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Mollereau B, Manié S, Napoletano F. Getting the better of ER stress. J Cell Commun Signal 2014; 8:311-21. [PMID: 25354560 DOI: 10.1007/s12079-014-0251-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 10/15/2014] [Indexed: 12/11/2022] Open
Abstract
Research over the past few years has highlighted the ability of the unfolded protein response (UPR) to minimize the deleterious effects of accumulated misfolded proteins under both physiological and pathological conditions. The endoplasmic reticulum (ER) adapts to endogenous and exogenous stressors by expanding its protein-folding capacity and by stimulating protective processes such as autophagy and antioxidant responses. Although it is clear that severe ER stress can elicit cell death, several recent studies have shown that low levels of ER stress may actually be beneficial to cells by eliciting an adaptive UPR that 'preconditions' the cell to a subsequent lethal insult; this process is called ER hormesis. The findings have important implications for the treatment of a wide variety of diseases associated with defective proteostasis, including neurodegenerative diseases, diabetes, and cancer. Here, we review the physiological and pathological functions of the ER, with a particular focus on the molecular mechanisms that lead to ER hormesis and cellular protection, and discuss the implications for disease treatment.
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Affiliation(s)
- Bertrand Mollereau
- Laboratory of Molecular Biology of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France,
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DeGracia DJ, Tri Anggraini F, Taha DTM, Huang ZF. Inductive and Deductive Approaches to Acute Cell Injury. INTERNATIONAL SCHOLARLY RESEARCH NOTICES 2014; 2014:859341. [PMID: 27437490 PMCID: PMC4897055 DOI: 10.1155/2014/859341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 06/25/2014] [Indexed: 11/28/2022]
Abstract
Many clinically relevant forms of acute injury, such as stroke, traumatic brain injury, and myocardial infarction, have resisted treatments to prevent cell death following injury. The clinical failures can be linked to the currently used inductive models based on biological specifics of the injury system. Here we contrast the application of inductive and deductive models of acute cell injury. Using brain ischemia as a case study, we discuss limitations in inductive inferences, including the inability to unambiguously assign cell death causality and the lack of a systematic quantitative framework. These limitations follow from an overemphasis on qualitative molecular pathways specific to the injured system. Our recently developed nonlinear dynamical theory of cell injury provides a generic, systematic approach to cell injury in which attractor states and system parameters are used to quantitatively characterize acute injury systems. The theoretical, empirical, and therapeutic implications of shifting to a deductive framework are discussed. We illustrate how a deductive mathematical framework offers tangible advantages over qualitative inductive models for the development of therapeutics of acutely injured biological systems.
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Affiliation(s)
- Donald J. DeGracia
- Department of Physiology, Wayne State University, 4116 Scott Hall, 540 East Canfield Avenue, Detroit, MI 48201, USA
| | - Fika Tri Anggraini
- Department of Physiology, Wayne State University, 4116 Scott Hall, 540 East Canfield Avenue, Detroit, MI 48201, USA
| | | | - Zhi-Feng Huang
- Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201, USA
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53
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Agrawal T, Gupta GK, Rai V, Carroll JD, Hamblin MR. Pre-conditioning with low-level laser (light) therapy: light before the storm. Dose Response 2014; 12:619-49. [PMID: 25552961 DOI: 10.2203/dose-response.14-032.agrawal] [Citation(s) in RCA: 285] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Pre-conditioning by ischemia, hyperthermia, hypothermia, hyperbaric oxygen (and numerous other modalities) is a rapidly growing area of investigation that is used in pathological conditions where tissue damage may be expected. The damage caused by surgery, heart attack, or stroke can be mitigated by pre-treating the local or distant tissue with low levels of a stress-inducing stimulus, that can induce a protective response against subsequent major damage. Low-level laser (light) therapy (LLLT) has been used for nearly 50 years to enhance tissue healing and to relieve pain, inflammation and swelling. The photons are absorbed in cytochrome(c) oxidase (unit four in the mitochondrial respiratory chain), and this enzyme activation increases electron transport, respiration, oxygen consumption and ATP production. A complex signaling cascade is initiated leading to activation of transcription factors and up- and down-regulation of numerous genes. Recently it has become apparent that LLLT can also be effective if delivered to normal cells or tissue before the actual insult or trauma, in a pre-conditioning mode. Muscles are protected, nerves feel less pain, and LLLT can protect against a subsequent heart attack. These examples point the way to wider use of LLLT as a pre-conditioning modality to prevent pain and increase healing after surgical/medical procedures and possibly to increase athletic performance.
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Affiliation(s)
- Tanupriya Agrawal
- The Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114; ; Department of Dermatology, Harvard Medical School, Boston, MA 02115
| | - Gaurav K Gupta
- The Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114; ; Department of Dermatology, Harvard Medical School, Boston, MA 02115; ; Department of Pathology and Laboratory Medicine, Tufts Medical Center, Boston, MA, 02111
| | - Vikrant Rai
- Wilf Family Cardiovascular Research Institute, Division of Cardiology, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461
| | - James D Carroll
- THOR Photomedicine Ltd, 18A East Street, Chesham, HP5 1HQ, UK
| | - Michael R Hamblin
- The Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114; ; Department of Dermatology, Harvard Medical School, Boston, MA 02115; ; Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA 02139
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Abstract
Stem cell transplantation therapy has emerged as a promising regenerative medicine for ischemic stroke and other neurodegenerative disorders. However, many issues and problems remain to be resolved before successful clinical applications of the cell-based therapy. To this end, some recent investigations have sought to benefit from well-known mechanisms of ischemic/hypoxic preconditioning. Ischemic/hypoxic preconditioning activates endogenous defense mechanisms that show marked protective effects against multiple insults found in ischemic stroke and other acute attacks. As in many other cell types, a sub-lethal hypoxic exposure significantly increases the tolerance and regenerative properties of stem cells and progenitor cells. So far, a variety of preconditioning triggers have been tested on different stem cells and progenitor cells. Preconditioned stem cells and progenitors generally show much better cell survival, increased neuronal differentiation, enhanced paracrine effects leading to increased trophic support, and improved homing to the lesion site. Transplantation of preconditioned cells helps to suppress inflammatory factors and immune responses, and promote functional recovery. Although the preconditioning strategy in stem cell therapy is still an emerging research area, accumulating information from reports over the last few years already indicates it as an attractive, if not essential, prerequisite for transplanted cells. It is expected that stem cell preconditioning and its clinical applications will attract more attention in both the basic research field of preconditioning as well as in the field of stem cell translational research. This review summarizes the most important findings in this active research area, covering the preconditioning triggers, potential mechanisms, mediators, and functional benefits for stem cell transplant therapy.
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Affiliation(s)
- Shan Ping Yu
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA 30322, USA
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55
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Gao C, Wang C, Liu B, Wu H, Yang Q, Jin J, Li H, Dong S, Gao G, Zhang H. Intermittent hypoxia preconditioning-induced epileptic tolerance by upregulation of monocarboxylate transporter 4 expression in rat hippocampal astrocytes. Neurochem Res 2014; 39:2160-9. [PMID: 25146899 DOI: 10.1007/s11064-014-1411-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Revised: 07/21/2014] [Accepted: 08/06/2014] [Indexed: 01/30/2023]
Abstract
Noxious stimuli applied at doses close to but below the threshold of cell injury induce adaptive responses that provide a defense against additional stress. Epileptic preconditioning protects neurons against status epilepticus and ischemia; however, it is not known if the converse is true. During hypoxia/ischemia (H/I), lactate released from astrocytes is taken up by neurons and is stored for energy, a process mediated by monocarboxylate transporter 4 (MCT4) in astroglia. The present study investigated whether H/I preconditioning can provide protection to neurons against epilepsy through upregulation of MCT4 expression in astrocytes in vitro and in vivo. An oxygen/glucose deprivation protocol was used in primary astrocyte cultures, while rats were subjected to an intermittent hypoxia preconditioning (IHP) paradigm followed by lithium-pilocarpine-induced epilepsy as well as lactate transportation inhibitor injection, with a subsequent evaluation of protein expression as well as behavior. H/I induced an upregulation of MCT4 expression, while an IHP time course of 5 days provided the greatest protection against epileptic seizures, which was most apparent by 3 days after IHP. However, lactate transport function disturbances can block the protective effect induced by IHP. These findings provide a potential basis for the clinical treatment of epilepsy.
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Affiliation(s)
- Chen Gao
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, Shanxi Province, China
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56
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Hu H, Zhou Y, Leng T, Liu A, Wang Y, You X, Chen J, Tang L, Chen W, Qiu P, Yin W, Huang Y, Zhang J, Wang L, Sang H, Yan G. The major cholesterol metabolite cholestane-3β,5α,6β-triol functions as an endogenous neuroprotectant. J Neurosci 2014; 34:11426-38. [PMID: 25143622 PMCID: PMC6615515 DOI: 10.1523/jneurosci.0344-14.2014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 06/10/2014] [Accepted: 06/25/2014] [Indexed: 12/11/2022] Open
Abstract
Overstimulation of NMDA-type glutamate receptors is believed to be responsible for neuronal death of the CNS in various disorders, including cerebral and spinal cord ischemia. However, the intrinsic and physiological mechanisms of modulation of these receptors are essentially unknown. Here we report that cholestane-3β,5α,6β-triol (triol), a major metabolite of cholesterol, is an endogenous neuroprotectant and protects against neuronal injury both in vitro and in vivo via negative modulation of NMDA receptors. Treatment of cultured neurons with triol protects against glutamate-induced neurotoxicity, and administration of triol significantly decreases neuronal injury after spinal cord ischemia in rabbits and transient focal cerebral ischemia in rats. An inducible elevation of triol is associated with ischemic preconditioning and subsequent neuroprotection in the spinal cord of rabbits. This neuroprotection is effectively abolished by preadministration of a specific inhibitor of triol synthesis. Physiological concentrations of triol attenuate [Ca(2+)]i induced by glutamate and decrease inward NMDA-mediated currents in cultured cortical neurons and HEK-293 cells transiently transfected with NR1/NR2B NMDA receptors. Saturable binding of [(3)H]triol to cerebellar granule neurons and displacement of [(3)H]MK-801 binding to NMDA receptors by triol suggest that direct blockade of NMDA receptors may underlie the neuroprotective properties. Our findings suggest that the naturally occurring oxysterol, the major cholesterol metabolite triol, functions as an endogenous neuroprotectant in vivo, which may provide novel insights into understanding and developing potential therapeutics for disorders in the CNS.
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Affiliation(s)
- Haiyan Hu
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510080, China
| | | | | | | | | | - Xiuhua You
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510080, China
| | | | | | | | | | - Wei Yin
- Biochemistry, Zhongshan School of Medicine and
| | | | | | - Liwei Wang
- Department of Physiology, School of Medicine, Ji-nan University, Guangzhou, Guangdong 510632, China, and
| | - Hanfei Sang
- Departments of Pharmacology and Department of Anesthesiology, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi 710032, China
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Abstract
Decreased oxygen availability impairs cellular energy production and, without a coordinated and matched decrease in energy consumption, cellular and whole organism death rapidly ensues. Of particular interest are mechanisms that protect brain from low oxygen injury, as this organ is not only the most sensitive to hypoxia, but must also remain active and functional during low oxygen stress. As a result of natural selective pressures, some species have evolved molecular and physiological mechanisms to tolerate prolonged hypoxia with no apparent detriment. Among these mechanisms are a handful of responses that are essential for hypoxia tolerance, including (i) sensors that detect changes in oxygen availability and initiate protective responses; (ii) mechanisms of energy conservation; (iii) maintenance of basic brain function; and (iv) avoidance of catastrophic cell death cascades. As the study of hypoxia-tolerant brain progresses, it is becoming increasingly apparent that mitochondria play a central role in regulating all of these critical mechanisms. Furthermore, modulation of mitochondrial function to mimic endogenous neuroprotective mechanisms found in hypoxia-tolerant species confers protection against otherwise lethal hypoxic stresses in hypoxia-intolerant organs and organisms. Therefore, lessons gleaned from the investigation of endogenous mechanisms of hypoxia tolerance in hypoxia-tolerant organisms may provide insight into clinical pathologies related to low oxygen stress.
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Affiliation(s)
- Matthew E. Pamenter
- Department of Zoology, The University of British Columbia, #4200-6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada
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58
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Morris-Blanco KC, Cohan CH, Neumann JT, Sick TJ, Perez-Pinzon MA. Protein kinase C epsilon regulates mitochondrial pools of Nampt and NAD following resveratrol and ischemic preconditioning in the rat cortex. J Cereb Blood Flow Metab 2014; 34:1024-32. [PMID: 24667915 PMCID: PMC4050248 DOI: 10.1038/jcbfm.2014.51] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 01/28/2014] [Accepted: 02/25/2014] [Indexed: 12/14/2022]
Abstract
Preserving mitochondrial pools of nicotinamide adenine dinucleotide (NAD) or nicotinamide phosphoribosyltransferase (Nampt), an enzyme involved in NAD production, maintains mitochondrial function and confers neuroprotection after ischemic stress. However, the mechanisms involved in regulating mitochondrial-localized Nampt or NAD have not been defined. In this study, we investigated the roles of protein kinase C epsilon (PKCɛ) and AMP-activated protein kinase (AMPK) in regulating mitochondrial pools of Nampt and NAD after resveratrol or ischemic preconditioning (IPC) in the cortex and in primary neuronal-glial cortical cultures. Using the specific PKCɛ agonist ψɛRACK, we found that PKCɛ induced robust activation of AMPK in vitro and in vivo and that AMPK was required for PKCɛ-mediated ischemic neuroprotection. In purified mitochondrial fractions, PKCɛ enhanced Nampt levels in an AMPK-dependent manner and was required for increased mitochondrial Nampt after IPC or resveratrol treatment. Analysis of intrinsic NAD autofluorescence using two-photon microscopy revealed that PKCɛ modulated NAD in the mitochondrial fraction. Further assessments of mitochondrial NAD concentrations showed that PKCɛ has a key role in regulating the mitochondrial NAD(+)/nicotinamide adenine dinucleotide reduced (NADH) ratio after IPC and resveratrol treatment in an AMPK- and Nampt-dependent manner. These findings indicate that PKCɛ is critical to increase or maintain mitochondrial Nampt and NAD after pathways of ischemic neuroprotection in the brain.
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Affiliation(s)
- Kahlilia C Morris-Blanco
- 1] Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, Florida, USA [2] Neuroscience Program, University of Miami Miller School of Medicine, Miami, Florida, USA [3] Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Charles H Cohan
- 1] Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, Florida, USA [2] Neuroscience Program, University of Miami Miller School of Medicine, Miami, Florida, USA [3] Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Jake T Neumann
- 1] Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, Florida, USA [2] Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Thomas J Sick
- 1] Neuroscience Program, University of Miami Miller School of Medicine, Miami, Florida, USA [2] Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Miguel A Perez-Pinzon
- 1] Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, Florida, USA [2] Neuroscience Program, University of Miami Miller School of Medicine, Miami, Florida, USA [3] Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA
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59
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Hagberg H, Mallard C, Rousset CI, Thornton C. Mitochondria: hub of injury responses in the developing brain. Lancet Neurol 2014; 13:217-32. [PMID: 24457191 DOI: 10.1016/s1474-4422(13)70261-8] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Progress in the field of mitochondrial biology in the past few years has shown that mitochondrial activities go beyond bioenergetics. These new aspects of mitochondrial physiology and pathophysiology have important implications for the immature brain. A picture emerges in which mitochondrial biogenesis, mitophagy, migration, and morphogenesis are crucial for brain development and synaptic pruning, and play a part in recovery after acute insults. Mitochondria also affect brain susceptibility to injury, and mitochondria-directed interventions can make the immature brain highly resistant to acute injury. Finally, the mitochondrion is a platform for innate immunity, contributes to inflammation in response to infection and acute damage, and participates in antiviral and antibacterial defence. Understanding of these new aspects of mitochondrial function will provide insights into brain development and neurological disease, and enable discovery and development of new strategies for treatment.
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Affiliation(s)
- Henrik Hagberg
- Centre for the Developing Brain, Perinatal Imaging & Health, King's College London, St Thomas' Hospital, London, UK; Perinatal Center, Departments of Clinical Sciences and Physiology & Neurosciences, Sahlgrenska Academy, Sahlgrenska University Hospital, Gothenburg, Sweden.
| | - Carina Mallard
- Perinatal Center, Departments of Clinical Sciences and Physiology & Neurosciences, Sahlgrenska Academy, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Catherine I Rousset
- Centre for the Developing Brain, Perinatal Imaging & Health, King's College London, St Thomas' Hospital, London, UK
| | - Claire Thornton
- Centre for the Developing Brain, Perinatal Imaging & Health, King's College London, St Thomas' Hospital, London, UK
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60
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Zhao L, Yang YF, Gao YB, Wang SM, Wang LF, Zuo HY, Dong J, Xu XP, Su ZT, Zhou HM, Zhu LL, Peng RY. Upregulation of HIF-1α via activation of ERK and PI3K pathway mediated protective response to microwave-induced mitochondrial injury in neuron-like cells. Mol Neurobiol 2014; 50:1024-34. [PMID: 24627260 DOI: 10.1007/s12035-014-8667-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Accepted: 02/20/2014] [Indexed: 01/01/2023]
Abstract
Microwave-induced learning and memory deficits in animal models have been gaining attention in recent years, largely because of increasing public concerns on growing environmental influences. The data from our group and others have showed that the injury of mitochondria, the major source of cellular adenosine triphosphate (ATP) in primary neurons, could be detected in the neuron cells of microwave-exposed rats. In this study, we provided some insights into the cellular and molecular mechanisms behind mitochondrial injury in PC12 cell-derived neuron-like cells. PC12 cell-derived neuron-like cells were exposed to 30 mW/cm(2) microwave for 5 min, and damages of mitochondrial ultrastructure could be observed by using transmission electron microscopy. Impairments of mitochondrial function, indicated by decrease of ATP content, reduction of succinate dehydrogenase (SDH) and cytochrome c oxidase (COX) activities, decrease of mitochondrial membrane potential (MMP), and increase of reactive oxygen species (ROS) production, could be detected. We also found that hypoxia-inducible factor-1 (HIF-1α), a key regulator responsible for hypoxic response of the mammalian cells, was upregulated in microwave-exposed neuron-like cells. Furthermore, HIF-1α overexpression protected mitochondria from injury by increasing the ATP contents and MMP, while HIF-1α silence promoted microwave-induced mitochondrial damage. Finally, we demonstrated that both ERK and PI3K signaling activation are required in microwave-induced HIF-1α activation and protective response. In conclusion, we elucidated a regulatory connection between impairments of mitochondrial function and HIF-1α activation in microwave-exposed neuron-like cells. By modulating mitochondrial function and protecting neuron-like cells against microwave-induced mitochondrial injury, HIF-1α represents a promising therapeutic target for microwave radiation injury.
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Affiliation(s)
- Li Zhao
- Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Haidian District, 27 Taiping Road, Beijing, 100850, People's Republic of China
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Garcia-Bonilla L, Benakis C, Moore J, Iadecola C, Anrather J. Immune mechanisms in cerebral ischemic tolerance. Front Neurosci 2014; 8:44. [PMID: 24624056 PMCID: PMC3940969 DOI: 10.3389/fnins.2014.00044] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 02/17/2014] [Indexed: 12/21/2022] Open
Abstract
Stressor-induced tolerance is a central mechanism in the response of bacteria, plants, and animals to potentially harmful environmental challenges. This response is characterized by immediate changes in cellular metabolism and by the delayed transcriptional activation or inhibition of genetic programs that are not generally stressor specific (cross-tolerance). These programs are aimed at countering the deleterious effects of the stressor. While induction of this response (preconditioning) can be established at the cellular level, activation of systemic networks is essential for the protection to occur throughout the organs of the body. This is best signified by the phenomenon of remote ischemic preconditioning, whereby application of ischemic stress to one tissue or organ induces ischemic tolerance (IT) in remote organs through humoral, cellular and neural signaling. The immune system is an essential component in cerebral IT acting simultaneously both as mediator and target. This dichotomy is based on the fact that activation of inflammatory pathways is necessary to establish IT and that IT can be, in part, attributed to a subdued immune activation after index ischemia. Here we describe the components of the immune system required for induction of IT and review the mechanisms by which a reprogrammed immune response contributes to the neuroprotection observed after preconditioning. Learning how local and systemic immune factors participate in endogenous neuroprotection could lead to the development of new stroke therapies.
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Affiliation(s)
- Lidia Garcia-Bonilla
- Brain and Mind Research Institute, Weill Cornell Medical College New York, NY, USA
| | - Corinne Benakis
- Brain and Mind Research Institute, Weill Cornell Medical College New York, NY, USA
| | - Jamie Moore
- Brain and Mind Research Institute, Weill Cornell Medical College New York, NY, USA
| | - Costantino Iadecola
- Brain and Mind Research Institute, Weill Cornell Medical College New York, NY, USA
| | - Josef Anrather
- Brain and Mind Research Institute, Weill Cornell Medical College New York, NY, USA
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62
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Ma ZF, Chen W, Cao CC, Chen X. Ischemic preconditioning attenuates brain injury induced by ischemia/reperfusion during moderate hypothermia low-flow procedures. Int J Neurosci 2014; 124:824-33. [DOI: 10.3109/00207454.2014.884088] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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63
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Zhang L, Wang S, Dong H, Li Y, Wang P, Li S, Guo Y, Yao R. Spermine attenuates the preconditioning of diazoxide against transient focal cerebral ischemia in rats. Neurol Res 2013; 36:666-72. [PMID: 24620960 DOI: 10.1179/1743132813y.0000000299] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
It is known that mitochondrial ATP-sensitive potassium channels (mitoKATP) play a significant role in protecting cerebral function from ischemia-reperfusion injury, which is related with a decrease in the mitochondrial matrix calcium. However, the effect of mitochondrial calcium uniporter (MCU) on diazoxide-induced cerebral protection is still indistinct. The purpose of the present paper is to further observe the relationship between mitoKATP and MCU, and to probe the mechanism. Adult male Wistar rats were randomly divided into five groups: the Sham group, the I-R group, the Dzx+I-R group, the Dzx+Sper+I-R group, and the Sper+I-R group. Rats not in the Sham group were exposed to 2-hour ischemia followed by 24-hour reperfusion. Diazoxide and spermine were administrated 30 minutes before ischemia or 10 minutes before reperfusion, respectively. After 24-hour reperfusion, animals were given neurological performance tests, overdosed with general anesthesia, and then their brains were excised for infarct volume, pathological changes, and apoptosis analysis. The beneficial effects of diazoxide (improved neurological deficits, decreased infarct volume, and apoptosis, evidenced by the decreased expression of cytochrome c and Bax) were significantly neutralized by spermine. The results of the present work suggest that diazoxide-induced cerebral protection against ischemia-reperfusion injury is mediated by spermine through apoptotic pathway.
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64
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Makrecka M, Svalbe B, Volska K, Sevostjanovs E, Liepins J, Grinberga S, Pugovics O, Liepinsh E, Dambrova M. Mildronate, the inhibitor of L-carnitine transport, induces brain mitochondrial uncoupling and protects against anoxia-reoxygenation. Eur J Pharmacol 2013; 723:55-61. [PMID: 24333219 DOI: 10.1016/j.ejphar.2013.12.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 12/03/2013] [Accepted: 12/04/2013] [Indexed: 01/21/2023]
Abstract
The preservation of mitochondrial function is essential for normal brain function after ischaemia-reperfusion injury. l-carnitine is a cofactor involved in the regulation of cellular energy metabolism. Recently, it has been shown that mildronate, an inhibitor of l-carnitine transport, improves neurological outcome after ischaemic damage of brain tissues. The aim of the present study was to elucidate the mitochondria targeted neuroprotective action of mildronate in the model of anoxia-reoxygenation-induced injury. Wistar rats were treated daily with mildronate (per os; 100mg/kg) for 14 days. The acyl-carnitine profile was determined in the brain tissues. Mitochondrial respiration and the activities of carnitine acetyltransferase (CrAT) and tricarboxylic acid (TCA) cycle enzymes were measured. To assess tolerance to ischaemia, isolated mitochondria were subjected to anoxia followed by reoxygenation. The mildronate treatment significantly reduced the concentrations of free l-carnitine (FC) and short-chain acyl-carnitine (AC) in brain tissue by 40-76%, without affecting the AC:FC ratio. The activities of CrAT and TCA cycle enzymes were slightly increased after mildronate treatment. Despite partially induced uncoupling, mildronate treatment did not affect mitochondrial bioenergetics function under normoxic conditions. After exposure to anoxia-reoxygenation, state 3 respiration and the respiration control ratio were higher in the mildronate-treated group. The results obtained demonstrate that mildronate treatment improves tolerance against anoxia-reoxygenation due to an uncoupling preconditioning-like effect. Regulating l-carnitine availability provides a potential novel target for the treatment of cerebral ischaemia and related complications.
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Affiliation(s)
- Marina Makrecka
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga LV-1006, Latvia; Riga Stradins University, Faculty of Pharmacy, Dzirciema Str. 16, Riga LV-1007, Latvia.
| | - Baiba Svalbe
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga LV-1006, Latvia; University of Latvia, Faculty of Medicine, Sarlotes St. 1a, Riga, LV-1001, Latvia
| | - Kristine Volska
- Riga Stradins University, Faculty of Pharmacy, Dzirciema Str. 16, Riga LV-1007, Latvia
| | - Eduards Sevostjanovs
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga LV-1006, Latvia
| | - Janis Liepins
- University of Latvia, Institute of Microbiology and Biotechnology, Kronvalda Blvd. 4, Riga LV-1586, Latvia
| | - Solveiga Grinberga
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga LV-1006, Latvia
| | - Osvalds Pugovics
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga LV-1006, Latvia
| | - Edgars Liepinsh
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga LV-1006, Latvia
| | - Maija Dambrova
- Latvian Institute of Organic Synthesis, Aizkraukles Str. 21, Riga LV-1006, Latvia; Riga Stradins University, Faculty of Pharmacy, Dzirciema Str. 16, Riga LV-1007, Latvia
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65
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Abstract
A transient, ischemia-resistant phenotype known as "ischemic tolerance" can be established in brain in a rapid or delayed fashion by a preceding noninjurious "preconditioning" stimulus. Initial preclinical studies of this phenomenon relied primarily on brief periods of ischemia or hypoxia as preconditioning stimuli, but it was later realized that many other stressors, including pharmacologic ones, are also effective. This review highlights the surprisingly wide variety of drugs now known to promote ischemic tolerance, documented and to some extent mechanistically characterized in preclinical animal models of stroke. Although considerably more experimentation is needed to thoroughly validate the ability of any currently identified preconditioning agent to protect ischemic brain, the fact that some of these drugs are already clinically approved for other indications implies that the growing enthusiasm for translational success in the field of pharmacologic preconditioning may be well justified.
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Chen J, Liao W, Gao W, Huang J, Gao Y. Intermittent hypoxia protects cerebral mitochondrial function from calcium overload. Acta Neurol Belg 2013; 113:507-13. [PMID: 24122478 DOI: 10.1007/s13760-013-0220-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 06/10/2013] [Indexed: 11/29/2022]
Abstract
Hypoxia leads to Ca(2+) overload and results in mitochondrial uncoupling, decreased ATP synthesis, and neuronal death. Inhibition of mitochondrial Ca(2+) overload protects mitochondrial function after hypoxia. The present study was aimed to investigate the effect of intermittent hypoxia on mitochondrial function and mitochondrial tolerance to Ca(2+) overload. Wistar rats were divided into control and intermittent hypoxia (IH) groups. The IH group was subject to hypoxia for 4 h daily in a hypobaric cabin (5,000 m) for 7 days. Brain mitochondria were isolated on day 7 following hypoxia. The baseline mitochondrial functions, such as ST3, ST4, and respiratory control ratio (RCR = ST3/ST4), were measured using a Clark-type oxygen electrode. Mitochondrial adenine nucleotide concentrations were measured by HPLC. Mitochondrial membrane potential was determined by measuring rhodamine 123 (Rh-123) fluorescence in the absence and presence of high Ca(2+) concentration (0.1 M), which simulates Ca(2+) overload. Our results revealed that IH did not affect mitochondrial respiratory functions, but led to a reduction in AMP and an increase in ADP concentrations in mitochondria. Both control and IH groups demonstrated decreased mitochondrial membrane potential in the presence of high Ca(2+) (0.1 M), while the IH group showed a relative higher mitochondrial membrane potential. These results indicated that the neuroprotective effect of intermittent hypoxia was resulted partly from preserving mitochondrial membrane potential, and increasing mitochondrial tolerance to high calcium levels. The increased ADP and decreased AMP in mitochondria following intermittent hypoxia may be a mechanism underlying this protection.
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Öxler EM, Dolga A, Culmsee C. AIF depletion provides neuroprotection through a preconditioning effect. Apoptosis 2013; 17:1027-38. [PMID: 22865232 DOI: 10.1007/s10495-012-0748-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Previous studies established a major role for apoptosis inducing factor (AIF) in neuronal cell death after acute brain injury. For example, AIF translocation from mitochondria to the nucleus determined delayed neuronal death, whereas reduced AIF expression provided neuroprotective effects in models of cerebral ischemia or brain trauma. The question remains, however, why reduced AIF levels are sufficient to mediate neuroprotection, since only very little AIF translocation to the nucleus is required for induction of cell death. Thus, the present study addresses the question, whether AIF gene silencing affects intrinsic death pathways upstream of nuclear translocation at the level of the mitochondria. Using MTT assays and real-time cell impedance measurements we confirmed the protective effect of AIF siRNA against glutamate toxicity in immortalized mouse hippocampal HT-22 neurons. Further, AIF siRNA prevented glutamate-induced mitochondrial fragmentation and loss of mitochondrial membrane potential. The protection of mitochondrial integrity was associated with preserved ATP levels, attenuated increases in lipid peroxidation and reduced complex I expression levels. Notably, low concentrations of the complex I inhibitor rotenone (20 nM), provided similar protective effects against glutamate toxicity at the mitochondrial level. These results expose a preconditioning effect as a mechanism for neuroprotection mediated by AIF depletion. In particular, they point out an association between mitochondrial complex I and AIF, which regulate each other's stability in mitochondria. Overall, these findings postulate that AIF depletion mediates a preconditioning effect protecting neuronal cells from subsequent glutamate toxicity through reduced levels of complex I protein.
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Affiliation(s)
- Eva-Maria Öxler
- Fachbereich Pharmazie, Institut für Pharmakologie und Klinische Pharmazie, Philipps-Universität Marburg, Karl-von-Frisch-Strasse 1, 35032 Marburg, Germany.
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Song M, Mohamad O, Gu X, Wei L, Yu SP. Restoration of Intracortical and Thalamocortical Circuits after Transplantation of Bone Marrow Mesenchymal Stem Cells into the Ischemic Brain of Mice. Cell Transplant 2013; 22:2001-15. [DOI: 10.3727/096368912x657909] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Transplantation of bone marrow mesenchymal stem cells (BMSCs) provides a promising regenerative medicine for stroke. Whether BMSC therapy could repair ischemia-damaged neuronal circuits and recover electrophysiological activity has largely been unknown. To address this issue, BMSCs were implanted into the ischemic barrel cortex of adult mice 1 and 7 days after focal barrel cortex stroke. Two days after the first transplantation (3 days after stroke), the infarct volume determined by TTC staining was significantly smaller in BMSC-treated compared to vehicle-treated stroke mice. The behavioral corner test showed better long-term recovery of sensorimotor function in BMSC-treated mice. Six weeks poststroke, thalamocortical slices were prepared and neuronal circuit activity in the peri-infarct region of the barrel cortex was determined by extracellular recordings of evoked field potentials. In BMSC-transplanted brain slices, the ischemia-disrupted intracortical activity from layer 4 to layer 2/3 was noticeably recovered, and the thalamocortical circuit connection was also partially restored. In contrast, much less and slower recovery was seen in control animals of barrel cortex stroke. Immunohistochemical staining disclosed that the density of neurons, axons, and blood vessels in the peri-infarct region was significantly higher in BMSC-treated mice, accompanied with enhanced local blood flow recovery. Western blotting showed that BMSC treatment increased the expression of stromal cell-derived factor-1 (SDF-1), vascular endothelial growth factor (VEGF), and brain-derived neurotrophic factor (BDNF) in the peri-infarct region. Moreover, the expression of the axonal growth associated protein-43 (GAP-43) was markedly increased, whereas the axonal growth inhibiting proteins ROCK II and NG2 were suppressed in the BMSC-treated brains. BMSC transplantation also promoted directional migration and survival of doublecortin (DCX)-positive neuroblasts in the peri-infarct region. The present investigation thus provides novel evidence that BMSC transplantation has the potential to repair the ischemia-damaged neural networks and restore lost neuronal connections. The recovered circuit activity likely contributes to the improved sensorimotor function after focal ischemic stroke and BMSC transplantation.
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Affiliation(s)
- Mingke Song
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Osama Mohamad
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Xiaohuan Gu
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Ling Wei
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA, USA
| | - Shan Ping Yu
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, GA, USA
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Xu T, Bo L, Wang J, Zhao Z, Xu Z, Deng X, Zhu W. Risk factors for early postoperative cognitive dysfunction after non-coronary bypass surgery in Chinese population. J Cardiothorac Surg 2013; 8:204. [PMID: 24175992 PMCID: PMC3818927 DOI: 10.1186/1749-8090-8-204] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Accepted: 10/28/2013] [Indexed: 11/17/2022] Open
Abstract
Background The present study was performed to investigate the incidence of early postoperative cognitive dysfunction (POCD) after non-coronary bypass surgery and the potential risk factors in Chinese population. Methods We performed a prospective study in a teaching tertiary hospital from May 2012 to August 2012. One hundred and seventy-six adult patients undergoing non-coronary bypass surgery were recruited. Mini-Mental State Examination (MMSE) score was evaluated before and 3 to 5 days after surgery. Patients with a MMSE score reduction of 2 was diagnosed with POCD. Results The general incidence of POCD was 33.0%, with no significant difference between the types of surgeries. In the univariate analysis, POCD associated factors included age, duration of surgery, anesthesia, cardiopulmonary bypass (CPB), cross-clamp and rewarming, and sevoflurane concentration. However, only age, cross-clamp duration and sevoflurane concentration were demonstrated to be independent risk factors for POCD. Conclusion Incidence of early POCD after non-coronary bypass surgery was relatively high in Chinese population. Advanced age, longer aortic cross-clamp duration and lower sevoflurane concentration was associated with a higher incidence of POCD.
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Affiliation(s)
| | | | | | | | | | | | - Wenzhong Zhu
- Department of Anesthesiology and Intensive Care Medicine, Changhai hospital, Second Military Medical University, Shanghai, China.
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70
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Abstract
Although severe stress can elicit toxicity, mild stress often elicits adaptations. Here we review the literature on stress-induced adaptations versus stress sensitization in models of neurodegenerative diseases. We also describe our recent findings that chronic proteotoxic stress can elicit adaptations if the dose is low but that high-dose proteotoxic stress sensitizes cells to subsequent challenges. In these experiments, long-term, low-dose proteasome inhibition elicited protection in a superoxide dismutase-dependent manner. In contrast, acute, high-dose proteotoxic stress sensitized cells to subsequent proteotoxic challenges by eliciting catastrophic loss of glutathione. However, even in the latter model of synergistic toxicity, several defensive proteins were upregulated by severe proteotoxicity. This led us to wonder whether high-dose proteotoxic stress can elicit protection against subsequent challenges in astrocytes, a cell type well known for their resilience. In support of this new hypothesis, we found that the astrocytes that survived severe proteotoxicity became harder to kill. The adaptive mechanism was glutathione dependent. If these findings can be generalized to the human brain, similar endogenous adaptations may help explain why neurodegenerative diseases are so delayed in appearance and so slow to progress. In contrast, sensitization to severe stress may explain why defenses eventually collapse in vulnerable neurons.
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Affiliation(s)
- Rehana K Leak
- Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University
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71
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Gao B, Zhang XY, Han R, Zhang TT, Chen C, Qin ZH, Sheng R. The endoplasmic reticulum stress inhibitor salubrinal inhibits the activation of autophagy and neuroprotection induced by brain ischemic preconditioning. Acta Pharmacol Sin 2013; 34:657-66. [PMID: 23603983 DOI: 10.1038/aps.2013.34] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
AIM To investigate whether endoplasmic reticulum (ER) stress participates in the neuroprotective effects of ischemic preconditioning (IPC)-induced neuroprotection and autophagy activation in rat brains. METHODS The right middle cerebral artery in SD rats was occluded for 10 min to induce focal cerebral IPC, and was occluded permanently 24 h later to induce permanent focal ischemia (PFI). ER stress inhibitor salubrinal (SAL) was injected via intracerebral ventricle infusion 10 min before the onset of IPC. Infarct volume and motor behavior deficits were examined after the ischemic insult. The protein levels of LC3, p62, HSP70, glucose-regulated protein 78 (GRP 78), p-eIF2α and caspase-12 in the ipsilateral cortex were analyzed using immunoblotting. LC3 expression pattern in the sections of ipsilateral cortex was observed with immunofluorescence. RESULTS Pretreatment with SAL (150 pmol) abolished the neuroprotective effects of IPC, as evidenced by the significant increases in mortality, infarct volume and motor deficits after PFI. At the molecular levels, pretreatment with SAL (150 pmol) significantly increased p-eIF2α level, and decreased GRP78 level after PFI, suggesting that SAL effectively inhibited ER stress in the cortex. Furthermore, the pretreatment with SAL blocked the IPC-induced upregulation of LC3-II and downregulation of p62 in the cortex, thus inhibiting the activation of autophagy. Moreover,SAL blocked the upregulation of HSP70, but significantly increased the cleaved caspase-12 level, thus promoting ER stress-dependent apoptotic signaling in the cortex. CONCLUSION ER stress-induced autophagy might contribute to the neuroprotective effect of brain ischemic preconditioning.
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72
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Levin SG, Shamsutdinova AA, Godukhin OV. Comparison of effects of ATP-gated potassium channel blockers on activity variations of rat CA1 pyramidal neurons in hippocampal slices triggered by short-term hypoxia. Bull Exp Biol Med 2013; 154:441-4. [PMID: 23486576 DOI: 10.1007/s10517-013-1972-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The study compared the effects of KATP channels blockers 5-hydroxydecanoat and glibenclamide on rapid hypoxic preconditioning and posthypoxic hyperexcitability of CA1 pyramidal neurons in rat hippocampal slices induced by short-term hypoxia. The population spikes of CA1 neurons were recorded before, during, and after exposure to a short-term hypoxia. The blockers of KATP channels significantly degraded the potency of hypoxia episodes to inhibit the evoked neuronal population activity. In contrast to glibenclamide, 5-hydroxydecanoat eliminated the preconditioning action of hypoxia. Despite mitochondrial KATP channels play an important role in the mechanisms of rapid hypoxic preconditioning in hippocampal CA1 pyramidal neurons, the tested KATP channels blockers produced no significant effect on the development of posthypoxic hyperexcitability in these neurons.
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Affiliation(s)
- S G Levin
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow region, Russia.
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73
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Pignataro G, Esposito E, Sirabella R, Vinciguerra A, Cuomo O, Di Renzo G, Annunziato L. nNOS and p-ERK involvement in the neuroprotection exerted by remote postconditioning in rats subjected to transient middle cerebral artery occlusion. Neurobiol Dis 2013; 54:105-14. [PMID: 23454199 DOI: 10.1016/j.nbd.2013.02.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 01/23/2013] [Accepted: 02/19/2013] [Indexed: 11/15/2022] Open
Abstract
It has recently been hypothesized that a sub-lethal ischemic insult induced in one organ is able to protect from a harmful ischemia occurring in a different organ. The objective of this study is to identify new putative mechanisms of neuroprotection elicited by remote ischemic femoral postconditioning. A 50% reduction in the infarct volume was observed when 100min of middle cerebral artery occlusion was followed, 10min later, by the remote postconditioning stimulus represented by 20min of femoral artery occlusion. The use of in vivo silencing strategy allowed to demonstrate that NO production through nNOS mediates part of the neuroprotection. Indeed, whereas CNS nNOS expression was up-regulated by remote postconditioning, the pharmacological inhibition of nNOS or its silencing-mediated knocking-down partially prevented this neuroprotective effect. This nNOS overexpression seemed to be p-ERK dependent. In fact, p-ERK expression increased in brain cortex after remote postconditioning, and its pharmacological inhibition prevented both nNOS overexpression and remote postconditioning-mediated neuroprotection. Interestingly, neuroprotection induced by remote postconditioning was partially prevented when ganglion transmission was pharmacologically interrupted by hexamethonium, thus showing that neural factors are involved in this phenomenon. Collectively, the present study demonstrates that p-ERK and nNOS take part to the complex cascade of events triggered by ischemic remote postconditioning.
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Affiliation(s)
- Giuseppe Pignataro
- Division of Pharmacology, Department of Neuroscience, School of Medicine, Federico II University of Naples, Via Pansini 5, 80131 Naples, Italy
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74
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Abstract
PURPOSE OF REVIEW Ischemic preconditioning (IPC) is gaining attention as a novel neuroprotective therapy and could provide an improved mechanistic understanding of tolerance to cerebral ischemia. The purpose of this article is to review the recent work in the field of IPC and its applications to clinical scenarios. RECENT FINDINGS The cellular signaling pathways that are activated following IPC are now better understood and have enabled investigators to identify several IPC mimetics. Most of these studies were performed in rodents, and efficacy of these mimetics remains to be evaluated in human patients. Additionally, remote ischemic preconditioning (RIPC) may have higher translational value than IPC. Repeated cycles of temporary ischemia in a remote organ can activate protective pathways in the target organ, including the heart and brain. Clinical trials are underway to test the efficacy of RIPC in protecting brain against subarachnoid hemorrhage. SUMMARY IPC, RIPC, and IPC mimetics have the potential to be therapeutic in various clinical scenarios. Further understanding of IPC-induced neuroprotection pathways and utilization of clinically relevant animal models are necessary to increase the translational potential of IPC in the near future.
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Affiliation(s)
- Srinivasan V Narayanan
- Department of Neurology, Cerebral Vascular Disease Research Center, University of Miami, Miller School of Medicine, Miami, Florida, USA
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75
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Li SQ, Li WB, Zhang M, Wu YZ, Hu YY. The role of neuroglobin in the neuroprotection of limb ischemic preconditioning in rats. Mol Neurobiol 2012. [PMID: 23180278 DOI: 10.1007/s12035-012-8373-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Recent evidence suggests that limb ischemic preconditioning (LIP) protects neurons against cerebral ischemia-reperfusion injury. However, the mechanisms of LIP are not well understood. Neuroglobin (Ngb) is a recently discovered globin that affords protection against hypoxic/ischemic brain injury. This study was performed to investigate the role of Ngb in the neuroprotection of LIP against brain ischemia and the involvements of mitochondria in the process. The rat global brain ischemic model was used, and the CA1 hippocampus was selected as the observational target. Ngb expression was investigated by RT-PCR and Western blot. Neuropathological evaluation was performed by thionin staining. Mitochondrial membrane potential (Δψm), Na(+)-K(+)-ATPase activity, and ultrastructure were examined by flow cytometry, spectrophotometry, and transmission electron microscopy, respectively. We also used Ngb antisense oligodeoxynucleotides (AS-ODNs) and Ngb inducer hemin to inhibit or mimic the effect of LIP. We found that LIP significantly up-regulated Ngb expression and protected neurons against ischemia. Furthermore, LIP effectively improved deterioration in the Δψm, mitochondrial Na(+)-K(+)-ATPase activity, and ultrastructure induced by cerebral ischemia. These effects of LIP were inhibited partly by Ngb AS-ODNs and mimicked by hemin. It could be concluded that up-regulation of Ngb expression played an important role in the neuroprotection induced by LIP, and the Ngb-mediated neuroprotection of LIP was, at least partly, associated with mitochondria.
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Affiliation(s)
- Shu-Qin Li
- Department of Pathophysiology, Hebei Medical University, 361 Zhongshan East Road, Shijiazhuang, 050017, China
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76
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Queiroga CSF, Tomasi S, Widerøe M, Alves PM, Vercelli A, Vieira HLA. Preconditioning triggered by carbon monoxide (CO) provides neuronal protection following perinatal hypoxia-ischemia. PLoS One 2012; 7:e42632. [PMID: 22952602 PMCID: PMC3429477 DOI: 10.1371/journal.pone.0042632] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 07/09/2012] [Indexed: 11/18/2022] Open
Abstract
Perinatal hypoxia-ischemia is a major cause of acute mortality in newborns and cognitive and motor impairments in children. Cerebral hypoxia-ischemia leads to excitotoxicity and necrotic and apoptotic cell death, in which mitochondria play a major role. Increased resistance against major damage can be achieved by preconditioning triggered by subtle insults. CO, a toxic molecule that is also generated endogenously, may have a role in preconditioning as low doses can protect against inflammation and apoptosis. In this study, the role of CO-induced preconditioning on neurons was addressed in vitro and in vivo. The effect of 1 h of CO treatment on neuronal death (plasmatic membrane permeabilization and chromatin condensation) and bcl-2 expression was studied in cerebellar granule cells undergoing to glutamate-induced apoptosis. CO's role was studied in vivo in the Rice-Vannucci model of neonatal hypoxia-ischemia (common carotid artery ligature +75 min at 8% oxygen). Apoptotic cells, assessed by Nissl staining were counted with a stereological approach and cleaved caspase 3-positive profiles in the hippocampus were assessed. Apoptotic hallmarks were analyzed in hippocampal extracts by Western Blot. CO inhibited excitotoxicity-induced cell death and increased Bcl-2 mRNA in primary cultures of neurons. In vivo, CO prevented hypoxia-ischemia induced apoptosis in the hippocampus, limited cytochrome c released from mitochondria and reduced activation of caspase-3. Still, Bcl-2 protein levels were higher in hippocampus of CO pre-treated rat pups. Our results show that CO preconditioning elicits a molecular cascade that limits neuronal apoptosis. This could represent an innovative therapeutic strategy for high-risk cerebral hypoxia-ischemia patients, in particular neonates.
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Affiliation(s)
- Cláudia S. F. Queiroga
- Chronic Diseases Research Center (CEDOC), Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal
- Instituto de Biologia Experimental e Tecnológica (IBET)/Instituto de Tecnologia Química e Biológica (ITQB), Universidade Nova de Lisboa, Oeiras, Portugal
| | - Simone Tomasi
- Neuroscience Institute Cavalieri Ottolenghi (NICO) - AOU San Luigi Gonzaga, Orbassano, Turin, Italy
- Department of Anatomy, Pharmacology and Forensic Medicine, University of Turin Medical School, Turin, Italy
| | - Marius Widerøe
- Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, Trondheim, Norway
| | - Paula M. Alves
- Chronic Diseases Research Center (CEDOC), Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Alessandro Vercelli
- Neuroscience Institute Cavalieri Ottolenghi (NICO) - AOU San Luigi Gonzaga, Orbassano, Turin, Italy
- Department of Anatomy, Pharmacology and Forensic Medicine, University of Turin Medical School, Turin, Italy
| | - Helena L. A. Vieira
- Chronic Diseases Research Center (CEDOC), Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal
- Instituto de Biologia Experimental e Tecnológica (IBET)/Instituto de Tecnologia Química e Biológica (ITQB), Universidade Nova de Lisboa, Oeiras, Portugal
- * E-mail:
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Bennet L, Davidson JO, Koome M, Gunn AJ. Glucocorticoids and preterm hypoxic-ischemic brain injury: the good and the bad. J Pregnancy 2012; 2012:751694. [PMID: 22970371 PMCID: PMC3431094 DOI: 10.1155/2012/751694] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 07/13/2012] [Indexed: 12/20/2022] Open
Abstract
Fetuses at risk of premature delivery are now routinely exposed to maternal treatment with synthetic glucocorticoids. In randomized clinical trials, these substantially reduce acute neonatal systemic morbidity, and mortality, after premature birth and reduce intraventricular hemorrhage. However, the overall neurodevelopmental impact is surprisingly unclear; worryingly, postnatal glucocorticoids are consistently associated with impaired brain development. We review the clinical and experimental evidence on how glucocorticoids may affect the developing brain and highlight the need for systematic research.
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Affiliation(s)
- Laura Bennet
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland 1142, New Zealand.
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78
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Scornavacca G, Gesuete R, Orsini F, Pastorelli R, Fanelli R, de Simoni MG, Airoldi L. Proteomic analysis of mouse brain cortex identifies metabolic down-regulation as a general feature of ischemic pre-conditioning. J Neurochem 2012; 122:1219-29. [DOI: 10.1111/j.1471-4159.2012.07874.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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79
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Abstract
Multifactorial injuries, such as ischemia, trauma, etc., have proven stubbornly elusive to clinical therapeutics, in spite of the binary outcome of recovery or death. This may be due, in part, to the lack of formal approaches to cell injury. We present a minimal system of nonlinear ordinary differential equations describing a theory of cell injury dynamics. A mutual antagonism between injury-driven total damage and total induced stress responses gives rise to attractors representing recovery or death. Solving across a range of injury magnitudes defines an 'injury course' containing a well-defined tipping point between recovery and death. Via the model, therapeutics is the diverting of a system on a pro-death trajectory to a pro-survival trajectory on bistable phase planes. The model plausibly explains why laboratory-based therapies have tended to fail clinically. A survival outcome is easy to achieve when lethal injury is close to the tipping point, but becomes progressively difficult as injury magnitudes increase, and there is an upper limit to salvageable injuries. The model offers novel insights into cell injury that may assist in overcoming barriers that have prevented development of clinically effective therapies for multifactorial conditions, as exemplified by brain ischemia.
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Affiliation(s)
- Donald J DeGracia
- Department of Physiology, Wayne State University, 540 East Canfield Avenue, Detroit, MI 48201, USA.
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80
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Prohibitin reduces mitochondrial free radical production and protects brain cells from different injury modalities. J Neurosci 2012; 32:583-92. [PMID: 22238093 DOI: 10.1523/jneurosci.2849-11.2012] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Prohibitin is an essential mitochondrial protein that has been implicated in a wide variety of functions in many cell types, but its role in neurons remains unclear. In a proteomic screen of rat brains in which ischemic tolerance was induced by electrical stimulation of the cerebellar fastigial nucleus, we found that prohibitin is upregulated in mitochondria. This observation prompted us to investigate the role of prohibitin in neuronal death and survival. We found that prohibitin is upregulated also in the ischemic tolerance induced by transient ischemia in vivo, or oxygen-glucose deprivation in neuronal cultures. Cell fractionation and electron-microscopic immunolabeling studies demonstrated that prohibitin is localized to neuronal mitochondria. Upregulation of prohibitin in neuronal cultures or hippocampal slices was markedly neuroprotective, whereas prohibitin gene silencing increased neuronal vulnerability, an effect associated with loss of mitochondrial membrane potential and increased mitochondrial production of reactive oxygen species. Prohibitin upregulation was associated with reduced production of reactive oxygen species in mitochondria exposed to the complex I inhibitor rotenone. In addition, prohibitin protected complex I activity from the inhibitory effects of rotenone. These observations, collectively, establish prohibitin as an endogenous neuroprotective protein involved in ischemic tolerance. Prohibitin exerts beneficial effects on neurons by reducing mitochondrial free radical production. The data with complex I activity suggest that prohibitin may stabilize the function of complex I. The protective effect of prohibitin has potential translational relevance in diseases of the nervous system associated with mitochondrial dysfunction and oxidative stress.
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81
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Sheng R, Liu XQ, Zhang LS, Gao B, Han R, Wu YQ, Zhang XY, Qin ZH. Autophagy regulates endoplasmic reticulum stress in ischemic preconditioning. Autophagy 2012; 8:310-25. [PMID: 22361585 DOI: 10.4161/auto.18673] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Recent studies have suggested that autophagy plays a prosurvival role in ischemic preconditioning (IPC). This study was taken to assess the linkage between autophagy and endoplasmic reticulum (ER) stress during the process of IPC. The effects of IPC on ER stress and neuronal injury were determined by exposure of primary cultured murine cortical neurons to 30 min of OGD 24 h prior to a subsequent lethal OGD. The effects of IPC on ER stress and ischemic brain damage were evaluated in rats by a brief ischemic insult followed by permanent focal ischemia (PFI) 24 h later using the suture occlusion technique. The results showed that both IPC and lethal OGD increased the LC3-II expression and decreased p62 protein levels, but the extent of autophagy activation was varied. IPC treatment ameliorated OGD-induced cell damage in cultured cortical neurons, whereas 3-MA (5-20 mM) and bafilomycin A 1 (75-150 nM) suppressed the neuroprotection induced by IPC. 3-MA, at the dose blocking autophagy, significantly inhibited IPC-induced HSP70, HSP60 and GRP78 upregulation; meanwhile, it also aggregated the ER stress and increased activated caspase-12, caspase-3 and CHOP protein levels both in vitro and in vivo models. The ER stress inhibitor Sal (75 pmol) recovered IPC-induced neuroprotection in the presence of 3-MA. Rapamycin 50-200 nM in vitro and 35 pmol in vivo 24 h before the onset of lethal ischemia reduced ER stress and ischemia-induced neuronal damage. These results demonstrated that pre-activation of autophagy by ischemic preconditioning can boost endogenous defense mechanisms to upregulate molecular chaperones, and hence reduce excessive ER stress during fatal ischemia.
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Affiliation(s)
- Rui Sheng
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Soochow University School of Medicine, Suzhou, China
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Xu T, Gong Z, Zhu WZ, Wang JF, Li B, Chen F, Deng XM. Remote ischemic preconditioning protects neurocognitive function of rats following cerebral hypoperfusion. Med Sci Monit 2012; 17:BR299-304. [PMID: 22037731 PMCID: PMC3539484 DOI: 10.12659/msm.882038] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Protection of remote ischemic preconditioning on neurocognitive function caused by bilateral common carotid artery occlusion has been investigated in rats. MATERIAL/METHODS Thirty-six male Sprague-Dawley rats were divided into 3 groups - control group (Group C, n=12), bilateral carotid arteries occlusion group (Group B, n=12) and remote ischemic precondition group (Group P, n=12). In Group P, remote ischemic preconditioning (RIPC) was performed on the right femoral artery with 3 cycles (10 min) of occlusion/perfusion. After 3 cycles of preconditioning, bilateral carotid arteries were occluded immediately for 60 min. In Group B, ischemic insults were conducted without RIPC. Sham surgeries were performed in Group C. Evaluation of memory and learning capacity was performed on days 5-8 after surgery by Morris water maze testing of spatial learning capacity (n=6 for each group). Apoptosis of cells in the hippocampus region was determined by TUNEL tests and Bcl-2 at this region was determined by ELISA 24 h and 9 days after vessel occlusion (n=6 for each group). RESULTS Neurocognitive tests showed that latency time was significantly longer in Group B than in Group P on day 7 (p=0.016) and day 8 (p=0.036). Moreover, frequency of platform crossings was significant less in group B than in the other 2 groups on day 9. Bcl-2 level was significantly increased in the hippocampal region of rats in Group P on days 1 and 9 after vessel occlusion. TUNEL test showed that apoptosis could be observed at 24 h after occlusion in Group B, but not in Group P and Group C. No apoptosis was observed on day 9. CONCLUSIONS Our results suggest that RIPC can protect neurocognitive function of rats after bilateral carotid occlusions, and that Bcl-2 may play an important role in this protective effect.
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Affiliation(s)
- Tao Xu
- Department of Anesthesiology and Intensive Care Medicine, Changhai Hospital, 2nd Military Medical University, Shanghai, P R China
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Mitochondrial hexokinase II (HKII) and phosphoprotein enriched in astrocytes (PEA15) form a molecular switch governing cellular fate depending on the metabolic state. Proc Natl Acad Sci U S A 2012; 109:1518-23. [PMID: 22233811 DOI: 10.1073/pnas.1108225109] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The metabolic state of a cell is a key determinant in the decision to live and proliferate or to die. Consequently, balanced energy metabolism and the regulation of apoptosis are critical for the development and maintenance of differentiated organisms. Hypoxia occurs physiologically during development or exercise and pathologically in vascular disease, tumorigenesis, and inflammation, interfering with homeostatic metabolism. Here, we show that the hypoxia-inducible factor (HIF)-1-regulated glycolytic enzyme hexokinase II (HKII) acts as a molecular switch that determines cellular fate by regulating both cytoprotection and induction of apoptosis based on the metabolic state. We provide evidence for a direct molecular interactor of HKII and show that, together with phosphoprotein enriched in astrocytes (PEA15), HKII inhibits apoptosis after hypoxia. In contrast, HKII accelerates apoptosis in the absence of PEA15 and under glucose deprivation. HKII both protects cells from death during hypoxia and functions as a sensor of glucose availability during normoxia, inducing apoptosis in response to glucose depletion. Thus, HKII-mediated apoptosis may represent an evolutionarily conserved altruistic mechanism to eliminate cells during metabolic stress to the advantage of a multicellular organism.
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Wagner-Golbs A, Luhmann HJ. Activity-dependent survival of developing neocortical neurons depends on PI3K signalling. J Neurochem 2011; 120:495-501. [PMID: 22118415 DOI: 10.1111/j.1471-4159.2011.07591.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Spontaneous electrical network activity plays a major role in the control of cell survival in the developing brain. Several intracellular pathways are implicated in transducing electrical activity into gene expression dependent and independent survival signals. These include activation of phosphatidylinositol 3-kinase (PI3K) and its downstream effector Akt, activation of Ras and subsequently MAPK/extracellular signal-regulated kinase (MEK) and extracellular signal-regulated kinase and signalling via calcium/calmodulin-dependent protein kinase (CaMK). In the present study, we analyzed the role of these pathways for the control of neuronal survival in different extracellular potassium concentrations ([K(+) ](ex) ). Organotypic neocortical slice cultures prepared from newborn mice were kept in 5.3, 8.0 and 25.0mM [K(+) ](ex) and treated with specific inhibitors of PI3K, MEK1, CaMKK and a broad spectrum CaMK inhibitor. After 6h of incubation, slices were immunostained for activated caspase 3 (a-caspase 3) and the number of apoptotic cells was quantified by computer based analysis. We found that in 5.3 and 8.0mM [K(+) ](ex) only PI3K was important for neuronal survival. When [K(+) ](ex) was raised to 25.0mM, a concentration above the depolarization block, we found no influence of PI3K on neuronal survival. Our data demonstrate that only the PI3K pathway, and not the MEK1, CaMKK or CaMKs pathway, plays a central role in the regulation of activity-dependent neuronal survival in the developing cerebral cortex.
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Affiliation(s)
- Antje Wagner-Golbs
- Institute of Physiology and Pathophysiology, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, Mainz, Germany
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Possible Involvement of Oxidative Stress and Inflammatory Mediators in the Protective Effects of the Early Preconditioning Window Against Transient Global Ischemia in Rats. Neurochem Res 2011; 37:614-21. [DOI: 10.1007/s11064-011-0651-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 11/01/2011] [Accepted: 11/04/2011] [Indexed: 01/25/2023]
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86
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Ischemic preconditioning-like effect of polyunsaturated fatty acid-rich diet on hepatic ischemia/reperfusion injury. J Gastrointest Surg 2011; 15:1679-88. [PMID: 21826546 DOI: 10.1007/s11605-011-1648-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 07/26/2011] [Indexed: 01/31/2023]
Abstract
AIM The aim of this study was to investigate a possible preconditioning effect of oral diet enriched with polyunsaturated fatty acids (PUFAs) on liver ischemia/reperfusion (I/R) injuries. METHODS Wistar male rats were fed a standard diet or polyunsaturated fatty acid-rich diet (PRD) enriched with (GII) or without (GIII) ω-3 PUFA. Rats were submitted to partial liver ischemia during 1 h and evaluated in pre- and post-I/R conditions. In pre-I/R condition, livers were collected for determination of fatty acid composition, liver mitochondrial function, malondialdehyde (MDA) content, and histological analysis. Four hours after liver reperfusion serum activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT), serum levels of tumor necrosis factor-alpha, interleukin-6, interleukin-10, and prostaglandin-E2, liver mitochondrial function, MDA content, and histology were evaluated. RESULTS In the pre-I/R condition, GII and GIII groups had an increase on PUFA content and exhibited slight increased macrosteatosis and microsteatosis in the liver. After 4 h of reperfusion, PRD-fed rats showed a marked decrease on steatosis, diminished necrosis, an increase in MDA formation, and mitochondrial uncoupling. We also observed a marked decrease in plasma levels of cytokines and ALT and AST activities in post-I/R condition in PRD groups. CONCLUSION In this experimental model in the rat, PRD has a preconditioning effect protecting the liver from I/R injury and should be object of future clinical studies.
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Mergenthaler P, Dirnagl U. Protective conditioning of the brain: expressway or roadblock? J Physiol 2011; 589:4147-55. [PMID: 21708907 DOI: 10.1113/jphysiol.2011.209718] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The brain responds to noxious stimulation with protective signalling. Over the last decades, a number of experimental strategies have been established to study endogenous brain protection. Pre-, per-, post- and remote 'conditioning' are now widely used to unravel the underlying mechanisms of endogenous neuroprotection. Some of these strategies are currently being tested in clinical trials to protect the human brain against anticipated damage or to boost protective responses during or after injury. Here we summarize the principles of 'conditioning' research and current efforts to translate this knowledge into effective treatment of patients. Conditioning to induce protected brain states provides an experimental window into endogenous brain protection and can lead to the discovery of drugs mimicking the effects of conditioning. Mechanisms of endogenous brain tolerance can be activated through a wide variety of stimuli that signal 'danger' to the brain. These danger signals lead to the induction of regulator and effector mechanisms, which suppress death and induce survival pathways, decrease metabolism, as well as increase substrate delivery. We conclude that preclinical research on endogenous brain protection has greatly benefited from conditioning strategies, but that clinical applications are challenging, and that we should not prematurely rush into ill-designed and underpowered clinical trials.
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Affiliation(s)
- Philipp Mergenthaler
- Center for Stroke Research Berlin (CSB), Department of Neurology and Experimental Neurology, Charité - University Medicine Berlin, Charitéplatz 1, 10117 Berlin, Germany
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88
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Lin HW, Thompson JW, Morris KC, Perez-Pinzon MA. Signal transducers and activators of transcription: STATs-mediated mitochondrial neuroprotection. Antioxid Redox Signal 2011; 14:1853-61. [PMID: 20712401 PMCID: PMC3078497 DOI: 10.1089/ars.2010.3467] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Cerebral ischemia is defined as little or no blood flow in cerebral circulation, characterized by low tissue oxygen and glucose levels, which promotes neuronal mitochondria dysfunction leading to cell death. A strategy to counteract cerebral ischemia-induced neuronal cell death is ischemic preconditioning (IPC). IPC results in neuroprotection, which is conferred by a mild ischemic challenge prior to a normally lethal ischemic insult. Although many IPC-induced mechanisms have been described, many cellular and subcellular mechanisms remain undefined. Some reports have suggested key signal transduction pathways of IPC, such as activation of protein kinase C epsilon, mitogen-activated protein kinase, and hypoxia-inducible factors, that are likely involved in IPC-induced mitochondria mediated-neuroprotection. Moreover, recent findings suggest that signal transducers and activators of transcription (STATs), a family of transcription factors involved in many cellular activities, may be intimately involved in IPC-induced ischemic tolerance. In this review, we explore current signal transduction pathways involved in IPC-induced mitochondria mediated-neuroprotection, STAT activation in the mitochondria as it relates to IPC, and functional significance of STATs in cerebral ischemia.
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Affiliation(s)
- Hung Wen Lin
- Cerebral Vascular Disease Research Center, Department of Neurology, University of Miami, Miller School of Medicine, Miami, Florida 33101, USA
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89
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Turovskaya MV, Turovsky EA, Zinchenko VP, Levin SG, Shamsutdinova AA, Godukhin OV. Repeated brief episodes of hypoxia modulate the calcium responses of ionotropic glutamate receptors in hippocampal neurons. Neurosci Lett 2011; 496:11-4. [DOI: 10.1016/j.neulet.2011.03.076] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 03/17/2011] [Accepted: 03/25/2011] [Indexed: 11/16/2022]
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90
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Intracellular Signaling: Mediators and Protective Responses. Stroke 2011. [DOI: 10.1016/b978-1-4160-5478-8.10010-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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91
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Calabrese V, Cornelius C, Dinkova-Kostova AT, Calabrese EJ, Mattson MP. Cellular stress responses, the hormesis paradigm, and vitagenes: novel targets for therapeutic intervention in neurodegenerative disorders. Antioxid Redox Signal 2010; 13:1763-811. [PMID: 20446769 PMCID: PMC2966482 DOI: 10.1089/ars.2009.3074] [Citation(s) in RCA: 589] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 04/27/2010] [Accepted: 05/01/2010] [Indexed: 12/22/2022]
Abstract
Despite the capacity of chaperones and other homeostatic components to restore folding equilibrium, cells appear poorly adapted for chronic oxidative stress that increases in cancer and in metabolic and neurodegenerative diseases. Modulation of endogenous cellular defense mechanisms represents an innovative approach to therapeutic intervention in diseases causing chronic tissue damage, such as in neurodegeneration. This article introduces the concept of hormesis and its applications to the field of neuroprotection. It is argued that the hormetic dose response provides the central underpinning of neuroprotective responses, providing a framework for explaining the common quantitative features of their dose-response relationships, their mechanistic foundations, and their relationship to the concept of biological plasticity, as well as providing a key insight for improving the accuracy of the therapeutic dose of pharmaceutical agents within the highly heterogeneous human population. This article describes in mechanistic detail how hormetic dose responses are mediated for endogenous cellular defense pathways, including sirtuin and Nrf2 and related pathways that integrate adaptive stress responses in the prevention of neurodegenerative diseases. Particular attention is given to the emerging role of nitric oxide, carbon monoxide, and hydrogen sulfide gases in hormetic-based neuroprotection and their relationship to membrane radical dynamics and mitochondrial redox signaling.
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92
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The effects of antidepressants on mitochondrial function in a model cell system and isolated mitochondria. Neurochem Res 2010; 36:327-38. [PMID: 21120605 DOI: 10.1007/s11064-010-0331-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2010] [Indexed: 12/16/2022]
Abstract
The in vitro effects of antidepressant drugs on mitochondrial function were investigated in a CHOβ(2)SPAP cell line used previously to determine the effects of antidepressants on gene transcription (Abdel-Razaq et al., Biochem Pharmacol 73:1995-2003, 2007) and in rat heart isolated mitochondria. Apoptotic effects of clomipramine (CLOM), desipramine (DMI) and of norfluoxetine (NORF, the active metabolite of fluoxetine), on cellular viability were indicated by morphological changes and concentration-dependent increases in caspase-3 activity in CHO cells after 18 h exposure to CLOM, DMI and NORF. However, tianeptine (TIAN) was without effect. CLOM and NORF both reduced integrated mitochondrial function as shown by marked reductions in membrane potential (MMP) in mitochondria isolated from rat hearts. DMI also showed a similar but smaller effect, whereas, TIAN did not elicit any significant change in MMP. Moreover, micromolar concentrations of CLOM, DMI and NORF caused significant inhibitions of the activities of mitochondrial complexes (I, II/III and IV). The inhibitory effects on complex IV activity were most marked. TIAN inhibited only complex I activity at concentrations in excess of 20 μM. The observed inhibitory effects of antidepressants on the mitochondrial complexes were accompanied by a significant decrease in the mitochondrial state-3 respiration at concentrations above 10 μM. The results demonstrate that the apoptotic cell death observed in antidepressant-treated cells could be due to disruption of mitochondrial function resulting from multiple inhibition of mitochondrial enzyme complexes. The possibility that antimitochondrial actions of antidepressants could provide a potentially protective pre-conditioning effect is discussed.
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93
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Fairbanks SL, Brambrink AM. Preconditioning and postconditioning for neuroprotection: the most recent evidence. Best Pract Res Clin Anaesthesiol 2010; 24:521-34. [PMID: 21619864 DOI: 10.1016/j.bpa.2010.10.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 10/11/2010] [Indexed: 11/13/2022]
Abstract
Stroke is a leading cause of morbidity and mortality, with perioperative stroke being an important complication in the practice of anaesthesia. Unfortunately, pharmacological treatment options are very limited and often not applicable in the perioperative period. The notion of applying a subtoxic stimulus prior to an otherwise lethal event is termed preconditioning. The main focus of the article is on describing the different concepts of preconditioning, including remote ischaemic preconditioning and anaesthetic preconditioning, as well as postconditioning and summarizing the most recent discoveries in this exciting field.
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Affiliation(s)
- Stacy L Fairbanks
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, UHS-2, Portland, OR 97239, USA.
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Correia SC, Santos RX, Perry G, Zhu X, Moreira PI, Smith MA. Mitochondria: the missing link between preconditioning and neuroprotection. J Alzheimers Dis 2010; 20 Suppl 2:S475-85. [PMID: 20463394 DOI: 10.3233/jad-2010-100669] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The quote "what does not kill you makes you stronger" perfectly describes the preconditioning phenomenon - a paradigm that affords robust brain tolerance in the face of neurodegenerative insults. Over the last few decades, many attempts have been made to identify the molecular mechanisms involved in preconditioning-induced protective responses, and recent data suggests that many of these mechanisms converge on the mitochondria, positing mitochondria as master regulators of preconditioning-triggered endogenous neuroprotection. In this review, we critically discuss evidence for the involvement of mitochondria within the preconditioning paradigm. We will highlight the crucial targets and mediators by which mitochondria are integrated into neuroprotective signaling pathways that underlie preconditioning, putting focus on mitochondrial respiratory chain and mitochondrial reactive oxygen species, mitochondrial ATP-sensitive potassium channels, mitochondrial permeability transition pore, uncoupling proteins, and mitochondrial antioxidant enzyme manganese superoxide dismutase. We also discuss the role of mitochondria in the induction of hypoxia-inducible factor-1, a transcription factor engaged in preconditioning-mediated neuroprotective effects. The identification of intrinsic mitochondrial mechanisms involved in preconditioning will provide new insights which can be translated into potential pharmacological interventions aimed at counteracting neurodegeneration.
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Affiliation(s)
- Sónia C Correia
- Center for Neuroscience and Cell Biology of Coimbra, University of Coimbra, Coimbra, Portugal
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Correia SC, Carvalho C, Cardoso S, Santos RX, Santos MS, Oliveira CR, Perry G, Zhu X, Smith MA, Moreira PI. Mitochondrial preconditioning: a potential neuroprotective strategy. Front Aging Neurosci 2010; 2. [PMID: 20838473 PMCID: PMC2936931 DOI: 10.3389/fnagi.2010.00138] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Accepted: 08/11/2010] [Indexed: 12/21/2022] Open
Abstract
Mitochondria have long been known as the powerhouse of the cell. However, these organelles are also pivotal players in neuronal cell death. Mitochondrial dysfunction is a prominent feature of chronic brain disorders, including Alzheimer's disease (AD) and Parkinson's disease (PD), and cerebral ischemic stroke. Data derived from morphologic, biochemical, and molecular genetic studies indicate that mitochondria constitute a convergence point for neurodegeneration. Conversely, mitochondria have also been implicated in the neuroprotective signaling processes of preconditioning. Despite the precise molecular mechanisms underlying preconditioning-induced brain tolerance are still unclear, mitochondrial reactive oxygen species generation and mitochondrial ATP-sensitive potassium channels activation have been shown to be involved in the preconditioning phenomenon. This review intends to discuss how mitochondrial malfunction contributes to the onset and progression of cerebral ischemic stroke and AD and PD, two major neurodegenerative disorders. The role of mitochondrial mechanisms involved in the preconditioning-mediated neuroprotective events will be also discussed. Mitochondrial targeted preconditioning may represent a promising therapeutic weapon to fight neurodegeneration.
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Affiliation(s)
- Sónia C Correia
- Center for Neuroscience and Cell Biology, University of Coimbra Coimbra, Portugal
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Abstract
This review focuses on mechanisms and emerging concepts that drive the science of stroke in a therapeutic direction. Once considered exclusively a disorder of blood vessels, growing evidence has led to the realization that the biological processes underlying stroke are driven by the interaction of neurons, glia, vascular cells, and matrix components, which actively participate in mechanisms of tissue injury and repair. As new targets are identified, new opportunities emerge that build on an appreciation of acute cellular events acting in a broader context of ongoing destructive, protective, and reparative processes. The burden of disease is great, and its magnitude widens as a role for blood vessels and stroke in vascular and nonvascular dementias becomes more clearly established. This review then poses a number of fundamental questions, the answers to which may generate new directions for research and possibly new treatments that could reduce the impact of this enormous economic and societal burden.
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Zeiger SLH, McKenzie JR, Stankowski JN, Martin JA, Cliffel DE, McLaughlin B. Neuron specific metabolic adaptations following multi-day exposures to oxygen glucose deprivation. Biochim Biophys Acta Mol Basis Dis 2010; 1802:1095-104. [PMID: 20656023 DOI: 10.1016/j.bbadis.2010.07.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Revised: 07/13/2010] [Accepted: 07/19/2010] [Indexed: 12/22/2022]
Abstract
Prior exposure to sub toxic insults can induce a powerful endogenous neuroprotective program known as ischemic preconditioning. Current models typically rely on a single stress episode to induce neuroprotection whereas the clinical reality is that patients may experience multiple transient ischemic attacks (TIAs) prior to suffering a stroke. We sought to develop a neuron-enriched preconditioning model using multiple oxygen glucose deprivation (OGD) episodes to assess the endogenous protective mechanisms neurons implement at the metabolic and cellular level. We found that neurons exposed to a five minute period of glucose deprivation recovered oxygen utilization and lactate production using novel microphysiometry techniques. Using the non-toxic and energetically favorable five minute exposure, we developed a preconditioning paradigm where neurons are exposed to this brief OGD for three consecutive days. These cells experienced a 45% greater survival following an otherwise lethal event and exhibited a longer lasting window of protection in comparison to our previous in vitro preconditioning model using a single stress. As in other models, preconditioned cells exhibited mild caspase activation, an increase in oxidized proteins and a requirement for reactive oxygen species for neuroprotection. Heat shock protein 70 was upregulated during preconditioning, yet the majority of this protein was released extracellularly. We believe coupling this neuron-enriched multi-day model with microphysiometry will allow us to assess neuronal specific real-time metabolic adaptations necessary for preconditioning.
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98
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Dale N, Frenguelli BG. Release of adenosine and ATP during ischemia and epilepsy. Curr Neuropharmacol 2010; 7:160-79. [PMID: 20190959 PMCID: PMC2769001 DOI: 10.2174/157015909789152146] [Citation(s) in RCA: 173] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Revised: 04/15/2009] [Accepted: 05/01/2009] [Indexed: 12/17/2022] Open
Abstract
Eighty years ago Drury & Szent-Györgyi described the actions of adenosine, AMP (adenylic acid) and ATP (pyrophosphoric or diphosphoric ester of adenylic acid) on the mammalian cardiovascular system, skeletal muscle, intestinal and urinary systems. Since then considerable insight has been gleaned on the means by which these compounds act, not least of which in the distinction between the two broad classes of their respective receptors, with their many subtypes, and the ensuing diversity in cellular consequences their activation invokes. These myriad actions are of course predicated on the release of the purines into the extracellular milieu, but, surprisingly, there is still considerable ambiguity as to how this occurs in various physiological and pathophysiological conditions. In this review we summarise the release of ATP and adenosine during seizures and cerebral ischemia and discuss mechanisms by which the purines adenosine and ATP may be released from cells in the CNS under these conditions.
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Affiliation(s)
- Nicholas Dale
- Department of Biological Sciences, University of Warwick, Coventry, CV4 7AL, UK
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Essential role of the redox-sensitive kinase p66shc in determining energetic and oxidative status and cell fate in neuronal preconditioning. J Neurosci 2010; 30:5242-52. [PMID: 20392947 DOI: 10.1523/jneurosci.6366-09.2010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Ischemic preconditioning is a phenomenon in which low-level stressful stimuli upregulate endogenous defensive programs, resulting in subsequent resistance to otherwise lethal injuries. We previously observed that signal transduction systems typically associated with neurodegeneration such as caspase activation are requisite events for the expression of tolerance and induction of HSP70. In this work, we sought to determine the extent and duration of oxidative and energetic dysfunction as well as the role of effector kinases on metabolic function in preconditioned cells. Using an in vitro neuronal culture model, we observed a robust increase in Raf and p66(Shc) activation within 1 h of preconditioning. Total ATP content decreased by 25% 3 h after preconditioning but returned to baseline by 24 h. Use of a free radical spin trap or p66(shc) inhibitor increased ATP content whereas a Raf inhibitor had no effect. Phosphorylated p66(shc) rapidly relocalized to the mitochondria and in the absence of activated p66(shc), autophagic processing increased. The constitutively expressed chaperone HSC70 relocalized to autophagosomes. Preconditioned cells experience significant total oxidative stress measured by F(2)-isoprostanes and neuronal stress evaluated by F(4)-neuroprostane measurement. Neuroprostane levels were enhanced in the presence of Shc inhibitors. Finally, we found that inhibiting either p66(shc) or Raf blocked neuroprotection afforded by preconditioning as well as upregulation of HSP70, suggesting both kinases are critical for preconditioning but function in fundamentally different ways. This is the first work to demonstrate the essential role of p66(shc) in mediating requisite mitochondrial and energetic compensation after preconditioning and suggests a mechanism by which protein and organelle damage mediated by ROS can increase HSP70.
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Queiroga CSF, Almeida AS, Martel C, Brenner C, Alves PM, Vieira HLA. Glutathionylation of adenine nucleotide translocase induced by carbon monoxide prevents mitochondrial membrane permeabilization and apoptosis. J Biol Chem 2010; 285:17077-88. [PMID: 20348099 DOI: 10.1074/jbc.m109.065052] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The present work demonstrates the ability of CO to prevent apoptosis in a primary culture of astrocytes. For the first time, the antiapoptotic behavior can be clearly attributed to the inhibition of mitochondrial membrane permeabilization (MMP), a key event in the intrinsic apoptotic pathway. In isolated non-synaptic mitochondria, CO partially inhibits (i) loss of potential, (ii) the opening of a nonspecific pore through the inner membrane, (iii) swelling, and (iv) cytochrome c release, which are induced by calcium, diamide, or atractyloside (a ligand of ANT). CO directly modulates ANT function by enhancing ADP/ATP exchange and prevents its pore-forming activity. Additionally, CO induces reactive oxygen species (ROS) generation, and its prevention by beta-carotene decreases CO cytoprotection in intact cells as well as in isolated mitochondria, revealing the key role of ROS. On the other hand, CO induces a slight increase in mitochondrial oxidized glutathione, which is essential for apoptosis modulation by (i) delaying astrocytic apoptosis, (ii) decreasing MMP, and (iii) enhancing ADP/ATP translocation activity of ANT. Moreover, CO and GSSG trigger ANT glutathionylation, a post-translational process regulating protein function in response to redox cellular changes. In conclusion, CO protects astrocytes from apoptosis by preventing MMP, acting on ANT (glutathionylation and inhibition of its pore activity) via a preconditioning-like process mediated by ROS and GSSG.
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Affiliation(s)
- Cláudia S F Queiroga
- Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901 Oeiras, Portugal
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