3. What are stem cells and why are they important?
Stem cells have the potential to develop into many
different cell types in the body during early life and
growth.
in many tissues they serve as a sort of internal repair
system
4. What is a stem cell?
Identical stem cells
Stem cell
SELF-
RENEWAL
(copying)
Stem cell
Specialized cells
DIFFERENTIATION
(specializing)
5. Properties of stem cells
they are capable of dividing and renewing themselves for
long periods
they are unspecialized
they can give rise to specialized cell types.
6. Where are stem cells found?
embryonic stem cells
blastocyst - a very early
embryo
adult stem cells
fetus, baby and throughout life
7. A few terms……
Potency: A measure of how many types of specialized
cells a stem cell can make
Totipotent: Each cell can develop into a new individual
Ex. Cells from early (1-3 days) embryos
Pluripotent: Can make all types of specialized cells in the
body.
Ex. Embryonic stem cells are pluripotent
Multipotent: Can make multiple types of specialized
cells, but not all types
Ex. Adult stem cells are multipotent
8. Embryonic stem (ES) cells:
Where we find them
blastocyst
outer layer of cells
= ‘trophectoderm’
cells inside
= ‘inner cell mass’
embryonic stem cells taken from
the inner cell mass
culture in the lab
to grow more cells
fluid with nutrients
9. Embryonic stem (ES) cells:
What they can do
embryonic stem cells
PLURIPOTENT
all possible types of specialized
cells
differentiation
13. Induced pluripotent stem cells (iPS cells)
cell from the body
‘genetic reprogramming’
= add certain genes to the cell
induced pluripotent stem (iPS)
cell
behaves like an embryonic stem
cell
Advantage: no need for embryos! all possible types of
specialized cells
culture iPS cells in the lab
differentiation
14. Induced pluripotent stem cells (iPS cells)
cell from the body (skin)
genetic reprograming
pluripotent stem cell
(iPS)
differentiation
15. Potential uses of human stem cells
http://video.pbs.org/video/1754537562/
16. Experimental model system
Heart muscle cells beating in a petri dish!
http://www.exploratorium.edu/tv/index.php?project=70&pr
ogram=746
1:37 – 2:43
Videos by the Exploratorium
18. Human trials:
The FDA approved the first clinical trial involving human
embryonic stem cells on January 23, 2009.
Geron Corporation - spinal cord injuries
In 2010
Stargardt’s Macular Dystrophy and Dry Age-Related
Macular Degeneration
In 2013
Severe myopia
19. Stem cells & Parkinson’s
http://www.youtube.com/watch?v=1yCgLythe00
Stem cells and ALS
Astrocytes in the spinal cord. Year 3 toward human
trial
http://www.youtube.com/watch?v=tplx_ftKdYc
Stem cells and Arthritis
http://www.ted.com/talks/kevin_stone_the_bio_future_of_j
oint_replacement