Stem cells derived from humans can spontaneously form the tissue that develops in the part of the eye that allows us to see, according to a new study published in the journal Cell Stem Cell.
Transplanting this tissue into patients could help patients with visual impairments see. “This is an important milestone for a new generation of regenerative medicine,” says senior study author Yoshiki Sasai of the RIKEN Center for Developmental Biology. “Our approach opens a new avenue to the use of human stem cell-derived complex tissues for therapy, as well as for other medical studies related to pathogenesis and drug discovery.”
During human development, the light-sensitive tissue lining the back of the eye, the retina, forms from a structure known as the optic cup. In the study, this structure spontaneously emerged from human embryonic stem cells (hESCs), which are cells derived from human embryos that are capable of developing into a variety of tissues. This was possible because of the cell culture methods optimized by Sasai and his research team.
The hESC-derived cells formed the correct shape and the two layers of the optic cup, including a layer containing a large number of light-responsive cells called photoreceptors. Retinal degeneration primarily results from damage to these cells, so the hESC-derived tissue could be ideal transplantation material.
Other than the clinical applications, the study will help accelerate the gathering of knowledge in the field of developmental biology. “For instance, the hESC-derived optic cup is much larger than the optic cup that Sasai and collaborators previously derived from mouse embryonic stem cells, suggesting that these cells contain innate species-specific instructions for building this eye structure.”
“This study opens the door to understanding human-specific aspects of eye development that researchers were not able to investigate before,” Sasai says.