1
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Iketani M, Hatomi M, Fujita Y, Watanabe N, Ito M, Kawaguchi H, Ohsawa I. Inhalation of hydrogen gas mitigates sevoflurane-induced neuronal apoptosis in the neonatal cortex and is associated with changes in protein phosphorylation. J Neurochem 2024. [PMID: 38849977 DOI: 10.1111/jnc.16142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 05/03/2024] [Accepted: 05/27/2024] [Indexed: 06/09/2024]
Abstract
Inhalation of hydrogen (H2) gas is therapeutically effective for cerebrovascular diseases, neurodegenerative disorders, and neonatal brain disorders including pathologies induced by anesthetic gases. To understand the mechanisms underlying the protective effects of H2 on the brain, we investigated the molecular signals affected by H2 in sevoflurane-induced neuronal cell death. We confirmed that neural progenitor cells are susceptible to sevoflurane and undergo apoptosis in the retrosplenial cortex of neonatal mice. Co-administration of 1-8% H2 gas for 3 h to sevoflurane-exposed pups suppressed elevated caspase-3-mediated apoptotic cell death and concomitantly decreased c-Jun phosphorylation and activation of the c-Jun pathway, all of which are induced by oxidative stress. Anesthesia-induced increases in lipid peroxidation and oxidative DNA damage were alleviated by H2 inhalation. Phosphoproteome analysis revealed enriched clusters of differentially phosphorylated proteins in the sevoflurane-exposed neonatal brain that included proteins involved in neuronal development and synaptic signaling. H2 inhalation modified cellular transport pathways that depend on hyperphosphorylated proteins including microtubule-associated protein family. These modifications may be involved in the protective mechanisms of H2 against sevoflurane-induced neuronal cell death.
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Affiliation(s)
- Masumi Iketani
- Biological Process of Aging, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan
| | - Mai Hatomi
- Biological Process of Aging, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan
- Department of Life Sciences, Toyo University, Asaka, Japan
| | - Yasunori Fujita
- Biological Process of Aging, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan
| | - Nobuhiro Watanabe
- Autonomic Neuroscience, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan
| | - Masafumi Ito
- Biological Process of Aging, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan
| | | | - Ikuroh Ohsawa
- Biological Process of Aging, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan
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2
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Jalalypour F, Howard RJ, Lindahl E. Allosteric Cholesterol Site in Glycine Receptors Characterized through Molecular Simulations. J Phys Chem B 2024; 128:4996-5007. [PMID: 38747451 PMCID: PMC11129184 DOI: 10.1021/acs.jpcb.4c01703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/29/2024] [Accepted: 05/06/2024] [Indexed: 05/24/2024]
Abstract
Glycine receptors are pentameric ligand-gated ion channels that conduct chloride ions across postsynaptic membranes to facilitate fast inhibitory neurotransmission. In addition to gating by the glycine agonist, interactions with lipids and other compounds in the surrounding membrane environment modulate their function, but molecular details of these interactions remain unclear, in particular, for cholesterol. Here, we report coarse-grained simulations in a model neuronal membrane for three zebrafish glycine receptor structures representing apparent resting, open, and desensitized states. We then converted the systems to all-atom models to examine detailed lipid interactions. Cholesterol bound to the receptor at an outer-leaflet intersubunit site, with a preference for the open and desensitized versus resting states, indicating that it can bias receptor function. Finally, we used short atomistic simulations and iterative amino acid perturbations to identify residues that may mediate allosteric gating transitions. Frequent cholesterol contacts in atomistic simulations clustered with residues identified by perturbation analysis and overlapped with mutations influencing channel function and pathology. Cholesterol binding at this site was also observed in a recently reported pig heteromeric glycine receptor. These results indicate state-dependent lipid interactions relevant to allosteric transitions of glycine receptors, including specific amino acid contacts applicable to biophysical modeling and pharmaceutical design.
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Affiliation(s)
- Farzaneh Jalalypour
- Science
for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, 17121 Solna, Sweden
| | - Rebecca J. Howard
- Science
for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, 17121 Solna, Sweden
- Science
for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17121 Solna, Sweden
| | - Erik Lindahl
- Science
for Life Laboratory, Department of Applied Physics, KTH Royal Institute of Technology, 17121 Solna, Sweden
- Science
for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17121 Solna, Sweden
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3
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Noguchi S, Kajimoto T, Kumamoto T, Shingai M, Narasaki S, Urabe T, Imamura S, Harada K, Hide I, Tanaka S, Yanase Y, Nakamura SI, Tsutsumi YM, Sakai N. Features and mechanisms of propofol-induced protein kinase C (PKC) translocation and activation in living cells. Front Pharmacol 2023; 14:1284586. [PMID: 38026993 PMCID: PMC10662334 DOI: 10.3389/fphar.2023.1284586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Background and purpose: In this study, we aimed to elucidate the action mechanisms of propofol, particularly those underlying propofol-induced protein kinase C (PKC) translocation. Experimental approach: Various PKCs fused with green fluorescent protein (PKC-GFP) or other GFP-fused proteins were expressed in HeLa cells, and their propofol-induced dynamics were observed using confocal laser scanning microscopy. Propofol-induced PKC activation in cells was estimated using the C kinase activity receptor (CKAR), an indicator of intracellular PKC activation. We also examined PKC translocation using isomers and derivatives of propofol to identify the crucial structural motifs involved in this process. Key results: Propofol persistently translocated PKCα conventional PKCs and PKCδ from novel PKCs (nPKCs) to the plasma membrane (PM). Propofol translocated PKCδ and PKCη of nPKCs to the Golgi apparatus and endoplasmic reticulum, respectively. Propofol also induced the nuclear translocation of PKCζ of atypical PKCs or proteins other than PKCs, such that the protein concentration inside and outside the nucleus became uniform. CKAR analysis revealed that propofol activated PKC in the PM and Golgi apparatus. Moreover, tests using isomers and derivatives of propofol predicted that the structural motifs important for the induction of PKC and nuclear translocation are different. Conclusion and implications: Propofol induced the subtype-specific intracellular translocation of PKCs and activated PKCs. Additionally, propofol induced the nuclear translocation of PKCs and other proteins, probably by altering the permeability of the nuclear envelope. Interestingly, propofol-induced PKC and nuclear translocation may occur via different mechanisms. Our findings provide insights into the action mechanisms of propofol.
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Affiliation(s)
- Soma Noguchi
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Taketoshi Kajimoto
- Division of Biochemistry, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Takuya Kumamoto
- Department of Synthetic Organic Chemistry, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Masashi Shingai
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Soshi Narasaki
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
- Department of Anesthesiology and Critical Care, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Tomoaki Urabe
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
- Department of Anesthesiology and Critical Care, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Serika Imamura
- Department of Dental Anesthesiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Kana Harada
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Izumi Hide
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Sigeru Tanaka
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Yuhki Yanase
- Department of Pharmacotherapy, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Shun-Ichi Nakamura
- Division of Biochemistry, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yasuo M. Tsutsumi
- Department of Anesthesiology and Critical Care, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Norio Sakai
- Department of Molecular and Pharmacological Neuroscience, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
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4
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Paladini A, Barrientos Penaloza J, Plancarte Sanchez R, Ergönenç T, Varrassi G. Bridging Old and New in Pain Medicine: An Historical Review. Cureus 2023; 15:e43639. [PMID: 37719480 PMCID: PMC10504912 DOI: 10.7759/cureus.43639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 08/17/2023] [Indexed: 09/19/2023] Open
Abstract
Pain is both one of the oldest complaints known to medicine and a field for some of medicine's latest breakthroughs and innovations. Pharmacologic treatment of pain is one of the oldest remedies, and opioids have been used since ancient times as an effective pain reliever but with certain specific risks for abuse. Greater knowledge of opioids led to a more thorough understanding of the complexities of pain, which may have any number of mechanisms. A greater understanding of nerve fibers and pain signaling led to the development of more drugs and the more targeted delivery of analgesics using the hollow needle. The hollow needle changed pain treatment and led to percutaneous injections and what would later become interventional pain medicine with regional anesthesia and nerve blocks. Today, imaging can be combined with interventional techniques for more precise localization of nerves for diagnosis and treatment. The role of artificial intelligence in interventional pain medicine, especially in imaging for interventional procedures, remains unknown but will likely become extremely beneficial.
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Affiliation(s)
- Antonella Paladini
- Life, Health & Environmental Sciences (MESVA), University of L'Aquila, L'Aquila, ITA
| | | | | | - Tolga Ergönenç
- Anesthesia and Reanimation, Morphological Madrid Research Center, Madrid, ESP
- Anesthesia and Reanimation, Akyazi Hospital Pain and Palliative Care, Sakarya, TUR
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5
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Goswami U, Rahman MM, Teng J, Hibbs RE. Structural interplay of anesthetics and paralytics on muscle nicotinic receptors. Nat Commun 2023; 14:3169. [PMID: 37264005 DOI: 10.1038/s41467-023-38827-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/17/2023] [Indexed: 06/03/2023] Open
Abstract
General anesthetics and neuromuscular blockers are used together during surgery to stabilize patients in an unconscious state. Anesthetics act mainly by potentiating inhibitory ion channels and inhibiting excitatory ion channels, with the net effect of dampening nervous system excitability. Neuromuscular blockers act by antagonizing nicotinic acetylcholine receptors at the motor endplate; these excitatory ligand-gated ion channels are also inhibited by general anesthetics. The mechanisms by which anesthetics and neuromuscular blockers inhibit nicotinic receptors are poorly understood but underlie safe and effective surgeries. Here we took a direct structural approach to define how a commonly used anesthetic and two neuromuscular blockers act on a muscle-type nicotinic receptor. We discover that the intravenous anesthetic etomidate binds at an intrasubunit site in the transmembrane domain and stabilizes a non-conducting, desensitized-like state of the channel. The depolarizing neuromuscular blocker succinylcholine also stabilizes a desensitized channel but does so through binding to the classical neurotransmitter site. Rocuronium binds in this same neurotransmitter site but locks the receptor in a resting, non-conducting state. Together, this study reveals a structural mechanism for how general anesthetics work on excitatory nicotinic receptors and further rationalizes clinical observations in how general anesthetics and neuromuscular blockers interact.
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Affiliation(s)
- Umang Goswami
- Department of Neuroscience and O'Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Md Mahfuzur Rahman
- Department of Neuroscience and O'Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Thermo Fisher Scientific, Rockford, IL, 61101, USA
| | - Jinfeng Teng
- Department of Neurobiology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Ryan E Hibbs
- Department of Neuroscience and O'Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
- Department of Neurobiology, University of California, San Diego, La Jolla, CA, 92093, USA.
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6
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Fröhlich E. Non-Cellular Layers of the Respiratory Tract: Protection against Pathogens and Target for Drug Delivery. Pharmaceutics 2022; 14:pharmaceutics14050992. [PMID: 35631578 PMCID: PMC9143813 DOI: 10.3390/pharmaceutics14050992] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 04/30/2022] [Accepted: 05/02/2022] [Indexed: 12/10/2022] Open
Abstract
Epithelial barriers separate the human body from the environment to maintain homeostasis. Compared to the skin and gastrointestinal tract, the respiratory barrier is the thinnest and least protective. The properties of the epithelial cells (height, number of layers, intercellular junctions) and non-cellular layers, mucus in the conducting airways and surfactant in the respiratory parts determine the permeability of the barrier. The review focuses on the non-cellular layers and describes the architecture of the mucus and surfactant followed by interaction with gases and pathogens. While the penetration of gases into the respiratory tract is mainly determined by their hydrophobicity, pathogens use different mechanisms to invade the respiratory tract. Often, the combination of mucus adhesion and subsequent permeation of the mucus mesh is used. Similar mechanisms are also employed to improve drug delivery across the respiratory barrier. Depending on the payload and target region, various mucus-targeting delivery systems have been developed. It appears that the mucus-targeting strategy has to be selected according to the planned application.
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Affiliation(s)
- Eleonore Fröhlich
- Center for Medical Research, Medical University of Graz, 8010 Graz, Austria; ; Tel.: +43-316-38573011
- Research Center Pharmaceutical Engineering GmbH, 8010 Graz, Austria
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7
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Rudge JD. A New Hypothesis for Alzheimer’s Disease: The Lipid Invasion Model. J Alzheimers Dis Rep 2022; 6:129-161. [PMID: 35530118 PMCID: PMC9028744 DOI: 10.3233/adr-210299] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 02/05/2022] [Indexed: 02/07/2023] Open
Abstract
This paper proposes a new hypothesis for Alzheimer’s disease (AD)—the lipid invasion model. It argues that AD results from external influx of free fatty acids (FFAs) and lipid-rich lipoproteins into the brain, following disruption of the blood-brain barrier (BBB). The lipid invasion model explains how the influx of albumin-bound FFAs via a disrupted BBB induces bioenergetic changes and oxidative stress, stimulates microglia-driven neuroinflammation, and causes anterograde amnesia. It also explains how the influx of external lipoproteins, which are much larger and more lipid-rich, especially more cholesterol-rich, than those normally present in the brain, causes endosomal-lysosomal abnormalities and overproduction of the peptide amyloid-β (Aβ). This leads to the formation of amyloid plaques and neurofibrillary tangles, the most well-known hallmarks of AD. The lipid invasion model argues that a key role of the BBB is protecting the brain from external lipid access. It shows how the BBB can be damaged by excess Aβ, as well as by most other known risk factors for AD, including aging, apolipoprotein E4 (APOE4), and lifestyle factors such as hypertension, smoking, obesity, diabetes, chronic sleep deprivation, stress, and head injury. The lipid invasion model gives a new rationale for what we already know about AD, explaining its many associated risk factors and neuropathologies, including some that are less well-accounted for in other explanations of AD. It offers new insights and suggests new ways to prevent, detect, and treat this destructive disease and potentially other neurodegenerative diseases.
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Affiliation(s)
- Jonathan D’Arcy Rudge
- School of Biological Sciences, University of Reading, Reading, Berkshire, United Kingdom
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8
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Oda R, Shou J, Zhong W, Ozeki Y, Yasui M, Nuriya M. Direct visualization of general anesthetic propofol on neurons by stimulated Raman scattering microscopy. iScience 2022; 25:103936. [PMID: 35252821 PMCID: PMC8894261 DOI: 10.1016/j.isci.2022.103936] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 01/28/2022] [Accepted: 02/14/2022] [Indexed: 11/29/2022] Open
Abstract
The consensus for the precise mechanism of action of general anesthetics is through allosteric interactions with GABA receptors in neurons. However, it has been speculated that these anesthetics may also interact with the plasma membrane on some level. Owing to the small size of anesthetics, direct visualization of these interactions is difficult to achieve. We demonstrate the ability to directly visualize a deuterated analog of propofol in living cells using stimulated Raman scattering (SRS) microscopy. Our findings support the theory that propofol is highly concentrated and interacts primarily through non-specific binding to the plasma membrane of neurons. Additionally, we show that SRS microscopy can be used to monitor the dynamics of propofol binding using real-time, live-cell imaging. The strategy used to visualize propofol can be applied to other small molecule drugs that have been previously invisible to traditional imaging techniques Multi-modal SRS developed for real-time biological imaging of small molecule substances Propofol primarily concentrates at the cell membrane of neurons Anesthesia dynamics can be monitored in real-time with SRS
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Affiliation(s)
- Robert Oda
- Department of Pharmacology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
- Department of Electrical Engineering and Information Systems, Graduate School of Engineering, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
- Corresponding author
| | - Jingwen Shou
- Department of Electrical Engineering and Information Systems, Graduate School of Engineering, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
| | - Wenying Zhong
- Department of Pharmacology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Yasuyuki Ozeki
- Department of Electrical Engineering and Information Systems, Graduate School of Engineering, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
| | - Masato Yasui
- Department of Pharmacology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Mutsuo Nuriya
- Department of Pharmacology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
- Graduate School of Environment and Information Sciences, Yokohama National University, 79-1 Tokiwadai, Hodogaya, Yokohama, Kanagawa 240-8501, Japan
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
- Corresponding author
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9
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Choo PP, Md Din N, Azmi N, Bastion MLC. Review of the management of sight-threatening diabetic retinopathy during pregnancy. World J Diabetes 2021; 12:1386-1400. [PMID: 34630896 PMCID: PMC8472492 DOI: 10.4239/wjd.v12.i9.1386] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 06/25/2021] [Accepted: 08/12/2021] [Indexed: 02/06/2023] Open
Abstract
Diabetes mellitus (DM) is a noncommunicable disease reaching epidemic proportions around the world. It affects younger individuals, including women of childbearing age. Diabetes can cause diabetic retinopathy (DR), which is potentially sight threatening when severe nonproliferative DR (NPDR), proliferative DR (PDR), or sight-threatening diabetic macular oedema (STDME) develops. Pregnancy is an independent risk factor for the progression of DR. Baseline DR at the onset of pregnancy is an important indicator of progression, with up to 10% of women with baseline NPDR progressing to PDR. Progression to sight-threatening DR (STDR) during pregnancy causes distress to the patient and often necessitates ocular treatment, which may have a systemic effect. Management includes prepregnancy counselling and, when possible, conventional treatment prior to pregnancy. During pregnancy, closer follow-up is required for those with a long duration of DM, poor baseline control of blood sugar and blood pressure, and worse DR, as these are risk factors for progression to STDR. Conventional treatment with anti-vascular endothelial growth factor agents for STDME can potentially lead to foetal loss. Treatment with laser photocoagulation may be preferred, and surgery under general anaesthesia should be avoided. This review provides a management plan for STDR from the perspective of practising ophthalmologists. A review of strategies for maintaining the eyesight of diabetic women with STDR with emphasis on prepregnancy counselling and planning, monitoring and safe treatment during pregnancy, and management of complications is presented.
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Affiliation(s)
- Priscilla Peixi Choo
- Department of Ophthalmology, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur 56000, Wilayah Persekutuan, Malaysia
| | - Norshamsiah Md Din
- Department of Ophthalmology, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur 56000, Wilayah Persekutuan, Malaysia
| | - Nooraniah Azmi
- Department of Ophthalmology, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur 56000, Wilayah Persekutuan, Malaysia
- Department of Ophthalmology, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
| | - Mae-Lynn Catherine Bastion
- Department of Ophthalmology, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur 56000, Wilayah Persekutuan, Malaysia
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10
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Progress in modelling of brain dynamics during anaesthesia and the role of sleep-wake circuitry. Biochem Pharmacol 2021; 191:114388. [DOI: 10.1016/j.bcp.2020.114388] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 12/28/2022]
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11
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Towards Quantum-Chemical Modeling of the Activity of Anesthetic Compounds. Int J Mol Sci 2021; 22:ijms22179272. [PMID: 34502179 PMCID: PMC8431746 DOI: 10.3390/ijms22179272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/16/2021] [Accepted: 08/17/2021] [Indexed: 12/16/2022] Open
Abstract
The modeling of the activity of anesthetics is a real challenge because of their unique electronic and structural characteristics. Microscopic approaches relevant to the typical features of these systems have been developed based on the advancements in the theory of intermolecular interactions. By stressing the quantum chemical point of view, here, we review the advances in the field highlighting differences and similarities among the chemicals within this group. The binding of the anesthetics to their partners has been analyzed by Symmetry-Adapted Perturbation Theory to provide insight into the nature of the interaction and the modeling of the adducts/complexes allows us to rationalize their anesthetic properties. A new approach in the frame of microtubule concept and the importance of lipid rafts and channels in membranes is also discussed.
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12
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Dincer B, Halici Z, Cadirci E. Investigation of the Role of Stimulation and Blockade of 5-HT 7 Receptors in Ketamine Anesthesia. J Mol Neurosci 2020; 71:1095-1111. [PMID: 33200380 DOI: 10.1007/s12031-020-01732-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 10/12/2020] [Indexed: 12/17/2022]
Abstract
Although several pieces of evidence have indicated the ability of the serotonin-7 receptor (5-HTR7) to modulate N-methyl-D-aspartate receptor (NMDAR) activation, the possible impact on ketamine anesthesia has not been examined directly. The purpose of the present study is thus to investigate the possible role of the 5-HTR7 in ketamine anesthesia using a 5-HTR7 agonist and/or antagonist. The influence of a 5-HTR7 agonist/antagonist on ketamine anesthesia for behavioral impact was assessed by testing potential anesthetic parameters. Its functional impact was assessed by mRNA expression with real-time PCR and immunostaining in the hippocampus and prefrontal cortex of mice. Two different doses of ketamine-high and low-were administered to induce anesthesia. In the high-dose ketamine-applied group in particular, the administration of both the 5-HTR7 agonist and antagonist intensified the anesthetic effect of ketamine. The reflection of the change in anesthesia parameters to 5-HTR7 expression was observed as an increase in the hippocampus and a decrease in the prefrontal cortex in the anesthetized groups by stimulation of 5-HTR7. It is noteworthy that the results of NMDAR expressions are parallel to the results of the 5-HTR7 expressions of both the hippocampus and the prefrontal cortex. The 5-HTR7 may play a role in ketamine anesthesia. It may act through NMDAR in ketamine anesthesia, depending on the parallelism between both receptors.
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Affiliation(s)
- Busra Dincer
- Department of Pharmacology, Faculty of Pharmacy, Erzincan Binali Yildirim University, Erzincan, 24100, Turkey
| | - Zekai Halici
- Department of Pharmacology, Faculty of Medicine, Ataturk University, Erzurum, 25240, Turkey.,Clinical Research, Development and Design Application and Research Center, Ataturk University, Erzurum, 25240, Turkey
| | - Elif Cadirci
- Department of Pharmacology, Faculty of Medicine, Ataturk University, Erzurum, 25240, Turkey. .,Clinical Research, Development and Design Application and Research Center, Ataturk University, Erzurum, 25240, Turkey.
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13
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Abstract
Here, we investigate the role of a dilute hydrophobic gas on the phase behavior of water confined in hydrophobic nanopores. Molecular dynamics showed that gas atoms are hydrophobically attracted within the pores, where even a single particle is able to induce spontaneous drying of the whole pore. The drying process is rationalized in terms of its free-energy landscape, revealing that the penetration of a gas atom is able to suppress the drying free-energy barriers of hydrophobic pores. Results provide insights into the role of gases on the wettability of nanopores and evidence of a possibile physical mechanism for the action of volatile anesthetics on some kinds of ion channels. Results also indicate a novel, bioinspired strategy for controlling bubble formation in nanopores for sensing and energy applications.
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Affiliation(s)
- Gaia Camisasca
- Dipartimento di Ingegneria Meccanica e Aerospaziale, Sapienza Università di Roma, Via Eudossiana 18, 00184 Rome, Italy
| | - Antonio Tinti
- Dipartimento di Ingegneria Meccanica e Aerospaziale, Sapienza Università di Roma, Via Eudossiana 18, 00184 Rome, Italy
| | - Alberto Giacomello
- Dipartimento di Ingegneria Meccanica e Aerospaziale, Sapienza Università di Roma, Via Eudossiana 18, 00184 Rome, Italy
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14
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Abstract
Anesthetics are used every day in thousands of hospitals to induce loss of consciousness, yet scientists and the doctors who administer these compounds lack a molecular understanding for their action. The chemical properties of anesthetics suggest that they could target the plasma membrane. Here the authors show anesthetics directly target a subset of plasma membrane lipids to activate an ion channel in a two-step mechanism. Applying the mechanism, the authors mutate a fruit fly to be less sensitive to anesthetics and convert a nonanesthetic-sensitive channel into a sensitive one. These findings suggest a membrane-mediated mechanism will be an important consideration for other proteins of which direct binding of anesthetic has yet to explain conserved sensitivity to chemically diverse anesthetics. Inhaled anesthetics are a chemically diverse collection of hydrophobic molecules that robustly activate TWIK-related K+ channels (TREK-1) and reversibly induce loss of consciousness. For 100 y, anesthetics were speculated to target cellular membranes, yet no plausible mechanism emerged to explain a membrane effect on ion channels. Here we show that inhaled anesthetics (chloroform and isoflurane) activate TREK-1 through disruption of phospholipase D2 (PLD2) localization to lipid rafts and subsequent production of signaling lipid phosphatidic acid (PA). Catalytically dead PLD2 robustly blocks anesthetic TREK-1 currents in whole-cell patch-clamp recordings. Localization of PLD2 renders the TRAAK channel sensitive, a channel that is otherwise anesthetic insensitive. General anesthetics, such as chloroform, isoflurane, diethyl ether, xenon, and propofol, disrupt lipid rafts and activate PLD2. In the whole brain of flies, anesthesia disrupts rafts and PLDnull flies resist anesthesia. Our results establish a membrane-mediated target of inhaled anesthesia and suggest PA helps set thresholds of anesthetic sensitivity in vivo.
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15
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Mitchell W, Ng EA, Tamucci JD, Boyd KJ, Sathappa M, Coscia A, Pan M, Han X, Eddy NA, May ER, Szeto HH, Alder NN. The mitochondria-targeted peptide SS-31 binds lipid bilayers and modulates surface electrostatics as a key component of its mechanism of action. J Biol Chem 2020; 295:7452-7469. [PMID: 32273339 PMCID: PMC7247319 DOI: 10.1074/jbc.ra119.012094] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 04/07/2020] [Indexed: 11/06/2022] Open
Abstract
Mitochondrial dysfunction underlies many heritable diseases, acquired pathologies, and aging-related declines in health. Szeto-Schiller (SS) peptides comprise a class of amphipathic tetrapeptides that are efficacious toward a wide array of mitochondrial disorders and are believed to target mitochondrial membranes because they are enriched in the anionic phospholipid cardiolipin (CL). However, little is known regarding how SS peptides interact with or alter the physical properties of lipid bilayers. In this study, using biophysical and computational approaches, we have analyzed the interactions of the lead compound SS-31 (elamipretide) with model and mitochondrial membranes. Our results show that this polybasic peptide partitions into the membrane interfacial region with an affinity and a lipid binding density that are directly related to surface charge. We found that SS-31 binding does not destabilize lamellar bilayers even at the highest binding concentrations; however, it did cause saturable alterations in lipid packing. Most notably, SS-31 modulated the surface electrostatics of both model and mitochondrial membranes. We propose nonexclusive mechanisms by which the tuning of surface charge could underpin the mitoprotective properties of SS-31, including alteration of the distribution of ions and basic proteins at the interface, and/or modulation of bilayer physical properties. As a proof of concept, we show that SS-31 alters divalent cation (calcium) distribution within the interfacial region and reduces the energetic burden of calcium stress in mitochondria. The mechanistic details of SS-31 revealed in this study will help inform the development of future compound variants with enhanced efficacy and bioavailability.
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Affiliation(s)
- Wayne Mitchell
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269
| | - Emily A Ng
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269
| | - Jeffrey D Tamucci
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269
| | - Kevin J Boyd
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269
| | - Murugappan Sathappa
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269
| | - Adrian Coscia
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269
| | - Meixia Pan
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Xianlin Han
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229; Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Nicholas A Eddy
- Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269
| | - Eric R May
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269
| | - Hazel H Szeto
- Social Profit Network Research Lab, Alexandria LaunchLabs, New York, New York 10016
| | - Nathan N Alder
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut 06269.
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16
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Lev B, Allen TW. Simulating ion channel activation mechanisms using swarms of trajectories. J Comput Chem 2020; 41:387-401. [PMID: 31743478 DOI: 10.1002/jcc.26102] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 10/16/2019] [Accepted: 10/17/2019] [Indexed: 12/14/2022]
Abstract
Atomic-level studies of protein activity represent a significant challenge as a result of the complexity of conformational changes occurring on wide-ranging timescales, often greatly exceeding that of even the longest simulations. A prime example is the elucidation of protein allosteric mechanisms, where localized perturbations transmit throughout a large macromolecule to generate a response signal. For example, the conversion of chemical to electrical signals during synaptic neurotransmission in the brain is achieved by specialized membrane proteins called pentameric ligand-gated ion channels. Here, the binding of a neurotransmitter results in a global conformational change to open an ion-conducting pore across the nerve cell membrane. X-ray crystallography has produced static structures of the open and closed states of the proton-gated GLIC pentameric ligand-gated ion channel protein, allowing for atomistic simulations that can uncover changes related to activation. We discuss a range of enhanced sampling approaches that could be used to explore activation mechanisms. In particular, we describe recent application of an atomistic string method, based on Roux's "swarms of trajectories" approach, to elucidate the sequence and interdependence of conformational changes during activation. We illustrate how this can be combined with transition analysis and Brownian dynamics to extract thermodynamic and kinetic information, leading to understanding of what controls ion channel function. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Bogdan Lev
- School of Science, RMIT University, Melbourne, Victoria, 3000, Australia
| | - Toby W Allen
- School of Science, RMIT University, Melbourne, Victoria, 3000, Australia
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17
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Mohamed AS, Hosney M, Bassiony H, Hassanein SS, Soliman AM, Fahmy SR, Gaafar K. Sodium pentobarbital dosages for exsanguination affect biochemical, molecular and histological measurements in rats. Sci Rep 2020; 10:378. [PMID: 31942001 PMCID: PMC6962368 DOI: 10.1038/s41598-019-57252-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 12/16/2019] [Indexed: 01/11/2023] Open
Abstract
Rodents are widely used for animal research in Egypt. Pentobarbital is the most common anesthetic agent; however overdoses may affect the experimental outcomes and limit the use of tissues. To investigate the effects of sodium pentobarbital overdoses during exsanguination, three groups (6 rats/group) of male and female rats were injected i.p. with 50, 100 and 150 mg/kg of sodium pentobarbital, then carotid exsanguination was performed immediately after loss of consciousness. Hypoxia-inducible factor 1-alpha (Hif1a) and tumor necrosis factor-alpha (Tnfa) mRNA expressions in liver and kidney organs were evaluated. As well as, serum aminotransferase activities (AST&ALT), glucose, urea, creatinine, malondialdehyde (MDA), reduced glutathione (GSH) and catalase (CAT) levels were determined. The histological alterations in liver, kidney and spleen were studied. It was found that Hif1a and Tnfa were significantly overexpressed in the studied organs and serum AST, glucose, creatinine and urea levels were significantly increased after sodium pentobarbital overdoses (100 and 150 mg/kg) compared to 50 mg/kg dose. Similarly, significant increase in MDA and GSH levels of liver, kidney and spleen were noticed. Results showed gender difference where Hif1a and Tnfa levels were significantly overexpressed at high dose of sodium pentobarbital of liver and kidney organs in female more than male rats. Since euthanasia protocol may influence the physiological variables and affect genes' expression, it is recommended to avoid sodium pentobarbital overdose during euthanasia as it may interfere with the biochemical, molecular and histological measurements.
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Affiliation(s)
- Ayman S Mohamed
- Department of Zoology, Faculty of Science, Cairo University, Giza, 12613, Egypt
| | - Mohamed Hosney
- Department of Zoology, Faculty of Science, Cairo University, Giza, 12613, Egypt
| | - Heba Bassiony
- Department of Zoology, Faculty of Science, Cairo University, Giza, 12613, Egypt.
| | - Sarah S Hassanein
- Department of Zoology, Faculty of Science, Cairo University, Giza, 12613, Egypt
| | - Amel M Soliman
- Department of Zoology, Faculty of Science, Cairo University, Giza, 12613, Egypt
| | - Sohair R Fahmy
- Department of Zoology, Faculty of Science, Cairo University, Giza, 12613, Egypt
| | - Khadiga Gaafar
- Department of Zoology, Faculty of Science, Cairo University, Giza, 12613, Egypt
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18
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Petersen EN, Pavel MA, Wang H, Hansen SB. Disruption of palmitate-mediated localization; a shared pathway of force and anesthetic activation of TREK-1 channels. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2020; 1862:183091. [PMID: 31672538 PMCID: PMC6907892 DOI: 10.1016/j.bbamem.2019.183091] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 09/15/2019] [Accepted: 09/17/2019] [Indexed: 12/22/2022]
Abstract
TWIK related K+ channel (TREK-1) is a mechano- and anesthetic sensitive channel that when activated attenuates pain and causes anesthesia. Recently the enzyme phospholipase D2 (PLD2) was shown to bind to the channel and generate a local high concentration of phosphatidic acid (PA), an anionic signaling lipid that gates TREK-1. In a biological membrane, the cell harnesses lipid heterogeneity (lipid compartments) to control gating of TREK-1 using palmitate-mediated localization of PLD2. Here we discuss the ability of mechanical force and anesthetics to disrupt palmitate-mediated localization of PLD2 giving rise to TREK-1's mechano- and anesthetic-sensitive properties. The likely consequences of this indirect lipid-based mechanism of activation are discussed in terms of a putative model for excitatory and inhibitory mechano-effectors and anesthetic sensitive ion channels in a biological context. Lastly, we discuss the ability of locally generated PA to reach mM concentrations near TREK-1 and the biophysics of localized signaling. Palmitate-mediated localization of PLD2 emerges as a central control mechanism of TREK-1 responding to mechanical force and anesthetic action. This article is part of a Special Issue entitled: Molecular biophysics of membranes and membrane proteins.
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Affiliation(s)
- E Nicholas Petersen
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, USA; Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Mahmud Arif Pavel
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, USA; Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Hao Wang
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, USA; Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Scott B Hansen
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL 33458, USA; Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA.
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19
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Patel J, Chowdhury EA, Noorani B, Bickel U, Huang J. Isoflurane increases cell membrane fluidity significantly at clinical concentrations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183140. [PMID: 31790694 DOI: 10.1016/j.bbamem.2019.183140] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 11/18/2019] [Accepted: 11/27/2019] [Indexed: 01/17/2023]
Abstract
There is an on-going debate whether anesthetic drugs, such as isoflurane, can cause meaningful structural changes in cell membranes at clinical concentrations. In this study, the effects of isoflurane on lipid membrane fluidity were investigated using fluorescence anisotropy and spectroscopy. In order to get a complete picture, four very different membrane systems (erythrocyte ghosts, a 5-lipid mixture that mimics brain endothelial cell membrane, POPC/Chol, and pure DPPC) were selected for the study. In all four systems, we found that fluorescence anisotropies of DPH-PC, nile-red, and TMA-DPH decrease significantly at the isoflurane concentrations of 1 mM and 5 mM. Furthermore, the excimer/monomer (E/M) ratio of dipyrene-PC jumps immediately after the addition of isoflurane. We found that isoflurane is quite effective to loosen up highly ordered lipid domains with saturated lipids. Interestingly, 1 mM isoflurane causes a larger decrease of nile-red fluorescence anisotropy in erythrocyte ghosts than 52.2 mM of ethanol, which is three times the legal limit of blood alcohol level. Our results paint a consistent picture that isoflurane at clinical concentrations causes significant and immediate increase of membrane fluidity in a wide range of membrane systems.
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Affiliation(s)
- Jigesh Patel
- Department of Physics and Astronomy, Texas Tech University, Lubbock, TX 79409, United States of America
| | - Ekram A Chowdhury
- Department of Pharmaceutical Sciences, Texas Tech University Health Science Center, Amarillo, TX 79106, United States of America
| | - Behnam Noorani
- Department of Pharmaceutical Sciences, Texas Tech University Health Science Center, Amarillo, TX 79106, United States of America
| | - Ulrich Bickel
- Department of Pharmaceutical Sciences, Texas Tech University Health Science Center, Amarillo, TX 79106, United States of America
| | - Juyang Huang
- Department of Physics and Astronomy, Texas Tech University, Lubbock, TX 79409, United States of America.
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20
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Bach-Rojecky L, Vađunec D, Lozić M, Žunić K, Špoljar GG, Čutura T, Erceg D, Primorac D. Challenges in anesthesia personalization: resolving the pharmacogenomic puzzle. Per Med 2019; 16:511-525. [DOI: 10.2217/pme-2019-0056] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Clinicians are witnessing differences in the doses required for induction and maintenance of anesthesia, as well as prolonged recovery in some patients. Predictable factors like patient characteristics, factors related to the procedure, pharmacological characteristics of anesthetics and adjunctive drugs, might explain some of the observed differences. However, the role of various polymorphisms of genes encoding for drugs’ molecular targets, transporters and metabolic enzymes can have a significant impact on anesthesia outcome, too. In the present paper, we critically discuss pharmacological characteristics of the most common drugs used in anesthesia, with a focus on the possible genetic background of unpredictable diversities in anesthesia outcomes.
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Affiliation(s)
- Lidija Bach-Rojecky
- Department of Pharmacology, University of Zagreb Faculty of Pharmacy & Biochemistry, Zagreb 10000, Croatia
| | - Dalia Vađunec
- Department of Pharmacology, University of Zagreb Faculty of Pharmacy & Biochemistry, Zagreb 10000, Croatia
| | - Marin Lozić
- Department of Anesthesia & ICU Care of Neurosurgical Patients, Clinic for Anesthesia & Intensive Care, University Clinical Hospital Zagreb, Zagreb 10000, Croatia
| | | | | | - Tomislav Čutura
- St. Catherine Specialty Hospital, Zagreb 10000 & Zabok 49210, Croatia
| | - Damir Erceg
- St. Catherine Specialty Hospital, Zagreb 10000 & Zabok 49210, Croatia
- Croatian Catholic University, Zagreb 10000, Croatia
- Srebrnjak Children's Hospital, Zagreb 10000, Croatia
- University Josip Juraj Strossmayer Faculty of Dental Medicine & Health, School of Medicine, Osijek 31000, Croatia
- University Josip Juraj Strossmayer School of Medicine, Osijek 31000, Croatia
| | - Dragan Primorac
- St. Catherine Specialty Hospital, Zagreb 10000 & Zabok 49210, Croatia
- University Josip Juraj Strossmayer Faculty of Dental Medicine & Health, School of Medicine, Osijek 31000, Croatia
- University Josip Juraj Strossmayer School of Medicine, Osijek 31000, Croatia
- Eberly College of Science, State College, Penn State University, PA 16802, USA
- The Henry C. Lee College of Criminal Justice & Forensic Sciences, University of New Haven, West Haven, CT 06516, USA
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21
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Sharma HS, Muresanu DF, Nozari A, Castellani RJ, Dey PK, Wiklund L, Sharma A. Anesthetics influence concussive head injury induced blood-brain barrier breakdown, brain edema formation, cerebral blood flow, serotonin levels, brain pathology and functional outcome. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2019; 146:45-81. [PMID: 31349932 DOI: 10.1016/bs.irn.2019.06.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Several lines of evidences show that anesthetics influence neurotoxicity and neuroprotection. The possibility that different anesthetic agents potentially influence the pathophysiological and functional outcome following neurotrauma was examined in a rat model of concussive head injury (CHI). The CHI was produced by an impact of 0.224N on the right parietal bone by dropping a weight of 114.6g from a 20cm height under different anesthetic agents, e.g., inhaled ether anesthesia or intraperitoneally administered ketamine, pentobarbital, equithesin or urethane anesthesia. Five hour CHI resulted in profound volume swelling and brain edema formation in both hemispheres showing disruption of the blood-brain barrier (BBB) to Evans blue and radioiodine. A marked decrease in the cortical CBF and a profound increase in plasma or brain serotonin levels were seen at this time. Neuronal damages were present in several parts of the brain. These pathological changes were most marked in CHI under ether anesthesia followed by ketamine (35mg/kg, i.p.), pentobarbital (50mg/kg, i.p.), equithesin (3mL/kg, i.p.) and urethane (1g/kg, i.p.). The functional outcome on Rota Rod performances or grid walking tests was also most adversely affected after CHI under ether anesthesia followed by pentobarbital, equithesin and ketamine. Interestingly, the plasma and brain serotonin levels strongly correlated with the development of brain edema in head injured animals in relation to different anesthetic agents used. These observations suggest that anesthetic agents are detrimental to functional and pathological outcomes in CHI probably through influencing the circulating plasma and brain serotonin levels, not reported earlier. Whether anesthetics could also affect the efficacy of different neuroprotective agents in CNS injuries is a new subject that is currently being examined in our laboratory.
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Affiliation(s)
- Hari Shanker Sharma
- International Experimental Central Nervous System Injury & Repair (IECNSIR), Department of Surgical Sciences, Anesthesiology & Intensive Care Medicine, Uppsala University Hospital, Uppsala University, Uppsala, Sweden.
| | - Dafin Fior Muresanu
- Department of Clinical Neurosciences, University of Medicine & Pharmacy, Cluj-Napoca, Romania; "RoNeuro" Institute for Neurological Research and Diagnostic, Cluj-Napoca, Romania
| | - Ala Nozari
- Anesthesia and Critical Care, Massachusetts General Hospital, Boston, MA, United States
| | - Rudy J Castellani
- Department of Pathology, University of Maryland, Baltimore, MD, United States
| | - Prasanta Kumar Dey
- Neurophysiology Research Unit, Department of Physiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Lars Wiklund
- International Experimental Central Nervous System Injury & Repair (IECNSIR), Department of Surgical Sciences, Anesthesiology & Intensive Care Medicine, Uppsala University Hospital, Uppsala University, Uppsala, Sweden
| | - Aruna Sharma
- International Experimental Central Nervous System Injury & Repair (IECNSIR), Department of Surgical Sciences, Anesthesiology & Intensive Care Medicine, Uppsala University Hospital, Uppsala University, Uppsala, Sweden
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22
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Flood E, Boiteux C, Lev B, Vorobyov I, Allen TW. Atomistic Simulations of Membrane Ion Channel Conduction, Gating, and Modulation. Chem Rev 2019; 119:7737-7832. [DOI: 10.1021/acs.chemrev.8b00630] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Emelie Flood
- School of Science, RMIT University, Melbourne, Victoria 3000, Australia
| | - Céline Boiteux
- School of Science, RMIT University, Melbourne, Victoria 3000, Australia
| | - Bogdan Lev
- School of Science, RMIT University, Melbourne, Victoria 3000, Australia
| | - Igor Vorobyov
- Department of Physiology & Membrane Biology/Department of Pharmacology, University of California, Davis, 95616, United States
| | - Toby W. Allen
- School of Science, RMIT University, Melbourne, Victoria 3000, Australia
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23
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Iqbal F, Thompson AJ, Riaz S, Pehar M, Rice T, Syed NI. Anesthetics: from modes of action to unconsciousness and neurotoxicity. J Neurophysiol 2019; 122:760-787. [PMID: 31242059 DOI: 10.1152/jn.00210.2019] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Modern anesthetic compounds and advanced monitoring tools have revolutionized the field of medicine, allowing for complex surgical procedures to occur safely and effectively. Faster induction times and quicker recovery periods of current anesthetic agents have also helped reduce health care costs significantly. Moreover, extensive research has allowed for a better understanding of anesthetic modes of action, thus facilitating the development of more effective and safer compounds. Notwithstanding the realization that anesthetics are a prerequisite to all surgical procedures, evidence is emerging to support the notion that exposure of the developing brain to certain anesthetics may impact future brain development and function. Whereas the data in support of this postulate from human studies is equivocal, the vast majority of animal research strongly suggests that anesthetics are indeed cytotoxic at multiple brain structure and function levels. In this review, we first highlight various modes of anesthetic action and then debate the evidence of harm from both basic science and clinical studies perspectives. We present evidence from animal and human studies vis-à-vis the possible detrimental effects of anesthetic agents on both the young developing and the elderly aging brain while discussing potential ways to mitigate these effects. We hope that this review will, on the one hand, invoke debate vis-à-vis the evidence of anesthetic harm in young children and the elderly, and on the other hand, incentivize the search for better and less toxic anesthetic compounds.
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Affiliation(s)
- Fahad Iqbal
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Andrew J Thompson
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Neuroscience, Faculty of Science, University of Calgary, Calgary, Alberta, Canada
| | - Saba Riaz
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Marcus Pehar
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Tiffany Rice
- Department of Anesthesiology, Perioperative and Pain Medicine, Alberta Children's Hospital, University of Calgary, Calgary, Alberta, Canada
| | - Naweed I Syed
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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24
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Kohn FPM, Hauslage J. The gravity dependence of pharmacodynamics: the integration of lidocaine into membranes in microgravity. NPJ Microgravity 2019; 5:5. [PMID: 30854420 PMCID: PMC6403312 DOI: 10.1038/s41526-019-0064-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 02/05/2019] [Indexed: 01/24/2023] Open
Abstract
To realize long-term manned space missions, e.g. to Mars, some important questions about pharmacology under conditions of different gravity will have to be answered to ensure safe usage of pharmaceuticals. Experiments on the International Space Station showed that the pharmacokinetics of drugs are changed in microgravity. On Earth, it is well known that the incorporation of substances into cellular membranes depends on membrane fluidity, therefore the finding that membrane fluidity is gravity dependent possibly has effects on pharmacodynamics of hydrophobic and amphiphilic substances in microgravity. To validate a possible effect of gravity on pharmacodynamics, experiments have been carried out to investigate the incorporation of lidocaine into plain lipid membranes under microgravity conditions. In microgravity, the induced increase in membrane fluidity associated with lidocaine incorporation is smaller compared to 1g controls. This experiment concerning the gravity dependence of pharmacodynamics in real microgravity clearly shows that the incorporation of amphipathic drugs into membranes is changed in microgravity. This might have significant impact on the pharmacology of drugs during long-term space missions and has to be investigated in more detail to be able to assess possible risks.
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Affiliation(s)
- Florian P. M. Kohn
- Department of Membrane Physiology (230b), Institute of Physiology, University of Hohenheim, Stuttgart, Germany
| | - Jens Hauslage
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Gravitational Biology, Linder Hoehe Cologne, Germany
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25
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Ozsoy HZ. Carbonic anhydrase enzymes: Likely targets for inhalational anesthetics. Med Hypotheses 2019; 123:118-124. [PMID: 30696581 DOI: 10.1016/j.mehy.2019.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 01/09/2019] [Indexed: 10/27/2022]
Abstract
Inhalational anesthetics such as isoflurane, desflurane and halothane are the mainstay medications for surgical procedures; upon inhalation, they produce anesthesia described as reversible unconsciousness with the features of amnesia, sleep, immobility and analgesia. To date, how they produce anesthesia is unknown. This study proposes that carbonic anhydrase enzymes are likely targets mediating the actions of inhalational anesthetics. Carbonic anhydrase enzymes, commonly expressed in living organisms, utilize carbon dioxide (CO2) as a substrate and can generate H+ and HCO3- from CO2 with a great efficiency. There are remarkable lines of evidence for their likely roles in mediating anesthetic actions. Firstly, carbonic anhydrase enzymes are extensively expressed in the brain and spinal cord, and their importance in the brain activity, especially for the GABA and NMDA receptor signaling pathways, has been demonstrated in numerous studies. According to these studies, they provide HCO3- for GABA-A receptor activities and also buffer HCO3- excess resulting from NMDA receptor activation. Activation of GABA-A and inhibition of NMDA receptors are associated with the induction of anesthesia by the intravenous general anesthetics propofol and ketamine, respectively. Secondly, the carbonic anhydrase inhibitors topiramate and zonisamide are effectively used in the treatment of epilepsy for decades; their chronic use results in the requirement of increased levels of amobarbital in order to produce anesthesia in the epileptic patients during WADA test. In addition, given that CO2 is a substrate for these enzymes, their tertiary structure is likely has a hydrophobic pocket suitable for the anesthetic molecules to bind. Inhalational anesthetic molecules, which are lipophilic and inert in nature, have an ability to cross the membranes and inhibit carbonic anhydrases, which might not be accessible by topiramate and zonisamide. Unlike carbonic anhydrase inhibitors, they could bind to the hydrophobic pocket for CO2 molecules and produce a profound effect called anesthesia. Finally, there is a great deal of similarities between the physiological actions of inhalational anesthetics and carbonic anhydrase inhibitors; moreover well-known side effects of inhalational anesthetics could be associated with the inhibition of carbonic anhydrases. Therefore, this article presents a hypothesis that the anesthetic actions of inhalational anesthetics could be due to their inhibitory effects on the carbonic anhydrases. Investigating this hypothesis might lead to the development of new safer anesthetics, and more importantly it might reveal an endogenous anesthetic pathway, in which the carbonic anhydrase system is a component along with the GABA-A and NMDA receptor systems.
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Affiliation(s)
- H Z Ozsoy
- 2515 Gramercy Street, Houston, TX 77030, United States.
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26
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Niga P, Hansson-Mille PM, Swerin A, Claesson PM, Schoelkopf J, Gane PAC, Dai J, Furó I, Campbell RA, Johnson CM. Propofol adsorption at the air/water interface: a combined vibrational sum frequency spectroscopy, nuclear magnetic resonance and neutron reflectometry study. SOFT MATTER 2018; 15:38-46. [PMID: 30516226 DOI: 10.1039/c8sm01677a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Propofol is an amphiphilic small molecule that strongly influences the function of cell membranes, yet data regarding interfacial properties of propofol remain scarce. Here we consider propofol adsorption at the air/water interface as elucidated by means of vibrational sum frequency spectroscopy (VSFS), neutron reflectometry (NR), and surface tensiometry. VSFS data show that propofol adsorbed at the air/water interface interacts with water strongly in terms of hydrogen bonding and weakly in the proximity of the hydrocarbon parts of the molecule. In the concentration range studied there is almost no change in the orientation adopted at the interface. Data from NR show that propofol forms a dense monolayer with a thickness of 8.4 Å and a limiting area per molecule of 40 Å2, close to the value extracted from surface tensiometry. The possibility that islands or multilayers of propofol form at the air/water interface is therefore excluded as long as the solubility limit is not exceeded. Additionally, measurements of the 1H NMR chemical shifts demonstrate that propofol does not form dimers or multimers in bulk water up to the solubility limit.
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Affiliation(s)
- Petru Niga
- RISE Research Institutes of Sweden - Chemistry, Materials and Surfaces, Box 5607, SE-114 86 Stockholm, Sweden.
| | - Petra M Hansson-Mille
- RISE Research Institutes of Sweden - Chemistry, Materials and Surfaces, Box 5607, SE-114 86 Stockholm, Sweden.
| | - Agne Swerin
- RISE Research Institutes of Sweden - Chemistry, Materials and Surfaces, Box 5607, SE-114 86 Stockholm, Sweden. and KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, SE-100 44 Stockholm, Sweden.
| | - Per M Claesson
- RISE Research Institutes of Sweden - Chemistry, Materials and Surfaces, Box 5607, SE-114 86 Stockholm, Sweden. and KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, SE-100 44 Stockholm, Sweden.
| | | | - Patrick A C Gane
- Omya International AG, Baslerstrasse 42, CH-4665 Oftringen, Switzerland and Aalto University, School of Chemical Technology, Department of Bioproducts and Biosystems, FI-00076 Aalto, Helsinki, Finland
| | - Jing Dai
- KTH Royal Institute of Technology, Department of Chemistry, Division of Applied Physical Chemistry, SE-100 44 Stockholm, Sweden
| | - István Furó
- KTH Royal Institute of Technology, Department of Chemistry, Division of Applied Physical Chemistry, SE-100 44 Stockholm, Sweden
| | - Richard A Campbell
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS20156, 38042 Grenoble Cedex 9, France and Division of Pharmacy and Optometry, University of Manchester, Manchester M13 9PT, UK
| | - C Magnus Johnson
- KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, SE-100 44 Stockholm, Sweden.
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Oakes V, Domene C. Capturing the Molecular Mechanism of Anesthetic Action by Simulation Methods. Chem Rev 2018; 119:5998-6014. [DOI: 10.1021/acs.chemrev.8b00366] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Victoria Oakes
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Carmen Domene
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
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Allosteric potentiation of a ligand-gated ion channel is mediated by access to a deep membrane-facing cavity. Proc Natl Acad Sci U S A 2018; 115:10672-10677. [PMID: 30275330 PMCID: PMC6196478 DOI: 10.1073/pnas.1809650115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Theories of general anesthesia have shifted in focus from bulk lipid effects to specific interactions with membrane proteins. Target receptors include several subtypes of pentameric ligand-gated ion channels; however, structures of physiologically relevant proteins in this family have yet to define anesthetic binding at high resolution. Recent cocrystal structures of the bacterial protein GLIC provide snapshots of state-dependent binding sites for the common surgical agent propofol (PFL), offering a detailed model system for anesthetic modulation. Here, we combine molecular dynamics and oocyte electrophysiology to reveal differential motion and modulation upon modification of a transmembrane binding site within each GLIC subunit. WT channels exhibited net inhibition by PFL, and a contraction of the cavity away from the pore-lining M2 helix in the absence of drug. Conversely, in GLIC variants exhibiting net PFL potentiation, the cavity was persistently expanded and proximal to M2. Mutations designed to favor this deepened site enabled sensitivity even to subclinical concentrations of PFL, and a uniquely prolonged mode of potentiation evident up to ∼30 min after washout. Dependence of these prolonged effects on exposure time implicated the membrane as a reservoir for a lipid-accessible binding site. However, at the highest measured concentrations, potentiation appeared to be masked by an acute inhibitory effect, consistent with the presence of a discrete, water-accessible site of inhibition. These results support a multisite model of transmembrane allosteric modulation, including a possible link between lipid- and receptor-based theories that could inform the development of new anesthetics.
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Winkler DA, Katz I, Farjot G, Warden AC, Thornton AW. Decoding the Rich Biological Properties of Noble Gases: How Well Can We Predict Noble Gas Binding to Diverse Proteins? ChemMedChem 2018; 13:1931-1938. [PMID: 30003691 DOI: 10.1002/cmdc.201800434] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Indexed: 12/19/2022]
Abstract
The chemically inert noble gases display a surprisingly rich spectrum of useful biological properties. Relatively little is known about the molecular mechanisms behind these effects. It is clearly not feasible to conduct large numbers of pharmacological experiments on noble gases to identify activity. Computational studies of the binding of noble gases and proteins can address this paucity of information and provide insight into mechanisms of action. We used bespoke computational grid calculations to predict the positions of energy minima in the interactions of noble gases with diverse proteins. The method was validated by quantifying how well simulations could predict binding positions in 131 diverse protein X-ray structures containing 399 Xe and Kr atoms. We found excellent agreement between calculated and experimental binding positions of noble gases. 94 % of all crystallographic xenon atoms were within 1 Xe van der Waals (vdW) diameter of a predicted binding site, and 97 % lay within 2 vdW diameters. 100 % of crystallographic krypton atoms were within 1 Kr vdW diameter of a predicted binding site. We showed the feasibility of large-scale computational screening of all ≈60 000 unique structures in the Protein Data Bank. This will elucidate biochemical mechanisms by which these novel 'atomic drugs' elicit their valuable biochemical properties and identify new medical uses.
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Affiliation(s)
- David A Winkler
- Manufacturing Business Unit, CSIRO, Bayview Avenue, Clayton, 3168, Australia
- Biochemistry and Genetics, La Trobe University, Kingsbury Drive, Bundoora, 3086, Australia
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, 3052, Australia
| | - Ira Katz
- Early Drug Development, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Jouy-en-Josas, France
- Department of Mechanical Engineering, Lafayette College, Easton, PA, USA
| | - Géraldine Farjot
- Early Drug Development, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Jouy-en-Josas, France
| | - Andrew C Warden
- Manufacturing Business Unit, CSIRO, Bayview Avenue, Clayton, 3168, Australia
| | - Aaron W Thornton
- Manufacturing Business Unit, CSIRO, Bayview Avenue, Clayton, 3168, Australia
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Regulatory Effect of General Anesthetics on Activity of Potassium Channels. Neurosci Bull 2018; 34:887-900. [PMID: 29948841 PMCID: PMC6129254 DOI: 10.1007/s12264-018-0239-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 04/12/2018] [Indexed: 12/19/2022] Open
Abstract
General anesthesia is an unconscious state induced by anesthetics for surgery. The molecular targets and cellular mechanisms of general anesthetics in the mammalian nervous system have been investigated during past decades. In recent years, K+ channels have been identified as important targets of both volatile and intravenous anesthetics. This review covers achievements that have been made both on the regulatory effect of general anesthetics on the activity of K+ channels and their underlying mechanisms. Advances in research on the modulation of K+ channels by general anesthetics are summarized and categorized according to four large K+ channel families based on their amino-acid sequence homology. In addition, research achievements on the roles of K+ channels in general anesthesia in vivo, especially with regard to studies using mice with K+ channel knockout, are particularly emphasized.
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Niga P, Hansson-Mille PM, Swerin A, Claesson PM, Schoelkopf J, Gane PAC, Bergendal E, Tummino A, Campbell RA, Magnus Johnson C. Interactions between model cell membranes and the neuroactive drug propofol. J Colloid Interface Sci 2018; 526:230-243. [PMID: 29734090 DOI: 10.1016/j.jcis.2018.03.052] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 03/12/2018] [Accepted: 03/14/2018] [Indexed: 12/13/2022]
Abstract
Vibrational sum frequency spectroscopy (VSFS) complemented by surface pressure isotherm and neutron reflectometry (NR) experiments were employed to investigate the interactions between propofol, a small amphiphilic molecule that currently is the most common general anaesthetic drug, and phospholipid monolayers. A series of biologically relevant saturated phospholipids of varying chain length from C18 to C14 were spread on either pure water or propofol (2,6-bis(1-methylethyl)phenol) solution in a Langmuir trough, and the change in the molecular structure of the film, induced by the interaction with propofol, was studied with respect to the surface pressure. The results from the surface pressure isotherm experiments revealed that propofol, as long as it remains at the interface, enhances the fluidity of the phospholipid monolayer. The VSF spectra demonstrate that for each phospholipid the amount of propofol in the monolayer region decreases with increasing surface pressure. Such squeeze out is in contrast to the enhanced interactions that can be exhibited by more complex amphiphilic molecules such as peptides. At surface pressures of 22-25 mN m-1, which are relevant for biological cell membranes, most of the propofol has been expelled from the monolayer, especially in the case of the C16 and C18 phospholipids that adopt a liquid condensed phase packing of its alkyl tails. At lower surface pressures of 5 mN m-1, the effect of propofol on the structure of the alkyl tails is enhanced when the phospholipids are present in a liquid expanded phase. Specifically, for the C16 phospholipid, NR data reveal that propofol is located exclusively in the head group region, which is rationalized in the context of previous studies. The results imply a non-homogeneous distribution of propofol in the plane of real cell membranes, which is an inference that requires urgent testing and may help to explain why such low concentration of the drug are required to induce general anaesthesia.
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Affiliation(s)
- Petru Niga
- RISE - Research Institute of Sweden, Bioscience and Materials - Surface, Process and Formulation Box 5607, SE-114 28 Stockholm, Sweden.
| | - Petra M Hansson-Mille
- RISE - Research Institute of Sweden, Bioscience and Materials - Surface, Process and Formulation Box 5607, SE-114 28 Stockholm, Sweden
| | - Agne Swerin
- RISE - Research Institute of Sweden, Bioscience and Materials - Surface, Process and Formulation Box 5607, SE-114 28 Stockholm, Sweden; KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, SE-100 44 Stockholm, Sweden
| | - Per M Claesson
- RISE - Research Institute of Sweden, Bioscience and Materials - Surface, Process and Formulation Box 5607, SE-114 28 Stockholm, Sweden; KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, SE-100 44 Stockholm, Sweden
| | | | - Patrick A C Gane
- Omya International AG, Baslerstrasse 42, CH-4665 Oftringen, Switzerland; Aalto University, School of Chemical Engineering, Department of Bioproducts and Biosystems, P.O. Box 16300, FI-00076 Aalto, Helsinki, Finland
| | - Erik Bergendal
- KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, SE-100 44 Stockholm, Sweden
| | - Andrea Tummino
- Institut Laue-Langevin, 71 avenue des Martyrs, 38042 Grenoble, France; Eötvös Loránd University, Budapest 112, P.O. Box 32, H-1518, Hungary
| | | | - C Magnus Johnson
- KTH Royal Institute of Technology, Department of Chemistry, Division of Surface and Corrosion Science, SE-100 44 Stockholm, Sweden.
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Sevoflurane Blocks the Induction of Long-term Potentiation When Present during, but Not When Present Only before, the High-frequency Stimulation. Anesthesiology 2018; 128:555-563. [DOI: 10.1097/aln.0000000000002057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Abstract
Background
This study tests the hypothesis that sevoflurane blocks long-term potentiation only if it is present during the high-frequency stimulation that induces long-term potentiation.
Methods
Long-term potentiation, an electrophysiologic correlate of memory, was induced by high-frequency stimulation and measured as a persistent increase in the field excitatory postsynaptic potential slope in the CA1 region.
Results
Long-term potentiation was induced in the no sevoflurane group (171 ± 58% vs. 96 ± 11%; n = 13, mean ± SD); when sevoflurane (4%) was present during the high-frequency stimulation, long-term potentiation was blocked (92 ± 22% vs. 99 ± 7%, n = 6). While sevoflurane reduced the size of the field excitatory postsynaptic potential to single test stimuli by 59 ± 17%, it did not significantly reduce the size of the field excitatory postsynaptic potentials during the 100 Hz high-frequency stimulation. If sevoflurane was removed from the artificial cerebrospinal fluid superfusing the slices 10 min before the high-frequency stimulation, then long-term potentiation was induced (185 ± 48%, n = 7); this was not different from long-term potentiation in the no sevoflurane slices (171 ± 58). Sevoflurane before, but not during, ⊖-burst stimulation, a physiologic stimulus, did not block the induction of long-term potentiation (151 ± 37% vs. 161 ± 34%, n = 7).
Conclusions
Sevoflurane blocks long-term potentiation formation if present during the high-frequency stimulation; this blockage of long-term potentiation does not persist if sevoflurane is discontinued before the high-frequency stimulation. These results may explain why short periods of insufficient sevoflurane anesthesia may lead to recall of painful or traumatic events during surgery.
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Borsacchi S, Geppi M, Macchi S, Ninham BW, Fratini E, Ambrosi M, Baglioni P, Lo Nostro P. Phase transitions in hydrophobe/phospholipid mixtures: hints at connections between pheromones and anaesthetic activity. Phys Chem Chem Phys 2018; 18:15375-83. [PMID: 27210443 DOI: 10.1039/c6cp00659k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The phase behavior of a mixture of a typical insect pheromone (olean) and a phospholipid (DOPC)/water dispersion is extensively explored through SAXS, NMR and DSC experiments. The results mimic those obtained with anaesthetics in phospholipid/water systems. They also mimic the behavior and microstructure of ternary mixtures of a membrane mimetic, bilayer-forming double chained surfactants, oils and water. Taken together with recent models for conduction of the nervous impulse, all hint at lipid involvement and the underlying unity in mechanisms of pheromone, anaesthetic and hydrophobic drugs, where a local phase change in the lipid membrane architecture may be at least partly involved in the transmission of the signal.
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Affiliation(s)
- Silvia Borsacchi
- Istituto di Chimica dei Composti OrganoMetallici (ICCOM) del CNR, 56124 Pisa, Italy
| | - Marco Geppi
- Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
| | - Sara Macchi
- Department of Chemistry and Industrial Chemistry, University of Pisa, 56124 Pisa, Italy
| | - Barry W Ninham
- Department of Chemistry & CSGI, University of Florence, 50019 Sesto Fiorentino (Firenze), Italy. and Department of Applied Mathematics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200, Australia
| | - Emiliano Fratini
- Department of Chemistry & CSGI, University of Florence, 50019 Sesto Fiorentino (Firenze), Italy.
| | - Moira Ambrosi
- Department of Chemistry & CSGI, University of Florence, 50019 Sesto Fiorentino (Firenze), Italy.
| | - Piero Baglioni
- Department of Chemistry & CSGI, University of Florence, 50019 Sesto Fiorentino (Firenze), Italy. and Enzo Ferroni Foundation, 50019 Sesto Fiorentino (Firenze), Italy
| | - Pierandrea Lo Nostro
- Department of Chemistry & CSGI, University of Florence, 50019 Sesto Fiorentino (Firenze), Italy. and Enzo Ferroni Foundation, 50019 Sesto Fiorentino (Firenze), Italy
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Gianti E, Carnevale V. Computational Approaches to Studying Voltage-Gated Ion Channel Modulation by General Anesthetics. Methods Enzymol 2018; 602:25-59. [DOI: 10.1016/bs.mie.2018.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Yamaguchi T, Shirai O, Kitazumi Y, Kano K. Inhibition of Ion Transport through Gramicidin A Channels by the Addition of Local Anesthetic Procaine. ELECTROANAL 2017. [DOI: 10.1002/elan.201700609] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Takuya Yamaguchi
- Division of Applied Life Sciences, Graduate School of Agriculture; Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku; Kyoto 606-8502 Japan
| | - Osamu Shirai
- Division of Applied Life Sciences, Graduate School of Agriculture; Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku; Kyoto 606-8502 Japan
| | - Yuki Kitazumi
- Division of Applied Life Sciences, Graduate School of Agriculture; Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku; Kyoto 606-8502 Japan
| | - Kenji Kano
- Division of Applied Life Sciences, Graduate School of Agriculture; Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku; Kyoto 606-8502 Japan
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Davis BM, Brenton J, Davis S, Shamsher E, Sisa C, Grgic L, Cordeiro MF. Assessing anesthetic activity through modulation of the membrane dipole potential. J Lipid Res 2017; 58:1962-1976. [PMID: 28818873 PMCID: PMC5625120 DOI: 10.1194/jlr.m073932] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 08/09/2017] [Indexed: 12/21/2022] Open
Abstract
There is great individual variation in response to general anesthetics (GAs) leading to difficulties in optimal dosing and sometimes even accidental awareness during general anesthesia (AAGA). AAGA is a rare, but potentially devastating, complication affecting between 0.1% and 2% of patients undergoing surgery. The development of novel personalized screening techniques to accurately predict a patient’s response to GAs and the risk of AAGA remains an unmet clinical need. In the present study, we demonstrate the principle of using a fluorescent reporter of the membrane dipole potential, di-8-ANEPPs, as a novel method to monitor anesthetic activity using a well-described inducer/noninducer pair. The membrane dipole potential has previously been suggested to contribute a novel mechanism of anesthetic action. We show that the fluorescence ratio of di-8-ANEPPs changed in response to physiological concentrations of the anesthetic, 1-chloro-1,2,2-trifluorocyclobutane (F3), but not the structurally similar noninducer, 1,2-dichlorohexafluorocyclobutane (F6), to artificial membranes and in vitro retinal cell systems. Modulation of the membrane dipole provides an explanation to overcome the limitations associated with the alternative membrane-mediated mechanisms of GA action. Furthermore, by combining this technique with noninvasive retinal imaging technologies, we propose that this technique could provide a novel and noninvasive technique to monitor GA susceptibility and identify patients at risk of AAGA.
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Affiliation(s)
| | - Jonathan Brenton
- University College London Institute of Ophthalmology, London EC1V 9EL, United Kingdom
| | - Sterenn Davis
- University College London Institute of Ophthalmology, London EC1V 9EL, United Kingdom
| | - Ehtesham Shamsher
- University College London Institute of Ophthalmology, London EC1V 9EL, United Kingdom
| | - Claudia Sisa
- University College London Institute of Ophthalmology, London EC1V 9EL, United Kingdom
| | - Ljuban Grgic
- University College London Institute of Ophthalmology, London EC1V 9EL, United Kingdom
| | - M Francesca Cordeiro
- University College London Institute of Ophthalmology, London EC1V 9EL, United Kingdom .,Western Eye Hospital, Imperial College Healthcare National Health Service Trust, and Imperial College Ophthalmic Research Group, Imperial College London, London NW1 5QH, United Kingdom
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Amin J, Subbarayan MS. Orthosteric- versus allosteric-dependent activation of the GABA A receptor requires numerically distinct subunit level rearrangements. Sci Rep 2017; 7:7770. [PMID: 28798394 PMCID: PMC5552871 DOI: 10.1038/s41598-017-08031-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 07/07/2017] [Indexed: 12/05/2022] Open
Abstract
Anaesthetic molecules act on synaptic transmission via the allosteric modulation of ligand-gated chloride channels, such as hetero-oligomeric α1β2γ2 GABAA receptors. To elucidate the overall activation paradigm via allosteric versus orthosteric sites, we used highly homologous, but homo-oligomeric, ρ1 receptors that are contrastingly insensitive to anaesthetics and respond partially to several full GABA α1β2γ2 receptor agonists. Here, we coexpressed varying ratios of RNAs encoding the wild-type and the mutated ρ1 subunits, which are anaesthetic-sensitive and respond with full efficacy to partial GABA agonists, to generate distinct ensembles of receptors containing five, four, three, two, one, or zero mutated subunits. Using these experiments, we then demonstrate that, in the pentamer, three anaesthetic-sensitive ρ1 subunits are needed to impart full efficacy to the partial GABA agonists. By contrast, five anaesthetic-sensitive subunits are required for direct activation by anaesthetics alone, and only one anaesthetic-sensitive subunit is sufficient to confer the anaesthetic-dependent potentiation to the GABA current. In conclusion, our data indicate that GABA and anaesthetics holistically activate the GABAA ρ1 receptor through distinct subunit level rearrangements and suggest that in contrast to the global impact of GABA via orthosteric sites, the force of anaesthetics through allosteric sites may not propagate to the neighbouring subunits and, thus, may have only a local and limited effect on the ρ1 GABAA receptor model system.
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Affiliation(s)
- Jahanshah Amin
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida, 33612, USA.
| | - Meena S Subbarayan
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida, 33612, USA
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Connolly C, Madden SF, Buggy DJ, Gallagher HC. Expression of anaesthetic and analgesic drug target genes in excised breast tumour tissue: Association with clinical disease recurrence or metastasis. PLoS One 2017; 12:e0177105. [PMID: 28558008 PMCID: PMC5448742 DOI: 10.1371/journal.pone.0177105] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 04/21/2017] [Indexed: 11/18/2022] Open
Abstract
Background Retrospective analyses suggest anaesthetic-analgesics technique during cancer surgery may affect recurrence/metastasis. This could involve direct effects of anaesthetic-analgesic drugs on cancer cells. While μ-opioid receptor over-expression in lung tumours is associated with greater metastasis, other anaesthetic-analgesic receptor targets in cancer recurrence/metastasis remain unexplored. Therefore, we evaluated the association between genetic expression of anaesthetic-analgesic receptor targets and recurrence/metastasis, using a repository of breast cancer gene expression and matching clinical data. Methods A list of 23 genes encoding for the most prominent anaesthetic-analgesic receptor targets was compiled. This was processed through BreastMark- an algorithm integrating gene expression data from ~17,000 samples and clinical data from >4,500 breast cancer samples. Gene expression data was dichotomized using disease-free survival (survival without recurrence) and distant disease-free survival (survival without metastasis) as end points. Hazard ratios were calculated by Cox-regression analysis. Enrichment for prognostic markers was determined by randomly choosing 23-member gene lists from all available genes, calculating how often >5 significant markers were observed and adjusting p-values for multiple testing. This was repeated 10,000 times and an empirical p-value calculated. Results Of 23 selected genes, 9 were significantly associated with altered rates of metastasis and 4 with recurrence on univariate analysis. Adjusting for multiple testing, 5 of these 9 genes remained significantly associated with metastasis, non with recurrence. This ratio of genes (5/23) was not significantly enriched for markers of metastasis (p = 0.07). Conclusion Several anaesthetic-analgesic receptor genes were associated with metastatic spread in breast cancer. Overall there was no significant enrichment in prognostic markers of metastasis, although a trend was observed.
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Affiliation(s)
- C. Connolly
- Dept. of Anaesthesia, Mater Misericordiae University Hospital, Dublin, Ireland
- School of Medicine, University College Dublin, Dublin, Ireland
- * E-mail: (CC); (DJB)
| | - S. F. Madden
- RCSI Population Health Sciences, Dept. of Psychology, Royal College of Surgeons, Dublin, Ireland
| | - D. J. Buggy
- Dept. of Anaesthesia, Mater Misericordiae University Hospital, Dublin, Ireland
- School of Medicine, University College Dublin, Dublin, Ireland
- Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
- Outcomes Research Consortium, Cleveland Clinic, Cleveland, Ohio, United States of America
- * E-mail: (CC); (DJB)
| | - H. C. Gallagher
- Dept. of Anaesthesia, Mater Misericordiae University Hospital, Dublin, Ireland
- School of Medicine, University College Dublin, Dublin, Ireland
- Conway Institute for Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
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Peschel A, Langhoff A, Uhl E, Dathathreyan A, Haindl S, Johannsmann D, Reviakine I. Lipid phase behavior studied with a quartz crystal microbalance: A technique for biophysical studies with applications in screening. J Chem Phys 2017; 145:204904. [PMID: 27908120 DOI: 10.1063/1.4968215] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Quartz crystal microbalance (QCM) is emerging as a versatile tool for studying lipid phase behavior. The technique is attractive for fundamental biophysical studies as well applications because of its simplicity, flexibility, and ability to work with very small amounts of material crucial for biomedical studies. Further progress hinges on the understanding of the mechanism, by which a surface-acoustic technique such as QCM, senses lipid phase changes. Here, we use a custom-built instrument with improved sensitivity to investigate phase behavior in solid-supported lipid systems of different geometries (adsorbed liposomes and bilayers). We show that we can detect a model anesthetic (ethanol) through its effect on the lipid phase behavior. Further, through the analysis of the overtone dependence of the phase transition parameters, we show that hydrodynamic effects are important in the case of adsorbed liposomes, and viscoelasticity is significant in supported bilayers, while layer thickness changes make up the strongest contribution in both systems.
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Affiliation(s)
- Astrid Peschel
- Institute of Physical Chemistry, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, Germany
| | - Arne Langhoff
- Institute of Physical Chemistry, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, Germany
| | - Eva Uhl
- Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Hermann-von Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Aruna Dathathreyan
- Institute of Physical Chemistry, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, Germany
| | - Susanne Haindl
- Institute of Physical Chemistry, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, Germany
| | - Diethelm Johannsmann
- Institute of Physical Chemistry, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, Germany
| | - Ilya Reviakine
- Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Hermann-von Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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Baluška F, Yokawa K, Mancuso S, Baverstock K. Understanding of anesthesia - Why consciousness is essential for life and not based on genes. Commun Integr Biol 2016; 9:e1238118. [PMID: 28042377 PMCID: PMC5193047 DOI: 10.1080/19420889.2016.1238118] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 08/05/2016] [Accepted: 09/14/2016] [Indexed: 01/14/2023] Open
Abstract
Anesthesia and consciousness represent 2 mysteries not only for biology but also for physics and philosophy. Although anesthesia was introduced to medicine more than 160 y ago, our understanding of how it works still remains a mystery. The most prevalent view is that the human brain and its neurons are necessary to impose the effects of anesthetics. However, the fact is that all life can be anesthesized. Numerous theories have been generated trying to explain the major impact of anesthetics on our human-specific consciousness; switching it off so rapidly, but no single theory resolves this enduring mystery. The speed of anesthetic actions precludes any direct involvement of genes. Lipid bilayers, cellular membranes, and critical proteins emerge as the most probable primary targets of anesthetics. Recent findings suggest, rather surprisingly, that physical forces underlie both the anesthetic actions on living organisms as well as on consciousness in general.
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Affiliation(s)
| | - Ken Yokawa
- IZMB, University of Bonn, Kirschalle, Bonn, Germany
| | - Stefano Mancuso
- Department of Plant, Soil and Environmental Science & LINV, University of Florence, Sesto Fiorentino, Italy
| | - Keith Baverstock
- Department of Environmental Science, University of Eastern Finland, Kuopio, Finland
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Licina A, Sidhu S, Xie J, Wan C. Local versus general anaesthesia for adults undergoing pars plana vitrectomy surgery. Cochrane Database Syst Rev 2016; 9:CD009936. [PMID: 27641718 PMCID: PMC6457833 DOI: 10.1002/14651858.cd009936.pub2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Vitrectomy surgery is one of the commonest ophthalmic procedures performed across the world. It may be performed using general or local anaesthesia encompassing regional or topical anaesthesia depending on a number of factors, including patient suitability, and patient, surgeon or anaesthetist preference. There have so far been no evidence-based recommendations on the best form of anaesthesia for this intervention. There is no clear collated evidence base as to the best type of anaesthesia to reduce harm, and provide best surgical conditions and optimal outcome for patients. OBJECTIVES To compare local with general anaesthesia for adults undergoing pars plana vitrectomy. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library and the reference lists of updated studies on the 25th of July 2016; MEDLINE via Ovid SP (1972 to July 2016) and Embase via Ovid SP (1972 to July 2016). In addition we searched the metaRegister of Controlled Trials (mRCT), ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) in July 2016. We searched the proceedings of the Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) up to July 2016 for information about other relevant studies.We also searched appropriate databases for ongoing reviews. We did not apply any language restriction. We assessed the search as up-to-date on the 25th of July 2016. SELECTION CRITERIA We planned to include all published randomized controlled trials (RCTs) involving comparison of different modalities of local anaesthesia with general anaesthesia for pars plana vitrectomy. We considered the following different modalities of local anaesthesia: sub-Tenon's anaesthesia, retrobulbar anaesthesia, topical anaesthesia, peribulbar anaesthesia. We planned to include cluster-randomized controlled trials. We excluded quasi-RCT trials. DATA COLLECTION AND ANALYSIS Two review authors conducted independent searches and assessed identified studies for inclusion according to the prespecified selection criteria. Two review authors assessed trial quality and planned to extract the data. MAIN RESULTS We found no eligible studies that met our inclusion criteria and were therefore unable to perform a meta-analysis or conduct a methodological quality assessment. AUTHORS' CONCLUSIONS This systematic review failed to locate relevant clinical evidence to support or refute a pars plana vitrectomy performed with various modalities of local anaesthesia versus general anaesthesia. Good-quality clinical trials are needed to define the role of local versus general anaesthesia for pars plana vitrectomy.
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Affiliation(s)
- Ana Licina
- Royal Victorian Eye and Ear Hospital/University of MelbourneDepartment of AnaesthesiaMelbourneAustralia
- Austin Health, Austin HospitalDepartment of AnaesthesiaMelbourneAustralia
| | - Sharan Sidhu
- Royal Victorian Eye and Ear HospitalDepartment of AnaesthesiaMelbourneAustralia
| | - Jing Xie
- University of MelbourneCentre for Eye Research AustraliaLevel 1, 32 Gisborne StreetMelbourneAustralia
| | - Crispin Wan
- Royal Victorian Eye and Ear HospitalDepartment of AnaesthesiaMelbourneAustralia
- St Vincent's HospitalDepartment of Anaesthesia and Acute Pain MedicineMelbourneAustralia
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Covarrubias M, Barber AF, Carnevale V, Treptow W, Eckenhoff RG. Mechanistic Insights into the Modulation of Voltage-Gated Ion Channels by Inhalational Anesthetics. Biophys J 2016; 109:2003-11. [PMID: 26588560 DOI: 10.1016/j.bpj.2015.09.032] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/31/2015] [Accepted: 09/30/2015] [Indexed: 12/20/2022] Open
Abstract
General anesthesia is a relatively safe medical procedure, which for nearly 170 years has allowed life saving surgical interventions in animals and people. However, the molecular mechanism of general anesthesia continues to be a matter of importance and debate. A favored hypothesis proposes that general anesthesia results from direct multisite interactions with multiple and diverse ion channels in the brain. Neurotransmitter-gated ion channels and two-pore K+ channels are key players in the mechanism of anesthesia; however, new studies have also implicated voltage-gated ion channels. Recent biophysical and structural studies of Na+ and K+ channels strongly suggest that halogenated inhalational general anesthetics interact with gates and pore regions of these ion channels to modulate function. Here, we review these studies and provide a perspective to stimulate further advances.
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Affiliation(s)
- Manuel Covarrubias
- Department of Neuroscience and Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania.
| | - Annika F Barber
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Vincenzo Carnevale
- Institute for Computational Molecular Science, College of Science and Technology, Temple University, Philadelphia, Pennsylvania
| | - Werner Treptow
- Laboratorio de Biologia Teorica e Computacional, Universidade de Brasilia, Brazil
| | - Roderic G Eckenhoff
- Department of Anesthesiology and Critical Care, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
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Constantinides C, Murphy K. Molecular and Integrative Physiological Effects of Isoflurane Anesthesia: The Paradigm of Cardiovascular Studies in Rodents using Magnetic Resonance Imaging. Front Cardiovasc Med 2016; 3:23. [PMID: 27525256 PMCID: PMC4965459 DOI: 10.3389/fcvm.2016.00023] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 07/04/2016] [Indexed: 12/19/2022] Open
Abstract
To-this-date, the exact molecular, cellular, and integrative physiological mechanisms of anesthesia remain largely unknown. Published evidence indicates that anesthetic effects are multifocal and occur in a time-dependent and coordinated manner, mediated via central, local, and peripheral pathways. Their effects can be modulated by a range of variables, and their elicited end-effect on the integrative physiological response is highly variable. This review summarizes the major cellular and molecular sites of anesthetic action with a focus on the paradigm of isoflurane (ISO) - the most commonly used anesthetic nowadays - and its use in prolonged in vivo rodent studies using imaging modalities, such as magnetic resonance imaging (MRI). It also presents established evidence for normal ranges of global and regional physiological cardiac function under ISO, proposes optimal, practical methodologies relevant to the use of anesthetic protocols for MRI and outlines the beneficial effects of nitrous oxide supplementation.
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Affiliation(s)
- Christakis Constantinides
- Chi Biomedical Ltd., Nicosia, Cyprus; Division of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Kathy Murphy
- Division of Biomedical Sciences, University of Oxford , Oxford , UK
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Ludin NM, Cheeseman JF, Merry AF, Millar CD, Warman GR. The effects of the general anaesthetic isoflurane on the honey bee (Apis mellifera) circadian clock. Chronobiol Int 2016; 33:128-33. [PMID: 26730506 DOI: 10.3109/07420528.2015.1113987] [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: 01/25/2023]
Abstract
General anaesthesia administered during the day has previously been shown to phase shift the honey bee clock. We describe a phase response curve for honey bees (n=105) to six hour isoflurane anaesthesia. The honey bee isoflurane PRC is "weak" with a delay portion (maximum shift of -1.88 hours, circadian time 0 - 3) but no advance zone. The isoflurane-induced shifts observed here are in direct opposition to those of light. Furthermore, concurrent administration of light and isoflurane abolishes the shifts that occur with isoflurane alone. Light may thus provide a means of reducing isoflurane-induced phase shifts.
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Affiliation(s)
- Nicola M Ludin
- a Department of Anaesthesiology, Faculty of Medical and Health Sciences , University of Auckland , Auckland , New Zealand
| | - James F Cheeseman
- a Department of Anaesthesiology, Faculty of Medical and Health Sciences , University of Auckland , Auckland , New Zealand
| | - Alan F Merry
- a Department of Anaesthesiology, Faculty of Medical and Health Sciences , University of Auckland , Auckland , New Zealand
| | - Craig D Millar
- a Department of Anaesthesiology, Faculty of Medical and Health Sciences , University of Auckland , Auckland , New Zealand.,b Allan Wilson Centre for Molecular Ecology and Evolution, School of Biological Sciences, Faculty of Science , University of Auckland , Auckland , New Zealand
| | - Guy R Warman
- a Department of Anaesthesiology, Faculty of Medical and Health Sciences , University of Auckland , Auckland , New Zealand
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Positive Allosteric Modulation of Kv Channels by Sevoflurane: Insights into the Structural Basis of Inhaled Anesthetic Action. PLoS One 2015; 10:e0143363. [PMID: 26599217 PMCID: PMC4657974 DOI: 10.1371/journal.pone.0143363] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 11/04/2015] [Indexed: 11/19/2022] Open
Abstract
Inhalational general anesthesia results from the poorly understood interactions of haloethers with multiple protein targets, which prominently includes ion channels in the nervous system. Previously, we reported that the commonly used inhaled anesthetic sevoflurane potentiates the activity of voltage-gated K+ (Kv) channels, specifically, several mammalian Kv1 channels and the Drosophila K-Shaw2 channel. Also, previous work suggested that the S4-S5 linker of K-Shaw2 plays a role in the inhibition of this Kv channel by n-alcohols and inhaled anesthetics. Here, we hypothesized that the S4-S5 linker is also a determinant of the potentiation of Kv1.2 and K-Shaw2 by sevoflurane. Following functional expression of these Kv channels in Xenopus oocytes, we found that converse mutations in Kv1.2 (G329T) and K-Shaw2 (T330G) dramatically enhance and inhibit the potentiation of the corresponding conductances by sevoflurane, respectively. Additionally, Kv1.2-G329T impairs voltage-dependent gating, which suggests that Kv1.2 modulation by sevoflurane is tied to gating in a state-dependent manner. Toward creating a minimal Kv1.2 structural model displaying the putative sevoflurane binding sites, we also found that the positive modulations of Kv1.2 and Kv1.2-G329T by sevoflurane and other general anesthetics are T1-independent. In contrast, the positive sevoflurane modulation of K-Shaw2 is T1-dependent. In silico docking and molecular dynamics-based free-energy calculations suggest that sevoflurane occupies distinct sites near the S4-S5 linker, the pore domain and around the external selectivity filter. We conclude that the positive allosteric modulation of the Kv channels by sevoflurane involves separable processes and multiple sites within regions intimately involved in channel gating.
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Vadakkan KI. A pressure-reversible cellular mechanism of general anesthetics capable of altering a possible mechanism for consciousness. SPRINGERPLUS 2015; 4:485. [PMID: 26380161 PMCID: PMC4561946 DOI: 10.1186/s40064-015-1283-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 08/28/2015] [Indexed: 12/20/2022]
Abstract
Different anesthetics are known to modulate different types of membrane-bound receptors. Their common mechanism of action is expected to alter the mechanism for consciousness. Consciousness is hypothesized as the integral of all the units of internal sensations induced by reactivation of inter-postsynaptic membrane functional LINKs during mechanisms that lead to oscillating potentials. The thermodynamics of the spontaneous lateral curvature of lipid membranes induced by lipophilic anesthetics can lead to the formation of non-specific inter-postsynaptic membrane functional LINKs by different mechanisms. These include direct membrane contact by excluding the inter-membrane hydrophilic region and readily reversible partial membrane hemifusion. The constant reorganization of the lipid membranes at the lateral edges of the postsynaptic terminals (dendritic spines) resulting from AMPA receptor-subunit vesicle exocytosis and endocytosis can favor the effect of anesthetic molecules on lipid membranes at this location. Induction of a large number of non-specific LINKs can alter the conformation of the integral of the units of internal sensations that maintain consciousness. Anesthetic requirement is reduced in the presence of dopamine that causes enlargement of dendritic spines. Externally applied pressure can transduce from the middle ear through the perilymph, cerebrospinal fluid, and the recently discovered glymphatic pathway to the extracellular matrix space, and finally to the paravenular space. The pressure gradient reduce solubility and displace anesthetic molecules from the membranes into the paravenular space, explaining the pressure reversal of anesthesia. Changes in membrane composition and the conversion of membrane hemifusion to fusion due to defects in the checkpoint mechanisms can lead to cytoplasmic content mixing between neurons and cause neurodegenerative changes. The common mechanism of anesthetics presented here can operate along with the known specific actions of different anesthetics.
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Affiliation(s)
- Kunjumon I Vadakkan
- Division of Neurology, Department of Medicine, University of Toronto, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Room A4-08, Toronto, ON M4N 3M5 Canada
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Abstract
Aging involves changes in several physiologic processes that lead to decreased volumes of distribution, slowed metabolism, and increased end-organ sensitivity to anesthetics. These changes generally result in increased potency. Elderly patients require less anesthetic medication, but the true extent of reduction is underappreciated and less uniformly practiced. The impact of potential anesthetic drug overdosing on intermediate and long-term outcomes is not fully appreciated. It may be necessary to consider age as a continuous variable for anesthetic drug dosing in older patients rather than treating adult versus elderly patients. Further pharmacologic studies are required in people more than 85 years old.
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Affiliation(s)
- Shamsuddin Akhtar
- Department of Anesthesiology, Yale University School of Medicine, 333 Cedar Street, Tompkins # 3, New Haven, CT 06520, USA.
| | - Ramachandran Ramani
- Department of Anesthesiology, Yale University School of Medicine, 333 Cedar Street, Tompkins # 3, New Haven, CT 06520, USA
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McEntire DM, Kirkpatrick DR, Kerfeld MJ, Hambsch ZJ, Reisbig MD, Agrawal DK, Youngblood CF. Effect of sedative-hypnotics, anesthetics and analgesics on sleep architecture in obstructive sleep apnea. Expert Rev Clin Pharmacol 2015; 7:787-806. [PMID: 25318836 DOI: 10.1586/17512433.2014.966815] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The perioperative care of obstructive sleep apnea (OSA) patients is currently receiving much attention due to an increased risk for complications. It is established that postoperative changes in sleep architecture occur and this may have pathophysiological implications for OSA patients. Upper airway muscle activity decreases during rapid eye movement sleep (REMS). Severe OSA patients exhibit exaggerated chemoreceptor-driven ventilation during non-rapid eye movement sleep (NREMS), which leads to central and obstructive apnea. This article critically reviewed the literature relevant to preoperative screening for OSA, prevalence of OSA in surgical populations and changes in postoperative sleep architecture relevant to OSA patients. In particular, we addressed three questions in regard to the effects of sedative-hypnotics, anesthetics and analgesics on sleep architecture, the underlying mechanisms and the relevance to OSA. Indeed, these classes of drugs alter sleep architecture, which likely significantly contributes to abnormal postoperative sleep architecture, exacerbation of OSA and postoperative complications.
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Affiliation(s)
- Dan M McEntire
- Department of Anesthesiology and the Center for Clinical and Translational Science, Creighton University School of Medicine, 601 N. 30th Street, Suite 3222, Omaha, NE 68131, USA
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Chen S, Hong Y, Zeng Y, Sun Q, Liu Y, Zhao E, Bai G, Qu J, Hao J, Tang BZ. Mapping Live Cell Viscosity with an Aggregation-Induced Emission Fluorogen by Means of Two-Photon Fluorescence Lifetime Imaging. Chemistry 2015; 21:4315-20. [DOI: 10.1002/chem.201405658] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Indexed: 01/05/2023]
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50
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Sloan TB, Toleikis JR, Toleikis SC, Koht A. Intraoperative neurophysiological monitoring during spine surgery with total intravenous anesthesia or balanced anesthesia with 3 % desflurane. J Clin Monit Comput 2014; 29:77-85. [DOI: 10.1007/s10877-014-9571-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Accepted: 03/12/2014] [Indexed: 10/25/2022]
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