Department of Biomedical Sciences, Catholic Kwandong University, Gangneung, Korea.
Department of Biotechnology, Institute of Animal Molecular Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Korea.
J Cell Physiol. 2019 Apr;234(4):4864-4873. doi: 10.1002/jcp.27275. Epub 2018 Sep 21.
Ephrin A1 has a role in a variety of biological events, including cell proliferation, differentiation, migration, and angiogenesis. Ephrin A1 expression is abundant in trophoblasts and endometrial cells during the implantation period; however, its intracellular activities have not yet been reported in bovine endometrial (BEND) epithelial cells. The aim of this study was to identify the functional role of ephrin A1 in BEND cells, which have served as a good model system for investigating the regulation of signal transduction following treatment with interferon-τ (IFNT) in vitro. Supplementation of ephrin A1 to BEND cells increased cell proliferation and increased levels of proliferating cell nuclear antigen and cyclin D1 protein in BEND cell nuclei. To investigate intracellular mechanisms regulated by ephrin A1, we performed Western blot analysis focused on mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) signaling, which are significantly involved in the successful maintenance of pregnancy. Ephrin A1 dose-dependently increased phosphorylation of extracellular signal-regulated kinases (ERK)1/2, c-Jun N-terminal kinases (JNK), P38, protein kinase B (AKT), P70S6K, S6, and cyclin D1, and the activated proteins were suppressed by pharmacological inhibitors including wortmannin (a PI3K inhibitor), U0126 (an ERK1/2 inhibitor), and SP600125 (a JNK inhibitor). Among ephrin A1 receptors, abundant expression of EPHA2 and EPHA4 messenger RNA was detected in BEND cells by reverse transcription polymerase chain reaction analysis. Furthermore, tunicamycin-induced endoplasmic reticulum (ER) stress was inactivated by ephrin A1 treatment of BEND cells. Our findings suggest that ephrin A1 promotes the development of BEND cells and likely enhances uterine capacity and maintenance of pregnancy by activating MAPK and PI3K signaling cascades and by restoring ER stress.
Ephrin A1 在多种生物学事件中发挥作用，包括细胞增殖、分化、迁移和血管生成。Ephrin A1 在植入期的滋养层和子宫内膜细胞中表达丰富；然而，其在牛子宫内膜 (BEND) 上皮细胞中的细胞内活性尚未报道。本研究旨在确定 Ephrin A1 在 BEND 细胞中的功能作用，BEND 细胞已成为研究体外用干扰素 -τ (IFNT) 处理后信号转导调节的良好模型系统。向 BEND 细胞中补充 Ephrin A1 可增加细胞增殖，并增加 BEND 细胞核中增殖细胞核抗原和细胞周期蛋白 D1 蛋白的水平。为了研究 Ephrin A1 调节的细胞内机制，我们进行了 Western blot 分析，重点关注丝裂原活化蛋白激酶 (MAPK) 和磷酸肌醇 3-激酶 (PI3K) 信号转导，这两个信号转导在成功维持妊娠中起着重要作用。Ephrin A1 剂量依赖性地增加细胞外信号调节激酶 (ERK)1/2、c-Jun N-末端激酶 (JNK)、P38、蛋白激酶 B (AKT)、P70S6K、S6 和细胞周期蛋白 D1 的磷酸化，并用药理学抑制剂如wortmannin（PI3K 抑制剂）、U0126（ERK1/2 抑制剂）和 SP600125（JNK 抑制剂）抑制激活的蛋白。在 Ephrin A1 受体中，通过逆转录聚合酶链反应分析检测到 BEND 细胞中大量表达 EPHA2 和 EPHA4 信使 RNA。此外，Ephrin A1 处理 BEND 细胞可使衣霉素诱导的内质网 (ER) 应激失活。我们的研究结果表明，Ephrin A1 通过激活 MAPK 和 PI3K 信号级联，并通过恢复 ER 应激，促进 BEND 细胞的发育，并可能通过增强子宫容量和维持妊娠来增强其功能。
