Purpose Human somatic cells can be efficiently reprogrammed into induced pluripotent stem (iPS) cells by ectopic expression of four key factors using integrating DNA viruses. We have successfully generated retinitis pigmentosa patient-derived iPS cells for disease modeling. However, the iPS cells generated by retroviral method should have potential risk of random integration in the host genome, which thereby might produce unpredictable side effect. In this study, we aimed to generate retinal cells from patient-specific iPS cells generated by a non-integrative method using Sendai-virus.
Methods and Results Human iPS cell lines were established by using Sendai-virus with OCT4, SOX2, KLF4 and c-MYC. The iPS cells were examined by karyotype analysis and in vitro and in vivo pluripotency testings. By using a sophisticated differentiation method with a 20-day suspension followed by a long-term adherent culture, we induced sequentially neural retinal progenitor, retinal pigment epithelial (RPE) progenitor, photoreceptor precursor, RPE, and photoreceptor cells which expressed specific markers. Differentiated rod cells showed diffused distribution of rhodopsin in cytoplasm and expressed Bip and CHOP, strongly indicating endoplasmic reticulum stress.
Conclusion In breif, compared with retroviral iPS cells, we generated non-integrating patient-specific iPS cells and with these new iPS cells, we successfully induced the retinal cells including rod cells with disease feature, which is a potential cell model for disease modeling and drug discovery.