Transcript Stem Cells and Diabetes

Stem Cells and Diabetes
The Present
Background
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Diabetes affects more people and causes
more deaths each year than breast
cancer and AIDS combined.
The American Diabetes Association
estimates that 16 million people, 5.9% of
the U.S. population, currently has some
type of diabetes.
What is diabetes?
group of diseases
 abnormally high levels of glucose in the
blood
 possible complications include blindness,
stroke, kidney failure, heart disease, poor
circulation, and amputation
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Type 1 Diabetes
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juvenile-onset
typically affects children and young adults
 immune system attacks and destroys
beta cells (β cells) in the islets of
Langerhans of the pancreas that normally
produce insulin
 glucose does not enter the cells and
therefore accumulates in the blood
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Type 2 Diabetes
adult-onset diabetes
 typically affects older, sedentary, and
overweight individuals with a family
history of diabetes
 body cannot use insulin effectively
 due to insulin resistance, glucose
accumulates in the blood
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Role of Pancreas in Diabetes
What is insulin?
peptide hormone
 synthesized within the β cells of the islets of
Langerhans located in the pancreas
 affects metabolism and other body functions
 causes cells in the liver, muscle, and fat
tissue to take up glucose from the
bloodstream
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Role of Pancreas in Diabetes
Question:
In type I diabetics, is it possible to get
 cells to produce insulin?
 two possible sources of  cells
• existing  cells
• adult stem cells
What are adult stem cells?
They are:
 undifferentiated cells that occur in
differentiated tissue
 able to make identical copies of
themselves
 able to yield specialized cell types of the
tissue from which they originated
 do not replicate indefinitely in culture
Researchers are Investigating:
Is it possible to activate the differentiation
of adult stem cells present in the
pancreas in order to produce needed
insulin in type I diabetics?
 What advantage/disadvantage would this
have over organ/islet transplantation or
insulin injection?
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Researchers Would Need to Know:
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Are there adult stem cells present in the
pancreas that differentiate into beta cells?
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Are adult pancreatic beta cells formed by
self-duplication, stem cell differentiation,
or a combination of the two processes?
Mouse-Model Study
A pulse-chase experiment performed
by Professor Douglas Melton and his
team provides important information
about how beta cells are replaced.
Keep in mind that cells are
replaced by:
Adult stem cells
 Mitotic division of existing cells
 Combination of the two
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