Human induced neural stem cells support functional recovery in spinal cord injury models

Spinal cord injury (SCI) is a clinical condition that leads to permanent and/or progressive disabilities of sensory, motor, and autonomic functions. Unfortunately, no medical standard of care for SCI exists to reverse the damage. Here, we assessed the effects of induced neural stem cells (iNSCs) directly converted from human urine cells (UCs) in SCI rat models. We successfully generated iNSCs from human UCs, commercial fibroblasts, and patient-derived fibroblasts. These iNSCs expressed various neural stem cell markers and differentiated into diverse neuronal and glial cell types. When transplanted into injured spinal cords, UC-derived iNSCs survived, engrafted, and expressed neuronal and glial markers. Large numbers of axons extended from grafts over long distances, leading to connections between host and graft neurons at 8 weeks post-transplantation with significant improvement of locomotor function. This study suggests that iNSCs have biomedical applications for disease modeling and constitute an alternative transplantation strategy as a personalized cell source for neural regeneration in several spinal cord diseases. Regenerative medicine: stem cell opportunity for spinal cord repairNeural stem cells (NSCs) directly converted from readily accessible cell populations can successfully initiate tissue repair in rodent models of severe spinal cord injury. While NSCs as a regenerative therapy are of increasing interest, they are difficult to obtain. Daryeon Son of Korea University, Seoul, South Korea, and colleagues have now demonstrated that highly accessible human urine-derived cells can be reprogrammed into induced NSCs (iNSCs). The researchers induced two types of severe spinal cord injury in rats and then transplanted human iNSCs to the damaged sites. Within months, they observed considerable tissue repair, including extensive axonal growth, the formation of synaptic connections between host and graft neurons, and improvement in locomotor function. iNSCs could create new opportunities for treating a range of currently untreatable traumatic injuries.