Role of cathepsin E in decidual macrophage of patients with recurrent miscarriage

MMP2 and MMP9 are associated with the pathogenesis of recurrent pregnancy loss through protein expression rather than genetic polymorphism

Matrix metalloproteinases (MMPs) degrade extracellular matrix proteins and are important for placenta formation during early pregnancy. Recurrent pregnancy loss (RPL) is associated with abnormalities in endometrial extracellular matrix remodeling. This study aimed to elucidate the roles of MMP2 and MMP9 in RPL pathogenesis. In total, 295 women with a history of RPL and 101 controls were included in this genetic study. Genotype analysis was performed using polymerase chain reaction (PCR) restriction fragment length polymorphisms. For proteolytic analysis, decidua and villi were collected from 10 RPL-miscarried women with normal fetal chromosomes (NC) and 19 women with fetal chromosome aberrations (AC). The expression of MMP2 and MMP9 in the decidua and villi was measured by IHC and ELISA. All samples were collected after obtaining informed consent. There were no statistically significant differences in MMP2-735 C/T and MMP9-1562 C/T frequencies between women with RPL and the controls. There was no significant difference in MMP2 expression levels in the villi; however, MMP9 expression was significantly higher in normal fetal chromosomes. In the decidua, the expression of MMP2 in the NC group was significantly lower, and MMP9 in the NC group was significantly higher than in the AC group. Although no differences in MMP2-735 C/T and MMP9-1562 C/T gene polymorphisms were observed in the present study, it is suggested that differences at the protein level are involved in the pathogenesis of RPL since MMP expression is not only regulated by genes but also by local inflammation and various inductive signals.

Imbalance polarization of M1/M2 macrophages in miscarried uterus

BACKGROUND

Lipopolysaccharides (LPS) is well known to manifest a miscarriage-inducing effector during early pregnancy and activate macrophage to induce M1 macrophage polarization. However, the role of macrophage polarization in LPS-related miscarriage-inducing effect is not apparent.

METHODS

In this work, gene expression changes and the percentage of M1/M2 macrophages and monocytes in LPS-induced miscarried uterus were firstly analyzed by RNA sequencing (RNA-seq) and Flow Cytometry. To explore the origin that contributes to M1/M2 macrophage differentiation, the expression of monocyte chemotactic protein (MCP-1), CCL3, and CCL4, chemokines related to monocyte/macrophage migration, was tested by quantitative real time PCR (qRT-PCR).

RESULTS

We found that percentage of M1 macrophages rose, while the percentage of M2 macrophages declined down in the injected mice uterus. Meanwhile, the percentage of M1 and M2 macrophages showed no significant difference in the spleens of LPS injected mice compared to PBS injected control mice. Expression of Mcp-1, Ccl3, and Ccl4 and numbers of monocytes were remarkably up-regulated in LPS-induced miscarried mice uterus.

CONCLUSION

These results indicated that polarization and proportion changes of macrophage in the uterus may contribute to miscarriage. Our work provides new evidence correlating the aberrant regulation of M1/M2 macrophage polarization with deleterious miscarriage-inducing effects. This will help us understand the roles of critical immune cell differentiation in maintaining normal pregnancy.

Innate and Adaptive Immune Systems in Physiological and Pathological Pregnancy

The dynamic immunological changes occurring throughout pregnancy are well-orchestrated and important for the success of the pregnancy. One of the key immune adaptations is the maternal immune tolerance towards the semi-allogeneic fetus. In this review, we provide a comprehensive overview of what is known about the innate and adaptive immunological changes in pregnancy and the role(s) of specific immune cells during physiological and pathological pregnancy. Alongside this, we provided details of remaining questions and challenges, as well as future perspectives for this growing field of research. Understanding the immunological changes that occur can inform potential strategies on treatments for the optimal health of the neonate and pregnant individual both during and after pregnancy.

Decidual macrophages in recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is defined as two or more pregnancy loss, affecting the happiness index of fertility couples. The mechanisms involved in the occurrence of RSA are not clear to date. The primary problem for the maternal immune system is how to establish and maintain the immune tolerance to the semi-allogeneic fetuses. During the pregnancy, decidual macrophages mainly play an important role in the immunologic dialogue. The purpose of this study is to explore decidual macrophages, and to understand whether there is a connection between these cells and RSA by analyzing their phenotypes and functions. Pubmed, Web of Science and Embase were searched. The eligibility criterion for this review was evaluating the literature about the pregnancy and macrophages. Any disagreement between the authors was resolved upon discussion and if required by the judgment of the corresponding author. We summarized the latest views on the phenotype, function and dysfunction of decidual macrophages to illuminate its relationship with RSA.

Contribution of macrophages to fetomaternal immunological tolerance

The semi-allogeneic fetus develops in a uniquely immune tolerant environment within the uterus. For successful pregnancy, both the innate and adaptive immune systems must favor acceptance of the fetal allograft. Macrophages are the second most abundant immune cells after natural killer (NK) cells in the decidua. In coordination with decidual NK cells and dendritic cells, macrophages aid in implantation, vascular remodeling, placental development, immune tolerance to placental cells, and maintenance of tissue homeostasis at the maternal-fetal interface. Decidual macrophages show the classical activated (M1) and alternatively activated (M2) phenotypes under the influence of the local milieu of growth factors and cytokines, and appropriate temporal regulation of the M1/M2 switch is vital for successful pregnancy. Disturbances in the mechanisms that control the M1/M2 balance and associated functions during pregnancy can trigger a spectrum of pregnancy complications ranging from preeclampsia and fetal growth restriction to preterm delivery. This review addresses various mechanisms of tolerance, focusing on the basic biology of macrophages, their plasticity and polarization, and their protective roles at the immune-privileged maternal-fetal interface, including direct and indirect roles in promoting fetomaternal immune tolerance.

Functional regulation of decidual macrophages during pregnancy

A successful pregnancy requires that the maternal immune system recognizes and tolerates the semi-allogeneic fetus without compromising the capability of protecting both mother and fetus from various pathogens. Decidual macrophages present unique phenotypes to play a key role in the establishment of the immunological aspects of maternal-fetal interaction. Dysfunction of decidual macrophages gives rise to pregnancy complications such as preeclampsia, recurrent spontaneous miscarriage, preterm labor and fetal growth restriction. Here, we reviewed the latest knowledge on the origin, differentiation, unique phenotype and function of macrophages in normal pregnancy and in pregnancy complications. We mainly focused on the significant roles of decidual macrophages in the process of extravillous trophoblast invasion, spiral arterial remodeling, decidual stromal cells cultivation and immune tolerance maintenance in normal pregnancy, and their pathological roles in pregnancy-related complications, offering more integrated information in maternal-fetal immunity.

The investigation of calpain in human placenta with fetal growth restriction

PROBLEM

The mechanism of fetal growth restriction (FGR) is not fully understood. In this study, we explored the contribution of the calpain-calpastatin system and the activated states of calpains in human FGR placenta.

METHOD OF STUDY

The placentas were collected from patients of FGR (n = 17) and controls (n = 23) at elective cesarean sections in Nagoya City University Hospital and used for experiments upon informed consent. The existence and the expression of calpains and calpastatin in human placenta were compared between FGR and controls using immunohistochemistry, SDS-PAGE, and Western blotting.

RESULTS

Staining of calpains (pre-, post-μ-calpain, pre-, post-m-calpain, and calpain-6) and calpastatin was observed in cytoplasm of trophoblast cells, both in FGR and control placenta. Pre-μ-calpain was located in the cytoplasm, and post-μ-calpain was located mainly in proximity to the cytoplasmic membrane. The expression of pre-μ-calpain was significantly higher (P < .001) and calpain-6 was significantly lower (P = .01) in FGR placentas. The inactive μ-calpain (80 kDa) was significantly elevated (P < .01), and active μ-calpain (76 kDa) was significantly decreased (P = .01) in FGR placentas.

CONCLUSION

The results demonstrate that activation of μ-calpain is suppressed in FGR placentas and that calpain-6 in human placenta is involved in the pathology of FGR.

Role of Macrophages in Pregnancy and Related Complications

Macrophages (MФs) are the leukocytes produced from differentiation of monocytes and are located in almost all tissues of human body. They are involved in various processes, such as phagocytosis, innate and adaptive immunity, proinflammatory (M1) and anti-inflammatory (M2) activity, depending on the tissue microenvironment. They play a crucial role in pregnancy, and their dysfunction or alteration of polarity is involved in pregnancy disorders, like preeclampsia, recurrent spontaneous abortion, infertility, intrauterine growth restriction, and preterm labor. About 50-60% of decidual leukocytes are natural killer (NK) cells followed by MФs (the second largest population). MФs are actively involved in trophoblast invasion, tissue and vascular remodeling during early pregnancy, besides their role as major antigen-presenting cells in the decidua. These cells have different phenotypes and polarities in different stages of pregnancy. They have also been observed to enhance tumor growth by their anti-inflammatory activity (M2 type) and prevent immunogenic rejection. Targeted alteration of polarity (M1-M2 or vice versa) could be a major focus in the future treatment of pregnancy complications. This review is focused on the role of MФs in pregnancy, their involvement in pregnancy disorders, and decidual MФs as possible therapeutic targets for the treatment of pregnancy complications.

Macrophage Polarization in Physiological and Pathological Pregnancy

The immunology of pregnancy is complex and poorly defined. During the complex process of pregnancy, macrophages secrete many cytokines/chemokines and play pivotal roles in the maintenance of maternal-fetal tolerance. Here, we summarized the current knowledge of macrophage polarization and the mechanisms involved in physiological or pathological pregnancy processes, including miscarriage, preeclampsia, and preterm birth. Although current evidence provides a compelling argument that macrophages are important in pregnancy, our understanding of the roles and mechanisms of macrophages in pregnancy is still rudimentary. Since macrophages exhibit functional plasticity, they may be ideal targets for therapeutic manipulation during pathological pregnancy. Additional studies are needed to better define the functions and mechanisms of various macrophage subsets in both normal and pathological pregnancy.

Identification of Novel Placentally Expressed Aspartic Proteinase in Humans

This study presents pioneering data concerning the human pregnancy-associated glycoprotein-Like family, identified in the genome, of the term placental transcriptome and proteome. RNA-seq allowed the identification of 1364 bp hPAG-L/pep cDNA with at least 56.5% homology with other aspartic proteinases (APs). In silico analyses revealed 388 amino acids (aa) of full-length hPAG-L polypeptide precursor, with 15 aa-signal peptide, 47 aa-blocking peptide and 326 aa-mature protein, and two Asp residues (D), specific for a catalytic cleft of the APs (VVFDTGSSNLWV91-102 and AIVDTGTSLLTG274-285). Capillary sequencing identified 9330 bp of the hPAG-L gene (Gen Bank Acc. No. KX533473), composed of nine exons and eight introns. Heterologous Western blotting revealed the presence of one dominant 60 kDa isoform of the hPAG-L amongst cellular placental proteins. Detection with anti-pPAG-P and anti-Rec pPAG2 polyclonals allowed identification of the hPAG-L proteins located within regions of chorionic villi, especially within the syncytiotrophoblast of term singleton placentas. Our novel data extend the present knowledge about the human genome, as well as placental transcriptome and proteome during term pregnancy. Presumably, this may contribute to establishing a new diagnostic tool for examination of some disturbances during human pregnancy, as well as growing interest from both scientific and clinical perspectives.

Gene expression changes in immune response pathways following oral administration of tetrabromobisphenol A (TBBPA) in female Wistar Han rats

Tetrabromobisphenol A (TBBPA) is a brominated flame retardant used globally at high volumes, primarily in the epoxy resin of circuit boards. It has been detected in the environment and in humans. The National Toxicology Program found that chronic oral TBBPA treatment of 250mg/kg and higher caused an increased incidence of uterine lesions in female Wistar Han rats. The present laboratory has previously reported changes in gene expression associated with estrogen homeostasis in liver and uterine tissue of adult female Wistar Han rats after five days of gavage with 250mg/kg of TBBPA. Microarray analysis of tissue from these same TBBPA-treated rats was performed to detect additional pathways perturbed by TBBPA. Microarray analysis of uterine tissue detected downregulation of genes in pathways of the immune response following TBBPA treatment. These results, along with validation of associated gene expression changes using droplet digital PCR, are reported here. Our findings suggest mechanisms that may be related to estrogen-mediated immunosuppression.

Activity of Proteolytic Enzymes and Level of Cystatin C in the Peripartum Period

Objectives. The aim of the study was to evaluate the activity of cathepsin B, collagenases, trypsin, and plasmin and concentration of cystatin C in serum of healthy pregnant women in peripartum period. Study Design. The study group included 45 women in uncomplicated pregnancies. Blood samples were collected in four time points. Enzyme activity was measured by spectrofluorometric method. The level of cystatin C was measured using immunonephelometric method. Results. Mean activity of cathepsin B and the level of serum cystatin C were significantly higher in the study group. Collagenase activity was significantly lower in the study group than the control group. No differences in collagenase, plasmin, and trypsin activity on each day of the peripartum period were found. Conclusion. High activity of cathepsin B and increased level of cystatin C are typical for women in late pregnancy. Those levels significantly decrease after delivery which can be associated with potential role of those markers in placental separation. The insignificant changes of cystatin C level in the peripartum period seem to exclude the possibility of using cystatin C as a marker for renal insufficiency in the peripartum period but additional research is necessary to investigate the matter further.