Ah, a German accent … plus, a little mixup in the understanding of the program agenda. I thought I would be talking next to someone talking about cell transplant .. But no.
The title of this talk is Locomotor Recovery Following Moderate or Severe Contusive SCI Does Not Require Oligodendrocyte Remyelination. (And that’s not just a mouthful, it’s also kind of provocative.)
The question is, how much de and re myelination is there in the rodent spinal cord after contusion injury? Also, does remylenation play a role in recovery after injury? (FYI … there exists this stuff called myelin, which is a sort of axon coating that’s produced by helper cells in the spinal cord. The helper cells are called oligodendrocytes. The job of the myelin coating is a little like the job of insulation around a copper wire; it helps the “current” travel along the axon.)
He says: What we have believed is that if you put oligodendrocyte precursors into the damaged cord, they would grow up to become mature oligodendrocytes that would then allow axons to function properly.
Okay, so the test he did involved putting those precursor cells into mice and watching to see if they really did develop into mature cells, and whether or not those mature cells really did produce myelin. And that’s what happened. Their analysis showed that 30% of the myelin in their injured animals was new. Did it matter that they got all that new myelin? To find out, they did a reversal process that knocked out the new myelin. Got rid of it.
(Oy, okay. We just saw about 10 slides of very technical data describing details of this experiment … most of which sailed way over the heads of the people in the room.) And guess what? There was NO CHANGE between the functional recovery of injured mice with myelin and without myelin.
The summary is that new myelin is not required for recovery. They published a paper saying this in August 2018; (you can guess that it wasn’t really welcomed). He says that the conclusion is that implantation of oligodendrocyte precursor cells isn’t worth doing.
One of the very first scientific presentations I ever heard was about remyelinating as a strategy for functional recovery. One of the very first cell transplants in SCI research was putting these cells — grown in the lab from embryonic stem cells — into human beings with acute injuries. This work has been going on for at least 15 years, and has already cost (directly) 10s of millions of dollars. So … yeah. It’s a bit of shock to hear him say it was all for nothing.