Stem cell science and policy. By: Rahul G. Thakar, Ph.D. Wednesday June 20, 2007. Overview. What are stem cells? Why use stem cells? Current application with stem cells. Public policy regarding stem cells. . Cells of the human body.
Rahul G. Thakar, Ph.D.
Wednesday June 20, 2007
a stem cell can reproduce itself by cell division
a stem cell can specialize into a particular type of somatic cellDifferentiation
A - stem cell
B - progenitor cell
C - differentiated cell
1 - symmetric stem cell division
2 - asymmetric stem cell division
3 - progenitor division
4 - terminal differentiation
Generates every cell in the body lineincluding the placenta and extra-embryonic tissues
Can form the entirehuman being
Can generate every cell in the body except placenta and extra-embryonic tissues
Cannot form the entire human being
Become specific cell types; may or may not have plasticity
Hematopoietic Stem Cell
START lineCell-based therapy-Spinal Cord Injury
Clinical trials starting for treatment
of spinal cord injury* in humans
(after much data gathered using rats
as an animal model)
(+ growth factors)
*Treatment may not work for the chronically paralyzed
Reya, T., et al. lineNature, 2001Drug Development-Cancer Stem Cells
Cell surface markers are a key difference.
Artificially directing stem cell fate
Why do you think this
What problems do you
foresee in trying to
transplant this tissue
into a human?
W.F. Liu, 2005
R. McBeath, 2004.
A. Engler, 2006.
R.G. Thakar, et. al, 2006
Coronary heart disease accounts for 36.3% deaths in the U.S. or 1 death every 36 seconds.
regulate growth, motility, and fate
at the site
promote attachment, alignment, and contractilie phenotype
arrangement similar to in vivo structures
C.M. Metallo, et al., Biotechnol. Prog., 23 (1), 18 -23, 2007.
D. Srivastava & K.N. Ivey Nature 441, 1097-1099(29 June 2006)
Note myofibrils in finger–like projections attaching to microrod. Also note all myofibrils are highly oriented.
A microrod-matrigel composite
Morphology of neonatal myocytes. A:: NRVM in 3D gel only. B: increased myocyte size with100μm microrods and gel. C: Note finger–like projections from myocytes attaching to microrods. Actin in red, α-actinin in green, SU-8 microrods in blue.
President Bush said in mid-May 2005, "I am a strong supporter of stem cell research, but I've made it very clear to Congress that the use of federal taxpayer money to promote science that destroys life in order to save life, I am against this."
This was in response to the House and Senate passing versions of the Stem Cell Resarch Enhancement Act of 2005. G.W. Bush vetoed the act on July 19, 2006.
Again in 2007, the Senate of the new, 110th Congress passed bill S.5, Stem Cell Research Enhancement Act of 2007. On June 7, 2007, the House passed this legislation.