The Power of Stem Cells Frontiers In Biology

The Power of Stem Cells Frontiers In Biology Dr. K. S. Dulai Spring 2008

What's all the fuss about! o. Stem cells are incredibly valuable to science o. They have the capacity to develop into any type of cell in the body o. They have the potential to be used for almost anything…

Headline news n n Past decade been in the news Potential use in treating diseases Political, ethical, moral, scientific concerns Need human embryos n n These die as a result of harvesting embryonic stem cells The embryos come from; n n n Unneeded in-vitro fertilization clinics Terminated pregnancies Embryo harvesting strategies

Specialized cells n An human adult is made up of over 200 different types of specialized cells Liver n Brain n Heart n Red blood cells n Bone n Photoreceptors, etc n

Stem Cells Each of the specialized cells arose from a less specialized cell - which itself arose from a lesser specialized one - these are the stem cells. n Every cell in the body (bar the red blood cells and the gametes - [sperm and egg]) has a nucleus with the same amount and quality of DNA - so each still has the capacity to make any other cell of the body n

What are stem cells? n n They are cells which have the potential to develop into other specialized cells. There are many different types of stem cells n n Adult Stem Cells - multipotent • All over your body • i. e. lining of the gut • i. e. there are special stem cells that give rise to the B and T cells of the immune system - no other just these Embryonic Stem Cells - pluripotent • Are different - see later… Fetal stem cells - pluripotent • Stem cells taken from aborted fetal tissue Umbilical stem cells - multipotent • Stem cells take from umbilical cords - treatment of blood disorders

New science n n n Stem cells are at the center of a new field of science called regenerative or reparative medicine Involves isolation of stem cells Growth of these in special environments Harvesting and use Cures for n n n Cancer? Diabetes? Parkinson's Disease? Organ failure? Already used in treating leukemia

Where did all the cells come from? When fertilization took place between a sperm and an egg there was just one cell - the zygote - which is totipotent n This one cell underwent cell division to form 2 cells - the embryo - which is also totipotent n These 2 cells divided to 4 cells, then 8, then 16, 32, 64… n

Simple embryo n n At about 50 -150 cells (4 days or so for humans) there is a defined structure to the embryo n n n We have the outer sphere of cells (which will form the placenta), and nested within it are some very special cells, the inner cell mass - these will make the baby - these are the embryonic stem cells which are the subject of news. Each of these has the capacity to form any tissue of the body To harvest these one has to destroy the embryo! Is the embryo a human life at this time or not?

No federal funding of new embryonic stem cells n n n G. W. Bush permitted cells that existed prior to 2001 to be used for research, but declared ineligible for federal funding any new lines Private funding is OK - California voters opted to allow $3 billion of state money to fund stem cell research here. Research continues in other countries - U. K. , China, India, Israel, etc. All three presidential candidates have plans to fund stem cell research with federal money!

Adult stem cells n n n Undifferentiated stem cells Also known as somatic stem cells - found in children and adults Organ or tissue specific n n n Heart stem cells can give rise to just heart tissue. Bone stem cells can give rise to just bone and blood cells. Does not demand the destruction of an embryo! Can be grown indefinitely - they self renew!

Real world uses n n n Stem. Cells Inc. of Palo Alto, California, recently announced successful early-stage trial results used stem cells to treat a patient with Batten's disease, a fatal neurodegenerative disorder Injected into the brain of patient stem cells designed to stimulate the production of an enzyme that's missing in such patients IT WORKED!

Park in sons n n Parkinson’s is one example of successful stem cell therapy: Primate studies show fetal stem cells can reverse Parkinson’s disease Parkinson’s is a muscle degeneration disorder that affects over 1, 000 people in the United States, and new cases being added at 9 per minute. The disease works in the exact opposite way as Alzheimer’s does…

Parkinson’s Disease n Parkinson’s begins with tremors and stiffness n eventually leaving the patient unable to • Move • Speak • Swallow n n It leaves a perfectly good mind trapped in a useless body, unable to move In recent studies done on primates n n who were injected with a neurotoxin that causes severe nerve damage, all symptoms were reversed after fetal stem cells were transplanted into the animals

M. J. Fox Ad n Interview n

New Promise Reverted Adult Stem Cells n n n Two groups have transformed skin cells into something very similar to embryonic stem cells. Using special genes added to the cells, the teams tricked the cells into reverting back to their embryonic state. Early days Solves the ethical issues! Self cells can be used easily.

Watch the video and answer these questions 1. 2. 3. 4. 5. 6. 7. Where was the research performed? Who performed this research? Which organs were made in the lab? Which animal had a broken back? Who donated the eggs for the research? Whose nuclear DNA was used for the stem cell therapy experiments? How many tries did it take the scientist to get the first dividing human embryonic stem cells?

Group questions 1. 2. 3. 4. 5. Is the embryo a human being yet? Why or why not? When would you consider it to be? Would you use stem cell research to help with curing a sick relative or child, if you had to? What problems do you see materializing with respect to using human embryonic stem cells? Should there be checks and balances to make sure the scientists behave and do not abuse the technology? What would these be? Would you be willing to accept a organ grown in another animal, such as a pig?