Pluripotent Stem Cell Breakthrough Could Let Us Grow New Human Eyes
Adam Rifkin stashed this in Medicine
Biologists led by Kohji Nishida at Osaka University in Japan have discovered a new way to nurture and grow the many separate tissues that make up the human eyeball, and the scientists need only a small sample adult skin to build them all.
Using their new method, Nishida's team can grow retinas, corneas, the eye's lens, and more.
In a preliminary trial, the Japanese researchers cultured and grew sheathes of rabbit cornea—the transparent cover of the eye— that restored sight in blind rabbits born without fully-grown corneas. The research is published in the journal Nature. Don't throw away your glasses (or eye patch) just yet, but human trials are up next.
"We are now in the position to initiate first in-human clinical trials of anterior eye transplantation to restore visual function," Nishida writes in Nature. He believes that within the next three years, we will be able to run trials to repair disease- or injury-damaged human corneas.
Nishida's new research builds upon a recent breakthrough in stem cell technology. In 2006, scientists found they could create fully fledged stem cells from ordinary child or adults cells like blood or skin with just a few simple DNA tweaks. This discovery won two researchers, Shinya Yamanaka and Sir John Gurdon, the 2012 Nobel Prize in Physiology or Medicine; the engineered cells are called induced pluripotent stem cells, or iPS.
This new team discovered they could coerce these iPS cells into forming a simple proto-eye, from which they could harvest a bounty of different eye tissues. The researchers kick-start the formation of this proto-eye by growing iPS cells in a petri dish lined with the right combination of proteins and other molecules. Essentially, these proto-eyes amount to four simple rings of different cell types that later transform into different parts of the eye, like the retina or lens. Think of them as one of the earliest and simplest phase in biological eye formation.