Concentrations of serum granulocyte-colony-stimulating factor in normal pregnancy and preeclampsia

A meta-analysis on first-trimester blood count parameters-is the neutrophil-to-lymphocyte ratio a potentially novel method for first-trimester preeclampsia screening?

Objective

Meta-analysis focusing on the role of first-trimester neutrophil-to-lymphocyte ratio (NLR) in the prediction of preeclampsia.

Data sources

PubMed, Scopus, Web of Science, Cochrane Library, and Embase databases were queried from inception up to December 31, 2022.

Study eligibility criteria

The study included all types of original research that was conducted in humans and values of NLR were measured during the first trimester, among patients who later developed preeclampsia, compared to the values of control groups.

Study appraisal and synthesis methods

Two reviewers independently performed data abstraction and quality appraisal, and disagreements were resolved by consensus and, if necessary, by the opinion of a third reviewer. During the analysis, PRISMA and MOOSE guidelines were followed. All statistical analyses were made with R.

Results

For the research on the predictive role of NLR values in the first trimester for preeclampsia, a total of 6 studies were selected for analysis, covering 2,469 patients. The meta-analysis revealed a 95% confidence interval (CI) for the effect size of 0.641 to 1.523, with a prediction interval of 0.027 to 2.137.

Conclusion

Based on the analysis, NLR is a promising biochemical marker for future pieces of research that try to find new screening methods for first-trimester preeclampsia. We encourage other researchers to examine NLR's predictive value combined with other markers in preeclampsia screening, this way being able to find new and affordable protocols for first-trimester preeclampsia screening.

Systematic review registration

identifier CRD42023392663.

Relaxin contributes to the elevation of monocytic myeloid-derived suppressor cells in peripheral blood of pregnant canines

Tolerance towards fetal alloantigens in the maternal immune system is essential for maintaining pregnancy. Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells characterized by their ability to suppress immune activity and maintain maternal-fetal immune tolerance. However, the mechanisms underlying MDSC induction have not been elucidated. Herein, we investigated the myeloid-derived suppressor cells (MDSCs) in the peripheral blood of pregnant canines and its induction mechanism. By analyzing the concentration of MDSCs in the peripheral blood of pregnant canines, elevation of MDSCs has been observed during pregnancy. In addition, MDSCs from pregnant canines inhibit T cell activation. These results suggest that the elevated MDSCs in canine pregnancy may contribute to reduces maternal immune activity. To clarify the cause of MDSCs elevation in canine pregnancy, we analyzed the relationship between pregnancy-related hormones (estradiol, progesterone, and relaxin) and MDSCs. Serum relaxin levels, but not estradiol and progesterone, were correlated with the ratio of monocyte MDSCs. Additionally, relaxin induced monocytic MDSCs as well as inhibited T cell activation in vitro. Therefore, relaxin contributes to the elevation of monocytic MDSCs in the peripheral blood of pregnant canines. Our findings highlight the novel role of relaxin in pregnancy and contribute to a better understanding of maternal-fetal immune tolerance.

Granulocyte colony-stimulating factor in reproductive-related disease: Function, regulation and therapeutic effect

Granulocyte colony-stimulating factor (G-CSF) is one of the cytokines which plays important roles in embryo implantation and normal pregnancy. At the maternal-fetal interface, G-CSF can be synthesized by multiple cells, and participates in regulation of trophoblast development, endometrial decidualization, placental metabolism and angiogenesis. Moreover, as an important medium of intercellular communication, G-CSF has also been shown to exert key roles in crosstalk between cellular components at the maternal-fetal interface. Recently, our study demonstrated that G-CSF derived from M2 macrophage could promote trophoblasts invasion and migration through activating PI3K/AKT/Erk1/2 pathway, thereby involving in normal pregnancy program. Herein, we will summarize the role and regulation of G-CSF in normal pregnancy and reproductive-related disease, and the clinical applications of G-CSF in patients undergoing in vitro fertilization with thin endometrium, repeated implantation failure, and women suffered with recurrent spontaneous abortion.

Gene Expression of Pregnancy Neutrophils Differs for Protease versus Lipopolysaccharide Stimulation

Neutrophils, which extensively infiltrate maternal systemic blood vessels in preeclampsia, express protease-activated receptor 1 (PAR-1) but only during pregnancy. Neutrophils are generally considered to be non-specific in their response, but the pregnancy-specific expression of PAR-1 could result in a gene expression profile unique to pregnancy, which could help explain why the maternal inflammatory response in preeclampsia is systemic rather than localized. We sought to determine if gene expression of pregnancy neutrophils would differ if stimulated by a protease versus bacterial lipopolysaccharide (LPS). We isolated neutrophils from normal pregnant women at 30 weeks’ gestation and cultured them with elastase or LPS. We used elastase because it is a protease elevated in women with preeclampsia, and it activates pregnancy neutrophils via PAR-1. RNA was isolated from the neutrophils for sequencing of the transcriptomes. We discovered many differences in the gene expression profiles. For example, exposure to elastase resulted in three times more uniquely expressed genes than LPS, and the number of significantly differentially upregulated and downregulated genes was greater for elastase. Analysis of canonical pathways revealed similarities for innate immunity but also differences. LPS treatment enriched more pathways, but elastase activated more genes in each pathway. Elastase treatment enriched the MAPK signaling pathway, whereas LPS did not. This is significant because MAPK is a key mediator of transcriptional responses. These findings indicate that protease stimulation of pregnancy neutrophils results in a different profile than stimulation with LPS, which may help explain why the sterile inflammatory response of preeclampsia is systemic and unique to pregnancy.

Epigenetic Regulation of Interleukin-17-Related Genes and Their Potential Roles in Neutrophil Vascular Infiltration in Preeclampsia

DNA methylation is an epigenetic mechanism controlling gene expression, and reduced methylation is associated with increased gene expression. We hypothesized that IL-17 cytokines are regulated by DNA methylation, are elevated in the circulation of preeclamptic women, and stimulate vascular neutrophil chemokine expression, which could account for vascular infiltration of neutrophils in preeclampsia. We found significantly reduced DNA methylation of IL17A, IL17E, and IL17F genes in omental arteries of preeclamptic women, significantly reduced methylation of IL2, which regulates IL-17-producing T-lymphocytes, and significantly reduced methylation of genes encoding neutrophil chemokines and TNFα receptors related to lymphocyte function. Maternal plasma levels of IL-17A were significantly elevated in the second trimester of preeclamptic pregnancy as compared to normal pregnancy. To test if methylation regulates IL-17 cytokines, a lymphocyte cell line (Jurkat) was cultured with a hypomethylating agent. Hypomethylation increased expression of IL17E (aka IL25), IL17F, and IL2. IL17A was not expressed by Jurkat cells. To test the potential role of IL-17 cytokines in vascular neutrophil infiltration associated with preeclampsia, human vascular smooth muscle cells were cultured with IL-17 cytokines. IL-17A, but not IL-17E or IL-17F, increased gene expression of neutrophil chemokines (IL-8, CXCL5, and CXCL6) that are increased in vascular smooth muscle of preeclamptic women. The monocyte chemokine, CCL-2, was not increased. TNFα also increased neutrophil chemokines. IL-17 cytokines are regulated by DNA methylation; IL-17A is elevated in preeclampsia and stimulates expression of neutrophil chemokines in vascular smooth muscle. IL-17A could be responsible for vascular infiltration of neutrophils in preeclampsia.

Circulatory Neutrophils Exhibit Enhanced Neutrophil Extracellular Trap Formation in Early Puerperium: NETs at the Nexus of Thrombosis and Immunity

Pregnancy is associated with elevated maternal levels of cell-free DNA of neutrophil extracellular trap (NET) origin, as circulatory neutrophils exhibit increased spontaneous NET formation, mainly driven by G-CSF and finely modulated by sex hormones. The postpartum period, on the other hand, involves physiological alterations consistent with the need for protection against infections and fatal haemorrhage. Our findings indicate that all relevant serum markers of neutrophil degranulation and NET release are substantially augmented postpartum. Neutrophil pro-NETotic activity in vitro is also upregulated particularly in post-delivery neutrophils. Moreover, maternal puerperal neutrophils exhibit a strong pro-NETotic phenotype, associated with increased levels of all key players in the generation of NETs, namely citH3, MPO, NE, and ROS, compared to non-pregnant and pregnant controls. Intriguingly, post-delivery NET formation is independent of G-CSF in contrast to late gestation and complemented by the presence of TF on the NETs, alterations in the platelet activity status, and activation of the coagulation cascade, triggered by circulating microparticles. Taken together, our results reveal the highly pro-NETotic and potentially procoagulant nature of postpartum neutrophils, bridging an overt immune activation with possible harmful thrombotic incidence.

Preeclampsia: inflammatory signature of decidual cells in early manifestation of disease

INTRODUCTION

Preeclampsia is a pregnancy-specific complication characterized by hypertension in combination with proteinuria and/or various manifestations of multiple organ failure. It is believed that etiology of preeclampsia lies in dysfunction of the placenta and disorder of the maternal-fetal interactions. In preeclampsia decidual membrane, the maternal part of the placenta which normally supports immunological tolerance of the maternal organism to the semi-allogeneic fetus, becomes a site of inflammation.

METHODS

The aim of our study was to characterize the phenotype of decidual macrophages and plasma profiles in patients with late- and early-onset preeclampsia as compared with controls (n = 43). Decidual cells were obtained by enzymatic digestion method and characterized by flow cytometry analysis, real-time PCR, bioinformatics analysis, immunohistochemistry, and Western blot. Plasma samples were analyzed by multiplex assay.

RESULTS

The number of inflammation-associated CD86+ and CX3CR1+ cells was significantly higher in the early-onset preeclampsia while the portion of CD163+ cells was significantly higher among studied groups. We observed significant increase of endothelin-1 gene expression and a significant decrease in eNOS and GNB3 expression and TGFβ relative protein level in decidual cells of the early-onset preeclampsia samples. We also revealed elevation of pro- and anti-inflammatory cytokines in plasma of preeclampsia groups.

DISCUSSION

Our findings reflect profound early-onset preeclampsia-associated alterations in the decidua and emphasize the importance of the decidua as a link in the development of preeclampsia.

Vitamin D Promotes Trophoblast Cell Induced Separation of Vascular Smooth Muscle Cells in Vascular Remodeling via Induction of G-CSF

Vitamin D deficiency is associated with complications of pregnancy such as pre-eclampsia, fetal growth restriction, and miscarriage, all of which are also associated with incomplete spiral artery (SpA) remodeling. We have previously shown that both uterine natural killer (uNK) cells and extravillous trophoblast cells (EVT) are required for successful SpA remodeling, but whether their activity in this process is modulated by vitamin D is not known. In the current study, we use a previously described chorionic plate artery (CPA) ex vivo model of vascular remodeling to determine the effects of 1,25(OH)₂D treated uNK cell, placental explant (PEx), and uNK/PEx conditioned medium (CM) on vascular smooth muscle cell (VSMC) disorganization and phenotypic switching. Significant results were followed up in VSMCs in vitro. We demonstrate that 1,25(OH)₂D can enhance the ability of PEx to induce SpA remodeling, via a mechanism associated with increased secretion of granulocyte-colony stimulating factor (G-CSF). G-CSF appears able to increase VSMC disorganization and phenotypic switching in both an ex vivo vascular model and in vitro VSMC cultures. The clinical relevance of these findings are still to be determined. G-CSF may have differential effects depending on dose and vascular bed, and vitamin D may play a role in potentiating these actions. G-CSF may be an interesting potential therapeutic target for facilitating physiological vascular remodeling for the prevention of adverse obstetric outcomes.

Local VEGF-A blockade modulates the microenvironment of the corneal graft bed

The microenvironment plays an important role in several immunological processes. Vascular endothelial growth factor-A (VEGF-A) not only regulates angiogenesis, but is known as a modulator of the immune microenvironment. Modulating the site of transplantation might be beneficial for subsequent transplant survival. In this study, we therefore analyzed the effect that a local blockade of VEGF-A in the inflamed cornea as the graft receiving tissue has on the immune system. We used the murine model of suture-induced neovascularization and subsequent high-risk corneal transplantation, which is an optimal model for local drug application. Mice were treated with VEGFR1/R2 trap prior to transplantation. We analyzed corneal gene expression, as well as protein levels in the cornea and serum on the day of transplantation, 2 and 8 weeks later. Local VEGF depletion prior to transplantation increases the expression of pro-inflammatory as well as immune regulatory cytokines only in the corneal microenvironment, but not in the serum. Furthermore, local VEGFR1/R2 trap treatment significantly inhibits the infiltration of CD11c+ dendritic cells into the cornea. Subsequent increased corneal transplantation success was accompanied by a local upregulation of Foxp3 gene expression. This study demonstrates that locally restricted VEGF depletion increases transplantation success by modulating the receiving corneal microenvironment and inducing tolerogenic mechanisms.

Multimodal Regulation of NET Formation in Pregnancy: Progesterone Antagonizes the Pro-NETotic Effect of Estrogen and G-CSF

Human pregnancy is associated with a mild pro-inflammatory state, characterized by circulatory neutrophil activation. In order to explore the mechanism underlying this alteration, we examined NETosis during normal gestation. Our data indicate that neutrophils exhibit a pro-NETotic state, modulated in a multimodal manner during pregnancy. In general, circulatory granulocyte colony-stimulating factor, the levels of which increase during gestation, promotes neutrophil extracellular trap (NET) formation. Early in pregnancy, NETosis is enhanced by chorionic gonadotropin, whereas toward term is stimulated by estrogen. A complex interaction between estrogen and progesterone arises, wherein progesterone restrains the NETotic process. In this state, extensive histone citrullination is evident, yet full NETosis is inhibited. This coincides with the inability of neutrophil elastase to translocate from the cytoplasm to the nucleus and is regulated by progesterone. Our findings provide new insight concerning gestational and hormone-driven pathologies, since neutrophil recruitment, activation, and NET release could be associated with excessive endothelial and placental injury.

Glucose and metformin modulate human first trimester trophoblast function: a model and potential therapy for diabetes-associated uteroplacental insufficiency

PROBLEM

Diabetes confers an increased risk of preeclampsia, but its pathogenic role in preeclampsia is poorly understood. The objective of this study was to elucidate the effects of excess glucose on trophoblast function and whether any changes could be reversed by metformin.

METHOD OF STUDY

The human first trimester trophoblast cell line (Sw.71) was treated with glucose at 5, 10, 25, and 50 mm, in the presence and absence of metformin. Trophoblast migration was quantified and supernatant cytokine, chemokine, and angiogenic factors measured.

RESULTS

Increasing concentrations of glucose significantly increased trophoblast secretion of the inflammatory cytokines/chemokines: IL-1β, IL-6, IL-8, GRO-α, RANTES, and G-CSF; significantly increased trophoblast secretion of the anti-angiogenic factors sFlt-1 and sEndoglin; and significantly decreased trophoblast migration. Excess glucose-induced trophoblast IL-1β production was inhibited by disabling the Nalp3/ASC inflammasome. Metformin partially reduced the glucose-induced inflammatory response, but had no effect on the anti-angiogenic or antimigratory response.

CONCLUSION

Excess glucose induced a pro-inflammatory, anti-angiogenic, and antimigratory state in first trimester trophoblast cells. Glucose-induced trophoblast IL-1β secretion was mediated by the inflammasome. Glucose-induced inflammation was partially reversed by metformin. These findings demonstrate the pleiotropic effects of hyperglycaemia on the trophoblast, providing potential explanations for the strong link between diabetes and preeclampsia.

Neutrophils, but not lymphocytes or monocytes, infiltrate maternal systemic vasculature in women with preeclampsia

OBJECTIVE

Leukocytes are activated in women with preeclampsia, but the class of leukocytes that infiltrates the maternal vasculature and, therefore, is most likely to cause vascular dysfunction is not known.

METHODS

Subcutaneous fat biopsies were obtained at Cesarean section or abdominal surgery from 7 normal non-pregnant women, 7 women with normal pregnancies, and 7 women with preeclampsia. Tissues were immunohistochemically stained for CD14, a monocyte/macrophage antigen, CD99, a lymphocyte antigen, and CD66b, a neutrophil antigen.

RESULTS

CD14 stained cells were found infiltrated into fat tissue but were not present in vessels for any of the groups. CD99-stained cells were present in approximately 20% to 30% of vessels with no difference among groups. CD66b-stained cells were present in all groups with a significantly greater percentage of vessels stained for preeclamptic than normal pregnant or normal non-pregnant women (70 +/- 6 vs. 43 +/- 9 vs. 21 +/- 5%, respectively, p < 0.01). CD66b cells were the most abundant cell type that infiltrated vessels of preeclamptic women.

CONCLUSIONS

1) A significantly greater number of neutrophils adhered to endothelium and infiltrated into the intimal space in the maternal systemic vasculature of preeclamptic women than in that of normal pregnant women or normal non-pregnant women; 2) No significant difference in lymphocyte infiltration was observed among the patient groups, and lymphocytes were present in much lower numbers than-neutrophils; 3) Monocytes/macrophages were found in fat tissue but not in vessels. We speculate that neutrophils are the class of leukocytes that cause the majority of vascular cell dysfunction in women with preeclampsia.

Multiplexed immunobead-based cytokine profiling for early detection of ovarian cancer

Early detection of ovarian cancer might improve clinical outcome. Some studies have shown the role of cytokines as a new group of tumor markers for ovarian cancer. We hypothesized that a panel comprised of multiple cytokines, which individually may not show strong correlation with the disease, might provide higher diagnostic power. To evaluate the diagnostic utility of cytokine panel, we used a novel multianalyte LabMAP profiling technology that allows simultaneous measurement of multiple markers. Concentrations of 24 cytokines (cytokines/chemokines, growth, and angiogenic factors) in combination with cancer antigen-125 (CA-125), were measured in sera of 44 patients with early-stage ovarian cancer, 45 healthy women, and 37 patients with benign pelvic tumors. Six markers, i.e., interleukin (IL)-6, IL-8, epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), monocyte chemoattractant protein-1 (MCP-1), and CA-125, showed significant differences in serum concentrations between ovarian cancer and control groups. Out of this group, IL-6, IL-8, VEGF, EGF, and CA-125, were used in a classification tree analysis that resulted in 84% sensitivity at 95% specificity. The receiver operator characteristic curve created using the combination of markers produced sensitivities between 90% and 100% in the area of 80% to 90% specificity, whereas the receiver operator characteristic curve for CA-125 alone resulted in sensitivities of 70% to 80%. The classification tree analysis for discrimination of benign condition from ovarian cancer used CA-125, granulocyte colony-stimulating factor (G-CSF), IL-6, EGF, and VEGF resulting in 86.5% sensitivity and 93.0% specificity. The presented data show that simultaneous testing of a panel of serum cytokines and CA-125 using LabMAP technology may present a promising approach for ovarian cancer detection.

Elevated levels of adhesion molecules derived from leukocytes and endothelial cells in patients with pregnancy-induced hypertension

OBJECTIVE

Our purpose was to elucidate the role of adhesion molecules in the pathogenesis of pregnancy-induced hypertension (PIH).

METHODS

Sera, peripheral lymphocytes, and polymorphonuclear cells (PMN) from PIH patients, normal pregnant women, and nonpregnant women were collected. Soluble intercellular adhesion molecule-1 (sICAM-1) in sera was measured by ELISA. ICAM-1 expression on endothelial cells (EC) incubated with sera was analyzed by flow cytometry and RT-PCR. CD11a, CD11b, and CD18 expression on lymphocytes and PMN were also measured by flow cytometory.

RESULTS

CD11a and CD18 expression levels on PMN and lymphocytes of PIH patients were significantly higher than those of normal pregnant women (p<0.05). The expression of CD11b was significantly increased in normal pregnancy compared with that in nonpregnant women (p<0.05). Serum sICAM-1 in PIH patients was higher than that in normal pregnant women (p<0.05). ICAM-1 expression level on EC incubated with PIH serum for 24 hr was significantly higher than that with normal pregnant serum (p<0.0005). ICAM-1 mRNA expression after 12-hr incubation with PIH serum was also significantly increased compared with serum from normal pregnant women (p<0.05).

CONCLUSION

Adhesion molecules may play an important role in the pathogenesis of PIH.

Physiological leukocytosis during pregnancy is associated with changes in glucose transporter expression of maternal peripheral blood granulocytes and monocytes

PROBLEM

The scarce data on glucose transporter expression of leukocytes are contradictory and nothing is known about changes accompanying physiological leukocytosis during pregnancy, which imposes acute metabolic demands on the cells.

METHOD OF STUDY

Cytospin preparations of intravascular leukocytes were searched immunocytochemically for the high affinity glucose transporters GLUT1, 3 and 4. Pregnancy-associated quantitative changes in transporter expression were assessed by flow cytometry.

RESULTS

Granulocytes and monocytes stained for GLUT1, 3 and 4. Major changes in cell surface transporter expression during pregnancy were a 36% (P < 0.05) down-regulation of granulocyte GLUT1 at term, and an increase in monocyte GLUT3 levels to 137% (P < 0.05), paralleled by a 24% (P < 0.05) decrease in GLUT4 content in second trimester. Apart from a minor subpopulation, lymphocytes were negative for these carriers.

CONCLUSION

GLUT1, 3 and 4 are abundantly expressed in granulocytes and monocytes. The particular isoforms are differentially regulated during pregnancy, suggesting an individual functional significance.