ISSN:
1040-452X
Keywords:
Embryonic stem cells
;
Insulin
;
IGF-I
;
IGF-II
;
Receptor
;
RT-PCR
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
Insulin and insulin-like growth factors (IGF-I and -II) are members of a family of growth factors which are known to be developmentally regulated during preimplantation mouse embryogenesis. The physiological actions of the insulin family of growth factors are mediated by interactions with specific cell surface receptors that are detectable on the cells of preimplantation mouse embryos. Mouse embryonic stem (ES) cells are totipotent cells derived directly from the inner cell mass of the blastocyst. ES cells have the ability to differentiate into all three germ layers and have unlimited growth potential under certain culture conditions. The great advantage of ES cells is the ability to obtain large amounts of tissue for biochemical studies as compared with preimplantation embryos. To examine in greater detail the biological actions of the insulin family of growth factors, the expression of their cognate receptors on ES cells was examined. ES cells were cultured in DMEM medium supplemented with leukemia inhibitory factor (LIF) to maintain the undifferentiated state. Receptor expression was evaluated at the mRNA level using the reverse transcription polymerase chain reaction (RT-PCR), and at the protein level by radioactive labeled ligand-receptor binding assay. Using RT-PCR, mRNAs of all three growth factor receptors were detected in ES cells. Messenger RNA from ES cells was reverse transcribed into cDNA by AMV reverse transcriptase at 42°C for 1 hr. The reverse transcription reaction was amplified with Taq polymerase and specific primers for insulin, IGF-I, or IGF-II receptors by PCR. RT-PCR and the control plasmid cDNA PCR products were resolved electrophoretically on 3% agarose gels. Each amplified PCR product showed the predicted correct size. The target sequence of RT-PCR amplified fragments were further verified by restriction enzyme digestion. The expression of receptors at the protein level was confirmed by Scatchard analysis, which showed specific binding of the radiolabeled ligands. This study shows that ES cells may provide a useful model to study the biological actions of the insulin family growth factors. © 1995 wiley-Liss, Inc.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrd.1080420206
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