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Wang G, Yang Q, Zheng C, Li D, Li J, Zhang F. Physiological Concentration of H 2O 2 Supports Dopamine Neuronal Survival via Activation of Nrf2 Signaling in Glial Cells. Cell Mol Neurobiol 2021; 41:163-171. [PMID: 32318898 DOI: 10.1007/s10571-020-00844-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 04/07/2020] [Indexed: 10/24/2022]
Abstract
Traditionally, hydrogen peroxide (H2O2) was formed from cellular oxidative metabolism and often viewed as toxic waste. In fact, H2O2 was a benefit messenger for neuron-glia signaling and synaptic transmission. Thus, H2O2 was a double-edged sword and neuroprotection vs. neurotoxicity produced by H2O2 was difficult to define. Nuclear factor erythroid 2-related factor 2 (Nrf2) has been implicated as an intracellular regulator of neuronal growth. Inactivation of Nrf2 participated in the development of Parkinson's disease (PD). Thus, suitable activation of Nrf2 was essential for the prevention and treatment of PD. This study aimed to explore whether H2O2-conferred neuroprotective effects to support neuronal survival. H2O2 were added into primary neuron-glia, neuron-astroglia and neuron-microglia co-cultures in concentration- and time-dependent manners. H2O2 increased dopamine (DA) neuronal survival in concentration- and time-dependent manners. In addition, glial cells Nrf2 activation involved in H2O2-supported DA neuronal survival with the following phenomenons. First, H2O2 activated Nrf2 signaling pathway. Second, H2O2 generated beneficial neuroprotection in neuron-glia, neuron-astroglia and neuron-microglia co-cultures but not in neuron-enriched cultures. Third, silence of Nrf2 in glial cells abolished H2O2-conferred DA neuronal survival. This study demonstrated that physiological concentration of H2O2-supported DA neuronal survival via activation of Nrf2 signaling in glial cells. Our data permit to re-evaluate the role of H2O2 in the pathogenesis and therapeutic strategies for PD.
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Affiliation(s)
- Guoqing Wang
- Joint International Research Laboratory of Ethnomedicine of Ministry of Education and Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou, China
| | - Qiuyu Yang
- Joint International Research Laboratory of Ethnomedicine of Ministry of Education and Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou, China
| | - Changqing Zheng
- Joint International Research Laboratory of Ethnomedicine of Ministry of Education and Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou, China
| | - Daidi Li
- Joint International Research Laboratory of Ethnomedicine of Ministry of Education and Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou, China
| | - Jingjie Li
- Joint International Research Laboratory of Ethnomedicine of Ministry of Education and Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou, China
| | - Feng Zhang
- Joint International Research Laboratory of Ethnomedicine of Ministry of Education and Key Laboratory of Basic Pharmacology of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou, China.
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Bahr HI, Abdelghany AA, Galhom RA, Barakat BM, Arafa ESA, Fawzy MS. Duloxetine protects against experimental diabetic retinopathy in mice through retinal GFAP downregulation and modulation of neurotrophic factors. Exp Eye Res 2019; 186:107742. [PMID: 31344388 DOI: 10.1016/j.exer.2019.107742] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 07/19/2019] [Accepted: 07/19/2019] [Indexed: 12/23/2022]
Abstract
Diabetic retinopathy (DR) is recognized as one of the leading causes of blindness worldwide. Searching and validation for a novel therapeutic strategy to prevent its progress are promising. This work aimed to assess the retinal protective effects of duloxetine (DLX) in Alloxan-induced diabetic mice model. Animals were equally and randomly divided to four groups (eight mice per group); group 1: is the control group, 2: diabetic group, 3&4: diabetic and after 9 weeks received DLX for 4 weeks (15 mg/kg and 30 mg/kg), respectively. Quantitative real-time PCR (qPCR) analysis revealed nerve growth factor (NGF), inducible nitric oxide synthase (iNOS) and transforming growth factor beta (TGF-β) genes upregulation in the diabetic group compared to controls. Also, increased retinal malondialdehyde (MDA) and the decline of reduced glutathione (GSH) levels were observed. The morphometric analysis of diabetic retina revealed a significant reduction in total retinal thickness compared to control. Diabetic retinal immunostaining and Western blot analyses displayed glial fibrillary acidic protein (GFAP) and vascular endothelial cell growth factor (VEGF) proteins expression upregulation as well as glucose transporter-1 (GLUT-1) downregulation comparing to controls. However, DLX-treated groups showed downregulated NGF, iNOS, and TGF-β that was more obviously seen in the DLX-30 mg/kg group than DLX-15 mg/kg group. Furthermore, these groups showed amelioration of the oxidative markers; MDA and GSH, retaining the total retinal thickness nearly to control, GFAP and VEGF downregulation, and GLUT-1 upregulation compared to diabetic group. Taken together, it could be summarized that duloxetine can attenuate DR via the anti-inflammatory and the anti-oxidative properties as well as modulating the angiogenic and the neurotrophic factors expressions. This could hopefully pave the road to be included in the novel list of the therapeutic regimen for DR after validation in the clinic.
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Affiliation(s)
- Hoda I Bahr
- Department of Biochemistry, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt.
| | - Ahmed A Abdelghany
- Department of Ophthalmology, Faculty of Medicine, Suez Canal University, Ismailia, 41522, Egypt.
| | - Rania A Galhom
- Department of Human Anatomy and Embryology, Faculty of Medicine, Suez Canal University, Ismailia, 41522, Egypt.
| | - Bassant M Barakat
- Department of Pharmacology and Toxicology, Faculty of Pharmacy (Girls), Al-Azhar University, Cairo, Egypt; Department of Clinical Pharmacy, College of Clinical Pharmacy, Al-Baha University, Al-Baha, Saudi Arabia.
| | - El-Shaimaa A Arafa
- Department of Clinical Sciences, College of Pharmacy and Health Sciences, Ajman University, Ajman, 346, United Arab Emirates; Department of Pharmacology and Toxicology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, 62514, Egypt.
| | - Manal S Fawzy
- Department of Biochemistry, Faculty of Medicine, Northern Border University, Arar, Saudi Arabia; Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Suez Canal University, Ismailia, 41522, Egypt.
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Xue M, Xuan YL, Wang Y, Hu HS, Li XL, Suo F, Li XR, Cheng WJ, Yan SH. Exogenous nerve growth factor promotes the repair of cardiac sympathetic heterogeneity and electrophysiological instability in diabetic rats. Cardiology 2013; 127:155-63. [PMID: 24356397 DOI: 10.1159/000355535] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 09/07/2013] [Indexed: 11/19/2022]
Abstract
OBJECTIVES Diabetic cardiac autonomic neuropathy can lead to an increased incidence of ventricular arrhythmias (VAs). However, few data are available regarding the pathogenesis and therapy of the VAs accompanying diabetic cardiac autonomic neuropathy. We aimed to explore whether or not exogenous nerve growth factor (NGF) can reduce the sympathetic heterogeneity and the incidence of VAs in diabetes mellitus (DM). METHODS Male Wistar rats were randomly divided into 3 groups: controls, rats with DM with saline infused into the left stellate ganglion (LSG), i.e. the DS group and rats with DM with NGF infused into the LSG, i.e. the DN group. After 28 weeks, all rats were subjected to electrophysiological experiments. Sympathetic innervations and NGF were studied by immunostaining, RT-PCR or Western blot analysis. RESULTS The incidence of inducible VAs was significantly higher in the DS group than in the control group, but was markedly decreased in the DN group. In the DS group, the tyrosine hydroxylase (TH) and NGF expression were significantly lower than in the other groups, and significant proximal-distal heterogeneities existed regarding the TH and NGF expression in the left ventricle, but were markedly repaired in the DN group. CONCLUSIONS NGF intervention in the LSG can reduce the heterogeneity of cardiac sympathetic innervations and the incidence of VAs in diabetic rats.
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Affiliation(s)
- Mei Xue
- Department of Cardiology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, P.R. China
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Kumar A, Sharma N, Gupta A, Kalonia H, Mishra J. Neuroprotective potential of atorvastatin and simvastatin (HMG-CoA reductase inhibitors) against 6-hydroxydopamine (6-OHDA) induced Parkinson-like symptoms. Brain Res 2012; 1471:13-22. [PMID: 22789904 DOI: 10.1016/j.brainres.2012.06.050] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 06/19/2012] [Accepted: 06/20/2012] [Indexed: 11/25/2022]
Abstract
Neuro-inflammation and oxidative stress plays a key role in the pathophysiology of Parkinson's disease (PD). Studies demonstrated that neuro-inflammation and associated infiltration of inflammatory cells into central nervous system are inhibited by 3-hydroxy-3-methyl glutaryl co-enzyme A (HMG-CoA) reductase inhibitors. Based on these experimental evidences, the present study has been designed to evaluate the neuroprotective effect of HMG-CoA reductase inhibitors (atorvastatin and simvastatin) against 6-hydroxydopamine (6-OHDA) induced unilateral lesion model of PD. In the present study, the animals were divided into nine groups (n=15 per group). Group I: Naive (without treatment); Group II: Sham (surgery performed, vehicle administered); Group III: Atorvastatin (20mg/kg); Group IV: Simvastatin (30 mg/kg); Group V: Control [Intrastriatal 6-OHDA (20 μg; single unilateral injection)]; Groups VI and VII: 6-OHDA (20 μg)+atorvastatin (10mg/kg and 20mg/kg) respectively; Groups VIII and IX: 6-OHDA (20 μg)+simvastatin (15 mg/kg and 30 mg/kg) respectively. Intrastriatal administration of 6-OHDA (20 μg; 4 μl of 5 μg/μl) significantly caused impairment in body weight, locomotor activity, rota-rod performance, oxidative defense and mitochondrial enzyme complex activity, and increase in the inflammatory cytokine levels (TNF-α and IL-6) as compared to naive animals. Atorvastatin (20mg/kg) and simvastatin (30 mg/kg) drug treatment significantly improved these behavioral and biochemical alterations restored mitochondrial enzyme complex activities and attenuated neuroinflammatory markers in 6-OHDA (20 μg) treated animals as compared to control group. The findings of the present study demonstrate the neuroprotective potential of statins in experimental model of 6-OHDA induced Parkinson like symptoms.
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Affiliation(s)
- Anil Kumar
- Pharmacology Division, University Institute of Pharmaceutical Sciences, UGC-Centre of Advanced Study (UGC-CAS), Panjab University, Chandigarh 160014, India.
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Wang Y, Xuan YL, Hu HS, Li XL, Xue M, Cheng WJ, Suo F, Yan SH. Risk of Ventricular Arrhythmias after Myocardial Infarction with Diabetes Associated with Sympathetic Neural Remodeling in Rabbits. Cardiology 2012; 121:1-9. [DOI: 10.1159/000336148] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 12/23/2011] [Indexed: 11/19/2022]
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Lee TM, Chen CC, Hsu YJ. Differential effects of NADPH oxidase and xanthine oxidase inhibition on sympathetic reinnervation in postinfarct rat hearts. Free Radic Biol Med 2011; 50:1461-70. [PMID: 21295134 DOI: 10.1016/j.freeradbiomed.2011.01.031] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2010] [Revised: 01/11/2011] [Accepted: 01/25/2011] [Indexed: 01/16/2023]
Abstract
Superoxide has been shown to play a major role in ventricular remodeling and arrhythmias after myocardial infarction. However, the source of increased myocardial superoxide production and the role of superoxide in sympathetic innervation remain to be further characterized. Male Wistar rats, after coronary artery ligation, were randomized to vehicle, allopurinol, or apocynin for 4weeks. To determine the role of peroxynitrite in sympathetic reinnervation, we also used 3-morpholinosydnonimine (a peroxynitrite generator). The postinfarction period was associated with increased oxidative stress, as measured by myocardial superoxide, nitrotyrosine, xanthine oxidase activity, NADPH oxidase activity, and dihydroethidium fluorescent staining. Measurement of myocardial norepinephrine levels revealed a significant elevation in vehicle-treated infarcted rats compared with sham. Sympathetic hyperinnervation was blunted after administration of allopurinol. Arrhythmic scores in the allopurinol-treated infarcted rats were significantly lower than those in vehicle. For similar levels of ventricular remodeling, apocynin had no beneficial effects on oxidative stress, sympathetic hyperinnervation, or arrhythmia vulnerability. Allopurinol-treated hearts had significantly decreased nerve growth factor expression, which was substantially increased after coadministration of 3-morpholinosydnonimine. These results indicate that xanthine oxidase but not NADPH oxidase largely mediates superoxide production after myocardial infarction. Xanthine oxidase inhibition ameliorates sympathetic innervation and arrhythmias possibly via inhibition of the peroxynitrite-mediated nerve growth factor pathway.
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Affiliation(s)
- Tsung-Ming Lee
- Department of Medicine, Cardiology Section, Chi-Mei Medical Center, Tainan, Taiwan.
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7
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Matesanz N, Lafuente N, Azcutia V, Martín D, Cuadrado A, Nevado J, Rodríguez-Mañas L, Sánchez-Ferrer CF, Peiró C. Xanthine oxidase-derived extracellular superoxide anions stimulate activator protein 1 activity and hypertrophy in human vascular smooth muscle via c-Jun N-terminal kinase and p38 mitogen-activated protein kinases. J Hypertens 2007; 25:609-18. [PMID: 17278978 DOI: 10.1097/hjh.0b013e328013e7c4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Vascular xanthine oxidase (XO) activity has been found to be elevated in chronic vascular disease. Although a role for XO in endothelial dysfunction has been proposed, little is known about its influence on vascular smooth muscle maladaptive growth. METHODS The proliferative and hypertrophic response of human aortic smooth muscle cells (HASMC) stimulated with xanthine/xanthine oxidase (X/XO) was quantified by determining cell number, cell size and protein synthesis. The levels and activity of the growth-related transcription factor activator protein 1 (AP-1) and the activation of mitogen-activated protein kinase (MAPK) by X/XO were determined by either Western blot or transient transfection experiments. RESULTS X/XO did not affect HASMC proliferation, but led to enhanced planar cell surface area and protein synthesis. In addition, X/XO enhanced c-jun levels and AP-1 transcriptional activity. Although X/XO did not modify extracellular signal-regulated protein kinases 1/2 MAPK or Akt/PKB activity, it promoted the activation of c-Jun N-terminal kinase and p38 MAPK, which were both necessary for X/XO to increase AP-1 activity and cell size in HASMC cultures. Finally, the effects of X/XO on MAPK activation, AP-1 activity and cell size were dependent on the extracellular release of superoxide anions through the enzymatic activity of XO, as they were prevented by both superoxide dismutase and allopurinol. CONCLUSION X/XO exhibits hypertrophic properties for human vascular smooth muscle, which are mediated by redox-sensitive pathways involving MAPK activation. XO can therefore participate in the maladaptive vascular remodeling observed in chronic cardiovascular diseases exhibiting elevated vascular XO activity.
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MESH Headings
- Allopurinol/pharmacology
- Aorta/cytology
- Aorta/drug effects
- Cell Enlargement/drug effects
- Cell Proliferation/drug effects
- Cells, Cultured
- Humans
- Hypertrophy
- JNK Mitogen-Activated Protein Kinases/metabolism
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Replication Protein C/metabolism
- Superoxides/pharmacology
- Xanthine Oxidase/antagonists & inhibitors
- Xanthine Oxidase/metabolism
- Xanthine Oxidase/pharmacology
- p38 Mitogen-Activated Protein Kinases/metabolism
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Affiliation(s)
- Nuria Matesanz
- Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
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Vacca RA, Valenti D, Bobba A, Merafina RS, Passarella S, Marra E. Cytochrome c is released in a reactive oxygen species-dependent manner and is degraded via caspase-like proteases in tobacco Bright-Yellow 2 cells en route to heat shock-induced cell death. PLANT PHYSIOLOGY 2006; 141:208-19. [PMID: 16531480 PMCID: PMC1459318 DOI: 10.1104/pp.106.078683] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Revised: 02/27/2006] [Accepted: 02/27/2006] [Indexed: 05/07/2023]
Abstract
To gain some insight into the mechanism of plant programmed cell death, certain features of cytochrome c (cyt c) release were investigated in heat-shocked tobacco (Nicotiana tabacum) Bright-Yellow 2 cells in the 2- to 6-h time range. We found that 2 h after heat shock, cyt c is released from intact mitochondria into the cytoplasm as a functionally active protein. Such a release did not occur in the presence of superoxide anion dismutase and catalase, thus showing that it depends on reactive oxygen species (ROS). Interestingly, ROS production due to xanthine plus xanthine oxidase results in cyt c release in sister control cultures. Maximal cyt c release was found 2 h after heat shock; later, activation of caspase-3-like protease was found to increase with time. Activation of this protease did not occur in the presence of ROS scavenger enzymes. The released cyt c was found to be progressively degraded in a manner prevented by either the broad-range caspase inhibitor (zVAD-fmk) or the specific inhibitor of caspase-3 (AC-DEVD-CHO), which have no effect on cyt c release. In the presence of these inhibitors, a significant increase in survival of the cells undergoing programmed cell death was found. We conclude that ROS can trigger release of cyt c, but do not cause cell death, which requires caspase-like activation.
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Affiliation(s)
- Rosa Anna Vacca
- Istituto di Biomembrane e Bioenergetica, Consiglio Nazionale delle Ricerche, I-70126 Bari, Italy
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Gonthier B, Signorini-Allibe N, Soubeyran A, Eysseric H, Lamarche F, Barret L. Ethanol can modify the effects of certain free radical-generating systems on astrocytes. Alcohol Clin Exp Res 2004; 28:526-34. [PMID: 15100602 DOI: 10.1097/01.alc.0000122271.32522.a7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The central nervous system is vulnerable to oxidative stress, especially when a toxicant can modify the physiological balance between anti- and pro-oxidant mechanisms. Among brain cells, astrocytes seem less vulnerable than neurons, but their impairment can dramatically affect neurons because of their protective role toward neurons. Ethanol is able to stimulate the formation of reactive oxygen species and modify the activity of most of the antioxidant agents. However, ethanol can react with the OH* radical to form the alpha-hydroxyethyl radical, which is considered to be less toxic. Ethanol also can stimulate H2O2 degradation through catalase activation. This study, therefore, sought to determine whether ethanol affected the sensitivity of astrocytes exposed to various free radical-generating systems. The cellular impact of such exposure was assessed by assays exploring cytotoxicity (i.e., NR (neutral red) and MMT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetiazolium bromide) reduction assays) and genotoxicity (comet assay) induced by these treatments. DNA alterations were evaluated by single-cell gel electrophoresis (comet assay), considered a precocious biomarker of intracellular alterations. After concomitant exposure to H2O2 and ethanol, the viability of astrocytes decreased significantly whereas the mean percentage of DNA in the tail increased,reflecting DNA damage (H2O2 was either directly added to the culture medium or endogenously produced from menadione). Ethanol also reduced the loss of viability and DNA alterations after exposure to OH* radicals produced by a Fenton system. The exposure to a xanthine/xanthine oxidase system had the same effect.
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Affiliation(s)
- B Gonthier
- Laboratoire ORSOX (Oligoéléments et Résistance au Stress Oxydant induit par les Xénobiotiques) UMR UJF/CEA-LCR CEA 8M, Université Joseph Fourier, La Tronche, France
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van Rossum GSAT, Drummen GPC, Verkleij AJ, Post JA, Boonstra J. Activation of cytosolic phospholipase A2 in Her14 fibroblasts by hydrogen peroxide: a p42/44MAPK-dependent and phosphorylation-independent mechanism. Biochim Biophys Acta Mol Cell Biol Lipids 2004; 1636:183-95. [PMID: 15164766 DOI: 10.1016/j.bbalip.2003.12.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2003] [Accepted: 12/03/2003] [Indexed: 11/24/2022]
Abstract
Reactive oxygen species (ROS) have been implicated in the pathogenesis of diseases as well as various normal cellular processes. It has been suggested that ROS function as mediators of signal transduction, given that they can mimic growth factor-induced signaling. The ROS H2O2 has been reported to activate phospholipase A2 (PLA2) and, therefore, we investigated if and through which pathway ROS activate cytosolic PLA2 (cPLA2) in Her14 fibroblasts. cPLA2 was activated concentration-dependently by H2O2 in a transient manner. In addition, the lipophilic cumene hydroperoxide was shown to induce cPLA2 activity in the same manner. H2O2-induced cPLA2 activity in Her14 cells was partially phosphorylation-dependent, which was mediated through the Raf-MEK-p42/44(MAPK) pathway and occurred partially through a phosphorylation-independent mechanism. ROS can lead to changes in the (micro) viscosity of membranes due to the presence oxidized lipids, thereby increasing the substrate availability for cPLA2. In support of this, treatment of Her14 cells with H2O2 induced lipid peroxidation time-dependently as determined from degradation of lipid arachidonate and linoleate and the formation of aldehydic degradation products. Furthermore, H2O2 induced translocation of cPLA2 to the membrane fraction in a calcium-independent fashion, with a concomitant increase in cPLA2 activity. Collectively, the results suggest that oxidative stress-induced cPLA2 activity is partially phosphorylation-dependent and is further increased due to increased substrate availability by the action of ROS on membranes.
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Affiliation(s)
- Gerda S A T van Rossum
- Department of Molecular Cell Biology, Institute and Graduate School of Biomembranes, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
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Dabbeni-Sala F, Franceschini D, Skaper SD, Giusti P. Melatonin protects against 6-OHDA-induced neurotoxicity in rats: a role for mitochondrial complex I activity. FASEB J 2001; 15:164-170. [PMID: 11149904 DOI: 10.1096/fj.00-0129com] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Unilateral injection into the right substantia nigra of the catecholaminergic neurotoxin 6-hydroxydopamine (6-OHDA) produces extensive loss of dopaminergic cells ('hemi-parkinsonian rat'). The pineal hormone melatonin, which is a potent antioxidant against different reactive oxygen species and has been reported to be neuroprotective in vivo and in vitro, was evaluated for potential anti-Parkinson effects in this model. Imbalance in dopaminergic innervation between the striata produced by intranigral administration of 6-OHDA results in a postural asymmetry causing rotation away from the nonlesioned side. Melatonin given systemically prevented apomorphine-induced circling behavior in 6-OHDA-lesioned rats. Reduced activity of mitochondrial oxidative phosphorylation enzymes has been suggested in some neurodegenerative diseases; in particular, selective decrease in complex I activity is observed in the substantia nigra of Parkinson's disease patients. Analysis of mitochondrial oxidative phosphorylation enzyme activities in nigral tissue from 6-OHDA-lesioned rats by a novel BN-PAGE histochemical procedure revealed a clear loss of complex I activity, which was protected against in melatonin-treated animals. A good correlation between behavioral parameters and enzymatic (complex I) analysis was observed independent of melatonin administration. A deficit in mitochondrial complex I could conceivably contribute to cell death in parkinsonism via free radical mechanisms, both directly via reactive oxygen species production and by decreased ATP synthesis and energy failure. Melatonin may have potential utility in the treatment of neurodegenerative disorders where oxidative stress is a participant.
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Affiliation(s)
- F Dabbeni-Sala
- Department of Pharmacology, University of Padova, 35131 Padova, Italy
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12
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Servitja JM, Masgrau R, Pardo R, Sarri E, Picatoste F. Effects of oxidative stress on phospholipid signaling in rat cultured astrocytes and brain slices. J Neurochem 2000; 75:788-94. [PMID: 10899956 DOI: 10.1046/j.1471-4159.2000.0750788.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Although reactive oxygen species (ROS) are conventionally viewed as toxic by-products of cellular metabolism, a growing body of evidence suggests that they may act as signaling molecules. We have studied the effects of hydrogen peroxide (H(2)O(2))-induced oxidative stress on phospholipid signaling in cultured rat cortical astrocytes. H(2)O(2) stimulated the formation of phosphatidic acid and the accumulation of phosphatidylbutanol, a product of the phospholipase D (PLD)-catalyzed transphosphatidylation reaction. The effect of exogenous H(2)O(2) on the PLD response was mimicked by menadione-induced production of endogenous H(2)O(2). Oxidative stress also elicited inositol phosphate accumulation resulting from phosphoinositide phospholipase C (PLC) activation. The PLD response to H(2)O(2) was totally suppressed by chelation of both extracellular and cytosolic Ca(2+) with EGTA and BAPTA/AM, respectively. Furthermore, H(2)O(2)-induced PLD stimulation was completely abolished by the protein kinase C (PKC) inhibitors bisindolylmaleimide and chelerythrine and by PKC down-regulation. Activation of PLD by H(2)O(2) was also inhibited by the protein-tyrosine kinase inhibitor genistein. Finally, H(2)O(2) also stimulated both PLC and PLD in rat brain cortical slices. These results show for the first time that oxidative stress elicits phospholipid breakdown by both PLC and PLD in rat cultured astrocytes and brain slices.
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Affiliation(s)
- J M Servitja
- Departament de Bioquímica i Biologia Molecular, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra (Barcelona), Catalonia, Spain.
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Youdim KA, Martin A, Joseph JA. Essential fatty acids and the brain: possible health implications. Int J Dev Neurosci 2000; 18:383-99. [PMID: 10817922 DOI: 10.1016/s0736-5748(00)00013-7] [Citation(s) in RCA: 350] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Linoleic and alpha-linolenic acid are essential for normal cellular function, and act as precursors for the synthesis of longer chained polyunsaturated fatty acids (PUFAs) such as arachidonic (AA), eicosapentaenoic (EPA) and docosahexaenoic acids (DHA), which have been shown to partake in numerous cellular functions affecting membrane fluidity, membrane enzyme activities and eicosanoid synthesis. The brain is particularly rich in PUFAs such as DHA, and changes in tissue membrane composition of these PUFAs reflect that of the dietary source. The decline in structural and functional integrity of this tissue appears to correlate with loss in membrane DHA concentrations. Arachidonic acid, also predominant in this tissue, is a major precursor for the synthesis of eicosanoids, that serve as intracellular or extracellular signals. With aging comes a likely increase in reactive oxygen species and hence a concomitant decline in membrane PUFA concentrations, and with it, cognitive impairment. Neurodegenerative disorders such as Parkinson's and Alzheimer's disease also appear to exhibit membrane loss of PUFAs. Thus it may be that an optimal diet with a balance of n-6 and n-3 fatty acids may help to delay their onset or reduce the insult to brain functions which these diseases elicit.
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Affiliation(s)
- K A Youdim
- Laboratory of Neuroscience, United States Department of Agriculture, Jean Mayer Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA.
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Robb SJ, Robb-Gaspers LD, Scaduto RC, Thomas AP, Connor JR. Influence of calcium and iron on cell death and mitochondrial function in oxidatively stressed astrocytes. J Neurosci Res 1999; 55:674-86. [PMID: 10220109 DOI: 10.1002/(sici)1097-4547(19990315)55:6<674::aid-jnr3>3.0.co;2-j] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Astrocytes protect neurons and oligodendrocytes by buffering ions, neurotransmitters, and providing metabolic support. However, astrocytes are also vulnerable to oxidative stress, which may affect their protective and supportive functions. This paper examines the influence of calcium and iron on astrocytes and determines if cell death could be mediated by mitochondrial dysfunction. We provide evidence that the events associated with peroxide-induced death of astrocytes involves generation of superoxide at the site of mitochondria, loss of mitochondrial membrane potential, and depletion of ATP. These events are iron-mediated, with iron loading exacerbating and iron chelation reducing oxidative stress. Iron chelation maintained the mitochondrial membrane potential, prevented peroxide-induced elevations in superoxide levels, and preserved ATP levels. Although increased intracellular calcium occurred after oxidative stress to astrocytes, the calcium increase was not necessary for collapse of mitochondrial membrane potential. Indeed, when astrocytes were oxidatively stressed in the absence of extracellular calcium, cell death was enhanced, mitochondrial membrane potential collapsed at an earlier time point, and superoxide levels increased. Additionally, our data do not support opening of the mitochondrial permeability transition pore as part of the mechanism of peroxide-induced oxidative stress of astrocytes. We conclude that the increase in intracellular calcium following peroxide exposure does not mediate astrocytic death and may even provide a protective function. Finally, the vulnerability of astrocytes and their mitochondria to oxidative stress correlates more closely with iron availability than with increased intracellular calcium.
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Affiliation(s)
- S J Robb
- Department of Neuroscience and Anatomy, The Pennsylvania State University College of Medicine, M.S. Hershey Medical Center, Hershey 17033, USA
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15
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Abstract
Astrocytes provide a vital protective function in the brain. These cells are also vulnerable to oxidative stress, thus their loss of function could contribute to neurodegeneration. The goal of this study is to develop a cell culture model to study oxidative stress in astrocytes. Enriched astrocytic cultures were generated from neonatal mice. tertiary-butyl hydroperoxide (t-bOOH) was used as an exogenous peroxide and lactate dehydrogenase (LDH) release as a measure of loss of viability. Exposure to t-bOOH resulted in a linear increase in astrocytic death reaching 91.2% after 4 h exposure. That cell death was due to oxidative injury, was shown by the ability of the antioxidant N,N'-diphenyl-1,4-phenylenediamine (DPPD) to protect the t-bOOH treated cells. The involvement of iron in cell toxicity was demonstrated by the ability of the iron specific chelator desferal (DF) to completely prevent t-bOOH induced LDH release. Cells treated with a lipid soluble iron compound 3,5, 5-trimethyl (hexanoyl) ferrocene (TMH-Ferrocene), were more vulnerable to t-bOOH whereas neither ferrous ammonium sulfate (FAS) nor ferric ammonium citrate (FAC) had an effect. The increased sensitivity of the cells exposed to TMHF was reversible with the iron chelator desferal. Addition of recombinant human heavy chain ferritin or human apo-transferrin (Tf) did not alter LDH release. Electron microscopic analysis indicated astrocytes exposed to t-bOOH exhibited mitochondrial swelling prior to cell death (lactate dehydrogenase release). Additional increases in mitochondrial swelling were seen when the astrocytes were exposed to the lipophilic iron compound TMH-ferrocene and t-bOOH. These studies show that astrocytes are exquisitely sensitive to oxidative stress and that their vulnerability is related to and enhanced by iron. Decreased mitochondrial function in response to oxidative stress may precede cell death.
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Affiliation(s)
- S J Robb
- George M. Leader Family Laboratory, Department of Neuroscience and Anatomy, Penn State University College of Medicine, M.S. Hershey Medical Center, Hershey, PA 17033, USA
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16
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Garcion E, Nataf S, Berod A, Darcy F, Brachet P. 1,25-Dihydroxyvitamin D3 inhibits the expression of inducible nitric oxide synthase in rat central nervous system during experimental allergic encephalomyelitis. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1997; 45:255-67. [PMID: 9149100 DOI: 10.1016/s0169-328x(96)00260-4] [Citation(s) in RCA: 133] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The inducible form of nitric oxide synthase (iNOS) generates nitric oxide of which the excessive production is associated with central nervous system (CNS) inflammatory diseases. The investigation of iNOS expression during experimental allergic encephalomyelitis (EAE) of the Lewis rat demonstrated iNOS immunoreactivity and mRNA both during inflammatory bursts (days 12 and 23 post-immunization) and during the remission phase (day 18). iNOS expression was region-specific and expanded with time along a caudo-rostral axis, thus, correlating with the development of inflammatory infiltrates. Whereas cells of the monocyte/macrophage lineage continuously contributed to iNOS expression, astrocytes only expressed iNOS immunoreactivity or mRNA during the relapse (day 23). In order to investigate possible regulatory effects of 1,25-dihydroxyvitamin D3 (1,25-D3) on iNOS expression, rats were treated with the hormone after the beginning of clinical signs (days 11, 13, 19, 21 and 23 post-immunization), and areas of the CNS were examined at day 23. 1,25-D3 exerted a drastic inhibitory effect on iNOS expression, both at the protein and the mRNA levels. However, this effect was region-specific, and was most pronounced in the cerebellum and brainstem, but non-existent in cerebral cortex. iNOS down-regulation occurred in macrophages, activated microglia and astrocytes. The inhibition of iNOS expression in some CNS structures could account for the improvement of clinical signs observed in EAE-rats treated with 1,25-D3. Since 1,25-D3 can be synthesized by activated macrophages or microglia, our results support the hypothesis that this hormone might be implicated in the control of the CNS-specific immune responses. 1,25-D3 or its analogues could, thus, be of therapeutic value in the management of iNOS-associated diseases of the CNS.
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Affiliation(s)
- E Garcion
- Institut National de la Santé et de la Recherche Médicale, Unité 298, Centre Hospitalier Universitaire, Angers, France
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17
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Furukawa K, Estus S, Fu W, Mark RJ, Mattson MP. Neuroprotective action of cycloheximide involves induction of bcl-2 and antioxidant pathways. J Biophys Biochem Cytol 1997; 136:1137-49. [PMID: 9060477 PMCID: PMC2132476 DOI: 10.1083/jcb.136.5.1137] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The ability of the protein synthesis inhibitor cycloheximide (CHX) to prevent neuronal death in different paradigms has been interpreted to indicate that the cell death process requires synthesis of "killer" proteins. On the other hand, data indicate that neurotrophic factors protect neurons in the same death paradigms by inducing expression of neuroprotective gene products. We now provide evidence that in embryonic rat hippocampal cell cultures, CHX protects neurons against oxidative insults by a mechanism involving induction of neuroprotective gene products including the antiapoptotic gene bcl-2 and antioxidant enzymes. Neuronal survival after exposure to glutamate, FeSO4, and amyloid beta-peptide was increased in cultures pretreated with CHX at concentrations of 50-500 nM; higher and lower concentrations were ineffective. Neuroprotective concentrations of CHX caused only a moderate (20-40%) reduction in overall protein synthesis, and induced an increase in c-fos, c-jun, and bcl-2 mRNAs and protein levels as determined by reverse transcription-PCR analysis and immunocytochemistry, respectively. At neuroprotective CHX concentrations, levels of c-fos heteronuclear RNA increased in parallel with c-fos mRNA, indicating that CHX acts by inducing transcription. Neuroprotective concentrations of CHX suppressed accumulation of H2O2 induced by FeSO4, suggesting activation of antioxidant pathways. Treatment of cultures with an antisense oligodeoxynucleotide directed against bcl-2 mRNA decreased Bcl-2 protein levels and significantly reduced the neuroprotective action of CHX, suggesting that induction of Bcl-2 expression was mechanistically involved in the neuroprotective actions of CHX. In addition, activity levels of the antioxidant enzymes Cu/Zn-superoxide dismutase, Mn-superoxide dismutase, and catalase were significantly increased in cultures exposed to neuroprotective levels of CHX. Our data suggest that low concentrations of CHX can promote neuron survival by inducing increased levels of gene products that function in antioxidant pathways, a neuroprotective mechanism similar to that used by neurotrophic factors.
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Affiliation(s)
- K Furukawa
- Sanders-Brown Research Center on Aging, University of Kentucky, Lexington 40536, USA
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18
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Tournier C, Thomas G, Pierre J, Jacquemin C, Pierre M, Saunier B. Mediation by arachidonic acid metabolites of the H2O2-induced stimulation of mitogen-activated protein kinases (extracellular-signal-regulated kinase and c-Jun NH2-terminal kinase). EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 244:587-95. [PMID: 9119028 DOI: 10.1111/j.1432-1033.1997.00587.x] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Reactive oxygen species modulate major cellular functions by mechanisms which are still poorly understood. Recently, H2O2 has been reported to stimulate the activity of the mitogen-activated protein kinases (MAPKs) ERK and JNK, and the expression of the proto-oncogenes c-fos and c-jun. As their expression is enhanced by H2O2 in astrocytes, we studied whether these MAPKs were stimulated by H2O2 in primary cultured astrocytes. The result was positive, a maximum of stimulation being reached with 200 microM H2O2 (0.3 pmol H2O2/cell) for both ERK and JNK. ERK was previously reported to stimulate cytosolic phospholipase A2 phosphorylation and activity. H2O2 stimulated the release of arachidonic acid in astrocytes, as already reported in other cell types. We found also that cPLA2 phosphorylation was increased by H2O2. Moreover, the stimulation by H2O2 of ERK and JNK was decreased by phospholipase A2 activity inhibitors. When astrocytes were incubated first with eicosatetraynoic acid, a structural analogue competing in arachidonic acid metabolism, the stimulation of JNK by H2O was also inhibited, suggesting the involvement of arachidonic acid metabolites. Cyclooxygenase or cytochrome P450 monooxygenase inhibitors failed in decreasing the MAPK stimulation by H2O2, whereas lipoxygenase inhibitors completely abolished that of JNK. Mitogenicity has been reported to be stimulated by H2O2 in other cell types. Although ERK was strongly and durably stimulated by 200 microM H2O2 in astrocytes, at the same extent as by mitogenic growth factors, basal thymidine incorporation rate was decreased by more than 80% after 12-15 h. Moreover, the stimulation of thymidine incorporation induced by basic fibroblast growth factor was transiently abolished by H2O2. Furthermore, H2O2 likely induced the expression of CL100/PAC1/MKP-1, a dual specificity phosphatase which has been implicated in ERK and JNK inactivation in the nucleus. Finally, the prior treatment of astrocytes with MK886, a 5-lipoxygenase-activating protein inhibitor, prevented JNK from stimulation, but did not prevent thymidine incorporation from inhibition, both induced by H2O2. These results strongly suggest an involvement of arachidonic acid and/or its metabolites in the stimulation of both ERK and JNK following the oxidative stress evoked by H2O2, which induced a cell cycle arrest probably independent of the stimulation of JNK.
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Affiliation(s)
- C Tournier
- Unité de recherches sur la glande thyröide et la régulation hormonale,IFR 21, U96 INSERM, Le Kremlin-Bicêtre, France
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19
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Glinka Y, Gassen M, Youdim MB. Mechanism of 6-hydroxydopamine neurotoxicity. JOURNAL OF NEURAL TRANSMISSION. SUPPLEMENTUM 1997; 50:55-66. [PMID: 9120425 DOI: 10.1007/978-3-7091-6842-4_7] [Citation(s) in RCA: 244] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The catecholaminergic neurotoxin 6-hydroxydopamine (6-OHDA) has recently been found to be formed endogenously in patients suffering from Parkinson's disease. In this article, we highlight the latest findings on the biochemical mechanism of 6-OHDA toxicity. 6-OHDA has two ways of action: it easily forms free radicals and it is a potent inhibitor of the mitochondrial respiratory chain complexes I and IV. The inhibition of respiratory enzymes by 6-OHDA is reversible and insensitive towards radical scavengers and iron chelators with the exception of desferrioxamine. We conclude that free radicals are not involved in the interaction between 6-OHDA and the respiratory chain and that the two mechanisms are biochemically independent, although they may act synergistically in vivo.
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Affiliation(s)
- Y Glinka
- Department of Pharmacology, Bruce Rappaport Family Research Institute, Faculty of Medicine, Technion, Haifa, Israel
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20
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Naveilhan P, Neveu I, Baudet C, Funakoshi H, Wion D, Brachet P, Metsis M. 1,25-Dihydroxyvitamin D3 regulates the expression of the low-affinity neurotrophin receptor. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1996; 41:259-68. [PMID: 8883959 DOI: 10.1016/0169-328x(96)00103-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
1,25-Dihydroxyvitamin D3 (1,25-(OH)2D3) is known to regulate the expression of neurotrophins [45,46]. Here, we report that 1,25-(OH)2D3 does not influence the expression of truncated or full-length forms of trkB and trkC receptors mRNAs in primary cultures of astrocytes and in C6 glioma cells. In contrast, low concentrations of 1,25-(OH)2D3 increased low-affinity neurotrophin receptor (P75NTR) mRNA and protein levels in C6 glioma cells. Putative vitamin D responsive elements (VDRE) in the P75NTR promoter have been investigated by transfecting plasmids containing sequences from P75NTR promoter fused to a cat reporter gene. A region between -610 and -860 bp upstream from the translation start codon was found to respond to 1,25-(OH)2D3. Interestingly, 1,25-(OH)2D3 does not regulate P75NTR in primary cultures of astrocytes even at concentration as high as 10(-7) M. Since long-term treatment of 1,25-(OH)2D3 induces cell death in C6 glioma cells but not in primary astrocytes [41], the possible involvement of P75NTR in 1,25-(OH)2D3-induced cell death is discussed. Finally, in-vivo studies show that treatment of 15-day-old and adult rats with 1,25-(OH)2D3 leads to a decrease in the level of P75NTR mRNA in the spinal cord but does not influence its expression in dorsal root ganglion or sciatic nerve. These results suggest that 1,25-(OH)2D3 may have a role in the specific regulation of P75NTR in vivo.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Astrocytes/drug effects
- Astrocytes/metabolism
- Base Sequence
- Brain Neoplasms/pathology
- Calcitriol/pharmacology
- Chloramphenicol O-Acetyltransferase/biosynthesis
- Chloramphenicol O-Acetyltransferase/genetics
- Female
- Ganglia, Spinal/drug effects
- Ganglia, Spinal/metabolism
- Gene Expression Regulation, Neoplastic/drug effects
- Genes, Reporter
- Glioma/pathology
- Molecular Sequence Data
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Nerve Tissue Proteins/biosynthesis
- Nerve Tissue Proteins/genetics
- Promoter Regions, Genetic
- Rats
- Rats, Sprague-Dawley
- Receptor Protein-Tyrosine Kinases/biosynthesis
- Receptor Protein-Tyrosine Kinases/genetics
- Receptor, Ciliary Neurotrophic Factor
- Receptor, trkC
- Receptors, Nerve Growth Factor/biosynthesis
- Receptors, Nerve Growth Factor/genetics
- Recombinant Fusion Proteins/biosynthesis
- Recombinant Fusion Proteins/genetics
- Sciatic Nerve/drug effects
- Sciatic Nerve/metabolism
- Spinal Cord/drug effects
- Spinal Cord/metabolism
- Transfection
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Affiliation(s)
- P Naveilhan
- Institut National de la Santé et de la Recherche Médicale, Unité U.298, Centre Hospitalier Universitaire, Angers, France
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21
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Gillardon F, Skutella T, Uhlmann E, Holsboer F, Zimmermann M, Behl C. Activation of c-Fos contributes to amyloid beta-peptide-induced neurotoxicity. Brain Res 1996; 706:169-72. [PMID: 8720507 DOI: 10.1016/0006-8993(95)01332-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Amyloid beta peptide, a major component of Alzheimer's disease plaques, is directly toxic to various neuronal cell lines and primary neurons in culture. The mechanism underlying A beta neurotoxicity may include an increase in intracellular calcium and reactive oxygen species. In the present study, exposure of a mouse hippocampal cell line (HT-22) to the 25-35 peptide fragment of A beta (10 microM) caused a rapid and sustained increase in nuclear c-Fos immunoreactivity. Inhibition of A beta-mediated c-Fos activation by c-fos antisense oligodeoxynucleotides (5 microM) significantly protected against A beta toxicity as assessed by MTT assay. The signal transduction pathway for c-fos induction remains speculative, however, there seems to be a causal relationship between c-Fos transcription factor and A beta toxicity.
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Affiliation(s)
- F Gillardon
- Physiologisches Institut der Universität Heidelberg, Germany
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22
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Langeveld CH, Jongenelen CA, Schepens E, Stoof JC, Bast A, Drukarch B. Cultured rat striatal and cortical astrocytes protect mesencephalic dopaminergic neurons against hydrogen peroxide toxicity independent of their effect on neuronal development. Neurosci Lett 1995; 192:13-6. [PMID: 7675299 DOI: 10.1016/0304-3940(95)11596-o] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Reactive oxygen species (ROS), including hydrogen peroxide, are supposed to be involved in the degeneration of dopaminergic neurons in Parkinson's disease. The potential role of astrocytes against neurotoxic effects of ROS was studied in cocultures of rat mesencephalic neurons and rat striatal or cortical astrocytes. Neuronal [3H]dopamine uptake, a marker of dopaminergic neuron integrity, was enhanced by striatal astrocytes, but not by cortical astrocytes, compared to uptake in mesencephalic neurons cultured alone. Whereas hydrogen peroxide at concentrations up to 100 microM reduced the [3H]dopamine uptake in neuronal cultures, no reduction of the uptake was observed in cocultures, regardless of the origin of the supporting astrocytes. These results suggest that astrocyte mediated protection of neurons against hydrogen peroxide induced toxicity is not directly related to a region-specific neurotrophic effect.
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Affiliation(s)
- C H Langeveld
- Graduate School Neurosciences Amsterdam, Research Institute Neurosciences Vrije Universiteit, Department of Neurology, The Netherlands
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23
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Middlemiss PJ, Gysbers JW, Rathbone MP. Extracellular guanosine and guanosine-5'-triphosphate increase: NGF synthesis and release from cultured mouse neopallial astrocytes. Brain Res 1995; 677:152-6. [PMID: 7606460 DOI: 10.1016/0006-8993(95)00156-k] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cultures of neonatal mouse cortical astrocytes synthesized NGF mRNA and released immunoreactive NGF (ir-NGF) into the culture medium. Addition of 10 microM guanosine or GTP to the cultures increased ir-NGF release by 6 and 2 fold, respectively, after 24 h, and increased NGF mRNA 6 fold after 4 h and 2-3 fold after 24 h. In contrast, neither adenosine nor ATP (each 1-100 microM) affected either NGF mRNA synthesis or ir-NGF release.
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Affiliation(s)
- P J Middlemiss
- Department of Biomedical Sciences, McMaster University, Hamilton, Ont., Canada
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