The process of embryo implantation is a multifaceted and intricate dynamic event that includes the development of endometrial receptivity, embryo localization, adhesion, and invasion. Adhesion molecules, acting as crucial mediators of communication between cells or between cells and the extracellular matrix, are essential for the maintenance of endometrial receptivity and the regulation of embryo localization, adhesion, and invasion. However, the mechanisms by which adhesion molecules of maternal and embryo are organized to regulate key events in the peri-implantation period have yet to be fully explored. Based on recent research findings, this review provides a summary of the functions of different adhesion molecules at the maternal-fetal interface and their potential regulatory mechanisms according to the key progress of embryo implantation. In particular, we discussed the interactions between decidual immune cells and other cells mediated by adhesion molecules during the invasion process, which will provide novel perspectives into the role of adhesion molecule dysfunction in contributing to implantation failure.

The process of embryo implantation is a multifaceted and intricate dynamic event that includes the development of endometrial receptivity, embryo localization, adhesion, and invasion. Adhesion molecules, acting as crucial mediators of communication between cells or between cells and the extracellular matrix, are essential for the maintenance of endometrial receptivity and the regulation of embryo localization, adhesion, and invasion. However, the mechanisms by which adhesion molecules of maternal and embryo are organized to regulate key events in the peri-implantation period have yet to be fully explored. Based on recent research findings, this review provides a summary of the functions of different adhesion molecules at the maternal-fetal interface and their potential regulatory mechanisms according to the key progress of embryo implantation. In particular, we discussed the interactions between decidual immune cells and other cells mediated by adhesion molecules during the invasion process, which will provide novel perspectives into the role of adhesion molecule dysfunction in contributing to implantation failure.

Successful pregnancy requires a balanced immune environment at the maternal-fetal interface, which not only maintains immune tolerance to ensure fetal development, but also requires a moderate immune response to resist infection. The distribution and dynamic changes of macrophages in decidual tissue suggested that it plays an important role in immune regulation, such as influencing vascular remodeling, regulating trophoblast cell function and immune cell activity. MicroRNA (miRNA) is a class of small non-coding RNA involved in the occurrence and development of diseases, and its functions and mechanisms in tumor have been extensively studied. The regulatory role of miRNA in pregnancy, especially in decidual macrophage polarization, is complex. In this paper, we systematically analyzed the phenotypic distribution of decidual macrophages at the maternal-fetal interface, and suggested that the inhibition of M2 phenotype polarization or abnormal activation of M1 was associated with pregnancy complications. We further discussed the regulation of miRNA transcription in immune responses of macrophages and metabolic regulation of macrophage polarization. It was confirmed that abnormal miRNA expression led to adverse pregnancy. A full understanding of the molecular mechanisms of miRNA in inflammatory response and metabolism of decidual macrophages can provide a new insight to the clinical diagnosis and treatment of adverse pregnancy.

Successful pregnancy requires a balanced immune environment at the maternal-fetal interface, which not only maintains immune tolerance to ensure fetal development, but also requires a moderate immune response to resist infection. The distribution and dynamic changes of macrophages in decidual tissue suggested that it plays an important role in immune regulation, such as influencing vascular remodeling, regulating trophoblast cell function and immune cell activity. MicroRNA (miRNA) is a class of small non-coding RNA involved in the occurrence and development of diseases, and its functions and mechanisms in tumor have been extensively studied. The regulatory role of miRNA in pregnancy, especially in decidual macrophage polarization, is complex. In this paper, we systematically analyzed the phenotypic distribution of decidual macrophages at the maternal-fetal interface, and suggested that the inhibition of M2 phenotype polarization or abnormal activation of M1 was associated with pregnancy complications. We further discussed the regulation of miRNA transcription in immune responses of macrophages and metabolic regulation of macrophage polarization. It was confirmed that abnormal miRNA expression led to adverse pregnancy. A full understanding of the molecular mechanisms of miRNA in inflammatory response and metabolism of decidual macrophages can provide a new insight to the clinical diagnosis and treatment of adverse pregnancy.

The endometrial microenvironment and the immune regulation of pregnancy is a recent focus and challenge in the field of reproductive immunology. During the establishment of pregnancy, the immune cells assist in shaping a fetus-friendly immune microenvironment through adaptive reprogramming, thereby allowing the embryo to obtain "immune privilege". Immunometabolism is an emerging research field that has been developing rapidly in the last decade, focusing on the interaction between the immunology and metabolism and their roles in the physiopathology. However, the current evidence regarding how immunometabolism is involved in the regulation of the endometrial microenvironment and maternal-fetal immune tolerance is insufficient. In light of the implications of tumor immunometabolism for immunometabolism in pregnancy, the metabolic pathways of immune cell differentiation and function are reviewed for their potential regulatory role in shaping the maternal-fetal tolerance microenvironment. The relationship between metabolic and nutritional abnormalities and pregnancy disorders is analyzed. Finally, the possibility of improving pregnancy outcomes through immunometabolic inhibitors or dietary interventions is explored from a clinical application perspective.

The endometrial microenvironment and the immune regulation of pregnancy is a recent focus and challenge in the field of reproductive immunology. During the establishment of pregnancy, the immune cells assist in shaping a fetus-friendly immune microenvironment through adaptive reprogramming, thereby allowing the embryo to obtain "immune privilege". Immunometabolism is an emerging research field that has been developing rapidly in the last decade, focusing on the interaction between the immunology and metabolism and their roles in the physiopathology. However, the current evidence regarding how immunometabolism is involved in the regulation of the endometrial microenvironment and maternal-fetal immune tolerance is insufficient. In light of the implications of tumor immunometabolism for immunometabolism in pregnancy, the metabolic pathways of immune cell differentiation and function are reviewed for their potential regulatory role in shaping the maternal-fetal tolerance microenvironment. The relationship between metabolic and nutritional abnormalities and pregnancy disorders is analyzed. Finally, the possibility of improving pregnancy outcomes through immunometabolic inhibitors or dietary interventions is explored from a clinical application perspective.

Objective:To evaluate the quantity and function changes of dendritic cells ( DC) in peripheral blood of patients with repeated implantation failure ( RIF).Methods:30 patients with RIF and 15 normal controls were enrolled in this study,and the peripheral blood was collected during the mid-luteal phase.The percentage of DC subsets and the expression levels of functional molecules were assessed by flow cytometric analysis.Results:Compared with normal controls,the percentage of lin-HLA-DR+DC cells accounting for leukocytes in patients with RIF was not significantly different ( P>0.05).There were also no significant differences in the expression levels of co-stimulatory molecules ( CD80 and CD86) and immune tolerant molecules CD200 on DC cells surfaces between patients with RIF and normal controls ( all P>0.05).In addition,the percentage of CD11c+CD123-mDC accounting for DC cells was significantly increased in patients with RIF (P<0.05),however,the percentage of CD11c-CD123+pDC was similar (P>0.05). Conclusion:The percentage of mDC accounting for DC cells was significantly increased in patients with RIF, which may be one of factors affecting pregnancy outcomes.