MLC1 alteration in human iPSCs give rise to disease-like cellular vacuolation phenotype in the astrocyte lineage

Megalencephalic Leukoencephalopathy with subcortical cysts (MLC), a rare and progressive neurodegenerative disorder involving the white matter, is not adequately recapitulated by current disease models. Somatic cell reprogramming, along with advancements in genome engineering, will allow the establishment of in-vitro human models of MLC for disease modeling and drug screening. In this study, we utilized cellular reprogramming and gene-editing techniques to develop induced Pluripotent Stem Cell (iPSC) models of MLC to recapitulate the cellular context of the classical MLC-impacted nervous system. MLC iPSCs were comprehensively characterized for pluripotency and were subsequently differentiated to disease-relevant cell types: Neural Stem Cells (NSCs) and astrocytes. RNA (Ribonucleic acid) sequencing profiling of MLC NSCs revealed a set of differentially expressed genes related to neurological disorders and epilepsy, a common clinical finding within MLC disease. This gene set can serve as a target for drug screening for the development of a potential therapeutic for this disease. Upon differentiation to the more disease relevant cell type- astrocytes, MLC-characteristic vacuoles were clearly observed, which were distinctly absent from controls. This emergence recapitulated a distinguishing phenotypic marker of the disease. Through the creation and analyses of iPSC models of MLC, our work addresses a critical lacunae in the field- relevant cellular models of MLC for use in both disease modeling and drug screening assays. Further investigation can utilize these MLC iPSC models, as well as generated transcriptomic data sets and analyses, to identify potential therapeutic interventions for this debilitating disease.