Stem cells are in the eyes of the beholder

And in everyone else’s eyes as well.  According to new research led by Sally Temple and her colleagues from Rensselaer, our retinal pigment epithelial (RPE) cells not only allow us to see, but also harbor multipotent stem cells.

The RPE, shown at the bottom of the retina (pigmented layer), is made up of a single layer of pigmented cells.  These cells are essential for nourishing the light sensitive photoreceptors within the retina.  Among their other talents, entire retinas can be regrown from a few RPE cells… At least in salamanders.  Of course, salamanders can also regenerate entire limbs.  Nevertheless, Temple and her team set out to determine whether human RPEs could be induced, if not to entirely regrow retinas, at least to repair them.

The researchers obtained RPE cells from cadavers ranging from 22 to 99 years old at the time of death.  After trying assorted growth mediums, they discovered that about ten percent of the cells had the ability to differentiate into a variety of cell types, including neurons and bone cells.  This was true even for cells derived from eyes that had been nearly a hundred years old.

Needless to say, this work has implications for treating many diseases, not the least of which is retinal repair. Before you despair that you’d have to be a cadaver to benefit from this, you should know that RPEs can easily be removed from living persons as well. 

As Temple cheerfully explains:

You can literally go in and poke a needle in the eye and get these cells from the subretinal space.