Silencing of B4Galnt1 Gene Prevents GM2 Accumulation in Tay-Sachs Cells

Abstract

Introduction. The Tay-Sachs disease (TSD) is a progressive neurodegenerative disorder resulting from genetic mutations in the HEXA gene encoding the α-subunit of β-hexosaminidase A leading to the accumulation of GM2 ganglioside in the central nervous system. Multiple therapeutical strategies have been investigated such as gene therapy for Tay-Sachs patients; however, there is still no cure. In the present study, we suggest a new approach for the treatment of the Tay-Sachs disease with the concept of substrate reduction therapy by using AAV9-mediated RNAi technology targeting the B4Galnt1 gene at the upstream of the enzymatic defect in TSD pathology to decrease GM2 biosynthesis and accumulation in cell models of TSD. Material and Methods. We employed AAV9-mediated shRNA transduction for mice and human Tay-Sachs cells. After transduction, expression levels of ganglioside metabolism genes were analyzed by RT-PCR and GM2 and lysosome-associated membrane protein 1 (LAMP1) protein levels were evaluated by immunocytochemistry analysis. Results. Here, we have shown that AAV9-shRNA transduction effectively reduced B4Galnt1 expression in TSD cells demonstrating a reduction in GM2 accumulation and LAMP1. Discussion. Our data shows that AAV-mediated B4Galnt1-shRNA transduction can ameliorate disease pathologies by decreasing the lysosomal accumulation of GM2 through selectively reducing B4Gant1 activity in cell models of the Tay-Sachs disease. Therefore, we suggest promising novel experimental therapy for this devastating disease using a mouse model in the future.