[Effects of hsa_circ_0019217 on the biological functions of human trophoblast cells and its mechanism in pre-eclampsia].

Objectives: To investigate the effect of circular RNA (circRNA) hsa_circ_0019217 on the biological function of chorionic trophoblast cell line (HTR8/SVneo) and its mechanism in the occurrence of pre-eclampsia (PE). Methods: The circRNA expression database was used to analyze the differentially expressed circRNA in placental tissues of PE women. The expression levels of hsa_circ_0019217 and miR-526b-5p were detected by reverse transcription real-time fluorescent quantitative PCR (RT-qPCR), and the subcellular localization of hsa_circ_0019217 was detected by fluorescence in situ hybridization. The proliferation, migration and invasion of trophoblast cells were detected by cell counting kit-8 (CCK-8) assay and transwell assay. Western blot and enzyme-linked immunosorbent assay (ELISA) were used to verify the effects of hsa_circ_0019217, miR-526b-5p and decorin (DCN) on matrix metalloproteinase 2 (MMP2), tissue inhibitor of metalloproteinase 2 (TIMP2), placental growth factor (PlGF) and human chorionic gonadotropin (hCG) protein expression levels. Dual luciferase reporter gene assay and RNA immunoprecipitation (RIP) assay were used to verify the interaction between hsa_circ_0019217, miR-526-5p and DCN. Results: (1) The analysis of circRNA expression database showed that the expression level of hsa_circ_0019217 was significantly increased in the placental tissues of PE women (fold change=67, P<0.05), and it was mainly located in the cytoplasm. (2) Knockdown of hsa_circ_0019217 promoted the proliferation, migration and invasion of HTR8/SVneo cells, increased the expression levels of MMP2 and PlGF, and decreased the expression levels of TIMP2 and hCG in HTR8/SVneo cells. (3) Hsa_circ_0019217 targeted adsorption of miR-526b-5p, and inhibition of miR-526b-5p reduced the proliferation, migration and invasion of HTR8/SVneo cells. The expression levels of MMP2 and PlGF in HTR8/SVneo cells were increased, and the expression levels of TIMP2 and hCG were decreased. Hsa_circ_0019217 knockdown and inhibiting miR-526b-5p could reverse the effect of hsa_circ_0019217 knockdown on promoting the proliferation, migration and invasion of HTR8/SVneo cells, and reversed the effect of hsa_circ_0019217 knockdown on the protein expression levels of MMP2, PlGF, TIMP2 and hCG. (4) miR-526b-5p targeted DCN in HTR8/SVneo cells, hsa_circ_0019217 knockdown reduced the expression level of DCN, and inhibiting miR-526b-5p increased the expression level of DCN. When hsa_circ_0019217 and miR-526b-5p were inhibited simultaneously, there was no significant change in the protein expression level of DCN. (5) Overexpression of miR-526b-5p promoted the proliferation, migration and invasion of HTR8/SVneo cells, while overexpression of DCN inhibited the proliferation, migration and invasion of HTR8/SVneo cells. Simultaneous overexpression of miR-526b-5p and DCN reversed the effects of miR-526b-5p overexpression on cell proliferation, migration and invasion. Overexpression of miR-526b-5p increased the expression levels of MMP2 and PlGF and decreased the expression levels of TIMP2 and hCG in HTR8/SVneo cells. Overexpression of DCN reduced the expression levels of MMP2 and PlGF and increased the expression levels of TIMP2 and hCG. Overexpression of miR-526b-5p and DCN reversed the effects of miR-526b-5p on the expression of these proteins. Conclusion: Hsa_circ_0019217 regulates the expression of DCN by adsorption of miR-526b-5p, thereby affecting the proliferation, migration and invasion of trophoblast cells and regulating the protein expression levels of MMP2, TIMP2, PlGF and hCG, which might be used as a target for early prevention of PE.