The effects of atorvastatin on C-reactive protein induced Toll-like receptor 4 expression on CD14+ monocyte
10.3760/cma.j.issn.0253-3758.2011.07.014
- VernacularTitle:阿托伐他汀对C反应蛋白诱导的CD14+单核细胞Toll样受体4表达影响的实验研究
- Author:
Long PENG
1
;
Yan-Ting LUO
;
Jin-Lai LIU
Author Information
1. 中山大学附属第三医院
- Keywords:
Inflammation;
C-reactive protein;
Toll like receptor-4;
Monocytes;
Atorvastatin
- From:
Chinese Journal of Cardiology
2011;39(7):664-669
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effects of atorvastatin on C-reactive protein (CRP)induced Toll-Like receptor 4(TLR4)expression on CD14+ monocyte, and the production of proinflammatory cytokines tumor necrosis factor α (TNFα), interleukin-6 (IL-6), matrix metalloproteinases-9 (MMP-9), and to study the anti-inflammatory mechanisms of statins. Methods The monocytes were isolated from blood of healthy volunteers by the Ficoll density gradient and stimulated by CRP with different doses (5, 25, 50, 100 μg/ml)and different exposure time (6, 12, 24, 48 h). Cells were also incubated with atorvastatin of different doses (1.0, 2.5, 5.0, 7.5, 10.0 μmol/L)in the presence of CRP 50 μg/ml. The protein expression of TLR4 was measured by flow cytometry, mRNA expression of TLR4 and of myeloid differentiation protein (MD2)was detected by quantitative PCR. TNFα, IL-6, MMP-9 concentrations in supernatants of cultured medium were measured by ELISA.Results (1)Compared with the un-stimulated control group, enhanced TLR4 protein expression was already detected at a concentration of 5 μg/ml of CRP and increased in a dose-dependent manner (32.22±2.80)%, (49.94±5.58)%, (74.82±3.24)% and (90.82±2.88)% at 5, 25, 50 and 100 μg/ml CRP. (2)TLR4 protein expression on 50 μg/ml CRP stimulated cells also increased in a time-dependent manner (29.80±2.70)%, (47.44±4.41)%, (81.71±2.92)% and (50.57±3.34)% after 6 h, 12 h, 24 h, 48 h.(3)When monocytes were incubated with CRP 50 μg/ml and atorvastatin (1.0, 2.5, 5.0, 7.5, 10.0 μmol/L), protein expression [(68.17±1.71)%, (52.43±1.38)%, (27.72±4.55)%, (17.46±3.20)%, (9.99±2.81)%］and mRNA expression (82.72%, 67.34%, 48.16%, 30.88%, 13.85%)of TLR4 as well as mRNA expression of MD2 (81.78%, 71.04%, 47.85%, 27.06%, 18.30%)were reduced in a dose-dependent manner. (4)Level of TNFα, IL-6 and MMP-9 in supernatants was significantly reduced by atorvastatin (2.5 μmol/L)compared with control group(P<0.01). When monocyte incubated with CRP 50 μg/ml and atorvastatin 10.0 μmol/L, the level of TNFα, IL-6, MMP-9 decreased to (25.8±2.5)pg/ml, (128.2±14.7)pg/ml, (65.2±12.3)ng/ml, respectively.Conclusion CRP increased the protein expression of TLR4 on CD14+ monocyte in a dose-dependent and time-dependent manner. Atorvastatin can inhibit the signal transduction of TLR4 and reduce proinflammatory cytokines release induced by CRP on CD14+ monocyte, and this might be one of the anti-inflammatory mechanisms of atorvastatin.
