Induced Pluripotent Stem Cell-Derived Neural Stem Cell Transplantations Reduced Behavioral Deficits and Ameliorated Neuropathological Changes in YAC128 Mouse Model of Huntington's Disease

Abstract

Huntington's disease (HD) is a genetic neurodegenerative disorder characterized by neuronal loss and motor dysfunction. Although there is no effective treatment, stem cell transplantation offers a promising therapeutic strategy, but the safety and efficacy of this approach needs to be optimized. The purpose of this study was to test the potential of intra-striatal transplantation of induced pluripotent stem cell-derived neural stem cells (iPS-NSCs) for treating HD. For this purpose, we developed mouse adenovirus-generated iPSCs, differentiated them into neural stem cells in vitro, labeled them with Hoechst, and transplanted them bilaterally into striata of 10-month old wild type (WT) and HD YAC128 mice. We assessed the efficiency of these transplanted iPS-NSCs to reduce motor deficits in YAC128 mice by testing them on an accelerating rotarod task at 1 day prior to transplantation, and then weekly for 10 weeks. Our results showed an amelioration of locomotor deficits in YAC128 mice that received iPS-NSC transplantations. Following testing, the mice were sacrificed, and their brains were analyzed using immunohistochemistry and Western blot (WB). The results from our histological examinations revealed no signs of tumors and evidence that many iPS-NSCs survived and differentiated into region-specific neurons (medium spiny neurons) in both WT and HD mice, as confirmed by co-labeling of Hoechst-labeled transplanted cells with NeuN and DARPP-32. Also, counts of Hoechst-labeled cells revealed that a higher proportion were co-labeled with DARPP-32 and NeuN in HD-, compared to WT- mice, suggesting a dissimilar differentiation pattern in HD mice. Whereas significant decreases were found in counts of NeuN- and DARPP-32-labeled cells, and for neuronal density measures in striata of HD vehicle controls, such decrements were not observed in the iPS-NSCs-transplanted-HD mice. WB analysis showed increase of BDNF and TrkB levels in striata of transplanted HD mice compared to HD vehicle controls. Collectively, our data suggest that iPS-NSCs may provide an effective option for neuronal replacement therapy in HD.

Therapeutic effects of stem cells in rodent models of Huntington's disease: Review and electrophysiological findings

“…Transplantation of iPSCs derived from somatic cells has demonstrated behavioral improvement in rodent models of HD. For instance, when mouse iPSCs from normal, healthy mice were differentiated into neural stem cells (iPSC‐NSCs) and implanted into striata of 10‐month‐old YAC128 mice, there was an improvement in motor abilities over the span of 10 weeks following implantation. In addition, the stem cells survived and differentiated into mature MSNs.…”

“…Furthermore, innovative technologies have rapidly emerged that will likely improve the effectiveness of these and other types of stem cell‐derived products for the treatment of neurological diseases. The CRISPR/Cas‐9 system can be used to edit patient‐derived iPSCs or induced NSCs (iNSCs) to have a normal CAG length expansion cassette within the HTT gene . These modified stem cells, particularly iNSCs, can be further differentiated into distinct cell types (eg, GABAergic MSNs) which may potentially serve as replacements for degenerating cells …”

“…PSCs, which can be differentiated into each of the three germ line lineages, provide an alternative therapeutic option for the treatment of HD. Human PSCs, both embryonic and induced patient fibroblasts, can be differentiated in culture to neurons with TA B L E 1 Summary of stem cell grafts implanted in HD rodent models and implanted into striata of 10-month-old YAC128 mice, 96 there was an improvement in motor abilities over the span of 10 weeks following implantation. In addition, the stem cells survived and differentiated into mature MSNs.…”

“…The CRISPR/Cas-9 system 118,119 can be used to edit patient-derived iPSCs or induced NSCs (iNSCs) to have a normal CAG length expansion cassette within the HTT gene. 96 These modified stem cells, particularly iNSCs, can be further differentiated into distinct cell types (eg, GABAergic MSNs) which may potentially serve as replacements for degenerating cells. 77 However, concerns that even healthy stem cells in a diseased environment will eventually become dysfunctional pose a challenge to this sort of therapeutic approach.…”

Revealing cell fate decisions during reprogramming by scRNA-seq

“…Since the integrating viral approaches for introduction of OSKM may lead to insertion mutations, interfering with the expression regulation of endogenous genes or being abnormally reactivated in terminally differentiated cells. Therefore, non-integrating viral approaches such as using Sendai virus or adenovirus to generate iPSCs was developed [33,34]. Non-transgene reprogramming techniques such as delivering reprogramming factors in the form of mRNA or protein is a safer approach, avoided the possible infections in patients and the lack of a need to handle viral particles.…”