Sialylated form of the neural cell adhesion molecule (NCAM): a new tool for the identification and sorting of beta-cell subpopulations with different functional activity.
To clarify the relationship between variations in beta-cell mass and pancreatic function, we investigated the possibility to analyze, quantify, and sort beta-cell subpopulations with different functional maturity. To this aim, we tested the reliability of the sialylated form of neural cell adhesion molecule (NCAM) (PSA-NCAM) as a marker of beta-cell functional activity. Islet cells isolated from adult rats were analyzed for their PSA-NCAM abundance using an anti-PSA-NCAM antibody. We found that PSA-NCAM is expressed only in beta-cells. The PSA-NCAM labeling was also studied with a fluorescence-activated cell sorter. We showed that the beta-cell population is heterogeneous for PSA-NCAM labeling. To directly determine the relationship between PSA-NCAM labeling and beta-cell activity, in vitro insulin secretion studies were performed on sorted beta-cell subpopulations using a perifusion technique. Two beta-cell subpopulations were analyzed: one that was highly labeled for PSA-NCAM and another that was poorly labeled. Insulin secretion from high PSA-NCAM-labeled beta-cells was significantly higher than that in low PSA-NCAM-labeled beta-cells. This differential expression in the beta-cell population was well correlated with differences in glucose responsiveness. PSA-NCAM seems thus suitable for use as a tool to identify beta-cell subpopulations according to their glucose responsiveness.
Laboratoire de Physiopathologie de la Nutrition, CNRS ESA 7059, Université Paris, France. cbernard@paris7.jussieu.fr
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Bernard-Kargar
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Kassis
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Berthault
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Pralong
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Ktorza
D000818:Animals; D002469:Cell Separation / Q000379:methods; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D005947:Glucose / Q000494:pharmacology; D007150:Immunohistochemistry; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008856:Microscopy, Fluorescence; D039842:Neural Cell Adhesion Molecule L1; D019006:Neural Cell Adhesion Molecules / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D012794:Sialic Acids / Q000032:analysis*
D007328:Insulin; D039842:Neural Cell Adhesion Molecule L1; D019006:Neural Cell Adhesion Molecules; D012794:Sialic Acids; C103469:polysialyl neural cell adhesion molecule; D005947:Glucose