Effect of oxLDL on the uptake and clearance rate of cholesterol in v-SMC originated from human apoA1 transgenic mice

oxLDL对转人apoA1基因小鼠动脉平滑肌细胞胆固醇摄取和清除的影响(英文)

To study the inhibition effect of oxLDL on the uptake and clearance of intra ce llular 3H cholesterol in v SMC from the human apoA1 transgenic m ice (C57BL/6) and the changes in human apoA1 mRNA expression in v SMC from hum an apoA1 transgenic mice after oxLDL stimulation Methods v SMC originally isolated from human apoA1 transgenic mice connected with a rec ombined mouse metallothionein Ⅰ (MT Ⅰ) promoter was used, and the effect of oxLDL on the uptake and clearance of intracellular 3H cholesterol was s tudied in v SMC of the transgenic and control mice respectively, the study of h apoAⅠ mRNA expression from v SMC of the transgenic mice were done by RT PCR and Northern blot Results oxLDL (30?μg/ml) strongly promoted the SMC proliferation No difference was f ound in 3H cholesterol uptake between nSMC and trSMC, and the uptak e rates of both kinds of SMC rose 100% after oxLDL stimulation The efflux rate s of 3H cholesterol in trSMC were much higher than those of nSMC (40% -50%) Afte r ox LDL stimulation, the clearance rates fell by 28% and 10%, respectively, for nSMC and trSMC The result of RT PCR and Northern blot showed that h apoA1 gene e xpression was markedly increased by the stimulation of oxLDL Conclusion Expression of the h apoA1 gene in C57BL/6 mice enables them to reduce the accum ulation of cholesterol in v SMC The trSMC can alleviate the harmful effect of oxLDL due to the increase of h apoA1 expression

目的 探讨①oxLDL对转人apoA1C5 7BL/ 6小鼠主动脉SMC(trSMC)胆固醇清除与摄取的影响 ,以衡量转入的apoA1基因是否有助于减轻oxLDL引起的SMC胆固醇积聚 ;②oxLDL刺激下 ,转入的apoAI基因的表达状况 ,以探知在致病的环境下 ,所转入的基因是否能增加表达 ,提高抗病能力。方法 ①用已建立的含小鼠金属硫蛋白Ⅰ (MT Ⅰ )启动子的人apoAI转基因C5 7BL/ 6小鼠主动脉SMC ,通过3H -胆固醇标记率和清除率测定 ,观察oxLDL对trSMC胆固醇摄取与清除的影响。②通过RT PCR及Northernblot技术检测oxLDL对trSMC基因表达的影响。结果 30 μg/mloxLDL明显促进小鼠SMC增生 ;未见trSMC与nSMC在标记率间的差别 ,oxLDL刺激后标记率增加约 10 0 % ;trSMC清除率与nSMC相比 ,增加 4 0 % - 5 0 % ;oxLDL刺激后 ,nSMC清除率下降 2 8% ,而trSMC下降10 % ;RT PCR及Northernblot表明oxLDL刺激后trSMC基因表达明显增加。结论 转人apoA1基因小鼠SMC的基因表达有助于减轻oxLDL引起的SMC胆固醇积聚 ;在oxLDL刺激下 ,trSMC的人apoA1基因表达增加 ,减轻了oxLDL的致病作用。