Transcript

Aging with dignity: the potential of regenerative medicine | Tracey Criswell | TEDxGreensboro

so i'd like to start with a quote uh by albert einstein the world as we have created it is is a process of our thinking so to change the world as we know it we have to change our thinking so what what does this mean to me this says to me that if you want to make big leaps you want to do revolutionary science as a scientist you really need to be able to think outside the box sometimes so i'm going to tell you about regenerative medicine today but i'd like to start with a couple of scenarios first imagine your soldier you're injured on the battlefield battlefield medic saves your life they take you back to the states get you to a hospital surgeon comes to you and says i can save your mangled legs because you were injured on the battlefield i can save your mangled legs however it's going to take dozens of surgeries and months of painful rehabilitation but i can't guarantee that you'll get full function back or we can take the leg and give you a prosthetic this is a true scenario and i can tell you a lot of soldiers automatically say just take the legs right i i don't want to undergo all of the surgeries in the painful physical therapy to not not be sure that i'm going to be able to walk or run do the other things that i've done previously in my life second scenario you're a diabetic um you've been on dialysis because your kidneys are starting to fail um your doctor says i need to put you on a transplant list none of your family members are a match they can't donate a kidney for you so we're going to put you on a list and basically you're going to have to wait for someone to die for us to save your life right to find an appropriate donor um the truth of the matter is patients on a transplant list whether it's for kidney or heart or any other organ you have a much greater chance of dying while waiting than actually getting an organ regenerative medicine has the potential of addressing both of these problems regenerative medicine also has the potential of dealing with more uh common injuries maladies birth defects uh injuries genetic defects diseases some of what you see back on the screen i'm a scientist at the wake forest institute of regenerative medicine i'm a trained cell biologist so i do basic research which means i work on cells and animals i'm not a clinician most of my patients have four legs so and they're small but my dream and my goal with my research is to be able to address some of these other issues not that transplantations aren't important but there are other issues that can be addressed by regenerative medicine that are probably more common to you and i so my research actually focuses on skeletal muscle i work with skeletal muscle skeletal muscle is the tissue in our body that allows us to move we contract we walk we move that's all skeletal muscle as we get older our skeletal muscle doesn't work as well and so my scientific research is based on understanding how our muscle function changes as we get older and how we heal after injury as we get older that leads me to aging so the definition of aging is a decline in the biological functions as we get older basically what that means is that our bodies don't work as well right as we start to get older we don't heal as fast i am sure a lot of you know exactly what i'm talking about uh getting up in the morning takes a little bit more time i can tell you for myself that coming down these steps i had to hold on to the handrail and really watch my feet because i'm finding that going down steps is actually harder than going up these days you know suddenly we don't see as well we need bifocals um men men lose their hair women women grow hair where we don't want it as we get older right so all of these things now i really want to talk about women as we go get older we face that dreaded time that change of life so yeah i'm talking about menopause menopause is often associated with hot flashes right redistribution of weight uh mood changes but that that period of time in the life when that when all those things are happening is really called the menopausal transition and it goes from the time of child rearing age when that starts to decline to one year after the last menses and that can last up to 10 years for women and this is really a particular sensitive time for women when it comes to diseases now men also undergo hormonal changes as they get older but as a middle aged woman myself menopause is personal oh i can tell you so once women reach the postmenopausal state there's increase in heart disease cardiovascular disease uh increased in osteoporosis which is bone loss which uh makes women more prone to breaks as they get older increased hypertension and we have a greater loss of muscle function and mass over time so so this is an important period of time for men and women as we get older because a loss a loss of skeletal muscle function in mass which is also called sarcopenia that leads to a lack of independence right lack of mobility can't get up and walk uh can't dress yourself lack of independence and really a decreased quality of life and so my research is not really focused on making us all live to be 120 because that's not what i'm interested in but i would really like to be able to spend the last years of my life you know maybe playing with the grandkids or great grandkids but hopefully not soon i'm speaking to my children out there [Laughter] you know walking the beaches you know doing these last things having a being able to age gracefully for my last chapters so what is regenerative medicine and how does it fit into this whole idea of aging the idea of tissue regeneration so to regenerate generate means to make new or to make regenerate is to remake so regenerative medicine we're talking about making new tissues and organs this this whole idea of tissue regeneration is not new it's been around for a long time this is prometheus and if you know your greek mythology prometheus was a titan he was a greek god and uh he formed man out of clay but he noticed that man was naked we don't have fur we don't have fangs or claws like some of the other animals we can't fly we don't run very fast we don't climb well we don't swim well which really left us at a disadvantage when it came to all the other creatures on the planet so he gave us a fire the problem with that is fire was not his to give fire belonged to zeus his big brother um which you know sibling rivalry i guess is on a whole another scale when you're a greek god uh zeus tied them up to a rock or mountain depending on which version you greed tied them up to a rock every day an eagle would come puck pluck out his liver and then every night it would regrow so the the ancient greeks understood that the liver has regenerative properties and it does our liver is highly regenerative probably the most regenerative tissue in our body the reason for that uh we have to think about what the liver does for us so the liver is our filter everything we put in our body the drugs the alcohol the fast food you know all these things get filtered through our liver all these things that are bad for the cells in our body so the lip the cells in the liver really take a beating and so we've evolved to regenerate those to regrow that part there are other animals that have a highly regenerative potential unlike us one of those being the axolotl so it's a cute guy there on your left he's a salamander and many of you may know already that if you cut the leg off a salamander it'll grow back takes about 60 days so month month and a half two months something like that not very long if you imagine if i were to cut my arm off right if i didn't die first and one of you knows how to put on a tourniquet to save my life i might be lucky if there's a talented surgeon available that could sew my arm back on it is certainly not going to grow back ever right however at one point during embryonic development we did grow into us right the cells that make up my body came from a single fertilized egg so fertilize one cell which then developed into my limbs and my hair my eyes and all my organs so at one point we were capable of doing that we just can't do it now now the axolotl was really the superhero of the newts the salamanders because with the axolotl it can regrow a leg but it can also regrow almost all of its organs so even even the brain if you take part of the brain of the axolotl it'll grow back um us our brain has a very low regenerative capacity so you injure your brain you live with it it's not going to come back uh traumatic brain injury for example right we hear about this with the football players all the time because they're running around hitting each other and the brain is doing this in the skull right it's kind of bouncing back and forth and it's fluid and they end up with traumatic brain injury can't do anything about that once it happens we have no way of healing the brain at this point in time but the axolotl can um the second animal up here on the screen the one in the middle that's a hydra some of you may know what the hydra is or you might have heard from mythology you cut the head off of hydra you get three back right it doesn't work exactly that way but the hydra is pretty amazing it is an animal although it's very small it's a carnivore so it catches things that float by the amazing thing about the hydra is that you can take you can go almost down to single cells and those cells will regrow to become another hydra why can't it do that well the hydra has this interesting property associated with it it has what's called a scaffold and so the protein scaffold that the cells are sitting on so the cells sit on this protein scaffold if part of that scaffold is removed with the cells the scaffold can tell the cells what they're supposed to do and kind of reorganizes them so that they can form another animal another hydra the last creature i want to talk about is the planaria the last one up here on the screen the worm um i'm a cell biologist as you heard i really like planaria um yeah it seems kind of weird doesn't it these are fresh water flatworms they grow to be about an inch in size so they're small and you'll find them all over the world so anywhere there's fresh water stream ponds there's some kind of planaria there um planaria remember i said they're about an inch right they can be cut into more than 250 pieces and you'll get 250 worms that are exactly the same um now that that was uh discovered in uh i think it was the mid-1800s right so you can imagine the scientists who figured that out he had to sit down and make little tiny cuts of the planaria and then draw them out every day right to see where they grew and how it grew back but it can grow if you cut if you cut it in half it'll grow two heads or two tails depending on which end they're they're incredible so what do they have well they're different than the hydra whereas the hydra has a protein scaffold that tells them how to regenerate the planaria are filled with stem cells and their cells so that's why it's my favorite creature of all stem cells are the cells in our body that fix our injured tissue well i think it can be argued that all the tissues in our body have a resident stem cell population these are called adult stem cells and they're vital because if you injure yourself they become activated and then they repopulate they grow and then they differentiate into whatever tissue needs to be healed so if we talk about skeletal muscle right the stem cells in the skeletal muscle are called satellite cells satellite cells sit right there on the muscle they don't do anything until they get a signal that the muscle's been injured those satellite cells then become active they migrate to the area of injury they differentiate and heal the muscle so most tissues in our body have this the brain it's disputed i wouldn't say that that uh that that we know 100 whether the brain has stem cells they might it might uh we know there are neural stem cells for neurons um but the brain doesn't heal um the heart the heart does have stem cells they're called cardiomyocytes but they don't grow very well and so when we talk about aging and skeletal muscle it's been shown that the stem cells in the skeletal muscle they don't grow as well either as we get older and they start to disappear so we lose the numbers and they don't work as well which is why when you injure yourself once you get older it takes a lot longer to heal and so with that being said imagine the possibilities that regenerative medicine could bring into this so if you need a knee replacement instead of getting the metal put into the knee right what if we could inject cells that would help reform the bone regrow regrow the lost cartilage right to heal the bone to heal that joint what about the soldier we talked about in the beginning what if they lose their leg but this is a little fantastical maybe right now what if you injected them with cells and growth factors biological factors that hold that leg turned on that growth process and the leg was able to grow back the salamander does it and as i said before we did it during embryonic development so the programming is there we just have to figure it out now i can't tell you that this is going to happen soon or even really within our lifetimes but these things are going to happen some of them are already happening some of it's already in the clinic so thank you you