GPX1 Regulates COX2 Via NFκB Pathway To Participate In Mammals Parturition

Parturiton initiation is a complicated physiological process with many factors,including the internal environment and external environment.External factors include foods intake,improper mechanical movement and etc.Internal regulations mainly include hormones,immune inflammations,the process of apoptosis and so on.But there are few studies on the specific mechanism of parturition initiation.In our laboratory large,we screened out the expressed genes significantly differentially called GPX1 from transcriptional sequencing data of large white pig placenta tissue before and after parturition intiation.Studies have shown that GPX1 could alleviate the level of oxidative stress and the lack of GPX1 could lead to abnormal parturition.The purpose of this study was to explore the role of GPX1 as glutathione peroxidase in the process of parturition initiation.To explore whether GPX1 played a important role in the process of parturition initiation,we injected LPS into the enterocoelia in 15.5 days pregnant mouse to build the preterm delivery model,detecting the level of ROS,oxidation marker gene,HSP90,inflammatory factor TNFα,IL1β and COX2 related parturition in the fetal membrane.the interference fragment si-GPX1 and recombinant plasmid pCMV-GPX1 were transfected into the WISH cells respectively,and HSP90,COX2,Caspase3,IL1β,and NFκB related parturition were detected.In order to verify the pathway that GPX1 worked,CAPE which was the inhibitor of NFκB was used to treat the WISH cells,and to detect the level of NFκB and COX2 by cell immunofluorescence.We measured the level of PGE2 in amniotic fluids with and without the sign of parturition initiation.In the WISH cells,transfection of superexpressed plasmid pCMV-GPX1 was followed 24 hours and 48 hours to detect the concentration level of PGE2 in the serum of cells.Finally,the WISH cells were treated with PGE2,detecting the effects on GPX1,NFκB and COX2.The main research results are as follows:1)The ROS level in the fetal membranes was significantly enhanced in the experimental group,and the expression level of the oxidative stress marker gene HSP90 was increased,and the expression level of inflammatory factor TNFα,IL1β and COX2 showed higher than control group,consistent with the protein results,which indicated that oxidative stress was higher in the experimental group.The expression level of the three types of antioxidant marker genes GPX1,SOD2 and Catalase in the experimental group were 1.80,1.27 and 1.18 as much as the control group were respectively,GPX1 changed most dramaticly.It was concluded that GPX1 was the main antioxidant gene.2)PGE2 was enhanced markedly in the amniotic fluid of Qingping sows with the sign of parturition initiation in the long and short pregnancy QingPing pig species.The high level of GPX1 could reduce the level of HSP90,which indicated GPX1 could slow down the oxidative stress,and GPX1 regulated the expression of COX2 through the NFκB pathway,thereby enhancing the level of PGE2 in both 24 hours and 48 hours.The lower level of GPX1 led to rise the level of HSP90 and elevate the levels of inflammatory factors IL1β.GPX1 participated in the regulation of pregnancy and parturition onset through hormone levels and immune inflammation.3)PGE2 had a positive effect on GPX1,and had a feedback effect on inhibiting NFκB and COX2 in WISH cells treated with PGE2,which prevents the further increasing of PGE2 and avoids PGE2 peak to result in premature delivery.The stable expression of GPX1 is a necessary condition for normal pregnancy and parturition.