| 1. |
- Hansson, Mattias, et al.
(författare)
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Artifactual insulin release from differentiated embryonic stem cells.
- 2004
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Ingår i: Diabetes. - 0012-1797. ; 53:10, s. 2603-9
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Tidskriftsartikel (refereegranskat)abstract
- Several recent reports claim the generation of insulin-producing cells from embryonic stem cells via the differentiation of progenitors that express nestin. Here, we investigate further the properties of these insulin-containing cells. We find that although differentiated cells contain immunoreactive insulin, they do not contain proinsulin-derived C-peptide. Furthermore, we find variable insulin release from these cells upon glucose addition, but C-peptide release is never detected. In addition, many of the insulin-immunoreactive cells are undergoing apoptosis or necrosis. We further show that cells cultured in the presence of a phosphoinositide 3-kinase inhibitor, which previously was reported to facilitate the differentiation of insulin(+) cells, are not C-peptide immunoreactive but take up fluorescein isothiocyanate-labeled insulin from the culture medium. Together, these data suggest that nestin(+) progenitor cells give rise to a population of cells that contain insulin, not as a result of biosynthesis but from the uptake of exogenous insulin. We conclude that C-peptide biosynthesis and secretion should be demonstrated to claim insulin production from embryonic stem cell progeny.
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| 2. |
- Sjögren, Klara, 1970, et al.
(författare)
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Liver-derived IGF-I is of importance for normal carbohydrate and lipid metabolism.
- 2001
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Ingår i: Diabetes. - 0012-1797. ; 50:7, s. 1539-45
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Tidskriftsartikel (refereegranskat)abstract
- IGF-I is important for postnatal body growth and exhibits insulin-like effects on carbohydrate metabolism. The function of liver-derived IGF-I is still not established, although we previously demonstrated that liver-derived IGF-I is not required for postnatal body growth. Mice whose IGF-I gene in the liver was inactivated at 24 days of age were used to investigate the long-term role of liver-derived IGF-I for carbohydrate and lipid metabolism. Serum levels of leptin in these mice were increased by >100% at 3 months of age, whereas the fat mass of the mice was decreased by 25% at 13 months of age. The mice became markedly hyperinsulinemic and yet normoglycemic, indicating an adequately compensated insulin resistance. Furthermore, they had increased serum levels of cholesterol. We conclude that liver-derived IGF-I is of importance for carbohydrate and lipid metabolism.
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