The derivation of astrocytes from human pluripotent stem cells is currently slow and inefficient. We demonstrate that overexpression of the transcription factors SOX9 and NFIB in human pluripotent stem cells rapidly and efficiently yields homogeneous populations of induced astrocytes. In our study these cells exhibited molecular and functional properties resembling those of adult human astrocytes and were deemed suitable for disease modeling. Our method provides new possibilities for the study of human astrocytes in health and disease.

A fundamental impediment to functional recovery from spinal cord injury (SCI) and traumatic brain injury is the lack of sufficient axonal regeneration in the adult central nervous system. There is thus a need to develop agents that can stimulate axon growth to re-establish severed connections. Given the critical role played by protein kinases in regulating axon growth and the potential for pharmacological intervention, small molecule protein kinase inhibitors present a promising therapeutic strategy. Here, we report a robust cell-based phenotypic assay, utilizing primary rat hippocampal neurons, for identifying small molecule kinase inhibitors that promote neurite growth. The assay is highly reliable and suitable for medium-throughput screening, as indicated by its Z'-factor of 0.73. A focused structurally diverse library of protein kinase inhibitors was screened, revealing several compound groups with the ability to strongly and consistently promote neurite growth. The best performing bioassay hit robustly and consistently promoted axon growth in a postnatal cortical slice culture assay. This study can serve as a jumping-off point for structure activity relationship (SAR) and other drug discovery approaches toward the development of drugs for treating SCI and related neurological pathologies.

ROCK kinases, which play central roles in the organization of the actin cytoskeleton, are tantalizing targets for the treatment of human diseases. Deletion of ROCK I in mice revealed a role in the pathophysiological responses to high blood pressure, and validated ROCK inhibition for the treatment of specific types of cardiovascular disease. To date, the only ROCK inhibitor employed clinically in humans is fasudil, which has been used safely in Japan since 1995 for the treatment of cerebral vasospasm. Clinical trials, mostly focusing on the cardiovascular system, have uncovered beneficial effects of fasudil for additional indications. Intriguing recent findings also suggest significant potential for ROCK inhibitors in the production and implantation of stem cells for disease therapies.