Stem Cells and Regenerative Biology 10 June 2007 Major Topics for Discussion: 1) What are Stem Cells? 2) What are the major types of Stem Cells and where are they found? 3) Advantages & Disadvantages to Embryonic SCs and Adult SCs 4) Why are Stem Cells so very important? 5) The Controversy over Stem Cells?

What are Stem Cells? Stem Cells are extraordinary because: They can divide and make identical copies of themselves over and over again (Self-Renewal) Remain Unspecialized with no ‘specific’ function or become.... ***Specialized (Differentiated) w/ the potential to produce over 200 different types of cells in the body.

Description: A colony of embryonic stem cells. 10X. Image in the Public Domain. Description: (A) Human ESCs; (B) Neurons derived from Human ESCs. Images courtesy of Nissim Benvenisty.

Click Below for Tutorial Caption: This image depicts a colony of human embryonic stem cells grown over a period of 10 months in the absence of mouse feeder cells. The cell nuclei are stained green; the cell surface in red. Photo Credit: Courtesy Ren-He Xu/University of WisconsinCourtesy Ren-He Xu/University of Wisconsin

The Major Types of Stem Cells A.Embryonic Stem Cells Embryonic cells left over from In-Vitro Fertilization in the laboratory From aborted fetuses B. Adult Stem Cells Stem cells have been found in the blood, bone marrow, liver, kidney, cornea, dental pulp, umbilical cord, brain, skin, muscle, salivary gland....

the cell that develops into an embryo is totipotent — it has the capacity to produce all human tissues.

late 1980s: Inner Cell Mass Cells, isolated from blastocysts, form colonies of undifferentiated cells some of which spontaneously develop into a variety of cell types

Step 5: Show the Breadth of Research Efforts What about Adult (somatic) stem cells?

Next: Cell Doping?

Advantages and Disadvantages to Embryonic and Adult Stem Cells. Embryonic S.C.Adult S.C. “Pluripotent” (can become any cell) “Multipotent” (“can become many but not any”) Stable. Can undergo many cell divisions. Less Stable. Capacity for self-renewal is limited. Easy to obtain but blastocyst is destroyed. Difficult to isolate in adult tissue. Possibility of rejection??Host rejection minimized

STEM CELLS = A HUGE HEATED DEBATE!!!!

Reprinted with permission of Do No Harm. Click on image for link to website.

Why is Stem Cell Research So Important to All of Us? Stem cells allow us to study how organisms grow and develop over time. Stem cells can replace diseased or damaged cells that can not heal or renew themselves. We can test different substances (drugs and chemicals) on stem cells. We can get a better understanding of our “genetic machinery.”

Reprinted with permission from the Univ. of Kansas Medical Center. Click on image for link to originating website.

What Human Diseases are Currently Being Treated with Stem Cells? Parkinson’s Disease Leukemia (Bone Marrow Transplants) Skin Grafts resulting from severe burns Stem Cell Therapy has the Potential to: Regenerate tissues/organs Cure diseases like diabetes, multiple sclerosis, etc.

Your Body Is Younger Than You Think You might just be 10 years old! Most body tissues are under constant renewal! Jonas Frisen, stem cell researcher Neurons in Cerebral cortex – long living cells! (DON’T RUIN THEM!!!!!) Gut/intercostal muscles by your ribs = 15 years New bones every 7-10 years!

Why doesn't the regeneration continue forever? DNA - accumulates mutations and its information is gradually degraded. Mitochondria- lacks the repair mechanisms available for the chromosomes. Stem cells that are the source of new cells in each tissue eventually grow feeble with age. … "The notion that stem cells themselves age and become less capable of generating progeny is gaining increasing support," SO… STEM CELLS = IMMORTALITY???? WHAT?

Why the Controversy Over Stem cells? Embryonic Stem cells are derived from extra blastocysts that would otherwise be discarded following IVF. Extracting stem cells destroys the developing blastocyst (embryo). Questions people are considering… Is an embryo a person? Is it morally acceptable to use embryos for research? When do we become “human beings?” For further information:

VIDEO!

Meaning: Cells with Embryonic Stem cell Properties can be produced from adult skin cells New Term: iPS cells [induced Pluripotent Stem cells] New Term: iPS cells [induced Pluripotent Stem cells]

Cell alchemist. Douglas Melton has turned pancreatic cells into insulin-producing cells. Nature: September 2008

March 2009

Feb 2009: iPS cells without viruses.

Phew….. We are starting to figure this all out…. But there is still a lot of work ahead of us…