Protein kinase Cε and protein kinase Cθ double-deficient mice have a bleeding diathesis

Summary Background: In comparison to the classical isoforms of protein kinase C (PKC), the novel isoforms are thought to play minor or inhibitory roles in the regulation of platelet activation and thrombosis. Objectives: To measure the levels of PKCθ and PKCε and to investigate the phenotype of mic...

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Main Authors: Unsworth, A, Finney, B, Navarro-Nunez, L, Pears, C, al., E
Format: Journal article
Published: Wiley 2012
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author Unsworth, A
Finney, B
Navarro-Nunez, L
Pears, C
al., E
author_facet Unsworth, A
Finney, B
Navarro-Nunez, L
Pears, C
al., E
author_sort Unsworth, A
collection OXFORD
description Summary Background: In comparison to the classical isoforms of protein kinase C (PKC), the novel isoforms are thought to play minor or inhibitory roles in the regulation of platelet activation and thrombosis. Objectives: To measure the levels of PKCθ and PKCε and to investigate the phenotype of mice deficient in both novel PKC isoforms. Methods: Tail bleeding and platelet activation assays were monitored in mice and platelets from mice deficient in both PKCθ and PKCε. Results: PKCε plays a minor role in supporting aggregation and secretion following stimulation of the collagen receptor GPVI in mouse platelets but has no apparent role in spreading on fibrinogen. PKCθ, in contrast, plays a minor role in supporting adhesion and filopodial generation on fibrinogen but has no apparent role in aggregation and secretion induced by GPVI despite being expressed at over 10 times the level of PKCε. Platelets deficient in both novel isoforms have a similar pattern of aggregation downstream of GPVI and spreading on fibrinogen as the single null mutants. Strikingly, a marked reduction in aggregation on collagen under arteriolar shear conditions is observed in blood from the double but not single-deficient mice along with a significant increase in tail bleeding. Conclusions: These results reveal a greater than additive role for PKCθ and PKCε in supporting platelet activation under shear conditions and demonstrate that, in combination, the two novel PKCs support platelet activation.
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spelling oxford-uuid:bd02964d-afbb-4769-8e5f-c06852d8a88e2022-03-27T05:28:39ZProtein kinase Cε and protein kinase Cθ double-deficient mice have a bleeding diathesisJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:bd02964d-afbb-4769-8e5f-c06852d8a88eSymplectic Elements at OxfordWiley2012Unsworth, AFinney, BNavarro-Nunez, LPears, Cal., ESummary Background: In comparison to the classical isoforms of protein kinase C (PKC), the novel isoforms are thought to play minor or inhibitory roles in the regulation of platelet activation and thrombosis. Objectives: To measure the levels of PKCθ and PKCε and to investigate the phenotype of mice deficient in both novel PKC isoforms. Methods: Tail bleeding and platelet activation assays were monitored in mice and platelets from mice deficient in both PKCθ and PKCε. Results: PKCε plays a minor role in supporting aggregation and secretion following stimulation of the collagen receptor GPVI in mouse platelets but has no apparent role in spreading on fibrinogen. PKCθ, in contrast, plays a minor role in supporting adhesion and filopodial generation on fibrinogen but has no apparent role in aggregation and secretion induced by GPVI despite being expressed at over 10 times the level of PKCε. Platelets deficient in both novel isoforms have a similar pattern of aggregation downstream of GPVI and spreading on fibrinogen as the single null mutants. Strikingly, a marked reduction in aggregation on collagen under arteriolar shear conditions is observed in blood from the double but not single-deficient mice along with a significant increase in tail bleeding. Conclusions: These results reveal a greater than additive role for PKCθ and PKCε in supporting platelet activation under shear conditions and demonstrate that, in combination, the two novel PKCs support platelet activation.
spellingShingle Unsworth, A
Finney, B
Navarro-Nunez, L
Pears, C
al., E
Protein kinase Cε and protein kinase Cθ double-deficient mice have a bleeding diathesis
title Protein kinase Cε and protein kinase Cθ double-deficient mice have a bleeding diathesis
title_full Protein kinase Cε and protein kinase Cθ double-deficient mice have a bleeding diathesis
title_fullStr Protein kinase Cε and protein kinase Cθ double-deficient mice have a bleeding diathesis
title_full_unstemmed Protein kinase Cε and protein kinase Cθ double-deficient mice have a bleeding diathesis
title_short Protein kinase Cε and protein kinase Cθ double-deficient mice have a bleeding diathesis
title_sort protein kinase cε and protein kinase cθ double deficient mice have a bleeding diathesis
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AT finneyb proteinkinaseceandproteinkinasecthdoubledeficientmicehaveableedingdiathesis
AT navarronunezl proteinkinaseceandproteinkinasecthdoubledeficientmicehaveableedingdiathesis
AT pearsc proteinkinaseceandproteinkinasecthdoubledeficientmicehaveableedingdiathesis
AT ale proteinkinaseceandproteinkinasecthdoubledeficientmicehaveableedingdiathesis