脂蛋白脂酶缺失症基因治疗载体的构建及功能验证

Construction and Verification of Gene Therapy Vector for Lipoprotein Lipase Deficiency Disease

脂蛋白脂酶(lipoprotein lipase,LPL)是甘油三酯分解的限速酶,LPL基因缺失会引起高血脂症,虽然发病率低,但到目前为止,尚无有效治疗手段。该文构建了用于纠正LPL缺失基因型的逆转录病毒载体MSCV-hLPL,结果表明,MSCV-hLPL可以高效侵染体外培养的细胞系C2C12、HEK293和3T3-L1,并且都可以产生具有活性的脂蛋白脂酶。利用MSCV-hLPL侵染后的C2C12、HEK293和3T3-L1,分别注射到裸鼠皮下组织,发现C2C12和3T3-L1可以分泌脂蛋白脂酶到临近的肌肉组织中,显著提高LPL活性。以上工作证明,基因治疗载体可以纠正脂蛋白脂酶缺失的基因型,而脂肪细胞和肌肉细胞移植入裸鼠体内后,均可以作为生物反应器产生具有活性的LPL。这是该领域中的一次开拓性尝试,为脂蛋白脂酶缺失症治疗方法的开发打下了坚实的基础。

Lipoprotein lipase （LPL） is the rate limiting enzyme for triglycerides hydrolysis, which catalyses the hydrolysis of the triacylglycerol component of chylomicrons and very low density lipoproteins, thereby providing fatty acids and monoacylglycerol for tissue utilization. LPL gene mutation or deletion may affect the activity of LPL, and result in lipid metabolism disorder. Although the LPL deficiency disease is rare, no cure method is developed till now. In this study, the gene therapy construct MSCV-hLPL was made, which could infect muscle cell line （C2C12）, kidney cell line （HEK293T） and pre-adipocyte cell line （3T3-L1） with over 80% efficiency. Nevertheless, active LPL could be detected at the surface of all these three kinds of cells. Then, three types of cells were injected into nude mice, LPL activity increased significantly in the muscle tissues under the injection sites of the 3T3-L1 line. Our results show that MSCV-hLPL could correct the LPL-/- genotype and the adipose tissue may be the best tissue for transplantation in the future. This is a ground-breaking test in LPL deficiency treatment field, which lays a good foundation for using iPSC to correct the LPL deficiency.