1. www.BioEdOnline.org BioEd Online Overview Mature tissue cell vs a stem cell What is a stem cell? How do we get stem cells? What is the difference between embryonic and adult stem cells? Why are stem cells medically important? Stem cells Photo: NIH Stem Cell Unit

2. www.BioEdOnline.org BioEd Online

3. www.BioEdOnline.org BioEd Online Stem cell sphere Cortical neurons

4. www.BioEdOnline.org BioEd Online Stem cell Terminology Differentiation - cell specialization that occurs at the end of the developmental pathway. Totipotent - a cell capable of giving rise to any of the cell types in the adult. In humans, the fertilized egg is totipotent until the eight-cell-stage. Multipotent - can give rise to several other cell types, but those types are limited in number. An example is a blood stem cell that can develop into several types of blood cells, but cannot develop into brain cells. bloodbrain cells.

5. www.BioEdOnline.org BioEd Online Unlimited Cell Division Pluripotent Tissue cells Limited Cell Division Found in tissues Multipotent Self-renewal decreases, Differentiation increases Blood, Brain etc. Differentiated

6. www.BioEdOnline.org BioEd Online What is a Stem Cell? Unspecialized cells Able to self-renew without differentiating for extended periods of time Types of stem cells Embryonic stem cells adult stem cells Umbilical cord stem cells. TIME 2001 Human blastocyst showing inner cell mass Photo: Mr. J. Conaghan

7. www.BioEdOnline.org BioEd Online Embryonic Stem Cells Can Become Any Tissue in the Body Blastocyst Cultured laboratory stem cells Scientific manipulations entice stem cells to become specialized tissues (blood, muscle, neuron, etc.). Blood cells Muscle cells Neuron (brain) cells Placenta cell Stem cell

8. www.BioEdOnline.org BioEd Online Adult Stem Cells Have two characteristics: Self-renewal. They can give rise to differentiated mature cells Found in the brain, spinal cord, blood, muscle, the digestive system, retina, liver and pancreas.

9. www.BioEdOnline.org BioEd Online Umbilical cord stem cells This blood is rich in cord blood stem cells that can be used to generate blood cells and cells of the immune system. can be used to treat a range of blood disorders such as Leukaemia or sickle cell anaemia. Leukaemia sickle cell anaemia

10. www.BioEdOnline.org BioEd Online What Diseases Could Be Impacted by Stem Cell Research? Millions of people suffer from diseases which might be alleviated by stem cell transplantation technologies. Examples include cardiovascular disease, autoimmune disease, diabetes, osteoporosis, cancer, Alzheimer’s disease and Parkinson’s disease. Stem cell treatment could potentially help patients with severe burns, spinal cord injuries, or birth defects. Science (2000) 287:1423.