51
|
Morris G, Walder K, Carvalho AF, Tye SJ, Lucas K, Berk M, Maes M. The role of hypernitrosylation in the pathogenesis and pathophysiology of neuroprogressive diseases. Neurosci Biobehav Rev 2017; 84:453-469. [PMID: 28789902 DOI: 10.1016/j.neubiorev.2017.07.017] [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] [Received: 01/23/2017] [Revised: 07/02/2017] [Accepted: 07/31/2017] [Indexed: 12/12/2022]
Abstract
There is a wealth of data indicating that de novo protein S-nitrosylation in general and protein transnitrosylation in particular mediates the bulk of nitric oxide signalling. These processes enable redox sensing and facilitate homeostatic regulation of redox dependent protein signalling, function, stability and trafficking. Increased S-nitrosylation in an environment of increasing oxidative and nitrosative stress (O&NS) is initially a protective mechanism aimed at maintaining protein structure and function. When O&NS becomes severe, mechanisms governing denitrosylation and transnitrosylation break down leading to the pathological state referred to as hypernitrosylation (HN). Such a state has been implicated in the pathogenesis and pathophysiology of several neuropsychiatric and neurodegenerative diseases and we investigate its potential role in the development and maintenance of neuroprogressive disorders. In this paper, we propose a model whereby the hypernitrosylation of a range of functional proteins and enzymes lead to changes in activity which conspire to produce at least some of the core abnormalities contributing to the development and maintenance of pathology in these illnesses.
Collapse
Affiliation(s)
- Gerwyn Morris
- Tir Na Nog, Bryn Road seaside 87, Llanelli, SA152LW, Wales, United Kingdom
| | - Ken Walder
- Deakin University, The Centre for Molecular and Medical Research, School of Medicine, P.O. Box 291, Geelong, 3220, Australia
| | - André F Carvalho
- Department of Clinical Medicine and Translational Psychiatry Research Group, Faculty of Medicine, Federal University of Ceará, 60430-040, Fortaleza, CE, Brazil
| | - Susannah J Tye
- Deakin University, The Centre for Molecular and Medical Research, School of Medicine, P.O. Box 291, Geelong, 3220, Australia; Department of Clinical Medicine and Translational Psychiatry Research Group, Faculty of Medicine, Federal University of Ceará, 60430-040, Fortaleza, CE, Brazil; Deakin University, IMPACT Strategic Research Centre, School of Medicine, P.O. Box 281, Geelong, 3220, Australia; Orygen Youth Health Research Centre and the Centre of Youth Mental Health, The Florey Institute for Neuroscience and Mental Health and the Department of Psychiatry, University of Melbourne, Parkville, 3052, Australia
| | - Kurt Lucas
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Michael Berk
- Deakin University, IMPACT Strategic Research Centre, School of Medicine, P.O. Box 281, Geelong, 3220, Australia; Orygen Youth Health Research Centre and the Centre of Youth Mental Health, The Florey Institute for Neuroscience and Mental Health and the Department of Psychiatry, University of Melbourne, Parkville, 3052, Australia.
| | - Michael Maes
- Deakin University, IMPACT Strategic Research Centre, School of Medicine, P.O. Box 281, Geelong, 3220, Australia; Department of Psychiatry, Chulalongkorn University, Faculty of Medicine, Bangkok, Thailand; Department of Psychiatry, Medical University of Plovdiv, Plovdiv, Bulgaria
| |
Collapse
|
52
|
Farrelly L, Rosato-Siri MV, Föcking M, Codagnone M, Reines A, Dicker P, Wynne K, Farrell M, Cannon M, Cagney G, Pasquini JM, Cotter DR. The Effects of Prenatal Iron Deficiency and Risperidone Treatment on the Rat Frontal Cortex: A Proteomic Analysis. Proteomics 2017; 17. [PMID: 28762254 DOI: 10.1002/pmic.201600407] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 06/12/2017] [Indexed: 11/11/2022]
Abstract
Prenatal iron deficiency (pID) has been described to increase the risk for neurodevelopmental disorders such as autism and schizophrenia; however, the precise molecular mechanisms are still unknown. Here, we utilized high-throughput MS to examine the proteomic effects of pID in adulthood on the rat frontal cortex area (FCA). In addition, the FCA proteome was examined in adulthood following risperidone treatment in adolescence to see if these effects could be prevented. We identified 1501 proteins of which 100 were significantly differentially expressed in the FCA at postnatal day 90. Pathway analysis of proteins affected by pID revealed changes in metabolic processes, including the tricyclic acid cycle, mitochondrial dysfunction, and P13K/Akt signaling. Interestingly, most of these protein changes were not present in the adult pID offspring who received risperidone in adolescence. Considering the link between pID and several neurodevelopmental disorders such as autism and schizophrenia these presented results bring new perspectives to understand the role of iron in metabolic pathways and provide novel biomarkers for future studies of pID.
Collapse
Affiliation(s)
- Lorna Farrelly
- Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Maria Victoria Rosato-Siri
- Department of Biological Chemistry, IQUIFIB, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
| | - Melanie Föcking
- Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Martin Codagnone
- De Robertis Institute, University of Buenos Aires, Buenos Aires, Argentina
| | - Analia Reines
- De Robertis Institute, University of Buenos Aires, Buenos Aires, Argentina
| | - Patrick Dicker
- Departments of Epidemiology & Public Health, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Kieran Wynne
- School of Biomolecular and Biomedical Research, Conway Institute, University College Dublin, Dublin, Ireland
| | - Michael Farrell
- Department of Neuropathology, Beaumont Hospital, Dublin, Ireland
| | - Mary Cannon
- Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| | - Gerard Cagney
- School of Biomolecular and Biomedical Research, Conway Institute, University College Dublin, Dublin, Ireland
| | - Juana Maria Pasquini
- Department of Biological Chemistry, IQUIFIB, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
| | - David R Cotter
- Department of Psychiatry, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin, Ireland
| |
Collapse
|
53
|
Silva E, Greene AF, Strauss K, Herrick JR, Schoolcraft WB, Krisher RL. Antioxidant supplementation during in vitro culture improves mitochondrial function and development of embryos from aged female mice. Reprod Fertil Dev 2017; 27:975-83. [PMID: 25739837 DOI: 10.1071/rd14474] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 01/20/2015] [Indexed: 12/31/2022] Open
Abstract
Maternal aging results in reduced oocyte and blastocyst quality, thought to be due, in part, to mitochondrial dysfunction and accumulation of reactive oxygen species. To reduce oxidative stress, the antioxidants α-lipoic acid (ALA; 10µM), α-tocopherol (250µM), hypotaurine (1mM) and N-acetylcysteine (NAC; 1mM), and sirtuin (100ngmL(-1)) were added to embryo culture medium (AntiOX) and compared with a control (CON) without antioxidants to assess blastocyst development after in vitro maturation and fertilisation of oocytes from aged B6D2F1 female mice (13.5 months). Development to the blastocyst stage increased in the AntiOX compared with CON group (87.6% vs 72.7%, respectively; P<0.01), in addition to higher mitochondrial membrane potential and ATP levels in the AntiOX group. Expression of genes associated with oxidative stress (PI3K, FOXO3A and GLRX2) was upregulated in the CON compared with AntiOX group. In addition to AntiOX, a medium containing only NAC and ALA (rAntiOX) was used to culture embryos from young CF1 females (6-8 weeks). More blastocysts developed in the rAntiOX compared with CON group (64.1% vs 43.3%, respectively; P<0.01), although AntiOX (48.0% blastocysts) did not result in improved development in young mice. Antioxidants improved mitochondrial activity, gene expression and development in embryos of older female mice, whereas a reduced level of antioxidants during culture was beneficial to embryos from young mice.
Collapse
Affiliation(s)
- Elena Silva
- National Foundation for Fertility Research, 10290 RidgeGate Cr., Lone Tree, CO 80124, USA
| | - Alison F Greene
- National Foundation for Fertility Research, 10290 RidgeGate Cr., Lone Tree, CO 80124, USA
| | - Kevin Strauss
- National Foundation for Fertility Research, 10290 RidgeGate Cr., Lone Tree, CO 80124, USA
| | - Jason R Herrick
- National Foundation for Fertility Research, 10290 RidgeGate Cr., Lone Tree, CO 80124, USA
| | - William B Schoolcraft
- Colorado Center for Reproductive Medicine, 10290 RidgeGate Cr., Lone Tree, CO 80124, USA
| | - Rebecca L Krisher
- National Foundation for Fertility Research, 10290 RidgeGate Cr., Lone Tree, CO 80124, USA
| |
Collapse
|
54
|
Zhang C, Li C, Chen S, Li Z, Jia X, Wang K, Bao J, Liang Y, Wang X, Chen M, Li P, Su H, Wan JB, Lee SMY, Liu K, He C. Berberine protects against 6-OHDA-induced neurotoxicity in PC12 cells and zebrafish through hormetic mechanisms involving PI3K/AKT/Bcl-2 and Nrf2/HO-1 pathways. Redox Biol 2017; 11:1-11. [PMID: 27835779 PMCID: PMC5107737 DOI: 10.1016/j.redox.2016.10.019] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 10/29/2016] [Accepted: 10/31/2016] [Indexed: 11/10/2022] Open
Abstract
Berberine (BBR) is a renowned natural compound that exhibits potent neuroprotective activities. However, the cellular and molecular mechanisms are still unclear. Hormesis is an adaptive mechanism generally activated by mild oxidative stress to protect the cells from further damage. Many phytochemicals have been shown to induce hormesis. This study aims to investigate whether the neuroprotective activity of BBR is mediated by hormesis and the related signaling pathways in 6-OHDA-induced PC12 cells and zebrafish neurotoxic models. Our results demonstrated that BBR induced a typical hormetic response in PC12 cells, i.e. low dose BBR significantly increased the cell viability, while high dose BBR inhibited the cell viability. Moreover, low dose BBR protected the PC12 cells from 6-OHDA-induced cytotoxicity and apoptosis, whereas relatively high dose BBR did not show neuroprotective activity. The hormetic and neuroprotective effects of BBR were confirmed to be mediated by up-regulated PI3K/AKT/Bcl-2 cell survival and Nrf2/HO-1 antioxidative signaling pathways. In addition, low dose BBR markedly mitigated the 6-OHDA-induced dopaminergic neuron loss and behavior movement deficiency in zebrafish, while high dose BBR only slightly exhibited neuroprotective activities. These results strongly suggested that the neuroprotection of BBR were attributable to the hormetic mechanisms via activating cell survival and antioxidative signaling pathways.
Collapse
Affiliation(s)
- Chao Zhang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China
| | - Chuwen Li
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China
| | - Shenghui Chen
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China; Lee's Pharmaceutical (Hong Kong) Ltd., Shatin, Hong Kong 999077, China
| | - Zhiping Li
- Key Laboratory for Drug Screening Technology of Shandong Academy of Sciences, Shandong Provincial Key Laboratory for Biosensor, Biology Institute of Shandong Academy of Sciences, Jinan 250014, China
| | - Xuejing Jia
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China
| | - Kai Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China
| | - Jiaolin Bao
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China
| | - Yeer Liang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China
| | - Xiaotong Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China
| | - Meiwan Chen
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China
| | - Peng Li
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China
| | - Huanxing Su
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China
| | - Jian-Bo Wan
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China
| | - Simon Ming Yuen Lee
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China
| | - Kechun Liu
- Key Laboratory for Drug Screening Technology of Shandong Academy of Sciences, Shandong Provincial Key Laboratory for Biosensor, Biology Institute of Shandong Academy of Sciences, Jinan 250014, China.
| | - Chengwei He
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao 999078, China.
| |
Collapse
|
55
|
Cheng Y, Loh YP, Birch NP. Neuroserpin Attenuates H 2O 2-Induced Oxidative Stress in Hippocampal Neurons via AKT and BCL-2 Signaling Pathways. J Mol Neurosci 2017; 61:123-131. [PMID: 27510267 DOI: 10.1007/s12031-016-0807-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 07/28/2016] [Indexed: 11/30/2022]
Abstract
Oxidative stress plays a critical role in neuronal injury and is associated with various neurological diseases. Here, we explored the potential protective effect of neuroserpin against oxidative stress in primary cultured hippocampal neurons. Our results show that neuroserpin inhibits H2O2-induced neurotoxicity in hippocampal cultures as measured by WST, LDH release, and TUNEL assays. We found that neuroserpin enhanced the activation of AKT in cultures subjected to oxidative stress and that the AKT inhibitor Ly294002 blocked this neuroprotective effect. Neuroserpin increased the expression of the anti-apoptotic protein BCL-2 and blocked the activation of caspase-3. Neuroserpin did not increase the level of neuroprotection over levels seen in neurons transduced with a BCL-2 expression vector, and an inhibitor of Trk receptors, K252a, did not block neuroserpin's effect. Taken together, our study demonstrates that neuroserpin protects against oxidative stress-induced dysfunction and death of primary cultured hippocampal neurons through the AKT-BCL-2 signaling pathway through a mechanism that does not involve the Trk receptors and leads to inhibition of caspase-3 activation.
Collapse
Affiliation(s)
- Yong Cheng
- Section on Cellular Neurobiology, Program on Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Y Peng Loh
- Section on Cellular Neurobiology, Program on Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Nigel P Birch
- School of Biological Sciences, Centre for Brain Research and Brain Research New Zealand, Rangahau Roro Aotearoa, University of Auckland, 3a Symonds Street 92019, Auckland, 1142, New Zealand.
| |
Collapse
|
56
|
Hadem IKH, Sharma R. Differential Regulation of Hippocampal IGF-1-Associated Signaling Proteins by Dietary Restriction in Aging Mouse. Cell Mol Neurobiol 2016; 37:985-993. [DOI: 10.1007/s10571-016-0431-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 09/30/2016] [Indexed: 12/22/2022]
|
57
|
Gsk3 Signalling and Redox Status in Bipolar Disorder: Evidence from Lithium Efficacy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:3030547. [PMID: 27630757 PMCID: PMC5007367 DOI: 10.1155/2016/3030547] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 06/28/2016] [Accepted: 07/20/2016] [Indexed: 12/15/2022]
Abstract
Objective. To discuss the link between glycogen synthase kinase-3 (GSK3) and the main biological alterations demonstrated in bipolar disorder (BD), with special attention to the redox status and the evidence supporting the efficacy of lithium (a GSK3 inhibitor) in the treatment of BD. Methods. A literature research on the discussed topics, using Pubmed and Google Scholar, has been conducted. Moreover, a manual selection of interesting references from the identified articles has been performed. Results. The main biological alterations of BD, pertaining to inflammation, oxidative stress, membrane ion channels, and circadian system, seem to be intertwined. The dysfunction of the GSK3 signalling pathway is involved in all the aforementioned “biological causes” of BD. In a complex scenario, it can be seen as the common denominator linking them all. Lithium inhibition of GSK3 could, at least in part, explain its positive effect on these biological dysfunctions and its superiority in terms of clinical efficacy. Conclusions. Deepening the knowledge on the molecular bases of BD is fundamental to identifying the biochemical pathways that must be targeted in order to provide patients with increasingly effective therapeutic tools against an invalidating disorder such as BD.
Collapse
|
58
|
Zhang D, Zhang H, Hao S, Yan H, Zhang Z, Hu Y, Zhuang Z, Li W, Zhou M, Li K, Hang C. Akt Specific Activator SC79 Protects against Early Brain Injury following Subarachnoid Hemorrhage. ACS Chem Neurosci 2016; 7:710-8. [PMID: 26983552 DOI: 10.1021/acschemneuro.5b00306] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A growing body of evidence demonstrates that Akt may serve as a therapeutic target for treatment of early brain injury following subarachnoid hemorrhage (SAH). The purpose of the current study was to evaluate the neuroprotective effect of Akt specific activator SC79 in an experimental rat model of SAH. SAH was induced by injecting 300 μL of blood into the prechiasmatic cistern. Intracerebroventricular (ICV) injection of SC79 (30 min post-SAH) induced the p-Akt (Ser473) expression in a dose-dependent manner. A single ICV dose treatment of SC79 (100 μg/rat) significantly increased the expression of Bcl-2 and p-GSK-3β (Ser9), decreased the protein levels of Bax, cytoplasm cytochrome c, and cleaved caspase-3, indicating the antiapoptotic effect of SC79. As a result, the number of apoptotic cells was reduced 24 h post SAH. Moreover, SC79 treatment alleviated SAH-induced oxidative stress, restored mitochondrial morphology, and improved neurological deficits. Strikingly, treatment of SC79 provided a beneficial outcome against neurologic deficit with a therapeutic window of at least 4 h post SAH by ICV injection and 30 min post SAH by intraperitoneal injection. Collectively, SC79 exerts its neuroprotective effect likely through the dual activities of antioxidation and antiapoptosis. These data provide a basic platform to consider SC79 as a novel therapeutic agent for treatment of SAH.
Collapse
Affiliation(s)
- Dingding Zhang
- Department
of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province, P. R. China
| | - Huasheng Zhang
- Department
of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province, P. R. China
| | - Shuangying Hao
- Jiangsu
Key Laboratory for Molecular Medicine, Medical School of Nanjing University, 22 Hankou Road, Nanjing 210093, Jiangsu Province, P. R. China
| | - Huiying Yan
- Department
of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province, P. R. China
| | - Zihuan Zhang
- Department
of Neurosurgery, Jinling Hospital, School of Medicine, Second Military Medical University, Shanghai 200433, China
| | - Yangchun Hu
- Department
of Neurosurgery, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230031, P. R. China
| | - Zong Zhuang
- Department
of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province, P. R. China
| | - Wei Li
- Department
of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province, P. R. China
| | - Mengliang Zhou
- Department
of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province, P. R. China
| | - Kuanyu Li
- Jiangsu
Key Laboratory for Molecular Medicine, Medical School of Nanjing University, 22 Hankou Road, Nanjing 210093, Jiangsu Province, P. R. China
| | - Chunhua Hang
- Department
of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province, P. R. China
| |
Collapse
|
59
|
Phosphoinositides: Two-Path Signaling in Neuronal Response to Oligomeric Amyloid β Peptide. Mol Neurobiol 2016; 54:3236-3252. [DOI: 10.1007/s12035-016-9885-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 03/28/2016] [Indexed: 12/12/2022]
|
60
|
Shi C, Viccaro K, Lee HG, Shah K. Cdk5-Foxo3 axis: initially neuroprotective, eventually neurodegenerative in Alzheimer's disease models. J Cell Sci 2016; 129:1815-1830. [PMID: 28157684 DOI: 10.1242/jcs.185009] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 03/03/2016] [Indexed: 12/12/2022] Open
Abstract
Deregulated Cdk5 causes neurotoxic amyloid beta peptide (Aβ) processing and cell death, two hallmarks of Alzheimer's disease, through the Foxo3 transcriptional factor in hippocampal cells, primary neurons and an Alzheimer's disease mouse model. Using an innovative chemical genetic screen, we identified Foxo3 as a direct substrate of Cdk5 in brain lysates. Cdk5 directly phosphorylates Foxo3, which increased its levels and nuclear translocation. Nuclear Foxo3 initially rescued cells from ensuing oxidative stress by upregulating MnSOD (also known as SOD2). However, following prolonged exposure, Foxo3 upregulated Bim (also known as BCL2L11) and FasL (also known as FASLG) causing cell death. Active Foxo3 also increased Aβ(1-42) levels in a phosphorylation-dependent manner. These events were completely inhibited either by expressing phosphorylation-resistant Foxo3 or by depleting Cdk5 or Foxo3, highlighting a key role for Cdk5 in regulating Foxo3. These results were confirmed in an Alzheimer's disease mouse model, which exhibited increased levels and nuclear localization of Foxo3 in hippocampal neurons, which preceded neurodegeneration and Aβ plaque formation, indicating this phenomenon is an early event in Alzheimer's disease pathogenesis. Collectively, these results show that Cdk5-mediated phospho-regulation of Foxo3 can activate several genes that promote neuronal death and aberrant Aβ processing, thereby contributing to the progression of neurodegenerative pathologies.
Collapse
Affiliation(s)
- Chun Shi
- Department of Chemistry and Purdue University Center for Cancer Research, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA
| | - Keith Viccaro
- Department of Chemistry and Purdue University Center for Cancer Research, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA
| | - Hyoung-Gon Lee
- Department of Pathology, Case Western Reserve University School of Medicine, Iris S. Bert L. Wolstein Research Building, 2103 Cornell Road, Room 5123, Cleveland, OH 44106, USA
| | - Kavita Shah
- Department of Chemistry and Purdue University Center for Cancer Research, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA
| |
Collapse
|
61
|
Bautista E, Vergara P, Segovia J. Iron-induced oxidative stress activates AKT and ERK1/2 and decreases Dyrk1B and PRMT1 in neuroblastoma SH-SY5Y cells. J Trace Elem Med Biol 2016; 34:62-9. [PMID: 26854247 DOI: 10.1016/j.jtemb.2015.11.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 10/06/2015] [Accepted: 11/23/2015] [Indexed: 11/27/2022]
Abstract
Iron is essential for proper neuronal functioning; however, excessive accumulation of brain iron is reported in Parkinson's, Alzheimer's, Huntington's diseases and amyotrophic lateral sclerosis. This indicates that dysregulated iron homeostasis is involved in the pathogenesis of these diseases. To determinate the effect of iron on oxidative stress and on cell survival pathways, such as AKT, ERK1/2 and DyrK1B, neuroblastoma SH-SY5Y cells were exposed to different concentration of FeCl2 (iron). We found that iron induced cell death in SH-SY5Y cells in a concentration-dependent manner. Detection of iNOS and 3-nitrotyrosine confirms the presence of increased nitrogen species. Furthermore, we found a decrease of catalase and protein arginine methyl-transferase 1 (PRMT1). Interestingly, iron increased the activity of ERK and AKT and reduced DyrK1B. Moreover, after FeCl2 treatment, the transcription factors c-Jun and pSmad1/5 were activated. These results indicate that the presence of high levels of iron increase the vulnerability of neurons to oxidative stress.
Collapse
Affiliation(s)
- Elizabeth Bautista
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Mexico
| | - Paula Vergara
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Mexico
| | - José Segovia
- Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN, Mexico.
| |
Collapse
|
62
|
Saha S, Sadhukhan P, Sinha K, Agarwal N, Sil PC. Mangiferin attenuates oxidative stress induced renal cell damage through activation of PI3K induced Akt and Nrf-2 mediated signaling pathways. Biochem Biophys Rep 2016; 5:313-327. [PMID: 28955838 PMCID: PMC5600319 DOI: 10.1016/j.bbrep.2016.01.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/28/2015] [Accepted: 01/12/2016] [Indexed: 12/19/2022] Open
Abstract
Background Mangiferin is a polyphenolic xanthonoid with remarkable antioxidant activity. Oxidative stress plays the key role in tert-butyl hydroperoxide (tBHP) induced renal cell damage. In this scenario, we consider mangiferin, as a safe agent in tBHP induced renal cell death and rationalize its action systematically, in normal human kidney epithelial cells (NKE). Methods NKE cells were exposed to 20 µM mangiferin for 2 h followed by 50 µM tBHP for 18 h. The effect on endogenous ROS production, antioxidant status (antioxidant enzymes and thiols), mitochondrial membrane potential, apoptotic signaling molecules, PI3K mediated signaling cascades and cell cycle progression were examined using various biochemical assays, FACS and immunoblot analyses. Results tBHP exposure damaged the NKE cells and decreased its viability. It also elevated the intracellular ROS and other oxidative stress-related biomarkers within the cells. However, mangiferin dose dependently, exhibited significant protection against this oxidative cellular damage. Mangiferin inhibited tBHP induced activation of different pro-apoptotic signals and thus protected the renal cells against mitochondrial permeabilization. Further, mangiferin enhanced the expression of cell proliferative signaling cascade molecules, Cyclin d1, NFκB and antioxidant molecules HO-1, SOD2, by PI3K/Akt dependent pathway. However, the inhibitor of PI3K abolished mangiferin's protective activity. Conclusions Results show Mangiferin maintains the intracellular anti-oxidant status, induces the expression of PI3K and its downstream molecules and shields NKE cells against the tBHP induced cytotoxicity. General significance Mangiferin can be indicated as a therapeutic agent in oxidative stress-mediated renal toxicity. This protective action of mangiferin primarily attributes to its potent antioxidant and antiapoptotic nature. Mangiferin relives oxidative stress on tBHP induced renal cytotoxicity. Mangiferin reduces tBHP-induced renal cell apoptosis. PI3K has been found to be the pivotal target of mangiferin. Mangiferin positively regulates cell cycle by modulating GSK3β and cyclin D1.
Collapse
Affiliation(s)
- Sukanya Saha
- Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata 700054, India
| | - Pritam Sadhukhan
- Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata 700054, India
| | - Krishnendu Sinha
- Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata 700054, India
| | - Namrata Agarwal
- Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata 700054, India
| | - Parames C Sil
- Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata 700054, India
| |
Collapse
|
63
|
Abstract
Globally, greater than 30 million individuals are afflicted with disorders of the nervous system accompanied by tens of thousands of new cases annually with limited, if any, treatment options. Erythropoietin (EPO) offers an exciting and novel therapeutic strategy to address both acute and chronic neurodegenerative disorders. EPO governs a number of critical protective and regenerative mechanisms that can impact apoptotic and autophagic programmed cell death pathways through protein kinase B (Akt), sirtuins, mammalian forkhead transcription factors, and wingless signaling. Translation of the cytoprotective pathways of EPO into clinically effective treatments for some neurodegenerative disorders has been promising, but additional work is necessary. In particular, development of new treatments with erythropoiesis-stimulating agents such as EPO brings several important challenges that involve detrimental vascular outcomes and tumorigenesis. Future work that can effectively and safely harness the complexity of the signaling pathways of EPO will be vital for the fruitful treatment of disorders of the nervous system.
Collapse
Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, Newark, New Jersey 07101
| |
Collapse
|
64
|
Fernández A, Ordóñez R, Reiter RJ, González-Gallego J, Mauriz JL. Melatonin and endoplasmic reticulum stress: relation to autophagy and apoptosis. J Pineal Res 2015. [PMID: 26201382 DOI: 10.1111/jpi.12264] [Citation(s) in RCA: 342] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Endoplasmic reticulum (ER) is a dynamic organelle that participates in a number of cellular functions by controlling lipid metabolism, calcium stores, and proteostasis. Under stressful situations, the ER environment is compromised, and protein maturation is impaired; this causes misfolded proteins to accumulate and a characteristic stress response named unfolded protein response (UPR). UPR protects cells from stress and contributes to cellular homeostasis re-establishment; however, during prolonged ER stress, UPR activation promotes cell death. ER stressors can modulate autophagy which in turn, depending of the situation, induces cell survival or death. Interactions of different autophagy- and apoptosis-related proteins and also common signaling pathways have been found, suggesting an interplay between these cellular processes, although their dynamic features are still unknown. A number of pathologies including metabolic, neurodegenerative and cardiovascular diseases, cancer, inflammation, and viral infections are associated with ER stress, leading to a growing interest in targeting components of the UPR as a therapeutic strategy. Melatonin has a variety of antioxidant, anti-inflammatory, and antitumor effects. As such, it modulates apoptosis and autophagy in cancer cells, neurodegeneration and the development of liver diseases as well as other pathologies. Here, we review the effects of melatonin on the main ER stress mechanisms, focusing on its ability to regulate the autophagic and apoptotic processes. As the number of studies that have analyzed ER stress modulation by this indole remains limited, further research is necessary for a better understanding of the crosstalk between ER stress, autophagy, and apoptosis and to clearly delineate the mechanisms by which melatonin modulates these responses.
Collapse
Affiliation(s)
- Anna Fernández
- Institute of Biomedicine (IBIOMED), University of León, León, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), León, Spain
| | - Raquel Ordóñez
- Institute of Biomedicine (IBIOMED), University of León, León, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), León, Spain
| | - Russel J Reiter
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Javier González-Gallego
- Institute of Biomedicine (IBIOMED), University of León, León, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), León, Spain
| | - José L Mauriz
- Institute of Biomedicine (IBIOMED), University of León, León, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), León, Spain
| |
Collapse
|
65
|
PARK7/DJ-1 dysregulation by oxidative stress leads to magnesium deficiency: implications in degenerative and chronic diseases. Clin Sci (Lond) 2015; 129:1143-50. [PMID: 26453619 DOI: 10.1042/cs20150355] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 09/25/2015] [Indexed: 11/17/2022]
Abstract
Disturbed magnesium (Mg(2+)) homoeostasis and increased levels of OS (oxidative stress) are associated with poor clinical outcomes in patients suffering from neurodegenerative, cardiovascular and metabolic diseases. Data from clinical and animal studies suggest that MD (Mg(2+) deficiency) is correlated with increased production of ROS (reactive oxygen species) in cells, but a straightforward causal relationship (including molecular mechanisms) between the two conditions is lacking. The multifactorial protein PARK7/DJ-1 is a major antioxidant protein, playing a key role in cellular redox homoeostasis, and is a positive regulator of AR (androgen receptor)-dependent transcription. SLC41A1 (solute carrier family 41 member 1), the gene encoding a ubiquitous cellular Mg(2+)E (Mg(2+)efflux) system, has been shown to be regulated by activated AR. We hypothesize that overexpression/up-regulation of PARK7/DJ-1, attributable to OS and related activation of AR, is an important event regulating the expression of SLC41A1 and consequently, modulating the Mg(2+)E capacity. This would involve changes in the transcriptional activity of PARK7/DJ-1, AR and SLC41A1, which may serve as biomarkers of intracellular MD and may have clinical relevance. Imipramine, in use as an antidepressant, has been shown to reduce the Mg(2+)E activity of SLC41A1 and OS. We therefore hypothesize further that administration of imipramine or related drugs will be beneficial in MD- and OS-associated diseases, especially when combined with Mg(2+) supplementation. If proved true, the OS-responsive functional axis, PARK7/DJ-1-AR-SLC41A1, may be a putative mechanism underlying intracellular MD secondary to OS caused by pro-oxidative stimuli, including extracellular MD. Furthermore, it will advance our understanding of the link between OS and MD.
Collapse
|
66
|
Koukoulitsa C, Villalonga-Barber C, Csonka R, Alexi X, Leonis G, Dellis D, Hamelink E, Belda O, Steele BR, Micha-Screttas M, Alexis MN, Papadopoulos MG, Mavromoustakos T. Biological and computational evaluation of resveratrol inhibitors against Alzheimer's disease. J Enzyme Inhib Med Chem 2015; 31:67-77. [PMID: 26147348 DOI: 10.3109/14756366.2014.1003928] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
It has been reported that beta amyloid induces production of radical oxygen species and oxidative stress in neuronal cells, which in turn upregulates β-secretase (BACE-1) expression and beta amyloid levels, thereby propagating oxidative stress and increasing neuronal injury. A series of resveratrol derivatives, known to be inhibitors of oxidative stress-induced neuronal cell death (oxytosis) were biologically evaluated against BACE-1 using homogeneous time-resolved fluorescence (TRF) assay. Correlation between oxytosis inhibitory and BACE-1 inhibitory activity of resveratrol derivatives was statistically significant, supporting the notion that BACE-1 may act as pivotal mediator of neuronal cell oxytosis. Four of the biologically evaluated resveratrol analogs demonstrated considerably higher activity than resveratrol in either assay. The discovery of some "hits" led us to initiate detailed docking studies associated with Molecular Dynamics in order to provide a plausible explanation for the experimental results and understand their molecular basis of action.
Collapse
Affiliation(s)
| | - Caroline Villalonga-Barber
- b Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation , Athens , Greece
| | - Robert Csonka
- b Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation , Athens , Greece
| | - Xanthippi Alexi
- b Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation , Athens , Greece
| | - Georgios Leonis
- b Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation , Athens , Greece
| | - Dimitris Dellis
- c Institute of Accelerating Systems and Applications , Panepistimiopolis Zografou , Athens , Greece , and
| | | | | | - Barry R Steele
- b Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation , Athens , Greece
| | - Maria Micha-Screttas
- b Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation , Athens , Greece
| | - Michael N Alexis
- b Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation , Athens , Greece
| | - Manthos G Papadopoulos
- b Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research Foundation , Athens , Greece
| | | |
Collapse
|
67
|
Leyton L, Hott M, Acuña F, Caroca J, Nuñez M, Martin C, Zambrano A, Concha MI, Otth C. Nutraceutical activators of AMPK/Sirt1 axis inhibit viral production and protect neurons from neurodegenerative events triggered during HSV-1 infection. Virus Res 2015; 205:63-72. [DOI: 10.1016/j.virusres.2015.05.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 05/20/2015] [Accepted: 05/20/2015] [Indexed: 11/29/2022]
|
68
|
Sánchez Campos S, Rodríguez Diez G, Oresti GM, Salvador GA. Dopaminergic Neurons Respond to Iron-Induced Oxidative Stress by Modulating Lipid Acylation and Deacylation Cycles. PLoS One 2015; 10:e0130726. [PMID: 26076361 PMCID: PMC4468124 DOI: 10.1371/journal.pone.0130726] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 05/22/2015] [Indexed: 12/12/2022] Open
Abstract
Metal-imbalance has been reported as a contributor factor for the degeneration of dopaminergic neurons in Parkinson Disease (PD). Specifically, iron (Fe)-overload and copper (Cu) mis-compartmentalization have been reported to be involved in the injury of dopaminergic neurons in this pathology. The aim of this work was to characterize the mechanisms of membrane repair by studying lipid acylation and deacylation reactions and their role in oxidative injury in N27 dopaminergic neurons exposed to Fe-overload and Cu-supplementation. N27 dopaminergic neurons incubated with Fe (1mM) for 24 hs displayed increased levels of reactive oxygen species (ROS), lipid peroxidation and elevated plasma membrane permeability. Cu-supplemented neurons (10, 50 μM) showed no evidence of oxidative stress markers. A different lipid acylation profile was observed in N27 neurons pre-labeled with [3H] arachidonic acid (AA) or [3H] oleic acid (OA). In Fe-exposed neurons, AA uptake was increased in triacylglycerols (TAG) whereas its incorporation into the phospholipid (PL) fraction was diminished. TAG content was 40% higher in Fe-exposed neurons than in controls. This increase was accompanied by the appearance of Nile red positive lipid bodies. Contrariwise, OA incorporation increased in the PL fractions and showed no changes in TAG. Lipid acylation profile in Cu-supplemented neurons showed AA accumulation into phosphatidylserine and no changes in TAG. The inhibition of deacylation/acylation reactions prompted an increase in oxidative stress markers and mitochondrial dysfunction in Fe-overloaded neurons. These findings provide evidence about the participation of lipid acylation mechanisms against Fe-induced oxidative injury and postulate that dopaminergic neurons cleverly preserve AA in TAG in response to oxidative stress.
Collapse
Affiliation(s)
- Sofía Sánchez Campos
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Universidad Nacional del Sur (UNS) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Guadalupe Rodríguez Diez
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Universidad Nacional del Sur (UNS) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Gerardo Martín Oresti
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Universidad Nacional del Sur (UNS) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
| | - Gabriela Alejandra Salvador
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Universidad Nacional del Sur (UNS) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina
- * E-mail:
| |
Collapse
|
69
|
Maiese K. FoxO proteins in the nervous system. Anal Cell Pathol (Amst) 2015; 2015:569392. [PMID: 26171319 PMCID: PMC4478359 DOI: 10.1155/2015/569392] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 05/31/2015] [Indexed: 02/07/2023] Open
Abstract
Acute as well as chronic disorders of the nervous system lead to significant morbidity and mortality for millions of individuals globally. Given the ability to govern stem cell proliferation and differentiated cell survival, mammalian forkhead transcription factors of the forkhead box class O (FoxO) are increasingly being identified as potential targets for disorders of the nervous system, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, and auditory neuronal disease. FoxO proteins are present throughout the body, but they are selectively expressed in the nervous system and have diverse biological functions. The forkhead O class transcription factors interface with an array of signal transduction pathways that include protein kinase B (Akt), serum- and glucocorticoid-inducible protein kinase (SgK), IκB kinase (IKK), silent mating type information regulation 2 homolog 1 (S. cerevisiae) (SIRT1), growth factors, and Wnt signaling that can determine the activity and integrity of FoxO proteins. Ultimately, there exists a complex interplay between FoxO proteins and their signal transduction pathways that can significantly impact programmed cell death pathways of apoptosis and autophagy as well as the development of clinical strategies for the treatment of neurodegenerative disorders.
Collapse
|
70
|
Kim SY, Yoo SJ, Ronnett GV, Kim EK, Moon C. Odorant Stimulation Promotes Survival of Rodent Olfactory Receptor Neurons via PI3K/Akt Activation and Bcl-2 Expression. Mol Cells 2015; 38:535-9. [PMID: 25997735 PMCID: PMC4469911 DOI: 10.14348/molcells.2015.0038] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 03/12/2015] [Indexed: 11/27/2022] Open
Abstract
Olfactory stimulation activates multiple signaling cascades in order to mediate activity-driven changes in gene expression that promote neuronal survival. To date, the mechanisms involved in activity-dependent olfactory neuronal survival have yet to be fully elucidated. In the current study, we observed that olfactory sensory stimulation, which caused neuronal activation, promoted activation of the phosphatidylinositol 3'-kinase (PI3K)/Akt pathway and the expression of Bcl-2, which were responsible for olfactory receptor neuron (ORN) survival. We demonstrated that Bcl-2 expression increased after odorant stimulation both in vivo and in vitro. We also showed that odorant stimulation activated Akt, and that Akt activation was completely blocked by incubation with both a PI3K inhibitor (LY294002) and Akt1 small interfering RNA. Moreover, blocking the PI3K/Akt pathway diminished the odorant-induced Bcl-2 expression, as well as the effects on odorant-induced ORN survival. A temporal difference was noted between the activation of Akt1 and the expression of Bcl-2 following odorant stimulation. Blocking the PI3K/Akt pathway did not affect ORN survival in the time range prior to the increase in Bcl-2 expression, implying that these two events, activation of the PI3K pathway and Bcl-2 induction, were tightly connected to promote post-translational ORN survival. Collectively, our results indicated that olfactory activity activated PI3K/Akt, induced Bcl-2, and promoted long term ORN survival as a result.
Collapse
Affiliation(s)
- So Yeun Kim
- Department of Brain & Cognitive Sciences, Graduate School Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu 711-873,
Korea
| | - Seung-Jun Yoo
- Department of Brain & Cognitive Sciences, Graduate School Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu 711-873,
Korea
| | - Gabriele V Ronnett
- Department of Brain & Cognitive Sciences, Graduate School Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu 711-873,
Korea
- Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205,
USA
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD 21205,
USA
| | - Eun-Kyoung Kim
- Department of Brain & Cognitive Sciences, Graduate School Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu 711-873,
Korea
| | - Cheil Moon
- Department of Brain & Cognitive Sciences, Graduate School Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu 711-873,
Korea
| |
Collapse
|
71
|
Bladder Oxidative Stress in Sleep Apnea Contributes to Detrusor Instability and Nocturia. J Urol 2015; 193:1692-9. [DOI: 10.1016/j.juro.2014.11.055] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2014] [Indexed: 11/21/2022]
|
72
|
Maiese K. Novel applications of trophic factors, Wnt and WISP for neuronal repair and regeneration in metabolic disease. Neural Regen Res 2015; 10:518-28. [PMID: 26170801 PMCID: PMC4424733 DOI: 10.4103/1673-5374.155427] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2015] [Indexed: 12/13/2022] Open
Abstract
Diabetes mellitus affects almost 350 million individuals throughout the globe resulting in significant morbidity and mortality. Of further concern is the growing population of individuals that remain undiagnosed but are susceptible to the detrimental outcomes of this disorder. Diabetes mellitus leads to multiple complications in the central and peripheral nervous systems that include cognitive impairment, retinal disease, neuropsychiatric disease, cerebral ischemia, and peripheral nerve degeneration. Although multiple strategies are being considered, novel targeting of trophic factors, Wnt signaling, Wnt1 inducible signaling pathway protein 1, and stem cell tissue regeneration are considered to be exciting prospects to overcome the cellular mechanisms that lead to neuronal injury in diabetes mellitus involving oxidative stress, apoptosis, and autophagy. Pathways that involve insulin-like growth factor-1, fibroblast growth factor, epidermal growth factor, and erythropoietin can govern glucose homeostasis and are intimately tied to Wnt signaling that involves Wnt1 and Wnt1 inducible signaling pathway protein 1 (CCN4) to foster control over stem cell proliferation, wound repair, cognitive decline, β-cell proliferation, vascular regeneration, and programmed cell death. Ultimately, cellular metabolism through Wnt signaling is driven by primary metabolic pathways of the mechanistic target of rapamycin and AMP activated protein kinase. These pathways offer precise biological control of cellular metabolism, but are exquisitely sensitive to the different components of Wnt signaling. As a result, unexpected clinical outcomes can ensue and therefore demand careful translation of the mechanisms that govern neural repair and regeneration in diabetes mellitus.
Collapse
Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, Newark, New Jersey 07101, USA
| |
Collapse
|
73
|
Bakunina N, Pariante CM, Zunszain PA. Immune mechanisms linked to depression via oxidative stress and neuroprogression. Immunology 2015; 144:365-373. [PMID: 25580634 DOI: 10.1111/imm.12443] [Citation(s) in RCA: 272] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 12/21/2014] [Accepted: 01/05/2015] [Indexed: 12/13/2022] Open
Abstract
Emerging evidence suggests the significant role of inflammation and oxidative stress as main contributors to the neuroprogression that is observed in major depressive disorder (MDD), where patients show increased inflammatory and oxidative stress biomarkers. The process of neuroprogression includes stage-related neurodegeneration, cell death, reduced neurogenesis, reduced neuronal plasticity and increased autoimmune responses. Oxidative stress is a consequence of the biological imbalance between Reactive Oxygen Species (ROS) and antioxidants, leading to the alteration of biomolecules and the loss of control of the intracellular redox-related signaling pathways. ROS serve as crucial secondary messengers in signal transduction and significantly affect inflammatory pathways by activating NF-κB and MAPK family stress kinases. When present in excess, ROS inflict damage, affecting cellular constituents with the formation of pro-inflammatory molecules, such as malondialdehyde, 4-Hydroxynonenal, neoepitopes and damage-associated molecular patterns promoting immune response, and ultimately leading to cell death. The failure of cells to adapt to the changes in redox homeostasis and the subsequent cell death, together with the damage caused by inflammatory mediators, have been considered as major causes of neuroprogression and hence MDD. Both an activated immune-inflammatory system and increased oxidative stress act synergistically, complicating our understanding of the pathogenesis of depression. The cascade of antioxidative and inflammatory events is orchestrated by several transcription factors, with Nrf2 and NF-κB having particular relevance to MDD. This review focuses on potential molecular mechanisms through which impaired redox homeostasis and neuroinflammation can affect the neuronal environment and contribute to depression This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Nataliia Bakunina
- Stress, Psychiatry and Immunology Laboratory, Institute of Psychiatry, Psychology & Neuroscience, King's College London, UK
| | | | | |
Collapse
|
74
|
Maiese K. FoxO Transcription Factors and Regenerative Pathways in Diabetes Mellitus. Curr Neurovasc Res 2015; 12:404-13. [PMID: 26256004 PMCID: PMC4567483 DOI: 10.2174/1567202612666150807112524] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 07/24/2015] [Accepted: 07/27/2015] [Indexed: 02/07/2023]
Abstract
Mammalian forkhead transcription factors of the O class (FoxO) are exciting targets under consideration for the development of new clinical entities to treat metabolic disorders and diabetes mellitus (DM). DM, a disorder that currently affects greater than 350 million individuals globally, can become a devastating disease that leads to cellular injury through oxidative stress pathways and affects multiple systems of the body. FoxO proteins can regulate insulin signaling, gluconeogenesis, insulin resistance, immune cell migration, and cell senescence. FoxO proteins also control cell fate through oxidative stress and pathways of autophagy and apoptosis that either lead to tissue regeneration or cell demise. Furthermore, FoxO signaling can be dependent upon signal transduction pathways that include silent mating type information regulation 2 homolog 1 (S. cerevisiae) (SIRT1), Wnt, and Wnt1 inducible signaling pathway protein 1 (WISP1). Cellular metabolic pathways driven by FoxO proteins are complex, can lead to variable clinical outcomes, and require in-depth analysis of the epigenetic and post-translation protein modifications that drive FoxO protein activation and degradation.
Collapse
Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, Newark, New Jersey 07101, USA.
| |
Collapse
|
75
|
Kempf SJ, Casciati A, Buratovic S, Janik D, von Toerne C, Ueffing M, Neff F, Moertl S, Stenerlöw B, Saran A, Atkinson MJ, Eriksson P, Pazzaglia S, Tapio S. The cognitive defects of neonatally irradiated mice are accompanied by changed synaptic plasticity, adult neurogenesis and neuroinflammation. Mol Neurodegener 2014; 9:57. [PMID: 25515237 PMCID: PMC4280038 DOI: 10.1186/1750-1326-9-57] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 12/12/2014] [Indexed: 02/07/2023] Open
Abstract
Background/purpose of the study Epidemiological evidence suggests that low doses of ionising radiation (≤1.0 Gy) produce persistent alterations in cognition if the exposure occurs at a young age. The mechanisms underlying such alterations are unknown. We investigated the long-term effects of low doses of total body gamma radiation on neonatally exposed NMRI mice on the molecular and cellular level to elucidate neurodegeneration. Results Significant alterations in spontaneous behaviour were observed at 2 and 4 months following a single 0.5 or 1.0 Gy exposure. Alterations in the brain proteome, transcriptome, and several miRNAs were analysed 6–7 months post-irradiation in the hippocampus, dentate gyrus (DG) and cortex. Signalling pathways related to synaptic actin remodelling such as the Rac1-Cofilin pathway were altered in the cortex and hippocampus. Further, synaptic proteins MAP-2 and PSD-95 were increased in the DG and hippocampus (1.0 Gy). The expression of synaptic plasticity genes Arc, c-Fos and CREB was persistently reduced at 1.0 Gy in the hippocampus and cortex. These changes were coupled to epigenetic modulation via increased levels of microRNAs (miR-132/miR-212, miR-134). Astrogliosis, activation of insulin-growth factor/insulin signalling and increased level of microglial cytokine TNFα indicated radiation-induced neuroinflammation. In addition, adult neurogenesis within the DG was persistently negatively affected after irradiation, particularly at 1.0 Gy. Conclusion These data suggest that neurocognitive disorders may be induced in adults when exposed at a young age to low and moderate cranial doses of radiation. This raises concerns about radiation safety standards and regulatory practices. Electronic supplementary material The online version of this article (doi:10.1186/1750-1326-9-57) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | - Soile Tapio
- Institute of Radiation Biology, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany.
| |
Collapse
|
76
|
Liu MH, Yuan C, He J, Tan TP, Wu SJ, Fu HY, Liu J, Yu S, Chen YD, Le QF, Tian W, Hu HJ, Zhang Y, Lin XL. Resveratrol protects PC12 cells from high glucose-induced neurotoxicity via PI3K/Akt/FoxO3a pathway. Cell Mol Neurobiol 2014; 35:513-22. [PMID: 25471227 DOI: 10.1007/s10571-014-0147-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Accepted: 11/26/2014] [Indexed: 12/17/2022]
Abstract
Diabetes is known to be associated with neurodegenerative diseases. Resveratrol, a plant-derived polyphenolic compound found in red wine, possesses antioxidant properties. In this study, we aimed to investigate the effects of resveratrol on the phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt)/FoxO3a pathway in mediating high glucose (HG)-induced injuries in neuronal PC12 cells. PC12 cells were exposed to HG to establish a model of HG neurotoxicity. Results showed that pre-treating PC12 cells with resveratrol before exposure to HG led to increased cell viability, decreased apoptotic cells, and reactive oxygen species generation. Western blot analysis showed that HG decreased the phosphorylation of Akt and FoxO3a and led to the nuclear localization of FoxO3a. These effects were significantly alleviated by resveratrol co-treatment. Furthermore, the protective effects of resveratrol were abolished by PI3K/Akt inhibitor LY294002. All these results demonstrate that resveratrol protected the PC12 cells from HG-induced oxidative stress and apoptosis via the activation of PI3K/Akt/FoxO3a signaling pathway.
Collapse
Affiliation(s)
- Mi-Hua Liu
- Department of Clinical Laboratory, Affiliated Nanhua Hospital, University of South China, No. 336 Dongfeng South Road, Hengyang, 421001, Hunan Province, People's Republic of China,
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
77
|
Abstract
A significant portion of the world's population suffers from sporadic Alzheimer's disease (AD) with available present therapies limited to symptomatic care that does not alter disease progression. Over the next decade, advancing age of the global population will dramatically increase the incidence of AD and severely impact health care resources, necessitating novel, safe, and efficacious strategies for AD. The mammalian target of rapamycin (mTOR) and its protein complexes mTOR Complex 1 (mTORC1) and mTOR Complex 2 (mTORC2) offer exciting and unique avenues of intervention for AD through the oversight of programmed cell death pathways of apoptosis, autophagy, and necroptosis. mTOR modulates multi-faceted signal transduction pathways that involve phosphoinositide 3-kinase (PI 3-K), protein kinase B (Akt), hamartin (tuberous sclerosis 1)/ tuberin (tuberous sclerosis 2) (TSC1/TSC2) complex, proline-rich Akt substrate 40 kDa (PRAS40), and p70 ribosomal S6 kinase (p70S6K) and can interface with the neuroprotective pathways of growth factors, sirtuins, wingless, forkhead transcription factors, and glycogen synthase kinase-3β. With the ability of mTOR to broadly impact cellular function, clinical strategies for AD that implement mTOR must achieve parallel objectives of protecting neuronal, vascular, and immune cell survival in conjunction with preserving networks that determine memory and cognitive function.
Collapse
Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling , Newark, New Jersey 07101 , USA
| |
Collapse
|
78
|
Li C, Pan Z, Xu T, Zhang C, Wu Q, Niu Y. Puerarin induces the upregulation of glutathione levels and nuclear translocation of Nrf2 through PI3K/Akt/GSK-3β signaling events in PC12 cells exposed to lead. Neurotoxicol Teratol 2014; 46:1-9. [PMID: 25195717 DOI: 10.1016/j.ntt.2014.08.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 07/14/2014] [Accepted: 08/29/2014] [Indexed: 01/16/2023]
Abstract
Oxidative stress is thought to be involved in lead-induced toxicity, especially affecting the brain. We reported previously that puerarin possesses antioxidative properties in the nervous system. Therefore, the aim of the present study was to test the hypothesis that puerarin inhibits lead acetate-induced oxidative stress in PC12 cells by interrupting phosphatidylinositol-3 kinase (PI3K)/Akt signaling through increasing glutathione (GSH) synthesis. Our results showed that puerarin attenuates oxidative stress in a concentration-dependent manner in PC12 cells exposed to lead acetate demonstrated by scavenging reactive oxygen species (ROS) and reducing lipid peroxidation (LPO). Treatment with puerarin significantly up-regulates glutamate cysteine ligase catalytic subunit (GCLc) expression both at its mRNA and protein levels, but not glutamate cysteine ligase modifier (GCLm) subunit, accompanying the elevation of cellular glutathione level. The increased nuclear accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2) was not because of increased transcription of Nrf2 as Nrf2 transcript levels did not change after puerarin treatment. The effects of puerarin could be partially blocked by pharmacologic inhibition of PI3K and the glycogen synthase kinase 3β (GSK-3β) pathways with LY294002 and LiCl, respectively. On the other hand, puerarin treatment promoted Akt and GSK-3β phosphorylation in PC12 cells exposed to lead acetate. Moreover, puerarin failed to modulate the phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), p-c-Jun N-terminal kinases (JNK), and p-p38 mitogen-activated protein kinase (MAPK) demonstrating some specificity for its action on the PI3K/GSK-3β pathway. These findings suggest that puerarin as a phytoestrogen might be an attractive agent for prevention and treatment of chronic diseases related to lead neurotoxicity.
Collapse
Affiliation(s)
- Chengchong Li
- The Institute of Medicine, Qiqihar Medical University, Qiqihar 161006, China
| | - Zhi Pan
- Center for New Medicine Research, Changchun University of Chinese Medicine, Changchun 130117, China
| | - Tianjiao Xu
- The Institute of Medicine, Qiqihar Medical University, Qiqihar 161006, China
| | - Chun Zhang
- Ningxia Key Laboratory of Cerebrocranial Diseases, Ningxia Medical University, Yinchuan 750004, China
| | - Qi Wu
- Medical Technology Department, Qiqihar Medical University, Qiqihar 161006, China
| | - Yingcai Niu
- The Institute of Medicine, Qiqihar Medical University, Qiqihar 161006, China.
| |
Collapse
|
79
|
Poirier GL, Imamura N, Zanoletti O, Sandi C. Social deficits induced by peripubertal stress in rats are reversed by resveratrol. J Psychiatr Res 2014; 57:157-64. [PMID: 24974003 DOI: 10.1016/j.jpsychires.2014.05.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 04/15/2014] [Accepted: 05/28/2014] [Indexed: 11/30/2022]
Abstract
Adolescence is increasingly recognized as a critical period for the development of the social system, through the maturation of social competences and of their underlying neural circuitries. The present study sought to test the utility of resveratrol, a dietary phenol recently reported to have mood lifting properties, in modulating social interaction that is deficient following early life adversity. The main aims were to 1) pharmacologically restore normative social investigation levels dampened by peripubertal stress in rats and 2) identify neural pathways engaged by this pharmacological approach. Following peripubertal (P28-42) stress consisting of unpredictable exposures to fearful experiences, at adulthood the subjects' propensity for social exploration was examined in the three-chamber apparatus, comparing time invested in social or non-social investigation. Administered intraperitoneally 30 min before testing, resveratrol (20 mg/kg) normalized the peripubertal stress-induced social investigation deficit seen in the vehicle group, selectively altering juvenile but not object exploration. Examination of prefrontal cortex subregion protein samples following acute resveratrol treatment in a separate cohort revealed that while monoamine oxidase A (MAOA) enzymatic activity remained unaltered, nuclear AKT activation was selectively increased in the infralimbic cortex, but not in the prelimbic or anterior cingulate cortex. In contrast, androgen receptor nuclear localization was increased in the prelimbic cortex, but not in the infralimbic or anterior cingulate cortex. This demonstration that social contact deficits are reversed by resveratrol administration emphasizes a prosocial role for this dietary phenol, and evokes the possibility of developing new treatments for social dysfunctions.
Collapse
Affiliation(s)
- Guillaume L Poirier
- Laboratory of Behavioral Genetics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
| | - Natsuko Imamura
- Laboratory of Behavioral Genetics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Olivia Zanoletti
- Laboratory of Behavioral Genetics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Carmen Sandi
- Laboratory of Behavioral Genetics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| |
Collapse
|
80
|
Tanti GK, Goswami SK. SG2NA recruits DJ-1 and Akt into the mitochondria and membrane to protect cells from oxidative damage. Free Radic Biol Med 2014; 75:1-13. [PMID: 25035075 DOI: 10.1016/j.freeradbiomed.2014.07.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 06/24/2014] [Accepted: 07/07/2014] [Indexed: 12/31/2022]
Abstract
SG2NA is a WD-40 repeat protein with multiple protein-protein interaction domains of unknown functions. We demonstrate that it associates with the antioxidant protein DJ-1 and the survival kinase Akt. The C-terminal WD-40 repeat domain of SG2NA is required for its interaction with Akt, while DJ-1 binds it further upstream. No interaction between DJ-1 and Akt occurs in the absence of SG2NA. SG2NA, DJ-1, and Akt colocalize in mitochondria and plasma membrane. Their association is enhanced by increasing levels of reactive oxygen species up to a threshold level but falters thereafter with further increase in oxidants. Mutants of DJ-1 found in patients with familial parkinsonism are not recruited by SG2NA, suggesting its role in neuroprotection. Cells depleted of SG2NA are susceptible, while those overexpressing it are resistant to apoptosis induced by oxidative stress. Our study thus unravels a novel pathway of recruitment of Akt and DJ-1 that provides protection against oxidative stress, especially in neurons.
Collapse
Affiliation(s)
- Goutam Kumar Tanti
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Shyamal K Goswami
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
| |
Collapse
|
81
|
Zeldich E, Chen CD, Colvin TA, Bove-Fenderson EA, Liang J, Tucker Zhou TB, Harris DA, Abraham CR. The neuroprotective effect of Klotho is mediated via regulation of members of the redox system. J Biol Chem 2014; 289:24700-15. [PMID: 25037225 DOI: 10.1074/jbc.m114.567321] [Citation(s) in RCA: 153] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Generation of reactive oxygen species (ROS), leading to oxidative damage and neuronal cell death, plays an important role in the pathogenesis of neurodegenerative disorders, including Alzheimer disease. The present study aimed to examine the mechanism by which the anti-aging protein Klotho exerts neuroprotective effects against neuronal damage associated with neurodegeneration and oxidative stress. Pretreatment of rat primary hippocampal neurons and mouse hippocampal neuronal cell line HT22 with recombinant Klotho protected these cells from glutamate and oligomeric amyloid β (oAβ)-induced cytotoxicity. In addition, primary hippocampal neurons obtained from Klotho-overexpressing mouse embryos were more resistant to both cytotoxic insults, glutamate and oAβ, compared with neurons from wild-type littermates. An antioxidative stress array analysis of neurons treated with Klotho revealed that Klotho significantly enhances the expression of the thioredoxin/peroxiredoxin (Trx/Prx) system with the greatest effect on the induction of Prx-2, an antioxidant enzyme, whose increase was confirmed at the mRNA and protein levels. Klotho-induced phosphorylation of the PI3K/Akt pathway, a pathway important in apoptosis and longevity, was associated with sustained inhibitory phosphorylation of the transcription factor forkhead box O3a (FoxO3a) and was essential for the induction of Prx-2. Down-regulation of Prx-2 expression using a lentivirus harboring shRNA almost completely abolished the ability of Klotho to rescue neurons from glutamate-induced death and significantly, but not completely, inhibited cell death mediated by oAβ, suggesting that Prx-2 is a key modulator of neuroprotection. Thus, our results demonstrate, for the first time, the neuroprotective role of Klotho and reveal a novel mechanism underlying this effect.
Collapse
Affiliation(s)
| | | | | | | | | | - Tracey B Tucker Zhou
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts 02118
| | | | - Carmela R Abraham
- From the Department of Biochemistry, Program in Molecular Medicine, and Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts 02118
| |
Collapse
|
82
|
Essential role of PH domain and leucine-rich repeat protein phosphatase 2 in Nrf2 suppression via modulation of Akt/GSK3β/Fyn kinase axis during oxidative hepatocellular toxicity. Cell Death Dis 2014; 5:e1153. [PMID: 24675471 PMCID: PMC3973230 DOI: 10.1038/cddis.2014.118] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 02/21/2014] [Accepted: 02/21/2014] [Indexed: 12/30/2022]
Abstract
Instances of sustained oxidative activity have been shown to involve dysregulation of Nrf2-mediated transcriptional induction; however, mechanisms warranting Nrf2-repression remain unclear. In this study, using primary rat hepatocytes, we have attempted to identify factors that may negatively influence Nrf2 survival pathway. Though studies indicate a conspicuous association between Akt and Nrf2, a confirmatory link between the two is unaddressed. On inhibiting PI3K/Akt pathway, we observed compromised activities of antioxidant and detoxification enzymes culminating in oxidative cytotoxicity. This was accompanied by reduced nuclear retention of Nrf2 and its ARE binding affinity, increased Nrf2 ubiquitination and concurrent decline in its downstream targets. Moreover, Akt inhibition enhanced nuclear translocation as well as phosphorylation of Fyn kinase, an enzyme linked to Nrf2 degradation, by relieving GSK3β from phosphorylation-mediated repression. The involvement of Akt and Fyn kinase in influencing Nrf2 signaling was further confirmed in oxidatively stressed hepatocytes by using tert-butyl hydroperoxide (tBHP). tBHP-induced decrease in Nrf2 levels was associated with enhanced Fyn kinase phosphorylation, Fyn kinase nuclear translocation and decreased levels of phosphorylated GSK3β(Ser9) in a time-dependent manner. Interestingly, tBHP induced site-specific deactivation of Akt as only Akt(Ser473) phosphorylation was observed to be affected. Further, protein expression as well as nuclear localization of PHLPP2, a phosphatase specific for Akt(Ser473), was found to be significantly enhanced in tBHP-stressed hepatocytes. Silencing of PHLPP2 not only resulted in considerable restoration of Nrf2 signaling, enhanced Nrf2-ARE binding and reduced Nrf2 ubiquitination but also significantly suppressed tBHP-induced ROS generation and alterations in mitochondrial permeability. We infer that cellular PHLPP2 levels may aggravate oxidative toxicity by suppressing Nrf2/ARE transcriptional regulation via Akt(Se473)/GSK3β/Fyn kinase axis. The study indicates that PHLPP2 could serve as a new target for developing strategies to manage pathological conditions exacerbated due to oxidative stress.
Collapse
|
83
|
Shukla A, Mohapatra TM, Parmar D, Seth K. Neuroprotective potentials of neurotrophin rich olfactory ensheathing cell's conditioned media against 6OHDA-induced oxidative damage. Free Radic Res 2014; 48:560-71. [PMID: 24528157 DOI: 10.3109/10715762.2014.894636] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
On the basis of recent reports, we propose that impaired neurotrophin signaling (PI3k/Akt), low antioxidant levels, and generation of reactive oxygen species (ROS) conjointly participate in the progressive events responsible for the dopaminergic cell loss in Parkinson's disease (PD). In the present study we tried to target these deficits collectively through multiple neurotrophic factors (NTFs) support in the form of Olfactory Ensheathing Cell's Conditioned Media (OEC CM) using human SH-SY5Y neuroblastoma cell line exposed to 6 hydroxydopamine (6OHDA). 6OHDA exposure induced, oxidative stress-mediated apoptotic cell death viz. enhanced ROS generation, diffused cytosolic cytochrome c (cyt c), impaired Bcl-2: Bax levels along with decrease in GSH content. These changes were accompanied by loss in Akt phosphorylation and TH levels in SH-SY5Y cells. OEC CM significantly checked apoptotic cell death by preserving pAkt levels which coincided with enhanced GSH and suppressed oxidative injury. Functional integrity of OEC CM supported cells was evident by maintained tyrosine hydroxylase (TH) expression. Intercepting Akt signaling by specific inhibitor LY294002 blocked the protective effect. Taken together our findings provide important evidence that the key to protective effect of multiple NTF support via OEC CM is enhanced Akt survival signaling which promotes antioxidant defense leading to suppression of oxidative damage.
Collapse
Affiliation(s)
- A Shukla
- Indian Institute of Toxicology Research (CSIR), Developmental Toxicology Division , Lucknow , India
| | | | | | | |
Collapse
|