Department of Biomedical Science, CHA University, Gyeonggi-Do 13488, the Republic of Korea.
Department of Obstetrics and Gynecology, CL Women's Hospital, Gwangju 61917, the Republic of Korea.
Biomed Pharmacother. 2023 Oct;166:115288. doi: 10.1016/j.biopha.2023.115288. Epub 2023 Aug 12.
In a previous study, we investigated the effects of high-temperature requirement factor A4 (HtrA4) deficiency on trophoblasts using the BeWo KO cell line. However, the effects of this deficiency on angiogenesis remain unclear. To explore the role of HtrA4 in angiogenesis, HUVECs were co-cultured with wild-type BeWo cells (BeWo WT), BeWo KO, and HtrA4-rescued BeWo KO (BeWo KO-HtrA4 rescue) cells. Dil staining and dextran analysis revealed that HUVECs co-cultured with BeWo KO formed tubes, but they were often disjointed compared to those co-cultured with BeWo WT, BeWo KO-HtrA4 rescue, and HUVECs controls. RT-PCR, ELISA, and western blot analysis were performed to assess angiogenesis-related factors at the mRNA and protein levels. HtrA4 deficiency inhibited IL-6 expression in trophoblasts, and the reduced secretion of IL-6 decreases VEGFA expression in HUVECs by modulating the JAK2/STAT3 signaling pathway to prevent tube formation. Moreover, rescuing HtrA4 expression restored the HUVEC tube formation ability. Interestingly, IL-6 expression was lower in supernatants with only cultured HUVECs than in co-cultured HUVECs with BeWo WT cells, but the HUVEC tube formation ability was similar. These findings suggest that the promoting angiogenesis-related signaling pathway differs between only HUVECs and co-cultured HUVECs, and that the deficiency of HtrA4 weakens the activation of the IL-6/JAK/STAT3/VEGFA signaling pathway, reducing the ability of tube formation in HUVECs. HtrA4 deficiency in trophoblasts hinders angiogenesis and may contribute to placental dysfunction.
在之前的研究中，我们使用 BeWo KO 细胞系研究了高温需求因子 A4 (HtrA4) 缺乏对滋养层的影响。然而，这种缺乏对血管生成的影响尚不清楚。为了探讨 HtrA4 在血管生成中的作用，将 HUVECs 与野生型 BeWo 细胞（BeWo WT）、BeWo KO 和 HtrA4 挽救的 BeWo KO（BeWo KO-HtrA4 挽救）细胞共培养。Dil 染色和葡聚糖分析表明，与 BeWo WT、BeWo KO-HtrA4 挽救和 HUVECs 对照共培养的 HUVECs 形成了管，但与 BeWo WT 共培养的管通常不连续，与 BeWo KO 共培养的管通常不连续。通过 RT-PCR、ELISA 和 Western blot 分析评估了血管生成相关因子在 mRNA 和蛋白水平上的表达。HtrA4 缺乏抑制滋养层中 IL-6 的表达，而 IL-6 分泌减少通过调节 JAK2/STAT3 信号通路降低 HUVECs 中的 VEGFA 表达，从而阻止管形成。此外，挽救 HtrA4 表达恢复了 HUVEC 管形成能力。有趣的是，仅培养的 HUVECs 的上清液中 IL-6 的表达低于与 BeWo WT 细胞共培养的 HUVECs 的上清液，但 HUVEC 管形成能力相似。这些发现表明，仅 HUVECs 和共培养的 HUVECs 之间促进血管生成的相关信号通路不同，HtrA4 的缺乏削弱了 IL-6/JAK/STAT3/VEGFA 信号通路的激活，降低了 HUVECs 的管形成能力。滋养层中 HtrA4 的缺乏阻碍了血管生成，可能导致胎盘功能障碍。
