophisticated intracellular signaling network leading to transcriptional activation, proliferation and differentiation of T cells. These events ultimately culminate in adaptive immune responses. Over recent years it has become evident that reactive oxygen species (ROS) play an important role in T-cell activation. It is now clear that ROS are involved in the regulation of T-cell mediated physiological and pathological processes. Upon TCR triggering, T cells produce oxidants, which originate from different cellular sources. In addition, within inflamed tissues, T cells are exposed to exocrine ROS produced by activated phagocytes or other ROS-producing cells. Oxidative modifications can have different effects on T-cell function. Indeed, they can stimulate T-cell activation but they can be also detrimental. These opposite effects of oxidation likely depend on different factors such as ROS concentration and source and also on the differentiation status of the T cells. Despite the well-stablished fact that ROS represent important modulators of T-cell activation, the precise molecular mechanisms of their action are far from clear. Here, we summarize the present knowledge on redox regulation of T-cell function with a particular emphasis on the redox regulation of TCR signaling.
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Mittal M, Urao N, Hecquet CM, Zhang M, Sudhahar V, Gao XP, Komarova Y, Ushio-Fukai M, Malik AB. Novel role of reactive oxygen species-activated Trp melastatin channel-2 in mediating angiogenesis and postischemic neovascularization. Arterioscler Thromb Vasc Biol 2015; 35:877-87. [PMID: 25675998 DOI: 10.1161/atvbaha.114.304802] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Transient receptor potential melastatin-2 (TRPM2) channel is a nonselective cation channel that mediates influx of Ca(2+) and Na(+) with relative permeability of PCa:PNa ≈0.6 in response to cellular oxidative stress. As angiogenesis and ischemic neovascularization are both significantly dependent on oxidant signaling, here we investigated the possible role of vascular endothelial growth factor (VEGF)-induced reactive oxygen species production in activating TRPM2-dependent Ca(2+) signaling and in the mechanism of angiogenesis and ischemic neovascularization. APPROACH AND RESULTS We observed that VEGF stimulation rapidly induced the association of TRPM2 and cellular Src kinase with vascular endothelial-cadherin forming a signalplex at vascular endothelial-cadherin junctions in endothelial cells. Using endothelial cells isolated from TRPM2(-/-) mice or after small interfering RNA depletion of TRPM2, we demonstrated that TRPM2-activated Ca(2+) signaling was required for cellular Src kinase-induced phosphorylation of vascular endothelial-cadherin at Y658 and Y731, the crucial sites involved in vascular endothelial-cadherin internalization in response to VEGF. VEGF-induced reactive oxygen species generation activated TRPM2-induced Ca(2+) entry, whereas the reactive oxygen species-insensitive TRPM2 mutant (C1008→A) showed impaired Ca(2+) entry. Endothelial cells depleted of TRPM2 also displayed significantly perturbed migratory phenotype and impaired activation of cellular Src in response to VEGF. TRPM2(-/-) mice reconstituted with wild-type myeloid cells demonstrated aberrant angiogenesis and neovascularization in the hindlimb ischemia model as compared with wild-type mice. CONCLUSIONS VEGF-induced angiogenesis and postischemic neovascularization in mice required reactive oxygen species generation in endothelial cells and resultant TRPM2 activation. Thus, our findings provide novel insight into the role of TRPM2 in mechanism of angiogenesis and ischemic neovascularization.
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Affiliation(s)
- Manish Mittal
- From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago
| | - Norifumi Urao
- From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago
| | - Claudie M Hecquet
- From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago
| | - Min Zhang
- From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago
| | - Varadarajan Sudhahar
- From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago
| | - Xiao-Pei Gao
- From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago
| | - Yulia Komarova
- From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago
| | - Masuko Ushio-Fukai
- From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago
| | - Asrar B Malik
- From the Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago.
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Liu W, Liu MR, Zhang H. Novel calcium ion channels TRPV5 and TRPV6 and gastrointestinal tumors. Shijie Huaren Xiaohua Zazhi 2014; 22:1966-1971. [DOI: 10.11569/wcjd.v22.i14.1966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Transient receptor potential cation channel, subfamily V, member 5 (TRPV5) and TRPV6 are the subfamily members of the transient receptor potential (TRP), representing new highly selective Ca2+ membrane transport channels, which are mainly responsible for active transport of Ca2+ across the cell membrane and participate in regulation of many physiological activities in the body. This paper discusses the structures and electrophysiological properties of TRPV5 and TRPV6, their related factors and their relationship with gastrointestinal tumors, highlighting the role of TRPV5 and TRPV6 in the formation of gastrointestinal tumors.
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Cabigas EB, Liu J, Boopathy AV, Che PL, Crawford BH, Baroi G, Bhutani S, Shen M, Wagner MB, Davis ME. Dysregulation of catalase activity in newborn myocytes during hypoxia is mediated by c-Abl tyrosine kinase. J Cardiovasc Pharmacol Ther 2014; 20:93-103. [PMID: 24831254 DOI: 10.1177/1074248414533746] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In the adult heart, catalase (CAT) activity increases appropriately with increasing levels of hydrogen peroxide, conferring cardioprotection. This mechanism is absent in the newborn for unknown reasons. In the present study, we examined how the posttranslational modification of CAT contributes to its activation during hypoxia/ischemia and the role of c-Abl tyrosine kinase in this process. Hypoxia studies were carried out using primary cardiomyocytes from adult (>8 weeks) and newborn rats. Following hypoxia, the ratio of phosphorylated to total CAT and c-Abl in isolated newborn rat myocytes did not increase and were significantly lower (1.3- and 4.2-fold, respectively; P < .05) than their adult counterparts. Similarly, there was a significant association (P < .0005) between c-Abl and CAT in adult cells following hypoxia (30.9 ± 8.2 to 70.7 ± 13.1 au) that was absent in newborn myocytes. Although ubiquitination of CAT was higher in newborns compared to adults following hypoxia, inhibition of this did not improve CAT activity. When a c-Abl activator (5-(1,3-diaryl-1H-pyrazol-4-yl)hydantoin [DPH], 200 µmol/L) was administered prior to hypoxia, not only CAT activity was significantly increased (P < .05) but also phosphorylation levels were also significantly improved (P < .01) in these newborn myocytes. Additionally, ischemia-reperfusion (IR) studies were performed using newborn (4-5 days) rabbit hearts perfused in a Langendorff method. The DPH given as an intracardiac injection into the right ventricle of newborn rabbit resulted in a significant improvement (P < .002) in the recovery of developed pressure after IR, a key indicator of cardiac function (from 74.6% ± 6.6% to 118.7% ± 10.9%). In addition, CAT activity was increased 3.92-fold (P < .02) in the same DPH-treated hearts. Addition of DPH to adult rabbits in contrast had no significant effect (from 71.3% ± 10.7% to 59.4% ± 12.1%). Therefore, in the newborn, decreased phosphorylation of CAT by c-Abl potentially mediates IR-induced dysfunction, and activation of c-Abl may be a strategy to prevent ischemic injury associated with surgical procedures.
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Affiliation(s)
- E Bernadette Cabigas
- Wallace H. Coulter Department of Biomedical Engineering at Emory University and Georgia Institute of Technology, Atlanta, GA, USA Division of Cardiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Jie Liu
- Wallace H. Coulter Department of Biomedical Engineering at Emory University and Georgia Institute of Technology, Atlanta, GA, USA Division of Cardiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Archana V Boopathy
- Wallace H. Coulter Department of Biomedical Engineering at Emory University and Georgia Institute of Technology, Atlanta, GA, USA Division of Cardiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Pao Lin Che
- Wallace H. Coulter Department of Biomedical Engineering at Emory University and Georgia Institute of Technology, Atlanta, GA, USA Division of Cardiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Brian H Crawford
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA Emory+Children's Center for Cardiovascular Biology, Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - Gitangali Baroi
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA Emory+Children's Center for Cardiovascular Biology, Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - Srishti Bhutani
- Wallace H. Coulter Department of Biomedical Engineering at Emory University and Georgia Institute of Technology, Atlanta, GA, USA Division of Cardiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Ming Shen
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA Emory+Children's Center for Cardiovascular Biology, Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - Mary B Wagner
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA Emory+Children's Center for Cardiovascular Biology, Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - Michael E Davis
- Wallace H. Coulter Department of Biomedical Engineering at Emory University and Georgia Institute of Technology, Atlanta, GA, USA Division of Cardiology, Emory University School of Medicine, Atlanta, GA, USA Emory+Children's Center for Cardiovascular Biology, Children's Healthcare of Atlanta, Atlanta, GA, USA
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18
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Bonini MG, Consolaro MEL, Hart PC, Mao M, de Abreu ALP, Master AM. Redox control of enzymatic functions: The electronics of life's circuitry. IUBMB Life 2014; 66:167-181. [PMID: 24668617 DOI: 10.1002/iub.1258] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 03/06/2014] [Indexed: 12/22/2022]
Abstract
The field of redox biology has changed tremendously over the past 20 years. Formerly regarded as bi-products of the aerobic metabolism exclusively involved in tissue damage, reactive oxygen species (ROS) are now recognized as active participants of cell signaling events in health and in disease. In this sense, ROS and the more recently defined reactive nitrogen species (RNS) are, just like hormones and second messengers, acting as fundamental orchestrators of cell signaling pathways. The chemical modification of enzymes by ROS and RNS (that result in functional enzymatic alterations) accounts for a considerable fraction of the transient and persistent perturbations imposed by variations in oxidant levels. Upregulation of ROS and RNS in response to stress is a common cellular response that foments adaptation to a variety of physiologic alterations (hypoxia, hyperoxia, starvation, and cytokine production). Frequently, these are beneficial and increase the organisms' resistance against subsequent acute stress (preconditioning). Differently, the sustained ROS/RNS-dependent rerouting of signaling produces irreversible alterations in cellular functioning, often leading to pathogenic events. Thus, the duration and reversibility of protein oxidations define whether complex organisms remain "electronically" healthy. Among the 20 essential amino acids, four are particularly susceptible to oxidation: cysteine, methionine, tyrosine, and tryptophan. Here, we will critically review the mechanisms, implications, and repair systems involved in the redox modifications of these residues in proteins while analyzing well-characterized prototypic examples. Occasionally, we will discuss potential consequences of amino acid oxidation and speculate on the biologic necessity for such events in the context of adaptative redox signaling. © 2014 IUBMB Life, 66(3):167-181, 2014.
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Affiliation(s)
- Marcelo G Bonini
- Department of Medicine, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.,Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.,Department of Pathology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.,Programa de Biociencias Aplicadas a Farmacia (PBF), Universidade Estadual de Maringa, Maringa, Parana, Brazil
| | - Marcia E L Consolaro
- Programa de Biociencias Aplicadas a Farmacia (PBF), Universidade Estadual de Maringa, Maringa, Parana, Brazil
| | - Peter C Hart
- Department of Medicine, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.,Department of Pathology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Mao Mao
- Department of Medicine, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.,Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.,Department of Pathology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Andre Luelsdorf Pimenta de Abreu
- Department of Medicine, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.,Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.,Department of Pathology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.,Programa de Biociencias Aplicadas a Farmacia (PBF), Universidade Estadual de Maringa, Maringa, Parana, Brazil
| | - Alyssa M Master
- Department of Medicine, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.,Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.,Department of Pathology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
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Nemoto S, Matsumoto T, Taguchi K, Kobayashi T. Relationships among protein tyrosine phosphatase 1B, angiotensin II, and insulin-mediated aortic responses in type 2 diabetic Goto-Kakizaki rats. Atherosclerosis 2014; 233:64-71. [PMID: 24529124 DOI: 10.1016/j.atherosclerosis.2013.12.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 11/26/2013] [Accepted: 12/09/2013] [Indexed: 10/25/2022]
Abstract
OBJECTIVE We investigated the relationships among protein tyrosine phosphatase 1B (PTP1B), angiotensin II (Ang II), and insulin signaling in the presence of endothelial dysfunction in type 2 diabetic Goto-Kakizaki (GK) rat aortas. METHODS AND RESULTS Aortas isolated from GK or control Wistar rats were examined in the presence or absence of Ang II with or without a selective antagonist of the Ang II type 1 (AT1) receptor or a PTP1B inhibitor to evaluate vascular functional and molecular mechanisms, such as insulin-induced relaxation, nitric oxide (NO) production, phosphorylation of insulin receptor substrate (IRS)-1, endothelial NO synthase (eNOS), and phosphorylation, and the subcellular localization of PTP1B. GK aortas exhibited reductions of: 1) insulin-induced relaxation, 2) NO production, 3) Ser(1177)-p-eNOS, and 4) Tyr(612)-p-IRS-1. Pre-incubation with a PTP1B inhibitor normalized these reductions. In Wistar aortas, the four above-mentioned parameters were reduced by Ang II, but were completely inhibited by co-treatment with the PTP1B inhibitor. The membrane expression of PTP1B was greater in GK than in Wistar aortas, and it was increased by Ang II in Wistar rats. The membrane PTP1B expression in the presence of insulin + Ang II was reduced by the PTP1B inhibitor or AT1-receptor antagonist. CONCLUSIONS These results suggest that the membrane PTP1B suppressed insulin-mediated aortic relaxation, and this was due to the Ang II-AT1-receptor signaling pathway. The inhibition of PTP1B warrants further investigation as a potential therapeutic target for endothelial dysfunction in type 2 diabetes.
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Affiliation(s)
- Shingo Nemoto
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Takayuki Matsumoto
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Kumiko Taguchi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Tsuneo Kobayashi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
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Oh MH, Wu X, Huber SC. Impact of Ca(2+) on structure of soybean CDPKβ and accessibility of the Tyr-24 autophosphorylation site. PLANT SIGNALING & BEHAVIOR 2013; 8:e27671. [PMID: 24394563 PMCID: PMC4091344 DOI: 10.4161/psb.27671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 12/24/2013] [Accepted: 12/27/2013] [Indexed: 05/09/2023]
Abstract
Several plant CDPKs were recently shown to be dual specificity kinases rather than Ser/Thr kinases as traditionally classified by sequence analysis. In the present study we confirm the autophosphorylation of recombinant soybean His 6-GmCDPKβ at the Tyr-24 site using sequence- and modification- specific antibodies. Homology modeling of soybean CDPKβ based on recent structures determined for several apicomplexan CDPKs suggested that phosphotyrosine-24 may be inaccessible to phosphatases. However, we report that dephosphorylation of CDPKβ by the protein tyrosine phosphatase 1B, PTP1B, was not restricted in the presence of calcium. Thus, despite conformational changes likely associated with calcium binding to the CDPKs, phosphotyrosine sites remain fully accessible to dephosphorylation suggesting the possibility of conformational breathing and flexing.
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Affiliation(s)
- Man-Ho Oh
- Department of Plant Biology; University of Illinois; Urbana, IL USA
- Department of Biological Science; College of Biological Sciences and Biotechnology; Chungnam National University; Daejeon, South Korea
| | - Xia Wu
- Department of Genome Sciences; University of Washington; Seattle, WA USA
| | - Steven C Huber
- Department of Plant Biology; University of Illinois; Urbana, IL USA
- US Department of Agriculture; Agricultural Research Service; Urbana, IL USA
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21
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Schernthaner M, Leitinger G, Wolinski H, Kohlwein SD, Reisinger B, Barb RA, Graier WF, Heitz J, Groschner K. Enhanced Ca 2+Entry and Tyrosine Phosphorylation Mediate Nanostructure-Induced Endothelial Proliferation. JOURNAL OF NANOMATERIALS 2013; 2013:251063. [PMID: 24729782 PMCID: PMC3982206 DOI: 10.1155/2013/251063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Nanostructured substrates have been recognized to initiate transcriptional programs promoting cell proliferation. Specifically β-catenin has been identified as transcriptional regulator, activated by adhesion to nanostructures. We set out to identify processes responsible for nanostructure-induced endothelial β-catenin signaling. Transmission electron microscopy (TEM) of cell contacts to differently sized polyethylene terephthalate (PET) surface structures (ripples with 250 to 300 nm and walls with 1.5 μm periodicity) revealed different patterns of cell-substrate interactions. Cell adhesion to ripples occurred exclusively on ripple peaks, while cells were attached to walls continuously. The Src kinase inhibitor PP2 was active only in cells grown on ripples, while the Abl inhibitors dasatinib and imatinib suppressed β-catenin translocation on both structures. Moreover, Gd3+ sensitive Ca2+ entry was observed in response to mechanical stimulation or Ca2+ store depletion exclusively in cells grown on ripples. Both PP2 and Gd3+ suppressed β-catenin nuclear translocation along with proliferation in cells grown on ripples but not on walls. Our results suggest that adhesion of endothelial cells to ripple structured PET induces highly specific, interface topology-dependent changes in cellular signalling, characterized by promotion of Gd3+ -sensitive Ca2+ entry and Src/Abl activation. We propose that these signaling events are crucially involved in nanostructure-induced promotion of cell proliferation.
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Affiliation(s)
| | - Gerd Leitinger
- Department of Cell Biology, Histology and Embryology, Core Facility Ultrastructure Analysis, Center for Medical Research, Medical University Graz, 8010 Graz, Austria
| | - Heimo Wolinski
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Sepp D. Kohlwein
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Bettina Reisinger
- Institute of Applied Physics, Johannes Kepler University Linz, 4040 Linz, Austria
| | - Ruxandra-A. Barb
- Institute of Applied Physics, Johannes Kepler University Linz, 4040 Linz, Austria
| | - Wolfgang F. Graier
- Institute of Molecular Biology and Biochemistry, Medical University Graz, 8010 Graz, Austria
| | - Johannes Heitz
- Institute of Applied Physics, Johannes Kepler University Linz, 4040 Linz, Austria
| | - Klaus Groschner
- Institute of Biophysics, Medical University Graz, 8010 Graz, Austria
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Huang YY, Nagata K, Tedford CE, McCarthy T, Hamblin MR. Low-level laser therapy (LLLT) reduces oxidative stress in primary cortical neurons in vitro. JOURNAL OF BIOPHOTONICS 2013; 6:829-38. [PMID: 23281261 PMCID: PMC3651776 DOI: 10.1002/jbio.201200157] [Citation(s) in RCA: 214] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Revised: 11/13/2012] [Accepted: 11/26/2012] [Indexed: 05/18/2023]
Abstract
Low-level laser (light) therapy (LLLT) involves absorption of photons being in the mitochondria of cells leading to improvement in electron transport, increased mitochondrial membrane potential (MMP), and greater ATP production. Low levels of reactive oxygen species (ROS) are produced by LLLT in normal cells that are beneficial. We exposed primary cultured murine cortical neurons to oxidative stressors: hydrogen peroxide, cobalt chloride and rotenone in the presence or absence of LLLT (3 J/cm², CW, 810 nm wavelength laser, 20 mW/cm²). Cell viability was determined by Prestoblue™ assay. ROS in mitochondria was detected using Mito-sox, while ROS in cytoplasm was detected with CellRox™. MMP was measured with tetramethylrhodamine. In normal neurons LLLT elevated MMP and increased ROS. In oxidatively-stressed cells LLLT increased MMP but reduced high ROS levels and protected cultured cortical neurons from death. Although LLLT increases ROS in normal neurons, it reduces ROS in oxidatively-stressed neurons. In both cases MMP is increased. These data may explain how LLLT can reduce clinical oxidative stress in various lesions while increasing ROS in cells in vitro.
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Affiliation(s)
- Ying-Ying Huang
- Wellman Center for Photomedicine, Massachusetts General Hospital, 40 Blossom Street, Boston MA 02114, USA
- Department of Dermatology, Harvard Medical School, Boston MA, USA
- Department of Pathology, Guangxi Medical University, Nanning, Guangxi, China
| | - Kazuya Nagata
- Wellman Center for Photomedicine, Massachusetts General Hospital, 40 Blossom Street, Boston MA 02114, USA
- Graduate School of Medicine, University of Tokyo, Japan
| | | | | | - Michael R. Hamblin
- Wellman Center for Photomedicine, Massachusetts General Hospital, 40 Blossom Street, Boston MA 02114, USA
- Department of Dermatology, Harvard Medical School, Boston MA, USA
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
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Souza LR, Silva E, Calloway E, Cabrera C, McLemore ML. G-CSF activation of AKT is not sufficient to prolong neutrophil survival. J Leukoc Biol 2013; 93:883-93. [PMID: 23559492 DOI: 10.1189/jlb.1211591] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Neutrophils play an important role in the innate immune response against bacterial and fungal infections. They have a short lifespan in circulation, and their survival can be modulated by several cytokines, including G-CSF. Previous studies have implicated AKT as a critical signaling intermediary in the regulation of neutrophil survival. Our results demonstrate that G-CSF activation of AKT is not sufficient to prolong neutrophil survival. Neutrophils treated with G-CSF undergo apoptosis, even in the presence of high levels of p-AKT. In addition, inhibitors of AKT and downstream targets failed to alter neutrophil survival. In contrast, neutrophil precursors appear to be dependent on AKT signaling pathways for survival, whereas high levels of p-AKT inhibit proliferation. Our data suggest that the AKT/mTOR pathway, although important in G-CSF-driven myeloid differentiation, proliferation, and survival of early hematopoietic progenitors, is less essential in G-CSF suppression of neutrophil apoptosis. Whereas basal AKT levels may be required for the brief life of neutrophils, further p-AKT expression is not able to extend the neutrophil lifespan in the presence of G-CSF.
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Affiliation(s)
- Liliana R Souza
- Winship Cancer Institute, Department of Hematology and Oncology, Emory University, Atlanta, GA 30322, USA.
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24
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Store-operated Ca2+ entry in hippocampal neurons: Regulation by protein tyrosine phosphatase PTP1B. Cell Calcium 2012; 53:125-38. [PMID: 23218930 DOI: 10.1016/j.ceca.2012.11.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 10/12/2012] [Accepted: 11/04/2012] [Indexed: 11/20/2022]
Abstract
Store operated Ca(2+) entry (SOCE) replenishes intracellular Ca(2+) stores and activates a number of intracellular signalling pathways. Whilst several molecular components forming store operated Ca(2+) channels (SOCC) have been identified, their modulation in neurons remains poorly understood. Here, we extend on our previous findings and show that neuronal SOCE is modulated by tyrosine phosphorylation. Cyclopiazonic acid induced SOCE was characterised in hippocampal cultures derived from forebrain specific protein tyrosine phosphatase 1B knockout (PTP1B KO) mice and wild type (WT) litter mates using Fura-2 Ca(2+) imaging. PTP1B KO cultures expressed elevated SOCE relative to WT cultures without changes in cytoplasmic Ca(2+) homeostasis or depolarisation-induced Ca(2+) influx. WT and PTP1B KO cultures displayed similar pharmacological sensitivities towards the SOCE inhibitors gadolinium and 2-aminoethoxydiphenyl borate, as well as the tyrosine kinase inhibitor Ag126 indicating an augmentation of native SOCCs by PTP1B. Following store depletion WT culture homogenates showed heightened phospho-tyrosine levels, an increase in Src tyrosine kinase activation and two minor PTP1B species. These data suggest tyrosine phosphorylation gating SOCE, and implicate PTP1B as a key regulatory enzyme. The involvement of PTP1B in SOCE and its relation to SOCC components and mechanism of regulation are discussed.
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25
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Spatiotemporal regulation of Src and its substrates at invadosomes. Eur J Cell Biol 2012; 91:878-88. [PMID: 22823952 DOI: 10.1016/j.ejcb.2012.06.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 06/19/2012] [Accepted: 06/19/2012] [Indexed: 01/07/2023] Open
Abstract
In the past decade, substantial progress has been made in understanding how Src family kinases regulate the formation and function of invadosomes. Invadosomes are organized actin-rich structures that contain an F-actin core surrounded by an adhesive ring and mediate invasive migration. Src kinases orchestrate, either directly or indirectly, each phase of the invadosome life cycle including invadosome assembly, maturation and matrix degradation and disassembly. Complex arrays of Src effector proteins are involved at different stages of invadosome maturation and their spatiotemporal activity must be tightly regulated to achieve effective invasive migration. In this review, we highlight some recent progress and the challenges of understanding how Src is regulated temporally and spatially to orchestrate the dynamics of invadosomes and mediate cell invasion.
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26
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Zhang H, Liu H, Borok Z, Davies KJ, Ursini F, Forman HJ. Cigarette smoke extract stimulates epithelial-mesenchymal transition through Src activation. Free Radic Biol Med 2012; 52:1437-42. [PMID: 22342303 PMCID: PMC3312989 DOI: 10.1016/j.freeradbiomed.2012.01.024] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Revised: 01/20/2012] [Accepted: 01/26/2012] [Indexed: 12/18/2022]
Abstract
Epithelial-mesenchymal transition (EMT) is implicated in the pathogenesis of lung fibrosis and cancer metastasis, two conditions associated with cigarette smoke (CS). CS has been reported to promote the EMT process. CS is the major cause of lung cancer and nearly half of lung cancer patients are active smokers. Nonetheless, the mechanism whereby CS induces EMT remains largely unknown. In this study we investigated the induction of EMT by CS and explored the underlying mechanisms in the human non-small-cell lung carcinoma (H358) cell line. We demonstrate that exposure to an extract of CS (CSE) decreases E-cadherin and increases N-cadherin and vimentin, markers of EMT, in H358 cells cultured in RPMI 1640 medium with 1% fetal bovine serum. Pretreatment with N-acetylcysteine (NAC), a potent antioxidant and precursor of glutathione, abrogated changes in these EMT markers. In addition, CSE activated Src kinase (shown as increased phosphorylation of Src at Tyr418), and the Src kinase inhibitor PP2 inhibited CS-stimulated EMT changes, suggesting that Src is critical in CSE-stimulated EMT induction. Furthermore, NAC treatment abrogated CSE-stimulated Src activation. However, co-incubation with catalase had no effect on CSE-mediated Src activation. Finally, acrolein, an unsaturated aldehyde present in CSE, caused Src activation. Taken together, these data suggest that CSE initiates EMT through Src, which is activated by CS through redox modification.
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Affiliation(s)
- Hongqiao Zhang
- Andrus Gerontology Center, Davis School of Gerontology, University of Southern California
| | - Honglei Liu
- Andrus Gerontology Center, Davis School of Gerontology, University of Southern California
| | - Zea Borok
- Will Rogers Institute Pulmonary Research Center, Division of Pulmonary and Critical Care Medicine, Department of Medicine, Keck School of Medicine, University of Southern California
| | - Kelvin J.A. Davies
- Andrus Gerontology Center, Davis School of Gerontology, University of Southern California
- Division of Molecular & Computational Biology, Dornsife College of Letters, Arts, and Sciences, University of Southern California
| | - Fulvio Ursini
- Dipartmento di Chimica Biologica, Università di Padova
| | - Henry Jay Forman
- Andrus Gerontology Center, Davis School of Gerontology, University of Southern California
- School of Natural Science, University of California, Merced
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27
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Bogeski I, Kappl R, Kummerow C, Gulaboski R, Hoth M, Niemeyer BA. Redox regulation of calcium ion channels: Chemical and physiological aspects. Cell Calcium 2011; 50:407-23. [DOI: 10.1016/j.ceca.2011.07.006] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 07/26/2011] [Indexed: 02/07/2023]
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28
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Zimmerman MC, Takapoo M, Jagadeesha DK, Stanic B, Banfi B, Bhalla RC, Miller FJ. Activation of NADPH oxidase 1 increases intracellular calcium and migration of smooth muscle cells. Hypertension 2011; 58:446-53. [PMID: 21810651 DOI: 10.1161/hypertensionaha.111.177006] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Redox-dependent migration and proliferation of vascular smooth muscle cells (SMCs) are central events in the development of vascular proliferative diseases; however, the underlying intracellular signaling mechanisms are not fully understood. We tested the hypothesis that activation of Nox1 NADPH oxidase modulates intracellular calcium ([Ca(2+)](i)) levels. Using cultured SMCs from wild-type and Nox1 null mice, we confirmed that thrombin-dependent generation of reactive oxygen species requires Nox1. Thrombin rapidly increased [Ca(2+)](i), as measured by fura-2 fluorescence ratio imaging, in wild-type but not Nox1 null SMCs. The increase in [Ca(2+)](i) in wild-type SMCs was inhibited by antisense to Nox1 and restored by expression of Nox1 in Nox1 null SMCs. Investigation into potential mechanisms by which Nox1 modulates [Ca(2+)](i) showed that thrombin-induced inositol triphosphate generation and thapsigargin-induced intracellular calcium mobilization were similar in wild-type and Nox1 null SMCs. To examine the effects of Nox1 on Ca(2+) entry, cells were either bathed in Ca(2+)-free medium or exposed to dihydropyridines to block L-type Ca(2+) channel activity. Treatment with nifedipine or removal of extracellular Ca(2+) reduced the thrombin-mediated increase of [Ca(2+)](i) in wild-type SMCs, whereas the response in Nox1 null SMCs was unchanged. Sodium vanadate, an inhibitor of protein tyrosine phosphatases, restored the thrombin-induced increase of [Ca(2+)](i) in Nox1 null SMCs. Migration of SMCs was impaired with deficiency of Nox1 and restored with expression of Nox1 or the addition of sodium vanadate. In summary, we conclude that Nox1 NADPH oxidase modulates Ca(2+) mobilization in SMCs, in part through regulation of Ca(2+) influx, to thereby promote cell migration.
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Affiliation(s)
- Matthew C Zimmerman
- Jr, University of Iowa, 285 Newton Rd, Room 2269 CBRB, Iowa City, IA 52242, USA
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29
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Chacon PJ, Garcia-Mejias R, Rodriguez-Tebar A. Inhibition of RhoA GTPase and the subsequent activation of PTP1B protects cultured hippocampal neurons against amyloid β toxicity. Mol Neurodegener 2011; 6:14. [PMID: 21294893 PMCID: PMC3038970 DOI: 10.1186/1750-1326-6-14] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Accepted: 02/04/2011] [Indexed: 11/10/2022] Open
Abstract
Background Amyloid beta (Aβ) is the main agent responsible for the advent and progression of Alzheimer's disease. This peptide can at least partially antagonize nerve growth factor (NGF) signalling in neurons, which may be responsible for some of the effects produced by Aβ. Accordingly, better understanding the NGF signalling pathway may provide clues as to how to protect neurons from the toxic effects of Aβ. Results We show here that Aβ activates the RhoA GTPase by binding to p75NTR, thereby preventing the NGF-induced activation of protein tyrosine phosphatase 1B (PTP1B) that is required for neuron survival. We also show that the inactivation of RhoA GTPase and the activation of PTP1B protect cultured hippocampal neurons against the noxious effects of Aβ. Indeed, either pharmacological inhibition of RhoA with C3 ADP ribosyl transferase or the transfection of cultured neurons with a dominant negative form of RhoA protects cultured hippocampal neurons from the effects of Aβ. In addition, over-expression of PTP1B also prevents the deleterious effects of Aβ on cultured hippocampal neurons. Conclusion Our findings indicate that potentiating the activity of NGF at the level of RhoA inactivation and PTP1B activation may represent a new means to combat the noxious effects of Aβ in Alzheimer's disease.
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Affiliation(s)
- Pedro J Chacon
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Americo Vespucio s/n, Isla de la Cartuja, 41092 Seville, Spain.
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30
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Cheng WY, Tong H, Miller EW, Chang CJ, Remington J, Zucker RM, Bromberg PA, Samet JM, Hofer TP. An integrated imaging approach to the study of oxidative stress generation by mitochondrial dysfunction in living cells. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:902-8. [PMID: 20413366 PMCID: PMC2920907 DOI: 10.1289/ehp.0901811] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Accepted: 04/22/2010] [Indexed: 05/13/2023]
Abstract
BACKGROUND The mechanisms of action of many environmental agents commonly involve oxidative stress resulting from mitochondrial dysfunction. Zinc is a common environmental metallic contaminant that has been implicated in a variety of oxidant-dependent toxicological responses. Unlike ions of other transition metals such as iron, copper, and vanadium, Zn(2+) does not generate reactive oxygen species (ROS) through redox cycling. OBJECTIVE To characterize the role of oxidative stress in zinc-induced toxicity. METHODS We used an integrated imaging approach that employs the hydrogen peroxide (H2O2)-specific fluorophore Peroxy Green 1 (PG1), the mitochondrial potential sensor 5,5 ,6,6 -tetrachloro-1,1 ,3,3 -tetraethylbenzimidazolylcarbocyanine iodide (JC-1), and the mitochondria-targeted form of the redox-sensitive genetically encoded fluorophore MTroGFP1 in living cells. RESULTS Zinc treatment in the presence of the Zn(2+) ionophore pyrithione of A431 skin carcinoma cells preloaded with the H(2)O(2)-specific indicator PG1 resulted in a significant increase in H(2)O(2) production that could be significantly inhibited with the mitochondrial inhibitor carbonyl cyanide 3-chlorophenylhydrazone. Mitochondria were further implicated as the source of zinc-induced H(2)O(2) formation by the observation that exposure to zinc caused a loss of mitochondrial membrane potential. Using MTroGFP1, we showed that zinc exposure of A431 cells induces a rapid loss of reducing redox potential in mitochondria. We also demonstrated that zinc exposure results in rapid swelling of mitochondria isolated from mouse hearts. CONCLUSION Taken together, these findings show a disruption of mitochondrial integrity, H(2)O(2) formation, and a shift toward positive redox potential in cells exposed to zinc. These data demonstrate the utility of real-time, live-cell imaging to study the role of oxidative stress in toxicological responses.
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Affiliation(s)
- Wan-Yun Cheng
- Department of Environmental Sciences and Engineering, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA
| | - Haiyan Tong
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Chapel Hill, North Carolina, USA
| | - Evan W. Miller
- Department of Chemistry and the Howard Hughes Medical Institute, University of California–Berkeley, Berkeley, California, USA
| | - Christopher J. Chang
- Department of Chemistry and the Howard Hughes Medical Institute, University of California–Berkeley, Berkeley, California, USA
| | - James Remington
- Department of Physics, Institute of Molecular Biology, University of Oregon, Eugene, Oregon, USA
| | - Robert M. Zucker
- Toxicology Assessment Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Philip A. Bromberg
- Center for Environmental Medicine and Lung Biology, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA
| | - James M. Samet
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Chapel Hill, North Carolina, USA
- Address correspondence to J.M. Samet, 104 Mason Farm Rd., EPA Human Studies Facility, Chapel Hill, NC 27599-7315 USA. Telephone: (919) 966-0665. Fax: (919) 962-6271. E-mail:
| | - Thomas P.J. Hofer
- Helmholtz Zentrum München, German Research Center for Environmental Health, Clinical Cooperation Group Inflammatory Lung Diseases, Gauting, Germany
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31
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Kummerow C, Junker C, Kruse K, Rieger H, Quintana A, Hoth M. The immunological synapse controls local and global calcium signals in T lymphocytes. Immunol Rev 2009; 231:132-47. [DOI: 10.1111/j.1600-065x.2009.00811.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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32
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Pouokam E, Rehn M, Diener M. Effects of H2O2 at rat myenteric neurones in culture. Eur J Pharmacol 2009; 615:40-9. [DOI: 10.1016/j.ejphar.2009.04.066] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2009] [Revised: 04/21/2009] [Accepted: 04/29/2009] [Indexed: 02/07/2023]
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33
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Albert Christophersen O, Haug A. More about hypervirulent avian influenza: Is the world now better prepared? MICROBIAL ECOLOGY IN HEALTH AND DISEASE 2009. [DOI: 10.1080/08910600701343286] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
| | - Anna Haug
- Norwegian University of Life Science (UMB), Arboretveien, Ås, Norway
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34
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Colli-Dulá R, Zúñiga-Aguilar JJ, Albores-Medina A, Zapata-Perez O. Identification of genes expressed as a result of lindane exposure in Oreochromis niloticus using differential display. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2009; 72:1406-1412. [PMID: 19403169 DOI: 10.1016/j.ecoenv.2009.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Revised: 03/23/2009] [Accepted: 03/25/2009] [Indexed: 05/27/2023]
Abstract
In order to assess the effect of lindane exposure on gene expression in tilapia (Oreochromis niloticus), twenty male fish were individually weighted and injected intraperitoneally with a single dose of lindane (19.09 mg/kg bw) using corn oil as a carrier vehicle, while a second group of twenty male fish (controls) was only injected with the carrier vehicle. Groups of four fish each were then sacrificed at 3, 6, 12, 18 and 24h after treatment application and total RNA was extracted from liver tissue. The differential display (DD) technique was then used to identify differentially expressed cDNA fragments between treatment and control fish. A total of fifty cDNA fragments were isolated and sequenced, from which only four showed homology with genes previously described in other fish species, namely the immunoglobulin heavy chain (IgH), coagulation factor V (FV), casein kinase 2 alpha (CK2a), and the receptor protein-tyrosine-like phosphatase (RPT-LP). The expression of such genes was confirmed using quantitative real time-polymerase chain reaction (QRT-PCR). Results showed that lindane exposure triggered the differential expression of these genes during the first 6, 18 and 24h subsequent to treatment application, suggesting that lindane exposure can trigger a rapid immune system response in tilapias.
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Affiliation(s)
- Reyna Colli-Dulá
- Departamento de Recursos del Mar, Cinvestav Unidad Merida, Merida, Yucatan, Mexico
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35
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Vriens J, Appendino G, Nilius B. Pharmacology of Vanilloid Transient Receptor Potential Cation Channels. Mol Pharmacol 2009; 75:1262-79. [DOI: 10.1124/mol.109.055624] [Citation(s) in RCA: 307] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
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36
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Mueller AS, Klomann SD, Wolf NM, Schneider S, Schmidt R, Spielmann J, Stangl G, Eder K, Pallauf J. Redox regulation of protein tyrosine phosphatase 1B by manipulation of dietary selenium affects the triglyceride concentration in rat liver. J Nutr 2008; 138:2328-36. [PMID: 19022953 DOI: 10.3945/jn.108.089482] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Protein tyrosine phosphatase 1B (PTP1B) is a key enzyme in the counter-regulation of insulin signaling and in the stimulation of fatty acid synthesis. Selenium (Se), via the activities of glutathione peroxidase (GPx) and thioredoxin reductase (TrxR), is involved in the removal of H(2)O(2) and organic peroxides, which are critical compounds in the modulation of PTP1B activity via glutathionylation. Our study with growing rats investigated how the manipulation of dietary Se concentration influences the regulation of PTP1B and lipogenic effects mediated by PTP1B. Weanling albino rats were divided into 3 groups of 10. The negative control group (NC) was fed a Se-deficient diet for 8 wk. Rats in groups Se75 and Se150 received diets supplemented with 75 or 150 microg Se/kg. Se supplementation of the rats strongly influenced expression and activity of the selenoenzymes cytosolic GPx, plasma GPx, phospholipidhydroperoxide GPx, and cytosolic TrxR, and liver PTP1B. Liver PTP1B activity was significantly higher in groups Se75 and Se150 than in the NC group and this was attributed to a lowered inhibition of the enzyme by glutathionylation. The increased liver PTP1B activity in groups Se75 and Se150 resulted in 1.1- and 1.4-fold higher liver triglyceride concentrations than in the NC rats. The upregulation of the sterol regulatory element binding protein-1c and of fatty acid synthase, 2 PTP1B targets, provided a possible explanation for the lipogenic effect of PTP1B due to the manipulation of dietary Se. We therefore conclude that redox-regulated proteins, such as PTP1B, represent important interfaces between dietary antioxidants such as Se and the regulation of metabolic processes.
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Affiliation(s)
- Andreas S Mueller
- Institute of Agricultural and Nutritional Sciences, Preventive Nutrition Group, Martin Luther University Halle Wittenberg, Halle, Saale, Germany.
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37
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Sly LM, Kalesnikoff J, Lam V, Wong D, Song C, Omeis S, Chan K, Lee CWK, Siraganian RP, Rivera J, Krystal G. IgE-induced mast cell survival requires the prolonged generation of reactive oxygen species. THE JOURNAL OF IMMUNOLOGY 2008; 181:3850-60. [PMID: 18768839 DOI: 10.4049/jimmunol.181.6.3850] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We show in this study that the ability of five different monomeric IgEs to enhance murine bone marrow-derived mast cell (BMMC) survival correlates with their ability to stimulate extracellular calcium (Ca(2+)) entry. However, whereas IgE+Ag more potently stimulates Ca(2+) entry, it does not enhance survival under our conditions. Exploring this further, we found that whereas all five monomeric IgEs stimulate a less robust Ca(2+) entry than IgE+Ag initially, they all trigger a more prolonged Ca(2+) influx, generation of reactive oxygen species (ROS), and ERK phosphorylation. These prolonged signaling events correlate with their survival-enhancing ability and positively feedback on each other to generate the prosurvival cytokine, IL-3. Interestingly, the prolonged ERK phosphorylation induced by IgE appears to be regulated by a MAPK phosphatase rather than MEK. IgE-induced ROS generation, unlike that triggered by IgE+Ag, is not mediated by 5-lipoxygenase. Moreover, ROS inhibitors, which block both IgE-induced ROS production and Ca(2+) influx, convert the prolonged ERK phosphorylation induced by IgE into the abbreviated phosphorylation pattern observed with IgE+Ag and prevent IL-3 generation. In support of the essential role that IgE-induced ROS plays in IgE-enhanced BMMC survival, we found the addition of H(2)O(2) to IgE+Ag-stimulated BMMCs leads to IL-3 secretion.
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Affiliation(s)
- Laura M Sly
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, Canada
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38
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Edwards DH, Li Y, Griffith TM. Hydrogen Peroxide Potentiates the EDHF Phenomenon by Promoting Endothelial Ca
2+
Mobilization. Arterioscler Thromb Vasc Biol 2008; 28:1774-81. [DOI: 10.1161/atvbaha.108.172692] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Objective—
The purpose of this study was to test the hypothesis that H
2
O
2
contributes to the EDHF phenomenon by mobilizing endothelial Ca
2+
stores.
Methods and Results—
Myograph studies with rabbit iliac arteries demonstrated that EDHF-type relaxations evoked by the SERCA inhibitor cyclopiazonic acid (CPA) required activation of K
Ca
channels and were potentiated by exogenous H
2
O
2
and the thiol oxidant thimerosal. Preincubation with a submaximal concentration of CPA unmasked an ability of exogenous H
2
O
2
to stimulate an EDHF-type response that was sensitive to K
Ca
channel blockade. Imaging of cytosolic and endoplasmic reticulum [Ca
2+
] in rabbit aortic valve endothelial cells with Fura-2 and Mag-fluo-4 demonstrated that H
2
O
2
and thimerosal, which sensitizes the InsP
3
receptor, both enhanced CPA-evoked Ca
2+
release from stores, and that the potentiating effect of H
2
O
2
was suppressed by the cell-permeant thiol reductant glutathione monoethylester. CPA-evoked relaxations were attenuated by exogenous catalase and potentiated by the catalase inhibitor 3-aminotriazole, and were abolished by the connexin-mimetic peptide
43
Gap26, which interrupts intercellular communication via gap junctions constructed from connexin 43.
Conclusions—
H
2
O
2
can enhance EDHF-type relaxations by potentiating Ca
2+
release from endothelial stores, probably via redox modification of the InsP
3
receptor, leading to the opening of hyperpolarizing endothelial K
Ca
channels and an electrotonically-mediated relaxant response.
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Affiliation(s)
- David H. Edwards
- From the Wales Heart Research Institute, School of Medicine, Cardiff University, UK
| | - Yiwen Li
- From the Wales Heart Research Institute, School of Medicine, Cardiff University, UK
| | - Tudor M. Griffith
- From the Wales Heart Research Institute, School of Medicine, Cardiff University, UK
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Chen L, Liu L, Huang S. Cadmium activates the mitogen-activated protein kinase (MAPK) pathway via induction of reactive oxygen species and inhibition of protein phosphatases 2A and 5. Free Radic Biol Med 2008; 45:1035-44. [PMID: 18703135 DOI: 10.1016/j.freeradbiomed.2008.07.011] [Citation(s) in RCA: 200] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Revised: 07/12/2008] [Accepted: 07/16/2008] [Indexed: 01/14/2023]
Abstract
Cadmium (Cd), a highly toxic environmental pollutant, induces neurodegenerative diseases. Recently we have demonstrated that Cd may induce neuronal apoptosis in part through activation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase 1/2 (Erk1/2) pathways. However, the underlying mechanism remains enigmatic. Here we show that Cd induced generation of reactive oxygen species (ROS), leading to apoptosis of PC12 and SH-SY5Y cells. Pretreatment with N-acetyl-L-cysteine (NAC) scavenged Cd-induced ROS, and prevented cell death, suggesting that Cd-induced apoptosis is attributed to its induction of ROS. Furthermore, we found that Cd-induced ROS inhibited serine/threonine protein phosphatases 2A (PP2A) and 5 (PP5), leading to activation of Erk1/2 and JNK, which was abrogated by NAC. Overexpression of PP2A or PP5 partially prevented Cd-induced activation of Erk1/2 and JNK, as well as cell death. Cd-induced ROS was also linked to the activation of caspase-3. Pretreatment with inhibitors of JNK (SP600125) and Erk1/2 (U0126) partially blocked Cd-induced cleavage of caspase-3 and prevented cell death. However, zVAD-fmk, a pan caspase inhibitor, only partially prevented Cd-induced apoptosis. The results indicate that Cd induction of ROS inhibits PP2A and PP5, leading to activation of JNK and Erk1/2 pathways, and consequently resulting in caspase-dependent and -independent apoptosis of neuronal cells. The findings strongly suggest that the inhibitors of JNK, Erk1/2, or antioxidants may be exploited for prevention of Cd-induced neurodegenerative diseases.
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Affiliation(s)
- Long Chen
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932, USA
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40
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Bogeski I, Mirčeski V, Hoth M. Probing the redox activity of T-lymphocytes deposited at electrode surfaces with voltammetric methods. ACTA ACUST UNITED AC 2008; 46:197-203. [DOI: 10.1515/cclm.2008.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Gulaboski R, Pereira CM, Cordeiro MNDS, Silva AF, Hoth M, Bogeski I. Redox properties of the calcium chelator Fura-2 in mimetic biomembranes. Cell Calcium 2007; 43:615-21. [PMID: 18001832 DOI: 10.1016/j.ceca.2007.10.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Revised: 09/26/2007] [Accepted: 10/03/2007] [Indexed: 11/26/2022]
Abstract
Fura-2 is one of the most commonly used fluorescent dyes to analyze the cytosolic Ca(2+) concentration ([Ca(2+)](i)) of living cells. Fura-2-dependent measurements of [Ca(2+)](i) are susceptible to changes of pH, reactive oxygen species concentration and membrane potential. Fura-2 is often loaded over the lipophilic cell membrane into the cytosol of a cell in its esterified form (Fura-2/AM) which is then cleaved by endogenous esterases. We have analyzed the electrochemical properties of Fura-2/AM and Fura-2 salt by cyclic voltammetry ("three-phase" and "thin-film" electrode methods). Using Fura-2/AM as a redox facilitator, we were able to mimic the transport of various ions across a lipophilic barrier. We show that Fura-2/AM in this biomimetic set-up can be reversibly oxidized in a single electrochemical step. Its redox reaction was highly proton sensitive in buffers with pH< or =6. At physiological pH of around 7.0, the oxidation of Fura-2/AM was coupled to an uptake of mono-anions across the liquid-liquid interface. The voltage-dependence of the redox cycle was sensitive to the free Ca(2+) concentration, either after de-esterification of Fura-2/AM, or when Fura-2 salt was used. The complex between Fura-2 and Ca(2+) ions is ionic (complexation occurs via the dissociated negative groups of Fura forms), while the redox transformations in Fura-2 occurs at the nitrogen atoms of the amino groups. Our results suggest that redox transformations of the Fura-2 forms do not affect the binding ability toward Ca(2+) ions and thus do not interfere with [Ca(2+)](i) measurements.
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Affiliation(s)
- Rubin Gulaboski
- CIQ-UP L4, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal
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Sternfeld L, Anderie I, Schmid A, Al-Shaldi H, Krause E, Magg T, Schreiner D, Hofer HW, Schulz I. Identification of tyrosines in the putative regulatory site of the Ca2+ channel TRPV6. Cell Calcium 2007; 42:91-102. [PMID: 17197020 DOI: 10.1016/j.ceca.2006.11.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2006] [Revised: 10/12/2006] [Indexed: 11/26/2022]
Abstract
In HEK293 cells, transfected with the Ca2+ channel protein TRPV6, Ca2+ influx is increased and TRPV6 is tyrosine phosphorylated following addition of the tyrosine phosphatase inhibitor N,N-dimethyl-hydroxamido hydroxovanadate to cells. This effect of DMHV is enhanced by co-transfection of cells with the tyrosine kinase Src and the tyrosine phosphatase 1B. It is abolished when cells had been treated with PP1, an inhibitor of Src family tyrosine kinases. PTP1B interacts with the N-terminal domain of TRPV6 within a region of amino acids 1-191 as shown by co-immunoprecipitation, bimolecular fluorescence complementation and the yeast 2-hybrid system. Point mutation of both tyrosines 161 and 162 in the TRPV6 protein abolishes the DMHV-effect on Ca2+ influx and tyrosine phosphorylation by Src. Single mutations of Y161 or Y162 shows that each of both tyrosines alone is sufficient for the DMHV-effect. We conclude that phosphorylation/dephosphorylation of tyrosines in position 161 and 162 is essential for regulation of Ca2+ influx through TRPV6 Ca2+ channels in HEK293 cells.
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Affiliation(s)
- Lutz Sternfeld
- Physiological Institute, University of Saarland, 66421 Homburg (Saar), Germany
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43
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Genestra M. Oxyl radicals, redox-sensitive signalling cascades and antioxidants. Cell Signal 2007; 19:1807-19. [PMID: 17570640 DOI: 10.1016/j.cellsig.2007.04.009] [Citation(s) in RCA: 349] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2007] [Accepted: 04/23/2007] [Indexed: 01/20/2023]
Abstract
Oxidative stress is an increase in the reduction potential or a large decrease in the reducing capacity of the cellular redox couples. A particularly destructive aspect of oxidative stress is the production of reactive oxygen species (ROS), which include free radicals and peroxides. Some of the less reactive of these species can be converted by oxidoreduction reactions with transition metals into more aggressive radical species that can cause extensive cellular damage. In animals, ROS may influence cell proliferation, cell death (either apoptosis or necrosis) and the expression of genes, and may be involved in the activation of several signalling pathways, activating cell signalling cascades, such as those involving mitogen-activated protein kinases. Most of these oxygen-derived species are produced at a low level by normal aerobic metabolism and the damage they cause to cells is constantly repaired. The cellular redox environment is preserved by enzymes and antioxidants that maintain the reduced state through a constant input of metabolic energy. This review summarizes current studies that have been regarding the production of ROS and the general redox-sensitive targets of cell signalling cascades.
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Affiliation(s)
- Marcelo Genestra
- Department of Immunology, Oswaldo Cruz Institute/FIOCRUZ, Avenida Brasil, 4365-Manguinhos, Rio de Janeiro, CEP 21045-900, RJ-Brazil.
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Altimimi HF, Schnetkamp PPM. Na+-dependent inactivation of the retinal cone/brain Na+/Ca2+-K+ exchanger NCKX2. J Biol Chem 2006; 282:3720-9. [PMID: 17164249 DOI: 10.1074/jbc.m609285200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The SLC24 gene family Na+/Ca2+-K+ exchangers (NCKX) are bidirectional plasma membrane transporters whose main function is the extrusion of Ca2+ from the cytosol. In this study, we used human embryonic kidney 293 cells expressing human retinal cone/brain NCKX2 to examine its Na+ affinity and kinetic parameters of Ca2+ transport. With the use of the ionophore gramicidin to control alkali cation concentrations across the plasma membrane, application of high intracellular Na+ promoted large NCKX2-mediated increases in intracellular free Ca2+ in the 15-20 microm range; this also resulted in inactivation of NCKX2 transport, the first description of this novel kinetic state. The affinity of NCKX2 for internal Na+ was found to be sigmoidal, with a Hill coefficient of 2.6 and Kd = 50 mm. The time-dependent (t(1/2) approximately 40s) inactivation of NCKX2 required high intracellular Na+ levels (Kd > 50 mm) as well as high occupancy of the extracellular Ca2+-binding site. Also reported are two residues whose substitution resulted in an increase in internal Na+ affinity to values of approximately 19 mm; these mutants also displayed enhanced inactivation, suggesting that inactivation requires binding of Na+ to its intracellular transport sites. These findings are the first report of a regulatory kinetic state of Ca2+ transport via NCKX2 Na+/Ca2+-K+ exchangers that may play a prominent role in regulation of Ca2+ extrusion in cellular environments such as neuronal synapses that experience frequent and dynamic Ca2+ fluxes.
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Affiliation(s)
- Haider F Altimimi
- Department of Physiology and Biophysics, Faculty of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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45
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Cruz CM, Rinna A, Forman HJ, Ventura ALM, Persechini PM, Ojcius DM. ATP activates a reactive oxygen species-dependent oxidative stress response and secretion of proinflammatory cytokines in macrophages. J Biol Chem 2006; 282:2871-9. [PMID: 17132626 PMCID: PMC2693903 DOI: 10.1074/jbc.m608083200] [Citation(s) in RCA: 591] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Secretion of the proinflammatory cytokines, interleukin (IL)-1beta and IL-18, usually requires two signals. The first, due to microbial products such as lipopolysaccharide, initiates transcription of the cytokine genes and accumulation of the precursor proteins. Cleavage and secretion of the cytokines is mediated by caspase-1, in association with an inflammasome containing Nalp3, which can be activated by binding of extracellular ATP to purinergic receptors. We show that treatment of macrophages with ATP results in production of reactive oxygen species (ROS), which stimulate the phosphatidylinositol 3-kinase (PI3K) pathway and subsequent Akt and ERK1/2 activation. ROS exerts its effect through glutathionylation of PTEN (phosphatase and tensin homologue deleted from chromosome 10), whose inactivation would shift the equilibrium in favor of PI3K. ATP-dependent ROS production and PI3K activation also stimulate transcription of genes required for an oxidative stress response. In parallel, ATP-mediated ROS-dependent PI3K is required for activation of caspase-1 and secretion of IL-1beta and IL-18. Thus, an increase in ROS levels in ATP-treated macrophages results in activation of a single pathway that promotes both adaptation to subsequent exposure to oxidants or inflammation, and processing and secretion of proinflammatory cytokines.
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Affiliation(s)
- Cristiane M. Cruz
- School of Natural Sciences, University of California, Merced, California 95344
- Laboratorio de Imunobiofisica, IBCCF, Federal University of Rio de Janeiro, 21949-900 Rio de Janeiro, Brazil
| | - Alessandra Rinna
- School of Natural Sciences, University of California, Merced, California 95344
| | - Henry Jay Forman
- School of Natural Sciences, University of California, Merced, California 95344
| | - Ana L. M. Ventura
- Laboratório de Neuroquímica, Instituto de Biologia, Universidade Federal Fluminense, Niterói 24030-210, Rio de Janeiro, Brazil
| | - Pedro M. Persechini
- Laboratório de Neuroquímica, Instituto de Biologia, Universidade Federal Fluminense, Niterói 24030-210, Rio de Janeiro, Brazil
| | - David M. Ojcius
- School of Natural Sciences, University of California, Merced, California 95344
- To whom correspondence should be addressed: P.O. Box 2039, Merced, CA 95344. Tel.: 209-724-2948; Fax: 209-724-2912; E-mail:
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Anderie I, Schulz I, Schmid A. Direct interaction between ER membrane-bound PTP1B and its plasma membrane-anchored targets. Cell Signal 2006; 19:582-92. [PMID: 17092689 DOI: 10.1016/j.cellsig.2006.08.007] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Accepted: 08/13/2006] [Indexed: 11/19/2022]
Abstract
The ubiquitously expressed protein tyrosine phosphatase PTP1B is involved in the regulation of numerous cellular signaling pathways. PTP1B is anchored to the ER membrane while many of its substrates are localized to the plasma membrane. This spatial separation raises the question how PTP1B can interact with its targets. In our study we demonstrate direct interaction of PTP1B with the Ser/Thr kinase PKCdelta, the non-receptor tyrosine kinase Src and the insulin receptor which all are key enzymes in cellular signaling cascades. Protein complex formation was visualized in vivo using Bimolecular Fluorescence Complementation (BiFC). We demonstrate that complex formation of PTP1B with plasma membrane-anchored proteins is possible without detachment of PTP1B from the ER. Our data indicate that the dynamic ER membrane network is in constant contact to the plasma membrane. Local attachments of the two membrane systems enable a direct communication of ER- and plasma membrane-anchored proteins. The reported formation of membrane junctions is an important step towards the understanding of signal transmissions between the ER and the plasma membrane.
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Affiliation(s)
- Ines Anderie
- Department of Physiology, University of the Saarland, D-66421, Homburg/Saar, Germany
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