title: Novel method to study pericyte contractility and responses to ischaemia in vitro using electrical impedance.
abstract: Pericytes are contractile vascular mural cells overlying capillary endothelium, and they have been implicated in a variety of functions including regulation of cerebral blood flow. Recent work has suggested that both in vivo and ex vivo, ischaemia causes pericytes to constrict and die, which has implications for microvascular reperfusion. Assessing pericyte contractility in tissue slices and in vivo is technically challenging, while in vitro techniques remain unreliable. Here, we used isolated cultures of human brain vascular pericytes to examine their contractile potential in vitro using the iCelligence electrical impedance system. Contraction was induced using the vasoactive peptide endothelin-1, and relaxation was demonstrated using adenosine and sodium nitroprusside. Endothelin-1 treatment also resulted in increased proliferation, which we were able to monitor in the same cell population from which we recorded contractile responses. Finally, the observation of pericyte contraction in stroke was reproduced using chemical ischaemia, which caused a profound and irreversible contraction clearly preceding cell death. These data demonstrate that isolated pericytes retain a contractile phenotype in vitro, and that it is possible to quantify this contraction using real-time electrical impedance recordings, providing a significant new platform for assessing the effects of vasoactive and vasculoprotective compounds on pericyte contractility.
authors.affiliation: 1 Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
authors.forename: Ain A
authors.initials: AA
authors.lastname: Neuhaus
authors.affiliation: 1 Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Couch
authors.affiliation: 1 Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.|4 School of Medicine, Faculty of Health, University of Tasmania, Hobart, Australia.
authors.forename: Brad A
authors.initials: BA
authors.lastname: Sutherland
authors.affiliation: 1 Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.|2 Medical Sciences Division, University of Oxford, Oxford, UK.|3 Acute Vascular Imaging Centre, University of Oxford, Oxford University Hospitals, Oxford, UK.
authors.forename: Alastair M
authors.initials: AM
authors.lastname: Buchan
mesh_terms: D001921:Brain / Q000098:blood supply*; D002545:Brain Ischemia / Q000503:physiopathology*; D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D017097:Electric Impedance; D019332:Endothelin-1 / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology*; D057166:High-Throughput Screening Assays; D006801:Humans; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000503:physiopathology*; D020286:Pericytes / Q000187:drug effects / Q000502:physiology*; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
chemical_list: D019332:Endothelin-1
keywords: Human brain vascular pericytes; contractility; iCelligence; ischemia