İzole Edilmiş Sıçan Pankreas Adacık Hücrelerine in Vitro Trombospondinin Etkisi
Özet
Pancreas islet cells are very sensitive to hypoxic stress because
of having small amount of anti-oxidant enzyme. Loss of islet cell
viability due to hipoxic damage decreases success of transplantation.
Islet- endothelial co-culture prevents the cell death and improves the
cell function. Furthermore, transplanted islets to portal system are
also in close contact with the endothelial cells. Some of the
endothelium derived substance improve the viability of islet cells and
some of them cause negative effects. Thrombospondin(TSP) is a
multifunctional substance that is released from islet endothelial cells
and its effect on islet cell is not clear.
The aim of this study is to investigate whether TSP, which is an
endothelial factor, is effective on the islet cell’s viability and function.
Isolated islet cells were divided into three groups: in the control
group no substance were added to the normal culture medium. In ER
stress generated group, 20 μg/ml tunicamycin (TUN) and in the third
group 200pM thrombospondin (TSP) was added. Then groups were
incubated for 24 hours. We measured islet cell viability with FDA/PI
and cell function with glucose stimulation. We explored ER stress with
western blot and oxidative stress parameters. We concluded that 200 pM TSP does not affect the cell viability
but cause cell dysfunction. It did not appeare to come by endoplasmic
reticulum stress or oxidative stress.
According to the results, TSP may cause damage in different
mechanisms like exocytosis in the islet cells. The results of this study
may be supported with in vivo experiments, various doses of TSP and
incubation periods. Additional studies are needed to clarify the
cellular mechanisms that cause functional loss.
