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Shin SS, Chattaraj R, Viaene A, Karmacharya M, Haddad S, Degani R, Sridharan A, Seghal C, Lee D, Kilbaugh TJ, Hwang M. Brain Targeted Xenon Protects Cerebral Vasculature After Traumatic Brain Injury. J Neurotrauma 2023. [PMID: 36927088 DOI: 10.1089/neu.2022.0468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023] Open
Abstract
Cerebrovascular dysfunction following traumatic brain injury (TBI) is a well characterized phenomenon. Given the therapeutic potential of xenon, we aimed to study its effects after localized delivery to the brain using microbubbles. We designed xenon containing microbubbles stabilized by dibehenoylphosphatidylcholine (DBPC) and polyethylene glycol (PEG) attached to saturated phospholipid (DPSE-PEG5000). Using a pig model of TBI, these microbubbles were intravenously injected, and ultrasound was used release xenon at the level of the carotid artery. Control group received perfluorobutane containing microbubbles. Diffusion tensor imaging (DTI) showed higher fractional anisotropy for pigs receiving xenon microbubbles compared to control group at 1 day after injury. Radial diffusivity analysis showed that this effect was mainly due acute edema. Pigs were sacrificed at 5 days, and the brain tissues of xenon treated animals showed reduction of perivascular inflammation and blood-brain barrier disruption. Endothelial cell culture experiment showed that glutamate reduces tight junction protein zona occludens-1 (ZO-1), but treatment with xenon microbubbles attenuates this effect. Xenon treatment protects cerebrovasculature and astroglial reactivity after TBI. Furthermore, these data support the future use of localized delivery of various therapeutic agents for brain injury using microbubbles in order to limit systemic side effects and reduce costs. .
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Affiliation(s)
- Samuel S Shin
- University of Pennsylvania Perelman School of Medicine, 14640, Department of Neurology, 3 West Gates Bldg, 3400 Spruce St, Philadelphia, Pennsylvania, United States, 19104;
| | - Rajarshi Chattaraj
- University of Pennsylvania, 6572, Philadelphia, Pennsylvania, United States;
| | - Angela Viaene
- University of Pennsylvania Perelman School of Medicine, 14640, Pathology, Philadelphia, Pennsylvania, United States;
| | - Mrigendra Karmacharya
- The Children's Hospital of Philadelphia, 6567, Philadelphia, Pennsylvania, United States;
| | - Sophie Haddad
- The Children's Hospital of Philadelphia, 6567, Department of Radiology, 3401 Civic Center Blvd, Philadelphia, Pennsylvania, United States, 19104;
| | - Rinat Degani
- The Children's Hospital of Philadelphia, 6567, Philadelphia, Pennsylvania, United States;
| | - Anush Sridharan
- The Children's Hospital of Philadelphia, 6567, Department of Radiology, 3401 Civic Center Blvd, Philadelphia, Pennsylvania, United States, 19104;
| | - Chandra Seghal
- University of Pennsylvania, 6572, Philadelphia, Pennsylvania, United States;
| | - Daeyeon Lee
- University of Pennsylvania, 6572, Philadelphia, Pennsylvania, United States;
| | - Todd J Kilbaugh
- The Children's Hospital of Philadelphia, 6567, Department of Anesthesiology and Critical Care Medicine, Philadelphia, Pennsylvania, United States;
| | - Misun Hwang
- The Children's Hospital of Philadelphia, 6567, Department of Radiology, 3401 Civic Center Blvd, Philadelphia, Philadelphia, Pennsylvania, United States, 19104;
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2
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Саракаева ЛР, Рыжкова ДВ, Митрофанова ЛБ, Баиров ВГ, Сухоцкая АА, Смородин АП, Ефтич ЕА, Кельмансон ИА, Никитина ИЛ. [Electroencephalogram features in children with congenital hyperinsulinism treated according to the international protocol in Russian Federation]. PROBLEMY ENDOKRINOLOGII 2023; 69:68-75. [PMID: 36842080 PMCID: PMC9978872 DOI: 10.14341/probl13174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 11/03/2022] [Indexed: 02/27/2023]
Abstract
BACKGROUND Congenital hyperinsulinism (CHI) is a rare life-threatening disease characterised by persistent hypoglycaemia as a result of inappropriate insulin secretion, which can lead to irreversible neurological defects in infants. AIM To evaluate neurophysiological characteristics of central nervous system in children with congenital hyperinsulinism treated according to the international protocol in Russian Federation. MATERIALS AND METHODS Our retrospective, prospective cohort study included 73 patients who received treatment for CHI according to the current international protocol at different departments of the Almazov National Medical Research Centre from 2017 to 2022. All patients underwent a comprehensive examination, including electroencephalography (EEG). RESULTS Among 73 patients with CHI, 35% (23) had focal form of the disease, 65% had non-focal form (49% (39) - diffuse form, 16% (11) - atypical form). All patients with focal form of CHI had a recovery as an outcome.Analysing the EEG data we found that paroxysmal activity was recorded in 23 patients (32%), 50 patients did not have paroxysmal activity (68%). Diffuse changes were observed in 47 patients (64%), whereas 26 patients (36%) were absent of it. By constructing Kaplan-Meier curves we found that the alpha rhythm is formed significantly (p=0.026) earlier in patients with a focal form of CHI. CONCLUSION CHI patients treated according to the international guidelines in Russian Federation show rather positive neurological outcome. We established that alpha rhythm earliest formation is associated with focal form of CHI.
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Affiliation(s)
- Л. Р. Саракаева
- Национальный медицинский исследовательский центр им. В.А. Алмазова
| | - Д. В. Рыжкова
- Национальный медицинский исследовательский центр им. В.А. Алмазова
| | | | - В. Г. Баиров
- Национальный медицинский исследовательский центр им. В.А. Алмазова
| | - А. А. Сухоцкая
- Национальный медицинский исследовательский центр им. В.А. Алмазова
| | - А. П. Смородин
- Национальный медицинский исследовательский центр им. В.А. Алмазова
| | - Е. А. Ефтич
- Национальный медицинский исследовательский центр им. В.А. Алмазова
| | - И. А. Кельмансон
- Национальный медицинский исследовательский центр им. В.А. Алмазова
| | - И. Л. Никитина
- Национальный медицинский исследовательский центр им. В.А. Алмазова
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3
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Kumar A, Kumari S, Singh D. Insights into the Cellular Interactions and Molecular Mechanisms of Ketogenic Diet for Comprehensive Management of Epilepsy. Curr Neuropharmacol 2022; 20:2034-2049. [PMID: 35450526 PMCID: PMC9886834 DOI: 10.2174/1570159x20666220420130109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 01/27/2022] [Accepted: 03/25/2022] [Indexed: 11/22/2022] Open
Abstract
A high-fat diet with appropriate protein and low carbohydrate content, widely known as the ketogenic diet (KD), is considered as an effective non-pharmacotherapeutic treatment option for certain types of epilepsies. Several preclinical and clinical studies have been carried out to elucidate its mechanism of antiepileptic action. Ketone bodies produced after KD's breakdown interact with cellular excito-inhibitory processes and inhibit abnormal neuronal firing. The generated ketone bodies decrease glutamate release by inhibiting the vesicular glutamate transporter 1 and alter the transmembrane potential by hyperpolarization. Apart from their effect on the well-known pathogenic mechanisms of epilepsy, some recent studies have shown the interaction of KD metabolites with novel neuronal targets, particularly adenosine receptors, adenosine triphosphate-sensitive potassium channel, mammalian target of rapamycin, histone deacetylase, hydroxycarboxylic acid receptors, and the NLR family pyrin domain containing 3 inflammasomes to suppress seizures. The role of KD in augmenting gut microbiota as a potential mechanism for epileptic seizure suppression has been established. Furthermore, some recent findings also support the beneficial effect of KD against epilepsy- associated comorbidities. Despite several advantages of the KD in epilepsy management, its use is also associated with a wide range of side effects. Hypoglycemia, excessive ketosis, acidosis, renal stones, cardiomyopathies, and other metabolic disturbances are the primary adverse effects observed with the use of KD. However, in some recent studies, modified KD has been tested with lesser side effects and better tolerability. The present review discusses the molecular mechanism of KD and its role in managing epilepsy and its associated comorbidities.
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Affiliation(s)
- Amit Kumar
- Pharmacology and Toxicology Laboratory, Dietetics and Nutrition Technology Division, CSIR- Institute of Himalayan Bioresource Technology, Palampur 176061, Himachal Pradesh, India; ,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Savita Kumari
- Pharmacology and Toxicology Laboratory, Dietetics and Nutrition Technology Division, CSIR- Institute of Himalayan Bioresource Technology, Palampur 176061, Himachal Pradesh, India; ,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Damanpreet Singh
- Pharmacology and Toxicology Laboratory, Dietetics and Nutrition Technology Division, CSIR- Institute of Himalayan Bioresource Technology, Palampur 176061, Himachal Pradesh, India; ,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India,Address correspondence to this author at the Pharmacology and Toxicology Laboratory, Dietetics and Nutrition Technology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur-176061, Himachal Pradesh, India; Tel: +91-9417923132; E-mails: ;
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4
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Li XT. The modulation of potassium channels by estrogens facilitates neuroprotection. Front Cell Dev Biol 2022; 10:998009. [PMID: 36393851 PMCID: PMC9643774 DOI: 10.3389/fcell.2022.998009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 10/11/2022] [Indexed: 08/31/2023] Open
Abstract
Estrogens, the sex hormones, have the potential to govern multiple cellular functions, such as proliferation, apoptosis, differentiation, and homeostasis, and to exert numerous beneficial influences for the cardiovascular system, nervous system, and bones in genomic and/or non-genomic ways. Converging evidence indicates that estrogens serve a crucial role in counteracting neurodegeneration and ischemic injury; they are thereby being considered as a potent neuroprotectant for preventing neurological diseases such as Alzheimer's disease and stroke. The underlying mechanism of neuroprotective effects conferred by estrogens is thought to be complex and multifactorial, and it remains obscure. It is well established that the K+ channels broadly expressed in a variety of neural subtypes determine the essential physiological features of neuronal excitability, and dysfunction of these channels is closely associated with diverse brain deficits, such as ataxia and epilepsy. A growing body of evidence supports a neuroprotective role of K+ channels in malfunctions of nervous tissues, with the channels even being a therapeutic target in clinical trials. As multitarget steroid hormones, estrogens also regulate the activity of distinct K+ channels to generate varying biological actions, and accumulated data delineate that some aspects of estrogen-mediated neuroprotection may arise from the impact on multiple K+ channels, including Kv, BK, KATP, and K2P channels. The response of these K+ channels after acute or chronic exposure to estrogens may oppose pathological abnormality in nervous cells, which serves to extend our understanding of these phenomena.
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Affiliation(s)
- Xian-Tao Li
- School of Medicine, Guizhou University, Guiyang, China
- Department of Neuroscience, South-Central University for Nationalities, Wuhan, China
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5
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Nakai-Shimoda H, Himeno T, Okawa T, Miura-Yura E, Sasajima S, Kato M, Yamada Y, Morishita Y, Tsunekawa S, Kato Y, Seino Y, Inoue R, Kondo M, Seino S, Naruse K, Kato K, Mizukami H, Nakamura J, Kamiya H. Kir6.2-deficient mice develop somatosensory dysfunction and axonal loss in the peripheral nerves. iScience 2022; 25:103609. [PMID: 35005553 PMCID: PMC8719014 DOI: 10.1016/j.isci.2021.103609] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 11/27/2021] [Accepted: 12/08/2021] [Indexed: 10/26/2022] Open
Abstract
Glucose-responsive ATP-sensitive potassium channels (KATP) are expressed in a variety of tissues including nervous systems. The depolarization of the membrane potential induced by glucose may lead to hyperexcitability of neurons and induce excitotoxicity. However, the roles of KATP in the peripheral nervous system (PNS) are poorly understood. Here, we determine the roles of KATP in the PNS using KATP-deficient (Kir6.2-deficient) mice. We demonstrate that neurite outgrowth of dorsal root ganglion (DRG) neurons was reduced by channel closers sulfonylureas. However, a channel opener diazoxide elongated the neurite. KATP subunits were expressed in mouse DRG, and expression of certain subunits including Kir6.2 was increased in diabetic mice. In Kir6.2-deficient mice, the current perception threshold, thermal perception threshold, and sensory nerve conduction velocity were impaired. Electron microscopy revealed a reduction of unmyelinated and small myelinated fibers in the sural nerves. In conclusion, KATP may contribute to the development of peripheral neuropathy.
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Affiliation(s)
- Hiromi Nakai-Shimoda
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan
| | - Tatsuhito Himeno
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan.,Department of Innovative Diabetes Therapy, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan
| | - Tetsuji Okawa
- Department of Endocrinology, Gifu Prefectural Tajimi Hospital, Tajimi 507-8522, Japan
| | - Emiri Miura-Yura
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan
| | - Sachiko Sasajima
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan
| | - Makoto Kato
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan
| | - Yuichiro Yamada
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan
| | - Yoshiaki Morishita
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan
| | - Shin Tsunekawa
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan
| | - Yoshiro Kato
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan
| | - Yusuke Seino
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Fujita Health University School of Medicine, Toyoake 470-1192, Aichi, Japan
| | - Rieko Inoue
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan
| | - Masaki Kondo
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan
| | - Susumu Seino
- Division of Molecular and Metabolic Medicine, Department of Physiology and Cell Biology, Kobe University Graduate School of Medicine, Kobe 650-0047, Japan
| | - Keiko Naruse
- Department of Internal Medicine, Aichi Gakuin University School of Dentistry, Nagoya 464-0821, Japan
| | - Koichi Kato
- Department of Medicine, Aichi Gakuin University School of Pharmacy, Nagoya 464-8650, Japan
| | - Hiroki Mizukami
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Jiro Nakamura
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan.,Department of Innovative Diabetes Therapy, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan
| | - Hideki Kamiya
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute 480-1185, Japan
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6
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Karagiannis A, Gallopin T, Lacroix A, Plaisier F, Piquet J, Geoffroy H, Hepp R, Naudé J, Le Gac B, Egger R, Lambolez B, Li D, Rossier J, Staiger JF, Imamura H, Seino S, Roeper J, Cauli B. Lactate is an energy substrate for rodent cortical neurons and enhances their firing activity. eLife 2021; 10:e71424. [PMID: 34766906 PMCID: PMC8651295 DOI: 10.7554/elife.71424] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 11/09/2021] [Indexed: 12/12/2022] Open
Abstract
Glucose is the mandatory fuel for the brain, yet the relative contribution of glucose and lactate for neuronal energy metabolism is unclear. We found that increased lactate, but not glucose concentration, enhances the spiking activity of neurons of the cerebral cortex. Enhanced spiking was dependent on ATP-sensitive potassium (KATP) channels formed with KCNJ11 and ABCC8 subunits, which we show are functionally expressed in most neocortical neuronal types. We also demonstrate the ability of cortical neurons to take-up and metabolize lactate. We further reveal that ATP is produced by cortical neurons largely via oxidative phosphorylation and only modestly by glycolysis. Our data demonstrate that in active neurons, lactate is preferred to glucose as an energy substrate, and that lactate metabolism shapes neuronal activity in the neocortex through KATP channels. Our results highlight the importance of metabolic crosstalk between neurons and astrocytes for brain function.
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Affiliation(s)
- Anastassios Karagiannis
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS)ParisFrance
| | - Thierry Gallopin
- Brain Plasticity Unit, CNRS UMR 8249, CNRS, ESPCI ParisParisFrance
| | - Alexandre Lacroix
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS)ParisFrance
| | - Fabrice Plaisier
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS)ParisFrance
| | - Juliette Piquet
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS)ParisFrance
| | - Hélène Geoffroy
- Brain Plasticity Unit, CNRS UMR 8249, CNRS, ESPCI ParisParisFrance
| | - Régine Hepp
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS)ParisFrance
| | - Jérémie Naudé
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS)ParisFrance
| | - Benjamin Le Gac
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS)ParisFrance
| | - Richard Egger
- Institute for Neurophysiology, Goethe University FrankfurtFrankfurtGermany
| | - Bertrand Lambolez
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS)ParisFrance
| | - Dongdong Li
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS)ParisFrance
| | - Jean Rossier
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS)ParisFrance
- Brain Plasticity Unit, CNRS UMR 8249, CNRS, ESPCI ParisParisFrance
| | - Jochen F Staiger
- Institute for Neuroanatomy, University Medical Center Göttingen, Georg-August- University GöttingenGoettingenGermany
| | - Hiromi Imamura
- Graduate School of Biostudies, Kyoto UniversityKyotoJapan
| | - Susumu Seino
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of MedicineHyogoJapan
| | - Jochen Roeper
- Institute for Neurophysiology, Goethe University FrankfurtFrankfurtGermany
| | - Bruno Cauli
- Sorbonne Université, CNRS, INSERM, Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS-IBPS)ParisFrance
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7
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Kir Channel Molecular Physiology, Pharmacology, and Therapeutic Implications. Handb Exp Pharmacol 2021; 267:277-356. [PMID: 34345939 DOI: 10.1007/164_2021_501] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
For the past two decades several scholarly reviews have appeared on the inwardly rectifying potassium (Kir) channels. We would like to highlight two efforts in particular, which have provided comprehensive reviews of the literature up to 2010 (Hibino et al., Physiol Rev 90(1):291-366, 2010; Stanfield et al., Rev Physiol Biochem Pharmacol 145:47-179, 2002). In the past decade, great insights into the 3-D atomic resolution structures of Kir channels have begun to provide the molecular basis for their functional properties. More recently, computational studies are beginning to close the time domain gap between in silico dynamic and patch-clamp functional studies. The pharmacology of these channels has also been expanding and the dynamic structural studies provide hope that we are heading toward successful structure-based drug design for this family of K+ channels. In the present review we focus on placing the physiology and pharmacology of this K+ channel family in the context of atomic resolution structures and in providing a glimpse of the promising future of therapeutic opportunities.
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8
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Whitney K, Nikulina E, Rahman SN, Alexis A, Bergold PJ. Delayed dosing of minocycline plus N-acetylcysteine reduces neurodegeneration in distal brain regions and restores spatial memory after experimental traumatic brain injury. Exp Neurol 2021; 345:113816. [PMID: 34310944 DOI: 10.1016/j.expneurol.2021.113816] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 07/07/2021] [Accepted: 07/20/2021] [Indexed: 11/16/2022]
Abstract
Multiple drugs to treat traumatic brain injury (TBI) have failed clinical trials. Most drugs lose efficacy as the time interval increases between injury and treatment onset. Insufficient therapeutic time window is a major reason underlying failure in clinical trials. Few drugs have been developed with therapeutic time windows sufficiently long enough to treat TBI because little is known about which brain functions can be targeted if therapy is delayed hours to days after injury. We identified multiple injury parameters that are improved by first initiating treatment with the drug combination minocycline (MINO) plus N-acetylcysteine (NAC) at 72 h after injury (MN72) in a mouse closed head injury (CHI) experimental TBI model. CHI produces spatial memory deficits resulting in impaired performance on Barnes maze, hippocampal neuronal loss, and bilateral damage to hippocampal neurons, dendrites, spines and synapses. MN72 treatment restores Barnes maze acquisition and retention, protects against hippocampal neuronal loss, limits damage to dendrites, spines and synapses, and accelerates recovery of microtubule associated protein 2 (MAP2) expression, a key protein in maintaining proper dendritic architecture and synapse density. These data show that in addition to the structural integrity of the dendritic arbor, spine and synapse density can be successfully targeted with drugs first dosed days after injury. Retention of substantial drug efficacy even when first dosed 72 h after injury makes MINO plus NAC a promising candidate to treat clinical TBI.
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Affiliation(s)
- Kristen Whitney
- Department of Physiology and Pharmacology, State University of New York-Downstate Health Sciences University, Brooklyn, NY 11215, United States of America; Program in Neural and Behavioral Science, School of Graduate Studies, State University of New York-Downstate Health Sciences University, Brooklyn, NY 11215, United States of America
| | - Elena Nikulina
- Department of Physiology and Pharmacology, State University of New York-Downstate Health Sciences University, Brooklyn, NY 11215, United States of America
| | - Syed N Rahman
- Department of Physiology and Pharmacology, State University of New York-Downstate Health Sciences University, Brooklyn, NY 11215, United States of America
| | - Alisia Alexis
- Department of Physiology and Pharmacology, State University of New York-Downstate Health Sciences University, Brooklyn, NY 11215, United States of America
| | - Peter J Bergold
- Department of Physiology and Pharmacology, State University of New York-Downstate Health Sciences University, Brooklyn, NY 11215, United States of America; Program in Neural and Behavioral Science, School of Graduate Studies, State University of New York-Downstate Health Sciences University, Brooklyn, NY 11215, United States of America.
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9
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Ikeno Y, Ghincea CV, Roda GF, Cheng L, Aftab M, Meng X, Weyant MJ, Cleveland JC, Fullerton DA, Reece TB. Optimizing Nicorandil for Spinal Cord Protection in a Murine Model of Complex Aortic Intervention. Semin Thorac Cardiovasc Surg 2021; 34:28-38. [PMID: 33444762 DOI: 10.1053/j.semtcvs.2021.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 01/05/2021] [Indexed: 01/07/2023]
Abstract
There are currently no clinically utilized pharmacological agents for the induction of metabolic tolerance to spinal cord ischemia-reperfusion injury in the setting of complex aortic intervention. Nicorandil, a nitric oxide donor and ATP-sensitive potassium (KATP) channel opener, has shown promise in neuroprotection. However, the optimized clinical application of the drug and its mechanism of neuroprotection remains unclear. We hypothesized that 3-days pretreatment would confer the most effective neuroprotection, mediated by mitochondrial KATP channel activation. Spinal cord injury was induced by 7 minutes of thoracic aortic cross-clamping in adult male C57BL/6 mice. Time course: mice received 0.1 mg/kg nicorandil for 10 min, 4 hours, and 3 consecutive days prior to ischemia compared with control. Dose challenge: mice received 3-days nicorandil pretreatment comparing 0.1 mg/kg, 1.0 mg/kg, 5.0 mg/kg, and saline administration. Mitochondrial KATP channel blocker 5-hydroxy-decanoate (5HD) was co-administered to elucidate mechanism. Limb motor function was evaluated, and viable anterior horn neurons quantified. Nicorandil pretreatment at 4 hours and 3 days before ischemia demonstrated significant motor function preservation; administration 10 minutes before ischemia showed no neuroprotection. All nicorandil doses showed significant motor function preservation. Three days administration of Nicorandil 1.0 mg/kg was most potent. Neuroprotection was completely abolished by 5HD co-administration. Histological analysis showed significant neuron preservation with nicorandil pretreatment, which was attenuated by 5HD co-administration. Three days administration of Nicorandil 1.0 mg/kg showed near-total motor function preservation in a murine spinal cord ischemia-reperfusion model, mediated by the mitochondrial KATP channel.
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Affiliation(s)
- Yuki Ikeno
- Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado, Aurora, Colorado
| | - Christian V Ghincea
- Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado, Aurora, Colorado
| | - Gavriel F Roda
- Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado, Aurora, Colorado
| | - Linling Cheng
- Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado, Aurora, Colorado
| | - Muhammad Aftab
- Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado, Aurora, Colorado
| | - Xianzhong Meng
- Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado, Aurora, Colorado
| | - Michael J Weyant
- Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado, Aurora, Colorado
| | - Joseph C Cleveland
- Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado, Aurora, Colorado
| | - David A Fullerton
- Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado, Aurora, Colorado
| | - Thomas Brett Reece
- Division of Cardiothoracic Surgery, Department of Surgery, University of Colorado, Aurora, Colorado.
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10
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Waixenicin A, a marine-derived TRPM7 inhibitor: a promising CNS drug lead. Acta Pharmacol Sin 2020; 41:1519-1524. [PMID: 32994545 DOI: 10.1038/s41401-020-00512-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 08/17/2020] [Indexed: 12/17/2022] Open
Abstract
Ion channels are the third largest class of targets for therapeutic drugs. The pharmacology of ion channels is an important research area for identifying new treatment options for human diseases. The past decade or so has seen increasing interest in an ion channel protein belonging to the transient receptor potential (TRP) family, namely the melastatin subfamily member 7 (TRPM7), as an emerging drug target. TRPM7 is a bifunctional protein with a magnesium and calcium-conducting divalent ion channel fused with an active kinase domain. TRPM7 is ubiquitously expressed in human tissues, including the brain, and regulates various cell biology processes such as magnesium and calcium homeostasis, cell growth and proliferation, and embryonic development. TRPM7 provides a link between cellular metabolic status and intracellular calcium homeostasis in neurons due to TRPM7's unique sensitivity to fluctuating intracellular Mg·ATP levels. Thus, the protein plays a key role in ischemic and hypoxic neuronal cell death and brain injury, and is one of the key nonglutamate mechanisms in cerebral ischemia and stroke. Currently, the most potent and specific TRPM7 inhibitor is waixenicin A, a xenicane diterpenoid from the Hawaiian soft coral Sarcothelia edmondsoni. Using waixenicin A as a pharmacological tool, we demonstrated that TRPM7 is involved in promoting neurite outgrowth in vitro. Most recently, we found that waixenicin A reduced hypoxic-ischemic brain injury and preserved long-term behavioral outcomes in mouse neonates. We here suggest that TRPM7 is an emerging drug target for CNS diseases and disorders, and waixenicin A is a viable drug lead for these disorders.
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11
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Drug development in targeting ion channels for brain edema. Acta Pharmacol Sin 2020; 41:1272-1288. [PMID: 32855530 PMCID: PMC7609292 DOI: 10.1038/s41401-020-00503-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 08/02/2020] [Indexed: 12/18/2022] Open
Abstract
Cerebral edema is a pathological hallmark of various central nervous system (CNS) insults, including traumatic brain injury (TBI) and excitotoxic injury such as stroke. Due to the rigidity of the skull, edema-induced increase of intracranial fluid significantly complicates severe CNS injuries by raising intracranial pressure and compromising perfusion. Mortality due to cerebral edema is high. With mortality rates up to 80% in severe cases of stroke, it is the leading cause of death within the first week. Similarly, cerebral edema is devastating for patients of TBI, accounting for up to 50% mortality. Currently, the available treatments for cerebral edema include hypothermia, osmotherapy, and surgery. However, these treatments only address the symptoms and often elicit adverse side effects, potentially in part due to non-specificity. There is an urgent need to identify effective pharmacological treatments for cerebral edema. Currently, ion channels represent the third-largest target class for drug development, but their roles in cerebral edema remain ill-defined. The present review aims to provide an overview of the proposed roles of ion channels and transporters (including aquaporins, SUR1-TRPM4, chloride channels, glucose transporters, and proton-sensitive channels) in mediating cerebral edema in acute ischemic stroke and TBI. We also focus on the pharmacological inhibitors for each target and potential therapeutic strategies that may be further pursued for the treatment of cerebral edema.
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12
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Pleiotropic effects of anti-diabetic drugs: A comprehensive review. Eur J Pharmacol 2020; 884:173349. [PMID: 32650008 DOI: 10.1016/j.ejphar.2020.173349] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 06/24/2020] [Accepted: 07/03/2020] [Indexed: 12/18/2022]
Abstract
Diabetes mellitus characterized by hyperglycaemia presents an array of comorbidities such as cardiovascular and renal failure, dyslipidemia, and cognitive impairments. Populations above the age of 60 are in an urgent need of effective therapies to deal with the complications associated with diabetes mellitus. Widely used anti-diabetic drugs have good safety profiles and multiple reports indicate their pleiotropic effects in diabetic patients or models. This review has been written with the objective of identifying the widely-marketed anti-diabetic drugs which can be efficiently repurposed for the treatment of other diseases or disorders. It is an updated, comprehensive review, describing the protective role of various classes of anti-diabetic drugs in mitigating the macro and micro vascular complications of diabetes mellitus, and differentiating these drugs on the basis of their mode of action. Notably, metformin, the anti-diabetic drug most commonly explored for cancer therapy, has also exhibited some antimicrobial effects. Unlike class specific effects, few instances of drug specific effects in managing cardiovascular complications have also been reported. A major drawback is that the pleiotropic effects of anti-diabetic drugs have been mostly investigated only in diabetic patients. Thus, for effective repurposing, more clinical trials devoted to analyse the effects of anti-diabetic drugs in patients irrespective of their diabetic condition, are required.
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13
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Kharade SV, Sanchez-Andres JV, Fulton MG, Shelton EL, Blobaum AL, Engers DW, Hofmann CS, Dadi PK, Lantier L, Jacobson DA, Lindsley CW, Denton JS. Structure-Activity Relationships, Pharmacokinetics, and Pharmacodynamics of the Kir6.2/SUR1-Specific Channel Opener VU0071063. J Pharmacol Exp Ther 2019; 370:350-359. [PMID: 31201216 PMCID: PMC6691189 DOI: 10.1124/jpet.119.257204] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 06/12/2019] [Indexed: 01/14/2023] Open
Abstract
Glucose-stimulated insulin secretion from pancreatic β-cells is controlled by ATP-regulated potassium (KATP) channels composed of Kir6.2 and sulfonylurea receptor 1 (SUR1) subunits. The KATP channel-opener diazoxide is FDA-approved for treating hyperinsulinism and hypoglycemia but suffers from off-target effects on vascular KATP channels and other ion channels. The development of more specific openers would provide critically needed tool compounds for probing the therapeutic potential of Kir6.2/SUR1 activation. Here, we characterize a novel scaffold activator of Kir6.2/SUR1 that our group recently discovered in a high-throughput screen. Optimization efforts with medicinal chemistry identified key structural elements that are essential for VU0071063-dependent opening of Kir6.2/SUR1. VU0071063 has no effects on heterologously expressed Kir6.1/SUR2B channels or ductus arteriole tone, indicating it does not open vascular KATP channels. VU0071063 induces hyperpolarization of β-cell membrane potential and inhibits insulin secretion more potently than diazoxide. VU0071063 exhibits metabolic and pharmacokinetic properties that are favorable for an in vivo probe and is brain penetrant. Administration of VU0071063 inhibits glucose-stimulated insulin secretion and glucose-lowering in mice. Taken together, these studies indicate that VU0071063 is a more potent and specific opener of Kir6.2/SUR1 than diazoxide and should be useful as an in vitro and in vivo tool compound for investigating the therapeutic potential of Kir6.2/SUR1 expressed in the pancreas and brain.
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Affiliation(s)
- Sujay V Kharade
- Departments of Anesthesiology (S.V.K., J.S.D.) and Pediatrics (E.L.S.), Vanderbilt University Medical Center, Nashville, Tennessee; Department of Medicine, Jaume I University, Castellon de la Plana, Spain (J.V.S.-A.); Departments of Chemistry (M.G.F., C.W.L.), Pharmacology (M.G.F., A.L.B., D.W.E., C.S.H., C.W.L., J.S.D.), and Molecular Physiology and Biophysics (P.K.D., D.A.J.), and Mouse Metabolic Phenotyping Core (L.L.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Center for Neuroscience Drug Discovery, Franklin, Tennessee (D.W.E., A.L.B., C.W.L.)
| | - Juan Vicente Sanchez-Andres
- Departments of Anesthesiology (S.V.K., J.S.D.) and Pediatrics (E.L.S.), Vanderbilt University Medical Center, Nashville, Tennessee; Department of Medicine, Jaume I University, Castellon de la Plana, Spain (J.V.S.-A.); Departments of Chemistry (M.G.F., C.W.L.), Pharmacology (M.G.F., A.L.B., D.W.E., C.S.H., C.W.L., J.S.D.), and Molecular Physiology and Biophysics (P.K.D., D.A.J.), and Mouse Metabolic Phenotyping Core (L.L.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Center for Neuroscience Drug Discovery, Franklin, Tennessee (D.W.E., A.L.B., C.W.L.)
| | - Mark G Fulton
- Departments of Anesthesiology (S.V.K., J.S.D.) and Pediatrics (E.L.S.), Vanderbilt University Medical Center, Nashville, Tennessee; Department of Medicine, Jaume I University, Castellon de la Plana, Spain (J.V.S.-A.); Departments of Chemistry (M.G.F., C.W.L.), Pharmacology (M.G.F., A.L.B., D.W.E., C.S.H., C.W.L., J.S.D.), and Molecular Physiology and Biophysics (P.K.D., D.A.J.), and Mouse Metabolic Phenotyping Core (L.L.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Center for Neuroscience Drug Discovery, Franklin, Tennessee (D.W.E., A.L.B., C.W.L.)
| | - Elaine L Shelton
- Departments of Anesthesiology (S.V.K., J.S.D.) and Pediatrics (E.L.S.), Vanderbilt University Medical Center, Nashville, Tennessee; Department of Medicine, Jaume I University, Castellon de la Plana, Spain (J.V.S.-A.); Departments of Chemistry (M.G.F., C.W.L.), Pharmacology (M.G.F., A.L.B., D.W.E., C.S.H., C.W.L., J.S.D.), and Molecular Physiology and Biophysics (P.K.D., D.A.J.), and Mouse Metabolic Phenotyping Core (L.L.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Center for Neuroscience Drug Discovery, Franklin, Tennessee (D.W.E., A.L.B., C.W.L.)
| | - Anna L Blobaum
- Departments of Anesthesiology (S.V.K., J.S.D.) and Pediatrics (E.L.S.), Vanderbilt University Medical Center, Nashville, Tennessee; Department of Medicine, Jaume I University, Castellon de la Plana, Spain (J.V.S.-A.); Departments of Chemistry (M.G.F., C.W.L.), Pharmacology (M.G.F., A.L.B., D.W.E., C.S.H., C.W.L., J.S.D.), and Molecular Physiology and Biophysics (P.K.D., D.A.J.), and Mouse Metabolic Phenotyping Core (L.L.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Center for Neuroscience Drug Discovery, Franklin, Tennessee (D.W.E., A.L.B., C.W.L.)
| | - Darren W Engers
- Departments of Anesthesiology (S.V.K., J.S.D.) and Pediatrics (E.L.S.), Vanderbilt University Medical Center, Nashville, Tennessee; Department of Medicine, Jaume I University, Castellon de la Plana, Spain (J.V.S.-A.); Departments of Chemistry (M.G.F., C.W.L.), Pharmacology (M.G.F., A.L.B., D.W.E., C.S.H., C.W.L., J.S.D.), and Molecular Physiology and Biophysics (P.K.D., D.A.J.), and Mouse Metabolic Phenotyping Core (L.L.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Center for Neuroscience Drug Discovery, Franklin, Tennessee (D.W.E., A.L.B., C.W.L.)
| | - Christopher S Hofmann
- Departments of Anesthesiology (S.V.K., J.S.D.) and Pediatrics (E.L.S.), Vanderbilt University Medical Center, Nashville, Tennessee; Department of Medicine, Jaume I University, Castellon de la Plana, Spain (J.V.S.-A.); Departments of Chemistry (M.G.F., C.W.L.), Pharmacology (M.G.F., A.L.B., D.W.E., C.S.H., C.W.L., J.S.D.), and Molecular Physiology and Biophysics (P.K.D., D.A.J.), and Mouse Metabolic Phenotyping Core (L.L.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Center for Neuroscience Drug Discovery, Franklin, Tennessee (D.W.E., A.L.B., C.W.L.)
| | - Prasanna K Dadi
- Departments of Anesthesiology (S.V.K., J.S.D.) and Pediatrics (E.L.S.), Vanderbilt University Medical Center, Nashville, Tennessee; Department of Medicine, Jaume I University, Castellon de la Plana, Spain (J.V.S.-A.); Departments of Chemistry (M.G.F., C.W.L.), Pharmacology (M.G.F., A.L.B., D.W.E., C.S.H., C.W.L., J.S.D.), and Molecular Physiology and Biophysics (P.K.D., D.A.J.), and Mouse Metabolic Phenotyping Core (L.L.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Center for Neuroscience Drug Discovery, Franklin, Tennessee (D.W.E., A.L.B., C.W.L.)
| | - Louise Lantier
- Departments of Anesthesiology (S.V.K., J.S.D.) and Pediatrics (E.L.S.), Vanderbilt University Medical Center, Nashville, Tennessee; Department of Medicine, Jaume I University, Castellon de la Plana, Spain (J.V.S.-A.); Departments of Chemistry (M.G.F., C.W.L.), Pharmacology (M.G.F., A.L.B., D.W.E., C.S.H., C.W.L., J.S.D.), and Molecular Physiology and Biophysics (P.K.D., D.A.J.), and Mouse Metabolic Phenotyping Core (L.L.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Center for Neuroscience Drug Discovery, Franklin, Tennessee (D.W.E., A.L.B., C.W.L.)
| | - David A Jacobson
- Departments of Anesthesiology (S.V.K., J.S.D.) and Pediatrics (E.L.S.), Vanderbilt University Medical Center, Nashville, Tennessee; Department of Medicine, Jaume I University, Castellon de la Plana, Spain (J.V.S.-A.); Departments of Chemistry (M.G.F., C.W.L.), Pharmacology (M.G.F., A.L.B., D.W.E., C.S.H., C.W.L., J.S.D.), and Molecular Physiology and Biophysics (P.K.D., D.A.J.), and Mouse Metabolic Phenotyping Core (L.L.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Center for Neuroscience Drug Discovery, Franklin, Tennessee (D.W.E., A.L.B., C.W.L.)
| | - Craig W Lindsley
- Departments of Anesthesiology (S.V.K., J.S.D.) and Pediatrics (E.L.S.), Vanderbilt University Medical Center, Nashville, Tennessee; Department of Medicine, Jaume I University, Castellon de la Plana, Spain (J.V.S.-A.); Departments of Chemistry (M.G.F., C.W.L.), Pharmacology (M.G.F., A.L.B., D.W.E., C.S.H., C.W.L., J.S.D.), and Molecular Physiology and Biophysics (P.K.D., D.A.J.), and Mouse Metabolic Phenotyping Core (L.L.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Center for Neuroscience Drug Discovery, Franklin, Tennessee (D.W.E., A.L.B., C.W.L.)
| | - Jerod S Denton
- Departments of Anesthesiology (S.V.K., J.S.D.) and Pediatrics (E.L.S.), Vanderbilt University Medical Center, Nashville, Tennessee; Department of Medicine, Jaume I University, Castellon de la Plana, Spain (J.V.S.-A.); Departments of Chemistry (M.G.F., C.W.L.), Pharmacology (M.G.F., A.L.B., D.W.E., C.S.H., C.W.L., J.S.D.), and Molecular Physiology and Biophysics (P.K.D., D.A.J.), and Mouse Metabolic Phenotyping Core (L.L.), Vanderbilt University, Nashville, Tennessee; and Vanderbilt Center for Neuroscience Drug Discovery, Franklin, Tennessee (D.W.E., A.L.B., C.W.L.)
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14
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Li F, Wong R, Luo Z, Du L, Turlova E, Britto LRG, Feng ZP, Sun HS. Neuroprotective Effects of AG490 in Neonatal Hypoxic-Ischemic Brain Injury. Mol Neurobiol 2019; 56:8109-8123. [PMID: 31190145 DOI: 10.1007/s12035-019-01656-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/20/2019] [Indexed: 11/28/2022]
Abstract
In infants and children, neonatal hypoxic-ischemic (HI) brain injury represents a major cause of chronic neurological morbidity. The transient receptor potential melastatin 2 (TRPM2), a non-selective cation channel that conducts calcium, can mediate neuronal death following HI brain injury. An important endogenous activator of TRPM2 is H2O2, which has previously been reported to be upregulated in the neonatal brain after hypoxic ischemic injury. Here, incorporating both in vitro (H2O2-induced neuronal cell death model) and in vivo (mouse HI brain injury model) approaches, we examined the effects of AG490, which can inhibit the H2O2-induced TRPM2 channel. We found that AG490 elicited neuroprotective effects. We confirmed that AG490 reduced H2O2-induced TRPM2 currents. Specifically, application of AG490 to neurons ameliorated H2O2-induced cell injury in vitro. In addition, AG490 administration reduced brain damage and improved neurobehavioral performance following HI brain injury in vivo. The neuroprotective benefits of AG490 suggest that pharmacological inhibition of H2O2-activated TRPM2 currents can be exploited as a potential therapeutic strategy to treat HI-induced neurological complications.
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Affiliation(s)
- Feiya Li
- Department of Surgery, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.,Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Raymond Wong
- Department of Surgery, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.,Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Zhengwei Luo
- Department of Surgery, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.,Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Lida Du
- Department of Surgery, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.,Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Ekaterina Turlova
- Department of Surgery, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.,Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Luiz R G Britto
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Zhong-Ping Feng
- Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.
| | - Hong-Shuo Sun
- Department of Surgery, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada. .,Department of Physiology, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada. .,Department of Pharmacology and Toxicology, Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada. .,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.
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15
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Gerzanich V, Stokum JA, Ivanova S, Woo SK, Tsymbalyuk O, Sharma A, Akkentli F, Imran Z, Aarabi B, Sahuquillo J, Simard JM. Sulfonylurea Receptor 1, Transient Receptor Potential Cation Channel Subfamily M Member 4, and KIR6.2:Role in Hemorrhagic Progression of Contusion. J Neurotrauma 2018; 36:1060-1079. [PMID: 30160201 PMCID: PMC6446209 DOI: 10.1089/neu.2018.5986] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In severe traumatic brain injury (TBI), contusions often are worsened by contusion expansion or hemorrhagic progression of contusion (HPC), which may double the original contusion volume and worsen outcome. In humans and rodents with contusion-TBI, sulfonylurea receptor 1 (SUR1) is upregulated in microvessels and astrocytes, and in rodent models, blockade of SUR1 with glibenclamide reduces HPC. SUR1 does not function by itself, but must co-assemble with either KIR6.2 or transient receptor potential cation channel subfamily M member 4 (TRPM4) to form KATP (SUR1-KIR6.2) or SUR1-TRPM4 channels, with the two having opposite effects on membrane potential. Both KIR6.2 and TRPM4 are reportedly upregulated in TBI, especially in astrocytes, but the identity and function of SUR1-regulated channels post-TBI is unknown. Here, we analyzed human and rat brain tissues after contusion-TBI to characterize SUR1, TRPM4, and KIR6.2 expression, and in the rat model, to examine the effects on HPC of inhibiting expression of the three subunits using intravenous antisense oligodeoxynucleotides (AS-ODN). Glial fibrillary acidic protein (GFAP) immunoreactivity was used to operationally define core versus penumbral tissues. In humans and rats, GFAP-negative core tissues contained microvessels that expressed SUR1 and TRPM4, whereas GFAP-positive penumbral tissues contained astrocytes that expressed all three subunits. Förster resonance energy transfer imaging demonstrated SUR1-TRPM4 heteromers in endothelium, and SUR1-TRPM4 and SUR1-KIR6.2 heteromers in astrocytes. In rats, glibenclamide as well as AS-ODN targeting SUR1 and TRPM4, but not KIR6.2, reduced HPC at 24 h post-TBI. Our findings demonstrate upregulation of SUR1-TRPM4 and KATP after contusion-TBI, identify SUR1-TRPM4 as the primary molecular mechanism that accounts for HPC, and indicate that SUR1-TRPM4 is a crucial target of glibenclamide.
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Affiliation(s)
- Volodymyr Gerzanich
- 1 Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland
| | - Jesse A Stokum
- 1 Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland
| | - Svetlana Ivanova
- 1 Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland
| | - Seung Kyoon Woo
- 1 Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland
| | - Orest Tsymbalyuk
- 1 Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland
| | - Amit Sharma
- 1 Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland
| | - Fatih Akkentli
- 1 Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland
| | - Ziyan Imran
- 1 Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland
| | - Bizhan Aarabi
- 1 Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland
| | - Juan Sahuquillo
- 2 Neurotraumatology and Neurosurgery Research Unit, Vall d'Hebron University Hospital, Universitat Autònoma de Barcelona, Barcelona, Spain.,3 Department of Neurosurgery, Vall d'Hebron University Hospital, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - J Marc Simard
- 1 Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland.,4 Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland.,5 Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland
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16
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Tinker A, Aziz Q, Li Y, Specterman M. ATP‐Sensitive Potassium Channels and Their Physiological and Pathophysiological Roles. Compr Physiol 2018; 8:1463-1511. [DOI: 10.1002/cphy.c170048] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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17
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Synaptic transmission and excitability during hypoxia with inflammation and reoxygenation in hippocampal CA1 neurons. Neuropharmacology 2018; 138:20-31. [PMID: 29775678 DOI: 10.1016/j.neuropharm.2018.05.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/19/2018] [Accepted: 05/08/2018] [Indexed: 12/30/2022]
Abstract
Although a number of experimental and clinical studies have shown that hypoxia typically accompanies acute inflammatory responses, the combinatorial effect of the two insults on basic neural function has not been thoroughly investigated. Previous studies have predominantly suggested that hypoxia reduces network activity; however, several studies suggest the opposite effect. Of note, inflammation is known to increase neural activity. In the current study, we examined the effects of limited oxygen in combination with an inflammatory stimulus, as well as the effects of reoxygenation, on synaptic transmission and excitability. We observed a significant reduction of both synaptic transmission and excitability when hypoxia and inflammation occurred in combination, whereas reoxygenation caused hyperexcitability of neurons. Further, we found that the observed reduction in synaptic transmission was due to compromised presynaptic release efficiency based on an adenosine-receptor-dependent increase in synaptic facilitation. Excitability changes in both directions were attributable to dynamic regulation of the hyperpolarization-activated cation current (Ih) and to changes in the input resistance and the voltage difference between resting membrane potential and action potential threshold. We found that zatebradine, an Ih current inhibitor, reduced the fluctuation in excitability, suggesting that it may have potential as a drug to ameliorate reperfusion brain injury.
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18
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Possible involvement of monoamine neurons in the emotional abnormality in Kir6.2-deficient mice. Physiol Behav 2018; 188:251-261. [PMID: 29432787 DOI: 10.1016/j.physbeh.2018.02.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 02/07/2018] [Accepted: 02/07/2018] [Indexed: 11/24/2022]
Abstract
ATP-sensitive potassium (KATP) channels consist of two structurally different subunits: a pore-forming subunit of the Kir6.0-family (Kir6.1 or Kir6.2) and a regulatory sulfonylurea receptor subunit (SUR1, SUR2A or SUR2B). Although Kir6.2 is widely distributed in the brain, the mechanisms that underlie the impact of Kir6.2 on emotional behavior are not yet fully understood. To clarify the role of Kir6.2 in emotional behavior, in the present study, we investigated the behavioral characteristics of Kir6.2-knockout (Kir6.2-/-) mice. Kir6.2-/- mice showed impaired general behavior in a locomotor activity test and open field test. In addition, anxiety-like behavior was observed in the open field test, elevated plus-maze test and light-dark test. In particular, excessive anxiety-like behavior was observed in female Kir6.2-/- mice. Moreover, we investigated whether Kir6.2 is expressed on monoamine neurons in the brain. Immunohistochemical studies showed that Kir6.2 was co-localized with tryptophan hydroxylase (TPH), a marker of serotonergic neurons, in dorsal raphe nuclei. Kir6.2 was also co-localized with tyrosine hydroxylase (TH), a marker of dopaminergic/noradrenergic neurons, in the ventral tegmental area and locus coeruleus. Next, we checked the protein levels of TH and TPH in the midbrain. Interestingly, TPH expression was significantly elevated in female Kir6.2-/- mice. These results suggest that Kir6.2 in monoamine neurons, especially serotonergic neurons, could play a key role in emotional behavior.
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Szeto V, Chen NH, Sun HS, Feng ZP. The role of K ATP channels in cerebral ischemic stroke and diabetes. Acta Pharmacol Sin 2018; 39:683-694. [PMID: 29671418 PMCID: PMC5943906 DOI: 10.1038/aps.2018.10] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/19/2018] [Indexed: 12/18/2022] Open
Abstract
ATP-sensitive potassium (KATP) channels are ubiquitously expressed on the plasma membrane of cells in multiple organs, including the heart, pancreas and brain. KATP channels play important roles in controlling and regulating cellular functions in response to metabolic state, which are inhibited by ATP and activated by Mg-ADP, allowing the cell to couple cellular metabolic state (ATP/ADP ratio) to electrical activity of the cell membrane. KATP channels mediate insulin secretion in pancreatic islet beta cells, and controlling vascular tone. Under pathophysiological conditions, KATP channels play cytoprotective role in cardiac myocytes and neurons during ischemia and/or hypoxia. KATP channel is a hetero-octameric complex, consisting of four pore-forming Kir6.x and four regulatory sulfonylurea receptor SURx subunits. These subunits are differentially expressed in various cell types, thus determining the sensitivity of the cells to specific channel modifiers. Sulfonylurea class of antidiabetic drugs blocks KATP channels, which are neuroprotective in stroke, can be one of the high stoke risk factors for diabetic patients. In this review, we discussed the potential effects of KATP channel blockers when used under pathological conditions related to diabetics and cerebral ischemic stroke.
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Affiliation(s)
- Vivian Szeto
- Departments of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Nai-hong Chen
- Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Hong-shuo Sun
- Departments of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada M5S 1A8
- Surgery
- Pharmacology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Zhong-ping Feng
- Departments of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada M5S 1A8
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20
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Kotoda M, Ishiyama T, Mitsui K, Hishiyama S, Matsukawa T. Nicorandil increased the cerebral blood flow via nitric oxide pathway and ATP-sensitive potassium channel opening in mice. J Anesth 2018; 32:244-249. [DOI: 10.1007/s00540-018-2471-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 02/17/2018] [Indexed: 11/29/2022]
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21
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Salgado-Puga K, Rodríguez-Colorado J, Prado-Alcalá RA, Peña-Ortega F. Subclinical Doses of ATP-Sensitive Potassium Channel Modulators Prevent Alterations in Memory and Synaptic Plasticity Induced by Amyloid-β. J Alzheimers Dis 2018; 57:205-226. [PMID: 28222502 DOI: 10.3233/jad-160543] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In addition to coupling cell metabolism and excitability, ATP-sensitive potassium channels (KATP) are involved in neural function and plasticity. Moreover, alterations in KATP activity and expression have been observed in Alzheimer's disease (AD) and during amyloid-β (Aβ)-induced pathology. Thus, we tested whether KATP modulators can influence Aβ-induced deleterious effects on memory, hippocampal network function, and plasticity. We found that treating animals with subclinical doses (those that did not change glycemia) of a KATP blocker (Tolbutamide) or a KATP opener (Diazoxide) differentially restrained Aβ-induced memory deficit, hippocampal network activity inhibition, and long-term synaptic plasticity unbalance (i.e., inhibition of LTP and promotion of LTD). We found that the protective effect of Tolbutamide against Aβ-induced memory deficit was strong and correlated with the reestablishment of synaptic plasticity balance, whereas Diazoxide treatment produced a mild protection against Aβ-induced memory deficit, which was not related to a complete reestablishment of synaptic plasticity balance. Interestingly, treatment with both KATP modulators renders the hippocampus resistant to Aβ-induced inhibition of hippocampal network activity. These findings indicate that KATP are involved in Aβ-induced pathology and they heighten the potential role of KATP modulation as a plausible therapeutic strategy against AD.
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Affiliation(s)
- Karla Salgado-Puga
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, QRO, México
| | - Javier Rodríguez-Colorado
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, QRO, México
| | - Roberto A Prado-Alcalá
- Departamento de Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, QRO, México
| | - Fernando Peña-Ortega
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, QRO, México
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22
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Nitric Oxide Regulates The Lymphatic Reactivity Following Hemorrhagic Shock Through Atp-Sensitive Potassium Channel. Shock 2018; 45:668-76. [PMID: 26796572 DOI: 10.1097/shk.0000000000000562] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Lymphatic reactivity has been shown to exhibit a biphasic change following hemorrhagic shock, and nitric oxide (NO) is involved in this process. However, the precise mechanism responsible for NO regulation of the lymphatic reactivity along with the progression of hemorrhagic shock is unclear. Therefore, the present study was to investigate how NO participates in regulating the shock-induced biphasic changes in lymphatic reactivity and its underlying mechanisms. First, the expressions or contents of inducible NO synthase, nitrite plus nitrate, and elements of cAMP-PKA-KATP and cGMP-PKG-KATP pathway in thoracic ducts tissue were assessed. The results revealed that levels of nitrite plus nitrate, cAMP, cyclic guanosine monophosphate (cGMP), p-PKA, and p-PKG were increased gradually along with the process of shock. Second, the roles of cAMP-PKA-KATP and cGMP-PKG-KATP in NO regulating lymphatic response to gradient substance P were evaluated with an isolated lymphatic perfusion system. The results showed that the NOS substrate (L-Arg), PKA donor (8-Br-cAMP) decreased the reactivity of shock 0.5 h-lymphatics, and that the PKA inhibitor (H-89) and KATP inhibitor (glibenclamide) restrained the effects of L-Arg while glibenclamide abolished the effects of 8-Br-cAMP. Meanwhile, NOS antagonist (L-NAME), protein kinase G (PKG) inhibitor (KT-5823), and soluble guanylate cyclase inhibitor (ODQ) increased the reactivity of shock 2 h-lymphatics, whereas KATP opener (pinacidil) inhibited these elevated effects induced by either L-NAME, ODQ, or KT-5823. Taken together, these results indicate that NO regulation of lymphatic reactivity during shock involves both cAMP-PKA-KATP and cGMP-PKG-KATP pathways. These findings have potential significance for the treatment of hemorrhagic shock through regulating lymphatic reactivity.
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23
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Martínez-François JR, Fernández-Agüera MC, Nathwani N, Lahmann C, Burnham VL, Danial NN, Yellen G. BAD and K ATP channels regulate neuron excitability and epileptiform activity. eLife 2018; 7:32721. [PMID: 29368690 PMCID: PMC5785210 DOI: 10.7554/elife.32721] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 01/12/2018] [Indexed: 12/17/2022] Open
Abstract
Brain metabolism can profoundly influence neuronal excitability. Mice with genetic deletion or alteration of Bad (BCL-2 agonist of cell death) exhibit altered brain-cell fuel metabolism, accompanied by resistance to acutely induced epileptic seizures; this seizure protection is mediated by ATP-sensitive potassium (KATP) channels. Here we investigated the effect of BAD manipulation on KATP channel activity and excitability in acute brain slices. We found that BAD’s influence on neuronal KATP channels was cell-autonomous and directly affected dentate granule neuron (DGN) excitability. To investigate the role of neuronal KATP channels in the anticonvulsant effects of BAD, we imaged calcium during picrotoxin-induced epileptiform activity in entorhinal-hippocampal slices. BAD knockout reduced epileptiform activity, and this effect was lost upon knockout or pharmacological inhibition of KATP channels. Targeted BAD knockout in DGNs alone was sufficient for the antiseizure effect in slices, consistent with a ‘dentate gate’ function that is reinforced by increased KATP channel activity.
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Affiliation(s)
| | | | - Nidhi Nathwani
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Carolina Lahmann
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Veronica L Burnham
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Nika N Danial
- Department of Neurobiology, Harvard Medical School, Boston, United States.,Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, United States
| | - Gary Yellen
- Department of Neurobiology, Harvard Medical School, Boston, United States
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24
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Abstract
Oncotic cell death or oncosis represents a major mechanism of cell death in ischaemic stroke, occurring in many central nervous system (CNS) cell types including neurons, glia and vascular endothelial cells. In stroke, energy depletion causes ionic pump failure and disrupts ionic homeostasis. Imbalance between the influx of Na+ and Cl- ions and the efflux of K+ ions through various channel proteins and transporters creates a transmembrane osmotic gradient, with ensuing movement of water into the cells, resulting in cell swelling and oncosis. Oncosis is a key mediator of cerebral oedema in ischaemic stroke, contributing directly through cytotoxic oedema, and indirectly through vasogenic oedema by causing vascular endothelial cell death and disruption of the blood-brain barrier (BBB). Hence, inhibition of uncontrolled ionic flux represents a novel and powerful strategy in achieving neuroprotection in stroke. In this review, we provide an overview of oncotic cell death in the pathology of stroke. Importantly, we summarised the therapeutically significant pathways of water, Na+, Cl- and K+ movement across cell membranes in the CNS and their respective roles in the pathobiology of stroke.
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25
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Xiao AJ, He L, Ouyang X, Liu JM, Chen MR. Comparison of the anti-apoptotic effects of 15- and 35-minute suspended moxibustion after focal cerebral ischemia/reperfusion injury. Neural Regen Res 2018; 13:257-264. [PMID: 29557375 PMCID: PMC5879897 DOI: 10.4103/1673-5374.226396] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Heat-sensitive suspended moxibustion has a neuroprotective effect against focal cerebral ischemia/reperfusion injury, but the underlying mechanisms remain unclear. The duration of heat-sensitive suspended moxibustion (usually from 30 minutes to 1 hour) is longer than traditional suspended moxibustion (usually 15 minutes). However, the effects of 15- and 35-minute suspended moxibustion in rats with cerebral ischemia/reperfusion injury are poorly understood. In this study, we performed 15- or 35-minute suspended moxibustion at acupoint Dazhui (GV14) in an adult rat model of focal cerebral ischemia/reperfusion injury. Infarct volume was evaluated with the 2,3,5-triphenyltetrazolium chloride assay. Histopathological changes and neuronal apoptosis at the injury site were assessed by hematoxylin-eosin staining and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Caspase-9 and caspase-3 expression at the injury site was detected using immunofluorescent staining. Bax and Bcl-2 expression at the injury site was assessed using western blot assay. In the 35-minute moxibustion group, infarct volume was decreased, neuronal apoptosis was reduced, caspase-9, caspase-3 and Bax expression was lower, and Bcl-2 expression was increased, compared with the 15-minute moxibustion group. Our findings show that 35-minute moxibustion has a greater anti-apoptotic effect than 15-minute moxibustion after focal cerebral ischemia/reperfusion injury.
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Affiliation(s)
- Ai-Jiao Xiao
- School of Basic Medical Science, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi Province, China
| | - Lin He
- School of Basic Medical Science, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi Province, China
| | - Xin Ouyang
- School of Moxibustion, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi Province, China
| | - Jie-Min Liu
- School of Basic Medical Science, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi Province, China
| | - Ming-Ren Chen
- School of Moxibustion, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi Province, China
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26
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Modulation Effects of Cordycepin on Voltage-Gated Sodium Channels in Rat Hippocampal CA1 Pyramidal Neurons in the Presence/Absence of Oxygen. Neural Plast 2017; 2017:2459053. [PMID: 29225974 PMCID: PMC5684588 DOI: 10.1155/2017/2459053] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 10/04/2017] [Indexed: 12/11/2022] Open
Abstract
Our previous study revealed that cordycepin features important neuroprotective effects against hypoxic insult by improvement of neuronal electrophysiological function. Modulation on voltage-gated sodium channel (VGSC) in CA1 neurons is the initial event during hypoxia/ischemia. However, no study comprehensively investigated cordycepin on VGSC. Hence, this study investigated modulation effects of cordycepin on VGSC not only in oxygen physiological conditions but also in acute oxygen deprivation injury conditions. Results revealed that cordycepin (80 μM) reduced the amplitude of VGSC currents (INa) (77.6% of control, p < 0.01) within 1 min of drug exposure coupled with a negative shift in steady-state inactivation and prolonged recovery time course from inactivation. Additionally, this mild reduction on the peak of INa induced by the pretreatment with cordycepin can attenuate and delay the following hypoxia causing rapid dramatic decrease in INa with no additive change in the voltage dependence of inactivation. As modulation on VGSC in CA1 neurons represents the initial event during ischemia, we propose that suppression effect of cordycepin on VGSC is an important neuronal protective mechanism that may enhance neuronal tolerance to acute oxygen deprivation and delay hypoxia-induced neuronal injuries.
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27
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Wu J, Sun Z, Sun HS, Wu J, Weisel RD, Keating A, Li ZH, Feng ZP, Li RK. Intravenously Administered Bone Marrow Cells Migrate to Damaged Brain Tissue and Improve Neural Function in Ischemic Rats. Cell Transplant 2017; 16:993-1005. [DOI: 10.3727/000000007783472435] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Accumulated evidence suggests that bone marrow stromal cells (BMSCs) are capable of regenerating damaged tissue. This study evaluated whether intravenously (noninvasively) administered, GFP-labeled BMSCs would migrate into damaged brain tissue and improve neurological function after a stroke. Wistar rats were subjected to middle cerebral artery occlusion and reperfusion. Twenty-four hours after injury, the rats received an IV injection of culture medium or BMSCs isolated from adult Wistar rats expressing green fluorescent protein (GFP). Two hours after injury and 1, 3, and 7 days after cell transplantation, neurological function was evaluated using a neurological severity scale. On day 7, the brain scar size was determined using tetrazolium chloride staining, and the implanted cells were identified using confocal microscopy. Immunohistochemistry was used to evaluate apoptosis and angiogenesis in the ischemic region, as well as the spatial distribution of the implanted BMSCs relative to the native neural cells. Implanted BMSCs migrated throughout the territory of the middle cerebral artery by 7 days after transplantation. Most implanted cells were located in the scar area and border zone of the ischemic region, and some expressed the neuronal marker NeuN. Rats receiving BMSC transplantation exhibited reduced scar size, limited apoptosis, and enhanced angiogenic factor expression and vascular density in the ischemic region relative to the control group, as well as significant improvements in the neurological severity scores. Intravenously administrated BMSCs facilitated the structural and functional recovery of neural tissue following ischemic injury, perhaps mediated by enhanced angiogenesis.
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Affiliation(s)
- Jiang Wu
- Division of Cardiovascular Surgery, Toronto General Research Institute and University of Toronto, Toronto, Ontario, Canada
- Department of Neurology, Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Zhuo Sun
- Division of Cardiovascular Surgery, Toronto General Research Institute and University of Toronto, Toronto, Ontario, Canada
| | - Hong-Shuo Sun
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Jun Wu
- Division of Cardiovascular Surgery, Toronto General Research Institute and University of Toronto, Toronto, Ontario, Canada
| | - Richard D. Weisel
- Division of Cardiovascular Surgery, Toronto General Research Institute and University of Toronto, Toronto, Ontario, Canada
| | - Armand Keating
- Division of Stem Cell and Developmental Biology, Toronto General Research Institute and University of Toronto, Toronto, Ontario, Canada
| | - Zhi-Hong Li
- Division of Cardiovascular Surgery, Toronto General Research Institute and University of Toronto, Toronto, Ontario, Canada
| | - Zhong-Ping Feng
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Ren-Ke Li
- Division of Cardiovascular Surgery, Toronto General Research Institute and University of Toronto, Toronto, Ontario, Canada
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28
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Bonnet F, Scheen AJ. Impact of glucose-lowering therapies on risk of stroke in type 2 diabetes. DIABETES & METABOLISM 2017; 43:299-313. [PMID: 28522196 DOI: 10.1016/j.diabet.2017.04.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Accepted: 04/21/2017] [Indexed: 02/07/2023]
Abstract
Patients with type 2 diabetes (T2D) have an increased risk of stroke compared with people without diabetes. However, the effects of glucose-lowering drugs on risk of ischaemic stroke in T2D have been less extensively investigated than in coronary heart disease. Some evidence, including the UKPDS, has suggested a reduced risk of stroke with metformin, although the number of studies is limited. Inhibition of the KATP channels increases ischaemic brain lesions in animals. This is in agreement with a recent meta-analysis showing an increased risk of stroke with sulphonylureas vs. various comparators as both mono- and combination therapy. Pioglitazone can prevent recurrence of stroke in patients with previous stroke, as already shown in PROactive, although results are less clear for first strokes. As for DPP-4 inhibitors, there was a non-significant trend towards benefit for stroke, whereas a possible increased risk of stroke with SGLT2 inhibitors-and in particular, empagliflozin in the EMPA-REG OUTCOME trial-has been suggested and requires clarification. Experimental results support a potential protective effect of GLP-1 receptor agonists against stroke that has, at least in part, been translated to clinical benefits in T2D patients in the LEADER and SUSTAIN-6 trials. Further interventional studies are now warranted to confirm the effects of glucose-lowering agents on risk of stroke in patients with T2D. In summary, the effects of antidiabetic drugs on risk of stroke appear to be heterogeneous, with some therapies (pioglitazone, GLP-1 receptor agonists) conferring possible protection against ischaemic stroke, other classes showing a neutral impact (DPP-4 inhibitors, insulin) and some glucose-lowering agents being associated with an increased risk of stroke (sulphonylureas, possibly SGLT2 inhibitors, high-dose insulin in the presence of insulin resistance).
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Affiliation(s)
- F Bonnet
- Centre Hospitalier Universitaire de Rennes, Université Rennes 1, Rennes, France; INSERM U1018, Villejuif, France.
| | - A J Scheen
- Division of Clinical Pharmacology, Centre for Interdisciplinary Research on Medicines (CIRM), University of Liège, Liège, Belgium; Division of Diabetes, Nutrition and Metabolic Disorders, Department of Medicine, CHU, Liège, Belgium
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29
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Sun HS. Role of TRPM7 in cerebral ischaemia and hypoxia. J Physiol 2017; 595:3077-3083. [PMID: 27891609 DOI: 10.1113/jp273709] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 11/11/2016] [Indexed: 01/07/2023] Open
Abstract
Transient receptor potential melastatin 7 (TRPM7) channel, a calcium-permeable non-selective divalent cation channel, is broadly expressed in various cells and tissues, including the brain. TRPM7 is thought to be coupled to the metabolic state and regulate calcium homeostasis in the cell. TRPM7 takes part in a wide range of cell biology processes that affect cell growth and proliferation, as well as in embryonic development and skeleton formation. TRPM7 plays a significant role in ischaemic and hypoxic brain injury and neuronal cell death. TRPM7, as a key non-glutamate mechanism of cerebral ischaemia, also triggers an intracellular ionic imbalance and neuronal cell death in ischaemia and hypoxia. We have reported that TRPM7 is expressed in neurons of the hippocampus and cortex and activation of TRPM7 induced ischaemic neuronal cell death; suppression of TRPM7 with virally mediated gene silencing using siRNA reduced ischaemic neuronal cell death and improved neurobehavioural outcomes in vivo. Recently, we also demonstrated that inhibition of TRPM7 using pharmacological means promoted neuronal outgrowth in vitro and provided neuroprotection against brain injury to hypoxia in vivo. Thus, we have shown the contributions of TRPM7 in many physiological and pathophysiological processes, including hypoxia and ischaemia.
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Affiliation(s)
- Hong-Shuo Sun
- Departments of Surgery, Physiology, and Pharmacology, Institute of Medical Science, Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada, M5S 1A8
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30
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Fogle KJ, Hertzler JI, Shon JH, Palladino MJ. The ATP-sensitive K channel is seizure protective and required for effective dietary therapy in a model of mitochondrial encephalomyopathy. J Neurogenet 2016; 30:247-258. [PMID: 27868454 DOI: 10.1080/01677063.2016.1252765] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Effective therapies are lacking for mitochondrial encephalomyopathies (MEs). MEs are devastating diseases that predominantly affect the energy-demanding tissues of the nervous system and muscle, causing symptoms such as seizures, cardiomyopathy, and neuro- and muscular degeneration. Even common anti-epileptic drugs which are frequently successful in ameliorating seizures in other diseases tend to have a lower success rate in ME, highlighting the need for novel drug targets, especially those that may couple metabolic sensitivity to neuronal excitability. Furthermore, alternative epilepsy therapies such as dietary modification are gaining in clinical popularity but have not been thoroughly studied in ME. Using the Drosophila ATP61 model of ME, we have studied dietary therapy throughout disease progression and found that it is highly effective against the seizures of ME, especially a high fat/ketogenic diet, and that the benefits are dependent upon a functional KATP channel complex. Further experiments with KATP show that it is seizure-protective in this model, and that pharmacological promotion of its open state also ameliorates seizures. These studies represent important steps forward in the development of novel therapies for a class of diseases that is notoriously difficult to treat, and lay the foundation for mechanistic studies of currently existing therapies in the context of metabolic disease.
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Affiliation(s)
- Keri J Fogle
- a Department of Pharmacology & Chemical Biology , University of Pittsburgh School of Medicine , Pittsburgh , PA , USA.,b Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine , Pittsburgh , PA , USA
| | - J Ian Hertzler
- a Department of Pharmacology & Chemical Biology , University of Pittsburgh School of Medicine , Pittsburgh , PA , USA.,b Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine , Pittsburgh , PA , USA
| | - Joy H Shon
- a Department of Pharmacology & Chemical Biology , University of Pittsburgh School of Medicine , Pittsburgh , PA , USA.,b Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine , Pittsburgh , PA , USA
| | - Michael J Palladino
- a Department of Pharmacology & Chemical Biology , University of Pittsburgh School of Medicine , Pittsburgh , PA , USA.,b Pittsburgh Institute for Neurodegenerative Diseases (PIND), University of Pittsburgh School of Medicine , Pittsburgh , PA , USA
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31
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Liu R, Wang H, Xu B, Chen W, Turlova E, Dong N, Sun CLF, Lu Y, Fu H, Shi R, Barszczyk A, Yang D, Jin T, Mannucci E, Feng ZP, Sun HS. Cerebrovascular Safety of Sulfonylureas: The Role of KATP Channels in Neuroprotection and the Risk of Stroke in Patients With Type 2 Diabetes. Diabetes 2016; 65:2795-809. [PMID: 27207539 DOI: 10.2337/db15-1737] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 05/11/2016] [Indexed: 11/13/2022]
Abstract
Sulfonylureas are ATP-sensitive potassium (KATP) channel blockers commonly used in the treatment of type 2 diabetes mellitus (T2DM). Activation of KATP channels plays a neuroprotective role in ischemia; thus, whether sulfonylureas affect the outcomes of stroke in patients with T2DM needs to be further studied. In our study, streptozotocin (STZ)-induced diabetic mice subjected to transient middle cerebral artery occlusion (MCAO) showed larger areas of brain damage and poorer behavioral outcomes. Blocking the KATP channel by tolbutamide increased neuronal injury induced by oxygen-glucose deprivation (OGD) in vitro and permanent MCAO (pMCAO) in vivo. Activating the KATP channel by diazoxide reduced the effects of both the OGD and pMCAO. Western blot analysis in STZ mouse brains indicated an early increase in protein levels of N-methyl-d-aspartate receptor 2B and postsynaptic density protein-95, followed by a decrease in phosphorylation of glycogen synthase kinase 3β. Our systematic meta-analysis indicated that patients with T2DM treated with sulfonylureas had a higher odds ratio for stroke morbidity than those who received comparator drugs. Taken together, these results suggest that sulfonylurea treatment in patients with T2DM may inhibit the neuroprotective effects of KATP channels and increase the risk of stroke.
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Affiliation(s)
- Rui Liu
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Haitao Wang
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Baofeng Xu
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Wenliang Chen
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada Department of Pharmacology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Ekaterina Turlova
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Nan Dong
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Christopher L F Sun
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Yangqingqin Lu
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Hanhui Fu
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Ranran Shi
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Andrew Barszczyk
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Dongzi Yang
- Department of Obstetrics and Gynecology, Memorial Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Tianru Jin
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Edoardo Mannucci
- Diabetology, Careggi Hospital, University of Florence, Florence, Italy
| | - Zhong-Ping Feng
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Hong-Shuo Sun
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada Department of Pharmacology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
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32
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Parkinson FE, Hatch GM. Is There Enhanced Risk of Cerebral Ischemic Stroke by Sulfonylureas in Type 2 Diabetes? Diabetes 2016; 65:2479-81. [PMID: 27555575 DOI: 10.2337/dbi16-0037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Fiona E Parkinson
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Canada
| | - Grant M Hatch
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Canada
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33
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Mehrjerdi FZ, Aboutaleb N, Pazoki-Toroudi H, Soleimani M, Ajami M, Khaksari M, Safari F, Habibey R. The Protective Effect of Remote Renal Preconditioning Against Hippocampal Ischemia Reperfusion Injury: Role of KATP Channels. J Mol Neurosci 2015; 57:554-60. [DOI: 10.1007/s12031-015-0636-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Accepted: 07/28/2015] [Indexed: 12/23/2022]
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34
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Kawano T. Potentiation of neuronal ATP-sensitive potassium channels as a novel target for neuropathic pain. Nihon Yakurigaku Zasshi 2015; 146:10-5. [PMID: 26165336 DOI: 10.1254/fpj.146.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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35
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Ji J, Yan H, Chen ZZ, Zhao Z, Yang DD, Sun XL, Shi YP. Iptakalim protects against ischemic injury by improving neurovascular unit function in the mouse brain. Clin Exp Pharmacol Physiol 2015; 42:766-71. [DOI: 10.1111/1440-1681.12426] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 05/12/2015] [Accepted: 05/13/2015] [Indexed: 01/06/2023]
Affiliation(s)
- Juan Ji
- Department of Pharmacology; Nanjing Medical University; Nanjing China
| | - Hui Yan
- Department of Pharmacology; Nanjing Medical University; Nanjing China
| | - Zheng-Zhen Chen
- Department of Pharmacology; Nanjing Medical University; Nanjing China
| | - Zhan Zhao
- Department of Pharmacology; Nanjing Medical University; Nanjing China
| | - Dan-Dan Yang
- Department of Pharmacology; Nanjing Medical University; Nanjing China
| | - Xiu-Lan Sun
- Department of Pharmacology; Nanjing Medical University; Nanjing China
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Longden TA, Nelson MT. Vascular inward rectifier K+ channels as external K+ sensors in the control of cerebral blood flow. Microcirculation 2015; 22:183-96. [PMID: 25641345 PMCID: PMC4404517 DOI: 10.1111/micc.12190] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 01/16/2015] [Indexed: 12/25/2022]
Abstract
For decades it has been known that external K(+) ions are rapid and potent vasodilators that increase CBF. Recent studies have implicated the local release of K(+) from astrocytic endfeet-which encase the entirety of the parenchymal vasculature-in the dynamic regulation of local CBF during NVC. It has been proposed that the activation of KIR channels in the vascular wall by external K(+) is a central component of these hyperemic responses; however, a number of significant gaps in our knowledge remain. Here, we explore the concept that vascular KIR channels are the major extracellular K(+) sensors in the control of CBF. We propose that K(+) is an ideal mediator of NVC, and discuss KIR channels as effectors that produce rapid hyperpolarization and robust vasodilation of cerebral arterioles. We provide evidence that KIR channels, of the KIR 2 subtype in particular, are present in both the endothelial and SM cells of parenchymal arterioles and propose that this dual positioning of KIR 2 channels increases the robustness of the vasodilation to external K(+), enables the endothelium to be actively engaged in NVC, and permits electrical signaling through the endothelial syncytium to promote upstream vasodilation to modulate CBF.
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Affiliation(s)
- Thomas A Longden
- Department of Pharmacology, College of Medicine, University of Vermont, Burlington, Vermont, USA
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Metabolism regulates the spontaneous firing of substantia nigra pars reticulata neurons via KATP and nonselective cation channels. J Neurosci 2015; 34:16336-47. [PMID: 25471572 DOI: 10.1523/jneurosci.1357-14.2014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Neurons use glucose to fuel glycolysis and provide substrates for mitochondrial respiration, but neurons can also use alternative fuels that bypass glycolysis and feed directly into mitochondria. To determine whether neuronal pacemaking depends on active glucose metabolism, we switched the metabolic fuel from glucose to alternative fuels, lactate or β-hydroxybutyrate, while monitoring the spontaneous firing of GABAergic neurons in mouse substantia nigra pars reticulata (SNr) brain slices. We found that alternative fuels, in the absence of glucose, sustained SNr spontaneous firing at basal rates, but glycolysis may still be supported by glycogen in the absence of glucose. To prevent any glycogen-fueled glycolysis, we directly inhibited glycolysis using either 2-deoxyglucose or iodoacetic acid. Inhibiting glycolysis in the presence of alternative fuels lowered SNr firing to a slower sustained firing rate. Surprisingly, we found that the decrease in SNr firing was not mediated by ATP-sensitive potassium (KATP) channel activity, but if we lowered the perfusion flow rate or omitted the alternative fuel, KATP channels were activated and could silence SNr firing. The KATP-independent slowing of SNr firing that occurred with glycolytic inhibition in the presence of alternative fuels was consistent with a decrease in a nonselective cationic conductance. Although mitochondrial metabolism alone can prevent severe energy deprivation and KATP channel activation in SNr neurons, active glucose metabolism appears important for keeping open a class of ion channels that is crucial for the high spontaneous firing rate of SNr neurons.
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38
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Inhibitory effects of imperatorin on voltage-gated K+ channels and ATP-sensitive K+ channels. Pharmacol Rep 2015; 67:134-9. [DOI: 10.1016/j.pharep.2014.08.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 08/13/2014] [Accepted: 08/13/2014] [Indexed: 11/24/2022]
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Lund TM, Ploug KB, Iversen A, Jensen AA, Jansen-Olesen I. The metabolic impact of β-hydroxybutyrate on neurotransmission: Reduced glycolysis mediates changes in calcium responses and KATP channel receptor sensitivity. J Neurochem 2015; 132:520-31. [PMID: 25330271 DOI: 10.1111/jnc.12975] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 10/06/2014] [Accepted: 10/13/2014] [Indexed: 11/30/2022]
Abstract
Glucose is the main energy substrate for neurons, and ketone bodies are known to be alternative substrates. However, the capacity of ketone bodies to support different neuronal functions is still unknown. Thus, a change in energy substrate from glucose alone to a combination of glucose and β-hydroxybutyrate might change neuronal function as there is a known coupling between metabolism and neurotransmission. The purpose of this study was to shed light on the effects of the ketone body β-hydroxybutyrate on glycolysis and neurotransmission in cultured murine glutamatergic neurons. Previous studies have shown an effect of β-hydroxybutyrate on glucose metabolism, and the present study further specified this by showing attenuation of glycolysis when β-hydroxybutyrate was present in these neurons. In addition, the NMDA receptor-induced calcium responses in the neurons were diminished in the presence of β-hydroxybutyrate, whereas a direct effect of the ketone body on transmitter release was absent. However, the presence of β-hydroxybutyrate augmented transmitter release induced by the KATP channel blocker glibenclamide, thus giving an indirect indication of the involvement of KATP channels in the effects of ketone bodies on transmitter release. Energy metabolism and neurotransmission are linked and involve ATP-sensitive potassium (KATP ) channels. However, it is still unclear how and to what degree available energy substrate affects this link. We investigated the effect of changing energy substrate from only glucose to a combination of glucose and R-β-hydroxybutyrate in cultured neurons. Using the latter combination, glycolysis was diminished, NMDA receptor-induced calcium responses were lower, and the KATP channel blocker glibenclamide caused a higher transmitter release.
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Affiliation(s)
- Trine M Lund
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kenneth B Ploug
- Danish Headache Center, Department of Neurology and Research Institute, Glostrup Hospital, University of Copenhagen, Glostrup, Denmark
| | - Anne Iversen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Danish Headache Center, Department of Neurology and Research Institute, Glostrup Hospital, University of Copenhagen, Glostrup, Denmark
| | - Anders A Jensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Inger Jansen-Olesen
- Danish Headache Center, Department of Neurology and Research Institute, Glostrup Hospital, University of Copenhagen, Glostrup, Denmark
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Sun HS, Xu B, Chen W, Xiao A, Turlova E, Alibraham A, Barszczyk A, Bae CYJ, Quan Y, Liu B, Pei L, Sun CLF, Deurloo M, Feng ZP. Neuronal K(ATP) channels mediate hypoxic preconditioning and reduce subsequent neonatal hypoxic-ischemic brain injury. Exp Neurol 2014; 263:161-71. [PMID: 25448006 DOI: 10.1016/j.expneurol.2014.10.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 08/23/2014] [Accepted: 10/10/2014] [Indexed: 12/16/2022]
Abstract
Neonatal hypoxic-ischemic brain injury and its related illness hypoxic-ischemic encephalopathy (HIE) are major causes of nervous system damage and neurological morbidity in children. Hypoxic preconditioning (HPC) is known to be neuroprotective in cerebral ischemic brain injury. K(ATP) channels are involved in ischemic preconditioning in the heart; however the involvement of neuronal K(ATP) channels in HPC in the brain has not been fully investigated. In this study, we investigated the role of HPC in hypoxia-ischemia (HI)-induced brain injury in postnatal seven-day-old (P7) CD1 mouse pups. Specifically, TTC (2,3,5-triphenyltetrazolium chloride) staining was used to assess the infarct volume, TUNEL (Terminal deoxynucleotidyl transferase mediated dUTP nick end-labeling) to detect apoptotic cells, Western blots to evaluate protein level, and patch-clamp recordings to measure K(ATP) channel current activities. Behavioral tests were performed to assess the functional recovery after hypoxic-ischemic insults. We found that hypoxic preconditioning reduced infarct volume, decreased the number of TUNEL-positive cells, and improved neurobehavioral functional recovery in neonatal mice following hypoxic-ischemic insults. Pre-treatment with a K(ATP) channel blocker, tolbutamide, inhibited hypoxic preconditioning-induced neuroprotection and augmented neurodegeneration following hypoxic-ischemic injury. Pre-treatment with a K(ATP) channel opener, diazoxide, reduced infarct volume and mimicked hypoxic preconditioning-induced neuroprotection. Hypoxic preconditioning induced upregulation of the protein level of the Kir6.2 isoform and enhanced current activities of K(ATP) channels. Hypoxic preconditioning restored the HI-reduced PKC and pAkt levels, and reduced caspase-3 level, while tolbutamide inhibited the effects of hypoxic preconditioning. We conclude that K(ATP) channels are involved in hypoxic preconditioning-induced neuroprotection in neonatal hypoxic-ischemic brain injury. K(ATP) channel openers may therefore have therapeutic effects in neonatal hypoxic-ischemic brain injury.
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Affiliation(s)
- Hong-Shuo Sun
- Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Pharmacology & Toxicology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
| | - Baofeng Xu
- Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Wenliang Chen
- Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Aijiao Xiao
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Ekaterina Turlova
- Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Ammar Alibraham
- Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Andrew Barszczyk
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Christine Y J Bae
- Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Yi Quan
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Baosong Liu
- Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Lin Pei
- Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Christopher L F Sun
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Faculty of Applied Science & Engineering, University of Toronto, Toronto, Ontario M5S 1A4, Canada
| | - Marielle Deurloo
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Zhong-Ping Feng
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
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Abstract
The field of mitochondrial ion channels has recently seen substantial progress, including the molecular identification of some of the channels. An integrative approach using genetics, electrophysiology, pharmacology, and cell biology to clarify the roles of these channels has thus become possible. It is by now clear that many of these channels are important for energy supply by the mitochondria and have a major impact on the fate of the entire cell as well. The purpose of this review is to provide an up-to-date overview of the electrophysiological properties, molecular identity, and pathophysiological functions of the mitochondrial ion channels studied so far and to highlight possible therapeutic perspectives based on current information.
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Michel PP, Toulorge D, Guerreiro S, Hirsch EC. Specific needs of dopamine neurons for stimulation in order to survive: implication for Parkinson disease. FASEB J 2013; 27:3414-23. [PMID: 23699175 DOI: 10.1096/fj.12-220418] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Parkinson disease (PD) is a degenerative brain disorder characterized by motor symptoms that are unequivocally associated with the loss of dopaminergic (DA) neurons in the substantia nigra (SN). Although our knowledge of the mechanisms that contribute to DA cell death in both hereditary and sporadic forms of the disease has advanced significantly, the nature of the pathogenic process remains poorly understood. In this review, we present evidence that neurodegeneration occurs when the electrical activity and excitability of these neurons is reduced. In particular, we will focus on the specific need these neurons may have for stimulation in order to survive and on the molecular and cellular mechanisms that may be compromised when this need is no longer met in PD.
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Affiliation(s)
- Patrick P Michel
- Université Pierre et Marie Curie-Paris 6, Centre de Recherche de l'Institut du Cerveau et de la Moelle Epinière, Unité Mixte de Recherche (UMR) S975, Paris, France.
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Dong YF, Wang LX, Huang X, Cao WJ, Lu M, Ding JH, Sun XL, Hu G. Kir6.1 knockdown aggravates cerebral ischemia/reperfusion-induced neural injury in mice. CNS Neurosci Ther 2013; 19:617-24. [PMID: 23663330 DOI: 10.1111/cns.12117] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 03/27/2013] [Accepted: 03/27/2013] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND AND PURPOSE ATP-sensitive potassium (K-ATP) channels couple energy metabolism with electric activity, which play important roles in brain diseases including stroke. However, the impacts of Kir6.1-containing K-ATP channels that mainly expressed on glia in stroke remain unclear. METHODS AND RESULTS In this study, we found that expression of Kir6.1 was significantly decreased in the ischemic brain area of C57BL/6J mice after 1-h middle cerebral artery occlusion (MCAO) and 24-h reperfusion. Then, we subjected Kir6.1 heterozygote knockout (Kir6.1(+/-) ) mice to cerebral ischemia/reperfusion (I/R) injury and found that Kir6.1(+/-) mice exhibited exacerbated neurological disorder and enlarged infarct size, companied by glial over-activation and blood-brain barrier (BBB) damages. Furthermore, we showed that Kir6.1 knockdown aggravated endoplasmic reticulum (ER) stress and thereby increased the levels of proinflammatory factors tumor necrosis factor-α and interleukin-1β (TNF-α and IL-1β) in mouse brain. CONCLUSIONS Our findings reveal that Kir6.1 knockdown exacerbates cerebral I/R-induced brain damages via increasing ER stress and inflammatory response, indicating that Kir6.1-containing K-ATP channels may be a potential therapeutic target for stroke.
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Affiliation(s)
- Yin-Feng Dong
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, Nanjing, Jiangsu, China
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Current understanding of TRPM7 pharmacology and drug development for stroke. Acta Pharmacol Sin 2013; 34:10-6. [PMID: 22820907 DOI: 10.1038/aps.2012.94] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The initial excitement and countless efforts to find a pharmacological agent that disrupts the excitotoxic pathway of ischemic neuronal death have only led to disappointing clinical trials. Currently, a thrombolytic agent called recombinant tissue plasminogen activator (rt-PA) is the only pharmacological treatment available for patients with acute ischemic stroke in most countries. Even though its efficacy has been confirmed repeatedly, rt-PA is considerably underused due to reasons including a short therapeutic window and repeated complications associated with its use. A search for alternative mechanisms that may operate dependently or independently with the well-established excitotoxic mechanism has led researchers to the discovery of newly described non-glutamate mechanisms. Among the latter, transient receptor potential melastatin 7 (TRPM7) is one of the important nonglutamate mechanisms in stroke, which has been evaluated in both in-vitro and in-vivo. In this review, we will discuss the current state of pharmacological treatments of ischemic stroke and provide evidence that TRPM7 is a promising therapeutic target of stroke.
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Neuroprotective role of ATP-sensitive potassium channels in cerebral ischemia. Acta Pharmacol Sin 2013; 34:24-32. [PMID: 23123646 DOI: 10.1038/aps.2012.138] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
ATP-sensitive potassium (K(ATP)) channels are weak, inward rectifiers that couple metabolic status to cell membrane electrical activity, thus modulating many cellular functions. An increase in the ADP/ATP ratio opens K(ATP) channels, leading to membrane hyperpolarization. K(ATP) channels are ubiquitously expressed in neurons located in different regions of the brain, including the hippocampus and cortex. Brief hypoxia triggers membrane hyperpolarization in these central neurons. In vivo animal studies confirmed that knocking out the Kir6.2 subunit of the K(ATP) channels increases ischemic infarction, and overexpression of the Kir6.2 subunit reduces neuronal injury from ischemic insults. These findings provide the basis for a practical strategy whereby activation of endogenous K(ATP) channels reduces cellular damage resulting from cerebral ischemic stroke. K(ATP) channel modulators may prove to be clinically useful as part of a combination therapy for stroke management in the future.
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Aiba I, Shuttleworth CW. Sustained NMDA receptor activation by spreading depolarizations can initiate excitotoxic injury in metabolically compromised neurons. J Physiol 2012; 590:5877-93. [PMID: 22907056 PMCID: PMC3528997 DOI: 10.1113/jphysiol.2012.234476] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Accepted: 08/15/2012] [Indexed: 01/09/2023] Open
Abstract
Spreading depolarizations (SDs) are slowly propagating waves of near-complete neuronal and glial depolarization. SDs have been recorded in patients with brain injury, and the incidence of SD significantly correlates with outcome severity. Although it is well accepted that the ionic dyshomeostasis of SD presents a severe metabolic burden, there is currently limited understanding of SD-induced injury processes at a cellular level. In the current study we characterized events accompanying SD in the hippocampal CA1 region of murine brain slices, using whole-cell recordings and single-cell Ca(2+) imaging. We identified an excitatory phase that persisted for approximately 2 min following SD onset, and accompanied with delayed dendritic ionic dyshomeostasis. The excitatory phase coincided with a significant increase in presynaptic glutamate release, evidenced by a transient increase in spontaneous EPSC frequency and paired-pulse depression of evoked EPSCs. Activation of NMDA receptors (NMDARs) during this late excitatory phase contributed to the duration of individual neuronal depolarizations and delayed recovery of extracellular slow potential changes. Selectively targeting the NMDAR activation following SD onset (by delayed pressure application of a competitive NMDAR antagonist) significantly decreased the duration of cellular depolarizations. Recovery of dendritic Ca(2+) elevations following SD were also sensitive to delayed NMDA antagonist application. Partial inhibition of neuronal energy metabolism converted SD into an irrecoverable event with persistent Ca(2+) overload and membrane compromise. Delayed NMDAR block was sufficient to prevent these acute injurious events in metabolically compromised neurons. These results identify a significant contribution of a late component of SD that could underlie neuronal injury in pathological circumstances.
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Affiliation(s)
- Isamu Aiba
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131-0001, USA
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Body cooling ameliorating spinal cord injury may be neurogenesis-, anti-inflammation- and angiogenesis-associated in rats. ACTA ACUST UNITED AC 2011; 70:885-93. [PMID: 20693909 DOI: 10.1097/ta.0b013e3181e7456d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Body cooling (BC) or mild hypothermia therapy (about 33°C) is reportedly effective for spinal cord injury (SCI). However, the mechanisms underlying the beneficial effects of BC remain unclear, so does BC ameliorating SCI via promoting neurogenesis, anti-inflammation, and angiogenesis. METHODS The standard rat compression SCI model was tested hypothetically in two groups: one receiving BC (33°C) and the other, normothermia (37°C). Afterward, the effects of BC therapy on the hind limb locomotion, spinal cord infarction and apoptosis, angiogenesis, neurogenesis, and inflammation in these two groups of SCI were assessed. The other group of sham SCI was used as controls. RESULTS Apoptosis (evidenced by higher numbers of terminal deoxynucleotidyl- transferase-mediated and duDP-biotin nick end-labeling-positive cells), infarct, activated inflammation (evidenced by higher levels of tumor necrosis factor-α, interleukin-1β, and myeloperoxidase), and hind limb locomotor dysfunction were inspected in the untreated (37°C) SCI rats 4 days after SCI. When compared with those of untreated SCI rats, SCI rats receiving BC (33°C) displayed lower levels of apoptosis, infarct volume, activated inflammation, and hind limb locomotor dysfunction. In addition, that BC promoted both angiogenesis (evidenced by increased numbers of both vascular endothelial growth factors and bromodeoxyuridine-positive endothelial cells) and neurogenesis (evidenced by increased numbers of both glial cell line-derived neurotrophic growth factors and bromodeoxyuridine-neuronal-specific nuclear protein double positive cells) in the injured spinal cord was evaluated 4 days after SCI. CONCLUSION BC (33°C) improved SCI outcomes by promoting angiogenesis, neurogenesis, and anti-inflammation in a rat SCI model.
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Chen BS, Wu SN. Functional role of the activity of ATP-sensitive potassium channels in electrical behavior of hippocampal neurons: Experimental and theoretical studies. J Theor Biol 2011; 272:16-25. [DOI: 10.1016/j.jtbi.2010.12.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 10/13/2010] [Accepted: 12/01/2010] [Indexed: 11/17/2022]
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Ludwig A, Ziegenhorn K, Empting S, Meissner T, Marquard J, Holl R, Mohnike K. Glucose metabolism and neurological outcome in congenital hyperinsulinism. Semin Pediatr Surg 2011; 20:45-9. [PMID: 21186004 DOI: 10.1053/j.sempedsurg.2010.10.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Advances in imaging and surgical techniques allow a complete cure for children with focal-type congenital hyperinsulinism (CHI). In contrast, management of diffuse-type CHI remains a matter of controversy. To prevent hypoglycemic brain damage, extensive surgery has been recommended in the past, resulting in diabetes. On the basis of 2 data sets of patients with congenital hyperinsulinism, the German registry for CHI with 235 patients (ages 1 day to 19 years) and the diabetes treatment register (Diabetes Patienten-Verlaufsdokumentationssystem initiative), a follow-up study was initiated for diabetes mellitus and the intellectual and physical development as well as motor function. In our ongoing study, we investigated 20 patients with CHI (12 male, mean ages 9.9 years). Six of 20 patients had undergone subtotal pancreatectomy. In early infantile development (0-3 years) we observed a trend to motor and speech delay. In early childhood (2.5-7 years) there appeared a trend to an advantage of results of nonverbal tasks compared with verbal tasks. Before 1990 most patients (∼75%) were treated by subtotal pancreatectomy; since 2000, a more conservative approach is obvious (4/68). All patients with diabetes (n = 25) developed the condition after undergoing subtotal pancreatectomy. No spontaneous manifestation of diabetes was noted before adulthood. There was a wide range of age (0-17.7 years) at manifestation indicating a long period during which glucose tolerance is compensated. Compared with >40.000 children with type 1 diabetes mellitus from the Diabetes Patienten-Verlaufsdokumentationssystem registry, we found significant differences with a tendency for being overweight as well as small stature. Mean daily insulin dose and HbA1c was comparable in both groups.
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Affiliation(s)
- Anja Ludwig
- Department of Pediatrics, O. v. Guericke University, Magdeburg, Germany.
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