Transcript Stem Cells - Rovira i Virgili University

Stem Cells
A basic overview
Eva Maria Lopez Mendoza
Department of Chemical Engineering
University Rovira i Virgili,
Tarragona
Topics
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Introduction
Stem cells and their main properties
Embryonic stem cells
Adult stem cells
Differences between adult and embryonic stem cells
Potential uses of human stem cells
Obstacles to these uses
Some more information
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Introduction
Two main reasons to do research:
1. How an organism develops from a single cell
2. How healthy cells replace damaged cells in adult organisms
Possibility of cell-based therapies to treat disease
Regenerative or reparative medicine
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Stem cells and main properties
Unspecialized human or animal cells that can produce
mature specialized body cells and at the same time
replicate themselves.
definition
properties
1. They can divide and renew themselves for long periods
2. They are unspecialized
3. They can give rise to specialized cell types: differentiation
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Embryonic stem cells
Embryonic stem cells are derived from a blastocyst, which is very young
embryo that contains 200 to 250 cells and is shaped like a hollow sphere.
The blastocyst includes three structures:
a.
the trophoblast, the layer of cells that
surrounds the blastocyst;
b.
the blastocoel, the hollow cavity
inside the blastocyst;
c.
the inner cell mass, a group of
approximately 30 cells at one end of
the blastocoel.
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Adult stem cells
An adult stem cell is an undifferentiated cell found among differentiated
cells in a tissue or organ, can renew itself, and can differentiate to yield
the major specialized cell types of the tissue or organ.
The primary roles of adult stem cells in a
living organism are to maintain and
repair the tissue in which they are found.
Scientists in many laboratories are trying to find ways to grow adult stem
cells in cell culture and manipulate them to generate specific cell types so
they can be used to treat injury or disease.
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Embryonic vs adult stem cells
Adult stem cells
Embryonic stem cells
Can become all cell types of the YES
body because they are pluripotent.
NO
Are limited to differentiating into
different cell types of their tissue of origin.
YES
Large numbers of embryonic
stem cells can be relatively easily
grown in culture.
NO
Are rare in mature tissues and
methods for expanding their numbers in
cell culture have not yet been worked out.
NO
Embryonic stem cells from a
donor introduced into a patient
could cause transplant rejection.
Patient's own cells could be expanded YES
in culture and then reintroduced into the
patient: the cells would not be rejected by
the immune system.
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Potential use of human stem cells
Studies of human embryonic stem cells may yield information about the
complex events that occur during human development.
A better understanding of the genetic and molecular controls of these
processes may yield information about how some diseases, such as cancer
and birth defects, arise and suggest new strategies for therapy.
Human stem cells could also be used to test new drugs: new medications
could be tested for safety on differentiated cells generated from human
pluripotent cell lines.
The most important potential application of human stem cells is the
generation of cells and tissues that could be used for cell-based therapies.
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Obstacles to these uses
Difficulty of identifying stem cells in tissue cultures, which contain
numerous types of cells.
Once stem cells are identified and isolated, the right biochemical solution
must be developed to cause these progenitor cells to differentiate into the
desired cell type. This too will require a great deal of experimentation.
The cells must be integrated into the patient's own tissues and organs and
"learn" to function in concert with the body's natural cells.
Possibility that tissue rejection can take place.
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Possible risk of cancer.
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Some more information
1. http://stemcells.nih.gov/
A listing of all the information about stem cells on the NIH Web site.
2. http://www.news.wisc.edu/packages/stemcells/
The University of Wisconsin's Web site about stem cells, written for general audiences.
3. http://www.eurekalert.org/
EurekAlert! is a publicly accessible science news site run by the American Association for
the Advancement of Sciences.
4. http://scitechdaily.com/
A site that offers a range of news articles, features, and commentaries about science and
technology topics.
5. http://www.sciam.com/index.cfm
The Web site for Scientific American.
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