Islets Studies Illustrating Chemical Messengers That May Contribute To The
Onset of Type 1 Diabetes
Waseem Ullah
Type 1 diabetes is when the insulin producing cells (-cells) in the pancreas are thought
to be destroyed by an immune response, and therefore no longer being able to function
correctly in the metabolism of glucose. Cytokines are chemical messengers that are
thought to play an important role in the onset of this chronic autoimmune disease. The
cytokine interleukin-1 (proinflammatory mediator) has been strongly linked to -cell
destruction.
The aim of this study was to investigate the cellular and molecular mechanisms that
lead to the destruction of the -cells. Islet cells were isolated from adult mice pancreas
and cultured for seven days in medium at 37ºC. 250 islets were then transferred into the
outer layer of the kidney. After a seven-day period these islets were then re-isolated along
with the spleen of the mice. The transplanted islets showed impaired glucose metabolism,
as there was no increase in glucose oxidation when exposed to different concentrations of
radioactively labelled glucose. This suggests that the -cells had been destroyed. Many
cells had died, mostly through apoptosis, which is an organized form of cell death
normally accompanying differentiation (as opposed to accidental cell death).
The spleen cells secrete cytokines, and play an important role in the immune
response. The amounts of protein was determined to see if any significant concentrations
of cytokine proteins were present that could have been responsible for cell death. No
significant amounts could be detected. Through another process the RNA encoding the
cytokines was measured, but also these results did not show any specific mRNA present
for specific cytokines that may lead to -cell death.
Examensarbete i biologi, 20p, fall 2001
Department of Molecular Cell Biology, Uppsala University
Supervisor: Stellan Sandler