1. Stem Cells: Scientific Potential and Alternatives

2. Review of Terminology DNA -
Gene - functional unit of heredity, a segment of DNA located at a specific site on a chromosome; genes direct the formation of proteins.
Nucleus –
Cell - the basic unit of life, all living organisms are made up of cells
somatic cell -
germ cell -

3. Differentiation of Human Tissues
Early embryonic cells unspecialized
Three primary tissue layers:
All tissues develop from here

5. Adult Stem Cells
Stem cells = cells that have the ability to divide for indefinite periods and
Remember:
Progenitor cells = partially specialized cells that can give rise

6. Stem Cells of the Bone Marrow

7. The Problem of Cell Potency
Multipotent –
Pluripotent –
Totipotent -

8. Derivation of hES Cells
“Excess” frozen blastocysts donated from fertility clinics
Inner cell mass (embryo) separated from trophoblast (placenta)
Cells dissociated and cultured in laboratory
Can be made to differentiate using chemical signals

9. Blastocyst Diagram

10. Dr. Hariom Yadav
12/4/2017

11. Dr. Hariom Yadav
12/4/2017

12. Dr. Hariom Yadav
12/4/2017

13. Applications of Pluripotent Stem Cells
“decision-making genes” (birth defects, cancer)
human cell lines for all cell types
replacement tissue for degenerative conditions (Parkinson’s and Alzheimer’s disease, diabetes, heart disease, stroke, arthritis)

14. Example: Diabetes Insufficient insulin production in
Insulin needed for
“ ” cells derived from stem cells produce insulin
Eliminates need for insulin injections

15. Scientific Challenges Remaining
Understanding of cellular events that lead to and
- Can stem cells be modified to minimize tissue incompatibility?
Time of development and expense of treatments

16. Rejection: Possible Solutions
Genetic engineering
Somatic cell nuclear transfer ( )
develops into a
Dolly the sheep

17. Alternatives to hES Cells
Umbilical cord blood
Contains and stem cells (lower potency than hES)
Patient specific
Cord blood banks
$2000 collection and $125/year storage fees
Some public banks for donated cells

18. Alternatives to hES Cells
Induced Pluripotent Stem Cells (iPS)

19. Alternatives to hES Cells
Induced Pluripotent Stem Cells (iPS)
Show potency than cord cells
Low efficiency (recent improvements)
Other problems

20. Alternatives to hES Cells
Direct Cell Reprogramming
Turns one cell
(ex. Skin cell  Neuron)
Uses RNA, no virus DNA needed
Eliminates need for
Potential and problems are uncertain

21. Autologous Stem Cell Therapies
Self-donation of
Injected (with or without chemical treatment) into
Not FDA approved
Clinical trials underway (heart attack, spinal cord injury, etc.)
Many Americans seek overseas options

22. Questions?
The United States has been criticized by some for being too restrictive to stem cell-based research and therapies. Should U.S. laws be relaxed to be more accommodating to those wishing treatment?
A recent study by Duke University predicted that by the year 2050, regenerative procedures based on stem cell and other biotechnologies could extend an average human life span by up to 100 years. Is this a desirable goal?
Many biotechnologies are vastly expensive, yet much of the basic research supporting these developments is paid for by taxpayers. Who should benefit?