Activation of TLR3 induces osteogenic responses in human aortic valve interstitial cells through the NF-κB and ERK1/2 pathways.
Int J Biol Sci
; 11(4): 482-93, 2015.
Article
en En
| MEDLINE
| ID: mdl-25798067
ABSTRACT
UNLABELLED Calcific aortic valve disease (CAVD) is characterized by chronic inflammation and progressive calcification in valve leaflets. Aortic valve interstitial cells (AVICs) play a critical role in the pathogenesis of CAVD. Previous studies show that stimulation of Toll-like receptor (TLR) 2 or TLR4 in AVICs in vitro up-regulates the expression of osteogenic mediators. Double-stranded RNA (dsRNA) can activate pro-inflammatory signaling through TLR3, the NLRP3 inflammasome and RIG-I-like receptors. The objective of this study is to determine the effect of dsRNA on AVIC osteogenic activities and the mechanism of its action. METHODS AND RESULTS:
AVICs isolated from normal human valves were exposed to polyinosinic-polycytidylic acid [poly(IC)], a mimic of dsRNA. Treatment with poly(IC) increased the production of bone morphogenetic protein-2 (BMP-2), transforming growth factor beta-1 (TGF-ß1) and alkaline phosphatase (ALP), and resulted in calcium deposit formation. Poly(IC) induced the phosphorylation of NF-κB and ERK1/2. Knockdown of TLR3 essentially abrogated NF-κB and ERK1/2 phosphorylation, and markedly reduced the effect of poly(IC) on the production of BMP-2, TGF-ß1 and ALP. Further, inhibition of either NF-κB or ERK1/2 markedly reduced the levels of BMP-2, TGF-ß1 and ALP in cells exposed to poly(IC).CONCLUSION:
Poly(IC) up-regulates the production of BMP-2, TGF-ß1 and ALP, and promotes calcium deposit formation in human AVICs. The pro-osteogenic effect of poly(IC) is mediated primarily by TLR3 and the NF-κB and ERK1/2 pathways. These findings suggest that dsRNA, when present in aortic valve tissue, may promote CAVD progression through up-regulation of AVIC osteogenic activities.Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
FN-kappa B
/
Receptor Toll-Like 3
Límite:
Humans
Idioma:
En
Revista:
Int J Biol Sci
Asunto de la revista:
BIOLOGIA
Año:
2015
Tipo del documento:
Article