The Effect Of FPR2 On The Regulation Of Trophoblast Autophagy Via The PI3K/AKT Signalling Pathway In Preeclampsia

ObjectivePreeclampsia(PE)is a pregnancy-specific disease that seriously affects maternal and foetal health.The pathogenesis of PE has not been fully elucidated,and termination of pregnancy remains the only effective treatment.At present,it is generally recognized that the emergence of PE,especially early onset preeclampsia(EOPE),is closely related to the abnormal biological behavior of extravillous trophoblasts(EVT).An imbalance of autophagic homeostasis affects trophoblast function and is related to the pathogenesis of PE.Formylpeptide receptor 2(FPR2)is a G protein-coupled receptor expressed in human placental trophoblast cells.FPR2 is intimately associated with the development and function of the placenta,but its role in pregnancy-related diseases is rarely studied.Therefore,we attempted to clarify the role of FPR2 in trophoblast function by regulating the autophagy involved in PE occurrence,which may provide new research strategies for PE control.MethodPlacental samples were gathered from EOPE patients and women with normotensive pregnancies.SiFPR2 transfection was used to knock down FPR2 in the HTR8/SVneo cell line.FPR2 was knocked down successfully,as proven by Western Blot.The microenvironment of the oxidative stress in HTR8/SVneo cells induced by H2O2 treatment has been used as a cell model for PE in vitro.Immunofluorescence staining and Western Blot were used to detect the expression of FPR2 and the level of autophagy in the placental tissue of PE patients.Cell proliferation,apoptosis,migration,and invasion abilities of HTR8/SVneo cells were observed by the CCK-8,FACS,wound healing,and transwell assays.MDC and Lyso-tracker double staining was used to detect the number of autophagic lysosomes in HTR8/SVneo cells,and the occurrence of autophagy in cells was directly observed by transmission electron microscopy.Western Blot was used to analyze the expression of FPR2 and autophagy marker proteins in HTR8/SVneo cells,as well as the expression of major driving molecules in the classical PI3K/AKT/mTOR autophagy pathway.3-MA was applied to further confirm the signalling pathway by which FPR2 regulates autophagy in HTR8/SVneo cells.ResultIn our study,the FPR2 autophagy level increased significantly in the placental tissues of PE patients.FPR2 expression and autophagy were upregulated by H2O2 treatment in HTR8/SVneo cells.FPR2 knockdown reversed the H2O2 induced attenuation of proliferation,migration,and invasion,but there was no significant change in cell apoptosis.In HTR8/SVneo cells,FPR2 knockdown alleviated the expression of autophagy-related proteins by H2O2 stimulation.In addition,the PI3K/AKT/mTOR signalling pathway was inhibited in HTR8/SVneo cells treated with H2O2,and FPR2 knockdown to some extent relieved the inhibition of this signal pathway.Subsequently,we found that the autophagy induced by H2O2 in HTR8/S Vneo cells was offset when the autophagy inhibitor 3-MA was present.After FPR2 knockdown,3-mA also did not affect the autophagy induced by H2O2 in HTR8/SVneo cells.ConclusionIn summary,we have affirmed that the expression of FPR2 and autophagy levels were increased in the placentas of EOPE patients and studied FPR2 regulatory mechanism on autophagy.We found that FPR2 regulates the trophoblastic function and autophagy of trophoblast cells via the PI3K/AKT/mTOR signalling pathway,which may be associated with the pathogenesis of PE.FPR2 can intervene in trophoblast autophagy and regulate its function,which may provide a new idea for the prevention and treatment of PE.