Effect and mechanism of mastoparan-1 antagonizing lipopolysaccharide in vitro
10.3760/cma.j.issn.1001-8050.2009.02.50
- VernacularTitle:蜂毒肽MP-1体外拮抗内毒素作用及其机制
- Author:
Yibin GUO
;
Jiang ZHENG
;
Hongwei CAO
;
Guangxia XIAO
;
Qingyi ZHENG
;
Jinghe CHEN
;
Shaofu CAI
- Publication Type:Journal Article
- Keywords:
Mastoparan;
Endotoxins;
Sepsis
- From:
Chinese Journal of Trauma
2009;25(2):164-168
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the mechanism of mastoparan-1 (MP-1) antagonizing lipopolysaecharide (LPS) in vitro. Methods The affinity of MP-1 for lipid A was assayed by biosensor, and the neutralization of MP-1 on LPS (2 μg/L) was detected by kinetic turbidimetric limulus test. After exposing fluorescin isothiecyanate (FITC) labeled LPS (FITC-LPS) to MP-1 at different concentrations (5, 10, 20, 40 μmol/L), the binding of FITC-LPS to murine RAW264.7 cells was analyzed by laser scanning confocal microscopy. The influence of MP-1 on TLR4 expression in RAW264.7 cells stimulated by LPS (100 μg/L) was detected by immunoeytochemieal staining. The expressions of TLR4, TNF-α and IL-6 at the gene and protein level were detected by RT-PCR and ELISA after exposing LPS (100 μg/ L) stimulated RAW264.7 cells to MP-1 at different concentrations. The effect of MP-1 on the viability of RAW264.7 cells was detected by MTT assay. Results MP-1 had high affinity to lipid A and could neutralize LPS. MP-1 at 10 μmol/L significantly inhibited not only binding of FITC-LPS to RAW264.7 (P < 0.05), but also protein and gene expressions of TLR4, TNF-α and IL-6 in LPS stimulated RAW264.7 cells in a dose-dependent manner (P < 0.05). No toxic effect of MP-1 on the viability of RAW264.7 cells was found (P > 0.05). Conclusions MP-1 inhibits cell viability mediated by LPS, which may be related to its neutralization of LPS and inhibition of binding of LPS to RAW264.7 cell membrane receptors.
