Stem cells

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14 Δεκ 2012 (πριν από 4 χρόνια και 6 μήνες)

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Stem Cells and Regenerative Medicine

“Glow
-
in
-
the
-
dark” dogs!

What is stem cell research?


Understand more about development, aging,
disease


Experimental model systems


Prevent or treat diseases and injuries


Cell
-
based therapies


Pharmaceutical development


Includes testing and drug delivery



Trachea transplantation:

Example of adult stem cell
-
based tissue regeneration

Outline of Presentation


Introduction to fertilization and embryonic
development


What makes stem cells unique?


What do stem cells look like?


What are the different types of stem cells?


What are examples of stem cell research, therapies,
and technologies?





How did they make those dogs?


Conclusion and future directions












In the IVF procedure, sperm and eggs “interact” in a dish leading to insemination.

They literally swim up to the egg and burrow toward the nucleus.

The first one to get there wins, and all others are blocked out.


Male fertility issue: Sometimes sperm cannot latch onto and penetrate the egg.

They may choose to have Intra(within)
-
Cytoplasmic Sperm Injection (ICSI)

Day
1

Embryonic

Stem

Cells

At what point is this a fetus?


Days
7
-
14
:
Uterine implantation


Day
14
:
Three distinct layers begin to form




(no more pluripotent stem cells)


Days
14
-
21
:
Beginning of future nervous system


Days
21
-
24
:
Beginning of future face, neck,




mouth, and nose


Weeks
3
-
8
:
Beginning of organ formation








This picture is Week
5


Week
5
-
8
+:
Now it’s called a fetus






(no consensus on a single timepoint)




Embryonic Development:


Zebrafish

model

Keller et al.
2008

Outline of Presentation


Introduction to fertilization and embryonic
development


What makes stem cells unique?


What do stem cells look like?


What are the different types of stem cells?


What are examples of stem cell research,
therapies, and technologies?


Conclusion and future directions












Symmetric cell division

Asymmetric cell division

1.
Self
-
renews

2.
Differentiates

Progenitor cell

Stem cell

Stem cell



SELF


RENEWAL


Outline of Presentation


Introduction to fertilization and embryonic
development


What makes stem cells unique?


What do stem cells look like?


What are the different types of stem cells?


What are examples of stem cell research,
therapies, and technologies?


Conclusion and future directions












Embryonic stem cells in the dish:

What do cultured ES cells look like?

Fluorescent imaging of embryonic

stem cell colonies.

Outline of Presentation


Introduction to fertilization and embryonic
development


What makes stem cells unique?


What do stem cells look like?


What are the different types of stem cells?


What are examples of stem cell research,
therapies, and technologies?


Conclusion and future directions












This cell

Can form the

Embryo and placenta

This cell

Can just form the

embryo

Fully mature

Stem cells in the adult brain:

Are they still working for us now?

Stem cells in mature skeletal muscle:

Is there power still in our stem cells?

Signals to Stem Cells

Other Cells

Matrix Molecules

Self
-
Renewal

Soluble Factors

Differentiation

Little, et al.

Chemical Reviews

(
2008
).

All cells in a person share the same genotype

Yet eye cells differ from nose cells

Central dogma of biology



RNA

Protein


Cell
type

Niche
factors

DNA

Genetic
engineering

Tissue
therapy

How do cells know what to become?

Induced Pluripotent Stem (
iPS
) Cells

Genetically engineering new stem cells

Skin cells

iPS cells

Recreating Pluripotency

Image courtesy of Clontech

Induced Pluripotent Stem (
iPS
) Cells

Genetically engineering new stem cells

Skin cells

iPS cells

Pros and Cons to iPS cell
technology


Pros:


Cells would be genetically identical to patient or
donor of skin cells (no immune rejection!)


Do not need to use an embryo


Cons:


Cells would still have genetic defects


One of the pluripotency genes is a cancer gene


Viruses might insert genes in places we don’t want
them (causing mutations)




Factors known to affect stem cells



Low stress levels


Regular exercise


Enriching experiences


Learning new information


Healthy diets: rich in antioxidants


Avoid excessive drinking


Outline of Presentation


Introduction to fertilization and embryonic
development


What makes stem cells unique?


What do stem cells look like?


What are the different types of stem cells?


What are examples of stem cell research,
therapies, and technologies?


Conclusion and future directions












Experimental model system

Heart muscle cells beating in a petri dish!


Videos by the Exploratorium

Bone marrow transplant:

Example of adult stem cell
-
based therapy

Spinal cord injury:

Example of embryonic stem cell
-
based therapy

Geron video:
http://www.geron.com/grnopc
1
clearance/

Stem cells for drug delivery

More focused delivery, fewer side affects

NSCs
injected

(no tumor)

NSCs
injected
(tumor)

Day
0

Day
7

Day
14

Shah et al.
Dev Neurosci

2004

What are stem cell technologies?


Cloning technologies


Is human cloning a technology?


What is different about cloning embryonic stem cells?



Induced Pluripotent Stem cells


New ways to potentially avoid the use of embryos


Disease
-
specific stem cell lines created


The promise and potential pitfalls of this approach


When does research actually become technology?



Somatic Cell Nuclear Transfer (SCNT)

Cloning of embryonic stem cells

Egg cell

Udder cell

Types of Cloning

Outline of Presentation


Introduction to fertilization and embryonic
development


What makes stem cells unique?


What do stem cells look like?


What are the different types of stem cells?


What are examples of stem cell research,
therapies, and technologies?


Conclusion and future directions












Why do researchers want to use embryonic
stem cells along with other technologies?


Pluripotent


Expanded developmental potential allows them


to be used in ways that adult stem cells cannot


Can proliferate indefinitely in culture


Easier to obtain than adult stem cells

Science is discovering the unknown


Stem cell field is still in its infancy


Human embryonic stem cell research is a decade old,
adult stem cell research
has
30
-
year head start


Holds hope for curing
or

improving

treatments for


70
+ diseases



How can
you

help to shape the direction of this field?


Students:


https://www.surveymonkey.com/s/stemcell
2010



Teacher:


https://www.surveymonkey.com/s/stemcellteach
2010

Take our survey please!