Aging with dignity: the potential of regenerative medicine | Tracey Criswell | TEDxGreensboro
The speaker argues that changing the world requires changing thinking, using regenerative medicine's potential to address issues like severe injury and organ failure, which can be modeled by studying highly regenerative organisms like the axolotl. The primary focus of research is skeletal muscle, which declines with age due to diminishing adult stem cells.
## Speakers & Context
- Unidentified speaker; a scientist at the Wake Forest Institute of Regenerative Medicine.
- The speaker is a trained cell biologist who conducts basic research, focusing on cells and animals, rather than clinical practice.
- The speaker noted having small patients with four legs, as most of their patients are small.
## Theses & Positions
- To change the world, one must first change thinking, citing Albert Einstein's philosophy.
- Regenerative medicine has the potential to address severe injuries (e.g., battlefield injuries) and life-threatening conditions (e.g., waiting for an organ transplant).
- Aging is defined as a decline in biological functions, resulting in slower healing and reduced bodily capabilities.
- The core goal of research is to restore regenerative capability, specifically focusing on skeletal muscle.
- The process of tissue regeneration is not new, drawing historical parallels to Prometheus and Zeus.
## Concepts & Definitions
- **Regenerative Medicine:** The concept of making new tissues and organs through tissue regeneration.
- **Skeletal Muscle:** The tissue that allows the body to contract, walk, and move.
- **Aging:** Defined as a decline in biological functions over time.
- **Sarcopenia:** The loss of skeletal muscle function and mass over time, leading to decreased mobility and independence.
- **Adult Stem Cells:** Cells in the body that fix injured tissue; they become activated upon injury to repopulate and differentiate.
- **Satellite Cells:** The specific adult stem cells residing on skeletal muscle; they become active after muscle injury to heal the muscle.
## Mechanisms & Processes
- **Skeletal Muscle Healing:** Satellite cells sit on the muscle and activate upon injury to migrate, differentiate, and heal the tissue.
- **Disease Impact:** Age leads to reduced function and fewer/less effective satellite cells, resulting in slow healing.
- **Regeneration Inspiration:**
- **Axolotl:** Can regrow a leg (takes about 60 days) and almost all its organs, including parts of the brain.
- **Hydra:** Can regenerate from single cells because the cells are supported by a protein scaffold.
- **Planaria:** Can be cut into over 250 pieces, with each piece regrowing into a complete worm.
- **Liver Regeneration:** Considered highly regenerative, capable of filtering all ingested substances (drugs, alcohol, fast food).
- **Transplant Waiting Risk:** Patients on transplant lists have a greater chance of dying while waiting than receiving an organ.
## Timeline & Sequence
- **Historical Reference (Liver):** The ancient Greeks understood the liver's regenerative properties.
- **Historical Reference (Mythology):** Zeus tying Prometheus to a rock, where an eagle ate and the liver regrew daily.
- **Evolutionary Milestone:** Embryonic development, when the body forms from a single fertilized egg.
- **Current Research Focus:** Understanding how muscle function and healing change with age.
## Named Entities
- **Wake Forest Institute of Regenerative Medicine:** Speaker's workplace.
- **Prometheus:** A Titan/Greek god who formed man out of clay.
- **Zeus:** Greek god; brother of Prometheus.
- **Axolotl:** A type of salamander noted for its high regenerative capacity.
- **Hydra:** Small carnivore mentioned for its ability to regrow from single cells due to a protein scaffold.
- **Planaria:** Freshwater flatworms noted for their exceptional regenerative abilities.
## Numbers & Data
- Regeneration period for an axolotl leg: **about 60 days** (month and a half/two months).
- Number of pieces Planaria can be cut into: **more than 250**.
- Number of minutes for regenerative process comparison: **10,000 atm** (deep sea pressure vs. 1 atm at surface).
## Examples & Cases
- **Scenario 1 (Battlefield):** Soldier injured on the battlefield is offered surgery/prosthetic versus undergoing "dozens of surgeries and months of painful rehabilitation."
- **Scenario 2 (Diabetic):** Patient needing a kidney transplant must wait for a donor, with a higher risk of death while waiting than receiving an organ.
- **Skeletal Muscle Deterioration:** Difficulty going down steps, requiring reliance on a handrail.
- **Menopause Transition:** Period lasting from the time of child-rearing age decline to one year after the last menses, lasting up to **10 years**.
- **Postmenopausal Health Risks:** Increased heart disease, cardiovascular disease, osteoporosis (bone loss), hypertension, and greater loss of muscle function/mass.
- **Ideal Future Scenario:** Replacing a metal knee implant with cells that help reform bone and regrow cartilage; injecting cells to let a lost limb regenerate fully.
## Counterarguments & Caveats
- The speaker explicitly states the current research goal is *not* to make people live to 120.
- Current understanding: The brain does not heal easily after injury (e.g., traumatic brain injury).
- Current understanding: The heart's stem cells (cardiomyocytes) do not grow very well.
- Timeline warning: The regenerative possibilities described are "a little fantastical" and "I can't tell you that this is going to happen soon or even really within our lifetimes."
## Methodology
- **Observation/Analysis:** Comparing the regenerative capacities of different organisms (liver, axolotl, hydra, planaria) against human limitations.
- **Model Study:** Focusing the research on skeletal muscle to understand age-related decline (sarcopenia).
- **Hypothetical Application:** Modeling future treatments like in-situ bone/cartilage regeneration or limb regrowth using growth factors and cells.
## Conclusions & Recommendations
- Regenerative medicine aims to remake tissues and organs by leveraging the body's natural ability to regenerate.
- The goal is functional restoration, allowing people to "age gracefully for my last chapters."
- Future potential includes injecting cells and growth factors to actively restart growth processes in lost or damaged tissues/limbs.
## Implications & Consequences
- The study of adult stem cells is crucial, as they are vital for tissue repair when activated.
- The potential for regenerative medicine shifts the focus from merely *treating* decline to *reversing* it at a cellular level.
- Failure to understand regeneration leads to chronic limitations, such as permanent deficits from traumatic brain injury.
## Verbatim Moments
- *"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"*
- *"I can't guarantee that you'll get full function back"*
- *"we're going to have to wait for someone to die for us to save your life"*
- *"The definition of aging is a decline in the biological functions as we get older"*
- *"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"*
- *"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"*
- *"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"*
- *"it can grow if you cut it in half it'll grow two heads or two tails depending on which end they're they're incredible"*
- *"they're filled with stem cells and their cells so that's why it's my favorite creature of all"*
- *"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"*
- *"what if we could inject cells that would help reform the bone regrow regrow the lost cartilage"*
- *"the programming is there we just have to figure it out now"*