PMID- 15888689
OWN - NLM
STAT- MEDLINE
DCOM- 20051103
LR  - 20181217
IS  - 1066-5099 (Print)
IS  - 1066-5099 (Linking)
VI  - 23
IP  - 7
DP  - 2005 Aug
TI  - Sequestration and synthesis: the source of insulin in cell clusters 
      differentiated from murine embryonic stem cells.
PG  - 862-7
AB  - The source of insulin released from insulin-releasing cell clusters (IRCCs) 
      differentiated from embryonic stem cells remains unclear. Rajagopal et al. have 
      suggested that IRCCs do not synthesize but secrete insulin that had been absorbed 
      from media during the multistep protocol. We report here further data relevant to 
      this controversy. No radioisotopic labeling of insulin was observed when IRCCs 
      were incubated in a medium containing 35S-cysteine. Less than 1% of the 
      extra-cellular stoichiometric C-peptide equivalent to insulin was secreted during 
      glucose stimulation. However, intracellular immunostaining and immunogold 
      labeling were both positive for C-peptide. Finally, a mass balance calculation 
      showed that simple equilibration of IRCCs by Fickian diffusion from media 
      accounted for at most 4% of secreted insulin. These findings and further analysis 
      of the results of others suggest that the mechanism of insulin secretion by IRCCs 
      is a combination of sequestration and de novo synthesis.
FAU - Paek, Hyun Joon
AU  - Paek HJ
AD  - Center for Biomedical Engineering, Brown University, Providence, Rhode Island, 
      USA. Hyun_Paek@brown.edu
FAU - Morgan, Jeffrey R
AU  - Morgan JR
FAU - Lysaght, Michael J
AU  - Lysaght MJ
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20050511
PL  - England
TA  - Stem Cells
JT  - Stem cells (Dayton, Ohio)
JID - 9304532
RN  - 0 (C-Peptide)
RN  - 0 (Insulin)
RN  - 0 (Peptides)
RN  - 0 (RNA, Messenger)
RN  - 0 (Radioisotopes)
RN  - IY9XDZ35W2 (Glucose)
RN  - K848JZ4886 (Cysteine)
SB  - IM
MH  - Animals
MH  - Autoradiography
MH  - C-Peptide/chemistry
MH  - Cell Differentiation
MH  - Cell Proliferation
MH  - Cells, Cultured
MH  - *Culture Techniques
MH  - Cysteine/metabolism
MH  - Diffusion
MH  - Electrophoresis, Polyacrylamide Gel
MH  - Embryo, Mammalian/*cytology
MH  - Fibroblasts/metabolism
MH  - Glucose/metabolism
MH  - Guinea Pigs
MH  - Immunohistochemistry
MH  - Immunoprecipitation
MH  - Insulin/*metabolism
MH  - Insulin Secretion
MH  - Islets of Langerhans/cytology
MH  - Mice
MH  - Microscopy, Electron, Transmission
MH  - Peptides/chemistry
MH  - RNA, Messenger/metabolism
MH  - Radioisotopes/metabolism
MH  - Rats
MH  - Stem Cells/*cytology
EDAT- 2005/05/13 09:00
MHDA- 2005/11/04 09:00
CRDT- 2005/05/13 09:00
PHST- 2005/05/13 09:00 [pubmed]
PHST- 2005/11/04 09:00 [medline]
PHST- 2005/05/13 09:00 [entrez]
AID - 2004-0288 [pii]
AID - 10.1634/stemcells.2004-0288 [doi]
PST - ppublish
SO  - Stem Cells. 2005 Aug;23(7):862-7. doi: 10.1634/stemcells.2004-0288. Epub 2005 May 
      11.