Cover Story:Intervertebral disc degeneration is believed to originate in the nucleus pulposus (NP) region, it is important to obtain greater numbers of active NP cells for the study and therapy of disc degenerative disease (DDD). Human induced pluripotent stem cells (iPSCs) are a powerful tool for modeling human development and disease, as well as for their potential applications in regenerative medicine. We isolated NP cells from DDD patients with our improved method, and reprogramed primary NP cells into iPSCs with Sendai virus vectors encoding 4 factors. Successful reprogramming of iPSCs was verified by specific surface markers and teratoma, and differentiation of iPSCs into NP-like cells was performed in culture plate and hydrogel, with skin fibroblast derived-iPSC used as control. It was demonstrated that iPSCs derived from NP cells were featured with normal karyotype, and showed expression of pluripotency markers and were able to form teratoma in nude mice. NP induction of iPSCs resulted in their expression of NP cell specific matrix proteins and related genes. NP derived-iPSCs without induction also showed a basal level of expression of some NP-like phenotype characteristics. What’s more, NP derived-iPSCs prefer to differentiate into NP-like cells in hydrogel rather than in culture plate.This is the first protocol for generation of iPSCs from NP cells of DDD patients, and we successfully differentiated this iPSCs into NP-like cells in hydrogel. This method opens a window in the treatment of DDD by using patient-specific NP cells in a relatively simple and straight forward manner.