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Zakharova IO, Akhmetshina AO, Bayunova LV, Kizhaeva LR, Avrova NF. The Effect of Alpha-Tocopherol on
Viability of PC12 Cells during Oxidative Stress and Expression of
Genes Encoding Pro- and Anti-Apoptotic Mitochondrial Proteins, SOD2
and Transcription Factors NRF-1, NRF-2 and TFAM. J EVOL BIOCHEM PHYS+ 2020. [DOI: 10.1134/s0022093020030084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Aguado-Llera D, Canelles S, Fernández-Mendívil C, Frago LM, Argente J, Arilla-Ferreiro E, López MG, Barrios V. Improvement in inflammation is associated with the protective effect of Gly-Pro-Glu and cycloprolylglycine against Aβ-induced depletion of the hippocampal somatostatinergic system. Neuropharmacology 2019; 151:112-126. [PMID: 30981749 DOI: 10.1016/j.neuropharm.2019.04.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 04/02/2019] [Accepted: 04/06/2019] [Indexed: 02/08/2023]
Abstract
Glycine-proline-glutamate (GPE) is a cleaved tripeptide of IGF-I that can be processed to cycloprolylglycine (cPG) in the brain. IGF-I protects the hippocampal somatostatinergic system from β-amyloid (Aβ) insult and although neither IGF-I-derived peptides bind to IGF-I receptors, they exert protective actions in several neurological disorders. As their effects on the hippocampal somatostatinergic system remain unknown, the objective of this study was to evaluate if cPG and/or GPE prevent the deleterious effects of Aβ25-35 infusion on this system and whether changes in intracellular-related signaling and interleukin (IL) content are involved in their protective effect. We also determined the effect of cPG or GPE co-administration with Aβ25-35 on IL secretion in glial cultures and the influence of these ILs on signaling activation and somatostatin synthesis in neuronal cultures. cPG or GPE co-administration reduced Aβ-induced cell death and pro-inflammatory ILs, increased IL-4 and partially avoided the reduction of components of the somatostatinergic system affected by Aβ25-35. GPE increased activation of Akt and CREB and reduced GSK3β activation and astrogliosis, whereas cPG increased phosphorylation of extracellular signal-regulated kinases. Both peptides converged in the activation of mTOR and S6 kinase. Co-administration of these peptides with Aβ25-35 to glial cultures increased IL-4 and reduced IL-1β; this release of IL-4 could be responsible for activation of Akt and increased somatostatin in neuronal cultures. Our findings suggest that cPG and GPE exert protective effects against Aβ on the somatostatinergic system by a reduction of the inflammatory environment that may activate different pro-survival pathways in these neurons.
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Affiliation(s)
- David Aguado-Llera
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación Sanitaria La Princesa, Madrid, Spain
| | - Sandra Canelles
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación Sanitaria La Princesa, Madrid, Spain; CIBER Fisiopatología Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, Madrid, Spain
| | - Cristina Fernández-Mendívil
- Department of Pharmacology and Therapeutics and Institute Teófilo Hernando for Drug Discovery, Universidad Autónoma de Madrid, Madrid, Spain
| | - Laura M Frago
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación Sanitaria La Princesa, Madrid, Spain; CIBER Fisiopatología Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, Madrid, Spain; Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
| | - Jesús Argente
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación Sanitaria La Princesa, Madrid, Spain; CIBER Fisiopatología Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, Madrid, Spain; Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain; IMDEA Food Institute, CEI UAM + CSIC, Madrid, Spain
| | | | - Manuela G López
- Department of Pharmacology and Therapeutics and Institute Teófilo Hernando for Drug Discovery, Universidad Autónoma de Madrid, Madrid, Spain
| | - Vicente Barrios
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación Sanitaria La Princesa, Madrid, Spain; CIBER Fisiopatología Obesidad y Nutrición (CB06/03), Instituto de Salud Carlos III, Madrid, Spain.
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α-Tocopherol protects renal cells from nicotine- or oleic acid-provoked oxidative stress via inducing heme oxygenase-1. J Physiol Biochem 2014; 71:1-7. [DOI: 10.1007/s13105-014-0372-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 11/18/2014] [Indexed: 02/06/2023]
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Alpha-tocopherol in the brain tissue preservation of stroke-prone spontaneously hypertensive rats. J Physiol Biochem 2013; 70:49-60. [DOI: 10.1007/s13105-013-0279-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 07/23/2013] [Indexed: 12/20/2022]
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Ulatowski L, Dreussi C, Noy N, Barnholtz-Sloan J, Klein E, Manor D. Expression of the α-tocopherol transfer protein gene is regulated by oxidative stress and common single-nucleotide polymorphisms. Free Radic Biol Med 2012; 53:2318-26. [PMID: 23079030 PMCID: PMC3612136 DOI: 10.1016/j.freeradbiomed.2012.10.528] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 09/24/2012] [Accepted: 10/08/2012] [Indexed: 12/22/2022]
Abstract
Vitamin E (α-tocopherol) is the major lipid-soluble antioxidant in most animal species. By controlling the secretion of vitamin E from the liver, the α-tocopherol transfer protein regulates whole-body distribution and levels of this vital nutrient. However, the mechanism(s) that regulates the expression of this protein is poorly understood. Here we report that transcription of the TTPA gene in immortalized human hepatocytes is induced by oxidative stress and by hypoxia, by agonists of the nuclear receptors PPARα and RXR, and by increased cAMP levels. The data show further that induction of TTPA transcription by oxidative stress is mediated by an already-present transcription factor and does not require de novo protein synthesis. Silencing of the cAMP response element-binding (CREB) transcription factor attenuated transcriptional responses of the TTPA gene to added peroxide, suggesting that CREB mediates responses of this gene to oxidative stress. Using a 1.9-kb proximal segment of the human TTPA promoter together with a site-directed mutagenesis approach, we found that single-nucleotide polymorphisms that are commonly found in healthy humans dramatically affect promoter activity. These observations suggest that oxidative stress and individual genetic makeup contribute to vitamin E homeostasis in humans. These findings may explain the variable responses to vitamin E supplementation observed in human clinical trials.
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Affiliation(s)
- Lynn Ulatowski
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Cara Dreussi
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Noa Noy
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Jill Barnholtz-Sloan
- Department of Epidemiology and Biostatistics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Eric Klein
- Glickman Urological Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - Danny Manor
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
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Perianes-Cachero A, Burgos-Ramos E, Puebla-Jiménez L, Canelles S, Viveros MP, Mela V, Chowen JA, Argente J, Arilla-Ferreiro E, Barrios V. Leptin-induced downregulation of the rat hippocampal somatostatinergic system may potentiate its anorexigenic effects. Neurochem Int 2012; 61:1385-96. [PMID: 23073237 DOI: 10.1016/j.neuint.2012.09.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 09/24/2012] [Accepted: 09/30/2012] [Indexed: 10/27/2022]
Abstract
The learning and memory mechanisms in the hippocampus translate hormonal signals of energy balance into behavioral outcomes involved in the regulation of food intake. As leptin and its receptors are expressed in the hippocampus and somatostatin (SRIF), an orexigenic neuropeptide, may inhibit leptin-mediated suppression of food intake in other brain areas, we asked whether chronic leptin infusion induces changes in the hippocampal somatostatinergic system and whether these modifications are involved in leptin-mediated effects. We studied 18 male Wistar rats divided into three groups: controls (C), treated intracerebroventricularly (icv) with leptin (12 μg/day) for 14 days (L) and a pair-fed group (PF) that received the same amount of food consumed by the L group. Food restriction increased whereas leptin decreased the hippocampal SRIF receptor density, due to changes in SRIF receptor 2 protein levels. These changes in the PF group were concurrent with an increase of hippocampal G protein-coupled receptor kinase 2 protein levels and activation of Akt and cyclic AMP response element binding protein. The inhibitory effect of SRIF on adenylyl cyclase (AC) activity, however, was decreased in L rats, coincident with lower G inhibitory α3 and higher AC-I levels as well as signal transducer and activator of transcription factor 3 activation. In addition, 20 male Wistar rats were included to analyze whether the leptin antagonist L39A/D40A/F41A and the SRIF receptor agonist SMS 201-995 modify SRIF signaling and food intake, respectively. Administration of L39A/D40A/F41A reversed changes in SRIF signaling, whereas SMS 201-995 ameliorated food consumption in L. Altogether, these results suggest that increased somatostatinergic tone in PF rats may be a mechanism to improve the hippocampal orexigenic effects in a situation of metabolic demand, whereas down-regulation of this system in L rats may represent a mechanism to enhance the anorexigenic effects of leptin.
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Affiliation(s)
- Arancha Perianes-Cachero
- Neurobiochemistry Unit, Department of Biochemistry and Molecular Biology, Facultad de Medicina, Universidad de Alcalá, Alcalá de Henares, E-28871 Madrid, Spain
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Hernández-Pinto AM, Puebla-Jiménez L, Perianes-Cachero A, Arilla-Ferreiro E. Vitamin E deficiency impairs the somatostatinergic receptor-effector system and leads to phosphotyrosine phosphatase overactivation and cell death in the rat hippocampus. J Nutr Biochem 2012; 24:848-58. [PMID: 22902329 DOI: 10.1016/j.jnutbio.2012.05.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 04/17/2012] [Accepted: 05/01/2012] [Indexed: 11/30/2022]
Abstract
Vitamin E plays an essential role in maintaining the structure and function of the nervous system, and its deficiency, commonly associated with fat malabsorption diseases, may reduce neuronal survival. We previously demonstrated that the somatostatinergic system, implicated in neuronal survival control, can be modulated by α-tocopherol in the rat dentate gyrus, increasing cyclic adenosine monophosphate response element binding protein phosphorylation. To gain a better understanding of the molecular actions of tocopherols and examine the link among vitamin E, somatostatin and neuronal survival, we have investigated the effects of a deficiency and subsequent administration of tocopherol on the somatostatin signaling pathway and neuronal survival in the rat hippocampus. No changes in somatostatin expression were detected in vitamin-E-deficient rats. These rats, however, showed a significant increase in the somatostatin receptor density and dissociation constant, which correlated with a significant increase in the protein levels of somatostatin receptors. Nevertheless, vitamin E deficiency impaired the ability of the somatostatin receptors to couple to the effectors adenylyl cyclase and phosphotyrosine phosphatase by diminishing Gi protein functionality. Furthermore, vitamin E deficiency significantly increased phosphotyrosine phosphatase activity and PTPη expression, as well as PKCδ activation, and decreased extracellular-signal-regulated kinase phosphorylation. All these changes were accompanied by an increase in neuronal cell death. Subsequent α-tocopherol administration partially or completely reversed all these values to control levels. Altogether, our results prove the importance of vitamin E homeostasis in the somatostatin receptor-effector system and suggest a possible mechanism by which this vitamin may regulate the neuronal cell survival in the adult hippocampus.
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Affiliation(s)
- Alberto M Hernández-Pinto
- Biochemical and Molecular Biology Department, Neuro-Biochemical Group, Faculty of Medicine, Universidad de Alcalá de Henares, Madrid, Spain
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