Progress in the use of induced pluripotent stem cells for cervical and thoracic traumatic spinal cord injuries: Meta-analysis and Review

Induced pluripotent stem cells (iPSCs) are cells that are genetically reprogrammed from human tissues such as blood or skin cells. These cells can be differentiated in vitro into specialized cells such as neurons that can replace damaged neurons in the spinal cord. A handful of studies have analyzed the functional use of iPSC-derived cells in vivo for treatment of cervical/ thoracic spinal cord injuries caused by physical trauma. The hypothesis is that cells derived from iPSCs are an effective treatment for cervical/ thoracic spinal cord injuries (SCI). This meta-analysis determined if significant motor improvement was restored after treatment with iPSC- derived cells compared to control treatments. Overall based on locomotion scales in rodents and monkeys, this approach indicates a therapeutic benefit for SCIs using cells derived from either iPSCs or embryonic stem cells (ESCs). The confirmation that treatment with iPSC-derived cells is as effective as cells derived from ESCs is important due to the controversies existing with current work using ESCs. By piecing together evidence of the successes and limitations of iPSCs in the recovery of motor skills, this intends to elucidate the progress achieved with transforming iPSCs into cells needed for spinal cord repair. Results from our analysis can be used to address questions that are still unanswered in this field and to determine the direction that future research needs to take.