Exosomes from Intrahepatic Cholestasis of Pregnancy Induce Cell Apoptosis Through the miRNA-6891-5p/YWHAE Pathway.

BACKGROUND: Intrahepatic cholestasis of pregnancy (ICP) is associated with adverse pregnancy outcomes; however, the underlying mechanisms are not fully understood. AIMS: This study aimed to determine the role of exosomal miR-6891-5p in placental trophoblast dysfunction in ICP and identify new biomarkers for ICP diagnosis. METHODS: Serum samples were collected from ICP patients and healthy pregnant women, and serum exosomes were extracted and identified. Fluorescent dye labeling of exosomes and cell-verified cell phagocytosis were performed. In vitro experiments were conducted by adding taurocholic acid to simulate the ICP environment. Cell proliferation and apoptosis levels were detected using flow cytometry and the cell counting kit-8 assay. Mimics were constructed to overexpress miR-6891-5p in cells, and the binding site between miR-6891-5p and YWHAE was verified using luciferase reporter genes. RESULTS: miR-6891-5p expression was significantly decreased in serum exosomes of ICP patients. Co-culturing with exosomes derived from ICP patients' serum (ICP-Exos) decreased HTR-8/SVeno cell proliferation and increased apoptosis levels. miR-6891-5p upregulation in HTR-8/SVeno cells significantly increased cell viability and reduced cell apoptosis levels, as determined by the cell counting kit-8 assay and flow cytometry. A double luciferase assay confirmed that miR-6891-5p affected the expression of the downstream YWHAE protein. CONCLUSIONS: This study indicates that serum exosomes from ICP patients can impact the apoptosis of placental trophoblast HTR-8/SVeno cells through the miR-6891-5P/YWHAE pathway and can serve as specific molecular markers for ICP diagnosis.

The role of ERp29/FOS/EMT pathway in excessive apoptosis of placental trophoblast cells in intrahepatic cholestasis of pregnancy.

BACKGROUND: Abnormal bile acid metabolism leading to changes in placental function during pregnancy. To determine whether endoplasmic reticulum protein 29 (ERp29) can mediate the pregnancy effects of cholestasis by altering the level of trophoblast cell apoptosis. METHODS: ERp29 in serum of 66 intrahepatic cholestasis of pregnancy (ICP) pregnant women and 74 healthy were detected by ELISA. Subcutaneous injection of ethinyl estradiol (E2) was used to induce ICP in pregnant rats. Taurocholic acid (TCA) was used to simulate the ICP environment, and TGF-ß1 was added to induce the epithelial mesenchymal transformation (EMT) process. The scratch, migration, and invasion test were used to detect the EMT process. ERp29 overexpression/knockdown vector were constructed and transfected to verify the role of ERp29 in the EMT process. Downstream gene was obtained through RNA-seq. RESULTS: Compared with the healthy pregnant women, the expression levels of ERp29 in serum of ICP pregnancy women were significantly increased (P < 0.001). ERp29 in the placenta tissue of the ICP pregnant rats increased significantly, and the level of apoptosis increased. The placental tissues of the ICP had high expression of E-cadherin and low expression of N-cadherin, snail1, vimentin. After HTR-8/SVneo cells were induced by TCA, EMT was inhibited, while the ERp29 increased. Cell and animal experiments showed that, knockdown of ERp29 reduced the inhibition of EMT, the ICP progress was alleviated. Overexpression of FOS salvaged the inhibitory effects of ERp29 on cell EMT. DISCUSSION: The high level of ERp29 in placental trophoblast cells reduced FOS mRNA levels, inhibited the EMT process and aggravated the occurrence and development of ICP.

Serum Exosomes MicroRNAs Are Novel Non-Invasive Biomarkers of Intrahepatic Cholestasis of Pregnancy.

Background: Intrahepatic cholestasis of pregnancy (ICP) is closely related to the occurrence of adverse outcomes. Currently, total bile acids (TBAs) are the only diagnostic index for ICP, and its sensitivity and specificity have certain limitations. In this study, we aimed to develop potential biomarkers for the diagnosis of ICP. Methods: Sixty pregnant women diagnosed with ICP and 48 healthy pregnant controls were enrolled in this study. We used the Agilent microRNA (miRNA) array followed by quantitative reverse transcriptase polymerase chain reaction assays to identify and validate the serum exosome miRNA profiles in ICP and healthy pregnant controls. We employed bioinformatics to identify metabolic processes associated with differentially expressed serum exosome miRNAs. Results: The expression levels of hsa-miR-4271, hsa-miR-1275, and hsa-miR-6891-5p in maternal serum exosomes were significantly lower in ICP patients compared to controls; the diagnostic accuracy of hsa-miR-4271, hsa-miR-1275, and hsa-miR-6891-5p was evaluated with the area under the receiver operating characteristic curve (AUC) values of 0.861, 0.886, and 0.838, respectively. Multiple logistic regression analysis showed that a combination of the levels of hsa-miR-4271and hsa-miR-1275 afforded a significantly higher AUC (0.982). The non-error rate of a combination of all three exosome miRNAs was the highest (95%), thus more reliable ICP diagnosis. The expression levels of all three exosome miRNAs were negatively associated with TBAs. Furthermore, according to bioinformatics analysis, the three exosome miRNAs were related to lipid metabolism, apoptosis, oxidative stress, and the Mitogen Activated Protein Kinase (MAPK) signaling pathway. Conclusions: This study may identify the novel non-invasive biomarkers for ICP and provided new insights into the important role of the exosome miRNA regulation in ICP.

Studies on Novel Diagnostic and Predictive Biomarkers of Intrahepatic Cholestasis of Pregnancy Through Metabolomics and Proteomics.

Background: Intrahepatic cholestasis of pregnancy (ICP) usually occurs in the third trimester and is associated with increased risks in fetal complications. Currently, the exact mechanism of this disease is unknown. The purpose of this study was to develop potential biomarkers for the diagnosis and prediction of ICP. Methods: We enrolled 40 pregnant women diagnosed with ICP and 40 healthy pregnant controls. The number of placental samples and serum samples between the two groups was 10 and 40 respectively. Ultra-performance liquid chromatography tandem high-resolution mass spectrometry was used to analyze placental metabolomics. Then, we verified the differentially expressed proteins and metabolites, both placental and blood serum, in the first, second, and third trimesters. Results: Metabolomic analysis of placental tissue revealed that fatty acid metabolism and primary bile acid biosynthesis were enriched. In the integrated proteomic and metabolomic analysis of placental tissue, peroxisomal acyl-CoA oxidase 1 (ACOX1), L-palmitoylcarnitine, and glycocholic acid were found to be three potential biomarkers. In a follow-up analysis, expression levels of both placental and serum ACOX1, L-palmitoylcarnitine, and glycocholic acid in both placenta and serum were found to be significantly higher in third-trimester ICP patients; the areas under the ROC curves were 0.823, 0.896, and 0.985, respectively. Expression levels of serum ACOX1, L-palmitoylcarnitine, and glycocholic acid were also significantly higher in first- and second-trimester ICP patients; the areas under the ROC curves were 0.726, 0.657, and 0.686 in the first trimester and 0.718, 0.727, and 0.670 in the second trimester, respectively. Together, levels of the three aforementioned biomarkers increased the value for diagnosing and predicting ICP (AUC: 0.993 for the third, 0.891 for the second, and 0.932 for the first trimesters). Conclusions: L-palmitoylcarnitine, ACOX1, and glycocholic acid levels taken together may serve as a new biomarker set for the diagnosis and prediction of ICP.