干扰PCSK9表达对狼疮小鼠免疫功能的影响

Effects of PCSK9 interference on immunoinflammatory reaction in pristane-induced lupus murine model

目的观察干扰PCSK9对狼疮模型小鼠免疫-炎症反应的影响。方法应用降植烷腹腔注射的方法构建狼疮小鼠模型,尾静脉注射PCSK shRNA以干扰PCSK9表达,并以免疫组化及Western blot验证PCSK9干扰效果;检测各组小鼠血脂情况;ELISA法检测小鼠血清抗核抗体、抗dsDNA抗体、抗Sm抗体、PCSK9水平以及细胞因子IL-17、TGF-β、IL-1β、TNF-α浓度;流式细胞术检测小鼠Th17细胞及Treg细胞比例。结果 SLE组小鼠出现狼疮样表现,狼疮相关自身抗体包括抗核抗体、抗dsDNA抗体、抗Sm抗体水平亦明显增高。SLE组小鼠血清及肝脏PCSK9表达水平、促炎因子IL-17、IL-1β、TNF-α浓度、Th17细胞比例较对照组小鼠明显增高,而具有抗炎作用的细胞因子TGF-β浓度、Treg细胞比例则偏低;干扰PCSK9表达可部分逆转上述变化趋势。SLE组小鼠各血脂参数相较对照组小鼠无显著差异,PCSK9干扰对SLE组小鼠血脂参数未见显著影响。结论抑制PCSK9表达可显著减轻SLE炎症状态,这一现象可能与Th17/Treg失衡状态的改善有关,并可独立于血脂参数的改变。

This study was designed to observe the effects of PCSK9 interference on immunoinflammatory reaction in lupus murine model. Lupus murine model was set up by intraperitoneally injection of pristane. PCSK9 expression was interfered by injection of PCSK9 shRNA via tail vein. Immunohistochemistry and Western blot were used to certify the PCSK9 interference. Lipids parameters was assessed in different group of mice. Antinuclear antibodies, anti-dsDNA antibody, anti-Sm antibody, serum PCSK9 concentration and cytokine levels(including IL-17, TGF-β, IL-1β, TNF-α) were quantified by ELISA. The ratio of Th17 and Treg were examined by flow cytometry. Lupus-like manifestation and positivity of lupus-associated autoantibodies including antinuclear antibodies, anti-dsDNA antibody and anti-Sm antibody were observed in SLE mice. Overexpression of PCSK9 in serum and liver was found in SLE mice, accompanied by the elevation of pro-inflammatory cytokines including IL-17, IL-1β and TNF-α, and the ratio of Th17 cells, while the levels of Treg and TGF-β were down-regulated.PCSK9 inhibition partially reversed these tendencies. No significant difference of lipids parameters was found between SLE mice and control mice;PCSK9 inhibition had no significant effects on lipids parameters in SLE mice. In conclusion, PCSK9 inhibition could reduce the inflammation in SLE, and the mechanism might be associated with the improvement of Th17/Treg imbalance, without reference to lipids parameters alteration.