372 Differences in Oligodendrogenesis Between Human and Rodent Spinal Cord Stem Cells

Abstract

INTRODUCTION: Research in pre-clinical rodent models suggests that targeting the endogenous neural stem/progenitor cells (NSPCs) in the spinal cord may hold the key to stimulating oligodendrocyte regeneration. However, it remains to be seen whether human spinal cord NSPCs possess the same regenerative potential as their rat counterparts. METHODS: To assess the potential for oligodendrogenesis between human and rat spinal cord NSPCs, primary tissue from adult donors and female rats was harvested and cultured using the Neurosphere assay. To induce spontaneous differentiation, primary-derived NSPCs were treated with 1% fetal bovine serum (n = 15 humans, n = 10 rats). To further promote oligodendrocyte differentiation, pdNSPCs were treated with 40 ng/µL or 100 ng/µL of platelet-derived growth factor AA (PDGF-AA) (n = 3 humans, n = 3 rats). Immunocytochemistry and RNA sequencing were then employed to compare the transcriptomes, with the differentially expressed genes and gene sets analyzed via DESeq and GSEA. RESULTS: Human NSPCs showed a reduced potential for oligodendrocyte generation compared to rat NSPCs (0.013 ± 0.01% and 0.029 ± 0.01% O4+ after one and two weeks in humans; 4.9 ± 0.4% and 6.3 ± 0.6% O4+ after one and two weeks in rats). PDGF-AA treatment at 40 ng/µL for one week was able to effectively promote oligodendrocyte differentiation in rat NSPCs, but had a minimal effect on human NSPCs (8.5 ± 1.4 fold increase in O4+). OLIG1/2, SOX10, and CNP gene transcripts were enriched in rat NSPCs. CONCLUSIONS: We compared the potential of oligodendrogenesis between primary human and rat spinal cord NSPCs and found a significantly lower capacity in the human NSPCs both functionally and transcriptionally, which could be an obstacle to the successful application of myelinating techniques.