Department of Obstetrics and Gynecology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong, China.
Department of Obstetrics and Gynecology, Wenzhou People's Hospital, Wenzhou Maternal and Child Health Care Hospital, The Third Clinical Institute Affiliated to Wenzhou Medical University, Wenzhou, Zhejiang, China.
Reproduction. 2020 May;159(6):669-677. doi: 10.1530/REP-19-0458.
Decorin (DCN) regulates a vast array of cellular processes including proliferation, migration, apoptosis, and autophagy, and its aberrant expression has been associated with poor extravillous trophoblasts (EVT) invasion of the uterus, which underlies the occurrence of preeclampsia (PE) and intrauterine growth restriction (IUGR). In this study, we aim to elucidate the molecular mechanism of how the DCN regulates the cell functions through the use of trophoblast cell line, HTR-8. Using a series of cell function assays, including CCK8, RTCA, transwell, scratch-wound assay, and Annexin V staining, we found that DCN suppressed proliferation and invasion, while promoted autophagy and apoptosis of HTR-8 in a dose-dependent manner. Transient stimulation of DCN have increased the activity of c-Met and its downstream effectors - Akt, FAK and m-TOR. However, a prolonged exposure to DCN have significantly downregulated the expression of c-Met, leading to suppression of its downstream effectors. Lentivirus that overexpressed c-Met targeting shRNA was used to knockdown c-Met expression and crizotinib was used to selectively inhibit the kinase activity of c-Met in HTR-8 cells. A combination of DCN and c-Met knockdown/inhibition have reduced the proliferation and invasion in HTR-8 cells; however, DCN-induced autophagy and apoptosis were not synergistically enhanced by c-Met inhibition. In conclusion, DCN promotes autophagy and apoptosis predominantly through downregulating c-Met/Akt/mTOR activity in human trophoblasts.
核心蛋白聚糖（DCN）调节包括增殖、迁移、凋亡和自噬在内的广泛的细胞过程，其异常表达与异常的绒毛外滋养细胞（EVT）浸润子宫有关，这是子痫前期（PE）和宫内生长受限（IUGR）发生的基础。在这项研究中，我们旨在通过绒毛细胞系 HTR-8 阐明 DCN 调节细胞功能的分子机制。通过一系列细胞功能测定，包括 CCK8、RTCA、transwell、划痕愈合试验和 Annexin V 染色，我们发现 DCN 以剂量依赖的方式抑制 HTR-8 的增殖和侵袭，同时促进自噬和凋亡。DCN 的瞬时刺激增加了 c-Met 及其下游效应物-Akt、FAK 和 m-TOR 的活性。然而，长时间暴露于 DCN 会显著下调 c-Met 的表达，从而抑制其下游效应物。使用过表达针对 c-Met 的 shRNA 的慢病毒来敲低 c-Met 的表达，并用克唑替尼选择性抑制 HTR-8 细胞中 c-Met 的激酶活性。DCN 和 c-Met 敲低/抑制的组合降低了 HTR-8 细胞的增殖和侵袭；然而，c-Met 抑制并没有协同增强 DCN 诱导的自噬和凋亡。总之，DCN 通过下调人滋养细胞中的 c-Met/Akt/mTOR 活性来促进自噬和凋亡。
