Download OP 08 Can we make new beta cells? 43 Differentiation of functional

OP 08 Can we make new beta cells?
43
Differentiation of functional human insulin-producing stem cell derived beta cells from iPS cells
F. Chimienti1, A. Kvist2, A. Forslöw2, J. Eriksson2, P. Stillemark-Billton1, M. Sörhede-Winzell1, C.
Wennberg-Huldt1, E.-M. Andersson1, P. Eliasson1, R. Hicks2, D. Shvartsman3, D.A. Melton3, B. Tyrberg1;
1
Cardiovascular and Metabolic Diseases, Innovative Medicines and Early Development Biotech Unit,
AstraZeneca R&D, 2Discovery Sciences, Innovative Medicines and Early Development Biotech Unit,
AstraZeneca R&D, Mölndal, Sweden, 3Department of Stem Cell and Regenerative Biology, Harvard
Stem Cell Institute, Harvard University, Cambridge, USA.
Background and aims: Drug discovery in the islet and beta cell field is in need of an “unlimited” source
of human, gene editable and functional islet cells to improve through-put and translability. We aimed to
establish a differentiation protocol to allow induced pluripotent stem cells (iPS) to differentiate to mature
beta-cells in vitro in an industrial setting suitable for use in screening for novel beta-cell drug targets.
Materials and methods: Two genetically different iPS cell lines were differentiated in spinner flasks
applying a six weeks differentiation protocol developed at Harvard University. Quality controls were
performed at each stage of differentiation. Sc-beta cells were characterized using flow cytometry,
immunochemistry and functional assays. We also aimed to establish an sc-beta transplantation model to
create a translatable in vivo disease models for testing of beta-cell regenerative and restorative drug
candidates. Furthermore we used flow cytometry to sort dispersed cells after differentiation and to obtain
an enriched population of sc-beta cells.
Results: We successfully produced functional sc-beta cells from iPSCs of two different genetic
backgrounds. Markers for undifferentiated cells, e.g. Oct4, rapidly disappeared (from 95% to <3 %) as
markers of pancreatic progenitors and endocrine sc-beta cells, e.g. Pdx-1, Nkx6.1, insulin/c-peptide
appeared. We obtained up to 53% Pdx positive cells, with 12% of cells being c-peptide and Nkx6.1
double positive. We then characterized sc-beta with different stimuli to induce insulin secretion. The scbeta cells demonstrated significant responsiveness to KCl (+460 %, p<0.0001) indicating proper
production and processing of insulin. The cells also responded well to IBMX/Forskolin (+257 %,
p<0.001) indicating cAMP signalling to be intact. The glucose responsiveness was however weaker and
gave only a maximal effect of 35% (p<0.005). After transplantation of differentiated clusters under the
kidney capsule of NMRI nude mice, human c-peptide increased from 14±7 pM to 109+/- 27 pM between
2 and 10 weeks (p<0.0005), indicating that the cells were functional in vivo. Insulin positive cells
represented ~10% of total cells in a cluster. We took advantage of the large amounts of zinc contained in
pancreatic beta-cells to sort insulin positive cells with a zinc-specific probe, Zinpyr-1. We obtained an
unprecedented level of enrichment in sc-beta cells, with up to 85% insulin positive cells after FACS cell
sorting. This method will allow producing cell clusters with higher beta cell numbers and will represent a
better cell model suitable for screening purposes or islet studies.
Conclusion: These cells represent a new opportunity for drug discovery in the islet and beta cell field,as
they are of human origin, gene editable and functional. Besides opening new avenues for an improved
understanding of human beta cell biology , they also provide a scalable platform for in vitro and in vivo
drug discovery in diabetes.
Disclosure: F. Chimienti: None.