Cooperation between ß- and γ-cytoplasmic actins in the mechanical regulation of endothelial microparticle formation.
FASEB J
; 27(2): 672-83, 2013 Feb.
Article
em En
| MEDLINE
| ID: mdl-23159932
ABSTRACT
Elevated endothelial microparticle (MP) levels are observed in numerous diseases, increasingly supporting roles as effectors and valuable markers of vascular dysfunction. While a contractile role for the actin cytoskeleton has been implicated in vesiculation, i.e., MP production, the precise interactions and mechanisms of its constituents, ß- and γ-cytoplasmic actins, is unknown. Human cerebral microvascular endothelial cells were stimulated with known agonists, and vesiculation development was monitored by scanning electron microscopy (SEM) and flow cytometry. These data in combination provide new insight into the kinetics, patterns of vesiculating cell recruitment, and degrees of response specific to stimuli. Reorganization of ß- and γ-actins, F-actin, vinculin, and talin accompanied significant MP release. ß-Actin redistribution into basal stress fibers following stimulation was associated with increased apically situated actin-rich particulate structures, which in turn directly correlated with electron-lucent membrane protrusions observed by SEM. Y-27632 Rho-kinase inhibition abolished basal ß-actin fiber formation, minimizing apically associated actin-rich structures, significantly reducing membrane protrusions and MP release to near basal levels. Cytoskeletal protein expression and distribution varied between MPs and mother cells, as determined by Western blot. These data strongly suggest that ß-actin plays an active facilitative role in agonist-induced protuberance formation, through mechanical interactions with newly described actin-rich structures.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Actinas
/
Células Endoteliais
/
Micropartículas Derivadas de Células
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
FASEB J
Assunto da revista:
BIOLOGIA
/
FISIOLOGIA
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Austrália