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

Transcriptomic analysis reveals potential biomarkers for early-onset pre-eclampsia using integrative bioinformatics and LASSO based approach

Pre-eclampsia (PE) is a severe vascular disorder during pregnancy, significantly affecting maternal and fetal health worldwide. However, the exact molecular mechanism of its pathophysiology remains unclear, highlighting the need for reliable early diagnostic methods. Our primary aim of this study was to identify key genes (KGs) that may affect the outcome of patients with PE via integrated bioinformatics analysis. We analysed a gene expression dataset from the national center for biotechnology information (NCBI) sequence read archive (SRA) database and performed standard preprocessing steps, including quality assessment, trimming, genome alignment, and feature counts. Following this, normalization and differentially expressed genes (DEGs) were performed using Deseq2, which identified 781 DEGs were identified comprising 457 upregulated and 324 downregulated genes. Identified DEGs were significantly enriched in the cytokine interaction pathway and cellular calcium ion homeostasis. PPI network analysis revealed eight KGs (CXCL8, GAPDH, MMP9, SPP1, PTGS2, LEP, FGF7, and FGF10). These KGs were further found to be regulated by ten transcription factors (TFs), among which NF-kB1 and RELA consistently interact with all the KGs, and four microRNAs (miRNAs) such as hsa-mir-335-5p, has-mir-16a-5p, has-let-7b-5p, and has-mir-204-5p. The least absolute shrinkage and selection operator (LASSO) regression with 10-fold cross-validation (CV) confirmed all eight KGs may act as potential biomarkers based on their coefficients. Among these, GAPDH, SPP1, FGF7, and FGF10 emerged as novel biomarkers. Additionally, receiver operating characteristic (ROC) curve analysis for these novel biomarkers showed an area under the curve (AUC) of 0.869, demonstrating strong discriminatory power between the healthy and EOPE groups. The drug-gene interaction was performed by DrugMap database revealed an important interaction of GAPDH and FGF7 with FDA-approved drugs, indicating their therapeutic significance in PE. This analysis also facilitates drug repurposing for PE treatment.

CX3CL1 (Fractalkine): An important cytokine in physiological and pathological pregnancies

C-X3-C motif chemokine ligand 1 (CX3CL1), commonly known as Fractalkine, is an important chemokine with dual functions of chemotaxis and adhesion. It plays a pivotal role in a variety of physiological processes and pathological conditions, particularly in conjunction with its receptor, C-X3-C motif chemokine receptor 1 (CX3CR1). This review focuses on the expression and intricate regulatory mechanisms of CX3CL1 at the maternal-fetal interface, emphasizing its multifaceted role during pregnancy. CX3CL1 was detected in the trophoblast and decidua tissues, playing a crucial role in recruitment of immune cells, enhancing endometrial receptivity, and modulating trophoblast cell activities. Abnormal expression of CX3CL1 has been correlated with adverse pregnancy outcomes such as spontaneous abortion, gestational diabetes, preeclampsia, and preterm births. By elucidating the complex interplay of CX3CL1 at the maternal-fetal interface, this review aims to shed light on its potential roles in pregnancy-related complications.

Integrated bioinformatics analysis reveals that CCBP2 and GPR87 are new GPCR-associated biomarkers for preeclampsia

BACKGROUND

Preeclampsia (PE) is a multifaceted pregnancy syndrome marked by multiple system involvement and a significant contributor to maternal mortality. This condition is characterized by a critical lack of early diagnostic measures and viable therapeutic options, underscoring an urgent need for the identification of reliable markers with both diagnostic and therapeutic potential.

METHODS

This study utilized Weighted Gene Co-expression Network Analysis (WGCNA) to explore the role of G protein-coupled receptors (GPCRs) in the pathogenesis of PE.

RESULTS

Our analysis pinpointed CCBP2 (ACKR2) and GPR87 as central PE-associated GPCRs. Experimental validation of these findings revealed that both CCBP2 and GPR87 significantly inhibit the proliferation, migration, and invasion of trophoblast cells-core phenomena underlying the pathology of PE.

CONCLUSION

Thus, our findings add valuable candidates to the growing list of biomarkers for preeclampsia and offer promising targets for future therapeutic development.

Different Lengths of Gestational Exposure to Secondhand Smoke or e-Cigarette Vapor Induce the Development of Placental Disease Symptoms

Exposure to cigarette smoke is known to induce disease during pregnancy. Recent evidence showed that exposure to secondhand smoke (SHS) negatively impacts fetal and placental weights, leading to the development of intrauterine growth restriction (IUGR). Electronic cigarettes (eCigs) represent a phenomenon that has recently emerged, and their use is also steadily rising. Even so, the effects of SHS or eCigs during gestation remain limited. In the present study, we wanted to characterize the effects of SHS or eCig exposure at two different important gestational points during mouse pregnancy. C57/Bl6 mice were exposed to SHS or eCigs via a nose-only delivery system for 4 days (from 14.5 to 17.5 gestational days (dGA) or for 6 days (from 12.5 dGA to 17.5 dGA)). At the time of necropsy (18.5 dGA), placental and fetal weights were recorded, maternal blood pressure was determined, and a dipstick test to measure proteinuria was performed. Placental tissues were collected, and inflammatory molecules in the placenta were identified. Treatment with SHS showed the following: (1) a significant decrease in placental and fetal weights following four days of exposure, (2) higher systolic and diastolic blood pressure following six days of exposure, and (3) increased proteinuria after six days of exposure. Treatment with eCigs showed the following: (1) a significant decrease in placental weight and fetal weight following four or six days of exposure, (2) higher systolic and diastolic blood pressure following six days of exposure, and (3) increased proteinuria after six days of exposure. We also observed different inflammatory markers associated with the development of IUGR or PE. We conclude that the detrimental effects of SHS or eCig treatment coincide with the length of maternal exposure. These results could be beneficial in understanding the long-term effects of SHS or eCig exposure in the development of placental diseases.

CX3CL1/Fractalkine as a biomarker for early pregnancy prediction of preterm premature rupture of membranes

OBJECTIVES

The objective of our study was to evaluate serum CX3CL1/Fractalkine, a monocyte/macrophage chemoattractant expressed in cytotrophoblasts and decidual cells, as a predictive biomarker for the occurrence of preterm premature rupture of membranes (PPROM).

METHODS

A case-control study of 438 pregnancies including 82 PPROM cases and 64 preterm labor with intact membranes cases with blood samples collected at first trimester, second trimester and delivery was conducted. The predictive ability of CX3CL1 and maternal risk factors for the occurrence of PPROM was assessed by receiver operating characteristic curve analysis. A second, independent cohort was prospectively constituted to confirm the case-control study results.

RESULTS

First trimester CX3CL1 was significantly increased in PPROM cases when compared to matched controls. Multivariate regression analysis highlighted a significant difference for CX3CL1 measured during the first trimester (p<0.001). Alone, CX3CL1 predicts PPROM with a 90 % sensitivity and a specificity around 40 %. The area under the receiver operating characteristic curve for PPROM prediction were 0.64 (95% confidence interval: 0.57-0.71) for first trimester CX3CL1, and 0.61 (95% confidence interval: 0.54-0.68) for maternal risk factors (body mass index<18.5 kg/m2, nulliparity, tobacco use and the absence of high school diploma). The combination of CX3CL1 and maternal risk factors significantly improved the area under the curve: 0.72 (95% confidence interval: 0.66-0.79) (p<0.001). The results were confirmed on a second independent cohort.

CONCLUSIONS

CX3CL1 is a promising blood biomarker in the early (first trimester) prediction of PPROM.

CX3CL1 (Fractalkine)-CX3CR1 Axis in Inflammation-Induced Angiogenesis and Tumorigenesis

The chemotactic cytokine fractalkine (FKN, chemokine CX3CL1) has unique properties resulting from the combination of chemoattractants and adhesion molecules. The soluble form (sFKN) has chemotactic properties and strongly attracts T cells and monocytes. The membrane-bound form (mFKN) facilitates diapedesis and is responsible for cell-to-cell adhesion, especially by promoting the strong adhesion of leukocytes (monocytes) to activated endothelial cells with the subsequent formation of an extracellular matrix and angiogenesis. FKN signaling occurs via CX3CR1, which is the only known member of the CX3C chemokine receptor subfamily. Signaling within the FKN-CX3CR1 axis plays an important role in many processes related to inflammation and the immune response, which often occur simultaneously and overlap. FKN is strongly upregulated by hypoxia and/or inflammation-induced inflammatory cytokine release, and it may act locally as a key angiogenic factor in the highly hypoxic tumor microenvironment. The importance of the FKN/CX3CR1 signaling pathway in tumorigenesis and cancer metastasis results from its influence on cell adhesion, apoptosis, and cell migration. This review presents the role of the FKN signaling pathway in the context of angiogenesis in inflammation and cancer. The mechanisms determining the pro- or anti-tumor effects are presented, which are the cause of the seemingly contradictory results that create confusion regarding the therapeutic goals.