Description
Induced pluripotent stem cell-derived neural progenitor cells (iPSC-NPCs) are a promising source of tailor-made cell therapy for neurological diseases. However, tumorigenicity and immunogenicity are major obstacles to translational use. Here we demonstrate epidural therapeutics of human iPSC-NPC grafts after experimental ischemic stroke to avoid surgical damage and intracerebral teratomas. We found that human iPSC-NPCs co-cultured trans-membranously with rat cortical cells subjected to oxygen-glucose deprivation, compared with human mesenchymal stem cells from bone marrow and umbilical cord Wharton's jelly, superiorly enhanced neural survival and growth as well as mitigated astrogliosis. Using comparative whole-genome microarrays and cytokine arrays, we identified a neurorestorative secretome from iPSC-NPCs and neutralization of the enriched cytokines potently abolished the neuroprotective effects in the iPSC-NPC co-cultures. Moreover, we implanted the human iPSC-NPCs epidurally using fibrin glue over the peri-infarct cortex at 7 days following permanent middle cerebral artery occlusion in adult rats. The cell-treated rats showed significant improvement in their paretic forelimb usage and grip strength from 10 days post-transplantation (dpt) onwards compared to the vehicle-treated rats, accompanied by ameliorated infarct/atrophy volumes, inflammatory infiltration and astrogliosis, as well as augmented angiogenesis, oligodendrocyte precursor cells and white matter integrity. Some iPSC-NPCs migrated into the peri-infarct cortex but poorly survived by 21 dpt. This proof-of-concept study demonstrates that a less invasive yet effective epidural delivery route of human iPSC-NPCs may promote functional remodeling of the peri-infarct brain predominantly through distinct paracrine effects.