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Gu Q, An Y, Xu M, Huang X, Chen X, Li X, Shan H, Zhang M. Disulfidptosis, A Novel Cell Death Pathway: Molecular Landscape and Therapeutic Implications. Aging Dis 2024:AD.2024.0083. [PMID: 38739940 DOI: 10.14336/ad.2024.0083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 05/02/2024] [Indexed: 05/16/2024] Open
Abstract
Programmed cell death is pivotal for several physiological processes, including immune defense. Further, it has been implicated in the pathogenesis of developmental disorders and the onset of numerous diseases. Multiple modes of programmed cell death, including apoptosis, pyroptosis, necroptosis, and ferroptosis, have been identified, each with their own unique characteristics and biological implications. In February 2023, Liu Xiaoguang and his team discovered "disulfidptosis," a novel pathway of programmed cell death. Their findings demonstrated that disulfidptosis is triggered in glucose-starved cells exhibiting high expression of a protein called SLC7A11. Furthermore, disulfidptosis is marked by a drastic imbalance in the NADPH/NADP+ ratio and the abnormal accumulation of disulfides like cystine. These changes ultimately lead to the destabilization of the F-actin network, causing cell death. Given that high SLC7A11 expression is a key feature of certain cancers, these findings indicate that disulfidptosis could serve as the basis of innovative anti-cancer therapies. Hence, this review delves into the discovery of disulfidptosis, its underlying molecular mechanisms and metabolic regulation, and its prospective applications in disease treatment.
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Affiliation(s)
- Qiuyang Gu
- Institute of Forensic Sciences, Suzhou Medical College, Soochow University, Suzhou, China
| | - Yumei An
- Institute of Forensic Sciences, Suzhou Medical College, Soochow University, Suzhou, China
| | - Mingyuan Xu
- Institute of Forensic Sciences, Suzhou Medical College, Soochow University, Suzhou, China
| | - Xinqi Huang
- Institute of Forensic Sciences, Suzhou Medical College, Soochow University, Suzhou, China
| | - Xueshi Chen
- Institute of Forensic Sciences, Suzhou Medical College, Soochow University, Suzhou, China
| | - Xianzhe Li
- Institute of Forensic Sciences, Suzhou Medical College, Soochow University, Suzhou, China
| | - Haiyan Shan
- Department of Obstetrics and Gynecology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
| | - Mingyang Zhang
- Institute of Forensic Sciences, Suzhou Medical College, Soochow University, Suzhou, China
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Carvajal P, Bahamondes V, Jara D, Castro I, Matus S, Aguilera S, Molina C, González S, Hermoso M, Barrera MJ, González MJ. The integrated stress response is activated in the salivary glands of Sjögren's syndrome patients. Front Med (Lausanne) 2023; 10:1118703. [PMID: 37035319 PMCID: PMC10079080 DOI: 10.3389/fmed.2023.1118703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 03/08/2023] [Indexed: 04/11/2023] Open
Abstract
Introduction Primary Sjögren's syndrome (SS) is an autoimmune exocrinopathy that affects the structure and function of salivary and lachrymal glands. Labial salivary gland (LSG) acinar cells from SS patients lose cellular homeostasis and experience endoplasmic reticulum and oxidative stress. The integrated cellular stress response (ISR) is an adaptive pathway essential for restoring homeostasis against various stress-inducing factors, including pro-inflammatory cytokines, and endoplasmic reticulum and oxidative stress. ISR activation leads eIF2α phosphorylation, which transiently blocks protein synthesis while allowing the ATF4 expression, which induces a gene expression program that seeks to optimize cellular recovery. PKR, HRI, GCN2, and PERK are the four sentinel stress kinases that control eIF2α phosphorylation. Dysregulation and chronic activation of ISR signaling have pathologic consequences associated with inflammation. Methods Here, we analyzed the activation of the ISR in LSGs of SS-patients and non-SS sicca controls, determining the mRNA, protein, and phosphorylated-protein levels of key ISR components, as well as the expression of some of ATF4 targets. Moreover, we performed a qualitative characterization of the distribution of ISR components in LSGs from both groups and evaluated if their levels correlate with clinical parameters. Results We observed that the four ISR sensors are expressed in LSGs of both groups. However, only PKR and PERK showed increased expression and/or activation in LSGs from SS-patients. eIF2α and p-eIF2α protein levels significantly increased in SS-patients; meanwhile components of the PP1c complex responsible for eIF2α dephosphorylation decreased. ATF4 mRNA levels were decreased in LSGs from SS-patients along with hypermethylation of the ATF4 promoter. Despite low mRNA levels, SS-patients showed increased levels of ATF4 protein and ATF4-target genes involved in the antioxidant response. The acinar cells of SS-patients showed increased staining intensity for PKR, p-PKR, p-PERK, p-eIF2α, ATF4, xCT, CHOP, and NRF2. Autoantibodies, focus score, and ESSDAI were correlated with p-PERK/PERK ratio and ATF4 protein levels. Discussion In summary, the results showed an increased ISR activation in LSGs of SS-patients. The increased protein levels of ATF4 and ATF4-target genes involved in the redox homeostasis could be part of a rescue response against the various stressful conditions to which the LSGs of SS-patients are subjected and promote cell survival.
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Affiliation(s)
- Patricia Carvajal
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Verónica Bahamondes
- Departamento de Tecnología Médica, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Edison Biotechnology Institute, Ohio University, Athens, OH, United States
| | - Daniela Jara
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Isabel Castro
- Departamento de Tecnología Médica, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Soledad Matus
- Fundación Ciencia and Vida, Santiago, Chile
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Providencia, Santiago, Chile
| | - Sergio Aguilera
- Departamento de Reumatología, Clínica INDISA, Santiago, Chile
| | - Claudio Molina
- Facultad de Odontología y Ciencias de la Rehabilitación, Universidad San Sebastián, Bellavista, Santiago, Chile
| | - Sergio González
- Escuela de Odontología, Facultad de Medicina y Ciencias de la Salud, Universidad Mayor, Santiago, Chile
| | - Marcela Hermoso
- Programa de Inmunología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - María-José Barrera
- Facultad de Odontología y Ciencias de la Rehabilitación, Universidad San Sebastián, Bellavista, Santiago, Chile
- María-José Barrera,
| | - María-Julieta González
- Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
- *Correspondence: María-Julieta González,
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Chen S, Zhu JY, Zang X, Zhai YZ. The Emerging Role of Ferroptosis in Liver Diseases. Front Cell Dev Biol 2022; 9:801365. [PMID: 34970553 PMCID: PMC8713249 DOI: 10.3389/fcell.2021.801365] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 11/22/2021] [Indexed: 12/23/2022] Open
Abstract
Ferroptosis is a newly discovered type of cell death mediated by iron-dependent lipid peroxide. The disturbance of iron metabolism, imbalance of the amino acid antioxidant system, and lipid peroxide accumulation are considered distinct fingerprints of ferroptosis. The dysregulation of ferroptosis has been intensively studied in recent years due to its participation in various diseases, including cancer, kidney injury, and neurodegenerative diseases. Notably, increasing evidence indicates that ferroptosis plays different roles in a wide spectrum of liver diseases. On the one hand, inhibiting ferroptosis may counteract the pathophysiological progression of several liver diseases, such as alcoholic liver injury, nonalcoholic steatosis hepatitis and fibrosis. On the other hand, inducing ferroptosis may restrict the emergence of secondary resistance to current medicines, such as sorafenib, for hepatocellular carcinoma (HCC) therapy. Here, we summarize the biological characteristics and regulatory signalling pathways of ferroptosis involved in liver disease. The current available medical agents targeting ferroptosis, including inducers or inhibitors applied in liver diseases, are also reviewed. This work aims to provide new insight into the emerging role of pathogenesis and therapeutic approaches for liver diseases.
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Affiliation(s)
- Si Chen
- Department of Neurology, The Fourth Affiliated Hospital of China Medical University, Shenyang, China
| | - Jun-Yao Zhu
- Department of Infectious Disease, Shengjing Hospital of China Medical University, Shenyang, China
| | - Xin Zang
- Department of Infectious Disease, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yong-Zhen Zhai
- Department of Infectious Disease, Shengjing Hospital of China Medical University, Shenyang, China
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Ananth S, Miyauchi S, Thangaraju M, Jadeja RN, Bartoli M, Ganapathy V, Martin PM. Selenomethionine (Se-Met) Induces the Cystine/Glutamate Exchanger SLC7A11 in Cultured Human Retinal Pigment Epithelial (RPE) Cells: Implications for Antioxidant Therapy in Aging Retina. Antioxidants (Basel) 2020; 10:antiox10010009. [PMID: 33374239 PMCID: PMC7823377 DOI: 10.3390/antiox10010009] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 12/15/2020] [Accepted: 12/21/2020] [Indexed: 12/12/2022] Open
Abstract
Oxidative damage has been identified as a major causative factor in degenerative diseases of the retina; retinal pigment epithelial (RPE) cells are at high risk. Hence, identifying novel strategies for increasing the antioxidant capacity of RPE cells, the purpose of this study, is important. Specifically, we evaluated the influence of selenium in the form of selenomethionine (Se-Met) in cultured RPE cells on system xc- expression and functional activity and on cellular levels of glutathione, a major cellular antioxidant. ARPE-19 and mouse RPE cells were cultured with and without selenomethionine (Se-Met), the principal form of selenium in the diet. Promoter activity assay, uptake assay, RT-PCR, northern and western blots, and immunofluorescence were used to analyze the expression of xc-, Nrf2, and its target genes. Se-Met activated Nrf2 and induced the expression and function of xc- in RPE. Other target genes of Nrf2 were also induced. System xc- consists of two subunits, and Se-Met induced the subunit responsible for transport activity (SLC7A11). Selenocysteine also induced xc- but with less potency. The effect of Se-met on xc- was associated with an increase in maximal velocity and an increase in substrate affinity. Se-Met increased the cellular levels of glutathione in the control, an oxidatively stressed RPE. The Se-Met effect was selective; under identical conditions, taurine transport was not affected and Na+-coupled glutamate transport was inhibited. This study demonstrates that Se-Met enhances the antioxidant capacity of RPE by inducing the transporter xc- with a consequent increase in glutathione.
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Affiliation(s)
- Sudha Ananth
- Department of Biochemistry and Molecular Biology, Augusta University, Augusta, GA 30912, USA; (S.A.); (S.M.); (M.T.); (R.N.J.)
| | - Seiji Miyauchi
- Department of Biochemistry and Molecular Biology, Augusta University, Augusta, GA 30912, USA; (S.A.); (S.M.); (M.T.); (R.N.J.)
| | - Muthusamy Thangaraju
- Department of Biochemistry and Molecular Biology, Augusta University, Augusta, GA 30912, USA; (S.A.); (S.M.); (M.T.); (R.N.J.)
| | - Ravirajsinh N. Jadeja
- Department of Biochemistry and Molecular Biology, Augusta University, Augusta, GA 30912, USA; (S.A.); (S.M.); (M.T.); (R.N.J.)
- Culver Vision Discovery Institute, Augusta University, Augusta, GA 30912, USA;
| | - Manuela Bartoli
- Culver Vision Discovery Institute, Augusta University, Augusta, GA 30912, USA;
- Department of Ophthalmology, Augusta University, Augusta, GA 30912, USA
| | - Vadivel Ganapathy
- Department of Cell Biology and Biochemistry, Texas Tech Health Science Center, Lubbock, TX 79430, USA;
| | - Pamela M. Martin
- Department of Biochemistry and Molecular Biology, Augusta University, Augusta, GA 30912, USA; (S.A.); (S.M.); (M.T.); (R.N.J.)
- Culver Vision Discovery Institute, Augusta University, Augusta, GA 30912, USA;
- Department of Ophthalmology, Augusta University, Augusta, GA 30912, USA
- Georgia Cancer Center, Augusta University, Augusta, GA 30912, USA
- Correspondence: ; Tel.: +706-721-4220; Fax: +706-721-6608
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Olson KR, Gao Y, DeLeon ER, Markel TA, Drucker N, Boone D, Whiteman M, Steiger AK, Pluth MD, Tessier CR, Stahelin RV. Extended hypoxia-mediated H 2 S production provides for long-term oxygen sensing. Acta Physiol (Oxf) 2020; 228:e13368. [PMID: 31442361 DOI: 10.1111/apha.13368] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 08/16/2019] [Accepted: 08/18/2019] [Indexed: 12/23/2022]
Abstract
AIM Numerous studies have shown that H2 S serves as an acute oxygen sensor in a variety of cells. We hypothesize that H2 S also serves in extended oxygen sensing. METHODS Here, we compare the effects of extended exposure (24-48 hours) to varying O2 tensions on H2 S and polysulphide metabolism in human embryonic kidney (HEK 293), human adenocarcinomic alveolar basal epithelial (A549), human colon cancer (HTC116), bovine pulmonary artery smooth muscle, human umbilical-derived mesenchymal stromal (stem) cells and porcine tracheal epithelium (PTE) using sulphur-specific fluorophores and fluorometry or confocal microscopy. RESULTS All cells continuously produced H2 S in 21% O2 and H2 S production was increased at lower O2 tensions. Decreasing O2 from 21% to 10%, 5% and 1% O2 progressively increased H2 S production in HEK293 cells and this was partially inhibited by a combination of inhibitors of H2 S biosynthesis, aminooxyacetate, propargyl glycine and compound 3. Mitochondria appeared to be the source of much of this increase in HEK 293 cells. H2 S production in all other cells and PTE increased when O2 was lowered from 21% to 5% except for HTC116 cells where 1% O2 was necessary to increase H2 S, presumably reflecting the hypoxic environment in vivo. Polysulphides (H2 Sn , where n = 2-7), the key signalling metabolite of H2 S also appeared to increase in many cells although this was often masked by high endogenous polysulphide concentrations. CONCLUSION These results show that cellular H2 S is increased during extended hypoxia and they suggest this is a continuously active O2 -sensing mechanism in a variety of cells.
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Affiliation(s)
- Kenneth R. Olson
- Indiana University School of Medicine‐South Bend South Bend Indiana
| | - Yan Gao
- Indiana University School of Medicine‐South Bend South Bend Indiana
| | - Eric R. DeLeon
- Indiana University School of Medicine‐South Bend South Bend Indiana
- Department of Biological Sciences University of Notre Dame Notre Dame Indiana
| | - Troy A. Markel
- Indiana University School of Medicine Riley Hospital for Children at IU Health Indianapolis Indiana
| | - Natalie Drucker
- Indiana University School of Medicine Riley Hospital for Children at IU Health Indianapolis Indiana
| | - David Boone
- Indiana University School of Medicine‐South Bend South Bend Indiana
| | | | - Andrea K. Steiger
- Department of Chemistry and Biochemistry University of Oregon Eugene Oregon
| | - Michael D. Pluth
- Department of Chemistry and Biochemistry University of Oregon Eugene Oregon
| | | | - Robert V. Stahelin
- Department of Medicinal Chemistry and Molecular Pharmacology Purdue University West Lafayette Indiana
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Olson KR. Reactive oxygen species or reactive sulfur species: why we should consider the latter. ACTA ACUST UNITED AC 2020; 223:223/4/jeb196352. [PMID: 32102833 DOI: 10.1242/jeb.196352] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The biological effects of oxidants, especially reactive oxygen species (ROS), include signaling functions (oxidative eustress), initiation of measures to reduce elevated ROS (oxidative stress), and a cascade of pathophysiological events that accompany excessive ROS (oxidative distress). Although these effects have long been studied in animal models with perturbed ROS, their actions under physiological conditions are less clear. I propose that some of the apparent uncertainty may be due to confusion of ROS with endogenously generated reactive sulfur species (RSS). ROS and RSS are chemically similar, but RSS are more reactive and versatile, and can be stored and reused. Both ROS and RSS signal via oxidation reactions with protein cysteine sulfur and they produce identical effector responses, but RSS appear to be more effective. RSS in the form of persulfidated cysteines (Cys-S-S) are produced endogenously and co-translationally introduced into proteins, and there is increasing evidence that many cellular proteins are persulfidated. A number of practical factors have contributed to confusion between ROS and RSS, and these are discussed herein. Furthermore, essentially all endogenous antioxidant enzymes appeared shortly after life began, some 3.8 billion years ago, when RSS metabolism dominated evolution. This was long before the rise in ROS, 600 million years ago, and I propose that these same enzymes, with only minor modifications, still effectively metabolize RSS in extant organisms. I am not suggesting that all ROS are RSS; however, I believe that the relative importance of ROS and RSS in biological systems needs further consideration.
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Affiliation(s)
- Kenneth R Olson
- Indiana University School of Medicine-South Bend, Raclin Carmichael Hall, 1234 Notre Dame Avenue, South Bend, IN 46617, USA
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Olson KR, Briggs A, Devireddy M, Xian M, Gao Y. Are the beneficial effects of 'antioxidant' lipoic acid mediated through metabolism of reactive sulfur species? Free Radic Biol Med 2020; 146:139-149. [PMID: 31676393 DOI: 10.1016/j.freeradbiomed.2019.10.410] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 10/08/2019] [Accepted: 10/21/2019] [Indexed: 12/28/2022]
Abstract
The health benefits of lipoic acid (LA) are generally attributed to mitigating the harmful effects of reactive oxygen species (ROS). ROS are chemically similar to reactive sulfur species (RSS) and signal through identical mechanisms. Here we examined the effects of LA on RSS in HEK293 cells using H2S and polysulfide (PS) specific fluorophores, AzMC and SSP4. We show that LA concentration-dependently increased both H2S and PS. Physioxia (5% O2) augmented the effects of LA on H2S production but decreased PS production. Thiosulfate, a known substrate for reduced LA, and an intermediate in the catabolism of H2S enhanced the effects of LA on H2S and PS production. Inhibiting peroxiredoxins with conoidin A and gluraredoxins with tiopronin augmented the effects of LA on PS and H2S, respectively while decreasing glutathione with buthionine-sulfoximine (BSO) or diethyl maleate (DEM) decreased the stimulatory effect of LA on H2S production but augmented LA's effect on PS. Aminooxyacetate (AOA) and propargylglycine (PPG), inhibitors of H2S production from cysteine partially inhibited LA augmentation of H2S production and further decreased the LA effect when applied concurrently with BSO and DEM. The selective and cell-permeable H2S scavenger, SS20, inhibited the effects of LA on cellular H2S. Estimates of single-cell H2S production suggest that 0.1-0.2% of O2 consumption is used to metabolize H2S and these requirements may increase to 1-2% with 1 mM LA. Collectively, these results suggest that LA rescues H2S from irreversible oxidation and that the effects of LA on RSS directly confer antioxidant, anti-inflammatory and cytoprotective responses. They also suggest that TS may be an effective supplement to increase the efficacy of LA in clinical settings.
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Affiliation(s)
- Kenneth R Olson
- Indiana University School of Medicine, South Bend Center, South Bend, IN, 46617, USA; Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, 46556, USA.
| | - Austin Briggs
- Indiana University School of Medicine, South Bend Center, South Bend, IN, 46617, USA
| | - Monesh Devireddy
- Indiana University School of Medicine, South Bend Center, South Bend, IN, 46617, USA
| | - Ming Xian
- Department of Chemistry, Washington State University, Pullman, WA, 99164, USA
| | - Yan Gao
- Indiana University School of Medicine, South Bend Center, South Bend, IN, 46617, USA
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Fournier M, Monin A, Ferrari C, Baumann PS, Conus P, Do K. Implication of the glutamate-cystine antiporter xCT in schizophrenia cases linked to impaired GSH synthesis. NPJ SCHIZOPHRENIA 2017; 3:31. [PMID: 28924227 PMCID: PMC5603608 DOI: 10.1038/s41537-017-0035-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 08/22/2017] [Accepted: 08/23/2017] [Indexed: 12/30/2022]
Abstract
xCT is the specific chain of the cystine/glutamate antiporter, which is widely reported to support anti-oxidant defenses in vivo. xCT is therefore at the crossroads between two processes that are involved in schizophrenia: oxidative stress and glutamatergic neurotransmission. But data from human studies implicating xCT in the illness and clarifying the upstream mechanisms of xCT imbalance are still scarce. Low glutathione (GSH) levels and genetic risk in GCLC (Glutamate–Cysteine Ligase Catalytic subunit), the gene of limiting synthesizing enzyme for GSH, are both associated with schizophrenia. In the present study, we aimed at determining if xCT regulation by the redox system is involved in schizophrenia pathophysiology. We assessed whether modulating GCLC expression impact on xCT expression and activity (i) in fibroblasts from patients and controls with different GCLC genotypes which are known to affect GCLC regulation and GSH levels; (ii) in rat brain glial cells, i.e., astrocytes and oligodendrocytes, with a knock-down of GCLC. Our results highlight that decreased GCLC expression leads to an upregulation of xCT levels in patients’ fibroblasts as well as in astrocytes. These results support the implication of xCT dysregulation in illness pathophysiology and further indicate that it can result from redox changes. Additionally, we showed that these anomalies may already take place at early stages of psychosis and be more prominent in a subgroup of patients with GCLC high-risk genotypes. These data add to the existing evidence identifying the inflammatory/redox systems as important targets to treat schizophrenia already at early stages. Deficit of antioxidant synthesis in schizophrenia leads to oxidative stress and changes in neurotransmitter transporter. Led by Kim Do, a team of researchers from Lausanne University in Switzerland investigated the role of the cell-surface transport protein xCT in schizophrenia. They found that an enzyme responsible for antioxidant production is disturbed in patients. This leads to decreased antioxidant levels and consequently to oxidative stress—i.e. the accumulation of reactive oxygen molecules, damaging the cells component and impairing cell functioning—which in turn affects the functioning of the antioxidant pathway, including xCT. xCT, which exports the neurotransmitter glutamate, is thus overproduced in schizophrenia. The resulting increase of neurotransmitter activity, alongside the increase in oxidative stress, is thought to play a major role in the pathophysiology of schizophrenia, including at early stages of the disease.
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Affiliation(s)
- M Fournier
- Department of Psychiatry, Center for Psychiatric Neuroscience, Lausanne University Hospital, Switzerland, Switzerland
| | - A Monin
- Department of Psychiatry, Center for Psychiatric Neuroscience, Lausanne University Hospital, Switzerland, Switzerland
| | - C Ferrari
- Department of Psychiatry, Center for Psychiatric Neuroscience, Lausanne University Hospital, Switzerland, Switzerland
| | - P S Baumann
- Department of Psychiatry, Center for Psychiatric Neuroscience, Lausanne University Hospital, Switzerland, Switzerland.,Department of Psychiatry, Service of general psychiatry, Lausanne University Hospital, Switzerland, Switzerland
| | - P Conus
- Department of Psychiatry, Service of general psychiatry, Lausanne University Hospital, Switzerland, Switzerland
| | - K Do
- Department of Psychiatry, Center for Psychiatric Neuroscience, Lausanne University Hospital, Switzerland, Switzerland.
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Čapek J, Hauschke M, Brůčková L, Roušar T. Comparison of glutathione levels measured using optimized monochlorobimane assay with those from ortho-phthalaldehyde assay in intact cells. J Pharmacol Toxicol Methods 2017. [PMID: 28642085 DOI: 10.1016/j.vascn.2017.06.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Fluorometric glutathione assays have been generally preferred for their high specificity and sensitivity. An additional advantage offered by fluorescent bimane dyes is their ability to penetrate inside the cell. Their ability to react with glutathione within intact cells is frequently useful in flow cytometry and microscopy. Hence, the aims of our study were to use monochlorobimane for optimizing a spectrofluorometric glutathione assay in cells and then to compare that assay with the frequently used ortho-phthalaldehyde assay. We used glutathione-depleting agents (e.g., cisplatin and diethylmalonate) to induce cell impairment. For glutathione assessment, monochlorobimane (40μM) was added to cells and fluorescence was detected at 394/490nm. In addition to the regularly used calculation of glutathione levels from fluorescence change after 60min, we used an optimized calculation from the linear part of the fluorescence curve after 10min of measurement. We found that 10min treatment of cells with monochlorobimane is sufficient for evaluating cellular glutathione concentration and provides results entirely comparable with those from the standard ortho-phthalaldehyde assay. In contrast, the results obtained by the standardly used evaluation after 60min of monochlorobimane treatment provided higher glutathione values. We conclude that measuring glutathione using monochlorobimane with the here-described optimized evaluation of fluorescence signal could be a simple and useful method for routine and rapid assessment of glutathione within intact cells in large numbers of samples.
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Affiliation(s)
- Jan Čapek
- Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic
| | - Martina Hauschke
- Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic
| | - Lenka Brůčková
- Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic
| | - Tomáš Roušar
- Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic.
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10
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Kong L, Albano R, Madayag A, Raddatz N, Mantsch JR, Choi S, Lobner D, Baker DA. Pituitary Adenylate cyclase-activating polypeptide orchestrates neuronal regulation of the astrocytic glutamate-releasing mechanism system xc (.). J Neurochem 2016; 137:384-93. [PMID: 26851652 DOI: 10.1111/jnc.13566] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 01/28/2016] [Accepted: 02/01/2016] [Indexed: 12/26/2022]
Abstract
Glutamate signaling is achieved by an elaborate network involving neurons and astrocytes. Hence, it is critical to better understand how neurons and astrocytes interact to coordinate the cellular regulation of glutamate signaling. In these studies, we used rat cortical cell cultures to examine whether neurons or releasable neuronal factors were capable of regulating system xc (-) (Sxc), a glutamate-releasing mechanism that is expressed primarily by astrocytes and has been shown to regulate synaptic transmission. We found that astrocytes cultured with neurons or exposed to neuronal-conditioned media displayed significantly higher levels of Sxc activity. Next, we demonstrated that the pituitary adenylate cyclase-activating polypeptide (PACAP) may be a neuronal factor capable of regulating astrocytes. In support, we found that PACAP expression was restricted to neurons, and that PACAP receptors were expressed in astrocytes. Interestingly, blockade of PACAP receptors in cultures comprised of astrocytes and neurons significantly decreased Sxc activity to the level observed in purified astrocytes, whereas application of PACAP to purified astrocytes increased Sxc activity to the level observed in cultures comprised of neurons and astrocytes. Collectively, these data reveal that neurons coordinate the actions of glutamate-related mechanisms expressed by astrocytes, such as Sxc, a process that likely involves PACAP. A critical gap in modeling excitatory signaling is how distinct components of the glutamate system expressed by neurons and astrocytes are coordinated. In these studies, we found that system xc (-) (Sxc), a glutamate release mechanism expressed by astrocytes, is regulated by releasable neuronal factors including PACAP. This represents a novel form of neuron-astrocyte communication, and highlights the possibility that pathological changes involving astrocytic Sxc may stem from altered neuronal activity.
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Affiliation(s)
- Linghai Kong
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Rebecca Albano
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Aric Madayag
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Nicholas Raddatz
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - John R Mantsch
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - SuJean Choi
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Doug Lobner
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - David A Baker
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, USA
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Womersley JS, Uys JD. S-Glutathionylation and Redox Protein Signaling in Drug Addiction. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 137:87-121. [PMID: 26809999 DOI: 10.1016/bs.pmbts.2015.10.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Drug addiction is a chronic relapsing disorder that comes at a high cost to individuals and society. Therefore understanding the mechanisms by which drugs exert their effects is of prime importance. Drugs of abuse increase the production of reactive oxygen and nitrogen species resulting in oxidative stress. This change in redox homeostasis increases the conjugation of glutathione to protein cysteine residues; a process called S-glutathionylation. Although traditionally regarded as a protective mechanism against irreversible protein oxidation, accumulated evidence suggests a more nuanced role for S-glutathionylation, namely as a mediator in redox-sensitive protein signaling. The reversible modification of protein thiols leading to alteration in function under different physiologic/pathologic conditions provides a mechanism whereby change in redox status can be translated into a functional response. As such, S-glutathionylation represents an understudied means of post-translational protein modification that may be important in the mechanisms underlying drug addiction. This review will discuss the evidence for S-glutathionylation as a redox-sensing mechanism and how this may be involved in the response to drug-induced oxidative stress. The function of S-glutathionylated proteins involved in neurotransmission, dendritic spine structure, and drug-induced behavioral outputs will be reviewed with specific reference to alcohol, cocaine, and heroin.
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Affiliation(s)
- Jacqueline S Womersley
- Department of Cellular and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Joachim D Uys
- Department of Cellular and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, South Carolina, USA.
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