Association between preeclampsia and the CXC chemokine family (Review)

Acute stress transiently activates macrophages and chemokines in cervical lymph nodes

Acute restraint stress (RS) is routinely used to study the effects of psychological and/or physiological stress. We evaluated the impact of RS on cervical lymph nodes in rats at molecular and cellular levels. Male Sprague-Dawley rats were subjected to stress by immobilization for 30, 60, and 120 min (RS30, RS60, and RS120, respectively) and compared with rats of a no-stress control (C) group. The expression of genes encoding chemokines CXCL1/CXCL2 (Cxcl1 and Cxcl2) and their receptor CXCR2 (Cxcr2) was analyzed using reverse transcription-quantitative PCR (RT-qPCR) and microarray analyses. Immunohistochemistry and in situ hybridization were performed to determine the expression of these proteins and the macrophage biomarker CD68. Microarray analysis revealed that the expression of 514 and 496 genes was upregulated and downregulated, respectively, in the RS30 group. Compared with the C group, the RS30 group exhibited a 23.0-, 13.0-, and 1.6-fold increase in Cxcl1, Cxcl2, and Cxcr2 expression. Gene Ontology analysis revealed the involvement of these three upregulated genes in the cytokine network, inflammation, and leukocyte chemotaxis and migration. RT-qPCR analysis indicated that the mRNA levels of Cxcl1 and Cxcl2 were significantly increased in the RS30 group but were reverted to normal levels in the RS60 and RS120 groups. Cxcr2 mRNA level was significantly increased in the RS30 and RS120 groups compared with that in the C group. RS-induced CXCL1-immunopositive cells corresponded to B/plasma cells, whereas CXCL2-immunopositive cells corresponded to endothelial cells of the high endothelial venules. Stress-induced CXCR2-immunopositive cells corresponded to macrophages. Psychological and/or physiological stress induces an acute stress response and formation of an immunoreactive microenvironment in cervical lymph nodes, with the CXCL1/CXCL2-CXCR2 axis being pivotal in the acute stress response.

Pathophysiological impact of CXC and CX3CL1 chemokines in preeclampsia and gestational diabetes mellitus

Diabetes-related pathophysiological alterations and various female reproductive difficulties were common in pregnant women with gestational diabetes mellitus (GDM), who had 21.1 million live births. Preeclampsia (PE), which increases maternal and fetal morbidity and mortality, affects approximately 3%-5% of pregnancies worldwide. Nevertheless, it is unclear what triggers PE and GDM to develop. Therefore, the development of novel moderator therapy approaches is a crucial advancement. Chemokines regulate physiological defenses and maternal-fetal interaction during healthy and disturbed pregnancies. Chemokines regulate immunity, stem cell trafficking, anti-angiogenesis, and cell attraction. CXC chemokines are usually inflammatory and contribute to numerous reproductive disorders. Fractalkine (CX3CL1) may be membrane-bound or soluble. CX3CL1 aids cell survival during homeostasis and inflammation. Evidence reveals that CXC and CX3CL1 chemokines and their receptors have been the focus of therapeutic discoveries for clinical intervention due to their considerable participation in numerous biological processes. This review aims to give an overview of the functions of CXC and CX3CL1 chemokines and their receptors in the pathophysiology of PE and GDM. Finally, we examined stimulus specificity for CXC and CX3CL1 chemokine expression and synthesis in PE and GDM and preclinical and clinical trials of CXC-based PE and GDM therapies.

Proteomics and Metabolomics Profiling of Platelets and Plasma Mediators of Thrombo-Inflammation in Gestational Hypertension and Preeclampsia

Platelets may be pivotal mediators of the thrombotic and coagulopathic complications of preeclampsia (PE), linking inflammation and thrombosis with endothelial and vascular dysfunction. Both PE and gestational hypertension (GH) fall within the spectrum of hypertensive complications of pregnancy, with GH being a risk factor for preeclampsia. However, it is unclear what biomarkers distinguish PE from GH. Using a discovery size cohort, we aimed to characterize specific plasma and platelet thrombo-inflammatory drivers indicative of PE and differentiate PE from GH. We performed multiplex immunoassays, platelet and plasma quantitative proteomics and metabolomics of PE patients, comparing with non-pregnant (NP), healthy pregnant controls (PC) and GH participants. The expression pattern of plasma proteins and metabolites in PE/GH platelets was distinct from that of NP and PC. Whilst procoagulation in PC may be fibrinogen driven, inter-alpha-trypsin inhibitors ITIH2 and ITIH3 are likely mediators of thrombo-inflammation in GH and PE, and fibronectin and S100A8/9 may be major procoagulant agonists in PE only. Also enriched in PE were CCL1 and CCL27 plasma cytokines, and the platelet leucine-rich repeat-containing protein 27 and 42 (LRRC27/42), whose effects on platelets were explored using STRING analysis. Through protein-protein interactions analysis, we generated a new hypothesis for platelets’ contribution to the thrombo-inflammatory states of preeclampsia.

Immunological comparison of pregnant Dahl salt-sensitive and Sprague-Dawley rats commonly used to model characteristics of preeclampsia

The pregnant Dahl salt-sensitive (S) rat is an established preclinical model of superimposed spontaneous preeclampsia characterized by exacerbated hypertension, increased urinary protein excretion, and increased fetal demise. Because of the underlying immune system dysfunction present in preeclamptic pregnancies in humans, we hypothesized that the pregnant Dahl S rat would also have an altered immune status. Immune system activation was assessed during late pregnancy in the Dahl S model and compared with healthy pregnant Sprague-Dawley (SD) rats subjected to either a sham procedure or a procedure to reduce uterine perfusion pressure (RUPP). Circulating immunoglobulin and cytokine levels were measured by enzyme-linked immunosorbent assay (ELISA) and Milliplex bead assay, respectively, and percentages of circulating, splenic, and placental immune cells were determined using flow cytometry. The pregnant Dahl S rat exhibited an increase in CD4+ T cells, and specifically TNFα+CD4+ T cells, in the spleen compared with virgin Dahl S rats. The Dahl also had increased neutrophils and decreased B cells in the peripheral blood as compared with Dahl virgin rats. SD rats that received the RUPP procedure had increases in circulating monocytes and increased IFN-ɣ+CD4+ splenic T cells. Together these findings suggest that dysregulated T cell activity is an important factor in both the pregnant Dahl S rats and SD rats after the RUPP procedure.

Bioinformatics-based identification of miRNA-, lncRNA-, and mRNA-associated ceRNA networks and potential biomarkers for preeclampsia

This study aimed to identify significantly altered long non-coding RNAs (lncRNAs), microRNAs (miRNAs), mRNAs, pathways in preeclampsia (PE), and to investigate their targeted relationships and biological functions.GSE96985 from Gene Expression Omnibus database was extracted, involving 3 PE and 4 normal tissues. After the differential expression analysis of miRNAs, lncRNAs, and mRNAs using the limma package, protein-protein interaction (PPI) network and module analyses were performed for differentially expressed mRNAs (dif-mRNAs). Combined with the miRanda and miRWalk tools, a regulatory relationship between dif-miRNAs and dif-mRNAs/lncRNAs (dif-mRNAs/dif-lncRNAs) was predicted. Finally, mRNA-miRNA-lncRNA regulatory network construction was performed using Cytoscape software.A total of 511 dif-mRNAs were screened in PE. The top 5 nodes in the PPI networks included up-regulated complement component 3 (C3), C-X-C motif chemokine ligand 8 (CXCL8), and fibronectin 1 (FN1). Three significant network modules were identified for dif-mRNAs. C3 and CXCL8 were identified in module A, and FN1 was identified in module C. A disintegrin and metalloproteinase with thrombospondin motifs 6 (ADAMTS6) was down-regulated by the miR-210-3p. Therefore, lnc-CTD-2383M3.1 functions as a competing endogenous RNA in ADAMTS6 expression regulation by competitively binding to miR-210-3p during the regulation process of PE.C3, CXCL8, FN1, and ADAMTS6 might be involved in the development of PE. The lnc-CTD-2383M3.1-miR-210-3p-ADAMTS6 axis might be a potential regulatory mechanism in PE.

The role of CXC chemokine ligand 16 in physiological and pathological pregnancies

The survival and development of a semi-allogeneic fetus during pregnancy require the involvement of a series of cytokines and immune cells. Chemokines are a type of special cytokine those were originally described as having a role in leukocyte trafficking. CXC chemokine ligand (CXCL) 16 is a member of the chemokine family, and CXC chemokine receptor (CXCR) 6 is its sole receptor. Emerging evidence has shown that CXCL16/CXCR6 is expressed at the maternal-fetal interface, by cell types that include trophoblast cells, decidual stroma cells, and decidual immune cells (eg, monocytes, γδT cells, and natural killer T (NKT) cells). The regulation of expression of CXCL16 is quite complex, and this process involves a multitude of factors. CXCL16 exerts a critical role in the establishment of a successful pregnancy through a series of molecular interactions at the maternal-fetal interface. However, an abnormal expression of CXCL16 is associated with certain pathological states associated with pregnancy, including recurrent miscarriage, pre-eclampsia, and gestational diabetes mellitus (GDM). In the present review, the expression and pleiotropic roles of CXCL16 under conditions of physiological and pathological pregnancy are systematically discussed.

Distribution, nature, and origin of CXCL14-immunoreactive fibers in rat parotid gland

The distribution and nature of CXCL14-immunoreactive nerve fibers in salivary glands, especially the parotid gland was immunohistochemically investigated. Furthermore, the origin of parotid CXCL14-immunoreactive nerve fibers was determined by retrograde tracing experiments. CXCL14-immunoreactive nerve fibers were localized in the parotid, submandibular, and sublingual glands, particularly in the parotid gland. Double staining using identical sections revealed that a subpopulation of cells neuropeptide Y (NPY)-containing fibers was immunopositive for CXCL14 in the parotid gland. In the peripheral regions of acinar cells, CXCL14-immunoreactive fibers tended to coexist with NPY; however, perivascular NPY-immunoreactive fibers tended to be immunonegative for CXCL14. Parotid CXCL14-immunoreactive fibers were immunopositive for tyrosine hydroxylase (TH) but immunonegative for choline acetyltransferase and vasoactive intestinal peptide (VIP). After injection of horseradish peroxidase-labeled wheat germ agglutinin (WGA-HRP) in the parotid gland, retrogradely labeled neurons were seen in the superior cervical ganglion (SCG) and otic ganglion. Some of the WGA-immunoreactive somata in the SCG were immunopositive for CXCL14; however, no doubly-labeled somata were noted in the otic ganglion. These results indicate that CXCL14-immunoreactive nerve fibers originate in the SCG, and are sympathetic in nature. The coexistence of CXCL14 with NPY/TH suggests that CXCL14 may be associated with NPY/TH functions as a neuromodulatory chemokine in the parotid gland. The localization of CXCL14 nerve fibers around the acinar cells of the parotid gland indicates its involvement in acinar cell function, but not vasoconstriction.

Forkhead box P3 gene silencing inhibits the expression of chemokines and chemokine receptors associated with cell growth, migration, and apoptosis in hepatocellular carcinoma cells

The aberrant expression of forkhead box P3 (FOXP3) leads to the formation of malignant tumors. FOXP3 expression levels are also elevated in hepatocellular carcinoma (HCC). The aim of the present study was to investigate the effects of FOXP3 silencing on cell proliferation, migration, apoptosis and chemokine/chemokine receptor expression in the MHCC-97H HCC cell line. Three FOXP3 short hairpin (sh)RNA constructs were designed: Sh-FOXP3-1-pGreenPuro, sh-FOXP3-2-pGreenPuro, and sh-FOXP3-3-pGreenPuro. MHCC-97H cells were transfected with shRNA-FOXP3, and the mRNA and protein expression levels of C-X-C motif chemokine (CXC) ligand 12 (CXCL12), CXCL11, CXC receptor 4 (CXCR4) and CXCR7 were measured. Cell Counting Kit-8, terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling and Transwell assays were used to evaluate cell proliferation, apoptosis and migration, respectively. Of the three FOXP3 lentivirus carriers constructed, sh-FOXP3-1 significantly reduced FOXP3 expression levels and was chosen for further experiments. sh-FOXP3-1 inhibited cell proliferation, promoted apoptosis and inhibited cell migration compared with the negative control. The mRNA and protein expression levels of CXCL12, CXCL11, CXCR4 and CXCR7 were decreased significantly in response to FOXP3 silencing. FOXP3 silencing may therefore inhibit cell growth, induce apoptosis and inhibit migration in HCC cells, possibly by impairing the chemokine/chemokine receptor axes.

Methylation profile of genes involved in inflammation, in the blood from pregnancies with maternal preeclampsia due to untreated gestational diabetes mellitus

PURPOSE

To investigate DNA methylation changes in peripheral blood from patients with gestational diabetes mellitus (GDM) and preeclampsia (PE) due to poorly treated GDM.

METHODS

Eighteen pregnant women participated in the study: 6 with GDM, 6 with PE, and 6 healthy controls. The promoter methylation status of genes was profiled using the Human Inflammatory Response and Autoimmunity EpiTect Methyl II Signature PCR Array profiles. The results were validated with quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

Fewer inflammation-related genes were significantly hypomethylated in PE cases compared to healthy subjects than in GDM cases. Some of the examined genes show different methylation patterns between GDM and PE.

CONCLUSIONS

The epigenetic changes observed in this study indicate that GDM and PE exhibit specific DNA methylation profiles, with possible clinical applications.

Candidate Gene, Genome-Wide Association and Bioinformatic Studies in Pre-eclampsia: a Review

PURPOSE OF REVIEW

Regardless of the familial linkage reported in pre-eclampsia development, understanding the polymorphic genes associated with pre-eclampsia remains limited. Hence, this review aims to outline the main genetic factors that have been investigated in respect to pre-eclampsia development.

RECENT FINDINGS

It is apparent that different genes show significance in varying populations. Notably, it is reported that apolipoprotein-1 gene polymorphisms are associated with pre-eclampsia development in an African-American population, which may be worthwhile to investigate in a Black South African cohort. Despite the research attention that is focused on this surreptitious syndrome, a definitive cause eludes scientists and physicians, alike. Genetic studies can fulfil a dual purpose of suggesting novel hypotheses through genome-wide screening and testing these hypotheses via candidate gene studies. However, publications to date have only presented inconsistent and conflicting results regarding candidate gene analysis.

Effects of CXCL3 on migration, invasion, proliferation and tube formation of trophoblast cells

CXCL3 was reportedly associated with the invasion and metastasis of various malignancies, the role of CXCL3, however, in preeclampsia has not been fully discussed. We previously found placental CXCL3 level in severe preeclampsia was significantly lower than that in healthy pregnancy and exogenous recombinant human CXCL3 protein was able to promote trophoblasts' migration and proliferation. The current study, therefore, is further to investigate effects of endogenous CXCL3 on migration, invasion, proliferation, tube formation and apoptosis of trophoblasts. Immunofluorescence staining demonstrated that CXCL3 localized in both trophoblasts of placenta and HTR-8/SVneo cells. Moreover, data showed that migration, invasion, proliferation and tube-formation capability of HTR-8/SVneo cells transfected with siRNA-CXCL3 were suppressed by down-regulation of CXCL3, while those behaviors of HTR-8/SVneo cells transfected with pEZ-CXCL3 were enhanced by upregulation of CXCL3. Nevertheless, the apoptosis of HTR-8/SVneo cells was not affected by neither siRNA nor overexpression plasmid. The result suggests that CXCL3 is involved in migration, invasion, proliferation and tubule formation of trophoblasts and may play a key role in the pathogenesis of preeclampsia.

CXCL14-like Immunoreactivity Exists in Somatostatin-containing Endocrine Cells, and in the Lamina Propria and Submucosal Somatostatinergic Nervous System of Mouse Alimentary Tract

In the present study, we investigated the distribution of CXCL14 immunoreactive endocrine cells and neurons in mouse alimentary tract by immunohistochemistry. CXCL14 immunoreactive endocrine cells were found as closed-type cells in the stomach and open-type cells in the small intestine. The immunostaining of these endocrine cells corresponded with that of the somatostatin-containing endocrine cells. Only a few CXCL14 immunoreactive endocrine cells were seen in the large intestine. CXCL14 immunoreactive fibers were observed in the muscular layer from the stomach to the rectum with most abundance in the rectum. Many CXCL14 immunoreactive fibers were observed in the lamina propria and submucosal layer from the duodenum to the rectum with most abundance in the rectum; these fibers corresponded to the somatostatin-containing nerve fibers. Some CXCL14 immunoreactive neuronal somata that were also immuno-positive for somatostatin, were noted in the submucosal layer of the rectum. However, the remaining parts of the alimentary tract presented with almost negligible immunoreactive somata. The co-localization of CXCL14 and somatostatin suggests that CXCL14 contributes to the function of somatostatin, which include the inhibition of other endocrine and exocrine cells and the enteric nervous systems.

High Levels of CXCL8 and Low Levels of CXCL9 and CXCL10 in Women with Maternal RhD Alloimmunization

Maternal RhD alloimmunization is an inflammatory response against protein antigens in fetal red blood cells (RBC). However, not all women become alloimmunized when exposed to RhD⁺ fetal RBC. Thus, this study aimed to evaluate levels of inflammatory chemokines in RhD⁻ pregnant women with erythrocyte alloimmunization. CXCL8, CXCL9, CCL5, and CXCL10 levels were determined from cell culture supernatants by flow cytometry in 46 (30 non-alloimmunized RhD⁻ and 16 previously alloimmunized RhD⁻) pregnant women. CXCL8 levels were significantly higher (P < 0.004), and CXCL9 (P < 0.008) and CXCL10 (P < 0.003) levels were significantly lower in alloimmunized pregnant women. No significant difference in CCL5 levels was detected between the groups. Fetal RHD genotyping was performed in the alloimmunized RhD⁻ group by real-time PCR. Anti-D alloantibody was detected in 10 mothers and anti-D and -C in six mothers. Twelve fetuses were RHD positive and four were RHD negative. Further studies of serum chemokines and placenta tissue could provide a better understanding of the cells involved in the pathogenesis of maternal erythrocyte alloimmunization.

Extravillous Trophoblast and Endothelial Cell Crosstalk Mediates Leukocyte Infiltration to the Early Remodeling Decidual Spiral Arteriole Wall

Decidual spiral arteriole (SpA) remodeling is essential to ensure optimal uteroplacental blood flow during human pregnancy, yet very little is known about the regulatory mechanisms. Uterine decidual NK (dNK) cells and macrophages infiltrate the SpAs and are proposed to initiate remodeling before colonization by extravillous trophoblasts (EVTs); however, the trigger for their infiltration is unknown. Using human first trimester placenta, decidua, primary dNK cells, and macrophages, we tested the hypothesis that EVTs activate SpA endothelial cells to secrete chemokines that have the potential to recruit maternal immune cells into SpAs. Gene array, real-time PCR, and ELISA analyses showed that treatment of endothelial cells with EVT conditioned medium significantly increased production of two chemokines, CCL14 and CXCL6. CCL14 induced chemotaxis of both dNK cells and decidual macrophages, whereas CXCL6 also induced dNK cell migration. Analysis of the decidua basalis from early pregnancy demonstrated expression of CCL14 and CXCL6 by endothelial cells in remodeling SpAs, and their cognate receptors are present in both dNK cells and macrophages. Neutralization studies identified IL-6 and CXCL8 as factors secreted by EVTs that induce endothelial cell CCL14 and CXCL6 expression. This study has identified intricate crosstalk between EVTs, SpA cells, and decidual immune cells that governs their recruitment to SpAs in the early stages of remodeling and has identified potential key candidate factors involved. This provides a new understanding of the interactions between maternal and fetal cells during early placentation and highlights novel avenues for research to understand defective SpA remodeling and consequent pregnancy pathology.

CXC chemokine receptor 1 predicts postoperative prognosis and chemotherapeutic benefits for TNM II and III resectable gastric cancer patients

Backround: Abnormal expression of CXC chemokine receptor 1 (CXCR1) has shown the ability to promote tumor angiogensis, invasion and metastasis in several cancers. The purpose of our curret study is to discover the clinical prognostic significance of CXCR1 in resectable gastric cancer.

METHODS

330 gastric cancer patients who underwent R0 gastrectomy with standard D2 lymphadenectomy at Zhongshan Hospital, Fudan University between 2007 and 2008 were enrolled. CXCR1 expression was evaluated with use of immunohistochemical staining. The relation between CXCR1 expression and clinicopathological features and postoperative prognosis was respectively inspected.

RESULTS

In both discovery and validation data sets, CXCR1 high expression indicated poorer overall survival (OS) in TNM II and III patients. Furthermore, multivariate analysis identified CXCR1 expression and TNM stage as two independent prognostic factors for OS. Incorporating CXCR1 expression into current TNM staging system could generate a novel clinical predictive model for gastric cancer, showing better prognostic accuracy with respect to patients' OS. More importantly, TNM II patients with higher CXCR1 expression were shown to significantly benefit from postoperative 5-fluorouracil (5-FU) based adjuvant chemotherapy (ACT).

CONCLUSION

CXCR1 in gastric cancer was identified as an independent adverse prognostic factor. Combining CXCR1 expression with current TNM staging system could lead to better risk stratification and more accurate prognosis for gastric cancer patients. High expression of CXCR1 identified a subgroup of TNM stage II gastric cancer patients who appeared to benefit from 5-FU based ACT.

Transthyretin regulates the migration and invasion of JEG-3 cells

Preeclampsia (PE) is a pregnancy-specific disorder characterized by new-onset hypertension and proteinuria that occurs after 20 weeks of gestation. It involves several organs and continues to be a leading cause of maternal and perinatal morbidity and mortality worldwide. Shallow trophoblast invasion is a common pathological feature of PE. Transthyretin (TTR) is a 56-kDa homotetrameric protein that binds thyroid hormone and retinol binding protein. Dysregulated TTR expression has been found in cases of PE. The aim of the present study was to determine the functional role of TTR in the migration and invasion of JEG-3 choriocarcinoma cells. JEG-3 cells were transfected with a plasmid construct expressing TTR (pCMV-Myc-TTR) or an empty plasmid (pCMV-Myc). Cell migration and invasion capacities were assessed by Transwell migration and invasion assays, respectively. These experiments demonstrated that TTR overexpression significantly increased the migration and invasion potential of JEG-3 cells. Matrix metalloproteinases (MMPs) are a family of zinc-containing endopeptidases capable of degrading a wide range of extracellular matrix components. Western blot analysis revealed that TTR overexpression resulted in significantly increased levels of MMP2 and MMP9 in JEG-3 cells. In conclusion, our findings suggest an important role for TTR in regulating trophoblast invasion and migration, representing a possible underlying pathological and molecular mechanisms of PE.

CXCR4, CXCR7, and CXCL12 are associated with trophoblastic cells apoptosis and linked to pathophysiology of severe preeclampsia

Preeclampsia is a pregnancy disorder with sudden onset of maternal hypertension and proteinuria, which is characterized by defective cytotrophoblast invasion, increased apoptosis in cytotrophoblast, and diminished syncytial differentiation. In this study, samples from 11 mild preeclamptic patients, 18 severe preeclamptic patients, and 21 normal pregnant women were collected. The expression level of CXCL12 and its two receptors (CXCR4 and CXCR7) in these samples and their relationship with apoptosis were investigated. Morphological change of trophoblast cells that was observed by scanning electron microscope (SEM) indicated a significant tendency of apoptosis in the preeclamptic placenta. Immunohistochemical staining showed that expression level of three proteins was significantly lower in severe preeclamptic placentas compared with normal placentas (P<0.05), whereas no significant difference was found between mild preeclamptic and normal placentas (P>0.05). Real time quantitative PCR (RT-qPCR) and Western blot showed that both mRNA and protein expression level of CXCR4, CXCR7, and CXCL12 of trophoblasts were lower in the severe preeclampsia group than that in the normal group (P<0.05 for mRNA, P<0.01 for protein). In conclusion, our data revealed that the roles of CXCR4, CXCR7, and CXCL12 are associated with trophoblastic cells apoptosis and may be linked to the occurrence and development of severe preeclampsia.