Neural stem cells for disease modeling of Wolman disease and evaluation of therapeutics

Francis Aguisanda,Wei Zheng,Catherine Z Chen,Charles D Yeh,Natasha Thorne,Jizhong Zou,Rong Li,Jeanette Beers

doi:10.1186/s13023-017-0670-9

Abstract

BackgroundWolman disease (WD) is a rare lysosomal storage disorder that is caused by mutations in the LIPA gene encoding lysosomal acid lipase (LAL). Deficiency in LAL function causes accumulation of cholesteryl esters and triglycerides in lysosomes. Fatality usually occurs within the first year of life. While an enzyme replacement therapy has recently become available, there is currently no small-molecule drug treatment for WD.ResultsWe have generated induced pluripotent stem cells (iPSCs) from two WD patient dermal fibroblast lines and subsequently differentiated them into neural stem cells (NSCs). The WD NSCs exhibited the hallmark disease phenotypes of neutral lipid accumulation, severely deficient LAL activity, and increased LysoTracker dye staining. Enzyme replacement treatment dramatically reduced the WD phenotype in these cells. In addition, δ-tocopherol (DT) and hydroxypropyl-beta-cyclodextrin (HPBCD) significantly reduced lysosomal size in WD NSCs, and an enhanced effect was observed in DT/HPBCD combination therapy.ConclusionThe results demonstrate that these WD NSCs are valid cell-based disease models with characteristic disease phenotypes that can be used to evaluate drug efficacy and screen compounds. DT and HPBCD both reduce LysoTracker dye staining in WD cells. The cells may be used to further dissect the pathology of WD, evaluate compound efficacy, and serve as a platform for high-throughput drug screening to identify new compounds for therapeutic development.

Highlights

Wolman disease (WD) is a rare lysosomal storage disorder that is caused by mutations in the LIPA gene encoding lysosomal acid lipase (LAL)
WD induced pluripotent stem cells (iPSCs) lines showed normal karyotype (Fig. 1b), and STR DNA analysis confirmed that their identities matched their parental fibroblasts (Additional file 1: Figure S2)
In addition to the four WD iPSC lines generated, a previously characterized iPSC line derived from a healthy donor, NCRM-1, was used as a control

Summary

Introduction

Wolman disease (WD) is a rare lysosomal storage disorder that is caused by mutations in the LIPA gene encoding lysosomal acid lipase (LAL). WD is caused by mutations in the gene encoding lysosomal acid lipase (LAL), which results in nonfunctional levels of LAL activity. This leads to the accumulation of triglycerides (TG) and cholesteryl esters (CE) in the lysosomes of many cells and tissues [2]. Clinical manifestations include adrenal calcification, hepatosplenomegaly, and enlarged lymph nodes [3]. Enzyme replacement therapy (ERT)—with sebelipase alfa (KANUMA®)—has recently been approved for treating WD [10, 11]. While ERT has reduced abdominal distention, hepatosplenomegaly, vomiting and diarrhea, and improved survival

Methods

Results

Discussion

Conclusion