Nanoscale Structural Characterisations of Ocular Tissues Derived from Human iPS Cells

The cells that comprise our body have specific functions and are adapted to suit the particular tissue in which they exist. Mature cells are generally known as differentiated cells because they have become tailored to their biological role. For a long time, it was accepted that once a cell had "chosen its path" and differentiated into a particular type of cell, it had embarked on an irreversible journey. However, in 2012 Professors Sir John Gurdon and Shinya Yamanaka, of Cambridge and Kyoto Universities, respectively, were awarded the Nobel Prize for their research, which showed that differentiated adult cells could be genetically reprogrammed to become less differentiated and capable of forming many different cell types. Such cells are called induced pluripotent stem cells, commonly abbreviated to iPS cells. The new research we propose originates with the discovery, made with our collaborators in Japan, that human iPS cells (hiPSCs) can be cultivated in the laboratory to grow in a manner that mimics the way cells in the human eye develop before birth.

Component tissues of the eye have interrelated developmental pathways, with the corneal and conjunctival epithelia that cover the eye's surface, the lens within the eye and the tear-producing lacrimal gland all evolving from the same cell type. Thin flat sheets of corneal and conjunctival epithelia have been generated from hiPSCs, and some of the corneal sheets have been used to restore sight in patients with vision loss. New research is now starting to show how hiPSCs can be used to form 3D organoids (miniaturised versions of an organ or selected aspects of it) of lacrimal gland and lens. These are key ocular tissues, which, respectively, help synthesise the tear film and focus light onto the retina. How accurately these organoids mimic the natural tissue, however, is yet to be fully appreciated. We now plan a series of experiments using high-specification electron microscopes and high-intensity x-ray...