Differentiation of COPAS-sorted non-endocrine pancreatic cells into insulin-positive cells in the mouse.
OBJECTIVE
The regenerative process in the pancreas is of particular interest, since insulin-producing beta cells are lost in diabetes. Differentiation of new beta cells from pancreatic non-endocrine cells has been reported in vivo and in vitro, a finding that implies the existence of pancreatic stem/progenitor cells. However, while tissue-specific stem cells are well documented in skin, intestine and testis, pancreatic stem cells have been elusive. We hypothesised that pancreatic stem/progenitor cells within the non-endocrine fraction could be a source of new islets in vitro.


METHODS
To test if there were such cells within the pancreas, we generated pancreatic cell aggregates from tissue remaining after islet isolation from mouse insulin promoter 1-green fluorescent protein (MIP-GFP) mice. To eliminate any contamination of insulin-positive cells, we deleted all GFP-positive aggregates using COPAS Select and cultured with Matrigel. Immunohistochemistry, quantitative real-time PCR and single-cell nested RT-PCR were performed to confirm formation of insulin-producing cells.


RESULTS
The GFP-negative cells were expanded as monolayers and then differentiated into three-dimensional cystic structures. After 1 week of culture, GFP-positive cells were found as clusters or single cells. By quantitative real-time PCR, no insulin mRNA was detected immediately after COPAS sorting, but after differentiation insulin mRNA of the whole preparation was 1.91 +/- 0.31% that of purified MIP-GFP beta cells. All GFP-positive cells expressed insulin 1; most expressed insulin 2, pancreas duodenum homeobox-1 and cytokeratin 19 by single cell nested RT-PCR.


CONCLUSIONS
Our data support the concept that within the exocrine (acinar and ductal) pancreas of the adult mouse there are cells that can give rise to insulin-positive cells in vitro.
Kikugawa
R
R
Section of Islet Transplantation and Cell Biology, Joslin Diabetes Center, 1 Joslin Place, Boston, MA, 02215, USA.
Katsuta
H
H
Akashi
T
T
Yatoh
S
S
Weir
G C
GC
Sharma
A
A
Bonner-Weir
S
S
D000818:Animals; D018929:Cell Culture Techniques; D002469:Cell Separation / Q000379:methods*; D003922:Diabetes Mellitus, Type 1 / Q000601:surgery; D005434:Flow Cytometry; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics; D007328:Insulin / Q000235:genetics; D050417:Insulin-Secreting Cells / Q000166:cytology* / Q000502:physiology / Q000637:transplantation; D007515:Islets of Langerhans / Q000166:cytology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010179:Pancreas / Q000166:cytology / Q000502:physiology; D010183:Pancreatic Ducts / Q000166:cytology; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
D007328:Insulin; D012333:RNA, Messenger; D049452:Green Fluorescent Proteins