动物实验,CRISPR/Cas9 z-bo 2020-08-27 563

　　CRISPR/Cas9 is a powerful genetic magic scissors with great potential to effectively correct disease-causing mutations. Through research, researchers have developed a dual-gene therapy for the first time. It can transfer the main components of the CRISPR/Cas9-mediated gene targeting system into mice to treat hemophilia B (hemophilia B). Factor IX deficiency, which is usually caused by a deficiency or defect in the clotting protein. In many single-gene diseases, such as hemophilia, researchers often need to develop usable vectors because different mutations rather than a single dominant mutation are usually scattered in specific genes. Have. For patients with mutations, this study is a proof-of-concept study. Researchers use the universal CRISPR/Cas9 gene targeting method to treat most patients with special diseases such as hemophilia B. According to the US Centers for Disease Control and Prevention (CDC), the incidence of hemophilia at birth is one in 5,000, and there are currently approximately 20,000 hemophilias in the United States.

　　James MWilson pointed out that he can basically cure mice. In order to confirm this new method, the researchers conducted experiments in a mouse model lacking clotting factor IX. It can express the SaCas9 gene driven by a liver-specific promoter, so gene editing tools can be installed in the liver. The liver is where blood coagulation factor IX is produced. The second vector is different from previous CRISPR-based gene therapies. It contains an RNA sequence that specifically targets the 5'end region of exon 2 of the IX gene and the IX cDNA sequence, which greatly improves the potential and accuracy of this method. The researchers used vectors related to adenovirus to deliver these components to mouse liver cells. This strategy is based on CRISPR-mediated homologous recombination, which can insert human cDNA into the IX site of the mouse genome. Wang researchers pointed out that targeted insertion can induce the expression of chimeric active Factor IX protein under the control of the natural mouse factor IX promoter. The results showed that increased doses of the two vectors injected into newborn and adult knockout mice resulted in sustained expression of stabilizing factor activity for more than 4 months. After 8 weeks of vector therapy, a subgroup of newborn and adult knockout mice underwent partial hepatectomy and continued to express the same level of factor IX, but survived without complications.

　　Finally, researcher Wang pointed out that the work in this article shows that the use of CRISPR/Cas9 technology can effectively treat mouse models of hemophilia B. Of course, this method is expected to be clinically tested in humans.