脂蛋白脂肪酶基因敲除小鼠脂代谢动态观察

Lipid metabolism in lipoprotein lipase gene knockout heterozygous mice

目的通过脂蛋白脂肪酶(LPL)基因敲除杂合子LPL(+/-)小鼠模型脂质代谢的动态观察,进一步明确LPL在脂代谢中的关键作用。方法野生型16周龄C57小鼠6只(对照组)、16周龄LPL(+/-)小鼠6只[LPL(+/-)16周龄组]、28周龄LPL(+/-)小鼠6只[LPL(+/-)28周龄组],螺旋CT测量小鼠内脏脂肪和皮下脂肪的含量,内眦静脉采血分离血清检测血清甘油三酯(TG)和游离脂肪酸(FFA)水平,然后处死小鼠,检测3组小鼠内脏脂肪和腹部及股部皮下脂肪的质量,并制备肝脏、四肢骨骼肌、腹部及股部皮下脂肪、内脏脂肪、胰腺组织匀浆,检测肝脏、骨骼肌、内脏脂肪、皮下脂肪和胰腺的TG和FFA水平。结果LPL(+/-)16周龄组小鼠血清、肝脏、骨骼肌、内脏脂肪、胰腺中的TG、FFA水平及皮下脂肪FFA水平较对照组均呈不同水平的增加,但差异无统计学意义(P>0.05),皮下脂肪TG的增加有统计学意义(P<0.05)。LPL(+/-)28周龄组小鼠血清、肝脏、骨骼肌、内脏脂肪、胰腺及皮下脂肪中的TG、FFA水平较LPL(+/-)16周龄组增加,但仅肝脏和内脏脂肪TG水平与LPL(+/-)16周龄组之间有统计学意义(P<0.05)。LPL(+/-)28周龄组的血清、肝脏、皮下脂肪、内脏脂肪TG及骨骼肌、皮下脂肪、胰腺FFA水平较对照组增高,差别有统计学意义(P<0.05)。LPL(+/-)16周龄组的内脏脂肪质量高于对照组,差别具有统计学意义(P<0.05);LPL(+/-)28周龄组小鼠内脏脂肪和皮下脂肪的质量和含量均高于对照组和LPL(+/-)16周龄组,差别均具有统计学意义(P<0.05)。结论LPL是脂代谢的关键酶,LPL(+/-)小鼠血清及组织脂质变化显著。

Objective To identify the role of lipoprotein lipase（LPL） in lipid metabolism through the dynamic observation of lipid levels in lipoprotein lipase gene knockout heterozygous mice（LPL＋/-mice）.Methods Six wild type C57 mice（16 weeks）（control group）,Six LPL gene knockout heterozygous mice（16 weeks）[LPL（＋/-）16 weeks group]and Six LPL（＋/-） mice（28 weeks）[LPL（＋/-）28 weeks group]were chosed.The contents of visceral fat and subcutaneous fat were measured by CT.The levels of triglyceride（TG） and free fatty acids（FFA） in serum obtained from angular vein were detected.All mice were killed,the weight of subcutaneous adipose tissue and visceral adipose tissue were detected.Then tissue homogenate of liver,skeletal muscle,subcutaneous adipose tissue from abdomen and thigh were prepared to detect the levels of TG and FFA in liver,skeletal muscle,subcutaneous adipose tissue,visceral adipose tissue and pancreas.Results The levels of TG and FFA in serum,liver,skeletal muscle,visceral adipose tissue and pancreas and the levels of FFA in subcutaneous adipose tissue in LPL（＋/-）16 weeks group were higher than control group,but these changes had no statistical significance（P〉0.05）.The levels of TG and FFA in serum,liver,skeletal muscle,visceral adipose tissue,pancreas and subcutaneous adipose tissue in LPL（＋/-）28 weeks group were higher than LPL（＋/-）16 weeks group,but only the changes of the levels of TG in liver and visceral adipose tissue were significantly（P〈0.05）.The levels of TG in serum,liver,subcutaneous adipose tissue,visceral adipose tissue and the levels of FFA in skeletal muscle,subcutaneous adipose tissue and pancreas in LPL（＋/-）28 weeks group were significantly higher than control group（P〈0.05）.The weight of visceral adipose tissue in LPL（＋/-）16 weeks group was significantly higher than control group（P〈0.05）.The weight and contents of subcutaneous adipose tissue and visceral adipose tissue in LPL（＋/-）28 weeks group were significantly higher than LPL（＋/-）16 weeks group and control group（P〈0.05）.Conclusion LPL is a key enzyme in lipid metabolism and LPL gene knockout can influence the levels of lipid in serum and tissue.