Starting with embryonic stem cells, researchers at RIKEN have been able to grow in the lab a small piece of the human retina, the back of the eyeball that senses the light coming through the lens. The research has obvious potential for treating eye disease.
Dr. Yoshiki Sasai's lab at the RIKEN Center for Developmental Biology in Japan cultivated an 1/2 millimeter in diameter optic cup. On the back inside of the eyeball, the optic cup is center point of the optic disc where the eye's nerve cells come together to form the optic nerve that runs from the eye to the brain.
Similar to the retinal structure in the normal eye, the lab-grown retinal tissue grew multiple cells layers and included photoreceptors--the cells that sense light coming into the eyes. The structure assembled spontaneously as the embryonic cells differentiated to form mature eye cells. The process required about 9,000 embryonic stem cells and took over 4 months.
This is the first time three dimensional human tissue structures have been engineered in a lab with human embryonic stem cells. It follows up the group's previous research published in April of last year where they used mouse embryonic stem cells to grow a mouse version of the optic cup. Differences between the two optic cups were seen. For example, the human optic cup that formed was about twice the size of the mouse version, and photoreceptor cells were not found in the mouse optic cup.