Renal Transplantation and Immunobiology Laboratory, The Royal Adelaide Hospital, Adelaide, South Australia, Australia.
Transplantation. 2013 Mar 15;95(5):671-8. doi: 10.1097/TP.0b013e31827fa453.
The early loss of functional islet mass (50-70%) due to apoptosis after clinical transplantation contributes to islet allograft failure. Insulin-like growth factor (IGF)-II is an antiapoptotic protein that is highly expressed in β-cells during development but rapidly decreases in postnatal life.
We used an adenoviral (Ad) vector to overexpress IGF-II in isolated rat islets and investigated its antiapoptotic action against exogenous cytokines interleukin-1β- and interferon-γ-induced islet cell death in vitro. Using an immunocompromised marginal mass islet transplant model, the ability of Ad-IGF-II-transduced rat islets to restore euglycemia in nonobese diabetic/severe combined immunodeficient diabetic recipients was assessed.
Ad-IGF-II transduction did not affect islet viability or function. Ad-IGF-II cytokine-treated islets exhibited decreased cell death (40% ± 2.8%) versus Ad-GFP and untransduced control islets (63.2% ± 2.5% and 53.6% ± 2.3%, respectively). Ad-IGF-II overexpression during cytokine treatment resulted in a marked reduction in terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive apoptotic cells (8.3% ± 1.4%) versus Ad-GFP control (41% ± 4.2%) and untransduced control islets (46.5% ± 6.2%). Western blot analysis confirmed that IGF-II inhibits apoptosis via activation of the phosphatidylinositol 3-kinase/Akt signaling pathway. Transplantation of IGF-II overexpressing islets under the kidney capsule of diabetic mice restored euglycemia in 77.8% of recipients compared with 18.2% and 47.5% of Ad-GFP and untransduced control islet recipients, respectively (P<0.05, log-rank [Mantel-Cox] test).
Antiapoptotic IGF-II decreases apoptosis in vitro and significantly improved islet transplant outcomes in vivo. Antiapoptotic gene transfer is a potentially powerful tool to improve islet survival after transplantation.
临床移植后，由于细胞凋亡导致功能性胰岛细胞群（50-70%）早期丢失，导致胰岛移植物衰竭。胰岛素样生长因子（IGF）-II 是一种抗凋亡蛋白，在β细胞发育过程中高度表达，但在出生后生命中迅速下降。
我们使用腺病毒（Ad）载体在分离的大鼠胰岛中过表达 IGF-II，并研究其在体外对抗外源性细胞因子白细胞介素-1β和干扰素-γ诱导的胰岛细胞死亡的抗凋亡作用。在免疫缺陷边缘质量胰岛移植模型中，评估 Ad-IGF-II 转导的大鼠胰岛恢复非肥胖型糖尿病/严重联合免疫缺陷型糖尿病受者的血糖正常的能力。
Ad-IGF-II 转导不影响胰岛的活力或功能。与 Ad-GFP 和未转导的对照胰岛相比，Ad-IGF-II 细胞因子处理的胰岛显示出减少的细胞死亡（40%±2.8%）（分别为 63.2%±2.5%和 53.6%±2.3%）。在细胞因子处理期间过表达 Ad-IGF-II 导致末端脱氧核苷酸转移酶介导的 dUTP 缺口末端标记阳性凋亡细胞明显减少（8.3%±1.4%），而 Ad-GFP 对照（41%±4.2%）和未转导的对照胰岛（46.5%±6.2%）。Western blot 分析证实 IGF-II 通过激活磷脂酰肌醇 3-激酶/Akt 信号通路抑制凋亡。在糖尿病小鼠的肾囊下移植 IGF-II 过表达胰岛，使 77.8%的受者恢复血糖正常，而 Ad-GFP 和未转导的对照胰岛受者分别为 18.2%和 47.5%（P<0.05，对数秩[Mantel-Cox]检验）。
抗凋亡 IGF-II 减少体外细胞凋亡，并显著改善体内胰岛移植结果。抗凋亡基因转移是改善移植后胰岛存活的一种潜在有力工具。
