Overview
- Researchers at Gladstone Institutes reported Thursday that they converted human induced pluripotent stem cells into V2a spinal interneurons and transplanted them into rats with cervical spinal cord injuries.
- Two months after transplant the human cells survived at the injury site, formed synaptic connections with host neurons and with descending brainstem inputs, and increased diaphragm activity when the graft was stimulated.
- The transplanted cells gave injured animals measurable respiratory reserve under stress, with about 75% of treated rats surviving low-oxygen or high-carbon-dioxide challenges that defeated most untreated controls.
- The team validated a manufacturable process by optimizing the differentiation protocol over roughly 18 months and showing the V2a cells can be cryopreserved for later use, while also identifying a subpopulation that seems especially effective.
- The work is a proof of principle limited to an acute rat model with two-month follow-up, and the authors say they must show consistent efficacy in larger animals, at chronic time points, and in other motor circuits before human trials.