The application of high levels of oxygen to severed bone facilitates
bone regrowth, according to a study presented at the American Society for
Biochemistry and Molecular Biology Annual Meeting in San Diego.
The study, funded by the Defense Advanced Research Projects Agency, was
conducted at Tulane University, where researchers have been exploring the
molecular foundation of limb regeneration under various circumstances. They
have been especially interested in why bone regrowth only occurs in specific
parts of the body and what genes, proteins and molecular activities are
utilized during bone regrowth.
“What it boils down to is genes that spur regeneration don’t
just turn themselves on. They turn on because something signals them. So I
thought, maybe it’s oxygen that’s turning them on,” lead
researcher Mimi Sammarco, PhD, stated in a press release. “Oxygen
is often the primary signal that turns on various genes.”
The researchers used a special incubator to expose a thin bone sample
taken from an amputation site in a mouse to high levels of oxygen. They found
that the bone responded favorably to 20% oxygen, but only after a certain
amount of time had passed since the amputation. If the bone was exposed too
early after the amputation, the oxygen had little effect.
“It’s all about timing. Obviously, there’s a sequence in
growing things back. And oxygen can push the button that has to be applied at a
certain time,” Sammarco stated.
Sammarco emphasized that even a partial regeneration would be a
significant improvement for amputees.
“Every effort to direct and control the extension of amputation
stump length contributes to the rehabilitation of amputees, while keeping in
mind the long-term goal of complete regeneration,” she stated.