Mechanisms underlying the role of endoplasmic reticulum stress in the placental injury and fetal growth restriction in an ovine gestation model

Background Exposure to bisphenol A(BPA),an environmental pollutant known for its endocrine-disrupting properties,during gestation has been reported to increase the risk of fetal growth restriction(FGR)in an ovine model of pregnancy.We hypothesized that the FGR results from the BPA-induced insufficiency and barrier dysfunction of the placenta,oxidative stress,inflammatory responses,autophagy and endoplasmic reticulum stress(ERS).However,precise mechanisms underlying the BPA-induced placental dysfunction,and subsequently,FGR,as well as the potential involvement of placental ERS in these complications,remain to be investigated.Methods In vivo experiment,16 twin-pregnant(from d 40 to 130 of gestation)Hu ewes were randomly distributed into two groups(8 ewes each).One group served as a control and received corn oil once a day,whereas the other group received BPA(5 mg/kg/d as a subcutaneous injection).In vitro study,ovine trophoblast cells(OTCs)were exposed to 4 treatments,6 replicates each.The OTCs were treated with 400μmol/L BPA,400μmol/L BPA+0.5μg/m L tunicamycin(Tm;ERS activator),400μmol/L BPA+1μmol/L 4-phenyl butyric acid(4-PBA;ERS antagonist)and DMEM/F12 complete medium(control),for 24 h.Results In vivo experiments,pregnant Hu ewes receiving the BPA from 40 to 130 days of pregnancy experienced a decrease in placental efficiency,progesterone(P4)level and fetal weight,and an increase in placental estrogen(E2)level,together with barrier dysfunctions,OS,inflammatory responses,autophagy and ERS in type A cotyledons.In vitro experiment,the OTCs exposed to BPA for 24 h showed an increase in the E2 level and related protein and gene expressions of autophagy,ERS,pro-apoptosis and inflammatory response,and a decrease in the P4 level and the related protein and gene expressions of antioxidant,anti-apoptosis and barrier function.Moreover,treating the OTCs with Tm aggravated BPA-induced dysfunction of barrier and endocrine(the increased E2 level and decreased P4 level),OS,inflammatory responses,autophagy,and ERS.However,treating the OTCs with 4-PBA reversed the counteracted effects of Tm mentioned above.Conclusions In general,the results reveal that BPA exposure can cause ERS in the ovine placenta and OTCs,and ERS induction might aggravate BPA-induced dysfunction of the placental barrier and endocrine,OS,inflammatory responses,and autophagy.These data offer novel mechanistic insights into whether ERS is involved in BPA-mediated placental dysfunction and fetal development.

Oracle中constraint的应用研究

数据完整性是数据库管理系统中重要的技术指标。本文研究在大型数据库Oracle平台,如何构建三类完整性约束,分别是实体完整性约束、参照完整性约束、用户自定义完整性约束,并研究其注意问题及如何绘制模式中表间的关系。

Dietary N-carbamylglutamate and L-arginine supplementation improves redox status and suppresses apoptosis in the colon of intrauterine growth-retarded suckling lambs

Previous studies have revealed that dietary N-carbamylglutamate(NCG)or L-arginine(Arg)improves small intestinal integrity and immune function in suckling Hu lambs that have experienced intrauterine growth retardation(IUGR).Whether these nutrients alter redox status and apoptosis in the colon of IUGR lambs is still unknown.This study,therefore,aimed at investigating whether dietary supplementation of Arg or NCG alters colonic redox status,apoptosis and endoplasmic reticulum(ER)stress and the underlying mechanism of these alterations in IUGR suckling Hu lambs.Forty-eight 7-d old Hu lambs,including 12 with normal birth weight(4.25±0.14 kg)and 36 with IUGR(3.01±0.12 kg),were assigned to 4 treatment groups(n=12 each;6 males and 6 females)for 3 weeks.The treatment groups were control(CON),IUGR,IUGR+Arg and IUGR+NCG.Relative to IUGR lambs,superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)content,as well as proliferation index,were higher(P<0.05)whereas reactive oxygen species(ROS),malondialdehyde(MDA)levels and apoptotic cell numbers were lower(P<0.05)in colonic tissue for both IUGR+Arg and NCG lambs.Both m RNA and protein levels of C/EBP homologous protein 10(CHOP10),B-cell lymphoma/leukaemia 2(Bcl-2)-associated X protein(Bax),apoptosis antigen 1(Fas),activating transcription factor 6(ATF6),caspase 3,and glucose-regulated protein 78(GRP78)were lower(P<0.05)while glutathione peroxidase 1(GPx1),Bcl-2 and catalase(CAT)levels were higher(P<0.05)in colonic tissue for IUGR+Arg and IUGR+NCG lambs compared with IUGR lambs.Based on our results,dietary NCG or Arg supplementation can improve colonic redox status and suppress apoptosis via death receptor-dependent,mitochondrial and ER stress pathways in IUGR suckling lambs.