Abstract
Chronic exposure of HIT-T15 beta cells to elevated glucose concentrations leads to decreased insulin gene transcription. The reduction in expression is accompanied by diminished binding of a glucose-sensitive transcription factor (termed GSTF) that interacts with two (A+T)-rich elements within the 5' flanking control region of the insulin gene. In this study we examined whether GSTF corresponds to the recently cloned insulin gene transcription factor STF-1, a homeodomain protein whose expression is restricted to the nucleus of endodermal cells of the duodenum and pancreas. We found that an affinity-purified antibody recognizing STF-1 supershifted the GSTF activator complex formed from HIT-T15 extracts. In addition, we demonstrated a reduction in STF-1 mRNA and protein levels that closely correlated with the change in GSTF binding in HIT-T15 cells chronically cultured under supraphysiologic glucose concentrations. The reduction in STF-1 expression in these cells could be accounted for by a change in the rate of STF-1 gene transcription, suggesting a posttranscriptional control mechanism. In support of this hypothesis, no STF-1 mRNA accumulated in HIT-T15 cells passaged in 11.1 mM glucose. The only RNA species detected was a 6.4-kb STF-1 RNA species that hybridized with 5' and 3' STF-1-specific cDNA probes. We suggest that the 6.4-kb RNA represents an STF-1 mRNA precursor and that splicing of this RNA is defective in these cells. Overall, this study suggests that reduced expression of a key transcriptional regulatory factor, STF-1, contributes to the decrease in insulin gene transcription in HIT-T15 cells chronically cultured in supraphysiologic glucose concentration.
Full text
PDFImages in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Boam D. S., Docherty K. A tissue-specific nuclear factor binds to multiple sites in the human insulin-gene enhancer. Biochem J. 1989 Nov 15;264(1):233–239. doi: 10.1042/bj2640233. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brunstedt J., Chan S. J. Direct effect of glucose on the preproinsulin mRNA level in isolated pancreatic islets. Biochem Biophys Res Commun. 1982 Jun 30;106(4):1383–1389. doi: 10.1016/0006-291x(82)91267-0. [DOI] [PubMed] [Google Scholar]
- Candia A. F., Hu J., Crosby J., Lalley P. A., Noden D., Nadeau J. H., Wright C. V. Mox-1 and Mox-2 define a novel homeobox gene subfamily and are differentially expressed during early mesodermal patterning in mouse embryos. Development. 1992 Dec;116(4):1123–1136. doi: 10.1242/dev.116.4.1123. [DOI] [PubMed] [Google Scholar]
- Chomczynski P., Sacchi N. Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal Biochem. 1987 Apr;162(1):156–159. doi: 10.1006/abio.1987.9999. [DOI] [PubMed] [Google Scholar]
- Efrat S., Surana M., Fleischer N. Glucose induces insulin gene transcription in a murine pancreatic beta-cell line. J Biol Chem. 1991 Jun 15;266(17):11141–11143. [PubMed] [Google Scholar]
- Feinberg A. P., Vogelstein B. "A technique for radiolabeling DNA restriction endonuclease fragments to high specific activity". Addendum. Anal Biochem. 1984 Feb;137(1):266–267. doi: 10.1016/0003-2697(84)90381-6. [DOI] [PubMed] [Google Scholar]
- Gamer L. W., Wright C. V. Murine Cdx-4 bears striking similarities to the Drosophila caudal gene in its homeodomain sequence and early expression pattern. Mech Dev. 1993 Sep;43(1):71–81. doi: 10.1016/0925-4773(93)90024-r. [DOI] [PubMed] [Google Scholar]
- German M. S., Moss L. G., Rutter W. J. Regulation of insulin gene expression by glucose and calcium in transfected primary islet cultures. J Biol Chem. 1990 Dec 25;265(36):22063–22066. [PubMed] [Google Scholar]
- German M. S., Moss L. G., Wang J., Rutter W. J. The insulin and islet amyloid polypeptide genes contain similar cell-specific promoter elements that bind identical beta-cell nuclear complexes. Mol Cell Biol. 1992 Apr;12(4):1777–1788. doi: 10.1128/mcb.12.4.1777. [DOI] [PMC free article] [PubMed] [Google Scholar]
- German M. S., Wang J. The insulin gene contains multiple transcriptional elements that respond to glucose. Mol Cell Biol. 1994 Jun;14(6):4067–4075. doi: 10.1128/mcb.14.6.4067. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Giddings S. J., Chirgwin J., Permutt M. A. Effects of glucose on proinsulin messenger RNA in rats in vivo. Diabetes. 1982 Jul;31(7):624–629. doi: 10.2337/diab.31.7.624. [DOI] [PubMed] [Google Scholar]
- Gunning P., Ponte P., Okayama H., Engel J., Blau H., Kedes L. Isolation and characterization of full-length cDNA clones for human alpha-, beta-, and gamma-actin mRNAs: skeletal but not cytoplasmic actins have an amino-terminal cysteine that is subsequently removed. Mol Cell Biol. 1983 May;3(5):787–795. doi: 10.1128/mcb.3.5.787. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Guz Y., Montminy M. R., Stein R., Leonard J., Gamer L. W., Wright C. V., Teitelman G. Expression of murine STF-1, a putative insulin gene transcription factor, in beta cells of pancreas, duodenal epithelium and pancreatic exocrine and endocrine progenitors during ontogeny. Development. 1995 Jan;121(1):11–18. doi: 10.1242/dev.121.1.11. [DOI] [PubMed] [Google Scholar]
- Hammonds P., Schofield P. N., Ashcroft S. J. Glucose regulates preproinsulin messenger RNA levels in a clonal cell line of simian virus 40-transformed B cells. FEBS Lett. 1987 Mar 9;213(1):149–154. doi: 10.1016/0014-5793(87)81481-3. [DOI] [PubMed] [Google Scholar]
- Hammonds P., Schofield P. N., Ashcroft S. J., Sutton R., Gray D. W. Regulation and specificity of glucose-stimulated insulin gene expression in human islets of Langerhans. FEBS Lett. 1987 Oct 19;223(1):131–137. doi: 10.1016/0014-5793(87)80523-9. [DOI] [PubMed] [Google Scholar]
- Jonsson J., Carlsson L., Edlund T., Edlund H. Insulin-promoter-factor 1 is required for pancreas development in mice. Nature. 1994 Oct 13;371(6498):606–609. doi: 10.1038/371606a0. [DOI] [PubMed] [Google Scholar]
- Karlsson O., Edlund T., Moss J. B., Rutter W. J., Walker M. D. A mutational analysis of the insulin gene transcription control region: expression in beta cells is dependent on two related sequences within the enhancer. Proc Natl Acad Sci U S A. 1987 Dec;84(24):8819–8823. doi: 10.1073/pnas.84.24.8819. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Leonard J., Peers B., Johnson T., Ferreri K., Lee S., Montminy M. R. Characterization of somatostatin transactivating factor-1, a novel homeobox factor that stimulates somatostatin expression in pancreatic islet cells. Mol Endocrinol. 1993 Oct;7(10):1275–1283. doi: 10.1210/mend.7.10.7505393. [DOI] [PubMed] [Google Scholar]
- Lillie J. W., Green M. R. Transcription activation by the adenovirus E1a protein. Nature. 1989 Mar 2;338(6210):39–44. doi: 10.1038/338039a0. [DOI] [PubMed] [Google Scholar]
- McKnight G. S., Palmiter R. D. Transcriptional regulation of the ovalbumin and conalbumin genes by steroid hormones in chick oviduct. J Biol Chem. 1979 Sep 25;254(18):9050–9058. [PubMed] [Google Scholar]
- Melloul D., Ben-Neriah Y., Cerasi E. Glucose modulates the binding of an islet-specific factor to a conserved sequence within the rat I and the human insulin promoters. Proc Natl Acad Sci U S A. 1993 May 1;90(9):3865–3869. doi: 10.1073/pnas.90.9.3865. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miller C. P., McGehee R. E., Jr, Habener J. F. IDX-1: a new homeodomain transcription factor expressed in rat pancreatic islets and duodenum that transactivates the somatostatin gene. EMBO J. 1994 Mar 1;13(5):1145–1156. doi: 10.1002/j.1460-2075.1994.tb06363.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ohlsson H., Karlsson K., Edlund T. IPF1, a homeodomain-containing transactivator of the insulin gene. EMBO J. 1993 Nov;12(11):4251–4259. doi: 10.1002/j.1460-2075.1993.tb06109.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ohlsson H., Thor S., Edlund T. Novel insulin promoter- and enhancer-binding proteins that discriminate between pancreatic alpha- and beta-cells. Mol Endocrinol. 1991 Jul;5(7):897–904. doi: 10.1210/mend-5-7-897. [DOI] [PubMed] [Google Scholar]
- Olson L. K., Redmon J. B., Towle H. C., Robertson R. P. Chronic exposure of HIT cells to high glucose concentrations paradoxically decreases insulin gene transcription and alters binding of insulin gene regulatory protein. J Clin Invest. 1993 Jul;92(1):514–519. doi: 10.1172/JCI116596. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Peshavaria M., Gamer L., Henderson E., Teitelman G., Wright C. V., Stein R. XIHbox 8, an endoderm-specific Xenopus homeodomain protein, is closely related to a mammalian insulin gene transcription factor. Mol Endocrinol. 1994 Jun;8(6):806–816. doi: 10.1210/mend.8.6.7935494. [DOI] [PubMed] [Google Scholar]
- Petersen H. V., Serup P., Leonard J., Michelsen B. K., Madsen O. D. Transcriptional regulation of the human insulin gene is dependent on the homeodomain protein STF1/IPF1 acting through the CT boxes. Proc Natl Acad Sci U S A. 1994 Oct 25;91(22):10465–10469. doi: 10.1073/pnas.91.22.10465. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Robertson R. P., Olson L. K., Zhang H. J. Differentiating glucose toxicity from glucose desensitization: a new message from the insulin gene. Diabetes. 1994 Sep;43(9):1085–1089. doi: 10.2337/diab.43.9.1085. [DOI] [PubMed] [Google Scholar]
- Robertson R. P., Zhang H. J., Pyzdrowski K. L., Walseth T. F. Preservation of insulin mRNA levels and insulin secretion in HIT cells by avoidance of chronic exposure to high glucose concentrations. J Clin Invest. 1992 Aug;90(2):320–325. doi: 10.1172/JCI115865. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rossetti L., Giaccari A., DeFronzo R. A. Glucose toxicity. Diabetes Care. 1990 Jun;13(6):610–630. doi: 10.2337/diacare.13.6.610. [DOI] [PubMed] [Google Scholar]
- Sadowski I., Ma J., Triezenberg S., Ptashne M. GAL4-VP16 is an unusually potent transcriptional activator. Nature. 1988 Oct 6;335(6190):563–564. doi: 10.1038/335563a0. [DOI] [PubMed] [Google Scholar]
- Sharma A., Stein R. Glucose-induced transcription of the insulin gene is mediated by factors required for beta-cell-type-specific expression. Mol Cell Biol. 1994 Feb;14(2):871–879. doi: 10.1128/mcb.14.2.871. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shelton K. D., Franklin A. J., Khoor A., Beechem J., Magnuson M. A. Multiple elements in the upstream glucokinase promoter contribute to transcription in insulinoma cells. Mol Cell Biol. 1992 Oct;12(10):4578–4589. doi: 10.1128/mcb.12.10.4578. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shih H. M., Towle H. C. Definition of the carbohydrate response element of the rat S14 gene. Evidence for a common factor required for carbohydrate regulation of hepatic genes. J Biol Chem. 1992 Jul 5;267(19):13222–13228. [PubMed] [Google Scholar]
- Smith D. B., Johnson K. S. Single-step purification of polypeptides expressed in Escherichia coli as fusions with glutathione S-transferase. Gene. 1988 Jul 15;67(1):31–40. doi: 10.1016/0378-1119(88)90005-4. [DOI] [PubMed] [Google Scholar]
- Unger R. H., Grundy S. Hyperglycaemia as an inducer as well as a consequence of impaired islet cell function and insulin resistance: implications for the management of diabetes. Diabetologia. 1985 Mar;28(3):119–121. doi: 10.1007/BF00273856. [DOI] [PubMed] [Google Scholar]
- Welsh M., Nielsen D. A., MacKrell A. J., Steiner D. F. Control of insulin gene expression in pancreatic beta-cells and in an insulin-producing cell line, RIN-5F cells. II. Regulation of insulin mRNA stability. J Biol Chem. 1985 Nov 5;260(25):13590–13594. [PubMed] [Google Scholar]
- Zhang H. J., Walseth T. F., Robertson R. P. Insulin secretion and cAMP metabolism in HIT cells. Reciprocal and serial passage-dependent relationships. Diabetes. 1989 Jan;38(1):44–48. doi: 10.2337/diab.38.1.44. [DOI] [PubMed] [Google Scholar]