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Bryniarska-Kubiak N, Kubiak A, Trojan E, Wesołowska J, Lekka M, Basta-Kaim A. Oxygen-Glucose Deprivation in Organotypic Hippocampal Cultures Leads to Cytoskeleton Rearrangement and Immune Activation: Link to the Potential Pathomechanism of Ischaemic Stroke. Cells 2023; 12:1465. [PMID: 37296586 PMCID: PMC10252361 DOI: 10.3390/cells12111465] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/18/2023] [Accepted: 05/19/2023] [Indexed: 06/12/2023] Open
Abstract
Ischaemic stroke is characterized by a sudden loss of blood circulation to an area of the brain, resulting in a corresponding loss of neurologic function. As a result of this process, neurons in the ischaemic core are deprived of oxygen and trophic substances and are consequently destroyed. Tissue damage in brain ischaemia results from a complex pathophysiological cascade comprising various distinct pathological events. Ischaemia leads to brain damage by stimulating many processes, such as excitotoxicity, oxidative stress, inflammation, acidotoxicity, and apoptosis. Nevertheless, less attention has been given to biophysical factors, including the organization of the cytoskeleton and the mechanical properties of cells. Therefore, in the present study, we sought to evaluate whether the oxygen-glucose deprivation (OGD) procedure, which is a commonly accepted experimental model of ischaemia, could affect cytoskeleton organization and the paracrine immune response. The abovementioned aspects were examined ex vivo in organotypic hippocampal cultures (OHCs) subjected to the OGD procedure. We measured cell death/viability, nitric oxide (NO) release, and hypoxia-inducible factor 1α (HIF-1α) levels. Next, the impact of the OGD procedure on cytoskeletal organization was evaluated using combined confocal fluorescence microscopy (CFM) and atomic force microscopy (AFM). Concurrently, to find whether there is a correlation between biophysical properties and the immune response, we examined the impact of OGD on the levels of crucial ischaemia cytokines (IL-1β, IL-6, IL-18, TNF-α, IL-10, IL-4) and chemokines (CCL3, CCL5, CXCL10) in OHCs and calculated Pearsons' and Spearman's rank correlation coefficients. The results of the current study demonstrated that the OGD procedure intensified cell death and nitric oxide release and led to the potentiation of HIF-1α release in OHCs. Moreover, we presented significant disturbances in the organization of the cytoskeleton (actin fibers, microtubular network) and cytoskeleton-associated protein 2 (MAP-2), which is a neuronal marker. Simultaneously, our study provided new evidence that the OGD procedure leads to the stiffening of OHCs and a malfunction in immune homeostasis. A negative linear correlation between tissue stiffness and branched IBA1 positive cells after the OGD procedure suggests the pro-inflammatory polarization of microglia. Moreover, the negative correlation of pro- and positive anti-inflammatory factors with actin fibers density indicates an opposing effect of the immune mediators on the rearrangement of cytoskeleton induced by OGD procedure in OHCs. Our study constitutes a basis for further research and provides a rationale for integrating biomechanical and biochemical methods in studying the pathomechanism of stroke-related brain damage. Furthermore, presented data pointed out the interesting direction of proof-of-concept studies, in which follow-up may establish new targets for brain ischemia therapy.
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Affiliation(s)
- Natalia Bryniarska-Kubiak
- Laboratory of Immunoendocrinology, Department of Experimental Neuroendocrinology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St., 31-343 Kraków, Poland
| | - Andrzej Kubiak
- Department of Biophysical Microstructures, Institute of Nuclear Physics, Polish Academy of Sciences, 152 Radzikowskiego St., 31-342 Kraków, Poland
- Laboratory of Stem Cell Biology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 7 Gronostajowa St., 30-387 Kraków, Poland
| | - Ewa Trojan
- Laboratory of Immunoendocrinology, Department of Experimental Neuroendocrinology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St., 31-343 Kraków, Poland
| | - Julita Wesołowska
- Laboratory for In Vivo and In Vitro Imaging, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St., 31-343 Kraków, Poland
| | - Małgorzata Lekka
- Department of Biophysical Microstructures, Institute of Nuclear Physics, Polish Academy of Sciences, 152 Radzikowskiego St., 31-342 Kraków, Poland
| | - Agnieszka Basta-Kaim
- Laboratory of Immunoendocrinology, Department of Experimental Neuroendocrinology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St., 31-343 Kraków, Poland
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Ramakrishna K, Krishnamurthy S. Indole-3-carbinol ameliorated the neurodevelopmental deficits in neonatal anoxic injury in rats. Int J Dev Neurosci 2023; 83:31-43. [PMID: 36259087 DOI: 10.1002/jdn.10234] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 10/01/2022] [Accepted: 10/13/2022] [Indexed: 02/04/2023] Open
Abstract
Neonatal anoxia is linked to long-lasting neurodevelopmental deficits. Due to the lack of pharmacological intervention to treat neonatal anoxia, there is interest in finding new molecules for its treatment. Indole-3-carbinol (I3C) has shown neuroprotective effects in some disease conditions. However, the neuroprotective role of I3C in neonatal anoxia has not been explored. Consequently, we have investigated the effect of I3C on neonatal anoxia-induced brain injury and neurodevelopmental deficits. Rat pups after 30 h of birth were subjected to two episodes of anoxia (10 min in each) at a time interval of 24 h by flowing 100% nitrogen. I3C was administered within 30 min of the second episode of anoxia on a postnatal day (PND) 3 and continued for PND 9. Neurodevelopmental deficits, cortical mitochondrial membrane potential (MMP), opening of mitochondrial permeability transition pore (MPTP), electron transport chain (ETC) enzyme activities, oxidative stress, hypoxia-inducible factor-1α (HIF-1α) levels, histopathological changes, and apoptosis were measured. I3C treatment dose-dependently ameliorated the neurodevelopmental deficits and somatic growth in anoxic pups. I3C improved mitochondrial function by enhancing the MMP, mitochondrial ETC enzymes, and antioxidants. It blocked the MPTP opening and release of cytochrome C in anoxic pups. Further, I3C reduced the elevated cortical HIF-1α in neonatal anoxic pups. Furthermore, I3C ameliorated histopathological abnormalities and mitochondrial-mediated apoptotic indicators Cyt C, caspase-9, and caspase-3. Our study concludes that I3C improved neuronal development in anoxic pups by enhancing mitochondrial function, reducing HIF-1α, and mitigating apoptosis.
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Affiliation(s)
- Kakarla Ramakrishna
- Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology, Banaras Hindu University (IIT BHU), Varanasi, India.,Department of Pharmacy, Koneru Lakshmaiah Education Foundation, Vaddeswaram, India
| | - Sairam Krishnamurthy
- Department of Pharmaceutical Engineering and Technology, Indian Institute of Technology, Banaras Hindu University (IIT BHU), Varanasi, India
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3
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Neuroprotective Efficacy of Betulinic Acid Hydroxamate, a B55α/PP2A Activator, in Acute Hypoxia-Ischemia-Induced Brain Damage in Newborn Rats. Transl Stroke Res 2022; 14:397-408. [PMID: 35419730 DOI: 10.1007/s12975-022-01017-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 01/12/2022] [Accepted: 03/29/2022] [Indexed: 10/18/2022]
Abstract
There is an increasing evidence of the neuroprotective effects of hypoxia inducing factor prolyl-hydroxylase inhibitors (HIF-PHDi) after hypoxic-ischemic (HI) brain damage (HIBD). We studied the neuroprotective effects of betulinic hydroxamate (BAH), a novel B55α/PP2A activator that dephosphorylates and inhibits PHD2 activity, in a rat model of neonatal HIBD. Seven-day-old (P7) Wistar rats were exposed to hypoxia after left carotid artery electrocoagulation and then received vehicle (HI + VEH) or BAH 3 mg/kg i.p. 30 min post-insult. Brain damage was assessed by magnetic resonance imaging (MRI) and neurobehavioral studies testing motor and cognitive performance at P14 and P37, as well as immunohistochemical studies (TUNEL and myelin basic protein (MBP) signal) at P37. Mechanisms of damage were assessed at P14 determining excitotoxicity (glutamate/N-acetylaspartate ratio by H+-magnetic resonance spectroscopy), oxidative stress (protein nitrosylation by Oxyblot), and inflammation (cytokine and chemokine concentration). BAH reduced brain damage volume and cell death, preventing the development of motor and working memory deficits. BAH showed a robust protective effect on myelination, restoring MBP expression at P37. BAH modulated excitotoxicity, oxidative stress, and inflammation. Most neuroprotective effects were still present despite BAH administration was delayed for 12 h, whereas beneficial effects on motor strength at P14 and on cell death and myelination at P37 were preserved even when BAH administration was delayed for 24 h. In conclusion, BAH appears as an effective neuroprotective treatment for neonatal HIBD in a manner associated with the modulation of excitotoxicity, oxidative stress, and inflammation, showing a broad therapeutic window.
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Ovcjak A, Xiao A, Kim JS, Xu B, Szeto V, Turlova E, Abussaud A, Chen NH, Miller SP, Sun HS, Feng ZP. Ryanodine receptor inhibitor dantrolene reduces hypoxic-ischemic brain injury in neonatal mice. Exp Neurol 2022; 351:113985. [DOI: 10.1016/j.expneurol.2022.113985] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 01/07/2022] [Accepted: 01/13/2022] [Indexed: 11/04/2022]
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Jha RM, Rani A, Desai SM, Raikwar S, Mihaljevic S, Munoz-Casabella A, Kochanek PM, Catapano J, Winkler E, Citerio G, Hemphill JC, Kimberly WT, Narayan R, Sahuquillo J, Sheth KN, Simard JM. Sulfonylurea Receptor 1 in Central Nervous System Injury: An Updated Review. Int J Mol Sci 2021; 22:11899. [PMID: 34769328 PMCID: PMC8584331 DOI: 10.3390/ijms222111899] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 12/17/2022] Open
Abstract
Sulfonylurea receptor 1 (SUR1) is a member of the adenosine triphosphate (ATP)-binding cassette (ABC) protein superfamily, encoded by Abcc8, and is recognized as a key mediator of central nervous system (CNS) cellular swelling via the transient receptor potential melastatin 4 (TRPM4) channel. Discovered approximately 20 years ago, this channel is normally absent in the CNS but is transcriptionally upregulated after CNS injury. A comprehensive review on the pathophysiology and role of SUR1 in the CNS was published in 2012. Since then, the breadth and depth of understanding of the involvement of this channel in secondary injury has undergone exponential growth: SUR1-TRPM4 inhibition has been shown to decrease cerebral edema and hemorrhage progression in multiple preclinical models as well as in early clinical studies across a range of CNS diseases including ischemic stroke, traumatic brain injury, cardiac arrest, subarachnoid hemorrhage, spinal cord injury, intracerebral hemorrhage, multiple sclerosis, encephalitis, neuromalignancies, pain, liver failure, status epilepticus, retinopathies and HIV-associated neurocognitive disorder. Given these substantial developments, combined with the timeliness of ongoing clinical trials of SUR1 inhibition, now, another decade later, we review advances pertaining to SUR1-TRPM4 pathobiology in this spectrum of CNS disease-providing an overview of the journey from patch-clamp experiments to phase III trials.
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Affiliation(s)
- Ruchira M. Jha
- Department of Neurology, Barrow Neurological Institute and St. Joseph’s Hospital and Medical Center, Phoenix, AZ 85013, USA; (R.M.J.); (S.M.D.)
- Department of Translational Neuroscience, Barrow Neurological Institute and St. Joseph’s Hospital and Medical Center, Phoenix, AZ 85013, USA; (A.R.); (S.R.); (S.M.); (A.M.-C.)
- Department of Neurosurgery, Barrow Neurological Institute and St. Joseph’s Hospital and Medical Center, Phoenix, AZ 85013, USA; (J.C.); (E.W.)
| | - Anupama Rani
- Department of Translational Neuroscience, Barrow Neurological Institute and St. Joseph’s Hospital and Medical Center, Phoenix, AZ 85013, USA; (A.R.); (S.R.); (S.M.); (A.M.-C.)
| | - Shashvat M. Desai
- Department of Neurology, Barrow Neurological Institute and St. Joseph’s Hospital and Medical Center, Phoenix, AZ 85013, USA; (R.M.J.); (S.M.D.)
| | - Sudhanshu Raikwar
- Department of Translational Neuroscience, Barrow Neurological Institute and St. Joseph’s Hospital and Medical Center, Phoenix, AZ 85013, USA; (A.R.); (S.R.); (S.M.); (A.M.-C.)
| | - Sandra Mihaljevic
- Department of Translational Neuroscience, Barrow Neurological Institute and St. Joseph’s Hospital and Medical Center, Phoenix, AZ 85013, USA; (A.R.); (S.R.); (S.M.); (A.M.-C.)
| | - Amanda Munoz-Casabella
- Department of Translational Neuroscience, Barrow Neurological Institute and St. Joseph’s Hospital and Medical Center, Phoenix, AZ 85013, USA; (A.R.); (S.R.); (S.M.); (A.M.-C.)
| | - Patrick M. Kochanek
- Clinical and Translational Science Institute, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA;
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Safar Center for Resuscitation Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Joshua Catapano
- Department of Neurosurgery, Barrow Neurological Institute and St. Joseph’s Hospital and Medical Center, Phoenix, AZ 85013, USA; (J.C.); (E.W.)
| | - Ethan Winkler
- Department of Neurosurgery, Barrow Neurological Institute and St. Joseph’s Hospital and Medical Center, Phoenix, AZ 85013, USA; (J.C.); (E.W.)
| | - Giuseppe Citerio
- School of Medicine and Surgery, University of Milan-Bicocca, 20126 Milan, Italy;
- Neurointensive Care Unit, Department of Neuroscience, San Gerardo Hospital, ASST—Monza, 20900 Monza, Italy
| | - J. Claude Hemphill
- Department of Neurology, University of California, San Francisco, CA 94143, USA;
| | - W. Taylor Kimberly
- Division of Neurocritical Care and Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA;
| | - Raj Narayan
- Department of Neurosurgery, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, North Shore University Hospital, Manhasset, NY 11549, USA;
| | - Juan Sahuquillo
- Neurotrauma and Neurosurgery Research Unit (UNINN), Vall d’Hebron Research Institute (VHIR), 08035 Barcelona, Spain;
- Neurotraumatology and Neurosurgery Research Unit, Universitat Autònoma de Barcelona (UAB), 08193 Barcelona, Spain
- Department of Neurosurgery, Vall d’Hebron University Hospital, 08035 Barcelona, Spain
| | - Kevin N. Sheth
- Division of Neurocritical Care and Emergency Neurology, Department of Neurology, School of Medicine, Yale University, New Haven, CT 06510, USA;
| | - J. Marc Simard
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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Herrera EA, González-Candia A. Gestational Hypoxia and Blood-Brain Barrier Permeability: Early Origins of Cerebrovascular Dysfunction Induced by Epigenetic Mechanisms. Front Physiol 2021; 12:717550. [PMID: 34489733 PMCID: PMC8418233 DOI: 10.3389/fphys.2021.717550] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/19/2021] [Indexed: 01/25/2023] Open
Abstract
Fetal chronic hypoxia leads to intrauterine growth restriction (IUGR), which is likely to reduce oxygen delivery to the brain and induce long-term neurological impairments. These indicate a modulatory role for oxygen in cerebrovascular development. During intrauterine hypoxia, the fetal circulation suffers marked adaptations in the fetal cardiac output to maintain oxygen and nutrient delivery to vital organs, known as the "brain-sparing phenotype." This is a well-characterized response; however, little is known about the postnatal course and outcomes of this fetal cerebrovascular adaptation. In addition, several neurodevelopmental disorders have their origins during gestation. Still, few studies have focused on how intrauterine fetal hypoxia modulates the normal brain development of the blood-brain barrier (BBB) in the IUGR neonate. The BBB is a cellular structure formed by the neurovascular unit (NVU) and is organized by a monolayer of endothelial and mural cells. The BBB regulates the entry of plasma cells and molecules from the systemic circulation to the brain. A highly selective permeability system achieves this through integral membrane proteins in brain endothelial cells. BBB breakdown and dysfunction in cerebrovascular diseases lead to leakage of blood components into the brain parenchyma, contributing to neurological deficits. The fetal brain circulation is particularly susceptible in IUGR and is proposed to be one of the main pathological processes deriving BBB disruption. In the last decade, several epigenetic mechanisms activated by IU hypoxia have been proposed to regulate the postnatal BBB permeability. However, few mechanistic studies about this topic are available, and little evidence shows controversy. Therefore, in this mini-review, we analyze the BBB permeability-associated epigenetic mechanisms in the brain exposed to chronic intrauterine hypoxia.
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Affiliation(s)
- Emilio A Herrera
- Laboratory of Vascular Function and Reactivity, Pathophysiology Program, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
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Bustelo M, Barkhuizen M, van den Hove DLA, Steinbusch HWM, Bruno MA, Loidl CF, Gavilanes AWD. Clinical Implications of Epigenetic Dysregulation in Perinatal Hypoxic-Ischemic Brain Damage. Front Neurol 2020; 11:483. [PMID: 32582011 PMCID: PMC7296108 DOI: 10.3389/fneur.2020.00483] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 05/04/2020] [Indexed: 12/18/2022] Open
Abstract
Placental and fetal hypoxia caused by perinatal hypoxic-ischemic events are major causes of stillbirth, neonatal morbidity, and long-term neurological sequelae among surviving neonates. Brain hypoxia and associated pathological processes such as excitotoxicity, apoptosis, necrosis, and inflammation, are associated with lasting disruptions in epigenetic control of gene expression contributing to neurological dysfunction. Recent studies have pointed to DNA (de)methylation, histone modifications, and non-coding RNAs as crucial components of hypoxic-ischemic encephalopathy (HIE). The understanding of epigenetic dysregulation in HIE is essential in the development of new clinical interventions for perinatal HIE. Here, we summarize our current understanding of epigenetic mechanisms underlying the molecular pathology of HI brain damage and its clinical implications in terms of new diagnostic, prognostic, and therapeutic tools.
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Affiliation(s)
- Martín Bustelo
- Department of Pediatrics, Maastricht University Medical Center (MUMC), Maastricht, Netherlands.,Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Maastricht University, Maastricht, Netherlands.,Instituto de Ciencias Biomédicas, Facultad de Ciencias Médicas, Universidad Católica de Cuyo, San Juan, Argentina.,Laboratorio de Neuropatología Experimental, Facultad de Medicina, Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis" (IBCN), Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
| | - Melinda Barkhuizen
- Department of Pediatrics, Maastricht University Medical Center (MUMC), Maastricht, Netherlands
| | - Daniel L A van den Hove
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Maastricht University, Maastricht, Netherlands.,Department of Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Würzburg, Germany
| | - Harry Wilhelm M Steinbusch
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Maastricht University, Maastricht, Netherlands
| | - Martín A Bruno
- Instituto de Ciencias Biomédicas, Facultad de Ciencias Médicas, Universidad Católica de Cuyo, San Juan, Argentina
| | - C Fabián Loidl
- Instituto de Ciencias Biomédicas, Facultad de Ciencias Médicas, Universidad Católica de Cuyo, San Juan, Argentina.,Laboratorio de Neuropatología Experimental, Facultad de Medicina, Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis" (IBCN), Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
| | - Antonio W Danilo Gavilanes
- Department of Pediatrics, Maastricht University Medical Center (MUMC), Maastricht, Netherlands.,Facultad de Ciencias Médicas, Instituto de Investigación e Innovación de Salud Integral, Universidad Católica de Santiago de Guayaquil, Guayaquil, Ecuador
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Chang J, Yang B, Zhou Y, Yin C, Liu T, Qian H, Xing G, Wang S, Li F, Zhang Y, Chen D, Aschner M, Lu R. Acute Methylmercury Exposure and the Hypoxia-Inducible Factor-1α Signaling Pathway under Normoxic Conditions in the Rat Brain and Astrocytes in Vitro. ENVIRONMENTAL HEALTH PERSPECTIVES 2019; 127:127006. [PMID: 31850806 PMCID: PMC6957278 DOI: 10.1289/ehp5139] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 11/07/2019] [Accepted: 11/18/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND As a ubiquitous environmental pollutant, methylmercury (MeHg) induces toxic effects in the nervous system, one of its main targets. However, the exact mechanisms of its neurotoxicity have not been fully elucidated. Hypoxia-inducible factor- 1 α (HIF- 1 α ), a transcription factor, plays a crucial role in adaptive and cytoprotective responses in cells and is involved in cell survival, proliferation, apoptosis, inflammation, angiogenesis, glucose metabolism, erythropoiesis, and other physiological activities. OBJECTIVES The aim of this study was to explore the role of HIF- 1 α in response to acute MeHg exposure in rat brain and primary cultured astrocytes to improve understanding of the mechanisms of MeHg-induced neurotoxicity and the development of effective neuroprotective strategies. METHODS Primary rat astrocytes were treated with MeHg (0 - 10 μ M ) for 0.5 h . Cell proliferation and cytotoxicity were assessed with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl diphenyltetrazolium bromide (MTT) assay and a lactate dehydrogenase (LDH) release assay, respectively. Reactive oxygen species (ROS) levels were analyzed to assess the level of oxidative stress using 2',7'-dichlorofluorescin diacetate (DCFH-DA) fluorescence. HIF- 1 α , and its downstream proteins, glucose transporter 1 (GLUT-1), erythropoietin (EPO), and vascular endothelial growth factor A (VEGF-A) were analyzed by means of Western blotting. Real-time PCR was used to detect the expression of HIF- 1 α mRNA. Pretreatment with protein synthesis inhibitor (CHX), proteasome inhibitor (MG132), or proline hydroxylase inhibitor (DHB) were applied to explore the possible mechanisms of HIF- 1 α inhibition by MeHg. To investigate the role of HIF- 1 α in MeHg-induced neurotoxicity, cobalt chloride (CoC l 2 ), 2-methoxyestradiol (2-MeOE2), small interfering RNA (siRNA) transfection and adenovirus overexpression were used. Pretreatment with N-acetyl-L-cysteine (NAC) and vitamin E (Trolox) were used to investigate the putative role of oxidative stress in MeHg-induced alterations in HIF- 1 α levels. The expression of HIF- 1 α and related downstream proteins was detected in adult rat brain exposed to MeHg (0 - 10 mg / kg ) for 0.5 h in vivo. RESULTS MeHg caused lower cell proliferation and higher cytotoxicity in primary rat astrocytes in a time- and concentration-dependent manner. In comparison with the control cells, exposure to 10 μ M MeHg for 0.5 h significantly inhibited the expression of astrocytic HIF- 1 α , and the downstream genes GLUT-1, EPO, and VEGF-A (p < 0.05 ), in the absence of a significant decrease in HIF- 1 α mRNA levels. When protein synthesis was inhibited by CHX, MeHg promoted the degradation rate of HIF- 1 α . MG132 and DHB significantly blocked the MeHg-induced decrease in HIF- 1 α expression (p < 0.05 ). Overexpression of HIF- 1 α significantly attenuated the decline in MeHg-induced cell proliferation, whereas the inhibition of HIF- 1 α significantly increased the decline in cell proliferation (p < 0.05 ). NAC and Trolox, two established antioxidants, reversed the MeHg-induced decline in HIF- 1 α protein levels and the decrease in cell proliferation (p < 0.05 ). MeHg suppressed the expression of HIF- 1 α and related downstream target proteins in adult rat brain. DISCUSSION MeHg induced a significant reduction in HIF- 1 α protein by activating proline hydroxylase (PHD) and the ubiquitin proteasome system (UPS) in primary rat astrocytes. Additionally, ROS scavenging by antioxidants played a neuroprotective role via increasing HIF- 1 α expression in response to MeHg toxicity. Moreover, we established that up-regulation of HIF- 1 α might serve to mitigate the acute toxicity of MeHg in astrocytes, affording a novel therapeutic target for future exploration. https://doi.org/10.1289/EHP5139.
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Affiliation(s)
- Jie Chang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Bobo Yang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Yun Zhou
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Changsheng Yin
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
- Institute of Life Sciences, Jiangsu University, Zhenjiang, China
| | - Tingting Liu
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Hai Qian
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Guangwei Xing
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Suhua Wang
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Fang Li
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
| | - Yubin Zhang
- Department of Occupational Health and Toxicology, School of Public Health, Fudan University, Shanghai, China
| | - Da Chen
- School of Environment, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, China
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Rongzhu Lu
- Department of Preventive Medicine and Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, China
- Center for Experimental Research, Kunshan Hospital Affiliated to Jiangsu University, Kunshan, China
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9
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Ding L, Gong Y, Yang Z, Zou B, Liu X, Zhang B, Li J. Lactobacillus rhamnosus GG Ameliorates Liver Injury and Hypoxic Hepatitis in Rat Model of CLP-Induced Sepsis. Dig Dis Sci 2019; 64:2867-2877. [PMID: 31049763 DOI: 10.1007/s10620-019-05628-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 04/15/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Probiotic use to prevent gastrointestinal infections in critical care has shown great promise in recent clinical trials. Although well-documented benefits of probiotic use in intestinal disorders, the potential for probiotic treatment to ameliorate liver injury and hypoxic hepatitis following sepsis has not been well explored. METHODS In order to evaluate, if Lactobacillus rhamnosus GG (LGG) treatment in septic rats will protect against liver injury, this study used 20-22-week-old Sprague-Dawley rats which were subjected to cecal ligation and puncture to establish sepsis model and examine mRNA and protein levels of IL-1β, NLRP3, IL-6, TNF-a, VEGF, MCP1, NF-kB and HIF-1α in the liver via real-time PCR, Elisa and Western blot. RESULTS This study showed that LGG treatment significantly ameliorated liver injury following experimental infection and sepsis. Liver mRNA and protein levels of IL-1β, NLRP3, IL-6, TNF-a, VEGF, MCP1, NF-kB and HIF-1α were significantly reduced in rats receiving LGG. CONCLUSIONS Thus, our study demonstrated that LGG treatment can reduce liver injury following experimental infection and sepsis and is associated with improved hypoxic hepatitis. Probiotic therapy may be a promising intervention to ameliorate clinical liver injury and hypoxic hepatitis following systemic infection and sepsis.
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Affiliation(s)
- Lei Ding
- Department of Hepatobiliary Surgery, The 5th Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong Province, China
| | - Yihang Gong
- Department of Hepatobiliary Surgery, The 5th Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong Province, China
| | - Zhengfei Yang
- Emergency Department, Sun Yat-sen Memorial Hospital, Guangzhou, Guangdong Province, China
| | - Baojia Zou
- Department of Hepatobiliary Surgery, The 5th Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong Province, China
| | - Xialei Liu
- Department of Hepatobiliary Surgery, The 5th Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong Province, China
| | - Baimeng Zhang
- Department of Hepatobiliary Surgery, The 5th Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong Province, China
| | - Jian Li
- Department of Hepatobiliary Surgery, The 5th Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong Province, China.
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10
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Liang X, Liu X, Lu F, Zhang Y, Jiang X, Ferriero DM. HIF1α Signaling in the Endogenous Protective Responses after Neonatal Brain Hypoxia-Ischemia. Dev Neurosci 2019; 40:1-10. [PMID: 30836371 PMCID: PMC6728223 DOI: 10.1159/000495879] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 11/27/2018] [Indexed: 12/21/2022] Open
Abstract
Hypoxia-inducible factor 1α (HIF1α) is a key regulator of oxygen homeostasis, and its target genes mediate adaptive, protective, and pathological processes. The role of HIF1α in neuronal survival is controversial and the brain maturation stage is important in determining its function in brain ischemia or hypoxia-ischemia (HI). In this study, we used neuron-specific HIF1α knockout mice at postnatal day 9 (P9), and immature cortical neurons (days 7-8 in vitro) treated with the HIF1α inhibitor 2-methoxyestradiol (2ME2) or stabilizer dimethyloxalylglycine (DMOG), to examine the function of neuronal HIF1α in neonatal HI in vivo (Vannucci model) and in vitro (oxygen glucose deprivation, OGD). Inhibition of HIF1α with 2ME2 in primary neurons or deletion of neuronal HIF1α in P9 mice increased both necrotic and apoptotic cell death following HI, as evaluated by the protein levels of 145/150-kDa and 120-kDa spectrin breakdown products 24 h after HI. DMOG attenuated neuronal death right after OGD. Acute pharmacological manipulation of HIF1α synchronously regulated the expression of its targets, vascular endothelial growth factor (VEGF) and erythropoietin (Epo), in the same manner. The in vivo findings agree with our previous data using the same HIF1α-deficient mice at an earlier age. This study confirms the role of neuronal HIF1α signaling in the endogenous protective responses following HI in the developing brain.
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Affiliation(s)
- Xiao Liang
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xuemei Liu
- Central Laboratory, Dongfang Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Fuxin Lu
- Department of Pediatrics, University of California San Francisco, San Francisco, California, USA
| | - Yunling Zhang
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiangning Jiang
- Department of Pediatrics, University of California San Francisco, San Francisco, California, USA
| | - Donna M Ferriero
- Department of Pediatrics, University of California San Francisco, San Francisco, California, USA,
- Department of Neurology, University of California San Francisco, San Francisco, California, USA,
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11
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Chen W, Ju XZ, Lu Y, Ding XW, Miao CH, Chen JW. Propofol improved hypoxia-impaired integrity of blood-brain barrier via modulating the expression and phosphorylation of zonula occludens-1. CNS Neurosci Ther 2019; 25:704-713. [PMID: 30680941 PMCID: PMC6515893 DOI: 10.1111/cns.13101] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/04/2018] [Accepted: 12/20/2017] [Indexed: 02/06/2023] Open
Abstract
Aims Hypoxia may damage blood‐brain barrier (BBB). The neuroprotective effect of propofol has been reported. We aimed to identify whether and how propofol improved hypoxia‐induced impairment of BBB integrity. Methods Mouse brain microvascular endothelial cells (MBMECs) and astrocytes were cocultured to establish in vitro BBB model. The effects of hypoxia and propofol on BBB integrity were examined. Further, zonula occludens‐1 (ZO‐1) expression and phosphorylation, hypoxia‐inducible factor‐1α (HIF‐1α) and vascular endothelial growth factor (VEGF) expression, intracellular calcium concentration and Ca2+/calmodulin‐dependent protein kinase II (CAMKII) activation were measured. Results Hypoxia‐impaired BBB integrity, which was protected by propofol. Hypoxia‐reduced ZO‐1 expression, while induced ZO‐1 phosphorylation. These effects were attenuated by propofol. The expression of HIF‐1α and VEGF was increased by hypoxia and was alleviated by propofol. The hypoxia‐mediated suppression of ZO‐1 and impaired BBB integrity was reversed by HIF‐α inhibitor and VEGF inhibitor. In addition, hypoxia increased the intracellular calcium concentration and induced the phosphorylation of CAMKII, which were mitigated by propofol. The hypoxia‐induced phosphorylation of ZO‐1 and impaired BBB integrity was ameliorated by calcium chelator and CAMKII inhibitor. Conclusion Propofol could protect against hypoxia‐mediated impairment of BBB integrity. The underlying mechanisms may involve the expression and phosphorylation of ZO‐1.
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Affiliation(s)
- Wei Chen
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xing-Zhu Ju
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.,Department of Gynecologic Oncology, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Yan Lu
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xiao-Wei Ding
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Chang-Hong Miao
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jia-Wei Chen
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
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12
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Davis CK, Jain SA, Bae ON, Majid A, Rajanikant GK. Hypoxia Mimetic Agents for Ischemic Stroke. Front Cell Dev Biol 2019; 6:175. [PMID: 30671433 PMCID: PMC6331394 DOI: 10.3389/fcell.2018.00175] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 12/10/2018] [Indexed: 12/27/2022] Open
Abstract
Every year stroke claims more than 6 million lives worldwide. The majority of them are ischemic stroke. Small molecule-based therapeutics for ischemic stroke has attracted a lot of attention, but none has been shown to be clinically useful so far. Hypoxia-inducible factor-1 (HIF-1) plays a crucial role in the transcriptional adaptation of cells to hypoxia. Small molecule-based hypoxia-mimetic agents either stabilize HIF-1α via HIF-prolyl hydroxylases (PHDs) inhibition or through other mechanisms. In both the cases, these agents have been shown to confer ischemic neuroprotection in vitro and in vivo. The agents which act via PHD inhibition are mainly classified into iron chelators, iron competitors, and 2 oxoglutarate (2OG) analogs. This review discusses HIF structure and key players in the HIF-1 degradation pathway as well as the genes, proteins and chemical molecules that are connected to HIF-1 and how they affect cell survival following ischemic injury. Furthermore, this review gives a summary of studies that used PHD inhibitors and other HIF-1α stabilizers as hypoxia-mimetic agents for the treatment of ischemic injury.
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Affiliation(s)
- Charles K Davis
- School of Biotechnology, National Institute of Technology Calicut, Calicut, India
| | - Saurabh A Jain
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, United Kingdom
| | - Ok-Nam Bae
- College of Pharmacy, Hanyang University, Ansan, South Korea
| | - Arshad Majid
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, United Kingdom
| | - G K Rajanikant
- School of Biotechnology, National Institute of Technology Calicut, Calicut, India
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13
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Concepcion KR, Zhang L. Corticosteroids and perinatal hypoxic-ischemic brain injury. Drug Discov Today 2018; 23:1718-1732. [PMID: 29778695 DOI: 10.1016/j.drudis.2018.05.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 04/13/2018] [Accepted: 05/11/2018] [Indexed: 01/15/2023]
Abstract
Perinatal hypoxic-ischemic (HI) brain injury is the major cause of neonatal mortality and severe long-term neurological morbidity. Yet, the effective therapeutic interventions currently available are extremely limited. Corticosteroids act on both mineralocorticoid (MR) and glucocorticoid (GR) receptors and modulate inflammation and apoptosis in the brain. Neuroinflammatory response to acute cerebral HI is a major contributor to the pathophysiology of perinatal brain injury. Here, we give an overview of current knowledge of corticosteroid-mediated modulations of inflammation and apoptosis in the neonatal brain, focusing on key regulatory cells of the innate and adaptive immune response. In addition, we provide new insights into targets of MR and GR in potential therapeutic strategies that could be beneficial for the treatment of infants with HI brain injury.
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Affiliation(s)
- Katherine R Concepcion
- Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA.
| | - Lubo Zhang
- Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92350, USA
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14
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Geng J, Wang L, Qu M, Song Y, Lin X, Chen Y, Mamtilahun M, Chen S, Zhang Z, Wang Y, Yang GY. Endothelial progenitor cells transplantation attenuated blood-brain barrier damage after ischemia in diabetic mice via HIF-1α. Stem Cell Res Ther 2017; 8:163. [PMID: 28697748 PMCID: PMC5505148 DOI: 10.1186/s13287-017-0605-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 04/20/2017] [Accepted: 06/07/2017] [Indexed: 12/20/2022] Open
Abstract
Background Blood-brain barrier impairment is a major indicator of endothelial dysfunction in diabetes. Studies showed that endothelial progenitor cell (EPC) transplantation promoted angiogenesis and improved function recovery after hind limb ischemia in diabetic mice. The effect of EPC transplantation on blood-brain barrier integrity after cerebral ischemia in diabetic animals is unknown. The aim of this study is to explore the effect of EPC transplantation on the integrity of the blood-brain barrier after cerebral ischemia in diabetic mice. Methods EPCs were isolated by density gradient centrifugation and characterized by flow cytometry and immunostaining. Diabetes was induced in adult male C57BL/6 mice by a single injection of streptozotocin at 4 weeks before surgery. Diabetic mice underwent 90-minute transient middle cerebral artery occlusion surgery and received 1 × 106 EPCs transplantation immediately after reperfusion. Brain infarct volume, blood-brain barrier permeability, tight junction protein expression, and hypoxia inducible factor-1α (HIF-1α) mRNA level were examined after treatment. Results We demonstrated that neurological deficits were attenuated and brain infarct volume was reduced in EPC-transplanted diabetic mice after transient cerebral ischemia compared to the controls (p < 0.05). Blood-brain barrier leakage and tight junction protein degradation were reduced in EPC-transplanted mice (p <0.05). EPCs upregulated HIF-1α expression while HIF-1α inhibitor PX-478 abolished the beneficial effect of EPCs. Conclusions We conclude that EPCs protected blood-brain barrier integrity after focal ischemia in diabetic mice through upregulation of HIF-1α signaling.
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Affiliation(s)
- Jieli Geng
- Department of Neurology, Shanghai Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China.,Department of Neurology, Shanghai Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Liping Wang
- Department of Neurology, Shanghai Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China.,Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Hua Shan Road, Shanghai, 200030, China
| | - Meijie Qu
- Department of Neurology, Shanghai Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China.,Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Hua Shan Road, Shanghai, 200030, China
| | - Yaying Song
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Hua Shan Road, Shanghai, 200030, China
| | - Xiaojie Lin
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Hua Shan Road, Shanghai, 200030, China
| | - Yajing Chen
- Department of Neurology, Shanghai Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China.,Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Hua Shan Road, Shanghai, 200030, China
| | - Muyassar Mamtilahun
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Hua Shan Road, Shanghai, 200030, China
| | - Shengdi Chen
- Department of Neurology, Shanghai Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China
| | - Zhijun Zhang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Hua Shan Road, Shanghai, 200030, China
| | - Yongting Wang
- Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Hua Shan Road, Shanghai, 200030, China.
| | - Guo-Yuan Yang
- Department of Neurology, Shanghai Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200025, China. .,Neuroscience and Neuroengineering Research Center, Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Hua Shan Road, Shanghai, 200030, China.
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15
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Raghava N, Das BC, Ray SK. Neuroprotective effects of estrogen in CNS injuries: insights from animal models. ACTA ACUST UNITED AC 2017; 6:15-29. [PMID: 28845391 PMCID: PMC5567743 DOI: 10.2147/nan.s105134] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Among the estrogens that are biosynthesized in the human body, 17β-estradiol (estradiol or E2) is the most common and the best estrogen for neuroprotection in animal models of the central nervous system (CNS) injuries such as spinal cord injury (SCI), traumatic brain injury (TBI), and ischemic brain injury (IBI). These CNS injuries are not only serious health problems, but also enormous economic burden on the patients, their families, and the society at large. Studies from animal models of these CNS injuries provide insights into the multiple neuroprotective mechanisms of E2 and also suggest the possibility of translating the therapeutic efficacy of E2 in the treatment SCI, TBI, and IBI in humans in the near future. The pathophysiology of these injuries includes loss of motor function in the limbs, arms and their extremities, cognitive deficit, and many other serious consequences including life-threatening paralysis, infection, and even death. The potential application of E2 therapy to treat the CNS injuries may become a trend as the results are showing significant therapeutic benefits of E2 for neuroprotection when administered into the animal models of SCI, TBI, and IBI. This article describes the plausible mechanisms how E2 works with or without the involvement of estrogen receptors and provides an overview of the known neuroprotective effects of E2 in these three CNS injuries in different animal models. Because activation of estrogen receptors has profound implications in maintaining and also affecting normal physiology, there are notable impediments in translating E2 therapy to the clinics for neuroprotection in CNS injuries in humans. While E2 may not yet be the sole molecule for the treatment of CNS injuries due to the controversies surrounding it, the neuroprotective effects of its metabolite and derivative or combination of E2 with another therapeutic agent are showing significant impacts in animal models that can potentially shape the new treatment strategies for these CNS injuries in humans.
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Affiliation(s)
- Narayan Raghava
- Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Bhaskar C Das
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Swapan K Ray
- Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, SC, USA
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16
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Shi X, Doycheva DM, Xu L, Tang J, Yan M, Zhang JH. Sestrin2 induced by hypoxia inducible factor1 alpha protects the blood-brain barrier via inhibiting VEGF after severe hypoxic-ischemic injury in neonatal rats. Neurobiol Dis 2016; 95:111-21. [PMID: 27425892 DOI: 10.1016/j.nbd.2016.07.016] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 06/19/2016] [Accepted: 07/13/2016] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVE Hypoxic ischemic (HI) encephalopathy remains the leading cause of perinatal brain injury resulting in long term disabilities. Stabilization of blood brain barrier (BBB) after HI is an important target, therefore, in this study we aim to determine the role of sestrin2, a stress inducible protein which is elevated after various insults, on BBB stabilization after moderate and severe HI injuries. METHODS Rat pups underwent common carotid artery ligation followed by either 150min (severe model) or 100min (moderate model) of hypoxia. 1h post HI, rats were intranasally administered with recombinant human sestrin2 (rh-sestrin2) and sacrificed for infarct area, brain water content, righting reflex and geotaxis reflex. Sestrin2 was silenced using siRNA and an activator/inhibitor of hypoxia inducible factor1α (HIF1α) was used to examine their roles on BBB permeability. RESULTS Rats subjected to severe HI exhibited larger infarct area and higher sestrin2 expression compared to rats in the moderate HI group. rh-sestrin2 attenuated brain infarct and edema, while silencing sestrin2 reversed these protective effects after severe HI. HIF1α induced sestrin2 activation in severe HI but not in moderate HI groups. A HIF1a agonist was shown to increase permeability of the BBB via vascular endothelial growth factor (VEGF) after moderate HI. However, after severe HI, HIF1α activated both VEGF and sestrin2. But HIF1α dependent sestrin2 activation was the predominant pathway after severe HI which inhibited VEGF and attenuated BBB permeability. CONCLUSIONS rh-sestrin2 attenuated BBB permeability via upregulation of endogenous sestrin2 which was induced by HIF1α after severe HI. However, HIF1α's effects as a prodeath or prosurvival signal were influenced by the severity of HI injury.
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Affiliation(s)
- Xudan Shi
- Department of Anesthesiology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310000, China; Department of Anesthesiology and Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA
| | - Desislava Met Doycheva
- Department of Anesthesiology and Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA
| | - Liang Xu
- Department of Anesthesiology and Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA
| | - Jiping Tang
- Department of Anesthesiology and Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA
| | - Min Yan
- Department of Anesthesiology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310000, China.
| | - John H Zhang
- Department of Anesthesiology and Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA 92354, USA.
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17
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Hypoxia-inducible factor-1α upregulates tyrosine hydroxylase and dopamine transporter by nuclear receptor ERRγ in SH-SY5Y cells. Neuroreport 2015; 26:380-6. [PMID: 25807177 DOI: 10.1097/wnr.0000000000000356] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor relevant to the development of many mammalian organs including the brain. However, the molecular mechanisms by which signaling events mediate neuronal differentiation have not been fully elucidated. In the present study, we show for the first time that the orphan nuclear receptor estrogen-related receptor γ (ERRγ) is upregulated by HIF-1α and plays essential roles in HIF-1α-induced upregulation of dopaminergic marker molecules such as tyrosine hydroxylase and dopamine transporter. We found that deferoxamine upregulated HIF-1α and enhanced the dopaminergic phenotype and neurite outgrowth of SH-SY5Y cells. Deferoxamine activated transcription and protein expression of ERRγ, and deferoxamine-induced upregulation of tyrosine hydroxylase and dopamine transporter was attenuated by using the ERRγ inverse agonist or silencing ERRγ. Altogether, these results suggest that HIF-1α can positively regulate the dopaminergic phenotype through ERRγ. This study could provide new perspectives for understanding the mechanisms underlying the promotion of dopaminergic neuronal differentiation by hypoxia.
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18
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Deferoxamine Preconditioning of Neural-Like Cells Derived from Human Wharton’s Jelly Mesenchymal Stem Cells as a Strategy to Promote Their Tolerance and Therapeutic Potential: An In Vitro Study. Cell Mol Neurobiol 2015; 36:689-700. [DOI: 10.1007/s10571-015-0249-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 07/26/2015] [Indexed: 01/22/2023]
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19
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Molecular Connections between Cancer Cell Metabolism and the Tumor Microenvironment. Int J Mol Sci 2015; 16:11055-86. [PMID: 25988385 PMCID: PMC4463690 DOI: 10.3390/ijms160511055] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 04/30/2015] [Accepted: 05/08/2015] [Indexed: 12/13/2022] Open
Abstract
Cancer cells preferentially utilize glycolysis, instead of oxidative phosphorylation, for metabolism even in the presence of oxygen. This phenomenon of aerobic glycolysis, referred to as the “Warburg effect”, commonly exists in a variety of tumors. Recent studies further demonstrate that both genetic factors such as oncogenes and tumor suppressors and microenvironmental factors such as spatial hypoxia and acidosis can regulate the glycolytic metabolism of cancer cells. Reciprocally, altered cancer cell metabolism can modulate the tumor microenvironment which plays important roles in cancer cell somatic evolution, metastasis, and therapeutic response. In this article, we review the progression of current understandings on the molecular interaction between cancer cell metabolism and the tumor microenvironment. In addition, we discuss the implications of these interactions in cancer therapy and chemoprevention.
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20
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Lee D, Nevo O. 2-Methoxyestradiol regulates VEGFR-2 and sFlt-1 expression in human placenta. Placenta 2015; 36:125-30. [DOI: 10.1016/j.placenta.2014.11.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 11/11/2014] [Accepted: 11/19/2014] [Indexed: 01/23/2023]
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21
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Stergiopoulos A, Elkouris M, Politis PK. Prospero-related homeobox 1 (Prox1) at the crossroads of diverse pathways during adult neural fate specification. Front Cell Neurosci 2015; 8:454. [PMID: 25674048 PMCID: PMC4306308 DOI: 10.3389/fncel.2014.00454] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 12/16/2014] [Indexed: 12/11/2022] Open
Abstract
Over the last decades, adult neurogenesis in the central nervous system (CNS) has emerged as a fundamental process underlying physiology and disease. Recent evidence indicates that the homeobox transcription factor Prox1 is a critical intrinsic regulator of neurogenesis in the embryonic CNS and adult dentate gyrus (DG) of the hippocampus, acting in multiple ways and instructed by extrinsic cues and intrinsic factors. In the embryonic CNS, Prox1 is mechanistically involved in the regulation of proliferation vs. differentiation decisions of neural stem cells (NSCs), promoting cell cycle exit and neuronal differentiation, while inhibiting astrogliogenesis. During the complex differentiation events in adult hippocampal neurogenesis, Prox1 is required for maintenance of intermediate progenitors (IPs), differentiation and maturation of glutamatergic interneurons, as well as specification of DG cell identity over CA3 pyramidal fate. The mechanism by which Prox1 exerts multiple functions involves distinct signaling pathways currently not fully highlighted. In this mini-review, we thoroughly discuss the Prox1-dependent phenotypes and molecular pathways in adult neurogenesis in relation to different upstream signaling cues and cell fate determinants. In addition, we discuss the possibility that Prox1 may act as a cross-talk point between diverse signaling cascades to achieve specific outcomes during adult neurogenesis.
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Affiliation(s)
- Athanasios Stergiopoulos
- Center for Basic Research, Biomedical Research Foundation of the Academy of Athens Athens, Greece
| | - Maximilianos Elkouris
- Center for Basic Research, Biomedical Research Foundation of the Academy of Athens Athens, Greece
| | - Panagiotis K Politis
- Center for Basic Research, Biomedical Research Foundation of the Academy of Athens Athens, Greece
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22
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Ampadu J, Morley JE. Heart failure and cognitive dysfunction. Int J Cardiol 2015; 178:12-23. [DOI: 10.1016/j.ijcard.2014.10.087] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
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23
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Related expressional change of HIF-1α to the neuroprotective activity of exendin-4 in transient global ischemia. Neuroreport 2014; 25:65-70. [PMID: 24201448 DOI: 10.1097/wnr.0000000000000046] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Transient global ischemia induces selective hippocampal pyramidal neuronal death. Under conditions of severe ischemic hypoxia, hypoxia-inducible factor-1α (HIF-1α) induces apoptosis. Exendin-4 (Ex-4), the glucagon-like peptide-1 receptor (GLP-1R) agonist, provides neuroprotection against brain damage after cerebral ischemia. We investigated the relationship between Ex-4 and HIF-1α by examining Ex-4-induced changes in HIF-1α expression in the gerbil hippocampus following global brain ischemia (in vivo) and in neuroblastoma cells (SH-SY5Y) and cortical primary neurons (in vitro). Twice-daily administration of Ex-4 (1 μg/kg) for 3 days after ischemia (30 min before and 30 min after ischemia on the day of surgery and 2 more days) decreased the number of Fluoro-Jade B-stained cells in the CA1 pyramidal region of the hippocampus of the ischemic brain. Western blot analysis indicated a significant decrease in HIF-1α expression in the ischemic compared with the Sham brain following Ex-4 treatment. These in-vivo results were confirmed in vitro in SH-SY5Y cells and primary cortical neurons treated with 100 nM of Ex-4 under hypoxic conditions (0.1%>O2). We found that Ex-4 decreased the HIF-1α expression in the SH-SY5Y cell line and primary cortical neurons under hypoxic conditions, and this effect was reversed by cotreatment with exendin (9-39), a GLP-1R antagonist. These results suggest that HIF-1α may be involved in the neuroprotective effect of Ex-4 in the hypoxia-damaged brain.
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24
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Jin G, Liu B, You Z, Bambakidis T, Dekker SE, Maxwell J, Halaweish I, Linzel D, Alam HB. Development of a novel neuroprotective strategy: combined treatment with hypothermia and valproic acid improves survival in hypoxic hippocampal cells. Surgery 2014; 156:221-8. [PMID: 24950983 DOI: 10.1016/j.surg.2014.03.038] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 03/20/2014] [Indexed: 01/11/2023]
Abstract
BACKGROUND Therapeutic hypothermia and histone deacetylase inhibitors, such as valproic acid (VPA), independently have been shown to have neuroprotective properties in models of cerebral ischemic and traumatic brain injury. However, the depth of hypothermia and the dose of VPA needed to achieve the desired result are logistically challenging. It remains unknown whether these two promising strategies can be combined to yield synergistic results. We designed an experiment to answer this question by subjecting hippocampal-derived HT22 cells to severe hypoxia in vitro. METHODS Mouse hippocampal HT22 cells were exposed to 200 μM cobalt chloride (CoCl(2)), which created hypoxic conditions in vitro. Cells were incubated for 6 or 30 hours under the following conditions: (1) Dulbecco's Modified Eagle Medium; (2) 200 μM CoCl(2); (3) 200 μM CoCl(2) plus 1 mmol/L VPA; (4) 200 μM CoCl(2) plus 32°C hypothermia; and (5) 200 μM CoCl(2) plus both 1 mmol/L VPA and 32°C hypothermia. Cellular viability was evaluated by (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) and lactate dehydrogenase release assays at 30 hours after treatment. Levels of acetylated histone H3, hypoxia-inducible factor-1α, phospho-GSK-3β, β-catenin, and high-mobility group box-1 were measured by Western blotting. RESULTS High levels of acetylated histone H3 were detected in the VPA-treated cells. The release of lactate dehydrogenase was greatly suppressed after the combined hypothermia + VPA treatment (0.269 ± 0.003) versus VPA (0.836 ± 0.026) or hypothermia (0.451 ± 0.005) treatments alone (n = 3, P = .0001). (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay showed that the number of viable cells was increased by 17.6 % when VPA and hypothermia were used in combination (n = 5, P = .0001). Hypoxia-inducible factor-1α and phospho-GSK-3β expression were synergistically affected by the combination treatment, whereas high-mobility group box-1 was increased by VPA treatment, and inhibited by the hypothermia. CONCLUSION This is the first study to demonstrate that the neuroprotective effects of VPA and hypothermia are synergistic. This novel approach can be used to develop more effective therapies for the prevention of neuronal death.
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Affiliation(s)
- Guang Jin
- Department of Surgery, University of Michigan, Ann Arbor, MI
| | - Baoling Liu
- Department of Surgery, University of Michigan, Ann Arbor, MI
| | - Zerong You
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA
| | - Ted Bambakidis
- Department of Surgery, University of Michigan, Ann Arbor, MI
| | - Simone E Dekker
- Department of Surgery, University of Michigan, Ann Arbor, MI
| | - Jake Maxwell
- Department of Surgery, University of Michigan, Ann Arbor, MI
| | - Ihab Halaweish
- Department of Surgery, University of Michigan, Ann Arbor, MI
| | - Durk Linzel
- Department of Surgery, University of Michigan, Ann Arbor, MI
| | - Hasan B Alam
- Department of Surgery, University of Michigan, Ann Arbor, MI.
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Yang Z, Zhao TZ, Zou YJ, Zhang JH, Feng H. Hypoxia Induces autophagic cell death through hypoxia-inducible factor 1α in microglia. PLoS One 2014; 9:e96509. [PMID: 24818601 PMCID: PMC4018331 DOI: 10.1371/journal.pone.0096509] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Accepted: 04/09/2014] [Indexed: 01/09/2023] Open
Abstract
As phagocytic cells of central nervous system, excessive activation or cell death of microglia is involved in a lot of nervous system injury and degenerative disease, such as stroke, epilepsy, Parkinson's disease, Alzheimer's disease. Accumulating evidence indicates that hypoxia upregulates HIF-1α expression leading to cell death of microglia. However, the exact mechanism of cell death induced by hypoxia in microglia is not clear. In the current study, we showed that hypoxia induced cell death and autophagy in microglia. The suppression of autophagy using either pharmacologic inhibitors (3-methyladenine, bafilomycin A1) or RNA interference in essential autophagy genes (BECN1 and ATG5) decreased the cell death induced by hypoxia in microglia cells. Moreover, the suppression of HIF-1α using either pharmacologic inhibitors (3-MA, Baf A1) or RNA interference decreased the microglia death and autophagy in vitro. Taken together, these data indicate that hypoxia contributes to autophagic cell death of microglia through HIF-1α, and provide novel therapeutic interventions for cerebral hypoxic diseases associated with microglia activation.
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Affiliation(s)
- Zhao Yang
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Tian-zhi Zhao
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Yong-jie Zou
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - John H. Zhang
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Hua Feng
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
- * E-mail:
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Zhang Z, Yan J, Taheri S, Liu KJ, Shi H. Hypoxia-inducible factor 1 contributes to N-acetylcysteine's protection in stroke. Free Radic Biol Med 2014; 68:8-21. [PMID: 24296245 PMCID: PMC3943875 DOI: 10.1016/j.freeradbiomed.2013.11.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 11/08/2013] [Accepted: 11/10/2013] [Indexed: 01/01/2023]
Abstract
Stroke is a leading cause of adult morbidity and mortality with very limited treatment options. Evidence from preclinical models of ischemic stroke has demonstrated that the antioxidant N-acetylcysteine (NAC) effectively protects the brain from ischemic injury. Here, we evaluated a new pathway through which NAC exerted its neuroprotection in a transient cerebral ischemia animal model. Our results demonstrated that pretreatment with NAC increased protein levels of hypoxia-inducible factor-1α (HIF-1α), the regulatable subunit of HIF-1, and its target proteins erythropoietin (EPO) and glucose transporter (GLUT)-3, in the ipsilateral hemispheres of rodents subjected to 90min middle cerebral artery occlusion (MCAO) and 24h reperfusion. Interestingly, after NAC pretreatment and stroke, the contralateral hemisphere also demonstrated increased levels of HIF-1α, EPO, and GLUT-3, but to a lesser extent. Suppressing HIF-1 activity with two widely used pharmacological inhibitors, YC-1 and 2ME2, and specific knockout of neuronal HIF-1α abolished NAC's neuroprotective effects. The results also showed that YC-1 and 2ME2 massively enlarged infarcts, indicating that their toxic effect was larger than just abolishing NAC's neuroprotective effects. Furthermore, we determined the mechanism of NAC-mediated HIF-1α induction. We observed that NAC pretreatment upregulated heat-shock protein 90 (Hsp90) expression and increased the interaction of Hsp90 with HIF-1α in ischemic brains. The enhanced association of Hsp90 with HIF-1α increased HIF-1α stability. Moreover, Hsp90 inhibition attenuated NAC-induced HIF-1α protein accumulation and diminished NAC-induced neuroprotection in the MCAO model. These results strongly indicate that HIF-1 plays an important role in NAC-mediated neuroprotection and provide a new molecular mechanism involved in the antioxidant's neuroprotection in ischemic stroke.
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Affiliation(s)
- Ziyan Zhang
- Department of Pharmacology & Toxicology, University of Kansas, Lawrence, KS 66045, USA
| | - Jingqi Yan
- Department of Pharmacology & Toxicology, University of Kansas, Lawrence, KS 66045, USA
| | - Saeid Taheri
- Department of Radiology, Medical University of South Carolina, Charleston, SC 29401, USA
| | - Ke Jian Liu
- Department of Pharmaceutical Sciences, University of New Mexico, Albuquerque, NM 87131, USA
| | - Honglian Shi
- Department of Pharmacology & Toxicology, University of Kansas, Lawrence, KS 66045, USA.
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Engelhardt S, Patkar S, Ogunshola OO. Cell-specific blood-brain barrier regulation in health and disease: a focus on hypoxia. Br J Pharmacol 2014; 171:1210-30. [PMID: 24641185 PMCID: PMC3952799 DOI: 10.1111/bph.12489] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 10/02/2013] [Accepted: 10/16/2013] [Indexed: 01/16/2023] Open
Abstract
The blood-brain barrier (BBB) is a complex vascular structure consisting of microvascular endothelial cells that line the vessel wall, astrocyte end-feet, pericytes, as well as the basal lamina. BBB cells act in concert to maintain the characteristic impermeable and low paracellular flux of the brain vascular network, thus ensuring a homeostatic neuronal environment. Alterations in BBB stability that occur during injury have dire consequences on disease progression and it is clear that BBB cell-specific responses, positive or negative, must make a significant contribution to injury outcome. Reduced oxygenation, or hypoxia, is a characteristic of many brain diseases that significantly increases barrier permeability. Recent data suggest that hypoxia-inducible factor (HIF-1), the master regulator of the hypoxic response, probably mediates many hypoxic effects either directly or indirectly via its target genes. This review discusses current knowledge of physiological cell-specific regulation of barrier function, their responses to hypoxia as well as consequences of hypoxic- and HIF-1-mediated mechanisms on barrier integrity during select brain diseases. In the final sections, the potential of current advances in targeting HIF-1 as a therapeutic strategy will be overviewed.
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Affiliation(s)
- S Engelhardt
- Institute of Veterinary Physiology, University of ZurichZurich, Switzerland
| | - S Patkar
- Institute of Veterinary Physiology, University of ZurichZurich, Switzerland
| | - O O Ogunshola
- Institute of Veterinary Physiology, University of ZurichZurich, Switzerland
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28
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Cheng YL, Park JS, Manzanero S, Choi Y, Baik SH, Okun E, Gelderblom M, Fann DYW, Magnus T, Launikonis BS, Mattson MP, Sobey CG, Jo DG, Arumugam TV. Evidence that collaboration between HIF-1α and Notch-1 promotes neuronal cell death in ischemic stroke. Neurobiol Dis 2013; 62:286-95. [PMID: 24141018 DOI: 10.1016/j.nbd.2013.10.009] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 09/11/2013] [Accepted: 10/07/2013] [Indexed: 12/17/2022] Open
Abstract
Recent findings suggest that Notch-1 signaling contributes to neuronal death in ischemic stroke, but the underlying mechanisms are unknown. Hypoxia inducible factor-1α (HIF-1α), a global regulator of cellular responses to hypoxia, can interact with Notch and modulate its signaling during hypoxic stress. Here we show that Notch signaling interacts with the HIF-1α pathway in the process of ischemic neuronal death. We found that a chemical inhibitor of the Notch-activating enzyme, γ-secretase, and a HIF-1α inhibitor, protect cultured cortical neurons against ischemic stress, and combined inhibition of Notch-1 and HIF-1α further decreased neuronal death. HIF-1α and Notch intracellular domain (NICD) are co-expressed in the neuronal nucleus, and co-immunoprecipitated in cultured neurons and in brain tissue from mice subjected to focal ischemic stroke. Overexpression of NICD and HIF-1α in cultured human neural cells enhanced cell death under ischemia-like conditions, and a HIF-1α inhibitor rescued the cells. RNA interference-mediated depletion of endogenous NICD and HIF-1α also decreased cell death under ischemia-like conditions. Finally, mice treated with inhibitors of γ-secretase and HIF-1α exhibited improved outcome after focal ischemic stroke, with combined treatment being superior to individual treatments. Additional findings suggest that the NICD and HIF-1α collaborate to engage pro-inflammatory and apoptotic signaling pathways in stroke.
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Affiliation(s)
- Yi-Lin Cheng
- Department of Physiology, Yong Loo Lin School Medicine, National University of Singapore, 117597, Singapore; School of Biomedical Sciences, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Jong-Sung Park
- School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Silvia Manzanero
- School of Biomedical Sciences, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Yuri Choi
- School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Sang-Ha Baik
- School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea
| | - Eitan Okun
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University, Ramat Gan, Israel
| | - Mathias Gelderblom
- Department of Neurology, University Clinic Hamburg-Eppendorf, Martinistr, 52, D-20246 Hamburg, Germany
| | - David Yang-Wei Fann
- School of Biomedical Sciences, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Tim Magnus
- Department of Neurology, University Clinic Hamburg-Eppendorf, Martinistr, 52, D-20246 Hamburg, Germany
| | - Bradley S Launikonis
- School of Biomedical Sciences, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Christopher G Sobey
- Department of Pharmacology, Monash University, Clayton, Victoria 3800, Australia
| | - Dong-Gyu Jo
- School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
| | - Thiruma V Arumugam
- Department of Physiology, Yong Loo Lin School Medicine, National University of Singapore, 117597, Singapore; School of Biomedical Sciences, The University of Queensland, St Lucia, QLD 4072, Australia; School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
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29
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Reinke SN, Walsh BH, Boylan GB, Sykes BD, Kenny LC, Murray DM, Broadhurst DI. 1H NMR derived metabolomic profile of neonatal asphyxia in umbilical cord serum: implications for hypoxic ischemic encephalopathy. J Proteome Res 2013; 12:4230-9. [PMID: 23931672 DOI: 10.1021/pr400617m] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Neonatal hypoxic ischemic encephalopathy (HIE) is a severe consequence of perinatal asphyxia (PA) that can result in life-long neurological disability. Disease mechanisms, including the role and interaction of individual metabolic pathways, remain unclear. As hypoxia is an acute condition, aerobic energy metabolism is central to global metabolic pathways, and these metabolites are detectable using 1H NMR spectroscopy, we hypothesized that characterizing the NMR-derived umbilical cord serum metabolome would offer insight into the consequences of PA that lead to HIE. Fifty-nine at-risk infants were enrolled, together with 1:1 matched healthy controls, and stratified by disease severity (n=25, HIE; n=34, non-HIE PA). Eighteen of 37 reproducibly detectable metabolites were significantly altered between study groups. Acetone, 3-hydroxybutyrate, succinate, and glycerol were significantly differentially altered in severe HIE. Multivariate data analysis revealed a metabolite profile associated with both asphyxia and HIE. Multiple-linear regression modeling using 4 metabolites (3-hydroxybutyrate, glycerol, O-phosphocholine, and succinate) predicted HIE severity with an adjusted R2 of 0.4. Altered ketones suggest that systemic metabolism may play a critical role in preventing neurological injury, while altered succinate provides a possible explanation for hypoxia-inducible factor 1-α (HIF-1α) stabilization in HI injury.
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Affiliation(s)
- Stacey N Reinke
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
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30
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Simard JM, Woo SK, Schwartzbauer GT, Gerzanich V. Sulfonylurea receptor 1 in central nervous system injury: a focused review. J Cereb Blood Flow Metab 2012; 32:1699-717. [PMID: 22714048 PMCID: PMC3434627 DOI: 10.1038/jcbfm.2012.91] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 05/03/2012] [Accepted: 05/09/2012] [Indexed: 01/13/2023]
Abstract
The sulfonylurea receptor 1 (Sur1)-regulated NC(Ca-ATP) channel is a nonselective cation channel that is regulated by intracellular calcium and adenosine triphosphate. The channel is not constitutively expressed, but is transcriptionally upregulated de novo in all cells of the neurovascular unit, in many forms of central nervous system (CNS) injury, including cerebral ischemia, traumatic brain injury (TBI), spinal cord injury (SCI), and subarachnoid hemorrhage (SAH). The channel is linked to microvascular dysfunction that manifests as edema formation and delayed secondary hemorrhage. Also implicated in oncotic cell swelling and oncotic (necrotic) cell death, the channel is a major molecular mechanism of 'accidental necrotic cell death' in the CNS. In animal models of SCI, pharmacological inhibition of Sur1 by glibenclamide, as well as gene suppression of Abcc8, prevents delayed capillary fragmentation and tissue necrosis. In models of stroke and TBI, glibenclamide ameliorates edema, secondary hemorrhage, and tissue damage. In a model of SAH, glibenclamide attenuates the inflammatory response due to extravasated blood. Clinical trials of an intravenous formulation of glibenclamide in TBI and stroke underscore the importance of recent advances in understanding the role of the Sur1-regulated NC(Ca-ATP) channel in acute ischemic, traumatic, and inflammatory injury to the CNS.
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Affiliation(s)
- J Marc Simard
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland 21201-1595, USA.
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Zhang Q, Qian Z, Pan L, Li H, Zhu H. Hypoxia-inducible factor 1 mediates the anti-apoptosis of berberine in neurons during hypoxia/ischemia. ACTA ACUST UNITED AC 2012; 99:311-23. [DOI: 10.1556/aphysiol.99.2012.3.8] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Shi GX, Andres DA, Cai W. Ras family small GTPase-mediated neuroprotective signaling in stroke. Cent Nerv Syst Agents Med Chem 2012; 11:114-37. [PMID: 21521171 DOI: 10.2174/187152411796011349] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 01/18/2011] [Accepted: 03/22/2011] [Indexed: 12/31/2022]
Abstract
Selective neuronal cell death is one of the major causes of neuronal damage following stroke, and cerebral cells naturally mobilize diverse survival signaling pathways to protect against ischemia. Importantly, therapeutic strategies designed to improve endogenous anti-apoptotic signaling appear to hold great promise in stroke treatment. While a variety of complex mechanisms have been implicated in the pathogenesis of stroke, the overall mechanisms governing the balance between cell survival and death are not well-defined. Ras family small GTPases are activated following ischemic insults, and in turn, serve as intrinsic switches to regulate neuronal survival and regeneration. Their ability to integrate diverse intracellular signal transduction pathways makes them critical regulators and potential therapeutic targets for neuronal recovery after stroke. This article highlights the contribution of Ras family GTPases to neuroprotective signaling cascades, including mitogen-activated protein kinase (MAPK) family protein kinase- and AKT/PKB-dependent signaling pathways as well as the regulation of cAMP response element binding (CREB), Forkhead box O (FoxO) and hypoxiainducible factor 1(HIF1) transcription factors, in stroke.
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Affiliation(s)
- Geng-Xian Shi
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, 741 S. Limestone St., Lexington, KY 40536-0509, USA.
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Sequential activation of hypoxia-inducible factor 1 and specificity protein 1 is required for hypoxia-induced transcriptional stimulation of Abcc8. J Cereb Blood Flow Metab 2012; 32:525-36. [PMID: 22086197 PMCID: PMC3293117 DOI: 10.1038/jcbfm.2011.159] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cerebral ischemia causes increased transcription of sulfonylurea receptor 1 (SUR1), which forms SUR1-regulated NC(Ca-ATP) channels linked to cerebral edema. We tested the hypothesis that hypoxia is an initial signal that stimulates transcription of Abcc8, the gene encoding SUR1, via activation of hypoxia-inducible factor 1 (HIF1). In the brain microvascular endothelial cells, hypoxia increased SUR1 abundance and expression of functional SUR1-regulated NC(Ca-ATP) channels. Luciferase reporter activity driven by the Abcc8 promoter was increased by hypoxia and by coexpression of HIF1α. Surprisingly, a series of luciferase reporter assays studying the Abcc8 promoter revealed that binding sites for specificity protein 1 (Sp1), but not for HIF, were required for stimulation of Abcc8 transcription by HIF1α. Luciferase reporter assays studying Sp1 promoters of three species, and chromatin immunoprecipitation analysis in rats after cerebral ischemia, indicated that HIF binds to HIF-binding sites on the Sp1 promoter to stimulate transcription of the Sp1 gene. We conclude that sequential activation of two transcription factors, HIF and Sp1, is required to stimulate transcription of Abcc8 following cerebral ischemia. Sequential gene activation in cerebral ischemia provides a plausible molecular explanation for the prolonged treatment window observed for inhibition of the end-target gene product, SUR1, by glibenclamide.
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Won SJ, Tang XN, Suh SW, Yenari MA, Swanson RA. Hyperglycemia promotes tissue plasminogen activator-induced hemorrhage by Increasing superoxide production. Ann Neurol 2011; 70:583-90. [PMID: 22002675 DOI: 10.1002/ana.22538] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Revised: 06/13/2011] [Accepted: 06/24/2011] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Risk of intracerebral hemorrhage is the primary factor limiting use of tissue plasminogen activator (tPA) for stroke. Clinical studies have established an association between admission hyperglycemia and the risk of hemorrhage with tPA use, independent of prior diabetes. Here we used an animal model of tPA-induced reperfusion hemorrhage to determine if this clinical association reflects a true causal relationship. METHODS Rats underwent 90 minutes of focal ischemia, and tPA infusion was begun 10 minutes prior to vessel reperfusion. Glucose was administered during ischemia to generate blood levels ranging from 5.9 ± 1.8mM (normoglycemia) to 21 ± 2.3mM. In some studies, apocynin was administered to block superoxide production by nicotinamide adenine dinucleotide phosphate (NADPH). Brains were harvested 1 hour or 3 days after reperfusion to evaluate the effects of hyperglycemia and apocynin on oxidative stress, blood-brain barrier breakdown, infarct volume, and hemorrhage volume. RESULTS Rats that were hyperglycemic during tPA infusion had diffusely increased blood-brain barrier permeability in the postischemic territory, and a 3- to 5-fold increase in intracerebral hemorrhage volumes. The hyperglycemic rats also showed increased superoxide formation in the brain parenchyma and vasculature during reperfusion. The effects of hyperglycemia on superoxide production, blood-brain barrier disruption, infarct size, and hemorrhage were all attenuated by apocynin. INTERPRETATION These findings demonstrate a causal relationship between hyperglycemia and hemorrhage in an animal model of tPA stroke treatment, and suggest that this effect of hyperglycemia is mediated through an increase in superoxide production by NADPH oxidase.
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Affiliation(s)
- Seok Joon Won
- Neurology and Rehabilitation Service, San Francisco Veterans Affairs Medical Center and Department of Neurology, University of California at San Francisco, CA, USA
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