Objective Investigating the impact of miR-15a-5p on autophagy in trophoblast cells of pre-eclamptic placenta.Methods Collect 20 cases of normal placental tissue and 20 cases of preeclamptic placental tissue from December 2020 to December 2022.Use fluorescence quantitative PCR to detect the expression of miR-15a-5p in placental tissue and trophoblast cells,and study its correlation with patient blood pressure.The HTR8-S/Vneo cells are divided into normal group(control)and hypoxia group,and the effect of hypoxia on the expression of miR-15a-5p is observed.Additionally,mimic-NC group,mimic-NC+hypoxia group,miR-15a-5p mimic group,miR-15a-5p mimic+hypoxia group,inhibitor-NC group,inhibitor-NC+hypoxia group,miR-15a-5p inhibitor group,and miR-15a-5p inhibitor+hypoxia groups are set up to observe the effect of miR-15a-5p on hypoxia-induced autophagy-related proteins LC3B and p62 protein in trophoblast cells.Western blot is used to detect the expression levels of autophagy-related proteins LC3B and p62 protein in each group;TargetScan website predicts the target genes of miR-15a-5p,and detects their expression levels in placental tissue and trophoblast cells.Results Compared with the control group,the expression levels of miR-15a-5p were significantly increased in the placentas and hypoxic trophoblasts of preeclampsia,and they were positively correlated with the blood pressure of the patients.Under hypoxic conditions,the overexpressed miR-15a-5p promoted the protein expression of LC3BII/I,while the relative expression of P62 was decreased.But after interference with miR-15a-5p,LC3BII/I expression was down-regulated and P62 expression was up-regulated.The results of quantitative PCR and Western blot showed that the expression levels of YAP1 in the preeclampsia placental tissues and hypoxic trophoblasts were significantly reduced.Conclusion The upregulation of miR-15a-5p in trophoblast cells of the placenta in individuals with preeclampsia could enhance autophagy in preeclampsia by forming a complex with YAP1.