Unacylated ghrelin and obestatin increase islet cell mass and prevent diabetes in streptozotocin-treated newborn rats

作者:Granata Riccarda*; Volante Marco; Settanni Fabio; Gauna Carlotta; Ghe Corrado; Annunziata Marta; Deidda Barbara; Gesmundo Iacopo; Abribat Thierry; van der Lely Aart Jan; Muccioli Giampiero; Ghigo Ezio; Papotti Mauro
来源:Journal of Molecular Endocrinology, 2010, 45(1): 9-17.
DOI:10.1677/JME-09-0141

摘要

The ghrelin gene products, namely acylated ghrelin (AG), unacylated ghrelin (UAG), and obestatin (Ob), were shown to prevent pancreatic beta-cell death and to improve beta-cell function under treatment with cytokines, which are major cause of beta-cell destruction in diabetes. Moreover, AG had been described previously to prevent streptozotocin (STZ)-induced diabetes in rats; however, the effect of either UAG or Ob has never been examined in this context. In the present study, we investigated the potential of UAG and Ob to increase islet beta-cell mass and to reduce diabetes at adult age in STZ-treated neonatal rats. One-day-old rats were injected with STZ and subsequently administered with either AG, UAG or Ob for 7 days. On day 70, plasma glucose levels, plasma and pancreatic insulin levels, pancreatic islet area and number, insulin and pancreatic/duodenal homeobox-1 (Pdx1) gene expression, and antiapoptotic BCL2 protein expression were determined. Similarly to AG, both UAG and Ob counteracted STZ-induced high glucose levels and improved plasma and pancreatic insulin levels, which were reduced by the diabetogenic compound. UAG and Ob increased islet area, islet number, and beta-cell mass with respect to STZ treatment alone. Finally, in STZ-treated animals, UAG and Ob up-regulated insulin and Pdx1 mRNA and increased the expression of BCL2 similarly to AG. Taken together, our results suggest that in STZ-treated newborn rats, UAG and Ob improve glucose metabolism and preserve islet cell mass, granting a therapeutic potential in medical conditions associated with impaired beta-cell function. Journal of Molecular Endocrinology (2010) 45, 9-17

  • 出版日期2010-7