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Maioli S, Leander K, Nilsson P, Nalvarte I. Estrogen receptors and the aging brain. Essays Biochem 2021; 65:913-925. [PMID: 34623401 PMCID: PMC8628183 DOI: 10.1042/ebc20200162] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/09/2021] [Accepted: 09/10/2021] [Indexed: 12/14/2022]
Abstract
The female sex hormone estrogen has been ascribed potent neuroprotective properties. It signals by binding and activating estrogen receptors that, depending on receptor subtype and upstream or downstream effectors, can mediate gene transcription and rapid non-genomic actions. In this way, estrogen receptors in the brain participate in modulating neural differentiation, proliferation, neuroinflammation, cholesterol metabolism, synaptic plasticity, and behavior. Circulating sex hormones decrease in the course of aging, more rapidly at menopause in women, and slower in men. This review will discuss what this drop entails in terms of modulating neuroprotection and resilience in the aging brain downstream of spatiotemporal estrogen receptor alpha (ERα) and beta (ERβ) signaling, as well as in terms of the sex differences observed in Alzheimer's disease (AD) and Parkinson's disease (PD). In addition, controversies related to ER expression in the brain will be discussed. Understanding the spatiotemporal signaling of sex hormones in the brain can lead to more personalized prevention strategies or therapies combating neurodegenerative diseases.
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Affiliation(s)
- Silvia Maioli
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Karin Leander
- Institute of Environmental Medicine, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Per Nilsson
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Ivan Nalvarte
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 57 Huddinge, Sweden
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2
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Azcoitia I, Barreto GE, Garcia-Segura LM. Molecular mechanisms and cellular events involved in the neuroprotective actions of estradiol. Analysis of sex differences. Front Neuroendocrinol 2019; 55:100787. [PMID: 31513774 DOI: 10.1016/j.yfrne.2019.100787] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/27/2019] [Accepted: 09/07/2019] [Indexed: 12/12/2022]
Abstract
Estradiol, either from peripheral or central origin, activates multiple molecular neuroprotective and neuroreparative responses that, being mediated by estrogen receptors or by estrogen receptor independent mechanisms, are initiated at the membrane, the cytoplasm or the cell nucleus of neural cells. Estrogen-dependent signaling regulates a variety of cellular events, such as intracellular Ca2+ levels, mitochondrial respiratory capacity, ATP production, mitochondrial membrane potential, autophagy and apoptosis. In turn, these molecular and cellular actions of estradiol are integrated by neurons and non-neuronal cells to generate different tissue protective responses, decreasing blood-brain barrier permeability, oxidative stress, neuroinflammation and excitotoxicity and promoting synaptic plasticity, axonal growth, neurogenesis, remyelination and neuroregeneration. Recent findings indicate that the neuroprotective and neuroreparative actions of estradiol are different in males and females and further research is necessary to fully elucidate the causes for this sex difference.
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Affiliation(s)
- Iñigo Azcoitia
- Department of Cell Biology, Faculty of Biology, Universidad Complutense de Madrid, 28040 Madrid, Spain; Centro de Investigación Biomédica en Red Fragilidad y Envejecimiento Saludables (CIBERFES), Instituto de Salud Carlos III, Avenida Monforte de Lemos, 3-5, 28029 Madrid, Spain.
| | - George E Barreto
- Department of Biological Sciences, School of Natural Sciences, University of Limerick, Limerick, Ireland.
| | - Luis M Garcia-Segura
- Centro de Investigación Biomédica en Red Fragilidad y Envejecimiento Saludables (CIBERFES), Instituto de Salud Carlos III, Avenida Monforte de Lemos, 3-5, 28029 Madrid, Spain; Instituto Cajal, CSIC, Avenida Doctor Arce 37, 28002 Madrid, Spain.
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3
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Choi YS, Horning P, Aten S, Karelina K, Alzate-Correa D, Arthur JSC, Hoyt KR, Obrietan K. Mitogen- and Stress-Activated Protein Kinase 1 Regulates Status Epilepticus-Evoked Cell Death in the Hippocampus. ASN Neuro 2018; 9:1759091417726607. [PMID: 28870089 PMCID: PMC5588809 DOI: 10.1177/1759091417726607] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Mitogen-activated protein kinase (MAPK) signaling has been implicated in a wide range of neuronal processes, including development, plasticity, and viability. One of the principal downstream targets of both the extracellular signal-regulated kinase/MAPK pathway and the p38 MAPK pathway is Mitogen- and Stress-activated protein Kinase 1 (MSK1). Here, we sought to understand the role that MSK1 plays in neuroprotection against excitotoxic stimulation in the hippocampus. To this end, we utilized immunohistochemical labeling, a MSK1 null mouse line, cell viability assays, and array-based profiling approaches. Initially, we show that MSK1 is broadly expressed within the major neuronal cell layers of the hippocampus and that status epilepticus drives acute induction of MSK1 activation. In response to the status epilepticus paradigm, MSK1 KO mice exhibited a striking increase in vulnerability to pilocarpine-evoked cell death within the CA1 and CA3 cell layers. Further, cultured MSK1 null neurons exhibited a heighted level of N-methyl-D-aspartate-evoked excitotoxicity relative to wild-type neurons, as assessed using the lactate dehydrogenase assay. Given these findings, we examined the hippocampal transcriptional profile of MSK1 null mice. Affymetrix array profiling revealed that MSK1 deletion led to the significant (>1.25-fold) downregulation of 130 genes and an upregulation of 145 genes. Notably, functional analysis indicated that a subset of these genes contribute to neuroprotective signaling networks. Together, these data provide important new insights into the mechanism by which the MAPK/MSK1 signaling cassette confers neuroprotection against excitotoxic insults. Approaches designed to upregulate or mimic the functional effects of MSK1 may prove beneficial against an array of degenerative processes resulting from excitotoxic insults.
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Affiliation(s)
- Yun-Sik Choi
- 1 Department of Pharmaceutical Science and Technology, Catholic University of Daegu, Gyeongbuk, Republic of Korea
| | - Paul Horning
- 2 Department of Neuroscience, 2647 Ohio State University , Columbus, OH, USA
| | - Sydney Aten
- 2 Department of Neuroscience, 2647 Ohio State University , Columbus, OH, USA
| | - Kate Karelina
- 2 Department of Neuroscience, 2647 Ohio State University , Columbus, OH, USA
| | | | - J Simon C Arthur
- 4 College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Kari R Hoyt
- 3 Division of Pharmacology, 2647 Ohio State University , Columbus, OH, USA
| | - Karl Obrietan
- 2 Department of Neuroscience, 2647 Ohio State University , Columbus, OH, USA
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4
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Gonadal hormone modulation of intracellular calcium as a mechanism of neuroprotection. Front Neuroendocrinol 2016; 42:40-52. [PMID: 26930421 DOI: 10.1016/j.yfrne.2016.02.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 02/22/2016] [Accepted: 02/26/2016] [Indexed: 12/28/2022]
Abstract
Hormones have wide-ranging effects throughout the nervous system, including the ability interact with and modulate many aspects of intracellular calcium regulation and calcium signaling. Indeed, these interactions specifically may help to explain the often opposing or paradoxical effects of hormones, such as their ability to both promote and prevent neuronal cell death during development, as well as reduce or exacerbate damage following an insult or injury in adulthood. Here, we review the basic mechanisms underlying intracellular calcium regulation-perhaps the most dynamic and flexible of all signaling molecules-and discuss how gonadal hormones might manipulate these mechanisms to coordinate diverse cellular responses and achieve disparate outcomes. Additional future research that specifically addresses questions of sex and hormone effects on calcium signaling at different ages will be critical to understanding hormone-mediated neuroprotection.
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5
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Pratap UP, Patil A, Sharma HR, Hima L, Chockalingam R, Hariharan MM, Shitoot S, Priyanka HP, ThyagaRajan S. Estrogen-induced neuroprotective and anti-inflammatory effects are dependent on the brain areas of middle-aged female rats. Brain Res Bull 2016; 124:238-53. [PMID: 27242078 DOI: 10.1016/j.brainresbull.2016.05.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 05/24/2016] [Accepted: 05/26/2016] [Indexed: 12/23/2022]
Abstract
BACKGROUND Reproductive aging in females is characterized by fluctuations and precipitous decline in estrogen levels, which may lead to reduction in cognitive function and age-associated neurodegenerative disorders. The nature of estrogen-mediated neuronal plasticity is unknown during reproductive aging. We hypothesize that estrogen treatment of early middle-aged ovariectomized rats may exert specific effects in the brain by modulating signaling pathways regulating metabolic enzymes, inflammatory markers, antioxidant status, cholinergic function and survival signals. PURPOSE To investigate the mechanisms of estrogen-induced effects on neuroprotection and neuroinflammation through the involvement of intracellular signaling pathways in brain areas of ovariectomized (OVX) middle-aged (MA) female rats. METHODS Ovariectomized early MA female Sprague-Dawley rats (n=8/group) were implanted with 17β-estradiol (E2) 30-day release pellets (0.6μg and 300μg). At the end of the treatment period, frontal cortex (FC), striatum (STR), medial basal hypothalamus (MBH), and hippocampus (HP) were isolated and examined for the expression of tyrosine hydroxylase (p-TH), nerve growth factor (NGF), p-NF-κB (p50 and p65)and p-ERK, p-CREB, p-Akt, and activities of cholinesterases and antioxidant enzymes, key regulatory enzymes of metabolic pathways, and nitric oxide production. RESULTS E2 enhanced p-TH expression in FC and HP, reduced NGF expression in HP, and suppressed p-NF-κB expression in FC and STR. It also increased the expression of molecular markers (p-ERK, p-CREB and p-Akt), and nitric oxide production in various brain areas, while differentially regulating the activities of metabolic enzymes and cholinesterases. CONCLUSION Estrogen modulates the neural and inflammatory factors, and intracellular markers depending on the brain areas that may influence differential remodeling of neuronal circuitry which can be used to develop therapeutic strategies in cognitive impairment and neurodegenerative disorders in aging.
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Affiliation(s)
- Uday P Pratap
- Integrative Medicine Laboratory, Department of Biotechnology, School of Bioengineering, SRM University, Kattankulathur 603203, Tamil Nadu, India
| | - Anushree Patil
- Integrative Medicine Laboratory, Department of Biotechnology, School of Bioengineering, SRM University, Kattankulathur 603203, Tamil Nadu, India
| | - Himanshu R Sharma
- Integrative Medicine Laboratory, Department of Biotechnology, School of Bioengineering, SRM University, Kattankulathur 603203, Tamil Nadu, India
| | - Lalgi Hima
- Integrative Medicine Laboratory, Department of Biotechnology, School of Bioengineering, SRM University, Kattankulathur 603203, Tamil Nadu, India
| | - Ramanathan Chockalingam
- Integrative Medicine Laboratory, Department of Biotechnology, School of Bioengineering, SRM University, Kattankulathur 603203, Tamil Nadu, India
| | - Murali M Hariharan
- Integrative Medicine Laboratory, Department of Biotechnology, School of Bioengineering, SRM University, Kattankulathur 603203, Tamil Nadu, India
| | - Sushrut Shitoot
- Integrative Medicine Laboratory, Department of Biotechnology, School of Bioengineering, SRM University, Kattankulathur 603203, Tamil Nadu, India
| | - Hannah P Priyanka
- Integrative Medicine Laboratory, Department of Biotechnology, School of Bioengineering, SRM University, Kattankulathur 603203, Tamil Nadu, India
| | - Srinivasan ThyagaRajan
- Integrative Medicine Laboratory, Department of Biotechnology, School of Bioengineering, SRM University, Kattankulathur 603203, Tamil Nadu, India.
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Ycaza Herrera A, Mather M. Actions and interactions of estradiol and glucocorticoids in cognition and the brain: Implications for aging women. Neurosci Biobehav Rev 2015; 55:36-52. [PMID: 25929443 DOI: 10.1016/j.neubiorev.2015.04.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 03/30/2015] [Accepted: 04/17/2015] [Indexed: 02/03/2023]
Abstract
Menopause involves dramatic declines in estradiol production and levels. Importantly, estradiol and the class of stress hormones known as glucocorticoids exert countervailing effects throughout the body, with estradiol exerting positive effects on the brain and cognition, glucocorticoids exerting negative effects on the brain and cognition, and estradiol able to mitigate negative effects of glucocorticoids. Although the effects of these hormones in isolation have been extensively studied, the effects of estradiol on the stress response and the neuroprotection offered against glucocorticoid exposure in humans are less well known. Here we review evidence suggesting that estradiol-related protection against glucocorticoids mitigates stress-induced interference with cognitive processes. Animal and human research indicates that estradiol-related mitigation of glucocorticoid damage and interference is one benefit of estradiol supplementation during peri-menopause or soon after menopause. The evidence for estradiol-related protection against glucocorticoids suggests that maintaining estradiol levels in post-menopausal women could protect them from stress-induced declines in neural and cognitive integrity.
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Affiliation(s)
- Alexandra Ycaza Herrera
- University of Southern California, 3715 McClintock Avenue, Los Angeles, CA 90089, United States.
| | - Mara Mather
- University of Southern California, 3715 McClintock Avenue, Los Angeles, CA 90089, United States.
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Song Z, Han S, Pan X, Gong Y, Wang M. Pterostilbene mediates neuroprotection against oxidative toxicity via oestrogen receptor α signalling pathways. J Pharm Pharmacol 2015; 67:720-30. [DOI: 10.1111/jphp.12360] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 11/02/2014] [Indexed: 01/09/2023]
Abstract
Abstract
Objectives
Accumulating evidence indicated protective role of phytoestrogens against neuronal damage induced by various insults, such as amyloid beta, oxygen deprivation and mitochondrial toxins. Hydrogen peroxide (H2O2) influences the mitochondrial membrane potential, which eventually results in cell apoptosis. In this study, we investigated the effects and possible mechanisms of a phytoestrogen, pterostilbene (PTER), in cell apoptosis induced by H2O2 in human neuronal SH-SY5Y cells. We also analysed the involvement of oestrogen receptors, oestrogen receptor-α and -β (ER-α and ER-β) in the protective role of PTER.
Methods
The effects of PTER on H2O2-stimulated cell were examined using MTT and FACS analysis. The signal pathways and estrogen receptors involved in PTER's effects were investigated using MTT and Western blot analysis.
Key findings
The results showed that H2O2 treatment significantly reduced cell viability in SY5Y cells, which was protected by PTER treatment. We also found that H2O2 inhibited the PI3K/AKT and MAPK/ERK signalling pathways, whereas PTER treatment restored these signalling pathways. We also found that the PTER effect could be largely blocked by an ER-α antagonist, 3-Bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy)phenol]-1H-pyrazole dihydrochloride (MPP), but not by an ER-β antagonist, 4-[2-Phenyl-5,7-bis(trifluoromethyl)pyrazolo[1,5-a] pyrimidin-3-yl]phenol (PHTPP), suggesting that ER-α is a major player in the neuroprotective activity of PTER.
Conclusion
Our study thus demonstrates that PTER is an effective neuroprotective agent presumably through ER-α-mediated signalling pathways.
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Affiliation(s)
- Zhen Song
- Department of Genetics, Key Laboratory for Experimental Teratology of the Ministry of Education, Shandong University, Jinan, Shandong, China
| | - Shuai Han
- Department of Genetics, Key Laboratory for Experimental Teratology of the Ministry of Education, Shandong University, Jinan, Shandong, China
| | - Xiaohua Pan
- Department of Breast and Thyroid Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, China
| | - Yaoqin Gong
- Department of Genetics, Key Laboratory for Experimental Teratology of the Ministry of Education, Shandong University, Jinan, Shandong, China
| | - Molin Wang
- Department of Genetics, Key Laboratory for Experimental Teratology of the Ministry of Education, Shandong University, Jinan, Shandong, China
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Ginsenoside Rd attenuates mitochondrial permeability transition and cytochrome C release in isolated spinal cord mitochondria: involvement of kinase-mediated pathways. Int J Mol Sci 2014; 15:9859-77. [PMID: 24897022 PMCID: PMC4100126 DOI: 10.3390/ijms15069859] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 05/08/2014] [Accepted: 05/21/2014] [Indexed: 12/17/2022] Open
Abstract
Ginsenoside Rd (Rd), one of the main active ingredients in Panax ginseng, has multifunctional activity via different mechanisms and neuroprotective effects that are exerted probably via its antioxidant or free radical scavenger action. However, the effects of Rd on spinal cord mitochondrial dysfunction and underlying mechanisms are still obscure. In this study, we sought to investigate the in vitro effects of Rd on mitochondrial integrity and redox balance in isolated spinal cord mitochondria. We verified that Ca2+ dissipated the membrane potential, provoked mitochondrial swelling and decreased NAD(P)H matrix content, which were all attenuated by Rd pretreatment in a dose-dependent manner. In contrast, Rd was not able to inhibit Ca2+ induced mitochondrial hydrogen peroxide generation. The results of Western blot showed that Rd significantly increased the expression of p-Akt and p-ERK, but had no effects on phosphorylation of PKC and p38. In addition, Rd treatment significantly attenuated Ca2+ induced cytochrome c release, which was partly reversed by antagonists of Akt and ERK, but not p-38 inhibitor. The effects of bisindolylmaleimide, a PKC inhibitor, on Rd-induced inhibition of cytochrome c release seem to be at the level of its own detrimental activity on mitochondrial function. Furthermore, we also found that pretreatment with Rd in vivo (10 and 50 mg/kg) protected spinal cord mitochondria against Ca2+ induced mitochondrial membrane potential dissipation and cytochrome c release. It is concluded that Rd regulate mitochondrial permeability transition pore formation and cytochrome c release through protein kinases dependent mechanism involving activation of intramitochondrial Akt and ERK pathways.
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Benmansour S, Privratsky AA, Adeniji OS, Frazer A. Signaling mechanisms involved in the acute effects of estradiol on 5-HT clearance. Int J Neuropsychopharmacol 2014; 17:765-77. [PMID: 24423185 PMCID: PMC3969768 DOI: 10.1017/s146114571300165x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Estradiol was found previously to have an antidepressant-like effect and to block the ability of selective serotonin reuptake inhibitors (SSRIs) to have an antidepressant-like effect. The antidepressant-like effect of estradiol was due to estrogen receptor β (ERβ) and/or GPR30 activation, whereas estradiol's blockade of the effect of an SSRI was mediated by ERα. This study focuses on investigating signaling pathways as well as interacting receptors associated with these two effects of estradiol. In vivo chronoamperometry was used to measure serotonin transporter (SERT) function. The effect of local application of estradiol or selective agonists for ERα (PPT) or ERβ (DPN) into the CA3 region of the hippocampus of ovariectomized (OVX) rats on 5-hydroxytryptamine (5-HT) clearance as well as on the ability of fluvoxamine to slow 5-HT clearance was examined after selective blockade of signaling pathways or that of interacting receptors. Estradiol- or DPN-induced slowing of 5-HT clearance mediated by ERβ was blocked after inhibition of MAPK/ERK1/2 but not of PI3K/Akt signaling pathways. This effect also involved interactions with TrkB, and IGF-1 receptors. Estradiol's or PPT's inhibition of the fluvoxamine-induced slowing of 5-HT clearance mediated by ERα, was blocked after inhibition of either MAPK/ERK1/2 or PI3K/Akt signaling pathways. This effect involved interactions with the IGF-1 receptor and with the metabotropic glutamate receptor 1, but not with TrkB. This study illustrates some of the signaling pathways required for the effects of estradiol on SERT function, and particularly shows that ER subtypes elicit different as well as common signaling pathways for their actions.
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Affiliation(s)
- Saloua Benmansour
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, Texas 78229
| | - Anthony A. Privratsky
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, Texas 78229
| | - Opeyemi S. Adeniji
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, Texas 78229
| | - Alan Frazer
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, Texas 78229
- South Texas Veterans Health Care System, San Antonio, Texas 78284, USA
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Zhang C, Zhu J, Zhang J, Li H, Zhao Z, Liao Y, Wang X, Su J, Sang S, Yuan X, Liu Q. Neuroprotective and anti-apoptotic effects of valproic acid on adult rat cerebral cortex through ERK and Akt signaling pathway at acute phase of traumatic brain injury. Brain Res 2014; 1555:1-9. [PMID: 24508577 DOI: 10.1016/j.brainres.2014.01.051] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 01/27/2014] [Accepted: 01/29/2014] [Indexed: 01/06/2023]
Abstract
Mood stabilizer valproic acid (VPA), a widely used antiepileptic drug that has been demonstrated neuroprotective effect against various insults through multiple signaling pathways. The role of VPA in traumatic brain injury (TBI) remains unclear. In the present study, we investigated the neuroprotective potency of VPA for protection against TBI in adult rats, focusing on studying signaling mediators of two well characterized pro-survival molecules, extracellular signal-regulated protein kinase (ERK) and Akt. We found that treatment of VPA after TBI significantly attenuated brain edema, reduced contusion volume and the rate of neuronal apoptosis. The treatment also partly blocked an increase in capase-3 activity. VPA markedly up-regulated the activity of ERK and Akt expression. Moreover, treatment with either PD98059, an ERK inhibitor and/or LY294002, an Akt inhibitor, attenuated the neuroprotection of VPA against TBI to varying degrees. Taken together, these results demonstrated that treatment with VPA after TBI could be neuroprotective via activation of ERK and Akt signaling pathways.
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Affiliation(s)
- Chi Zhang
- Department of Neurosurgery, Xiangya Hospital, Central-South University, Changsha, Hunan 410008, PR China
| | - Jie Zhu
- Department of Neurosurgery, 101th Hospital of PLA, Rescue Center of Craniocerebral Injuries of PLA, Wuxi, Jiangsu 214044, PR China
| | - Jing Zhang
- Department of Otorhinolaryngology, Head and Neck Surgery, Lanzhou General Hospital of Lanzhou Military Command, Lanzhou, Gansu 730050, PR China
| | - Haoyu Li
- Department of Neurosurgery, Xiangya Hospital, Central-South University, Changsha, Hunan 410008, PR China
| | - Zijin Zhao
- Department of Neurosurgery, Xiangya Hospital, Central-South University, Changsha, Hunan 410008, PR China
| | - Yiwei Liao
- Department of Neurosurgery, Xiangya Hospital, Central-South University, Changsha, Hunan 410008, PR China
| | - Xiangyu Wang
- Department of Neurosurgery, Xiangya Hospital, Central-South University, Changsha, Hunan 410008, PR China
| | - Jun Su
- Department of Neurosurgery, Xiangya Hospital, Central-South University, Changsha, Hunan 410008, PR China
| | - Shushan Sang
- Department of Neurosurgery, Xiangya Hospital, Central-South University, Changsha, Hunan 410008, PR China
| | - Xianrui Yuan
- Department of Neurosurgery, Xiangya Hospital, Central-South University, Changsha, Hunan 410008, PR China.
| | - Qing Liu
- Department of Neurosurgery, Xiangya Hospital, Central-South University, Changsha, Hunan 410008, PR China.
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11
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Dine J, Ducourneau VRR, Fénelon VS, Fossat P, Amadio A, Eder M, Israel JM, Oliet SHR, Voisin DL. Extracellular signal-regulated kinase phosphorylation in forebrain neurones contributes to osmoregulatory mechanisms. J Physiol 2014; 592:1637-54. [PMID: 24492838 DOI: 10.1113/jphysiol.2013.261008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Vasopressin secretion from the magnocellular neurosecretory cells (MNCs) is crucial for body fluid homeostasis. Osmotic regulation of MNC activity involves the concerted modulation of intrinsic mechanosensitive ion channels, taurine release from local astrocytes as well as excitatory inputs derived from osmosensitive forebrain regions. Extracellular signal-regulated protein kinases (ERK) are mitogen-activated protein kinases that transduce extracellular stimuli into intracellular post-translational and transcriptional responses, leading to changes in intrinsic neuronal properties and synaptic function. Here, we investigated whether ERK activation (i.e. phosphorylation) plays a role in the functioning of forebrain osmoregulatory networks. We found that within 10 min after intraperitoneal injections of hypertonic saline (3 m, 6 m) in rats, many phosphoERK-immunopositive neurones were observed in osmosensitive forebrain regions, including the MNC containing supraoptic nuclei. The intensity of ERK labelling was dose-dependent. Reciprocally, slow intragastric infusions of water that lower osmolality reduced basal ERK phosphorylation. In the supraoptic nucleus, ERK phosphorylation predominated in vasopressin neurones vs. oxytocin neurones and was absent from astrocytes. Western blot experiments confirmed that phosphoERK expression in the supraoptic nucleus was dose dependent. Intracerebroventricular administration of the ERK phosphorylation inhibitor U 0126 before a hyperosmotic challenge reduced the number of both phosphoERK-immunopositive neurones and Fos expressing neurones in osmosensitive forebrain regions. Blockade of ERK phosphorylation also reduced hypertonically induced depolarization and an increase in firing of the supraoptic MNCs recorded in vitro. It finally reduced hypertonically induced vasopressin release in the bloodstream. Altogether, these findings identify ERK phosphorylation as a new element contributing to the osmoregulatory mechanisms of vasopressin release.
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Affiliation(s)
- Julien Dine
- Inserm, U862, Neurocentre Magendie, Université de Bordeaux, 146 Rue Léo-Saignat, F-33077 Bordeaux, France.
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Zhao Y, Luo P, Guo Q, Li S, Zhang L, Zhao M, Xu H, Yang Y, Poon W, Fei Z. Interactions between SIRT1 and MAPK/ERK regulate neuronal apoptosis induced by traumatic brain injury in vitro and in vivo. Exp Neurol 2012; 237:489-98. [PMID: 22828134 DOI: 10.1016/j.expneurol.2012.07.004] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2012] [Revised: 06/27/2012] [Accepted: 07/14/2012] [Indexed: 12/14/2022]
Abstract
Traumatic brain injury (TBI) is a serious insult that frequently leads to neurological dysfunction or death. Silent information regulator family protein 1 (SIRT1), as the founding member of nicotinamide adenine dinucleotide (NAD)-dependent deacetylases, has recently been demonstrated to have neuroprotective effect in several models of neurodegenerative diseases. The present study attempts to determine whether SIRT1 has a neuroprotective effect in the model of TBI, and further to investigate the possible regulatory mechanism of neuron death. Thus, we employ transection model in vitro and weight-drop model in vivo to mimic the insults of TBI. The study shows that the expressions of SIRT1, phosphorylation extracellular signal-regulated kinase (p-ERK) and cleaved Caspase-3 are induced after trauma injury in vitro or in vivo. Furthermore, inhibiting SIRT1 by pharmacological inhibitor salermide or SIRT1 siRNA significantly promotes apoptotic neuron death and reduces ERK1/2 activation induced by mechanical injury in vitro and in vivo. Inhibition of ERK1/2 activation with PD98059 or U0126 (two mitogen activated protein kinase kinase inhibitors) in vitro and in vivo significantly attenuates the SIRT1 and cleaved Caspase-3 expression to protect neuron against TBI-induced apoptosis. These results reveal that SIRT1 plays a neuroprotective effect against neuronal apoptosis induced by TBI. The interactions between SIRT1 and MAPK/ERK pathway regulate neuronal apoptosis induced by mechanical trauma injury in vitro and in vivo.
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Affiliation(s)
- Yongbo Zhao
- Institute of Neurosurgery, Xijing Hospital, Fourth Military Medical University, 17 Changlexi Street, Xi'an, Shaanxi Province 710032, People's Republic of China
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Hernández-Ortega K, Arias C. ERK activation and expression of neuronal cell cycle markers in the hippocampus after entorhinal cortex lesion. J Neurosci Res 2012; 90:2116-26. [PMID: 22811014 DOI: 10.1002/jnr.23106] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 05/22/2012] [Accepted: 05/29/2012] [Indexed: 12/22/2022]
Abstract
Current findings suggest that neuronal cell death is frequently associated with the aberrant expression of cell cycle-regulatory proteins in postmitotic neurons. Aberrant cell cycle reentry has been implicated in diverse neurodegenerative conditions, including Alzheimer's disease (AD). Previously we reported that the appearance of cell cycle markers in postmitotic neurons of the entorhinal cortex (EC) after excitotoxic hippocampal damage is associated with the expression of phospho-tau and amyloid precursor protein (APP). However, the question of the signaling pathway involved in this cell cycle reentry remains unresolved. Differentiated neurons use the molecular mechanisms initially acquired to direct cell proliferation, such as the Ras-extracellular signal-regulated kinase (ERK1/2) pathway, to regulate synaptic plasticity. In this work we explored whether ERK1/2-related signaling might contribute to the cell cycle reentry in hippocampal neurons after a unilateral EC lesion. We showed that, within the first 24 hr after hippocampal deafferentation, numerous neurons expressed phospho-ERK1/2, concomitantly with the gradual increases in cyclin D1 and cyclin B immunoreactivity in the dentate gyrus and hilus. Several of these immunopositive cells to phospho-ERK1/2 and cyclin B in hippocampus are postmitotic neurons, insofar as they are positive to NeuN. The intracisternal administration of U0126 (an MEK inhibitor), previous to the excitotoxic lesion, decreased the activation of ERK1/2 and the expression of cyclin D1 and cyclin B in the hippocampus. The present findings support the notion that ERK1/2 plays a role in cell cycle reactivation in mature neurons efferently connected to the lesion site.
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Affiliation(s)
- Karina Hernández-Ortega
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México D.F., México
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14
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Fiocchetti M, Ascenzi P, Marino M. Neuroprotective effects of 17β-estradiol rely on estrogen receptor membrane initiated signals. Front Physiol 2012; 3:73. [PMID: 22493583 PMCID: PMC3319910 DOI: 10.3389/fphys.2012.00073] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Accepted: 03/13/2012] [Indexed: 12/15/2022] Open
Abstract
Besides its crucial role in many physiological events, 17β-estradiol (E2) exerts protective effects in the central nervous system. The E2 effects are not restricted to the brain areas related with the control of reproductive function, but rather are widespread throughout the developing and the adult brain. E2 actions are mediated through estrogen receptors (i.e., ERα and ERβ) belonging to the nuclear receptor super-family. As members of the ligand-regulated transcription factor family, classically, the actions of ERs in the brain were thought to mediate only the E2 long-term transcriptional effects. However, a growing body of evidence highlighted rapid, membrane initiated E2 effects in the brain that are independent of ER transcriptional activities and are involved in E2-induced neuroprotection. The aim of this review is to focus on the rapid effects of E2 in the brain highlighting the specific role of the signaling pathway(s) of the ERβ subtype in the neuroprotective actions of E2.
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15
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Estrogens: mechanisms of neuroprotective effects. J Physiol Biochem 2012; 68:455-60. [DOI: 10.1007/s13105-012-0159-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 02/15/2012] [Indexed: 02/04/2023]
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16
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Scott E, Zhang QG, Wang R, Vadlamudi R, Brann D. Estrogen neuroprotection and the critical period hypothesis. Front Neuroendocrinol 2012; 33:85-104. [PMID: 22079780 PMCID: PMC3288697 DOI: 10.1016/j.yfrne.2011.10.001] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 10/21/2011] [Accepted: 10/24/2011] [Indexed: 12/15/2022]
Abstract
17β-Estradiol (estradiol or E2) is implicated as a neuroprotective factor in a variety of neurodegenerative disorders. This review focuses on the mechanisms underlying E2 neuroprotection in cerebral ischemia, as well as emerging evidence from basic science and clinical studies, which suggests that there is a "critical period" for estradiol's beneficial effect in the brain. Potential mechanisms underlying the critical period are discussed, as are the neurological consequences of long-term E2 deprivation (LTED) in animals and in humans after natural menopause or surgical menopause. We also summarize the major clinical trials concerning postmenopausal hormone therapy (HT), comparing their outcomes with respect to cardiovascular and neurological disease and discussing their relevance to the critical period hypothesis. Finally, potential caveats, controversies and future directions for the field are highlighted and discussed throughout the review.
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Affiliation(s)
- Erin Scott
- Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, Augusta, GA 30912, USA
| | - Quan-guang Zhang
- Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, Augusta, GA 30912, USA
| | - Ruimin Wang
- Experimental and Research Center, Hebei United University, 57 South Jian-she Road, Tangshan, Hebei, 063600, PR China
| | - Ratna Vadlamudi
- Department of Obstetrics & Gynecology, University of Texas Health Science Center at San Antonio, Floyd Curl Drive, San Antonio, TX 78229, USA
| | - Darrell Brann
- Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, Augusta, GA 30912, USA
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17
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Chen T, Zhang L, Qu Y, Huo K, Jiang X, Fei Z. The selective mGluR5 agonist CHPG protects against traumatic brain injury in vitro and in vivo via ERK and Akt pathway. Int J Mol Med 2011; 29:630-6. [PMID: 22211238 PMCID: PMC3577346 DOI: 10.3892/ijmm.2011.870] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 10/27/2011] [Indexed: 12/31/2022] Open
Abstract
Group I metabotropic glutamate receptors (mGluRs) have been implicated in the pathophysiology of central nervous system injury, but the role of mGluR5 in traumatic brain injury (TBI) remains unclear. In the present study, we investigated the neuroprotective potency of (R,S)-2-chloro-5-hydroxyphenylglycine (CHPG), a selective mGluR5 agonist, for protecting against TBI in both in vitro and in vivo models. Primary cortical neurons were treated with 1 mM CHPG in an in vitro preparation 30 min before TBI, and 250 nM CHPG was injected into the right lateral ventricle of rats 30 min before TBI was induced in in vivo studies. The results showed that CHPG significantly attenuated lactate dehydrogenase (LDH) release and neuronal apoptosis and reduced lesion volume. Compared to the control or vehicle group, the phosphorylation levels of extracellular signal-regulated kinase (ERK) and Akt were increased in the presence of CHPG, even following the induction of TBI. Furthermore, treatment with either the ERK inhibitor PD98059 or Akt inhibitor LY294002 partially reversed the CHPG's neuroprotective effects. These data suggest that CHPG minimizes brain damage after induction of TBI both in vitro and in vivo, and that these protective effects were possibly mediated by activation of the ERK and Akt signaling pathways. Thus, potentiating mGluR5 activity with selective agonists such as CHPG may be useful for the treatment of traumatic brain injury.
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Affiliation(s)
- Tao Chen
- Department of Neurosurgery, Xijing Institute of Clinical Neuroscience, Xijing Hospital, Fourth Military Medical University, Xi'an, Shannxi 710032, PR China
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18
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Simpkins JW, Perez E, Wang X, Yang S, Wen Y, Singh M. The potential for estrogens in preventing Alzheimer's disease and vascular dementia. Ther Adv Neurol Disord 2011; 2:31-49. [PMID: 19890493 DOI: 10.1177/1756285608100427] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Estrogens are the best-studied class of drugs for potential use in the prevention of Alzheimer's disease (AD). These steroids have been shown to be potent neuroprotectants both in vitro and in vivo, and to exert effects that are consistent with their potential use in prevention of AD. These include the prevention of the processing of amyloid precursor protein (APP) into beta-amyloid (Aß), the reduction in tau hyperphosphorylation, and the elimination of catastrophic attempts at neuronal mitosis. Further, epidemiological data support the efficacy of early postmenopausal use of estrogens for the delay or prevention of AD. Collectively, this evidence supports the further development of estrogen-like compounds for prevention of AD. Several approaches to enhance brain specificity of estrogen action are now underway in an attempt to reduce the side effects of chronic estrogen therapy in AD.
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Affiliation(s)
- James W Simpkins
- Department of Pharmacology and Neuroscience, Institute for Aging and Alzheimer's Disease Research, Center FOR HER (Focused On Resources for her Health, Education and Research), University of North Texas Health Science Center, Fort Worth, TX, USA
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19
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ConBr, a Lectin from Canavalia brasiliensis Seeds, Protects Against Quinolinic Acid-Induced Seizures in Mice. Neurochem Res 2011; 37:288-97. [DOI: 10.1007/s11064-011-0608-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 09/12/2011] [Accepted: 09/16/2011] [Indexed: 10/17/2022]
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20
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Chen T, Liu W, Chao X, Qu Y, Zhang L, Luo P, Xie K, Huo J, Fei Z. Neuroprotective effect of osthole against oxygen and glucose deprivation in rat cortical neurons: involvement of mitogen-activated protein kinase pathway. Neuroscience 2011; 183:203-11. [DOI: 10.1016/j.neuroscience.2011.03.038] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Revised: 03/10/2011] [Accepted: 03/20/2011] [Indexed: 11/30/2022]
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21
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Aenlle KK, Foster TC. Aging alters the expression of genes for neuroprotection and synaptic function following acute estradiol treatment. Hippocampus 2011; 20:1047-60. [PMID: 19790252 DOI: 10.1002/hipo.20703] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This study used microarray analysis to examine age-related changes in gene expression 6 and 12 h following a single estradiol injection in ovariectomized mice. Estradiol-responsive gene expression at the 6 h time point was reduced in aged (18 months) animals compared with young (4 months) and middle-aged (MA, 12 months) mice. Examination of gene clustering within biological and functional pathways indicated that young and MA mice exhibited increased expression of genes for cellular components of the synapse and decreased expression of genes related to oxidative phosphorylation and mitochondrial dysfunction. At the 12 h time point, estradiol-responsive gene expression increased in aged animals and decreased in young and MA mice compared with the 6 h time point. Gene clustering analysis indicated that aged mice exhibited increased expression of genes for signaling pathways that are rapidly influenced by estradiol. The age differences in gene expression for rapid signaling pathways may relate to disparity in basal pathway activity and estradiol mediated activation of rapid signaling cascades.
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Affiliation(s)
- Kristina K Aenlle
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
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22
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Nishio M, Watanabe Y. Hippocampal leptin suppresses methamphetamine-induced hyperlocomotion. Basic Clin Pharmacol Toxicol 2010; 107:842-6. [PMID: 20486923 DOI: 10.1111/j.1742-7843.2010.00591.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Leptin is an anorexigenic peptide which is synthesized in white adipose tissue. The actions of leptin are mediated by the leptin receptor which is abundantly localized in the hypothalamus and is involved in energy regulation and balance. Recently, there has been evidence suggesting that the leptin receptor is also present in the hippocampus and may be involved with hippocampal excitability and long-term depression. To investigate the physiological function of leptin signalling in the hippocampus, we studied the effects of leptin on methamphetamine-induced ambulatory hyperactivity by utilizing intra-hippocampal infusion (i.h.) in mice. Our results show that the infusion of leptin (5 ng each bilaterally i.h.) does not affect the basal ambulatory activity but significantly suppresses methamphetamine-induced ambulatory hyperactivity as compared to saline-infused controls. Interestingly, higher dose of leptin increases the suppression of the methamphetamine-induced ambulatory hyperactivity. The i.h. infusion of leptin did not activate the JAK-STAT pathway, which is the cellular signalling pathway through which leptin acts in the hypothalamus. The infusion of leptin also did not affect activation of p42/44 MAPK which is known to be another leptin-induced signalling pathway in the brain. These results demonstrate that leptin has a novel potential suppressive effect on methamphetamine-induced hyperlocomotion and also suggest that there must be an alternative pathway in the hippocampus through which leptin signalling is being mediated.
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Affiliation(s)
- Masahiro Nishio
- Department of Pharmacology, National Defense Medical College, Namiki, Tokorozawa, Japan
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23
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Lee CH, Yoo KY, Park OK, Choi JH, Kang IJ, Bae E, Kim SK, Hwang IK, Won MH. Phosphorylated extracellular signal-regulated kinase 1/2 immunoreactivity and its protein levels in the gerbil hippocampus during normal aging. Mol Cells 2010; 29:373-8. [PMID: 20213312 DOI: 10.1007/s10059-010-0046-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 12/14/2009] [Accepted: 12/17/2009] [Indexed: 12/11/2022] Open
Abstract
Phosphorylated extracellular signal-regulated kinase (pERK) mediates neuronal synaptic plasticity, long-term potentiation, and learning and memory in the hippocampus. In this study, we examined pERK1/2 immunoreactivity and its protein level in the gerbil hippocampus at various ages. In the postnatal month 1 (PM 1) group, very weak pERK1/2 immunoreactivity was detected in the hippocampus. In the CA1 region, pERK1/2 immunoreactivity was considerably increased in the stratum pyramidale in the PM 6 group. Thereafter, pERK1/2 immunoreactivity was decreased. In the CA2/3 region, pERK1/2 immunoreactivity increased in an age-dependent manner until PM 12. Thereafter, numbers of pERK1/2-immunoreactive neurons were decreased. However, in the mossy fiber zone, pERK1/2 immunostaining became stronger with age. In the dentate gyrus, a few pERK1/2-immunoreactive cells were observed until PM 12. In the PM 18 and 24 groups, numbers of pERK1/2-immunoreactive cells were increased, especially in the polymorphic layer. In Western blot analysis, pERK1/2 level in the gerbil hippocampus was increased with age. These results indicate that total pERK1/2 levels are increased in the hippocampus with age. However pERK1/2 immunoreactivity in subregions of the gerbil hippocampus was changed with different pattern during normal aging.
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Affiliation(s)
- Choong Hyun Lee
- Department of Anatomy and Neurobiology, and Institute of Neurodegeneration and Neuroregeneration, College of Medicine, Hallym University, Chuncheon, 200-702, Korea
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24
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Interactions of estradiol and insulin-like growth factor-I signalling in the nervous system: new advances. PROGRESS IN BRAIN RESEARCH 2010; 181:251-72. [PMID: 20478442 DOI: 10.1016/s0079-6123(08)81014-x] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Estradiol and insulin-like growth factor-I (IGF-I) interact in the brain to regulate a variety of developmental and neuroplastic events. Some of these interactions are involved in the control of hormonal homeostasis and reproduction. However, the interactions may also potentially impact on affection and cognition by the regulation of adult neurogenesis in the hippocampus and by promoting neuroprotection under neurodegenerative conditions. Recent studies suggest that the interaction of estradiol and IGF-I is also relevant for the control of cholesterol homeostasis in neural cells. The molecular mechanisms involved in the interaction of estradiol and IGF-I include the cross-regulation of the expression of estrogen and IGF-I receptors, the regulation of estrogen receptor-mediated transcription by IGF-I and the regulation of IGF-I receptor signalling by estradiol. Current investigations are evidencing the role exerted by key signalling molecules, such as glycogen synthase kinase 3 and beta-catenin, in the cross-talk of estrogen receptors and IGF-I receptors in neural cells.
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25
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Pruessner JC, Dedovic K, Pruessner M, Lord C, Buss C, Collins L, Dagher A, Lupien SJ. Stress regulation in the central nervous system: evidence from structural and functional neuroimaging studies in human populations - 2008 Curt Richter Award Winner. Psychoneuroendocrinology 2010; 35:179-91. [PMID: 19362426 DOI: 10.1016/j.psyneuen.2009.02.016] [Citation(s) in RCA: 218] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Revised: 02/19/2009] [Accepted: 02/20/2009] [Indexed: 11/26/2022]
Abstract
The metabolic effects of stress are known to have significant health effects in both humans and animals. Most of these effects are mediated by the major stress hormonal axis in the body, the hypothalamic-pituitary-adrenal (HPA) axis. Within the central nervous system (CNS), the hippocampus, the amygdala and the prefrontal cortex as part of the limbic system are believed to play important roles in the regulation of the HPA axis. With the advent of structural and functional neuroimaging techniques, the role of different CNS structures in the regulation of the HPA axis can be investigated more directly. In the current paper, we summarize the findings obtained in our laboratory in the context of stress and HPA axis regulation. Our laboratory has developed and contributed to the development of manual and automated segmentation protocols from structural magnetic resonance imaging (MRI) scans for assessment of hippocampus, amygdala, medial temporal lobe and frontal lobe structures. Employing these protocols, we could show significant age-related changes in HC volumes, which were different between men and women, with pre-menopausal women showing smaller age-related volume decline compared to men. We could recently extent these findings by showing how estrogen therapy after menopause leads to higher volumes in the HC. Investigating possible neurotoxicity effects of steroids, we showed effects of long-term steroid exposure on HC volumes, and investigated variability of HC volumes in relation to HPA axis regulation in young and elderly populations. Here, we were able to follow-up from non-imaging studies showing that subjects low in self-esteem have higher cortisol stress responses, and the HC emerged as the critical link between these variables. Recently, we have made two more important discoveries with regard to HC volume: we could show that HC volume is as variable in young as it is in older adults, in subjects ranging in age from 18 to 80 years. Also, we have linked birth weight and maternal care to HC volumes in young adults, demonstrating the effects of variations in maternal care on the integrity of the CNS. Besides structural assessments, there is increasing interest in functional techniques to investigate possible links between CNS activity and HPA axis regulation. These two approaches complement each other; some aspects of HPA axis regulation might be linked to the integrity of a specific CNS structure, while other aspects might be linked to the function of a specific structure with no involvement of CNS morphology. Thus, we have developed a mental arithmetic stress task that can be employed in functional neuroimaging studies, and have used it in a number of functional neuroimaging studies. Employing positron emission tomography (PET), we were able to demonstrate that stress causes dopamine release if subjects reported low maternal care early in life. Finally, employing the task in functional magnetic resonance imaging (fMRI), we could show how exposure to stress and activation of the HPA axis are associated with decreased activity in major portions of the limbic system, a result that allows to speculate on the effects of stress on cognitive and emotional regulation in the brain. Taken together, the use of neuroimaging techniques in Psychoneuroendocrinology opens exciting new possibilities for the investigation of stress effects in the central nervous system.
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Affiliation(s)
- Jens C Pruessner
- Douglas Mental Health Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada.
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26
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Picazo O, Becerril-Montes A, Huidobro-Perez D, Garcia-Segura LM. Neuroprotective Actions of the Synthetic Estrogen 17α-Ethynylestradiol in the Hippocampus. Cell Mol Neurobiol 2010; 30:675-82. [DOI: 10.1007/s10571-009-9490-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2009] [Accepted: 12/15/2009] [Indexed: 12/23/2022]
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27
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Yague JG, Azcoitia I, DeFelipe J, Garcia-Segura LM, Muñoz A. Aromatase expression in the normal and epileptic human hippocampus. Brain Res 2009; 1315:41-52. [PMID: 19815003 DOI: 10.1016/j.brainres.2009.09.111] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 09/28/2009] [Accepted: 09/28/2009] [Indexed: 12/29/2022]
Abstract
Aromatase is a key enzyme in estrogen biosynthesis that is involved in neuronal plasticity in the rodent hippocampus. Although aromatase mRNA expression has been detected in the human hippocampus, its cellular distribution has yet to be determined. Here, we have examined the immunohistochemical distribution of aromatase in the normal and the epileptic and sclerotic human hippocampus. In both the normal and epileptic hippocampus, aromatase was detected in numerous CA1-CA3 pyramidal neurons, in granule cells of the dentate gyrus and in interneurons that co-expressed the calcium-binding proteins calbindin, calretinin or parvalbumin. However, only a small subpopulation of astrocytes was immunoreactive for aromatase in either the normal and epileptic hippocampus. The widespread expression of aromatase in a large population of neurons in the normal and damaged hippocampus suggests that local estrogen formation may play an important role in human hippocampal function.
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Affiliation(s)
- Josue G Yague
- Instituto Cajal, CSIC, Avenida Doctor Arce 37, E-28002 Madrid, Spain
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28
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Bourque M, Dluzen DE, Di Paolo T. Neuroprotective actions of sex steroids in Parkinson's disease. Front Neuroendocrinol 2009; 30:142-57. [PMID: 19410597 DOI: 10.1016/j.yfrne.2009.04.014] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Revised: 04/22/2009] [Accepted: 04/23/2009] [Indexed: 12/16/2022]
Abstract
The sex difference in Parkinson's disease, with a higher susceptibility in men, suggests a modulatory effect of sex steroids in the brain. Numerous studies highlight that sex steroids have neuroprotective properties against various brain injuries. This paper reviews the protective effects of sex hormones, particularly estradiol, progesterone and androgens, in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) animal model of Parkinson's disease as compared to methamphetamine toxicity. The molecular mechanisms underlying beneficial actions of sex steroids on the brain have been investigated showing steroid, dose, timing and duration specificities and presently focus is on the dopamine signaling pathways, the next frontier. Both genomic and non-genomic actions of estrogen converge to promote survival factors and show sex differences. Neuroprotection by estrogen involves activation of signaling molecules such as the phosphatidylinositol-3 kinase/Akt and the mitogen-activated protein kinase pathways. Interaction with growth factors, such as insulin-like growth factor 1, also contributes to protective actions of estrogen.
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Affiliation(s)
- Mélanie Bourque
- Molecular Endocrinology and Genomic Research Center, Laval University Medical Center, CHUL, Quebec City, Quebec, Canada
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29
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Lee ESY, Yin Z, Milatovic D, Jiang H, Aschner M. Estrogen and tamoxifen protect against Mn-induced toxicity in rat cortical primary cultures of neurons and astrocytes. Toxicol Sci 2009; 110:156-67. [PMID: 19383943 DOI: 10.1093/toxsci/kfp081] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Chronic exposure to manganese (Mn) leads to a neurological disorder, manganism, which shares multiple common features with idiopathic Parkinson disease (IPD). 17beta-Estradiol (E2) and some selective estrogen receptor modulators, including tamoxifen (TX), afford neuroprotection in various experimental models of neurodegeneration. However, the neuroprotective effects and mechanisms of E2/TX in Mn-induced toxicity have yet to be documented. Herein, we studied the ability of E2/TX to protect rat cortical primary neuronal and astroglial cultures from Mn-induced toxicity. Cell viability, Western blot, and reactive oxygen species (ROS) generation were assessed. Results established that both E2 (10nM) and TX (1 microM) attenuated Mn-induced toxicity. The protective effects of E2/TX were more pronounced in astrocytes versus neurons. The E2-mediated attenuation of Mn-induced ROS generation in astrocytes at 6-h treatment (where no cell death was detected) was mediated by a classical estrogen receptor (ER) pathway and the TX-mediated effect on Mn-induced ROS generation was not mediated via classical ER-dependent mechanisms and likely by its antioxidant properties. The phosphatidylinositol-3 kinase (PI3K)/Akt signaling pathway was involved in both E2- and TX-induced attenuation of Mn-induced ROS formation (6 h) in astrocytes. Treatments with Mn for a longer duration (24 h) led to significant cell death, and the protective effects of E2 and TX were (1) not mediated by a classical ER pathway and (2) associated with activation of both mitogen-activated protein kinase/extracellular signal-regulated kinase and PI3K/Akt signaling pathways. Taken together, the results suggest that both E2 and TX offer effective therapeutic means for neuroprotection against Mn-induced toxicity.
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Affiliation(s)
- Eun-Sook Y Lee
- Department of Neurology, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208, USA.
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30
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Mahajan SD, Aalinkeel R, Reynolds JL, Nair BB, Sykes DE, Hu Z, Bonoiu A, Ding H, Prasad PN, Schwartz SA. Therapeutic targeting of "DARPP-32": a key signaling molecule in the dopiminergic pathway for the treatment of opiate addiction. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2009; 88:199-222. [PMID: 19897079 DOI: 10.1016/s0074-7742(09)88008-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The 32-kDa dopamine- and adenosine 3',5'-monophosphate-regulated phosphoprotein (DARPP-32) is recognized to be critical to the pathogenesis of drug addiction. Opiates via the mu-receptor act on the dopaminergic system in the brain and modulates the expression of DARPP-32 phosphoprotein which is an important mediator of the activity of the extracellular signal-regulated kinase (ERK) signaling cascades, the activation of which represents an exciting nexus for drug-induced changes in neural long-term synaptic plasticity. Silencing of DARPP-32 using an siRNA against DARPP-32 may provide a novel gene therapy strategy to overcome drug addiction. In this study, we investigated the effect of the opiate (heroin) on D1 receptor (D1R) and DARPP-32 expression and additionally, evaluated the effects of DARPP-32-siRNA gene silencing on protein phosphatase-1 (PP-1), ERK, and cAMP response element-binding (CREB) gene expression in primary normal human astrocytes (NHA) cells in vitro. Our results indicate that heroin significantly upregulated both D1R and DARPP-32 gene expression, and that DARPP-32 silencing in the NHA cells resulted in the significant modulation of the activity of downstream effector molecules such as PP-1, ERK, and CREB which are known to play an important role in opiate abuse-induced changes in long-term neural plasticity. These findings have the potential to facilitate the development of DARPP32 siRNA-based therapeutics against drug addiction.
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Affiliation(s)
- Supriya D Mahajan
- Department of Medicine, Division of Allergy, Immunology, and Rheumatology, Buffalo General Hospital, State University of New York, Buffalo, New York 14203, USA
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31
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Zhang H, Xie M, Schools GP, Feustel PF, Wang W, Lei T, Kimelberg HK, Zhou M. Tamoxifen mediated estrogen receptor activation protects against early impairment of hippocampal neuron excitability in an oxygen/glucose deprivation brain slice ischemia model. Brain Res 2008; 1247:196-211. [PMID: 18992727 DOI: 10.1016/j.brainres.2008.10.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 10/02/2008] [Accepted: 10/04/2008] [Indexed: 12/18/2022]
Abstract
Pretreatment of ovarectomized rats with estrogen shows long-term protection via activation of the estrogen receptor (ER). However, it remains unknown whether activation of the ER can provide protection against early neuronal damage when given acutely. We simulated ischemic conditions by applying oxygen and glucose deprived (OGD) solution to acute male rat hippocampal slices and examined the neuronal electrophysiological changes. Pyramidal neurons and interneurons showed a time-dependent membrane potential depolarization and reduction in evoked action potential frequency and amplitude over a 10 to 15 min OGD exposure. These changes were largely suppressed by 10 microM TAM. The TAM effect was neuron-specific as the OGD-induced astrocytic membrane potential depolarization was not altered. The TAM effect was mediated through ER activation because it could be simulated by 17beta-estradiol and was completely inhibited by the ER inhibitor ICI 182, 780, and is therefore an example of TAM's selective estrogen receptor modulator (SERM) action. We further show that TAM's effects on OGD-induced impairment of neuronal excitability was largely due to activation of neuroprotective BK channels, as the TAM effect was markedly attenuated by the BK channel inhibitor paxilline at 10 microM. TAM also significantly reduced the frequency and amplitude of AMPA receptor mediated spontaneous excitatory postsynaptic currents (sEPSCs) in pyramidal neurons which is an early consequence of OGD. Altogether, this study demonstrates that both 17beta-estradiol and TAM attenuate neuronal excitability impairment early on in a simulated ischemia model via ER activation mediated potentiation of BK K(+) channels and reduction in enhanced neuronal AMPA/NMDA receptor-mediated excitotoxicity.
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Affiliation(s)
- Huaqiu Zhang
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong, University of Science and Technology, Wuhan, 430030, PR China
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32
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Yune TY, Park HG, Lee JY, Oh TH. Estrogen-Induced Bcl-2 Expression after Spinal Cord Injury Is Mediated through Phosphoinositide-3-Kinase/Akt-Dependent CREB Activation. J Neurotrauma 2008; 25:1121-31. [DOI: 10.1089/neu.2008.0544] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- Tae Y. Yune
- Age-Related and Brain Diseases Research Center, Kyunghee University, Seoul, Korea
| | - Hong G. Park
- Age-Related and Brain Diseases Research Center, Kyunghee University, Seoul, Korea
| | - Jee Y. Lee
- Age-Related and Brain Diseases Research Center, Kyunghee University, Seoul, Korea
- Bioanalysis and Biotransformation Research Center, Korea Institute of Science and Technology, Seoul, Korea
| | - Tae H. Oh
- Age-Related and Brain Diseases Research Center, Kyunghee University, Seoul, Korea
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33
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Daniels D, Mietlicki EG, Nowak EL, Fluharty SJ. Angiotensin II stimulates water and NaCl intake through separate cell signalling pathways in rats. Exp Physiol 2008; 94:130-7. [PMID: 18723579 DOI: 10.1113/expphysiol.2008.044446] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Angiotensin II (AngII) stimulation of water and NaCl intake is a classic model of the behavioural effects of hormones. In vitro studies indicate that the AngII type 1 (AT(1)) receptor stimulates intracellular pathways that include protein kinase C (PKC) and mitogen-activated protein (MAP) kinase activation. Previous studies support the hypotheses that PKC is involved in AngII-induced water, but not NaCl intake and that MAP kinase plays a role in NaCl consumption, but not water intake, after injection of AngII. The present experiments test these hypotheses in rats using central injections of AngII in the presence or absence of a PKC inhibitor or a MAP kinase inhibitor. Pretreatment with the PKC inhibitor chelerythrine attenuated AngII-induced water intake, but NaCl intake was unaffected. In contrast, pretreatment with U0126, a MAP kinase inhibitor, had no effect on AngII-induced water intake, but attenuated NaCl intake. These data support the working hypotheses and significantly extend our earlier findings and those of others. Perhaps more importantly, these experiments demonstrate the remarkable diversity of peptide receptor systems and add support for the surprising finding that intracellular signalling pathways can have divergent behavioural relevance.
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Affiliation(s)
- Derek Daniels
- Behavioral Neuroscience Program, Department of Psychology, University at Buffalo, SUNY, Buffalo, NY 14260, USA.
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34
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Morissette M, Al Sweidi S, Callier S, Di Paolo T. Estrogen and SERM neuroprotection in animal models of Parkinson's disease. Mol Cell Endocrinol 2008; 290:60-9. [PMID: 18515001 DOI: 10.1016/j.mce.2008.04.008] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 04/14/2008] [Accepted: 04/14/2008] [Indexed: 12/12/2022]
Abstract
A higher prevalence and incidence of Parkinson disease (PD) is observed in men and beneficial motor effects of estrogens are observed in parkinsonian women. Lesion of the dopamine (DA) nigrostriatal pathway in animals with 1-methyl 4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) provides a model of PD and this is based on its use in humans as side-product of a drug abuse. Presently treatment of PD is mainly symptomatic. The MPTP mouse is used to study the neuroprotective roles of estrogenic drugs on the DA system. Estrogens, but not androgens, are active neuroprotectants as well as progesterone and dehydroepiandrosterone. An estrogen receptor agonist PPT and the selective estrogen receptor modulator raloxifene are also neuroprotective. Striatal DA neurons of estrogen receptor alpha knockout mice are more susceptible to MPTP toxicity than wild-type mice and neuroprotection by estradiol is associated with the activation of the PI3-K pathway involving Akt, GSK3beta, Bcl2 and BAD.
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Affiliation(s)
- Marc Morissette
- Molecular Endocrinology and Oncology Research Center, Laval University Medical Center (CHUL), Quebec, QC, Canada
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35
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Vasudevan N, Pfaff DW. Non-genomic actions of estrogens and their interaction with genomic actions in the brain. Front Neuroendocrinol 2008; 29:238-57. [PMID: 18083219 DOI: 10.1016/j.yfrne.2007.08.003] [Citation(s) in RCA: 255] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Accepted: 08/14/2007] [Indexed: 12/16/2022]
Abstract
Ligands for the nuclear receptor superfamily have at least two mechanisms of action: (a) classical transcriptional regulation of target genes (genomic mechanisms); and (b) non-genomic actions, which are initiated at the cell membrane, which could also impact transcription. Though transcriptional mechanisms are increasingly well understood, membrane-initiated actions of these ligands are incompletely understood. This has led to considerable debate over the physiological relevance of membrane-initiated actions of hormones versus genomic actions of hormones, with genomic actions predominating in the endocrine field. There is good evidence that the membrane-limited actions of hormones, particularly estrogens, involve the rapid activation of kinases and the release of calcium and that these are linked to physiologically relevant scenarios in the brain. We show evidence in this review, that membrane actions of estrogens, which activate these rapid signaling cascades, can also potentiate nuclear transcription in both the central nervous system and in non-neuronal cell lines. We present a theoretical scenario which can be used to understand this phenomenon. These signaling cascades may occur in parallel or in series but subsequently, converge at the modification of transcriptionally relevant molecules such as nuclear receptors and/or coactivators. In addition, other non-cognate hormones or neurotransmitters may also activate cascades to crosstalk with estrogen receptor-mediated transcription, though the relevance of this is less clear. The idea that coupling between membrane-initiated and genomic actions of hormones is a novel idea in neuroendocrinology and provides us with a unified view of hormone action in the central nervous system.
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Affiliation(s)
- Nandini Vasudevan
- Cell and Molecular Biology Department, Tulane University, LA 70118, USA.
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36
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Raz L, Khan MM, Mahesh VB, Vadlamudi RK, Brann DW. Rapid Estrogen Signaling in the Brain. Neurosignals 2008; 16:140-53. [DOI: 10.1159/000111559] [Citation(s) in RCA: 157] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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37
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Morissette M, Le Saux M, D'Astous M, Jourdain S, Al Sweidi S, Morin N, Estrada-Camarena E, Mendez P, Garcia-Segura LM, Di Paolo T. Contribution of estrogen receptors alpha and beta to the effects of estradiol in the brain. J Steroid Biochem Mol Biol 2008; 108:327-38. [PMID: 17936613 DOI: 10.1016/j.jsbmb.2007.09.011] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Clinical and experimental studies show a modulatory role of estrogens in the brain and suggest their beneficial action in mental and neurodegenerative diseases. The estrogen receptors ERalpha and ERbeta are present in the brain and their targeting could bring selectivity and reduced risk of cancer. Implication of ERs in the effect of estradiol on dopamine, opiate and glutamate neurotransmission is reviewed. The ERalpha agonist, PPT, is shown as estradiol to modulate hippocampal NMDA receptors and AMPA receptors in cortex and striatum of ovariectomized rats whereas the ERbeta agonist DPN is inactive. Striatal DPN activity suggests implication of ERbeta in estradiol modulation of D2 receptors and transporters in ovariectomized rats and is supported by the lack of effect of estradiol in ERbeta knockout (ERKObeta) mice. Both ERalpha and ERbeta agonists modulate striatal preproenkephalin (PPE) gene expression in ovariectomized rats. In male mice PPT protects against MPTP toxicity to striatal dopamine; this implicates Akt/GSK3beta signaling and the apoptotic regulators Bcl2 and Bad. This suggests a role for ERalpha in striatal dopamine neuroprotection. ERKOalpha mice are more susceptible to MPTP toxicity and not protected by estradiol; differences in ERKObeta mice are subtler. These results suggest therapeutic potential for the brain of ER specific agonists.
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Affiliation(s)
- M Morissette
- Molecular Endocrinology and Oncology Research Center, Medical Center and Faculty of Pharmacy, Laval University, 2705 Laurier Boulevard, Sainte-Foy, Québec, Canada
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38
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Sawe N, Steinberg G, Zhao H. Dual roles of the MAPK/ERK1/2 cell signaling pathway after stroke. J Neurosci Res 2008; 86:1659-69. [DOI: 10.1002/jnr.21604] [Citation(s) in RCA: 172] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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39
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Activation of ERK in the rostral ventromedial medulla is involved in hyperalgesia during peripheral inflammation. Brain Res 2007; 1187:103-10. [PMID: 18037394 DOI: 10.1016/j.brainres.2007.10.075] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2007] [Revised: 10/25/2007] [Accepted: 10/25/2007] [Indexed: 01/19/2023]
Abstract
We have previously shown that the extracellular signal-regulated kinase (ERK) is activated in the rostral ventromedial medulla (RVM) during peripheral inflammation. In the present study, the relationship between ERK signaling in the RVM and pain hypersensitivity was investigated in the rat. Microinjection of U0126, a mitogen-activated protein kinase kinase inhibitor, into the RVM decreased phosphorylated ERK at 7 h after complete Freund's adjuvant (CFA) injection into the hindpaw. The U0126 microinjection also attenuated thermal hyperalgesia in the ipsilateral hindpaw at 24 h after CFA injection. The ipsilateral paw withdrawal latency in the U0126 group (67.9%+/-5.3% vs. baseline, n=7) was significantly longer than that in the control group (52.0%+/-3.6% vs. baseline, n=8). These findings suggest that activation of ERK in the RVM contributes to thermal hyperalgesia during peripheral inflammation.
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40
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Xi ZQ, Wang XF, He RQ, Li MW, Liu XZ, Wang LY, Zhu X, Xiao F, Sun JJ, Li JM, Gong Y, Guan LF. Extracellular signal-regulated protein kinase in human intractable epilepsy. Eur J Neurol 2007; 14:865-72. [PMID: 17662006 DOI: 10.1111/j.1468-1331.2007.01777.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Extracellular signal-regulated kinases (ERK) such as ERK1 [p44 mitogen-activated protein kinase (MAPK)] and ERK2 (p42 MAPK) are activated in the central nervous system under physiological and pathological conditions such as ischemia and epilepsy. Our aim is to investigate ERK1, ERK2, and phosphorylated ERK (p-ERK) (Thr202/Tyr 204) expression in the temporal lobe of patients with intractable epilepsy (IE) and to explore its possible role of ERK in it. Tissue samples from temporal neocortices of 40 patients who had surgery for IE were used to detect ERK1, ERK2, and p-ERK (Thr 202/Tyr 204) expression through immunohistochemistry and western blot. We compared these tissues against 17 histological normal temporal lobes from head-trauma patients. ERK1, ERK2, and p-ERK in IE were significantly higher than those in the controls. They were mainly expressed in the cytoplasm of neurons and glial cells. There was also increased detection of p-ERK in the gliotic cortex of IE compared with the non-gliotic cortex. These findings were consistently observed in western blot and immunohistochemistry techniques. ERK expression in patients with IE was significantly increased compared with the controls. This suggested a probable role of ERK in the pathogenesis of IE.
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Affiliation(s)
- Z-Q Xi
- Department of Neurology, The First Affiliated Hospital, Chongqing Medical University, Chongqing, China
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41
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Hayashi Y, Kitaoka Y, Munemasa Y, Ohtani-Kaneko R, Kikusui T, Uematsu A, Takeda H, Hirata K, Mori Y, Ueno S. Neuroprotective effect of 17beta-estradiol against N-methyl-D-aspartate-induced retinal neurotoxicity via p-ERK induction. J Neurosci Res 2007; 85:386-94. [PMID: 17131424 DOI: 10.1002/jnr.21127] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We investigated whether the neuroprotective effect of estrogen is mediated by the estrogen receptor (ER) and whether extracellular signal-regulated kinase (ERK) is involved in the protective effect of estrogen against N-methyl-D-aspartate (NMDA)-induced retinal neurotoxicity. Retrograde labeling of retinal ganglion cells (RGCs) showed that pretreatment with 17beta-estradiol (E2) using a silastic implant significantly attenuated the loss of RGCs induced by intravitreal injection of NMDA. Simultaneous administration of U0126, an ERK inhibitor, with NMDA completely abolished the protective effect of E2. Moreover, ICI182,780, an ER antagonist, also significantly diminished the protective effect of E2. Pretreatment with E2 significantly reduced the number of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells in the retinal ganglion cell layer (RGCL) and the inner nuclear layer (INL) 12 hr after NMDA injection. Moreover, ICI182,780 inhibited the ameliorative effect of E2 on TUNEL-positive cells in a dose-dependent manner. Immunostaining of anti-ERalpha monoclonal antibody was observed mainly in the RGCL and the INL. Western blot analysis showed a significant increase in the level of phosphorylated ERK (p-ERK) 6 hr after NMDA injection. However, NMDA did not increase the level of p-ERK protein 7 days after injection. Pretreatment of E2 induced further increases of p-ERK expression 6 hr and 7 days after NMDA injection, and U0126 and ICI182,780 significantly inhibited E2-induced p-ERK expression after 6 hr. These results suggest that E2 has an ER-mediated neuroprotective effect against NMDA-induced retinal neurotoxicity and that this effect may be associated with induction of p-ERK in the retina.
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Affiliation(s)
- Yasuhiro Hayashi
- Department of Ophthalmology, St. Marianna University School of Medicine, Miyamae-ku, Kawasaki-shi, Kanagawa, Japan
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42
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Ragonese P, D'Amelio M, Savettieri G. Implications for estrogens in Parkinson's disease: an epidemiological approach. Ann N Y Acad Sci 2007; 1089:373-82. [PMID: 17261781 DOI: 10.1196/annals.1386.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Evidence from experimental and epidemiological studies suggests a role of sex hormones in the pathogenic process leading to neurodegenerative diseases, (i.e., Alzheimer's and Parkinson's disease). The effects of sexual steroid hormones are complex and vary with the events of women's fertile life. Estrogens are supposed to influence dopamine synthesis, metabolism, and transport; however, there is no consensus regarding the direction, locus, and mechanism of the effect of estrogens on the dopaminergic system. A neuroprotective effect of estrogens has been demonstrated in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-animal models of Parkinson's disease (PD). Epidemiological studies indicate gender differences regarding the onset and the prognosis of PD. Most of the analytical studies explored the relationship between PD and exogenous estrogens. Only three studies investigated the role of endogenous estrogens in the risk of developing PD. These studies reported an increased risk of PD in conditions causing an early reduction in endogenous estrogens (early menopause, reduced fertile life length). Longer cumulative length of pregnancies has also been associated with an increased PD risk. A lack of consensus still exists on the effect of the type of menopause (surgical vs. natural) on PD risk. Finally, the effect of postmenopausal estrogen replacement therapy is still debated. Inconsistencies across studies are in part explained by the complexity of the mechanisms of action of sexual hormones and by the paucity of analytical studies.
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Affiliation(s)
- Paolo Ragonese
- Dipartimento Universitario di Neuroscienze Cliniche, Università di Palermo, Via Gaetano La Loggia 1-90129 Palermo, Italy
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43
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Jover-Mengual T, Zukin RS, Etgen AM. MAPK signaling is critical to estradiol protection of CA1 neurons in global ischemia. Endocrinology 2007; 148:1131-43. [PMID: 17138646 PMCID: PMC2528200 DOI: 10.1210/en.2006-1137] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The importance of hormone therapy in affording protection against the sequelae of global ischemia in postmenopausal women remains controversial. Global ischemia arising during cardiac arrest or cardiac surgery causes highly selective, delayed death of hippocampal CA1 neurons. Exogenous estradiol ameliorates global ischemia-induced neuronal death and cognitive impairment in male and female rodents. However, the molecular mechanisms by which estrogens intervene in global ischemia-induced apoptotic cell death are unclear. Here we show that estradiol acts via the classical estrogen receptors, the IGF-I receptor, and the ERK/MAPK signaling cascade to protect CA1 neurons in ovariectomized female rats and gerbils. We demonstrate that global ischemia promotes early dephosphorylation and inactivation of ERK1 and the transcription factor cAMP-response element binding protein (CREB), subsequent down-regulation of the antiapoptotic protein Bcl-2, a known gene target of estradiol and CREB, and activation of caspase-3. Estradiol treatment increases basal phosphorylation of both ERK1 and ERK2 in hippocampal CA1 and prevents ischemia-induced dephosphorylation and inactivation of ERK1 and CREB, down-regulation of Bcl-2 and activation of the caspase death cascade. Whereas ERK/MAPK signaling is critical to CREB activation and neuronal survival, the impact of estradiol on Bcl-2 levels is ERK independent. These findings support a model whereby estradiol acts via the classical estrogen receptors and IGF-I receptors, which converge on activation of ERK/MAPK signaling and CREB to promote neuronal survival in the face of global ischemia.
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Affiliation(s)
- Teresa Jover-Mengual
- Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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44
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Abstract
Hormonal ligands for the nuclear receptor superfamily have at least two interacting mechanisms of action: 1) classical transcriptional regulation of target genes (genomic mechanisms); and 2) nongenomic actions that are initiated at the cell membrane, which could impact transcription. Although transcriptional mechanisms are increasingly well understood, membrane-initiated actions of these ligands are incompletely understood. Historically, this has led to a considerable divergence of thought in the molecular endocrine field. We have attempted to uncover principles of hormone action that are relevant to membrane-initiated actions of estrogens. There is evidence that the membrane-limited actions of hormones, particularly estrogens, involve the rapid activation of kinases and the release of calcium. Membrane actions of estrogens, which activate these rapid signaling cascades, can also potentiate nuclear transcription. These signaling cascades may occur in parallel or in series but subsequently converge at the level of modification of transcriptionally relevant molecules such as nuclear receptors and/or coactivators. In addition, other hormones or neurotransmitters may also activate cascades to crosstalk with estrogen receptor-mediated transcription. The idea of synergistic coupling between membrane-initiated and genomic actions of hormones fundamentally revises the paradigms of cell signaling in neuroendocrinology.
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Affiliation(s)
- Nandini Vasudevan
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
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45
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Jara JH, Singh BB, Floden AM, Combs CK. Tumor necrosis factor alpha stimulates NMDA receptor activity in mouse cortical neurons resulting in ERK-dependent death. J Neurochem 2007; 100:1407-20. [PMID: 17241124 PMCID: PMC3619402 DOI: 10.1111/j.1471-4159.2006.04330.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Multiple cytokines are secreted in the brain during pro-inflammatory conditions and likely affect neuron survival. Previously, we demonstrated that glutamate and tumor necrosis factor alpha (TNFalpha) kill neurons via activation of the N-methyl-d-aspartate (NMDA) and TNFalpha receptors, respectively. This report continues characterizing the signaling cross-talk pathway initiated during this inflammation-related mechanism of death. Stimulation of mouse cortical neuron cultures with TNFalpha results in a transient increase in NMDA receptor-dependent calcium influx that is additive with NMDA stimulation and inhibited by pre-treatment with the NMDA receptor antagonist, DL-2-amino-5-phosphonovaleric acid, or the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate/kainate receptor antagonist, 6,7-dinitroquinoxaline-2,3-dione. Pre-treatment with N-type calcium channel antagonist, omega-conotoxin, or the voltage-gated sodium channel antagonist, tetrodotoxin, also prevents the TNFalpha-stimulated calcium influx. Combined TNFalpha and NMDA stimulation results in a transient increase in activity of extracellular signal-regulated kinases (ERKs) and c-Jun N-terminal kinases (JNKs). Specific inhibition of ERKs but not JNKs is protective against TNFalpha and NMDA-dependent death. Death is mediated via the low-affinity TNFalpha receptor, TNFRII, as agonist antibodies for TNFRII but not TNFRI stimulate NMDA receptor-dependent calcium influx and death. These data demonstrate how microglial pro-inflammatory secretions including TNFalpha can acutely facilitate glutamate-dependent neuron death.
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Affiliation(s)
- Javier H. Jara
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA
| | - Brij B. Singh
- Department of Biochemistry and Molecular Biology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA
| | - Angela M. Floden
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA
| | - Colin K. Combs
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA
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46
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Mendez P, Wandosell F, Garcia-Segura LM. Cross-talk between estrogen receptors and insulin-like growth factor-I receptor in the brain: cellular and molecular mechanisms. Front Neuroendocrinol 2006; 27:391-403. [PMID: 17049974 DOI: 10.1016/j.yfrne.2006.09.001] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 08/11/2006] [Accepted: 09/01/2006] [Indexed: 01/02/2023]
Abstract
Accumulating evidence suggests that insulin-like growth factor-I (IGF-I) and estradiol interact to regulate neural function. In this review, we focus on the cellular and molecular mechanisms involved in this interaction. The expression of estrogen receptors (ERs) and IGF-I receptor is cross-regulated in the central nervous system and many neurons and astrocytes coexpress both receptors. Furthermore, estradiol activates IGF-I receptor and its intracellular signaling. This effect may involve classical ERs since recent findings suggest that ERalpha may affect IGF-I actions in the brain by a direct interaction with some of the components of IGF-I signaling. In turn, IGF-I may regulate ER transcriptional activity in neuronal cells. In conclusion, ERs appear to be part of the signaling mechanism of IGF-I, and IGF-I receptor part of the mechanism of estradiol signaling in the nervous system.
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Affiliation(s)
- Pablo Mendez
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), E-28002 Madrid, Spain
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47
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Park CH, Kim YS, Cheon EW, Noh HS, Cho CH, Chung IY, Yoo JM, Kang SS, Choi WS, Cho GJ. Action of citicoline on rat retinal expression of extracellular-signal-regulated kinase (ERK1/2). Brain Res 2006; 1081:203-10. [PMID: 16696125 DOI: 10.1016/j.brainres.2005.12.128] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Citicoline is an essential endogenous intermediate in the biosynthesis of phosphatidylcholine, which acts as a therapeutic agent in models of central nervous system injury and neurodegenerative diseases. The present study investigated the effects of citicoline on extracellular-signal-regulated kinase 1/2 (ERK1/2) expression in the rat retina after kainic acid (KA) treatment. KA (6 nmol) was injected into the vitreous of the rat eyes. The animals were then injected intraperitoneally with citicoline (500 mg/kg) twice daily after the KA injection. The neuroprotective effects of citicoline were estimated by evaluating temporal changes in ERK1/2 using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL), immunoblotting and immunohistochemical techniques. The expression of phosphorylated ERK1/2 was slightly decreased after 6 h, and significantly reduced after 12 h, in the rats receiving the KA injection plus citicoline treatment. Our results demonstrated that citicoline decreased the activation of ERK1/2 due to the KA treatment, suggesting that it exerts its neuroprotective activity by reducing the concentrations of proteins involved in apoptosis.
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Affiliation(s)
- Chang Hwan Park
- Department of Anatomy and Neurobiology, College of Medicine, Institute of Health Science, Medical Research Center for Neural Dysfunction, Gyeongsang National University, 92 Chilam-dong, Jinju, Kyungnam 660-751, South Korea
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48
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Nakazawa T, Takahashi H, Shimura M. Estrogen has a neuroprotective effect on axotomized RGCs through ERK signal transduction pathway. Brain Res 2006; 1093:141-9. [PMID: 16696958 DOI: 10.1016/j.brainres.2006.03.084] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2005] [Revised: 03/19/2006] [Accepted: 03/22/2006] [Indexed: 12/28/2022]
Abstract
The neuroprotective effects of estrogen on neuronal cells in central nervous system have been described previously, however, the mechanisms of neuroprotective effect of estrogen against retinal ganglion cell (RGC) death has not been well identified. To examine the role of endogenous sex steroids produced in ovary, retina samples were prepared from female rats with or without ovariectomy and the density of RGC was calculated. Ovariectomy alone had no effect on the density of fluorogold (FG)-labeled RGC without injury, while the density of surviving RGC after optic nerve axotomy with ovariectomy was significantly decreased compared to that without ovariectomy. To examine the role of exogenous sex steroids, 17beta-estradiol was injected into the vitreous cavity in ovariectomized rats and showed neuroprotective effect on axotomy-induced RGC death while exogenous progesterone showed no effect. Immunoblot and immunohistochemical analysis demonstrated that ERK-c-Fos signal transduction pathway was activated by exogenous 17beta-estradiol in ganglion cell layer. U0126, an ERK inhibitor, inhibited the neuroprotective effect of estrogen on axotomized RGC death. These data suggest that estrogen has neuroprotective effect through activation of ERK-c-Fos signaling pathway on axotomy-induced RGC death. The neuroprotective effect of estrogen may have therapeutic benefits in retinal diseases associated with RGC death such as glaucoma.
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Affiliation(s)
- Toru Nakazawa
- Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, 980-8574 Miyagi, Japan.
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49
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Park EM, Cho S. Enhanced ERK dependent CREB activation reduces apoptosis in staurosporine-treated human neuroblastoma SK-N-BE(2)C cells. Neurosci Lett 2006; 402:190-4. [PMID: 16678346 DOI: 10.1016/j.neulet.2006.04.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Revised: 03/25/2006] [Accepted: 04/05/2006] [Indexed: 11/19/2022]
Abstract
Activation of cAMP response element binding protein (CREB) is implicated in neuronal survival. The mitogen-activated protein kinase/extracellular signal regulated kinase (MAPK/ERK) activates a transcription factor CREB. Previously, we reported that N-acetyl-O-methyldopamine (NAMDA) protects neurons from ischemia via enhancing ERK dependent CREB phosphorylation. To investigate whether NAMDA induces endogenous survival pathways in apoptotic conditions and whether the neuroprotectant enhances a preexisting survival pathway, we determined the degree of ERK-CREB activation and resistance to apoptosis in staurosporine-treated SK-N-BE(2)C neurons. Compared to forskolin-treated apoptotic cultures, NAMDA-treated cultures induced a minimum activation on ERK (pERK) or CREB (pCREB). However, NAMDA enhanced the activation of ERK and CREB in the presence of forskolin (1.7-fold increase for pCREB, 2.1-fold increase for pERK2, p<0.05 from forskolin). The effect was completely blocked by a specific MEK inhibitor U0126, suggesting the involvement of ERK dependent CREB signaling. Cleavage of caspase-3 and poly-(ADP-ribose)-polymerase was additively reduced in cultures treated with NAMDA and forskolin simultaneously, but not in the presence of U0126. The data showed that NAMDA enhances forskolin-induced ERK-CREB activation and potentiates forskolin-induced resistance to apoptosis. The study indicates that enhancing endogenous survival pathways by NAMDA combined with other neuroprotective measure(s) might be a useful strategy to reduce apoptosis.
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Affiliation(s)
- Eun-Mi Park
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, at W.M. Burke Medical Research Institute, White Plains, New York 10065, USA.
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Bryant DN, Sheldahl LC, Marriott LK, Shapiro RA, Dorsa DM. Multiple pathways transmit neuroprotective effects of gonadal steroids. Endocrine 2006; 29:199-207. [PMID: 16785596 DOI: 10.1385/endo:29:2:199] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2005] [Revised: 11/30/1999] [Accepted: 10/25/2005] [Indexed: 12/27/2022]
Abstract
Numerous preclinical studies suggest that gonadal steroids, particularly estrogen, may be neuroprotective against insult or disease progression. This paper reviews the mechanisms contributing to estrogen-mediated neuroprotection. Rapid signaling pathways, such as MAPK, PI3K, Akt, and PKC, are required for estrogen's ability to provide neuroprotection. These rapid signaling pathways converge on genomic pathways to modulate transcription of E2-responsive genes via ERE-dependent and ERE-independent mechanisms. It is clear that both rapid signaling and transcription are important for estrogen's neuroprotective effects. A mechanistic understanding of estrogen-mediated neuroprotection is crucial for the development of therapeutic interventions that enhance quality of life without deleterious side effects.
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Affiliation(s)
- Damani N Bryant
- Department of Physiology and Pharmacology (L334), Oregon Health & Science University, Portland, OR 97239, USA
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