Stem Cells Webquest

Stem Cells

Research using stem cells is a controversial and often misunderstood area of modern scientific research. In this exercise you will visit the official National Institutes of Health (NIH) website on stem cell information to gain a greater understanding of the fundamentals of this topic.

Activity:

Go to the NIH site on stem cells: http://stemcells.nih.gov/index.asp and click on the Info Center link “Stem Cell Basics.”  Starting with the “Introduction” section, read the information presented.

Use the site’s glossary to find definitions for these important terms:

Cell-based therapies-Treatment in which stem cells are induced to differentiate into the specific cell type required to repair damaged or destroyed cells or tissues.

Differentiation-The process whereby an unspecialized embryonic cell acquires the features of a specialized cell such as a heart, liver, or muscle cell. Differentiation is controlled by the interaction of a cell's genes with the physical and chemical conditions outside the cell, usually through signaling pathways involving proteins embedded in the cell surface.

Embryonic stem cell line-Embryonic stem cells, which have been cultured under in vitro conditions that allow proliferation without differentiation for months to years.

Proliferation-Expansion of the number of cells by the continuous division of single cells into two identical daughter cells.

Plasticity- The ability to change and adapt, especially the ability of the central nervous system to acquire alternative pathways for sensory perception or motor skills.

Pluripotent- Having the ability to give rise to all of the various cell types of the body. Pluripotent cells cannot make extra-embryonic tissues such as the amnion, chorion, and other components of the placenta. Scientists demonstrate pluripotency by providing evidence of stable developmental potential, even after prolonged culture, to form derivatives of all three embryonic germ layers from the progeny of a single cell and to generate a teratoma after injection into an immunosuppressed mouse.

Answer the following questions:

1. What are the unique properties of all stem cells?  Explain in your own words what each property means.

Stem cells are capable of dividing and renewing themselves for long periods; they are unspecialized; and they can give rise to specialized cell types.

2. What are the two main kinds of stem cells used by researchers?  What are the major differences between the two types in terms of their sources and usefulness to researchers?  Give examples for each type of stem cell.

Researchers used embrotic stem cells and adult stem cells. Embryonic stem cells come from embryos. They are useful to the researchers because they can become all cell types of the body. Adult stem cell is a body cell other than gametes. Adult stem cells are limited to differentiating into different cell types of there tissue or origin.

3. List some of the diseases that scientists think may be treated using stem cell research and suggest how stem cells might be used to treat each disease.

Scientists believe they may be able to treat diseases including Alzheimer's diseases, spinal cord injury, stroke, burns, heart disease, diabetes, osteoarthritis, and rheumatoid arthritis.

4. What are the necessary characteristics that laboratory-manipulated stem cells will need to have in order to be successfully used in cell-based therapies?

Before being used as theropy stem cells will need to Proliferate extensively and generate sufficient quantities of tissue, Differentiate into the desired cell type(s), Survive in the recipient after transplant, Integrate into the surrounding tissue after transplant, Function appropriately for the duration of the recipient's life, and Avoid harming the recipient in any way.