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Balamurugan K, Chandra K, Sai Latha S, Swathi M, Joshi MB, Misra P, Parsa KVL. PHLPPs: Emerging players in metabolic disorders. Drug Discov Today 2022; 27:103317. [PMID: 35835313 DOI: 10.1016/j.drudis.2022.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/21/2022] [Accepted: 07/07/2022] [Indexed: 12/15/2022]
Abstract
That reversible protein phosphorylation by kinases and phosphatases occurs in metabolic disorders is well known. Various studies have revealed that a multi-faceted and tightly regulated phosphatase, pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP)-1/2 displays robust effects in cardioprotection, ischaemia/reperfusion (I/R), and vascular remodelling. PHLPP1 promotes foamy macrophage development through ChREBP/AMPK-dependent pathways. Adipocyte-specific loss of PHLPP2 reduces adiposity, improves glucose tolerance,and attenuates fatty liver via the PHLPP2-HSL-PPARα axis. Discoveries of PHLPP1-mediated insulin resistance and pancreatic β cell death via the PHLPP1/2-Mst1-mTORC1 triangular loop have shed light on its significance in diabetology. PHLPP1 downregulation attenuates diabetic cardiomyopathy (DCM) by restoring PI3K-Akt-mTOR signalling. In this review, we summarise the functional role of, and cellular signalling mediated by, PHLPPs in metabolic tissues and discuss their potential as therapeutic targets.
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Affiliation(s)
- Keerthana Balamurugan
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India; Department of Ageing Research, Manipal School of Life Sciences, Manipal Academy of Higher Education (MAHE), Manipal 576104, Karnataka, India
| | - Kanika Chandra
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India; Department of Ageing Research, Manipal School of Life Sciences, Manipal Academy of Higher Education (MAHE), Manipal 576104, Karnataka, India
| | - S Sai Latha
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India
| | - M Swathi
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India
| | - Manjunath B Joshi
- Department of Ageing Research, Manipal School of Life Sciences, Manipal Academy of Higher Education (MAHE), Manipal 576104, Karnataka, India
| | - Parimal Misra
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India
| | - Kishore V L Parsa
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India.
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Ipp E. Diabetic Retinopathy and Insulin Insufficiency: Beta Cell Replacement as a Strategy to Prevent Blindness. Front Endocrinol (Lausanne) 2021; 12:734360. [PMID: 34912295 PMCID: PMC8667804 DOI: 10.3389/fendo.2021.734360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 09/28/2021] [Indexed: 12/02/2022] Open
Abstract
Diabetic retinopathy (DR) is a potentially devastating complication of diabetes because it puts patients at risk of blindness. Diabetes is a common cause of blindness in the U.S. and worldwide and is dramatically increasing in global prevalence. Thus new approaches are needed to prevent this dreaded complication. There is extensive data that indicates beta cell secretory failure is a risk factor for DR, independent of its influence on glycemic control. This perspective article will provide evidence for insufficient endogenous insulin secretion as an important factor in the development of DR. The areas of evidence discussed are: (a) Presence of insulin receptors in the retina, (b) Clinical studies that show an association of beta cell insufficiency with DR, (c) Treatment with insulin in type 2 diabetes, a marker for endogenous insulin deficiency, is an independent risk factor for DR, (d) Recent clinical studies that link DR with an insulin deficient form of type 2 diabetes, and (e) Beta cell replacement studies that demonstrate endogenous insulin prevents progression of DR. The cumulative data drive our conclusion that beta cell replacement will have an important role in preventing DR and/or mitigating its severity in both type 1 diabetes and insulinopenic type 2 diabetes.
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Affiliation(s)
- Eli Ipp
- Department of Medicine, The Lundquist Institute at Harbor-University of California Los Angeles (UCLA) Medical Center, Torrance, CA, United States
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3
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Enz TJ, Tribble JR, Williams PA. Comparison of Glaucoma-Relevant Transcriptomic Datasets Identifies Novel Drug Targets for Retinal Ganglion Cell Neuroprotection. J Clin Med 2021; 10:3938. [PMID: 34501387 PMCID: PMC8432026 DOI: 10.3390/jcm10173938] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/10/2021] [Accepted: 08/27/2021] [Indexed: 12/20/2022] Open
Abstract
Glaucoma is a leading cause of blindness and is characterized by the progressive dysfunction and irreversible death of retinal ganglion cells. We aimed to identify shared differentially expressed genes (DE genes) between different glaucoma relevant models of retinal ganglion cell injury using existing RNA-sequencing data, thereby discovering targets for neuroprotective therapies. A comparison of DE genes from publicly available transcriptomic datasets identified 12 shared DE genes. The Comparative Toxicogenomics Database (CTD) was screened for compounds targeting a significant proportion of the identified DE genes. Forty compounds were identified in the CTD that interact with >50% of these shared DE genes. We next validated this approach by testing select compounds for an effect on retinal ganglion cell survival using a mouse retinal explant model. Folic acid, genistein, SB-431542, valproic acid, and WY-14643 (pirinixic acid) were tested. Folic acid, valproic acid, and WY-14643 demonstrated significant protection against retinal ganglion cell death in this model. The increasing prevalence of open access-omics data presents a resource to discover targets for future therapeutic investigation.
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Affiliation(s)
| | | | - Pete A. Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, 171 64 Stockholm, Sweden; (T.J.E.); (J.R.T.)
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4
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Abstract
The field of phosphoinositide signaling has expanded significantly in recent years. Phosphoinositides (also known as phosphatidylinositol phosphates or PIPs) are universal signaling molecules that directly interact with membrane proteins or with cytosolic proteins containing domains that directly bind phosphoinositides and are recruited to cell membranes. Through the activities of phosphoinositide kinases and phosphoinositide phosphatases, seven distinct phosphoinositide lipid molecules are formed from the parent molecule, phosphatidylinositol. PIP signals regulate a wide range of cellular functions, including cytoskeletal assembly, membrane budding and fusion, ciliogenesis, vesicular transport, and signal transduction. Given the many excellent reviews on phosphoinositide kinases, phosphoinositide phosphatases, and PIPs in general, in this review, we discuss recent studies and advances in PIP lipid signaling in the retina. We specifically focus on PIP lipids from vertebrate (e.g., bovine, rat, mouse, toad, and zebrafish) and invertebrate (e.g., Drosophila, horseshoe crab, and squid) retinas. We also discuss the importance of PIPs revealed from animal models and human diseases, and methods to study PIP levels both in vitro and in vivo. We propose that future studies should investigate the function and mechanism of activation of PIP-modifying enzymes/phosphatases and further unravel PIP regulation and function in the different cell types of the retina.
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Affiliation(s)
- Raju V S Rajala
- Departments of Ophthalmology, Physiology, and Cell Biology, and Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104.
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Xiong YC, Chen T, Yang XB, Deng CL, Ning QL, Quan R, Yu XR. 17β-Oestradiol Attenuates the Photoreceptor Apoptosis in Mice with Retinitis Pigmentosa by Regulating N-myc Downstream Regulated Gene 2 Expression. Neuroscience 2020; 452:280-294. [PMID: 33246060 DOI: 10.1016/j.neuroscience.2020.11.010] [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: 04/03/2020] [Revised: 07/23/2020] [Accepted: 11/08/2020] [Indexed: 10/22/2022]
Abstract
Retinitis pigmentosa (RP) is a heterogeneous group of retinal degenerative diseases in which the final pathological feature is photoreceptor cell apoptosis. Currently, the pathogenesis of RP remains poorly understood and therapeutics are ineffective. 17β-Oestradiol (βE2) is universally acknowledged as a neuroprotective factor in neurodegenerative diseases and has manifested neuroprotective effects in a light-induced retinal degeneration model. Recently, we identified N-myc downstream regulated gene 2 (NDRG2) suppression as a molecular marker of mouse retinal photoreceptor-specific cell death. βE2 has also been reported to regulate NDRG2 in salivary acinar cells. Therefore, in this study, we investigated whether βE2 plays a protective role in RP and regulates NDRG2 in photoreceptor cells. To this end, we generated RP models and observed that βE2 not only reduced the apoptosis of photoreceptor cells, but also restored the level of NDRG2 expression in RP models. Then, we showed that siNDRG2 inhibits the anti-apoptotic effect of βE2 on photoreceptor cells in a cellular RP model. Subsequently, we used a classic oestrogen receptor (ER) antagonist to attenuate the effects of βE2, suggesting that βE2 exerted its effects on RP models via the classic ERs. In addition, we performed a bioinformatics analysis, and the results indicated that the reported oestrogen response element (ERE) sequence is present in the promoter region of the mouse NDRG2 gene. Overall, our results suggest that βE2 attenuated the apoptosis of photoreceptor cells in RP models by maintaining NDRG2 expression via a classic ER-mediated mechanism.
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Affiliation(s)
- Ye-Cheng Xiong
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Tao Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Xiao-Bei Yang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Chun-Lei Deng
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Qi-Lan Ning
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Rui Quan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Xiao-Rui Yu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China; Key Laboratory of Environment and Genes Related to Diseases (Xi'an Jiaotong University), Ministry of Education, Xi'an, Shaanxi 710061, China.
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Girl Power in Glaucoma: The Role of Estrogen in Primary Open Angle Glaucoma. Cell Mol Neurobiol 2020; 42:41-57. [PMID: 33040237 DOI: 10.1007/s10571-020-00965-5] [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: 03/17/2020] [Accepted: 09/22/2020] [Indexed: 12/24/2022]
Abstract
Estrogen is essential in maintaining various physiological features in women, and a decline in estrogen levels are known to give rise to numerous unfortunate symptoms associated with menopause. To alleviate these symptoms hormone replacement therapy with estrogen is often used, and has been shown to be fruitful in improving quality of life in women suffering from postmenopausal discomforts. An often forgotten condition associated with menopause is the optic nerve disorder, glaucoma. Thus, estrogen may also have an impact in maintaining the retinal ganglion cells (RGCs), which make up the optic nerve, thereby preventing glaucomatous neurodegeneration. This review aims to provide an overview of possible associations of estrogen and the glaucoma subtype, primary open-angle glaucoma (POAG), by evaluating the current literature through a PubMed-based literature search. Multiple in vitro and in vivo studies of RGC protection, as well as clinical and epidemiological data concerning the well-defined retinal neurodegenerative disorder POAG have been reviewed. Over all, deficiencies in retinal estrogen may potentially instigate RGC loss, visual disability, and eventual blindness. Estrogen replacement therapy may therefore be a beneficial future treatment. However, more studies are needed to confirm the relevance of estrogen in glaucoma prevention.
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Soler L, Stella A, Seva J, Pallarés FJ, Lahjouji T, Burlet-Schiltz O, Oswald IP. Proteome changes induced by a short, non-cytotoxic exposure to the mycoestrogen zearalenone in the pig intestine. J Proteomics 2020; 224:103842. [PMID: 32454255 DOI: 10.1016/j.jprot.2020.103842] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 04/28/2020] [Accepted: 05/21/2020] [Indexed: 12/15/2022]
Abstract
Intestinal epithelial homeostasis is regulated by a complex network of signaling pathways. Among them is estrogen signaling, important for the proliferation and differentiation of epithelial cells, immune signaling and metabolism. The mycotoxin zearalenone (ZEN) is an estrogen disruptor naturally found in food and feed. The exposure of the intestine to ZEN has toxic effects including alteration of the immune status and is possibly implicated in carcinogenesis, but the molecular mechanisms linked with these effects are not clear. Our objective was to explore the proteome changes induced by a short, non-cytotoxic exposure to ZEN in the intestine using pig jejunal explants. Our results indicated that ZEN promotes little proteome changes, but significantly related with an induction of ERα signaling and a consequent disruption of highly interrelated signaling cascades, such as NF-κB, ERK1/2, CDX2 and HIF1α. The toxicity of ZEN leads also to an altered immune status characterized by the activation of the chemokine CXCR4/SDF-1 axis and an accumulation of MHC-I proteins. Our results connect the estrogen disrupting activity of ZEN with its intestinal toxic effect, associating the exposure to ZEN with cell-signaling disorders similar to those involved in the onset and progression of diseases such as cancer and chronic inflammatory disorders. SIGNIFICANCE: The proteomics results presented in our study indicate that the endocrine disruptor activity of ZEN is able to regulate a cascade of highly inter-connected signaling events essential for the small intestinal crypt-villus cycle and immune status. These molecular mechanisms are also implicated in the onset and progress of intestinal immune disorders and cancer indicating that exposure to ZEN could play an important role in intestinal pathogenesis.
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Affiliation(s)
- Laura Soler
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, Toulouse, France.
| | - Alexandre Stella
- Toulouse Proteomics Infrastructure, Institut de Pharmacologie et Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Juan Seva
- Department of Anatomy and Comparative Pathology, Faculty of Veterinary Medicine, University of Murcia, Mare Nostrum Excellence Campus, Murcia, Spain
| | - Francisco Jose Pallarés
- Department of Anatomy and Comparative Pathology, Faculty of Veterinary Medicine, University of Murcia, Mare Nostrum Excellence Campus, Murcia, Spain
| | - Tarek Lahjouji
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, Toulouse, France
| | - Odile Burlet-Schiltz
- Toulouse Proteomics Infrastructure, Institut de Pharmacologie et Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Isabelle P Oswald
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, Toulouse, France
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8
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Rajala A, Rajala RVS. A non-canonical rhodopsin-mediated insulin receptor signaling pathway in retinal photoreceptor neurons. Cell Biol Int 2020; 44:1020-1027. [PMID: 31889373 DOI: 10.1002/cbin.11299] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 12/28/2019] [Indexed: 01/08/2023]
Abstract
We previously reported a ligand-independent and rhodopsin-dependent insulin receptor (IR) neuroprotective signaling pathway in both rod and cone photoreceptor cells, which is activated through protein-protein interaction. Our previous studies were performed with either retina or isolated rod or cone outer segment preparations and the expression of IR signaling proteins were examined. The isolation of outer segments with large portions of the attached inner segments is a technical challenge. Optiprep™ density gradient medium has been used to isolate the cells and subcellular organelles, Optiprep™ is a non-ionic iodixanol-based medium with a density of 1.320 g/mL. We employed this method to examine the expression of IR and its signaling proteins, and activation of one of the downstream effectors of the IR in isolated photoreceptor cells. Identification of the signaling complexes will be helpful for therapeutic targeting in disease conditions.
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Affiliation(s)
- Ammaji Rajala
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, Oklahoma, OK, 73104, USA.,Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, Oklahoma City, OK, 73104, USA
| | - Raju V S Rajala
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, Oklahoma, OK, 73104, USA.,Department of Physiology, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, Oklahoma, OK, 73104, USA.,Department of Cell Biology, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, Oklahoma, OK, 73104, USA.,Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Blvd, Oklahoma City, OK, 73104, USA
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9
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Jiang M, Ma X, Zhao Q, Li Y, Xing Y, Deng Q, Shen Y. The neuroprotective effects of novel estrogen receptor GPER1 in mouse retinal ganglion cell degeneration. Exp Eye Res 2019; 189:107826. [PMID: 31586450 DOI: 10.1016/j.exer.2019.107826] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 08/15/2019] [Accepted: 10/01/2019] [Indexed: 01/09/2023]
Abstract
PURPOSE To investigate the potential protective effect of novel G protein coupled estrogen receptor (GPER1) against the neurotoxicity induced by NMDA in the mouse retina. METHODS We induce retinal ganglion cells (RGCs) toxic injury through intravitreal injection of NMDA or acute ocular hypertension (AOH) induced by anterior chamber infusion with saline. Endogenous ligand 17-β-estradiol (E2), GPER1 agonist (G-1), and E2 with GPER1 antagonist (G-15) or classic estrogen receptor α and β (ERα and ERβ) antagonist tamoxifen (TAM) were subcutaneous administered before NMDA to identify the possible involved receptors. Immunofluorescence staining was performed to explore the survival of RGCs and Müller cell gliosis. TUNEL staining was used to evaluate the RGC apoptosis. The involved molecular pathway was detected via antibody array expression profiling. RESULTS Activation of estrogen receptor by E2 or G-1 could significantly rescue the RGCs injury in NMDA administration. The protective effect was carried exclusively by GPER1 activation. E2 application can still mimicked the protective function when estrogen receptor α and β (ERα and ERβ) blocked by tamoxifen (TAM), while the effects was blocked by GPER1 antagonist G-15. Moreover, the TUNEL positive RGCs and GFAP expression level were both attenuated in G-1 application and the effects could be reversed by G-15. In addition, application of the PI3K/Akt antagonist LY294002 counteracted the effect of G-1. And a number of apoptosis regulatory factors decreased dramatically in the G-1 group, including Bad, Caspase 3, Caspase 7, Smad2, P-53 and TAK1. Also, similar protective effect of G-1 was spotted in acute ocular hypertension (AOH) model. CONCLUSION Estrogen played a protective role via a novel estrogen receptor, GPER1, instead of classical receptors ERα or ERβ. Activation of GPER1 attenuated RGCs apoptosis and Müller cells gliosis, indicating GPER1 as a potential treatment target in RGCs degeneration diseases.
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Affiliation(s)
- Mengnan Jiang
- Eye Center, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, 430060, Hubei, China
| | - Xueyun Ma
- Eye Center, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, 430060, Hubei, China; Urumqi City Ophthalmology and Otolaryngology Hospital, Urumqi, 830000, Xinjiang, China
| | - Qingqing Zhao
- Eye Center, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, 430060, Hubei, China
| | - Ying Li
- Eye Center, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, 430060, Hubei, China
| | - Yiqiao Xing
- Eye Center, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, 430060, Hubei, China
| | - Qinqin Deng
- Eye Center, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, 430060, Hubei, China.
| | - Yin Shen
- Eye Center, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, 430060, Hubei, China.
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10
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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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11
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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.
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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.
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12
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Bauzá-Thorbrügge M, Rodríguez-Cuenca S, Vidal-Puig A, Galmés-Pascual BM, Sbert-Roig M, Gianotti M, Lladó I, Proenza AM. GPER and ERα mediate estradiol enhancement of mitochondrial function in inflamed adipocytes through a PKA dependent mechanism. J Steroid Biochem Mol Biol 2019; 185:256-267. [PMID: 30253224 DOI: 10.1016/j.jsbmb.2018.09.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 08/31/2018] [Accepted: 09/17/2018] [Indexed: 01/16/2023]
Abstract
Obesity is associated with inflammation, dysregulated adipokine secretion, and disrupted adipose tissue mitochondrial function. Estradiol (E2) has been previously reported to increase mitochondrial function and biogenesis in several cell lines, but neither the type of oestrogen receptor (ERα, ERβ and GPER) involved nor the mechanism whereby such effects are exerted have been fully described. Considering the anti-inflammatory activity of E2 as well as its effects in enhancing mitochondrial biogenesis, the aim of this study was to investigate the contribution of ERα, ERβ, and GPER signaling to the E2-mediated enhancement of adipocyte mitochondrial function in a pro-inflammatory situation. 3T3-L1 cells were treated for 24 h with ER agonists (PPT, DPN, and G1) and antagonists (MPP, PHTPP, and G15) in the presence or absence of interleukin 6 (IL6), as a pro-inflammatory stimulus. Inflammation, mitochondrial function and biogenesis markers were analyzed. To confirm the involvement of the PKA pathway, cells were treated with a GPER agonist, a PKA inhibitor, and IL6. Mitochondrial function markers were analyzed. Our results showed that activation of ERα and GPER, but not ERβ, was able to counteract the proinflammatory effects of IL6 treatment, as well as mitochondrial biogenesis and function indicators. Inhibition of PKA prevented the E2- and G1-associated increase in mitochondrial function markers. In conclusion E2 prevents IL6 induced inflammation in adipocytes and promotes mitochondrial function through the combined activation of both GPER and ERα. These findings expand our understanding of ER interactions under inflammatory conditions in female rodent white adipose tissue.
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Affiliation(s)
- Marco Bauzá-Thorbrügge
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Palma de Mallorca, Spain; Instituto de Investigación Sanitaria Illes Balears (IdISBa), Palma de Mallorca, Spain
| | - Sergio Rodríguez-Cuenca
- Metabolic Research Laboratories, Wellcome Trust MRC-Institute of Metabolic Science, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Antonio Vidal-Puig
- Metabolic Research Laboratories, Wellcome Trust MRC-Institute of Metabolic Science, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Bel M Galmés-Pascual
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Palma de Mallorca, Spain; Instituto de Investigación Sanitaria Illes Balears (IdISBa), Palma de Mallorca, Spain
| | - Miquel Sbert-Roig
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Palma de Mallorca, Spain; Instituto de Investigación Sanitaria Illes Balears (IdISBa), Palma de Mallorca, Spain
| | - Magdalena Gianotti
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Palma de Mallorca, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y la Nutrición (CIBERobn, CB06/03/0043), Instituto de Salud Carlos III, Spain; Instituto de Investigación Sanitaria Illes Balears (IdISBa), Palma de Mallorca, Spain.
| | - Isabel Lladó
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Palma de Mallorca, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y la Nutrición (CIBERobn, CB06/03/0043), Instituto de Salud Carlos III, Spain; Instituto de Investigación Sanitaria Illes Balears (IdISBa), Palma de Mallorca, Spain
| | - Ana M Proenza
- Grup Metabolisme Energètic i Nutrició, Departament de Biologia Fonamental i Ciències de la Salut, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Universitat de les Illes Balears, Palma de Mallorca, Spain; Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y la Nutrición (CIBERobn, CB06/03/0043), Instituto de Salud Carlos III, Spain; Instituto de Investigación Sanitaria Illes Balears (IdISBa), Palma de Mallorca, Spain
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13
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Polis B, Srikanth KD, Gurevich V, Gil-Henn H, Samson AO. L-Norvaline, a new therapeutic agent against Alzheimer's disease. Neural Regen Res 2019; 14:1562-1572. [PMID: 31089055 PMCID: PMC6557086 DOI: 10.4103/1673-5374.255980] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Growing evidence highlights the role of arginase activity in the manifestation of Alzheimer’s disease (AD). Upregulation of arginase was shown to contribute to neurodegeneration. Regulation of arginase activity appears to be a promising approach for interfering with the pathogenesis of AD. Therefore, the enzyme represents a novel therapeutic target. In this study, we administered an arginase inhibitor, L-norvaline (250 mg/L), for 2.5 months to a triple-transgenic model (3×Tg-AD) harboring PS1M146V, APPSwe, and tauP301L transgenes. Then, the neuroprotective effects of L-norvaline were evaluated using immunohistochemistry, proteomics, and quantitative polymerase chain reaction assays. Finally, we identified the biological pathways activated by the treatment. Remarkably, L-norvaline treatment reverses the cognitive decline in AD mice. The treatment is neuroprotective as indicated by reduced beta-amyloidosis, alleviated microgliosis, and reduced tumor necrosis factor transcription levels. Moreover, elevated levels of neuroplasticity related postsynaptic density protein 95 were detected in the hippocampi of mice treated with L-norvaline. Furthermore, we disclosed several biological pathways, which were involved in cell survival and neuroplasticity and were activated by the treatment. Through these modes of action, L-norvaline has the potential to improve the symptoms of AD and even interferes with its pathogenesis. As such, L-norvaline is a promising neuroprotective molecule that might be tailored for the treatment of a range of neurodegenerative disorders. The study was approved by the Bar-Ilan University Animal Care and Use Committee (approval No. 82-10-2017) on October 1, 2017.
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Affiliation(s)
- Baruh Polis
- Drug Discovery Laboratory, The Azrieli Faculty of Medicine; Laboratory of Cell Migration and Invasion, The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Kolluru D Srikanth
- Laboratory of Cell Migration and Invasion, The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Vyacheslav Gurevich
- Laboratory of Cancer Personalized Medicine and Diagnostic Genomics, The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Hava Gil-Henn
- Laboratory of Cell Migration and Invasion, The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Abraham O Samson
- Drug Discovery Laboratory, The Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
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14
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Tarchick MJ, Cutler AH, Trobenter TD, Kozlowski MR, Makowski ER, Holoman N, Shao J, Shen B, Anand-Apte B, Samuels IS. Endogenous insulin signaling in the RPE contributes to the maintenance of rod photoreceptor function in diabetes. Exp Eye Res 2018; 180:63-74. [PMID: 30543793 DOI: 10.1016/j.exer.2018.11.020] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 11/19/2018] [Accepted: 11/20/2018] [Indexed: 01/01/2023]
Abstract
In diabetes, there are two major physiological aberrations: (i) Loss of insulin signaling due to absence of insulin (type 1 diabetes) or insulin resistance (type 2 diabetes) and (ii) increased blood glucose levels. The retina has a high proclivity to damage following diabetes, and much of the pathology seen in diabetic retinopathy has been ascribed to hyperglycemia and downstream cascades activated by increased blood glucose. However, less attention has been focused on the direct role of insulin on retinal physiology, likely due to the fact that uptake of glucose in retinal cells is not insulin-dependent. The retinal pigment epithelium (RPE) is instrumental in maintaining the structural and functional integrity of the retina. Recent studies have suggested that RPE dysfunction is a precursor of, and contributes to, the development of diabetic retinopathy. To evaluate the role of insulin on RPE cell function directly, we generated a RPE specific insulin receptor (IR) knockout (RPEIRKO) mouse using the Cre-loxP system. Using this mouse, we sought to determine the impact of insulin-mediated signaling in the RPE on retinal function under physiological control conditions as well as in streptozotocin (STZ)-induced diabetes. We demonstrate that loss of RPE-specific IR expression resulted in lower a- and b-wave electroretinogram amplitudes in diabetic mice as compared to diabetic mice that expressed IR on the RPE. Interestingly, RPEIRKO mice did not exhibit significant differences in the amplitude of the RPE-dependent electroretinogram c-wave as compared to diabetic controls. However, loss of IR-mediated signaling in the RPE reduced levels of reactive oxygen species and the expression of pro-inflammatory cytokines in the retina of diabetic mice. These results imply that IR-mediated signaling in the RPE regulates photoreceptor function and may play a role in the generation of oxidative stress and inflammation in the retina in diabetes.
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Affiliation(s)
- Matthew J Tarchick
- Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA; Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Alecia H Cutler
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Timothy D Trobenter
- Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA; Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Michael R Kozlowski
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Emily R Makowski
- Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA; Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Nicholas Holoman
- Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA; Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Jianning Shao
- Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Bailey Shen
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Bela Anand-Apte
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA; Department of Molecular Medicine, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Ivy S Samuels
- Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA; Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA.
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15
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Damage-associated molecular pattern recognition is required for induction of retinal neuroprotective pathways in a sex-dependent manner. Sci Rep 2018; 8:9115. [PMID: 29904087 PMCID: PMC6002365 DOI: 10.1038/s41598-018-27479-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 06/04/2018] [Indexed: 12/29/2022] Open
Abstract
Retinal degeneration is a common cause of irreversible blindness and is caused by the death of retinal light-sensitive neurons called photoreceptors. At the onset of degeneration, stressed photoreceptors cause retinal glial cells to secrete neuroprotective factors that slow the pace of degeneration. Leukemia inhibitory factor (LIF) is one such factor that is required for endogenous neuroprotection. Photoreceptors are known to release signals of cellular stress, called damage-associated molecular patterns (DAMPs) early in degeneration, and we hypothesized that receptors for DAMPs or pattern recognition receptors (PRRs) play a key role in the induction of LIF and neuroprotective stress responses in retinal glial cells. Toll-like receptor 2 (TLR2) is a well-established DAMP receptor. In our experiments, activation of TLR2 protected both male and female mice from light damage, while the loss of TLR2 in female mice did not impact photoreceptor survival. In contrast, induction of protective stress responses, microglial phenotype and photoreceptor survival were strongly impacted in male TLR2−/− mice. Lastly, using publicly available gene expression data, we show that TLR2 is expressed highly in resting microglia prior to injury, but is also induced in Müller cells in inherited retinal degeneration.
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16
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Saraceno GE, Bellini MJ, Garcia-Segura LM, Capani F. Estradiol Activates PI3K/Akt/GSK3 Pathway Under Chronic Neurodegenerative Conditions Triggered by Perinatal Asphyxia. Front Pharmacol 2018; 9:335. [PMID: 29686616 PMCID: PMC5900006 DOI: 10.3389/fphar.2018.00335] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 03/22/2018] [Indexed: 11/24/2022] Open
Abstract
Perinatal asphyxia (PA) remains as one of the most important causes of short-term mortality, psychiatric and neurological disorders in children, without an effective treatment. In previous studies we have observed that the expression of different neurodegenerative markers increases in CA1 hippocampal area of 4-months-old male rats born by cesarean section and exposed for 19 min to PA. We have also shown that a late treatment with 17β estradiol (daily dose of 250 μg/kg for 3 days) was able to revert the brain alterations observed in those animals. Based on these previous results, the main aim of the present study was to explore the mechanism by which the estrogenic treatment is involved in the reversion of the chronic neurodegenerative conditions induced by PA. We demonstrated that estradiol treatment of adult PA exposed animals induced an increase in estrogen receptor (ER) α and insulin-like growth factor receptor (IGF-1R) protein levels, an activation of the phosphatidylinositol 3-kinase/Akt/glycogen synthase kinase 3 beta/β-catenin signaling pathway and an increase in Bcl-2/Bax ratio in the hippocampus in comparison to PA exposed animals treated with vehicle. Taking together, our data suggest that the interaction between ERα and IGF-IR, with the subsequent downstream activation, underlies the beneficial effects of estradiol observed in late treatment of PA.
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Affiliation(s)
- G Ezequiel Saraceno
- Laboratorio de Citoarquitectura y Plasticidad Neuronal, Instituto de Investigaciones Cardiológicas "Prof. Dr. Alberto C. Taquini", Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina.,Interdisciplinary Institute for Neuroscience, Centre Broca Nouvelle-Aquitaine, UMR 5297, Université de Bordeaux, Bordeaux, France
| | - Maria J Bellini
- Instituto de Investigaciones Bioquímicas de La Plata, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Luis M Garcia-Segura
- Instituto Cajal, Consejo Nacional de Investigaciones Científicas y Técnicas, Madrid, Spain.,Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable, Instituto de Salud Carlos III, Madrid, Spain
| | - Francisco Capani
- Laboratorio de Citoarquitectura y Plasticidad Neuronal, Instituto de Investigaciones Cardiológicas "Prof. Dr. Alberto C. Taquini", Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina.,Universidad Autónoma de Chile, Santiago, Chile
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17
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Káldi I, Berta A. Progesterone Administration Fails to Protect Albino Male Rats against Photostress-Induced Retinal Degeneration. Eur J Ophthalmol 2018; 14:306-14. [PMID: 15309975 DOI: 10.1177/112067210401400405] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Female patients show better recovery after brain injury and lower incidence of vascular diseases before menopause. The aim of this study was to test the protective effect of female sexual hormones against photostress-induced photoreceptor apoptosis. METHODS Five week old male albino Sprague-Dawley rats were injected intraperitoneally with progesterone (60 mg/kg body weight) for 4 days. The control group was injected with the vehicle only (benzyl alcohol). Both groups were halved and one was stressed with light (2700 lux for 24 hours) and the other remained under the original dim cyclic light condition. For functional evaluation, baseline electroretinograms (ERGs) were recorded 7 days before light stress, with follow-up ERGs 5 days after the cessation of light exposure. Animals were sacrificed and their eyes enucleated for histology. RESULTS Light exposure caused pronounced decrease in the ERG a- and b-wave amplitudes compared to controls. However, in the light-stressed group, the difference in retinal function between progesterone-treated and nontreated animals was not statistically significant. The thickness of the outer nuclear layer and the length of rod outer and inner segments were significantly reduced in the light-stressed group, indicating loss of rod photoreceptor cells. Progesterone had no neuroprotective effect on rod cell structure. CONCLUSIONS The administration of progesterone did not prove to be protective against excessive light-caused retinal degeneration on male albino rats. The role of other sexual steroids and their interaction need to be clarified.
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Affiliation(s)
- I Káldi
- Department of Ophthalmology, Kenézy Hospital, Debrecen, Hungary.
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18
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Polis B, Samson AO. Arginase as a Potential Target in the Treatment of Alzheimer’s Disease. ACTA ACUST UNITED AC 2018. [DOI: 10.4236/aad.2018.74009] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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19
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Landfried B, Grimm C. Neuroprotektion geschädigter Photorezeptoren. MED GENET-BERLIN 2017. [DOI: 10.1007/s11825-017-0130-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Zusammenfassung
Der Schutz der Sehzellen durch Neuroprotektion ist ein vielversprechender Ansatz, der bei vielen degenerativen Netzhauterkrankungen entweder als Mono- oder Kombinationstherapie zum Einsatz kommen könnte. Viele neuroprotektive Substanzen wurden im Tiermodell identifiziert und erfolgreich getestet. Einige dieser Substanzen wurden auch bereits in klinischen Versuchen am Patienten untersucht, allerdings mit unterschiedlichem Erfolg. Diverse Versuchsansätze werden derzeit überprüft.
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Affiliation(s)
- Britta Landfried
- Aff1 0000 0004 0478 9977 grid.412004.3 Augenklinik Universitätsspital Zürich Zürich Schweiz
- Aff4 0000 0004 1937 0650 grid.7400.3 Labor für Zellbiologie der Netzhaut, Augenklinik Universität Zürich Wagistrasse 14 8952 Schlieren Schweiz
| | - Christian Grimm
- Aff1 0000 0004 0478 9977 grid.412004.3 Augenklinik Universitätsspital Zürich Zürich Schweiz
- Aff2 0000 0004 1937 0650 grid.7400.3 Zentrum für integrative Humanphysiologie (ZIHP) Universität Zürich Zürich Schweiz
- Aff3 0000 0004 1937 0650 grid.7400.3 Zentrum für Neurowissenschaften Zürich (ZNZ) Universität Zürich Zürich Schweiz
- Aff4 0000 0004 1937 0650 grid.7400.3 Labor für Zellbiologie der Netzhaut, Augenklinik Universität Zürich Wagistrasse 14 8952 Schlieren Schweiz
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20
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Yazğan Y, Nazıroğlu M. Ovariectomy-Induced Mitochondrial Oxidative Stress, Apoptosis, and Calcium Ion Influx Through TRPA1, TRPM2, and TRPV1 Are Prevented by 17β-Estradiol, Tamoxifen, and Raloxifene in the Hippocampus and Dorsal Root Ganglion of Rats. Mol Neurobiol 2016; 54:7620-7638. [PMID: 27832523 DOI: 10.1007/s12035-016-0232-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 10/16/2016] [Indexed: 01/12/2023]
Abstract
Relative 17β-estradiol (E2) deprivation and excessive production of mitochondrial oxygen free radicals (OFRs) with a high amount of Ca2+ influx TRPA1, TRPM2, and TRPV1 activity is one of the main causes of neurodegenerative disease in postmenopausal women. In addition to the roles of tamoxifen (TMX) and raloxifene (RLX) in cancer and bone loss treatments, regulator roles in Ca2+ influx and mitochondrial oxidative stress in neurons have not been reported. The aim of this study was to evaluate whether TMX and RLX interactions with TRPA1, TRPM2, and TRPV1 in primary hippocampal (HPC) and dorsal root ganglion (DRG) neuron cultures of ovariectomized (OVX) rats. Forty female rats were divided into five groups: a control group, an OVX group, an OVX+E2 group, an OVX+TMX group, and an OVX+RLX group. The OVX+E2, OVX+TMX, and OVX+RLX groups received E2, TMX, and RLX, respectively, for 14 days after the ovariectomy. E2, ovariectomy-induced TRPA1, TRPM2, and TRPV1 current densities, as well as accumulation of cytosolic free Ca2+ in the neurons, were returned to the control levels by E2, TMX, and RLX treatments. In addition, E2, TMX, and RLX via modulation of TRPM2 and TRPV1 activity reduced ovariectomy-induced mitochondrial membrane depolarization, apoptosis, and cytosolic OFR production. TRPM2, TRPV1, PARP, and caspase-3 and caspase-9 expressions were also decreased in the neurons by the E2, TMX, and RLX treatments. In conclusion, we first reported the molecular effects of E2, TMX, and RLX on TRPA1, TRPM2, and TRPV1 channel activation in the OVX rats. In addition, we observed neuroprotective effects of E2, RLX, and TMX on oxidative and apoptotic injuries of the hippocampus and peripheral pain sensory neurons (DRGs) in the OVX rats. Graphical Abstract Possible molecular pathways of involvement of DEX in cerebral ischemia-induced apoptosis, oxidative stress, and calcium accumulation through TRPA1, TRPM2 and TRPV1 in the hippocampus and DRG neurons of rats. The N domain of the TRPM2 contains ADP-ribose (ADPR) pyrophosphate enzyme, which is separately activated by ADPR and oxidative stress, although the channel is reversibly inhibited by N-(p-amylcinnamoyl) anthranilic acid (ACA). The TRPV1 is also activated by mitochondrial oxidative stress and capsaicin, and it is blocked by capsazepine (CPZ). TRPA1 is also activated by oxidative stress it is inhibited by AP18. Increased cytosolic Ca2+ concentration through TRPA1, TRPM2 and TRPV1 in ovariectomized (OVX) rats may lead to neuronal toxicity, reactive oxygen species (ROS) processes, and eventual cell death. 17β-Estradiol (E2), tamoxifen (TMX), and raloxifene (RLX) reduced oxidative stress, apoptosis (including caspase-3 and caspase-9), mitochondrial membrane depolarization, and Ca2+ influx through the inhibition of TRPA1, TRPM2 and TRPV1 activation.
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Affiliation(s)
- Yener Yazğan
- Department of Biophysics, Institute of Health Science, Suleyman Demirel University, Isparta, Turkey
| | - Mustafa Nazıroğlu
- Department of Biophysics, Institute of Health Science, Suleyman Demirel University, Isparta, Turkey.
- Neuroscience Research Center, University of Suleyman Demirel, Isparta, Turkey.
- Nörolojik Bilimler Uygulama ve Araştırma Merkezi Müdürü, Süleyman Demirel Üniversitesi, TR 32260, Isparta, Turkey.
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21
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Li H, Zhu C, Wang B, Zhu W, Feng Y, Du F, Wang S, Hu C, Ma J, Yu X. 17β-Estradiol Protects the Retinal Nerve Cells Suppressing TLR2 Mediated Immune-Inflammation and Apoptosis from Oxidative Stress Insult Independent of PI3K. J Mol Neurosci 2016; 60:195-204. [PMID: 27596287 DOI: 10.1007/s12031-016-0794-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 06/30/2016] [Indexed: 01/04/2023]
Affiliation(s)
- Hongbo Li
- The Department of Biochemistry and Molecular Biology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China
- The Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Xi'an Medical University, Xi'an, Shaanxi, 710021, China
| | - Chunhui Zhu
- The Department of Biochemistry and Molecular Biology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China
| | - Baoying Wang
- The Department of Biochemistry and Molecular Biology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China
| | - Wenhua Zhu
- The Department of Biochemistry and Molecular Biology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China
| | - Yan Feng
- The Department of Biochemistry and Molecular Biology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China
| | - Fangying Du
- The Department of Biochemistry and Molecular Biology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China
| | - Shaolan Wang
- The Department of Biochemistry and Molecular Biology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China
| | - Chenghu Hu
- The Department of Biochemistry and Molecular Biology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China
| | - Jie Ma
- The Department of Biochemistry and Molecular Biology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China
| | - Xiaorui Yu
- The Department of Biochemistry and Molecular Biology, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China.
- The Department of Biochemistry and Molecular Biology, The Environment and Genes Related to Diseases Key Laboratory of Education Ministry, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, 710061, China.
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22
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Kong L, Liu B, Zhang C, Wang B, Wang H, Song X, Yang Y, Ren X, Yin L, Kong H, Ma H. The therapeutic potential of sulforaphane on light-induced photoreceptor degeneration through antiapoptosis and antioxidant protection. Neurochem Int 2016; 100:52-61. [PMID: 27567738 DOI: 10.1016/j.neuint.2016.08.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 08/18/2016] [Accepted: 08/23/2016] [Indexed: 01/26/2023]
Abstract
Oxidative stress due to excessive light exposure can exacerbate a variety of human retinal diseases by accelerating photoreceptor cell death. The thioredoxin (Trx) system is considered to play a crucial role in reduction/oxidation (redox) regulation of signal transduction and in cell defense against oxidative stresses. Sulforaphane (SF) protects cells from oxidative damage through nuclear factor (erythroid-derived 2)-like 2 (Nrf2), which is responsible for multiple detoxification processes, including elevating the expression of Trx. This study sought to demonstrate whether SF increased Trx expression in retinal tissues in vivo and whether it could preserve the photoreceptors from degeneration induced by oxidative stress. Our data clearly showed that pretreatment with SF abated photoreceptor cell loss, in association with increased expression of Nrf2 and Trx, subsequently activating the Ras/Raf1/Erk signaling pathway and decreasing the expression of Bak1, Cyt-c release and the activity of caspase-3 in light-induced mouse retinas. These data suggested that the therapeutic potential of SF in retinal degeneration due to oxidative stress might partially involve anti-caspase and antioxidant protection mediated by Trx.
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Affiliation(s)
- Li Kong
- Department of Histoembryology of Dalian Medical University, 116044, Dalian, Liaoning, China
| | - Bo Liu
- Department of Histoembryology of Dalian Medical University, 116044, Dalian, Liaoning, China
| | - Chenghong Zhang
- Department of Histoembryology of Dalian Medical University, 116044, Dalian, Liaoning, China
| | - Bing Wang
- Department of Histoembryology of Dalian Medical University, 116044, Dalian, Liaoning, China
| | - Hongfei Wang
- Department of Histoembryology of Dalian Medical University, 116044, Dalian, Liaoning, China
| | - Xiaoxia Song
- Department of Histoembryology of Dalian Medical University, 116044, Dalian, Liaoning, China
| | - Yang Yang
- Department of Histoembryology of Dalian Medical University, 116044, Dalian, Liaoning, China
| | - Xiang Ren
- Department of Histoembryology of Dalian Medical University, 116044, Dalian, Liaoning, China
| | - Liangwei Yin
- Department of Oncology, Dalian Central Hospital, 116033, Dalian, Liaoning, China
| | - Hui Kong
- Department of Otorhinolaryngology, The Second Hospital of Dalian Medical University, 116023, Dalian, Liaoning, China.
| | - Haiying Ma
- Department of Histoembryology of Dalian Medical University, 116044, Dalian, Liaoning, China.
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Yazğan B, Yazğan Y, Övey İS, Nazıroğlu M. Raloxifene and Tamoxifen Reduce PARP Activity, Cytokine and Oxidative Stress Levels in the Brain and Blood of Ovariectomized Rats. J Mol Neurosci 2016; 60:214-22. [PMID: 27372663 DOI: 10.1007/s12031-016-0785-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 06/21/2016] [Indexed: 01/14/2023]
Abstract
It is well known that 17β-estradiol (E2) has an antioxidant role on neurological systems in the brain. Raloxifene (RLX) and tamoxifen (TMX) are selective estrogen receptor modulators. An E2 deficiency stimulates mitochondrial functions for promoting apoptosis and increasing reactive oxygen species (ROS) production. However, RLX and TMX may reduce the mitochondrial ROS production via their antioxidant properties in the brain and erythrocytes of ovariectomized (OVX) rats. We aimed to investigate the effects of E2, RLX, and TMX on oxidative stress, apoptosis, and cytokine production in the brain and erythrocytes of OVX rats.Forty female rats were divided into five groups. The first group was used as a control group. The second group was the OVX group. The third, fourth, and fifth groups were OVX + E2, OVX + TMX, and OVX + RLX groups, respectively. E2, TMX, and RLX were given subcutaneously to the OVX + E2 and OVX + TMX, OVX + RLX groups for 14 days after the ovariectomy respectively.While brain and erythrocyte lipid peroxidation levels were high in the OVX group, they were low in the OVX + E2, OVX + RLX, and OVX + TMX groups. OVX + E2, OVX + RLX, and OVX + TMX treatments increased the lowered glutathione peroxidase activity in erythrocytes and the brain and reduced glutathione and vitamin E concentrations in the brain. β-carotene and vitamin A concentrations in the brain and TNF-α and interleukin (IL)-1β levels in the plasma of the five groups were not significantly changed by the treatments. However, increased plasma IL-4 levels and Western blot results for brain poly (ADP-ribose) polymerase (PARP) in the OVX groups were decreased by E2, TMX, and RLX treatments, although proapoptotic procaspase 3 and 9 activities were increased by the treatments.In conclusion, we observed that E2, RLX, and TMX administrations were beneficial on oxidative stress, inflammation, and PARP levels in the serum and brain of OVX rats by modulating antioxidant systems, DNA damage, and cytokine production.
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Affiliation(s)
- Betül Yazğan
- Department of Physiology, Medical Faculty, Adıyaman University, Adıyaman, Turkey
| | - Yener Yazğan
- Department of Biophysics, Medical Faculty, Suleyman Demirel University, Isparta, Turkey
| | - İshak Suat Övey
- Department of Biophysics, Medical Faculty, Suleyman Demirel University, Isparta, Turkey
| | - Mustafa Nazıroğlu
- Department of Biophysics, Medical Faculty, Suleyman Demirel University, Isparta, Turkey. .,Neuroscience Research Center, Suleyman Demirel University, Isparta, Turkey.
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Rajala RV, Kanan Y, Anderson RE. Photoreceptor Neuroprotection: Regulation of Akt Activation Through Serine/Threonine Phosphatases, PHLPP and PHLPPL. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:419-24. [DOI: 10.1007/978-3-319-17121-0_55] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Mangan G, Iqbal S, Hubbard A, Hamilton V, Bombardier E, Tiidus PM. Delay in post-ovariectomy estrogen replacement negates estrogen-induced augmentation of post-exercise muscle satellite cell proliferation. Can J Physiol Pharmacol 2015; 93:945-51. [PMID: 26406298 DOI: 10.1139/cjpp-2015-0106] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study examined the effects of a delay in post-ovariectomy replacement of 17β-estradiol (estrogen) on the post-exercise proliferation of muscle satellite cells. Nine-week-old, ovariectomized, female Sprague-Dawley rats (n = 64) were distributed among 8 groups based on estrogen status (0.25 mg estrogen pellet or sham), exercise status (90 min run at 17 m·min(-1) and a grade of -13.5° or unexercised), and estrogen replacement ("proximal", estrogen replacement within 2 weeks; or "delayed", estrogen replacement at 11 weeks following ovariectomy). Significant increases in satellite cells were found in the soleus and white gastrocnemius muscle (immunofluorescent colocalization of nuclei with Pax7) 72 h following eccentric exercise (p < 0.05) in all exercised groups. Proximal E2 replacement resulted in a further augmentation of muscle satellite cells in exercised rats (p < 0.05) relative to the delayed estrogen replacement group. Expression of PI3K was unaltered and phosphorylation of Akt relative to total Akt increased following estrogen supplementation and exercise. Exercise alone did not alter the expression levels of Akt. An 11 week delay in post-ovariectomy estrogen replacement negated the augmenting influence seen with proximal (2 week delay) post-ovariectomy estrogen replacement on post-exercise muscle satellite cell proliferation. This effect appears to be independent of the PI3K-Akt signaling pathway.
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Affiliation(s)
- Gary Mangan
- a Departments of Kinesiology & Physical Education and Health Sciences, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada
| | - Sobia Iqbal
- a Departments of Kinesiology & Physical Education and Health Sciences, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada
| | - Andrew Hubbard
- a Departments of Kinesiology & Physical Education and Health Sciences, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada
| | - Victoria Hamilton
- a Departments of Kinesiology & Physical Education and Health Sciences, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada
| | - Eric Bombardier
- b Department of Kinesiology, University of Waterloo, Waterloo, ON N2L 3C5, Canada
| | - Peter M Tiidus
- a Departments of Kinesiology & Physical Education and Health Sciences, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada
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Song Z, Han S, Pan X, Gong Y, Wang M. Pterostilbene mediates neuroprotection against oxidative toxicity via oestrogen receptor α signalling pathways. J Pharm Pharmacol 2015; 67:720-30. [DOI: 10.1111/jphp.12360] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 11/02/2014] [Indexed: 01/09/2023]
Abstract
Abstract
Objectives
Accumulating evidence indicated protective role of phytoestrogens against neuronal damage induced by various insults, such as amyloid beta, oxygen deprivation and mitochondrial toxins. Hydrogen peroxide (H2O2) influences the mitochondrial membrane potential, which eventually results in cell apoptosis. In this study, we investigated the effects and possible mechanisms of a phytoestrogen, pterostilbene (PTER), in cell apoptosis induced by H2O2 in human neuronal SH-SY5Y cells. We also analysed the involvement of oestrogen receptors, oestrogen receptor-α and -β (ER-α and ER-β) in the protective role of PTER.
Methods
The effects of PTER on H2O2-stimulated cell were examined using MTT and FACS analysis. The signal pathways and estrogen receptors involved in PTER's effects were investigated using MTT and Western blot analysis.
Key findings
The results showed that H2O2 treatment significantly reduced cell viability in SY5Y cells, which was protected by PTER treatment. We also found that H2O2 inhibited the PI3K/AKT and MAPK/ERK signalling pathways, whereas PTER treatment restored these signalling pathways. We also found that the PTER effect could be largely blocked by an ER-α antagonist, 3-Bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy)phenol]-1H-pyrazole dihydrochloride (MPP), but not by an ER-β antagonist, 4-[2-Phenyl-5,7-bis(trifluoromethyl)pyrazolo[1,5-a] pyrimidin-3-yl]phenol (PHTPP), suggesting that ER-α is a major player in the neuroprotective activity of PTER.
Conclusion
Our study thus demonstrates that PTER is an effective neuroprotective agent presumably through ER-α-mediated signalling pathways.
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Affiliation(s)
- Zhen Song
- Department of Genetics, Key Laboratory for Experimental Teratology of the Ministry of Education, Shandong University, Jinan, Shandong, China
| | - Shuai Han
- Department of Genetics, Key Laboratory for Experimental Teratology of the Ministry of Education, Shandong University, Jinan, Shandong, China
| | - Xiaohua Pan
- Department of Breast and Thyroid Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, China
| | - Yaoqin Gong
- Department of Genetics, Key Laboratory for Experimental Teratology of the Ministry of Education, Shandong University, Jinan, Shandong, China
| | - Molin Wang
- Department of Genetics, Key Laboratory for Experimental Teratology of the Ministry of Education, Shandong University, Jinan, Shandong, China
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Abstract
Although photoreceptors account for most of the mass and metabolic activity of the retina, their role in the pathogenesis of diabetic retinopathy has been largely overlooked. Recent studies suggest that photoreceptors might play a critical role in the diabetes-induced degeneration of retinal capillaries, and thus can no longer be ignored. The present review summarizes diabetes-induced alterations in photoreceptor structure and function, and provides a rationale for further study of a role of photoreceptors in the pathogenesis of the retinopathy.
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Affiliation(s)
- Timothy S Kern
- Case Western Reserve University, Department of Medicine and Center for Diabetes Research Cleveland, Ohio, USA ; Veterans Administration Medical Center Research Service 151 Cleveland, Ohio, USA
| | - Bruce A Berkowitz
- Wayne State University School of Medicine, Departments of Anatomy and Cell Biology and Ophthalmology Detroit, Michigan, USA
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Rao YK, Shih HN, Lee YC, Cheng WT, Hung HC, Wang HC, Chen CJ, Tzeng YM, Lee MJ. Purification of kavalactones from Alpinia zerumbet and their protective actions against hydrogen peroxide-induced cytotoxicity in PC12 cells. J Biosci Bioeng 2014; 118:679-88. [DOI: 10.1016/j.jbiosc.2014.05.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 05/12/2014] [Accepted: 05/13/2014] [Indexed: 12/11/2022]
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Benmansour S, Privratsky AA, Adeniji OS, Frazer A. Signaling mechanisms involved in the acute effects of estradiol on 5-HT clearance. Int J Neuropsychopharmacol 2014; 17:765-77. [PMID: 24423185 PMCID: PMC3969768 DOI: 10.1017/s146114571300165x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Estradiol was found previously to have an antidepressant-like effect and to block the ability of selective serotonin reuptake inhibitors (SSRIs) to have an antidepressant-like effect. The antidepressant-like effect of estradiol was due to estrogen receptor β (ERβ) and/or GPR30 activation, whereas estradiol's blockade of the effect of an SSRI was mediated by ERα. This study focuses on investigating signaling pathways as well as interacting receptors associated with these two effects of estradiol. In vivo chronoamperometry was used to measure serotonin transporter (SERT) function. The effect of local application of estradiol or selective agonists for ERα (PPT) or ERβ (DPN) into the CA3 region of the hippocampus of ovariectomized (OVX) rats on 5-hydroxytryptamine (5-HT) clearance as well as on the ability of fluvoxamine to slow 5-HT clearance was examined after selective blockade of signaling pathways or that of interacting receptors. Estradiol- or DPN-induced slowing of 5-HT clearance mediated by ERβ was blocked after inhibition of MAPK/ERK1/2 but not of PI3K/Akt signaling pathways. This effect also involved interactions with TrkB, and IGF-1 receptors. Estradiol's or PPT's inhibition of the fluvoxamine-induced slowing of 5-HT clearance mediated by ERα, was blocked after inhibition of either MAPK/ERK1/2 or PI3K/Akt signaling pathways. This effect involved interactions with the IGF-1 receptor and with the metabotropic glutamate receptor 1, but not with TrkB. This study illustrates some of the signaling pathways required for the effects of estradiol on SERT function, and particularly shows that ER subtypes elicit different as well as common signaling pathways for their actions.
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Affiliation(s)
- Saloua Benmansour
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, Texas 78229
| | - Anthony A. Privratsky
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, Texas 78229
| | - Opeyemi S. Adeniji
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, Texas 78229
| | - Alan Frazer
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, Texas 78229
- South Texas Veterans Health Care System, San Antonio, Texas 78284, USA
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31
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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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32
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Ishihara Y, Fujitani N, Kawami T, Adachi C, Ishida A, Yamazaki T. Suppressive effects of 17β-estradiol on tributyltin-induced neuronal injury via Akt activation and subsequent attenuation of oxidative stress. Life Sci 2014; 99:24-30. [PMID: 24486302 DOI: 10.1016/j.lfs.2014.01.061] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 12/19/2013] [Accepted: 01/13/2014] [Indexed: 11/24/2022]
Abstract
AIMS Neuroactive steroids are reported to protect neurons from various harmful compounds; however, the protective mechanisms remain largely unclear. In this study, we examined the suppressive effects of 17β-estradiol (E2) on tributyltin (TBT)-induced neurotoxicity. MAIN METHODS Organotypic hippocampal slices were prepared from neonatal rats and then cultured. Cell death was assayed by propidium iodide uptake. Levels of reactive oxygen species (ROS) were determined by dihydroethidium staining. Protein phosphorylation was evaluated by immunoblotting. KEY FINDINGS Pretreatment of the slices with E2 dose-dependently attenuated the neuronal injury induced by TBT. An estrogen receptor antagonist, ICI182,780 abrogated these neuroprotective effects. The de novo protein synthesis inhibitors actinomycin D and cycloheximide showed no effects on the neuroprotective mechanism, indicating that a nongenomic pathway acting via the estrogen receptor may be involved in the neuroprotection conferred by E2. E2 suppressed the ROS production and lipid peroxidation induced by TBT, and these effects were almost completely canceled by ICI182,780. TBT decreased Akt phosphorylation, and this reduction was suppressed by E2. An Akt inhibitor, triciribine, attenuated the decreases in both the ROS production and neuronal injury mediated by E2. SIGNIFICANCE E2 enhances the phosphorylation of Akt, thereby attenuating the oxidative stress and subsequent neuronal injury induced by TBT.
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Affiliation(s)
- Yasuhiro Ishihara
- Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan.
| | - Noriko Fujitani
- Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan
| | - Tomohito Kawami
- Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan
| | - Chika Adachi
- Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan
| | - Atsuhiko Ishida
- Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan
| | - Takeshi Yamazaki
- Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan
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Al-Rahbi B, Zakaria R, Othman Z, Hassan A, Mohd Ismail ZI, Muthuraju S. Tualang honey supplement improves memory performance and hippocampal morphology in stressed ovariectomized rats. Acta Histochem 2014; 116:79-88. [PMID: 23810156 DOI: 10.1016/j.acthis.2013.05.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Revised: 05/13/2013] [Accepted: 05/16/2013] [Indexed: 01/07/2023]
Abstract
Recently, our research team has reported that Tualang honey was able to improve immediate memory in postmenopausal women comparable with that of estrogen progestin therapy. Therefore the aim of the present study was to examine the effects of Tualang honey supplement on hippocampal morphology and memory performance in ovariectomized (OVX) rats exposed to social instability stress. Female Sprague-Dawley rats were divided into six groups: (i) sham-operated controls, (ii) stressed sham-operated controls, (iii) OVX rats, (iv) stressed OVX rats, (v) stressed OVX rats treated with 17β-estradiol (E2), and (vi) stressed OVX rats treated with Tualang honey. These rats were subjected to social instability stress procedure followed by novel object recognition (NOR) test. Right brain hemispheres were subjected to Nissl staining. The number and arrangement of pyramidal neurons in regions of CA1, CA2, CA3 and the dentate gyrus (DG) were recorded. Two-way ANOVA analyses showed significant interactions between stress and OVX in both STM and LTM test as well as number of Nissl-positive cells in all hippocampal regions. Both E2 and Tualang honey treatments improved both short-term and long-term memory and enhanced the neuronal proliferation of hippocampal CA2, CA3 and DG regions compared to that of untreated stressed OVX rats.
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Affiliation(s)
- Badriya Al-Rahbi
- Department of Physiology, School of Medical Sciences, Universiti Sains Malaysia Health Campus, 16150 Kubang Kerian, Malaysia
| | - Rahimah Zakaria
- Department of Physiology, School of Medical Sciences, Universiti Sains Malaysia Health Campus, 16150 Kubang Kerian, Malaysia.
| | - Zahiruddin Othman
- Department of Psychiatry, School of Medical Sciences, Universiti Sains Malaysia Health Campus, 16150 Kubang Kerian, Malaysia
| | - Asma Hassan
- Department of Anatomy, School of Medical Sciences, Universiti Sains Malaysia Health Campus, 16150 Kubang Kerian, Malaysia
| | - Zul Izhar Mohd Ismail
- Department of Anatomy, School of Medical Sciences, Universiti Sains Malaysia Health Campus, 16150 Kubang Kerian, Malaysia
| | - Sangu Muthuraju
- Department of Neuroscience, School of Medical Sciences, Universiti Sains Malaysia Health Campus, 16150 Kubang Kerian, Malaysia
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Feng Y, Wang B, Du F, Li H, Wang S, Hu C, Zhu C, Yu X. The involvement of PI3K-mediated and L-VGCC-gated transient Ca2+ influx in 17β-estradiol-mediated protection of retinal cells from H2O2-induced apoptosis with Ca2+ overload. PLoS One 2013; 8:e77218. [PMID: 24223708 PMCID: PMC3818527 DOI: 10.1371/journal.pone.0077218] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 09/02/2013] [Indexed: 12/13/2022] Open
Abstract
Intracellular calcium concentration ([Ca2+]i) plays an important role in regulating most cellular processes, including apoptosis and survival, but its alterations are different and complicated under diverse conditions. In this study, we focused on the [Ca2+]i and its control mechanisms in process of hydrogen peroxide (H2O2)-induced apoptosis of primary cultured Sprague-Dawley (SD) rat retinal cells and 17β-estradiol (βE2) anti-apoptosis. Fluo-3AM was used as a Ca2+ indicator to detect [Ca2+]i through fluorescence-activated cell sorting (FACS), cell viability was assayed using MTT assay, and apoptosis was marked by Hoechst 33342 and annexin V/Propidium Iodide staining. Besides, PI3K activity was detected by Western blotting. Results showed: a) 100 μM H2O2-induced retinal cell apoptosis occurred at 4 h after H2O2 stress and increased in a time-dependent manner, but [Ca2+]i increased earlier at 2 h, sustained to 12 h, and then recovered at 24 h after H2O2 stress; b) 10 μM βE2 treatment for 0.5-24 hrs increased cell viability by transiently increasing [Ca2+]i, which appeared only at 0.5 h after βE2 application; c) increased [Ca2+]i under 100 µM H2O2 treatment for 2 hrs or 10 µM βE2 treatment for 0.5 hrs was, at least partly, due to extracellular Ca2+ stores; d) importantly, the transiently increased [Ca2+]i induced by 10 µM βE2 treatment for 0.5 hrs was mediated by the phosphatidylinositol-3-kinase (PI3K) and gated by the L-type voltage-gated Ca2+ channels (L-VGCC), but the increased [Ca2+]i induced by 100 µM H2O2 treatment for 2 hrs was not affected; and e) pretreatment with 10 µM βE2 for 0.5 hrs effectively protected retinal cells from apoptosis induced by 100 µM H2O2, which was also associated with its transient [Ca2+]i increase through L-VGCC and PI3K pathway. These findings will lead to better understanding of the mechanisms of βE2-mediated retinal protection and to exploration of the novel therapeutic strategies for retina degeneration.
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Affiliation(s)
- Yan Feng
- Department of Genetics and Molecular Biology, School of Medicine, Xi’an Jiaotong University, Xi’an, China
| | - Baoying Wang
- Department of Genetics and Molecular Biology, School of Medicine, Xi’an Jiaotong University, Xi’an, China
| | - Fangying Du
- Department of Genetics and Molecular Biology, School of Medicine, Xi’an Jiaotong University, Xi’an, China
| | - Hongbo Li
- Department of Genetics and Molecular Biology, School of Medicine, Xi’an Jiaotong University, Xi’an, China
| | - Shaolan Wang
- Department of Genetics and Molecular Biology, School of Medicine, Xi’an Jiaotong University, Xi’an, China
| | - Chenghu Hu
- Department of Genetics and Molecular Biology, School of Medicine, Xi’an Jiaotong University, Xi’an, China
| | - Chunhui Zhu
- Department of Genetics and Molecular Biology, School of Medicine, Xi’an Jiaotong University, Xi’an, China
| | - Xiaorui Yu
- Department of Genetics and Molecular Biology, School of Medicine, Xi’an Jiaotong University, Xi’an, China
- Key Laboratory of Environment-and-Gene Related Diseases of the Ministry of Education, School of Medicine, Xi’an Jiaotong University, Xi’an, China
- * E-mail:
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Li J, Wu H, Xue G, Wang P, Hou Y. 17β-Oestradiol Protects Primary-Cultured Rat Cortical Neurons from Ketamine-Induced Apoptosis by Activating PI3K/Akt/Bcl-2 Signalling. Basic Clin Pharmacol Toxicol 2013; 113:411-8. [PMID: 23981522 DOI: 10.1111/bcpt.12124] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 08/12/2013] [Indexed: 12/30/2022]
Affiliation(s)
- Jianli Li
- Hebei Medical University; Shijiazhuang Hebei Province China
- Hebei General Hospital; Shijiazhuang Hebei Province China
| | - Honghai Wu
- Department of Pharmacy; Bethune International Peace Hospital of Chinese PLA; Shijiazhuang Hebei Province China
| | - Gai Xue
- Department of Pharmacy; Bethune International Peace Hospital of Chinese PLA; Shijiazhuang Hebei Province China
| | - Pei Wang
- Hebei General Hospital; Shijiazhuang Hebei Province China
| | - Yanning Hou
- Hebei Medical University; Shijiazhuang Hebei Province China
- Department of Pharmacy; Bethune International Peace Hospital of Chinese PLA; Shijiazhuang Hebei Province China
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36
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Rajala A, Dilly AK, Rajala RV. Protein tyrosine phosphatase-1B regulates the tyrosine phosphorylation of the adapter Grb2-associated binder 1 (Gab1) in the retina. Cell Commun Signal 2013; 11:20. [PMID: 23521888 PMCID: PMC3637500 DOI: 10.1186/1478-811x-11-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 03/19/2013] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Gab1 (Grb2-associated binder 1) is a key coordinator that belongs to the insulin receptor substrate-1 like family of adaptor molecules and is tyrosine phosphorylated in response to various growth factors, cytokines, and numerous other molecules. Tyrosine phosphorylated Gab1 is able to recruit a number of signaling effectors including PI3K, SHP2 and PLC-γ. In this study, we characterized the localization and regulation of tyrosine phosphorylation of Gab1 in the retina. RESULTS Our immuno localization studies suggest that Gab1 is expressed in rod photoreceptor inner segments. We found that hydrogen peroxide activates the tyrosine phosphorylation of Gab1 ex vivo and hydrogen peroxide has been shown to inhibit the protein tyrosine phosphatase PTP1B activity. We found a stable association between the D181A substrate trap mutant of PTP1B and Gab1. Our studies suggest that PTP1B interacts with Gab1 through Tyrosine 83 and this residue may be the major PTP1B target residue on Gab1. We also found that Gab1 undergoes a light-dependent tyrosine phosphorylation and PTP1B regulates the phosphorylation state of Gab1. Consistent with these observations, we found an enhanced Gab1 tyrosine phosphorylation in PTP1B deficient mice and also in retinas treated ex vivo with a PTP1B specific allosteric inhibitor. CONCLUSIONS Our laboratory has previously reported that retinas deficient of PTP1B are resistant to light damage compared to wild type mice. Since Gab1 is negatively regulated by PTP1B, a part of the retinal neuroprotective effect we have observed previously in PTP1B deficient mice could be contributed by Gab1 as well. In summary, our data suggest that PTP1B regulates the phosphorylation state of retinal Gab1 in vivo.
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Affiliation(s)
- Ammaji Rajala
- Departments of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
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17β-estradiol impedes Bax-involved mitochondrial apoptosis of retinal nerve cells induced by oxidative damage via the phosphatidylinositol 3-kinase/Akt signal pathway. J Mol Neurosci 2013; 50:482-93. [PMID: 23361188 DOI: 10.1007/s12031-013-9968-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2012] [Accepted: 01/15/2013] [Indexed: 01/17/2023]
Abstract
Oxidative stress leading to retinal nerve cells (RNCs) apoptosis is a major cause of neurodegenerative disorders of the retina. 17β-Estradiol (E2) has been suggested to be a neuroprotective agent in the central nervous system; however, at present, the underlying mechanisms are not well understood, and the related research on the RNCs is less reported. Here, in order to investigate the protective role and mechanism of E2 against oxidative stress-induced damage on RNCs, the transmission electron microscopy and annexin V-FITC/propidium iodide assay were applied to detect the RNCs apoptosis. Western blot and real-time PCR were used to determine the expression of the critical molecules in Bcl-2 and caspase family associated with apoptosis. The transmission electron microscopy results showed that H(2)O(2) could induce typical features of apoptosis in RNCs, including formation of the apoptosome. E2 could, however, suppress the H(2)O(2)-induced morphological changes of apoptosis. Intriguingly, we observed E2-mediated phagocytic scavenging of apoptosome. In response to H(2)O(2)-induced apoptosis, Bax, acting as one of the pivotal pro-apoptotic members of Bcl-2 family, increased significantly, which directly resulted in an increased ratio of Bax to anti-apoptotic protein Bcl-2 (Bax/Bcl-2). Additionally, caspases 9 and 3, which are the critical molecules of the mitochondrial apoptosis pathway, were activated by H(2)O(2). In contrast, E2 exerted anti-apoptotic effects by reducing the expression of Bax to decrease the ratio of Bax/Bcl-2 and impeded the caspases 9/3 activation. Moreover, LY294002, a phosphatidylinositol 3-kinase (PI3K) inhibitor, could sharply block the effect of E2 in reducing the percentage of apoptotic cells resistance to H(2)O(2). And the attenuation of Bax, the reduced activities of caspases 9/3 and the impeded release of mitochondrial cytochrome c mediated by E2 resistance to H(2)O(2) damage were significantly retrieved by LY294002 administration. Taken together, E2 protects the RNCs against H(2)O(2)-induced apoptosis by significantly inhibiting the Bax-involved mitochondrial apoptosis via the activation of PI3K/Akt signal pathway.
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PI3K/Akt and NF-κB activation following intravitreal administration of 17β-estradiol: Neuroprotection of the rat retina from light-induced apoptosis. Neuroscience 2013; 228:1-12. [DOI: 10.1016/j.neuroscience.2012.10.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 09/30/2012] [Accepted: 10/01/2012] [Indexed: 11/23/2022]
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Chen CS, Tseng YT, Hsu YY, Lo YC. Nrf2-Keap1 antioxidant defense and cell survival signaling are upregulated by 17β-estradiol in homocysteine-treated dopaminergic SH-SY5Y cells. Neuroendocrinology 2013; 97:232-41. [PMID: 22948038 DOI: 10.1159/000342692] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 08/09/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND AND AIMS A recent neuroimaging study discovered the neurotoxicity effects of homocysteine (Hcy), which is only seen in elderly women. Estrogens exert a variety of actions on brain function that influence cognitive function, mood, and neuroprotection. The Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant defense pathway has been well-known to afford neuroprotection. Here, we first demonstrate the roles of Nrf2-Keap1 in 17β-estradiol (E2) cytoprotection and Hcy toxicity and the protective mechanisms of E2 on Hcy cytotoxicity in human dopaminergic SH-SY5Y cells. METHODS Cell viability was determined by trypan blue method. Protein expression was determined by Western blot analysis. Superoxide dismutase (SOD) activity was determined by ELISA. Reactive oxygen species (ROS) production was determined by flow cytometry. RESULTS In Hcy-treated SH-SY5Y cells, E2 increased cell viability, attenuated ROS production, activated Akt signaling and inhibited glycogen synthase kinase-3β (GSK-3β), a kinase known to participate in neurodegeneration. Moreover, E2 treatment led to Nrf2 dissociation from Keap1, the main negative regulator of Nrf2 activity in the cytoplasm, and increased the protein level of Nrf2 in the nucleus, with a significant increase in HO-1 expression and SOD activity in Hcy-treated cells. E2-induced Nrf2 activation was attenuated by the PI3K inhibitor LY294002 and the estrogen receptor antagonist ICI 182,780. Further, E2 decreased Hcy-induced apoptotic death by upregulating the antiapoptotic protein Bcl-2, decreasing cytochrome c release from mitochondria, and attenuating apoptotic cascade activation (Bax, caspase-9, and caspase-3). CONCLUSION E2 activates cell survival signaling and Nrf2-Keap1 antioxidant defense pathway and attenuates Hcy cytotoxicity.
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Affiliation(s)
- Cheng-Sheng Chen
- Department of Psychiatry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan, ROC
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Basavarajappa DK, Gupta VK, Rajala RVS. Protein tyrosine phosphatase 1B: a novel molecular target for retinal degenerative diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 723:829-34. [PMID: 22183413 DOI: 10.1007/978-1-4614-0631-0_106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Protein tyrosine phosphatase 1B (PTP1B) is considered as a major negative regulator of insulin receptor (IR) signaling. IR signaling in retina has been demonstrated to be neuroprotective. Photoreceptor specific deletion of PTP1B results in enhanced retinal IR-mediated neuroprotection indicating the importance of PTP1B as a negative regulator in the retina. Elevated levels of retinal PTP1B activity has been observed in mice lacking retinal pigment epithelium (Rpe65-/-), a mouse model of leber congenital amaurosis (LCA-type 2), retinitis pigmentosa and diabetic retinopathy animal models. This enhanced PTP1B activity could down regulate the IR signaling which may contribute to the death of photoreceptor neurons and ultimately lead to retinal degenerations. The potential therapeutic agents that specifically reduce or inhibit the PTP1B activity could be beneficial in protecting or delaying the photoreceptor cell death in the retinal degenerative diseases.
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Affiliation(s)
- Devaraj K Basavarajappa
- Department of Ophthalmology, Dean A. McGee Eye Institute, University of Oklahoma Health Sciences Center, 608 Stanton L. Young Boulevard, Oklahoma City, OK 73104, USA
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Simpkins JW, Perez E, Wang X, Yang S, Wen Y, Singh M. The potential for estrogens in preventing Alzheimer's disease and vascular dementia. Ther Adv Neurol Disord 2011; 2:31-49. [PMID: 19890493 DOI: 10.1177/1756285608100427] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Estrogens are the best-studied class of drugs for potential use in the prevention of Alzheimer's disease (AD). These steroids have been shown to be potent neuroprotectants both in vitro and in vivo, and to exert effects that are consistent with their potential use in prevention of AD. These include the prevention of the processing of amyloid precursor protein (APP) into beta-amyloid (Aß), the reduction in tau hyperphosphorylation, and the elimination of catastrophic attempts at neuronal mitosis. Further, epidemiological data support the efficacy of early postmenopausal use of estrogens for the delay or prevention of AD. Collectively, this evidence supports the further development of estrogen-like compounds for prevention of AD. Several approaches to enhance brain specificity of estrogen action are now underway in an attempt to reduce the side effects of chronic estrogen therapy in AD.
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Affiliation(s)
- James W Simpkins
- Department of Pharmacology and Neuroscience, Institute for Aging and Alzheimer's Disease Research, Center FOR HER (Focused On Resources for her Health, Education and Research), University of North Texas Health Science Center, Fort Worth, TX, USA
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Ivanovic I, Allen DT, Dighe R, Le YZ, Anderson RE, Rajala RVS. Phosphoinositide 3-kinase signaling in retinal rod photoreceptors. Invest Ophthalmol Vis Sci 2011; 52:6355-62. [PMID: 21730346 DOI: 10.1167/iovs.10-7138] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
PURPOSE Phosphoinositide 3-kinase (PI3K) consists of a p110 catalytic protein and a p85α regulatory protein, required for the stabilization and localization of p110-PI3K activity. The biological significance of PI3K was investigated in vertebrate rod photoreceptors by deleting its regulatory p85α protein and examining its role in photoreceptor structure, function, and protein trafficking. METHODS Mice that expressed Cre recombinase in rods were bred to mice with a floxed p85α (pik3r1) regulatory subunit of PI3K to generate a conditional deletion of pik3r1 in rods. Functional and structural changes were determined by ERG and morphometric analysis, respectively. PI3K activity was measured in retinal homogenates immunoprecipitated with an anti-PY antibody. Akt activation was determined by Western blot analysis with a pAkt antibody. RESULTS Light-induced stress increased PI3K activity in retinal immunoprecipitates and phosphorylation of Akt. There was no effect of pik3r1 deletion on retinal structure. However, twin flash electroretinography revealed a slight delay in recovery kinetics in pik3r1 knockout (KO) mice compared with wild-type controls. The movement of arrestin in the pik3r1 KO mice was slower than that in the wild-type mouse retinas at 5 minutes of exposure to light. At 10 minutes of exposure, the ROS localization of arrestin was almost identical between the wild-type and pik3r1 KO mice. CONCLUSIONS The results provide the first direct evidence that rods use PI3K-generated phosphoinositides for photoreceptor function. The lack of phenotype in pik3r1 KO rod photoreceptors suggests a redundant role in controlling PIP(3) synthesis.
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Affiliation(s)
- Ivana Ivanovic
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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Caceres LG, Uran SL, Zorrilla Zubilete MA, Romero JI, Capani F, Guelman LR. An early treatment with 17-β-estradiol is neuroprotective against the long-term effects of neonatal ionizing radiation exposure. J Neurochem 2011; 118:626-35. [PMID: 21631508 DOI: 10.1111/j.1471-4159.2011.07334.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Ionizing radiations can induce oxidative stress on target tissues, acting mainly through reactive oxygen species (ROS). The aim of this work was to investigate if 17-β-estradiol (βE) was able to prevent hippocampal-related behavioral and biochemical changes induced by neonatal ionizing radiation exposure and to elucidate a potential neuroprotective mechanism. Male Wistar rats were irradiated with 5 Gy of X-rays between 24 and 48 h after birth. A subset of rats was subcutaneously administered with successive injections of βE or 17-α-estradiol (αE), prior and after irradiation. Rats were subjected to different behavioral tasks to evaluate habituation and associative memory as well as anxiety levels. Hippocampal ROS levels and protein kinase C (PKC) activity were also assessed. Results show that although βE was unable to prevent radiation-induced hippocampal PKC activity changes, most behavioral abnormalities were reversed. Moreover, hippocampal ROS levels in βE-treated irradiated rats approached control values. In addition, αE administered to irradiated animals was effective in preventing radiation-induced alterations. In conclusion, βE was able to counteract behavioral and biochemical changes induced in irradiated animals, probably acting through an antioxidant mechanism.
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Affiliation(s)
- Lucila G Caceres
- 1ª Cátedra de Farmacología, Facultad de Medicina, UBA, CEFYBO-CONICET, Buenos Aires, Argentina
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Decrease of Tau hyperphosphorylation by 17β estradiol requires sphingosine kinase in a glutamate toxicity model. Neurochem Res 2011; 34:2206-14. [PMID: 19543831 DOI: 10.1007/s11064-009-0017-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2009] [Indexed: 01/08/2023]
Abstract
Several studies have linked estrogens with sphingosine kinase (SphK) activity, enzyme responsible of sphingosine-1-phosphate synthesis (S-1P), however their possible interaction in the nervous system is not documented yet. In the present study, we developed a glutamate toxicity model in SH-SY5Y cells to evaluate the possible effect of the inhibition of SphK activity on the protective capability of 17β-estradiol (E2). Glutamate induced cytoskeletal actin changes associated to cytotoxic stress, significant increase of apoptotic-like nuclear fragmentation, Tau hyperphosphorylation and increase of p25/p35 cleavage. These effects were prevented by E2 pre-treatment during 24 h. Although the inhibition of SphK did not block this protective effect, significantly increased Tau hyperphosphorylation by glutamate, in a way that was not reverted by E2. Our results suggest that the decrease of glutamate-induced Tau hyperphosphorylation by 17β-estradiol requires SphK.
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Zhou X, Wong LL, Karakoti AS, Seal S, McGinnis JF. Nanoceria inhibit the development and promote the regression of pathologic retinal neovascularization in the Vldlr knockout mouse. PLoS One 2011; 6:e16733. [PMID: 21364932 PMCID: PMC3043063 DOI: 10.1371/journal.pone.0016733] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 12/28/2010] [Indexed: 02/07/2023] Open
Abstract
Many neurodegenerative diseases are known to occur and progress because of oxidative stress, the presence of reactive oxygen species (ROS) in excess of the cellular defensive capabilities. Age related macular degeneration (AMD), diabetic retinopathy (DR) and inherited retinal degeneration share oxidative stress as a common node upstream of the blinding effects of these diseases. Knockout of the Vldlr gene results in a mouse that develops intraretinal and subretinal neovascular lesions within the first month of age and is an excellent model for a form of AMD called retinal angiomatous proliferation (RAP). Cerium oxide nanoparticles (nanoceria) catalytically scavenge ROS by mimicking the activities of superoxide dismutase and catalase. A single intravitreal injection of nanoceria into the Vldlr-/- eye was shown to inhibit: the rise in ROS in the Vldlr-/- retina, increases in vascular endothelial growth factor (VEGF) in the photoreceptor layer, and the formation of intraretinal and subretinal neovascular lesions. Of more therapeutic interest, injection of nanoceria into older mice (postnatal day 28) resulted in the regression of existing vascular lesions indicating that the pathologic neovessels require the continual production of excessive ROS. Our data demonstrate the unique ability of nanoceria to prevent downstream effects of oxidative stress in vivo and support their therapeutic potential for treatment of neurodegenerative diseases such as AMD and DR.
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Affiliation(s)
- Xiaohong Zhou
- Department of Ophthalmology, University of Oklahoma, College of Medicine, Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
| | - Lily L. Wong
- Department of Ophthalmology, University of Oklahoma, College of Medicine, Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
- * E-mail: (JFM); (LLW)
| | - Ajay S. Karakoti
- Department of Ophthalmology, University of Oklahoma, College of Medicine, Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
- Advanced Materials Processing Analysis Center, Mechanical Materials Aerospace Engineering, Nanoscience, and Technology Center, University of Central Florida, Orlando, Florida, United States of America
| | - Sudipta Seal
- Department of Ophthalmology, University of Oklahoma, College of Medicine, Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
- Advanced Materials Processing Analysis Center, Mechanical Materials Aerospace Engineering, Nanoscience, and Technology Center, University of Central Florida, Orlando, Florida, United States of America
| | - James F. McGinnis
- Department of Ophthalmology, University of Oklahoma, College of Medicine, Dean McGee Eye Institute, Oklahoma City, Oklahoma, United States of America
- Department of Ophthalmology and Cell Biology, Oklahoma Center for Neuroscience, Oklahoma City, Oklahoma, United States of America
- * E-mail: (JFM); (LLW)
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Siriphorn A, Chompoopong S, Floyd CL. 17β-estradiol protects Schwann cells against H2O2-induced cytotoxicity and increases transplanted Schwann cell survival in a cervical hemicontusion spinal cord injury model. J Neurochem 2010; 115:864-72. [PMID: 20456002 DOI: 10.1111/j.1471-4159.2010.06770.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Schwann cell (SC) transplantation is a promising repair strategy after spinal cord injury (SCI); however, a large number of SCs do not survive following transplantation. Previous studies have shown that 17β-estradiol (E2) protects several cell types against cytotoxicity. Thus, this study evaluated the protective potential of E2 on SCs in vitro and investigated the effect of E2 on transplanted SC survival in a rat model of SCI. Primary SC cultures were found to robustly express estrogen receptors (ER) and incubation with E2 protected SCs against hydrogen peroxide-induced cell death. This protection was not inhibited by the ER antagonist ICI 182,780, suggesting that genomic signaling is not necessary for protection. In a subsequent experiment, cervical hemicontusion SCI was induced in male rats followed by sustained administration of E2 or placebo. Eight days after SCI, SCs were transplanted into the injury epicenter. E2 treatment significantly increased the number of surviving labeled transplanted SCs evaluated 7 days after transplantation. These data demonstrate that E2 protects SCs against oxidative stress and improves transplanted SC survival, which suggests that E2 administration may be an intervention of choice for enhancing survival of transplanted SCs after SCI.
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Affiliation(s)
- Akkradate Siriphorn
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, Birmingham, Alabama, USA
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Rhodopsin-regulated insulin receptor signaling pathway in rod photoreceptor neurons. Mol Neurobiol 2010; 42:39-47. [PMID: 20407846 DOI: 10.1007/s12035-010-8130-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Accepted: 04/05/2010] [Indexed: 10/19/2022]
Abstract
The retina is an integral part of the central nervous system and retinal cells are known to express insulin receptors (IR), although their function is not known. This article describes recent studies that link the photoactivation of rhodopsin to tyrosine phosphorylation of the IR and subsequent activation of phosphoinositide 3-kinase, a neuron survival factor. Our studies suggest that the physiological role of this process is to provide neuroprotection of the retina against light damage by activating proteins that protect against stress-induced apoptosis. We focus mainly on our recently identified regulation of the IR pathway through the G-protein-coupled receptor rhodopsin. Various mutant and knockout proteins of phototransduction cascade have been used to study the light-induced activation of the retinal IR. Our studies suggest that rhodopsin may have additional previously uncharacterized signaling functions in photoreceptors.
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Kong L, Zhou X, Li F, Yodoi J, McGinnis J, Cao W. Neuroprotective effect of overexpression of thioredoxin on photoreceptor degeneration in Tubby mice. Neurobiol Dis 2010; 38:446-55. [PMID: 20298786 DOI: 10.1016/j.nbd.2010.03.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 03/02/2010] [Accepted: 03/07/2010] [Indexed: 01/29/2023] Open
Abstract
The Tubby mouse is a phenotypic model for sensorineural deafness and retinal dystrophy including Usher syndrome type 1. Thioredoxin is a small 13kDa protein which, when ubiquitously expressed as a transgene in the mouse, provides protection against multiple disease states including light-induced and oxidative stress-induced neurodegeneration and is down-regulated in the Tubby retina. We tested if overexpression of human thioredoxin in the Tubby mouse inhibits retinal degeneration and loss of visual function. Electroretinography, immunocytochemistry, quantitative histology, RT-PCR and Western blots were used to obtain data which showed that thioredoxin overexpression prevented loss of photoreceptors and retinal function. Analysis of signal pathways showed that thioredoxin up-regulated neurotrophic factors BDNF and GDNF and activated survival signaling pathways Akt, Ras/Raf1/ and the ERKs while inhibiting the ASK1/JNK apoptosis pathway. Relationships between the Tubby gene, its pathological phenotype and regulation of the thioredoxin system remain to be established.
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Affiliation(s)
- Li Kong
- Ophthalmology, Oklahoma University Health Sciences Center, Oklahoma City, OK, USA
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Abstract
The phosphoinositide (PI) cycle, discovered over 50 years ago by Mabel and Lowell Hokin, describes a series of biochemical reactions that occur on the inner leaflet of the plasma membrane of cells in response to receptor activation by extracellular stimuli. Studies from our laboratory have shown that the retina and rod outer segments (ROSs) have active PI metabolism. Biochemical studies revealed that the ROSs contain the enzymes necessary for phosphorylation of phosphoinositides. We showed that light stimulates various components of the PI cycle in the vertebrate ROS, including diacylglycerol kinase, PI synthetase, phosphatidylinositol phosphate kinase, phospholipase C, and phosphoinositide 3-kinase (PI3K). This article describes recent studies on the PI3K-generated PI lipid second messengers in the control and regulation of PI-binding proteins in the vertebrate retina.
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Affiliation(s)
- Raju V S Rajala
- Departments of Ophthalmology and Cell Biology, and Dean A. McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA. r
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Kanan Y, Matsumoto H, Song H, Sokolov M, Anderson RE, Rajala RVS. Serine/threonine kinase akt activation regulates the activity of retinal serine/threonine phosphatases, PHLPP and PHLPPL. J Neurochem 2010; 113:477-88. [PMID: 20089132 DOI: 10.1111/j.1471-4159.2010.06609.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In our previous studies, we have shown that insulin receptor (IR) activation leads to the activation of phosphoinositide 3-kinase (PI3K) and Akt activation in rod photoreceptors. This pathway is functionally important for photoreceptor survival as deletion of IR and one of the isoforms of Akt (Akt2) resulted in stress-induced photoreceptor degeneration. However, the molecular mechanism of this degeneration is not known. Akt signaling is known to be regulated by the serine/threonine phosphatases, PH domain and leucine-rich repeat protein phosphatases (PHLPP) and PHLPP-like (PHLPPL). In this study, we characterized these two phosphatases in the retina and examined the role of IR, PI3K, and Akt signaling on the activity of PHLPP and PHLPPL. Most of the studies published on PHLPP and PHLPPL are directed toward Akt dephosphorylation; however, there are no studies available to date on how the enzyme activities of these phosphatases are regulated. We made a novel finding in this study that both PHLPP and PHLPPL activities were significantly decreased in the presence of insulin ex vivo. The insulin-induced decrease of phosphatase activities were PI3K-dependent as pre-treatment of ex vivo retinal cultures with LY294002 significantly reversed the insulin-induced inhibition. It has been shown previously that PHLPP and PHLPPL regulate the dephosphorylation of Akt isoforms, and our results demonstrate for the first time that retinal PHLPP and PHLPPL activities are under the control of the IR-activated PI3K/Akt pathway.
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Affiliation(s)
- Yogita Kanan
- Departments of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma city, Oklahoma 73104, USA
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