, Volume 35, Issue 3, pp 238–242 | Cite as

Expression of an islet regenerating (reg) gene in isolated rat islets: effects of nutrient and non-nutrient growth factors

  • P. J. Francis
  • J. L. Southgate
  • T. J. Wilkin
  • A. J. Bone


The expression of a novel regenerating (reg) gene has been reported previously in the regenerating islets of a surgical model of diabetes in rats. We exposed collagenase-isolated rat islets for three days to nutrient and non-nutrient growth factors in minimally supplemented RPMI medium (2.7 mmol/l glucose, 2% fetal calf serum), and investigated the relationship between reg gene expression and islet cell replication. RNA was prepared from half of the islets by homogenisation in guanidinium isothiocyanate followed by phenol/chloroform extraction. Northern/dot blot analyses were used to semi-quantify reg mRNA. Islet cell replication was estimated by culturing the remaining islets in radiolabelled thymidine to determine de novo DNA synthesis. Thymidine uptake was stimulated by the following factors: 11 mmol/l glucose (50% increase); 10% amino acids (126% increase); 10% fetal calf serum (39% increase); 100 ng/ml insulin (45% increase); 250 ng/ml growth hormone (65% increase); 1.5 nmol/l aldosterone (29% increase); 2U/ml platelet derived growth factor (116% increase). The results are expressed as a percentage of the thymidine incorporated into control islets cultured in minimal RPMI (1118±100 (SD) cpm/μg protein, n=15). Increased islet cell replication was paralleled in each case by a clear rise in reg mRNA expression compared to controls. Furthermore, the rank order for reg gene expression was the same as that for thymidine uptake (r=0.90). The present findings suggest a clear association between reg gene expression and islet cell replication in vitro, and are the first to demonstrate reg gene expression in response to individual growth factors.

Key words

Islets growth factors replication gene expression 


  1. 1.
    Oakley WG, Pyke DA, Taylor KW (1973) Biochemical basis of diabetes. In: Diabetes and its management. Blackwell Scientific Pubs, Oxford, pp 1–12Google Scholar
  2. 2.
    Terazono K, Yamamoto H, Takasawa S et al. (1987) A novel gene activated in regenerating islets. J Biol Chem 263: 2111–2114Google Scholar
  3. 3.
    Terazono K, Uchijama Y, Ide M et al. (1990) Expression of reg protein in rat regenerating islets and its co-localisation with insulin in the Beta-cell secretory granules. Diabetologia 33: 250–252PubMedGoogle Scholar
  4. 4.
    Patthy L (1988) Homology of pancreatic stone protein with animal lectins. Biochem J 253: 309–311Google Scholar
  5. 5.
    Peterson TE (1988) The amino terminal domain of thrombomodulin and PSP are homologous with lectins. FEBS Lett 231: 51–53CrossRefPubMedGoogle Scholar
  6. 6.
    Miyaura C, Ling C, Appel M et al. (1991) Expression of reg/PSP, a pancreatic exocrine gene: relationship to changes in islet Betacell mass. Mol Endocrinol 5: 226–234PubMedGoogle Scholar
  7. 7.
    Hehmke B, Kohnert KD, Odselius R (1986) The use of a new dextran gradient for the isolation of functionally intact neonatal pancreatic islets. Diab Res 3: 13–16Google Scholar
  8. 8.
    Chomoczynski P, Saachi N (1987) Single step method of RNA extraction by acid guanidinium isothiocyanate-phenol-chloroform extraction. Analyt Biochem 162: 156–159CrossRefPubMedGoogle Scholar
  9. 9.
    Maniatis T, Fritsch RF, Sambrook J (1982) Molecular cloning: a laboratory manual. Cold Spring Harbour LaboratoryGoogle Scholar
  10. 10.
    Swenne I, Bone AJ (1981) Effects, in tissue culture, of serum from obese mice on the DNA synthesis of the pancreatic Betacell. Cell Biol Int Rep 5: 215–221Google Scholar
  11. 11.
    Hellerström C, Swenne I (1985) Growth pattern of pancreatic islets. In: Volk B, Arquilla E (eds) Animals in the diabetic pancreas. Plenum Corp, pp 53–59Google Scholar
  12. 12.
    King GL, Kahn CR, Rechler MM, Nissley SP (1980) Direct demonstration of separate receptors for growth and metabolic activities of insulin and multiplication-stimulating activity (an insulin-like growth factor) using antibodies to the insulin receptor. J Clin Invest 66: 130–140PubMedGoogle Scholar
  13. 13.
    Koontz JW, Iwahashi M (1981) Insulin as a potent, specific growth factor in a rat hepatoma cell line. Science 211: 947–949PubMedGoogle Scholar
  14. 14.
    Baxter RC, Bryson JM, Turtle JR (1980) Somatic receptors of rat liver: regulation by insulin. Endocrinology 107: 1176–1181PubMedGoogle Scholar
  15. 15.
    Maes M, Ketelsegers J-M, Underwood JM (1983) Low plasma somatomedin-C in streptozotocin-induced diabetes mellitus. Correlation with changes in somatogenic and lactogenic liver binding sites. Diabetes 32: 1060–1069PubMedGoogle Scholar
  16. 16.
    Schwander JC, Hauri C, Zapf J, Froesch FR (1983) Synthesis and secretion of insulin-like growth factor-1 and its binding protein by the perfused rat liver: dependence on growth hormone status. Endocrinology 113: 297–305PubMedGoogle Scholar
  17. 17.
    D'Ercole AJ, Stiles AD, Underwood LE (1984) Tissue concentrations of somatomedin C: further evidence for multiple sites of synthesis and paracrine or autocrine mechanisms of actions. Proc Natl Acad Sci USA 81: 935–939PubMedGoogle Scholar
  18. 18.
    Isgaard J, Nilsson A, Lindahl A, Jansson J-O, Isaaksson OGP (1986) Effects of local administration of growth hormone and insulin-like growth factor-1 on longitudinal bone growth in rats. Am J Physiol 250: E367-E372PubMedGoogle Scholar
  19. 19.
    Swenne I, Heldin CH, Hellerström C (1988) Effects of PDGF and SM-C/IGF-I on the DNA replication of fetal rat islets of Langerhans in tissue culture. Endocrinology 122: 214–218PubMedGoogle Scholar
  20. 20.
    McEvoy RC, Hegre OD, Lazarow A (1976) Foetal rat pancreas in organ culture. Effect of corticosterone concentrations on the acinar and islet cell components. Differentiation 6: 17–26PubMedGoogle Scholar

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • P. J. Francis
    • 1
  • J. L. Southgate
    • 1
  • T. J. Wilkin
    • 1
  • A. J. Bone
    • 1
  1. 1.Endocrine Section, Medicine IISouthampton General HospitalSouthamptonUK

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