Direct Reprogramming of Human Astrocytes into Spinal Cord Organoids Facilitating Spinal Cord Regeneration

Human astrocytes have reported to reprogram into neurons, but they have yet to be induced to three-dimensional (3D) neural tissue for neural organogenesis. Here, we demonstrate a remarkable strategy for 3D organoid generation by direct reprogramming human astrocytes. By combining overexpression OCT4, suppression p53 and small molecules CHIR99021, SB431542, RepSox and Y27632, termed as Op53-CSBRY, we successfully reprogramed human astrocytes into neural ectodermal cells and further induced human 3D-brain organoid. Those organoids can be finally induced into spinal cord organoids by activating FGF, SHH and BMP signaling. The grafts of Human astrocyte derived spinal cord organoids (hADSC-Organs) can survived, differentiated into spinal cord neurons, migrated long distance, formed synaptic connectivity with host neurons, bridged complete injury spinal cord tissue in mice. This method indicates that human astrocytes could be directly triggered neural organogenesis, and may hold a great promising to support local astrocytes in situ organogenesis after brain damages, such as stroke and spinal cord injury. Screen of molecular conbined with factors to direct reprogramming astrocyte into neuron progenitors cell and therapy for spinal cord injuy.