Differentiation of Adipocyte-Derived Adult Mesenchymal Stem Cells into Insulin Expressing Cells In Vitro.

Pfützner, Andreas; Rutkowski, Andrej; Tappe, Mareike; Roitzheim, Barbara; Pansky, Andreas; Forst, Thomas; Tobiasch, Edda

A major hurdle for widespread use of islet-cell transplantation in patients with type I diabetes is the limited availability of islet donor cells. One solution for this problem could be the differentiation of (preferably adult) stem cells into β-cells in vitro. To investigate this possibility in a proof-of-concept approach, we isolated mesenchymal adult stem ceils derived from human liposuction aspirates and cultivated them for 5 days with several induction factors, including nicotinamide, mifepristone, triiodothyronine and β-mercaptoethanol in low-glucose and low-FCS medium. We tested different induction media compositions and also added rat insulinoma cell lysates, as a source for further β-cell transcription factors. Each experiment was carried out in three replicates with unstimulated cells serving as control. After stimulation, the cells were microscopically controlled, stained with dithizone to test for insulin peptide presence, and RT PCR was applied to measure the expression level oft-cell specific RNA markers including insulin, ISL-1 and SOX. Insulin secretion into the cell supernatants was tested by chemiluminescence assay. At the end of the 5 day stimulation period, the stimulated cells had a different morphological appearance under the microscope and absorbed dithizone much stronger as compared to the un-stimulated control. RT-PCR analysis from these cells showed an increase in mRNA levels of insulin, ISL-1 and Sox2 and a slight decrease in the stem cell specific markers CD73 and CD 105. Insulin concentrations, as measured in the cell culture supernatants were elevated in the stimulated cells. The result of our pilot experiment demonstrates the potential of adult adipose tissue-derived stem cells to produce insulin after a specific stimulation. Further experiments, e.g. regarding the sensitivity of insulin mRNA expression to glucose in this cell population, are required to explore the option of using adipose-tissue derived stem cells as donor cell source in islet ceil transplantation.

FAT cells; STEM cells; INSULIN; CELLS; ADIPOSE tissues; ISLANDS of Langerhans transplantation

Diabetes, 2007, Vol 56, pA683

0012-1797

Academic Journal