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Nadel G, Maik-Rachline G, Seger R. JNK Cascade-Induced Apoptosis-A Unique Role in GqPCR Signaling. Int J Mol Sci 2023; 24:13527. [PMID: 37686335 PMCID: PMC10487481 DOI: 10.3390/ijms241713527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/27/2023] [Accepted: 08/28/2023] [Indexed: 09/10/2023] Open
Abstract
The response of cells to extracellular signals is mediated by a variety of intracellular signaling pathways that determine stimulus-dependent cell fates. One such pathway is the cJun-N-terminal Kinase (JNK) cascade, which is mainly involved in stress-related processes. The cascade transmits its signals via a sequential activation of protein kinases, organized into three to five tiers. Proper regulation is essential for securing a proper cell fate after stimulation, and the mechanisms that regulate this cascade may involve the following: (1) Activatory or inhibitory phosphorylations, which induce or abolish signal transmission. (2) Regulatory dephosphorylation by various phosphatases. (3) Scaffold proteins that bring distinct components of the cascade in close proximity to each other. (4) Dynamic change of subcellular localization of the cascade's components. (5) Degradation of some of the components. In this review, we cover these regulatory mechanisms and emphasize the mechanism by which the JNK cascade transmits apoptotic signals. We also describe the newly discovered PP2A switch, which is an important mechanism for JNK activation that induces apoptosis downstream of the Gq protein coupled receptors. Since the JNK cascade is involved in many cellular processes that determine cell fate, addressing its regulatory mechanisms might reveal new ways to treat JNK-dependent pathologies.
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Affiliation(s)
| | | | - Rony Seger
- Department of Immunology and Regenerative Biology, Weizmann Institute of Science, Rehovot 7610001, Israel; (G.N.); (G.M.-R.)
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2
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Anti-Inflammatory Actions of G-Protein-Coupled Estrogen Receptor 1 (GPER) and Brain-Derived Estrogen Following Cerebral Ischemia in Ovariectomized Rats. BIOLOGY 2023; 12:biology12010099. [PMID: 36671793 PMCID: PMC9855882 DOI: 10.3390/biology12010099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/13/2022] [Accepted: 01/03/2023] [Indexed: 01/12/2023]
Abstract
Global cerebral ischemia can elicit rapid innate neuroprotective mechanisms that protect against delayed neuronal death. Brain-derived 17β-estradiol (BDE2), an endogenous neuroprotectant, is synthesized from testosterone by the enzyme aromatase (Aro) and is upregulated by brain ischemia and inflammation. Our recent study revealed that G1, a specific G-protein-coupled estrogen receptor 1 (GPER) agonist, exerts anti-inflammatory and anti-apoptotic roles after global cerebral ischemia (GCI). Herein, we aimed to elucidate whether G1 modulates the early inflammatory process and the potential underlying mechanisms in the ovariectomized rat hippocampal CA1 region. G1 was found to markedly reduce pro-inflammatory (iNOS, MHCII, and CD68) and to enhance anti-inflammatory (CD206, Arginase 1, IL1RA, PPARγ, and BDNF) markers after 1 and 3 days of reperfusion after GCI. Intriguingly, the neuroprotection of G1 was blocked by the Aro inhibitor, letrozole. Conversely, the GPER antagonist, G36, inhibited Aro-BDE2 signaling and exacerbated neuronal damage. As a whole, this work demonstrates a novel anti-inflammatory role of GPER, involving a synergistic mediation with BDE2 during the early stage of GCI.
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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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4
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Cooke PS, Nanjappa MK, Ko C, Prins GS, Hess RA. Estrogens in Male Physiology. Physiol Rev 2017; 97:995-1043. [PMID: 28539434 PMCID: PMC6151497 DOI: 10.1152/physrev.00018.2016] [Citation(s) in RCA: 259] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 01/06/2017] [Accepted: 01/17/2017] [Indexed: 02/06/2023] Open
Abstract
Estrogens have historically been associated with female reproduction, but work over the last two decades established that estrogens and their main nuclear receptors (ESR1 and ESR2) and G protein-coupled estrogen receptor (GPER) also regulate male reproductive and nonreproductive organs. 17β-Estradiol (E2) is measureable in blood of men and males of other species, but in rete testis fluids, E2 reaches concentrations normally found only in females and in some species nanomolar concentrations of estrone sulfate are found in semen. Aromatase, which converts androgens to estrogens, is expressed in Leydig cells, seminiferous epithelium, and other male organs. Early studies showed E2 binding in numerous male tissues, and ESR1 and ESR2 each show unique distributions and actions in males. Exogenous estrogen treatment produced male reproductive pathologies in laboratory animals and men, especially during development, and studies with transgenic mice with compromised estrogen signaling demonstrated an E2 role in normal male physiology. Efferent ductules and epididymal functions are dependent on estrogen signaling through ESR1, whose loss impaired ion transport and water reabsorption, resulting in abnormal sperm. Loss of ESR1 or aromatase also produces effects on nonreproductive targets such as brain, adipose, skeletal muscle, bone, cardiovascular, and immune tissues. Expression of GPER is extensive in male tracts, suggesting a possible role for E2 signaling through this receptor in male reproduction. Recent evidence also indicates that membrane ESR1 has critical roles in male reproduction. Thus estrogens are important physiological regulators in males, and future studies may reveal additional roles for estrogen signaling in various target tissues.
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Affiliation(s)
- Paul S Cooke
- Department of Physiological Sciences, University of Florida, Gainesville, Florida; Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, Illinois; Department of Urology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Manjunatha K Nanjappa
- Department of Physiological Sciences, University of Florida, Gainesville, Florida; Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, Illinois; Department of Urology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - CheMyong Ko
- Department of Physiological Sciences, University of Florida, Gainesville, Florida; Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, Illinois; Department of Urology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Gail S Prins
- Department of Physiological Sciences, University of Florida, Gainesville, Florida; Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, Illinois; Department of Urology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Rex A Hess
- Department of Physiological Sciences, University of Florida, Gainesville, Florida; Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, Illinois; Department of Urology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
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Wang S, Zhang T, Yang Z, Lin J, Cai B, Ke Q, Lan W, Shi J, Wu S, Lin W. Heme oxygenase-1 protects spinal cord neurons from hydrogen peroxide-induced apoptosis via suppression of Cdc42/MLK3/MKK7/JNK3 signaling. Apoptosis 2017; 22:449-462. [PMID: 27864650 DOI: 10.1007/s10495-016-1329-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The mechanisms by which oxidative stress induces spinal cord neuron death has not been completely understood. Investigation on the molecular signal pathways involved in oxidative stress-mediated neuronal death is important for development of new therapeutics for oxidative stress-associated spinal cord disorders. In current study we examined the role of heme oxygenase-1 (HO-1) in the modulation of MLK3/MKK7/JNK3 signaling, which is a pro-apoptotic pathway, after treating primary spinal cord neurons with H2O2. We found that MLK3/MKK7/JNK3 signaling was substantially activated by H2O2 in a time-dependent manner, demonstrated by increase of activating phosphorylation of MLK3, MKK7 and JNK3. H2O2 also induced expression of HO-1. Transduction of neurons with HO-1-expressing adeno-associated virus before H2O2 treatment introduced expression of exogenous HO-1 in neurons. Exogenous HO-1 reduced phosphorylation of MLK3, MKK7 and JNK3. Consistent with its inhibitory effect on MLK3/MKK7/JNK3 signaling, exogenous HO-1 decreased H2O2-induced neuronal apoptosis and necrosis. Furthermore, we found that exogenous HO-1 inhibited expression of Cdc42, which is crucial for MLK3 activation. In addition, HO-1-induced down-regulation of MLK3/MKK7/JNK3 signaling might be related to up-regulation of microRNA-137 (mir-137). A mir-137 inhibitor alleviated the inhibitory effect of HO-1 on JNK3 activation. This inhibitor also increased neuronal death even when exogenous HO-1 was expressed. Therefore, our study suggests a novel mechanism by which HO-1 exerted its neuroprotective efficacy on oxidative stress.
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Affiliation(s)
- Siyuan Wang
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Fujian Medical University, 34 North Zhongshan Road, Quanzhou, 362000, China
| | - Tao Zhang
- Department of Orthopedic Surgery, The Second Hospital of Fuzhou Affiliated to Xiamen University, Fuzhou, 350007, China
| | - Zhen Yang
- Department of Orthopedic Surgery, The People's Hospital of Guizhou Province, Guiyang, 550002, China
| | - Jianhua Lin
- Department of Orthopedic Surgery, The First Affiliated Hospital, Fujian Medical University, Fuzhou, 350004, China
| | - Bin Cai
- Department of Neurology and Institute of Neurology, The First Affiliated Hospital, Fujian Medical University, Fuzhou, 350004, China
| | - Qingfeng Ke
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Fujian Medical University, 34 North Zhongshan Road, Quanzhou, 362000, China
| | - Wenbin Lan
- Department of Orthopedic Surgery, The First Affiliated Hospital, Fujian Medical University, Fuzhou, 350004, China
| | - Jinxing Shi
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Fujian Medical University, 34 North Zhongshan Road, Quanzhou, 362000, China
| | - Shiqiang Wu
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Fujian Medical University, 34 North Zhongshan Road, Quanzhou, 362000, China
| | - Wenping Lin
- Department of Orthopedic Surgery, The Second Affiliated Hospital, Fujian Medical University, 34 North Zhongshan Road, Quanzhou, 362000, China.
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Lin W, Wang S, Yang Z, Lin J, Ke Q, Lan W, Shi J, Wu S, Cai B. Heme Oxygenase-1 Inhibits Neuronal Apoptosis in Spinal Cord Injury through Down-Regulation of Cdc42-MLK3-MKK7-JNK3 Axis. J Neurotrauma 2017; 34:695-706. [PMID: 27526795 DOI: 10.1089/neu.2016.4608] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The mechanism by which spinal cord injury (SCI) induces neuronal death has not been thoroughly understood. Investigation on the molecular signal pathways involved in SCI-mediated neuronal apoptosis is important for development of new therapeutics for SCI. In the current study, we explore the role of heme oxygenase-1 (HO-1) in the modulation of mixed lineage kinase 3/mitogen-activated protein kinase kinase/cJUN N-terminal kinase 3 (MLK3/MKK7/JNK3) signaling, which is a pro-apoptotic pathway, after SCI. We found that MLK3/MKK7/JNK3 signaling was activated by SCI in a time-dependent manner, demonstrated by increase in activating phosphorylation of MLK3, MKK7, and JNK3. SCI also induced HO-1 expression. Administration of HO-1-expressing adeno-associated virus before SCI introduced expression of exogenous HO-1 in injured spinal cords. Exogenous HO-1 reduced phosphorylation of MLK3, MKK7, and JNK3. Consistent with its inhibitory effect on MLK3/MKK7/JNK3 signaling, exogenous HO-1 decreased SCI-induced neuronal apoptosis and improved neurological score. Further, we found that exogenous HO-1 inhibited expression of cell division cycle 42 (Cdc42), which is crucial for MLK3 activation. In vitro experiments indicated that Cdc42 was essential for neuronal apoptosis, while transduction of neurons with HO-1-expressing adeno-associated virus significantly reduced neuronal apoptosis to enhance neuronal survival. Therefore, our study disclosed a novel mechanism by which HO-1 exerted its neuroprotective efficacy. Our discovery might be valuable for developing a new therapeutic approach for SCI.
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Affiliation(s)
- Wenping Lin
- 1 Department of Orthopedic Surgery, the Second Affiliated Hospital, Fujian Medical University , Quanzhou, China
| | - Siyuan Wang
- 1 Department of Orthopedic Surgery, the Second Affiliated Hospital, Fujian Medical University , Quanzhou, China
| | - Zhen Yang
- 2 Department of Orthopedic Surgery, the People's Hospital of Guizhou Province , Guiyang, China
| | - Jianhua Lin
- 3 Department of Orthopedic Surgery, the First Affiliated Hospital, Fujian Medical University , Fuzhou, China
| | - Qingfeng Ke
- 1 Department of Orthopedic Surgery, the Second Affiliated Hospital, Fujian Medical University , Quanzhou, China
| | - Wenbin Lan
- 3 Department of Orthopedic Surgery, the First Affiliated Hospital, Fujian Medical University , Fuzhou, China
| | - Jinxing Shi
- 1 Department of Orthopedic Surgery, the Second Affiliated Hospital, Fujian Medical University , Quanzhou, China
| | - Shiqiang Wu
- 1 Department of Orthopedic Surgery, the Second Affiliated Hospital, Fujian Medical University , Quanzhou, China
| | - Bin Cai
- 4 Department of Neurology and Institute of Neurology, the First Affiliated Hospital, Fujian Medical University , Fuzhou, China
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Brkic Z, Petrovic Z, Franic D, Mitic M, Adzic M. Male-specific effects of lipopolysaccharide on glucocorticoid receptor nuclear translocation in the prefrontal cortex of depressive rats. Psychopharmacology (Berl) 2016; 233:3315-30. [PMID: 27387895 DOI: 10.1007/s00213-016-4374-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 06/28/2016] [Indexed: 12/17/2022]
Abstract
RATIONALE Inflammation plays a key role in the pathogenesis of major depressive disorder (MDD) for a subset of depressed individuals. One of the possible routes by which cytokines can induce depressive symptoms is by promoting the dysregulation of hypothalamic-pituitary-adrenal (HPA) axis via altering glucocorticoid receptor (GR) function. OBJECTIVES We investigated the mechanisms that finely tune the GR functioning upon lipopolysaccharide (LPS), i.e., subcellular localization of the GR, the levels of its co-chaperones FK506 binding protein 52 (FKBP4) and FK506 binding protein 51 (FKBP5), the receptor phosphorylation status along with its upstream kinases, as well as mRNA levels of GR-regulated genes in the prefrontal cortex (PFC) of male and female Wistar rats. RESULTS We found that upon LPS treatment, animals of both sexes exhibited depressive-like behavior and elevated serum corticosterone. However, the nuclear translocation of the GR and both FKBPs was found only in males, together with elevated phosphorylation of the GR at serine 232 and 246 and the activation and nuclear translocation of all analyzed kinases. This activation of the GR in males was paralleled with altered expression of GR-related genes, particularly PTGS2 and BDNF. CONCLUSION Our data suggest that LPS treatment produced alterations in the mechanisms that control the GR nuclear translocation in the PFC of males, and that these mechanisms may contribute to the sex-specific dysfunction of GR-related neurotrophic and neuroinflammatory processes in inflammation-associated depression.
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Affiliation(s)
- Zeljka Brkic
- Department of Molecular Biology and Endocrinology, VINCA Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522-MBE090, Belgrade, 11001, Serbia
| | - Zorica Petrovic
- Department of Molecular Biology and Endocrinology, VINCA Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522-MBE090, Belgrade, 11001, Serbia
| | - Dusanka Franic
- Department of Molecular Biology and Endocrinology, VINCA Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522-MBE090, Belgrade, 11001, Serbia
| | - Milos Mitic
- Department of Molecular Biology and Endocrinology, VINCA Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522-MBE090, Belgrade, 11001, Serbia
| | - Miroslav Adzic
- Department of Molecular Biology and Endocrinology, VINCA Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522-MBE090, Belgrade, 11001, Serbia.
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Stanojlović M, Guševac I, Grković I, Mitrović N, Zlatković J, Horvat A, Drakulić D. Repeated Estradiol Treatment Attenuates Chronic Cerebral Hypoperfusion-Induced Neurodegeneration in Rat Hippocampus. Cell Mol Neurobiol 2015; 36:989-999. [PMID: 26689702 DOI: 10.1007/s10571-015-0289-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 10/14/2015] [Indexed: 11/28/2022]
Abstract
Although a substantial number of pre-clinical and experimental studies have investigated effects of 17β-estradiol, its precise molecular mechanism of action in the early state of chronic cerebral hypoperfusion remains controversial. The present study attempted to verify whether post-ischemic estradiol treatment (33.3 μg/kg for seven consecutive days) affects previously reported number of hippocampal apoptotic cells and amount of DNA fragmentation characteristic for apoptosis as well as the expression of key elements within synaptosomal Akt and Erk signal transduction pathways (NF-κB, Bax, Bcl-2, cytochrome C, caspase 3, and PARP). Additionally, alterations of aforementioned molecules linked to protection in various neurodegenerative disorders were monitored in the cytosolic, mitochondrial, and nuclear fractions associating investigated kinases and NF-κB with gene expression of their downstream effectors-Bcl-2, Bax, and caspase 3. The results revealed that an initial increase in the number of apoptotic cells and amount of DNA fragmentation induced by chronic cerebral hypoperfusion was significantly reduced by 17β-estradiol. In synaptic regions, an altered profile with respect to the protein expression of Bcl-2 and phosphorylated Akt was detected, although the level of other examined proteins was not modified. In other investigated sub-cellular fractions, 17β-estradiol elicited phosphorylation and translocation of Akt and Erk along with modulation of the expression of their subsequent effectors. Our findings support the concept that repeated post-ischemic 17β-estradiol treatment attenuates neurodegeneration induced by chronic cerebral hypoperfusion in hippocampus through the activation of investigated kinases and regulation of their downstream molecules in sub-cellular manner indicating a time window and regime of its administration as a valid therapeutic intervention.
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Affiliation(s)
- Miloš Stanojlović
- Department of Molecular Biology and Endocrinology, VINCA Institute of Nuclear Sciences, University of Belgrade, P.O.Box 522, Belgrade, 11001, Republic of Serbia
| | - Ivana Guševac
- Department of Molecular Biology and Endocrinology, VINCA Institute of Nuclear Sciences, University of Belgrade, P.O.Box 522, Belgrade, 11001, Republic of Serbia
| | - Ivana Grković
- Department of Molecular Biology and Endocrinology, VINCA Institute of Nuclear Sciences, University of Belgrade, P.O.Box 522, Belgrade, 11001, Republic of Serbia
| | - Nataša Mitrović
- Department of Molecular Biology and Endocrinology, VINCA Institute of Nuclear Sciences, University of Belgrade, P.O.Box 522, Belgrade, 11001, Republic of Serbia
| | - Jelena Zlatković
- Department of Molecular Biology and Endocrinology, VINCA Institute of Nuclear Sciences, University of Belgrade, P.O.Box 522, Belgrade, 11001, Republic of Serbia
| | - Anica Horvat
- Department of Molecular Biology and Endocrinology, VINCA Institute of Nuclear Sciences, University of Belgrade, P.O.Box 522, Belgrade, 11001, Republic of Serbia
| | - Dunja Drakulić
- Department of Molecular Biology and Endocrinology, VINCA Institute of Nuclear Sciences, University of Belgrade, P.O.Box 522, Belgrade, 11001, Republic of Serbia.
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Ramírez-Sánchez J, Simões Pires EN, Nuñez-Figueredo Y, Pardo-Andreu GL, Fonseca-Fonseca LA, Ruiz-Reyes A, Ochoa-Rodríguez E, Verdecia-Reyes Y, Delgado-Hernández R, Souza DO, Salbego C. Neuroprotection by JM-20 against oxygen-glucose deprivation in rat hippocampal slices: Involvement of the Akt/GSK-3β pathway. Neurochem Int 2015; 90:215-23. [PMID: 26361722 DOI: 10.1016/j.neuint.2015.09.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 09/03/2015] [Accepted: 09/04/2015] [Indexed: 12/25/2022]
Abstract
Cerebral ischemia is the third most common cause of death and a major cause of disability worldwide. Beyond a shortage of essential metabolites, ischemia triggers many interconnected pathophysiological events, including excitotoxicity, oxidative stress, inflammation and apoptosis. Here, we investigated the neuroprotective mechanisms of JM-20, a novel synthetic molecule, focusing on the phosphoinositide-3-kinase (PI3K)/Akt survival pathway and glial cell response as potential targets of JM-20. For this purpose, we used organotypic hippocampal slice cultures exposed to oxygen-glucose deprivation (OGD) to achieve ischemic/reperfusion damage in vitro. Treatment with JM-20 at 0.1 and 10 μM reduced PI incorporation (indicative of cell death) after OGD. OGD decreased the phosphorylation of Akt (pro-survival) and GSK 3β (pro-apoptotic), resulting in respective inhibition and activation of these proteins. Treatment with JM20 prevented the reduced phosphorylation of these proteins after OGD, representing a shift from pro-apoptotic to pro-survival signaling. The OGD-induced activation of caspase-3 was also attenuated by JM-20 treatment at 10 μM. Moreover, in cultures treated with JM-20 and exposed to OGD conditioning, we observed a decrease in activated microglia, as well as a decrease in interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α release into the culture medium, while the level of the anti-inflammatory IL-10 increased. GFAP immunostaining and IB4 labeling showed that JM-20 treatment significantly augmented GFAP immunoreactivity after OGD, when compared with cultures exposed to OGD only, suggesting the activation of astroglial cells. Our results confirm that JM-20 has a strong neuroprotective effect against ischemic injury and suggest that the mechanisms involved in this effect may include the modulation of reactive astrogliosis, as well as neuroinflammation and the anti-apoptotic cell signaling pathway.
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Affiliation(s)
- Jeney Ramírez-Sánchez
- Centro de Investigación y Desarrollo de Medicamentos, Ave 26, No. 1605 Boyeros y Puentes Grandes, CP 10600 La Habana, Cuba
| | - Elisa Nicoloso Simões Pires
- Programa de Pós-graduação em Bioquímica, Departamento de Bioquímica, ICBS, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo I, Porto Alegre, RS 90035-003, Brazil
| | - Yanier Nuñez-Figueredo
- Centro de Investigación y Desarrollo de Medicamentos, Ave 26, No. 1605 Boyeros y Puentes Grandes, CP 10600 La Habana, Cuba
| | - Gilberto L Pardo-Andreu
- Centro de Estudio para las Investigaciones y Evaluaciones Biológicas, Instituto de Farmacia y Alimentos, Universidad de La Habana, ave. 23 # 21425 e/214 y 222, La Coronela, La Lisa CP 13600, La Habana, Cuba
| | - Luis Arturo Fonseca-Fonseca
- Centro de Investigación y Desarrollo de Medicamentos, Ave 26, No. 1605 Boyeros y Puentes Grandes, CP 10600 La Habana, Cuba
| | - Alberto Ruiz-Reyes
- Laboratorio de Síntesis Orgánica de La Facultad de Química de La Universidad de La Habana, Zapata s/n entre G y Carlitos Aguirre, Vedado Plaza de la Revolución, CP 10400, La Habana, Cuba
| | - Estael Ochoa-Rodríguez
- Laboratorio de Síntesis Orgánica de La Facultad de Química de La Universidad de La Habana, Zapata s/n entre G y Carlitos Aguirre, Vedado Plaza de la Revolución, CP 10400, La Habana, Cuba
| | - Yamila Verdecia-Reyes
- Laboratorio de Síntesis Orgánica de La Facultad de Química de La Universidad de La Habana, Zapata s/n entre G y Carlitos Aguirre, Vedado Plaza de la Revolución, CP 10400, La Habana, Cuba
| | - René Delgado-Hernández
- Centro de Investigación y Desarrollo de Medicamentos, Ave 26, No. 1605 Boyeros y Puentes Grandes, CP 10600 La Habana, Cuba
| | - Diogo O Souza
- Programa de Pós-graduação em Bioquímica, Departamento de Bioquímica, ICBS, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo I, Porto Alegre, RS 90035-003, Brazil; Departamento de Bioquímica, PPG em Bioquímica, PPG em Educação em Ciência, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 anexo, Porto Alegre, RS 90035-003, Brazil
| | - Christianne Salbego
- Programa de Pós-graduação em Bioquímica, Departamento de Bioquímica, ICBS, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo I, Porto Alegre, RS 90035-003, Brazil; Departamento de Bioquímica, PPG em Bioquímica, PPG em Educação em Ciência, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 anexo, Porto Alegre, RS 90035-003, Brazil.
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Le XT, Nguyet Pham HT, Van Nguyen T, Minh Nguyen K, Tanaka K, Fujiwara H, Matsumoto K. Protective effects of Bacopa monnieri on ischemia-induced cognitive deficits in mice: the possible contribution of bacopaside I and underlying mechanism. JOURNAL OF ETHNOPHARMACOLOGY 2015; 164:37-45. [PMID: 25660331 DOI: 10.1016/j.jep.2015.01.041] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 01/11/2015] [Accepted: 01/14/2015] [Indexed: 06/04/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Bacopa monnieri (L.) Wettst. (BM) is a medicinal plant which has been not only used as a traditional medicine to improve intelligence and memory but also taken as vegetables in Vietnam for a long time. We previously demonstrated that Bacopa monnieri (BM) alcohol extract attenuated olfactory bulbectomy-induced cognitive deficits and the deterioration of septo-hippocampal cholinergic neurons, suggesting the beneficial effects of BM for dementia patients. AIM OF STUDY The present study was conducted to further clarify the anti-dementia effects of BM, using transient 2 vessels occlusion (T2VO)-induced cognitive deficits in mice, an animal model of vascular dementia, and also to investigate the constituent(s) contributing to the actions of BM, using oxygen- and glucose-deprivation (OGD)-induced hippocampal cell damage as an in vitro model of ischemia. MATERIALS AND METHODS In the in vivo experiments, T2VO mice were treated daily with a standardized BM extract (50mg/kg, p.o.) 1 week before and continuously 3 days after surgery. In the in vitro experiments, organotypic hippocampal slice cultures (OHSCs) were incubated with triterpenoid saponins from BM (bacosides) or MK-801 1h before and during a 45-min period of OGD. Neuronal cell damage in OHSCs was analyzed by measurement of propidium iodide uptake 24h after OGD. RESULTS The BM treatment significantly ameliorated T2VO-induced impairments in non-spatial short term memory performance in the object recognition test. Among the bacosides tested in the in vitro experiments using OHSCs, bacopaside I (25 μM) exhibited potent neuroprotective effects against OGD-induced neuronal cell damage. Double staining with TUNEL and PI revealed that OGD caused necrosis and apoptosis and that bacopaside I attenuated the effects of OGD. The neuroprotective effects of bacopaside I were blocked by the PKC inhibitor Ro-31-8220 and PI3K inhibitor LY294002, but not by the ERK inhibitor U0126. OGD reduced the level of phospho-Akt (p-Akt), an anti-apoptotic factor, in OHSCs. This decrease was reversed by bacopaside I. Moreover, the treatment with bacopaside I itself was able to elevate the level of p-Akt in OHSCs. CONCLUSION These results suggest that BM was beneficial for the prevention of cognitive deficits related to cerebral ischemia and also that bacopaside I, via PKC and PI3K/Akt mechanisms, played a role in the neuroprotective effects of BM observed in the mouse model.
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Affiliation(s)
- Xoan Thi Le
- Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama-shi, Toyama 930-0194, Japan; National Institute of Medicinal Materials, 3B Quang Trung Str., Hoan Kiem Dist., Hanoi, Viet Nam
| | - Hang Thi Nguyet Pham
- Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama-shi, Toyama 930-0194, Japan; National Institute of Medicinal Materials, 3B Quang Trung Str., Hoan Kiem Dist., Hanoi, Viet Nam
| | - Tai Van Nguyen
- National Institute of Medicinal Materials, 3B Quang Trung Str., Hoan Kiem Dist., Hanoi, Viet Nam
| | - Khoi Minh Nguyen
- National Institute of Medicinal Materials, 3B Quang Trung Str., Hoan Kiem Dist., Hanoi, Viet Nam
| | - Ken Tanaka
- Department of Pharmacognosy, College of Pharmaceutical Sciences, Ritsumeikan University, 1-1-1 Nogi-Higashi, Kusatsu-shi, Siga 525-0058, Japan
| | - Hironori Fujiwara
- Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama-shi, Toyama 930-0194, Japan
| | - Kinzo Matsumoto
- Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama-shi, Toyama 930-0194, Japan.
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Han D, Scott EL, Dong Y, Raz L, Wang R, Zhang Q. Attenuation of mitochondrial and nuclear p38α signaling: a novel mechanism of estrogen neuroprotection in cerebral ischemia. Mol Cell Endocrinol 2015; 400:21-31. [PMID: 25462588 DOI: 10.1016/j.mce.2014.11.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Revised: 11/16/2014] [Accepted: 11/17/2014] [Indexed: 12/12/2022]
Abstract
P38 mitogen-activated protein kinase (MAPK) is a pro-apoptotic and pro-inflammatory protein that is activated in response to cellular stress. While p38 is known to be activated in response to cerebral ischemia, the precise role of p38 and its isoforms in ischemia-induced neuronal apoptosis remains unclear. In the current study, we examined the differential activation and functional roles of p38α and p38β MAPK isoforms in short-term ovariectomized female rats treated with either the neuroprotective ovarian hormone 17beta-estradiol (E2) or placebo in a model of global cerebral ischemia (GCI). GCI induced biphasic activation of total p38 in the hippocampal CA1, with peaks at 30 min and 1 day after 10-min ischemia-reperfusion. Further study demonstrated that activated p38α, but not p38β, translocated to the nucleus 30 min and 3 h post reperfusion, and that this event coincided with increased phosphorylation of activating transcription factor 2 (ATF2), a p38 target protein. Intriguingly, activated p38α was also enhanced in mitochondrial fractions of CA1 neurons 1 day after GCI, and there was loss of mitochondrial membrane potential, as well as enhanced cytochrome c release and caspase-3 cleavage at 2 days post GCI. Importantly, E2 prevented the biphasic activation of p38, as well as both nuclear and mitochondrial translocation of p38α after GCI, and these findings correlated with attenuation of mitochondrial dysfunction and delayed neuronal cell death in the hippocampal CA1. Furthermore, administration of a p38 inhibitor was able to mimic the neuroprotective effects of E2 in the hippocampal CA1 region by preventing nuclear and mitochondrial translocation of p38α, loss of mitochondrial membrane potential, and neuronal apoptosis. As a whole, this study suggests that changes in subcellular localization of the activated p38α isoform are required for neuronal apoptosis following GCI, and that E2 exerts robust neuroprotection, in part, through dual inhibition of activation and subcellular trafficking of p38α.
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Affiliation(s)
- Dong Han
- Jiangsu Key Laboratory of Anesthesiology, Xuzhou Medical College, Jiangsu 221004, China
| | - Erin L Scott
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Georgia Regents University, Augusta, GA 30912, USA
| | - Yan Dong
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Georgia Regents University, Augusta, GA 30912, USA
| | - Limor Raz
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Georgia Regents University, Augusta, GA 30912, USA
| | - Ruimin Wang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Georgia Regents University, Augusta, GA 30912, USA; Neurobiology Institute of Medical Research Centre, Hebei United University, Tangshan, Hebei 06300, China
| | - Quanguang Zhang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Georgia Regents University, Augusta, GA 30912, USA.
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12
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Arevalo MA, Azcoitia I, Garcia-Segura LM. The neuroprotective actions of oestradiol and oestrogen receptors. Nat Rev Neurosci 2014; 16:17-29. [PMID: 25423896 DOI: 10.1038/nrn3856] [Citation(s) in RCA: 300] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Hormones regulate homeostasis by communicating through the bloodstream to the body's organs, including the brain. As homeostatic regulators of brain function, some hormones exert neuroprotective actions. This is the case for the ovarian hormone 17β-oestradiol, which signals through oestrogen receptors (ERs) that are widely distributed in the male and female brain. Recent discoveries have shown that oestradiol is not only a reproductive hormone but also a brain-derived neuroprotective factor in males and females and that ERs coordinate multiple signalling mechanisms that protect the brain from neurodegenerative diseases, affective disorders and cognitive decline.
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Affiliation(s)
- Maria-Angeles Arevalo
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, E-28002 Madrid, Spain
| | - Iñigo Azcoitia
- Department of Cell Biology, Faculty of Biology, Universidad Complutense, E-28040 Madrid, Spain
| | - Luis M Garcia-Segura
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, E-28002 Madrid, Spain
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13
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Petrone A, Simpkins JW, Barr TL. 17β-estradiol and inflammation: implications for ischemic stroke. Aging Dis 2014; 5:340-5. [PMID: 25276492 DOI: 10.14336/ad.2014.0500340] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 06/26/2014] [Accepted: 07/08/2014] [Indexed: 01/17/2023] Open
Abstract
Although typically associated with maintenance of female reproductive function, estrogens mediate physiological processes in nearly every body tissue, including the central nervous system. Numerous pre-clinical studies have shown that estrogen, specifically 17-beta-estradiol (17β-E2), protects the brain from ischemic injury following stroke. There are multiple mechanisms of 17β-E2's neuroprotection, including activation of several neuroprotective pathways in the brain, but 17β-E2 also mediates the local and systemic immune response to ischemic stroke. This review summarizes the immune response to stroke, sex differences in stroke pathophysiology, and the role of estrogen as an immunomodulator. This review will focus almost entirely on the role of 17β-E2; however, there will be a brief review and comparison to other forms of estrogen. Understanding the immunomodulatory action of estrogens may provide an opportunity for the use of estrogens in treatment of stroke and other inflammatory disease.
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Affiliation(s)
| | - James W Simpkins
- Center for Neuroscience, West Virginia University School of Medicine, WV 26506, USA ; Center for Basic and Translational Stroke Research, West Virginia University School of Medicine, WV 26506, USA ; Department of Physiology and Pharmacology, West Virginia University School of Medicine, WV 26506, USA
| | - Taura L Barr
- Center for Neuroscience, West Virginia University School of Medicine, WV 26506, USA ; Center for Basic and Translational Stroke Research, West Virginia University School of Medicine, WV 26506, USA ; West Virginia University School of Nursing, Morgantown, WV 26506, USA
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14
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Chen YW, Kao HY, Min MY, Lai WS. A sex- and region-specific role of Akt1 in the modulation of methamphetamine-induced hyperlocomotion and striatal neuronal activity: implications in schizophrenia and methamphetamine-induced psychosis. Schizophr Bull 2014; 40:388-98. [PMID: 23474853 PMCID: PMC3932084 DOI: 10.1093/schbul/sbt031] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AKT1 (also known as protein kinase B, α), a serine/threonine kinase of AKT family, has been implicated in both schizophrenia and methamphetamine (Meth) use disorders. AKT1 or its protein also has epistatic effects on the regulation of dopamine-dependent behaviors or drug effects, especially in the striatum. The aim of this study is to investigate the sex-specific role of Akt1 in the regulation of Meth-induced behavioral sensitization and the alterations of striatal neurons using Akt1(-/-) mice and wild-type littermates as a model. A series of 4 Experiments were conducted. Meth-induced hyperlocomotion and Meth-related alterations of brain activity were measured. The neural properties of striatal medium spiny neurons (MSNs) were also characterized. Further, 17β-estradiol was applied to examine its protective effect in Meth-sensitized male mice. Our findings indicate that (1) Akt1(-/-) males were less sensitive to Meth-induced hyperlocomotion during Meth challenge compared with wild-type controls and Akt1(-/-) females, (2) further sex differences were revealed by coinjection of Meth with raclopride but not SCH23390 in Meth-sensitized Akt1(-/-) males, (3) Meth-induced alterations of striatal activity were confirmed in Akt1(-/-) males using microPET scan with (18)F-flurodeoxyglucose, (4) Akt1 deficiency had a significant impact on the electrophysiological and neuromorphological properties of striatal MSNs in male mice, and (5) subchronic injections of 17β-estradiol prevented the reduction of Meth-induced hyperactivity in Meth-sensitized Akt1(-/-) male mice. This study highlights a sex- and region-specific effect of Akt1 in the regulation of dopamine-dependent behaviors and implies the importance of AKT1 in the modulation of sex differences in Meth sensitivity and schizophrenia.
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Affiliation(s)
- Yi-Wen Chen
- *To whom correspondence should be addressed; 1 Roosevelt Road, Sec. 4, Taipei 10617, Taiwan; tel: 886-2-3366-3112, fax: 886-2-3362-9909, e-mail:
| | - Hui-Yun Kao
- Institute of Zoology, National Taiwan University, Taipei, Taiwan
| | - Ming-Yuan Min
- Institute of Zoology, National Taiwan University, Taipei, Taiwan;,Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan;,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
| | - Wen-Sung Lai
- Department of Psychology, National Taiwan University, Taipei, Taiwan;,Graduate Institute of Brain and Mind Sciences, National Taiwan University, Taipei, Taiwan;,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan,*To whom correspondence should be addressed; 1 Roosevelt Road, Sec. 4, Taipei 10617, Taiwan; tel: 886-2-3366-3112, fax: 886-2-3362-9909, e-mail:
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15
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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]
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16
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Yuryev A, Kotelnikova E, Daraselia N. Ariadne's ChemEffect and Pathway Studio knowledge base. Expert Opin Drug Discov 2013; 4:1307-18. [PMID: 23480468 DOI: 10.1517/17460440903413488] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
IMPORTANCE OF THE FIELD Drug discovery and development is a very complex and costly process. Understanding the detailed molecular mechanisms of a disease and drug actions can make it more efficient not only for new target discovery but also for lead prioritization, drug repositioning and development of biomarkers for drug efficacy and safety. Access to formalized knowledge about functions of proteins and small molecules is crucial for rationalization of the drug development process, and scientific publications are the main source of this knowledge. Protein knowledge networks capturing protein functions, protein-protein relations and organization of proteins in complex cellular sub-systems are making their way into modern drug discovery. Chemical networks representing multiple aspects of chemical functional information integrated into a protein systems biology network is even more advanced and promising paradigm. AREAS COVERED IN THIS REVIEW This review describes utilization of literature-derived protein and chemical functional knowledge bases in drug development. WHAT THE READER WILL GAIN Readers will gain an understanding of how integrated protein and chemical knowledge networks can be used for understanding and building the models of cellular events, disease mechanisms, and drug actions, finding biomarkers of drug efficacy and safety, as well as interpretation of high-throughput gene expression, proteomic and metabolomic experiments. TAKE HOME MESSAGE Integrated literature-derived protein and chemical knowledge bases can rationalize many aspects of drug development process including drug repositioning and biomarker design.
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Affiliation(s)
- Anton Yuryev
- Ariadne Genomics, Inc. 9430 Key West Ave, Rockville MD, 20850, USA +1 240 453 6296 ; +1 240 453 9026 ;
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Zhu J, Shen W, Gao L, Gu H, Shen S, Wang Y, Wu H, Guo J. PI3K/Akt-independent negative regulation of JNK signaling by MKP-7 after cerebral ischemia in rat hippocampus. BMC Neurosci 2013; 14:1. [PMID: 23280045 PMCID: PMC3583678 DOI: 10.1186/1471-2202-14-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 12/26/2012] [Indexed: 01/26/2023] Open
Abstract
Background The inactivation of c-Jun N-terminal kinase (JNK) is associated with anti-apoptotic and anti-inflammatory effects in cerebral ischemia, which can be induced by an imbalance between upstream phosphatases and kinases. Result Mitogen-activated protein kinase phosphatase 7 (MKP-7) was upregulated significantly at 4 h of reperfusion postischemia in rat hippocampi. By administration of cycloheximide or siRNA against mitogen-activated protein kinase phosphatase 7 (MKP-7) in a rat model of ischemia/reperfusion, an obvious enhancement of JNK activity was observed in 4 h of reperfusion following ischemia, suggesting MKP-7 was involved in JNK inactivation after ischemia. The subcellular localization of MKP-7 altered after ischemia, and the inhibition of MKP-7 nuclear export by Leptomycin B up-regulated JNK activity. Although PI3K/Akt inhibition could block downregulation of JNK activity through SEK1 and MKK-7 activation, PI3K/Akt activity was not associated with the regulation of JNK by MKP-7. Conclusions MKP-7, independently of PI3K/Akt pathway, played a key role in downregulation of JNK activity after ischemia in the rat hippocampus, and the export of MKP-7 from the nucleus was involved in downregulation of cytoplasmic JNK activity in response to ischemic stimuli.
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Affiliation(s)
- JianXi Zhu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing, 210029, People's Republic of China
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Hu J, Luo CX, Chu WH, Shan YA, Qian ZM, Zhu G, Yu YB, Feng H. 20-Hydroxyecdysone protects against oxidative stress-induced neuronal injury by scavenging free radicals and modulating NF-κB and JNK pathways. PLoS One 2012; 7:e50764. [PMID: 23239983 PMCID: PMC3519785 DOI: 10.1371/journal.pone.0050764] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 10/24/2012] [Indexed: 01/22/2023] Open
Abstract
Oxidative stress plays an important role in the pathological processes of ischemic brain damage. Many antioxidants have been shown to protect against cerebral ischemia injury by inhibiting oxidative stress both in vitro and in vivo. 20-Hydroxyecdysone (20E), an ecdysteroid hormone, exhibits antioxidative effects. For the work described in this paper, we used an in vitro oxidative damage model and an in vivo ischemic model of middle cerebral artery occlusion (MCAO) to investigate the neuroprotective effects of 20E and the mechanisms related to these effects. Treatment of cells with H2O2 led to neuronal injury, intracellular ROS/RNS generation, mitochondrial membrane potential dissipation, cellular antioxidant potential descent, an increase in malondialdehyde (MDA) and an elevation of intracellular [Ca2+], all of which were markedly attenuated by 20E. Inhibition of the activation of the ASK1-MKK4/7-JNK stress signaling pathway and cleaved caspase-3 induced by oxidative stress were involved in the neuroprotection afforded by 20E. In addition, 20E reduced the expression of iNOS protein by inhibition of NF-κB activation. The neuroprotective effect of 20E was also confirmed in vivo. 20E significantly decreased infarct volume and the neurological deficit score, restored antioxidant potential and inhibited the increase in MDA and TUNEL-positive and cleaved caspase-3-positive cells in the cerebral cortex in MCAO rats. Together, these results support that 20E protects against cerebral ischemia injury by inhibiting ROS/RNS production and modulating oxidative stress-induced signal transduction pathways.
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Affiliation(s)
- Jun Hu
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Chun Xia Luo
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Wei Hua Chu
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - You An Shan
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Zhong-Ming Qian
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Gang Zhu
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Yan Bing Yu
- Department of Neurosurgery, China-Japan Friendship Hospital, 2, Beijing, People's Republic of China
- * E-mail: (YBY); (HF)
| | - Hua Feng
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China
- * E-mail: (YBY); (HF)
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Shi GX, Andres DA, Cai W. Ras family small GTPase-mediated neuroprotective signaling in stroke. Cent Nerv Syst Agents Med Chem 2012; 11:114-37. [PMID: 21521171 DOI: 10.2174/187152411796011349] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 01/18/2011] [Accepted: 03/22/2011] [Indexed: 12/31/2022]
Abstract
Selective neuronal cell death is one of the major causes of neuronal damage following stroke, and cerebral cells naturally mobilize diverse survival signaling pathways to protect against ischemia. Importantly, therapeutic strategies designed to improve endogenous anti-apoptotic signaling appear to hold great promise in stroke treatment. While a variety of complex mechanisms have been implicated in the pathogenesis of stroke, the overall mechanisms governing the balance between cell survival and death are not well-defined. Ras family small GTPases are activated following ischemic insults, and in turn, serve as intrinsic switches to regulate neuronal survival and regeneration. Their ability to integrate diverse intracellular signal transduction pathways makes them critical regulators and potential therapeutic targets for neuronal recovery after stroke. This article highlights the contribution of Ras family GTPases to neuroprotective signaling cascades, including mitogen-activated protein kinase (MAPK) family protein kinase- and AKT/PKB-dependent signaling pathways as well as the regulation of cAMP response element binding (CREB), Forkhead box O (FoxO) and hypoxiainducible factor 1(HIF1) transcription factors, in stroke.
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Affiliation(s)
- Geng-Xian Shi
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, 741 S. Limestone St., Lexington, KY 40536-0509, USA.
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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: 97] [Impact Index Per Article: 8.1] [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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Marin R, Marrero-Alonso J, Fernández C, Cury D, Díaz M. Membrane-initiated signaling of estrogen related to neuroprotection. "Social networks" are required. Horm Mol Biol Clin Investig 2011; 7:393-401. [PMID: 25961340 DOI: 10.1515/hmbci.2011.109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 06/06/2011] [Indexed: 11/15/2022]
Abstract
Numerous studies indicate that estrogens are crucial in normal brain functioning and preservation against different injuries. At the neuronal membrane, estrogens, binding to estrogen receptors (ERs) or other surface targets, exert rapid actions involving a plethora of signaling pathways that may converge in neuronal survival. Emerging work reveals that at least part of these actions may require the compartmentalization of ERs in signaling platforms, composed of macromolecular signaling proteins and particular lipid composition integrated in lipid rafts. These particular microstructures may provide the optimal microenvironment to trigger multiple ER interactions that may be crucial for neuroprotection against different brain impairments, such as Alzheimer's disease (AD). In this order of ideas, recent evidence has demonstrated that a membrane ER (mER) physically interacts with a voltage-dependent anion channel (VDAC) in lipid rafts from septal, hippocampal and cortical neurons, and these interactions may have important consequences in the alternative mechanisms developed by estrogens to achieve neuroprotection against amyloid beta (Aβ)-induced toxicity. This review includes a survey of some of the rapid mechanisms developed by estrogen to prevent neuronal death, and the ER interactions that are involved in the structural maintenance and signal transduction mechanisms important for neuronal survival against AD neuro-pathology. A special emphasis is put on the biological relevance of neuronal membrane VDAC in Aβ-related neurotoxicity, and the potential modulation of this channel as a part of a signaling complex with mER, which may be modified in AD brains.
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Kotelnikova E, Yuryev A, Mazo I, Daraselia N. Computational approaches for drug repositioning and combination therapy design. J Bioinform Comput Biol 2010; 8:593-606. [PMID: 20556864 DOI: 10.1142/s0219720010004732] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Revised: 12/31/2009] [Accepted: 01/15/2010] [Indexed: 01/02/2023]
Abstract
Heterogeneous high-throughput biological data become readily available for various diseases. The amount of data points generated by such experiments does not allow manual integration of the information to design the most optimal therapy for a disease. We describe a novel computational workflow for designing therapy using Ariadne Genomics Pathway Studio software. We use publically available microarray experiments for glioblastoma and automatically constructed ResNet and ChemEffect databases to exemplify how to find potentially effective chemicals for glioblastoma--the disease yet without effective treatment. Our first approach involved construction of signaling pathway affected in glioblastoma using scientific literature and data available in ResNet database. Compounds known to affect multiple proteins in this pathway were found in ChemEffect database. Another approach involved analysis of differential expression in glioblastoma patients using Sub-Network Enrichment Analysis (SNEA). SNEA identified angiogenesis-related protein Cyr61 as the major positive regulator upstream of genes differentially expressed in glioblastoma. Using our findings, we then identified breast cancer drug Fulvestrant as a major inhibitor of glioblastoma pathway as well as Cyr61. This suggested Fulvestrant as a potential treatment against glioblastoma. We further show how to increase efficacy of glioblastoma treatment by finding optimal combinations of Fulvestrant with other drugs.
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Ekuni D, Tomofuji T, Irie K, Kasuyama K, Umakoshi M, Azuma T, Tamaki N, Sanbe T, Endo Y, Yamamoto T, Nishida T, Morita M. Effects of periodontitis on aortic insulin resistance in an obese rat model. J Transl Med 2010; 90:348-59. [PMID: 20065945 DOI: 10.1038/labinvest.2009.141] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The combination of obesity and its associated risk factors, such as insulin resistance and inflammation, results in the development of atherosclerosis. However, the effects of periodontitis on atherosclerosis in an obese body remain unclear. The aim of the study was to investigate the effects of ligature-induced periodontitis in Zucker fatty rats on initiation of atherosclerosis by evaluating aortic insulin resistance. Zucker fatty rats (n=24) were divided into two groups. In the periodontitis group, periodontitis was ligature-induced for 4 weeks, whereas the control group was left unligated. After the 4-week experimental period, descending aorta was used for measuring the levels of lipid deposits, immunohistochemical analysis, and evaluation of gene expression. Levels of serum C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-alpha), and insulin were also measured. Rats in the periodontitis group had significantly enhanced lipid deposits in the aorta, but not in the control group. Expression of suppressor of cytokine signaling 3, vascular cell adhesion molecule 1, reactive oxygen species, nitrotyrosine, and endothelin-1 in the periodontitis group was more intense than that in the control group. Significantly decreased levels of phosphatidylinositol 3-kinase (Pi3k) catalytic beta-polypeptide (Pi3kcb), Pi3kp85, and insulin receptor substrate 1 and 2 were observed in the periodontitis group. Levels of serum CRP and TNF-alpha were significantly increased in the periodontitis group. Under insulin-stimulated conditions, aorta in the periodontitis group altered the Akt phosphorylation. Periodontitis in obesity induced the initial stage of atherosclerosis and disturbed aortic insulin signaling.
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Affiliation(s)
- Daisuke Ekuni
- Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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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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Liu M, Dziennis S, Hurn PD, Alkayed NJ. Mechanisms of gender-linked ischemic brain injury. Restor Neurol Neurosci 2009; 27:163-79. [PMID: 19531872 DOI: 10.3233/rnn-2009-0467] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Biological sex is an important determinant of stroke risk and outcome. Women are protected from cerebrovascular disease relative to men, an observation commonly attributed to the protective effect of female sex hormones, estrogen and progesterone. However, sex differences in brain injury persist well beyond the menopause and can be found in the pediatric population, suggesting that the effects of reproductive steroids may not completely explain sexual dimorphism in stroke. We review recent advances in our understanding of sex steroids (estradiol, progesterone and testosterone) in the context of ischemic cell death and neuroprotection. Understanding the molecular and cell-based mechanisms underlying sex differences in ischemic brain injury will lead to a better understanding of basic mechanisms of brain cell death and is an important step toward designing more effective therapeutic interventions in stroke.
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Affiliation(s)
- Mingyue Liu
- Department of Anesthesiology & Peri-Operative Medicine, Oregon Health & Science University, 3181 S.W. Sam Jackson Park Road, UHS-2, Portland, OR 97239-3098, USA.
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26
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Cui HS, Matsumoto K, Murakami Y, Hori H, Zhao Q, Obi R. Berberine exerts neuroprotective actions against in vitro ischemia-induced neuronal cell damage in organotypic hippocampal slice cultures: involvement of B-cell lymphoma 2 phosphorylation suppression. Biol Pharm Bull 2009; 32:79-85. [PMID: 19122285 DOI: 10.1248/bpb.32.79] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this study we elucidated the effects of berberine, a major alkaloid component contained in medicinal herbs, such as Phellodendri Cortex and Coptidis Rhizoma, on ischemic neuronal damage in mouse organotypic hippocampal slice cultures (OHSCs) caused by oxygen and glucose deprivation (OGD) and N-methyl-D-aspartate (NMDA) -type glutamate receptor stimulation. Hippocampal slices obtained from 7-d-old ICR mice were cultured for 10 d before the experiments. Ischemia-related damage was induced by OGD (5, 15, 45 min) or NMDA (10 microM) treatment, and was evaluated by measuring propidium iodide (PI) uptake. Levels of apoptotic marker proteins, B-cell lymphoma 2 (Bcl-2) and phosphorylated-Bcl-2 (p-Bcl-2), in the OHSCs were measured as indices of biochemical neuronal cell damage by Western blotting. Berberine (5, 25 microM) or the NMDA antagonist MK-801 (25 microM) was added to the medium 30 min before OGD or NMDA treatment. OGD time-dependently increased PI uptake of the OHSCs. Both berberine (5, 25 microM) and MK-801 (25 microM) significantly inhibited PI uptake at 24 h after 45-min OGD treatment and PI uptake in OHSCs exposed to NMDA for 24 h. OGD treatment also significantly increased the level of p-Bcl-2 but not that of Bcl-2 or glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in OHSCs. Berberine (5-25 microM) significantly suppressed the OGD-induced increase of p-Bcl-2 level in OHSCs when tissue was exposed to the alkaloid prior to OGD or simultaneously with OGD. These findings suggest that berberine has protective effects against ischemic damage in mouse OHSCs and that the effects are at least partly mediated by suppression of Bcl-2 phosphorylation.
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Affiliation(s)
- Hu-Shan Cui
- Division of Medicinal Pharmacology, Institute of Natural Medicine, University of Toyama, Japan
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27
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Marin R, Díaz M, Alonso R, Sanz A, Arévalo MA, Garcia-Segura LM. Role of estrogen receptor alpha in membrane-initiated signaling in neural cells: interaction with IGF-1 receptor. J Steroid Biochem Mol Biol 2009; 114:2-7. [PMID: 19167493 DOI: 10.1016/j.jsbmb.2008.12.014] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Accepted: 12/31/2008] [Indexed: 12/25/2022]
Abstract
The mechanisms of action of estradiol in the nervous system involve nuclear-initiated steroid signaling and membrane-initiated steroid signaling. Estrogen receptors (ERs) are involved in both mechanisms. ERalpha interacts with the signaling of IGF-1 receptor in neural cells: ERalpha transcriptional activity is regulated by IGF-1 receptor signaling and estradiol regulates IGF-1 receptor signaling. The interaction between ERalpha and the IGF-1 receptor in the brain may occur at the plasma membrane of neurons and glial cells. Caveolin-1 may provide the scaffolding for the interaction of different membrane-associated molecules, including voltage-dependent anion channel, ERalpha and IGF-I receptor.
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Affiliation(s)
- Raquel Marin
- Laboratory of Cellular Neurobiology, Department of Physiology & Institute of Biomedical Technologies, University of La Laguna, School of Medicine, Santa Cruz de Tenerife, Spain
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28
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Schreihofer DA, Redmond L. Soy phytoestrogens are neuroprotective against stroke-like injury in vitro. Neuroscience 2009; 158:602-9. [PMID: 18976694 PMCID: PMC2652887 DOI: 10.1016/j.neuroscience.2008.10.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 09/30/2008] [Accepted: 10/06/2008] [Indexed: 11/19/2022]
Abstract
Diets high in soy are neuroprotective in experimental stroke. This protective effect is hypothesized to be mediated by phytoestrogens contained in soy, because some of these compounds have neuroprotective effects in in vitro models of cell death. We tested the ability of the soy phytoestrogens genistein, daidzein, and the daidzein metabolite equol to protect embryonic rat primary cortical neurons from ischemic-like injury in vitro at doses typical of circulating concentrations in human populations (0.1-1 microM). All three phytoestrogens inhibited lactate dehydrogenase (LDH) release from cells exposed to glutamate toxicity or the calcium-ATPase inhibitor, thapsigargin. In cells exposed to hypoxia or oxygen-glucose deprivation (OGD), pretreatment with the phytoestrogens inhibited cell death in an estrogen receptor (ER) dependent manner. Although OGD results in multiple modes of cell death, examination of alpha-spectrin cleavage and caspase-3 activation revealed that the phytoestrogens were able to inhibit apoptotic cell death in this model. In addition, blockade of phosphoinositide 3-kinase prevented the protective effects of genistein and daidzein, and blockade of mitogen-activated protein kinase prevented genistein-dependent neuroprotection. These results suggest that pretreatment with dietary levels of soy phytoestrogens can mimic neuroprotective effects observed with estrogen and appear to use the same ER-kinase pathways to inhibit apoptotic cell death.
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Affiliation(s)
- D A Schreihofer
- Department of Physiology, CA3145, Medical College of Georgia, 1120 15th Street, Augusta, GA 30912-3000, USA.
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29
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Narayanan R, Coss CC, Yepuru M, Kearbey JD, Miller DD, Dalton JT. Steroidal androgens and nonsteroidal, tissue-selective androgen receptor modulator, S-22, regulate androgen receptor function through distinct genomic and nongenomic signaling pathways. Mol Endocrinol 2008; 22:2448-65. [PMID: 18801930 DOI: 10.1210/me.2008-0160] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Androgen receptor (AR) ligands are important for the development and function of several tissues and organs. However, the poor oral bioavailability, pharmacokinetic properties, and receptor cross-reactivity of testosterone, coupled with side effects, place limits on its clinical use. Selective AR modulators (SARMs) elicit anabolic effects in muscle and bone, sparing reproductive organs like the prostate. However, molecular mechanisms underlying the tissue selectivity remain ambiguous. We performed a variety of in vitro studies to compare and define the molecular mechanisms of an aryl propionamide SARM, S-22, as compared with dihydrotestosterone (DHT). Studies indicated that S-22 increased levator ani muscle weight but decreased the size of prostate in rats. Analysis of the upstream intracellular signaling events indicated that S-22 and DHT mediated their actions through distinct pathways. Modulation of these pathways altered the recruitment of AR and its cofactors to the PSA enhancer in a ligand-dependent fashion. In addition, S-22 induced Xenopus laevis oocyte maturation and rapid phosphorylation of several kinases, through pathways distinct from steroids. These studies reveal novel differences in the molecular mechanisms by which S-22, a nonsteroidal SARM, and DHT mediate their pharmacological effects.
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Affiliation(s)
- Ramesh Narayanan
- Preclinical Research and Development, GTx, Inc., 3 North Dunlap Street, Memphis, Tennessee 38163, USA
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30
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Xiao Y, Word B, Starlard-Davenport A, Haefele A, Lyn-Cook BD, Hammons G. Age and gender affect DNMT3a and DNMT3b expression in human liver. Cell Biol Toxicol 2008; 24:265-72. [PMID: 17929180 DOI: 10.1007/s10565-007-9035-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Accepted: 09/03/2007] [Indexed: 12/31/2022]
Abstract
DNA methylation is catalyzed by a family of DNA methyltransferases (DNMTs) including the maintenance enzyme DNMT 1 and de novo methyltransferases DNMT 3a and DNMT 3b. Elevated levels of DNMTs have been found in cancer cells and in several types of human tumors. A polymorphism found in DNMT3b has been associated with increased risk for several cancers. The factors influencing DNMT expression in human tissues have not been clearly determined. he present study examined TDNMT3a and DNMT3b levels in human liver tissue samples and compared the effect of ageing, cigarette smoking, and gender. DNMT3a and DNMT3b expression levels in the samples from older individuals (56-78 years, n = 28) were both significantly higher than those of the younger group (16-48 years, n = 27) (73.2 +/- 3.4 vs 8.3 +/- 2.8 and 56.1 +/- 1.9 vs 17.5 +/- 5.7, respectively; p < 0.05). Levels of DNMT3b in females were significantly higher than those in males (75.4 +/- 2.2 vs 16.3 +/- 4.7; p < 0.05); however, DNMT3a levels were similar for females and males (52.7 +/- 2.7 vs 48.4 +/- 2.0). Expression levels of DNMT3a and DNMT3b were similar in smokers and nonsmokers (58.1 +/- 3.5 vs 60.8 +/- 3.1 and 54.5 +/- 2.3 vs 48.3 +/- 1.8, respectively). Genotyping for DNMT3b (C-->T) variant in this sample pool showed a frequency distribution of CC (41%), CT (50%), and TT (9%). The findings from this study suggest that ageing and gender may be important factors influencing DNA methylation status.
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Affiliation(s)
- Yongmei Xiao
- Division of Personalized Nutrition and Medicine, National Center for Toxicological Research, Jefferson, AR 72079, USA
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31
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Pozo Devoto VM, Giusti S, Chavez JC, de Plazas SF. Hypoxia-induced apoptotic cell death is prevented by oestradiol via oestrogen receptors in the developing central nervous system. J Neuroendocrinol 2008; 20:375-80. [PMID: 18208555 DOI: 10.1111/j.1365-2826.2008.01652.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The neuroprotective effects of oestrogens have been demonstrated against a variety of insults, including excitotoxicity, oxidative stress and cerebral ischemia under certain conditions. However, the molecular mechanisms underlying oestrogen neuroprotection are still unclear. We aimed to determine whether 17beta-oestradiol (E(2)) administration post-hypoxia (p-hx) was neuroprotective and whether these actions were mediated through oestrogen receptors (ER). For this purpose, 12-embyonic day-old chickens were subjected to acute hypoxia [8% (O(2)), 60 min], followed by different reoxygenation periods. To test the neuroprotective effect of E(2) and its mechanism, embryos were injected 30 min after the end of hypoxia with E(2) alone or with ICI 182 780, a competitive antagonist of ER. Cytochrome c (cyt c) release, an indicator of mitochondrial apoptotic pathway, was measured by western blot in optic lobe cytosolic extracts. DNA fragmentation by TUNEL fluorescence and caspase-3 fragmentation by immunofluorescence were detected on optic lobe sections. Acute hypoxia produces a significant increase in cyt c release from mitochondria at 4 h p-hx, followed by an increase in TUNEL positive cells 2 h later (6 h p-hx). Administration of E(2) (0.5 mg/egg) produced a significant decrease in cytosolic cyt c levels at 4 h p-hx, in caspase-3 activation and in TUNEL positive cells at 6 h p-hx compared to vehicle treated embryos. In the E(2)-ICI 182 780 treated embryos, cyt c release, caspase-3 fragmentation and TUNEL positive cells were similar to the hypoxic embryos, thus suggesting the requirement of an E(2)-ER interaction for E(2) mediated neuroprotective effects. In conclusion, E(2) prevents hypoxia-induced cyt c release and posterior cell death and these effects are mediated by oestrogen receptors.
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Affiliation(s)
- V M Pozo Devoto
- Institute of Cell Biology and Neuroscience Prof. E. De Robertis, School of Medicine, University of Buenos Aires, Paraguay, Buenos Aires, Argentina
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32
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Li J, Lang J, Zeng Z, McCullough LD. Akt1 gene deletion and stroke. J Neurol Sci 2008; 269:105-12. [PMID: 18258266 DOI: 10.1016/j.jns.2007.12.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Revised: 12/20/2007] [Accepted: 12/21/2007] [Indexed: 10/22/2022]
Abstract
Activation of Akt has been implicated as a major contributor to neuronal survival after an ischemic insult. Numerous neuroprotective agents have been shown to augment Akt activity, suggesting that this protein represents a major mechanism of cellular salvage after injury. Estrogen is known to augment Akt, but the possibility that Akt plays a differential role in the male and female brain has yet to be evaluated. In this study, we employed both pharmacological and genetic approaches to investigate the role of Akt in stroke. Utilizing a focal stroke model we show that deletion of the Akt1 isoform does not affect stroke outcome in either male or female mice. Akt1 deficient mice had equivalent levels of phosphorylated Akt (p-Akt) when compared to their WT controls following stroke suggesting that alternative isoforms can compensate for Akt1 loss. Secondly, estrogen's neuroprotective effect is maintained in Akt1(-/-) mice and estrogen exposure did not enhance p-Akt levels in WT female mice. Thirdly, we show that inhibiting Akt using the direct pan-Akt inhibitor triciribine has no effect on stroke outcome despite dramatic reductions in p-Akt. Our study demonstrates the limitations of genetic mouse models and suggests that the importance of Akt to ischemic outcome remains unclear.
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Affiliation(s)
- Jun Li
- Department of Neurology, University of Connecticut Health Center, Farmington CT, 06030, United States
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33
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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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34
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Brann DW, Dhandapani K, Wakade C, Mahesh VB, Khan MM. Neurotrophic and neuroprotective actions of estrogen: basic mechanisms and clinical implications. Steroids 2007; 72:381-405. [PMID: 17379265 PMCID: PMC2048656 DOI: 10.1016/j.steroids.2007.02.003] [Citation(s) in RCA: 429] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Revised: 02/07/2007] [Accepted: 02/09/2007] [Indexed: 12/16/2022]
Abstract
Estrogen is an important hormone signal that regulates multiple tissues and functions in the body. This review focuses on the neurotrophic and neuroprotective actions of estrogen in the brain, with particular emphasis on estrogen actions in the hippocampus, cerebral cortex and striatum. Sex differences in the risk, onset and severity of neurodegenerative disease such as Alzheimer's disease, Parkinson's disease and stroke are well known, and the potential role of estrogen as a neuroprotective factor is discussed in this context. The review assimilates a complex literature that spans research in humans, non-human primates and rodent animal models and attempts to contrast and compare the findings across species where possible. Current controversies regarding the Women's Health Initiative (WHI) study, its ramifications, concerns and the new studies needed to address these concerns are also addressed. Signaling mechanisms underlying estrogen-induced neuroprotection and synaptic plasticity are reviewed, including the important concepts of genomic versus nongenomic mechanisms, types of estrogen receptor involved and their subcellular targeting, and implicated downstream signaling pathways and mediators. Finally, a multicellular mode of estrogen action in the regulation of neuronal survival and neurotrophism is discussed, as are potential future directions for the field.
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Affiliation(s)
- Darrell W Brann
- Institute of Molecular Medicine and Genetics, School of Medicine, Medical College of Georgia, Augusta, GA 30912, United States.
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