Who Needs IPS Cells: Old Cells made Young Again by Simple Exposure to the Stuff of Youth
I’ve been a big critic of IPS (induced pluripotent stem cells), as the concept seems to represent a solution without a problem cooked up not by clinicians, but by business models. To review, IPS is the lab process of taking a regular old cell like a skin cell and exposing it to substances or genes that make it revert back to a stem cell. The unintended consequences scale couldn’t be more magnified, a bit like playing with matches at a gas station. The problem is that we understand this process about as well as we understand the body at a genetic level-meaning we’re in Kindergarten and it’s before recess. Case in point that illustrates why IPS isn’t needed is a recent study out of University of Texas, showing that old mesenchymal stem cells (MSC’s) reproduce and make bone like young cells when they’re exposed to young extracellular matrix (ECM). ECM is the goo that cells produce to live in, a bit like a bird building a nest. The researchers figured out that old MSC’s lost some of their ability to grow quickly in culture and weren’t as good at making new bone as young cells. However, by simply exposing the old cells to young ECM, the old cells grew and repaired bone like young cells. The authors theorized that it’s actually the old ECM that tells old MSC’s to be old and not some internal property of the cells themselves. So here’s a very simple solution to dealing with older patients and trying to get their stem cells to behave like young stem cells without tricking skin cells to become stem cells. Or you can teach a old cell new tricks!