肥大细胞改变THP-1巨噬细胞源性泡沫细胞胆固醇含量及抑制胆固醇流出  

Mast cells change cellular cholesterol content and inhibit cholesterol efflux from THP-1 macrophage-derived foam cells

作　　者：赵战芝[1] 杨永宗[1] 王佐[1] 危当恒[1] 

机构地区：[1]南华大学心血管病研究所,机能学实验中心湖南衡阳421001

出　　处：《中国病理生理杂志》2007年第8期1457-1463,共7页Chinese Journal of Pathophysiology

基　　金：国家973项目子课题资助项目(No.G2000056905)

摘　　要：目的:以THP-1巨噬细胞源性泡沫细胞为研究对象,探讨肥大细胞(MC)对THP-1巨噬细胞源性泡沫细胞内胆固醇含量、分配和流出的影响及机制。方法:THP-1巨噬细胞源性泡沫细胞在MC颗粒释放物存在或缺乏下与高密度脂蛋白3(HDL3)共育。高效液相色谱检测泡沫细胞内总胆固醇(TC)、游离胆固醇(FC)和酯化胆固醇(EC)含量,用液体闪烁计数器检测细胞内胆固醇流出,运用逆转录聚合酶链反应检测三磷酸腺苷结合盒转运体A1(ABCA1)的mRNA水平,采用琼脂糖凝胶电泳和聚丙烯酰胺凝胶电泳检测HDL3及apoA-Ⅰ的降解。结果:MC组泡沫细胞内TC、FC明显高于对照组(TC对照组为527.3 mg/g,MC组为917.9 mg/g);EC/TC比值低于对照组(7.6%vs47.5%);细胞内胆固醇流出少于对照组(26.92%±2.6%vs40.98%±3.4%,P<0.05);而泡沫细胞ABCA1的mRNA水平与对照组无明显差异。MC颗粒释放物处理HDL3后,聚丙烯酰胺凝胶电泳结果显示,约有28%的apoA-Ⅰ被降解,在分子量26 kD左右处出现了新的条带,产生了1个26 kD的小多肽。结论:肥大细胞可通过降解HDL3及apoA-Ⅰ抑制细胞内胆固醇流出而增加细胞内胆固醇蓄积,这个作用与ABCA1表达无直接关系。AIM： Mast ceils （MC） are present in the arterial intima, the site of atherogenesis. The present studies explore the effect of MC on cholesterol content, distribution and efflux in THP - 1 macrophage - derived foam cells （THP- 1FCs）. METHODS： THP- 1FCs were incubated with high- density lipoproteins 3 （HDL3 ） in the absence or presence of mast cell granules （MCGs） harvested from compound 48/80 - stimulated rat peritoneal MC. The intracellular cholesterol level, cholesterol ettluxing capacity, ATP - binding cassette transporter A1 （ ABCA1 ） mRNA and HDL3 treated with MCGs were detected to characterize the role of MC on intracellular cholesterol. RESULTS： MCGs had high levels of cellular total cholesterol （TC） , free cholesterol（FC） but not esterifed cholesterol（ EC ） compared to control group where the TC concentrations ranged from 527. 3 mg/g to 917. 9 mg/g cellular protein with EC accounting for 7. 6% of the cholesterol. Cholesterol efflux was 14% less in MCGs group compared to control group. ABCA1 mRNA expression in MCG - treated THP - 1 FCs remained unchanged in 20 hours. In contrast, treatment of HDL3 with MCGs resulted in rapid degradation of the main HDL3 apoliproteins, apoA -Ⅰ . SDS - PAGE revealed that a minor polypeptide band with about 26 kD molecular mass appeared below the apoA -Ⅰ band. Densitometric analysis of the gel demonstrated that ≈ 28% of apoA -Ⅰ had been degraded by the MCGs. CONCLUSION： These results indicate that MC decreases cholesterol efflux, increases cellular accumulation in TC and FC by depleting HDL3 and apoA -Ⅰ , but not by inhibiting ABCA1 mRNA expression.

关 键 词：肥大细胞 THP-1巨噬细胞源性泡沫细胞 胆固醇 脂蛋白类 HDL ATP结合匣式转运体 

分 类 号：R363[医药卫生—病理学]