云芝多糖B抑制血管紧张素Ⅱ诱导的巨噬细胞骨调素基因上调表达

Effect of Coriolus versicolor polysaccharides B on osteopontin mRNA expression in macrophages induced by angiotensin Ⅱ

目的探讨野生云芝多糖水溶性新组分CVPS-B对血管紧张素Ⅱ(AngⅡ)诱导的RAW264.7巨噬细胞骨调素(OPN)基因表达的影响及p38丝裂原活化蛋白激酶(p38MAPK)及其转录因子ATF-2可能的调控作用。方法用RT-PCR检测CVPS-B对AngⅡ诱导的RAW264.7巨噬细胞OPN基因表达的影响;用Western blot测定AngⅡ(1μmol.L-1)诱导RAW264.7细胞p38MAPK转录因子-激活转录因子2(ATF2)表达的时间模式;用Western blot测定CVPS-B对RAW264.7巨噬细胞p38MAPK及其转录因子ATF2磷酸化表达的影响。结果CVPS-B(10mg·L-1)在AngⅡ(1μmol·L-1)刺激前30min加入培养基抑制作用最明显,共同孵育12h,抑制率达到50.3%(P<0.01);不同浓度CVPS-B1、10、50mg·L-1在AngⅡ(1μmol·L-1)刺激前30min加入培养基,共同孵育12h,其抑制率分别为13.8%、41.2%(P<0.01)及63.7%(P<0.01)。不同浓度CVPS-B及SB202190预孵12h,SB202190在5μmol·L-1(高浓度)时能明显抑制p38MAPK的磷酸化表达,相反,CVPS-B在10、50mg·L-1(高与低浓度)时均不能明显抑制p38MAPK的磷酸化表达。CVPS-B能明显抑制ATF2的磷酸化表达并呈剂量依赖性;而且,SB202190加CVPS-B在低剂量时(SB2021901μmol·L-1加CVPS-B10mg·L-1)也能明显抑制ATF2的磷酸化表达。结论CVPS-B能明显抑制AngⅡ诱导的RAW264.7巨噬细胞OPN基因表达。CVPS-B的抑制作用可能是通过调控转录因子ATF-2的活性实现的。

Aim To investigate the effect of Coriolus versicolor polysaccharides B （CVPS-B） , an immunopotentiator[ a new water-soluble component of polysaccharide from the fungus Coriolus versicolor（Fr） L） , on osteopontin （OPN） mRNA expression induced by angiotensin Ⅱ （Ang Ⅱ ） in RAW264. 7 macrophages and the possible roles of p38 mitogen-activated protein kinase （p38MAPK） and activating transcription factor-2 （ATF-2） in the process. Methods RT-PCR was used for examining the OPN mRNA expression, and the phosphorylation of p38MAPK and its transcription factor, ATF-2, was detected by Western blot. Results Pre-treatment with CVPS-B （10 mg · L^-1） for 30 min, the expression of OPN mRNA induced by Ang Ⅱ （1 μmol ·L^-1） was decreased by 50.3% （P 〈 0. 01 ） ; pre-treatment with CVPS-B （ 1,10,50 mg · L^-1） for 30 min, the expression of OPN mRNA induced by Ang Ⅱ （1 μmol · L^-1） was decreased by 13.8%,41.2%（P〈0.01） and63.7% （P〈0.01）,respectively. SB202190 （5 μmol · L^-1 ） markedly decreased the phospho-p38MAPK expression induced by AngⅡ （1 Ⅱ）,whereas CVPS-B （10 or 50 mg· L^-1） did not affect the phospho-p38MAPK expression induced by Ang Ⅱ （1 μmol · L^-1）. Both SB202190 and CVPS-B significantly inhibited the phospho-ATF2 expression induced by Ang Ⅱ （1 μmol · L^-1 ） in a dose-dependent manner. Furthermore, addition of SB202190 （1 μmol · L^-1） and CVPS-B （10 mg · L^-1） also significantly decreased the phospho- ATF2 expression induced by Ang Ⅱ （1 μmol · L^-1）. Conclusions OPN mRNA expression stimulated by Ang Ⅱ could be suppressed by CVPS-B, and the inhibition might be mediated by ATF-2 transcriptional activity.