上海交通大学学报（医学版）

›› 2012, Vol. 32 ›› Issue (6): 706-.doi: 10.3969/j.issn.1674-8115.2012.06.004

• 论著（基础研究） • 上一篇    下一篇

氧化型低密度脂蛋白调控MerTK受体表达抑制巨噬细胞对凋亡细胞的吞噬

黄晓菁, 江立生, 徐 瑾, 何 奔, 陈颖敏   

  1. 上海交通大学 医学院附属仁济医院心内科, 上海 200001
  • 出版日期:2012-06-28 发布日期:2012-07-02
  • 通讯作者: 陈颖敏, 电子信箱: chenyingmin@medmail.com.cn。
  • 作者简介:黄晓菁（1986—）, 女, 硕士生；电子信箱: hxjv107@163.com。
  • 基金资助:

    国家自然科学基金（81000086）；上海市科委基金（2011-36059）

Oxidized low-density lipoprotein reduces macrophage phagocytosis of apoptotic cells by inhibiting expression of receptor MerTK

HUANG Xiao-jing, JIANG Li-sheng, XU Jin, HE Ben, CHEN Ying-min   

  1. Department of Cardiology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200001, China
  • Online:2012-06-28 Published:2012-07-02
  • Supported by:

    National Natural Science Foundation of China, 81000086；Shanghai Science and Technology Committee Foundation, 2011-36059

PDF (PC)

1423

摘要：

目的 研究氧化型低密度脂蛋白（ox-LDL）对巨噬细胞吞噬清除凋亡细胞的作用及其机制。方法 RAW264.7小鼠巨噬细胞随机分为对照组（无血清的DMEM培养液）、10 μg/mL ox-LDL组（10 μg/mL ox-LDL无血清DMEM培养液）和20 μg/mL ox-LDL组（20 μg/mL ox-LDL无血清DMEM培养液），采用紫外光照射诱导RAW264.7小鼠巨噬细胞发生凋亡，流式细胞分析法检测RAW264.7小鼠巨噬细胞对凋亡细胞的吞噬指数，Western blotting和 Real-Time PCR技术分别检测促吞噬受体MerTK蛋白和mRNA表达的变化。结果 ①孵育24 h后，10 μg/mL ox-LDL组和20 μg/mL ox-LDL组吞噬指数分别较对照组下降（4.7±2.8）%和（12.6±2.2）%，20 μg/mL ox-LDL组显著小于对照组和10 μg/mL ox-LDL组（P＜0.05﹚。②孵育24 h后，10 μg/mL ox-LDL组和20 μg/mL ox-LDL组MerTK蛋白表达灰度值分别较对照组下降（20.0±16.5）%和（47.0±15.4）%，20 μg/mL ox-LDL组显著小于对照组(P＜0.05)。③孵育12 h后，10 μg/mL ox-LDL组和20 μg/mL ox-LDL组MerTK mRNA相对表达量分别较对照组减少（33.0±17.5）%和（60.0±10.0）%，10 μg/mL ox-LDL组和20 μg/mL ox-LDL组均显著小于对照组（P均<0.05）。结论 ox-LDL可抑制巨噬细胞对凋亡细胞的吞噬功能，其机制与抑制促吞噬受体MerTK的表达有关，这也可能是ox-LDL致动脉粥样硬化斑块不稳定和进展的机制之一。

关键词: 氧化型低密度脂蛋白, 清除凋亡细胞作用, 巨噬细胞, MerTK受体

Abstract:

Objective To investigate the effect and mechanism of macrophage phagocytosis of apoptotic cells (efferocytosis) treated by oxidized low-density lipoprotein (ox-LDL). Methods RAW264.7 murine macrophages were randomly divided into control group (treated by serum-free DMEM culture medium), 10 μg/mL ox-LDL group (treated by 10 μg/mL ox-LDL serum-free DMEM culture medium) and 20 μg/mL ox-LDL group (treated by 20 μg/mL ox-LDL serum-free DMEM culture medium). RAW264.7 murine macrophage apoptosis was induced by ultraviolet radiation, phagocytic index of RAW264.7 macrophages of apoptotic cells was determined by flow cytometry, and Western blotting and Real-Time PCR were employed to detect the expression of receptor MerTK protein and mRNA respectively. Results ①Twenty-four hours after treatment, the phagocytic indexes in 10 μg/mL ox-LDL group and 20 μg/mL ox-LDL group decreased by (4.7±2.8)% and (12.6±2.2)% respectively of that in control group, and the phagocytic index of 20 μg/mL ox-LDL group was significantly lower than that in control group and 10 μg/mL ox-LDL group （P<0.05). ②Twenty-four hours after treatment, the relative expression of MerTK protein in 10 μg/mL ox-LDL group and 20 μg/mL ox-LDL group decreased by (20.0±16.5)% and (47.0±15.4)% respectively of that in control group, and the relative expression of MerTK protein in 20 μg/mL ox-LDL group was significantly lower than that in control group （P<0.05). ③Twelve hours after treatment, the relative expression of MerTK mRNA in 10 μg/mL ox-LDL group and 20 μg/mL ox-LDL group decreased by (33.0±17.5)% and (60.0±10.0)% respectively of that in control group, and the relative expression of MerTK mRNA in 10 μg/mL ox-LDL group and 20 μg/mL ox-LDL group was significantly lower than that in control group （P<0.05). Conclusion ox-LDL can reduce the macrophage phagocytosis of apoptotic cells, and the mechanism may be related to inhibiting the expression of receptor MerTK, which may also be one of the causes for the instability and progression of ox-LDL-induced atherosclerotic plaque.

Key words: oxidized low-density lipoprotein, effrocytosis, macrophage, MerTK receptor