Stem Cells and Diabetes

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Stem Cells and Diabetes
The Present
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Background

• 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.

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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

• juvenile-onset
• typically affects children and young adults
• immune system attacks and destroys? beta cells (ß
  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
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What is insulin?

• peptide hormone
• synthesized within the ß 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
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Question

• In type I diabetics, is it possible to get ?
  cells to produce insulin?
• two possible sources of ? cells
• existing ? cells
• adult stem cells

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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

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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

• Are there adult stem cells present in the
  pancreas that differentiate into beta cells?
• Are adult pancreatic beta cells formed by
  self-duplication, stem cell differentiation, or a
  combination of the two processes?

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Mouse-Model Study
A pulse-chase experiment performed by Professor
Douglas Melton and his team provides important
information about how beta cells are replaced.
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Keep in mind that cells are replaced by

• Adult stem cells
• Mitotic division of existing cells
• Combination of the two