Evaluation of fetoplacental oxygenation in a rat model of gestational diabetes mellitus using BOLD-MRI at 7.0-T

Objective:To compare the differences in blood oxygen level-dependent(BOLD)parameters following maternal hyperoxia between normal pregnancy and pregnancy in the rat model of gestational diabetes mellitus(GDM).Methods:GDM was induced by high-fat and sucrose diet(HFS)combined with an intraperitoneal injection of streptozotocin(STZ).On embryonic day 19(E19),the two groups of pregnant rats were imaged using a 7.0-T animal MRI scanner.TurboRARE was initially used to localize the fetoplacental units(FPUs).Next,multiple gradient echo BOLD was performed during the air and oxygen inhalation periods.T2^(*)map was then generated,and the baseline T2^(*)and absolute changes in T2^(*)value(ΔT2^(*),difference between T2^(*)oxy and T2^(*)air)were calculated.Following the MRI scan,the placentas and fetuses were aseptically stripped,weighed,and immunostained.Results:Nine rats were used in this study.After maternal oxygen inhalation,T2^(*)increased significantly in all subjects in both groups.TheΔT2^(*)for the placenta(5.97 vs.7.81 msec;P=0.007)and fetal brain(2.23 vs.3.97 msec;P=0.005)differed significantly between the GDM and control groups.Histochemical detection of placental glycogen content and inflammatory cytokines(IL-6 and TNF-α)showed significantly higher levels in the GDM than in the normal placenta.Conclusions:BOLD-MRI revealed abnormalities in the fetoplacental response to maternal hyperoxygenation in rats with GDM.We believe that this approach can potentially be used to evaluate placental dysfunction and assess the state of the fetus during pregnancy with GDM.

The Application of Aspirin in Pregnancy-Related Complications

Aspirin,one of the most widely applied medicines,not only possesses the effects on reducing fever,anti-vascular hyperplasia,and anti-inflammation,but also has the capacity of preventing platelet aggregation.So far,it is acceptable to adopt aspirin,especially low-dose aspirin(LDA),to prevent pregnancy-related complications,such as pregnancy complicated by antiphospholipid syndrome,systemic lupus erythematosus,or preeclampsia;unexplained recurrent spontaneous abortion;fetal growth restriction;and preterm birth.In this article,we reviewed the possible mechanism of action and applications of aspirin in these pregnancy-related complications.

CCL2 Enhances the Viability of Human Chorionic Trophoblast Cell Line HTR-8/SVneo Cells by Inhibiting Interleukin-24 Expression

Background:To investigate the regulatory effect of interleukin-24(IL-24)on cell viability of human chorionic trophoblast cell line(HTR-8/SVneo cells).Methods:Immunohistochemical staining was used to detect the expression of IL-24 and its receptors IL-20R1,IL-20R2,and IL-22R1 in villus tissue at early normal pregnancy.The effect of thymic stromal lymphopoietin(TSLP)and chemokine CCL2 on the expression of IL-24 in human chorionic trophoblast cell line HTR-8/SVneo cells was analyzed by In-cell Western.In addition,the effect of recombinant human IL-24(rhIL-24)and CCL2 on the viability of HTR-8/SVneo cells was analyzed by MTT assay.Results:IL-24 and its receptors showed a strong positive staining in trophoblasts at early normal pregnancy.Compared with control group,expression of IL-24 in HTR-8/SVneo cells was significantly inhibited after in vitro stimulation of recombinant human CCL2 protein(rhCCL2)(P<0.001).The viability of HTR-8/SVneo cells was significantly decreased after treatment with rhIL-24(P<0.001).In contrast,anti-IL-24 neutralizing antibody significantly enhanced the viability of HTR-8/SVneo cells(P<0.01).In addition,rhCCL2(100μg/L);enhanced the viability of HTR-8/SVneo cells(P<0.01)in vitro,but this effect was inhibited by treatment with rhIL-24.Conclusions:CCL2 enhances the viability of human trophoblast cell line HTR-8/SVneo cells in vitro by inhibiting the secretion of IL-24,which may be beneficial to blastocyst implantation and placental development.

Role of Autoantibodies in Infertility, Miscarriage, and Assisted Reproductive Technology Outcomes

Although considerable advances have been made in the field of assisted reproductive technology(ART),millions of couples still suffer from infertility and miscarriage.In a large number of cases,the etiology of these common reproductive failures remains unknown.However,the significance of autoantibodies in infertility and miscarriage has sparked extensive interest because of their pleiotropic roles in disrupting normal pregnancy.This review discusses the pleiotropic roles of a series of autoantibodies in infertility and miscarriage.A brief recapitulation of how the autoantibodies interfere with ART outcomes and treatments for this type of idiopathic infertility or miscarriage is also provided.While several disputes remain to be resolved,further studies employing better designs and larger sample sizes are required in view of the therapeutic potential of autoantibody inhibitors and the future of contraceptive vaccines.

Aspirin Enhances the Protective Effect of Progesterone on Trophoblast Cell from Oxidative Stress and Apoptosis

Objective:Clinically,low-dose aspirin and progesterone are frequently used to prevent pregnancy loss.We investigated the effect of these drugs on the biological behavior of human extravillous trophoblasts in vitro.Methods:HTR-8/SVneo cells were cultured in vitro and treated with different concentrations of aspirin and progesterone.The proliferation,invasion,and apoptosis of HTR-8/SVneo cells were assessed using a cell counting Kit-8 assay,Matrigel Transwell assay,and Hoechst staining,respectively.Reverse transcriptase polymerase chain reaction was used to verify the expression of related genes.Reactive oxygen species(ROS)levels were detected using the 2,7-dichlorofluorescin diacetate assay.Results:Low-dose aspirin alone,progesterone alone,or aspirin plus progesterone upregulated the proliferation and invasion and decreased the apoptosis of HTR-8/SVneo cells.Moreover,the expression of marker of proliferation Ki-67(MKI67),matrix metalloproteinases 2(MMP2),and MMP9 was increased.In addition,low-dose aspirin plus progesterone exerted stronger anti-apoptosis effects than low-dose aspirin and progesterone alone.Interestingly,aspirin upregulated the expression of progesterone receptor(PGR).Treatment with hydrogen peroxide(H_(2)O_(2))promoted ROS production in HTR-8/SVneo cells;however,low-dose aspirin plus progesterone significantly restricted H_(2)O_(2)-mediated ROS production and apoptosis in HTR-8/SVneo cells.Conclusions:These data suggest that low-dose aspirin and progesterone promote proliferation and invasion and cooperatively reduce oxidative stress and apoptosis in trophoblasts in vitro.These results may provide an experimental basis for the combined application of aspirin and progesterone to prevent unexplained recurrent spontaneous miscarriage,especially in patients with trophoblast dysfunction.

Interaction between Kynurenine and Aryl Hydrocarbon Receptor in Regulating the Balance of T helper 17 Cells and Regulatory T-cells in Decidua during Early Gestation

Objective:To investigate whether kynurenine/aryl hydrocarbon receptor(AHR)affects the maternal-fetal tolerance by involving the differentiation of T helper 17(Th17)/regulatory T(Treg)cells,and to provide theoretical basic for new treatment of unexplained abortion.Methods:Flow cytometry(FCM)was used to detect the expression of AHR in peripheral/decidual CD4+T,Treg,and Th17 cells.The effect of Kyn on the differentiation of peripheral/decidual naïve T-cells under Treg-/Th17-polarizing condition was detected by FCM;enzyme-linked immunosorbent assay was performed to examine the level of Kyn in villus and decidual tissues from normal pregnancy(NP)and unexplained abortion(UA).Student’s t-test in the case of two groups or one-way ANOVA in multiple groups was used.Results:AHR expression in CD4+T-cells was decreased in decidua versus blood in early pregnancy(P<0.0001).Kyn could promote the differentiation of peripheral and decidual naïve T-cells to Th17 cells under Treg-polarizing conditions(P<0.01).There was no statistical significance about the concentration of Kyn in decidual or villi tissues between NP and UA,and compared with NP,the expression of AHR in decidual CD4+T-cells from UA was increased(P<0.001).Conclusions:Kyn/AHR promotes Th17 and restricts Treg cells’differentiation,which is involved in maintaining the balance of Treg/Th17 cells at the maternal-fetal interface.

A Defective CXCL16/CXCR6 Axis Increases the Risk of Pregnancy Loss via the Abnormal Crosstalk between Decidual γδ T Cells and Trophoblasts

Objective::The maternal-fetal interface undergoes dynamic changes to allow the fetus to grow and develop in the uterus.The interaction between decidualγδT cells and trophoblasts plays a pivotal role during successful pregnancy;however,their physiological functions in early-term human pregnancy are still not completely illustrated.This study was undertaken to illustrate the functional roles of CXCL16/CXCR6 to prevent pregnancy loss via the crosstalk between decidualγδT cells and HTR8/SVneo trophoblast cells.Methods::The percentile of CXCR6+γδT cells in the peripheral blood from normal female and recurrent spontaneous abortion(RSA)patients was analyzed by flow cytometry.The expression of CXCR6 was detected in decidual immune cells via flow cytometry,and the expression of CXCL16 was analyzed in HTR8/SVneo trophoblast cells and lentivirus(LV)-HTR8/SVneo trophoblast cells via enzyme-linked immunosorbent assay.Reverse transcriptase-polymerase chain reaction was used to verify the expression of the CXCL16 gene in LV-HTR8/SVneo trophoblast cells.Expression of granzyme B and cytokines and proliferation of decidualγδT cocultured with HTR8/SVneo trophoblast cells were analyzed by flow cytometry.Invasion of HTR8/SVneo trophoblast cells was assessed via Matrigel transwell assay.Adoptive transfer was induced in vivo further to illustrate that the normal expression of CXCL16/CXCR6 could prevent pregnancy loss.Results::The percentile of CXCR6+γδT cells in the peripheral blood from RSA patients was lower than normal pregnancies.The expression of CXCR6 was highest in the decidualγδT cells among decidual immune cells,and the expression of CXCL16 increased as the amount of HTR8/SVneo trophoblast cells increased.Expression of granzyme B in the decidualγδT cells was downregulated by cocultured with HTR8/SVneo cells dependent of CXCL16,and HTR8/SVneo trophoblast cells induced the Th2 cytokines production in the decidualγδT cells.Both the expression of CXCR6 in the decidualγδT cells and proliferation of the decidualγδT cells were promoted by HTR8/SVneo trophoblast cells.On the other hand,decidualγδT cells enhanced the invasion of HTR8/SVneo trophoblast cells and thus promoted embryo implantation.In vivo study was taken further and shown that low expression of CXCL16/CXCR6 results in pregnancy loss because of dialog disorder between decidualγδT cells and trophoblasts.Conclusions::Low expression of CXCL16/CXCR6 results in pregnancy loss because of the dialog disorder between decidualγδT cells and trophoblasts,and it showed a light on the effective strategy of adoptive transfer of CXCR6+γδT cells on the treatment of RSA.This observation provides a scientific basis on which a potential strategy can be applied to the early-detect and treatment of RSA.

Cyclooxygenase-2 and Decidual Immune Cells

Cyclooxygenase-2(COX-2)is a rate-limiting enzyme in arachidonic acid(AA)metabolism.COX-2 and its products(prostanoids)serve versatile biological functions during pregnancy.Numerous evidences demonstrate special reprogramming of COX-2-catalyzing AA metabolism in decidual immune cells(DICs),particularly in decidual macrophages,corresponding to special gestational phases.This review summarizes the reprogramming of COX-2-catalyzing AA metabolism in DICs as well as the immunoregulation of diverse COX-2-generating prostanoids in DICs during the different phases of gestation.

Immune Regulation at Maternal-fetal Interface in Early Pregnancy

Decidual immune cells(DICs),including T-cells,regulatory T-cells,macrophages/dendritic cells,natural killer cells,and neutrophils,are resident at the maternal-fetal interface,and play vital roles in regulating trophoblast migration,decidual angiogenesis,immune tolerance,placentation,and decidualization during the early pregnancy.Extensive researches have revealed that these maternal DICs cooperated with each other,or with maternal decidual stromal cells,or with fetal-derived trophoblasts,and further formed a special maternal-fetal cross talk at the maternal-fetal interface,which was essential for the construction and maintenance of physiological pregnancy.Once aberrant cross talk and immune regulation arise,many pregnancy complications will inevitably occur,such as spontaneous abortion,intrauterine growth restriction(IUGR),preeclampsia(PE),and preterm birth.Here,we reviewed how critical immune cells are either enriched or excluded from the decidua,how their function is regulated within the decidua,and how they variously contribute to pregnancy success or failure.

Innate Lymphoid Cells in Normal Pregnancy and Pregnancy-Related Diseases

Innate lymphoid cells(ILCs)are a group of lymphocytes without diversified antigen receptors encoded by gene rearrangement on T and B cells.ILCs,which are tissue-resident innate immune cells,expressed particularly in the mucosa or the barrier surface,contribute to the formation of lymphoid organs,the maintenance of tissue homeostasis,and the regulation of antimicrobial defenses.It has been recently reported that ILCs were enriched at the maternal-fetal interface.During a successful pregnancy,the maternal immune system must tolerate a fetus as an allograft.With the new defined of ILCs,a number of studies have shown that three types of ILCs are involved in embryonic development and pregnancy maintenance as well as the occurrence and development of pregnancy-related complications.This article reviews the types and roles of ILCs in normal pregnancy and pregnancy-related diseases.

Indoleamine 2,3-Dioxygenase in Endometriosis

Endometriosis(EMS)is a chronic inflammatory and estrogen-dependent gynecological disease characterized by the presence of endometrial tissue outside the uterine cavity.Although it is a benign disease,EMS is tumor-like in several aspects,which include unrestrained growth,decreased apoptosis,and aggressive invasion.EMS involves endocrine disorders and immunological factors.Indoleamine 2,3-dioxygenase(IDO)is an intracellular enzyme that catalyzes the initial and rate-limiting step of the metabolism of tryptophan.IDO is a potential candidate facilitating EMS development.Increased IDO expression in both eutopic and ectopic endometria of women with EMS is biologically important in aspects,which include regulation of endometrial stromal cell function and modulation of adjacent local immunocytes to generate a supportive microenvironment.In turn,the expression of IDO can be regulated by the complex endocrine-immune microenvironment networks in endometrial lesions.Here,we systematically review the roles of IDO in EMS to explore its pathological implications and treatment potential.

Role of Decidual Natural Killer Cells at the Maternal-Fetal Interface during Pregnancy

Pregnancy is a complicated process with intricate cell-to-cell crosstalk and immune regulation.Decidual natural killer(NK)cells account for 50%-70% of decidual immune cells in early pregnancy,suggesting that they play important roles in various events,such as embryo implantation and vascular remodeling.Many studies have shown that decidual NK cells interact with other cells either through direct contact or the secretion factors such as cytokines and chemokines.Hence,this review aimed to present the phenotypic characteristics,classification,and functions of decidual NK cells at the maternal-fetal interface during pregnancy.