Reg and Reg-related genes are members of a multifunctional family. Under physiological conditions Reg protein is not expressed in pancreatic beta cells, although the Reg protein receptor is expressed. When islets are damaged, the expression of Reg gene is increased in the islets of Langherans. In type 1 diabetes (T1D), insulin secretion may be still detectable in some subjects with long-standing disease indicating the existence of a small population of surviving beta cells or continued renewal of beta cells. Beta cell apoptosis has been shown in pancreas of subjects with long standing T1D indicating that continued source of beta cell replenishment may take place. No measurement is available in vivo up to now of this phenomenon. The aim of this study was to evaluate circulating levels of Reg1-α in T1D subjects as a potential marker of beta cell regeneration. We investigated serum samples of newly diagnosed T1D (n=31) (mean age 18.8 years±7.4), long standing T1D (n=46) (mean age 36.8 years±11.8), type 2 diabetes (n=63) (mean age 63.1 years±10.4) and in a group of control (n=50) (mean age 32.7 years±12.5).
Levels of Reg1-α were measured using an enzyme linked immunoabsorbent assay. A significant difference was detected in Reg1-α circulating levels between long standing T1D and controls (P=0.03), between newly diagnosed and longstanding T1D (P=0.04), between T2D and newly diagnosed T1D (P=0.002) and between T2D and controls (P=0.0001) No correlation were found between Reg1-α levels and typical markers of diabetes (C-peptide, HbA1c and duration of diabetes).
In conclusion, raised circulating levels of Reg1-α are detectable in T1D and T2D indicating the presence of active expression of Reg1-α gene. Further studies are ongoing to understand the significance of this serum marker and whether it can be used to monitor therapies for beta cell regeneration.
03 - 07 May 2008
European Society of Endocrinology