Increased oxidative stress and autophagy in NGLY1 patient iPSC-derived neural stem cells.

NGLY1 (N-glycanase) is a de-glycosylating enzyme that promotes clearance of misfolded glycan proteins. NGLY1 deficiency leads to a disease pathology with varied symptoms, including severe neurological defects. There are no therapeutic options currently available for the treatment of this rare disease. With the goal of finding potential therapeutic avenues, we performed comprehensive characterization of aberrant cellular stress pathways in a patient relevant model of NGLY1 deficiency. For a more accurate study of NGLY1 deficiency without other confounding factors, we compared differences between iPSC-derived neural stem cells carrying the commonly occurring nonsense mutation c.1201A > T (p.R401X) and their genetically similar CRISPR-corrected isogenic controls. Our findings demonstrate that NGLY1 deficiency in neural stem cells leads to an upregulation of ER stress, increased autophagic flux and significant signs of oxidative stress. These results provide new insights into the cellular dysfunctions associated with this disorder. Moreover, they point to better establishing reliable high throughput phenotypic assays that can be utilized for drug discovery.