论文部分内容阅读
探讨非诺贝特对血管紧张素Ⅱ(AngⅡ)诱导的小鼠巨噬细胞株RAW264.7细胞Toll样受体4(TLR4)mRNA、蛋白表达及髓过氧化物酶(MPO)活性、mRNA及蛋白表达的影响及其抗炎机制。采用RT-PCR检测TLR4和MPOmRNA水平,Western blotting检测TLR4和MPO的蛋白表达,比色法测定细胞培养上清液中的MPO活性。结果显示,非诺贝特浓度依赖性地减少AngⅡ诱导的RAW264.7细胞TLR4mRNA及蛋白表达,抑制AngⅡ诱导的RAW264.7细胞MPO活性、mRNA及蛋白表达。此外,TLR4阻断剂对AngⅡ诱导的RAW264.7细胞MPO活性有部分的抑制作用,而非诺贝特可增强这一抑制效应。同时非诺贝特明显拮抗TLR4特异性配体脂多糖的促MPO分泌效应。以上结果表明,非诺贝特可下调AngⅡ诱导的RAW264.7细胞TLR4表达,并通过干预TLR4,影响胞内信号转导途径,抑制MPO分泌,减轻炎症反应,这可能是其新的抗炎机制之一。
To investigate the effect of fenofibrate on Toll-like receptor 4 (TLR4) mRNA and protein expression and the activity of myeloperoxidase (MPO) in RAW264.7 cells induced by angiotensin Ⅱ (AngⅡ) Effect of protein expression and anti-inflammatory mechanism. The levels of TLR4 and MPO mRNA were detected by RT-PCR. The protein expressions of TLR4 and MPO were detected by Western blotting. The MPO activity in cell culture supernatant was determined by colorimetric assay. The results showed that fenofibrate reduced the Ang Ⅱ-induced TLR4 mRNA and protein expression in RAW264.7 cells in a concentration-dependent manner, and inhibited Angiotrophin-induced MPO activity, mRNA and protein expression in RAW264.7 cells. In addition, TLR4 blockers partially inhibited Angiotrophin-induced MPO activity in RAW264.7 cells, while fenofibrate enhanced this inhibitory effect. At the same time, fenofibrate significantly inhibited the pro-MPO secretion effect of TLR4-specific ligand lipopolysaccharide. These results indicate that fenofibrate can down-regulate the expression of TLR4 in RAW264.7 cells induced by AngⅡ, which may be its new anti-inflammatory mechanism by interfering with TLR4, affecting the intracellular signal transduction pathway, inhibiting the secretion of MPO and reducing the inflammatory reaction one.