Suppression of PKC-α attenuates TNF-α-evoked cerebral barrier breakdown via regulations of MMP-2 and plasminogen–plasmin system
Ischaemic stroke, accompanied by neuroinflammation, impairs blood-brain barrier integrity through a complex mechanism involving both protein kinase C (PKC) and urokinase. Using an in vitro model of human blood-brain barrier (BBB) composed of brain microvascular endothelial cells (HBMEC) and astrocyt...
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| Format: | Article |
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Elsevier
2016
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| Online Access: | https://eprints.nottingham.ac.uk/37937/ |
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| author | Abdullah, Zuraidah Bayraktutan, Ulvi |
| author_facet | Abdullah, Zuraidah Bayraktutan, Ulvi |
| author_sort | Abdullah, Zuraidah |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Ischaemic stroke, accompanied by neuroinflammation, impairs blood-brain barrier integrity through a complex mechanism involving both protein kinase C (PKC) and urokinase. Using an in vitro model of human blood-brain barrier (BBB) composed of brain microvascular endothelial cells (HBMEC) and astrocytes, this study assessed the putative roles of these elements in BBB damage evoked by enhanced availability of pro-inflammatory cytokine, TNF-α. Treatment of HBMEC with TNF-α significantly increased the mRNA and protein expressions of all plasminogen-plasmin system (PPS) components, namely tissue plasminogen activator, urokinase, urokinase plasminogen activator receptor and plasminogen activator inhibitor-1 and also the activities of urokinase, total PKC and extracellular MMP-2. Inhibition of urokinase by amiloride abated the effects of TNF-α on BBB integrity and MMP-2 activity without affecting that of total PKC. Conversely, pharmacological inhibition of conventional PKC isoforms dramatically suppressed TNF-α-induced overactivation of urokinase. Knockdown of PKC-α gene via specific siRNA in HBMEC suppressed the stimulatory effects of TNF-α on protein expression of all PPS components, MMP-2 activity, DNA fragmentation rates and pro-apoptotic caspase-3/7 activities. Establishment of co-cultures with BMEC transfected with PKC-α siRNA attenuated the disruptive effects of TNF- on BBB integrity and function. This was partly due to elevations observed in expression of a tight junction protein, claudin-5 and partly to prevention of stress fibre formation. In conclusion, specific inhibition of PKC-α in cerebral conditions associated with exaggerated release of pro-inflammatory cytokines, notably TNF- may be of considerable therapeutic value and help maintain endothelial cell viability, appropriate cytoskeletal structure and basement membrane. |
| first_indexed | 2025-11-14T19:34:06Z |
| format | Article |
| id | nottingham-37937 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:34:06Z |
| publishDate | 2016 |
| publisher | Elsevier |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-379372020-05-04T17:58:47Z https://eprints.nottingham.ac.uk/37937/ Suppression of PKC-α attenuates TNF-α-evoked cerebral barrier breakdown via regulations of MMP-2 and plasminogen–plasmin system Abdullah, Zuraidah Bayraktutan, Ulvi Ischaemic stroke, accompanied by neuroinflammation, impairs blood-brain barrier integrity through a complex mechanism involving both protein kinase C (PKC) and urokinase. Using an in vitro model of human blood-brain barrier (BBB) composed of brain microvascular endothelial cells (HBMEC) and astrocytes, this study assessed the putative roles of these elements in BBB damage evoked by enhanced availability of pro-inflammatory cytokine, TNF-α. Treatment of HBMEC with TNF-α significantly increased the mRNA and protein expressions of all plasminogen-plasmin system (PPS) components, namely tissue plasminogen activator, urokinase, urokinase plasminogen activator receptor and plasminogen activator inhibitor-1 and also the activities of urokinase, total PKC and extracellular MMP-2. Inhibition of urokinase by amiloride abated the effects of TNF-α on BBB integrity and MMP-2 activity without affecting that of total PKC. Conversely, pharmacological inhibition of conventional PKC isoforms dramatically suppressed TNF-α-induced overactivation of urokinase. Knockdown of PKC-α gene via specific siRNA in HBMEC suppressed the stimulatory effects of TNF-α on protein expression of all PPS components, MMP-2 activity, DNA fragmentation rates and pro-apoptotic caspase-3/7 activities. Establishment of co-cultures with BMEC transfected with PKC-α siRNA attenuated the disruptive effects of TNF- on BBB integrity and function. This was partly due to elevations observed in expression of a tight junction protein, claudin-5 and partly to prevention of stress fibre formation. In conclusion, specific inhibition of PKC-α in cerebral conditions associated with exaggerated release of pro-inflammatory cytokines, notably TNF- may be of considerable therapeutic value and help maintain endothelial cell viability, appropriate cytoskeletal structure and basement membrane. Elsevier 2016-07-31 Article PeerReviewed Abdullah, Zuraidah and Bayraktutan, Ulvi (2016) Suppression of PKC-α attenuates TNF-α-evoked cerebral barrier breakdown via regulations of MMP-2 and plasminogen–plasmin system. Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, 1862 (7). pp. 1354-1366. ISSN 0006-3002 TNF-α; blood-brain barrier; PKC-α; PPS components; MMP-2; claudin-5; apoptosis; stress fibres http://www.sciencedirect.com/science/article/pii/S0925443916300710 doi:10.1016/j.bbadis.2016.03.014 doi:10.1016/j.bbadis.2016.03.014 |
| spellingShingle | TNF-α; blood-brain barrier; PKC-α; PPS components; MMP-2; claudin-5; apoptosis; stress fibres Abdullah, Zuraidah Bayraktutan, Ulvi Suppression of PKC-α attenuates TNF-α-evoked cerebral barrier breakdown via regulations of MMP-2 and plasminogen–plasmin system |
| title | Suppression of PKC-α attenuates TNF-α-evoked cerebral barrier breakdown via regulations of MMP-2 and plasminogen–plasmin system |
| title_full | Suppression of PKC-α attenuates TNF-α-evoked cerebral barrier breakdown via regulations of MMP-2 and plasminogen–plasmin system |
| title_fullStr | Suppression of PKC-α attenuates TNF-α-evoked cerebral barrier breakdown via regulations of MMP-2 and plasminogen–plasmin system |
| title_full_unstemmed | Suppression of PKC-α attenuates TNF-α-evoked cerebral barrier breakdown via regulations of MMP-2 and plasminogen–plasmin system |
| title_short | Suppression of PKC-α attenuates TNF-α-evoked cerebral barrier breakdown via regulations of MMP-2 and plasminogen–plasmin system |
| title_sort | suppression of pkc-α attenuates tnf-α-evoked cerebral barrier breakdown via regulations of mmp-2 and plasminogen–plasmin system |
| topic | TNF-α; blood-brain barrier; PKC-α; PPS components; MMP-2; claudin-5; apoptosis; stress fibres |
| url | https://eprints.nottingham.ac.uk/37937/ https://eprints.nottingham.ac.uk/37937/ https://eprints.nottingham.ac.uk/37937/ |