AKT 同工型 1 和 3 调节人类基础状态和表皮生长因子刺激的 SGHPL-5 滋养层细胞迁移。
AKT isoforms 1 and 3 regulate basal and epidermal growth factor-stimulated SGHPL-5 trophoblast cell migration in humans.
机构信息
Department of Obstetrics and Fetal-Maternal Medicine, Reproductive Biology Unit, Medical University of Vienna, Vienna, Austria.
出版信息
Biol Reprod. 2013 Mar 7;88(3):54. doi: 10.1095/biolreprod.112.104778. Print 2013 Mar.
Protein kinase B/AKT is critically involved in murine placental development and migration of human placental trophoblasts into maternal uterine tissue. However, localization of the three AKT isoforms within human placenta and their roles in extravillous trophoblasts have not been elucidated. Therefore, we analyzed the expression pattern and function of AKT1, AKT2, and AKT3 in migratory human trophoblasts using SGHPL-5 cell pools stably expressing small-hairpin microRNA (shRNAmir) against AKT1, AKT2, or AKT3 as a model. Western blot analyses using isoform-specific antibodies revealed ubiquitous expression of AKT1, AKT2, and AKT3 in primary villous and extravillous trophoblasts and the trophoblastic cell lines JEG-3, HTR-8/SVneo, and SGHPL-5. Immunofluorescence of first-trimester placentae localized AKT2 and AKT3 to the cytoplasm and nucleus, respectively, in all subtypes of cytotrophoblasts, whereas AKT1 was detected in both cellular compartments. A similar distribution of AKT isoforms was detectable in SGHPL-5 cells. Gene silencing using shRNAmir decreased protein expression of AKT1, AKT2, and AKT3 to 16%, 8%, and 11%, respectively, in SGHPL-5 cells. Compared with shRNAmir controls, proliferation and camptothecin-induced apoptosis were not affected in the different AKT knockdown cells. However, basal and epidermal growth factor (EGF)-induced trophoblast migration was significantly reduced in AKT1 and AKT3 gene-silenced cells, whereas downregulation of AKT2 was not effective. Accordingly, a decrease in EGF-stimulated phosphorylation of AKT (Ser473 and Thr308) and its downstream target mTORC1 (Ser2448) was noticed in AKT1 and AKT3 shRNAmir cell pools. In summary, the results suggest that the AKT isoforms 1 and 3 promote basal as well as EGF-induced trophoblast migration.
蛋白激酶 B/AKT 对于鼠类胎盘的发育和人类胎盘滋养细胞向母体子宫组织的迁移至关重要。然而,在人胎盘内 AKT 的三种同工型的定位及其在绒毛外滋养细胞中的作用尚未阐明。因此,我们使用 SGHPL-5 细胞池作为模型,分析了 AKT1、AKT2 和 AKT3 在迁移中的人类滋养细胞中的表达模式和功能,该细胞池稳定表达针对 AKT1、AKT2 或 AKT3 的短发夹 microRNA (shRNAmir)。使用同工型特异性抗体进行的 Western blot 分析显示,AKT1、AKT2 和 AKT3 在原代绒毛和绒毛外滋养细胞以及滋养细胞系 JEG-3、HTR-8/SVneo 和 SGHPL-5 中广泛表达。对早孕期胎盘的免疫荧光定位显示,AKT2 和 AKT3 分别位于所有滋养细胞亚型的细胞质和细胞核中,而 AKT1 则存在于这两个细胞区室中。在 SGHPL-5 细胞中可检测到 AKT 同工型的类似分布。使用 shRNAmir 进行基因沉默将 SGHPL-5 细胞中的 AKT1、AKT2 和 AKT3 蛋白表达分别降低至 16%、8%和 11%。与 shRNAmir 对照相比,不同 AKT 敲低细胞的增殖和喜树碱诱导的凋亡不受影响。然而,AKT1 和 AKT3 基因沉默细胞中的基础和表皮生长因子 (EGF) 诱导的滋养细胞迁移显著减少,而 AKT2 的下调则无效。因此,在 AKT1 和 AKT3 shRNAmir 细胞池中,观察到 EGF 刺激的 AKT(Ser473 和 Thr308)及其下游靶标 mTORC1(Ser2448)磷酸化的减少。总之,这些结果表明 AKT 同工型 1 和 3 促进了基础和 EGF 诱导的滋养细胞迁移。