清道夫受体AⅠ/Ⅱ对小鼠脂质代谢的影响

目的:鉴定清道夫受体AⅠ/Ⅱ(SR-AⅠ/Ⅱ)基因敲除小鼠, 观察SR-AⅠ/Ⅱ基因敲除对小鼠脂质代谢的影响。方法:应用SR-AⅠ/ⅡcDNA基因部分序列作探针, 用Southernblot方法检测SR-AⅠ/Ⅱ基因敲除小鼠及其同系对照小鼠靶基因敲除结果, 用生化分析仪检测血脂、载脂蛋白和血肌酐, 观察SR-AⅠ/Ⅱ基因敲除和未敲除小鼠分别在普通饮食和高脂饮食情况下脂质代谢的改变情况。结果:SR-AⅠ/Ⅱ基因敲除后小鼠的低密度脂蛋白(LDL)、体重较正常对照小鼠明显增高(P<005), 出现了脂质代谢严重失衡, 在高脂饮食情况下这种失衡更为明显, 体重、LDL的升高幅度均大于对照组(P<0.01).结论:SR-AⅠ/Ⅱ参与对组织和循环中的LDL的摄取和清除, 有利于保持机体脂质代谢的正常调节。小鼠SR-AⅠ/Ⅱ基因敲除后脂质代谢发生了明显紊乱, 机体对脂质代谢的调节功能减弱。

The impact of scavenger receptor class A type Ⅰ/Ⅱ on lipid metabolism in mice

AIM: To investigate the impact of scavenger receptor class A type Ⅰ/Ⅱ(SR-A Ⅰ/Ⅱ) on the lipid metabolism in SR-A Ⅰ/Ⅱ gene deficient mice. METHODS: A probe of 660 bp fragment of SR-A Ⅰ/Ⅱ cDNA digested with PstⅠ and XhoⅠ from plasmid 122 was used to identify whether SR-A Ⅰ/Ⅱ had been knocked out in the tail DNA of the mutant(SR-/-) and control(SR+/+) mice by the method of Southern-blot analysis. The serum levels of triglycerides(TG), cholesterol(CH), low density lipoprotein(LDL), high density lipoprotein(HDL), apolipoprotein(Apo) A and ApoB of the mice fed with normal food and higher lipid food respectively were tested by biochemical method. RESULTS: The serum levels of LDL and body weights of group with SR-A Ⅰ/Ⅱ gene knocked out were higher than that of control group(P<0.05). Although the disorders of serum levels of LDL and body weights deteriorated after high lipid diet in both groups, the disorders in group of SR-/- were worse than those in control group(P<0.01). CONCLUSION: The results demonstrated that SR-A Ⅰ/Ⅱ were involved in the regulation of lipid metabolism, and SR-A Ⅰ/Ⅱ deficiency is harmful for removing LDL from blood circulation.