中国组织工程研究 ›› 2016, Vol. 20 ›› Issue (7): 1000-1005.doi: 10.3969/j.issn.2095-4344.2016.07.012

• 组织构建细胞学实验 cytology experiments in tissue construction • 上一篇    下一篇

细胞胆固醇外流率的测定以及细胞外胆固醇和脂多糖对其的抑制作用

刘 杰,郑云梅,田志辉,常光明,李海东   

  1. 天津医科大学基础医学院生物化学与分子生物学系,天津市 300070
  • 收稿日期:2015-11-29 出版日期:2016-02-12 发布日期:2016-02-12
  • 作者简介:刘杰,女,1990年生,黑龙江省哈尔滨市人,汉族,天津医科大学在读硕士,主要从事分子免疫学研究。

Inhibitory effects of extracellular cholesterol and lipopolysaccharide on cellular cholesterol efflus

Liu Jie, Zheng Yun-mei, Tian Zhi-hui, Chang Guang-ming, Li Hai-dong   

  1. Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tianjin Medical University, Tianjin 300070, China
  • Received:2015-11-29 Online:2016-02-12 Published:2016-02-12
  • About author:Liu Jie, Studying for master’s degree, Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tianjin Medical University, Tianjin 300070, China

摘要:

文章快速阅读:

文题释义:

脂多糖的结构特征:脂多糖是脂质和多糖的复合物;为革兰阴性细菌外璧层中特有的一种化学成分,相对分子质量大于10 000,结构复杂,在不同类群、甚至菌株之间都有差异。以沙门氏菌为例,其脂多糖由核心多糖、O-多糖侧链、和类脂A组成。为革兰阴性细菌细胞壁的主要成分,脂多糖是内毒素和重要群特异性抗原(O抗原)。

脂多糖:由3部分组成,与磷脂相似,有一亲水头和一疏水尾。脂质A(Lipid A)为构成内毒素活性的糖脂,以共价键联结到杂多糖链,有两部分:一是核心多糖,在有关的株内是恒定的;另一O特异性链(O-specific chain)是高度可变的。大肠杆菌的脂多糖在实验室免疫学中是常用的B细胞促分裂因子即多克隆活化因子(polyclonal activator)。

  

背景:胆固醇与动脉粥样硬化等疾病的发生、发展密切相关。目前研究细胞胆固醇动态变化的方法有局限性。
目的:通过BODIPY-Cholesterol标记RAW 264.7小鼠巨噬细胞,检测细胞胆固醇的外流率,并研究细胞外胆固醇浓度和脂多糖对其的影响。
方法:RAW264.7细胞采用含有体积分数10%FBS的DMEM培养基体外培养,再用0.025 mmol/L的BODIPY-Cholesterol标记细胞1,2,4,8 h,以无血清DMEM洗涤细胞后,再孵育细胞6,12,24,48,96 h,优化标记细胞的时间及孵育时间。分别采用胆固醇、脂多糖、异常高胆固醇人血清和正常胆固醇人血清处理细胞,再对其胆固醇外流率进行测定和比较。
结果与结论:BODIPY-Cholesterol标记细胞2-8 h后,测定胆固醇外流率的结果较好。RAW 264.7小鼠巨噬细胞经过BODIPY-Cholesterol荧光染料标记2 h后,测定胆固醇外流率,发现其随外加胆固醇浓度(0.1,0.5,2.5 mmol/L)的增大呈递减趋势(P < 0.01)。脂多糖刺激后细胞的胆固醇外流率降低(P < 0.05)。采用高胆固醇人血清处理细胞后,胆固醇的外流率降低(P < 0.05)。结果说明,利用BODIPY-Cholesterol可以定量测定细胞胆固醇外流率,并能研究环境中胆固醇和脂多糖对其的影响。

ORCID: 0000-0002-5583-6257(刘杰)

关键词: 组织构建, 组织工程, 胆固醇外流率, RAW 264.7, BODIPY-Cholesterol, 脂多糖

Abstract:

BACKGROUND: Cholesterol is closely linked to the occurrence and progression of atherosclerosis. Current approaches to study cellular cholesterol dynamics have their own limitations.
OBJECTIVE: To measure the cholesterol efflux rate of RAW 264.7 mouse macrophages by BODIPY-Cholesterol labeling and to explore the effects of extracellular cholesterol and lipopolysaccharide on the cholesterol efflux rate.
METHODS: RAW 264.7 cells were cultured in vitro with DMEM containing 10% fetal bovine serum, and labeled with BODIPY-Cholesterol for 1, 2, 4, 8 hours. Then, the cells were rinsed with serum-free DMEM and inoculated for 6, 12, 24, 48, 96 hours to optimize the labeling time and incubation time. We measured and compared the cholesterol efflux rates after cultured cells were treated with cholesterol, lipopolysaccharide, human sera with high cholesterol or human sera with normal cholesterol.
RESULTS AND CONCLUSION: The best labeling time for BODIPY-Cholesterol was 2-8 hours. Cholesterol efflux rates were gradually decreased after the cells that were labeled for 2 hours were incubated with increasing concentrations of cholesterol (0.1, 0.5, 2.5 mmol/L, P < 0.01). Treating cells with lipopolysaccharide also decreased the cholesterol efflux rate (P < 0.05). Furthermore, the cholesterol efflux rate was decreased after cells were treated with human sera with high cholesterol (P < 0.05). These findings indicate that BODIPY-Cholesterol can be used to measure cellular cholesterol efflux rate and to study the effects of extracellular cholesterol and lipopolysaccharide on the cholesterol efflux rate.