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Villa-González M, Rubio M, Martín-López G, Mallavibarrena PR, Vallés-Saiz L, Vivien D, Wandosell F, Pérez-Álvarez MJ. Pharmacological inhibition of mTORC1 reduces neural death and damage volume after MCAO by modulating microglial reactivity. Biol Direct 2024; 19:26. [PMID: 38582839 PMCID: PMC10999095 DOI: 10.1186/s13062-024-00470-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 03/25/2024] [Indexed: 04/08/2024] Open
Abstract
Ischemic stroke is a sudden and acute disease characterized by neuronal death, increment of reactive gliosis (reactive microglia and astrocytes), and a severe inflammatory process. Neuroinflammation is an early event after cerebral ischemia, with microglia playing a leading role. Reactive microglia involve functional and morphological changes that drive a wide variety of phenotypes. In this context, deciphering the molecular mechanisms underlying such reactive microglial is essential to devise strategies to protect neurons and maintain certain brain functions affected by early neuroinflammation after ischemia. Here, we studied the role of mammalian target of rapamycin (mTOR) activity in the microglial response using a murine model of cerebral ischemia in the acute phase. We also determined the therapeutic relevance of the pharmacological administration of rapamycin, a mTOR inhibitor, before and after ischemic injury. Our data show that rapamycin, administered before or after brain ischemia induction, reduced the volume of brain damage and neuronal loss by attenuating the microglial response. Therefore, our findings indicate that the pharmacological inhibition of mTORC1 in the acute phase of ischemia may provide an alternative strategy to reduce neuronal damage through attenuation of the associated neuroinflammation.
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Affiliation(s)
- Mario Villa-González
- Departamento de Biología (Fisiología Animal), Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Marina Rubio
- Physiopathology and Imaging of Neurological Disorders, Normandie University, UNICAEN, UMR-S U1237, INSERM, Institut Blood and Brain @ CaenNormandie, GIP Cyceron, Caen, France
| | - Gerardo Martín-López
- Departamento de Biología (Fisiología Animal), Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Paula R Mallavibarrena
- Departamento de Biología (Fisiología Animal), Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | | | - Denis Vivien
- Physiopathology and Imaging of Neurological Disorders, Normandie University, UNICAEN, UMR-S U1237, INSERM, Institut Blood and Brain @ CaenNormandie, GIP Cyceron, Caen, France
- Department of Clinical Research, Caen-Normandie Hospital (CHU), Caen, France
| | - Francisco Wandosell
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain.
- Centro de Investigaciones Biológicas en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain.
| | - Maria José Pérez-Álvarez
- Departamento de Biología (Fisiología Animal), Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain.
- Instituto Universitario de Biología Molecular (IUBM-UAM), Madrid, Spain.
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Zhang Y, Li D, Gao H, Zhao H, Zhang S, Li T. Rapamycin Alleviates Neuronal Injury and Modulates Microglial Activation After Cerebral Ischemia. Mol Neurobiol 2024:10.1007/s12035-023-03904-9. [PMID: 38224443 DOI: 10.1007/s12035-023-03904-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/21/2023] [Indexed: 01/16/2024]
Abstract
Neurons and microglia are sensitive to cerebral microcirculation and their responses play a crucial part in the pathological processes, while they are also the main target cells of many drugs used to treat brain diseases. Rapamycin exhibits beneficial effects in many diseases; however, whether it can affect neuronal injury or alter the microglial activation after global cerebral ischemia remains unclear. In this study, we performed global cerebral ischemia combined with rapamycin treatment in CX3CR1GFP/+ mice and explored the effects of rapamycin on neuronal deficit and microglial activation. Our results showed that rapamycin reduced neuronal loss, neurodegeneration, and ultrastructural damage after ischemia by histological staining and transmission electron microscopy (TEM). Interestingly, rapamycin suppressed de-ramification and proliferation of microglia and reduced the density of microglia. Immunofluorescence staining indicated that rapamycin skewed microglial polarization toward an anti-inflammatory state. Furthermore, rapamycin as well suppressed the activation of astrocytes. Meanwhile, quantitative real-time polymerase chain reaction (qRT-PCR) analyses revealed a significant reduction of pro-inflammatory factors as well as an elevation of anti-inflammatory factors upon rapamycin treatment. As a result of these effects, behavioral tests showed that rapamycin significantly alleviated the brain injury after stroke. Together, our study suggested that rapamycin attenuated neuronal injury, altered microglial activation state, and provided a more beneficial immune microenvironment for the brain, which could be used as a promising therapeutic approach to treat ischemic cerebrovascular diseases.
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Affiliation(s)
- Yue Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Donghai Li
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, China
| | - Hao Gao
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, China
| | - Haiyu Zhao
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, China
| | - Shengxiang Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, China.
| | - Ting Li
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, China.
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Yu X, Duan W, Wu F, Yang D, Wang X, Wu J, Zhou D, Shen Y. LncRNA-HOTAIRM1 promotes aerobic glycolysis and proliferation in osteosarcoma via the miR-664b-3p/Rheb/mTOR pathway. Cancer Sci 2023; 114:3537-3552. [PMID: 37316683 PMCID: PMC10475784 DOI: 10.1111/cas.15881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 04/08/2023] [Accepted: 05/27/2023] [Indexed: 06/16/2023] Open
Abstract
Osteosarcoma (OS), which is a common and aggressive primary bone malignancy, occurs mainly in children and adolescent. Long noncoding RNAs (lncRNAs) are reported to play a pivotal role in various cancers. Here, we found that the lncRNA HOTAIRM1 is upregulated in OS cells and tissues. A set of functional experiments suggested that HOTAIRM1 knockdown attenuated the proliferation and stimulated the apoptosis of OS cells. A subsequent mechanistic study revealed that HOTAIRM1 functions as a competing endogenous RNA to elevate ras homologue enriched in brain (Rheb) expression by sponging miR-664b-3p. Immediately afterward, upregulated Rheb facilitates proliferation and suppresses apoptosis by promoting the mTOR pathway-mediated Warburg effect in OS. In summary, our findings demonstrated that HOTAIRM1 promotes the proliferation and suppresses the apoptosis of OS cells by enhancing the Warburg effect via the miR-664b-3p/Rheb/mTOR axis. Understanding the underlying mechanisms and targeting the HOTAIRM1/miR-664b-3p/Rheb/mTOR axis are essential for OS clinical treatment.
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Affiliation(s)
- Xuecheng Yu
- Department of OrthopedicsThe Affiliated Changzhou Second People's Hospital of Nanjing Medical University, Changzhou Medical Center, Nanjing Medical UniversityChangzhouChina
| | - Weihao Duan
- Department of OrthopedicsThe Affiliated Changzhou Second People's Hospital of Nanjing Medical University, Changzhou Medical Center, Nanjing Medical UniversityChangzhouChina
| | - Furen Wu
- Department of OrthopedicsThe Affiliated Changzhou Second People's Hospital of Nanjing Medical University, Changzhou Medical Center, Nanjing Medical UniversityChangzhouChina
- Dalian Medical UniversityDalianChina
| | - Daibin Yang
- Department of OrthopedicsThe Affiliated Changzhou Second People's Hospital of Nanjing Medical University, Changzhou Medical Center, Nanjing Medical UniversityChangzhouChina
- Dalian Medical UniversityDalianChina
| | - Xin Wang
- Department of OrthopedicsThe Affiliated Changzhou Second People's Hospital of Nanjing Medical University, Changzhou Medical Center, Nanjing Medical UniversityChangzhouChina
| | - Jingbin Wu
- Department of OrthopedicsThe Affiliated Changzhou Second People's Hospital of Nanjing Medical University, Changzhou Medical Center, Nanjing Medical UniversityChangzhouChina
| | - Dong Zhou
- Changzhou No.6 People's HospitalNanjing Medical UniversityChangzhouChina
- Changzhou Medical CenterNanjing Medical UniversityChangzhouChina
- Department of OrthopedicsWuqia People's HospitalXinjiangChina
| | - Yifei Shen
- Department of OrthopedicsThe Affiliated Changzhou Second People's Hospital of Nanjing Medical University, Changzhou Medical Center, Nanjing Medical UniversityChangzhouChina
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Melanis K, Stefanou MI, Themistoklis KM, Papasilekas T. mTOR pathway - a potential therapeutic target in stroke. Ther Adv Neurol Disord 2023; 16:17562864231187770. [PMID: 37576547 PMCID: PMC10413897 DOI: 10.1177/17562864231187770] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 06/27/2023] [Indexed: 08/15/2023] Open
Abstract
Stroke is ranked as the second leading cause of death worldwide and a major cause of long-term disability. A potential therapeutic target that could offer favorable outcomes in stroke is the mammalian target of rapamycin (mTOR) pathway. mTOR is a serine/threonine kinase that composes two protein complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), and is regulated by other proteins such as the tuberous sclerosis complex. Through a significant number of signaling pathways, the mTOR pathway can modulate the processes of post-ischemic inflammation and autophagy, both of which play an integral part in the pathophysiological cascade of stroke. Promoting or inhibiting such processes under ischemic conditions can lead to apoptosis or instead sustained viability of neurons. The purpose of this review is to examine the pathophysiological role of mTOR in acute ischemic stroke, while highlighting promising neuroprotective agents such as hamartin for therapeutic modulation of this pathway. The therapeutic potential of mTOR is also discussed, with emphasis on implicated molecules and pathway steps that warrant further elucidation in order for their neuroprotective properties to be efficiently tested in future clinical trials.
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Affiliation(s)
- Konstantinos Melanis
- Second Department of Neurology, School of Medicine and ‘Attikon’ University Hospital, National and Kapodistrian University of Athens, Rimini 1 Chaidari, Athens 12462, Greece
- Center of Basic Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Maria-Ioanna Stefanou
- Second Department of Neurology, School of Medicine and ‘Attikon’ University Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Konstantinos M. Themistoklis
- Center of Basic Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
- Department of Neurosurgery, ‘Korgialenio, Benakio, H.R.C’. General Hospital of Athens, Athens, Greece
| | - Themistoklis Papasilekas
- Center of Basic Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
- Department of Neurosurgery, ‘Korgialenio, Benakio, H.R.C’. General Hospital of Athens, Athens, Greece
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Tang X, Balachandran RC, Aschner M, Bowman AB. IGF/mTORC1/S6 Signaling Is Potentiated and Prolonged by Acute Loading of Subtoxicological Manganese Ion. Biomolecules 2023; 13:1229. [PMID: 37627294 PMCID: PMC10452562 DOI: 10.3390/biom13081229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 08/01/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023] Open
Abstract
The insulin-like growth factor (IGF)/insulin signaling (IIS) pathway is involved in cellular responses against intracellular divalent manganese ion (Mn2+) accumulation. As a pathway where multiple nodes utilize Mn2+ as a metallic co-factor, how the IIS signaling patterns are affected by Mn2+ overload is unresolved. In our prior studies, acute Mn2+ exposure potentiated IIS kinase activity upon physiological-level stimulation, indicated by elevated phosphorylation of protein kinase B (PKB, also known as AKT). AKT phosphorylation is associated with IIS activity; and provides direct signaling transduction input for the mammalian target of rapamycin complex 1 (mTORC1) and its downstream target ribosomal protein S6 (S6). Here, to better define the impact of Mn2+ exposure on IIS function, Mn2+-induced IIS activation was evaluated with serial concentrations and temporal endpoints. In the wild-type murine striatal neuronal line STHdh, the acute treatment of Mn2+ with IGF induced a Mn2+ concentration-sensitive phosphorylation of S6 at Ser235/236 to as low as 5 μM extracellular Mn2+. This effect required both the essential amino acids and insulin receptor (IR)/IGF receptor (IGFR) signaling input. Similar to simultaneous stimulation of Mn2+ and IGF, when a steady-state elevation of Mn2+ was established via a 24-h pre-exposure, phosphorylation of S6 also displayed higher sensitivity to sub-cytotoxic Mn2+ when compared to AKT phosphorylation at Ser473. This indicates a synergistic effect of sub-cytotoxic Mn2+ on IIS and mTORC1 signaling. Furthermore, elevated intracellular Mn2+, with both durations, led to a prolonged activation in AKT and S6 upon stimulation. Our data demonstrate that the downstream regulator S6 is a highly sensitive target of elevated Mn2+ and is well below the established acute cytotoxicity thresholds (<50 μM). These findings indicate that the IIS/mTORC1 pathways, in which Mn2+ normally serves as an essential co-factor, are dually responsible for the cellular changes in exposures to real-world Mn2+ concentrations.
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Affiliation(s)
- Xueqi Tang
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA; (X.T.)
| | - Rekha C. Balachandran
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA; (X.T.)
- Exponent Inc., Alexandria, VA 22314, USA
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Aaron B. Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA; (X.T.)
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Chakraborty AD, Kooiker K, Kobak KA, Cheng Y, Lee CF, Razumova M, Granzier H H, Regnier M, Rabinovitch PS, Moussavi-Harami F, Chiao YA. Late-life Rapamycin Treatment Enhances Cardiomyocyte Relaxation Kinetics and Reduces Myocardial Stiffness. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.12.544619. [PMID: 37398078 PMCID: PMC10312630 DOI: 10.1101/2023.06.12.544619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Diastolic dysfunction is a key feature of the aging heart. We have shown that late-life treatment with mTOR inhibitor, rapamycin, reverses age-related diastolic dysfunction in mice but the molecular mechanisms of the reversal remain unclear. To dissect the mechanisms by which rapamycin improves diastolic function in old mice, we examined the effects of rapamycin treatment at the levels of single cardiomyocyte, myofibril and multicellular cardiac muscle. Compared to young cardiomyocytes, isolated cardiomyocytes from old control mice exhibited prolonged time to 90% relaxation (RT 90 ) and time to 90% Ca 2+ transient decay (DT 90 ), indicating slower relaxation kinetics and calcium reuptake with age. Late-life rapamycin treatment for 10 weeks completely normalized RT 90 and partially normalized DT 90 , suggesting improved Ca 2+ handling contributes partially to the rapamycin-induced improved cardiomyocyte relaxation. In addition, rapamycin treatment in old mice enhanced the kinetics of sarcomere shortening and Ca 2+ transient increase in old control cardiomyocytes. Myofibrils from old rapamycin-treated mice displayed increased rate of the fast, exponential decay phase of relaxation compared to old controls. The improved myofibrillar kinetics were accompanied by an increase in MyBP-C phosphorylation at S282 following rapamycin treatment. We also showed that late-life rapamycin treatment normalized the age-related increase in passive stiffness of demembranated cardiac trabeculae through a mechanism independent of titin isoform shift. In summary, our results showed that rapamycin treatment normalizes the age-related impairments in cardiomyocyte relaxation, which works conjointly with reduced myocardial stiffness to reverse age-related diastolic dysfunction.
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Hei C, Zhou Y, Zhang C, Gao F, Cao M, Yuan S, Qin Y, Li PA, Yang X. Rapamycin ameliorates brain damage and maintains mitochondrial dynamic balance in diabetic rats subjected to middle cerebral artery occlusion. Metab Brain Dis 2023; 38:409-418. [PMID: 35670992 DOI: 10.1007/s11011-022-01020-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 05/26/2022] [Indexed: 01/25/2023]
Abstract
To investigate the effect of rapamycin on mitochondrial dynamic balance in diabetic rats subjected to cerebral ischemia-reperfusion injury. Male Sprague Dawley (SD) rats (n = 78) were treated with high fat diet combined with streptozotocin injection to construct diabetic model in rats. Transient middle cerebral artery occlusion (MCAO) of 2 hours was induced and the brains were harvested after 1 and 3 days of reperfusion. Rapamycin was injected intraperitoneally for 3 days prior to and immediately after operation, once a day. The neurological function was assessed, infarct volumes were measured and HE staining as well as immunohistochemistry were performed. The protein of hippocampus was extracted and Western blotting were performed to detect the levels of mTOR, mitochondrial dynamin related proteins (DRP1, p-DRP1, OPA1), SIRT3, and Nix/BNIP3L. Diabetic hyperglycemia worsened the neurological function performance (p < 0.01), enlarged infarct size (p < 0.01) and increased ischemic neuronal cell death (p < 0.01). The increased damage was associated with elevations of p-mTOR, p-S6, and p-DRP1; and suppressions of SIRT3 and Nix/BNIP3L. Rapamycin ameliorated diabetes-enhanced ischemic brain damage and reversed the biomarker alterations caused by diabetes. High glucose activated mTOR pathway and caused mitochondrial dynamics toward fission. The protective effect of rapamycin against diabetes-enhanced ischemic brain damage was associated with inhibiting mTOR pathway, redressing mitochondrial dynamic imbalance, and elevating SIRT3 and Nix/BNIP3L expression.
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Affiliation(s)
- Changchun Hei
- Department of Human Anatomy, Histology and Embryology, Ningxia Medical University, Key Laboratory for Craniocerebral Diseases of Ningxia Hui Autonomous Region, Yinchuan, China
| | - Yujia Zhou
- Neuroscience Center, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Chenyang Zhang
- Neuroscience Center, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Furong Gao
- Medical Audit Department, Medical Security Bureau of Jiaxiang County, Jining, China
| | - Meiling Cao
- Neuroscience Center, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Shilin Yuan
- Neuroscience Center, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Yixin Qin
- Neuroscience Center, General Hospital of Ningxia Medical University, Yinchuan, China
| | - P Andy Li
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Technology Enterprise (BRITE), College of Health and Sciences, North Carolina Central University, Durham, NC, USA
| | - Xiao Yang
- Neuroscience Center, General Hospital of Ningxia Medical University, Yinchuan, China.
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Kumar S, Mehan S, Narula AS. Therapeutic modulation of JAK-STAT, mTOR, and PPAR-γ signaling in neurological dysfunctions. J Mol Med (Berl) 2023; 101:9-49. [PMID: 36478124 DOI: 10.1007/s00109-022-02272-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 10/10/2022] [Accepted: 11/11/2022] [Indexed: 12/12/2022]
Abstract
The cytokine-activated Janus kinase (JAK)-signal transducer and activator of transcription (STAT) cascade is a pleiotropic pathway that involves receptor subunit multimerization. The mammalian target of rapamycin (mTOR) is a ubiquitously expressed serine-threonine kinase that perceives and integrates a variety of intracellular and environmental stimuli to regulate essential activities such as cell development and metabolism. Peroxisome proliferator-activated receptor-gamma (PPARγ) is a prototypical metabolic nuclear receptor involved in neural differentiation and axon polarity. The JAK-STAT, mTOR, and PPARγ signaling pathways serve as a highly conserved signaling hub that coordinates neuronal activity and brain development. Additionally, overactivation of JAK/STAT, mTOR, and inhibition of PPARγ signaling have been linked to various neurocomplications, including neuroinflammation, apoptosis, and oxidative stress. Emerging research suggests that even minor disruptions in these cellular and molecular processes can have significant consequences manifested as neurological and neuropsychiatric diseases. Of interest, target modulators have been proven to alleviate neuronal complications associated with acute and chronic neurological deficits. This research-based review explores the therapeutic role of JAK-STAT, mTOR, and PPARγ signaling modulators in preventing neuronal dysfunctions in preclinical and clinical investigations.
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Affiliation(s)
- Sumit Kumar
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy, Punjab, Moga, India
| | - Sidharth Mehan
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy, Punjab, Moga, India.
| | - Acharan S Narula
- Narula Research, LLC, 107 Boulder Bluff, Chapel Hill, NC, 27516, USA
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Díaz A, Flores I, Treviño S. Neurotrophic fragments as therapeutic alternatives to ameliorate brain aging. Neural Regen Res 2023; 18:51-56. [PMID: 35799508 PMCID: PMC9241392 DOI: 10.4103/1673-5374.331867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Aging is a global phenomenon and a complex biological process of all living beings that introduces various changes. During this physiological process, the brain is the most affected organ due to changes in its structural and chemical functions, such as changes in plasticity and decrease in the number, diameter, length, and branching of dendrites and dendritic spines. Likewise, it presents a great reduction in volume resulting from the contraction of the gray matter. Consequently, aging can affect not only cognitive functions, including learning and memory, but also the quality of life of older people. As a result of the phenomena, various molecules with notable neuroprotective capacity have been proposed, which provide a therapeutic alternative for people under conditions of aging or some neurodegenerative diseases. It is important to indicate that in recent years the use of molecules with neurotrophic activity has shown interesting results when evaluated in in vivo models. This review aims to describe the neurotrophic potential of molecules such as resveratrol (3,5,4′-trihydroxystilbene), neurotrophins (brain-derived neurotrophic factor), and neurotrophic-type compounds such as the terminal carboxyl domain of the heavy chain of tetanus toxin, cerebrolysin, neuropeptide-12, and rapamycin. Most of these molecules have been evaluated by our research group. Studies suggest that these molecules exert an important therapeutic potential, restoring brain function in aging conditions or models of neurodegenerative diseases. Hence, our interest is in describing the current scientific evidence that supports the therapeutic potential of these molecules with active neurotrophic.
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FDA-Approved Kinase Inhibitors in Preclinical and Clinical Trials for Neurological Disorders. Pharmaceuticals (Basel) 2022; 15:ph15121546. [PMID: 36558997 PMCID: PMC9784968 DOI: 10.3390/ph15121546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 12/09/2022] [Accepted: 12/09/2022] [Indexed: 12/14/2022] Open
Abstract
Cancers and neurological disorders are two major types of diseases. We previously developed a new concept termed "Aberrant Cell Cycle Diseases" (ACCD), revealing that these two diseases share a common mechanism of aberrant cell cycle re-entry. The aberrant cell cycle re-entry is manifested as kinase/oncogene activation and tumor suppressor inactivation, which are hallmarks of both tumor growth in cancers and neuronal death in neurological disorders. Therefore, some cancer therapies (e.g., kinase inhibition, tumor suppressor elevation) can be leveraged for neurological treatments. The United States Food and Drug Administration (US FDA) has so far approved 74 kinase inhibitors, with numerous other kinase inhibitors in clinical trials, mostly for the treatment of cancers. In contrast, there are dire unmet needs of FDA-approved drugs for neurological treatments, such as Alzheimer's disease (AD), intracerebral hemorrhage (ICH), ischemic stroke (IS), traumatic brain injury (TBI), and others. In this review, we list these 74 FDA-approved kinase-targeted drugs and identify those that have been reported in preclinical and/or clinical trials for neurological disorders, with a purpose of discussing the feasibility and applicability of leveraging these cancer drugs (FDA-approved kinase inhibitors) for neurological treatments.
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Possible Involvement of DNA Methylation in TSC1 Gene Expression in Neuroprotection Induced by Hypoxic Preconditioning. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:9306097. [PMID: 36120601 PMCID: PMC9481362 DOI: 10.1155/2022/9306097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 07/19/2022] [Accepted: 08/13/2022] [Indexed: 11/18/2022]
Abstract
Background. It has been reported that ischemia and ischemic preconditioning (IPC) have different effects on the expression of tuberous sclerosis complex 1 (TSC1), which may contribute to the tolerance to ischemia/hypoxia with the increase of autophagy. The mechanisms of TSC1 differential expression are still unclear under ischemia/IPC conditions in hippocampal Cornu Ammon 1 (CA1) and Cornu Ammon 3 (CA3) area neuronal cells. While we have shown that 5-Aza-CdR, a DNA methyltransferase inhibitor, can upregulate TSC1 and increase hypoxic tolerance by autophagy in vivo and in vitro, in this study, we examined whether DNA methylation was involved in the differential expression of TSC1 in the CA1 and CA3 regions induced by hypoxic preconditioning (HPC). Methods. Level of rapamycin (mTOR) autophagy, a downstream molecular pathway of TSC1/TSC2 complex, was detected in HPC mouse hippocampal CA1 and CA3 areas as well as in the HPC model of mouse hippocampal HT22 cells. DNA methylation level of TSC1 promoter (-720 bp~ -360 bp) was determined in CA1 and CA3 areas by bisulfite-modified DNA sequencing (BMDS). At the same time, autophagy was detected in HT22 cells transfected with GFP-LC3 plasmid. The role of TSC1 in neuroprotection was measured by cell viability and apoptosis, and the role of TSC1 in metabolism was checked by ATP assay and ROS assay in HT22 cells that overexpressed/knocked down TSC1. Results. HPC upregulated the expression of TSC1, downregulated the level of P-mTOR (Ser2448) and P-p70S6K (Thr389), and enhanced the activity of autophagy in both in vivo and in vitro. The increased expression of TSC1 in HPC may depend on its DNA hypomethylation in the promoter region in vivo. HPC also could reduce energy consumption in HT22 cells. Overexpression and knockdown of TSC1 can affect cell viability, cell apoptosis, and metabolism in HT22 cells exposed to hypoxia. Conclusion. TSC1 expression induced by HPC may relate to the downregulation of its DNA methylation level with the increase of autophagy and the decrease of energy demand.
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Novel Therapeutic Strategies for Ischemic Stroke: Recent Insights into Autophagy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:3450207. [PMID: 35720192 PMCID: PMC9200548 DOI: 10.1155/2022/3450207] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 04/24/2022] [Accepted: 05/11/2022] [Indexed: 11/18/2022]
Abstract
Stroke is one of the leading causes of death and disability worldwide. Autophagy is a conserved cellular catabolic pathway that maintains cellular homeostasis by removal of damaged proteins and organelles, which is critical for the maintenance of energy and function homeostasis of cells. Accumulating evidence demonstrates that autophagy plays important roles in pathophysiological mechanisms under ischemic stroke. Previous investigations show that autophagy serves as a “double-edged sword” in ischemic stroke as it can either promote the survival of neuronal cells or induce cell death in special conditions. Following ischemic stroke, autophagy is activated or inhibited in several cell types in brain, including neurons, astrocytes, and microglia, as well as microvascular endothelial cells, which involves in inflammatory activation, modulation of microglial phenotypes, and blood-brain barrier permeability. However, the exact mechanisms of underlying the role of autophagy in ischemic stroke are not fully understood. This review focuses on the recent advances regarding potential molecular mechanisms of autophagy in different cell types. The focus is also on discussing the “double-edged sword” effect of autophagy in ischemic stroke and its possible underlying mechanisms. In addition, potential therapeutic strategies for ischemic stroke targeting autophagy are also reviewed.
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Kamel R, El Morsy EM, Elsherbiny ME, Nour-Eldin M. Chrysin promotes angiogenesis in rat hindlimb ischemia: Impact on PI3K/Akt/mTOR signaling pathway and autophagy. Drug Dev Res 2022; 83:1226-1237. [PMID: 35662099 DOI: 10.1002/ddr.21954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 05/01/2022] [Accepted: 05/17/2022] [Indexed: 11/09/2022]
Abstract
Limb ischemia occurs due to obstruction of blood perfusion to lower limbs, a manifestation that is associated with peripheral artery disease (PAD). Angiogenesis is important for adequate oxygen delivery. The present study investigated a potential role for chrysin, a naturally occurring flavonoid, in promoting angiogenesis in hindlimb ischemia (HLI) rat model. Rats were allocated into four groups: (1) sham-operated control, (2) HLI: subjected to unilateral femoral artery ligation, (3) HLI + chrysin: received 100 mg/kg, i.p. chrysin immediately after HLI, and (4) HLI + chrysin + rapamycin: received 6 mg/kg/day rapamycin i.p. for 5 days then subjected to HLI and dosed with 100 mg/kg chrysin, i.p. Rats were killed 18 h later and gastrocnemius muscles were collected and divided into parts for (1) immunohistochemistry detection of CD31 and CD105, (2) qRT-PCR analysis of eNOS and VEGFR2, (3) colorimetric analysis of NO, (4) ELISA estimation of TGF-β, VEGF, ATG5 and Beclin-1, and (5) Western blot analysis of p-PI3K, PI3K, p-Akt, Akt, p-mTOR, mTOR, and HIF-1α. Chrysin significantly enhanced microvessels growth in HLI muscles as indicated by increased CD31 and CD105 levels and decreased TGF-β. Chrysin's proangiogenic effect is potentially mediated by increased VEGF, VEGFR2 and activation of PI3K/AKT/mTOR pathway, which promoted eNOS and NO levels as it was reversed by the mTOR inhibitor, rapamycin. Chrysin also inhibited autophagy as it decreased ATG5 and Beclin-1. The current study shows that chrysin possesses a proangiogenic effect in HLI rats and might be useful in patients with PAD.
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Affiliation(s)
- Rehab Kamel
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Helwan University, Cairo, Egypt.,Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ahram Canadian University, Giza, Egypt
| | - Engy M El Morsy
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Helwan University, Cairo, Egypt
| | - Marwa E Elsherbiny
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ahram Canadian University, Giza, Egypt
| | - Mahmoud Nour-Eldin
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Sadat City (USC), Menoufia, Egypt
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AKINCI UYSAL Ç, TEMİZ REŞİTOĞLU M, GÜDEN DS, ŞENOL SP, VEZİR Ö, SUCU N, TUNÇTAN B, MALİK KU, FIRAT S. Inhibition of mTOR protects against skeletal muscle and kidney injury following hindlimb ischemia-reperfusion in rats by regulating MERK1/ERK1/2 activity. CUKUROVA MEDICAL JOURNAL 2022. [DOI: 10.17826/cumj.1021518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Liu P, Yang X, Niu J, Hei C. Hyperglycemia aggravates ischemic brain damage via ERK1/2 activated cell autophagy and mitochondrial fission. Front Endocrinol (Lausanne) 2022; 13:928591. [PMID: 35992111 PMCID: PMC9388937 DOI: 10.3389/fendo.2022.928591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 07/11/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Hyperglycemia is one of the major risk factors for stroke and stroke recurrence, leading to aggravated neuronal damage after cerebral ischemia/reperfusion (I/R). ERK1/2 signaling pathway plays a vital role in cerebral ischemic injury. However, the role of the ERK1/2 pathway in hyperglycemia-aggravated ischemic brain damage is not clear. METHODS Streptozotocin (STZ; 50 mg/kg)-induced diabetes (blood glucose ≥12 mmol/L) or control groups in adult Sprague-Dawley rats were further subdivided into I/R (carotid artery/vein clamping), I/R + PD98059 (I/R plus ERK1/2 inhibitor), and Sham-operated groups (n = 10 each). Neurobehavioral status (Neurological behavior scores) and the volume of the cerebral infarction (TTC staining); brain mitochondrial potential (JCI ratio test) and cell apoptosis (TUNEL assay); RAS protein expression, phosphorylated/total ERK1/2 and Drp-1 (Dynamic-related protein 1) protein levels (Western blotting); mitochondrial fusion-related proteins mitofusin-1/2 (Mfn1/2), optic atrophy (OPA-1) and mitochondrial fission 1 (Fis1), and autophagy-associated proteins Beclin-1, LC3-I/II and P62 (Western blotting and immunohistochemistry) were analyzed. RESULTS The I/R + PD98059 group demonstrated better neurobehavior on the 1st (p < 0.05) and the 3rd day (p < 0.01) than the I/R group. Compared to the Sham group, cerebral ischemia/reperfusion brought about neuronal damage in the I/R group (p <0.01). However, treatment with PD98059 showed an improved situation with faster recovery of mitochondrial potential and less apoptosis of neuronal cells in the I/R + PD98059 group (p < 0.01). The I/R group had a higher-level expression of RAS and phosphorylated ERK1/2 and Drp-1 than the diabetes mellitus (DM) group (p < 0.01). The PD98059 treated group showed decreased expression of p-ERK1/2, p-Drp-1, Fis1, and Beclin-1, LC3-I/II and P62, but increased Mfn1/2 and OPA-1 than the I/R group (p < 0.01). CONCLUSION Hyperglycemia worsens cerebral ischemia/reperfusion-induced neuronal damage via ERK1/2 activated cell autophagy and mitochondrial fission.
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Affiliation(s)
- Ping Liu
- Department of Endocrinology, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Xiao Yang
- Neuroscience Center, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Jianguo Niu
- Ningxia Key Laboratory of Cerebrocranial Disease, Ningxia Medical University, Yinchuan, China
| | - Changchun Hei
- Ningxia Key Laboratory of Cerebrocranial Disease, Ningxia Medical University, Yinchuan, China
- Department of Human Anatomy, Histology and Embryology, Ningxia Medical University, Yinchuan, China
- *Correspondence: Changchun Hei,
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Lipid metabolism, inflammation, and foam cell formation in health and metabolic disorders: targeting mTORC1. J Mol Med (Berl) 2021; 99:1497-1509. [PMID: 34312684 DOI: 10.1007/s00109-021-02117-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 07/12/2021] [Accepted: 07/14/2021] [Indexed: 02/07/2023]
Abstract
Metabolic homeostasis is important for maintaining a healthy lifespan. Lipid metabolism is particularly necessary for the maintenance of metabolic energy sources and their storage, and the structure and function of cell membranes, as well as for the regulation of nutrition through lipogenesis, lipolysis, and lipophagy. Dysfunctional lipid metabolism leads to the development of metabolic disorders, such as atherosclerosis, diabetes mellitus, and non-alcoholic fatty liver disease (NAFLD). Furthermore, dyslipidaemia causes inflammatory responses and foam cell formation. Mechanistic target of rapamycin (mTOR) signalling is a key regulator of diverse cellular processes, including cell metabolism and cell fate. mTOR complex 1 (mTORC1) is involved in lipid metabolism and immune responses in the body. Therefore, the mTORC1 signalling pathway has been suggested as a potential therapeutic target for the treatment of metabolic disorders. In this review, we focus on the roles of mTORC1 in lipid metabolism and inflammation, and present current evidence on its involvement in the development and progression of metabolic disorders.
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Guo M, Xu J, Wang S, Dong B. Asiaticoside reduces autophagy and improves memory in a rat model of dementia through mTOR signaling pathway regulation. Mol Med Rep 2021; 24:645. [PMID: 34278477 DOI: 10.3892/mmr.2021.12284] [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: 10/10/2020] [Accepted: 05/14/2021] [Indexed: 11/06/2022] Open
Abstract
Vascular dementia (VD) is one of the leading causes of neurological disorder following Alzheimer's disease. The present study evaluated the possible role of asiaticoside in the treatment of rats with VD and its inhibitory effects on autophagy in hippocampal tissues. Double ligation was used for permanent occlusion of the arteries, and spatial memory was assessed using the T‑maze test. Western blotting was used for determination of protein expression levels and H&E staining for histological analysis. Treatment of rats with VD with asiaticoside significantly alleviated the impairment in spontaneously altered behaviors and significantly reduced escape latency. VD mediated a decrease in distance travelled, swim time and number of platform crossings, whereas this was alleviated by asiaticoside. Furthermore, VD‑mediated hippocampal tissue damage was significantly alleviated by asiaticoside treatment (P<0.05), and asiaticoside alleviated formation of autophagosomes and markedly suppressed the number of primary lysosomes. In asiaticoside‑treated rats, VD‑mediated increases in Beclin 1 and microtubule‑associated protein light chain 3 (LC3) II expression in the hippocampal tissues were alleviated. Asiaticoside treatment also prevented suppression of mammalian target of rapamycin (mTOR) phosphorylation in VD rat hippocampal tissues. Notably, the rapamycin‑mediated suppression of phosphorylated‑mTOR, and elevation of Beclin 1 and LC3II expression in the rat hippocampus could not be alleviated by asiaticoside treatment. In conclusion, asiaticoside effectively prevented cerebral ischemia‑mediated cognitive impairment and neuronal damage in the rats. Moreover, autophagy was inhibited and the mTOR pathway was activated in rats with cerebral ischemia by asiaticoside treatment. Therefore, asiaticoside may warrant further study as a therapeutic agent for the treatment of dementia.
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Affiliation(s)
- Min Guo
- Department of Neurology, Aerospace Center Hospital, Peking University Aerospace School of Clinical Medicine, Beijing 100049, P.R. China
| | - Jianmeng Xu
- Department of Neurosurgery, Dongying District People's Hospital of Dongying City, Dongying, Shandong 257000, P.R. China
| | - Shiwei Wang
- Department of Traditional Chinese Medicine, Dongying District People's Hospital of Dongying City, Dongying, Shandong 257000, P.R. China
| | - Baohua Dong
- Department of Neurology, Dongying District People's Hospital of Dongying City, Dongying, Shandong 257000, P.R. China
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Lu JH, Wu YH, Juan TJ, Lin HY, Lin RJ, Chueh KS, Lee YC, Chang CY, Juan YS. Autophagy Alters Bladder Angiogenesis and Improves Bladder Hyperactivity in the Pathogenesis of Ketamine-Induced Cystitis in a Rat Model. BIOLOGY 2021; 10:biology10060488. [PMID: 34070854 PMCID: PMC8228861 DOI: 10.3390/biology10060488] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/23/2021] [Accepted: 05/24/2021] [Indexed: 12/23/2022]
Abstract
Simple Summary Long-term ketamine abuse may increase urinary frequency, nocturia, urgency, bladder pain, dysuria, and sometimes hematuria. Evaluation of the pathophysiological mechanism of bladder voiding dysfunction in ketamine-induced cystitis (KIC) patients is a critical step for therapy. This study uses autophagy inducer (rapamycin, mTOR inhibitor) and inhibitor (wortmannin, PI3K-III inhibitor) to identify the role of autophagy in bladder angiogenesis alteration and bladder hyperactivity improvement. Abstract The present study attempts to elucidate whether autophagy alters bladder angiogenesis, decreases inflammatory response, and ameliorates bladder hyperactivity—thereby influencing bladder function in ketamine-induced cystitis (KIC). In our methodology, female Sprague-Dawley (S-D) rats were randomly divided into the control group, the ketamine group, the ketamine+rapamycin group, and the ketamine+wortmannin group. The bladder function, contractile activity of detrusor smooth muscle, distribution of autophagosome and autolysosome, total white blood cells (WBCs) and leukocyte differential counts, the expressions of autophagy-associated protein, angiogenesis markers, and signaling pathway molecules involved in KIC were tested, respectively. The data revealed that treatment with ketamine significantly results in bladder overactivity, enhanced interstitial fibrosis, impaired endothelium, induced eosinophil-mediated inflammation, swelling, and degraded mitochondria and organelles, inhibited angiogenesis, and elevated the phosphorylation of Akt. However, treatment with rapamycin caused an inhibitory effect on vascular formation, removed ketamine metabolites, decreased the eosinophil-mediated inflammation, and ameliorated bladder hyperactivity, leading to improve bladder function in KIC. Moreover, wortmannin treatment reduced basophil-mediated inflammatory response, improved bladder angiogenesis by increasing capillary density and VEGF expression, to reverse antiangiogenic effect to repair KIC. In conclusion, these findings suggested that autophagy could modulate inflammatory responses and angiogenesis, which improved bladder function in KIC.
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Affiliation(s)
- Jian-He Lu
- Emerging Compounds Research Center, Department of Environmental Science and Engineering, College of Engineering, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan;
| | - Yi-Hsuan Wu
- Department of Urology, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
- Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan;
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Tai-Jui Juan
- Department of Medicine, National Defense Medical College, Taipei 11490, Taiwan;
| | - Hung-Yu Lin
- School of Medicine, College of Medicine, I-Shou University, Kaohsiung 84001, Taiwan;
- Division of Urology, Department of Surgery, E-Da Cancer Hospital, Kaohsiung 82445, Taiwan
- Division of Urology, Department of Surgery, E-Da Hospital, Kaohsiung 82445, Taiwan
| | - Rong-Jyh Lin
- Department of Parasitology, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; (Y.-C.L.); (C.-Y.C.)
| | - Kuang-Shun Chueh
- Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan;
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Department of Urology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung 80661, Taiwan
| | - Yi-Chen Lee
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; (Y.-C.L.); (C.-Y.C.)
- Department of Anatomy, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Chao-Yuan Chang
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; (Y.-C.L.); (C.-Y.C.)
- Department of Anatomy, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Yung-Shun Juan
- Department of Urology, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
- Department of Urology, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan;
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Department of Urology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung 80661, Taiwan
- Correspondence: ; Tel.: +886-7-312-1101; Fax: +886-7-350-6269
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Sharma A, Mehan S. Targeting PI3K-AKT/mTOR signaling in the prevention of autism. Neurochem Int 2021; 147:105067. [PMID: 33992742 DOI: 10.1016/j.neuint.2021.105067] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/29/2021] [Accepted: 05/02/2021] [Indexed: 12/16/2022]
Abstract
PI3K-AKT/mTOR signaling pathway represents an essential signaling mechanism for mammalian enzyme-related receptors in transducing signals or biological processes such as cell development, differentiation, cell survival, protein synthesis, and metabolism. Upregulation of the PI3K-AKT/mTOR signaling pathway involves many human brain abnormalities, including autism and other neurological dysfunctions. Autism is a neurodevelopmental disorder associated with behavior and psychiatric illness. This research-based review discusses the functional relationship between the neuropathogenic factors associated with PI3K-AKT/mTOR signaling pathway. Ultimately causes autism-like conditions associated with genetic alterations, neuronal apoptosis, mitochondrial dysfunction, and neuroinflammation. Therefore, inhibition of the PI3K-AKT/mTOR signaling pathway may have an effective therapeutic value for autism treatment. The current review also summarizes the involvement of PI3K-AKT/mTOR signaling pathway inhibitors in the treatment of autism and other neurodegenerative disorders.
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Affiliation(s)
- Aarti Sharma
- Neuropharmacology Division, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India
| | - Sidharth Mehan
- Neuropharmacology Division, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India.
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20
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Morris-Blanco KC, Chokkalla AK, Bertogliat MJ, Vemuganti R. TET3 regulates DNA hydroxymethylation of neuroprotective genes following focal ischemia. J Cereb Blood Flow Metab 2021; 41:590-603. [PMID: 32380888 PMCID: PMC7922754 DOI: 10.1177/0271678x20912965] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The 5-hydroxymethylcytosine (5hmC) epigenetic modification is highly enriched in the CNS and a critical modulator of neuronal function and development. We found that cortical 5hmC was enhanced from 5 min to three days of reperfusion following focal ischemia in adult mice. Blockade of the 5hmC-producing enzyme ten-eleven translocase 3 (TET3) increased edema, infarct volume, and motor function impairments. To determine the mechanism by which TET3 provides ischemic neuroprotection, we assessed the genomic regions where TET3 modulates 5hmC. Genome-wide sequencing analysis of differentially hydroxymethylated regions (DhMRs) revealed that focal ischemia robustly increased 5hmC at the promoters of thousands of genes in a TET3-dependent manner. TET3 inhibition reduced 5hmC at the promoters of neuroprotective genes involved in cell survival, angiogenesis, neurogenesis, antioxidant defense, DNA repair, and metabolism demonstrating a role for TET3 in endogenous protection against stroke. The mRNA expression of several genes with known involvement in ischemic neuroprotection were also reduced with TET3 knockdown in both male and female mice, establishing a correlation between decreased promoter 5hmC levels and decreased gene expression. Collectively, our results indicate that TET3 globally increases 5hmC at regulatory regions and overwhelmingly modulates 5hmC in several neuroprotective pathways that may improve outcome after ischemic injury.
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Affiliation(s)
- Kahlilia C Morris-Blanco
- Department of Neurological Surgery, University of Wisconsin-Madison, Madison, WI, USA.,Department of Research, William S. Middleton Veterans Administration Hospital, Madison, WI, USA
| | - Anil K Chokkalla
- Department of Neurological Surgery, University of Wisconsin-Madison, Madison, WI, USA.,Cellular and Molecular Pathology Graduate Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Mario J Bertogliat
- Department of Neurological Surgery, University of Wisconsin-Madison, Madison, WI, USA
| | - Raghu Vemuganti
- Department of Neurological Surgery, University of Wisconsin-Madison, Madison, WI, USA.,Department of Research, William S. Middleton Veterans Administration Hospital, Madison, WI, USA.,Cellular and Molecular Pathology Graduate Program, University of Wisconsin-Madison, Madison, WI, USA
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21
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de la Torre JC. Deciphering Alzheimer's Disease Pathogenic Pathway: Role of Chronic Brain Hypoperfusion on p-Tau and mTOR. J Alzheimers Dis 2021; 79:1381-1396. [PMID: 33459641 DOI: 10.3233/jad-201165] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This review examines new biomolecular findings that lend support to the hemodynamic role played by chronic brain hypoperfusion (CBH) in driving a pathway to Alzheimer's disease (AD). CBH is a common clinical feature of AD and the current topic of intense investigation in AD models. CBH is also the basis for the vascular hypothesis of AD which we originally proposed in 1993. New biomolecular findings reveal the interplay of CBH in increasing tau phosphorylation (p-Tau) in the hippocampus and cortex of AD mice, damaging fast axonal transport, increasing signaling of mammalian target of rapamycin (mTOR), impairing learning-memory function, and promoting the formation of neurofibrillary tangles, a neuropathologic hallmark of AD. These pathologic elements have been singularly linked with neurodegeneration and AD but their abnormal, collective participation during brain aging have not been fully examined. The format for this review will provide a consolidated analysis of each pathologic phase contributing to cognitive decline and AD onset, summarized in nine chronological steps. These steps galvanize each factor's active participation and contribution in constructing a biomolecular pathway to AD onset generated by CBH.
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Affiliation(s)
- Jack C de la Torre
- Department of Psychology, University of Texas at Austin, Austin, TX, USA.,Department of Physiology, University of Valencia Faculty of Medicine, Valencia, Spain
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Li S, Ren C, Stone C, Chandra A, Xu J, Li N, Han C, Ding Y, Ji X, Shao G. Hamartin: An Endogenous Neuroprotective Molecule Induced by Hypoxic Preconditioning. Front Genet 2020; 11:582368. [PMID: 33193709 PMCID: PMC7556298 DOI: 10.3389/fgene.2020.582368] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 09/08/2020] [Indexed: 11/23/2022] Open
Abstract
Hypoxic/ischemic preconditioning (HPC/IPC) is an innate neuroprotective mechanism in which a number of endogenous molecules are known to be involved. Tuberous sclerosis complex 1 (TSC1), also known as hamartin, is thought to be one such molecule. It is also known that hamartin is involved as a target in the rapamycin (mTOR) signaling pathway, which functions to integrate a variety of environmental triggers in order to exert control over cellular metabolism and homeostasis. Understanding the role of hamartin in ischemic/hypoxic neuroprotection will provide a novel target for the treatment of hypoxic-ischemic disease. Therefore, the proposed molecular mechanisms of this neuroprotective role and its preconditions are reviewed in this paper, with emphases on the mTOR pathway and the relationship between the expression of hamartin and DNA methylation.
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Affiliation(s)
- Sijie Li
- Beijing Key Laboratory of Hypoxic Conditioning Translational Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China.,Inner Mongolia Key Laboratory of Hypoxic Translational Medicine, Baotou Medical College, Baotou, China
| | - Changhong Ren
- Beijing Key Laboratory of Hypoxic Conditioning Translational Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China.,Inner Mongolia Key Laboratory of Hypoxic Translational Medicine, Baotou Medical College, Baotou, China
| | - Christopher Stone
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, United States
| | - Ankush Chandra
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, United States
| | - Jiali Xu
- Beijing Key Laboratory of Hypoxic Conditioning Translational Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Ning Li
- Beijing Key Laboratory of Hypoxic Conditioning Translational Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Cong Han
- Department of Neurosurgery, The Fifth Medical Centre of PLA General Hospital, Beijing, China
| | - Yuchuan Ding
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, United States
| | - Xunming Ji
- Beijing Key Laboratory of Hypoxic Conditioning Translational Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Guo Shao
- Beijing Key Laboratory of Hypoxic Conditioning Translational Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China.,Inner Mongolia Key Laboratory of Hypoxic Translational Medicine, Baotou Medical College, Baotou, China.,Public Health Department, Biomedicine Research Center, Basic Medical College, Baotou, China.,Baotou Medical College of Neuroscience Institute, Baotou Medical College, Baotou, China
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Chloride channel 7 protects from redox status impairment-induced renal tubular epithelial cell apoptosis by activating autophagy. Life Sci 2020; 261:118484. [PMID: 32976885 DOI: 10.1016/j.lfs.2020.118484] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 09/08/2020] [Accepted: 09/18/2020] [Indexed: 02/07/2023]
Abstract
AIM Chloride channel 7 (CLC-7), broadly expressed in kidney tissues, affects the lysosome degradation pathway. And redox status impairment contributes to cell apoptosis and activates autophagy flux. This study mainly investigates the role and molecular mechanism of CLC-7 in redox status impairment-induced autophagic flux and apoptosis. MAIN METHODS When NRK52E cells, rat renal tubular epithelial cells, were exposed to H2O2 treatment, apoptosis, autophagy flux, and CLC-7 expression were detected. Further investigation was done to observe the change of apoptosis and autophagy flux in renal cells under overexpression or knocking down of CLC-7. The lysosomes acidity, lysosome enzyme Cathepsin D activity and phosphorylation of Ampk/mTOR were also examined when CLC-7 was overexpressed or knocked down. KEY FINDINGS Redox status impairment induced apoptosis and autophagy flux in NRK52E cells and upregulated CLC-7. Overexpression of CLC-7 increased lysosome acidity and Cathepsin D activity. In cells with CLC-7 overexpression, we observed a significant increase of autophagy flux and decline of apoptosis, as well as an apparent increase of p-Ampk and decrease of p-mTOR. On the contrary, cells with knocking down CLC-7 led to opposite results. SIGNIFICANCES CLC-7 is essential to maintain and enhance acidity and enzyme activity in lysosome. Through activating autophagy flux, it exerts survival against renal tubular epithelial cell apoptosis induced by redox status impairment. Its function to modulate Ampk/mTOR pathway is the possible reason why CLC-7 can trigger autophagy flux.
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Li Y, Luo Y, Li B, Niu L, Liu J, Duan X. miRNA-182/Deptor/mTOR axis regulates autophagy to reduce intestinal ischaemia/reperfusion injury. J Cell Mol Med 2020; 24:7873-7883. [PMID: 32510855 PMCID: PMC7348187 DOI: 10.1111/jcmm.15420] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 05/01/2020] [Accepted: 05/06/2020] [Indexed: 02/06/2023] Open
Abstract
It had been reported miR‐182 was down‐regulated after intestinal ischaemia/reperfusion (I/R) damage. However, its role and potential mechanisms are still unknown. This study was aimed to elucidate the function of miR‐182 in intestinal I/R injury and the underlying mechanisms. The model of intestinal injury was constructed in wild‐type and Deptor knockout (KO) mice. Haematoxylin‐eosin staining, Chiu's score and diamine oxidase were utilized to detect intestinal damage. RT‐qPCR assay was used to detected miR‐182 expression. Electronic microscopy was used to detect autophagosome. Western blot was applied to detect the expression of Deptor, S6/pS6, LC3‐II/LC3‐I and p62. Dual‐luciferase reporter assay was used to verify the relationship between miR‐182 and Deptor. The results showed miR‐182 was down‐regulated following intestinal I/R. Up‐regulation of miR‐182 reduced intestinal damage, autophagy, Deptor expression and enhanced mTOR activity following intestinal I/R. Moreover, suppression of autophagy reduced intestinal damage and inhibition of mTOR by rapamycin aggravated intestinal damage following intestinal I/R. Besides, damage of intestine was reduced and mTOR activity was enhanced in Deptor KO mice. In addition, Deptor was the target gene of miR‐182 and was indispensable for the protection of miR‐182 on intestine under I/R condition. Together, our research implicated up‐regulation of miR‐182 inhibited autophagy to alleviate intestinal I/R injury via mTOR by targeting Deptor.
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Affiliation(s)
- Yunsheng Li
- Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Yanhua Luo
- Department of Anesthesiology, Zhongshan Ophthalmic Center of Sun Yat-sen University, Guangzhou, China
| | - Baochuan Li
- Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Lijun Niu
- Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Jiaxin Liu
- Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Xiaoyun Duan
- Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
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25
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Zimmerman MA, Wilkison S, Qi Q, Chen G, Li PA. Mitochondrial dysfunction contributes to Rapamycin-induced apoptosis of Human Glioblastoma Cells - A synergistic effect with Temozolomide. Int J Med Sci 2020; 17:2831-2843. [PMID: 33162811 PMCID: PMC7645350 DOI: 10.7150/ijms.40159] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 01/03/2020] [Indexed: 12/22/2022] Open
Abstract
Mammalian target of rapamycin (mTOR) is upregulated in a high percentage of glioblastomas. While a well-known mTOR inhibitor, rapamycin, has been shown to reduce glioblastoma survival, the role of mitochondria in achieving this therapeutic effect is less well known. Here, we examined mitochondrial dysfunction mechanisms that occur with the suppression of mTOR signaling. We found that, along with increased apoptosis, and a reduction in transformative potential, rapamycin treatment significantly affected mitochondrial health. Specifically, increased production of reactive oxygen species (ROS), depolarization of the mitochondrial membrane potential (MMP), and altered mitochondrial dynamics were observed. Furthermore, we verified the therapeutic potential of rapamycin-induced mitochondrial dysfunction through co-treatment with temzolomide (TMZ), the current standard of care for glioblastoma. Together these results demonstrate that the mitochondria remain a promising target for therapeutic intervention against human glioblastoma and that TMZ and rapamycin have a synergistic effect in suppressing glioblastoma viability, enhancing ROS production, and depolarizing MMP.
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Affiliation(s)
- Mary A Zimmerman
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, 1801 Fayetteville St, Durham, NC, 27707, USA.,Department of Biology, University of Wisconsin-La Crosse, 1725 State St, La Crosse, WI, 54601, USA
| | - Samantha Wilkison
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, 1801 Fayetteville St, Durham, NC, 27707, USA.,Department of Pharmacology and Cancer Biology, Duke University, Durham, NC, 27708, USA
| | - Qi Qi
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, 1801 Fayetteville St, Durham, NC, 27707, USA.,Department of Neurology, Neuroscience Center, General Hospital of Ningxia Medical University, and Key Laboratory of Craniocerebral Diseases of Ningxia Hui Autonomous Region, Yinchuan 750004, China
| | - Guisheng Chen
- Department of Neurology, Neuroscience Center, General Hospital of Ningxia Medical University, and Key Laboratory of Craniocerebral Diseases of Ningxia Hui Autonomous Region, Yinchuan 750004, China
| | - P Andy Li
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, 1801 Fayetteville St, Durham, NC, 27707, USA
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26
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Tian A, Ma X, Li H, Zhang R. Dl-3n-butylphthalide improves spatial learning and memory in rats with vascular dementia by reducing autophagy via regulation of the mTOR signaling pathway. Exp Ther Med 2019; 19:1940-1946. [PMID: 32104252 DOI: 10.3892/etm.2019.8402] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 11/08/2019] [Indexed: 12/18/2022] Open
Abstract
Dl-3n-butylphthalide (NBP) has been reported to be a beneficial and promising drug for the treatment and prevention of vascular dementia (VD). NBP has been demonstrated to improve learning and memory in rats with vascular cognitive impairment by activating the silent information regulator 1/brain-derived neurotrophic factor pathway. However, NBP is a multi-target drug. Therefore, the present study aimed to determine whether the protective effects of NBP on learning deficits in a rat model of VD were due to the inhibition of autophagy via the phosphorylated mammalian target of rapamycin (p-mTOR) pathway. NBP treatment attenuated memory damage in rats with VD, as demonstrated by T-maze and Morris water maze tests. NBP administration also significantly reduced the levels of the characteristic autophagic proteins Beclin 1 and LC3II and upregulated phosphorylation levels of mTOR at Ser-2448 compared with the VD group. However, treatment of rats with VD with NBP plus the mTOR inhibitor rapamycin failed to significantly suppress Beclin 1 and LC3II expression. These results suggested that the beneficial effects of NBP on learning deficits in a rat model of VD were due to the suppression of ischemia-induced autophagy via the p-mTOR signaling pathway.
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Affiliation(s)
- Ayong Tian
- Department of Anesthesiology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Xiaochuan Ma
- Department of Gerontology and Geriatrics, The Third Hospital of Shenyang, Shenyang, Liaoning 110001, P.R. China
| | - Hui Li
- Department of Gerontology and Geriatrics, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Rongwei Zhang
- Department of Gerontology and Geriatrics, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China
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27
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Protective Role of mTOR in Liver Ischemia/Reperfusion Injury: Involvement of Inflammation and Autophagy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:7861290. [PMID: 31827701 PMCID: PMC6885218 DOI: 10.1155/2019/7861290] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/24/2019] [Accepted: 10/14/2019] [Indexed: 02/06/2023]
Abstract
Liver ischemia/reperfusion (IR) injury is a common phenomenon after liver resection and transplantation, which often results in liver graft dysfunction such as delayed graft function and primary nonfunction. The mammalian target of rapamycin (mTOR) is an evolutionarily highly conserved serine/threonine protein kinase, which coordinates cell growth and metabolism through sensing environmental inputs under physiological or pathological conditions, involved in the pathophysiological process of IR injury. In this review, we mainly present current evidence of the beneficial role of mTOR in modulating inflammation and autophagy under liver IR to provide some evidence for the potential therapies for liver IR injury.
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28
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Yang X, Hei C, Liu P, Li PA. Prevention of post-ischemic seizure by rapamycin is associated with deactivation of mTOR and ERK1/2 pathways in hyperglycemic rats. Biochem Biophys Res Commun 2019; 520:47-53. [PMID: 31564412 DOI: 10.1016/j.bbrc.2019.09.096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 09/22/2019] [Indexed: 12/11/2022]
Abstract
Pre-ischemic hyperglycemia increases the occurrence of post-ischemic seizures both in experimental and clinical settings. The underlying mechanisms are not fully delineated; however, activation of mammalian target of rapamycin (mTOR) has been shown to be engaged in the pathogenesis of epilepsy, in which seizures are a regular occurrence. Therefore, we wanted to explore specifically the capacity of an mTOR inhibitor, rapamycin, in preventing post-ischemic seizures in hyperglycemic rats and to explore the underlying molecular mechanisms. The results showed that none of the rats in the sham control, EG ischemic, or within 3 h of I/R in hyperglycemic ischemic groups experienced seizures. Generalized tonic-clonic seizures were observed in all 8/8 of hyperglycemic ischemic rats at 16 h of I/R. Treatment with rapamycin successfully blocked post-ischemic seizures in 7/8 hyperglycemic ischemic animals. Rapamycin also lessened the neuronal death extraordinarily in hyperglycemic ischemic animals as revealed by histopathological studies. Protein analysis revealed that transient ischemia resulted in increases in p-mTOR and p-S6, especially in the hippocampi of the hyperglycemic ischemic rats. Rapamycin treatment completely blocked mTOR activation. Furthermore, hyperglycemic ischemia induced a much prominent rise of p-ERK1/2 both in the cortex and the hippocampi compared with EG counterparts; whereas rapamycin suppressed it. We conclude that the development of post-ischemic seizures in the hyperglycemic animals may be associated with activations of mTOR and ERK1/2 pathways and that rapamycin treatment inhibited the post-ischemic seizures effectively by suppressing the mTOR and ERK1/2 signaling.
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Affiliation(s)
- Xiao Yang
- Neuroscience Center, General Hospital of Ningxia Medical University, Key Laboratory for Craniocerebral Diseases of Ningxia Hui Autonomous Region, Yinchuan, China; Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Technology Enterprise (BRITE), College of Arts and Sciences, North Carolina Central University, Durham, USA
| | - Changchun Hei
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Technology Enterprise (BRITE), College of Arts and Sciences, North Carolina Central University, Durham, USA; Department of Human Anatomy, Histology and Embryology, Ningxia Medical University, Yinchuan, China
| | - Ping Liu
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Technology Enterprise (BRITE), College of Arts and Sciences, North Carolina Central University, Durham, USA; Department of Endocrinology, General Hospital of Ningxia Medical University, Yinchuan, China
| | - P Andy Li
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Technology Enterprise (BRITE), College of Arts and Sciences, North Carolina Central University, Durham, USA.
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29
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A 2-Min Transient Ischemia Confers Cerebral Ischemic Tolerance in Non-Obese Gerbils, but Results in Neuronal Death in Obese Gerbils by Increasing Abnormal mTOR Activation-Mediated Oxidative Stress and Neuroinflammation. Cells 2019; 8:cells8101126. [PMID: 31546722 PMCID: PMC6830098 DOI: 10.3390/cells8101126] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 09/19/2019] [Accepted: 09/20/2019] [Indexed: 12/24/2022] Open
Abstract
A brief episode of transient ischemia (TI) can confer cerebral ischemic tolerance against a subsequent severer TI under standard condition. The brain under obesity’s conditions is more sensitive to ischemic injury. However, the impact of a brief episode of TI under obesity’s conditions has not been fully addressed yet. Thus, the objective of this study was to determine the effect of a brief TI in the hippocampus of high-fat diet (HFD)-induced obese gerbils and related mechanisms. Gerbils were maintained on HFD or normal diet (ND) for 12 weeks and subjected to 2 min TI. HFD gerbils were heavier, with higher blood glucose, serum total cholesterol, triglycerides, and leptin levels. Massive loss of pyramidal neurons occurred in the hippocampal cornu ammonis 1 (CA1) field of HFD animals at 5 days after 2 min of TI, but 2 min of TI did not elicit death of pyramidal neurons in ND gerbils. The HFD group showed significantly increased levels of oxidative stress indicators (dihydroethidium and 4-hydroxynonenal) and proinflammatory cytokines (tumor necrosis factor-α and interleukin-1β) and microglial activation in pre- and/or post-ischemic phases compared to the ND group. Levels of mammalian target of rapamycin (mTOR) and phosphorylated-mTOR in the CA1 field of the HFD group were also significantly higher than the ND group. On the other hand, inhibition of mTOR activation by rapamycin (an allosteric mTOR inhibitor) significantly attenuated neuronal death induced by HFD, showing reduction of HFD-induced increases of oxidative stress indicators and proinflammatory cytokines, and microglia activation. Taken together, a brief episode of TI can evoke neuronal death under obesity’s conditions. It might be closely associated with an abnormal increase of mTOR activation-mediated, severe oxidative stress and neuroinflammation in pre- and/or post-ischemic phases.
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30
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Pang L, Ji S, Xing J. Amiloride Alleviates Neurological Deficits Following Transient Global Ischemia and Engagement of Central IL-6 and TNF-α Signal. Curr Mol Med 2019; 19:597-604. [PMID: 31272354 DOI: 10.2174/1566524019666190704100444] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 06/04/2019] [Accepted: 06/17/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND Central pro-inflammatory cytokine (PIC) signal is involved in neurological deficits after transient global ischemia induced by cardiac arrest (CA). The present study was to examine if blocking acid sensing ion channels (ASICs) using amiloride in the Central Nervous System can alleviate neurological deficits after the induction of CA and further examine the participation of PIC signal in the hippocampus for the effects of amiloride. METHODS CA was induced by asphyxia and then cardiopulmonary resuscitation was performed in rats. Western blot analysis and ELISA were used to determine the protein expression of ASIC subunit ASIC1 in the hippocampus, and the levels of PICs. As noted, it is unlikely that this procedure is clinically used although amiloride and other pharmacological agents were given into the brain in this study. RESULTS CA increased ASIC1 in the hippocampus of rats in comparison with control animals. This was associated with the increase in IL-1β, IL-6 and TNF-α together with Caspase-3 and Caspase-9. The administration of amiloride into the lateral ventricle attenuated the upregulation of Caspase-3/Caspase-9 and this further alleviated neurological severity score and brain edema. Inhibition of central IL-6 and TNF-α also decreased ASIC1 in the hippocampus of CA rats. CONCLUSION Transient global ischemia induced by CA amplifies ASIC1a in the hippocampus likely via PIC signal. Amiloride administered into the Central Nervous System plays a neuroprotective role in the process of global ischemia. Thus, targeting ASICs (i.e., ASIC1a) is suggested for the treatment and improvement of CA-evoked global cerebral ischemia.
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Affiliation(s)
- Li Pang
- Department of Emergency Medicine, The First Hospital of Jilin University, Changchun, Jilin 130021, China
| | - Shouqin Ji
- Jiutai District People's Hospital of Changchun, Changchun, Jilin 130500, China
| | - Jihong Xing
- Department of Emergency Medicine, The First Hospital of Jilin University, Changchun, Jilin 130021, China
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31
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Hou K, Xu D, Li F, Chen S, Li Y. The progress of neuronal autophagy in cerebral ischemia stroke: Mechanisms, roles and research methods. J Neurol Sci 2019; 400:72-82. [PMID: 30904689 DOI: 10.1016/j.jns.2019.03.015] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 02/25/2019] [Accepted: 03/15/2019] [Indexed: 12/26/2022]
Abstract
There is increasing evidence indicating that autophagy may be a new target in the treatment of ischemic stroke. Moderate autophagy can clear damaged organelles, thereby protecting cells against various injuries. However, long-term excessive autophagy brings redundant degradation of cell contents, leading to cell death and eventually serious damage to tissues and organs. A number of different animal models of ischemic brain injury shows that autophagy is activated and involved in the regulation of neuronal death during ischemic brain injury. This article summarizes the role of autophagy, its underlying regulators and mechanisms in ischemic neuronal injury. We briefly introduce the relationship between apoptosis and autophagy and give a summary of research methods and modulators of autophagy.
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Affiliation(s)
- Kai Hou
- State Key Laboratory of Natural Medicines, Department of Physiology, China Pharmaceutical University, Nanjing 210009, China.
| | - Dan Xu
- State Key Laboratory of Natural Medicines, Department of Physiology, China Pharmaceutical University, Nanjing 210009, China.
| | - Fengyang Li
- State Key Laboratory of Natural Medicines, Department of Physiology, China Pharmaceutical University, Nanjing 210009, China.
| | - Shijie Chen
- State Key Laboratory of Natural Medicines, Department of Physiology, China Pharmaceutical University, Nanjing 210009, China.
| | - Yunman Li
- State Key Laboratory of Natural Medicines, Department of Physiology, China Pharmaceutical University, Nanjing 210009, China.
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32
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Zimmerman MA, Biggers CD, Li PA. Rapamycin treatment increases hippocampal cell viability in an mTOR-independent manner during exposure to hypoxia mimetic, cobalt chloride. BMC Neurosci 2018; 19:82. [PMID: 30594149 PMCID: PMC6310999 DOI: 10.1186/s12868-018-0482-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 12/17/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Cobalt chloride (CoCl2) induces chemical hypoxia through activation of hypoxia-inducible factor-1 alpha (HIF-1α). Mammalian target of rapamycin (mTOR) is a multifaceted protein capable of regulating cell growth, angiogenesis, metabolism, proliferation, and survival. In this study, we tested the efficacy of a well-known mTOR inhibitor, rapamycin, in reducing oxidative damage and increasing cell viability in the mouse hippocampal cell line, HT22, during a CoCl2-simulated hypoxic insult. RESULTS CoCl2 caused cell death in a dose-dependent manner and increased protein levels of cleaved caspase-9 and caspase-3. Rapamycin increased viability of HT22 cells exposed to CoCl2 and reduced activation of caspases-9 and -3. Cells exposed to CoCl2 displayed increased reactive oxygen species (ROS) production and hyperpolarization of the mitochondrial membrane, both of which rapamycin successfully blocked. mTOR protein itself, along with its downstream signaling target, phospho-S6 ribosomal protein (pS6), were significantly inhibited with CoCl2 and rapamycin addition did not significantly lower expression further. Rapamycin promoted protein expression of Beclin-1 and increased conversion of microtubule-associated protein light chain 3 (LC3)-I into LC3-II, suggesting an increase in autophagy. Pro-apoptotic protein, Bcl-2 associated × (Bax), exhibited a slight, but significant decrease with rapamycin treatment, while its anti-apoptotic counterpart, B cell lymphoma-2 (Bcl-2), was to a similar degree upregulated. Finally, the protein expression ratio of phosphorylated mitogen-activated protein kinase (pMAPK) to its unphosphorylated form (MAPK) was dramatically increased in rapamycin and CoCl2 co-treated cells. CONCLUSIONS Our results indicate that rapamycin confers protection against CoCl2-simulated hypoxic insults to neuronal cells. This occurs, as suggested by our results, independent of mTOR modification, and rather through stabilization of the mitochondrial membrane with concomitant decreases in ROS production. Additionally, inhibition of caspase-9 and -3 activation and stimulation of protective autophagy reduces cell death, while a decrease in the Bax/Bcl-2 ratio and an increase in pMAPK promotes cell survival during CoCl2 exposure. Together these results demonstrate the therapeutic potential of rapamycin against hypoxic injury and highlight potential pathways mediating the protective effects of rapamycin treatment.
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Affiliation(s)
- Mary A. Zimmerman
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, Durham, NC USA
| | - Christan D. Biggers
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, Durham, NC USA
| | - P. Andy Li
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, Durham, NC USA
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Beard DJ, Hadley G, Thurley N, Howells DW, Sutherland BA, Buchan AM. The effect of rapamycin treatment on cerebral ischemia: A systematic review and meta-analysis of animal model studies. Int J Stroke 2018; 14:137-145. [PMID: 30489210 DOI: 10.1177/1747493018816503] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Amplifying endogenous neuroprotective mechanisms is a promising avenue for stroke therapy. One target is mammalian target of rapamycin (mTOR), a serine/threonine kinase regulating cell proliferation, cell survival, protein synthesis, and autophagy. Animal studies investigating the effect of rapamycin on mTOR inhibition following cerebral ischemia have shown conflicting results. AIM To conduct a systematic review and meta-analysis evaluating the effectiveness of rapamycin in reducing infarct volume in animal models of ischemic stroke. SUMMARY OF REVIEW Our search identified 328 publications. Seventeen publications met inclusion criteria (52 comparisons: 30 reported infarct size and 22 reported neurobehavioral score). Study quality was modest (median 4 of 9) with no evidence of publication bias. The point estimate for the effect of rapamycin was a 21.6% (95% CI, 7.6%-35.7% p < 0.01) improvement in infarct volume and 30.5% (95% CI 17.2%-43.8%, p < 0.0001) improvement in neuroscores. Effect sizes were greatest in studies using lower doses of rapamycin. CONCLUSION Low-dose rapamycin treatment may be an effective therapeutic option for stroke. Modest study quality means there is a potential risk of bias. We recommend further high-quality preclinical studies on rapamycin in stroke before progressing to clinical trials.
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Affiliation(s)
- Daniel J Beard
- 1 Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Gina Hadley
- 1 Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,2 Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Neal Thurley
- 3 Bodleian Healthcare Libraries, University of Oxford, Oxford, UK
| | - David W Howells
- 4 School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, Australia
| | - Brad A Sutherland
- 4 School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, Australia
| | - Alastair M Buchan
- 1 Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,5 Medical Sciences Division, University of Oxford, Oxford, UK.,6 Acute Vascular Imaging Centre, University of Oxford, Oxford University Hospitals, Oxford, UK
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Song M, Ahn JH, Kim H, Kim DW, Lee TK, Lee JC, Kim YM, Lee CH, Hwang IK, Yan BC, Won MH, Park JH. Chronic high-fat diet-induced obesity in gerbils increases pro-inflammatory cytokines and mTOR activation, and elicits neuronal death in the striatum following brief transient ischemia. Neurochem Int 2018; 121:75-85. [PMID: 30267768 DOI: 10.1016/j.neuint.2018.09.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 09/14/2018] [Accepted: 09/25/2018] [Indexed: 02/06/2023]
Abstract
Recent studies have shown that obesity and its related metabolic dysfunction exacerbate outcomes of ischemic brain injuries in some brain areas, such as the hippocampus and cerebral cortex when they are subjected to transient ischemia. However, the impact of obesity in the striatum after brief transient ischemia has not yet been addressed. The objective of this study was to investigate effects of obesity on neuronal damage and inflammation in the striatum after transient ischemia and to examine the role of mTOR which is involved in the pathogenesis of metabolic and neurological diseases. Gerbils were fed with normal diet (ND) or high-fat diet (HFD) for 12 weeks and subjected to 5 min of transient ischemia. HFD-fed gerbils showed significant increase in body weight, blood glucose level, serum triglycerides, total cholesterol and low-density lipoprotein cholesterol without affecting food intake. Neuronal death/loss in the HFD-fed gerbils occurred in the dorsolateral striatum 2 days after transient ischemia, and neuronal loss was increased 5 days after transient ischemia, although no neuronal loss was observed in ND-fed gerbils at any time after transient ischemia. The HFD-fed gerbils showed hypertrophied microglia and further increased expressions of tumor necrosis factor-alpha, interukin-1beta, mammalian target of rapamycin (mTOR) and phosphorylated-mTOR during pre- and post-ischemic phases compared with the ND-fed gerbils. Additionally, we found that treatment with mTOR inhibitor rapamycin in the HFD-fed gerbils significantly attenuated transient ischemia-induced neuronal death in the dorsolateral striatum. These findings reveal that chronic HFD-induced obesity results in severe neuroinflammation and significant increase of mTOR activation, which could contribute to neuronal death in the stratum following 5 min of transient ischemia. Especially, abnormal mTOR activation would play a key role in mediating obesity-induced severe ischemic brain injury.
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Affiliation(s)
- Minah Song
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon, 24341, Republic of Korea
| | - Ji Hyeon Ahn
- Department of Biomedical Science and Research Institute for Bioscience and Biotechnology, Hallym University, Chuncheon, Gangwon, 24252, Republic of Korea
| | - Hyunjung Kim
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon, 24341, Republic of Korea
| | - Dae Won Kim
- Department of Biochemistry and Molecular Biology, and Research Institute of Oral Sciences, College of Dentistry, Gangnung-Wonju National University, Gangneung, Gangwon, 25457, Republic of Korea
| | - Tae-Kyeong Lee
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon, 24341, Republic of Korea
| | - Jae-Chul Lee
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon, 24341, Republic of Korea
| | - Young-Myeong Kim
- Department of Molecular and Cellular Biochemistry, School of Medicine, Kangwon National University, Chuncheon, Gangwon, 24341, Republic of Korea
| | - Choong-Hyun Lee
- Department of Pharmacy, College of Pharmacy, Dankook University, Cheonan, 31116, Republic of Korea
| | - In Koo Hwang
- Department of Anatomy and Cell Biology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Bing Chun Yan
- Jiangsu Key Laboratory of Integrated Traditional Chinese, Western Medicine for Prevention and Treatment of Senile Diseases, Yangzhou, Jiangsu, 225001, PR China
| | - Moo-Ho Won
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon, 24341, Republic of Korea.
| | - Joon Ha Park
- Department of Biomedical Science and Research Institute for Bioscience and Biotechnology, Hallym University, Chuncheon, Gangwon, 24252, Republic of Korea.
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Majd S, Power JHT, Chataway TK, Grantham HJM. A comparison of LKB1/AMPK/mTOR metabolic axis response to global ischaemia in brain, heart, liver and kidney in a rat model of cardiac arrest. BMC Cell Biol 2018; 19:7. [PMID: 29921218 PMCID: PMC6010165 DOI: 10.1186/s12860-018-0159-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 06/12/2018] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Cellular energy failure in high metabolic rate organs is one of the underlying causes for many disorders such as neurodegenerative diseases, cardiomyopathies, liver and renal failures. In the past decade, numerous studies have discovered the cellular axis of LKB1/AMPK/mTOR as an essential modulator of cell homeostasis in response to energy stress. Through regulating adaptive mechanisms, this axis adjusts the energy availability to its demand by a systematized control on metabolism. Energy stress, however, could be sensed at different levels in various tissues, leading to applying different strategies in response to hypoxic insults. METHODS Here the immediate strategies of high metabolic rate organs to time-dependent short episodes of ischaemia were studied by using a rat model (n = 6/group) of cardiac arrest (CA) (15 and 30 s, 1, 2, 4 and 8 min CA). Using western blot analysis, we examined the responses of LKB1/AMPK/mTOR pathway in brain, heart, liver and kidney from 15 s up to 8 min of global ischaemia. The ratio of ADP/ATP was assessed in all ischemic and control groups, using ApoSENSOR bioluminescent assay kit. RESULTS Brain, followed by kidney showed the early dephosphorylation response in AMPK (Thr172) and LKB1 (Ser431); in the absence of ATP decline (ADP/ATP elevation). Dephosphorylation of AMPK was followed by rephosphorylation and hyperphosphorylation, which was associated with a significant ATP decline. While heart's activity of AMPK and LKB1 remained at the same level during short episodes of ischaemia, liver's LKB1 was dephosphorylated after 2 min. AMPK response to ischaemia in liver was mainly based on an early alternative and a late constant hyperphosphorylation. No significant changes was observed in mTOR activity in all groups. CONCLUSION Together our results suggest that early AMPK dephosphorylation followed by late hyperphosphorylation is the strategy of brain and kidney in response to ischaemia. While the liver seemed to get benefit of its AMPK system in early ischameia, possibly to stabilize ATP, the level of LKB1/AMPK activity in heart remained unchanged in short ischaemic episodes up to 8 min. Further researches must be conducted to elucidate the molecular mechanism underlying LKB1/AMPK response to oxygen supply.
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Affiliation(s)
- Shohreh Majd
- Centre for Neuroscience, Neuronal Injury and Repair Laboratory, College of Medicine and Health Sciences, Flinders University, Adelaide, SA 5042 Australia
- Centre for Neuroscience, Neuronal Injury and Repair Laboratory, College of Medicine and Public Health, Flinders University of South Australia, Adelaide, SA 5042 Australia
| | - John H. T. Power
- Centre for Neuroscience, Neuronal Injury and Repair Laboratory, College of Medicine and Public Health, Flinders University of South Australia, Adelaide, SA 5042 Australia
| | - Timothy K. Chataway
- Proteomics Facility, College of Medicine and Public Health, Flinders University, Adelaide, SA 5042 Australia
| | - Hugh J. M. Grantham
- Centre for Neuroscience, Neuronal Injury and Repair Laboratory, College of Medicine and Public Health, Flinders University of South Australia, Adelaide, SA 5042 Australia
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Wang JT, Xie WQ, Liu FQ, Bi Y, Zhu XJ, Wang QE, Zheng YF. NADH protect against radiation enteritis by enhancing autophagy and inhibiting inflammation through PI3K/AKT pathway. Am J Transl Res 2018; 10:1713-1721. [PMID: 30018712 PMCID: PMC6038089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 05/26/2018] [Indexed: 06/08/2023]
Abstract
Radiotherapy is an important method for cancer treatment but it has serious side-effects at high doses. One of the greatest challenges in radiotherapy is that radiation affects both healthy tissue and cancer tissues. For abdominal or pelvic lesions, the bowel is the most easily injured by irradiation. Radiation may cause radiation enteritis, intestinal inflammatory infiltration, or intestinal perforation. Coenzyme NADH involves in energy metabolism and transportation of nucleic acid, proteins and carbohydrates. In our study, NADH was used to protect the intestinal wall from irradiation injury in IEC-6 normal intestinal epithelial cells. By flow cytometry, we found that NADH can inhibit the cell death and the producing of reactive oxygen species (ROS). The immunofluorescence assay showed that cell autophagy was increased in the NADH group. Western blot data indicated that NADH promoted the microtubule associated protein 1A/1B-light chain 3(LC3)-I to LC3II and the expression of IL-1β and TNFα decreased in a dose dependent manner. Interestingly, a specific PI3K/AKT inhibitor (3MA) decreased the expression of inflammatory factors. In the animal experiment, after 12 Gy radiation, there were less TNFα and more LC3II in the RT+NADH group than that of RT group. Compared with the mock, there was no significant damage in the NADH group. Thus, our study provides the evidence that NADH may protect against radiation enteritis by suppressing inflammation and enhancing autophagy through PI3K/AKT pathway in normal intestinal cells.
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Affiliation(s)
- Jin-Ting Wang
- Oncology Center, Zhujiang Hospital, Southern Medical University Guangzhou 510282, China
| | - Wen-Quan Xie
- Oncology Center, Zhujiang Hospital, Southern Medical University Guangzhou 510282, China
| | - Fa-Quan Liu
- Department of Gastroenterology, The Fifth Affiliated Hospital of Southern Medical University Guangzhou 510900, China
| | - Yue Bi
- Oncology Center, Zhujiang Hospital, Southern Medical University Guangzhou 510282, China
| | - Xiong-Jie Zhu
- Oncology Center, Zhujiang Hospital, Southern Medical University Guangzhou 510282, China
| | - Qi-En Wang
- Department of Radiology, Division of Radiobiology, The Ohio State University Wexner Medical Center Columbus, OH, USA
| | - Yan-Fang Zheng
- Oncology Center, Zhujiang Hospital, Southern Medical University Guangzhou 510282, China
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Wu M, Zhang H, Kai J, Zhu F, Dong J, Xu Z, Wong M, Zeng LH. Rapamycin prevents cerebral stroke by modulating apoptosis and autophagy in penumbra in rats. Ann Clin Transl Neurol 2017; 5:138-146. [PMID: 29468175 PMCID: PMC5817831 DOI: 10.1002/acn3.507] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 10/31/2017] [Accepted: 11/01/2017] [Indexed: 12/13/2022] Open
Abstract
Objective Whether activation or inhibition of the mTOR pathway is beneficial to ischemic injury remains controversial. It may result from the different reaction of ischemic penumbra and core to modulation of mTOR pathway after cerebral ischemia-reperfusion injury in rats. Methods Longa's middle cerebral artery occlusion (MCAO) method was conducted to induce the focal cerebral ischemia-reperfusion. Western blot analysis was used to examine the protein expression involving mTOR pathway, apoptosis, and autophagy-related proteins. TTC staining and Fluoro-Jade B staining was conducted to detect the infarct volume and cell apoptosis, respectively. Neurological function was measured by modified neurological severity score and left-biased swing. Results mTOR signaling pathway was activated in ischemic penumbra and decreased in ischemic core after ischemia and ischemia-reperfusion. Ischemia-reperfusion injury induced the increase in cleaved caspase 9 and caspase 3 both in ischemic penumbra and in ischemic core, whereas the expression of phosphorylated ULK1, Beclin 1 and LC3-II was decreased. Rapamycin pre or postadministration inhibited the overactivation of mTOR pathway in ischemic penumbra. Ameliorated neurological function and reduced infarct volume were observed after pre or postrapamycin treatment. Rapamycin markedly decreased the number of FJB-positive cells and the expression of cleaved caspase-3 and cleaved caspase-9 proteins as well as increased the activation of autophagy reflected by ULK1, Beclin-1 and LC3. Interpretation mTOR signaling pathway was activated in ischemic penumbra after cerebral ischemia-reperfusion injury in rats. mTOR inhibitor rapamycin significantly decreased the mTOR activation and infarct volume and subsequently improved neurological function. These results may relate to inhibition of neuron apoptosis and activation of autophagy.
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Affiliation(s)
- Meiling Wu
- Department of Pharmacology School of Medicine Zhejiang University City College Hangzhou Zhejiang 310015 China
| | - Huadan Zhang
- Department of Pharmacology School of Medicine Zhejiang University City College Hangzhou Zhejiang 310015 China
| | - Jiejing Kai
- Department of Pharmacology School of Medicine Zhejiang University City College Hangzhou Zhejiang 310015 China
| | - Feng Zhu
- Department of Pharmacology School of Medicine Zhejiang University City College Hangzhou Zhejiang 310015 China
| | - Jingyin Dong
- Department of Pharmacology School of Medicine Zhejiang University City College Hangzhou Zhejiang 310015 China
| | - Ziwei Xu
- Department of Pharmacology School of Medicine Zhejiang University City College Hangzhou Zhejiang 310015 China
| | - Michael Wong
- Department of Neurology School of Medicine Washington University in St. Louis Saint Louis Missouri 63110
| | - Ling-Hui Zeng
- Department of Pharmacology School of Medicine Zhejiang University City College Hangzhou Zhejiang 310015 China
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Arabian M, Aboutaleb N, Soleimani M, Ajami M, Habibey R, Rezaei Y, Pazoki-Toroudi H. Preconditioning with morphine protects hippocampal CA1 neurons from ischemia-reperfusion injury via activation of the mTOR pathway. Can J Physiol Pharmacol 2017; 96:80-87. [PMID: 28881154 DOI: 10.1139/cjpp-2017-0245] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The signaling pathway of chronic morphine treatment to prevent neuronal damage following transient cerebral ischemia is not clear. In this study, we examined the role of mammalian target of rapamycin (mTOR) to identify the neuroprotective effects of chronic morphine preconditioning on the hippocampus following ischemia-reperfusion (I/R) injury. Morphine was administered for 5 days, twice a day, before inducing I/R injury. The possible role of mTOR was evaluated by the injection of rapamycin (5 mg/kg body weight, by intraperitoneal injection) before I/R was induced. The passive avoidance test was used to evaluate memory performance. Neuronal density and apoptosis were measured in the CA1 region, 72 h after I/R injury. The expressions of mTOR and phosphorylated mTOR (p-mTOR), as well as superoxide dismutase (SOD) activity were determined 24 h after I/R injury. Chronic morphine treatment attenuated apoptosis and neuronal loss in the hippocampus after I/R injury, which led to improvement in memory (P < 0.05 vs. untreated I/R) and increase in the expression of p-mTOR (P < 0.05 vs. untreated I/R) and SOD activity (P < 0.05 vs. untreated I/R) in the hippocampus. Pretreatment with rapamycin abolished all the above-mentioned protective effects. These results describe novel findings whereby chronic morphine preconditioning in hippocampal CA1 neurons is mediated by the mTOR pathway, and through increased phosphorylation of mTOR can alleviate oxidative stress and apoptosis, and eventually protect the hippocampus from I/R injury.
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Affiliation(s)
- Maedeh Arabian
- a Rajaie Cardiovascular, Medical, and Research Centre, Iran University of Medical Sciences, Tehran, Iran
| | - Nahid Aboutaleb
- b Physiology Research Center, Physiology Department, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mansoureh Soleimani
- c Cellular and Molecular Research Centre, Department of Anatomy, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Marjan Ajami
- d Nutrition and Food Technology Research Institute, Faculty of Nutrition Science and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Rouhollah Habibey
- e Department of Neuroscience and Brain Technologies-Istituto Italiano di Technologia, Via Morego, 30, 16163 Genova, Italy
| | - Yousef Rezaei
- f Heart Valve Disease Research Center, Rajaie Cardiovascular, Medical, and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Hamidreza Pazoki-Toroudi
- b Physiology Research Center, Physiology Department, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
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Global gene expression profile of cerebral ischemia-reperfusion injury in rat MCAO model. Oncotarget 2017; 8:74607-74622. [PMID: 29088811 PMCID: PMC5650366 DOI: 10.18632/oncotarget.20253] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 06/30/2017] [Indexed: 12/19/2022] Open
Abstract
It is well-established that reperfusion following cerebral ischemic injury gives rise to secondary injury accompanied by structural and functional damage. However, it remains unclear how global genes changes in cerebral ischemia-reperfusion injury (IRI). This study investigated global gene expression in the hippocampi of Wistar rats following transient cerebral IRI using an RNA-sequencing strategy. The results revealed ≥2-fold up-regulation of 156 genes and ≥2-fold down-regulation of 26 genes at 24 h post-reperfusion. Fifteen differentially expressed genes were selected to confirm the RNA-sequencing results. Gene expression levels were dynamic, with the peak expression level of each gene occurring at different time points post-reperfusion. Gene Ontology (GO) analysis classified the differentially expressed genes as mainly involved in inflammation, stress and immune response, glucose metabolism, proapoptosis, antiapoptosis, and biological processes. KEGG pathway analysis suggested that IRI activated different signaling pathways, including focal adhesion, regulation of actin cytoskeleton, cytokine-cytokine receptor interaction, MAPK signaling, and Jak-STAT signaling. This study describes global gene expression profiles in the hippocampi of Wistar rats using the middle cerebral artery occlusion (MCAO) model. These findings provide new insights into the molecular pathogenesis of IRI and potential drug targets for the prevention and treatment of IRI in the future.
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Park JA, Lee CH. Temporal changes in mammalian target of rapamycin (mTOR) and phosphorylated-mTOR expressions in the hippocampal CA1 region of rat with vascular dementia. J Vet Sci 2017; 18:11-16. [PMID: 27297423 PMCID: PMC5366295 DOI: 10.4142/jvs.2017.18.1.11] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 03/21/2016] [Accepted: 05/12/2016] [Indexed: 01/08/2023] Open
Abstract
Mammalian target of rapamycin (mTOR) has an important role in various biological processes in cells. In the present study, we investigated temporal changes in mTOR and phosphorylated-mTOR (p-mTOR) expressions in the rat hippocampal CA1 region following chronic cerebral hypoperfusion (CCH) induced by permanent bilateral common carotid arteries occlusion (2VO). The mTOR immunoreactivity in the pyramidal neurons and mTOR protein level in the hippocampal CA1 region were markedly decreased at 21 and 28 days after 2VO surgery. However, p-mTOR protein expression was significantly increased at 7 days following CCH but then decreased with time. The results indicate that mTOR and p-mTOR expressions change in the hippocampal CA1 region after 2VO surgery and that reduced expressions of mTOR and p-mTOR may be closely related to the CCH-induced neuronal damage in the hippocampal CA1 region.
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Affiliation(s)
- Jin-A Park
- Department of Pharmacy, College of Pharmacy, Dankook University, Cheonan 31116, Korea
| | - Choong-Hyun Lee
- Department of Pharmacy, College of Pharmacy, Dankook University, Cheonan 31116, Korea
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Hei C, Liu P, Yang X, Niu J, Li PA. Inhibition of mTOR signaling Confers Protection against Cerebral Ischemic Injury in Acute Hyperglycemic Rats. Int J Biol Sci 2017; 13:878-887. [PMID: 28808420 PMCID: PMC5555105 DOI: 10.7150/ijbs.18976] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 01/28/2017] [Indexed: 01/04/2023] Open
Abstract
Hyperglycemia is known to exacerbate neuronal death resulted from cerebral ischemia. The mechanisms are not fully understood. The mammalian target of rapamycin (mTOR) pathway regulates cell growth, division and apoptosis. Recent studies suggest that activation of mTOR may mediate ischemic brain damage. The objective of the present experiment is to explore whether mTOR mediates ischemic brain damage in acute hyperglycemic animals. Rats were subjected to 10 min of forebrain ischemia under euglycemic, hyperglycemic and rapamycin-treated hyperglycemic conditions. The rat brain samples were collected from the cortex and hippocampi after 3h and 16h of reperfusion. The results showed that hyperglycemia significantly increased neuronal death in the cortex and hippocampus and the exacerbation effect of hyperglycemia was associated with further activation of mTOR under control and/or ischemic conditions. Inhibition of mTOR with rapamycin ameliorated the damage and suppressed hyperglycemia-elevated p-MTOR, p-P70S6K and p-S6. In addition, hyperglycemia per se increased the levels of cytosolic cytochrome c and autophagy marker LC3-II, while rapamycin alleviated these alterations. It is concluded that activation of mTOR signaling may play a detrimental role in mediating the aggravating effect of hyperglycemia on cerebral ischemia.
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Affiliation(s)
- Changchun Hei
- Key Laboratory of Craniocerebral Diseases of Ningxia Hui Autonomous Region and Department Human Anatomy, Histology and Embryology, Ningxia Medical University, Yinchuan 750004, China.,Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, 1801 Fayetteville Street, Durham, NC 27707, USA
| | - Ping Liu
- Department of Endocrinology, General Hospital of Ningxia Medical University, Yinchuan 750004, China.,Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, 1801 Fayetteville Street, Durham, NC 27707, USA
| | - Xiao Yang
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, 1801 Fayetteville Street, Durham, NC 27707, USA.,Neuroscience Center, General Hospital of Ningxia Medical University, and Key Laboratory of Craniocerebral Diseases of Ningxia Hui Autonomous Region, Yinchuan 750004, China
| | - Jianguo Niu
- Key Laboratory of Craniocerebral Diseases of Ningxia Hui Autonomous Region and Department Human Anatomy, Histology and Embryology, Ningxia Medical University, Yinchuan 750004, China
| | - P Andy Li
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, 1801 Fayetteville Street, Durham, NC 27707, USA
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Wang D, Lin Q, Su S, Liu K, Wu Y, Hai J. URB597 improves cognitive impairment induced by chronic cerebral hypoperfusion by inhibiting mTOR-dependent autophagy. Neuroscience 2016; 344:293-304. [PMID: 28042028 DOI: 10.1016/j.neuroscience.2016.12.034] [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: 09/10/2016] [Revised: 12/16/2016] [Accepted: 12/21/2016] [Indexed: 12/19/2022]
Abstract
Chronic cerebral hypoperfusion (CCH) is associated with various ischemic cerebrovascular diseases that are characterized by cognitive impairment. The role of autophagy in cognitive dysfunction under conditions of CCH is poorly understood. To address this issue, the present study investigated the effect of the fatty acid amide hydrolase (FAAH) inhibitor URB597 on autophagy and cognition in a CCH model as well as the underlying mechanisms. Cognitive function was evaluated with the Morris water maze and by assessing long-term potentiation (LTP). The expression of autophagy-related proteins and mammalian target of rapamycin (mTOR) signaling pathway components was evaluated by immunofluorescence and western blot analyses, and ultrastructural changes were examined by transmission electron microscopy (EM). URB597 improved cognitive impairment by inhibiting CCH-induced autophagy, which was associated with mTOR signaling. Moreover, the ultrastructural deterioration resulting from CCH was improved by chronic treatment with URB597. These findings indicate that URB597 modulates autophagy in an mTOR-dependent manner, and mitigates neuronal damage and cognitive deterioration caused by CCH.
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Affiliation(s)
- Dapeng Wang
- Department of Neurosurgery, Tong Ji Hospital, Tong Ji University School of Medicine, Shanghai 200065, China
| | - Qi Lin
- Department of Pharmacy, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Shaohua Su
- Department of Neurosurgery, Tong Ji Hospital, Tong Ji University School of Medicine, Shanghai 200065, China
| | - Kejia Liu
- Department of Cell Biology, Key Laboratory of Education Ministry for Cell Differentiation and Apoptosis, Institutes of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yifang Wu
- Department of Neurosurgery, Tong Ji Hospital, Tong Ji University School of Medicine, Shanghai 200065, China
| | - Jian Hai
- Department of Neurosurgery, Tong Ji Hospital, Tong Ji University School of Medicine, Shanghai 200065, China.
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Demarest TG, Waite EL, Kristian T, Puche AC, Waddell J, McKenna MC, Fiskum G. Sex-dependent mitophagy and neuronal death following rat neonatal hypoxia-ischemia. Neuroscience 2016; 335:103-13. [PMID: 27555552 DOI: 10.1016/j.neuroscience.2016.08.026] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 08/11/2016] [Accepted: 08/12/2016] [Indexed: 12/19/2022]
Abstract
Males are more susceptible than females to long-term cognitive deficits following neonatal hypoxic-ischemic encephalopathy (HIE). Mitochondrial dysfunction is implicated in the pathophysiology of cerebral hypoxia-ischemia (HI), but the influence of sex on mitochondrial quality control (MQC) after HI is unknown. Therefore, we tested the hypothesis that mitophagy is sexually dimorphic and neuroprotective 20-24h following the Rice-Vannucci model of rat neonatal HI at postnatal day 7 (PN7). Mitochondrial and lysosomal morphology and degree of co-localization were determined by immunofluorescence in the cerebral cortex. No difference in mitochondrial abundance was detected in the cortex after HI. However, net mitochondrial fission increased in both hemispheres of female brain, but was most extensive in the ipsilateral hemisphere of male brain following HI. Basal autophagy, assessed by immunoblot for the autophagosome marker LC3BI/II, was greater in males suggesting less intrinsic reserve capacity for autophagy following HI. Autophagosome formation, lysosome size, and TOM20/LAMP2 co-localization were increased in the contralateral hemisphere following HI in female, but not male brain. An accumulation of ubiquitinated mitochondrial protein was observed in male, but not female brain following HI. Moreover, neuronal cell death with NeuN/TUNEL co-staining occurred in both hemispheres of male brain, but only in the ipsilateral hemisphere of female brain after HI. In summary, mitophagy induction and neuronal cell death are sex dependent following HI. The deficit in elimination of damaged/dysfunctional mitochondria in the male brain following HI may contribute to male vulnerability to neuronal death and long-term neurobehavioral deficits following HIE.
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Affiliation(s)
- T G Demarest
- Department of Anesthesiology and the Center for Shock, Trauma, and Anesthesiology Research (S.T.A.R.), University of Maryland School of Medicine, Baltimore, MD 21201, USA; Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - E L Waite
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 21201, USA
| | - T Kristian
- Department of Anesthesiology and the Center for Shock, Trauma, and Anesthesiology Research (S.T.A.R.), University of Maryland School of Medicine, Baltimore, MD 21201, USA; Veterans Affairs Medical Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - A C Puche
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - J Waddell
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - M C McKenna
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - G Fiskum
- Department of Anesthesiology and the Center for Shock, Trauma, and Anesthesiology Research (S.T.A.R.), University of Maryland School of Medicine, Baltimore, MD 21201, USA; Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Liu P, Yang X, Hei C, Meli Y, Niu J, Sun T, Li PA. Rapamycin Reduced Ischemic Brain Damage in Diabetic Animals Is Associated with Suppressions of mTOR and ERK1/2 Signaling. Int J Biol Sci 2016; 12:1032-40. [PMID: 27489506 PMCID: PMC4971741 DOI: 10.7150/ijbs.15624] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/28/2016] [Indexed: 12/17/2022] Open
Abstract
The objectives of the present study are to investigate the activation of mTOR and ERK1/2 signaling after cerebral ischemia in diabetic rats and to examine the neuroprotective effects of rapamycin. Ten minutes transient global cerebral ischemia was induced in straptozotocin-induced diabetic hyperglycemic rats and non-diabetic, euglycemic rats. Brain samples were harvested after 16 h of reperfusion. Rapamycin or vehicle was injected 1 month prior to the induction of ischemia. The results showed that diabetes increased ischemic neuronal cell death and associated with elevations of p-P70S6K and Ras/ERK1/2 and suppression of p-AMPKα. Rapamycin ameliorated diabetes-enhanced ischemic brain damage and suppressed phosphorylation of P70S6K and ERK1/2. It is concluded that diabetes activates mTOR and ERK1/2 signaling pathways in rats subjected to transient cerebral ischemia and inhibition of mTOR by rapamycin reduces ischemic brain damage and suppresses the mTOR and ERK1/2 signaling in diabetic settings.
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Affiliation(s)
- Ping Liu
- 1. Department of Endocrinology, General Hospital of Ningxia Medical University, Yinchuan 750004, China
- 2. Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, 1801 Fayetteville Street, Durham, NC 27707, USA
| | - Xiao Yang
- 2. Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, 1801 Fayetteville Street, Durham, NC 27707, USA
- 3. Neuroscience Center, General Hospital of Ningcia Medical University, and Key Laboratory of Craniocerebral Diseases of Ningxia Hui Autonomous Region, Yinchuan 750004, China
| | - Changchun Hei
- 2. Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, 1801 Fayetteville Street, Durham, NC 27707, USA
- 4. Department of Human Anatomy, Histology and Embryology, Ningxia Medical University, Yinchuan 75004, China
| | - Yvonne Meli
- 2. Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, 1801 Fayetteville Street, Durham, NC 27707, USA
| | - Jianguo Niu
- 4. Department of Human Anatomy, Histology and Embryology, Ningxia Medical University, Yinchuan 75004, China
| | - Tao Sun
- 4. Department of Human Anatomy, Histology and Embryology, Ningxia Medical University, Yinchuan 75004, China
| | - P. Andy Li
- 2. Department of Pharmaceutical Sciences, Biomanufacturing Research Institute Biotechnology Enterprise (BRITE), North Carolina Central University, 1801 Fayetteville Street, Durham, NC 27707, USA
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Gu J, Hu W, Song ZP, Chen YG, Zhang DD, Wang CQ. Rapamycin Inhibits Cardiac Hypertrophy by Promoting Autophagy via the MEK/ERK/Beclin-1 Pathway. Front Physiol 2016; 7:104. [PMID: 27047390 PMCID: PMC4796007 DOI: 10.3389/fphys.2016.00104] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 03/03/2016] [Indexed: 01/07/2023] Open
Abstract
Rapamycin, also known as sirolimus, is an antifungal agent and immunosuppressant drug used to prevent organ rejection in transplantation. However, little is known about the role of rapamycin in cardiac hypertrophy and the signaling pathways involved. Here, the effect of rapamycin was examined using phenylephrine (PE) induced cardiomyocyte hypertrophy in vitro and in a rat model of aortic banding (AB) - induced hypertrophy in vivo. Inhibition of MEK/ERK signaling reversed the effect of rapamycin on the up-regulation of LC3-II, Beclin-1 and Noxa, and the down-regulation of Mcl-1 and p62. Silencing of Noxa or Beclin-1 suppressed rapamycin-induced autophagy, and co-immunoprecipitation experiments showed that Noxa abolishes the inhibitory effect of Mcl-1 on Beclin-1, promoting autophagy. In vivo experiments showed that rapamycin decreased AB-induced cardiac hypertrophy in a MEK/ERK dependent manner. Taken together, our results indicate that rapamycin attenuates cardiac hypertrophy by promoting autophagy through a mechanism involving the modulation of Noxa and Beclin-1 expression by the MEK/ERK signaling pathway.
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Affiliation(s)
- Jun Gu
- Department of Cardiology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of MedicineShanghai, China; Department of Cardiology, Shanghai Minhang Hospital, Fudan UniversityShanghai, China
| | - Wei Hu
- Department of Cardiology, Shanghai Minhang Hospital, Fudan University Shanghai, China
| | - Zhi-Ping Song
- Department of Cardiology, Shanghai Minhang Hospital, Fudan University Shanghai, China
| | - Yue-Guang Chen
- Department of Cardiology, Shanghai Minhang Hospital, Fudan University Shanghai, China
| | - Da-Dong Zhang
- Department of Cardiology, Shanghai Minhang Hospital, Fudan University Shanghai, China
| | - Chang-Qian Wang
- Department of Cardiology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine Shanghai, China
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