So in most individuals, if you want to regrow muscle,
it's pretty straightforward.
The first line of therapy is always some type of rehabilitation.
So standard physical therapy is what's prescribed
and is usually very effective in younger adults.
Unfortunately there are certain populations, including older adults and
those with different types of neuromuscular disease, that have limited mobility or pain issues.
And they're not able to fully rehabilitate.
So, under this condition, they can lose a significant amount of muscle mass and function.
And they can fall into a downward spiral of not being able to regrow muscle,
to a point where they actually can become disabled, and it can cause early mortality.
A large focus for our laboratory is identifying and characterizing cell types; mononuclear cell types.
And we're trying to understand some of the mechanisms by which muscle mass is lost upon disuse.
And then we're trying to develop different therapies that allow for regrowth of muscle.
So, in this particular study, we are using an animal-based model,
where we immobilize one of the legs (the hind limb).
And we find, by two weeks, there is significant loss of muscle mass in that immobilized leg.
We also find, and report in the study, that there's a significant decrease
in the quantity of pericytes.
And pericytes are very supportive to vascular health.
And so we thought, well, based on this finding,
that perhaps this loss of pericyte was involved in the loss of muscle mass.
We performed a study where we replaced the pericytes --
we inject them directly into the muscle after disuse --
and we find that it enhances the recovery, accelerates recovery.
In the mice that did not receive pericytes, two weeks after the period of immobilization,
where they're able to reuse their muscles,
there's still significant loss of muscle mass.
But the animals that did receive the pericytes are fully recovered.
So there's a drastic difference, a significant difference, between
not having the pericyte present during the recovery period
and having it replaced.
We know that pericytes are not necessarily always stable in the muscle micro-environment,
especially the aged micro-environment.
They die very easily. Or they can be rejected too.
And so, thinking about the future of our research, we really want to try to
determine if we can extract those beneficial chemical materials --
growth and neurotrophic factors --
that are, in fact, initiating the growth that we're observing.
And, specifically, we really are targeting the extracellular vesicles
that are released by the pericyte that, we know, occur in response to contraction.
So an exciting part of our future research is to identify the EVs secreted by the pericytes.
And perhaps use those as a means of therapy.
So we are now deriving some of thetherapeutic materials
from the pericyte from the serum, from the blood.
And, once we optimize these methods, we'll be able to then introduce this therapy to humans.
So we're very excited about that possibility.
And so we think that, if we can target what's causing the atrophy,
that that might be the best approach towards regrowing muscle under this condition.
So, much more effective than any other approach that you can think of --
either hormones, maybe, or nutritional approaches -- getting right at the source
of the cause of the atrophy might be, truly, the most effective approach.