Investigation of Ephrin-A Reverse Signaling in Pancreatic Islets

我们已经证明小鼠和人类胰腺中的β细胞强烈表达ephrin-A1和ephrin-A5。ephrin-A5缺陷小鼠有糖耐量缺陷和葡萄糖刺激的胰岛素分泌减少，表明正常胰岛素分泌需要ephrin-A5。相反，通过EphA5-Fc融合蛋白激活ephrin-A反向信号，可强烈增加小鼠和人胰岛以及小鼠胰岛素瘤细胞的胰岛素分泌（MIN6）。因此，我们的研究结果表明，ephrin-A反向信号可能在糖尿病中发挥作用，并可能对人类糖尿病的治疗有用。为了继续这个项目，我们希望在胰腺细胞中识别和表征这一信号通路的组成部分。我们希望了解ephrin-A1在胰岛素分泌中的作用，并揭示ephrin- a刺激胰岛素分泌的机制。

We have shown that beta cells in the mouse and human pancreas strongly express ephrin-A1 and ephrin-A5. Ephrin-A5-deficient mice have a defective glucose tolerance and decreased glucose-stimulated insulin secretion, showing that ephrin-A5 is required for normal insulin secretion. Conversely, activation of ephrin-A reverse signaling via EphA5-Fc fusion proteins strongly increases insulin secretion from mouse and human pancreatic islets as well as mouse insulinoma cells (MIN6). Our results therefore suggest that ephrin-A reverse signaling may play a role in diabetes and might be useful for diabetes treatment in humans. To continue this project, we would like to identify and characterize the components of this signaling pathway in pancreatic beta cells. We want to understand the role of ephrin-A1 in insulin secretion as well as uncover the mechanisms by which ephrin-As stimulate insulin secretion.