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

Unveiling the placental secrets: Exploring histopathological changes and TROP2 expression in intrahepatic cholestasis of pregnancy

INTRODUCTION

Gestational cholestasis, also known as intrahepatic cholestasis of pregnancy (ICP) or obstetric cholestasis, is a liver disease that can manifest in late pregnancy. Trophoblast cell surface antigen (TROP2) is a type I transmembrane glycoprotein identified in placental trophoblast cells that plays a critical role in trophoblast invasion of the decidua upon implantation into the placenta. Our study aims to investigate the role of TROP2 in pregnancy cholestasis.

MATERIALS AND METHODS

Study groups: Group 1 (control group) (n = 10): consists of healthy normal pregnant women without any disease, Group 2 (cholestasis group) (n = 10): consists of pregnant women diagnosed with cholestasis. After routine histological follow-up, hematoxylin and eosin staining and TROP2 immunostaining were performed and scored.

RESULTS

In the cholestasis group, in contrast to the control group, thrombus structures were observed in the intervillous space. In the cholestasis group compared to the control group, villus mesenchymal connective tissue cells, capillary endothelium and trophoblasts around the villus showed significantly stronger anti-TROP2 staining (p < 0.05).

DISCUSSION

Cholestasis, a condition that may manifest during pregnancy, may be associated not only with observable pathological changes in placental tissues at the light microscopic level, but also with an increase in TROP2 expression. Given the critical role of TROP2 in trophoblast invasion during placental implantation, we hypothesize that TROP2 may serve as a key marker of the cholestatic processes occurring during pregnancy.

Core biomarkers analysis benefit for diagnosis on human intrahepatic cholestasis of pregnancy

BACKGROUND

The pregnant women with intrahepatic cholestasis were at high risk of fetal distress, preterm birth and unexpected stillbirth. Intrahepatic cholestasis of pregnancy (ICP) was mainly caused by disorder of bile acid metabolism, whereas the specific mechanism was obscure.

METHODS

We performed proteomics analysis of 10 ICP specimens and 10 placenta specimens from patients without ICP through data-independent acquisition (DIA) technique to disclose differentially expressed proteins. We executed metabolomic analysis of 30 ICP specimens and 30 placenta specimens from patients without ICP through UPLC-MS/MS to identify differentially expressed metabolites. Enrichment and correlation analysis was used to obtain the direct molecular insights of ICP development. The ICP rat models were constructed to validate pathological features.

RESULTS

The heatmap of proteomics analysis showed the top 30 up-regulated and 30 down-regulated proteins. The metabolomic analysis revealed 20 richer and 4 less abundant metabolites in ICP samples compared with placenta specimens from patients without ICP, and enrichment pathways by these metabolites included primary bile acid biosynthesis, cholesterol metabolism, bile secretion, nicotinate and nicotinamide metabolism, purine metabolism and metabolic pathways. Combined analysis of multiple omics results demonstrated that bile acids such as Glycohyocholic acid, Glycine deoxycholic acid, beta-Muricholic acid, Noncholic acid, cholic acid, Gamma-Mercholic Acid, alpha-Muricholic acid and Glycochenodeoxycholic Aicd were significantly associated with the expression of GLRX3, MYL1, MYH7, PGGT1B, ACTG1, SP3, LACTB2, C2CD5, APBB2, IPO9, MYH2, PPP3CC, PIN1, BLOC1S1, DNAJC7, RASAL2 and ATCN3 etc. The core protein ACAT2 was involved in lipid metabolic process and animal model showed that ACAT2 was up-regulated in placenta and liver of pregnant rats and fetal rats. The neonates had low birth weight and Safranin O-Fast green FCF staining of animal models showed that poor osteogenic and chondrogenic differentiation of fetal rats.

CONCLUSION

Multiple metabolites-alpha-Muricholic acid, beta-Muricholic acid, Glycine deoxycholic acid and Glycochenodeoxycholic Acid etc. were perfect biomarkers to predict occurrence of ICP. Bile acids were significantly associated with varieties of protein expression and these proteins were differentially expressed in ICP samples. Our study provided several biomarkers for ICP detection and potential therapeutic targets for ICP development.

Arsenic exposure at environmentally relevant levels induced metabolic toxicity in development mice: Mechanistic insights from integrated transcriptome and metabolome

Emerging evidence has linked arsenic exposure and metabolic homeostasis, but the mechanism is incompletely understood, especially at relatively low concentrations. In this study, we used a mouse model to evaluate the health impacts and metabolic toxicity of arsenic exposure in drinking water at environmentally relevant levels (0.25 and 1.0 ppm). Our results indicated that arsenic damaged intestinal barrier and induced arsenic accumulation, oxidative stress, and pathological changes in the liver and illum. Interestingly, arsenic increased the hepatic triglyceride (TG) and total cholesterol (TC), while reduced serum TG and TC levels. The liver transcriptome found that arsenic exposure caused transcriptome perturbation and promoted hepatic lipid accumulation by regulating the exogenous fatty acids degradation and apolipoproteins related genes. The serum metabolomics identified 74 and 88 differential metabolites in 0.25 and 1.0 ppm, respectively. The KEGG disease and subcellular location analysis indicated that arsenic induced liver and intestinal diseases, and the mitochondrion might be the target organelle for arsenic-induced toxicity. Co-enrichment of transcriptome and metabolome identified 24 metabolites and 9 genes as metabolic toxicity biomarkers. Moreover, 40 male (20 nonalcoholic fatty liver disease (NAFLD) cases and 20 healthy controls) was further selected to validate our findings. Importantly, the significantly changed L-palmitoylcarnitine, 3-hydroxybutyric acid, 2-hydroxycaproic acid and 6 genes of Hadha, Acadl, Aldh3a2, Cpt1a, Cpt2, and Acox1 were found in the NAFLD cases. The results from integrated multi-omics and chemical-protein network analysis indicated that L-palmitoylcarnitine played a critical role in metabolic toxicity by regulating mitochondrial fatty acids β-oxidation genes (Cpt1a, Cpt2). In conclusion, these findings provided new clues for the metabolic toxicity of arsenic exposure at environmentally relevant levels, which involved in the late-life NAFLD development. Our results also contribute to understanding the human responses and phenotypic changes to this hazardous material exposure in the environment.

Cutaneous Melanoma and 486 Human Blood Metabolites: A Mendelian Randomization Study

BACKGROUND

Cutaneous melanoma (CM) has long been recognized as a lethal form of cancer. Despite persistent research endeavors, the precise underlying pathological mechanisms remain largely unclear, and the optimal treatment for this patient population remains undetermined.

OBJECTIVES

This study aims to examine the causal associations between CM and 486 metabolites.

METHODS

A two-sample Mendelian randomization (MR) analysis was conducted to ascertain the causal relationship between blood metabolites and CM. The causality analysis involved the inverse variance weighted (IVW) method, followed by the MR-Egger and weighted median (WM) methods. To increase the robustness of our findings, several sensitivity analyses, including the MR-Egger intercept, Cochran's Q test, and MR-pleiotropy residual sum and outlier (MR-PRESSO), were performed. The robustness of our results was further validated in independent outcome samples followed by a meta-analysis. Additionally, a metabolic pathway analysis was carried out.

RESULTS

The two-sample MR analysis yielded a total of 27 metabolites as potential causal metabolites. After incorporating the outcomes of the sensitivity analyses, seven causal metabolites remained. Palmitoylcarnitine (OR 0.9903 95% CI 0.9848-0.9958, p = 0.0005) emerged as the sole metabolite with a significant causality after Bonferroni correction. Furthermore, the reverse MR analysis provided no evidence of reverse causality from CM to the identified metabolites.

CONCLUSIONS

This study suggested a causal relationship between seven human blood metabolites and the development of CM, thereby offering novel insights into the underlying mechanisms involved.

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Metabolomic profiling of serum and tongue coating of pregnant women with intrahepatic cholestasis in pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is associated with an increased risk of cesarean section and adverse fetal outcomes. Currently, ICP diagnosis depends largely on serum levels of bile acids and lacks sensitivity and specificity for accurate diagnosis. Tongue diagnosis is an important diagnostic tool in traditional Chinese medicine (TCM) and is used in our clinic as complementary treatment and personalized medicine for ICP. However, the molecular basis of the manifestation of greasy white tongue coatings in ICP remains unknown. In this study, we performed untargeted metabolomic profiling of the serum, tongue coating, and saliva of 66 pregnant women, including 22 with ICP. The metabolomic profiles of the serum and tongue coatings showed marked differences between the two clinical groups. Forty-six differentially abundant metabolites were identified, and their relative concentrations correlated with total bile acid levels. These differential metabolites included bile acids, lipids, microbiota- and diet-related metabolites, and exposomes. Conventional biochemical markers, including serum aminotransferases and bilirubin, were not significantly increased in the ICP group, whereas the total cholesterol and triglyceride levels were significantly increased as early as the first trimester. Our data provide insights into the pathophysiology of ICP and implicate the gut-liver axis and environmental exposure. Tongue coating has the potential to be a non-invasive diagnostic approach. Further studies are required to validate the clinical utility of these findings.

Navigating Perinatal Challenges: A Comprehensive Review of Cholestasis of Pregnancy and Its Impact on Maternal and Fetal Health

Cholestasis of pregnancy (CP), or intrahepatic CP (ICP), represents a condition peculiar to pregnancy, marked by impaired bile acid flow and consequent accumulation in the maternal bloodstream. Primarily emerging in the third trimester, CP is linked with considerable risks to both the mother and fetus, including heightened incidences of preterm birth, fetal distress, and stillbirth, alongside maternal complications such as intense pruritus and liver dysfunction. Despite its clinical significance, the etiology of CP, which involves genetic, hormonal, and environmental factors, remains partially understood. This comprehensive review delves into the physiology and pathophysiology of CP, outlines its clinical manifestations and diagnostic criteria, and discusses the associated maternal and fetal complications. Furthermore, it evaluates current management strategies, prognostic implications, and potential long-term effects on maternal and child health. It also explores future research directions, emphasizing the need for advancements in understanding the pathophysiology of CP, developing novel therapeutic interventions, and improving risk stratification models. By offering a thorough overview of CP, this review aims to enhance clinical awareness, guide management practices, and identify areas requiring further investigation, ultimately contributing to better health outcomes for affected women and their babies.

Proteomic profiling of cerebrospinal fluid in pediatric myelin oligodendrocyte glycoprotein antibody-associated disease

BACKGROUND

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is an autoimmune demyelinating disorder of the central nervous system.

METHODS

Extracted proteins from 34 cerebrospinal fluid (CSF) samples [patients with MOGAD (MOG group, n = 12); healthy controls (HC group, n = 12); patients with MOG seronegative and metagenomics next-generation sequencing-negative inflammatory neurological diseases (IND group, n = 10)] were processed and subjected to label-free quantitative proteomics. Supervised partial least squares-discriminant analysis (PLS-DA) and orthogonal PLS-DA (O-PLS-DA) models were also performed based on proteomics data. Functional analysis of differentially expressed proteins (DEPs) was performed using Gene Ontology, InterPro, and Kyoto Encyclopedia Genes and Genomes. An enzyme-linked immunosorbent assay was used to determine the complement levels in serum from patients with MOGAD.

RESULTS

Four hundred and twenty-nine DEPs (149 upregulated and 280 downregulated proteins) were identified in the MOG group compared to the HC group according to the P value and fold change (FC). Using the O-PLS-DA model, 872 differentially abundant proteins were identified with variable importance projection (VIP) scores > 1. Five proteins (gamma-glutamyl hydrolase, cathepsin F, interalpha-trypsin inhibitor heavy chain 5, latent transforming growth factor beta-binding protein 4 and leukocyte-associated immunoglobulin-like receptor 1) overlapping between the top 30 DEPs with top-ranked P value and FC and top 30 proteins in PLS-DA VIP lists were acquired. Functional analysis revealed that the dysregulated proteins in the MOG group were primarily involved in complement and coagulation cascades, cell adhesion, axon guidance, and glycosphingolipid biosynthesis compared to the HC group.

CONCLUSION

The proteomic alterations in CSF samples from children with MOGAD identified in the current study might provide opportunities for developing novel biomarker candidates.

Intrahepatic cholestasis of pregnancy: insights into pathogenesis and advances in omics studies

Intrahepatic cholestasis of pregnancy (ICP) is the most common pregnancy-specific liver disease. It is characterized by pruritus, abnormal liver function and elevated total bile acid (TBA) levels, increasing the risk of maternal and fetal adverse outcomes. Its etiology remains poorly elucidated. Over the years, various omics techniques, including metabolomics, microbiome, genomics, etc., have emerged with the advancement of bioinformatics, providing a new direction for exploring the pathogenesis, diagnosis and treatment of ICP. In this review, we first summarize the role of bile acids and related components in the pathogenesis of ICP and then further illustrate the results of omics studies.

Liver damage parameters and peripheral blood parameters for prediction and diagnosis of intrahepatic cholestasis in pregnancy

OBJECTIVE

Intrahepatic cholestasis of pregnancy (ICP) manifests in late pregnancy. Elevated serum bile acid is a diagnostic criterion: however, its measurement is troublesome. Prediction of ICP by blood markers is not established. Serum bile acid level is associated with liver damage and inflammation. We hypothesized that the following markers could predict the occurrence of ICP and have diagnostic value for it: Liver damage-indicating scores (albumin-bilirubin [ALBI], Model for End-Stage Liver Disease [MELD], aspartate aminotransferase-to-platelet ratio [APRI]) and inflammatory markers (platelet-to-lymphocyte ratio [PLR] and neutrophil-to-lymphocyte ratio [NLR]).

METHODS

Eighty ICP patients and 200 controls were studied. The values of MELD, APRI, ALBI, PLR, and NLR were measured in the 1st trimester and at the time of diagnosis.

RESULTS

Patients with ICP had significantly higher ALBI, MELD, and APRI scores both in the first trimester and at diagnosis. Multivariate logistic regression (MLR) showed that age, ALBI, MELD, and APRI scores were statistically significant (p < 0.05). By receiver operating characteristic (ROC) analysis, the sensitivity of MELD, ALBI, APRI, and NLR in the first trimester was 62%, 73%, 58%, and 29%, respectively, and MELD, ALBI, APRI, and PLR at diagnosis was 28%, 38%, 57%, and 8%, respectively, with a fixed false-positive rate of 10%.

CONCLUSION

This study has demonstrated the usability of the MELD, ALBI, and APRI scores in predicting and diagnosing ICP. They are easy to obtain and might be used in routine practice.

Predictors of Adverse Fetal Outcomes in Intrahepatic Cholestasis of Pregnancy (ICP): a Narrative Review

Intrahepatic cholestasis of pregnancy (ICP) is a hepatic disorder in pregnancy linked with adverse fetal outcomes, which primarily manifests in the late second and third trimesters of pregnancy. This review aims to recapitulate the existing evidence on factors that can predict detrimental perinatal outcomes in pregnant women diagnosed with intrahepatic cholestasis of pregnancy. We searched PubMed, Web of Science, Cochrane Library, Scopus, Medline, and Embase databases and selected studies related to predictors of fetal outcome in intrahepatic cholestasis of pregnancy. Studies of the articles showed that predictors of an adverse fetal outcome include in vitro fertilization (IVF) pregnancy, multifetal pregnancy, biochemical markers, gestational age of ICP onset, presence of comorbidities (preeclampsia and gestational diabetes mellitus), maternal history of ICP, and hepatobiliary disease.Intrahepatic cholestasis of pregnancy (ICP) complicates the pregnancy. Hence, early assessment of low-risk and high-risk groups will help to administer definite management protocols and strategies to prevent adverse neonatal outcomes. Further research should concentrate on the number of conditions/factors and the predictive power of different factors to determine the most reliable predictors and biomarkers that can predict adverse fetal outcomes and improve the assessment of risk in pregnancy complicated with ICP.

An omics review and perspective of researches on intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is one of the common pregnancy complications that may threaten the health of both pregnant women and their fetuses. Hence, it is of vital importance to identify key moleculars and the associated functional pathways of ICP, which will help us to better understand the pathological mechanisms as well as to develop precise clinical biomarkers. The emerging and developing of multiple omics approaches enable comprehensive studies of the genome, transcriptome, proteome and metabolome of clinical samples. The present review collected and summarized the omics based studies of ICP, aiming to provide an overview of the current progress, limitations and future directions. Briefly, these studies covered a broad range of research contents by the comparing of different experimental groups including ICP patients, ICP subtypes, ICP fetuses, ICP models and other complications. Correspondingly, the studied samples contain various types of clinical samples, in vitro cultured tissues, cell lines and the samples from animal models. According to the main research objectives, we further categorized these studies into two groups: pathogenesis and diagnosis analyses. The pathogenesis studies identified tens of functional pathways that may represent the key regulatory events for the occurrence, progression, treatment and fetal effects of ICP. On the other hand, the diagnosis studies tested more than 40 potential models for the early-prediction, diagnosis, grading, prognosis or differential diagnosis of ICP. Apart from these achievements, we also evaluated the limitations of current studies, and emphasized that many aspects of clinical characteristics, sample processing, and analytical method can greatly affect the reliability and repeatability of omics results. Finally, we also pointed out several new directions for the omics based analyses of ICP and other perinatal associated conditions in the future.

Serum placental growth factor, total cholesterol, and triglycerides for prediction of intrahepatic cholestasis of pregnancy

This study aims to investigate the predictive values of serum placental growth factor (PIGF), total cholesterol (TC), and triglycerides (TG) in the context of intrahepatic cholestasis of pregnancy (ICP). This retrospective case control study recruited pregnant women from January 2021 to December 2021 at the Maternal and Child Health Hospital of Hunan Province, encompassing pregnant women diagnosed with ICP and those with unremarkable prenatal examinations. A total of 433 pregnant women were included, among whom 167 were diagnosed with ICP after 24 weeks of pregnancy. Patients with ICP exhibited an average age of 31.30 ± 4.54 years and an average pregnancy week at delivery of 37.63 ± 1.45 weeks. Multivariable regression analysis showed that the pregnancy week at delivery (OR = 0.823, 95% CI: 0.769-0.879, P < .001), PIGF (OR = 0.994, 95% CI: 0.992-0.996, P < .001), TC (OR = 1.955, 95% CI: 1.586-2.409, P < .001), and TG (OR = 3.786, 95% CI: 2.655-5.399, P < .001) were independent risk factors for ICP. The area under the curve values for PIGF, TC, and TG in predicting ICP were 0.858 (95% CI: 0.822-0.893), 0.721 (95% CI: 0.670-0.772), and 0.830 (95% CI: 0.788-0.871), respectively. However, their combination yielded an area under the curve value of 0.922 (95% CI: 0.898-0.946). The composite assessment of PIGF, TC, and TG demonstrates potential efficacy in predicting ICP among pregnant women.

Identification and validation of diagnostic biomarkers for intrahepatic cholestasis of pregnancy based on untargeted and targeted metabolomics analyses of urine metabolite profiles

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) is a prevalent pregnancy-specific complication that presents with maternal itching and elevated serum bile acid levels. ICP is associated with unfavorable pregnancy outcomes, severely decreasing the pregnant woman's quality of life. Timely identification of ICP is crucial for effective management and improved outcomes.

METHODS

We collected urine samples from 8 patients with ICP and 8 healthy individuals. We used Liquid Chromatography-Mass Spectrometry (LC-MS) to detect metabolite expression levels, then conducted a series of bioinformatic analyses to explore the potential biological meanings of differentially expressed metabolites, and preliminarily discovered several candidate biomarkers. To validate these candidate biomarkers, we performed Gas Chromatography-Mass Spectrometry (GC-MS) detection and analyzed their diagnostic values using receiver operating characteristic (ROC) curve.

RESULTS

Untargeted metabolomics data showed that 6129 positive peaks and 6218 negative peaks were extracted from each specimen. OPLS-DA analysis and the heat map for cluster analysis showed satisfactory capability in discriminating ICP specimens from controls. Subsequent analysis extracted 64 significantly differentially expressed metabolites, which could be potential biomarkers for diagnosis of ICP. Based on the KEGG enrichment analyses, six candidate biomarkers were preliminarily identified. Two most promising biomarkers (3-hydroxypropionic acid and uracil) were validated by targeted metabolomics analyses with the area under the curve (AUC) of 0.920 and 0.850 respectively.

CONCLUSION

Based on preliminary screening from untargeted metabolomics and subsequent validation through targeted metabolomics, 3-hydroxypropionic acid and uracil were identified as promising diagnostic biomarkers for ICP.

Secreted proteins in plasma and placenta as novel non-invasive biomarkers for intrahepatic cholestasis of pregnancy: A case-control study

Background

Intrahepatic cholestasis of pregnancy (ICP) is likely to lead to unfavorable consequences. Total bile acid (TBA) is thought to be the sole ICP indicator available as of now, but it comes with some kind of restrictions in terms of sensitivity and specificity. We were endeavoring to find potential diagnostic biomarkers for ICP in this investigation.

Methods

This case-control study with a prospective nature included 40 females in the stage of pregnancy who were diagnosed with ICP. It also included another 20 females who were also pregnant but with sound physical condition(control). Placental and plasma samples were collected from all females that were in the stage of pregnancy, except for 20 ICP patients, in which only plasma was collected. We used four-dimensional data-independent acquisition followed by enzyme-linked immunosorbent assay and immunohistochemistry to identify and validate plasma and placental profiles in ICP patients and controls. Bioinformatics was adopted in an effort to demonstrate the relevant biological processes and signalling pathways. Correlation analysis was used to analyse the consistency of tissue and plasma protein expression and the correlation between sequencing and experimental results.

Results

The expression levels of nectin-1 (NECTIN1), Kunitz-type protease inhibitor 1 (SPINT1), and inter-alpha-trypsin inhibitor heavy chain H3 (ITIH3) were remarkably higher in ICP patients than in controls. However, heparin cofactor 2 (SERPIND1) expression levels in female participants in the stage of pregnancy who were diagnosed with ICP were remarkably lower than those pregnant females with good physical fitness. In addition to the negative correlation between SERPIND1 and TBA, NECTIN1, SPINT1, and ITIH3 expression positively correlated with TBA. Area under the receiver operating characteristic curve (AUC) values of 0.7925, 0.8313, 0.8163, and 0.9025, respectively, were used to assess the diagnostic accuracies of NECTIN1, SPINT1, ITIH3, and SERPIND1. AUC (0.9438) was considerably greater when NECTIN1, SPINT1, and SERPIND1 were integrated, according to binary logistic regression. The AUC of the ROC curve for various combinations of SERPIND1 and other indicators was higher than itself, thus providing a more reliable ICP diagnosis. Furthermore, according to the bioinformatics analysis, the NECTIN1, SPINT1, ITIH3, and SERPIND1 were identified as secreted proteins because they were localized in the extracellular region.

Conclusions

This research discovered new non-invasive ICP indicators. On top of this, it sheds new light on the crucial diagnostic function of secreted proteins in ICP.

Early Pregnancy Markers in the Serum of Ewes Identified via Proteomic and Metabolomic Analyses

The diagnosis of ewes' pregnancy status at an early stage is an efficient way to enhance the reproductive output of sheep and allow producers to optimize production and management. The techniques of proteomics and metabolomics have been widely used to detect regulatory factors in various physiological processes of animals. The aim of this study is to explore the differential metabolites and proteins in the serum of pregnant and non-pregnant ewes by proteomics and metabolomics. The serum of ewes at 21, 28 and 33 days after artificial insemination (AI) were collected. The pregnancy stratus of the ewes was finally determined through ultrasound examination and then the ewes were grouped as Pregnant (n = 21) or N on-pregnant (n = 9). First, the serum samples from pregnant or non-pregnant ewes at 21 days after AI were selected for metabolomic analysis. It was found that the level of nine metabolites were upregulated and 20 metabolites were downregulated in the pregnant animals (p < 0.05). None of these differential metabolomes are suitable as markers of pregnancy due to their small foldchange. Next, the proteomes of serum from pregnant or non-pregnant ewes were evaluated. At 21 days after AI, the presence of 321 proteins were detected, and we found that the level of three proteins were upregulated and 11 proteins were downregulated in the serum of pregnant ewes (p < 0.05). The levels of serum amyloid A (SAA), afamin (AFM), serpin family A member 6 (SERPINA6) and immunoglobulin-like domain-containing protein between pregnant and non-pregnant ewes at 21-, 28- and 33-days post-AI were also analyzed via enzyme-linked immunosorbent assay (ELISA). The levels of SAA and AFM were significantly higher in pregnant ewes than in non-pregnant ewes, and could be used as markers for early pregnancy detection. Overall, our results show that SAA and AFM are potential biomarkers to determine the early pregnancy status of ewes.

Maternal hepatic immunology during pregnancy

The liver plays pivotal roles in immunologic responses, and correct hepatic adaptations in maternal immunology are required during pregnancy. In this review, we focus on anatomical and immunological maternal hepatic adaptations during pregnancy, including our recent reports in this area. Moreover, we summarize maternal pregnancy-associated liver diseases, including hyperemesis gravidarum; intrahepatic cholestasis of pregnancy; preeclampsia, specifically hemolysis, elevated liver enzymes, and low platelet count syndrome; and acute fatty liver of pregnancy. In addition, the latest information about the factors that regulate hepatic immunology during pregnancy are reviewed for the first time, including human chorionic gonadotropin, estrogen, progesterone, growth hormone, insulin like growth factor 1, oxytocin, adrenocorticotropic hormone, adrenal hormone, prolactin, melatonin and prostaglandins. In summary, the latest progress on maternal hepatic anatomy and immunological adaptations, maternal pregnancy-associated diseases and the factors that regulate hepatic immunology during pregnancy are discussed, which may be used to prevent embryo loss and abortion, as well as pregnancy-associated liver diseases.

A comprehensive review of novel biomarkers in the diagnosis of intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a disease specific to pregnancy, featuring maternal itching and elevated serum bile acid levels. It leads to a series of adverse pregnancy outcomes as well as increased fetal mortality. Routine biochemical markers fail to fulfill the tremendous clinical requirements, thereby novel effective biomarkers are urgently desired. In our review, the potential novel biomarkers for ICP diagnosis are classified into four categories and elaborated in detail. The concrete diagnostic performances (sensitivity, specificity and area under the curve) of these biomarkers are demonstrated in tables. Moreover, the relationships between some biomarkers and ICP pathogenesis are briefly expounded. Nevertheless, only a few novel biomarkers are ideal, and their clinical applicability requires more evidence from larger multicenter trials.

SWATH proteomics analysis of placental tissue with intrahepatic cholestasis of pregnancy

INTRODUCTION

Intrahepatic cholestasis of pregnancy (ICP) usually occurs in the second and third trimesters. The disease's etiology and diagnostic criteria are currently unknown. Based on a sequence window to obtain all theoretical fragment ions (SWATH) proteomic approach, this study sought to identify potential proteins in placental tissue that may be involved in the pathogenesis of ICP and adverse fetal pregnancy outcomes.

METHODS

The postpartum placental tissue of pregnant women with ICP were chosen as the case group (ICP group) (subdivided into mild ICP group (MICP group) and severe ICP group (SICP group)), and healthy pregnant women were chosen as the control group (CTR). The hematoxylin-eosin (HE) staining was used to observe the histologic changes of placenta. The SWATH analysis combined with liquid chromatography-tandem mass spectrometry (LC-MS) was used to screen the differentially expressed proteins (DEPs) in ICP and CTR groups, and bioinformatics analysis was used to find out the biological process of these differential proteins.

RESULTS

Proteomic studies showed there were 126 DEPs from pregnant women with ICP and healthy pregnant women. Most of the identified proteins were functionally related to humoral immune response, cell response to lipopolysaccharide, antioxidant activity and heme metabolism. A subsequent examination of placentas from patients with mild and severe ICP revealed 48 proteins that were differentially expressed. Through death domain receptors and fibrinogen complexes, these DEPs primarily regulate extrinsic apoptotic signaling pathways, blood coagulation, and fibrin clot formation. The differential expressions of HBD, HPX, PDE3A, and PRG4 were down-regulated by Western blot analysis, which was consistent with proteomics.

DISCUSSION

This preliminary study helps us to understand the changes in the placental proteome of ICP patients, and provides new insights into the pathophysiology of ICP.

Expression and clinical significance of short-chain fatty acids in pregnancy complications

Objective

To investigate the expression of short-chain fatty acids (SCFAs)-metabolites of intestinal flora-in gestational complications of gestational diabetes mellitus (GDM), preeclampsia (PE), and intrahepatic cholestasis of pregnancy (ICP), and its clinical significance.

Methods

Targeted metabonomics was used to detect SCFAs in the serum of 28 GDM pregnant women, 28 PE pregnant women, 29 ICP pregnant women, and 27 healthy pregnant women (NP); their expression changes were observed; the correlation between SCFAs and clinical characteristics was studied; and their potential as biomarkers for clinical diagnosis was evaluated.

Results

There were significant differences in the SCFA metabolic spectrum between the GDM, PE, ICP, and NP groups. Quantitative analysis showed that the content of isobutyric acid in the three pregnancy complications groups (the GDM, PE, and ICP groups) was significantly higher than that in the NP group (p < 0.05), and other SCFAs also showed significant differences in the three pregnancy complications groups compared with the NP group (p < 0.05). Receiver operating characteristic (ROC) curve analysis of the generalized linear model showed that multiple SCFAs were highly sensitive and specific as diagnostic markers in the pregnancy complications groups, where isobutyric acid was highly predictive in GDM (area under the ROC curve (AUC) = 0.764) and PE (AUC = 1), and caproic acid was highly predictive in ICP (AUC = 0.968), with potential clinical application.

Conclusion

The metabolic products of intestinal flora, SCFAs, during pregnancy are closely related to pregnancy complications (GDM, PE, and ICP), and SCFAs can be used as potential markers of pregnancy complications.

LC-MS/MS based metabolomics and proteomics reveal candidate biomarkers and molecular mechanism of early IgA nephropathy

BACKGROUND

Immunoglobulin A nephropathy (IgAN), a globally common primary chronic glomerulopathy, is one of the leading causes of end-stage renal disease. However, the underlying mechanisms of IgAN have yet to be demonstrated. There were no adequate and reliable plasma biomarkers for clinical diagnosis, especially at the early stage. In the present study, integrative proteomics and metabolomics were aimed at exploring the mechanism of IgAN and identifying potential biomarkers.

METHODS

Plasma from IgAN and healthy individuals were collected and analyzed in a randomized controlled manner. Data-independent acquisition quantification proteomics and mass spectrometry based untargeted metabolomics techniques were used to profile the differentially expressed proteins (DEPs) and differentially abundant metabolites (DAMs) between two groups and identify potential biomarkers for IgAN from health at the early stage. Disease-related pathways were screened out by clustering and function enrichment analyses of DEPs and DAMs. And the potential biomarkers for IgAN were identified through the machine learning approach. Additionally, an independent cohort was used to validate the priority candidates by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Proteomic and metabolomic analyses of IgAN plasma showed that the complement and the immune system were activated, while the energy and amino acid metabolism were disordered in the IgAN patients. PRKAR2A, IL6ST, SOS1, and palmitoleic acid have been identified as potential biomarkers. Based on the AUC value for the training and test sets, the classification performance was 0.994 and 0.977, respectively. The AUC of the external validation of the four biomarkers was 0.91.

CONCLUSION

In this study, we combined proteomics and metabolomics techniques to analyze the plasma of IgAN patients and healthy individuals, constructing a biomarker panel, which could provide new insights and provide potential novel molecular diagnoses for IgAN.

Application of metabolomics in intrahepatic cholestasis of pregnancy: a systematic review

Background

Intrahepatic cholestasis of pregnancy (ICP) is a severe idiopathic disorder of bile metabolism; however, the etiology and pathogenesis of ICP remain unclear.

Aims

This study comprehensively reviewed metabolomics studies related to ICP, to help in identifying the pathophysiological changes of ICP and evaluating the potential application of metabolomics in its diagnosis.

Methods

Relevant articles were searched through 2 online databases (PubMed and Web of Science) from January 2000 to March 2022. The metabolites involved were systematically examined and compared. Pathway analysis was conducted through the online software MetaboAnalyst 5.0.

Results

A total of 14 papers reporting 212 metabolites were included in this study. There were several highly reported metabolites: bile acids, such as glycocholic acid, taurochenodeoxycholic acid, taurocholic acid, tauroursodeoxycholic acid, and glycochenodeoxycholic acid. Dysregulation of metabolic pathways involved bile acid metabolism and lipid metabolism. Metabolites related to lipid metabolism include phosphatidylcholine, phosphorylcholine, phosphatidylserine, sphingomyelin, and ceramide.

Conclusions

This study provides a systematic review of metabolomics of ICP and deepens our understanding of the etiology of ICP.

Circulatory Metabolomics Reveals the Association of the Metabolites With Clinical Features in the Patients With Intrahepatic Cholestasis of Pregnancy

Objective: Intrahepatic cholestasis of pregnancy (ICP) is associated with an increased risk of adverse pregnancy to the mother and fetus. As yet, the metabolic profiles and the association of the clinical features remain obscure.

Methods: Fifty-seven healthy pregnant women and 52 patients with ICP were recruited in this study. Plasma samples were collected from pregnancies who received prenatal care between 30 and 36 weeks. Untargeted metabolomics to portray the metabolic profiles were performed by LC/MS. Multivariate combined with the univariate analysis was performed to screen out differential metabolites between the ICP and control groups. A de-biased sparse partial correlation (DSPC) network analysis of differential metabolites was conducted to explore the potential mutual regulation among metabolites on the basis of de-sparsified graphical lasso modeling. The pathway analysis was carried out using MetaboAnalyst. Linear regression and Pearson correlation analysis was applied to analyze correlations of bile acid levels, metabolites, newborn weights, and pregnancy outcomes in ICP patients.

Results: Conspicuous metabolic changes and choreographed metabolic profiles were disclosed: 125 annotated metabolites and 18 metabolic pathways were disturbed in ICP patients. DSPC networks indicated dense interactions among amino acids and their derivatives, bile acids, carbohydrates, and organic acids. The levels of total bile acid (TBA) were increased in ICP patients with meconium-stained amniotic fluid (MSAF) compared with those without MSAF. An abnormal tryptophan metabolism, elevated long chain saturated fatty acids and estrone sulfate levels, and a low-antioxidant capacity were relevant to increased bile acid levels. Newborn weights were significantly associated with the levels of bile acids and some metabolites of amino acids.

Conclusion: Our study revealed the metabolomic profiles in circulation and the correlation of the metabolites with clinical features in ICP patients. Our data suggest that disturbances in metabolic pathways might be associated with adverse pregnancy outcomes.

Predictive value of serum bile acids as metabolite biomarkers for liver cirrhosis: a systematic review and meta-analysis

INTRODUCTION

A large number of studies have explored the potential biomarkers for detecting liver cirrhosis in an early stage, yet consistent conclusions are still warranted.

OBJECTIVES

To conduct a review and a meta-analysis of the existing studies that test the serum level of bile acids in cirrhosis as the potential biomarkers to predict cirrhosis.

METHODS

Six databases had been searched from inception date to April 12, 2021. Screening and selection of the records were based on the inclusion criteria. The risk of bias was assessed with the Newcastle-Ottawa quality assessment scale (NOS). Mean difference (MD) and confidence intervals 95% (95% CI) were calculated by using the random effect model for the concentrations of bile acids in the meta-analysis, and I² statistic was used to measure studies heterogeneity. This study was registered on PROSPERO.

RESULTS

A total of 1583 records were identified and 31 studies with 2679 participants (1263 in the cirrhosis group, 1416 in the healthy control group) were included. The quality of included studies was generally high, with 25 studies (80.6%) rated over 7 stars. A total of 45 bile acids or their ratios in included studies were extracted. 36 increased in the cirrhosis group compared with those of the healthy controls by a qualitative summary, 5 decreased and 4 presented with mixing results. The result of meta-analysis among 12 studies showed that 13 bile acids increased, among which four primary conjugated bile acids showed the most significant elevation in the cirrhosis group: GCDCA (MD = 11.38 μmol/L, 95% CI 8.21-14.55, P < 0.0001), GCA (MD = 5.72 μmol/L, 95% CI 3.47-7.97, P < 0.0001), TCDCA (MD = 3.57 μmol/L, 95% CI 2.64-4.49, P < 0.0001) and TCA (MD = 2.14 μmol/L, 95% CI 1.56-2.72, P < 0.0001). No significant differences were found between the two groups in terms of DCA (MD = - 0.1 μmol/L, 95% CI - 0.18 to - 0.01, P < 0.0001) and LCA (MD = - 0.01 μmol/L, 95% CI - 0.01 to - 0.02, P < 0.0001), UDCA (MD = - 0.14 μmol/L, 95% CI - 0.04 to - 0.32, P < 0.0001), and TLCA (MD = 0 μmol/L, 95% CI 0-0.01, P < 0.0001). Subgroup analysis in patients with hepatitis B cirrhosis showed similar results.

CONCLUSION

Altered serum bile acids profile seems to be associated with cirrhosis. Some specific bile acids (GCA, GCDCA, TCA, and TCDCA) may increase with the development of cirrhosis, which possibly underlay their potential role as predictive biomarkers for cirrhosis. Yet this predictive value still needs further investigation and validation in larger prospective cohort studies.