Regulation of glucose transport as well as glucose transporter and immediate early gene expression in 3T3‐L1 preadipocytes by 8‐bromo‐cAMP
- 1 February 1991
- journal article
- research article
- Published by Wiley in Journal of Cellular Physiology
- Vol. 146 (2), 298-308
- https://doi.org/10.1002/jcp.1041460215
Abstract
In the present study we have examined the ability of 8-bromoadenosine cyclic 3′, 5′-phosphate (8-bromo-cAMP; the membrane permeant analog of cAMP which can activate protein kinase A) to mimic hormone action and stimulate glucose transport and glucose transporter (GLUT-1) gene expression as well as the expression of several growth-related protooncogenes in quiescent 3T3-L1 fibroblasts. 8-Bromo-cAMP induced a rapid and prolonged increase in the rate of hexose transport. Early activation of hexose transport (within 30 min) was associated with increased plasma membrane immunoreactive glucose transporters, which corresponded to a doubling in the number of D-glucose-displaceable, plasma membrane cytochalasin B binding sites. The time course for 8-bromo-cAMP-induced hexose transport preceded the accumulation of GLUT-1 mRNA, which peaked between 4 and 8 h after exposure to the agent, and subsequently declined to approach basal (control) levels. Expression of the immediate-early genes c-fos and jun-B was induced by 8-bromo-cAMP on a rapid, but sustained time course, whereas induction of c-jun expression was delayed. Alterations in specific mRNAs following exposure to 8-bromo-cAMP were due to increased gene transcription (as judged by nuclear transcription run-on assays), although with respect to GLUT-1, an increase in mRNA stability was also observed. Treatment of the cells with forskolin resulted in the induction of GLUT-1 expression as well as expression of the immediate early genes. Exposure of quiescent 3T3-L1 fibroblasts to 8-bromo-cAMP resulted in a substantial increase in rates of total protein and RNA synthesis, but had little effect on DNA synthesis. The results demonstrate that 8-bromo-cAMP initiated a G0/G1 transition, but did not permit progression into S-phase. The results further suggest that increased cytosolic cAMP results in the stimulation of glucose transport by three distinct mechanisms to include translocation of pre-existing transporters, increased transcription of the GLUT-1 gene and increased stability of GLUT-1 mRNA.Keywords
This publication has 74 references indexed in Scilit:
- Regulation of glucose transport activity and expression of glucose transporter mRNA by serum, growth factors and phorbol ester in quiescent mouse fibroblastsBiochimica et Biophysica Acta (BBA) - Biomembranes, 1989
- Regulation of glucose transporter-specific mRNA levels in rat adipose cells with fasting and refeeding. Implications for in vivo control of glucose transporter number.JCI Insight, 1989
- Involvement of common and cell type-specific pathways in c-fos gene control: Stable induction by cAMP in macrophagesCell, 1986
- HORMONAL REGULATION OF MAMMALIAN GLUCOSE TRANSPORTAnnual Review of Biochemistry, 1986
- The activation of specific gene transcription in the adipose conversion of 3T3 cellsJournal of Cellular Physiology, 1985
- Stimulation of 3T3 cells induces transcription of the c-fos proto-oncogeneNature, 1984
- Studies of insulin resistance in adipocytes induced by macrophage mediator.The Journal of Experimental Medicine, 1983
- The stimulating effect of 3′,5′-(cyclic)adenosine monophosphate and lipolytic hormones onBiochimica et Biophysica Acta (BBA) - Biomembranes, 1982
- Number and evolutionary conservation of α- and β-tubulin and cytoplasmic β- and γ-actin genes using specific cloned cDNA probesCell, 1980
- Effect of aphidicolin on viral and human DNA polymerasesBiochemical and Biophysical Research Communications, 1979