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Song YT, Li SS, Chao CY, Shuang-Guo, Chen GZ, Wang SX, Zhang MX, Yin YL, Li P. Floralozone regulates MiR-7a-5p expression through AMPKα2 activation to improve cognitive dysfunction in vascular dementia. Exp Neurol 2024; 376:114748. [PMID: 38458310 DOI: 10.1016/j.expneurol.2024.114748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 02/07/2024] [Accepted: 03/04/2024] [Indexed: 03/10/2024]
Abstract
BACKGROUND The pathogenesis of vascular dementia (VD) is complex, and currently, no effective treatments have been recommended. Floralozone is a colorless liquid first discovered in Lagotis Gaertn. Recently, its medicinal value has been increasingly recognized. Our previous study has demonstrated that Floralozone can improve cognitive dysfunction in rats with VD by regulating the transient receptor potential melastatin 2 (TRPM2) and N-methyl-D-aspartate receptor (NMDAR) signaling pathways. However, the mechanism by which Floralozone regulates TRPM2 and NMDAR to improve VD remains unclear. AMP-activated protein kinase (AMPK) is an energy regulator in vivo; however, its role of AMPK activation in stroke remains controversial. MiR-7a-5p has been identified to be closely related to neuronal function. PURPOSE To explore whether Floralozone can regulate the miR-7a-5p level in vivo through AMPKα2 activation, affect the TRPM2 and NR2B expression levels, and improve VD symptoms. METHODS The VD model was established by a modified bilateral occlusion of the common carotid arteries (2-VO) of Sprague-Dawley (SD) rats and AMPKα2 KO transgenic (AMPKα2-/-) mice. Primary hippocampal neurons were modeled using oxygen and glucose deprivation (OGD). Morris water maze (MWM) test, hematoxylin-eosin staining (HE staining), and TUNEL staining were used to investigate the effects of Floralozone on behavior and hippocampal morphology in rats. Minichromosome maintenance complex component 2(MCM2) positive cells were used to investigate the effect of Floralozone on neurogenesis. Immunofluorescence staining, qRT-PCR, and western blot analysis were used to investigate the effect of Floralozone on the expression levels of AMPKα2, miR-7a-5p, TRPM2, and NR2B. RESULTS The SD rat experiment revealed that Floralozone improved spatial learning and memory, improved the morphology and structure of hippocampal neurons, reduced apoptosis of hippocampal neurons and promoted neurogenesis in VD rats. Floralozone could increase the miR-7a-5p expression level, activate AMPKα2 and NR2B expressions, and inhibit TRPM2 expression in hippocampal neurons of VD rats. The AMPKα2 KO transgenic (AMPKα2-/-) mice experiment demonstrated that Floralozone could regulate miR-7a-5p, TRPM2, and NR2B expression levels through AMPKα2 activation. The cell experiment revealed that the TRPM2 and NR2B expression levels were regulated by miR-7a-5p, whereas the AMPKα2 expression level was not. CONCLUSION Floralozone could regulate miR-7a-5p expression level by activating the protein expression of AMPKα2, control the protein expression of TRPM2 and NR2B, improve the morphology and structure of hippocampus neurons, reduce the apoptosis of hippocampus neurons, promote neurogenesis and improve the cognitive dysfunction.
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Affiliation(s)
- Yu-Ting Song
- Henan international joint laboratory of cardiovascular remodeling and drug intervention, Sino-UK Joint Laboratory of Brain Function and Injury and Department of Physiology and Neurobiology, School of Basic Medical Sciences, College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China; JinShan Hospital of Fudan University, Shanghai 201508, China
| | - Shan-Shan Li
- Henan international joint laboratory of cardiovascular remodeling and drug intervention, Sino-UK Joint Laboratory of Brain Function and Injury and Department of Physiology and Neurobiology, School of Basic Medical Sciences, College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China
| | - Chun-Yan Chao
- Henan international joint laboratory of cardiovascular remodeling and drug intervention, Sino-UK Joint Laboratory of Brain Function and Injury and Department of Physiology and Neurobiology, School of Basic Medical Sciences, College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China; Huang Huai University, Zhumadian 463000, China
| | - Shuang-Guo
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning 437100, China
| | - Gui-Zi Chen
- Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Shuang-Xi Wang
- Henan international joint laboratory of cardiovascular remodeling and drug intervention, Sino-UK Joint Laboratory of Brain Function and Injury and Department of Physiology and Neurobiology, School of Basic Medical Sciences, College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China
| | - Ming-Xiang Zhang
- Henan international joint laboratory of cardiovascular remodeling and drug intervention, Sino-UK Joint Laboratory of Brain Function and Injury and Department of Physiology and Neurobiology, School of Basic Medical Sciences, College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China
| | - Ya-Ling Yin
- Henan international joint laboratory of cardiovascular remodeling and drug intervention, Sino-UK Joint Laboratory of Brain Function and Injury and Department of Physiology and Neurobiology, School of Basic Medical Sciences, College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China.
| | - Peng Li
- Henan international joint laboratory of cardiovascular remodeling and drug intervention, Sino-UK Joint Laboratory of Brain Function and Injury and Department of Physiology and Neurobiology, School of Basic Medical Sciences, College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China.
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Peivasteh-roudsari L, Barzegar-bafrouei R, Sharifi KA, Azimisalim S, Karami M, Abedinzadeh S, Asadinezhad S, Tajdar-oranj B, Mahdavi V, Alizadeh AM, Sadighara P, Ferrante M, Conti GO, Aliyeva A, Mousavi Khaneghah A. Origin, dietary exposure, and toxicity of endocrine-disrupting food chemical contaminants: A comprehensive review. Heliyon 2023; 9:e18140. [PMID: 37539203 PMCID: PMC10395372 DOI: 10.1016/j.heliyon.2023.e18140] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 07/03/2023] [Accepted: 07/09/2023] [Indexed: 08/05/2023] Open
Abstract
Endocrine-disrupting chemicals (EDCs) are a growing public health concern worldwide. Consumption of foodstuffs is currently thought to be one of the principal exposure routes to EDCs. However, alternative ways of human exposure are through inhalation of chemicals and dermal contact. These compounds in food products such as canned food, bottled water, dairy products, fish, meat, egg, and vegetables are a ubiquitous concern to the general population. Therefore, understanding EDCs' properties, such as origin, exposure, toxicological impact, and legal aspects are vital to control their release to the environment and food. The present paper provides an overview of the EDCs and their possible disrupting impact on the endocrine system and other organs.
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Affiliation(s)
| | - Raziyeh Barzegar-bafrouei
- Department of Food Hygiene and Safety, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Kurush Aghbolagh Sharifi
- Department of Food Science and Technology, Faculty of Agriculture, Urmia University, Urmia, Iran
| | - Shamimeh Azimisalim
- Department of Food Science and Technology, School of Nutrition Sciences and Food Technology, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Marziyeh Karami
- Food Safety and Hygiene Division, Department of Environmental Health Engineering, Tehran University of Medical Sciences, Tehran, Iran
| | - Solmaz Abedinzadeh
- Department of Food Science and Technology, Faculty of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Shabnam Asadinezhad
- Department of Food Science and Engineering, Faculty of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
| | - Behrouz Tajdar-oranj
- Food and Drug Administration of Iran, Ministry of Health and Medical Education, Tehran, Iran
| | - Vahideh Mahdavi
- Iranian Research Institute of Plant Protection, Agricultural Research, Education and Extension Organization (AREEO), P.O. Box 1475744741, Tehran, Iran
| | - Adel Mirza Alizadeh
- Social Determinants of Health Research Center, Zanjan University of Medical Sciences, Zanjan, Iran
- Department of Food Safety and Hygiene, School of Public Health, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Parisa Sadighara
- Food Safety and Hygiene Division, Department of Environmental Health Engineering, Tehran University of Medical Sciences, Tehran, Iran
| | - Margherita Ferrante
- Department of Medical, Surgical and Advanced Technologies “G.F. Ingrassia,” Hygiene and Public Health, University of Catania, Via Santa Sofia 87, 95123, Catania, Italy
| | - Gea Oliveri Conti
- Department of Medical, Surgical and Advanced Technologies “G.F. Ingrassia,” Hygiene and Public Health, University of Catania, Via Santa Sofia 87, 95123, Catania, Italy
| | - Aynura Aliyeva
- Department of Technology of Chemistry, Azerbaijan State Oil and Industry University, Baku, Azerbaijan
| | - Amin Mousavi Khaneghah
- Department of Technology of Chemistry, Azerbaijan State Oil and Industry University, Baku, Azerbaijan
- Department of Fruit and Vegetable Product Technology, Prof. Wacław Dąbrowski Institute of Agricultural and Food Biotechnology – State Research Institute, 36 Rakowiecka St., 02-532, Warsaw, Poland
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Inhibition of VDAC1 Rescues A β 1-42-Induced Mitochondrial Dysfunction and Ferroptosis via Activation of AMPK and Wnt/ β-Catenin Pathways. Mediators Inflamm 2023; 2023:6739691. [PMID: 36816741 PMCID: PMC9937775 DOI: 10.1155/2023/6739691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Revised: 11/04/2022] [Accepted: 11/28/2022] [Indexed: 02/12/2023] Open
Abstract
Beta-amyloid (Aβ) accumulation in the brains of Alzheimer's disease (AD) patients leads to mitochondrial dysfunction and ferroptosis in neurons. Voltage-dependent anion channel 1 (VDAC1) is a major protein in the mitochondrial outer membrane. It has been reported that VDAC1 associated with mitochondrial dysfunction and ferroptosis. However, the mechanism by which VDAC1 regulates mitochondrial dysfunction and ferroptosis of neurons in AD remains unclear. This study is aimed at investigating the mechanism of action of VDAC1 in mitochondrial dysfunction and ferroptosis in neurons of the AD model. In this study, we determined cell viability after treatment with Aβ 1-42 via the MTT assay. The SOD, MDA, ROS, and MMP production was measured via the SOD kit, MDA kit, DCFDA staining, and JC-1 staining. The memory abilities of mice were detected via the Morris water maze test. The expression of AMPK/mTOR, Wnt/β-catenin, and GPX4 regulated by VDAC1 was detected via western blotting. Our present study showed that PC12 cells had decreased cell viability, increased LDH release, and decreased GPX4 expression after Aβ 1-42 treatment. Meanwhile, Aβ 1-42 induced MMP and SOD downregulation and increased MDA and ROS generation in PC12 cells. In addition, the expression of VDAC1 is increased in the brain tissue of AD mice and Aβ 1-42-treated PC12 cells. Further investigation of the role of VDAC1 in regulating AD found that all effects induced by Aβ 1-42 were reversed by inhibition of VDAC1. Additionally, inhibition of VDAC1 activates the AMPK/mTOR and Wnt/β-catenin pathways. Taken together, these findings demonstrate that inhibition of VDAC1 alleviates mitochondrial dysfunction and ferroptosis in AD neurons by activating AMPK/mTOR and Wnt/β-catenin.
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Bustamante-Barrientos FA, Méndez-Ruette M, Molina L, Koning T, Ehrenfeld P, González CB, Wyneken U, Henzi R, Bátiz LF. Alpha-SNAP (M105I) mutation promotes neuronal differentiation of neural stem/progenitor cells through overactivation of AMPK. Front Cell Dev Biol 2023; 11:1061777. [PMID: 37113766 PMCID: PMC10127105 DOI: 10.3389/fcell.2023.1061777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 03/13/2023] [Indexed: 04/29/2023] Open
Abstract
Background: The M105I point mutation in α-SNAP (Soluble N-ethylmaleimide-sensitive factor attachment protein-alpha) leads in mice to a complex phenotype known as hyh (hydrocephalus with hop gait), characterized by cortical malformation and hydrocephalus, among other neuropathological features. Studies performed by our laboratory and others support that the hyh phenotype is triggered by a primary alteration in embryonic neural stem/progenitor cells (NSPCs) that leads to a disruption of the ventricular and subventricular zones (VZ/SVZ) during the neurogenic period. Besides the canonical role of α-SNAP in SNARE-mediated intracellular membrane fusion dynamics, it also negatively modulates AMP-activated protein kinase (AMPK) activity. AMPK is a conserved metabolic sensor associated with the proliferation/differentiation balance in NSPCs. Methods: Brain samples from hyh mutant mice (hydrocephalus with hop gait) (B6C3Fe-a/a-Napahyh/J) were analyzed by light microscopy, immunofluorescence, and Western blot at different developmental stages. In addition, NSPCs derived from WT and hyh mutant mice were cultured as neurospheres for in vitro characterization and pharmacological assays. BrdU labeling was used to assess proliferative activity in situ and in vitro. Pharmacological modulation of AMPK was performed using Compound C (AMPK inhibitor) and AICAR (AMPK activator). Results: α-SNAP was preferentially expressed in the brain, showing variations in the levels of α-SNAP protein in different brain regions and developmental stages. NSPCs from hyh mice (hyh-NSPCs) displayed reduced levels of α-SNAP and increased levels of phosphorylated AMPKα (pAMPKαThr172), which were associated with a reduction in their proliferative activity and a preferential commitment with the neuronal lineage. Interestingly, pharmacological inhibition of AMPK in hyh-NSPCs increased proliferative activity and completely abolished the increased generation of neurons. Conversely, AICAR-mediated activation of AMPK in WT-NSPCs reduced proliferation and boosted neuronal differentiation. Discussion: Our findings support that α-SNAP regulates AMPK signaling in NSPCs, further modulating their neurogenic capacity. The naturally occurring M105I mutation of α-SNAP provokes an AMPK overactivation in NSPCs, thus connecting the α-SNAP/AMPK axis with the etiopathogenesis and neuropathology of the hyh phenotype.
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Affiliation(s)
| | - Maxs Méndez-Ruette
- Neuroscience Program, Centro de Investigación e Innovación Biomédica (CiiB), Universidad de los Andes, Santiago, Chile
- PhD Program in Biomedicine, Facultad de Medicina, Universidad de los Andes, Santiago, Chile
- IMPACT, Center of Interventional Medicine for Precision and Advanced Cellular Therapy, Santiago, Chile
| | - Luis Molina
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Puerto Montt, Chile
| | - Tania Koning
- Instituto de Inmunología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
| | - Pamela Ehrenfeld
- Laboratory of Cellular Pathology, Institute of Anatomy, Histology and Pathology, Faculty of Medicine, Universidad Austral de Chile, Valdivia, Chile
- Center for Interdisciplinary Studies on Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Carlos B. González
- Instituto de Fisiología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile
| | - Ursula Wyneken
- Neuroscience Program, Centro de Investigación e Innovación Biomédica (CiiB), Universidad de los Andes, Santiago, Chile
- IMPACT, Center of Interventional Medicine for Precision and Advanced Cellular Therapy, Santiago, Chile
- School of Medicine, Facultad de Medicina, Universidad de Los Andes, Santiago, Chile
| | - Roberto Henzi
- Neuroscience Program, Centro de Investigación e Innovación Biomédica (CiiB), Universidad de los Andes, Santiago, Chile
- Laboratorio de Reproducción Animal, Escuela de Medicina Veterinaria, Facultad de Recursos Naturales, Universidad Católica de Temuco, Temuco, Chile
- *Correspondence: Luis Federico Bátiz, ; Roberto Henzi,
| | - Luis Federico Bátiz
- Neuroscience Program, Centro de Investigación e Innovación Biomédica (CiiB), Universidad de los Andes, Santiago, Chile
- IMPACT, Center of Interventional Medicine for Precision and Advanced Cellular Therapy, Santiago, Chile
- School of Medicine, Facultad de Medicina, Universidad de Los Andes, Santiago, Chile
- *Correspondence: Luis Federico Bátiz, ; Roberto Henzi,
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Muraleedharan R, Dasgupta B. AMPK in the brain: its roles in glucose and neural metabolism. FEBS J 2021; 289:2247-2262. [PMID: 34355526 DOI: 10.1111/febs.16151] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 07/22/2021] [Accepted: 08/04/2021] [Indexed: 11/28/2022]
Abstract
The adenosine monophosphate-activated protein kinase (AMPK) is an integrative metabolic sensor that maintains energy balance at the cellular level and plays an important role in orchestrating intertissue metabolic signaling. AMPK regulates cell survival, metabolism, and cellular homeostasis basally as well as in response to various metabolic stresses. Studies so far show that the AMPK pathway is associated with neurodegeneration and CNS pathology, but the mechanisms involved remain unclear. AMPK dysregulation has been reported in neurodegenerative diseases such as amyotrophic lateral sclerosis, multiple sclerosis, Alzheimer's disease, Parkinson's disease, Huntington's disease, and other neuropathies. AMPK activation appears to be both neuroprotective and pro-apoptotic, possibly dependent upon neural cell types, the nature of insults, and the intensity and duration of AMPK activation. While embryonic brain development in AMPK null mice appears to proceed normally without any overt structural abnormalities, our recent study confirmed the full impact of AMPK loss in the postnatal and aging brain. Our studies revealed that Ampk deletion in neurons increased basal neuronal excitability and reduced latency to seizure upon stimulation. Three major pathways, glycolysis, pentose phosphate shunt, and glycogen turnover, contribute to utilization of glucose in the brain. AMPK's regulation of aerobic glycolysis in astrocytic metabolism warrants further deliberation, particularly glycogen turnover and shuttling of glucose- and glycogen-derived lactate from astrocytes to neurons during activation. In this minireview, we focus on recent advances in AMPK and energy-sensing in the brain.
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Affiliation(s)
| | - Biplab Dasgupta
- Division of Oncology, Cincinnati Children's Hospital Medical Center, OH, USA
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Fu SC, Lin JW, Liu JM, Liu SH, Fang KM, Su CC, Hsu RJ, Wu CC, Huang CF, Lee KI, Chen YW. Arsenic induces autophagy-dependent apoptosis via Akt inactivation and AMPK activation signaling pathways leading to neuronal cell death. Neurotoxicology 2021; 85:133-144. [PMID: 34038756 DOI: 10.1016/j.neuro.2021.05.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 05/18/2021] [Accepted: 05/18/2021] [Indexed: 12/19/2022]
Abstract
Inorganic arsenic (As3+), a well-known worldwide industrial and environmental pollutant, has been linked to neurodegenerative disorders (NDs). Autophagy plays an important role in controlling neuronal cell survival/death. However, limited information is available regarding the toxicological mechanism at the interplay between autophagy and As3+-induced neurotoxicity. The present study found that As3+ exposure induced a concomitant activation of apoptosis and autophagy in Neuro-2a cells, which was accompanied with the increase of phosphatidylserine exposure on outer membrane leaflets and apoptotic cell population, and the activation of caspase-3, -7, and PARP as well as the elevation of protein expressions of LC3-II, Atg-5, and Beclin-1, and the accumulation of autophagosome. Pretreatment of cells with autophagy inhibitor 3-MA, but not that of Z-VAD-FMK (a pan-caspase inhibitor), effectively prevented the As3+-induced autophagic and apoptotic responses, indicating that As3+-triggered autophagy was contributing to neuronal cell apoptosis. Furthermore, As3+ exposure evoked the dephosphorylation of Akt. Pretreatment with SC79, an Akt activator, could significantly attenuated As3+-induced Akt inactivation as well as autophagic and apoptotic events. Expectedly, inhibition of Akt signaling with LY294002 obviously enhanced As3+-triggered autophagy and apoptosis. Exposure to As3+ also dramatically increased the phosphorylation level of AMPKα. Pretreatment of AMPK inhibitor (Compound C) could markedly abrogate the As3+-induced phosphorylated AMPKα expression, and autophagy and apoptosis activation. Taken together, these results indicated that As3+ exerted its cytotoxicity in neuronal cells via the Akt inactivation/AMPK activation downstream-regulated autophagy-dependent apoptosis pathways, which ultimately lead to cell death. Our findings suggest that the regulation of Akt/AMPK signals may be a promising intervention to against As3+-induced neurotoxicity and NDs.
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Affiliation(s)
- Shih-Chang Fu
- Division of Urology, Department of Surgery, Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan, 330, Taiwan
| | - Jhe-Wei Lin
- Department of Physiology and Graduate Institute of Basic Medical Science, School of Medicine, College of Medicine, China Medical University, Taichung, 404, Taiwan
| | - Jui-Ming Liu
- Division of Urology, Department of Surgery, Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan, 330, Taiwan
| | - Shing-Hwa Liu
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, 100, Taiwan
| | - Kai-Min Fang
- Department of Otolaryngology, Far Eastern Memorial Hospital, New Taipei City 220, Taiwan
| | - Chin-Chuan Su
- Department of Otorhinolaryngology, Head and Neck Surgery, Changhua Christian Hospital, Changhua County, 500, Taiwan; School of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
| | - Ren-Jun Hsu
- Department of Pathology and Graduate Institute of Pathology and Parasitology, Tri-Service General Hospital, Taiwan; Biobank Management Center of Tri-Service General Hospital and Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, 114, Taiwan
| | - Chin-Ching Wu
- Department of Public Health, China Medical University, Taichung, 404, Taiwan
| | - Chun-Fa Huang
- School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, 404, Taiwan; Department of Nursing, College of Medical and Health Science, Asia University, Taichung, 413, Taiwan
| | - Kuan-I Lee
- Department of Emergency, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, 427, Taiwan.
| | - Ya-Wen Chen
- Department of Physiology and Graduate Institute of Basic Medical Science, School of Medicine, College of Medicine, China Medical University, Taichung, 404, Taiwan.
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Wang L, Wang A, Guo H, Zhang Z, Wang S, Pei T, Liu Z, Yang D, Liu Y, Ruan C. Neuroprotective Effects of Long-Term Metformin Preconditioning on Rats with Ischemic Brain Injuries. Eur Neurol 2021; 84:212-218. [PMID: 33845479 DOI: 10.1159/000514431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 01/10/2021] [Indexed: 11/19/2022]
Abstract
INTRODUCTION This study is to analyze the neuroprotective effects of long-term metformin (Met) preconditioning on rats with ischemic brain injuries and the related mechanisms. METHODS Twenty-five Sprague-Dawley rats were randomly divided into 5 groups: sham group, middle cerebral artery occlusion (MCAO) group, normal saline + MCAO group, pre- Met + MCAO group, and 3-MA + Met + MCAO group. Pathological changes of brain were observed by hematoxylin-eosin staining. Neurobehavior scores were calculated. Infarct area was assessed by 2,3,5-triphenyltetrazolium chloride staining. Apoptosis of neurons was detected by TdT-mediated dUTP Nick-End Labeling (TUNEL). Western blot tested the expression of LC3 (microtubule-associated protein 1 light chain 3), Beclin-1, adenosine 5'-monophosphate ([AMP]-activated protein kinase [AMPK]), and p-AMPK in hippocampal CA1 region. RESULTS Compared with the sham group, the MCAO group induced severe pathological changes in the brain. The neurobehavior scores and infarct area in the brain were increased in the MCAO group than in the sham group. The apoptosis level in the MCAO group was also higher than in the sham group. However, after pretreatment with Met, the pathological changes in the brain were attenuated. Compared with the MCAO group, the pre-Met + MCAO group also had decreased neurobehavior scores and infarct area in the brain. Additionally, the apoptosis level in the pre-Met + MCAO group was lower than in the MCAO group. Moreover, the MCAO group had increased levels of LC3 and Beclin-1 than in the sham group. In the pre-Met + MCAO group, their levels were decreased than in the MCAO group. The p-AMPK level in the pre-Met + MCAO group was also increased than in the MCAO group, suggesting activation of p-AMPK by Met. CONCLUSION Long-term Met pretreatment has neuroprotective effect on ischemic brain injury, which may be related to the regulation of autophagy-related protein expression and apoptosis.
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Affiliation(s)
- Lu Wang
- Department of Medicine, Xi'an Jiao Tong University, Xi'an, China.,Department of Anatomy, Medical College, Yan'an University, Yan'an, China
| | - Aqian Wang
- Department of Anatomy, Medical College, Yan'an University, Yan'an, China
| | - Hongtao Guo
- Department of Anatomy, Medical College, Yan'an University, Yan'an, China
| | - Zhenxian Zhang
- Imaging Department, Yan'an People's Hospital, Yan'an, China
| | - Shenghai Wang
- Imaging Department, Yan'an People's Hospital, Yan'an, China
| | - Tengbo Pei
- Department of Anatomy, Medical College, Yan'an University, Yan'an, China
| | - Zhiyong Liu
- Department of Anatomy, Medical College, Yan'an University, Yan'an, China
| | - Dandan Yang
- Department of Anatomy, Medical College, Yan'an University, Yan'an, China
| | - Yong Liu
- Department of Medicine, Xi'an Jiao Tong University, Xi'an, China
| | - Cailian Ruan
- Department of Medicine, Xi'an Jiao Tong University, Xi'an, China.,Department of Anatomy, Medical College, Yan'an University, Yan'an, China
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Emodin inhibits zinc-induced neurotoxicity in neuroblastoma SH-SY5Y cells. Biosci Rep 2019; 39:BSR20182378. [PMID: 31023967 PMCID: PMC6522748 DOI: 10.1042/bsr20182378] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 04/01/2019] [Accepted: 04/09/2019] [Indexed: 02/06/2023] Open
Abstract
Emodin is a natural anthraquinone derivative with numerous beneficial effects, including antioxidant properties, anti-tumor activities, and protecting the nerves. Zinc-induced neurotoxicity plays a crucial role in the pathogenesis of vascular dementia (VD) and Parkinson’s disease (PD). Here, the protective activity of emodin inhibiting zinc-induced neurotoxicity and its molecular mechanisms such as cellular Zn2+ influx and zinc-induced gene expression were examined using human neuroblastoma cells (SH-SY5Y cells). Our findings showed that emodin obviously enhanced cell viability and reduced cell apoptosis and lactate dehydrogenase release. Bedsides, we detected a decrease of intracellular Zn2+ concentration after SH-SY5Y cells were pretreated with emodin. Simultaneously, the expression of zinc transporter-1, metallothionein-1, and metallothionein-2 were weakened in emodin-pretreated SH-SY5Y cells. In addition, emodin prevented the depletion of NAD+ and ATP induced by zinc. Emodin also reduced intracellular reactive oxygen species and endoplasmic reticulum-stress levels. Strikingly, emodin elevated SH-SY5Y cell viability and inhibited cell apoptosis caused by AMP-activated protein kinase signaling pathway activation. Thus, emodin could protect against neurotoxicity induced by Zn2+ in neuroblastoma SH-SY5Y cells. It is expected to have future therapeutic potential for VD or PD and other neurodegenerative diseases.
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Kotake Y. [Neurotoxicity Mechanism of Environmental Chemicals and Its Evaluation System]. YAKUGAKU ZASSHI 2018; 138:1227-1233. [PMID: 30270264 DOI: 10.1248/yakushi.18-00014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is pivotal to assess the toxicity and safety of chemicals, including medicines, in the research field of environmental health science. Here we introduce neurotoxic mechanisms in mammals of environmental organotin and Parkinson's disease-related chemicals. We clarified that low concentrations of tributyltin decrease α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptor subunit GluA2 (GluR2) expression, leading to the vulnerability of cultured neurons. That is, tributyltin reduces GluA2 prior to neuronal death. This GluA2 decrease can be used as a sensitive evaluation index of neurotoxicity, since low levels of certain chemicals, for example some agrochemicals, decrease GluA2 expression. We also elucidated the mechanisms of abnormal protein metabolism induced by low levels of two Parkinson's disease-related chemicals: 1-methyl-4-phenylpyridinium ion (MPP+) and 1,2,3,4-tetrahydroisoquinoline derivatives. It is expected that these findings will become clues in accurately evaluating the toxicity of chemicals and/or in investigating the causes of disease.
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Affiliation(s)
- Yaichiro Kotake
- Graduate School of Biomedical and Health Sciences, Hiroshima University
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AMPK is activated early in cerebellar granule cells undergoing apoptosis and influences VADC1 phosphorylation status and activity. Apoptosis 2018. [PMID: 28643197 DOI: 10.1007/s10495-017-1389-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The neurodegeneration of cerebellar granule cells, after low potassium induced apoptosis, is known to be temporally divided into an early and a late phase. Voltage-dependent anion channel-1 (VDAC1) protein, changing from the closed inactive state to the active open state, is central to the switch between the early and late phase. It is also known that: (i) VDAC1 can undergo phosphorylation events and (ii) AMP-activated protein kinase (AMPK), the sensor of cellular stress, may have a role in neuronal homeostasis. In the view of this, the involvement of AMPK activation and its correlation with VDAC1 status and activity has been investigated in the course of cerebellar granule cells apoptosis. The results reported in this study show that an increased level of the phosphorylated, active, isoform of AMPK occurs in the early phase, peaks at 3 h and guarantees an increase in the phosphorylation status of VDCA1, resulting in a reduced activity of this latter. However this situation is transient in nature, since, in the late phase, AMPK activation decreases as well as the level of phosphorylated VDAC1. In a less phosphorylated status, VDAC1 fully recovers its gating activity and drives cells along the death route.
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11
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Prenatal exposure to oxidative phosphorylation xenobiotics and late-onset Parkinson disease. Ageing Res Rev 2018; 45:24-32. [PMID: 29689408 DOI: 10.1016/j.arr.2018.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 04/20/2018] [Accepted: 04/20/2018] [Indexed: 12/21/2022]
Abstract
Late-onset Parkinson disease is a multifactorial and multietiological disorder, age being one of the factors implicated. Genetic and/or environmental factors, such as pesticides, can also be involved. Up to 80% of dopaminergic neurons of the substantia nigra are lost before motor features of the disorder begin to appear. In humans, these neurons are only formed a few weeks after fertilization. Therefore, prenatal exposure to pesticides or industrial chemicals during crucial steps of brain development might also alter their proliferation and differentiation. Oxidative phosphorylation is one of the metabolic pathways sensitive to environmental toxicants and it is crucial for neuronal differentiation. Many inhibitors of this biochemical pathway, frequently found as persistent organic pollutants, affect dopaminergic neurogenesis, promote the degeneration of these neurons and increase the risk of suffering late-onset Parkinson disease. Here, we discuss how an early, prenatal, exposure to these oxidative phosphorylation xenobiotics might trigger a late-onset, old age, Parkinson disease.
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12
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An P, Wu T, Yu H, Fang K, Ren Z, Tang M. Hispidulin Protects Against Focal Cerebral Ischemia Reperfusion Injury in Rats. J Mol Neurosci 2018; 65:203-212. [PMID: 29799104 DOI: 10.1007/s12031-018-1086-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/11/2018] [Indexed: 02/02/2023]
Abstract
Focal cerebral ischemia is associated with ischemia/reperfusion (I/R) injury. Hispidulin is a flavonoid compound with a variety of pharmacological properties. The neuroprotective effects of hispidulin have not been fully elucidated. Herein, we demonstrated that pretreatment of animals with hispidulin improved the neurological outcomes and decreased the infarct size and brain edema in the cerebral focal I/R model. Mechanistically, we showed in vivo and in vitro that hispidulin exerted a protective effect against I/R injury by inducing the Nrf2 antioxidant pathway through modulation of AMPK/GSK3β signaling. Taken together, our results suggest that hispidulin may be a useful neuroprotective agent against ischemia/reperfusion (I/R) injury.
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Affiliation(s)
- Pengpeng An
- The Affiliated Qingdao Hiser Hospital of Qingdao University (Qingdao Hospital of Traditional Chinese Medicine), Renming Road 4, Qingdao, 266000, China
| | - Tianhui Wu
- Qingdao Fifth People's Hospital (Shandong Qingdao Hospital of Integrated Traditional and Western Medicine), Qingdao, China
| | - Huanqing Yu
- Qingdao Fifth People's Hospital (Shandong Qingdao Hospital of Integrated Traditional and Western Medicine), Qingdao, China
| | - Kun Fang
- Qingdao Fifth People's Hospital (Shandong Qingdao Hospital of Integrated Traditional and Western Medicine), Qingdao, China
| | - Zhizhen Ren
- Community Health Service Center of Shinan District, Qingdao, China
| | - Ming Tang
- The Affiliated Qingdao Hiser Hospital of Qingdao University (Qingdao Hospital of Traditional Chinese Medicine), Renming Road 4, Qingdao, 266000, China.
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13
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Ishida K, Saiki T, Umeda K, Miyara M, Sanoh S, Ohta S, Kotake Y. Prenatal Exposure to Tributyltin Decreases GluR2 Expression in the Mouse Brain. Biol Pharm Bull 2017; 40:1121-1124. [PMID: 28674256 DOI: 10.1248/bpb.b17-00209] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Tributyltin (TBT), a common environmental contaminant, is widely used as an antifouling agent in paint. We previously reported that exposure of primary cortical neurons to TBT in vitro decreased the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit glutamate receptor 2 (GluR2) expression and subsequently increased neuronal vulnerability to glutamate. Therefore, to identify whether GluR2 expression also decreases after TBT exposure in vivo, we evaluated the changes in GluR2 expression in the mouse brain after prenatal or postnatal exposure to 10 and 25 ppm TBT through pellet diets. Although the mean feed intake and body weight did not decrease in TBT-exposed mice compared with that in control mice, GluR2 expression in the cerebral cortex and hippocampus decreased after TBT exposure during the prenatal period. These results indicate that a decrease in neuronal GluR2 may be involved in TBT-induced neurotoxicity, especially during the fetal period.
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Affiliation(s)
- Keishi Ishida
- Graduate School of Biomedical and Health Sciences, Hiroshima University.,Research Fellow of the Japan Society for the Promotion of Science
| | - Takashi Saiki
- Graduate School of Biomedical and Health Sciences, Hiroshima University
| | - Kanae Umeda
- Graduate School of Biomedical and Health Sciences, Hiroshima University
| | - Masatsugu Miyara
- Graduate School of Biomedical and Health Sciences, Hiroshima University.,Global Career Design Center, Hiroshima University
| | - Seigo Sanoh
- Graduate School of Biomedical and Health Sciences, Hiroshima University
| | - Shigeru Ohta
- Graduate School of Biomedical and Health Sciences, Hiroshima University
| | - Yaichiro Kotake
- Graduate School of Biomedical and Health Sciences, Hiroshima University
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14
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Su KH, Dai C. Metabolic control of the proteotoxic stress response: implications in diabetes mellitus and neurodegenerative disorders. Cell Mol Life Sci 2016; 73:4231-4248. [PMID: 27289378 PMCID: PMC5599143 DOI: 10.1007/s00018-016-2291-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 05/13/2016] [Accepted: 06/07/2016] [Indexed: 12/12/2022]
Abstract
Proteome homeostasis, or proteostasis, is essential to maintain cellular fitness and its disturbance is associated with a broad range of human health conditions and diseases. Cells are constantly challenged by various extrinsic and intrinsic insults, which perturb cellular proteostasis and provoke proteotoxic stress. To counter proteomic perturbations and preserve proteostasis, cells mobilize the proteotoxic stress response (PSR), an evolutionarily conserved transcriptional program mediated by heat shock factor 1 (HSF1). The HSF1-mediated PSR guards the proteome against misfolding and aggregation. In addition to proteotoxic stress, emerging studies reveal that this proteostatic mechanism also responds to cellular energy state. This regulation is mediated by the key cellular metabolic sensor AMP-activated protein kinase (AMPK). In this review, we present an overview of the maintenance of proteostasis by HSF1, the metabolic regulation of the PSR, particularly focusing on AMPK, and their implications in the two major age-related diseases-diabetes mellitus and neurodegenerative disorders.
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Affiliation(s)
- Kuo-Hui Su
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Chengkai Dai
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA.
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15
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Bo E, Farinetti A, Marraudino M, Sterchele D, Eva C, Gotti S, Panzica G. Adult exposure to tributyltin affects hypothalamic neuropeptide Y, Y1 receptor distribution, and circulating leptin in mice. Andrology 2016; 4:723-34. [PMID: 27310180 DOI: 10.1111/andr.12222] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/29/2016] [Accepted: 04/15/2016] [Indexed: 12/25/2022]
Abstract
Tributyltin (TBT), a pesticide used in antifouling paints, is toxic for aquatic invertebrates. In vertebrates, TBT may act in obesogen- inducing adipogenetic gene transcription for adipocyte differentiation. In a previous study, we demonstrated that acute administration of TBT induces c-fos expression in the arcuate nucleus. Therefore, in this study, we tested the hypothesis that adult exposure to TBT may alter a part of the nervous pathways controlling animal food intake. In particular, we investigated the expression of neuropeptide Y (NPY) immunoreactivity. This neuropeptide forms neural circuits dedicated to food assumption and its action is mediated by Y1 receptors that are widely expressed in the hypothalamic nuclei responsible for the regulation of food intake and energy homeostasis. To this purpose, TBT was orally administered at a dose of 0.025 mg/kg/day/body weight to adult animals [male and female C57BL/6 (Y1-LacZ transgenic mice] for 4 weeks. No differences were found in body weight and fat deposition, but we observed a significant increase in feed efficiency in TBT-treated male mice and a significant decrease in circulating leptin in both sexes. Computerized quantitative analysis of NPY immunoreactivity and Y1-related β-galactosidase activity demonstrated a statistically significant reduction in NPY and Y1 transgene expression in the hypothalamic circuit controlling food intake of treated male mice in comparison with controls. In conclusion, the present results indicate that adult exposure to TBT is profoundly interfering with the nervous circuits involved in the stimulation of food intake.
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Affiliation(s)
- E Bo
- Department Neuroscience "Rita Levi Montalcini", University of Torino, Torino, Italy.,Neuroscience Institute Cavalieri-Ottolenghi (NICO), Torino, Italy
| | - A Farinetti
- Department Neuroscience "Rita Levi Montalcini", University of Torino, Torino, Italy.,Neuroscience Institute Cavalieri-Ottolenghi (NICO), Torino, Italy
| | - M Marraudino
- Department Neuroscience "Rita Levi Montalcini", University of Torino, Torino, Italy.,Neuroscience Institute Cavalieri-Ottolenghi (NICO), Torino, Italy
| | - D Sterchele
- Department Neuroscience "Rita Levi Montalcini", University of Torino, Torino, Italy.,Neuroscience Institute Cavalieri-Ottolenghi (NICO), Torino, Italy
| | - C Eva
- Department Neuroscience "Rita Levi Montalcini", University of Torino, Torino, Italy.,National Institute of Neuroscience (INN), Torino, Italy.,Neuroscience Institute Cavalieri-Ottolenghi (NICO), Torino, Italy
| | - S Gotti
- Department Neuroscience "Rita Levi Montalcini", University of Torino, Torino, Italy.,Neuroscience Institute Cavalieri-Ottolenghi (NICO), Torino, Italy
| | - G Panzica
- Department Neuroscience "Rita Levi Montalcini", University of Torino, Torino, Italy.,National Institute of Neuroscience (INN), Torino, Italy.,Neuroscience Institute Cavalieri-Ottolenghi (NICO), Torino, Italy
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16
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Eom JW, Lee JM, Koh JY, Kim YH. AMP-activated protein kinase contributes to zinc-induced neuronal death via activation by LKB1 and induction of Bim in mouse cortical cultures. Mol Brain 2016; 9:14. [PMID: 26856538 PMCID: PMC4746814 DOI: 10.1186/s13041-016-0194-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 02/01/2016] [Indexed: 12/25/2022] Open
Abstract
Background We reported that zinc neurotoxicity, a key mechanism of ischemic neuronal death, was mediated by poly ADP-ribose polymerase (PARP) over-activation following NAD+/ATP depletion in cortical cultures. Because AMP-activated protein kinase (AMPK) can be activated by ATP depletion, and AMPK plays a key role in excitotoxicity and ischemic neuronal death, we examined whether AMPK could be involved in zinc neurotoxicity in mouse cortical neuronal cultures. Results Compound C, an AMPK inhibitor, significantly attenuated zinc-induced neuronal death. Activation of AMPK was detected beginning 2 h after a 10-min exposure of mouse cortical neurons to 300 μM zinc, although a significant change in AMP level was not detected until 4 h after zinc treatment. Thus, AMPK activation might not have been induced by an increase in intracellular AMP in zinc neurotoxicity. Furthermore, we observed that liver kinase B1 (LKB1) but not Ca2+/calmodulin-dependent protein kinase kinase β (CaMKKβ), was involved in AMPK activation. Although STO-609, a chemical inhibitor of CaMKKβ, significantly attenuated zinc neurotoxicity, zinc-induced AMPK activation was not affected, which suggested that CaMKKβ was not involved in AMPK activation. Knockdown of LKB1 by siRNA significantly reduced zinc neurotoxicity, as well as zinc-induced AMPK activation, which indicated a possible role for LKB1 as an upstream kinase for AMPK activation. In addition, mRNA and protein levels of Bim, a pro-apoptotic Bcl-2 family member, were noticeably increased by zinc in an AMPK-dependent manner. Finally, caspase-3 activation in zinc-induced neuronal death was mediated by LKB1 and AMPK activation. Conclusions The results suggested that AMPK mediated zinc-induced neuronal death via up-regulation of Bim and activation of caspase-3. Rapid activation of AMPK was detected after exposure of cortical neuronal cultures to zinc, which was induced by LKB1 activation but not increased intracellular AMP levels or CaMKKβ activation. Hence, blockade of AMPK in the brain may protect against zinc neurotoxicity, which is likely to occur after acute brain injury.
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Affiliation(s)
- Jae-Won Eom
- Department of Molecular Biology, Sejong University, Seoul, 143-747, South Korea.
| | - Jong-Min Lee
- Department of Molecular Biology, Sejong University, Seoul, 143-747, South Korea. .,Department of Integrative Bioscience and Biotechnology, Sejong University, Seoul, 143-747, South Korea.
| | - Jae-Young Koh
- Neural Injury Research Lab & Department of Neurology, University of Ulsan College of Medicine, Seoul, 138-736, South Korea.
| | - Yang-Hee Kim
- Department of Molecular Biology, Sejong University, Seoul, 143-747, South Korea. .,Department of Integrative Bioscience and Biotechnology, Sejong University, Seoul, 143-747, South Korea.
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17
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Triorganotin compounds - ligands for “rexinoid” inducible transcription factors: Biological effects. Toxicol Lett 2015; 234:50-8. [DOI: 10.1016/j.toxlet.2015.02.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 11/18/2022]
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18
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Shah SA, Yoon GH, Kim HO, Kim MO. Vitamin C Neuroprotection Against Dose-Dependent Glutamate-Induced Neurodegeneration in the Postnatal Brain. Neurochem Res 2015; 40:875-84. [DOI: 10.1007/s11064-015-1540-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 02/01/2015] [Accepted: 02/09/2015] [Indexed: 11/24/2022]
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19
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Wang Y, Wang S, Luo X, Yang Y, Jian F, Wang X, Xie L. The roles of DNA damage-dependent signals and MAPK cascades in tributyltin-induced germline apoptosis in Caenorhabditis elegans. CHEMOSPHERE 2014; 108:231-238. [PMID: 24534158 DOI: 10.1016/j.chemosphere.2014.01.045] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 12/23/2013] [Accepted: 01/11/2014] [Indexed: 06/03/2023]
Abstract
The induction of apoptosis is recognized to be a major mechanism of tributyltin (TBT) toxicity. However, the underlying signaling pathways for TBT-induced apoptosis remain unclear. In this study, using the nematode Caenorhabditis elegans, we examined whether DNA damage response (DDR) pathway and mitogen-activated protein kinase (MAPK) signaling cascades are involved in TBT-induced germline apoptosis and cell cycle arrest. Our results demonstrated that exposing worms to TBT at the dose of 10nM for 6h significantly increased germline apoptosis in N2 strain. Germline apoptosis was absent in strains that carried ced-3 or ced-4 loss-of-function alleles, indicating that both caspase protein CED-3 and Apaf-1 protein CED-4 were required for TBT-induced apoptosis. TBT-induced apoptosis was blocked in the Bcl-2 gain-of-function strain ced-9(n1950), whereas TBT induced a minor increase in the BH3-only protein EGL-1 mutated strain egl-1(n1084n3082). Checkpoint proteins HUS-1 and CLK-2 exerted proapoptotic effects, and the null mutation of cep-1, the homologue of tumor suppressor gene p53, significantly inhibited TBT-induced apoptosis. Apoptosis in the loss-of-function strains of ERK, JNK and p38 MAPK signaling pathways were completely or mildly suppressed under TBT stress. These results were supported by the results of mRNA expression levels of corresponding genes. The present study indicated that TBT-induced apoptosis required the core apoptotic machinery, and that DDR genes and MAPK pathways played essential roles in signaling the processes.
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Affiliation(s)
- Yun Wang
- Department of Life Sciences, Huainan Normal University, Huainan, Anhui 232001, PR China.
| | - Shunchang Wang
- Department of Life Sciences, Huainan Normal University, Huainan, Anhui 232001, PR China
| | - Xun Luo
- Department of Life Sciences, Huainan Normal University, Huainan, Anhui 232001, PR China
| | - Yanan Yang
- Department of Life Sciences, Huainan Normal University, Huainan, Anhui 232001, PR China
| | - Fenglei Jian
- Department of Life Sciences, Huainan Normal University, Huainan, Anhui 232001, PR China
| | - Xuemin Wang
- Department of Life Sciences, Huainan Normal University, Huainan, Anhui 232001, PR China
| | - Lucheng Xie
- Department of Life Sciences, Huainan Normal University, Huainan, Anhui 232001, PR China
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20
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Gomes MB, Negrato CA. Alpha-lipoic acid as a pleiotropic compound with potential therapeutic use in diabetes and other chronic diseases. Diabetol Metab Syndr 2014; 6:80. [PMID: 25104975 PMCID: PMC4124142 DOI: 10.1186/1758-5996-6-80] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/11/2014] [Indexed: 02/07/2023] Open
Abstract
Alpha-lipoic acid is a naturally occurring substance, essential for the function of different enzymes that take part in mitochondria's oxidative metabolism. It is believed that alpha-lipoic acid or its reduced form, dihydrolipoic acid have many biochemical functions acting as biological antioxidants, as metal chelators, reducers of the oxidized forms of other antioxidant agents such as vitamin C and E, and modulator of the signaling transduction of several pathways. These above-mentioned actions have been shown in experimental studies emphasizing the use of alpha-lipoic acid as a potential therapeutic agent for many chronic diseases with great epidemiological as well economic and social impact such as brain diseases and cognitive dysfunctions like Alzheimer disease, obesity, nonalcoholic fatty liver disease, burning mouth syndrome, cardiovascular disease, hypertension, some types of cancer, glaucoma and osteoporosis. Many conflicting data have been found concerning the clinical use of alpha-lipoic acid in the treatment of diabetes and of diabetes-related chronic complications such as retinopathy, nephropathy, neuropathy, wound healing and diabetic cardiovascular autonomic neuropathy. The most frequent clinical condition in which alpha-lipoic acid has been studied was in the management of diabetic peripheral neuropathy in patients with type 1 as well type 2 diabetes. Considering that oxidative stress, a imbalance between pro and antioxidants with excessive production of reactive oxygen species, is a factor in the development of many diseases and that alpha-lipoic acid, a natural thiol antioxidant, has been shown to have beneficial effects on oxidative stress parameters in various tissues we wrote this article in order to make an up-to-date review of current thinking regarding alpha-lipoic acid and its use as an antioxidant drug therapy for a myriad of diseases that could have potential benefits from its use.
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Affiliation(s)
- Marilia Brito Gomes
- />Department of Internal Medicine, Diabetes Unit, State University Hospital of Rio de Janeiro, Avenida 28 de Setembro, 77, 3° andar CEP 20.551-030, Rio de Janeiro, Brazil
| | - Carlos Antonio Negrato
- />Department of Internal Medicine, Bauru’s Diabetics Association, 17012-433 Bauru, São Paulo, Brazil
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21
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Iwabuchi S, Kawahara K, Harata NC. Effects of pharmacological inhibition of AMP-activated protein kinase on GLUT3 expression and the development of ischemic tolerance in astrocytes. Neurosci Res 2014; 84:68-71. [PMID: 24815515 DOI: 10.1016/j.neures.2014.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 04/25/2014] [Accepted: 04/28/2014] [Indexed: 02/08/2023]
Abstract
Ischemic tolerance resulting from preconditioning ischemia is a neuroprotective mechanism. In cultured astrocytes, its development depends on regulation of the expression of glucose transporter 3 (GLUT3) by the stress sensor/effector AMP-activated protein kinase (AMPK). Here we demonstrate that GLUT3 is upregulated during preconditioning and then downregulated during recovery. We also found that, although AMPK inhibition during preconditioning initially suppressed the upregulation of GLUT3 as shown previously, this was followed by a period of GLUT3 upregulation, enhanced glycogen accumulation, and enhanced tolerance to a subsequent ischemic challenge. These results reveal that AMPK has a complex influence on ischemic tolerance.
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Affiliation(s)
- Sadahiro Iwabuchi
- Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine, Iowa City, USA; Laboratory of Cellular Cybernetics, Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Japan.
| | - Koichi Kawahara
- Laboratory of Cellular Cybernetics, Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Japan
| | - N Charles Harata
- Department of Molecular Physiology & Biophysics, University of Iowa Carver College of Medicine, Iowa City, USA
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22
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Ullah I, Park HY, Kim MO. Anthocyanins protect against kainic acid-induced excitotoxicity and apoptosis via ROS-activated AMPK pathway in hippocampal neurons. CNS Neurosci Ther 2014; 20:327-38. [PMID: 24393263 DOI: 10.1111/cns.12218] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 11/20/2013] [Accepted: 11/24/2013] [Indexed: 12/15/2022] Open
Abstract
INTRODUCTION Excitotoxicity is an important mechanism involved in neurodegeneration. Kainic acid (KA)-induced excitotoxicity results an unfavorable stress, and we investigated the signaling pathways activated in such conditions. AIMS Here, we sought to determine the cellular and biochemical benefits of anthocyanins extracted from Korean black bean against KA-induced excitotoxicity and neuronal cell death. METHODS AND RESULTS Mouse hippocampal cell line (HT22) and primary prenatal rat hippocampal neurons were treated with KA to induce excitotoxicity. Incubation of the cells with KA alone significantly decreased cell viability, elevated intracellular Ca(2+) level, increased generation of reactive oxygen species (ROS) and loss of mitochondrial membrane potential (Δψ(M)). These events were accompanied by sustained phosphorylation and activation of AMP-activated protein kinase (AMPK). Kainic acid induced upregulation of Bax, decrease in Bcl-2, release of cytochrome-c, and activation of caspase-3 in both cell types. Anthocyanins attenuated KA-induced dysregulation of Ca(2+), ROS accumulation, activation of AMPK, and increase in percentage of apoptotic cells. Pretreatment of the cells with compound C, an inhibitor of AMPK, diminished the KA-induced activation of AMPK and caspase-3. The activation of AMPK through elevation of cellular ROS and Ca(2+) levels is required for KA-induced apoptosis in hippocampal neurons. CONCLUSIONS In summary, our data suggest that although anthocyanins have diverse activities, at least part of their beneficial effects against KA-induced hippocampal degeneration can be attributed to their well-recognized antioxidant properties.
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Affiliation(s)
- Ikram Ullah
- Department of Biology, College of Natural Sciences (RINS), Applied Life Science (BK 21) Gyeongsang National University, Jinju, Korea
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23
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Abstract
The obesogen hypothesis postulates the role of environmental chemical pollutants that disrupt homeostatic controls and adaptive mechanisms to promote adipose-dependent weight gain leading to obesity and metabolic syndrome complications. One of the most direct molecular mechanisms for coupling environmental chemical exposures to perturbed physiology invokes pollutants mimicking endogenous endocrine hormones or bioactive dietary signaling metabolites that serve as nuclear receptor ligands. The organotin pollutant tributyltin can exert toxicity through multiple mechanisms but most recently has been shown to bind, activate, and mediate RXR-PPARγ transcriptional regulation central to lipid metabolism and adipocyte biology. Data in support of long-term obesogenic effects on whole body adipose tissue are also reported. Organotins represent an important model test system for evaluating the impact and epidemiological significance of chemical insults as contributing factors for obesity and human metabolic health.
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Affiliation(s)
- Felix Grün
- The Center for Complex Biological Systems, University of California Irvine, Irvine, California, USA.
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24
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Isomura M, Kotake Y, Masuda K, Miyara M, Okuda K, Samizo S, Sanoh S, Hosoi T, Ozawa K, Ohta S. Tributyltin-induced endoplasmic reticulum stress and its Ca2+-mediated mechanism. Toxicol Appl Pharmacol 2013; 272:137-46. [DOI: 10.1016/j.taap.2013.05.026] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 05/15/2013] [Accepted: 05/24/2013] [Indexed: 11/16/2022]
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25
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Manwani B, McCullough LD. Function of the master energy regulator adenosine monophosphate-activated protein kinase in stroke. J Neurosci Res 2013; 91:1018-29. [PMID: 23463465 PMCID: PMC4266469 DOI: 10.1002/jnr.23207] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Revised: 12/24/2012] [Accepted: 01/05/2013] [Indexed: 01/09/2023]
Abstract
Adenosine monophosphate-activated protein kinase (AMPK) is an evolutionarily conserved signaling molecule that is emerging as one of the most important energy sensors in the body. AMPK monitors cellular energy status and is activated via phosphorylation when energy stores are low. This allows for maintenance of energy homeostasis by promoting catabolic pathways for ATP production and limiting processes that consume ATP. Growing number of stimuli have been shown to activate AMPK, and AMPK has been implicated in many diverse biological processes, including cell polarity, autophagy, and senescence. The effect of AMPK activation and its biological functions are extremely diverse and depend on both the overall energy "milieu" and the location and duration of activation. AMPK has tissue- and isoform-specific functions in the brain vs. periphery. These functions and the pathways activated also appear to differ by cell location (hypothalamus vs. cortex), cell type (astrocyte vs. neuron), and duration of exposure. Short bursts of AMPK activation have been found to be involved in ischemic preconditioning and neuronal survival; however, prolonged AMPK activity during ischemia leads to neuronal cell death. AMPK may also underlie some of the beneficial effects of hypothermia, a potential therapy for ischemic brain injury. This review discusses the role of AMPK in ischemic stroke, a condition of severe energy depletion.
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Affiliation(s)
- Bharti Manwani
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut
| | - Louise D. McCullough
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut
- Department of Neurology, University of Connecticut Health Center, Farmington, Connecticut
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26
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Mitra S, Gera R, Siddiqui WA, Khandelwal S. Tributyltin induces oxidative damage, inflammation and apoptosis via disturbance in blood–brain barrier and metal homeostasis in cerebral cortex of rat brain: An in vivo and in vitro study. Toxicology 2013; 310:39-52. [DOI: 10.1016/j.tox.2013.05.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 05/22/2013] [Accepted: 05/24/2013] [Indexed: 01/06/2023]
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Kotake Y. Molecular mechanisms of environmental organotin toxicity in mammals. Biol Pharm Bull 2013; 35:1876-80. [PMID: 23123459 DOI: 10.1248/bpb.b212017] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Organotins such as tributyltin are suspected of having multiple toxic effects in mammals, in addition to their endocrine-disrupting function. Endogenous organotin concentrations in human blood range from a few to a few hundred nM. In this review, we summarize recent findings on the mechanisms of toxicity of environmental organotins such as tributyltin (TBT) and triphenyltin (TPT) in mammals. TBT and TPT are potent inhibitors of mitochondrial ATP synthase, and a recent study suggests that TBT binds directly to ATP synthase. Organotins disturb steroid biosynthesis and degradation. TBT and TPT are dual agonists of retinoid X receptor (RXR) and peroxisome proliferator-activated receptor γ (PPARγ); they also induce the differentiation of adipocytes in vitro and in vivo, probably through PPARγ activation, suggesting that they may work as obesogens. Environmental organotins are also neurotoxic; they induce behavioral abnormality and are toxic to the developing central nervous system. In vitro studies have shown that organotins induce intracellular Ca(2+) elevation and glutamate excitotoxicity. Recently, it was reported that endogenous levels of TBT decrease expression of 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl)propanoic acid (AMPA) receptor subunit GluR2, leading to neuronal vulnerability. Most of the experimental studies have employed organotins at concentrations of µM order, and it remains important to clarify the molecular mechanisms of events induced by endogenous levels of environmental organotins.
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Affiliation(s)
- Yaichiro Kotake
- Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
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28
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Yamada S, Kotake Y, Sekino Y, Kanda Y. AMP-activated protein kinase-mediated glucose transport as a novel target of tributyltin in human embryonic carcinoma cells. Metallomics 2013; 5:484-91. [DOI: 10.1039/c3mt20268b] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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29
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Ramamurthy S, Ronnett G. AMP-Activated Protein Kinase (AMPK) and Energy-Sensing in the Brain. Exp Neurobiol 2012; 21:52-60. [PMID: 22792025 PMCID: PMC3381212 DOI: 10.5607/en.2012.21.2.52] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Accepted: 02/09/2012] [Indexed: 12/25/2022] Open
Abstract
5'-adenosine monophosphate-activated protein kinase (AMPK) is an evolutionarily conserved cellular and organismal energy integrator that responds to numerous stimuli with the overall intention to facilitate energy conservation and enhance energy balance while also affecting cellular survival and behaviors. AMPK has been appreciated for many years to function in peripheral organs that contribute to the generation or disposition of cellular energy, while its role in the brain has been only recently elucidated. While acknowledged to respond to organismal energy balance, we now recognize that energy balance within neurons also affects the brain's response to these peripheral signals. In this review, we discuss AMPK's regulation and its ever-expanding role as a neuronal energy integrator at both the cellular and systems levels.
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Affiliation(s)
- Santosh Ramamurthy
- Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Ishihara Y, Kawami T, Ishida A, Yamazaki T. Tributyltin induces oxidative stress and neuronal injury by inhibiting glutathione S-transferase in rat organotypic hippocampal slice cultures. Neurochem Int 2012; 60:782-90. [PMID: 22449404 DOI: 10.1016/j.neuint.2012.03.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 03/03/2012] [Accepted: 03/08/2012] [Indexed: 11/19/2022]
Abstract
Tributyltin (TBT) has been used as a heat stabilizer, agricultural pesticide and antifouling agents on ships, boats and fish-farming nets; however, the neurotoxicity of TBT has recently become a concern. TBT is suggested to stimulate the generation of reactive oxygen species (ROS) inside cells. The aim of this study was to determine the mechanism of neuronal oxidative injury induced by TBT using rat organotypic hippocampal slice cultures. The treatment of rat hippocampal slices with TBT induced ROS production, lipid peroxidation and cell death. Pretreatment with antioxidants such as superoxide dismutase, catalase or trolox, suppressed the above phenomena induced by TBT, indicating that TBT elicits oxidative stress in hippocampal slices, which causes neuronal cell death. TBT dose-dependently inhibited glutathione S-transferase (GST), but not glutathione peroxidase or glutathione reductase in the cytosol of rat hippocampus. The treatment of hippocampal slices with TBT decreased the GST activity. Pretreatment with reduced glutathione attenuated the reduction of GST activity and cell death induced by TBT, indicating that the decrease in GST activity by TBT is involved in hippocampal cell death. When hippocampal slices were treated with sulforaphane, the expression and activity of GST were increased. Notably, TBT-induced oxidative stress and cell death were significantly suppressed by pretreatment with sulforaphane. These results indicate that GST inhibition could contribute, at least in part, to the neuronal cell death induced by TBT in hippocampal slices. This study is the first report to show the link between neuronal oxidative injury and the GST inhibition elicited by TBT.
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Affiliation(s)
- Yasuhiro Ishihara
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, Japan.
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31
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Liu F, Benashski SE, Persky R, Xu Y, Li J, McCullough LD. Age-related changes in AMP-activated protein kinase after stroke. AGE (DORDRECHT, NETHERLANDS) 2012; 34:157-68. [PMID: 21360073 PMCID: PMC3260368 DOI: 10.1007/s11357-011-9214-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 01/26/2011] [Indexed: 05/15/2023]
Abstract
Adenosine monophosphate-activated protein kinase (AMPK) is an evolutionary conserved energy sensor sensitive to changes in cellular AMP/ATP ratio which is activated by phosphorylation (pAMPK). pAMPK levels decrease in peripheral tissues with age, but whether this also occurs in the aged brain, and how this contributes to the ability of the aged brain to cope with ischemic stress is unknown. This study investigated the activation of AMPK and the response to AMPK inhibition after induced stroke in both young and aged male mice. Baseline levels of phosphorylated AMPK were higher in aged brains compared to young mice. Stroke-induced a robust activation of AMPK in young mice, yet this response was muted in the aged brain. Young mice had larger infarct volumes compared with aged animals; however, more severe behavioral deficits and higher mortality were seen in aged mice after stroke. Inhibition of AMPK with Compound C decreased infarct size in young animals, but had no effect in aged mice. Compound C administration led to a reduction in brain ATP levels and induced hypothermia, which led to enhanced neuroprotection in young but not aged mice. This work demonstrates that aging increases baseline brain pAMPK levels; aged mice have a muted stroke-induced pAMPK response; and that AMPK inhibition and hypothermia are less efficacious neuroprotective agents in the aged brain. This has important translational relevance for the development of neuroprotective agents in preclinical models and our understanding of the enhanced metabolic stress experienced by the aged brain.
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Affiliation(s)
- Fudong Liu
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT USA
| | - Sharon E. Benashski
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT USA
| | - Rebecca Persky
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT USA
| | - Yan Xu
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT USA
| | - Jun Li
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT USA
| | - Louise D. McCullough
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT USA
- Department of Neurology, University of Connecticut Health Center and the Stroke Center at Hartford Hospital, 263 Farmington Ave, Farmington, CT 06030 USA
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32
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Day RM, Lee YH, Han L, Kim YC, Feng YH. Angiotensin II activates AMPK for execution of apoptosis through energy-dependent and -independent mechanisms. Am J Physiol Lung Cell Mol Physiol 2011; 301:L772-81. [PMID: 21856818 DOI: 10.1152/ajplung.00072.2011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
At the cellular level, 5'-AMP-activated protein kinase (AMPK) serves as a critical link between energy homeostasis and the regulation of fundamental biological activities, including apoptosis. Angiotensin (Ang) II plays a key role in fibrotic lung remodeling. We recently demonstrated that Ang II induces apoptosis in pulmonary artery endothelial cells (PAEC) through the Ang type 2 receptor (AT(2)). AT(2) activates Src-homology two-domain-containing phosphatase-2 (SHP-2) in a signaling cascade leading to Bcl-x(L) mRNA destabilization and initiation of intrinsic apoptosis. We investigated the requirement of AMPK and ATP generation for Ang II-induced apoptosis in PAEC. Ang II activated AMPK, which was required for ATP generation. Inhibition of ATP production by compound C, an AMPK inhibitor, or by oligomycin suppressed Ang II-induced apoptosis. Experiments in Chinese hamster ovary-K1 cells expressing ectopic AT(2) (wild-type, mutant D90A, or carboxy terminal truncated mutant tC319) demonstrated that AT(2) activation of AMPK required the active conformation of the receptor and the carboxy terminal 44 amino acids. AMPK associated with and activated SHP-2 and was required for Bcl-x(L) mRNA destabilization. These are the first findings demonstrating that AMPK is activated by Ang II to produce ATP required for apoptosis. Our data also indicate that AMPK plays an energy-independent role by mediating SHP-2 activation.
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Affiliation(s)
- Regina M Day
- Dept. of Pharmacology, Uniformed Services Univ. of the Health Sciences, 4301 Jones Bridge Rd., Bethesda, MD 20814-4799, USA.
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Wallace BK, Foroutan S, O'Donnell ME. Ischemia-induced stimulation of Na-K-Cl cotransport in cerebral microvascular endothelial cells involves AMP kinase. Am J Physiol Cell Physiol 2011; 301:C316-26. [PMID: 21562306 PMCID: PMC3154550 DOI: 10.1152/ajpcell.00517.2010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Accepted: 05/09/2011] [Indexed: 11/22/2022]
Abstract
Increased blood-brain barrier (BBB) Na-K-Cl cotransporter activity appears to contribute to cerebral edema formation during ischemic stroke. We have shown previously that inhibition of BBB Na-K-Cl cotransporter activity reduces edema and infarct in the rat middle cerebral artery occlusion (MCAO) model of ischemic stroke. We have also shown that the BBB cotransporter is stimulated by the ischemic factors hypoxia, aglycemia, and arginine vasopressin (AVP), although the mechanisms responsible are not well understood. AMP-activated protein kinase (AMPK), a key mediator of cell responses to stress, can be activated by a variety of stresses, including ischemia, hypoxia, and aglycemia. Previous studies have shown that the AMPK inhibitor Compound C significantly reduces infarct in mouse MCAO. The present study was conducted to evaluate the possibility that AMPK participates in ischemic factor-induced stimulation of the BBB Na-K-Cl cotransporter. Cerebral microvascular endothelial cells (CMEC) were assessed for Na-K-Cl cotransporter activity as bumetanide-sensitive (86)Rb influx. AMPK activity was assessed by Western blot analysis and immunofluorescence methods using antibodies that detect total versus phosphorylated (activated) AMPK. We found that hypoxia (7% and 2% O(2)), aglycemia, AVP, and oxygen-glucose deprivation (5- to 120-min exposures) increase activation of AMPK. We also found that Compound C inhibition of AMPK reduces hypoxia-, aglycemia-, and AVP-induced stimulation of CMEC Na-K-Cl cotransporter activity. Confocal immunofluorescence of perfusion-fixed rat brain slices revealed the presence of AMPK, both total and phosphorylated kinase, in BBB in situ of both control and ischemic brain. These findings suggest that ischemic factor stimulation of the BBB Na-K-Cl cotransporter involves activation of AMPK.
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Affiliation(s)
- Breanna K Wallace
- Department of Physiology and Membrane Biology, University of California, Davis, CA 95616, USA
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Bo E, Viglietti-Panzica C, Panzica GC. Acute exposure to tributyltin induces c-fos activation in the hypothalamic arcuate nucleus of adult male mice. Neurotoxicology 2010; 32:277-80. [PMID: 21185327 DOI: 10.1016/j.neuro.2010.12.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 12/16/2010] [Indexed: 11/28/2022]
Abstract
Tributyltin (TBT) is a largely diffused environmental pollutant, banned from paints in the European Union from 2003. However, the level of TBT (and other organotins) in food, particularly fish and shellfish, remains still high. Several studies demonstrated that TBT is involved in the development of obesity, via peripheral action, but currently, there are only a few data illustrating effects of TBT on the nervous system. In the present study, we tested the hypothesis that acute exposure to TBT may directly activate brain cells in particular, in those hypothalamic nuclei regulating the food intake. To this purpose, TBT was orally administered at a single dose (10 mg/kg/body weight) to two groups of adult male mice: regularly fed or fasted for 24 h. Mice were sacrificed 90 min after the TBT administration and perfused by 4% paraformaldehyde. Brains were quickly dissected, frozen and sectioned for immunocytochemical detection of c-fos, a common marker of cell activation. In both, fed or fasted mice, exposure to TBT induced a significant increase of c-fos expression in the arcuate nucleus in comparison to control mice. The other nuclei involved in the control of feeding behavior did not show any significant increase. These data are the first in vivo demonstration that TBT has not only peripheral effects, but also may activate elements in the brain, in particular in a crucial region for the regulation of food intake like the arcuate nucleus.
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Affiliation(s)
- E Bo
- Laboratory of Neuroendocrinology, Neuroscience Institute of Torino (NIT), National Institute of Neuroscience (INN, Torino), Dept. Anatomy, Pharmacology and Forensic Medicine, University of Torino, corso M. D'Azeglio 52, 10126 Torino, Italy
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35
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Nakatsu Y, Kotake Y, Takai N, Ohta S. Involvement of autophagy via mammalian target of rapamycin (mTOR) inhibition in tributyltin-induced neuronal cell death. J Toxicol Sci 2010; 35:245-51. [PMID: 20371977 DOI: 10.2131/jts.35.245] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Tributyltin chloride (TBT) is a neurotoxic environmental pollutant that inhibits mitochondrial adenosine triphosphate (ATP) synthase. Autophagy is one of the major protein degradation systems induced by a decrease of intracellular ATP following activation of AMP-activated protein kinase (AMPK). Because we previously found that TBT induces activation of AMPK, here we examined whether TBT induces autophagic neuronal death. Exposure of cortical neurons to 500 nM TBT reduced the phosphorylation of mammalian target of rapamycin (mTOR), a regulator of autophagy. An autophagy inhibitor, 3-methyladenine (3-MA), markedly decreased TBT-induced neuronal death. TBT also induced the formation of LC3-II, an autophagy marker. These results suggest that TBT-induced neuronal death is at least partly autophagic.
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Abstract
AMP-activated protein kinase (AMPK) is a serine threonine kinase that is highly conserved through evolution. AMPK is found in most mammalian tissues including the brain. As a key metabolic and stress sensor/effector, AMPK is activated under conditions of nutrient deprivation, vigorous exercise, or heat shock. However, it is becoming increasingly recognized that changes in AMPK activation not only signal unmet metabolic needs, but also are involved in sensing and responding to 'cell stress', including ischemia. The downstream effect of AMPK activation is dependent on many factors, including the severity of the stressor as well as the tissue examined. This review discusses recent in vitro and in vivo studies performed in the brain/neuronal cells and vasculature that have contributed to our understanding of AMPK in stroke. Recent data on the potential role of AMPK in angiogenesis and neurogenesis and the interaction of AMPK with 3-hydroxy-3-methy-glutaryl-CoA reductase inhibitors (statins) agents are highlighted. The interaction between AMPK and nitric oxide signaling is also discussed.
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Affiliation(s)
- Jun Li
- Department of Neuroscience, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
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37
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Nakatsu Y, Kotake Y, Takishita T, Ohta S. Long-term exposure to endogenous levels of tributyltin decreases GluR2 expression and increases neuronal vulnerability to glutamate. Toxicol Appl Pharmacol 2009; 240:292-8. [DOI: 10.1016/j.taap.2009.06.024] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Revised: 06/25/2009] [Accepted: 06/26/2009] [Indexed: 11/29/2022]
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Jin J, Mullen TD, Hou Q, Bielawski J, Bielawska A, Zhang X, Obeid LM, Hannun YA, Hsu YT. AMPK inhibitor Compound C stimulates ceramide production and promotes Bax redistribution and apoptosis in MCF7 breast carcinoma cells. J Lipid Res 2009; 50:2389-97. [PMID: 19528633 DOI: 10.1194/jlr.m900119-jlr200] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Compound C is commonly used as an inhibitor of AMP-activated protein kinase (AMPK), which serves as a key energy sensor in cells. In this study, we found that Compound C treatment of MCF7 cells led to Bax redistribution from the cytoplasm to mitochondria and cell death. However, this effect does not involve AMPK. In addition, we found that treatment with this compound leads to an enhanced ceramide production. Analyses by quantitative PCR and ceramide synthase activity assay suggest that ceramide synthase 5 (LASS/CerS 5) is involved in Compound C-induced ceramide upregulation. Downregulation of LASS/CerS 5 was found to attenuate Compound C-mediated ceramide production, Bax redistribution, and cell death.
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Affiliation(s)
- Junfei Jin
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
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Abstract
The recent dramatic rise in obesity rates is an alarming global health trend that consumes an ever increasing portion of health care budgets in Western countries. The root cause of obesity is thought to be a prolonged positive energy balance. Hence, the major focus of preventative programs for obesity has been to target overeating and inadequate physical exercise. Recent research implicates environmental risk factors, including nutrient quality, stress, fetal environment and pharmaceutical or chemical exposure as relevant contributing influences. Evidence points to endocrine disrupting chemicals that interfere with the body's adipose tissue biology, endocrine hormone systems or central hypothalamic-pituitary-adrenal axis as suspects in derailing the homeostatic mechanisms important to weight control. This review highlights recent advances in our understanding of the molecular targets and mechanisms of action for these compounds and areas of future research needed to evaluate the significance of their contribution to obesity.
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Affiliation(s)
- Felix Grün
- Department of Developmental & Cell Biology, University of California Irvine, 92697-2300, USA
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40
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Spasić MR, Callaerts P, Norga KK. AMP-activated protein kinase (AMPK) molecular crossroad for metabolic control and survival of neurons. Neuroscientist 2009; 15:309-16. [PMID: 19359670 DOI: 10.1177/1073858408327805] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AMP-activated protein kinase (AMPK) constitutes a molecular hub for cellular metabolic control, common to all eukaryotic cells. Numerous reports have established how AMPK responds to changes in the AMP:ATP ratio as a measure of cellular energy levels. In this way, it integrates control over a number of metabolic enzymes and adapts cellular processes to the current energy status in various cell types, such as muscle and liver cells. The role of AMPK in the development, function, and maintenance of the nervous system, on the other hand, has only recently gained attention. Neurons, while highly metabolically active, have poor capacity for nutrient storage and are thus sensitive to energy fluctuations. Recent reports demonstrate that AMPK may have neuroprotective properties and is activated in neurons by resveratrol but also by metabolic stress in the form of ischemia/hypoxia and glucose deprivation. Novel studies on AMPK also implicate neuronal activity as a critical factor in neurodegeneration. Here we discuss the latest advances in the knowledge of AMPK's role in the metabolic control and survival of excitable cells.
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Affiliation(s)
- Milos R Spasić
- Laboratory of Developmental Genetics, Flanders Institute for Biotechnology (VIB), Leuven, Belgium
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Jeon BT, Lee DH, Kim KH, Kim HJ, Kang SS, Cho GJ, Choi WS, Roh GS. Ketogenic diet attenuates kainic acid-induced hippocampal cell death by decreasing AMPK/ACC pathway activity and HSP70. Neurosci Lett 2009; 453:49-53. [PMID: 19429014 DOI: 10.1016/j.neulet.2009.01.068] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Revised: 01/28/2009] [Accepted: 01/28/2009] [Indexed: 12/11/2022]
Abstract
The ketogenic diet (KD) prevents kainic acid (KA)-induced hippocampal cell death. There are reports that AMP-activated protein kinase (AMPK) activation regulates the intracellular signaling pathways involved in cellular survival or apoptotic cell death. In this study, we investigated the effect of the KD consumption on the expression of signaling pathway proteins AMPK and ACC, and heat shock protein (HSP) 70 in mouse hippocampus after KA treatment. Mice were fed the KD for 6 weeks and then sacrificed 48h after KA (30mg/kg) injection. The marked cell death found commonly in normal diet (ND)-fed mice treated with KA was not observed in the KD-fed KA-treated mice. Western blot analysis revealed that phosphorylation of AMPK and ACC was increased after KA treatment. However, phosphorylation of these proteins was reduced in those animals that received the KD. In addition, increased expression of HSP70 in the hippocampus of KA-treated mice was decreased in animals receiving the KD. These results indicate that the KD promotes neuroprotective effects through suppression of the AMPK cascade and that HSP70 is involved in neuronal cell death or oxidative stress.
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Affiliation(s)
- Byeong Tak Jeon
- Department of Anatomy and Neurobiology, Institute of Health Sciences, Medical Research Center for Neural Dysfunction, Gyeongsang National University, School of Medicine, 92 Chilam-dong, Jinju, Gyeongnam, 660-751, Republic of Korea
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