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Pramanik S, Devi M H, Chakrabarty S, Paylar B, Pradhan A, Thaker M, Ayyadhury S, Manavalan A, Olsson PE, Pramanik G, Heese K. Microglia signaling in health and disease - Implications in sex-specific brain development and plasticity. Neurosci Biobehav Rev 2024; 165:105834. [PMID: 39084583 DOI: 10.1016/j.neubiorev.2024.105834] [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: 05/05/2024] [Revised: 07/21/2024] [Accepted: 07/27/2024] [Indexed: 08/02/2024]
Abstract
Microglia, the intrinsic neuroimmune cells residing in the central nervous system (CNS), exert a pivotal influence on brain development, homeostasis, and functionality, encompassing critical roles during both aging and pathological states. Recent advancements in comprehending brain plasticity and functions have spotlighted conspicuous variances between male and female brains, notably in neurogenesis, neuronal myelination, axon fasciculation, and synaptogenesis. Nevertheless, the precise impact of microglia on sex-specific brain cell plasticity, sculpting diverse neural network architectures and circuits, remains largely unexplored. This article seeks to unravel the present understanding of microglial involvement in brain development, plasticity, and function, with a specific emphasis on microglial signaling in brain sex polymorphism. Commencing with an overview of microglia in the CNS and their associated signaling cascades, we subsequently probe recent revelations regarding molecular signaling by microglia in sex-dependent brain developmental plasticity, functions, and diseases. Notably, C-X3-C motif chemokine receptor 1 (CX3CR1), triggering receptors expressed on myeloid cells 2 (TREM2), calcium (Ca2+), and apolipoprotein E (APOE) emerge as molecular candidates significantly contributing to sex-dependent brain development and plasticity. In conclusion, we address burgeoning inquiries surrounding microglia's pivotal role in the functional diversity of developing and aging brains, contemplating their potential implications for gender-tailored therapeutic strategies in neurodegenerative diseases.
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Affiliation(s)
- Subrata Pramanik
- Jyoti and Bhupat Mehta School of Health Sciences and Technology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
| | - Harini Devi M
- Jyoti and Bhupat Mehta School of Health Sciences and Technology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Saswata Chakrabarty
- Jyoti and Bhupat Mehta School of Health Sciences and Technology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Berkay Paylar
- Biology, The Life Science Center, School of Science and Technology, Örebro University, Örebro 70182, Sweden
| | - Ajay Pradhan
- Biology, The Life Science Center, School of Science and Technology, Örebro University, Örebro 70182, Sweden
| | - Manisha Thaker
- Eurofins Lancaster Laboratories, Inc., 2425 New Holland Pike, Lancaster, PA 17601, USA
| | - Shamini Ayyadhury
- The Donnelly Centre, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Arulmani Manavalan
- Department of Cariology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu 600077, India
| | - Per-Erik Olsson
- Biology, The Life Science Center, School of Science and Technology, Örebro University, Örebro 70182, Sweden
| | - Gopal Pramanik
- Department of Pharmaceutical Sciences and Technology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand 835215, India.
| | - Klaus Heese
- Graduate School of Biomedical Science and Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133791, the Republic of Korea.
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Guerra-Cantera S, Frago LM, Espinoza-Chavarria Y, Collado-Pérez R, Jiménez-Hernaiz M, Torrecilla-Parra M, Barrios V, Belsham DD, Laursen LS, Oxvig C, Argente J, Chowen JA. Palmitic Acid Modulation of the Insulin-Like Growth Factor System in Hypothalamic Astrocytes and Neurons. Neuroendocrinology 2024:1-17. [PMID: 39043147 DOI: 10.1159/000540442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 07/17/2024] [Indexed: 07/25/2024]
Abstract
INTRODUCTION Insulin-like growth factor (IGF)1 and IGF2 have neuroprotective effects, but less is known regarding how other members of the IGF system, including IGF binding proteins (IGFBPs) and the regulatory proteinase pappalysin-1 (PAPP-A) and its endogenous inhibitor stanniocalcin-2 (STC2) participate in this process. Here, we analyzed whether these members of the IGF system are modified in neurons and astrocytes in response to palmitic acid (PA), a fatty acid that induces cell stress when increased centrally. METHODS Primary hypothalamic astrocyte cultures from male and female PND2 rats and the pro-opiomelanocortin (POMC) neuronal cell line, mHypoA-POMC/GFP-2, were treated with PA, IGF1 or both. To analyze the role of STC2 in astrocytes, siRNA assays were employed. RESULTS In astrocytes of both sexes, PA rapidly increased cell stress factors followed by increased Pappa and Stc2 mRNA levels and then a decrease in Igf1, Igf2, and Igfbp2 expression and cell number. Exogenous IGF1 did not revert these effects. In mHypoA-POMC/GFP-2 neurons, PA reduced cell number and Pomc and Igf1 mRNA levels, and increased Igfbp2 and Stc2, again with no effect of exogenous IGF1. PA increased STC2 expression, but no effects of decreasing its levels by interference assays or exogenous STC2 treatment in astrocytes were found. CONCLUSIONS The response of the IGF system to PA was cell and sex specific, but no protective effects of the IGFs were found. However, the modifications in hypothalamic PAPP-A and STC2 indicate that further studies are required to determine their role in the response to fatty acids and possibly in metabolic control.
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Affiliation(s)
- Santiago Guerra-Cantera
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Laura M Frago
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Yesenia Espinoza-Chavarria
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
| | - Roberto Collado-Pérez
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
| | - María Jiménez-Hernaiz
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Torrecilla-Parra
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
| | - Vicente Barrios
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Denise D Belsham
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Lisbeth S Laursen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Claus Oxvig
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Jesús Argente
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- IMDEA Food Institute, CEI UAM + CSIC, Madrid, Spain
| | - Julie A Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
- IMDEA Food Institute, CEI UAM + CSIC, Madrid, Spain
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Marghani BH, Rezk S, Ateya AI, Alotaibi BS, Othman BH, Sayed SM, Alshehri MA, Shukry M, Mansour MM. The Effect of Cerebrolysin in an Animal Model of Forebrain Ischemic-Reperfusion Injury: New Insights into the Activation of the Keap1/Nrf2/Antioxidant Signaling Pathway. Int J Mol Sci 2023; 24:12080. [PMID: 37569457 PMCID: PMC10418386 DOI: 10.3390/ijms241512080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/19/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
Forebrain ischemia-reperfusion (IR) injury causes neurological impairments due to decreased cerebral autoregulation, hypoperfusion, and edema in the hours to days following the restoration of spontaneous circulation. This study aimed to examine the protective and/or therapeutic effects of cerebrolysin (CBL) in managing forebrain IR injury and any probable underlying mechanisms. To study the contribution of reperfusion to forebrain injury, we developed a transient dual carotid artery ligation (tDCAL/IR) mouse model. Five equal groups of six BLC57 mice were created: Group 1: control group (no surgery was performed); Group 2: sham surgery (surgery was performed without IR); Group 3: tDCAL/IR (surgery with IR via permanently ligating the left CA and temporarily closing the right CA for 30 min, followed by reperfusion for 72 h); Group 4: CBL + tDCAL/IR (CBL was given intravenously at a 60 mg/kg BW dose 30 min before IR); and Group 5: tDCAL/IR + CBL (CBL was administered i.v. at 60 mg/kg BW three hours after IR). At 72 h following IR, the mice were euthanized. CBL administration 3 h after IR improved neurological functional recovery, enhanced anti-inflammatory and antioxidant activities, alleviated apoptotic neuronal death, and inhibited reactive microglial and astrocyte activation, resulting in neuroprotection after IR injury in the tDCAL/IR + CBL mice group as compared to the other groups. Furthermore, CBL reduced the TLRs/NF-kB/cytokines while activating the Keap1/Nrf2/antioxidant signaling pathway. These results indicate that CBL may improve neurologic function in mice following IR.
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Affiliation(s)
- Basma H. Marghani
- Department of Physiology, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt
- Department of Biochemistry, Physiology, and Pharmacology, Faculty of Veterinary Medicine, King Salman International University, El Tor 46612, Egypt
| | - Shaymaa Rezk
- Department of Cytology and Histology, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt
| | - Ahmed I. Ateya
- Department of Husbandry and Development of Animal Wealth, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt
| | - Badriyah S. Alotaibi
- Department of Pharmaceutical Sciences, College of Pharmacy, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Basma H. Othman
- Medical Experimental Research Center, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt;
| | - Samy M. Sayed
- Faculty of Agriculture, Cairo University, Giza 12613, Egypt;
- Department of Science and Technology, Ranyah University College, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Mohammed Ali Alshehri
- Biology Department, College of Science, University of Tabuk, Tabuk 71491, Saudi Arabia;
| | - Mustafa Shukry
- Physiology Department, Faculty of Veterinary Medicine, Kafrelsheikh University, Kafrelsheikh 33516, Egypt;
| | - Mohamed M. Mansour
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt
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Kisielinski K, Wagner S, Hirsch O, Klosterhalfen B, Prescher A. Possible toxicity of chronic carbon dioxide exposure associated with face mask use, particularly in pregnant women, children and adolescents - A scoping review. Heliyon 2023; 9:e14117. [PMID: 37057051 PMCID: PMC9981272 DOI: 10.1016/j.heliyon.2023.e14117] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 02/14/2023] [Accepted: 02/21/2023] [Indexed: 03/06/2023] Open
Abstract
Introduction During the SARS-CoV-2-pandemic, face masks have become one of the most important ubiquitous factors affecting human breathing. It increases the resistance and dead space volume leading to a re-breathing of CO2. So far, this phenomenon and possible implications on early life has not been evaluated in depth. Method As part of a scoping review, literature was systematically reviewed regarding CO2 exposure and facemask use. Results Fresh air has around 0.04% CO2, while wearing masks more than 5 min bears a possible chronic exposure to carbon dioxide of 1.41% to 3.2% of the inhaled air. Although the buildup is usually within the short-term exposure limits, long-term exceedances and consequences must be considered due to experimental data. US Navy toxicity experts set the exposure limits for submarines carrying a female crew to 0.8% CO2 based on animal studies which indicated an increased risk for stillbirths. Additionally, mammals who were chronically exposed to 0.3% CO2 the experimental data demonstrate a teratogenicity with irreversible neuron damage in the offspring, reduced spatial learning caused by brainstem neuron apoptosis and reduced circulating levels of the insulin-like growth factor-1. With significant impact on three readout parameters (morphological, functional, marker) this chronic 0.3% CO2 exposure has to be defined as being toxic. Additional data exists on the exposure of chronic 0.3% CO2 in adolescent mammals causing neuron destruction, which includes less activity, increased anxiety and impaired learning and memory. There is also data indicating testicular toxicity in adolescents at CO2 inhalation concentrations above 0.5%. Discussion There is a possible negative impact risk by imposing extended mask mandates especially for vulnerable subgroups. Circumstantial evidence exists that extended mask use may be related to current observations of stillbirths and to reduced verbal motor and overall cognitive performance in children born during the pandemic. A need exists to reconsider mask mandates.
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Affiliation(s)
- Kai Kisielinski
- Independent Researcher, Surgeon, Private Practice, 40212 Düsseldorf, Germany
| | - Susanne Wagner
- Non Clinical Expert, Veterinarian, Wagner MSL Management, 15831 Mahlow, Germany
| | - Oliver Hirsch
- Department of Psychology, FOM University of Applied Sciences, 57078 Siegen, Germany
| | | | - Andreas Prescher
- Institute of Molecular and Cellular Anatomy (MOCA), 52074 Aachen, Germany
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5
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Corrê MDS, de Freitas BS, Machado GDB, Pires VN, Bromberg E, Hallak JEC, Zuardi AW, Crippa JAS, Schröder N. Cannabidiol reverses memory impairments and activates components of the Akt/GSK3β pathway in an experimental model of estrogen depletion. Behav Brain Res 2022; 417:113555. [PMID: 34450240 DOI: 10.1016/j.bbr.2021.113555] [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: 05/31/2021] [Revised: 08/16/2021] [Accepted: 08/23/2021] [Indexed: 11/28/2022]
Abstract
Clinical and preclinical evidence has indicated that estrogen depletion leads to memory impairments and increases the susceptibility to neural damage. Here, we have sought to investigate the effects of Cannabidiol (CBD) a non-psychotomimetic compound from Cannabis sativa, on memory deficits induced by estrogen depletion in rats, and its underlying mechanisms. Adult rats were subjected to bilateral ovariectomy, an established estrogen depletion model in rodents, or sham surgery and allowed to recover for three weeks. After that, they received daily injections of CBD (10 mg/kg) for fourteen days. Rats were tested in the inhibitory avoidance task, a type of emotionally-motivated memory. After behavioral testing they were euthanized, and their hippocampi were isolated for analysis of components of the Akt/GSK3β survival pathway and the antiapoptotic protein Bcl2. Results revealed that ovariectomy impaired avoidance memory, and CBD was able to completely reverse estrogen depletion-induced memory impairment. Ovariectomy also reduced Akt/GSK3β pathway's activation by decreasing the phosphorylation levels of Akt and GSK3β and Bcl2 levels, which were ameliorated by CBD. The present results indicate that CBD leads to a functional recovery accompanied by the Akt/GSK3β survival pathway's activation, supporting its potential as a treatment for estrogen decline-induced deterioration of neural functioning and maintenance.
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Affiliation(s)
- Márcio da Silveira Corrê
- Neurobiology and Developmental Biology Laboratory, School of Health and Life Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil; Faculty of Medicine, Department of Health, Integrated Regional University of Upper Uruguay and Missions, Erechim, Brazil
| | - Betânia Souza de Freitas
- Neurobiology and Developmental Biology Laboratory, School of Health and Life Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Gustavo Dalto Barroso Machado
- Neurobiology and Developmental Biology Laboratory, School of Health and Life Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Vivian Naziaseno Pires
- Neurobiology and Developmental Biology Laboratory, School of Health and Life Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Elke Bromberg
- Neurobiology and Developmental Biology Laboratory, School of Health and Life Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil; National Institute of Science and Technology for Translational Medicine (INCT-TM), Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasília, Brazil
| | - Jaime E C Hallak
- National Institute of Science and Technology for Translational Medicine (INCT-TM), Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasília, Brazil; Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - Antônio Waldo Zuardi
- National Institute of Science and Technology for Translational Medicine (INCT-TM), Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasília, Brazil; Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - José Alexandre S Crippa
- National Institute of Science and Technology for Translational Medicine (INCT-TM), Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasília, Brazil; Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - Nadja Schröder
- National Institute of Science and Technology for Translational Medicine (INCT-TM), Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasília, Brazil; Department of Physiology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
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6
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Corne R, Besson V, Ait Si Slimane S, Coutan M, Palhas MLC, Shen FX, Marchand-Leroux C, Ogier M, Mongeau R. Insulin-like Growth Factors may be Markers of both Traumatic Brain Injury and Fear-Related Stress. Neuroscience 2021; 466:205-221. [PMID: 33895341 DOI: 10.1016/j.neuroscience.2021.04.013] [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: 06/18/2020] [Revised: 04/08/2021] [Accepted: 04/15/2021] [Indexed: 10/21/2022]
Abstract
Insulin-like growth factors (IGF) are potent neurotrophic and neurorepair factors that were recently proposed as biomarkers of traumatic brain injury (TBI) and associated psychiatric comorbidities, in particular post-traumatic stress disorder (PSTD). We tested the hypothesis that the IGF system is differentially deregulated in the acute and early chronic stages of TBI, and under acute stress. Plasma and brain IGF1 and IGF2 levels were evaluated in mice 3 weeks and 3 days after a controlled cortical impact (CCI)-induced mild-to-moderate TBI. The effects of conditioned fear on IGF levels and its interaction with TBI (TBI followed, 3 weeks later, by fear-inducing procedures) were also evaluated. In the plasma, IGF1 decreased 3 weeks post-TBI only (-9%), whereas IGF2 remained unaffected. In the brain, IGF1 increased only in the cortex and hippocampus at 3 weeks post-TBI (up to +650%). At 3 days, surpringly, this increase was more diffuse and more important in sham (craniotomized) animals. Additionally, IGF2 immunostaining in brain ventricles was reorganized in TBI animals at both post-TBI stages. Conditioned fear exposure did not influence the effects of early chronic TBI on plasma IGF1 levels, but reduced plasma IGF2 (-6%) levels. It also dampened the effects of TBI on brain IGF systems, but brain IGF1 level and IGF2 tissue distribution remained statistically different from controls under these conditions. In co-exposed animals, DNA methylation increased at the hippocampal Igf1 gene promoter. These results show that blood IGF1 and IGF2 are most reduced in the early chronic phase of TBI and after exposure to a stressful event, and that the brain IGF system is up-regulated after TBI, and more so in the acute phase.
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Affiliation(s)
- Rémi Corne
- EA4475 Pharmacologie de la Circulation Cérébrale, Université Paris Descartes, 4 avenue de l'Observatoire, 75006 Paris, France
| | - Valérie Besson
- EA4475 Pharmacologie de la Circulation Cérébrale, Université Paris Descartes, 4 avenue de l'Observatoire, 75006 Paris, France; UMR_S1144 Optimisation Thérapeutique en Neuropsychopharmacologie, Université Paris Descartes, 4 avenue de l'Observatoire, 75006 Paris, France
| | - Sofiane Ait Si Slimane
- EA4475 Pharmacologie de la Circulation Cérébrale, Université Paris Descartes, 4 avenue de l'Observatoire, 75006 Paris, France
| | - Mathieu Coutan
- Institut de Recherche Biomédicale de Armées, 1 place du Général Valérie André, 91223 Brétigny sur Orge Cedex, France
| | - Marta L C Palhas
- EA4475 Pharmacologie de la Circulation Cérébrale, Université Paris Descartes, 4 avenue de l'Observatoire, 75006 Paris, France
| | - Fang Xue Shen
- EA4475 Pharmacologie de la Circulation Cérébrale, Université Paris Descartes, 4 avenue de l'Observatoire, 75006 Paris, France
| | - Catherine Marchand-Leroux
- EA4475 Pharmacologie de la Circulation Cérébrale, Université Paris Descartes, 4 avenue de l'Observatoire, 75006 Paris, France; UMR_S1144 Optimisation Thérapeutique en Neuropsychopharmacologie, Université Paris Descartes, 4 avenue de l'Observatoire, 75006 Paris, France
| | - Michaël Ogier
- Institut de Recherche Biomédicale de Armées, 1 place du Général Valérie André, 91223 Brétigny sur Orge Cedex, France
| | - Raymond Mongeau
- EA4475 Pharmacologie de la Circulation Cérébrale, Université Paris Descartes, 4 avenue de l'Observatoire, 75006 Paris, France; CNRS ERL 3649 T3S-1124 - UMR-S 1124 - Addictions, Pharmacology and Therapy, Université Paris Descartes, 45, rue des Saint-Pères, 75006 Paris, France.
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Zhang H, Liu Y, Cheng L, Ma X, Luo X. Exendin-4 induces a novel extended effect of ischemic tolerance via crosstalk with IGF-1R. Brain Res Bull 2020; 169:145-155. [PMID: 33197537 DOI: 10.1016/j.brainresbull.2020.11.008] [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: 03/19/2020] [Revised: 10/09/2020] [Accepted: 11/11/2020] [Indexed: 11/15/2022]
Abstract
Glucagon-like peptide-1 (GLP-1) receptor (GLP-1R) agonist exendin-4 (Ex-4), a drug that has been used in the clinical treatment of type 2 diabetes mellitus, also confers a neuroprotective effect against stroke. Although GLP-1 analogs were reported to induce sustained insulin secretion and glucose tolerance improved after cessation of treatment, no study has revealed whether Ex-4 exerts sustained neuroprotection against stroke and the underlying mechanism after treatment cessation. In this study, mice were pretreated with Ex-4 for 7 days, and middle cerebral artery occlusion (MCAO) was performed on different days after cessation of Ex-4 treatment. Ex-4 ameliorated neurological dysfunction and reduced the infarct volume induced by MCAO. These protective effects lasted for 6 days after the cessation of Ex-4 treatment and were associated with sustained upregulation of PI3K, AKT, mTOR, and HIF-1α levels, as well as HIF-1α downstream genes. Knockdown of GLP-1R or HIF-1α in the brain by short hairpin RNA abolished Ex-4 treatment-mediated neuroprotection. In normal mice, Ex-4 treatment led to instant upregulation of p-PI3K, p-AKT, p-mTOR, and HIF-1α expression levels, which quickly returned to normal after cessation of Ex-4 treatment, while the expression levels of insulin growth factor-1 receptor (IGF-1R) remained high for 6 days after Ex-4 cessation. Additionally, Ex-4 did not directly induce IGF-1 production, which was only induced by MCAO. Ex-4 induces extended cerebral ischemic tolerance. This neuroprotective effect is associated with activation of GLP-1R and upregulation of IGF-1R in the brain, and the latter then activates the PI3K/AKT/mTOR/HIF-1 signaling pathway via binding to IGF-1 secreted from the ischemic brain.
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Affiliation(s)
- Huinan Zhang
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Xi'an, China
| | - Yunhan Liu
- Department of Neurology Impatient, the Second Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Liusiyuan Cheng
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Xi'an, China
| | - Xue Ma
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Xi'an, China.
| | - Xiaoxing Luo
- Department of Pharmacology, School of Pharmacy, Fourth Military Medical University, Key Laboratory of Gastrointestinal Pharmacology of Chinese Materia Medica of the State Administration of Traditional Chinese Medicine, Xi'an, China.
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8
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Hwang Y, Kim HC, Shin EJ. Enhanced neurogenesis is involved in neuroprotection provided by rottlerin against trimethyltin-induced delayed apoptotic neuronal damage. Life Sci 2020; 262:118494. [PMID: 32991881 DOI: 10.1016/j.lfs.2020.118494] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/12/2020] [Accepted: 09/20/2020] [Indexed: 12/26/2022]
Abstract
AIMS We here investigated the effect of late- and post-ictal treatment with rottlerin, a polyphenol compound isolated from Mallotus philippinensis, on delayed apoptotic neuronal death induced by trimethyltin (TMT) in mice. MAIN METHODS Male C57BL/6N mice received a single injection of TMT (2.4 mg/kg, i.p.), and mice were treated with rottlerin after a peak time (i.e., 2 d post-TMT) of convulsive behaviors and apoptotic cell death (5.0 mg/kg, i.p. at 3 and 4 d after TMT injection). Object location test and tail suspension test were performed at 5 d after TMT injection. In addition, changes in the expression of apoptotic and neurogenic markers in the dentate gyrus were examined. KEY FINDINGS Late- and post-ictal treatment with rottlerin suppressed delayed neuronal apoptosis in the dentate gyrus, and attenuated memory impairments (as evaluated by object location test) and depression-like behaviors (as evaluated by tail suspension test) at 5 days after TMT injection in mice. In addition, rottlerin enhanced the expression of Sox2 and DCX, and facilitated p-ERK expression in BrdU-incorporated cells in the dentate gyrus of TMT-treated mice. Rottlerin also increased p-Akt expression, and attenuated the increase in the ratio of pro-apoptotic factors/anti-apoptotic factors, and consequent cytosolic cytochrome c release and caspase-3 cleavage. Rottlerin-mediated action was significantly reversed by SL327, an ERK inhibitor. SIGNIFICANCE Our results suggest that late- and post-ictal treatment with rottlerin attenuates TMT-induced delayed neuronal apoptosis in the dentate gyrus of mice via promotion of neurogenesis and inhibition of an on-going apoptotic process through up-regulation of p-ERK.
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Affiliation(s)
- Yeonggwang Hwang
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon 24341, Republic of Korea
| | - Hyoung-Chun Kim
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon 24341, Republic of Korea.
| | - Eun-Joo Shin
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Chunchon 24341, Republic of Korea.
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9
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Gray SC, Kinghorn KJ, Woodling NS. Shifting equilibriums in Alzheimer's disease: the complex roles of microglia in neuroinflammation, neuronal survival and neurogenesis. Neural Regen Res 2020; 15:1208-1219. [PMID: 31960800 PMCID: PMC7047786 DOI: 10.4103/1673-5374.272571] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 09/02/2019] [Accepted: 10/22/2019] [Indexed: 12/13/2022] Open
Abstract
Alzheimer's disease is the leading cause of dementia. Its increased prevalence in developed countries, due to the sharp rise in ageing populations, presents one of the costliest challenges to modern medicine. In order to find disease-modifying therapies to confront this challenge, a more complete understanding of the pathogenesis of Alzheimer's disease is necessary. Recent studies have revealed increasing evidence for the roles played by microglia, the resident innate immune system cells of the brain. Reflecting the well-established roles of microglia in reacting to pathogens and inflammatory stimuli, there is now a growing literature describing both protective and detrimental effects for individual cytokines and chemokines produced by microglia in Alzheimer's disease. A smaller but increasing number of studies have also addressed the divergent roles played by microglial neurotrophic and neurogenic factors, and how their perturbation may play a key role in the pathogenesis of Alzheimer's disease. Here we review recent findings on the roles played by microglia in neuroinflammation, neuronal survival and neurogenesis in Alzheimer's disease. In each case, landmark studies have provided evidence for the divergent ways in which microglia can either promote neuronal function and survival, or perturb neuronal function, leading to cell death. In many cases, the secreted molecules of microglia can lead to divergent effects depending on the magnitude and context of microglial activation. This suggests that microglial functions must be maintained in a fine equilibrium, in order to support healthy neuronal function, and that the cellular microenvironment in the Alzheimer's disease brain disrupts this fine balance, leading to neurodegeneration. Thus, an understanding of microglial homeostasis, both in health and across the trajectory of the disease state, will improve our understanding of the pathogenic mechanisms underlying Alzheimer's disease, and will hopefully lead to the development of microglial-based therapeutic strategies to restore equilibrium in the Alzheimer's disease brain.
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Affiliation(s)
- Sophie C. Gray
- Institute of Healthy Ageing and Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Kerri J. Kinghorn
- Institute of Healthy Ageing and Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Nathaniel S. Woodling
- Institute of Healthy Ageing and Department of Genetics, Evolution and Environment, University College London, London, UK
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10
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Serhan A, Boddeke E, Kooijman R. Insulin-Like Growth Factor-1 Is Neuroprotective in Aged Rats With Ischemic Stroke. Front Aging Neurosci 2019; 11:349. [PMID: 31920629 PMCID: PMC6918863 DOI: 10.3389/fnagi.2019.00349] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 11/29/2019] [Indexed: 01/01/2023] Open
Abstract
Post-stroke systemic injections of insulin-like growth factor-1 (IGF-1) exert neuroprotective effects in rats. In the current study, we aimed to test the efficacy of IGF-1 neuroprotection in aged rats (24–25 months old) and to compare the results with adult rats (6–7 months old). Furthermore, we addressed putative differences in microglial responses to IGF-1 in adult and aged rats. Rats were subjected to ischemic stroke while they were conscious by infusing endothelin-1 (Et-1) through a guide cannula that was implemented in the vicinity of the middle cerebral artery (MCA). Rats were given subcutaneous injections of IGF-1 (1 mg/kg) at 30 min and 120 min after the insult. Post-stroke IGF-1 treatment reduced the infarct size by 34% and 38% in aged and adult rats, respectively. The IGF-1 treated adult rats also showed significant improvement in sensorimotor function following stroke, while this function was not significantly affected in aged rats. Furthermore, aged rats displayed exaggerated activation of microglia in the ischemic hemisphere. Significant reduction of microglial activation by IGF-1 was only detected at specific regions in the ipsilateral hemisphere of adult rats. We show that IGF-1 reduced infarct size in aged rats with an ischemic stroke. It remains to be established, however, whether the age-related changes in microglial function affect the improvement in behavioral outcomes.
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Affiliation(s)
- Ahmad Serhan
- Department of Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium.,Department of Neuroscience, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Erik Boddeke
- Department of Neuroscience, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Ron Kooijman
- Department of Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
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11
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Norling AM, Gerstenecker AT, Buford TW, Khan B, Oparil S, Lazar RM. The role of exercise in the reversal of IGF-1 deficiencies in microvascular rarefaction and hypertension. GeroScience 2019; 42:141-158. [PMID: 31808026 DOI: 10.1007/s11357-019-00139-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 11/19/2019] [Indexed: 12/18/2022] Open
Abstract
Hypertension has been linked with peripheral and central reductions in vascular density, and with devastating effects on brain function. However, the underlying mechanisms in the relationship between blood pressure and cognitive impairment have yet to be fully elucidated. Here, we review compelling evidence from two lines of inquiry: one that links microvascular rarefaction with insulin-like growth factor 1 (IGF-1) deficiencies, and another which posits that vascular dysfunction precedes hypertension. Based on the findings from experimental and clinical studies, we propose that these lines of evidence converge, and suggest that age-related declines in IGF-1 concentrations precede microvascular rarefaction, initiate an increase in vascular resistance, and therefore are causally linked to onset of hypertension. Physical exercise provides a relevant model for supporting our premise, given the well-established effects of exercise in attenuating vascular dysfunction, hypertension, IGF-1 deficiency, and cognitive decline. We highlight here the role of exercise-induced increases in blood flow in improving vascular integrity and enhancing angiogenesis via the actions of IGF-1, resulting in reversal of rarefaction and hypertension, and enhancement of cerebral blood flow and cognition.
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Affiliation(s)
- Amani M Norling
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.,The UAB Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Alabama, AL, 35294, USA
| | - Adam T Gerstenecker
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.,The UAB Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Alabama, AL, 35294, USA
| | - Thomas W Buford
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Bilal Khan
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Suzanne Oparil
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Ronald M Lazar
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA. .,The UAB Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Alabama, AL, 35294, USA.
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12
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Lee TK, Park JH, Ahn JH, Kim H, Song M, Lee JC, Kim JD, Jeon YH, Choi JH, Lee CH, Hwang IK, Yan BC, Won MH, Kang IJ. Pretreatment of Populus tomentiglandulosa protects hippocampal CA1 pyramidal neurons from ischemia-reperfusion injury in gerbils via increasing SODs expressions and maintaining BDNF and IGF-I expressions. Chin J Nat Med 2019; 17:424-434. [PMID: 31262455 DOI: 10.1016/s1875-5364(19)30050-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Indexed: 12/31/2022]
Abstract
To examine the effects of Populus tomentiglandulosa (PT) extract on the expressions of antioxidant enzymes and neurotrophic factors in the cornu ammonis 1 (CA1) region of the hippocampus at 5 min after inducing transient global cerebral ischemia (TGCI) in gerbils, TGCI was induced by occlusion of common carotid arteries for 5 min. Before ischemic surgery, 200 mg·kg-1 PT extract was orally administrated once daily for 7 d. We performed neuronal nuclear antigen immunohistochemistry and Fluoro-Jade B staining. Furthermore, we determined in situ production of superoxide anion radical, expression levels of SOD1 and SOD2 as antioxidant enzymes and brain-derived neurotrophic factor (BDNF) and insulin-like growth factor I (IGF-I) as neurotrophic factors. Pretreatment with 200 mg·kg-1 PT extract prevented neuronal death (loss). Furthermore, pretreatment with 200 mg·kg-1 PT extract significantly inhibited the production of superoxide anion radical, increased expressions of SODs and maintained expressions of BDNF and IGF-I. Such increased expressions of SODs were maintained in the neurons after IRI. In summary, pretreated PT extract can significantly increase levels of SODs and protect the neurons against TGCI, suggesting that PT can be a useful natural agent to protect against TGCI.
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Affiliation(s)
- Tae-Kyeong Lee
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Joon Ha Park
- Department of Biomedical Science, Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Ji Hyeon Ahn
- Department of Biomedical Science, Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Hyunjung Kim
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Minah Song
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Jae-Chul Lee
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Jong Dai Kim
- Division of Food Biotechnology, School of Biotechnology, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Yong Hwan Jeon
- Department of Radiology, School of Medicine, Kangwon National University, Chuncheon 24289, Republic of Korea
| | - Jung Hoon Choi
- Department of Anatomy, College of Veterinary Medicine, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Choong Hyun Lee
- Department of Pharmacy, College of Pharmacy, Dankook University, Cheonan 31116, Republic of Korea
| | - In Koo Hwang
- Department of Anatomy and Cell Biology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Bing-Chun Yan
- Jiangsu Key Laboratory of Integrated Traditional Chinese, Western Medicine for Prevention and Treatment of Senile Diseases, Yangzhou 225001, China
| | - Moo-Ho Won
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon 24341, Republic of Korea.
| | - Il Jun Kang
- Department of Food Science and Nutrition, Hallym University, Chuncheon 24252, Republic of Korea.
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13
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Banagozar Mohammadi A, Sadigh-Eteghad S, Torbati M, Bagher Fazljou SM, Vatandoust SM, Ej Golzari S, Farajdokht F, Mahmoudi J. Identification and applications of neuroactive silk proteins: a narrative review. J Appl Biomed 2019; 17:147-156. [PMID: 34907702 DOI: 10.32725/jab.2019.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 03/20/2019] [Indexed: 01/24/2023] Open
Abstract
In traditional medicine, natural silk is regarded as a cognitive enhancer and a cure for ameliorating the symptoms of heart disease, atherosclerosis, and metabolic disorders. In this review, general characteristics of both silk proteins, fibroin and sericin, extracted from silkworm Bombyx mori and their potential use in the neuronal disorders was discussed. Evidence shows that silk proteins exhibit neuroprotective effects in models of neurotoxicity. The antioxidant, neuroprotective, and acetylcholinesterase inhibitory mechanisms of silk proteins could prove promising in the treatment of neurodegenerative diseases. Owing to their excellent neurocompatibility and physicochemical properties, silk proteins have been used as scaffolds and drug delivery materials in the neuronal tissue engineering. These data support the potential of silk proteins as an effective complementary agent for central and peripheral neurological disorders.
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Affiliation(s)
- Ahad Banagozar Mohammadi
- Tabriz University of Medical Sciences, Faculty of Traditional Medicine, Department of Traditional Medicine, Tabriz, Iran.,Tabriz University of Medical Sciences, Neurosciences Research Center (NSRC), Tabriz, Iran
| | - Saeed Sadigh-Eteghad
- Tabriz University of Medical Sciences, Neurosciences Research Center (NSRC), Tabriz, Iran
| | - Mohammadali Torbati
- Tabriz University of Medical Sciences, Faculty of Nutrition, Department of Food Science and Technology, Tabriz, Iran
| | - Seyyed Mohammad Bagher Fazljou
- Tabriz University of Medical Sciences, Faculty of Traditional Medicine, Department of Traditional Medicine, Tabriz, Iran
| | - Seyed Mehdi Vatandoust
- Tabriz University of Medical Sciences, Neurosciences Research Center (NSRC), Tabriz, Iran
| | - Samad Ej Golzari
- Tabriz University of Medical Sciences, Research Center for Evidence Based Medicine, Tabriz, Iran.,Tabriz University of Medical Sciences, Health Management and Safety Promotion Research Institute, Road Traffic Injury Research Center, Tabriz, Iran
| | - Fereshteh Farajdokht
- Tabriz University of Medical Sciences, Neurosciences Research Center (NSRC), Tabriz, Iran
| | - Javad Mahmoudi
- Tabriz University of Medical Sciences, Neurosciences Research Center (NSRC), Tabriz, Iran
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14
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Wrigley S, Arafa D, Tropea D. Insulin-Like Growth Factor 1: At the Crossroads of Brain Development and Aging. Front Cell Neurosci 2017; 11:14. [PMID: 28203146 PMCID: PMC5285390 DOI: 10.3389/fncel.2017.00014] [Citation(s) in RCA: 143] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/16/2017] [Indexed: 12/15/2022] Open
Abstract
Insulin-like growth factor 1 (IGF1) is a polypeptide hormone structurally similar to insulin. It is central to the somatotropic axis, acting downstream of growth hormone (GH). It activates both the mitogen-activated protein (MAP) kinase and PI3K signaling pathways, acting in almost every tissue in the body to promote tissue growth and maturation through upregulation of anabolic processes. Overall GH and IGF1 signaling falls with age, suggesting that it is this reduced IGF1 activity that leads to age-related changes in organisms. However, mutations that reduce IGF1-signaling activity can dramatically extend the lifespan of organisms. Therefore, the role of IGF1 in the overall aging process is unclear. This review article will focus on the role of IGF1 in brain development and aging. The evidence points towards a role for IGF1 in neurodevelopment both prenatally and in the early post-natal period, and in plasticity and remodeling throughout life. This review article will then discuss the hallmarks of aging and cognitive decline associated with falls in IGF1 levels towards the end of life. Finally, the role of IGF1 will be discussed within the context of both neuropsychiatric disorders caused by impaired development of the nervous system, and neurodegenerative disorders associated with aging. IGF1 and its derivatives are shown to improve the symptoms of certain neuropsychiatric disorders caused by deranged neurodevelopment and these effects have been correlated with changes in the underlying biology in both in vitro and in vivo studies. On the other hand, studies looking at IGF1 in neurodegenerative diseases have been conflicting, supporting both a role for increased and decreased IGF1 signaling in the underlying pathogenesis of these diseases.
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Affiliation(s)
- Sarah Wrigley
- School of Medicine, Trinity College Dublin Dublin, Ireland
| | - Donia Arafa
- School of Medicine, Trinity College Dublin Dublin, Ireland
| | - Daniela Tropea
- Neuropsychiatric Genetics, Trinity Translational Medicine Institute St. James HospitalDublin, Ireland; Institute of Neuroscience, Trinity College DublinDublin, Ireland
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15
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Morel GR, León ML, Uriarte M, Reggiani PC, Goya RG. Therapeutic potential of IGF-I on hippocampal neurogenesis and function during aging. NEUROGENESIS 2016; 4:e1259709. [PMID: 28405590 DOI: 10.1080/23262133.2016.1259709] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 11/03/2016] [Accepted: 11/05/2016] [Indexed: 10/20/2022]
Abstract
In rats, learning and memory performance decline during normal aging, which is paralleled by a severe reduction of the levels of neurogenesis in the hippocampal dentate gyrus (DG). A promising therapeutic strategy to restore neurogenesis in the hippocampus of old rats and their spatial memory involves the use of insulin-like growth factor-I (IGF-I). The peptide exerts pleiotropic effects in the brain, regulating multiple cellular processes. Thus, 4-week intracerebroventricular (ICV) perfusion of IGF-I significantly restored spatial memory and hippocampal neurogenesis in old male rats. Similar results were achieved by ICV IGF-I gene therapy in aging female rats. Thus, the treatment seemed to increase the number of immature neurons in the DG of 28 mo old rats, which was paralleled by an increase in the accuracy of the animals to remember specific patterns, which is known as pattern separation memory. The DG is thought to be the main hippocampal structure involved in pattern separation memory and there is evidence that the level of neurogenesis in the DG is directly related to pattern separation performance in rodents. Summing up, IGF-I emerges as a promising restorative molecule for increasing hippocampal neurogenesis and memory accuracy in aged individuals and possibly, in neurodegenerative pathologies.
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Affiliation(s)
- Gustavo R Morel
- INIBIOLP- Histology B - Pathology B; School of Medicine, UNLP , La Plata, Argentina
| | - Micaela López León
- INIBIOLP- Histology B - Pathology B; School of Medicine, UNLP , La Plata, Argentina
| | - Maia Uriarte
- INIBIOLP- Histology B - Pathology B; School of Medicine, UNLP , La Plata, Argentina
| | - Paula C Reggiani
- INIBIOLP- Histology B - Pathology B; School of Medicine, UNLP , La Plata, Argentina
| | - Rodolfo G Goya
- INIBIOLP- Histology B - Pathology B; School of Medicine, UNLP , La Plata, Argentina
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16
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More SV, Kumar H, Cho DY, Yun YS, Choi DK. Toxin-Induced Experimental Models of Learning and Memory Impairment. Int J Mol Sci 2016; 17:E1447. [PMID: 27598124 PMCID: PMC5037726 DOI: 10.3390/ijms17091447] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 08/24/2016] [Accepted: 08/25/2016] [Indexed: 02/07/2023] Open
Abstract
Animal models for learning and memory have significantly contributed to novel strategies for drug development and hence are an imperative part in the assessment of therapeutics. Learning and memory involve different stages including acquisition, consolidation, and retrieval and each stage can be characterized using specific toxin. Recent studies have postulated the molecular basis of these processes and have also demonstrated many signaling molecules that are involved in several stages of memory. Most insights into learning and memory impairment and to develop a novel compound stems from the investigations performed in experimental models, especially those produced by neurotoxins models. Several toxins have been utilized based on their mechanism of action for learning and memory impairment such as scopolamine, streptozotocin, quinolinic acid, and domoic acid. Further, some toxins like 6-hydroxy dopamine (6-OHDA), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and amyloid-β are known to cause specific learning and memory impairment which imitate the disease pathology of Parkinson's disease dementia and Alzheimer's disease dementia. Apart from these toxins, several other toxins come under a miscellaneous category like an environmental pollutant, snake venoms, botulinum, and lipopolysaccharide. This review will focus on the various classes of neurotoxin models for learning and memory impairment with their specific mechanism of action that could assist the process of drug discovery and development for dementia and cognitive disorders.
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Affiliation(s)
- Sandeep Vasant More
- Department of Biotechnology, College of Biomedical and Health Science, Konkuk University, Chungju 27478, Korea.
| | - Hemant Kumar
- Department of Biotechnology, College of Biomedical and Health Science, Konkuk University, Chungju 27478, Korea.
| | - Duk-Yeon Cho
- Department of Biotechnology, College of Biomedical and Health Science, Konkuk University, Chungju 27478, Korea.
| | - Yo-Sep Yun
- Department of Biotechnology, College of Biomedical and Health Science, Konkuk University, Chungju 27478, Korea.
| | - Dong-Kug Choi
- Department of Biotechnology, College of Biomedical and Health Science, Konkuk University, Chungju 27478, Korea.
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17
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Song Y, Pimentel C, Walters K, Boller L, Ghiasvand S, Liu J, Staley KJ, Berdichevsky Y. Neuroprotective levels of IGF-1 exacerbate epileptogenesis after brain injury. Sci Rep 2016; 6:32095. [PMID: 27561791 PMCID: PMC4999804 DOI: 10.1038/srep32095] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 08/02/2016] [Indexed: 02/06/2023] Open
Abstract
Exogenous Insulin-Like Growth Factor-1 (IGF-1) is neuroprotective in animal models of brain injury, and has been considered as a potential therapeutic. Akt-mTOR and MAPK are downstream targets of IGF-1 signaling that are activated after brain injury. However, both brain injury and mTOR are linked to epilepsy, raising the possibility that IGF-1 may be epileptogenic. Here, we considered the role of IGF-1 in development of epilepsy after brain injury, using the organotypic hippocampal culture model of post-traumatic epileptogenesis. We found that IGF-1 was neuroprotective within a few days of injury but that long-term IGF-1 treatment was pro-epileptic. Pro-epileptic effects of IGF-1 were mediated by Akt-mTOR signaling. We also found that IGF-1 - mediated increase in epileptic activity led to neurotoxicity. The dualistic nature of effects of IGF-1 treatment demonstrates that anabolic enhancement through IGF-1 activation of mTOR cascade can be beneficial or harmful depending on the stage of the disease. Our findings suggest that epilepsy risk may need to be considered in the design of neuroprotective treatments for brain injury.
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Affiliation(s)
- Yu Song
- Bioengineering Program, Lehigh University, Bethlehem, PA 18015, USA
| | - Corrin Pimentel
- Bioengineering Program, Lehigh University, Bethlehem, PA 18015, USA
| | - Katherine Walters
- Integrated Degree in Engineering, Arts, and Sciences (IDEAS) Program, Lehigh University, PA 18015, USA
| | - Lauren Boller
- Bioengineering Program, Lehigh University, Bethlehem, PA 18015, USA
| | | | - Jing Liu
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Kevin J Staley
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02129, USA.,Harvard Medical School, Boston, MA 02129, USA
| | - Yevgeny Berdichevsky
- Bioengineering Program, Lehigh University, Bethlehem, PA 18015, USA.,Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA
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18
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p53 isoforms regulate astrocyte-mediated neuroprotection and neurodegeneration. Cell Death Differ 2016; 23:1515-28. [PMID: 27104929 DOI: 10.1038/cdd.2016.37] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 03/11/2016] [Accepted: 03/19/2016] [Indexed: 12/25/2022] Open
Abstract
Bidirectional interactions between astrocytes and neurons have physiological roles in the central nervous system and an altered state or dysfunction of such interactions may be associated with neurodegenerative diseases, such as Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS). Astrocytes exert structural, metabolic and functional effects on neurons, which can be either neurotoxic or neuroprotective. Their neurotoxic effect is mediated via the senescence-associated secretory phenotype (SASP) involving pro-inflammatory cytokines (e.g., IL-6), while their neuroprotective effect is attributed to neurotrophic growth factors (e.g., NGF). We here demonstrate that the p53 isoforms Δ133p53 and p53β are expressed in astrocytes and regulate their toxic and protective effects on neurons. Primary human astrocytes undergoing cellular senescence upon serial passaging in vitro showed diminished expression of Δ133p53 and increased p53β, which were attributed to the autophagic degradation and the SRSF3-mediated alternative RNA splicing, respectively. Early-passage astrocytes with Δ133p53 knockdown or p53β overexpression were induced to show SASP and to exert neurotoxicity in co-culture with neurons. Restored expression of Δ133p53 in near-senescent, otherwise neurotoxic astrocytes conferred them with neuroprotective activity through repression of SASP and induction of neurotrophic growth factors. Brain tissues from AD and ALS patients possessed increased numbers of senescent astrocytes and, like senescent astrocytes in vitro, showed decreased Δ133p53 and increased p53β expression, supporting that our in vitro findings recapitulate in vivo pathology of these neurodegenerative diseases. Our finding that Δ133p53 enhances the neuroprotective function of aged and senescent astrocytes suggests that the p53 isoforms and their regulatory mechanisms are potential targets for therapeutic intervention in neurodegenerative diseases.
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19
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Lycium barbarum Polysaccharides Protect against Trimethyltin Chloride-Induced Apoptosis via Sonic Hedgehog and PI3K/Akt Signaling Pathways in Mouse Neuro-2a Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:9826726. [PMID: 27143997 PMCID: PMC4838808 DOI: 10.1155/2016/9826726] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 02/19/2016] [Accepted: 03/10/2016] [Indexed: 02/04/2023]
Abstract
Trimethyltin chloride (TMT) is a classic neurotoxicant that can cause severe neurodegenerative diseases. Some signaling pathways involving cell death play pivotal roles in the central nervous system. In this study, the role of Sonic Hedgehog (Shh) and PI3K/Akt pathways in TMT-induced apoptosis and protective effect of Lycium barbarum polysaccharides (LBP) on mouse neuro-2a (N2a) cells were investigated. Results showed that TMT treatment significantly enhanced apoptosis, upregulated proapoptotic Bax, downregulated antiapoptotic Bcl-2 expression, and increased caspase-3 activity in a dose-dependent manner in N2a cells. TMT induced oxidative stress in cells, performing reactive oxygen species (ROS) and malondialdehyde (MDA) excessive generation, and superoxide dismutase (SOD) activity reduction. TMT significantly decreased phosphorylated glycogen synthase kinase-3β (GSK-3β) and inhibited Shh and PI3K/Akt pathways. However, the addition of LBP upregulated GSK-3β phosphorylation, activated Shh and PI3K/Akt pathways, and eventually reduced apoptosis and oxidative stress caused by TMT. The interaction between Shh and PI3K/Akt pathways was clarified by specific PI3K inhibitor LY294002 or Shh inhibitor GDC-0449. Moreover, LY294002 and GDC-0449 pretreatment both induced phosphorylated GSK-3β downregulation and significantly promoted apoptosis induced by TMT. These results suggest that LBP could reduce TMT-induced N2a cells apoptosis by regulating GSK-3β phosphorylation, Shh, and PI3K/Akt signaling pathways.
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After Myocardial Ischemia-Reperfusion, miR-29a, and Let7 Could Affect Apoptosis through Regulating IGF-1. BIOMED RESEARCH INTERNATIONAL 2015; 2015:245412. [PMID: 26844226 PMCID: PMC4710957 DOI: 10.1155/2015/245412] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 10/10/2015] [Accepted: 12/09/2015] [Indexed: 12/14/2022]
Abstract
Cardiovascular and cerebrovascular ischemic disease is a large class of diseases that is harmful to human health. The primary treatment for the ischemic disease is to recover the blood perfusion and relieve the tissue hypoxia and the shortage of the nutrients in the supply of nutrients. In recent years, investigations found that IGF-1 has a protective effect on cardiovascular disease, especially in myocardial ischemia-reperfusion injury. Investigation into molecular mechanism of ischemia-reperfusion injury may offer potential targets for the development of novel diagnostic strategies. In this study we defined IGF-1 was differentially expressed in the I/R model of the Mus musculus and IGF-1 was the target gene of miR-29a and Let7f. After ischemia-reperfusion, the expression of miR-29a and Let7f increased, while the expression of IGF-1 decreased significantly in the animal model assay. Further studies have found that IGF-1 could inhibit cell apoptosis signaling pathway, thus protecting the reperfusion injury. These results provide new understanding of ischemia-reperfusion injury, with the hope of offering theoretical support for future therapeutic studies.
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Xiong JY, Li SC, Sun YX, Zhang XS, Dong ZZ, Zhong P, Sun XR. Long-term treadmill exercise improves spatial memory of male APPswe/PS1dE9 mice by regulation of BDNF expression and microglia activation. Biol Sport 2015; 32:295-300. [PMID: 26681831 PMCID: PMC4672160 DOI: 10.5604/20831862.1163692] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 01/30/2015] [Accepted: 05/22/2015] [Indexed: 12/28/2022] Open
Abstract
Increasing evidence suggests that physical activity could delay or attenuate the symptoms of Alzheimer's disease (AD). But the underlying mechanisms are still not fully understood. To investigate the effect of long-term treadmill exercise on the spatial memory of AD mice and the possible role of β-amyloid, brain-derived neurotrophic factor (BDNF) and microglia in the effect, male APPswe/PS1dE9 AD mice aged 4 months were subjected to treadmill exercise for 5 months with 6 sessions per week and gradually increased load. A Morris water maze was used to evaluate the spatial memory. Expression levels of β-amyloid, BDNF and Iba-1 (a microglia marker) in brain tissue were detected by immunohistochemistry. Sedentary AD mice and wildtype C57BL/6J mice served as controls. The results showed that 5-month treadmill exercise significantly decreased the escape latencies (P < 0.01 on the 4th day) and improved the spatial memory of the AD mice in the water maze test. Meanwhile, treadmill exercise significantly increased the number of BDNF-positive cells and decreased the ratios of activated microglia in both the cerebral cortex and the hippocampus. However, treadmill exercise did not significantly alleviate the accumulation of β-amyloid in either the cerebral cortex or the hippocampus of the AD mice (P > 0.05). The study suggested that long-term treadmill exercise could improve the spatial memory of the male APPswe/PS1dE9 AD mice. The increase in BDNF-positive cells and decrease in activated microglia might underpin the beneficial effect.
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Affiliation(s)
- J Y Xiong
- School of Physical Education, Lingnan Normal University, Zhanjiang 524048, China ; Equal contribution
| | - S C Li
- School of Physical Education, Lingnan Normal University, Zhanjiang 524048, China ; Equal contribution
| | - Y X Sun
- Library of Mudanjiang Medical University, Mudanjiang 157011, China ; Equal contribution
| | - X S Zhang
- School of Physical Education, Lingnan Normal University, Zhanjiang 524048, China ; Equal contribution
| | - Z Z Dong
- The Second Affiliated Hospital, Wenzhou Medical University, Wenzhou 325200, China
| | - P Zhong
- Laboratory of Physiological Science, Guangdong Medical University, Dongguan 523808, China
| | - X R Sun
- Key Laboratory for Medical Molecular Diagnostics of Guangdong Province, Guangdong Medical University, Dongguan 523808, China ; Institute of Aging Research, Dongguan Scientific Center, Guangdong Medical University, Dongguan 523808, China
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Wadowska M, Woods J, Rogozinska M, Briones TL. Neuroprotective effects of enriched environment housing after transient global cerebral ischaemia are associated with the upregulation of insulin-like growth factor-1 signalling. Neuropathol Appl Neurobiol 2015; 41:544-56. [PMID: 24750178 PMCID: PMC4201886 DOI: 10.1111/nan.12146] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 04/08/2014] [Indexed: 11/30/2022]
Abstract
Aims Use of enriched environment (EE) housing has been shown to promote recovery from cerebral ischaemic injury but the underlying mechanisms of their beneficial effects remains unclear. Here we examined whether the beneficial effects of EE housing on ischaemia‐induced neurodegeneration and cognitive impairment are associated with increased insulin‐like growth factor‐1 (IGF‐1) signalling in the hippocampus. Methods Forty‐two adult male Wistar rats were included in the study and received either ischaemia or sham surgery. Rats in each group were further randomized to either: EE or standard laboratory cage housing (control). Rats were placed in their assigned housing condition immediately after recovery from anaesthesia. Behavioural testing in the cued learning and discrimination learning tasks were conducted 2 weeks after ischaemia. Rats were euthanized after behavioural testing and the hippocampus was analysed for IGF‐1 level, IGF‐1 receptor (IGF‐1R) activation, protein kinase B (Akt) pathway activation, neurone loss and caspase 3 expression. Results Our data showed that EE housing: (1) mitigated ischaemia‐induced neuronal loss; (2) attenuated ischaemia‐induced increase in caspase 3 immunoreactivity in the hippocampus; (3) ameliorated ischaemia‐induced cognitive impairments; and (4) increased IGF‐1R activation and signalling through the Akt pathway after ischaemic injury. Conclusion Ultimately, these findings suggest the possibility that IGF‐1 signalling may be one of the underlying mechanisms involved in the beneficial effects of EE in optimizing recovery following cerebral ischaemic injury.
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Affiliation(s)
- Magdalena Wadowska
- Department of Biobehavioral Health Science, University of Illinois at Chicago, Chicago, IL, USA
| | - Julie Woods
- Department of Biobehavioral Health Science, University of Illinois at Chicago, Chicago, IL, USA
| | - Magdalena Rogozinska
- Department of Biobehavioral Health Science, University of Illinois at Chicago, Chicago, IL, USA
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Barrientos RM, Kitt MM, Watkins LR, Maier SF. Neuroinflammation in the normal aging hippocampus. Neuroscience 2015; 309:84-99. [PMID: 25772789 DOI: 10.1016/j.neuroscience.2015.03.007] [Citation(s) in RCA: 228] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 02/25/2015] [Accepted: 03/04/2015] [Indexed: 02/01/2023]
Abstract
A consequence of normal aging is a greater susceptibility to memory impairments following an immune challenge such as infection, surgery, or traumatic brain injury. The neuroinflammatory response, produced by these challenges results in increased and prolonged production of pro-inflammatory cytokines in the otherwise healthy aged brain. Here we discuss the mechanisms by which long-lasting elevations in pro-inflammatory cytokines in the hippocampus produce memory impairments. Sensitized microglia are a primary source of this exaggerated neuroinflammatory response and appear to be a hallmark of the normal aging brain. We review the current understanding of the causes and effects of normal aging-induced microglial sensitization, including dysregulations of the neuroendocrine system, potentiation of neuroinflammatory responses following an immune challenge, and the impairment of memories. We end with a discussion of therapeutic approaches to prevent these deleterious effects.
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Affiliation(s)
- R M Barrientos
- Dept. of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA.
| | - M M Kitt
- Dept. of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA
| | - L R Watkins
- Dept. of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA
| | - S F Maier
- Dept. of Psychology and Neuroscience, Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA
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Chen Z, Yang S, He Y, Song C, Liu Y. Effect of sericin on diabetic hippocampal growth hormone/insulin-like growth factor 1 axis. Neural Regen Res 2014; 8:1756-64. [PMID: 25206472 PMCID: PMC4145953 DOI: 10.3969/j.issn.1673-5374.2013.19.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 04/07/2013] [Indexed: 01/23/2023] Open
Abstract
Previous studies have shown that sericin extracted from silk cocoon significantly reduces blood glucose levels and protects the nervous system against diabetes mellitus. In this study, a rat type 2 diabetes mellitus model was established by intraperitoneal injection of 25 mg/kg streptozotocin for 3 successive days, following which the rats were treated with sericin for 35 days. After treatment, the blood glucose levels of the diabetic rats decreased significantly, the growth hormone level in serum and its expression in the hippocampus decreased significantly, while the insulin-like growth factor-1 level in serum and insulin-like growth factor-1 and growth hormone receptor expression in the hippocampus increased significantly. The experimental findings indicate that sericin improves disorders of the growth hormone/insulin-like growth factor 1 axis to alleviate hippocampal damage in diabetic rats.
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Affiliation(s)
- Zhihong Chen
- Department of Human Anatomy, Chengde Medical College, Chengde 067000, Hebei Province, China
| | - Songhe Yang
- Department of Human Anatomy, Chengde Medical College, Chengde 067000, Hebei Province, China
| | - Yaqiang He
- Department of Human Anatomy, Chengde Medical College, Chengde 067000, Hebei Province, China
| | - Chengjun Song
- Department of Human Anatomy, Chengde Medical College, Chengde 067000, Hebei Province, China
| | - Yongping Liu
- Department of Biochemistry, Chengde Medical College, Chengde 067000, Hebei Province, China
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Blood brain barrier and neuroinflammation are critical targets of IGF-1-mediated neuroprotection in stroke for middle-aged female rats. PLoS One 2014; 9:e91427. [PMID: 24618563 PMCID: PMC3949985 DOI: 10.1371/journal.pone.0091427] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 02/10/2014] [Indexed: 01/06/2023] Open
Abstract
Ischemia-induced cerebral infarction is more severe in older animals as compared to younger animals, and is associated with reduced availability of insulin-like growth factor (IGF)-1. This study determined the effect of post-stroke IGF-1 treatment, and used microRNA profiling to identify mechanisms underlying IGF-1’s neuroprotective actions. Post-stroke ICV administration of IGF-1 to middle-aged female rats reduced infarct volume by 39% when measured 24h later. MicroRNA analyses of ischemic tissue collected at the early post-stroke phase (4h) indicated that 8 out of 168 disease-related miRNA were significantly downregulated by IGF-1. KEGG pathway analysis implicated these miRNA in PI3K-Akt signaling, cell adhesion/ECM receptor pathways and T-and B-cell signaling. Specific components of these pathways were subsequently analyzed in vehicle and IGF-1 treated middle-aged females. Phospho-Akt was reduced by ischemia at 4h, but elevated by IGF-1 treatment at 24h. IGF-1 induced Akt activation was preceded by a reduction of blood brain barrier permeability at 4h post-stroke and global suppression of cytokines including IL-6, IL-10 and TNF-α. A subset of these cytokines including IL-6 was also suppressed by IGF-1 at 24h post-stroke. These data are the first to show that the temporal and mechanistic components of post-stroke IGF-1 treatment in older animals, and that cellular components of the blood brain barrier may serve as critical targets of IGF-1 in the aging brain.
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Kiray M, Sisman AR, Camsari UM, Evren M, Dayi A, Baykara B, Aksu I, Ates M, Uysal N. Effects of carbon dioxide exposure on early brain development in rats. Biotech Histochem 2014; 89:371-83. [DOI: 10.3109/10520295.2013.872298] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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27
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Uysal N, Kiray M, Sisman AR, Baykara B, Aksu I, Dayi A, Gencoglu C, Evren M, Buyuk E, Cetin F, Acikgoz O. Effects of exercise and poor indoor air quality on learning, memory and blood IGF-1 in adolescent mice. Biotech Histochem 2013; 89:126-35. [DOI: 10.3109/10520295.2013.825318] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Gene expression profiling as a tool to investigate the molecular machinery activated during hippocampal neurodegeneration induced by trimethyltin (TMT) administration. Int J Mol Sci 2013; 14:16817-35. [PMID: 23955266 PMCID: PMC3759937 DOI: 10.3390/ijms140816817] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 08/06/2013] [Accepted: 08/08/2013] [Indexed: 12/31/2022] Open
Abstract
Trimethyltin (TMT) is an organotin compound exhibiting neurotoxicant effects selectively localized in the limbic system and especially marked in the hippocampus, in both experimental animal models and accidentally exposed humans. TMT administration causes selective neuronal death involving either the granular neurons of the dentate gyrus or the pyramidal cells of the Cornu Ammonis, with a different pattern of localization depending on the different species studied or the dosage schedule. TMT is broadly used to realize experimental models of hippocampal neurodegeneration associated with cognitive impairment and temporal lobe epilepsy, though the molecular mechanisms underlying the associated selective neuronal death are still not conclusively clarified. Experimental evidence indicates that TMT-induced neurodegeneration is a complex event involving different pathogenetic mechanisms, probably acting differently in animal and cell models, which include neuroinflammation, intracellular calcium overload, and oxidative stress. Microarray-based, genome-wide expression analysis has been used to investigate the molecular scenario occurring in the TMT-injured brain in different in vivo and in vitro models, producing an overwhelming amount of data. The aim of this review is to discuss and rationalize the state-of-the-art on TMT-associated genome wide expression profiles in order to identify comparable and reproducible data that may allow focusing on significantly involved pathways.
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Kim J, Yang M, Kim SH, Kim JC, Wang H, Shin T, Moon C. Possible role of the glycogen synthase kinase-3 signaling pathway in trimethyltin-induced hippocampal neurodegeneration in mice. PLoS One 2013; 8:e70356. [PMID: 23940567 PMCID: PMC3734066 DOI: 10.1371/journal.pone.0070356] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 06/13/2013] [Indexed: 11/18/2022] Open
Abstract
Trimethyltin (TMT) is an organotin compound with potent neurotoxic effects characterized by neuronal destruction in selective regions, including the hippocampus. Glycogen synthase kinase-3 (GSK-3) regulates many cellular processes, and is implicated in several neurodegenerative disorders. In this study, we evaluated the therapeutic effect of lithium, a selective GSK-3 inhibitor, on the hippocampus of adult C57BL/6 mice with TMT treatment (2.6 mg/kg, intraperitoneal [i.p.]) and on cultured hippocampal neurons (12 days in vitro) with TMT treatment (5 µM). Lithium (50 mg/kg, i.p., 0 and 24 h after TMT injection) significantly attenuated TMT-induced hippocampal cell degeneration, seizure, and memory deficits in mice. In cultured hippocampal neurons, lithium treatment (0–10 mM; 1 h before TMT application) significantly reduced TMT-induced cytotoxicity in a dose-dependent manner. Additionally, the dynamic changes in GSK-3/β-catenin signaling were observed in the mouse hippocampus and cultured hippocampal neurons after TMT treatment with or without lithium. Therefore, lithium inhibited the detrimental effects of TMT on the hippocampal neurons in vivo and in vitro, suggesting involvement of the GSK-3/β-catenin signaling pathway in TMT-induced hippocampal cell degeneration and dysfunction.
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Affiliation(s)
- Juhwan Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju, Republic of Korea
| | - Miyoung Yang
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju, Republic of Korea
- Department of Physiology and Neurosceince Program, Michigan State University, East Lansing, Michigan, United States of America
| | - Sung-Ho Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju, Republic of Korea
| | - Jong-Choon Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju, Republic of Korea
| | - Hongbing Wang
- Department of Physiology and Neurosceince Program, Michigan State University, East Lansing, Michigan, United States of America
| | - Taekyun Shin
- Department of Veterinary Anatomy, College of Veterinary Medicine, Jeju National University, Jeju, Republic of Korea
- * E-mail: (TS); (CM)
| | - Changjong Moon
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and Animal Medical Institute, Chonnam National University, Gwangju, Republic of Korea
- * E-mail: (TS); (CM)
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Álvarez XA, Figueroa J, Muresanu D. Peptidergic drugs for the treatment of traumatic brain injury. FUTURE NEUROLOGY 2013. [DOI: 10.2217/fnl.12.95] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Traumatic brain injury (TBI) is a devastating medical condition that has an enormous socioeconomic impact because it affects more than 10 million people annually worldwide and is associated with high rates of hospitalization, mortality and disability. Although TBI survival has improved continuously for decades, particularly in developing countries, implementation of an effective drug therapy for TBI represents an unmet clinical need. All confirmatory trials conducted to date with drugs targeting a single TBI pathological pathway failed to show clinical efficacy, probably because TBI pathophysiology involves multiple cellular and molecular mechanisms of secondary brain damage. According to current scientific evidence of the participation of peptide-mediated mechanisms in the processes of brain injury and repair after TBI, peptidergic drugs represent a multimodal therapy alternative to improve acute outcome and long-term recovery in TBI patients. Preliminary randomized-controlled clinical trials and open-label studies conducted to date with the peptidergic drug Cerebrolysin® (Ever Neuro Pharma GmbH, Unterach, Austria) and with the endogenous neuropeptides progesterone and erythropoietin, showed positive clinical results. Cerebrolysin-treated patients had a faster clinical recovery, a shorter hospitalization time and a better long-term outcome. Treatment with progesterone showed advantages over placebo regarding TBI mortality and clinical outcome, whereas erythropoietin only reduced mortality. Further validation of these promising findings in confirmatory randomized-controlled clinical trials is warranted. This article reviews the scientific basis and clinical evidence on the development of multimodal peptidergic drugs as a therapeutic option for the effective treatment of TBI patients.
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Affiliation(s)
| | - Jesús Figueroa
- Rehabilitation Department, Santiago University Hospital, Santiago de Compostela, Spain
| | - Dafin Muresanu
- Department of Neurology, University of Medicine & Pharmacy ‘Iuliu Hatieganu’, Cluj-Napoca, Romania
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Kohman RA, DeYoung EK, Bhattacharya TK, Peterson LN, Rhodes JS. Wheel running attenuates microglia proliferation and increases expression of a proneurogenic phenotype in the hippocampus of aged mice. Brain Behav Immun 2012; 26:803-10. [PMID: 22056294 PMCID: PMC3275652 DOI: 10.1016/j.bbi.2011.10.006] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 10/17/2011] [Accepted: 10/18/2011] [Indexed: 11/23/2022] Open
Abstract
Aging is associated with low-grade neuroinflammation including primed microglia that may contribute to deficits in neural plasticity and cognitive function. The current study evaluated whether exercise modulates division and/or activation state of microglia in the dentate gyrus of the hippocampus, as activated microglia can express a classic inflammatory or an alternative neuroprotective phenotype. We also assessed hippocampal neurogenesis to determine whether changes in microglia were associated with new neuron survival. Adult (3.5 months) and aged (18 months) male BALB/c mice were individually housed with or without running wheels for 8 weeks. Mice received bromodeoxyuridine injections during the first or last 10 days of the experiment to label dividing cells. Immunofluorescence was conducted to measure microglia division, co-expression of the neuroprotective indicator insulin-like growth factor (IGF-1), and new neuron survival. The proportion of new microglia was increased in aged mice, and decreased from wheel running. Running increased the proportion of microglia expressing IGF-1 suggesting exercise shifts microglia phenotype towards neuroprotection. Additionally, running enhanced survival of new neurons in both age groups. Findings suggest that wheel running may attenuate microglia division and promote a proneurogenic phenotype in aged mice.
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Affiliation(s)
- Rachel A Kohman
- Department of Psychology, University of Illinois, Beckman Institute, Urbana, IL 61801-3873, USA.
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Exercise inhibits neuronal apoptosis and improves cerebral function following rat traumatic brain injury. J Neural Transm (Vienna) 2011; 118:1263-72. [PMID: 21442353 DOI: 10.1007/s00702-011-0629-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Accepted: 03/13/2011] [Indexed: 10/18/2022]
Abstract
Exercise is reported to inhibit neuronal apoptotic cell death in the hippocampus and improve learning and memory. However, the effect of exercise on inhibition of neuronal apoptosis surrounding the area of damage after traumatic brain injury (TBI) and the improvement of cerebral dysfunction following TBI are unknown. Here, we investigate the effect of exercise on morphology and cerebral function following TBI in rats. Wistar rats received TBI by a pneumatic controlled injury device were randomly divided into two groups: (1) non-exercise group and (2) exercise group. The exercise group ran on a treadmill for 30 min/day at 22 m/min for seven consecutive days. Immunohistochemical and behavioral studies were performed following TBI. The number of single-stranded DNA (ssDNA)-positive cells around the damaged area early after TBI was significantly reduced in the exercise group compared with the non-exercise group (P < 0.05). Furthermore, most ssDNA-positive cells in the non-exercise group co-localized with neuronal cells. However, in the exercise group, a few ssDNA-positive cells co-localized with neurons. In addition, there was a significant increase in neuronal cell number and improvement in cerebral dysfunction after TBI in the exercise group compared with the non-exercise group (P < 0.05). These results indicate that exercise following TBI inhibits neuronal degeneration and apoptotic cell death around the damaged area, which results in improvement of cerebral dysfunction. In summary, treadmill running improved cerebral dysfunction following TBI, indicating its potential as an effective clinical therapy. Therefore, exercise therapy (rehabilitation) in the early phase following TBI is important for recuperation from cerebral dysfunction.
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The adaptor protein SH2B1β reduces hydrogen peroxide-induced cell death in PC12 cells and hippocampal neurons. J Mol Signal 2010; 5:17. [PMID: 20868529 PMCID: PMC2954984 DOI: 10.1186/1750-2187-5-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Accepted: 09/27/2010] [Indexed: 11/25/2022] Open
Abstract
Background SH2B1β is a signaling adaptor protein that has been shown to promote neuronal differentiation in PC12 cells and is necessary for the survival of sympathetic neurons. However, the mechanism by which SH2B1β may influence cell survival is not known. Results In this study, we investigated the role of SH2B1β in oxidative stress-induced cell death. Our results suggest that overexpressing SH2B1β reduced H2O2-induced, caspase 3-dependent apoptosis in PC12 cells and hippocampal neurons. In response to H2O2, overexpressing SH2B1β enhanced PI3K (phosphatidylinositol 3-kinas)-AKT (protein kinase B) and MEK (MAPK/ERK kinase)-extracellular-signal regulated kinases 1 and 2 (ERK1/2) signaling pathways. We further demonstrated that SH2B1β was able to reduce H2O2-induced nuclear localization of FoxO1 and 3a transcription factors, which lie downstream of PI3K-AKT and MEK-ERK1/2 pathways. Moreover, overexpressing SH2B1β reduced the expression of Fas ligand (FasL), one of the target genes of FoxOs. Conclusions Overexpressing the adaptor protein SH2B1β enhanced H2O2-induced PI3K-AKT and MEK-ERK1/2 signaling, reduced nucleus-localized FoxOs and the expression of a pro-apoptotic gene, FasL.
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McPherson CA, Kraft AD, Harry GJ. Injury-induced neurogenesis: consideration of resident microglia as supportive of neural progenitor cells. Neurotox Res 2010; 19:341-52. [PMID: 20524106 DOI: 10.1007/s12640-010-9199-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 04/29/2010] [Accepted: 05/03/2010] [Indexed: 01/26/2023]
Abstract
The induction of neurogenesis in the adult subgranular zone (SGZ) by injury is often accompanied by changes in the extracellular environment that can have significant impacts on neural progenitor cells (NPCs). We examined the induction of neurogenesis in the SGZ at 72 h following an injection of the hippocampal toxicant, trimethyltin (TMT; 2 mg/kg, ip) inducing apoptosis in dentate granule neurons. BrdU+ incorporation during the active period of neuronal death indicated NPC proliferation and migration of newly generated cells into the granule cell layer (GCL). BrdU+ cells were transiently in contact with process bearing microglia within the inner SGZ layer. Contact with GFAP+ astrocyte processes occurred once cells were within the GCL. A small percentage of the BrdU+ cells within the SGZ region showed immunoreactivity for tumor necrosis factor (TNF) p75 receptor (TNFp75R). In mice deficient for TNFp75R, TMT injection produced an equivalent level of dentate granule cell death however; BrdU+ cells were localized at the SGZ as compared to the presence of cells within the GCL in the WT mice dosed with TMT. These data suggest that cells generated by NPCs in the SGZ induced with a focal lesion to the dentate granule neurons of adolescent mice maintain the capacity to utilize the neuroinflammation and microglia responses within their environment for migration into the GCL.
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Affiliation(s)
- Christopher A McPherson
- Neurotoxicology Group, Laboratory of Molecular Toxicology, National Institute of Environmental Health Science, National Institutes of Health, MD C1-04, P.O. Box 12233, Research Triangle Park, NC 27709, USA
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Sun X, Huang L, Zhang M, Sun S, Wu Y. Insulin like growth factor-1 prevents 1-mentyl-4-phenylphyridinium-induced apoptosis in PC12 cells through activation of glycogen synthase kinase-3beta. Toxicology 2010; 271:5-12. [DOI: 10.1016/j.tox.2010.01.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 12/18/2009] [Accepted: 01/05/2010] [Indexed: 10/20/2022]
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Nyberg F. The role of the somatotrophic axis in neuroprotection and neuroregeneration of the addictive brain. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2010; 88:399-427. [PMID: 19897085 DOI: 10.1016/s0074-7742(09)88014-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Early studies have shown that the abuse of alcohol, central stimulants, and opiates such as heroin destroys brain cells, reducing attention span and memory. However, new research has suggested that there may be a way to regain some of the lost attention and recall. It has recently been shown that brain cells targeted for early death by continued opiate use can be salvaged by injections of synthetic human growth hormone (GH). GH is a polypeptide hormone, normally secreted by the anterior pituitary gland, which stimulates cell growth and controls body metabolism. Recombinant human GH is currently used in replacement therapy to alleviate the symptoms of adults and children with GH deficiency syndrome. The recent observation that GH can reverse morphine-induced cell damage could open the door to new ways of treating and preventing damage from the abuse of opiates in addicts and also of treating cell damage induced by alcohol and central stimulants. This article reviews current knowledge of the somatotrophic axis, including GH and insulin-like growth factor-1 (IGF-1), in the brain and also discusses the potential use of GH/IGF-1 as agents for treatment of brain pathology in addictive diseases.
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Affiliation(s)
- Fred Nyberg
- Department of Pharmaceutical Biosciences, Division of Biological Research on Drug Dependence, Uppsala University, S-75124 Uppsala, Sweden
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Cardoso S, Santos R, Correia S, Carvalho C, Zhu X, Lee HG, Casadesus G, Smith MA, Perry G, Moreira PI. Insulin and Insulin-Sensitizing Drugs in Neurodegeneration: Mitochondria as Therapeutic Targets. Pharmaceuticals (Basel) 2009; 2:250-286. [PMID: 27713238 PMCID: PMC3978547 DOI: 10.3390/ph2030250] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 12/21/2009] [Accepted: 12/22/2009] [Indexed: 12/13/2022] Open
Abstract
Insulin, besides its glucose lowering effects, is involved in the modulation of lifespan, aging and memory and learning processes. As the population ages, neurodegenerative disorders become epidemic and a connection between insulin signaling dysregulation, cognitive decline and dementia has been established. Mitochondria are intracellular organelles that despite playing a critical role in cellular metabolism are also one of the major sources of reactive oxygen species. Mitochondrial dysfunction, oxidative stress and neuroinflammation, hallmarks of neurodegeneration, can result from impaired insulin signaling. Insulin-sensitizing drugs such as the thiazolidinediones are a new class of synthetic compounds that potentiate insulin action in the target tissues and act as specific agonists of the peroxisome proliferator-activated receptor gamma (PPAR-γ). Recently, several PPAR agonists have been proposed as novel and possible therapeutic agents for neurodegenerative disorders. Indeed, the literature shows that these agents are able to protect against mitochondrial dysfunction, oxidative damage, inflammation and apoptosis. This review discusses the role of mitochondria and insulin signaling in normal brain function and in neurodegeneration. Furthermore, the potential protective role of insulin and insulin sensitizers in Alzheimer´s, Parkinson´s and Huntington´s diseases and amyotrophic lateral sclerosis will be also discussed.
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Affiliation(s)
- Susana Cardoso
- Center for Neuroscience and Cell Biology, University of Coimbra, 3000-354 Coimbra, Portugal
- Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, 3000- 354 Coimbra, Portugal
| | - Renato Santos
- Center for Neuroscience and Cell Biology, University of Coimbra, 3000-354 Coimbra, Portugal
- Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, 3000- 354 Coimbra, Portugal
| | - Sonia Correia
- Center for Neuroscience and Cell Biology, University of Coimbra, 3000-354 Coimbra, Portugal
- Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, 3000- 354 Coimbra, Portugal
| | - Cristina Carvalho
- Center for Neuroscience and Cell Biology, University of Coimbra, 3000-354 Coimbra, Portugal
- Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, 3000- 354 Coimbra, Portugal
| | - Xiongwei Zhu
- School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Hyoung-Gon Lee
- School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Gemma Casadesus
- School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Mark A Smith
- School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - George Perry
- College of Sciences, The University of Texas at San Antonio, TX 78249, USA
| | - Paula I Moreira
- Center for Neuroscience and Cell Biology, University of Coimbra, 3000-354 Coimbra, Portugal.
- Institute of Physiology, Faculty of Medicine, University of Coimbra, 3000-354 Coimbra, Portugal.
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Kraft AD, McPherson CA, Harry GJ. Heterogeneity of microglia and TNF signaling as determinants for neuronal death or survival. Neurotoxicology 2009; 30:785-93. [PMID: 19596372 PMCID: PMC3329780 DOI: 10.1016/j.neuro.2009.07.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Accepted: 07/01/2009] [Indexed: 12/30/2022]
Abstract
Microglia do not constitute a single, uniform cell population, but rather comprise cells with varied phenotypes, some which are beneficial and others that may require active regulatory control. Thus, gaining a better understanding of the heterogeneity of resident microglia responses will contribute to any interpretation regarding the impact of any such response in the brain. Microglia are the primary source of the pro-inflammatory cytokine, tumor necrosis factor (TNF) that can initiate various effects through the activation of membrane receptors. The TNF p55 receptor contains a death domain and activation normally leads to cellular apoptosis; however, under specific conditions, receptor activation can also lead to the activation of NF-kappaB and contribute to cell survival. These divergent outcomes have been linked to receptor localization with receptor internalization leading to cell death and membrane localization supporting cell survival. A second TNF receptor, TNF p75 receptor, is normally linked to cell growth and survival, however, it can cooperate with the p55 receptor and contribute to cell death. Thus, while an elevation in TNFalpha in the brain is often considered an indicator of microglia activation and neuroinflammation, a number of factors come into play to determine the final outcome. Data are reviewed demonstrating that heterogeneity in morphological response of microglia and the expression of TNFalpha and TNF receptors are critical in identifying and characterizing neurotoxic events as they relate to neuroinflammation, neuronal damage and in stimulating neuroprotection.
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Affiliation(s)
- Andrew D. Kraft
- Neurotoxicology Group, Laboratory of Molecular Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Dept of Health and Human Services, Research Triangle Park, NC
| | - Christopher A McPherson
- Neurotoxicology Group, Laboratory of Molecular Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Dept of Health and Human Services, Research Triangle Park, NC
| | - G. Jean Harry
- Neurotoxicology Group, Laboratory of Molecular Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Dept of Health and Human Services, Research Triangle Park, NC
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