Transplantation of mouse embryonic stem cell-derived oligodendrocytes in the murine model of globoid cell leukodystrophy

Xiao Ling Kuai, Run Zhou Ni, Guo Xiong Zhou, Zheng Biao Mao, Jian Feng Zhang, Nan Yi, Zhao Xiu Liu, Nan Shao, Wen Kai Ni, Zhi Wei Wang

Globoid cell leukodystrophy (GLD) is a severe disorder of the central and peripheral nervous system caused by the absence of galactocerebrosidase (GALC) activity. Cell-based therapies are highly promising strategies for GLD. In this study, G-Olig2 mouse embryonic stem cells (ESCs) were induced into oligodendrocyte progenitor cells (OPCs) and were implanted into the brains of twitcher mice, an animal model of GLD, to explore the therapeutic potential of the cells. The G-Olig2 ESCs were induced into OPCs using cytokines and a multi-step differentiation procedure. Oligodendrocyte markers were detected by RT-PCR and immunocytochemistry. The toxicity of psychosine to OPCs was determined by cell proliferation assay kit. The GALC level of OPCs was also examined. OPCs were labeled with Dir and transplanted into the brains of twitcher mice. The transplanted cells were detected by in-Vivo Multispectral Imaging System and real-time PCR. The physiological effects of twitcher mice were assessed. Oligodendrocyte markers were expressed in OPCs, and 76% ± 5.76% of the OPCs were enhanced green fluorescent protein (eGFP) positive, which was driven by the Olig2 promoter. The effect of psychosine on cell viability indicated that OPCs were more resistant to psychosine toxicity. The GALC level of OPCs was 10.0 ± 1.23 nmol/h/mg protein, which was significantly higher than other cells. Dir labeled OPCs were injected into the forebrain of postnatal day (PND) 10 twitcher mice. The transplanted OPCs were MBP positive and remained along the injection tract as observed by fluorescent microscopy. The level of the Dir fluorescent signal and eGFP mRNA significantly decreased at day 10 and day 20 post injection, as indicated by in-Vivo Multispectral Imaging System and real-time PCR. Because of poor cell survival and limited migration ability, there was no significant improvement in brain GALC activity, MBP level, life span, body weight and behavioral deficits of twitcher mice. ES cell derived OPC transplantation was not sufficient to reverse the clinical course of GLD in twitcher mice.