Generation of Spinal Dorsal GABAergic Neurons from Human Urine Cells by Defined Transcriptional Factors for the Treatment of Neuropathic Pain in Spinal Cord Injury

Description

Central neuropathic pain (CNP) is a devastating disorder following spinal cord injury (SCI) causing spontaneous hyperalgesia and allodynia, which significantly affect quality of life for many SCI patients. To date, there is no effective cure for CNP. Although multiple pharmacological treatments and physiotherapies have been developed, these approaches are frequently well tolerated that limits their efficacy. Loss of dorsal spinal GABAergic inhibitory tone in the injured spinal cord is the major triggering factor for CNP. Since adult spinal cord is lack of regenerative capacity to form new neurons after injury, stem cell-based therapy is a promising strategy for compensating neuronal loss after SCI. A few reports have shown that transplantation of pluripotent stem cells-derived forebrain interneuron precursors into adult spinal cord could reduce injury-induced neuropathic pain. However, several caveats of these studies including risk of propagating tumor-prone from pluripotent stem cells, heterogeneity of grafted cells, and unmatched graft with recipient spinal tissue would limit clinical applicability and therapeutic efficacy. Therefore, it is essential to generate homogenous population of dorsal spinal GABAergic neurons derived from patient somatic cells by direct lineage reprogramming.Our previous work has established protocols to differentiate human pluripotent stem cells into dorsal spinal GABAergic neurons using small molecules and has identified four transcription factors implicated in GABAergic specification and differentiation. Consistently, we further demonstrated their sufficiency in converting induced pluripotent stem cells into dorsal spinal GABAergic neurons. To acquire patient-specific somatic cells from a non-invasive approach for lineage reprogramming, we have successfully converted human urine cells into dorsal spinal neural progenitors using defined transcription factors. Based on the established platform and identified genetic factors for transdifferentiation of human somatic cells into GABAergic neurons, we aim to generate enriched population of dorsal spinal GABAergic neurons from somatic cells for therapeutic treatment of CNP following SCI. Our objectives are to: 1) Establish human GABAergic reporter system for gene expression profiling and live monitoring of reprogramming efficacy; 2) Using defined transcription factors to convert human urinederived cells into dorsal spinal GABAergic neurons; 3) Evaluation of the therapeutic potential of induced dorsal spinal GABAergic neurons in spinal injury rodent model. Our proposed studies will develop a safer, faster and cheaper strategy in generating patient-specific dorsal spinal GABAergic neurons in the treatment of CNP following SCI, which hold great potential for future clinical applications in transplantation therapy in a large cohort of individuals with neurological disorders.