Biosensor Technology Reveals the Disruption of the Endothelial Barrier Function and the Subsequent Death of Blood Brain Barrier Endothelial Cells to Sodium Azide and Its Gaseous Products
Open Access
- 21 September 2017
- journal article
- research article
- Published by MDPI AG in Biosensors
- Vol. 7 (4), 41
- https://doi.org/10.3390/bios7040041
Abstract
Herein we demonstrate the sensitive nature of human blood-brain barrier (BBB) endothelial cells to sodium azide and its gaseous product. Sodium azide is known to be acutely cytotoxic at low millimolar concentrations, hence its use as a biological preservative (e.g., in antibodies). Loss of barrier integrity was noticed in experiments using Electric Cell-substrate Impedance Sensing (ECIS) biosensor technology, to measure endothelial barrier integrity continuously in real-time. Initially the effect of sodium azide was observed as an artefact where it was present in antibodies being employed in neutralisation experiments. This was confirmed where antibody clones that were azide-free did not mediate loss of barrier function. A delayed loss of barrier function in neighbouring wells implied the influence of a liberated gaseous product. ECIS technology demonstrated that the BBB endothelial cells had a lower level of direct sensitivity to sodium azide of ~3 µM. Evidence of gaseous toxicity was consistently observed at 30 µM and above, with disrupted barrier function and cell death in neighbouring wells. We highlight the ability of this cellular biosensor technology to reveal both the direct and gaseous toxicity mediated by sodium azide. The sensitivity and temporal dimension of ECIS technology was instrumental in these observations. These findings have substantial implications for the wide use of sodium azide in biological reagents, raising issues of their application in live-cell assays and with regard to the protection of the user. This research also has wider relevance highlighting the sensitivity of brain endothelial cells to a known mitochondrial disruptor. It is logical to hypothesise that BBB endothelial dysfunction due to mitochondrial dys-regulation could have an important but underappreciated role in a range of neurological diseases.Keywords
This publication has 32 references indexed in Scilit:
- The Mechanisms of Cerebral Vascular Dysfunction and Neuroinflammation by MMP-Mediated Degradation of VEGFR-2 in Alcohol IngestionArteriosclerosis, Thrombosis, and Vascular Biology, 2012
- Blood-brain barrier and retroviral infectionsVirulence, 2012
- Expression of Tight Junction and Drug Efflux Transporter Proteins in an in vitro Model of Human Blood–Brain BarrierFrontiers in Psychiatry, 2012
- Comparison of Two Blood-Brain Barrier In Vitro Systems: Cytotoxicity and Transfer Assessments of Malathion/Oxon and Lead AcetateToxicological Sciences, 2010
- CSF follow-up in HIV-1 infection: intrathecal production of HIV-specific and unspecific IGG, and beta-2-microglobulin increase with duration of HIV-1 infectionActa Neurologica Scandinavica, 2009
- The Blood-Brain Barrier in Health and Chronic Neurodegenerative DisordersNeuron, 2008
- Human Health Effects of Sodium Azide Exposure: A Literature Review and AnalysisInternational Journal of Toxicology, 2003
- Nitric Oxide and Blood–Brain Barrier IntegrityAntioxidants and Redox Signaling, 2001
- Blood-brain barrier biology and methodologyJournal of NeuroVirology, 1999
- Effect of aging on the blood-brain barrierNeurobiology of Aging, 1988