A single intravenous injection of the gene therapy rAAV9-coGAA can increase the activity of the acid α-glucosidase (GAA) enzyme, decrease the accumulation of glycogen, and improve pathology in a mouse model of Pompe disease.
This is according to a new study by Chinese researchers published in the journal China Biotechnology. The researchers also showed that the therapeutic effect of rAAV9-coGAA was dose-dependent and still present even in aged mice.
“This study laid a theoretical foundation for the clinical application of AAV9 mediated gene therapy via intravenous route in Pompe disease,” the researchers wrote.
There is currently no cure for Pompe disease but researchers are working on gene therapy approaches aimed at increasing the production of the GAA enzyme by providing the body with the gene coding for the enzyme using adeno-associated viruses (AAV).
Read more about gene therapy for Pompe disease.
In the present study, a team of researchers from Beijing University of Technology and Beijing GeneCradle Pharmaceutical used an AAV9 vector to transfer the GAA gene to a mouse model of Pompe disease by intravenous injection and assessed the effect of this on GAA enzyme activity and glycogen accumulation. They also assessed the effect of the transfer on disease pathology.
The results showed that 5 weeks after the administration of the viral vector carrying the codon-optimized GAA gene, the GAA protein was found in all the tissues of the animals. The heart and the liver showed the highest expression and the brain and spinal cord showed the lowest.
The treatment also led to a decrease in glycogen content and vacuolar degeneration in the heart and skeletal muscles. The glycogen content in the brain also decreased.
Some of these effects were also observed in aged animals, however, pathological improvements were limited.
Pompe disease is a lysosomal glycogen storage disease caused by the deficiency of the GAA enzyme due to mutations in the gene coding for the enzyme.
Wu ZJ, Ma WH, Dong ZY, Wu XB, Yang YS, Sheng W. AAV vector mediated gene therapy in Pompe model mice. China Biotechnology. 2022;42(7):24-34. doi:10.13523/j.cb.2202040