载脂蛋白AI在骨骼肌系统的表达

Gene Expression of Apolipoprotein AI in Skeletal Muscle

载脂蛋白 Ａ Ｉ在胆固醇逆转运过程中起关键作用，已成为防治动脉粥样硬化的重要首选基因之一。为探讨借用骨骼肌异源表达进而发展一种简易安全的基因治疗方法，将人载脂蛋白 Ａ Ｉ基因构建成腺病毒载体（ Ａｄ － Ｒ Ｓ Ｖ－ 载脂蛋白 Ａ Ｉ） ，导入小鼠骨骼肌。体外细胞实验发现，载脂蛋白 Ａ Ｉ可以在肌源性细胞中表达并分泌至培养基中，表达量与病毒滴度及转染时间相关。在体动物实验中，将 Ａｄ － Ｒ Ｓ Ｖ－ 载脂蛋白 Ａ Ｉ直接注入小鼠骨骼肌５ 日后，肌肉和血清中载脂蛋白 Ａ Ｉ的表达达到高峰，前者每条为９ ．７５ ±０ ．２５ ｎｇ，后者为７ ．２５ ±０ ．７５ μｇ／ Ｌ。以后随时间延长逐渐减少，第３０ 日血清中载脂蛋白 Ａ Ｉ消失，第４０ 日仍可在肌肉中检测到一定量的载脂蛋白 Ａ Ｉ表达。此结果提示，利用骨骼肌细胞的异位表达可提高体内载脂蛋白 Ａ Ｉ的水平，为动脉粥样硬化的基因治疗提供新的途径。

Aim Plasma apolipoprotein AI (apo AI) play an important role in reverse cholesterol transport and have becoming attractive target for prevention or treatment of atherosclerosis. The present study was undertaken to search for the possibility of human apo AI gene expression and secretion to blood by transferred Ad-RSV-apo AI into mouse skeletal muscles and developing mathod of atherosclerotic gene therapy. Methods An E1-/E3- adenoviral vector, with an RSV-driven human apo AI cDNA expression vector (Ad-RSV-apo AI) was constracted. Transfected myogenic cells in vitro or directly injected into mouse skeletal muscle with the vector. The result was examined by ELISA and immuncytochemistry. Results In the primary cultured myoblasts, the expression level of apo AI in the culture medium increased with the increassing MOI of Ad-RSV-apo AI (from 10 5 pfu to 10 8 pfu). The expression of apo AI was also increased with time. It peaked on the 6th day .After direct injection of Ad-RSV-apo AI into muscle, apo AI mass could be detected, which peaked on day 5 both in the muscle and plasma. On day 30, apo AI was disappeared in the plasma, but the expression in the muscle existed till day 40. Conclusions Apo AI gene can be expressed in the skeletal muscle and secreted to the circulation. It might be an approach for the atherosclerotic gene therapy.