Objective To examine the role of lipoprotein(a) [Lp(a)] on the inflammatory response of cells in the nervous system by investigating its effect on lipopolysaccharide (LPS)-induced interleukin-6 (IL-6) secretion. Materials and methods Human astrocytoma U373 cells were treated with recombinant apolipoprotein(a) [r-apo(a)] A10K (175–11 nM), alone or in combination with LPS (100 and 10 ng/ml). IL-6 levels were evaluated by immunoblotting. Statistical analysis was performed by one-way ANOVA. Results r-apo(a) caused dose-dependent inhibition of LPS-induced IL-6 secretion (100 ng/ml LPS, p = 0.0205; 10 ng/ml LPS, p = 0.0005). Pre-treatment of cells with 88 nM r-apo(a), rinsing, and activation with 10 ng/ml LPS did not reverse the inhibition (p = 0.0048), which could be reversed by supplementation with excess serum (5–20%) (p = 0.0454) or recombinant CD14 (2.0–0.05 lg/ml) (p = 0.0230). Conclusions Our data indicate that apo(a) plays a natural anti-endotoxin role which relies on its interference with cell-associated and serum components of LPS signaling.
Apolipoprotein(a) inhibits lipopolysaccharide-induced IL-6 secretion in human astrocytoma cell line by interfering with lipopolysaccharide signaling
CHIMIENTI, Guglielmina Alessandra;LIUZZI, Grazia Maria;LATRONICO, TIZIANA;
2011-01-01
Abstract
Objective To examine the role of lipoprotein(a) [Lp(a)] on the inflammatory response of cells in the nervous system by investigating its effect on lipopolysaccharide (LPS)-induced interleukin-6 (IL-6) secretion. Materials and methods Human astrocytoma U373 cells were treated with recombinant apolipoprotein(a) [r-apo(a)] A10K (175–11 nM), alone or in combination with LPS (100 and 10 ng/ml). IL-6 levels were evaluated by immunoblotting. Statistical analysis was performed by one-way ANOVA. Results r-apo(a) caused dose-dependent inhibition of LPS-induced IL-6 secretion (100 ng/ml LPS, p = 0.0205; 10 ng/ml LPS, p = 0.0005). Pre-treatment of cells with 88 nM r-apo(a), rinsing, and activation with 10 ng/ml LPS did not reverse the inhibition (p = 0.0048), which could be reversed by supplementation with excess serum (5–20%) (p = 0.0454) or recombinant CD14 (2.0–0.05 lg/ml) (p = 0.0230). Conclusions Our data indicate that apo(a) plays a natural anti-endotoxin role which relies on its interference with cell-associated and serum components of LPS signaling.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
