[胃饥饿素通过生长激素促分泌素受体依赖性途径下调THP-1来源的泡沫细胞中的ACAT-1]

[Ghrelin down-regulates ACAT-1 in THP-1 derived foam cells via growth hormone secretagogue receptor-dependent pathway].

作者信息

Wan Jing-Jing, Cheng Bei, Wang Yan-Fu, Mei Chun-Li, Liu Wei, Ke Li, He Ping

机构信息

Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.

出版信息

Zhonghua Xin Xue Guan Bing Za Zhi. 2009 Nov;37(11):1030-4.

PMID:20137333

Abstract

OBJECTIVE

To investigate the effects of Ghrelin on the expression of acyl coenzyme A:cholesterol acyltransferases-1 (ACAT-1) in THP-1 derived foam cells.

METHODS

The human monocytic leukemia cell line (THP-1) was chosen in our study. The differentiation of THP-1 cells into macrophages was induced by phorbol 12-myristate 13-acetate. Macrophages were then incubated with oxidized LDL (ox-LDL) to generate foam cells. Ghrelin and [D-Lys3]-GHRP-6, the special antagonist of growth hormone secretagogue receptor (GHS-R), were treated during foam cells formation. The ACAT-1 protein and mRNA levels were detected by Western blot and RT-PCR. The effect of variance of cholesterol content was measured by zymochemistry via-fluorospectrophotometer.

RESULTS

Ghrelin reduced the content of cholesterol ester in foam cells obviously. ACAT-1 protein and mRNA levels were also decreased. The antagonist of GHS-R inhibited the effects of Ghrelin on ACAT-1 expression in dose-dependent manner. The ACAT-1 mRNA levels of the GHS-R specific antagonist groups (10(-5), 5 x 10(-5), 10(-4) mol/L) were 1.14 +/- 0.04, 1.58 +/- 0.03, 2.40 +/- 0.16, significantly higher than that of the Ghrelin group (0.89 +/- 0.05). And the protein expressions were 1.25 +/- 0.09, 1.77 +/- 0.11, 2.30 +/- 0.09, also higher than that of the Ghrelin group (0.86 +/- 0.08).

CONCLUSIONS

Ghrelin might interfere atherosclerosis by down-regulating the expression of ACAT-1 via GHS-R pathway.

摘要

目的

探讨胃饥饿素（Ghrelin）对人单核细胞白血病细胞系（THP-1）源性泡沫细胞中酰基辅酶A：胆固醇酰基转移酶-1（ACAT-1）表达的影响。

方法

本研究选用人单核细胞白血病细胞系（THP-1）。用佛波酯诱导THP-1细胞分化为巨噬细胞。然后将巨噬细胞与氧化型低密度脂蛋白（ox-LDL）共同孵育以生成泡沫细胞。在泡沫细胞形成过程中加入胃饥饿素及生长激素促分泌素受体（GHS-R）特异性拮抗剂[D-Lys3]-GHRP-6。采用蛋白质免疫印迹法（Western blot）和逆转录-聚合酶链反应（RT-PCR）检测ACAT-1蛋白和mRNA水平。通过酶化学荧光分光光度计检测胆固醇含量变化的影响。

结果

胃饥饿素明显降低了泡沫细胞中胆固醇酯的含量。ACAT-1蛋白和mRNA水平也降低。GHS-R拮抗剂以剂量依赖方式抑制胃饥饿素对ACAT-1表达的影响。GHS-R特异性拮抗剂组（10⁻⁵、5×10⁻⁵、10⁻⁴mol/L）的ACAT-1 mRNA水平分别为1.14±0.04、1.58±0.03、2.40±0.16，显著高于胃饥饿素组（0.89±0.05）。其蛋白表达分别为1.25±0.09、1.77±0.11、2.30±0.09，也高于胃饥饿素组（0.86±0.08）。