Lecture 4: Stem Cells and the End of Aging
by Nadia Rosenthal, Ph.D.
Play Lecture Four in Full
Welcome by HHMI President Dr. Thomas Cech
Dr. Nadia Rosenthal on teaching
Physiological characteristics of aging
Relationship between stem cell pool and ability to regenerate tissue
Three ways stem cells could affect aging
Capacity to rebuild muscle decreases with age
Older muscle has fewer satellite cells
Satellite cells from aging muscle are still potent
Aging reduces satellite cell signaling
The Notch-Delta molecular signaling pathway
Notch-Delta response differs in young and old muscle
Changing Notch levels affects muscle repair
Does the stem cell's environment change during aging?
Response of old mouse stem cells to young mouse environment
Young-old "pairing" improves repairing ability of old muscle
Serum factors can activate Notch pathway in old cells
Old muscle revival is due to young molecules, not young cells
Summary of factors involved in aging and stem cell response
Q&A: How do muscle cells "know" that they are injured?
Q&A: Why do tissues with high regeneration have medium stem cell numbers?
Q&A: Do old stem cells revert if the young environment is removed?
Q&A: In rapid aging diseases, do stem cells appear old or young?
Can we improve the heart's ability to regenerate?
Animation: Heart structure and function
Heart function is crucial, but the heart is a poor regenerator
Demo: Cause and effect of a heart attack
After a heart attack, cardiac tissue is lost
Other organisms can regenerate heart muscle
Animation: Zebrafish heart regeneration
Potential cell therapy for heart failure
Evidence that the heart can incorporate circulating cells
Using bone marrow stem cells to rebuild heart tissue
In recent trial, stem cell heart therapy had mixed results
Using the IGF-1 mouse to see if heart muscle can make new cells
Damage to cardiac tissue heals in the IGF-1 mouse
Cellular basis of IGF-1's role in cardiac tissue regeneration
IGF-1 animals express signaling factors that aid in regrowth
Tβ4 found to reduce scarring in heart damage
Tβ4 and FGF create a response similar to zebrafish regeneration
Stem cells for potential heart repair
Acknowledgments
Q&A: Are blood types a factor in heart transplants?
Dr. Thomas Cech announces speakers for next Holiday Lectures