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Mázala DA, Chen D, Chin ER. SERCA1 Overexpression in Skeletal Muscle Attenuates Muscle Atrophy and Improves Motor Function in a Mouse Model of ALS. J Neuromuscul Dis 2024; 11:315-326. [PMID: 38217607 PMCID: PMC10977371 DOI: 10.3233/jnd-230123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2023] [Indexed: 01/15/2024]
Abstract
Background Amyotrophic lateral sclerosis (ALS) is characterized by progressive loss of muscle mass and muscle function. Previous work from our lab demonstrated that skeletal muscles from a mouse model of ALS show elevated intracellular calcium (Ca2+) levels and heightened endoplasmic reticulum (ER) stress. Objective To investigate whether overexpression of sarcoplasmic reticulum (SR) Ca2+ ATPase 1 (SERCA1) in skeletal muscle would improve intracellular Ca2+ handling, attenuate ER stress, and improve motor function ALS transgenic mice. Methods B6SJL-Tg (SOD1*G93A)1Gur/J (ALS-Tg) mice were bred with skeletal muscle α-actinin SERCA1 overexpressing mice to generate wild type (WT), SERCA1 overexpression (WT/+SERCA1), ALS-Tg, and SERCA1 overexpressing ALS-Tg (ALS-Tg/+SERCA1) mice. Motor function (grip test) was assessed weekly and skeletal muscles were harvested at 16 weeks of age to evaluate muscle mass, SR-Ca2+ ATPase activity, levels of SERCA1 and ER stress proteins - protein disulfide isomerase (PDI), Grp78/BiP, and C/EBP homologous protein (CHOP). Single muscle fibers were also isolated from the flexor digitorum brevis muscle to assess changes in resting and peak Fura-2 ratios. Results ALS-Tg/+SERCA1 mice showed improved motor function, delayed onset of disease, and improved muscle mass compared to ALS-Tg. Further, ALS-Tg/+SERCA1 mice returned levels of SERCA1 protein and SR-Ca2+ ATPase activity back to levels in WT mice. Unexpectedly, SERCA-1 overexpression increased levels of the ER stress maker Grp78/BiP in both WT and ALS-Tg mice, while not altering protein levels of PDI or CHOP. Lastly, single muscle fibers from ALS-Tg/+SERCA1 had similar resting but lower peak Fura-2 levels (at 30 Hz and 100 Hz) compared to ALS-Tg mice. Conclusions These data indicate that SERCA1 overexpression attenuates the progressive loss of muscle mass and maintains motor function in ALS-Tg mice while not lowering resting Ca2+ levels or ER stress.
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Affiliation(s)
- Davi A.G. Mázala
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, MD, USA
- Department of Kinesiology, College of Health Professions, Towson University, Towson, MD, USA
- Center for Genetic Medicine Research, Children’s National Research Institute, Children’s National Hospital, Washington, DC, USA
| | - Dapeng Chen
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, MD, USA
- Zeteo Tech, Inc., Sykesville, MD, USA
| | - Eva R. Chin
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, MD, USA
- Solve FSHD, Vancouver, British Columbia, Canada
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2
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Galvan-Alvarez V, Martin-Rincon M, Gallego-Selles A, Martínez Canton M, HamedChaman N, Gelabert-Rebato M, Perez-Valera M, García-Gonzalez E, Santana A, Holmberg HC, Boushel R, Hallén J, Calbet JAL. Determinants of the maximal functional reserve during repeated supramaximal exercise by humans: The roles of Nrf2/Keap1, antioxidant proteins, muscle phenotype and oxygenation. Redox Biol 2023; 66:102859. [PMID: 37666117 PMCID: PMC10491831 DOI: 10.1016/j.redox.2023.102859] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/18/2023] [Accepted: 08/19/2023] [Indexed: 09/06/2023] Open
Abstract
When high-intensity exercise is performed until exhaustion a "functional reserve" (FR) or capacity to produce power at the same level or higher than reached at exhaustion exists at task failure, which could be related to reactive oxygen and nitrogen species (RONS)-sensing and counteracting mechanisms. Nonetheless, the magnitude of this FR remains unknown. Repeated bouts of supramaximal exercise at 120% of VO2max interspaced with 20s recovery periods with full ischaemia were used to determine the maximal FR. Then, we determined which muscle phenotypic features could account for the variability in functional reserve in humans. Exercise performance, cardiorespiratory variables, oxygen deficit, and brain and muscle oxygenation (near-infrared spectroscopy) were measured, and resting muscle biopsies were obtained from 43 young healthy adults (30 males). Males and females had similar aerobic (VO2max per kg of lower extremities lean mass (LLM): 166.7 ± 17.1 and 166.1 ± 15.6 ml kg LLM-1.min-1, P = 0.84) and anaerobic fitness (similar performance in the Wingate test and maximal accumulated oxygen deficit when normalized to LLM). The maximal FR was similar in males and females when normalized to LLM (1.84 ± 0.50 and 2.05 ± 0.59 kJ kg LLM-1, in males and females, respectively, P = 0.218). This FR depends on an obligatory component relying on a reserve in glycolytic capacity and a putative component generated by oxidative phosphorylation. The aerobic component depends on brain oxygenation and phenotypic features of the skeletal muscles implicated in calcium handling (SERCA1 and 2 protein expression), oxygen transport and diffusion (myoglobin) and redox regulation (Keap1). The glycolytic component can be predicted by the protein expression levels of pSer40-Nrf2, the maximal accumulated oxygen deficit and the protein expression levels of SOD1. Thus, an increased capacity to modulate the expression of antioxidant proteins involved in RONS handling and calcium homeostasis may be critical for performance during high-intensity exercise in humans.
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Affiliation(s)
- Victor Galvan-Alvarez
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera Felipe "Físico" s/n, 35017, Las Palmas de Gran Canaria, Spain
| | - Marcos Martin-Rincon
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera Felipe "Físico" s/n, 35017, Las Palmas de Gran Canaria, Spain
| | - Angel Gallego-Selles
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera Felipe "Físico" s/n, 35017, Las Palmas de Gran Canaria, Spain
| | - Miriam Martínez Canton
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera Felipe "Físico" s/n, 35017, Las Palmas de Gran Canaria, Spain
| | - NaDer HamedChaman
- Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera Felipe "Físico" s/n, 35017, Las Palmas de Gran Canaria, Spain; Department of Exercise Physiology, Faculty of Sports Sciences, University of Mazandaran, Babolsar, Mazandaran, Iran
| | - Miriam Gelabert-Rebato
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera Felipe "Físico" s/n, 35017, Las Palmas de Gran Canaria, Spain
| | - Mario Perez-Valera
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera Felipe "Físico" s/n, 35017, Las Palmas de Gran Canaria, Spain
| | - Eduardo García-Gonzalez
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera Felipe "Físico" s/n, 35017, Las Palmas de Gran Canaria, Spain
| | - Alfredo Santana
- Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera Felipe "Físico" s/n, 35017, Las Palmas de Gran Canaria, Spain; Complejo Hospitalario Universitario Insular-Materno Infantil de Las Palmas de Gran Canaria, Clinical Genetics Unit, 35016, Las Palmas de Gran Canaria, Spain
| | - Hans-Christer Holmberg
- Department of Health Sciences, Luleå University of Technology, Sweden; School of Kinesiology, Faculty of Education, The University of British Columbia, Vancouver, BC, Canada
| | - Robert Boushel
- School of Kinesiology, Faculty of Education, The University of British Columbia, Vancouver, BC, Canada
| | - Jostein Hallén
- Department of Physical Performance, The Norwegian School of Sport Sciences, Postboks, 4014 Ulleval Stadion, 0806, Oslo, Norway
| | - Jose A L Calbet
- Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera Felipe "Físico" s/n, 35017, Las Palmas de Gran Canaria, Spain; School of Kinesiology, Faculty of Education, The University of British Columbia, Vancouver, BC, Canada; Department of Physical Performance, The Norwegian School of Sport Sciences, Postboks, 4014 Ulleval Stadion, 0806, Oslo, Norway.
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3
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Wu L, Li Z, Yao Y. Hydrogen peroxide preconditioning is of dual role in cardiac ischemia/reperfusion. Eur J Pharmacol 2023; 947:175684. [PMID: 36997049 DOI: 10.1016/j.ejphar.2023.175684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 03/23/2023] [Accepted: 03/23/2023] [Indexed: 03/30/2023]
Abstract
Moderate reactive oxygen species (ROS) at reperfusion would trigger cardioprotection and various antioxidants for pharmacological preconditioning failed to achieve cardioprotection. The causes for different roles of preischemic ROS during cardiac ischemia/reperfusion (I/R) require reevaluation. We investigated the precise role of ROS and its working model in this study. Different doses of hydrogen peroxide (H2O2, the most stable form of ROS) were added 5 min before ischemia using isolated perfused rat hearts, only moderate-dose H2O2 preconditioning (H2O2PC) achieved contractile recovery, whereas the low dose and high dose led to injury. Similar results were observed in isolated rat cardiomyocytes on cytosolic free Ca2+ concentration ([Ca2+]c) overload, ROS production, the recovery of Ca2+ transient, and cell shortening. Based on the data mentioned above, we set up a mathematics model to describe the effects of H2O2PC with the fitting curve by the percentage of recovery of heart function and Ca2+ transient in I/R. Besides, we used the two models to define the initial thresholds of H2O2PC achieving cardioprotection. We also detected the expression of redox enzymes and Ca2+ signaling toolkits to explain the mathematics models of H2O2PC in a biological way. The expression of tyrosine 705 phosphorylation of STAT3, Nuclear factor E2-related factor 2, manganese superoxide dismutase, phospholamban, catalase, ryanodine receptors, and sarcoendoplasmic reticulum calcium ATPase 2 were similar with the control I/R and low-dose H2O2PC but were increased in the moderate H2O2PC and decreased in the high-dose H2O2PC. Thus, we concluded that preischemic ROS are of dual role in cardiac I/R.
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4
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Bassot A, Chen J, Takahashi-Yamashiro K, Yap MC, Gibhardt CS, Le GNT, Hario S, Nasu Y, Moore J, Gutiérrez T, Mina L, Mast H, Moses A, Bhat R, Ballanyi K, Lemieux H, Sitia R, Zito E, Bogeski I, Campbell RE, Simmen T. The endoplasmic reticulum kinase PERK interacts with the oxidoreductase ERO1 to metabolically adapt mitochondria. Cell Rep 2023; 42:111899. [PMID: 36586409 DOI: 10.1016/j.celrep.2022.111899] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 10/04/2022] [Accepted: 12/08/2022] [Indexed: 12/31/2022] Open
Abstract
Endoplasmic reticulum (ER) homeostasis requires molecular regulators that tailor mitochondrial bioenergetics to the needs of protein folding. For instance, calnexin maintains mitochondria metabolism and mitochondria-ER contacts (MERCs) through reactive oxygen species (ROS) from NADPH oxidase 4 (NOX4). However, induction of ER stress requires a quick molecular rewiring of mitochondria to adapt to new energy needs. This machinery is not characterized. We now show that the oxidoreductase ERO1⍺ covalently interacts with protein kinase RNA-like ER kinase (PERK) upon treatment with tunicamycin. The PERK-ERO1⍺ interaction requires the C-terminal active site of ERO1⍺ and cysteine 216 of PERK. Moreover, we show that the PERK-ERO1⍺ complex promotes oxidization of MERC proteins and controls mitochondrial dynamics. Using proteinaceous probes, we determined that these functions improve ER-mitochondria Ca2+ flux to maintain bioenergetics in both organelles, while limiting oxidative stress. Therefore, the PERK-ERO1⍺ complex is a key molecular machinery that allows quick metabolic adaptation to ER stress.
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Affiliation(s)
- Arthur Bassot
- Department of Cell Biology, Faculty of Medicine and Dentistry, Edmonton, AB T6G 2G2, Canada
| | - Junsheng Chen
- Department of Cell Biology, Faculty of Medicine and Dentistry, Edmonton, AB T6G 2G2, Canada
| | | | - Megan C Yap
- Department of Cell Biology, Faculty of Medicine and Dentistry, Edmonton, AB T6G 2G2, Canada
| | - Christine Silvia Gibhardt
- Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Giang N T Le
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Saaya Hario
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yusuke Nasu
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Jack Moore
- Alberta Proteomics and Mass Spectrometry Facility, University of Alberta, 4096 Katz Research Building, Edmonton AB T6G2E1, Canada
| | - Tomas Gutiérrez
- Department of Cell Biology, Faculty of Medicine and Dentistry, Edmonton, AB T6G 2G2, Canada
| | - Lucas Mina
- Department of Cell Biology, Faculty of Medicine and Dentistry, Edmonton, AB T6G 2G2, Canada
| | - Heather Mast
- Faculty Saint-Jean, Department of Medicine, Faculty of Medicine and Dentistry, Edmonton, AB T6G2H7, Canada
| | - Audric Moses
- Department of Pediatrics, Edmonton, AB T6G2H7, Canada
| | - Rakesh Bhat
- Precision Biolaboratories, St. Albert, AB T8N 5A7, Canada
| | - Klaus Ballanyi
- Department of Physiology, University of Alberta, Edmonton, AB T6G2H7, Canada
| | - Hélène Lemieux
- Faculty Saint-Jean, Department of Medicine, Faculty of Medicine and Dentistry, Edmonton, AB T6G2H7, Canada
| | - Roberto Sitia
- Division of Genetics and Cell Biology, Università Vita-Salute IRCCS Ospedale San Raffaele, 20132 Milano, Italy
| | - Ester Zito
- Istituto di Ricerche Farmacologiche Mario Negri, 20156 Milano, Italy; Department of Biomolecular Sciences, University of Urbino Carlo Bo, 61029 Urbino PU, Italy
| | - Ivan Bogeski
- Molecular Physiology, Institute of Cardiovascular Physiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Robert E Campbell
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada; Department of Chemistry, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Thomas Simmen
- Department of Cell Biology, Faculty of Medicine and Dentistry, Edmonton, AB T6G 2G2, Canada.
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Xu H, Ahn B, Van Remmen H. Impact of aging and oxidative stress on specific components of excitation contraction coupling in regulating force generation. SCIENCE ADVANCES 2022; 8:eadd7377. [PMID: 36288318 PMCID: PMC9604602 DOI: 10.1126/sciadv.add7377] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
Muscle weakness associated with sarcopenia is a major contributor to reduced health span and quality of life in the elderly. However, the underlying mechanisms of muscle weakness in aging are not fully defined. We investigated the effect of oxidative stress and aging on specific molecular mechanisms involved in muscle force production in mice and skinned permeabilized single fibers in mice lacking the antioxidant enzyme CuZnSod (Sod1KO) and in aging (24-month-old) wild-type mice. Loss of muscle strength occurs in both models, potentially because of reduced membrane excitability with altered NKA signaling and RyR stability, decreased fiber Ca2+ sensitivity and suppressed SERCA activity via modification of the Cys674 residue, dysregulated SR and cytosolic Ca2+ homeostasis, and impaired mitochondrial Ca2+ buffering and respiration. Our results provide a better understanding of the specific impacts of aging and oxidative stress on mechanisms related to muscle weakness that may point to future interventions for countering muscle weakness.
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Affiliation(s)
- Hongyang Xu
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Bumsoo Ahn
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Holly Van Remmen
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
- Oklahoma City VA Medical Center, Oklahoma City, OK, USA
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García-Castañeda M, Michelucci A, Zhao N, Malik S, Dirksen RT. Postdevelopmental knockout of Orai1 improves muscle pathology in a mouse model of Duchenne muscular dystrophy. J Gen Physiol 2022; 154:213383. [PMID: 35939054 PMCID: PMC9365874 DOI: 10.1085/jgp.202213081] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 07/07/2022] [Indexed: 11/20/2022] Open
Abstract
Duchenne muscular dystrophy (DMD), an X-linked disorder caused by loss-of-function mutations in the dystrophin gene, is characterized by progressive muscle degeneration and weakness. Enhanced store-operated Ca2+ entry (SOCE), a Ca2+ influx mechanism coordinated by STIM1 sensors of luminal Ca2+ within the sarcoplasmic reticulum (SR) and Ca2+-permeable Orai1 channels in the sarcolemma, is proposed to contribute to Ca2+-mediated muscle damage in DMD. To directly determine the impact of Orai1-dependent SOCE on the dystrophic phenotype, we crossed mdx mice with tamoxifen-inducible, muscle-specific Orai1 knockout mice (mdx-Orai1 KO mice). Both constitutive and SOCE were significantly increased in flexor digitorum brevis fibers from mdx mice, while SOCE was absent in fibers from both Orai1 KO and mdx-Orai1 KO mice. Compared with WT mice, fibers from mdx mice exhibited (1) increased resting myoplasmic Ca2+ levels, (2) reduced total releasable Ca2+ store content, and (3) a prolonged rate of electrically evoked Ca2+ transient decay. These effects were partially normalized in fibers from mdx-Orai1 KO mice. Intact extensor digitorum longus muscles from mdx mice exhibited a significant reduction of maximal specific force, which was rescued in muscles from mdx-Orai1 KO mice. Finally, during exposure to consecutive eccentric contractions, muscles from mdx mice displayed a more pronounced decline in specific force compared with that of WT mice, which was also significantly attenuated by Orai1 ablation. Together, these results indicate that enhanced Orai1-dependent SOCE exacerbates the dystrophic phenotype and that Orai1 deficiency improves muscle pathology by both normalizing Ca2+ homeostasis and promoting sarcolemmal integrity/stability.
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Affiliation(s)
- Maricela García-Castañeda
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY
| | - Antonio Michelucci
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY,Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Nan Zhao
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY
| | - Sundeep Malik
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY
| | - Robert T. Dirksen
- Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY
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7
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Regulation of calcium homeostasis and flux between the endoplasmic reticulum and the cytosol. J Biol Chem 2022; 298:102061. [PMID: 35609712 PMCID: PMC9218512 DOI: 10.1016/j.jbc.2022.102061] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 05/17/2022] [Accepted: 05/18/2022] [Indexed: 12/20/2022] Open
Abstract
The concentration of Ca2+ in the endoplasmic reticulum (ER) is critically important for maintaining its oxidizing environment as well as for maintaining luminal ATP levels required for chaperone activity. Therefore, local luminal Ca2+ concentrations and the dynamic Ca2+ flux between the different subcellular compartments are tightly controlled. Influx of Ca2+ into the ER is enabled by a reductive shift, which opens the sarcoendoplasmic reticulum calcium transport ATPase pump, building the Ca2+ gradient across the ER membrane required for ATP import. Meanwhile, Ca2+ leakage from the ER has been reported to occur via the Sec61 translocon following protein translocation. In this review, we provide an overview of the complex regulation of Ca2+ homeostasis, Ca2+ flux between subcellular compartments, and the cellular stress response (the unfolded protein response) induced upon dysregulated luminal Ca2+ metabolism. We also provide insight into the structure and gating mechanism at the Sec61 translocon and examine the role of ER-resident cochaperones in assisting the central ER-resident chaperone BiP in the control of luminal Ca2+ concentrations.
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Ahn B, Ranjit R, Kneis P, Xu H, Piekarz KM, Freeman WM, Kinter M, Richardson A, Ran Q, Brooks SV, Van Remmen H. Scavenging mitochondrial hydrogen peroxide by peroxiredoxin 3 overexpression attenuates contractile dysfunction and muscle atrophy in a murine model of accelerated sarcopenia. Aging Cell 2022; 21:e13569. [PMID: 35199907 PMCID: PMC8920438 DOI: 10.1111/acel.13569] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 01/21/2022] [Accepted: 02/01/2022] [Indexed: 01/14/2023] Open
Abstract
Age-related muscle atrophy and weakness, or sarcopenia, are significant contributors to compromised health and quality of life in the elderly. While the mechanisms driving this pathology are not fully defined, reactive oxygen species, neuromuscular junction (NMJ) disruption, and loss of innervation are important risk factors. The goal of this study is to determine the impact of mitochondrial hydrogen peroxide on neurogenic atrophy and contractile dysfunction. Mice with muscle-specific overexpression of the mitochondrial H2 O2 scavenger peroxiredoxin3 (mPRDX3) were crossed to Sod1KO mice, an established mouse model of sarcopenia, to determine whether reduced mitochondrial H2 O2 can prevent or delay the redox-dependent sarcopenia. Basal rates of H2 O2 generation were elevated in isolated muscle mitochondria from Sod1KO, but normalized by mPRDX3 overexpression. The mPRDX3 overexpression prevented the declines in maximum mitochondrial oxygen consumption rate and calcium retention capacity in Sod1KO. Muscle atrophy in Sod1KO was mitigated by ~20% by mPRDX3 overexpression, which was associated with an increase in myofiber cross-sectional area. With direct muscle stimulation, maximum isometric specific force was reduced by ~20% in Sod1KO mice, and mPRDX3 overexpression preserved specific force at wild-type levels. The force deficit with nerve stimulation was exacerbated in Sod1KO compared to direct muscle stimulation, suggesting NMJ disruption in Sod1KO. Notably, this defect was not resolved by overexpression of mPRDX3. Our findings demonstrate that muscle-specific PRDX3 overexpression reduces mitochondrial H2 O2 generation, improves mitochondrial function, and mitigates loss of muscle quantity and quality, despite persisting NMJ impairment in a murine model of redox-dependent sarcopenia.
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Affiliation(s)
- Bumsoo Ahn
- Aging & Metabolism Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA,Department of Internal MedicineWake Forest School of MedicineWinston‐SalemNorth CarolinaUSA
| | - Rojina Ranjit
- Aging & Metabolism Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA
| | - Parker Kneis
- Aging & Metabolism Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA
| | - Hongyang Xu
- Aging & Metabolism Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA
| | - Katarzyna M. Piekarz
- Aging & Metabolism Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA,Oklahoma Center for NeuroscienceUniversity of Oklahoma Health Sciences CenterOklahoma CityOklahomaUSA
| | - Willard M. Freeman
- Genes and Human Disease Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA
| | - Michael Kinter
- Aging & Metabolism Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA,Oklahoma Nathan Shock Center for AgingOklahoma CityOklahomaUSA
| | - Arlan Richardson
- Oklahoma Nathan Shock Center for AgingOklahoma CityOklahomaUSA,Department of BiochemistryOUHSCOklahoma CityOklahomaUSA,Oklahoma City VA Medical CenterOklahoma CityOklahomaUSA
| | - Qitao Ran
- Department of Cell Systems & AnatomyUT Health San AntonioSan AntonioTexasUSA
| | - Susan V. Brooks
- Department of Molecular and Integrative PhysiologyUniversity of MichiganAnn ArborMichiganUSA
| | - Holly Van Remmen
- Aging & Metabolism Research ProgramOklahoma Medical Research FoundationOklahoma CityOklahomaUSA,Oklahoma Center for NeuroscienceUniversity of Oklahoma Health Sciences CenterOklahoma CityOklahomaUSA,Oklahoma Nathan Shock Center for AgingOklahoma CityOklahomaUSA,Oklahoma City VA Medical CenterOklahoma CityOklahomaUSA,Department of PhysiologyOUHSCOklahoma CityOklahomaUSA
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9
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Peters EC, Gee MT, Pawlowski LN, Kath AM, Polk FD, Vance CJ, Sacoman JL, Pires PW. Amyloid- β disrupts unitary calcium entry through endothelial NMDA receptors in mouse cerebral arteries. J Cereb Blood Flow Metab 2022; 42:145-161. [PMID: 34465229 PMCID: PMC8721780 DOI: 10.1177/0271678x211039592] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 01/07/2023]
Abstract
Transient increases in intracellular Ca2+ activate endothelium-dependent vasodilatory pathways. This process is impaired in cerebral amyloid angiopathy, where amyloid-β(1-40) accumulates around blood vessels. In neurons, amyloid-β impairs the Ca2+-permeable N-methyl-D-aspartate receptor (NMDAR), a mediator of endothelium-dependent dilation in arteries. We hypothesized that amyloid-β(1-40) reduces NMDAR-elicited Ca2+ signals in mouse cerebral artery endothelial cells, blunting dilation. Cerebral arteries isolated from 4-5 months-old, male and female cdh5:Gcamp8 mice were used for imaging of unitary Ca2+ influx through NMDAR (NMDAR sparklets) and intracellular Ca2+ transients. The NMDAR agonist NMDA (10 µmol/L) increased frequency of NMDAR sparklets and intracellular Ca2+ transients in endothelial cells; these effects were prevented by NMDAR antagonists D-AP5 and MK-801. Next, we tested if amyloid-β(1-40) impairs NMDAR-elicited Ca2+ transients. Cerebral arteries incubated with amyloid-β(1-40) (5 µmol/L) exhibited reduced NMDAR sparklets and intracellular Ca2+ transients. Lastly, we observed that NMDA-induced dilation of pial arteries is reduced by acute intraluminal amyloid-β(1-40), as well as in a mouse model of Alzheimer's disease, the 5x-FAD, linked to downregulation of Grin1 mRNA compared to wild-type littermates. These data suggest that endothelial NMDAR mediate dilation via Ca2+-dependent pathways, a process disrupted by amyloid-β(1-40) and impaired in 5x-FAD mice.
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Affiliation(s)
- Emily C Peters
- Department of Physiology, University of Arizona College of Medicine Tucson, Tucson, AZ, USA
| | - Michael T Gee
- Department of Physiology, University of Arizona College of Medicine Tucson, Tucson, AZ, USA
| | - Lukas N Pawlowski
- Department of Physiology, University of Arizona College of Medicine Tucson, Tucson, AZ, USA
| | - Allison M Kath
- Department of Physiology, University of Arizona College of Medicine Tucson, Tucson, AZ, USA
| | - Felipe D Polk
- Department of Physiology, University of Arizona College of Medicine Tucson, Tucson, AZ, USA
| | - Christopher J Vance
- Department of Physiology, University of Arizona College of Medicine Tucson, Tucson, AZ, USA
| | - Juliana L Sacoman
- Department of Physiology, University of Arizona College of Medicine Tucson, Tucson, AZ, USA
| | - Paulo W Pires
- Department of Physiology, University of Arizona College of Medicine Tucson, Tucson, AZ, USA
- Sarver Heart Center, University of Arizona College of Medicine Tucson, Tucson, AZ, USA
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10
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Xu H, Ranjit R, Richardson A, Van Remmen H. Muscle mitochondrial catalase expression prevents neuromuscular junction disruption, atrophy, and weakness in a mouse model of accelerated sarcopenia. J Cachexia Sarcopenia Muscle 2021; 12:1582-1596. [PMID: 34559475 PMCID: PMC8718066 DOI: 10.1002/jcsm.12768] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 06/22/2021] [Accepted: 07/10/2021] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Oxidative stress and damage are associated with a number of ageing phenotypes, including age-related loss of muscle mass and reduced contractile function (sarcopenia). Our group and others have reported loss of neuromuscular junction (NMJ) integrity and increased denervation as initiating factors in sarcopenia, leading to mitochondrial dysfunction, generation of reactive oxygen species and peroxides, and loss of muscle mass and weakness. Previous studies from our laboratory show that denervation-induced skeletal muscle mitochondrial peroxide generation is highly correlated to muscle atrophy. Here, we directly test the impact of scavenging muscle mitochondrial hydrogen peroxide on the structure and function of the NMJ and muscle mass and function in a mouse model of denervation-induced muscle atrophy CuZnSOD (Sod1-/- mice, Sod1KO). METHODS Whole-body Sod1KO mice were crossed to mice with increased expression of human catalase (MCAT) targeted specifically to mitochondria in skeletal muscle (mMCAT mice) to determine the impact of reduced hydrogen peroxide levels on key targets of sarcopenia, including mitochondrial function, NMJ structure and function, and indices of muscle mass and function. RESULTS Female adult (~12-month-old) Sod1KO mice show a number of sarcopenia-related phenotypes in skeletal muscle including reduced mitochondrial oxygen consumption and elevated reactive oxygen species generation, fragmentation, and loss of innervated NMJs (P < 0.05), a 30% reduction in muscle mass (P < 0.05), a 36% loss of force generation (P < 0.05), and a loss of exercise capacity (305 vs. 709 m in wild-type mice, P < 0.05). Muscle from Sod1KO mice also shows a 35% reduction in sarco(endo)plasmic reticulum ATPase activity (P < 0.05), changes in the amount of calcium-regulating proteins, and altered fibre-type composition. In contrast, increased catalase expression in the mMCAT × Sod1KO mice completely prevents the mitochondrial and NMJ-related phenotypes and maintains muscle mass and force generation. The reduction in exercise capacity is also partially inhibited (~35%, P < 0.05), and the loss of fibre cross-sectional area is inhibited by ~50% (P < 0.05). CONCLUSIONS Together, these striking findings suggest that scavenging of mitochondrial peroxide generation by mMCAT expression efficiently prevents mitochondrial dysfunction and NMJ disruption associated with denervation-induced atrophy and weakness, supporting mitochondrial H2 O2 as an important effector of NMJ alterations that lead to phenotypes associated with sarcopenia.
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Affiliation(s)
- Hongyang Xu
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Rojina Ranjit
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Arlan Richardson
- Department of Biochemistry & Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Oklahoma City VA Medical Center, Oklahoma City, OK, USA
| | - Holly Van Remmen
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.,Oklahoma City VA Medical Center, Oklahoma City, OK, USA
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11
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Xu H, Van Remmen H. The SarcoEndoplasmic Reticulum Calcium ATPase (SERCA) pump: a potential target for intervention in aging and skeletal muscle pathologies. Skelet Muscle 2021; 11:25. [PMID: 34772465 PMCID: PMC8588740 DOI: 10.1186/s13395-021-00280-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 10/26/2021] [Indexed: 01/13/2023] Open
Abstract
As a key regulator of cellular calcium homeostasis, the Sarcoendoplasmic Reticulum Calcium ATPase (SERCA) pump acts to transport calcium ions from the cytosol back to the sarcoplasmic reticulum (SR) following muscle contraction. SERCA function is closely associated with muscle health and function, and SERCA activity is susceptible to muscle pathogenesis. For example, it has been well reported that pathological conditions associated with aging, neurodegeneration, and muscular dystrophy (MD) significantly depress SERCA function with the potential to impair intracellular calcium homeostasis and further contribute to muscle atrophy and weakness. As a result, targeting SERCA activity has attracted attention as a therapeutical method for the treatment of muscle pathologies. The interventions include activation of SERCA activity and genetic overexpression of SERCA. This review will focus on SERCA function and regulation mechanisms and describe how those mechanisms are affected under muscle pathological conditions including elevated oxidative stress induced by aging, muscle disease, or neuromuscular disorders. We also discuss the current progress and therapeutic approaches to targeting SERCA in vivo.
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Affiliation(s)
- Hongyang Xu
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA
| | - Holly Van Remmen
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, 73104, USA. .,Oklahoma City VA Medical Center, Oklahoma City, OK, USA. .,Department of Physiology, OUHSC, Oklahoma City, OK, USA.
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12
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Yamashita R, Fujii S, Ushioda R, Nagata K. Ca 2+ imbalance caused by ERdj5 deletion affects mitochondrial fragmentation. Sci Rep 2021; 11:20772. [PMID: 34728782 PMCID: PMC8563984 DOI: 10.1038/s41598-021-99980-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 09/28/2021] [Indexed: 11/29/2022] Open
Abstract
The endoplasmic reticulum (ER) is the organelle responsible for the folding of secretory/membrane proteins and acts as a dynamic calcium ion (Ca2+) store involved in various cellular signalling pathways. Previously, we reported that the ER-resident disulfide reductase ERdj5 is involved in the ER-associated degradation (ERAD) of misfolded proteins in the ER and the activation of SERCA2b, a Ca2+ pump on the ER membrane. These results highlighted the importance of the regulation of redox activity in both Ca2+ and protein homeostasis in the ER. Here, we show that the deletion of ERdj5 causes an imbalance in intracellular Ca2+ homeostasis, the activation of Drp1, a cytosolic GTPase involved in mitochondrial fission, and finally the aberrant fragmentation of mitochondria, which affects cell viability as well as phenotype with features of cellular senescence. Thus, ERdj5-mediated regulation of intracellular Ca2+ is essential for the maintenance of mitochondrial homeostasis involved in cellular senescence.
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Affiliation(s)
- Riyuji Yamashita
- Laboratory of Molecular and Cellular Biology, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, 603-8555, Japan
| | - Shohei Fujii
- Laboratory of Molecular and Cellular Biology, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, 603-8555, Japan
| | - Ryo Ushioda
- Laboratory of Molecular and Cellular Biology, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, 603-8555, Japan. .,Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto, 605-8555, Japan.
| | - Kazuhiro Nagata
- Laboratory of Molecular and Cellular Biology, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, 603-8555, Japan. .,Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto, 605-8555, Japan. .,JT Biohistory Research Hall, Murasaki Town 1-1, Takatsuki City, Osaka, 569-1125, Japan.
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13
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A conserved, buried cysteine near the P-site is accessible to cysteine modifications and increases ROS stability in the P-type plasma membrane H+-ATPase. Biochem J 2021; 478:619-632. [DOI: 10.1042/bcj20200559] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 12/16/2020] [Accepted: 01/08/2021] [Indexed: 02/06/2023]
Abstract
Sulfur-containing amino acid residues function in antioxidative responses, which can be induced by the reactive oxygen species generated by excessive copper and hydrogen peroxide. In all Na+/K+, Ca2+, and H+ pumping P-type ATPases, a cysteine residue is present two residues upstream of the essential aspartate residue, which is obligatorily phosphorylated in each catalytic cycle. Despite its conservation, the function of this cysteine residue was hitherto unknown. In this study, we analyzed the function of the corresponding cysteine residue (Cys-327) in the autoinhibited plasma membrane H+-ATPase isoform 2 (AHA2) from Arabidopsis thaliana by mutagenesis and heterologous expression in a yeast host. Enzyme kinetics of alanine, serine, and leucine substitutions were identical with those of the wild-type pump but the sensitivity of the mutant pumps was increased towards copper and hydrogen peroxide. Peptide identification and sequencing by mass spectrometry demonstrated that Cys-327 was prone to oxidation. These data suggest that Cys-327 functions as a protective residue in the plasma membrane H+-ATPase, and possibly in other P-type ATPases as well.
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14
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Addinsall AB, Wright CR, Kotsiakos TL, Smith ZM, Cook TR, Andrikopoulos S, van der Poel C, Stupka N. Impaired exercise performance is independent of inflammation and cellular stress following genetic reduction or deletion of selenoprotein S. Am J Physiol Regul Integr Comp Physiol 2020; 318:R981-R996. [PMID: 32186893 DOI: 10.1152/ajpregu.00321.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Selenoprotein S (Seps1) can be protective against oxidative, endoplasmic reticulum (ER), and inflammatory stress. Seps1 global knockout mice are less active, possess compromised fast muscle ex vivo strength, and, depending on context, heightened inflammation. Oxidative, ER, and inflammatory stress modulates contractile function; hence, our aim was to investigate the effects of Seps1 gene dose on exercise performance. Seps1-/- knockout, Seps1-/+ heterozygous, and wild-type mice were randomized to 3 days of incremental, high-intensity treadmill running or a sedentary control group. On day 4, the in situ contractile function of fast tibialis anterior (TA) muscles was determined. Seps1 reduction or deletion compromised exercise capacity, decreasing distance run. TA strength was also reduced. In sedentary Seps1-/- knockout mice, TA fatigability was greater than wild-type mice, and this was ameliorated with exercise. Whereas, in Seps1+/- heterozygous mice, exercise compromised TA endurance. These impairments in exercise capacity and TA contractile function were not associated with increased inflammation or a dysregulated redox state. Seps1 is highly expressed in muscle fibers and blood vessels. Interestingly, Nos1 and Vegfa mRNA transcripts were decreased in TA muscles from Seps1-/- knockout and Seps1-/+ heterozygous mice. Impaired exercise performance with Seps1 reduction or deletion cannot be attributed to heightened cellular stress, but it may potentially be mediated, in part, by the effects of Seps1 on the microvasculature.
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Affiliation(s)
- Alex Bernard Addinsall
- Centre for Molecular and Medical Research, School of Medicine, Deakin University, Geelong, Victoria, Australia.,Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Craig Robert Wright
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Taryan L Kotsiakos
- Centre for Molecular and Medical Research, School of Medicine, Deakin University, Geelong, Victoria, Australia
| | - Zoe M Smith
- School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | - Taylah R Cook
- School of Life and Environmental Sciences, Deakin University, Geelong, Victoria, Australia
| | | | - Chris van der Poel
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia
| | - Nicole Stupka
- Centre for Molecular and Medical Research, School of Medicine, Deakin University, Geelong, Victoria, Australia.,Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia.,Department of Medicine-Western Health, The University of Melbourne, St. Albans, Victoria, Australia.,Australian Institute for Musculoskeletal Science, St. Albans, Victoria, Australia
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15
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Schöneich C. Photo-Degradation of Therapeutic Proteins: Mechanistic Aspects. Pharm Res 2020; 37:45. [DOI: 10.1007/s11095-020-2763-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 01/15/2020] [Indexed: 12/11/2022]
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16
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Hawkins CL, Davies MJ. Detection, identification, and quantification of oxidative protein modifications. J Biol Chem 2019; 294:19683-19708. [PMID: 31672919 PMCID: PMC6926449 DOI: 10.1074/jbc.rev119.006217] [Citation(s) in RCA: 205] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Exposure of biological molecules to oxidants is inevitable and therefore commonplace. Oxidative stress in cells arises from both external agents and endogenous processes that generate reactive species, either purposely (e.g. during pathogen killing or enzymatic reactions) or accidentally (e.g. exposure to radiation, pollutants, drugs, or chemicals). As proteins are highly abundant and react rapidly with many oxidants, they are highly susceptible to, and major targets of, oxidative damage. This can result in changes to protein structure, function, and turnover and to loss or (occasional) gain of activity. Accumulation of oxidatively-modified proteins, due to either increased generation or decreased removal, has been associated with both aging and multiple diseases. Different oxidants generate a broad, and sometimes characteristic, spectrum of post-translational modifications. The kinetics (rates) of damage formation also vary dramatically. There is a pressing need for reliable and robust methods that can detect, identify, and quantify the products formed on amino acids, peptides, and proteins, especially in complex systems. This review summarizes several advances in our understanding of this complex chemistry and highlights methods that are available to detect oxidative modifications-at the amino acid, peptide, or protein level-and their nature, quantity, and position within a peptide sequence. Although considerable progress has been made in the development and application of new techniques, it is clear that further development is required to fully assess the relative importance of protein oxidation and to determine whether an oxidation is a cause, or merely a consequence, of injurious processes.
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Affiliation(s)
- Clare L Hawkins
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen 2200, Denmark
| | - Michael J Davies
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen 2200, Denmark
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17
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Weise-Cross L, Resta TC, Jernigan NL. Redox Regulation of Ion Channels and Receptors in Pulmonary Hypertension. Antioxid Redox Signal 2019; 31:898-915. [PMID: 30569735 PMCID: PMC7061297 DOI: 10.1089/ars.2018.7699] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 12/11/2018] [Indexed: 02/06/2023]
Abstract
Significance: Pulmonary hypertension (PH) is characterized by elevated vascular resistance due to vasoconstriction and remodeling of the normally low-pressure pulmonary vasculature. Redox stress contributes to the pathophysiology of this disease by altering the regulation and activity of membrane receptors, K+ channels, and intracellular Ca2+ homeostasis. Recent Advances: Antioxidant therapies have had limited success in treating PH, leading to a growing appreciation that reductive stress, in addition to oxidative stress, plays a role in metabolic and cell signaling dysfunction in pulmonary vascular cells. Reactive oxygen species generation from mitochondria and NADPH oxidases has substantial effects on K+ conductance and membrane potential, and both receptor-operated and store-operated Ca2+ entry. Critical Issues: Some specific redox changes resulting from oxidation, S-nitrosylation, and S-glutathionylation are known to modulate membrane receptor and ion channel activity in PH. However, many sites of regulation that have been elucidated in nonpulmonary cell types have not been tested in the pulmonary vasculature, and context-specific molecular mechanisms are lacking. Future Directions: Here, we review what is known about redox regulation of membrane receptors and ion channels in PH. Further investigation of the mechanisms involved is needed to better understand the etiology of PH and develop better targeted treatment strategies.
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Affiliation(s)
- Laura Weise-Cross
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Thomas C. Resta
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - Nikki L. Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
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18
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Changes in Redox Signaling in the Skeletal Muscle with Aging. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:4617801. [PMID: 30800208 PMCID: PMC6360032 DOI: 10.1155/2019/4617801] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 11/05/2018] [Accepted: 11/22/2018] [Indexed: 01/01/2023]
Abstract
Reduction in muscle strength with aging is due to both loss of muscle mass (quantity) and intrinsic force production (quality). Along with decreased functional capacity of the muscle, age-related muscle loss is associated with corresponding comorbidities and healthcare costs. Mitochondrial dysfunction and increased oxidative stress are the central driving forces for age-related skeletal muscle abnormalities. The increased oxidative stress in the aged muscle can lead to altered excitation-contraction coupling and calcium homeostasis. Furthermore, apoptosis-mediated fiber loss, atrophy of the remaining fibers, dysfunction of the satellite cells (muscle stem cells), and concomitant impaired muscle regeneration are also the consequences of increased oxidative stress, leading to a decrease in muscle mass, strength, and function of the aged muscle. Here we summarize the possible effects of oxidative stress in the aged muscle and the benefits of physical activity and antioxidant therapy.
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19
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Qaisar R, Bhaskaran S, Ranjit R, Sataranatarajan K, Premkumar P, Huseman K, Van Remmen H. Restoration of SERCA ATPase prevents oxidative stress-related muscle atrophy and weakness. Redox Biol 2018; 20:68-74. [PMID: 30296699 PMCID: PMC6174848 DOI: 10.1016/j.redox.2018.09.018] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/13/2018] [Accepted: 09/25/2018] [Indexed: 01/01/2023] Open
Abstract
Molecular targets to reduce muscle weakness and atrophy due to oxidative stress have been elusive. Here we show that activation of Sarcoplasmic Reticulum (SR) Ca2+ ATPase (SERCA) with CDN1163, a novel small molecule allosteric SERCA activator, ameliorates the muscle impairment in the CuZnSOD deficient (Sod1-/-) mouse model of oxidative stress. Sod1-/- mice are characterized by reduced SERCA activity, muscle weakness and atrophy, increased oxidative stress and mitochondrial dysfunction. Seven weeks of CDN1163 treatment completely restored SERCA activity and reversed the 23% reduction in gastrocnemius mass and 22% reduction in specific force in untreated Sod1-/- versus wild type mice. These changes were accompanied by restoration of autophagy protein markers to the levels found in wild-type mice. CDN1163 also reversed the increase in mitochondrial ROS generation and oxidative damage in muscle tissue from Sod1-/- mice. Taken together our findings suggest that the pharmacological restoration of SERCA is a promising therapeutic approach to counter oxidative stress-associated muscle impairment.
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Affiliation(s)
- Rizwan Qaisar
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Shylesh Bhaskaran
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Rojina Ranjit
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | | | - Pavithra Premkumar
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Kendra Huseman
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Holly Van Remmen
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA; Oklahoma City VA Medical Center, Oklahoma City, OK 73104, USA.
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20
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Carroll L, Pattison DI, Davies JB, Anderson RF, Lopez-Alarcon C, Davies MJ. Superoxide radicals react with peptide-derived tryptophan radicals with very high rate constants to give hydroperoxides as major products. Free Radic Biol Med 2018; 118:126-136. [PMID: 29496618 DOI: 10.1016/j.freeradbiomed.2018.02.033] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 02/22/2018] [Accepted: 02/23/2018] [Indexed: 11/23/2022]
Abstract
Oxidative damage is a common process in many biological systems and proteins are major targets for damage due to their high abundance and very high rate constants for reaction with many oxidants (both radicals and two-electron species). Tryptophan (Trp) residues on peptides and proteins are a major sink for a large range of biological oxidants as these side-chains have low radical reduction potentials. The resulting Trp-derived indolyl radicals (Trp•) have long lifetimes in some circumstances due to their delocalized structures, and undergo only slow reaction with molecular oxygen, unlike most other biological radicals. In contrast, we have shown previously that Trp• undergo rapid dimerization. In the current study, we show that Trp• also undergo very fast reaction with superoxide radicals, O2•-, with k 1-2 × 109 M-1 s-1. These values do not alter dramatically with peptide structure, but the values of k correlate with overall peptide positive charge, consistent with positive electrostatic interactions. These reactions compete favourably with Trp• dimerization and O2 addition, indicating that this may be a major fate in some circumstances. The Trp• + O2•- reactions occur primarily by addition, rather than electron transfer, with this resulting in high yields of Trp-derived hydroperoxides. Subsequent degradation of these species, both stimulated and native decay, gives rise to N-formylkynurenine, kynurenine, alcohols and diols. These data indicate that reaction of O2•- with Trp• should be considered as a major pathway to Trp degradation on peptides and proteins subjected to oxidative damage.
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Affiliation(s)
- Luke Carroll
- The Heart Research Institute, Sydney, Australia; Sydney Medical School, University of Sydney, Australia; Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Denmark
| | - David I Pattison
- The Heart Research Institute, Sydney, Australia; Sydney Medical School, University of Sydney, Australia
| | - Justin B Davies
- Australian Nuclear Science and Technology Organisation, Lucas Heights, Australia
| | - Robert F Anderson
- School of Chemical Sciences, University of Auckland, Auckland, New Zealand
| | - Camilo Lopez-Alarcon
- Departmento de Quimica Fisica, Facultad de Quimica, Pontificia Universidad Catolica de Chile, Chile
| | - Michael J Davies
- The Heart Research Institute, Sydney, Australia; Sydney Medical School, University of Sydney, Australia; Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Denmark.
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21
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Schöneich C. Novel chemical degradation pathways of proteins mediated by tryptophan oxidation: tryptophan side chain fragmentation. J Pharm Pharmacol 2017; 70:655-665. [DOI: 10.1111/jphp.12688] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 12/11/2016] [Indexed: 01/04/2023]
Abstract
Abstract
Objectives
This minireview focuses on novel degradation pathways of proteins in solution via intermediary tryptophan (Trp) radical cations, which are generated via photo-induced electron transfer to suitable acceptors such as disulfide bonds.
Methods
Gas-phase mass spectrometry studies had indicated the potential for Trp radical cations to fragment via release of 3-methylene-3H-indol-1-ium from the side chain. HPLC-MS/MS analysis demonstrates that analogous fragmentation reactions occur during the exposure of peptides and proteins to light or accelerated stability testing.
Key findings
The light exposure of selected peptides and monoclonal antibodies leads to the conversion of Trp to glycine (Gly) or glycine hydroperoxide (GlyOOH), where GlyOOH could be reduced to hydroxyglycine, which undergoes subsequent cleavage. Product formation is consistent with Cα–Cβ fragmentation of intermediary Trp radical cations. For the peptide octreotide and specific glycoforms of IgG1 Fc domains, Trp side chain cleavage in aqueous solution is indicated by the formation of 3-methyleneindolenine (3-MEI), which adds to nucleophilic side chains, for example to Lys residues adjacent to the original Trp residues.
Conclusions
Trp side chain cleavage leads to novel reaction products on specific peptide and protein sequences, which may have consequences for potency and immunogenicity.
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Affiliation(s)
- Christian Schöneich
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, KS, USA
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22
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Photo-oxidation of IgG1 and Model Peptides: Detection and Analysis of Triply Oxidized His and Trp Side Chain Cleavage Products. Pharm Res 2016; 34:229-242. [DOI: 10.1007/s11095-016-2058-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 10/24/2016] [Indexed: 12/15/2022]
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Abstract
Proteins are major targets for radicals and two-electron oxidants in biological systems due to their abundance and high rate constants for reaction. With highly reactive radicals damage occurs at multiple side-chain and backbone sites. Less reactive species show greater selectivity with regard to the residues targeted and their spatial location. Modification can result in increased side-chain hydrophilicity, side-chain and backbone fragmentation, aggregation via covalent cross-linking or hydrophobic interactions, protein unfolding and altered conformation, altered interactions with biological partners and modified turnover. In the presence of O2, high yields of peroxyl radicals and peroxides (protein peroxidation) are formed; the latter account for up to 70% of the initial oxidant flux. Protein peroxides can oxidize both proteins and other targets. One-electron reduction results in additional radicals and chain reactions with alcohols and carbonyls as major products; the latter are commonly used markers of protein damage. Direct oxidation of cysteine (and less commonly) methionine residues is a major reaction; this is typically faster than with H2O2, and results in altered protein activity and function. Unlike H2O2, which is rapidly removed by protective enzymes, protein peroxides are only slowly removed, and catabolism is a major fate. Although turnover of modified proteins by proteasomal and lysosomal enzymes, and other proteases (e.g. mitochondrial Lon), can be efficient, protein hydroperoxides inhibit these pathways and this may contribute to the accumulation of modified proteins in cells. Available evidence supports an association between protein oxidation and multiple human pathologies, but whether this link is causal remains to be established.
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Affiliation(s)
- Michael J Davies
- Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Blegdamsvej 3, Copenhagen 2200, Denmark
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24
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Houée-Lévin C, Bobrowski K, Horakova L, Karademir B, Schöneich C, Davies MJ, Spickett CM. Exploring oxidative modifications of tyrosine: An update on mechanisms of formation, advances in analysis and biological consequences. Free Radic Res 2015; 49:347-73. [DOI: 10.3109/10715762.2015.1007968] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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25
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Rutin stimulates sarcoplasmic reticulum Ca(2+)-ATPase activity (SERCA1) and protects SERCA1 from peroxynitrite mediated injury. Mol Cell Biochem 2014; 402:51-62. [PMID: 25547066 DOI: 10.1007/s11010-014-2313-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 12/20/2014] [Indexed: 01/13/2023]
Abstract
In this study we analyzed the protective action of the flavonoid rutin on peroxynitrite (ONOO(-)) mediated impairment of sarcoplasmic reticulum Ca(2+)-ATPase (SERCA1 isoform), especially related to posttranslational and conformational changes. Rutin concentration dependently protected ONOO(-) induced SERCA1 activity decrease with effective concentration EC50 of 18 ± 1.5 µM. Upon treatment with ONOO(-), this flavonoid also prevented SERCA1 from thiol group oxidation and significantly reduced tyrosine nitration and protein carbonyl formation. In the absence of ONOO(-), rutin (250 and 350 µM) stimulated SERCA1 activity at 2.1 mM [ATP] and 10 µM [Ca(2+)]free. According to changes in the kinetic parameters V max and K m with regard to [ATP], rutin (250 µM) increased the rate of enzyme catalysis and decreased the affinity of SERCA1 to ATP. FITC fluorescence decreased in the presence of rutin (150 and 250 µM), indicating conformational changes in the cytosolic ATP binding region of SERCA1. In silico study confirmed the binding of rutin in the cytosolic region of SERCA1, in the vicinity of the ATP binding site. Residue Glu183 localized within the conserved TGES loop was identified to play a key role in rutin-SERCA1 interaction (H-bond length of 1.7 Å), elucidating the ability of rutin to affect the affinity of SERCA1 to ATP. The binding of rutin in the proximity of Lys515 is likely to cause a decrease in FITC fluorescence.
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Schöneich C, Dremina E, Galeva N, Sharov V. Apoptosis in differentiating C2C12 muscle cells selectively targets Bcl-2-deficient myotubes. Apoptosis 2014; 19:42-57. [PMID: 24129924 DOI: 10.1007/s10495-013-0922-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Muscle cell apoptosis accompanies normal muscle development and regeneration, as well as degenerative diseases and aging. C2C12 murine myoblast cells represent a common model to study muscle differentiation. Though it was already shown that myogenic differentiation of C2C12 cells is accompanied by enhanced apoptosis in a fraction of cells, either the cell population sensitive to apoptosis or regulatory mechanisms for the apoptotic response are unclear so far. In the current study we characterize apoptotic phenotypes of different types of C2C12 cells at all stages of differentiation, and report here that myotubes of differentiated C2C12 cells with low levels of anti-apoptotic Bcl-2 expression are particularly vulnerable to apoptosis even though they are displaying low levels of pro-apoptotic proteins Bax, Bak and Bad. In contrast, reserve cells exhibit higher levels of Bcl-2 and high resistance to apoptosis. The transfection of proliferating myoblasts with Bcl-2 prior to differentiation did not protect against spontaneous apoptosis accompanying differentiation of C2C12 cells but led to Bcl-2 overexpression in myotubes and to significant protection from apoptotic cell loss caused by exposure to hydrogen peroxide. Overall, our data advocate for a Bcl-2-dependent mechanism of apoptosis in differentiated muscle cells. However, downstream processes for spontaneous and hydrogen peroxide induced apoptosis are not completely similar. Apoptosis in differentiating myoblasts and myotubes is regulated not through interaction of Bcl-2 with pro-apoptotic Bcl-2 family proteins such as Bax, Bak, and Bad.
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Endoplasmic reticulum stress in insulin resistance and diabetes. Cell Calcium 2014; 56:311-22. [PMID: 25239386 DOI: 10.1016/j.ceca.2014.08.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 08/07/2014] [Indexed: 02/07/2023]
Abstract
The endoplasmic reticulum is the main intracellular Ca(2+) store for Ca(2+) release during cell signaling. There are different strategies to avoid ER Ca(2+) depletion. Release channels utilize first Ca(2+)-bound to proteins and this minimizes the reduction of the free luminal [Ca(2+)]. However, if release channels stay open after exhaustion of Ca(2+)-bound to proteins, then the reduction of the free luminal ER [Ca(2+)] (via STIM proteins) activates Ca(2+) entry at the plasma membrane to restore the ER Ca(2+) load, which will work provided that SERCA pump is active. Nevertheless, there are several noxious conditions that result in decreased activity of the SERCA pump such as oxidative stress, inflammatory cytokines, and saturated fatty acids, among others. These conditions result in a deficient restoration of the ER [Ca(2+)] and lead to the ER stress response that should facilitate recovery of the ER. However, if the stressful condition persists then ER stress ends up triggering cell death and the ensuing degenerative process leads to diverse pathologies; particularly insulin resistance, diabetes and several of the complications associated with diabetes. This scenario suggests that limiting ER stress should decrease the incidence of diabetes and the mobility and mortality associated with this illness.
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Tadic V, Prell T, Lautenschlaeger J, Grosskreutz J. The ER mitochondria calcium cycle and ER stress response as therapeutic targets in amyotrophic lateral sclerosis. Front Cell Neurosci 2014; 8:147. [PMID: 24910594 PMCID: PMC4039088 DOI: 10.3389/fncel.2014.00147] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 05/07/2014] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive loss of upper and lower motor neurons. Although the etiology remains unclear, disturbances in calcium homoeostasis and protein folding are essential features of neurodegeneration in this disorder. Here, we review recent research findings on the interaction between endoplasmic reticulum (ER) and mitochondria, and its effect on calcium signaling and oxidative stress. We further provide insights into studies, providing evidence that structures of the ER mitochondria calcium cycle serve as a promising targets for therapeutic approaches for treatment of ALS.
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Affiliation(s)
- Vedrana Tadic
- Hans Berger Department of Neurology, Jena University HospitalJena, Germany
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Wang X, Ni L, Yang L, Duan Q, Chen C, Edin ML, Zeldin DC, Wang DW. CYP2J2-derived epoxyeicosatrienoic acids suppress endoplasmic reticulum stress in heart failure. Mol Pharmacol 2013; 85:105-15. [PMID: 24145329 DOI: 10.1124/mol.113.087122] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Prolonged endoplasmic reticulum (ER) stress causes apoptosis and is associated with heart failure. Whether CYP2J2 and its arachidonic acid metabolites [epoxyeicosatrienoic acids (EETs)] have a protective influence on ER stress and heart failure has not been studied. Assays of myocardial samples from patients with end-stage heart failure showed evidence of ER stress. Chronic infusion of isoproterenol (ISO) or angiotensin II (AngII) by osmotic mini-pump induced cardiac hypertrophy and heart failure in mice as evaluated by hemodynamic measurements and echocardiography. Interestingly, transgenic (Tr) mice with cardiomyocyte-specific CYP2J2 expression were protected against heart failure compared with wild-type mice. ISO or AngII administration induced ER stress and apoptosis, and increased levels of intracellular Ca(2+). These phenotypes were abolished by CYP2J2 overexpression in vivo or exogenous EETs treatment of cardiomyocytes in vitro. ISO or AngII reduced sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA2a) expression in hearts or isolated cardiomyocytes; however, loss of SERCA2a expression was prevented in CYP2J2 Tr hearts in vivo or in cardiomyocytes treated with EETs in vitro. The reduction of SERCA2a activity was concomitant with increased oxidation of SERCA2a. EETs reversed SERCA2a oxidation through increased expression of antioxidant enzymes and reduced reactive oxygen species levels. Tempol, a membrane-permeable radical scavenger, similarly decreased oxidized SERCA2a levels, restored SERCA2a activity, and markedly reduced ER stress response in the mice treated with ISO. In conclusion, CYP2J2-derived EETs suppress ER stress response in the heart and protect against cardiac failure by maintaining intracellular Ca(2+) homeostasis and SERCA2a expression and activity.
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Affiliation(s)
- Xingxu Wang
- Department of Internal Medicine, Institute of Hypertension, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China (X.W., L.N., L.Y., Q.D., C.C., D.W.W.); and the Division of Intramural Research, National Institutes of Health National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina (M.L.E., D.C.Z.)
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Haywood J, Mozziconacci O, Allegre KM, Kerwin BA, Schöneich C. Light-induced conversion of Trp to Gly and Gly hydroperoxide in IgG1. Mol Pharm 2013; 10:1146-50. [PMID: 23363477 DOI: 10.1021/mp300680c] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The exposure of IgG1 in aqueous solution to light with λ = 254 nm or λ > 295 nm yields products consistent with Trp radical cation formation followed by (α)C-(β)C cleavage of the Trp side chain. The resulting glycyl radicals either are reduced to Gly or add oxygen prior to reduction to Gly hydroperoxide. Photoirradiation at λ = 254 nm targets Trp at positions 191 (light chain), 309 and 377 (heavy chain) while photoirradiation at λ > 295 nm targets Trp at position 309 (heavy chain). Mechanistically, the formation of Trp radical cations likely proceeds via photoinduced electron or hydrogen transfer to disulfide bonds, yielding thiyl radicals and thiols, where thiols may serve as reductants for the intermediary glycyl or glycylperoxyl radicals.
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Affiliation(s)
- Jessica Haywood
- Department of Pharmaceutical Chemistry, 2095 Constant Avenue, University of Kansas, 2095 Constant Avenue, Lawrence, Kansas 66047, USA
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Plasma Protein Hydroperoxides During Aging in Humans: Correlation with Paraoxonase 1 (PON1) Arylesterase Activity and Plasma Total Thiols. Arch Med Res 2013; 44:136-41. [DOI: 10.1016/j.arcmed.2013.01.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 01/18/2013] [Indexed: 11/19/2022]
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Sovari AA, Dudley SC. Reactive oxygen species-targeted therapeutic interventions for atrial fibrillation. Front Physiol 2012; 3:311. [PMID: 22934062 PMCID: PMC3429082 DOI: 10.3389/fphys.2012.00311] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 07/15/2012] [Indexed: 01/14/2023] Open
Abstract
Atrial fibrillation (AF) is the most common arrhythmia that requires medical attention, and its incidence is increasing. Current ion channel blockade therapies and catheter ablation have significant limitations in treatment of AF, mainly because they do not address the underlying pathophysiology of the disease. Oxidative stress has been implicated as a major underlying pathology that promotes AF; however, conventional antioxidants have not shown impressive therapeutic effects. A more careful design of antioxidant therapies and better selection of patients likely are required to treat effectively AF with antioxidant agents. Current evidence suggest inhibition of prominent cardiac sources of reactive oxygen species (ROS) such as nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and targeting subcellular compartments with the highest levels of ROS may prove to be effective therapies for AF. Increased serum markers of oxidative stress may be an important guide in selecting the AF patients who will most likely respond to antioxidant therapy.
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Affiliation(s)
- Ali A Sovari
- Section of Cardiology, Center for Cardiovascular Research, University of Illinois at Chicago Chicago, IL, USA
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Abdelsaid MA, El-Remessy AB. S-glutathionylation of LMW-PTP regulates VEGF-mediated FAK activation and endothelial cell migration. J Cell Sci 2012; 125:4751-60. [PMID: 22854047 DOI: 10.1242/jcs.103481] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although promising, the ability to regulate angiogenesis through delivery of VEGF remains an unrealized goal. We have shown previously that physiological levels of peroxynitrite (1 µM) are required for a VEGF-mediated angiogenic response, yet the redox-regulated mechanisms that govern the VEGF signal remain unexplored. We assessed the impact of VEGF and peroxynitrite on modifying redox-state, the level of reduced-glutathione (GSH) and S-glutathionylation on regulation of the low molecular weight protein tyrosine phosphatase (LMW-PTP) and focal adhesion kinase (FAK), which are key mediators of VEGF-mediated cell migration. Stimulation of human microvascular endothelial (HME) cells with VEGF (20 ng/ml) or peroxynitrite (1 µM) caused an immediate and reversible negative-shift in the cellular redox-state and thiol oxidation of LMW-PTP, which culminated in cell migration. VEGF causes reversible S-glutathionylation of LMW-PTP, which inhibits its phosphorylation and activity, and causes the transient activation of FAK. Modulating the redox-state using decomposing peroxynitrite (FeTPPS, 2.5 µM) or the GSH-precursor [N-acetylcysteine (NAC), 1 mM] caused a positive-shift of the redox-state and prevented VEGF-mediated S-glutathionylation and oxidative inhibition of LMW-PTP. NAC and FeTPPS prevented the activation of FAK, its association with LMW-PTP and cell migration. Inhibiting LMW-PTP expression markedly enhanced FAK activation and cell migration. Although mild oxidative stress achieved by combining VEGF with 0.1-0.2 mM peroxynitrite augmented cell migration, an acute shift to oxidative stress achieved by combining VEGF with 0.5 mM peroxynitrite induced and sustained FAK activation, and LMW-PTP S-glutathionylation, resulting in LMW-PTP inactivation and inhibited cell migration. In conclusion, our findings demonstrate that a balanced redox-state is required for VEGF to facilitate reversible S-glutathionylation of LMW-PTP, FAK activation and endothelial cell migration. Shifting the redox-state to reductive stress or oxidative stress inhibited the VEGF-mediated angiogenic response.
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Abstract
We propose that the well-documented therapeutic actions of repeated physical activities over human lifespan are mediated by the rapidly turning over proto-oncogenic Myc (myelocytomatosis) network of transcription factors. This transcription factor network is unique in utilizing promoter and epigenomic (acetylation/deacetylation, methylation/demethylation) mechanisms for controlling genes that include those encoding intermediary metabolism (the primary source of acetyl groups), mitochondrial functions and biogenesis, and coupling their expression with regulation of cell growth and proliferation. We further propose that remote functioning of the network occurs because there are two arms of this network, which consists of driver cells (e.g., working myocytes) that metabolize carbohydrates, fats, proteins, and oxygen and produce redox-modulating metabolites such as H₂O₂, NAD⁺, and lactate. The exercise-induced products represent autocrine, paracrine, or endocrine signals for target recipient cells (e.g., aortic endothelium, hepatocytes, and pancreatic β-cells) in which the metabolic signals are coupled with genomic networks and interorgan signaling is activated. And finally, we propose that lactate, the major metabolite released from working muscles and transported into recipient cells, links the two arms of the signaling pathway. Recently discovered contributions of the Myc network in stem cell development and maintenance further suggest that regular physical activity may prevent age-related diseases such as cardiovascular pathologies, cancers, diabetes, and neurological functions through prevention of stem cell dysfunctions and depletion with aging. Hence, regular physical activities may attenuate the various deleterious effects of the Myc network on health, the wild side of the Myc-network, through modulating transcription of genes associated with glucose and energy metabolism and maintain a healthy human status.
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Affiliation(s)
- Kishorchandra Gohil
- Exercise Physiology Laboratory, Dept. of Integrative Biology, University of California, Berkeley, CA 94720, USA
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Pimentel D, Haeussler DJ, Matsui R, Burgoyne JR, Cohen RA, Bachschmid MM. Regulation of cell physiology and pathology by protein S-glutathionylation: lessons learned from the cardiovascular system. Antioxid Redox Signal 2012; 16:524-42. [PMID: 22010840 PMCID: PMC3270052 DOI: 10.1089/ars.2011.4336] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
SIGNIFICANCE Reactive oxygen and nitrogen species contributing to homeostatic regulation and the pathogenesis of various cardiovascular diseases, including atherosclerosis, hypertension, endothelial dysfunction, and cardiac hypertrophy, is well established. The ability of oxidant species to mediate such effects is in part dependent on their ability to induce specific modifications on particular amino acids, which alter protein function leading to changes in cell signaling and function. The thiol containing amino acids, methionine and cysteine, are the only oxidized amino acids that undergo reduction by cellular enzymes and are, therefore, prime candidates in regulating physiological signaling. Various reports illustrate the significance of reversible oxidative modifications on cysteine thiols and their importance in modulating cardiovascular function and physiology. RECENT ADVANCES The use of mass spectrometry, novel labeling techniques, and live cell imaging illustrate the emerging importance of reversible thiol modifications in cellular redox signaling and have advanced our analytical abilities. CRITICAL ISSUES Distinguishing redox signaling from oxidative stress remains unclear. S-nitrosylation as a precursor of S-glutathionylation is controversial and needs further clarification. Subcellular distribution of glutathione (GSH) may play an important role in local regulation, and targeted tools need to be developed. Furthermore, cellular redundancies of thiol metabolism complicate analysis and interpretation. FUTURE DIRECTIONS The development of novel pharmacological analogs that specifically target subcellular compartments of GSH to promote or prevent local protein S-glutathionylation as well as the establishment of conditional gene ablation and transgenic animal models are needed.
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Affiliation(s)
- David Pimentel
- Myocardial Biology Unit, Whitaker Cardiovascular Institute, Boston University School of Medicine, Massachusetts, USA
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Cook NL, Viola HM, Sharov VS, Hool LC, Schöneich C, Davies MJ. Myeloperoxidase-derived oxidants inhibit sarco/endoplasmic reticulum Ca2+-ATPase activity and perturb Ca2+ homeostasis in human coronary artery endothelial cells. Free Radic Biol Med 2012; 52:951-61. [PMID: 22214747 PMCID: PMC3736816 DOI: 10.1016/j.freeradbiomed.2011.12.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 11/24/2011] [Accepted: 12/01/2011] [Indexed: 12/30/2022]
Abstract
The sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) plays a critical role in Ca(2+) homeostasis via sequestration of this ion in the sarco/endoplasmic reticulum. The activity of this pump is inhibited by oxidants and impaired in aging tissues and cardiovascular disease. We have shown previously that the myeloperoxidase (MPO)-derived oxidants HOCl and HOSCN target thiols and mediate cellular dysfunction. As SERCA contains Cys residues critical to ATPase activity, we hypothesized that HOCl and HOSCN might inhibit SERCA activity, via thiol oxidation, and increase cytosolic Ca(2+) levels in human coronary artery endothelial cells (HCAEC). Exposure of sarcoplasmic reticulum vesicles to preformed or enzymatically generated HOCl and HOSCN resulted in a concentration-dependent decrease in ATPase activity; this was also inhibited by the SERCA inhibitor thapsigargin. Decomposed HOSCN and incomplete MPO enzyme systems did not decrease activity. Loss of ATPase activity occurred concurrent with oxidation of SERCA Cys residues and protein modification. Exposure of HCAEC, with or without external Ca(2+), to HOSCN or HOCl resulted in a time- and concentration-dependent increase in intracellular Ca(2+) under conditions that did not result in immediate loss of cell viability. Thapsigargin, but not inhibitors of plasma membrane or mitochondrial Ca(2+) pumps/channels, completely attenuated the increase in intracellular Ca(2+) consistent with a critical role for SERCA in maintaining endothelial cell Ca(2+) homeostasis. Angiotensin II pretreatment potentiated the effect of HOSCN at low concentrations. MPO-mediated modulation of intracellular Ca(2+) levels may exacerbate endothelial dysfunction, a key early event in atherosclerosis, and be more marked in smokers because of their higher SCN(-) levels.
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Affiliation(s)
- Naomi L. Cook
- Free Radical Group, The Heart Research Institute, 7 Eliza St, Newtown NSW 2042, Australia
| | - Helena M. Viola
- School of Biomedical, Biomolecular and Chemical Sciences, University of Western Australia, Crawley WA 6009, Australia
| | - Victor S. Sharov
- Department of Pharmaceutical Chemistry, University of Kansas, 2095 Constant Ave, Lawrence, Kansas 66047, USA
| | - Livia C. Hool
- School of Biomedical, Biomolecular and Chemical Sciences, University of Western Australia, Crawley WA 6009, Australia
| | - Christian Schöneich
- Department of Pharmaceutical Chemistry, University of Kansas, 2095 Constant Ave, Lawrence, Kansas 66047, USA
| | - Michael J. Davies
- Free Radical Group, The Heart Research Institute, 7 Eliza St, Newtown NSW 2042, Australia
- Faculty of Medicine, University of Sydney, Sydney, NSW 2006, Australia
- Corresponding author. Free Radical Group, The Heart Research Institute, Newtown, Sydney, NSW 2042, Australia. Fax: +61 2 9565 5584. (M.J. Davies)
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Suryo Rahmanto A, Davies MJ. Catalytic activity of selenomethionine in removing amino acid, peptide, and protein hydroperoxides. Free Radic Biol Med 2011; 51:2288-99. [PMID: 22015433 DOI: 10.1016/j.freeradbiomed.2011.09.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 09/23/2011] [Accepted: 09/23/2011] [Indexed: 11/21/2022]
Abstract
Selenium is a critical trace element, with deficiency associated with numerous diseases including cardiovascular disease, diabetes, and cancer. Selenomethionine (SeMet; a selenium analogue of the amino acid methionine, Met) is a major form of organic selenium and an important dietary source of selenium for selenoprotein synthesis in vivo. As selenium compounds can be readily oxidized and reduced, and selenocysteine residues play a critical role in the catalytic activity of the key protective enzymes glutathione peroxidase and thioredoxin reductase, we investigated the ability of SeMet (and its sulfur analogue, Met) to scavenge hydroperoxides present on amino acids, peptides, and proteins, which are key intermediates in protein oxidation. We show that SeMet, but not Met, can remove these species both stoichiometrically and catalytically in the presence of glutathione (GSH) or a thioredoxin reductase (TrxR)/thioredoxin (Trx)/NADPH system. Reaction of the hydroperoxide with SeMet results in selenoxide formation as detected by HPLC. Recycling of the selenoxide back to SeMet occurs rapidly with GSH, TrxR/NADPH, or a complete TrxR/Trx/NADPH reducing system, with this resulting in an enhanced rate of peroxide removal. In the complete TrxR/Trx/NADPH system loss of peroxide is essentially stoichiometric with NADPH consumption, indicative of a highly efficient system. Similar reactions do not occur with Met under these conditions. Studies using murine macrophage-like J774A.1 cells demonstrate a greater peroxide-removing capacity in cells supplemented with SeMet, compared to nonsupplemented controls. Overall, these findings demonstrate that SeMet may play an important role in the catalytic removal of damaging peptide and protein oxidation products.
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Zangar RC, Bollinger N, Weber TJ, Tan RM, Markillie LM, Karin NJ. Reactive oxygen species alter autocrine and paracrine signaling. Free Radic Biol Med 2011; 51:2041-7. [PMID: 21963990 PMCID: PMC3219223 DOI: 10.1016/j.freeradbiomed.2011.09.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 09/01/2011] [Accepted: 09/01/2011] [Indexed: 12/12/2022]
Abstract
Cytochrome P450 (P450) 3A4 (CYP3A4) is the most abundant P450 protein in human liver and intestine and is highly inducible by a variety of drugs and other compounds. The P450 catalytic cycle is known to uncouple and release reactive oxygen species (ROS), but the effects of ROS from P450 and other enzymes in the endoplasmic reticulum have been poorly studied from the perspective of effects on cell biology. In this study, we expressed low levels of CYP3A4 in HepG2 cells, a human hepatocarcinoma cell line, and examined effects on intracellular levels of ROS and on the secretion of a variety of growth factors that are important in extracellular communication. Using the redox-sensitive dye RedoxSensor red, we demonstrate that CYP3A4 expression increases levels of ROS in viable cells. A custom ELISA microarray platform was employed to demonstrate that expression of CYP3A4 increased secretion of amphiregulin, intracellular adhesion molecule 1, matrix metalloprotease 2, platelet-derived growth factor (PDGF), and vascular endothelial growth factor, but suppressed secretion of CD14. The antioxidant N-acetylcysteine suppressed all P450-dependent changes in protein secretion except for CD14. Quantitative RT-PCR demonstrated that changes in protein secretion were consistently associated with corresponding changes in gene expression. Inhibition of the NF-κB pathway blocked P450 effects on PDGF secretion. CYP3A4 expression also altered protein secretion in human mammary epithelial cells and C10 mouse lung cells. Overall, these results suggest that increased ROS production in the endoplasmic reticulum alters the secretion of proteins that have key roles in paracrine and autocrine signaling.
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Affiliation(s)
- Richard C Zangar
- Cell Biology and Biochemistry, Pacific Northwest National Laboratory, Richland, WA 99354, USA.
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Flavonoids in prevention of diseases with respect to modulation of Ca-pump function. Interdiscip Toxicol 2011; 4:114-24. [PMID: 22058652 PMCID: PMC3203913 DOI: 10.2478/v10102-011-0019-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 08/10/2011] [Accepted: 08/13/2011] [Indexed: 11/20/2022] Open
Abstract
Flavonoids, natural phenolic compounds, are known as agents with strong antioxidant properties. In many diseases associated with oxidative/nitrosative stress and aging they provide multiple biological health benefits. Ca2+-ATPases belong to the main calcium regulating proteins involved in the balance of calcium homeostasis, which is impaired in oxidative/nitrosative stress and related diseases or aging. The mechanisms of Ca2+-ATPases dysfunction are discussed, focusing on cystein oxidation and tyrosine nitration. Flavonoids act not only as antioxidants but are also able to bind directly to Ca2+-ATPases, thus changing their conformation, which results in modulation of enzyme activity. Dysfunction of Ca2+-ATPases is summarized with respect to their posttranslational and conformational changes in diseases related to oxidative/nitrosative stress and aging. Ca2+-ATPases are discussed as a therapeutic tool and the possible role of flavonoids in this process is suggested.
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Pycnogenol and Ginkgo biloba extract: effect on peroxynitrite-oxidized sarcoplasmic reticulum Ca-ATPase. Interdiscip Toxicol 2011; 3:132-6. [PMID: 21331179 PMCID: PMC3035570 DOI: 10.2478/v10102-010-0053-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 12/02/2010] [Accepted: 12/05/2010] [Indexed: 01/08/2023] Open
Abstract
The effect of two natural standardized plant extracts, Pycnogenol(®) and EGb 761, on sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) activity and posttranslational modifications induced by peroxynitrite was investigated to assess their possible protective role. EGb 761 was found to have a protective effect on SERCA activity in the concentration range of 5-40 µg/ml. On the other hand, Pycnogenol(®) caused a decrease of SERCA activity at concentrations of 25 µg/ml. EGb 761 did not prevent protein carbonyl formation upon oxidation with peroxynitrite. On the contrary, Pycnogenol(®) at the concentrations of 5 and 10 µg/ml significantly decreased the level of protein carbonyls by 44% and 54%, respectively. Neither Pycnogenol(®) nor EGb 761 exerted a protective effect against thiol group oxidation.The plant extracts studied modulated peroxynitrite-injured SERCA activity by different ways and failed to correlate with posttranslational modifications. Their effect seems to be associated with their ability to change SERCA conformation rather than by their antioxidant capacity.
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Gracanin M, Lam MA, Morgan PE, Rodgers KJ, Hawkins CL, Davies MJ. Amino acid, peptide, and protein hydroperoxides and their decomposition products modify the activity of the 26S proteasome. Free Radic Biol Med 2011; 50:389-99. [PMID: 21111806 DOI: 10.1016/j.freeradbiomed.2010.11.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Revised: 10/14/2010] [Accepted: 11/11/2010] [Indexed: 10/18/2022]
Abstract
Proteins are major biological targets for oxidative damage within cells because of their high abundance and rapid rates of reaction with radicals and singlet oxygen. These reactions generate high yields of hydroperoxides. The turnover of both native and modified/damaged proteins is critical for maintaining cell homeostasis, with this occurring via the proteasomal and endosomal-lysosomal systems; the former is of particular importance for intracellular proteins. In this study we have examined whether oxidation products generated on amino acids, peptides, and proteins modulate 26S proteasome activity. We show that oxidation products, and particularly protein hydroperoxides, are efficient inhibitors of the 26S proteasome tryptic and chymotryptic activities, with this depending, at least in part, on the presence of hydroperoxide groups. Removal of these species by reduction significantly reduces proteasome inhibition. This loss of activity is accompanied by a loss of thiol residues, but an absence of radical formation, consistent with molecular, rather than radical, reactions being responsible for proteasome inhibition. Aldehydes also seem to play a role in the inhibition of chymotryptic activity, with this prevented by treatment with NaBH(4), which reduces these groups. Inhibition occurred at hydroperoxide concentrations of ≥1μM for oxidized amino acids and peptides and ≥10μM for oxidized proteins, compared with ca. 100μM for H(2)O(2), indicating that H(2)O(2) is a much less effective inhibitor. These data indicate that the formation of oxidized proteins within cells may modulate cell function by interfering with the turnover of native proteins and the clearance of modified materials.
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Affiliation(s)
- Michelle Gracanin
- Free Radical Group, The Heart Research Institute, Newtown, Sydney, NSW 2042, Australia
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42
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Removal of amino acid, peptide and protein hydroperoxides by reaction with peroxiredoxins 2 and 3. Biochem J 2010; 432:313-21. [PMID: 20840079 DOI: 10.1042/bj20101156] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Prxs (peroxiredoxins) are a ubiquitous family of cysteine-dependent peroxidases that react rapidly with H2O2 and alkyl hydroperoxides and provide defence against these reactive oxidants. Hydroperoxides are also formed on amino acids and proteins during oxidative stress, and they too are a potential cause of biological damage. We have investigated whether Prxs react with amino acid, peptide and protein hydroperoxides, and whether the reactions are sufficiently rapid for these enzymes to provide antioxidant protection against these oxidants. Isolated Prx2, which is a cytosolic protein, and Prx3, which resides within mitochondria, were reacted with a selection of hydroperoxides generated by γ-radiolysis or singlet oxygen, on free amino acids, peptides and proteins. Reactions were followed by measuring the accumulation of disulfide-linked Prx dimers, via non-reducing SDS/PAGE, or the loss of the corresponding hydroperoxide, using quench-flow and LC (liquid chromatography)/MS. All the hydroperoxides induced rapid oxidation, with little difference in reactivity between Prx2 and Prx3. N-acetyl leucine hydroperoxides reacted with Prx2 with a rate constant of 4 × 10(4) M-1 · s-1. Hydroperoxides present on leucine, isoleucine or tyrosine reacted at a comparable rate, whereas histidine hydroperoxides were ~10-fold less reactive. Hydroperoxides present on lysozyme and BSA reacted with rate constants of ~100 M-1 · s-1. Addition of an uncharged derivative of leucine hydroperoxide to intact erythrocytes caused Prx2 oxidation with no concomitant loss in GSH, as did BSA hydroperoxide when added to concentrated erythrocyte lysate. Prxs are therefore favoured intracellular targets for peptide/protein hydroperoxides and have the potential to detoxify these species in vivo.
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43
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Rahmanto AS, Morgan PE, Hawkins CL, Davies MJ. Cellular effects of photogenerated oxidants and long-lived, reactive, hydroperoxide photoproducts. Free Radic Biol Med 2010; 49:1505-15. [PMID: 20708682 DOI: 10.1016/j.freeradbiomed.2010.08.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Revised: 08/02/2010] [Accepted: 08/05/2010] [Indexed: 11/22/2022]
Abstract
Reaction of radicals and singlet oxygen ((1)O(2)) with proteins results in both direct damage and the formation of long-lived reactive hydroperoxides. Elevated levels of protein hydroperoxide-derived products have been detected in multiple human pathologies, suggesting that these secondary oxidants contribute to tissue damage. Previous studies have provided evidence for protein hydroperoxide-mediated inhibition of thiol-dependent enzymes and modulation of signaling processes in isolated systems. In this study (1)O(2) and hydroperoxides have been generated in J774A.1 macrophage-like cells using visible light and the photosensitizer rose bengal, with the consequences of oxidant formation examined both immediately and after subsequent (dark-phase) incubation. Significant losses of GSH (≤50%), total thiols (≤20%), and activity of thiol-dependent proteins (GAPDH, thioredoxin, protein tyrosine phosphatases, creatine kinase, and cathepsins B and L; 10-50% inhibition) were detected after 1 or 2 min photo-oxidation. Non-thiol-dependent enzymes were not affected. In contrast, NADPH levels increased, together with the activity of glutathione reductase, glutathione peroxidase, and thioredoxin reductase; these increases may be components of a rapid global cytoprotective cellular response to stress. Neither oxidized thioredoxin nor radical-mediated protein oxidation products were detected at significant levels. Further decreases in thiol levels and enzyme activity occurred during dark-phase incubation, with this accompanied by decreased cell viability. These secondary events are ascribed to the reactions of long-lived hydroperoxides, generated by (1)O(2)-mediated reactions. Overall, this study provides novel insights into early cellular responses to photo-oxidative damage and indicates that long-lived hydroperoxides can play a significant role in cellular damage.
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44
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The myeloperoxidase-derived oxidant HOSCN inhibits protein tyrosine phosphatases and modulates cell signalling via the mitogen-activated protein kinase (MAPK) pathway in macrophages. Biochem J 2010; 430:161-9. [PMID: 20528774 PMCID: PMC2911680 DOI: 10.1042/bj20100082] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
MPO (myeloperoxidase) catalyses the oxidation of chloride, bromide and thiocyanate by hydrogen peroxide to HOCl (hypochlorous acid), HOBr (hypobromous acid) and HOSCN (hypothiocyanous acid) respectively. Specificity constants indicate that SCN− is a major substrate for MPO. HOSCN is also a major oxidant generated by other peroxidases including salivary, gastric and eosinophil peroxidases. While HOCl and HOBr are powerful oxidizing agents, HOSCN is a less reactive, but more specific, oxidant which targets thiols and especially low pKa species. In the present study we show that HOSCN targets cysteine residues present in PTPs (protein tyrosine phosphatases) with this resulting in a loss of PTP activity for the isolated enzyme, in cell lysates and intact J774A.1 macrophage-like cells. Inhibition also occurs with MPO-generated HOCl and HOBr, but is more marked with MPO-generated HOSCN, particularly at longer incubation times. This inhibition is reversed by dithiothreitol, particularly at early time points, consistent with the reversible oxidation of the active site cysteine residue to give either a cysteine–SCN adduct or a sulfenic acid. Inhibition of PTP activity is associated with increased phosphorylation of p38a and ERK2 (extracellular-signal-regulated kinase 2) as detected by Western blot analysis and phosphoprotein arrays, and results in altered MAPK (mitogen-activated protein kinase) signalling. These data indicate that the highly selective targeting of some protein thiols by HOSCN can result in perturbation of cellular phosphorylation and altered cell signalling. These changes occur with (patho)physiological concentrations of SCN− ions, and implicate HOSCN as an important mediator of inflammation-induced oxidative damage, particularly in smokers who have elevated plasma levels of SCN−.
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45
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Dong Y, Zhang M, Liang B, Xie Z, Zhao Z, Asfa S, Choi HC, Zou MH. Reduction of AMP-activated protein kinase alpha2 increases endoplasmic reticulum stress and atherosclerosis in vivo. Circulation 2010; 121:792-803. [PMID: 20124121 DOI: 10.1161/circulationaha.109.900928] [Citation(s) in RCA: 228] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Aberrant endoplasmic reticulum (ER) stress is associated with several cardiovascular diseases, including atherosclerosis. The mechanism by which aberrant ER stress develops is poorly understood. This study investigated whether dysfunction of AMP-activated protein kinase (AMPK) causes aberrant ER stress and atherosclerosis in vivo. METHODS AND RESULTS Human umbilical vein endothelial cells and mouse aortic endothelial cells from AMPK-deficient mice were used to assess the level of ER stress with Western blotting. Reduction of AMPKalpha2 expression significantly increased the level of ER stress in human umbilical vein endothelial cells. In addition, mouse aortic endothelial cells from AMPKalpha2 knockout (AMPKalpha2(-/-)) mice had higher expression of markers of ER stress and increased levels of intracellular Ca2+. These phenotypes were abolished by adenovirally overexpressing constitutively active AMPK mutants (Ad-AMPK-CA) or by transfecting sarcoendoplasmic reticulum calcium ATPase (SERCA). Inhibition of SERCA induced ER stress in endothelial cells. Furthermore, reduction of AMPKalpha expression suppressed SERCA activity. In addition, SERCA activity was significantly reduced concomitantly with increased oxidation of SERCA in mouse aortic endothelial cells from AMPKalpha2(-/-) mice. Both of these phenotypes were abolished by adenovirally overexpressing Ad-AMPK-CA. Furthermore, Tempol, which restored SERCA activity and decreased oxidized SERCA levels, markedly reduced the level of ER stress in mouse aortic endothelial cells from AMPKalpha2(-/-) mice. Finally, oral administration of tauroursodeoxycholic acid, a chemical chaperone that inhibits ER stress, significantly reduced both ER stress and aortic lesion development in low-density lipoprotein receptor- and AMPKalpha2-deficient mice. CONCLUSIONS These results suggest that AMPK functions as a physiological suppressor of ER stress by maintaining SERCA activity and intracellular Ca2+ homeostasis.
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Affiliation(s)
- Yunzhou Dong
- Department of Medicine and Endocrinology, University of Oklahoma Health Science Center, Oklahoma City, OK 73104, USA
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46
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Salanova M, Schiffl G, Blottner D. Atypical fast SERCA1a protein expression in slow myofibers and differential S-nitrosylation prevented by exercise during long term bed rest. Histochem Cell Biol 2009; 132:383-94. [DOI: 10.1007/s00418-009-0624-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2009] [Indexed: 10/20/2022]
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47
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Gracanin M, Hawkins CL, Pattison DI, Davies MJ. Singlet-oxygen-mediated amino acid and protein oxidation: formation of tryptophan peroxides and decomposition products. Free Radic Biol Med 2009; 47:92-102. [PMID: 19375501 DOI: 10.1016/j.freeradbiomed.2009.04.015] [Citation(s) in RCA: 364] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 02/10/2009] [Accepted: 04/10/2009] [Indexed: 10/20/2022]
Abstract
Proteins are major biological targets for oxidative damage within cells owing to their high abundance and rapid rates of reaction with radicals and excited-state species, including singlet oxygen. Reaction of Tyr, Trp, and His residues, both free and on proteins, with singlet oxygen generates peroxides in high yield. Peroxides have also been detected on proteins within intact cells on exposure to visible light in the presence of a photosensitizer. The structures of some of these materials have been elucidated for free amino acids, but less is known about peptide- and protein-bound species. In this study we have characterized Trp-derived peroxides, radicals, and breakdown products generated on free Trp and Trp residues in peptides and proteins, using LC/MS/MS. With free Trp, seven major photoproducts were characterized, including two isomeric hydroperoxides, two alcohols, two diols, and N-formylkynurenine, consistent with singlet oxygen-mediated reactions. The hydroperoxides decompose rapidly at elevated temperatures and in the presence of reductants to the corresponding alcohols. Some of these materials were detected on proteins after complete enzymatic (Pronase) hydrolysis and LC/MS/MS quantification, providing direct evidence for peroxide formation on proteins. This approach may allow the quantification of protein modification in intact cells arising from singlet oxygen formation.
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48
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Steinert JR, Wyatt AW, Jacob R, Mann GE. Redox modulation of Ca2+ signaling in human endothelial and smooth muscle cells in pre-eclampsia. Antioxid Redox Signal 2009; 11:1149-63. [PMID: 19125611 DOI: 10.1089/ars.2008.2303] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Pre-eclampsia (PE) is a leading cause of maternal hypertension in pregnancy and is associated with fetal growth restriction, premature birth, and fetal and maternal mortality. Activation and dysfunction of the maternal and fetal endothelium in PE appears to be a consequence of increased oxidative stress, resulting from elevated levels of circulating lipid peroxides. Accumulating evidence implicates reactive oxygen species (ROS) in the pathogenesis of vascular dysfunction in PE, perhaps involving a disturbance in intracellular Ca(2+) signaling. Several ion-transport pathways are highly sensitive to oxidative stress, and the resulting modulation of ion transport by ROS will affect intracellular Ca(2+) homeostasis. We review the evidence that changes in ion transport induced by ROS may be linked with abnormalities in Ca(2+)-mediated signal transduction, leading to endothelial and smooth muscle dysfunction in maternal and fetal circulations in PE. As dysregulation of Ca(2+) signaling in fetal umbilical endothelial cells is maintained in culture and embryonic, fetal, and postnatal development is affected by the cellular redox state, we hypothesize that impaired redox signaling in PE may influence "programming" of the fetal cardiovascular system and endothelial function in adulthood.
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Affiliation(s)
- Joern R Steinert
- Cardiovascular Division, School of Medicine, King's College London, London, England
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49
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Hawkins CL, Morgan PE, Davies MJ. Quantification of protein modification by oxidants. Free Radic Biol Med 2009; 46:965-88. [PMID: 19439229 DOI: 10.1016/j.freeradbiomed.2009.01.007] [Citation(s) in RCA: 338] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Revised: 01/12/2009] [Accepted: 01/12/2009] [Indexed: 12/19/2022]
Abstract
Proteins are major targets for oxidative damage due to their abundance and rapid rates of reaction with a wide range of radicals and excited state species, such as singlet oxygen. Exposure of proteins to these oxidants results in loss of the parent amino acid residue, formation of unstable intermediates, and the generation of stable products. Each of these events can be used, to a greater or lesser extent, to quantify damage to proteins. In this review the advantages and disadvantages of a number of these approaches are discussed, with an emphasis on methods that yield absolute quantitative data on the extent of protein modification. Detailed methods sheets are provided for many of these techniques.
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50
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Rosch JW, Sublett J, Gao G, Wang YD, Tuomanen EI. Calcium efflux is essential for bacterial survival in the eukaryotic host. Mol Microbiol 2008; 70:435-44. [PMID: 18761687 DOI: 10.1111/j.1365-2958.2008.06425.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In dynamic environments, intracellular homeostasis is maintained by transport systems found in all cells. While bacterial influx systems for essential trace cations are known to contribute to pathogenesis, efflux systems have been characterized mainly in contaminated environmental sites. We describe that the high calcium concentrations in the normal human host were toxic to pneumococci and that bacterial survival in vivo depended on CaxP, the first Ca2+ exporter reported in bacteria. CaxP homologues were found in the eukaryotic sacroplasmic reticulum and in many bacterial genomes. A caxP- mutant accumulated intracellular calcium, a state that was used to reveal signalling networks responsive to changes in intracellular calcium concentration. Chemical inhibition of CaxP was bacteriostatic in physiological calcium concentrations, suggesting a new antibiotic target uncovered under conditions in the eukaryotic host.
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Affiliation(s)
- Jason W Rosch
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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