Science News

Key signal for nerve rebirth

Good news for sufferers of nerve damage – or at least tiny nematode worms with nerve damage – as researchers in Utah have discovered the molecular signals that cause regeneration of damaged nerves.  The team, led by Marc Hammarlund, were studying little worms known as C. elegans, and published their results this week online in the journal ScienceExpress. What’s exciting- and intriguing -  about their finding, is that the signals required to regenerate nerves are different from those that are needed to grow nerves in the first place, which could shed light on why attempts to regrow nerves in mammals such as humans don’t work so well.

The team were studying tiny worms with genetic faults in a gene called beta-spectrin, whose neurons break very easily.  The worms attempt to repair this damage, but they don’t do it very well. But the scientists found that when they removed another gene, called dlk1, the worms couldn’t fix their damaged nerves at all. The team then went on to use a precision laser to cut nerves in healthy worms, and compared their regeneration with worms lacking dlk1. Again, they found that dlk1 was important for nerve regrowth.

It’s something called a MAP kinase kinase kinase. Put simply, it’s a type of protein known as a kinase that sticks molecular “flags” on other proteins, which activates them. Dlk1 is the first in a long chain of kinases that pass signals on within cells, like a game of Chinese whispers, to tell the cell to regrow.  And as well as helping to fix damaged nerves, the team also found that adding extra Dlk1 could help to stave off the slowdown in nerve repair in worms as they age.

Well it’s not quite ready to be a miracle anti-aging nerve-repair serum just yet.  This is just the first step in a long road towards understanding the molecular signalling pathways that tell damaged nerves to regrow. And, of course, these are just tiny worms rather than damaged humans.  But it certainly provides some interesting inroads for researchers who are looking for ways to repair damaged nerve fibres, so hopefully it could pave the way for future therapies.

22nd Jan 2009