Human embryonic stem cells (ES cells) have, for the first time, been used to grow a crucial part of the eye, a paper in Cell Stem Cell reports. It is hoped that in the future transplantation of such tissue could help visually impaired people recover their sight.
Scientists working at the RIKEN Centre for Developmental Biology in Kobe, Japan, managed to encourage human ES cells to self-organise into a three-dimensional and multi-layered human eye precursors, called an optic cup. The cup, just over half a millimetre in diameter, contained the important light-sensitive rod and cone cells – called photoreceptors – on its inner surface, as well as retinal cells in its outer wall.
As Professor Austin Smith, director of the Centre for Stem Cell Research in Cambridge, UK, who was not involved in the study, told Nature: ‘The morphology [of the optic cup] is a truly extraordinary thing’. But only very recently have researchers been able to grow stem cells in three dimensions rather than as two-dimensional sheets in a dish. The optic cup self-assembled into its complicated three-dimensional shape without any direction, morphologically speaking, from the scientists.