Proplatelet generation in the mouse requires PKCε-dependent RhoA inhibition.
Blood
; 122(7): 1305-11, 2013 Aug 15.
Article
em En
| MEDLINE
| ID: mdl-23838351
ABSTRACT
During thrombopoiesis, megakaroycytes undergo extensive cytoskeletal remodeling to form proplatelet extensions that eventually produce mature platelets. Proplatelet formation is a tightly orchestrated process that depends on dynamic regulation of both tubulin reorganization and Rho-associated, coiled-coil containing protein kinase/RhoA activity. A disruption in tubulin dynamics or RhoA activity impairs proplatelet formation and alters platelet morphology. We previously observed that protein kinase Cepsilon (PKCε), a member of the protein kinase C family of serine/threonine-kinases, expression varies during human megakaryocyte differentiation and modulates megakaryocyte maturation and platelet release. Here we used an in vitro model of murine platelet production to investigate a potential role for PKCε in proplatelet formation. By immunofluorescence we observed that PKCε colocalizes with α/ß-tubulin in specific areas of the marginal tubular-coil in proplatelets. Moreover, we found that PKCε expression escalates during megakarocyte differentiation and remains elevated in proplatelets, whereas the active form of RhoA is substantially downregulated in proplatelets. PKCε inhibition resulted in lower proplatelet numbers and larger diameter platelets in culture as well as persistent RhoA activation. Finally, we demonstrate that pharmacological inhibition of RhoA is capable of reversing the proplatelet defects mediated by PKCε inhibition. Collectively, these data indicate that by regulating RhoA activity, PKCε is a critical mediator of mouse proplatelet formation in vitro.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tubulina (Proteína)
/
Plaquetas
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Megacariócitos
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Proteína rhoA de Ligação ao GTP
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Trombopoese
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Proteína Quinase C-épsilon
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Blood
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Itália