Low-Dose Endothelial Monocyte-Activating Polypeptide-II Induces Blood-Tumor Barrier Opening Via the cAMP/PKA/Rac1 Pathway.
J Mol Neurosci
; 58(2): 153-61, 2016 Feb.
Article
en En
| MEDLINE
| ID: mdl-26358039
ABSTRACT
Previous studies have demonstrated that low-dose endothelial monocyte-activating polypeptide-II (EMAP-II) induces blood-tumor barrier (BTB) hyperpermeability via both paracellular and transcellular pathways. In a recent study, we revealed that cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)-dependent signaling pathway is involved in EMAP-II-induced BTB hyperpermeability. This study further investigated the exact mechanisms through which the cAMP/PKA-dependent signaling pathway affects EMAP-II-induced BTB hyperpermeability. In an in vitro BTB model, low-dose EMAP-II (0.05 nM) induced a significant decrease in Rac1 activity in rat brain microvascular endothelial cells (RBMECs). Pretreatment with forskolin to elevate intracellular cAMP concentration completely blocked EMAP-II-induced inactivation of Rac1. Besides, pretreatment with 6Bnz-cAMP to activate PKA partially attenuated EMAP-II-induced Rac1 inactivation. Moreover, 6Bnz-cAMP pretreatment significantly diminished EMAP-II-induced changes in BTB permeability, myosin light chain (MLC) phosphorylation, expression and distribution of ZO-1, and actin cytoskeleton arrangement in RBMECs. These effects of 6Bnz-cAMP were completely blocked in the presence of NSC-23766 (the specific inhibitor of Rac1). In conclusion, this study demonstrates that low-dose EMAP-II induces BTB hyperpermeability via the cAMP/PKA/Rac1 signaling pathway.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Neoplasias Encefálicas
/
Permeabilidad Capilar
/
Endotelio Vascular
/
Barrera Hematoencefálica
/
Citocinas
/
Proteínas de Unión al ARN
/
AMP Cíclico
/
Glioma
/
Proteínas de Neoplasias
Límite:
Animals
Idioma:
En
Revista:
J Mol Neurosci
Asunto de la revista:
BIOLOGIA MOLECULAR
/
NEUROLOGIA
Año:
2016
Tipo del documento:
Article