Skip to main content
NCBI home page
The Journal of Clinical Investigation logoLink to The Journal of Clinical Investigation
. 1988 Jan;81(1):176–184. doi: 10.1172/JCI113291

Effects of aging on insulin synthesis and secretion. Differential effects on preproinsulin messenger RNA levels, proinsulin biosynthesis, and secretion of newly made and preformed insulin in the rat.

S Y Wang 1, P A Halban 1, J W Rowe 1
PMCID: PMC442490  PMID: 3275693

Abstract

Aging in men and rodents is associated with a marked decline in glucose stimulated insulin secretion by pancreatic beta cells (B cells). Secreted insulin is the end result of a series of steps along the biosynthetic protein-secretion pathway, including insulin gene transcription, processing of transcripts to preproinsulin mRNA, translation of mRNA, segregation and processing of newly made proinsulin in secretory vesicles, proinsulin to insulin conversion, transport of vesicles to the plasma membrane, and exocytosis. We have examined the influence of age at three stages along this pathway: preproinsulin mRNA levels, proinsulin synthesis, and secretion of newly made and preformed insulin, using Fischer rats, a widely studied rodent model of aging. Pancreatic weights and total insulin contents, islet sizes, and mean insulin content per islet were the same in young adult (4-5 mo) and senescent (21-22 mo) animals. There was no effect of age on preproinsulin mRNA levels in whole pancreata of fed animals, or in isolated islets cultured for 16 h in 5.5 mM glucose. Proinsulin biosynthesis and the secretion of newly made insulin were compared in isolated islets preincubated in 5.5 mM glucose. After a pulse label at 16.7 mM glucose, proinsulin synthesis, assayed by immunoprecipitation, was decreased 16% in 7 mo islets and 39% in 21-22 mo islets, compared with 4-5 mo islets, though total protein synthesis was not reduced. When chased at 2.8 mM glucose, 4-5 month and 21-22 mo islets showed no difference in release of preformed or newly made insulin. When chased at 16.7 mM glucose, there was a significant decrease in the secretion of newly made insulin in the old islets compared with the young islets. There was preferential release of newly made insulin over preformed insulin in both young and old islets. However, since secretion of preformed insulin was decreased much more than secretion of newly made insulin in senescent islets, these displayed a two- to threefold increase in the proportion of newly made insulin relative to total immunoreactive insulin released compared with young adult islets. The differential effects of aging on these steps in the insulin synthesis-secretion pathway may be due to varying impairments in signals transducing the glucose stimulus into the wide range of B cell responses to glucose.

Full text

PDF
176

Images in this article

179Image
on p.179

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Andres R., Tobin J. D. Aging and the disposition of glucose. Adv Exp Med Biol. 1975;61:239–249. doi: 10.1007/978-1-4615-9032-3_13. [DOI] [PubMed] [Google Scholar]
  2. Ashcroft S. J. Glucoreceptor mechanisms and the control of insulin release and biosynthesis. Diabetologia. 1980 Jan;18(1):5–15. doi: 10.1007/BF01228295. [DOI] [PubMed] [Google Scholar]
  3. Bleich H. L., Boro E. S., Rowe J. W. Clinical research on aging: strategies and directions. N Engl J Med. 1977 Dec 15;297(24):1332–1336. doi: 10.1056/NEJM197712152972406. [DOI] [PubMed] [Google Scholar]
  4. 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]
  5. Chaudhuri M., Sartin J. L., Adelman R. C. A role for somatostatin in the impaired insulin secretory response to glucose by islets from aging rats. J Gerontol. 1983 Jul;38(4):431–435. doi: 10.1093/geronj/38.4.431. [DOI] [PubMed] [Google Scholar]
  6. Chen M., Bergman R. N., Pacini G., Porte D., Jr Pathogenesis of age-related glucose intolerance in man: insulin resistance and decreased beta-cell function. J Clin Endocrinol Metab. 1985 Jan;60(1):13–20. doi: 10.1210/jcem-60-1-13. [DOI] [PubMed] [Google Scholar]
  7. Chirgwin J. M., Przybyla A. E., MacDonald R. J., Rutter W. J. Isolation of biologically active ribonucleic acid from sources enriched in ribonuclease. Biochemistry. 1979 Nov 27;18(24):5294–5299. doi: 10.1021/bi00591a005. [DOI] [PubMed] [Google Scholar]
  8. Cordell B., Diamond D., Smith S., Pünter J., Schöne H. H., Goodman H. M. Disproportionate expression of the two nonallelic rat insulin genes in a pancreatic tumor is due to translational control. Cell. 1982 Dec;31(3 Pt 2):531–542. doi: 10.1016/0092-8674(82)90309-9. [DOI] [PubMed] [Google Scholar]
  9. Curry D. L., Reaven G., Reaven E. Glucose-induced insulin secretion by perfused pancreas of 2- and 12-mo-old Fischer 344 rats. Am J Physiol. 1984 Sep;247(3 Pt 1):E385–E388. doi: 10.1152/ajpendo.1984.247.3.E385. [DOI] [PubMed] [Google Scholar]
  10. Defronzo R. A. Glucose intolerance and aging: evidence for tissue insensitivity to insulin. Diabetes. 1979 Dec;28(12):1095–1101. doi: 10.2337/diab.28.12.1095. [DOI] [PubMed] [Google Scholar]
  11. Draznin B., Steinberg J. P., Leitner J. W., Sussman K. E. The nature of insulin secretory defect in aging rats. Diabetes. 1985 Nov;34(11):1168–1173. doi: 10.2337/diab.34.11.1168. [DOI] [PubMed] [Google Scholar]
  12. Elahi D., Muller D. C., Andersen D. K., Tobin J. D., Andres R. The effect of age and glucose concentration on insulin secretion by the isolated perfused rat pancreas. Endocrinology. 1985 Jan;116(1):11–16. doi: 10.1210/endo-116-1-11. [DOI] [PubMed] [Google Scholar]
  13. Fink R. I., Huecksteadt T., Karaoghlanian Z. The effects of aging on glucose metabolism in adipocytes from Fischer rats. Endocrinology. 1986 Mar;118(3):1139–1147. doi: 10.1210/endo-118-3-1139. [DOI] [PubMed] [Google Scholar]
  14. Fink R. I., Kolterman O. G., Griffin J., Olefsky J. M. Mechanisms of insulin resistance in aging. J Clin Invest. 1983 Jun;71(6):1523–1535. doi: 10.1172/JCI110908. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Flier J. S., Minaker K. L., Landsberg L., Young J. B., Pallotta J., Rowe J. W. Impaired in vivo insulin clearance in patients with severe target-cell resistance to insulin. Diabetes. 1982 Feb;31(2):132–135. doi: 10.2337/diab.31.2.132. [DOI] [PubMed] [Google Scholar]
  16. Giddings S. J., Chirgwin J. M., Permutt M. A. Glucose regulated insulin biosynthesis in isolated rat pancreatic islets is accompanied by changes in proinsulin mRNA. Diabetes Res. 1985 Mar;2(2):71–75. [PubMed] [Google Scholar]
  17. 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]
  18. Giddings S. J., Chirgwin J., Permutt M. A. Evaluation of rat insulin messenger RNA in pancreatic and extrapancreatic tissues. Diabetologia. 1985 Jun;28(6):343–347. doi: 10.1007/BF00283141. [DOI] [PubMed] [Google Scholar]
  19. Gold G., Gishizky M. L., Grodsky G. M. Evidence that glucose "marks" beta cells resulting in preferential release of newly synthesized insulin. Science. 1982 Oct 1;218(4567):56–58. doi: 10.1126/science.6181562. [DOI] [PubMed] [Google Scholar]
  20. Gold G., Landahl H. D., Gishizky M. L., Grodsky G. M. Heterogeneity and compartmental properties of insulin storage and secretion in rat islets. J Clin Invest. 1982 Mar;69(3):554–563. doi: 10.1172/JCI110481. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Grodsky G. M. A threshold distribution hypothesis for packet storage of insulin and its mathematical modeling. J Clin Invest. 1972 Aug;51(8):2047–2059. doi: 10.1172/JCI107011. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Halban P. A. Differential rates of release of newly synthesized and of stored insulin from pancreatic islets. Endocrinology. 1982 Apr;110(4):1183–1188. doi: 10.1210/endo-110-4-1183. [DOI] [PubMed] [Google Scholar]
  23. Halban P. A., Rhodes C. J., Shoelson S. E. High-performance liquid chromatography (HPLC): a rapid, flexible and sensitive method for separating islet proinsulin and insulin. Diabetologia. 1986 Dec;29(12):893–896. doi: 10.1007/BF00870146. [DOI] [PubMed] [Google Scholar]
  24. Halban P. A., Wollheim C. B., Blondel B., Renold A. E. Long-term exposure of isolated pancreatic islets to mannoheptulose: evidence for insulin degradation in the beta cell. Biochem Pharmacol. 1980 Oct 1;29(19):2625–2633. doi: 10.1016/0006-2952(80)90077-5. [DOI] [PubMed] [Google Scholar]
  25. Hayward W. S. Size and genetic content of viral RNAs in avian oncovirus-infected cells. J Virol. 1977 Oct;24(1):47–63. doi: 10.1128/jvi.24.1.47-63.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Hedeskov C. J. Mechanism of glucose-induced insulin secretion. Physiol Rev. 1980 Apr;60(2):442–509. doi: 10.1152/physrev.1980.60.2.442. [DOI] [PubMed] [Google Scholar]
  27. Herbert V., Lau K. S., Gottlieb C. W., Bleicher S. J. Coated charcoal immunoassay of insulin. J Clin Endocrinol Metab. 1965 Oct;25(10):1375–1384. doi: 10.1210/jcem-25-10-1375. [DOI] [PubMed] [Google Scholar]
  28. Itoh N., Okamoto H. Translational control of proinsulin synthesis by glucose. Nature. 1980 Jan 3;283(5742):100–102. doi: 10.1038/283100a0. [DOI] [PubMed] [Google Scholar]
  29. Kitahara A., Adelman R. C. Altered regulation of insulin secretion in isolated islets of different sizes in aging rats. Biochem Biophys Res Commun. 1979 Apr 27;87(4):1207–1213. doi: 10.1016/s0006-291x(79)80035-2. [DOI] [PubMed] [Google Scholar]
  30. Lacy P. E., Kostianovsky M. Method for the isolation of intact islets of Langerhans from the rat pancreas. Diabetes. 1967 Jan;16(1):35–39. doi: 10.2337/diab.16.1.35. [DOI] [PubMed] [Google Scholar]
  31. Molina J. M., Premdas F. H., Lipson L. G. Insulin release in aging: dynamic response of isolated islets of Langerhans of the rat to D-glucose and D-glyceraldehyde. Endocrinology. 1985 Feb;116(2):821–826. doi: 10.1210/endo-116-2-821. [DOI] [PubMed] [Google Scholar]
  32. Nielsen D. A., Welsh M., Casadaban M. J., Steiner D. F. Control of insulin gene expression in pancreatic beta-cells and in an insulin-producing cell line, RIN-5F cells. I. Effects of glucose and cyclic AMP on the transcription of insulin mRNA. J Biol Chem. 1985 Nov 5;260(25):13585–13589. [PubMed] [Google Scholar]
  33. Permutt M. A., Kakita K., Malinas P., Karl I., Bonner-Weir S., Weir G., Giddings S. J. An in vivo analysis of pancreatic protein and insulin biosynthesis in a rat model for non-insulin-dependent diabetes. J Clin Invest. 1984 May;73(5):1344–1350. doi: 10.1172/JCI111337. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Permutt M. A., Kipnis D. M. Insulin biosynthesis. I. On the mechanism of glucose stimulation. J Biol Chem. 1972 Feb 25;247(4):1194–1199. [PubMed] [Google Scholar]
  35. Reaven E., Wright D., Mondon C. E., Solomon R., Ho H., Reaven G. M. Effect of age and diet on insulin secretion and insulin action in the rat. Diabetes. 1983 Feb;32(2):175–180. doi: 10.2337/diab.32.2.175. [DOI] [PubMed] [Google Scholar]
  36. Rowe J. W., Minaker K. L., Pallotta J. A., Flier J. S. Characterization of the insulin resistance of aging. J Clin Invest. 1983 Jun;71(6):1581–1587. doi: 10.1172/JCI110914. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Samols E., Bonner-Weir S., Weir G. C. Intra-islet insulin-glucagon-somatostatin relationships. Clin Endocrinol Metab. 1986 Feb;15(1):33–58. doi: 10.1016/s0300-595x(86)80041-x. [DOI] [PubMed] [Google Scholar]
  38. Scharp D. W., Kemp C. B., Knight M. J., Ballinger W. F., Lacy P. E. The use of ficoll in the preparation of viable islets of langerhans from the rat pancreas. Transplantation. 1973 Dec;16(6):686–689. doi: 10.1097/00007890-197312000-00028. [DOI] [PubMed] [Google Scholar]
  39. Steinberg J. P., Leitner J. W., Draznin B., Sussman K. E. Calmodulin and cyclic AMP. Possible different sites of action of these two regulatory agents in exocytotic hormone release. Diabetes. 1984 Apr;33(4):339–345. doi: 10.2337/diab.33.4.339. [DOI] [PubMed] [Google Scholar]
  40. Ullrich A., Shine J., Chirgwin J., Pictet R., Tischer E., Rutter W. J., Goodman H. M. Rat insulin genes: construction of plasmids containing the coding sequences. Science. 1977 Jun 17;196(4296):1313–1319. doi: 10.1126/science.325648. [DOI] [PubMed] [Google Scholar]
  41. Weir G. C. Non-insulin-dependent diabetes mellitus: interplay between B-cell inadequacy and insulin resistance. Am J Med. 1982 Oct;73(4):461–464. doi: 10.1016/0002-9343(82)90321-7. [DOI] [PubMed] [Google Scholar]
  42. 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]

Articles from Journal of Clinical Investigation are provided here courtesy of American Society for Clinical Investigation

RESOURCES