Human iPSC-derived neural stem cells with ALDH5A1 mutation as a model of succinic semialdehyde dehydrogenase deficiency

Abstract

Background Succinic semialdehyde dehydrogenase deficiency (SSADH-D) is an autosomal recessive gamma-aminobutyric acid (GABA) metabolism disorder that can arise due to ALDH5A1 mutations, resulting in severe, progressive, untreatable neurodegeneration. SSADH-D is primarily studied using simplified models, such as HEK293 cells overexpressing genes of interest, but such overexpression can result in protein aggregation or pathway saturation that may not be representative of actual underlying disease phenotypes. Methods We used a CRISPR/Cas9 approach to generate human iPSC cell lines bearing ALDH5A1 mutations. Through screening, two different mutant cell lines, NM_001080.3: c.727_735del (p.L243_S245del) and NM_001080.3: c.730_738del (p.A244_Q246del), were obtained. We induced iPSCs to neural stem cells and analyzed the characteristics of ALDH5A1 mutations in stem cells. Results The human iPSC and NSC cell lines presented typical stem cell–like morphology. We found changes in ALDH5A1 expression and GABA accumulation in the different cell lines. In addition, by analyzing the cDNA between the wild-type and the mutant cell lines, we found that the mutant cell lines had a splicing variant. Conclusions iPSCs represent a promising in vitro model for SSADH-D that can be used to study early central nervous system developmental alterations and pathogenic mechanisms.

Clinical and molecular outcomes from the 5-Year natural history study of SSADH Deficiency, a model metabolic neurodevelopmental disorder

“…This approach was taken to generate neural stem cells to model SSADHD, showing increased GABA levels in ALDH5A1 −/− . However, no other biochemical hallmarks of SSADHD were detected [ 58 ]. To overcome this limitation, iPSCs can be further differentiated into neurons in vitro to model SSADHD.…”