扇贝糖胺聚糖对巨噬细胞低密度脂蛋白受体表达的影响

 目的探讨扇贝糖胺聚糖(SS-GAG)的抗动脉粥样硬化作用机制。方法以体外培养的小鼠单核巨噬细胞RAW264.7为模型,与不同浓度的SS-GAG、肝素孵育12h后,加入氧化低密度脂蛋白(OX-LDL)作用24h,采用免疫组化和逆转录聚合链反应(RT-PCR)分别检测低密度脂蛋白受体(LDL-R)蛋白和mRNA表达的情况。结果OX-LDL与单核巨噬细胞RAW264.7作用24h后能降低LDL-R的蛋白和mRNA表达,SS-GAG对OX-LDL引起的LDL-R表达降低有保护作用,以200mg.L^-1组作用最为明显。结论OX-LDL可降低巨噬细胞LDL-R的表达,而SS-GAG可逆转OX-LDL的作用,这可能是其抗动脉粥样硬化的作用机制之一。

Effects of Glycosaminoglycan of Scallop Skirt on Expression of LDL Receptor in Macrophage

OBJECTIVE To investigate the antiartherosclerosis mechanism of scallop skirt glycosaminoglycan(SS-GAG).METHODS The cell model was established by culturing mouse macrophage RAW264.7 in vitro. The cell was incubated with different concentration of SS-GAG or heparin for 12 h,then OX-LDL was added into culture plate .After OX-LDL took action for 24 h, the experiment was terminated. The expressions of LDL-R protein and mRNA were determined by immunohistochemistry or RT-PCR,respectively.RESULTS The expression of LDL-R protein and mRNA in mouse macrophage RAW264.7 was decreased after being incubated with OX-LDL for 24 h.SS-GAG elevated the expressions of LDL-R protein and mRNA which were decreased by OX-LDL. The action was showed strongliest in SS-GAG 200 mg·L^-1 group.CONCLUSION OX-LDL can down regulate the expression of LDL-R protein and mRNA in macrophage. SS-GAG can reverse this action of OX-LDL. This may be one of its mechanism of antiartherosclerosis action.