Background: Niemann-Pick disease type C (NPC) is caused by the mutation of NPC genes, which leads to the abnormal accumulation of unesterified cholesterol and glycolipids in lysosomes. This autosomal recessive disease is characterized by liver dysfunction, hepatosplenomegaly, and progressive neurodegeneration. Recently, the application of induced neural stem cells (iNSCs), converted from fibroblasts using specific transcription factors, to repair degenerated lesions has been considered a novel therapy. Objectives: The therapeutic effects on NPC by human iNSCs generated by our research group have not yet been studied in vivo; in this study, we investigate those effects. Methods: We used an NPC mouse model to efficiently evaluate the therapeutic effect of iNSCs, because neurodegeneration progress is rapid in NPC. In addition, application of human iNSCs from NPC patient-derived fibroblasts in an NPC model in vivo can give insight into the clinical usefulness of iNSC treatment. The iNSCs, generated from NPC patientderived fibroblasts using the SOX2 and HMGA2 reprogramming factors, were transplanted by intracerebral injection into NPC mice. Results: Transplantation of iNSCs showed positive results in survival and body weight change in vivo. Additionally, iNSC-treated mice showed improved learning and memory in behavior test results. Furthermore, through magnetic resonance imaging and histopathological assessments, we observed delayed neurodegeneration in NPC mouse brains. Conclusions iNSCs converted from patient-derived fibroblasts can become another choice of treatment for neurodegenerative diseases such as NPC.

Recent advances have shown the direct reprogramming of mouse and human fibroblasts into induced neural stem cells (iNSCs) without passing through an intermediate pluripotent state. Thus, direct reprogramming strategy possibly provides a safe and homogeneous cellular platform. However, the applications of iNSCs for regenerative medicine are limited by the restricted availability of cell sources. Human umbilical cord blood (hUCB) cells hold great potential in that immunotyped hUCB units can be immediately obtained from public banks. Moreover, hUCB samples do not require invasive procedures during collection or an extensive culture period prior to reprogramming. We recently reported that somatic cells can be directly converted into iNSCs with high efficiency and a short turnaround time. Here, we describe the detailed method for the generation of iNSCs derived from hUCB (hUCB iNSCs) using the lineage-specific transcription factors SOX2 and HMGA2. The protocol for deriving iNSC-like colonies takes 1~2 weeks and establishment of homogenous hUCB iNSCs takes additional 2 weeks. Established hUCB iNSCs are clonally expandable and multipotent producing neurons and glia. Our study provides an accessible method for generating hUCB iNSCs, contributing development of in vitro neuropathological model systems.
Animals ; Fetal Blood* ; Fibroblasts ; Humans* ; In Vitro Techniques ; Methods ; Mice ; Neural Stem Cells* ; Neuroglia ; Neurons ; Regenerative Medicine ; Transcription Factors ; Umbilical Cord*