1
|
Abstract
The timing of life on Earth is remarkable: between individuals of the same species, a highly similar temporal pattern is observed, with shared periods of activity and inactivity each day. At the individual level, this means that over the course of a single day, a person alternates between two states. They are either upright, active, and communicative or they lie down in a state of (un)consciousness called sleep where even the characteristic of neuronal signals in the brain shows distinctive properties. The circadian clock governs both of these time stamps-activity and (apparent) inactivity-making them come and go consistently at the same approximate time each day. This behavior thus represents the meeting of two pervasive systems: the circadian clock and metabolism. In this article, we will describe what is known about how the circadian clock anticipates daily changes in oxygen usage, how circadian clock regulation may relate to normal physiology, and to hypoxia and ischemia that can result from pathologies such as myocardial infarction and stroke.
Collapse
Affiliation(s)
- Francesca Sartor
- Institute of Medical Psychology, Medical Faculty, LMU Munich, Germany (F.S., B.F.-B., M.M.)
| | - Borja Ferrero-Bordera
- Institute of Medical Psychology, Medical Faculty, LMU Munich, Germany (F.S., B.F.-B., M.M.)
| | - Jeffrey Haspel
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO (J.H.)
| | - Markus Sperandio
- Institute for Cardiovascular Physiology and Pathophysiology, Walter Brendel Center for Experimental Medicine, and the Biomedical Center (BMC), Medical Faculty, LMU Munich, Germany (M.S.)
| | - Paul M Holloway
- Radcliffe Department of Medicine, University of Oxford, United Kingdom (P.M.H.)
| | - Martha Merrow
- Institute of Medical Psychology, Medical Faculty, LMU Munich, Germany (F.S., B.F.-B., M.M.)
| |
Collapse
|
2
|
Walther J, Kirsch EM, Hellwig L, Schmerbeck SS, Holloway PM, Buchan AM, Mergenthaler P. Reinventing the Penumbra - the Emerging Clockwork of a Multi-modal Mechanistic Paradigm. Transl Stroke Res 2023; 14:643-666. [PMID: 36219377 PMCID: PMC10444697 DOI: 10.1007/s12975-022-01090-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 09/16/2022] [Accepted: 09/21/2022] [Indexed: 11/25/2022]
Abstract
The concept of the ischemic penumbra was originally defined as the area around a necrotic stroke core and seen as the tissue at imminent risk of further damage. Today, the penumbra is generally considered as time-sensitive hypoperfused brain tissue with decreased oxygen and glucose availability, salvageable tissue as treated by intervention, and the potential target for neuroprotection in focal stroke. The original concept entailed electrical failure and potassium release but one short of neuronal cell death and was based on experimental stroke models, later confirmed in clinical imaging studies. However, even though the basic mechanisms have translated well, conferring brain protection, and improving neurological outcome after stroke based on the pathophysiological mechanisms in the penumbra has yet to be achieved. Recent findings shape the modern understanding of the penumbra revealing a plethora of molecular and cellular pathophysiological mechanisms. We now propose a new model of the penumbra, one which we hope will lay the foundation for future translational success. We focus on the availability of glucose, the brain's central source of energy, and bioenergetic failure as core pathophysiological concepts. We discuss the relation of mitochondrial function in different cell types to bioenergetics and apoptotic cell death mechanisms, autophagy, and neuroinflammation, to glucose metabolism in what is a dynamic ischemic penumbra.
Collapse
Affiliation(s)
- Jakob Walther
- Charité - Universitätsmedizin Berlin, Department of Neurology with Experimental Neurology, Charitéplatz 1, 10117, Berlin, Germany
- Charité - Universitätsmedizin Berlin, Center for Stroke Research Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Elena Marie Kirsch
- Charité - Universitätsmedizin Berlin, Department of Neurology with Experimental Neurology, Charitéplatz 1, 10117, Berlin, Germany
- Charité - Universitätsmedizin Berlin, Center for Stroke Research Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Lina Hellwig
- Charité - Universitätsmedizin Berlin, Department of Neurology with Experimental Neurology, Charitéplatz 1, 10117, Berlin, Germany
- Charité - Universitätsmedizin Berlin, Center for Stroke Research Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Sarah S Schmerbeck
- Charité - Universitätsmedizin Berlin, Department of Neurology with Experimental Neurology, Charitéplatz 1, 10117, Berlin, Germany
- Charité - Universitätsmedizin Berlin, Center for Stroke Research Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Paul M Holloway
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK
| | - Alastair M Buchan
- Charité - Universitätsmedizin Berlin, Center for Stroke Research Berlin, Charitéplatz 1, 10117, Berlin, Germany.
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK.
| | - Philipp Mergenthaler
- Charité - Universitätsmedizin Berlin, Department of Neurology with Experimental Neurology, Charitéplatz 1, 10117, Berlin, Germany.
- Charité - Universitätsmedizin Berlin, Center for Stroke Research Berlin, Charitéplatz 1, 10117, Berlin, Germany.
- Charité - Universitätsmedizin Berlin, NeuroCure Clinical Research Center, Charitéplatz 1, 10117, Berlin, Germany.
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, OX3 9DU, UK.
| |
Collapse
|
3
|
Klerman EB, Brager A, Carskadon MA, Depner CM, Foster R, Goel N, Harrington M, Holloway PM, Knauert MP, LeBourgeois MK, Lipton J, Merrow M, Montagnese S, Ning M, Ray D, Scheer FAJL, Shea SA, Skene DJ, Spies C, Staels B, St‐Onge M, Tiedt S, Zee PC, Burgess HJ. Keeping an eye on circadian time in clinical research and medicine. Clin Transl Med 2022; 12:e1131. [PMID: 36567263 PMCID: PMC9790849 DOI: 10.1002/ctm2.1131] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/15/2022] [Accepted: 11/17/2022] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Daily rhythms are observed in humans and almost all other organisms. Most of these observed rhythms reflect both underlying endogenous circadian rhythms and evoked responses from behaviours such as sleep/wake, eating/fasting, rest/activity, posture changes and exercise. For many research and clinical purposes, it is important to understand the contribution of the endogenous circadian component to these observed rhythms. CONTENT The goal of this manuscript is to provide guidance on best practices in measuring metrics of endogenous circadian rhythms in humans and promote the inclusion of circadian rhythms assessments in studies of health and disease. Circadian rhythms affect all aspects of physiology. By specifying minimal experimental conditions for studies, we aim to improve the quality, reliability and interpretability of research into circadian and daily (i.e., time-of-day) rhythms and facilitate the interpretation of clinical and translational findings within the context of human circadian rhythms. We describe protocols, variables and analyses commonly used for studying human daily rhythms, including how to assess the relative contributions of the endogenous circadian system and other daily patterns in behaviours or the environment. We conclude with recommendations for protocols, variables, analyses, definitions and examples of circadian terminology. CONCLUSION Although circadian rhythms and daily effects on health outcomes can be challenging to distinguish in practice, this distinction may be important in many clinical settings. Identifying and targeting the appropriate underlying (patho)physiology is a medical goal. This review provides methods for identifying circadian effects to aid in the interpretation of published work and the inclusion of circadian factors in clinical research and practice.
Collapse
Affiliation(s)
- Elizabeth B. Klerman
- Department of NeurologyMassachusetts General Hospital, Brigham and Women's HospitalBostonMassachusettsUSA
- Division of Sleep MedicineHarvard Medical SchoolBostonMassachusettsUSA
| | - Allison Brager
- PlansAnalysis, and FuturesJohn F. Kennedy Special Warfare Center and SchoolFort BraggNorth CarolinaUSA
| | - Mary A. Carskadon
- Alpert Medical School of Brown UniversityDepartment of Psychiatry and Human BehaviorEP Bradley HospitalChronobiology and Sleep ResearchProvidenceRhode IslandUSA
| | | | - Russell Foster
- Sir Jules Thorn Sleep and Circadian Neuroscience InstituteNuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUK
| | - Namni Goel
- Biological Rhythms Research LaboratoryDepartment of Psychiatry and Behavioral SciencesRush University Medical CenterChicagoIllinoisUSA
| | - Mary Harrington
- Neuroscience ProgramSmith CollegeNorthamptonMassachusettsUSA
| | | | - Melissa P. Knauert
- Section of PulmonaryCritical Care, and Sleep MedicineDepartment of Internal MedicineYale School of MedicineNew HavenConnecticutUSA
| | - Monique K. LeBourgeois
- Sleep and Development LaboratoryDepartment of Integrative PhysiologyUniversity of Colorado BoulderBoulderColoradoUSA
| | - Jonathan Lipton
- Boston Children's Hospital and Kirby Neurobiology CenterBostonMassachusettsUSA
| | - Martha Merrow
- Institute of Medical PsychologyFaculty of MedicineLMUMunichGermany
| | - Sara Montagnese
- Department of MedicineUniversity of PadovaPadovaItaly
- ChronobiologyFaculty of Health and Medical SciencesUniversity of SurreyGuildfordUK
| | - Mingming Ning
- Clinical Proteomics Research Center and Cardio‐Neurology DivisionMassachusetts General HospitalHarvard Medical SchoolBostonMassachusettsUSA
| | - David Ray
- NIHR Oxford Biomedical Research CentreJohn Radcliffe HospitalOxfordUK
- Oxford Centre for DiabetesEndocrinology and MetabolismUniversity of OxfordOxfordUK
| | - Frank A. J. L. Scheer
- Division of Sleep MedicineHarvard Medical SchoolBostonMassachusettsUSA
- Medical Chronobiology ProgramDivision of Sleep and Circadian DisordersDepartments of Medicine and NeurologyBrigham and Women's HospitalBostonMassachusettsUSA
| | - Steven A. Shea
- Oregon Institute of Occupational Health SciencesOregon Health and Science UniversityPortlandOregonUSA
| | - Debra J. Skene
- ChronobiologyFaculty of Health and Medical SciencesUniversity of SurreyGuildfordUK
| | - Claudia Spies
- Department of Anesthesiology and Intensive Care MedicineCharité – Universitaetsmedizin BerlinBerlinGermany
| | - Bart Staels
- UnivLilleInsermCHU LilleInstitut Pasteur de LilleU1011‐EGIDLilleFrance
| | - Marie‐Pierre St‐Onge
- Division of General Medicine and Center of Excellence for Sleep and Circadian ResearchDepartment of MedicineColumbia University Irving Medical CenterNew YorkNew YorkUSA
| | - Steffen Tiedt
- Institute for Stroke and Dementia ResearchUniversity HospitalLMUMunichGermany
| | - Phyllis C. Zee
- Center for Circadian and Sleep MedicineDivision of Sleep MedicineNorthwestern University Feinberg School of MedicineChicagoIllinoisUSA
| | - Helen J. Burgess
- Sleep and Circadian Research LaboratoryDepartment of PsychiatryUniversity of MichiganAnn ArborMichiganUSA
| |
Collapse
|
4
|
Holloway PM. Novel, Emerging Chip Models of the Blood-Brain Barrier and Future Directions. Methods Mol Biol 2022; 2492:193-224. [PMID: 35733046 DOI: 10.1007/978-1-0716-2289-6_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The use of microfluidic chips is now allowing for more advanced modelling of the blood-brain barrier (BBB) in vitro, recapitulating heterotypic interactions, 3D architecture, and physiological flow. This chapter will give an introduction to these new technologies and how they are being applied to model the BBB and neurovascular unit (NVU). A foundational understanding of the fluid dynamics germane to the effective use of these chips will be set and an overview of how physical phenomena at the microscale can be exploited to enable new possibilities to control the cell culture environment. The four main approaches to construct microfluidic blood vessel mimetics will be discussed with examples of how these techniques are being applied to model the BBB and more recently to study specific neurovascular disease processes. Finally, practical guidance will be given for researchers wishing to adopt these new techniques along with a summary of the challenges, limitations faced, and new opportunities opened up by these advanced cell culture systems.
Collapse
Affiliation(s)
- Paul M Holloway
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
| |
Collapse
|
5
|
Holloway PM, Willaime-Morawek S, Siow R, Barber M, Owens RM, Sharma AD, Rowan W, Hill E, Zagnoni M. Advances in microfluidic in vitro systems for neurological disease modeling. J Neurosci Res 2021; 99:1276-1307. [PMID: 33583054 DOI: 10.1002/jnr.24794] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/21/2020] [Accepted: 12/19/2020] [Indexed: 12/19/2022]
Abstract
Neurological disorders are the leading cause of disability and the second largest cause of death worldwide. Despite significant research efforts, neurology remains one of the most failure-prone areas of drug development. The complexity of the human brain, boundaries to examining the brain directly in vivo, and the significant evolutionary gap between animal models and humans, all serve to hamper translational success. Recent advances in microfluidic in vitro models have provided new opportunities to study human cells with enhanced physiological relevance. The ability to precisely micro-engineer cell-scale architecture, tailoring form and function, has allowed for detailed dissection of cell biology using microphysiological systems (MPS) of varying complexities from single cell systems to "Organ-on-chip" models. Simplified neuronal networks have allowed for unique insights into neuronal transport and neurogenesis, while more complex 3D heterotypic cellular models such as neurovascular unit mimetics and "Organ-on-chip" systems have enabled new understanding of metabolic coupling and blood-brain barrier transport. These systems are now being developed beyond MPS toward disease specific micro-pathophysiological systems, moving from "Organ-on-chip" to "Disease-on-chip." This review gives an outline of current state of the art in microfluidic technologies for neurological disease research, discussing the challenges and limitations while highlighting the benefits and potential of integrating technologies. We provide examples of where such toolsets have enabled novel insights and how these technologies may empower future investigation into neurological diseases.
Collapse
Affiliation(s)
- Paul M Holloway
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | | | - Richard Siow
- King's British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine & Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Melissa Barber
- King's British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine & Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Róisín M Owens
- Department Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Anup D Sharma
- New Orleans BioInnovation Center, AxoSim Inc., New Orleans, LA, USA
| | - Wendy Rowan
- Novel Human Genetics Research Unit, GSK R&D, Stevenage, UK
| | - Eric Hill
- School of Life and Health sciences, Aston University, Birmingham, UK
| | - Michele Zagnoni
- Electronic and Electrical Engineering, University of Strathclyde, Glasgow, UK
| |
Collapse
|
6
|
Butement JT, Holloway PM, Welsh JA, Holloway JA, Englyst NA, Horak P, West J, Wilkinson JS. Monolithically-integrated cytometer for measuring particle diameter in the extracellular vesicle size range using multi-angle scattering. Lab Chip 2020; 20:1267-1280. [PMID: 32149292 DOI: 10.1039/c9lc01182j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Size measurement of extracellular vesicles is hampered by the high cost and measurement uncertainty of conventional flow cytometers which is mainly due to the use of non-specialised free space optics. Integrated cytometry, where the optics and fluidics are embedded in a monolithic chip shows promise for the production of low cost, micro-flow cytometers dedicated for extracellular vesicle (EV) analysis with improved size measurement accuracy and precision. This research demonstrates a unique integrated cytometer for sub-micron particle size measurement using multi-angle scattering analysis. A combination of three technologies is used: (i) Dean-based hydrodynamic focussing to deliver a tight sample core stream to the analysis region, (ii) integrated waveguides with multimode interference devices to focus a narrow excitation beam onto the sample stream, and (iii) an angular array of collection waveguides to measure particle scattering distribution and calculate diameter. Low index 200 nm liposomes could be detected and polystyrene size standards as small as 400 nm diameter could be measured with an uncertainty of ±21 nm (1/2 IQR) demonstrating a first step on the path to high performance integrated cytometry of EVs.
Collapse
|
7
|
Holloway PM, Hallinan GI, Hegde M, Lane SIR, Deinhardt K, West J. Asymmetric confinement for defining outgrowth directionality. Lab Chip 2019; 19:1484-1489. [PMID: 30899932 DOI: 10.1039/c9lc00078j] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Directional connectivity is required to develop accurate in vitro models of the nervous system. This research investigated the interaction of murine neuronal outgrowths with asymmetric microstructured geometries to provide insights into the mechanisms governing unidirectional outgrowth bias. The structures were designed using edge-guidance and critical turning angle principles to study different prohibitive to permissive edge-guidance ratios. The different structures enable outgrowth in the permissive direction, while reducing outgrowth in the prohibitive direction. Outgrowth bias was probabilistic in nature, requiring multiple structures for effective unidirectional bias in primary hippocampal cultures at 14 days in vitro. Arrowhead structures with acute posterior corners were optimal, enabling 100% unidirectional outgrowth bias by virtue of re-routing and delay effects.
Collapse
Affiliation(s)
- Paul M Holloway
- Cancer Sciences, Faculty of Medicine, University of Southampton, UK.
| | | | | | | | | | | |
Collapse
|
8
|
Gillespie S, Holloway PM, Becker F, Rauzi F, Vital SA, Taylor KA, Stokes KY, Emerson M, Gavins FNE. The isothiocyanate sulforaphane modulates platelet function and protects against cerebral thrombotic dysfunction. Br J Pharmacol 2018; 175:3333-3346. [PMID: 29797311 DOI: 10.1111/bph.14368] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 04/30/2018] [Accepted: 05/04/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND AND PURPOSE Platelet activation provides a critical link between inflammation and thrombosis. Sulforaphane (SFN), a naturally occurring isothiocyanate, has been shown to display both anti-inflammatory and anti-thrombotic actions in the systemic microvasculature. As inflammation promotes thrombosis and vice versa, in this study we investigated whether SFN is able to reduce inflammatory potentiation of thrombotic events, suppress platelet activation and thrombus formation in the cerebral microvasculature. EXPERIMENTAL APPROACH Thrombosis was induced in the murine brain using the light/dye-injury model, in conjunction with LPS treatment, with and without SFN treatment. In vitro and in vivo platelet assays (aggregation, flow and other functional tests) were also employed, using both human and murine platelets. KEY RESULTS SFN was found to reduce LPS-mediated enhancement of thrombus formation in the cerebral microcirculation. In tail-bleed experiments, LPS treatment prolonged bleeding time, and SFN treatment was found to protect against this LPS-induced derangement of platelet function. SFN inhibited collagen-mediated platelet aggregation in vitro and in vivo and the associated adhesion and impaired calcium signalling. Furthermore, glycoprotein VI was shown to be involved in the protective effects observed with SFN treatment. CONCLUSIONS AND IMPLICATIONS The data presented here provide evidence for the use of SFN in preventing stroke in selected high-risk patient cohorts.
Collapse
Affiliation(s)
| | - Paul M Holloway
- Division of Brain Sciences, Imperial College London, London, UK.,Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center - Shreveport, Shreveport, LA, USA
| | - Felix Becker
- Department of General, Visceral and Transplant Surgery, University Hospital Muenster, Muenster, Germany
| | - Francesca Rauzi
- Platelet Biology Group, National Heart and Lung Institute, Imperial College London, London, UK
| | - Shantel A Vital
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center - Shreveport, Shreveport, LA, USA
| | - Kirk A Taylor
- Platelet Biology Group, National Heart and Lung Institute, Imperial College London, London, UK
| | - Karen Y Stokes
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center - Shreveport, Shreveport, LA, USA
| | - Michael Emerson
- Platelet Biology Group, National Heart and Lung Institute, Imperial College London, London, UK
| | - Felicity N E Gavins
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center - Shreveport, Shreveport, LA, USA.,Department of Neurology, Louisiana State University Health Sciences Center - Shreveport, Shreveport, LA, USA
| |
Collapse
|
9
|
Holloway PM, Butement J, Hegde M, West J. Serial integration of Dean-structured sample cores with linear inertial focussing for enhanced particle and cell sorting. Biomicrofluidics 2018; 12:044104. [PMID: 30034567 PMCID: PMC6037536 DOI: 10.1063/1.5038965] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 06/24/2018] [Indexed: 06/02/2023]
Abstract
In this contribution, a channel aspect ratio of >2 was used to access high velocity regimes to provide confined sample cores by Dean focussing in advance of linear inertial focussing. This produces a singular separation origin with a mirrored transport path for efficient particle and blood cell sorting, while also increasing the spatial resolution for multiscale sorting.
Collapse
Affiliation(s)
- Paul M. Holloway
- Centre for Hybrid Biodevices and Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Jonathan Butement
- Centre for Hybrid Biodevices and Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | | | - Jonathan West
- Centre for Hybrid Biodevices and Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, United Kingdom
| |
Collapse
|
10
|
Holloway PM, Gillespie S, Becker F, Vital SA, Nguyen V, Alexander JS, Evans PC, Gavins FNE. Sulforaphane induces neurovascular protection against a systemic inflammatory challenge via both Nrf2-dependent and independent pathways. Vascul Pharmacol 2016; 85:29-38. [PMID: 27401964 DOI: 10.1016/j.vph.2016.07.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 07/01/2016] [Accepted: 07/03/2016] [Indexed: 12/25/2022]
Abstract
Sepsis is often characterized by an acute brain inflammation and dysfunction, which is associated with increased morbidity and mortality worldwide. Preventing cerebral leukocyte recruitment may provide the key to halt progression of systemic inflammation to the brain. Here we investigated the influence of the anti-inflammatory and anti-oxidant compound, sulforaphane (SFN) on lipopolysaccharide (LPS)-induced cellular interactions in the brain. The inflammatory response elicited by LPS was blunted by SFN administration (5 and 50mg/kg i.p.) 24h prior to LPS treatment in WT animals, as visualized and quantified using intravital microscopy. This protective effect of SFN was lost in Nrf2-KO mice at the lower dose tested, however 50mg/kg SFN revealed a partial effect, suggesting SFN works in part independently of Nrf2 activity. In vitro, SFN reduced neutrophil recruitment to human brain endothelial cells via a down regulation of E-selectin and vascular cell adhesion molecule 1 (VCAM-1). Our data confirm a fundamental dose-dependent role of SFN in limiting cerebral inflammation. Furthermore, our data demonstrate that not only is Nrf2 in part essential in mediating these neuroprotective effects, but they occur via down-regulation of E-selectin and VCAM-1. In conclusion, SFN may provide a useful therapeutic drug to reduce cerebral inflammation in sepsis.
Collapse
Affiliation(s)
- Paul M Holloway
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, USA
| | - Scarlett Gillespie
- Division of Brain Sciences, Imperial College London, London, United Kingdom
| | - Felix Becker
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, USA; Department for General and Visceral Surgery, University Hospital Muenster, Muenster, Germany
| | - Shantel A Vital
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, USA
| | - Victoria Nguyen
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, USA
| | - J Steven Alexander
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, USA
| | - Paul C Evans
- Department of Cardiovascular Science, University of Sheffield, Sheffield, United Kingdom
| | - Felicity N E Gavins
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, USA; Division of Brain Sciences, Imperial College London, London, United Kingdom.
| |
Collapse
|
11
|
Vital SA, Becker F, Holloway PM, Russell J, Perretti M, Granger DN, Gavins FNE. Formyl-Peptide Receptor 2/3/Lipoxin A4 Receptor Regulates Neutrophil-Platelet Aggregation and Attenuates Cerebral Inflammation: Impact for Therapy in Cardiovascular Disease. Circulation 2016; 133:2169-79. [PMID: 27154726 PMCID: PMC4889496 DOI: 10.1161/circulationaha.115.020633] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Accepted: 04/04/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Platelet activation at sites of vascular injury is essential for hemostasis, but it is also a major pathomechanism underlying ischemic injury. Because anti-inflammatory therapies limit thrombosis and antithrombotic therapies reduce vascular inflammation, we tested the therapeutic potential of 2 proresolving endogenous mediators, annexin A1 N-terminal derived peptide (AnxA1Ac2-26) and aspirin-triggered lipoxin A4 (15-epi-lipoxin A4), on the cerebral microcirculation after ischemia/reperfusion injury. Furthermore, we tested whether the lipoxin A4 receptor formyl-peptide receptor 2/3 (Fpr2/3; ortholog to human FPR2/lipoxin A4 receptor) evoked neuroprotective functions after cerebral ischemia/reperfusion injury. METHODS AND RESULTS Using intravital microscopy, we found that cerebral ischemia/reperfusion injury was accompanied by neutrophil and platelet activation and neutrophil-platelet aggregate formation within cerebral microvessels. Moreover, aspirin-triggered lipoxin A4 activation of neutrophil Fpr2/3 regulated neutrophil-platelet aggregate formation in the brain and inhibited the reactivity of the cerebral microvasculature. The same results were obtained with AnxA1Ac2-26 administration. Blocking Fpr2/lipoxin A4 receptor with the antagonist Boc2 reversed this effect, and treatments were ineffective in Fpr2/3 knockout mice, which displayed an exacerbated disease severity, evidenced by increased infarct area, blood-brain barrier dysfunction, increased neurological score, and elevated levels of cytokines. Furthermore, aspirin treatment significantly reduced cerebral leukocyte recruitment and increased endogenous levels of aspirin-triggered lipoxin A4, effects again mediated by Fpr2/3. CONCLUSION Fpr2/lipoxin A4 receptor is a therapeutic target for initiating endogenous proresolving, anti-inflammatory pathways after cerebral ischemia/reperfusion injury.
Collapse
Affiliation(s)
- Shantel A Vital
- From Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport (S.A.V., P.M.H., J.R., D.N.G., F.N.E.G.); Department for General and Visceral Surgery, University Hospital Muenster, Germany (F.B.); William Harvey Research Institute, Queen Mary University of London, UK (M.P.); and Division of Brain Sciences, Imperial College London, UK (F.N.E.G.)
| | - Felix Becker
- From Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport (S.A.V., P.M.H., J.R., D.N.G., F.N.E.G.); Department for General and Visceral Surgery, University Hospital Muenster, Germany (F.B.); William Harvey Research Institute, Queen Mary University of London, UK (M.P.); and Division of Brain Sciences, Imperial College London, UK (F.N.E.G.)
| | - Paul M Holloway
- From Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport (S.A.V., P.M.H., J.R., D.N.G., F.N.E.G.); Department for General and Visceral Surgery, University Hospital Muenster, Germany (F.B.); William Harvey Research Institute, Queen Mary University of London, UK (M.P.); and Division of Brain Sciences, Imperial College London, UK (F.N.E.G.)
| | - Janice Russell
- From Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport (S.A.V., P.M.H., J.R., D.N.G., F.N.E.G.); Department for General and Visceral Surgery, University Hospital Muenster, Germany (F.B.); William Harvey Research Institute, Queen Mary University of London, UK (M.P.); and Division of Brain Sciences, Imperial College London, UK (F.N.E.G.)
| | - Mauro Perretti
- From Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport (S.A.V., P.M.H., J.R., D.N.G., F.N.E.G.); Department for General and Visceral Surgery, University Hospital Muenster, Germany (F.B.); William Harvey Research Institute, Queen Mary University of London, UK (M.P.); and Division of Brain Sciences, Imperial College London, UK (F.N.E.G.)
| | - D Neil Granger
- From Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport (S.A.V., P.M.H., J.R., D.N.G., F.N.E.G.); Department for General and Visceral Surgery, University Hospital Muenster, Germany (F.B.); William Harvey Research Institute, Queen Mary University of London, UK (M.P.); and Division of Brain Sciences, Imperial College London, UK (F.N.E.G.)
| | - Felicity N E Gavins
- From Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport (S.A.V., P.M.H., J.R., D.N.G., F.N.E.G.); Department for General and Visceral Surgery, University Hospital Muenster, Germany (F.B.); William Harvey Research Institute, Queen Mary University of London, UK (M.P.); and Division of Brain Sciences, Imperial College London, UK (F.N.E.G.).
| |
Collapse
|
12
|
Affiliation(s)
- Paul M Holloway
- From the Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA
| | - Felicity N E Gavins
- From the Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA.
| |
Collapse
|
13
|
Stasiuk GJ, Holloway PM, Rivas C, Trigg W, Luthra SK, Morisson Iveson V, Gavins FNE, Long NJ. (99m)Tc SPECT imaging agent based on cFLFLFK for the detection of FPR1 in inflammation. Dalton Trans 2015; 44:4986-93. [PMID: 25603955 DOI: 10.1039/c4dt02980a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Non-invasive imaging of the inflammatory process can provide great insight into a wide variety of disease states, aiding diagnosis, evaluation and effective targeted treatment. During inflammation, blood borne leukocytes are recruited, through a series of activation and adhesion steps, to the site of injury or infection where they migrate across the blood vessel wall into the tissue. Thus, tracking leukocyte recruitment and accumulation provides a dynamic and localised read out of inflammatory events. Current leukocyte imaging techniques require ex vivo labelling of patient blood, involving laborious processing and potential risks to both patient and laboratory staff. Utilising high affinity ligands for leukocyte specific receptors may allow for injectable tracers that label leukocytes in situ, omitting potentially hazardous ex vivo handling. Formyl peptide receptors (FPRs) are a group of G-protein coupled receptors involved in the chemotaxis and inflammatory functioning of leukocytes. Highly expressed on leukocytes, and up-regulated during inflammation, these receptors provide a potential target for imaging inflammatory events. Herein we present the synthesis and initial in vitro testing of a potential Single Photon Emission Computed Tomography (SPECT) leukocyte tracer. The FPR1 antagonist cFLFLFK-NH2, which displays high affinity with little physiological effect, has been linked via a PEG motif to a (99m)Tc chelate. This tracer shows in vitro binding to human embryonic kidney cells expressing the FPR1 receptor, and functional in vitro tests reveal cFLFLFK-NH2 compounds to have no effect on inflammatory cell functioning. Overall, these data show that (99m)Tc.cFLFLFK-NH2 may be a useful tool for non-invasive imaging of leukocyte accumulation in inflammatory disease states.
Collapse
Affiliation(s)
- Graeme J Stasiuk
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK.
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Holloway PM, Durrenberger PF, Trutschl M, Cvek U, Cooper D, Orr AW, Perretti M, Getting SJ, Gavins FNE. Both MC1 and MC3 Receptors Provide Protection From Cerebral Ischemia-Reperfusion-Induced Neutrophil Recruitment. Arterioscler Thromb Vasc Biol 2015; 35:1936-44. [PMID: 26112010 DOI: 10.1161/atvbaha.115.305348] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 06/11/2015] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Neutrophil recruitment is a key process in the pathogenesis of stroke, and may provide a valuable therapeutic target. Targeting the melanocortin (MC) receptors has previously shown to inhibit leukocyte recruitment in peripheral inflammation, however, it is not known whether treatments are effective in the unique cerebral microvascular environment. Here, we provide novel research highlighting the effects of the MC peptides on cerebral neutrophil recruitment, demonstrating important yet discrete roles for both MC1 and MC3. APPROACH AND RESULTS Using intravital microscopy, in 2 distinct murine models of cerebral ischemia-reperfusion (I/R) injury, we have investigated MC control for neutrophil recruitment. After global I/R, pharmacological treatments suppressed pathological neutrophil recruitment. MC1 selective treatment rapidly inhibited neutrophil recruitment while a nonselective MC agonist provided protection even when coadministered with an MC3/4 antagonist, suggesting the importance of early MC1 signaling. However, by 2-hour reperfusion, MC1-mediated effects were reduced, and MC3 anti-inflammatory circuits predominated. Mice bearing a nonfunctional MC1 displayed a transient exacerbation of neutrophil recruitment after global I/R, which diminished by 2 hours. However importantly, enhanced inflammatory responses in both MC1 mutant and MC3 (-/-) mice resulted in increased infarct size and poor functional outcome after focal I/R. Furthermore, we used an in vitro model of leukocyte recruitment to demonstrate these anti-inflammatory actions are also effective in human cells. CONCLUSIONS These studies reveal for the first time MC control for neutrophil recruitment in the unique pathophysiological context of cerebral I/R, while also demonstrating the potential therapeutic value of targeting multiple MCs in developing effective therapeutics.
Collapse
MESH Headings
- Animals
- Brain Ischemia/etiology
- Brain Ischemia/metabolism
- Brain Ischemia/prevention & control
- Disease Models, Animal
- Gene Expression Regulation
- Humans
- Male
- Melanocyte-Stimulating Hormones/pharmacology
- Mice
- Neutrophil Infiltration/genetics
- RNA, Messenger/genetics
- Receptor, Melanocortin, Type 1/antagonists & inhibitors
- Receptor, Melanocortin, Type 1/biosynthesis
- Receptor, Melanocortin, Type 1/genetics
- Receptor, Melanocortin, Type 3/antagonists & inhibitors
- Receptor, Melanocortin, Type 3/biosynthesis
- Receptor, Melanocortin, Type 3/genetics
- Reperfusion Injury/complications
- Reperfusion Injury/metabolism
Collapse
Affiliation(s)
- Paul M Holloway
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - Pascal F Durrenberger
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - Marjan Trutschl
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - Urska Cvek
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - Dianne Cooper
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - A Wayne Orr
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - Mauro Perretti
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - Stephen J Getting
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.)
| | - Felicity N E Gavins
- From the Division of Brain Sciences, Imperial College London, London, United Kingdom (P.M.H., P.F.D., F.N.E.G.); LSU Shreveport, LA (M.T., U.C.); William Harvey Research Institute, Barts and The Royal London School of Medicine, London, United Kingdom (D.C., M.P.); Faculty of Science and Technology, University of Westminster, London, United Kingdom (S.J.G.); and LSU Health Science Center, Shreveport, LA (P.M.H., A.W.O., F.N.E.G.).
| |
Collapse
|
15
|
Holloway PM, Getting SJ, Gavins FNE. Targeting the melanocortin receptor system to reduce leukocyte recruitment following stroke. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.lb727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Paul M Holloway
- Division of Brain SciencesImperial CollegeLondonUnited Kingdom
| | - Stephen J Getting
- School of Life SciencesUniversity of WestminsterLondonUnited Kingdom
| | | |
Collapse
|
16
|
Gavins FNE, Hughes EL, Buss NAPS, Holloway PM, Getting SJ, Buckingham JC. Leukocyte recruitment in the brain in sepsis: involvement of the annexin 1-FPR2/ALX anti-inflammatory system. FASEB J 2012; 26:4977-89. [PMID: 22964301 DOI: 10.1096/fj.12-205971] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Unregulated inflammation underlies many diseases, including sepsis. Much interest lies in targeting anti-inflammatory mechanisms to develop new treatments. One such target is the anti-inflammatory protein annexin A1 (AnxA1) and its receptor, FPR2/ALX. Using intravital videomicroscopy, we investigated the role of AnxA1 and FPR2/ALX in a murine model of endotoxin-induced cerebral inflammation [intraperitoneal injection of lipopolysaccharide (LPS)]. An inflammatory response was confirmed by elevations in proinflammatory serum cytokines, increased cerebrovascular permeability, elevation in brain myeloperoxidase, and increased leukocyte rolling and adhesion in cerebral venules of wild-type (WT) mice, which were further exacerbated in AnxA1-null mice. mRNA expression of TLR2, TLR4, MyD-88, and Ly96 was also assessed. The AnxA1-mimetic peptide, AnxA1(Ac2-26) (100 μg/mouse, ∼33 μmol) mitigated LPS-induced leukocyte adhesion in WT and AnxA1-null animals without affecting leukocyte rolling, in comparison to saline control. AnxA1(Ac2-26) effects were attenuated by Boc2 (pan-FPR antagonist, 10 μg/mouse, ∼12 nmol), and by minocycline (2.25 mg/mouse, ∼6.3 nmol). The nonselective Fpr agonists, fMLP (6 μg/mouse, ∼17 nmol) and AnxA1(Ac2-26), and the Fpr2-selective agonist ATLa (5 μg/mouse, ∼11 nmol) were without effect in Fpr2/3(-/-) mice. In summary, our novel results demonstrate that the AnxA1/FPR2 system has an important role in effecting the resolution of cerebral inflammation in sepsis and may, therefore, provide a novel therapeutic target.
Collapse
Affiliation(s)
- Felicity N E Gavins
- Division of Brain Sciences, Imperial College Faculty of Medicine, Hammersmith Hospital Campus, Burlington Danes Bldg., Du Cane Rd., London W12 0NN, UK.
| | | | | | | | | | | |
Collapse
|
17
|
Holloway PM, Smith HK, Renshaw D, Flower RJ, Getting SJ, Gavins FNE. Targeting the melanocortin receptor system for anti-stroke therapy. Trends Pharmacol Sci 2010; 32:90-8. [PMID: 21185610 DOI: 10.1016/j.tips.2010.11.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Revised: 11/23/2010] [Accepted: 11/24/2010] [Indexed: 10/18/2022]
Abstract
The melanocortin receptors are a subfamily of G-protein-coupled, rhodopsin-like receptors that are rapidly being acknowledged as an extremely promising target for pharmacological intervention in a variety of different inflammatory pathologies, including stroke. Stroke continues to be a leading cause of death worldwide, with risk factors including smoking, diabetes, hypertension and obesity. The pathophysiology of stroke is highly complex: reintroduction of blood flow to the infarcted brain region is paramount in limiting ischaemic damage caused by stroke, yet a concomitant inflammatory response can compound tissue damage. The possibilities of pro-resolving treatments that target this inflammatory response have only recently begun to be explored. This review discusses the endogenous roles of the melanocortin system in reducing characterized aspects of inflammation, and how these, together with potent neuroprotective actions, suggest its potential as a therapeutic target in stroke.
Collapse
Affiliation(s)
- Paul M Holloway
- Wolfson Neuroscience Laboratories, Imperial College Faculty of Medicine, Imperial College, London, UK
| | | | | | | | | | | |
Collapse
|
18
|
Holloway PM, Platt JH, Reybrouck G, Lilly HA, Mehtar S, Drabu Y. A multi-centre evaluation of two chlorhexidine-containing formulations for surgical hand disinfection. J Hosp Infect 1990; 16:151-9. [PMID: 1976679 DOI: 10.1016/0195-6701(90)90059-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Many experimental methods have been used to assess the efficacy of products intended for surgical hand disinfection. In this study, a modification of the Peterson glove juice method was used to compare two chlorhexidine-based surgical hand disinfectants, 'Hibiscrub' and an experimental formulation, F.6115. The study was performed by four independent laboratories and data merged for analysis. There was found to be no significant difference between the two formulations. The results illustrate that this modified Peterson glove juice method has the potential to form the basis of a standard method for testing surgical hand disinfectants which is both relevant to the practical situation and reproducible in different laboratories.
Collapse
Affiliation(s)
- P M Holloway
- ICI Pharmaceuticals, Alderley Park, Macclesfield, Cheshire
| | | | | | | | | | | |
Collapse
|
19
|
Holloway PM. Effect of chlorhexidine on bacterial pathogenicity. J Hosp Infect 1989; 13:96. [PMID: 2564026 DOI: 10.1016/0195-6701(89)90102-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
20
|
Abstract
Suspensions of Escherichia coli and Klebsiella aerogenes were exposed to low levels of chlorhexidine, which had little effect on their in vitro viability. A substantial reduction in their in vivo infectivity measured by intraperitoneal inoculation of mice was found. This selective reduction in bacterial infectivity by chlorhexidine should be taken into account when conventional in vitro tests are used to assess the clinical effectiveness of chlorhexidine-containing antiseptics.
Collapse
|