Abstract： Objective To investigate the expression and significance of the mechanosensitive ion channel Piezo1 in human placental chorionic arteries(HPCA)of pre-eclampsia(PE)patients.Methods HPCA tissues were collect-ed from pregnant women undergoing cesarean section delivery at the Department of Obstetrics,Affiliated Hospital of South-west Medical University.The samples included a normal control(NC)group,a PE group,and a severe pre-eclampsia(SPE)group,each comprising 10 cases.Immunofluorescence staining was used to detect the expression of Piezo1 and the endothelial marker CD31 in the HPCA of the NC,PE,and SPE groups.Real-time quantitative PCR(qPCR)was em-ployed to measure the relative mRNA expression of Piezo1 in the HPCA of the NC,PE,and SPE groups.Western blotting(WB)was conducted to assess the relative protein expression of Piezo1 in the HPCA of the NC,PE,and SPE groups.Hydrogen peroxide(H2O2)was used to simulate oxidative stress in human umbilical vein endothelial cells(HUVECs),and qPCR and WB were performed to evaluate the mRNA and protein expression of Piezo1 in the NC group,H2O2-trea-ted 6 h group,and H2O2-treated 12 h group of HUVECs.Results Piezo1 co-localized with the endothelial marker CD31 in the HPCA tissues of the NC,PE,and SPE groups.The mRNA expression of Piezo1 showed a decreasing trend in the HPCA tissues of the NC,PE,and SPE groups,with statistically significant differences(P＜0.05).Similarly,the protein expression of Piezo1 exhibited a decreasing trend in the HPCA tissues of the NC,PE,and SPE groups,with statis-tically significant differences(P＜0.05).In HUVECs,both mRNA and protein expression of Piezo1 showed a decreasing trend in the NC group,H2O2-treated 6 h group,and H2O2-treated 12 h group,with statistically significant differences(P＜0.05).Conclusion Piezo1 is expressed in endothelial cells of HPCA tissues,and its abnormal expression may be associated with the pathophysiological changes in pre-eclampsia.The occurrence and development of pre-eclampsia-related oxidative stress response may lead to decreased expression of Piezo1.