Modulation of glucose transport by parathyroid hormone and insulin in UMR 106-01, a clonal rat osteogenic sarcoma cell line
| Autor: | M W Sleeman, F. R. Bringhurst, Suzanne Rogers, David Thomas, Jeffrey D Zajac, James D. Best, G.M.F Pasquini, Kong Wah Ng |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
medicine.medical_specialty
Monosaccharide Transport Proteins medicine.medical_treatment Parathyroid hormone 8-Bromo Cyclic Adenosine Monophosphate Bone Neoplasms Deoxyglucose Endocrinology Internal medicine Teriparatide medicine Cyclic AMP Tumor Cells Cultured Animals Insulin Northern blot RNA Messenger RNA Neoplasm Protein kinase A Molecular Biology Glucose Transporter Type 1 Osteosarcoma biology Dose-Response Relationship Drug Chemistry Glucose transporter Osteoblast Biological Transport Cyclic AMP-Dependent Protein Kinases Peptide Fragments Clone Cells Neoplasm Proteins Rats Gene Expression Regulation Neoplastic Kinetics medicine.anatomical_structure Glucose Organ Specificity Parathyroid Hormone biology.protein GLUT1 Signal Transduction |
| Zdroj: | Journal of molecular endocrinology. 14(2) |
| ISSN: | 0952-5041 |
| Popis: | This study characterizes the actions of insulin and parathyroid hormone (PTH) on the glucose transport system in the rat osteogenic sarcoma cell line UMR 106–01, which expresses a number of features of the osteoblast phenotype. Using [1,2-3H]2-deoxyglucose (2-DOG) as a label, UMR 106–01 cells were shown to possess a glucose transport system which was enhanced by insulin. In contrast, PTH influenced glucose transport in a biphasic manner with a stimulatory effect at 1 h and a more potent inhibitory effect at 16 h on basal and insulin-stimulated 2-DOG transport. To explore the mechanism of PTH action, a direct agonist of cAMP-dependent protein kinase (PKA) was tested. 8-Bromo-cAMP had no acute stimulatory effect but inhibited basal and insulin-stimulated 2-DOG transport at 16 h. This result suggested that the prolonged, but not the acute, effect of PTH was mediated by the generation of cAMP. Further studies with the cell line UMR 4–7, a UMR 106–01 clone stably transfected with an inducible mutant inactive regulatory subunit of PKA, confirmed that the inhibitory but not the stimulatory effect of PTH was mediated by the PKA pathway. Northern blot data indicated that the prolonged inhibitory effects of PTH and 8-bromo-cAMP on glucose transport were likely to be mediated in part by reduction in the levels of GLUT1 (HepG2/brain glucose transporter) mRNA. |
| Databáze: | OpenAIRE |
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