1
|
Ren XQ, Huang X, Xing SY, Long Y, Yuan DH, Hong H, Tang SS. Neuroprotective effects of novel compound FMDB on cognition, neurogenesis and apoptosis in APP/PS1 transgenic mouse model of Alzheimer's disease. Neurochem Int 2023; 165:105510. [PMID: 36893915 DOI: 10.1016/j.neuint.2023.105510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 02/02/2023] [Accepted: 03/05/2023] [Indexed: 03/09/2023]
Abstract
Clinical and experimental studies have shown that the sharp reduction of estrogen is one of the important reasons for the high incidence of Alzheimer's disease (AD) in elderly women, but there is currently no such drug for treatment of AD. Our group first designed and synthesized a novel compound R-9-(4fluorophenyl)-3-methyl-10,10,-Hydrogen-6-hydrogen-benzopyran named FMDB. In this study, our aim is to investigate the neuroprotective effects and mechanism of FMDB in APP/PS1 transgenic mice. 6 months old APP/PS1 transgenic mice were intragastrical administered with FMDB (1.25, 2.5 and 5 mg/kg) every other day for 8 weeks. LV-ERβ-shRNA was injected bilaterally into the hippocampus of APP/PS1 mice to knockdown estrogen receptor β (ERβ). We found that FMDB ameliorated cognitive impairment in the Morris water maze and novel object recognition tests, increased hippocampal neurogenesis and prevented hippocampal apoptotic responses in APP/PS1 mice. Importantly, FMDB activated nuclear ERβ mediated CBP/p300, CREB and brain-derived neurotrophic factor (BDNF) signaling, and membrane ERβ mediated PI3K/Akt, CREB and BDNF signaling in the hippocampus. Our study demonstrated the contributions and mechanism of FMDB to cognition, neurogenesis and apoptosis in APP/PS1 mice. These lay the experimental foundation for the development of new anti-AD drugs.
Collapse
Affiliation(s)
- Xiao-Qian Ren
- Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Xin Huang
- Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Shu-Yun Xing
- Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Yan Long
- Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Dan-Hua Yuan
- Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Hao Hong
- Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Su-Su Tang
- Department of Pharmacology, China Pharmaceutical University, Nanjing, China.
| |
Collapse
|
2
|
Mansour SW, Selim SA, Salama SA, Hussein S, Abozaid ER. Anti-apoptotic effect of menaquinone-7 protects the brain of ovariectomized rats. BENI-SUEF UNIVERSITY JOURNAL OF BASIC AND APPLIED SCIENCES 2023. [DOI: 10.1186/s43088-023-00359-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
Abstract
Background
Mood and memory deterioration occurs after ovariectomy (OVX) with various degrees and sometimes requires medical intervention. Menaquinone-7 (MK-7) is a potent isoform of vitamin K2 and has many effects on the bone and cardiovascular system. However, the effect of MK-7 on the brain and its mechanisms of action are still unclear. This study was performed to investigate the effect of MK-7 on mood and memory disorders following ovariectomy. Thirty-two female albino rats were divided into four groups (n = 8). Group I (control group) included sham-operated rats with sunflower oil intake. Group II (K2) included sham-operated rats with an intake of MK-7 dissolved in sunflower oil. Group III (K2 OVX) included ovariectomized rats with an intake of MK-7 dissolved in sunflower oil. Group IV(OVX) included ovariectomized rats with sunflower oil intake. Working memory, anxiety, depression, and sociability behaviors were investigated in all groups. Gene expression of BAX, BCL2, and p53 was measured in the hippocampus of all groups by real-time PCR. Besides, BAX/BCL2 ratio was calculated.
Results
Working memory, anxiety, depression, and sociability behaviors in the OVX rats showed a significant change compared to the sham-operated. However, the intake of MK-7 after the OVX resulted in significant improvement. Regarding hydrogen peroxide and MDA activity, they were significantly higher in the OVX group compared to the sham-operated groups, while in the K2OVX group, their activity showed a significant decrease in comparison with the OVX group. However, catalase and total antioxidant capacity were significantly lower in the OVX group compared to the sham-operated group, while in the k2OVX group, their activity showed a significant increase in comparison with the OVX group. The OVX group showed a significant elevation in the BAX, BAX/BCl2 ratio, and P53, but BCL2 was significantly reduced. However, the intake of MK-7 caused a significant improvement.
Conclusions
Our study showed that the OVX group showed significant physiological, biochemical, and molecular changes, which can be prevented by MK-7 intake.
Collapse
|
3
|
Xu J, Zhou Y, Yan C, Wang X, Lou J, Luo Y, Gao S, Wang J, Wu L, Gao X, Shao A. Neurosteroids: A novel promise for the treatment of stroke and post-stroke complications. J Neurochem 2021; 160:113-127. [PMID: 34482541 DOI: 10.1111/jnc.15503] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 08/22/2021] [Accepted: 08/23/2021] [Indexed: 01/14/2023]
Abstract
Stroke is the primary reason for death and disability worldwide, with few treatment strategies to date. Neurosteroids, which are natural molecules in the brain, have aroused great interest in the field of stroke. Neurosteroids are a kind of steroid that acts on the nervous system, and are synthesized in the mitochondria of neurons or glial cells using cholesterol or other steroidal precursors. Neurosteroids mainly include estrogen, progesterone (PROG), allopregnanolone, dehydroepiandrosterone (DHEA), and vitamin D (VD). Most of the preclinical studies have confirmed that neurosteroids can decrease the risk of stroke, and improve stroke outcomes. In the meantime, neurosteroids have been shown to have a positive therapeutic significance in some post-stroke complications, such as epilepsy, depression, anxiety, cardiac complications, movement disorders, and post-stroke pain. In this review, we report the historical background, modulatory mechanisms of neurosteroids in stroke and post-stroke complications, and emphasize on the application prospect of neurosteroids in stroke therapy.
Collapse
Affiliation(s)
- Jiawei Xu
- The First Affiliated Hospital of Zhejiang, Chinese Medical University, Hangzhou, Zhejiang, China
| | - Yunxiang Zhou
- Department of Surgical Oncology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Caochong Yan
- The Key Laboratory of Reproductive Genetics, Ministry of Education, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiaoyu Wang
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jianyao Lou
- Department of General Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yi Luo
- The Second Affiliated Hospital of Zhejiang University School of Medicine (Changxing Branch), Changxing, Huzhou, Zhejiang, China
| | - Shiqi Gao
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Junjie Wang
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Liang Wu
- Department of Pathology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiangfu Gao
- The First Affiliated Hospital of Zhejiang, Chinese Medical University, Hangzhou, Zhejiang, China
| | - Anwen Shao
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| |
Collapse
|
4
|
Vahidinia Z, Karimian M, Joghataei MT. Neurosteroids and their receptors in ischemic stroke: From molecular mechanisms to therapeutic opportunities. Pharmacol Res 2020; 160:105163. [DOI: 10.1016/j.phrs.2020.105163] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/17/2020] [Accepted: 08/17/2020] [Indexed: 01/09/2023]
|
5
|
Rauf S, Soesatyo MH, Agustiningsih D, Partadiredja G. Moderate intensity intermittent exercise upregulates neurotrophic and neuroprotective genes expression and inhibits Purkinje cell loss in the cerebellum of ovariectomized rats. Behav Brain Res 2020; 382:112481. [PMID: 31954098 DOI: 10.1016/j.bbr.2020.112481] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 01/01/2020] [Accepted: 01/13/2020] [Indexed: 12/23/2022]
Abstract
Decreases in estrogen levels due to menopause or ovariectomy may disrupt cerebellar motor functions. This study aimed at investigating the effects of Moderate Intensity Intermittent Exercise (MIEx) on the cerebellum of ovariectomized rats by analyzing neurotrophic and neuroprotective markers, as well as cerebellar motor functions. Thirty-two female Sprague Dawley rats were divided into four groups, i.e. Sham and ovariectomy (Ovx) of non-MIEx (NMIEx) groups, and Sham and Ovx with MIEx groups. MIEx was performed 5 days a week on treadmill for 6 weeks. Motor functions were assessed using rotarod, footprint, open field, and wire hanging tests. Real-time polymerase chain reaction was performed to determine messenger RNA (mRNA) expressions of Pgc-1α, BDNF, synaptophysin, Bcl-2, and Bax. Unbiased stereology was used to estimate the total number of cerebellar Purkinje cells. The Ovx MIEx group had higher Pgc-1α and Bcl-2 mRNA expressions, and number of Purkinje cells, but lower Bax mRNA expression than the Ovx NMIEx group. All motor functions of MIEx groups were better than the Sham and Ovx groups without MIEx. Motor functions on rotarod task, OFT, and FPT correlated significantly with the mRNAs expression of Bcl-2, Bax, BDNF, synaptophysin, Pgc-1α, and the number of cerebellar Purkinje cells in ovariectomized rats. MIEx improves cerebellar neurotrophic and neuroprotective markers, as well as motor functions of ovariectomized rats.
Collapse
Affiliation(s)
- Saidah Rauf
- Doctoral Program, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia; Masohi Nursing Study Program, Maluku Health Polytechnic, Maluku, Indonesia.
| | - Marsetyawan Hne Soesatyo
- Department of Histology and Cell Biology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Denny Agustiningsih
- Department of Physiology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Ginus Partadiredja
- Department of Physiology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| |
Collapse
|
6
|
Guo H, Liu M, Zhang L, Wang L, Hou W, Ma Y, Ma Y. The Critical Period for Neuroprotection by Estrogen Replacement Therapy and the Potential Underlying Mechanisms. Curr Neuropharmacol 2020; 18:485-500. [PMID: 31976839 PMCID: PMC7457406 DOI: 10.2174/1570159x18666200123165652] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Revised: 12/03/2019] [Accepted: 01/14/2020] [Indexed: 01/13/2023] Open
Abstract
17β-Estradiol (estradiol or E2) is a steroid hormone that has been broadly applied as a neuroprotective therapy for a variety of neurodegenerative and cerebrovascular disorders such as ischemic stroke, Alzheimer's disease, and Parkinson's disease. Several laboratory and clinical studies have reported that Estrogen Replacement Therapy (ERT) had no effect against these diseases in elderly postmenopausal women, and at worst, increased their risk of onset and mortality. This review focuses on the growing body of data from in vitro and animal models characterizing the potential underlying mechanisms and signaling pathways that govern successful neuroprotection by ERT, including the roles of E2 receptors in mediating neuroprotection, E2 genomic regulation of apoptosis- related pathways, membrane-bound receptor-mediated non-genomic signaling pathways, and the antioxidant mechanisms of E2. Also discussed is the current evidence for a critical period of effective treatment with estrogen following natural or surgical menopause and the outcomes of E2 administration within an advantageous time period. The known mechanisms governing the duration of the critical period include depletion of E2 receptors, the switch to a ketogenic metabolic profile by neuronal mitochondria, and a decrease in acetylcholine that accompanies E2 deficiency. Also the major clinical trials and observational studies concerning postmenopausal Hormone Therapy (HT) are summarized to compare their outcomes with respect to neurological disease and discuss their relevance to the critical period hypothesis. Finally, potential controversies and future directions for this field are discussed throughout the review.
Collapse
Affiliation(s)
| | | | | | | | | | - Yaqun Ma
- Address correspondence to these authors at the Anesthesia and Operation Center, The First Medical Center to Chinese PLA General Hospital, Beijing 100853, China; Tel: +86 010 66938152; E-mail: and Department of Anesthesiology, The Seventh Medical Center to Chinese PLA General Hospital, Beijing 100700, China; E-mail:
| | - Yulong Ma
- Address correspondence to these authors at the Anesthesia and Operation Center, The First Medical Center to Chinese PLA General Hospital, Beijing 100853, China; Tel: +86 010 66938152; E-mail: and Department of Anesthesiology, The Seventh Medical Center to Chinese PLA General Hospital, Beijing 100700, China; E-mail:
| |
Collapse
|
7
|
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.
Collapse
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.
| |
Collapse
|
8
|
Mohajeri M, Martín-Jiménez C, Barreto GE, Sahebkar A. Effects of estrogens and androgens on mitochondria under normal and pathological conditions. Prog Neurobiol 2019; 176:54-72. [DOI: 10.1016/j.pneurobio.2019.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 02/23/2019] [Accepted: 03/05/2019] [Indexed: 02/06/2023]
|
9
|
Characteristics of adverse events of endocrine therapies among older patients with breast cancer. Support Care Cancer 2019; 27:3813-3822. [DOI: 10.1007/s00520-019-04674-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 09/26/2018] [Indexed: 11/26/2022]
|
10
|
Baez-Jurado E, Rincón-Benavides MA, Hidalgo-Lanussa O, Guio-Vega G, Ashraf GM, Sahebkar A, Echeverria V, Garcia-Segura LM, Barreto GE. Molecular mechanisms involved in the protective actions of Selective Estrogen Receptor Modulators in brain cells. Front Neuroendocrinol 2019; 52:44-64. [PMID: 30223003 DOI: 10.1016/j.yfrne.2018.09.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 09/09/2018] [Accepted: 09/12/2018] [Indexed: 02/06/2023]
Abstract
Synthetic selective modulators of the estrogen receptors (SERMs) have shown to protect neurons and glial cells against toxic insults. Among the most relevant beneficial effects attributed to these compounds are the regulation of inflammation, attenuation of astrogliosis and microglial activation, prevention of excitotoxicity and as a consequence the reduction of neuronal cell death. Under pathological conditions, the mechanism of action of the SERMs involves the activation of estrogen receptors (ERs) and G protein-coupled receptor for estrogens (GRP30). These receptors trigger neuroprotective responses such as increasing the expression of antioxidants and the activation of kinase-mediated survival signaling pathways. Despite the advances in the knowledge of the pathways activated by the SERMs, their mechanism of action is still not entirely clear, and there are several controversies. In this review, we focused on the molecular pathways activated by SERMs in brain cells, mainly astrocytes, as a response to treatment with raloxifene and tamoxifen.
Collapse
Affiliation(s)
- E Baez-Jurado
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C., Colombia
| | - M A Rincón-Benavides
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C., Colombia
| | - O Hidalgo-Lanussa
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C., Colombia
| | - G Guio-Vega
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C., Colombia
| | - G M Ashraf
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - A Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - V Echeverria
- Universidad San Sebastián, Fac. Cs de la Salud, Lientur 1457, Concepción 4080871, Chile; Research & Development Service, Bay Pines VA Healthcare System, Bay Pines, FL 33744, USA
| | - L M Garcia-Segura
- Instituto Cajal, CSIC, Madrid, Spain; Centro de Investigación Biomédica en Red Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - G E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C., Colombia; Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile.
| |
Collapse
|
11
|
ERα and/or ERβ activation ameliorates cognitive impairment, neurogenesis and apoptosis in type 2 diabetes mellitus mice. Exp Neurol 2018; 311:33-43. [PMID: 30201537 DOI: 10.1016/j.expneurol.2018.09.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 08/30/2018] [Accepted: 09/05/2018] [Indexed: 12/17/2022]
Abstract
Estrogen receptors (ERs) are thought to be associated with the onset and progression of neurodegenerative injuries and diseases, but the relationship and mechanisms underlying between ERs and cognition in type 2 diabetes remain elusive. In the current study, we investigated the effects of ERα and ERβ on the cognition, neurogenesis and apoptosis in high-fat diet and streptozocin-induced diabetic mice. We found that ERα and/or ERβ activation using their agonists (0.5 mg/kg E2, PPT or DPN) ameliorate memory impairment in the Morris water maze and Y-maze tests, increase hippocampal neurogenesis and prevent hippocampal apoptotic responses. Importantly, treatment with the pharmacologic ERs agonists caused significant increases in the membrane ERα and ERβ expression and subsequent PI3K/Akt, CREB and BDNF activation in the hippocampus of type 2 diabetes mellitus mice. Our data indicate that ERα and ERβ are involved in the cognitive impairment in type 2 diabetes, and that activated ERs, such as application of ERs agonists, could be a novel and promising strategy for the treatment of diabetic cognitive impairment.
Collapse
|
12
|
Tang SS, Ren Y, Xu LJ, Cao JR, Hong H, Ji H, Hu QH. Activation of ERα and/or ERβ ameliorates cognitive impairment and apoptosis in streptozotocin-induced diabetic mice. Horm Behav 2018; 105:95-103. [PMID: 30096284 DOI: 10.1016/j.yhbeh.2018.08.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 07/18/2018] [Accepted: 08/07/2018] [Indexed: 02/02/2023]
Abstract
Estrogen receptors (ERs) are thought to be associated with the onset and progression of neurodegenerative injuries and diseases, but the relationship and mechanisms underlying between ERs and cognition in type 1 diabetes remain elusive. In the current study, we investigated the effects of ERα and ERβ on the memory impairment and apoptosis in streptozotocin-induced diabetic mice. We found that ERα and/or ERβ activation using their agonists (0.5 mg/kg E2, PPT or DPN) ameliorate memory impairment in the Morris water maze (MWM) and Y-maze tests and suppress apoptosis as evidenced by decreased caspase-3 activity and increased ratio of Bcl-2/Bax. Importantly, treatment with the pharmacologic ERs agonists caused significant increases in the membrane ERα and ERβ expression and subsequent PI3K/Akt, CREB and BDNF activation in the hippocampus of diabetic mice. Our data indicate that ERα and ERβ are involved in the cognitive impairment of type 1 diabetes and that activation of ERs via administration of ERs agonists could be a novel and promising strategy for the treatment of diabetic cognitive impairment.
Collapse
Affiliation(s)
- Su-Su Tang
- Department of Pharmacology, Key Laboratory of Neuropsychiatric Diseases, China Pharmaceutical University, Nanjing 210009, China.
| | - Yi Ren
- Department of Pharmacology, Key Laboratory of Neuropsychiatric Diseases, China Pharmaceutical University, Nanjing 210009, China
| | - Li-Jie Xu
- Department of Pharmacology, Key Laboratory of Neuropsychiatric Diseases, China Pharmaceutical University, Nanjing 210009, China
| | - Jing-Ran Cao
- Department of Pharmacology, Key Laboratory of Neuropsychiatric Diseases, China Pharmaceutical University, Nanjing 210009, China
| | - Hao Hong
- Department of Pharmacology, Key Laboratory of Neuropsychiatric Diseases, China Pharmaceutical University, Nanjing 210009, China
| | - Hui Ji
- Department of Pharmacology, Key Laboratory of Neuropsychiatric Diseases, China Pharmaceutical University, Nanjing 210009, China
| | - Qing-Hua Hu
- Department of Pharmacology, Key Laboratory of Neuropsychiatric Diseases, China Pharmaceutical University, Nanjing 210009, China.
| |
Collapse
|
13
|
Sasmita AO, Kuruvilla J, Ling APK. Harnessing neuroplasticity: modern approaches and clinical future. Int J Neurosci 2018; 128:1061-1077. [DOI: 10.1080/00207454.2018.1466781] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Andrew Octavian Sasmita
- Division of Applied Biomedical Sciences and Biotechnology, School of Health Sciences, International Medical University, Kuala Lumpur, Malaysia
| | - Joshua Kuruvilla
- Division of Applied Biomedical Sciences and Biotechnology, School of Health Sciences, International Medical University, Kuala Lumpur, Malaysia
| | - Anna Pick Kiong Ling
- Division of Applied Biomedical Sciences and Biotechnology, School of Health Sciences, International Medical University, Kuala Lumpur, Malaysia
| |
Collapse
|
14
|
Ebrahimzadeh-Bideskan AR, Mansouri S, Ataei ML, Jahanshahi M, Hosseini M. The effects of soy and tamoxifen on apoptosis in the hippocampus and dentate gyrus in a pentylenetetrazole-induced seizure model of ovariectomized rats. Anat Sci Int 2018; 93:218-230. [PMID: 28283880 DOI: 10.1007/s12565-017-0398-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 03/02/2017] [Indexed: 12/13/2022]
Abstract
The effects of tamoxifen and soy on apoptosis of the hippocampus and dentate gyrus of ovariectomized rats after repeated seizures were investigated. Female rats were divided into: (1) Control, (2) Sham, (3) Sham-Tamoxifen (Sham-T), (4) Ovariectomized (OVX), (5) OVX-Tamoxifen (OVX-T), (6)OVX-Soy(OVX-S) and (7) OVX-S-T. The animals in the OVX-S, OVX-T and OVX-S-T groups received soy extract (60 mg/kg; i.p.), tamoxifen (10 mg/kg) or both for 2 weeks before induction of seizures. The animals in these groups additionally received the mentioned treatments before each injection of pentylenetetrazole (PTZ; 40 mg/kg) for 6 days. The animals in the Sham and OVX groups received a vehicle of tamoxifen and soy. A significant decrease in the seizure score and TUNEL-positive neurons was seen in the OVX group compared to the Sham (P < 0.001). The animals in both the OVX-T and OVX-S groups had a significantly higher seizure score as well as number of TUNEL-positive neurons compared to the OVX group (P < 0.01-P < 0.001). Co-treatment of the OVX rats by the extract and tamoxifen decreased the seizure score and number of TUNEL-positive neurons compared to OVX-S (P < 0.001). Treatment of the OVX rats by either soy or tamoxifen increased the seizure score as well as the number of TUNEL-positive neurons in the hippocampal formation. Co-administration of tamoxifen and soy extract inhibited the effects of the soy extract and tamoxifen when they were administered alone. It might be suggested that both soy and tamoxifen have agonistic effects on estrogen receptors by changing the seizure severity.
Collapse
Affiliation(s)
- Ali Reza Ebrahimzadeh-Bideskan
- Department of Anatomy and Cell Biology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
- Microanatomy Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Somaieh Mansouri
- Department of Anatomy and Cell Biology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mariam Lale Ataei
- Department of Anatomy and Cell Biology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mehrdad Jahanshahi
- Department of Anatomy, School of Medicine, Golestan University of Medical Sciences, Grogan, Iran
| | - Mahmoud Hosseini
- Division of Neurocognitive Sciences, Psychiatry and Behavioral Sciences Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
- Pharmacological Research Center of Medicinal Plants, Mashhad University of Medical Sciences, Mashhad, Iran.
- Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Azadi Square, Mashhad, Iran.
| |
Collapse
|
15
|
Zhang ZL, Qin P, Liu Y, Zhang LX, Guo H, Deng YL, Yizhao-Liu, Hou YS, Wang LY, Miao Y, Ma YL, Hou WG. Alleviation of ischaemia-reperfusion injury by endogenous estrogen involves maintaining Bcl-2 expression via the ERα signalling pathway. Brain Res 2017; 1661:15-23. [DOI: 10.1016/j.brainres.2017.02.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 02/04/2017] [Accepted: 02/06/2017] [Indexed: 10/20/2022]
|
16
|
Evaluating the role of astrocytes on β-estradiol effect on seizures of Pilocarpine epileptic model. Eur J Pharmacol 2017; 797:32-38. [DOI: 10.1016/j.ejphar.2017.01.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 01/03/2017] [Accepted: 01/11/2017] [Indexed: 02/07/2023]
|
17
|
Botsakis K, Theodoritsi S, Grintzalis K, Angelatou F, Antonopoulos I, Georgiou C, Margarity M, Matsokis N, Panagopoulos N. 17β-Estradiol/N-acetylcysteine interaction enhances the neuroprotective effect on dopaminergic neurons in the weaver model of dopamine deficiency. Neuroscience 2016; 320:221-9. [DOI: 10.1016/j.neuroscience.2016.01.068] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 01/26/2016] [Accepted: 01/30/2016] [Indexed: 11/28/2022]
|
18
|
Estrogen replacement therapy-induced neuroprotection against brain ischemia-reperfusion injury involves the activation of astrocytes via estrogen receptor β. Sci Rep 2016; 6:21467. [PMID: 26891996 PMCID: PMC4759820 DOI: 10.1038/srep21467] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 01/22/2016] [Indexed: 01/18/2023] Open
Abstract
The incidence of ischemic stroke is significantly increased in postmenopausal women. However, the neuroprotective effects of estrogen replacement therapy (ERT) against stroke remain controversial, and the role of astrocytes in ERT has rarely been explored. In this study, we investigated the effects of estrogen and selective estrogen receptor (ER) agonists on astrocytes activation and neuronal apoptosis in mice under conditions of cell culture oxygen and glucose deprivation and reperfusion (OGD-R), and global cerebral ischemia (GCI). We demonstrated that hippocampal astrocytes primarily express ERβ. In astrocytes, 2.5-20 nM 17β-estradiol (E2) or 10 nM DPN (ERβ agonist) not 10 nM PPT (ERα agonist), significantly increased GFAP expression. And 10 nM E2, DPN or E2+MPP (ERα antagonist), but not PPT or E2+PHTPP (ERβ antagonist), significantly reduced neuronal apoptosis following the subjection of astrocyte and neuronal cocultures to OGD-R. We also found that either 50 μg/kg E2 or 8 mg/kg DPN replacement (3 weeks) significantly increased GFAP expression and reduced GCI-induced neuronal apoptosis in hippocampal CA1 region of ovariectomized mice. These results indicate that estrogen-induced neuroprotection against ischemia-reperfusion injury involves activation of astrocytes via ERβ. Thus, the discovery and design of astrocyte-selective ERβ modulators may offer a new strategy for ERT of ischemic stroke.
Collapse
|
19
|
Kim TW, Kim CS, Kim JY, Kim CJ, Seo JH. Combined exercise ameliorates ovariectomy-induced cognitive impairment by enhancing cell proliferation and suppressing apoptosis. Menopause 2016; 23:18-26. [DOI: 10.1097/gme.0000000000000486] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
20
|
|
21
|
Ebrahimzadeh Bideskan AR, Lale Ataei M, Mansouri S, Hosseini M. The effects of tamoxifen and soy on dark neuron production in hippocampal formation after pentylenetetrazole-induced repeated seizures in rats. PATHOPHYSIOLOGY 2015; 22:125-35. [DOI: 10.1016/j.pathophys.2015.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 04/10/2015] [Accepted: 04/30/2015] [Indexed: 11/25/2022] Open
|
22
|
Khan MM, Wakade C, de Sevilla L, Brann DW. Selective estrogen receptor modulators (SERMs) enhance neurogenesis and spine density following focal cerebral ischemia. J Steroid Biochem Mol Biol 2015; 146:38-47. [PMID: 24815952 PMCID: PMC4419701 DOI: 10.1016/j.jsbmb.2014.05.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/23/2014] [Accepted: 05/02/2014] [Indexed: 12/23/2022]
Abstract
Selective estrogen receptor modulators (SERMs) have been reported to enhance synaptic plasticity and improve cognitive performance in adult rats. SERMs have also been shown to induce neuroprotection against cerebral ischemia and other CNS insults. In this study, we sought to determine whether acute regulation of neurogenesis and spine remodeling could be a novel mechanism associated with neuroprotection induced by SERMs following cerebral ischemia. Toward this end, ovariectomized adult female rats were either implanted with pellets of 17β-estradiol (estrogen) or tamoxifen, or injected with raloxifene. After one week, cerebral ischemia was induced by the transient middle-cerebral artery occlusion (MCAO) method. Bromodeoxyuridine (BrdU) was injected to label dividing cells in brain. We analyzed neurogenesis and spine density at day-1 and day-5 post MCAO. In agreement with earlier findings, we observed a robust induction of neurogenesis in the ipsilateral subventricular zone (SVZ) of both the intact as well as ovariectomized female rats following MCAO. Interestingly, neurogenesis in the ipsilateral SVZ following ischemia was significantly higher in estrogen and raloxifene-treated animals compared to placebo-treated rats. In contrast, this enhancing effect on neurogenesis was not observed in tamoxifen-treated rats. Finally, both SERMs, as well as estrogen significantly reversed the spine density loss observed in the ischemic cortex at day-5 post ischemia. Taken, together these results reveal a profound structural remodeling potential of SERMs in the brain following cerebral ischemia. This article is part of a Special Issue entitled "Sex steroids and brain disorders".
Collapse
Affiliation(s)
- Mohammad M Khan
- Department of Biochemistry, Faculty of Medicine, Zaiwa University, AZ-Zawia, Libya
| | - Chandramohan Wakade
- Department of Physical Therapy, Georgia Regents University, Augusta, GA 30912, USA; Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912, USA
| | - Liesl de Sevilla
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912, USA
| | - Darrell W Brann
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912, USA.
| |
Collapse
|
23
|
Dixit S, Dhar P, Mehra RD. Alpha lipoic acid (ALA) modulates expression of apoptosis associated proteins in hippocampus of rats exposed during postnatal period to sodium arsenite (NaAsO 2). Toxicol Rep 2015; 2:78-87. [PMID: 28962340 PMCID: PMC5598373 DOI: 10.1016/j.toxrep.2015.01.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 01/20/2015] [Accepted: 01/20/2015] [Indexed: 12/15/2022] Open
Abstract
The present study focused on the role of exogenous alpha lipoic acid (ALA) in amelioration of inorganic arsenic (iAs) induced effects on apoptosis and apoptosis associated proteins in developing rat hippocampus. NaAsO2 (1.5/2.0 mg/kg bw) alone or along with ALA (70 mg/kg bw) was administered to rat pups (experimental groups) by intraperitoneal (i.p.) route from postnatal day (PND) 4-15. Controls received no treatment/distilled water/ALA. On PND 16, the animals were perfusion fixed and the brains were processed for paraffin embedding (CV and TUNEL staining) and cryopreservation (immunohistochemistry). The fresh brain tissue was used for Western blotting. Significant increase was observed in TUNEL positive cells and Bax (pro-apoptotic protein) expression in hippocampal sub-regions of iAs alone treated groups, whereas Bcl-2 expression was intensified in animals receiving ALA with iAs. Densitometric analysis (Western blots) revealed optimal restoration of Bax and Bcl-2 ratio in animals receiving ALA with iAs, thereby suggesting the protective role of ALA in iAs induced developmental neurotoxicity.
Collapse
Key Words
- ALA, alpha lipoic acid
- Arsenic (iAs)
- Bax
- Bcl-2
- CA1, CA2, CA3, cornu amonis subregions
- CV, cresyl violet
- DG, dentate gyrus
- Hippocampus
- Na2AsO2, sodium arsenite
- Oxidative stress
- PND, post natal day
- TUNEL, TdT mediated dUTP biotin nick-end labeling
- i.p., intraperitoneal
- iAs, arsenic
- α-Lipoic acid (ALA)
Collapse
Affiliation(s)
| | - Pushpa Dhar
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi 110029, India
| | | |
Collapse
|
24
|
Zabihi H, Hosseini M, Pourganji M, Oryan S, Soukhtanloo M, Niazmand S. The effects of tamoxifen on learning, memory and brain tissues oxidative damage in ovariectomized and naïve female rats. Adv Biomed Res 2014; 3:219. [PMID: 25371876 PMCID: PMC4219215 DOI: 10.4103/2277-9175.143297] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 05/15/2013] [Indexed: 12/18/2022] Open
Abstract
Background: Regarding the modulatory effects of tamoxifen (TAM) on the actions of estrogen in the present study, the effects of TAM on learning, memory and brain tissues oxidative damage in ovariectomized (OVX) and naοve female rats was investigated. Materials and Methods: The animals were divided into: (1) Sham, (2) OVX, (3) Sham-tamoxifen (Sham-TAM) and (4) ovariectomized-tamoxifen (OVX-TAM). The animals of the Sham-TAM and OVX-TAM groups were treated by TAM (1 mg/kg; 4 weeks). Results: In Morris water maze, the escape latency in the OVX group was higher than in the Sham group (P < 0.01). The time latency in the animals of OVX-TAM group was lower than that of OVX group (P < 0.01); however, there were no significant differences between the Sham-TAM and Sham groups. In the probe trial, the time spent in target quadrant (Q1) by the animals of OVX group was lower than that of Sham group (P < 0.01). Interestingly, the animals of OVX-TAM group spent more times in target quadrant (Q1) compared with OVX group (P < 0.01). In passive avoidance test, the animals of OVX group had lower latencies to enter the dark compartment compared with the Sham group (P < 0.05). The time latency to enter the dark compartment by animals of OVX-TAM group was higher than in OVX group (P < 0.01). In OVX-TAM group, the total thiol concentration was significantly higher (P < 0.05) and malondialdehyde concentration was lower (P < 0.01) than OVX group. Conclusions: These results allow us to propose that TAM enhances learning and memory of OVX rats. The possible mechanism may be due to the protective effects against brain tissues oxidative damage.
Collapse
Affiliation(s)
- Hoda Zabihi
- Department of Biology, Faculty of Science, Tarbiat Moallem University of Tehran, Tehran, Iran
| | - Mahmoud Hosseini
- Neurocognitive Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Masoume Pourganji
- Neurocognitive Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Shahrbanoo Oryan
- Department of Biology, Faculty of Science, Tarbiat Moallem University of Tehran, Tehran, Iran
| | - Mohammad Soukhtanloo
- Department of Biochemistry, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Saeed Niazmand
- Neurogenic Inflammation Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| |
Collapse
|
25
|
Kireev RA, Vara E, Viña J, Tresguerres JAF. Melatonin and oestrogen treatments were able to improve neuroinflammation and apoptotic processes in dentate gyrus of old ovariectomized female rats. AGE (DORDRECHT, NETHERLANDS) 2014; 36:9707. [PMID: 25135305 PMCID: PMC4453938 DOI: 10.1007/s11357-014-9707-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 08/11/2014] [Indexed: 06/03/2023]
Abstract
The aim of this study was to determine the outcomes of oestrogen and melatonin treatments following long-term ovarian hormone depletion on neuroinflammation and apoptotic processes in dentate gyrus of hippocampi. Forty-six female Wistar rats of 22 months of age were used. Twelve of them remained intact, and the other 34 were ovariectomized at 12 months of age. Ovariectomized animals were divided into three groups and treated for 10 weeks with oestrogens, melatonin or saline. All rats were killed by decapitation at 24 months of age, and dentate gyri were collected. A group of 2 month-old intact female rats was used as young control. The levels of pro-inflammatory cytokines and heat shock protein 70 (HSP 70) were analysed by ELISA. The expressions of TNFα, IL1β, GFAP, nNOS, iNOS, HO-1, NFκB, Bax, Bad, AIF, Bcl2 and SIRT1 genes were detected by real-time (RT)-PCR. Western blots were used to measure the protein expression of NFκB p65, NFκB p50/105, IκBα, IκBβ, p38 MAPK, MAP-2 and synapsin I. We have assessed the ability of 17β-oestradiol and melatonin administration to downregulate markers of neuroinflammation in the dentate gyrus of ovariectomized female rats. Results indicated that 17β-oestradiol and melatonin treatments were able to significantly decrease expression of pro-inflammatory cytokines, iNOS and HO-1 in the hippocampus when compared to non-treated animals. A similar age- and long-term ovarian hormone depletion- related increase in GFAP was also attenuated after both melatonin and oestradiol treatments. In a similar way to oestradiol, melatonin decreased the activation of p38 MAPK and NFκB pathways. The treatments enhanced the levels of synaptic molecules synapsin I and MAP-2 and have been shown to modulate the pro-antiapoptotic ratio favouring the second and to increase SIRT1 expression. These findings support the potential therapeutic role of melatonin and oestradiol as protective anti-inflammatory agents for the central nervous system during menopause.
Collapse
Affiliation(s)
- Roman A Kireev
- Instituto de Investigación Biomédica de Vigo (IBIV), Xerencia de Xestión Integrada de Vigo, SERGAS, Biomedical Research Unit, Hospital Rebullón (CHUVI), Puxeiros s/n, 36415, MOS Pontevedra, Spain,
| | | | | | | |
Collapse
|
26
|
Tsai YT, Wang CC, Leung PO, Lin KC, Chio CC, Hu CY, Kuo JR. Extracellular signal–regulated kinase 1/2 is involved in a tamoxifen neuroprotective effect in a lateral fluid percussion injury rat model. J Surg Res 2014; 189:106-16. [DOI: 10.1016/j.jss.2014.02.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 12/20/2013] [Accepted: 02/11/2014] [Indexed: 12/13/2022]
|
27
|
Bian C, Zhu H, Zhao Y, Cai W, Zhang J. Intriguing roles of hippocampus-synthesized 17β-estradiol in the modulation of hippocampal synaptic plasticity. J Mol Neurosci 2014; 54:271-81. [PMID: 24729128 DOI: 10.1007/s12031-014-0285-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 03/06/2014] [Indexed: 10/25/2022]
Abstract
Accumulated studies have shown that 17β-estradiol (E2) can be de novo synthesized in the hippocampus, and its role in the regulation of hippocampal synaptic plasticity, which is the basis of learning and memory, has long been exploring. Steroidogenic enzymes (e.g., aromatase) that are essential to the hippocampus-synthesized synthesis of E2 have been detected in the hippocampus. Inhibition of E2 synthesis by aromatase inhibitors significantly reduces the density of hippocampal spine synapses, levels of some synaptic proteins such as spinopholin and synaptophysin. Moreover, the electrophysiological properties of hippocampal neurons are also changed in response to this inhibition. The influences of gonadal and hippocampal E2 on synaptic plasticity may exist some differences, since some reports showed that gonadal (or circulating) estrogens have no obvious effects in the modulation of hippocampal synaptic proteins as evidenced in some ovariectomized animals and postmenopausal women who suffered from Alzheimer's disease (AD). These evidences leads to a hypothesis that hippocampal E2 may play a more important role in modulation of synaptic plasticity than gonadal E2. The signaling pathways, whereby hippocampal E2 modulates synaptic plasticity, insist of classical chronic genomic pathway and rapid nongenomic pathway, which mediated by nonnuclear estrogen receptor (GPER) and/or nuclear or nonnuclear estrogen receptors, which require coactivators for their transcription activity. Among which steroid receptor coactivator-1 (SRC-1) is the predominant coactivator p160 family members in the brain. Several clues have shown that SRC-1 is expressed in hippocampus and is highly correlated with some key synaptic proteins developmentally or after orchidectomy but not ovariectomy, indicating SRC-1 may be regulated by hippocampus-synthesized E2 and profoundly involved in the mediation of hippocampal E2 regulation of hippocampal synaptic plasticity. Further studies about the exact roles of hippocampus-synthesized E2 and therefore SRC-1 are urgently needed in order to facilitate our understanding of hippocampal E2, which will be very important to the development of novel strategies of estrogen replacement therapy against neurodegenerative deficits such as Alzheimer's disease (AD).
Collapse
Affiliation(s)
- Chen Bian
- Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, Gaotanyan 30, Chongqing, 400038, China
| | | | | | | | | |
Collapse
|
28
|
Dos Santos Pereira RT, Porto CS, Abdalla FMF. Ovariectomy and 17β-estradiol replacement play a role on the expression of Endonuclease-G and phosphorylated cyclic AMP response element-binding (CREB) protein in hippocampus. Mol Cell Endocrinol 2014; 382:227-233. [PMID: 24121025 DOI: 10.1016/j.mce.2013.09.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 09/16/2013] [Accepted: 09/30/2013] [Indexed: 11/19/2022]
Abstract
The aim of the present study was to investigate the effects of different periods of ovariectomy and 17β-estradiol (E2) replacement on the expression of Cytochrome C, apoptosis inducing factor (AIF) and Endonuclease-G (Endo-G) in mitochondrial and cytosolic fractions obtained from hippocampus of the adult female rats. In addition, the expression of phosphorylated CREB (phospho-CREB) was also analyzed in hippocampus. Ovariectomy or E2 treatment did not change the expression of Cytochrome C and AIF. Ovariectomy (15, 21 and 36 days) decreased the expression of Endo-G in the mitochondrial fractions and increased it in the cytosolic fractions obtained from hippocampus. The treatment with E2 after 15 days of ovariectomy for 7 days or 21 days, and throughout the post-ovariectomy period prevented the effects of ovariectomy on Endo-G expression. Our results suggest that ovariectomy-induced apoptotic cell death in hippocampal tissue could be mediated by Endo-G, but not by AIF, via a caspase-independent apoptotic pathway. Furthermore, ovariectomy decreased the expression of phospho-CREB and the treatment with E2 prevented these effects. In conclusion, E2 may help maintain long-term neuronal viability by regulating the expression of members of the Bcl-2 family. Regulation of Endo-G released from mitochondria, but not of Cytochrome C and AIF, is also involved in the neuroprotective actions of E2. Furthermore, CREB may be involved in the expression of Bcl-2. These data provide new understanding into the mechanisms involved in the neuroprotective role of estrogen.
Collapse
Affiliation(s)
| | - Catarina Segreti Porto
- Section of Experimental Endocrinology, Department of Pharmacology, Escola Paulista de Medicina-Universidade Federal de São Paulo, São Paulo, Brazil
| | | |
Collapse
|
29
|
Newhouse P, Albert K, Astur R, Johnson J, Naylor M, Dumas J. Tamoxifen improves cholinergically modulated cognitive performance in postmenopausal women. Neuropsychopharmacology 2013; 38:2632-43. [PMID: 23867982 PMCID: PMC3828534 DOI: 10.1038/npp.2013.172] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 06/25/2013] [Accepted: 07/02/2013] [Indexed: 12/15/2022]
Abstract
Tamoxifen (TMX) is a selective estrogen receptor modulator that is used as an estrogen receptor antagonist for the treatment and prevention of breast cancer. Whether TMX has antagonist activities in the human brain is less clear and its effects on cognitive function have not been experimentally explored. This study examined how TMX affected cognitive performance in older women using a model of anticholinergic drug-induced cognitive dysfunction. Twenty-one postmenopausal women were administered 20 mg of oral TMX or placebo for 3 months. Participants then took part in five drug challenges using the anticholinergic antinicotinic agent mecamylamine (MECA) and antimuscarinic agent scopolamine (SCOP) and were tested on a comprehensive battery including tasks of attention and psychomotor function, verbal episodic memory, and spatial navigation. After a 3-month placebo washout, participants were then crossed over to the alternate treatment and repeated the drug challenges after 3 months. Compared with placebo treatment, TMX significantly attenuated the impairment from cholinergic blockade on tasks of verbal episodic memory and spatial navigation, but effects on attentional/psychomotor tasks were more variable. Analysis by APOE genotype showed that APO ɛ4+ women showed a greater beneficial effect of TMX on reversing the cholinergic impairment than APO ɛ4- women on most tasks. This study provides evidence that TMX may act as an estrogen-like agonist to enhance cholinergic system activity and hippocampally mediated learning.
Collapse
Affiliation(s)
- Paul Newhouse
- Vanderbilt Center for Cognitive Medicine, Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, TN, USA,Clinical Neuroscience Research Unit, Department of Psychiatry, University of Vermont College of Medicine, Burlington, VT, USA,Vanderbilt Center for Cognitive Medicine, Department of Psychiatry, Vanderbilt University School of Medicine, 1601 23rd Avenue, Nashville, TN 37212, USA, Tel: +1 615 936 0928, Fax: +1 615 875 0686, E-mail:
| | - Kimberly Albert
- Vanderbilt Center for Cognitive Medicine, Department of Psychiatry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Robert Astur
- Department of Psychology, University of Connecticut, Storrs, CT, USA
| | - Julia Johnson
- Department of Obstetrics and Gynecology, University of Massachusetts School of Medicine, Worcester, MA, USA
| | - Magdalena Naylor
- Clinical Neuroscience Research Unit, Department of Psychiatry, University of Vermont College of Medicine, Burlington, VT, USA
| | - Julie Dumas
- Clinical Neuroscience Research Unit, Department of Psychiatry, University of Vermont College of Medicine, Burlington, VT, USA
| |
Collapse
|
30
|
Franco Rodríguez N, Dueñas Jiménez J, De la Torre Valdovinos B, López Ruiz J, Hernández Hernández L, Dueñas Jiménez S. Tamoxifen favoured the rat sensorial cortex regeneration after a penetrating brain injury. Brain Res Bull 2013; 98:64-75. [DOI: 10.1016/j.brainresbull.2013.07.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 07/10/2013] [Accepted: 07/15/2013] [Indexed: 02/01/2023]
|
31
|
Karki P, Webb A, Smith K, Lee K, Son DS, Aschner M, Lee E. cAMP response element-binding protein (CREB) and nuclear factor κB mediate the tamoxifen-induced up-regulation of glutamate transporter 1 (GLT-1) in rat astrocytes. J Biol Chem 2013; 288:28975-86. [PMID: 23955341 DOI: 10.1074/jbc.m113.483826] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Tamoxifen (TX), a selective estrogen receptor modulator, exerts antagonistic effects on breast tissue and is used to treat breast cancer. Recent evidence also suggests that it may act as an agonist in brain tissue. We reported previously that TX enhanced the expression and function of glutamate transporter 1 (GLT-1) in rat astrocytes, an effect that was mediated by TGF-α. To gain further insight into the mechanisms that mediate TX-induced up-regulation of GLT-1 (EAAT2 in humans), we investigated its effect on GLT-1 at the transcriptional level. TX phosphorylated the cAMP response element-binding protein (CREB) and recruited CREB to the GLT-1 promoter consensus site. The effect of TX on astrocytic GLT-1 was attenuated by the inhibition of PKA, the upstream activator of the CREB pathway. In addition, the effect of TX on GLT-1 promoter activity was abolished by the inhibition of the NF-κB pathway. Furthermore, TX recruited the NF-κB subunits p65 and p50 to the NF-κB binding domain of the GLT-1 promoter. Mutation of NF-κB (triple, -583/-282/-251) or CRE (-308) sites on the GLT-1 promoter led to significant repression of the promoter activity, but neither mutant completely abolished the TX-induced GLT-1 promoter activity. Mutation of both the NF-κB (-583/-282/-251) and CRE (-308) sites led to a complete abrogation of the effect of TX on GLT-1 promoter activity. Taken together, our findings establish that TX regulates GLT-1 via the CREB and NF-κB pathways.
Collapse
Affiliation(s)
- Pratap Karki
- From the Department of Physiology, Meharry Medical College, Nashville, Tennessee 37208
| | | | | | | | | | | | | |
Collapse
|
32
|
Mansouri S, Ataei ML, Hosseini M, Bideskan ARE. Tamoxifen mimics the effects of endogenous ovarian hormones on repeated seizures induced by pentylenetetrazole in rats. Exp Neurobiol 2013; 22:116-23. [PMID: 23833560 PMCID: PMC3699672 DOI: 10.5607/en.2013.22.2.116] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 06/03/2013] [Accepted: 06/03/2013] [Indexed: 11/19/2022] Open
Abstract
In the present study, the effects of tamoxifen on pentylenetetrazole (PTZ)-induced repeated seizures and hippocampal neuronal damage in ovariectomized rats were investigated. Thirty seven virgin female Wistar rats were divided to: (1) control, (2) sham-PTZ, (3) sham-PTZ-tamoxifen (sham-PTZ-T), (4) Ovariectomized -PTZ (OVX-PTZ) and (5) OVX-PTZ-tamoxifen (OVX-PTZ-T) groups. The animals of groups 3 and 5 were injected by tamoxifen (10 mg/kg) on 7 consecutive days. After 7 days of tamoxifen injection, they also were then injected by tamoxifen 30 min prior each PTZ injection. PTZ (40 mg/kg) was injected on 6 consecutive days and the animal behaviors were observed for 60 min. The histological methods were then used to determine dark neurons in hippocampus. A significant decrease in the seizure score was seen in OVX-PTZ group compared to Sham-PTZ. The animals of OVX-PTZ-T group had a significant higher seizure score compared to OVX-PTZ group. The dark neurons in DG of OVX group were lower than sham group (p<0.01). The numbers of dark neurons in CA1 area of OVX-PTZ-T group was higher than OVX-PTZ group (p<0.05) compared to control, the numbers of dark neurons in CA3 area showed a significant increase in Sham-PTZ and OVX-PTZ group (p<0.05 and p<0.01 respectively). Dark neurons in OVX-PTZ-T group were higher than OVX-PTZ group (p<0.05). It is concluded that pretreatment of the ovariectomized rats by tamoxifen increased PTZ-induced seizure score and dark neurons. It might be suggested that tamoxifen has agonistic effects for estrogen receptors to change the seizure severity.
Collapse
Affiliation(s)
- Somaeh Mansouri
- Department of Anatomy and Cell Biology, School of Medicine, Mashhad University of Medical Sciences, Mashhad 91779-48564, Iran
| | | | | | | |
Collapse
|
33
|
Schreihofer DA, Ma Y. Estrogen receptors and ischemic neuroprotection: Who, what, where, and when? Brain Res 2013; 1514:107-22. [DOI: 10.1016/j.brainres.2013.02.051] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 02/27/2013] [Accepted: 02/28/2013] [Indexed: 02/08/2023]
|
34
|
Ahmed HH, Estefan SF, Mohamd EM, Farrag AERH, Salah RS. Does melatonin ameliorate neurological changes associated with Alzheimer's disease in ovariectomized rat model? Indian J Clin Biochem 2012; 28:381-9. [PMID: 24426241 DOI: 10.1007/s12291-012-0284-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 11/21/2012] [Indexed: 02/07/2023]
Abstract
This study aimed to elucidate the mechanisms of melatonin to manage neurological damage in Alzheimer's disease (AD) induced in ovariectomized rats. Forty adult female rats were enrolled in our study and were classified as; gonad intact control, ovariectomized control group, ovariectomized rats received melatonin, ovariectomized rats injected with AlCl3 to induce AD and AD-induced rats treated with melatonin. Hydrogen peroxide (H2O2), malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT), B cell lymphoma 2 (Bcl-2), brain derived neurotrophic factor (BDNF), acetylcholinesterase (AchE) and acetylcholine (Ach) were estimated in the brain tissues of the different groups. Treatment of AD-induced rats with melatonin produced marked improvement in the most studied biomarkers which was confirmed by histological investigation of the brain. In Conclusion, melatonin significantly ameliorates the neurodegeneration characteristic of AD in experimental animal model due to its antioxidant, antiapoptotic, neurotrophic and anti-amyloidogenic activities.
Collapse
Affiliation(s)
- Hanaa H Ahmed
- Hormones Department, Medical Research Division, National Research Centre, Dokki, Cairo, 12622 Egypt
| | - Selim F Estefan
- Hormones Department, Medical Research Division, National Research Centre, Dokki, Cairo, 12622 Egypt
| | - Ehab M Mohamd
- Chemistry Department, Faculty of Science, Tanta University, Tanta, Egypt
| | | | - Rania S Salah
- Hormones Department, Medical Research Division, National Research Centre, Dokki, Cairo, 12622 Egypt
| |
Collapse
|
35
|
Lee E, Sidoryk-Wegrzynowicz M, Yin Z, Webb A, Son DS, Aschner M. Transforming growth factor-α mediates estrogen-induced upregulation of glutamate transporter GLT-1 in rat primary astrocytes. Glia 2012; 60:1024-36. [PMID: 22488924 PMCID: PMC3353324 DOI: 10.1002/glia.22329] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 02/28/2012] [Indexed: 01/02/2023]
Abstract
Glutamate transporter-1 (GLT-1) plays a central role in preventing excitotoxicity by removing excess glutamate from the synaptic clefts. 17β-Estradiol (E2) and tamoxifen (TX), a selective estrogen receptor (ER) modulator, afford neuroprotection in a range of experimental models. However, the mechanisms that mediate E2 and TX neuroprotection have yet to be elucidated. We tested the hypothesis that E2 and TX enhance GLT-1 function by increasing transforming growth factor (TGF)-α expression and, thus, attenuate manganese (Mn)-induced impairment in astrocytic GLT-1 expression and glutamate uptake in rat neonatal primary astrocytes. The results showed that E2 (10 nM) and TX (1 μM) increased GLT-1 expression and reversed the Mn-induced reduction in GLT-1, both at the mRNA and protein levels. E2/TX also concomitantly reversed the Mn-induced inhibition of astrocytic glutamate uptake. E2/TX activated the GLT-1 promoter and attenuated the Mn-induced repression of the GLT-1 promoter in astrocytes. TGF-α knockdown (siRNA) abolished the E2/TX effect on GLT-1 expression, and inhibition of epidermal growth factor receptor (TGF-α receptor) suppressed the effect of E2/TX on GLT-1 expression and GLT-1 promoter activity. E2/TX also increased TGF-α mRNA and protein levels with a concomitant increase in astrocytic glutamate uptake. All ERs (ER-α, ER-β, and G protein-coupled receptor 30) were involved in mediating E2 effects on the regulation of TGF-α, GLT-1, and glutamate uptake. These results indicate that E2/TX increases GLT-1 expression in astrocytes via TGF-α signaling, thus offering an important putative target for the development of novel therapeutics for neurological disorders.
Collapse
Affiliation(s)
- Eunsook Lee
- Department of Physiology, Meharry Medical College, Nashville, TN 37208, USA.
| | | | | | | | | | | |
Collapse
|
36
|
Ge C, Yu M, Zhang C. G protein-coupled receptor 30 mediates estrogen-induced proliferation of primordial germ cells via EGFR/Akt/β-catenin signaling pathway. Endocrinology 2012; 153:3504-16. [PMID: 22635679 DOI: 10.1210/en.2012-1200] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
In vertebrates, estrogens are required for the normal development and function of postnatal gonads. However, it remains unclear whether estrogens are able to modulate development of the fetal germ cells. Here, we show that, unexpectedly, chicken primordial germ cells (PGC) lacking estrogen receptor α/β still proliferate in response to 17β-estradiol (E(2)). This is due to the capacity of G protein-coupled receptor 30 (GPR30), existing on PGC, to directly bind E(2). Knockdown experiments suggest that GPR30 is required for E(2)-stimulated PGC proliferation. Furthermore, this estrogen-induced activation of GPR30 is revealed to occur through the Gβγ-subunit protein-dependent and through the matrix metalloproteinase-dependent transactivation of the epidermal growth factor receptor. Epidermal growth factor receptor activation results in a series of intracellular events, including activation of the phosphatidylinositol 3-kinase/serine-threonine kinase/β-catenin pathway, which are followed by the induction of c-fos, c-myc, cyclin D1/E, and B-cell lymphoma 2 expression, and the inhibition of B-cell lymphoma 2-associated X protein expression and caspase3/9 activity. This eventually leads to decreased apoptosis and increased PGC proliferation. Collectively, these findings offer novel insights into the dynamic mechanism of estrogen action on PGC proliferation and suggest that E(2)/GPR30 signaling might play an important role in regulating fetal germ cell development, particularly at the stage before sexual differentiation.
Collapse
Affiliation(s)
- Chutian Ge
- Department of Veterinary Medicine , College of Animal Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, People's Republic of China
| | | | | |
Collapse
|
37
|
Bourque M, Dluzen DE, Di Paolo T. Signaling pathways mediating the neuroprotective effects of sex steroids and SERMs in Parkinson's disease. Front Neuroendocrinol 2012; 33:169-78. [PMID: 22387674 DOI: 10.1016/j.yfrne.2012.02.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 02/15/2012] [Accepted: 02/21/2012] [Indexed: 11/27/2022]
Abstract
Studies with the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) animal model of Parkinson's disease have shown the ability of 17β-estradiol to protect the nigrostriatal dopaminergic system. This paper reviews the signaling pathways mediating the neuroprotective effect of 17β-estradiol against MPTP-induced toxicity. The mechanisms of 17β-estradiol action implicate activation of signaling pathways such as the phosphatidylinositol-3 kinase/Akt and the mitogen-activated protein kinase pathways. 17β-estradiol signaling is complex and integrates multiple interactions with signaling molecules that act to potentiate a protective effect. 17β-estradiol signaling is mediated via estrogen receptors, including GPER1, but others receptors, such as the IGF-1 receptor, are implicated in the neuroprotective effect. Glial and neuronal crosstalk is a critical factor in the maintenance of dopamine neuronal survival and in the neuroprotective action of 17β-estradiol. Compounds that stimulate GPER1 such as selective estrogen receptor modulators and phytoestrogens show neuroprotective activity and are alternatives to 17β-estradiol.
Collapse
Affiliation(s)
- Mélanie Bourque
- Molecular Endocrinology and Genomic Research Center, Centre de recherche du CHUQ (CHUL), Quebec City, QC, Canada G1V 4G2
| | | | | |
Collapse
|
38
|
The neuroprotective effects of phytoestrogen α-zearalanol on β-amyloid-induced toxicity in differentiated PC-12 cells. Eur J Pharmacol 2011; 670:392-8. [DOI: 10.1016/j.ejphar.2011.09.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2011] [Revised: 08/29/2011] [Accepted: 09/07/2011] [Indexed: 11/24/2022]
|
39
|
Jung ME, Ju X, Metzger DB, Simpkins JW. Ethanol withdrawal hastens the aging of cytochrome c oxidase. Neurobiol Aging 2011; 33:618.e21-32. [PMID: 21439684 DOI: 10.1016/j.neurobiolaging.2011.02.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Revised: 01/18/2011] [Accepted: 02/03/2011] [Indexed: 01/01/2023]
Abstract
We investigated whether abrupt ethanol withdrawal (EW) age-specifically inhibits a key mitochondrial enzyme, cytochrome c oxidase (COX), and whether estrogen mitigates this problem. We also tested whether this possible effect of EW involves a substrate (cytochrome c) deficiency that is associated with proapoptotic Bcl2-associated X protein (BAX) and mitochondrial membrane swelling. Ovariectomized young, middle age, and older rats, with or without 17β-estradiol (E2) implantation, underwent repeated EW. Cerebelli were collected to measure COX activity and the mitochondrial membrane swelling using spectrophotometry and the mitochondrial levels of cytochrome c and BAX using an immunoblot method. The loss of COX activity and the mitochondrial membrane swelling occurred only in older rats under control diet conditions but occurred earlier, starting in the young rats under EW conditions. E2 treatment mitigated these EW effects. EW increased mitochondrial BAX particularly in middle age rats but did not alter cytochrome c. Collectively EW hastens but E2 delays the age-associated loss of COX activity. This EW effect is independent of cytochrome c but may involve the mitochondrial overload of BAX and membrane vulnerability.
Collapse
Affiliation(s)
- Marianna E Jung
- Department of Pharmacology and Neuroscience, Institute for Aging and Alzheimer's disease, University of North Texas, Health Science Center at Fort Worth, Fort Worth, TX 76107-2699,
| | | | | | | |
Collapse
|
40
|
Mechanisms of estrogens' dose-dependent neuroprotective and neurodamaging effects in experimental models of cerebral ischemia. Int J Mol Sci 2011; 12:1533-62. [PMID: 21673906 PMCID: PMC3111617 DOI: 10.3390/ijms12031533] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 02/10/2011] [Accepted: 02/22/2011] [Indexed: 02/08/2023] Open
Abstract
Ever since the hypothesis was put forward that estrogens could protect against cerebral ischemia, numerous studies have investigated the mechanisms of their effects. Despite initial studies showing ameliorating effects, later trials in both humans and animals have yielded contrasting results regarding the fundamental issue of whether estrogens are neuroprotective or neurodamaging. Therefore, investigations of the possible mechanisms of estrogen actions in brain ischemia have been difficult to assess. A recently published systematic review from our laboratory indicates that the dichotomy in experimental rat studies may be caused by the use of insufficiently validated estrogen administration methods resulting in serum hormone concentrations far from those intended, and that physiological estrogen concentrations are neuroprotective while supraphysiological concentrations augment the damage from cerebral ischemia. This evidence offers a new perspective on the mechanisms of estrogens’ actions in cerebral ischemia, and also has a direct bearing on the hormone replacement therapy debate. Estrogens affect their target organs by several different pathways and receptors, and the mechanisms proposed for their effects on stroke probably prevail in different concentration ranges. In the current article, previously suggested neuroprotective and neurodamaging mechanisms are reviewed in a hormone concentration perspective in an effort to provide a mechanistic framework for the dose-dependent paradoxical effects of estrogens in stroke. It is concluded that five protective mechanisms, namely decreased apoptosis, growth factor regulation, vascular modulation, indirect antioxidant properties and decreased inflammation, and the proposed damaging mechanism of increased inflammation, are currently supported by experiments performed in optimal biological settings.
Collapse
|
41
|
Sun K, Hu Q, Zhou CM, Xu XS, Wang F, Hu BH, Zhao XY, Chang X, Chen CH, Huang P, An LH, Liu YY, Fan JY, Wang CS, Yang L, Han JY. Cerebralcare Granule, a Chinese herb compound preparation, improves cerebral microcirculatory disorder and hippocampal CA1 neuron injury in gerbils after ischemia-reperfusion. JOURNAL OF ETHNOPHARMACOLOGY 2010; 130:398-406. [PMID: 20580803 DOI: 10.1016/j.jep.2010.05.030] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 05/13/2010] [Accepted: 05/17/2010] [Indexed: 05/29/2023]
Abstract
AIM OF THE STUDY Cerebralcare Granule (CG) is a Chinese herb compound preparation that has been used for treatment of cerebrovascular related diseases. However, the effect of post-treatment with CG on ischemia and reperfusion (I/R) induced cerebral injury is so far unclear. MATERIALS AND METHODS In present study, cerebral global I/R was induced in Mongolian gerbils by clamping bilateral carotid arteries for 30 min followed by reperfusion for 5 days, and CG (0.4 g/kg or 0.8 g/kg) was administrated 3h after the initiation of reperfusion. RESULTS Post-treatment with CG for 5 days attenuated the I/R-induced production of hydrogen peroxide in, leukocyte adhesion to, and albumin leakage from cerebral microvessels, and, meanwhile, protected neuron from death, reduced the number of caspase-3- and Bax-positive cells, and increased Bcl-2-positive cells in hippocampal CA1 region. CONCLUSION The results suggest that CG given after initiation of reperfusion is able to ameliorate cerebral microvascular dysfunction and hippocampal CA1 neuron damage caused by I/R.
Collapse
Affiliation(s)
- Kai Sun
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Effects of 17beta-estradiol replacement on the apoptotic effects caused by ovariectomy in the rat hippocampus. Life Sci 2010; 86:832-8. [PMID: 20394757 DOI: 10.1016/j.lfs.2010.04.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 03/22/2010] [Accepted: 04/06/2010] [Indexed: 12/12/2022]
Abstract
AIMS The aim of the present study was to investigate the effects of different periods of ovariectomy and 17beta-estradiol replacement on apoptotic cell death and expression of members of the Bcl-2 family in the rat hippocampus. MAIN METHODS Hippocampi were obtained from rats in proestrus, ovariectomized (15 days, 21 days and 36 days), ovariectomized for 15 days and then treated with 17beta-estradiol for 7 or 21 days, and rats ovariectomized and immediately treated with 17beta-estradiol for 21 days. The expression of Bcl-2 and Bax and the number of apoptotic cells were determined. KEY FINDINGS Ovariectomy decreased Bcl-2 expression and increased Bax expression and the number of apoptotic cells. Replacement with 17beta-estradiol (21 days) throughout the post-ovariectomy period reduced the number of apoptotic cells to the control levels, and prevented the effects of ovariectomy on Bax expression, but only partially restored the Bcl-2 expression. After 15 days of ovariectomy, the replacement with 17beta-estradiol for 21 days, but not for 7 days, restored the Bcl-2 and Bax expression and the percentage of apoptotic cells to the levels found in the proestrus control. SIGNIFICANCE The present results show that a physiological concentration of 17beta-estradiol may help maintain long-term neuronal viability by regulating the expression of members of the Bcl-2 family. Even after a period of hormonal deprivation, treatment with 17beta-estradiol is able to restore the expression of Bax and Bcl-2 to control levels, but the duration of the treatment is a key factor to obtain the desired effect. These data provide new understanding into the mechanisms contributing to the neuroprotective action of estrogen.
Collapse
|
43
|
Bethea CL, Reddy AP, Tokuyama Y, Henderson JA, Lima FB. Protective actions of ovarian hormones in the serotonin system of macaques. Front Neuroendocrinol 2009; 30:212-38. [PMID: 19394356 PMCID: PMC2704571 DOI: 10.1016/j.yfrne.2009.04.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Revised: 04/14/2009] [Accepted: 04/15/2009] [Indexed: 12/19/2022]
Abstract
The serotonin neurons of the dorsal and medial raphe nuclei project to all areas of the forebrain and play a key role in mood disorders. Hence, any loss or degeneration of serotonin neurons could have profound ramifications. In a monkey model of surgical menopause with hormone replacement and no neural injury, E and P decreased gene expression in the dorsal raphe nucleus of c-jun n-terminal kinase (JNK1) and kynurenine mono-oxygenase (KMO) that promote cell death. In concert, E and P increased gene expression of superoxide dismutase (SOD1), VEGF, and caspase inhibitory proteins that promote cellular resilience in the dorsal raphe nucleus. Subsequently, we showed that ovarian steroids inhibit pivotal genes in the caspase-dependent and caspase-independent pathways in laser-captured serotonin neurons including apoptosis activating factor (Apaf1), apoptosis-inducing factor (AIF) and second mitochondria-derived activator of caspases (Smac/Diablo). SOD1 was also increased specifically in laser-captured serotonin neurons. Examination of protein expression in the dorsal raphe block revealed that JNK1, phosphoJNK1, AIF and the translocation of AIF from the mitochondria to the nucleus decreased with hormone therapy, whereas pivotal execution proteins in the caspase pathway were unchanged. In addition, cyclins A, B, D1 and E were inhibited, which would prevent re-entry into the cell cycle and catastrophic death. These data indicated that in the absence of gross injury to the midbrain, ovarian steroids inhibit the caspase-independent pathway and cell cycle initiation in serotonin neurons. To determine if these molecular actions prevented cellular vulnerability or death, we examined DNA fragmentation in the dorsal raphe nucleus with the TUNEL assay (terminal deoxynucleotidyl transferase nick end labeling). Ovarian steroids significantly decreased the number of TUNEL-positive cells in the dorsal raphe. Moreover, TUNEL staining prominently colocalized with TPH immunostaining, a marker for serotonin neurons. In summary, ovarian steroids increase the cellular resilience of serotonin neurons and may prevent serotonin neuron death in women facing decades of life after menopause. The survival of serotonin neurons would support cognition and mental health.
Collapse
Affiliation(s)
- Cynthia L Bethea
- Divisions of Reproductive Sciences, Oregon National Primate Research Center, Beaverton, OR 97006, United States.
| | | | | | | | | |
Collapse
|