GWAS meta-analysis of intrahepatic cholestasis of pregnancy implicates multiple hepatic genes and regulatory elements

Genetic study of intrahepatic cholestasis of pregnancy in Chinese women unveils East Asian etiology linked to historic HBV epidemic

BACKGROUND & AIMS

Intrahepatic cholestasis of pregnancy (ICP) is the most common and high-risk liver disorder during pregnancy, with varying prevalence across populations. Our understanding of the mechanisms underlying ICP and population-level differences remains limited. This study delves into the genetic etiology of ICP in East Asians, drawing comparisons with Europeans to comprehend ICP etiology in the context of genetic background and evolution.

METHODS

We conducted the hitherto largest-scale genome-wide association study on fasting total serum bile acids (TBA) and ICP in 98,269 Chinese pregnancies. The findings were replicated in three cohorts and compared with European populations. Additionally, phenome-wide association and spatio-temporal evolution analyses were employed to investigate the function and evolutionary patterns of ICP-associated loci.

RESULTS

We identified eight loci for fasting TBA and four for ICP, including ten novel loci. Notably, we discovered an East Asian-specific locus within a 0.4 Mbp region at 14q24.1, which increases fasting TBA by 6.12 μmol/L and ICP risk by 16.56-fold per risk allele (95% CI 16.43 to 16.69, p = 7.06×10-381). Phenome-wide association and spatial-temporal evolution analyses revealed that this 14q24.1 ICP risk locus confers resistance to hepatitis B and has become prevalent in East and Southeast Asia within the last 3,000 years.

CONCLUSIONS

We uncovered a distinct genetic etiology of ICP in East Asians, likely linked to a historic HBV epidemic in East and Southeast Asia within the last 3,000 years. These findings enhance our understanding of ICP pathophysiology and offer potential for more precise detection, assessment, and treatment of the disorder.

IMPACT AND IMPLICATIONS

This study provides novel insights into the genetic basis of intrahepatic cholestasis of pregnancy (ICP) in East Asian populations, where little was previously known. The identification of the East-Asian-specific 14q24.1 locus, associated with both fasting total serum bile acids and ICP, and its connection to a historical hepatitis B epidemic emphasize the importance of incorporating population-specific history into disease research. These findings are crucial for researchers studying pregnancy-related liver disorders and clinicians providing care to pregnant women, enabling more accurate screening, risk assessment, and targeted interventions for ICP.

Unresolved alterations in bile acid composition and dyslipidemia in maternal and cord blood after UDCA treatment for intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is characterized by elevated plasma bile acid levels. ICP is linked to adverse metabolic outcomes, including a reported increased risk of gestational diabetes. The standard therapeutic approach for managing ICP is treatment with ursodeoxycholic acid (UDCA) and induction of labor before 40 wk of gestation. To investigate bile acid and metabolic parameters after UDCA treatment, we enrolled 12 ICP patients with singleton pregnancies-half with and half without gestational diabetes-and 7 controls. Our study reveals that after UDCA treatment, notwithstanding a reduction in total bile acid and alanine aminotransferase levels, imbalances persist in the cholic acid (CA) to chenodeoxycholic acid (CDCA) ratio in maternal and cord blood plasma. This indicates a continued dysregulation of bile acid metabolism despite therapeutic intervention. Maternal plasma lipid analysis showed a distinct maternal dyslipidemia pattern among patients with ICP, marked by elevated cholesterol levels on VLDL particles and heightened triglyceride concentrations on LDL particles, persisting even after UDCA treatment. Cord plasma lipid profiles in patients with ICP exhibited elevated triglyceride and free fatty acid levels alongside a tendency toward increased β-hydroxybutyrate. The changes in lipid metabolism in both maternal and cord blood correlated with the high CA/CDCA ratio but not total bile acid levels or gestational diabetes status. Understanding the imbalances in maternal and cord bile acid and lipid profiles that persist after standard UDCA therapy provides insights for improving management strategies and mitigating the long-term consequences of ICP.NEW & NOTEWORTHY This study uncovers that despite ursodeoxycholic acid treatment, intrahepatic cholestasis of pregnancy (ICP) is associated with increases in the ratio of cholic acid to chenodeoxycholic acid in both maternal and cord blood, suggesting ongoing dysregulation of bile acid metabolism. The high cholic to chenodeoxycholic acid ratio is correlated with maternal dyslipidemia and high cord blood lipids. These findings may inform more targeted approaches to managing ICP.

Atlas of genetic and phenotypic associations across 42 female reproductive health diagnoses

The genetic background of many female reproductive health diagnoses remains uncharacterized, compromising our understanding of the underlying biology. Here, we map the genetic architecture across 42 female-specific health conditions using data from up to 293,618 women from two large population-based cohorts, the Estonian Biobank and the FinnGen study. Our study illustrates the utility of genetic analyses in understanding women's health better. As specific examples, we describe genetic risk factors for ovarian cysts that elucidate the genetic determinants of folliculogenesis and, by leveraging population-specific variants, uncover new candidate genes for uterine fibroids. We find that most female reproductive health diagnoses have a heritable component, with varying degrees of polygenicity and discoverability. Finally, we identify pleiotropic loci and genes that function in genital tract development (WNT4, PAX8, WT1, SALL1), hormonal regulation (FSHB, GREB1, BMPR1B, SYNE1/ESR1) and folliculogenesis (CHEK2), underlining their integral roles in female reproductive health.

Global and regional incidence of intrahepatic cholestasis of pregnancy: a systematic review and meta-analysis

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) can be a source of significant distress for both pregnant women and the fetus, impairing the quality of life and well-being of pregnant women, leading to psychological disorders among pregnant women with severe or recurrent ICP, and causing life-threatening complications among fetuses. Regrettably, our current understanding of ICP globally is limited, lacking a comprehensive estimation of its incidence. Therefore, in this systematic review and meta-analysis, we aimed to investigate the global and regional incidence of ICP and identify factors that account for its variety across studies.

METHODS

A comprehensive search strategy was implemented across PubMed, Scopus, and Web of Science databases. To stabilize the variance, the Freeman-Tukey double arcsine transformation was employed. Subgroup analyses were conducted based on continent, publication type, study design and timing, regional classifications, developmental status, and World Bank income grouping. A multivariate meta-regression analysis was performed to estimate the effects of the continuous moderators on the effect size.

RESULTS

A total of 42,972,872 pregnant women were analyzed from 302 studies. The overall pooled incidence [95% confidence interval] of ICP was 2.9% [2.5, 3.3]. Studies with larger sample sizes tended to provide significantly lower estimates of ICP incidence: 1.6% [1.3, 2] vs 4.7% [3.9, 5.5]. Asia had the highest incidence of ICP among the continents, whereas Oceania had the lowest. Countries that were classified as developed and with higher income had a lower incidence of ICP than those classified as developing and low and middle income.

CONCLUSIONS

The findings of this study will provide valuable insights into the current knowledge regarding the association of the quality of public health and socioeconomic variations with the incidence of ICP on a global scale.

Comparing risk factors and neonatal outcomes in women with intrahepatic cholestasis of pregnancy between assisted reproductive technology and spontaneous conception

OBJECTIVE

The aim of the present study was to investigate the incidence of intrahepatic cholestasis of pregnancy (ICP) as well as neonatal outcomes between conception via in vitro fertilization (IVF) compared with spontaneous conception (SC) and screen the risk factors of ICP in IVF.

METHODS

This retrospective cohort study included 4467 puerperae who conceived via IVF, and 28 336 puerperae who conceived spontaneously and linked the information from neonates. The general linear model (GLM), multivariate logistic regression analysis, a forest plot, and nomogram were used to assess impact factors and risk prediction.

RESULTS

Logistic analysis adjusted for confounders revealed significant differences in the ICP rate of singleton delivery (4.24% vs 3.41%, adjusted OR [aOR] = 1.26; 95% confidence interval [CI] 1.03-1.53, P = 0.025) and in groups with total bile acids (TBA) ≥40 and <100 μmol/L (14.77% vs 10.39%, aOR = 1.31; 95% CI: 1.06-1.63, P = 0.023) between IVF and SC. When we divided newborns into singleton and twins delivery, the GLM revealed a higher rate with Apgar score <7 (13.44% vs 3.87%, aOR = 3.85; 95% CI: 2.07-7.17, P < 0.001) and fetal distress for IVF in comparison with SC (19.32% vs 5.55%, OR = 3.48; 95% CI: 2.39-6.95, P < 0.001) in the singleton group. In multivariate logistic regression analysis, body mass index (BMI) (aOR = 1.29; P = 0.031), number of embryo transfers (ET) (single ET vs double ET, aOR = 2.82; P < 0.001), E2 level on the ET day (aOR = 2.79; P = 0.011), fresh ET which compared with frozen ET (FET) (aOR = 1.45; P = 0.014), embryo stage (cleavage embryo vs blastocyst, aOR = 1.75; P = 0.009) and severe ovarian hyperstimulation syndrome (OHSS) which compared with non-OHSS (aOR = 3.73; P = 0.006) were independent predictors of ICP. These predictive factors in the logistic regression model were integrated into the nomogram (C-index = 0.735; 95% CI: 0.702-0.764); for each patient, higher total points indicated a higher risk of ICP.

CONCLUSION

We observed that the ICP rate of singleton delivery was higher in IVF than in SC. In ICP patients, there were higher rates of neonatal Apgar score <7 and fetal distress in IVF than SC and found the predictors of ICP in IVF.

Whole-exome sequencing identifies novel mutation in intrahepatic cholestasis of pregnancy: A case report and literature review

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease characterized by pruritus and elevated total bile acid (TBA) levels. The most serious impact of ICP is sudden unexplained intrauterine fetal death, especially when an associated TBA ≥ 100 µmol/L is confirmed.We report a case of a 27-year-old female patient with early-onset severe refractory ICP. Whole-exome sequencing and mutation analyses were performed to obtain genetic data on the patient and her mother. Sanger sequencing was performed to screen the mutation site. Computer-based algorithms were applied to predict the pathogenesis of the identified mutation. Subsequently, we conducted a literature review to characterize the pathological features and perinatal management of severe refractory ICP, especially ICP with genetic susceptibility.A heterozygous mutation in the ABCD3 gene: c.130C > T/p.Pro44Ser was detected in this patient. Through the analysis of pathogenicity prediction software, the mutations were disease-causing. This is the first report to identify the novel p.Pro44Ser mutations of ABCD3 gene in ICP patients.Our report provides new insights into the genetic architecture of ICP involving ABCD3 variants. Early-onset severe refractory ICP is rare and mutations in bile acid metabolism genes might accentuate the phenotype. Emphasized perinatal management and screening for potential pathogenicity sites of variants that drive specific recognition of ICP is necessary.

Association of PM2.5 exposure in early pregnancy and maternal liver function: A retrospective cohort study in Shenzhen, China

OBJECTIVE

Studies have shown that fine particulate matter (PM2.5) has adverse effects on the liver function, but epidemiological evidence is limited, especially regarding pregnant women. This study aims to investigate the association between PM2.5 exposure in early pregnancy and maternal liver function during pregnancy.

METHODS

This retrospective cohort study included 13,342 pregnant participants. PM2.5 and Ozone (O3) exposure level, mean temperature, and relative humidity for each participant were assessed according to their residential address. The levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin (TBIL) were measured during the second and third trimesters. Data on PM2.5 and O3 exposure level were sourced from Tracking Air Pollution in China (TAP), while the mean temperature and relative humidity were obtained from the ERA5 dataset. The Generalized Additive Model (GAM) was used to analyze the associations between PM2.5 exposure and maternal liver function during pregnancy, adjusting for potential confounding factors.

RESULTS

According to the results, each 10 μg/m3 increase in PM2.5 was associated with an increase of 3.57% (95% CI: 0.29%, 6.96%) in ALT and 4.25% (95% CI: 2.33%, 6.21%) in TBIL during the second trimester and 4.51% (95% CI: 2.59%, 6.47%) in TBIL during the third trimester, respectively. After adjusting for O3, these associations remained significant, and the effect of PM2.5 on ALT during the second trimester was further strengthened. No significant association observed between PM2.5 and AST.

CONCLUSIONS

PM2.5 exposure in early pregnancy is associated with increasement of maternal ALT and TBIL, suggesting that PM2.5 exposure may have an adverse effect on maternal liver function. Although this finding indicates an association between PM2.5 exposure and maternal liver function, more research is needed to confirm our findings and explore the underlying biological mechanisms.

Hepatic immune regulation and sex disparities

Chronic liver disease is a major cause of morbidity and mortality worldwide. Epidemiology, clinical phenotype and response to therapies for gastrointestinal and liver diseases are commonly different between women and men due to sex-specific hormonal, genetic and immune-related factors. The hepatic immune system has unique regulatory functions that promote the induction of intrahepatic tolerance, which is key for maintaining liver health and homeostasis. In liver diseases, hepatic immune alterations are increasingly recognized as a main cofactor responsible for the development and progression of chronic liver injury and fibrosis. In this Review, we discuss the basic mechanisms of sex disparity in hepatic immune regulation and how these mechanisms influence and modify the development of autoimmune liver diseases, genetic liver diseases, portal hypertension and inflammation in chronic liver disease. Alterations in gut microbiota and their crosstalk with the hepatic immune system might affect the progression of liver disease in a sex-specific manner, creating potential opportunities for novel diagnostic and therapeutic approaches to be evaluated in clinical trials. Finally, we identify and propose areas for future basic, translational and clinical research that will advance our understanding of sex disparities in hepatic immunity and liver disease.

PUFA and intrahepatic cholestasis of pregnancy: a two-sample Mendelian randomisation analysis

This study aimed to explore the potential causal association between PUFA and the risk of intrahepatic cholestasis of pregnancy (ICP) using Mendelian randomisation (MR) analysis. A two-sample MR analysis was conducted utilising large-scale European-based genome-wide association studies summary databases. The primary MR analysis was carried out using the inverse variance-weighted (IVW) method, complemented by other methods such as MR-egger, weighted-median and weighted mode. Sensitivity analysis was also performed to validate the robustness of the findings. Results indicated a 31 % reduced risk of ICP for every 1 standard deviation (sd) increase in n-3 fatty acids levels (OR = 0·69, 95 % CI: 0·54, 0·89, P = 0·004) and in the ratio of n-3 fatty acids to total fatty acids (OR = 0·69, 95 % CI: 0·53, 0·91, P = 0·008). Conversely, there was a 51 % increased risk of ICP for every 1 sd increase in the ratio of n-6 fatty acids to n-3 fatty acids (OR = 1·51, 95 % CI: 1·20, 1·91, P < 0·001) and a 138 % increased risk for every 1 sd increase in the ratio of linoleic fatty acids to total fatty acids (OR = 2·38, 95 % CI: 1·55, 3·66, P < 0·001). The findings suggest that n-3 fatty acids may have a protective effect against the risk of ICP, while n-6 fatty acids and linoleic fatty acids could be potential risk factors for ICP. The supplementation of n-3 fatty acids, as opposed to n-6 fatty acids, could be a promising strategy for the prevention and management of ICP.

The severity of intrahepatic cholestasis of pregnancy and its association with pregnancy complications and neonatal asphyxia: A single-center case analysis and systematic review

Intrahepatic cholestasis of pregnancy (ICP) poses significant risks to maternal and neonatal health. Our study at Jiangxi Provincial Maternal and Child Health Hospital analyzed clinical and biochemical markers in singleton pregnancies diagnosed with ICP from October 2016 to December 2022. This research, supported by a systematic review and meta-analysis of existing studies, highlights the increasing incidence of ICP and its association with elevated levels of total bile acids, transaminases, and bilirubin. Our findings indicate a marked increase in the risk of preterm birth, cesarean delivery, and neonatal asphyxia as the severity of ICP escalates. This underscores the need for vigilant monitoring and management of affected pregnancies. By confirming the relationship between biochemical marker abnormalities and adverse pregnancy outcomes, our study advocates for enhanced clinical strategies and paves the way for future research aimed at improving prevention, diagnosis, and treatment methods for ICP.

Genetic issues in ICP

Intrahepatic cholestasis of pregnancy (ICP) is the commonest gestational liver disorder with variable global incidence. Genetic susceptibility, combined with hormonal and environmental influences, contributes to ICP aetiology. Adverse pregnancy outcomes linked to elevated serum bile acids highlight the importance of comprehensive risk assessment. ABCB4 and ABCB11 gene variants play a significant role in about 20% of severe ICP cases. Several other genes including ATP8B1, NR1H4, ABCC2, TJP2, SERPINA1, GCKR and HNF4A have also been implicated with ICP. Additionally, ABCB4 variants elevate the risk of drug-induced intrahepatic cholestasis, gallstone disease, gallbladder and bile duct carcinoma, liver cirrhosis and abnormal liver function tests. Genetic variations, both rare and common, intricately contribute to ICP susceptibility. Leveraging genetic insights holds promise for personalised management and intervention strategies. Further research is needed to elucidate variant-specific phenotypic expressions and therapeutic implications, advancing precision medicine in ICP management.

ICP - could there be a virus in the works?

Intrahepatic cholestasis of pregnancy (ICP) is the most common liver-specific disorder affecting pregnant women, with an Australian incidence of 0.6% pa and recurring in 70% of those affected. ICP causes mild to severe pruritus, often resulting in considerable skin excoriations, profound sleep disturbances, and severe anxiety, and yet the aetiology and optimal treatment or management of this condition remains unknown. In this review, we consider the role of viruses in causing or exacerbating ICP and discuss viruses that have been most closely implicated in the disease, including the role of Hepatitis B and Hepatitis C viruses in ICP.

ICP: A midwifery perspective

Background

ICP is a liver condition specific to pregnancy affecting 0.5-0.6% of pregnancies in Australia.

Aims

to review the SOMANZ guidelines and extrapolate information relevant to midwives proving care for women with ICP.

Findings

Multidisciplinary input is essential in caring for women with ICP and their families. Non-fasting TSBA samples ≥19 µmol/L are diagnostic in the presence of pruritus. Peak TSBA denotes the severity of the disease. Increased risk of stillbirth is small when peak TSBA ≥100 µmol/L.

Conclusion

Midwives play an essential role in supporting women with ICP helping them navigate complex appointments and manage the pruritus and concomitant issues.

Unresolved alterations in bile acid composition and dyslipidemia in maternal and cord blood after ursodeoxycholic acid treatment for intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is characterized by elevated plasma bile acid levels. ICP is linked to adverse metabolic outcomes, including a reported increased risk of gestational diabetes. The standard therapeutic approach for managing ICP is treatment with ursodeoxycholic acid (UDCA) and induction of labor prior to 40 weeks of gestation. To investigate bile acid and metabolic parameters after UDCA treatment, we enrolled 12 ICP patients with singleton pregnancies-half with and half without gestational diabetes-and 7 controls. Our study reveals that after UDCA treatment, notwithstanding a reduction in total bile acid and ALT levels, imbalances persist in the cholic acid (CA) to chenodeoxycholic acid (CDCA) ratio in maternal and cord blood plasma. This indicates a continued dysregulation of bile acid metabolism despite therapeutic intervention. Maternal plasma lipid analysis showed a distinct maternal dyslipidemia pattern among ICP patients, marked by elevated cholesterol levels on VLDL particles and heightened triglyceride concentrations on LDL particles, persisting even after UDCA treatment. Cord plasma lipid profiles in ICP patients exhibited elevated triglyceride and free fatty acid levels alongside a tendency toward increased β-hydroxybutyrate. The changes in lipid metabolism in both maternal and cord blood correlated with the high CA/CDCA ratio, but not total bile acid levels or gestational diabetes status. Understanding the imbalances in maternal and cord bile acid and lipid profiles that persist after standard UDCA therapy provides insights for improving management strategies and mitigating the long-term consequences of ICP.

News and Noteworthy

This study uncovers that despite ursodeoxycholic acid treatment, intrahepatic cholestasis of pregnancy (ICP) is associated with increases in the ratio of cholic acid to chenodeoxycholic acid in both maternal and cord blood, suggesting ongoing dysregulation of bile acid metabolism. The high cholic to chenodeoxycholic acid ratio is correlated with maternal dyslipidemia and high cord blood lipids. These findings may inform more targeted approaches to managing ICP.

Preliminary effects of risk-adapted PSA screening for prostate cancer after integrating PRS-specific and age-specific variation

Background

Although the risk of prostate cancer (PCa) varies across different ages and genetic risks, it's unclear about the effects of genetic-specific and age-specific prostate-specific antigen (PSA) screening for PCa.

Methods

Weighed and unweighted polygenic risk scores (PRS) were constructed to classify the participants from the PLCO trial into low- or high-PRS groups. The age-specific and PRS-specific cut-off values of PSA for PCa screening were determined with time-dependent receiver-operating-characteristic curves and area-under-curves (tdAUCs). Improved screening strategies integrating PRS-specific and age-specific cut-off values of PSA were compared to traditional PSA screening on accuracy, detection rates of high-grade PCa (Gleason score ≥7), and false positive rate.

Results

Weighted PRS with 80 SNPs significantly associated with PCa was determined as the optimal PRS, with an AUC of 0.631. After stratifying by PRS, the tdAUCs of PSA with a 10-year risk of PCa were 0.818 and 0.816 for low- and high-PRS groups, whereas the cut-off values were 1.42 and 1.62 ng/mL, respectively. After further stratifying by age, the age-specific cut-off values of PSA were relatively lower for low PRS (1.42, 1.65, 1.60, and 2.24 ng/mL for aged <60, 60-64, 65-69, and ≥70 years) than high PRS (1.48, 1.47, 1.89, and 2.72 ng/mL). Further analyses showed an obvious interaction of positive PSA and high PRS on PCa incidence and mortality. Very small difference in PCa risk were observed among subgroups with PSA (-) across different age and PRS, and PCa incidence and mortality with PSA (+) significantly increased as age and PRS, with highest risk for high-PRS/PSA (+) in participants aged ≥70 years [HRs (95%CI): 16.00 (12.62-20.29) and 19.48 (9.26-40.96)]. The recommended screening strategy reduced 12.8% of missed PCa, ensured high specificity, but not caused excessive false positives than traditional PSA screening.

Conclusion

Risk-adapted screening integrating PRS-specific and age-specific cut-off values of PSA would be more effective than traditional PSA screening.

Sarmentol H derived from Sedum sarmentosum Bunge directly targets FXR to mitigate cholestasis by recruiting SRC-1

BACKGROUND

Farnesoid X receptor (FXR) is a vital receptor for bile acids and plays an important role in the treatment of cholestatic liver disease. In addition to traditional bile acid-based steroidal agonists, synthetic alkaloids are the most commonly reported non-steroidal FXR agonists. Sarmentol H is a nor-sesquiterpenoid obtained from Sedum sarmentosum Bunge, and in vitro screening experiments have shown that it might be related to the regulation of the FXR pathway in a previous study.

PURPOSE

To investigate the therapeutic effects of sarmentol H on cholestasis and to determine whether sarmentol H directly targets FXR to mitigate cholestasis. Furthermore, this study aimed to explore the key amino acid residues involved in the binding of sarmentol H to FXR through site-directed mutagenesis.

METHODS

An intrahepatic cholestasis mouse model was established to investigate the therapeutic effects of sarmentol H on cholestasis. In vitro experiments, including Co-Ip and FXR-EcRE-Luc assays, were performed to assess whether sarmentol H activates FXR by recruiting the receptor coactivator SRC1. CETSA, SIP, DARTS, and ITC were used to determine the binding of sarmentol H to FXR protein. The key amino acid residues for sarmentol H binding to FXR were analyzed by molecular docking and site-directed mutagenesis. Finally, we conducted in vivo experiments on wild-type and Fxr-/- mice to further validate the anticholestatic target of sarmentol H.

RESULTS

Sarmentol H had significant ameliorative effects on the pathological conditions of cholestatic mice induced with ANIT. In vitro experiments suggested that it is capable of activating FXR and regulating downstream signaling pathways by recruiting SRC1. The target validation experiments showed that sarmentol H had the ability to bind to FXR as a ligand (KD = 2.55 μmol/L) and enhance the stability of its spatial structure. Moreover, site-directed mutagenesis revealed that THR292 and TYR365 were key binding sites for sarmentol H and FXR. Furthermore, knockout of the Fxr gene resulted in a significantly higher degree of ANIT-induced cholestatic liver injury than that in wild-type cholestatic mice, and the amelioration of cholestasis or regulatory effects on FXR downstream genes by sarmentol H also disappeared in Fxr-/- cholestatic mice.

CONCLUSION

Sarmentol H is an FXR agonist. This is the first study to show that it exerts a significant therapeutic effect on cholestatic mice, and can directly bind to FXR and activate it by recruiting the coactivator SRC1.

Genetically predicted lipids mediate the association between intrahepatic cholestasis of pregnancy and cardiovascular disease

Introduction

Intrahepatic cholestasis of pregnancy (ICP), the most prevalent liver disorder specific to pregnancy, affects approximately 1.5%-4% of pregnancies. However, the influence of ICP on cardiovascular disease (CVD), including hypertension (HTN) and coronary artery disease (CAD), has not been thoroughly investigated.

Methods

This study explores the causal relationship between ICP and CVD (HTN, CAD) using Mendelian Randomization (MR). Utilizing summary-level data from Genome-Wide Association Studies (GWAS), we applied the inverse-variance weighted (IVW) method, supplemented by sensitivity and reverse MR analyses, to ascertain robustness.

Results

Our findings reveal significant causal links, indicating ICP notably increases the risk of CVD (P = 0.001), hypertension (HTN, P = 0.024), and coronary artery disease (CAD, P = 0.039). A two-step MR analysis highlighted the mediation role of lipid profiles, with LDL, TC, and Apo-B contributing to increased CVD risk by 25.5%, 12.2%, and 21.3%, respectively. Additionally, HTN was identified as a mediator in the ICP-CAD association, accounting for a 14.5% mediation effect.

Discussion

The results underscore the genetic predisposition of ICP to elevate CVD risk and the critical mediating role of lipid levels, emphasizing the need for vigilant lipid monitoring and early intervention in individuals with ICP.

Genome-wide characterization of circulating metabolic biomarkers

Genome-wide association analyses using high-throughput metabolomics platforms have led to novel insights into the biology of human metabolism1-7. This detailed knowledge of the genetic determinants of systemic metabolism has been pivotal for uncovering how genetic pathways influence biological mechanisms and complex diseases8-11. Here we present a genome-wide association study for 233 circulating metabolic traits quantified by nuclear magnetic resonance spectroscopy in up to 136,016 participants from 33 cohorts. We identify more than 400 independent loci and assign probable causal genes at two-thirds of these using manual curation of plausible biological candidates. We highlight the importance of sample and participant characteristics that can have significant effects on genetic associations. We use detailed metabolic profiling of lipoprotein- and lipid-associated variants to better characterize how known lipid loci and novel loci affect lipoprotein metabolism at a granular level. We demonstrate the translational utility of comprehensively phenotyped molecular data, characterizing the metabolic associations of intrahepatic cholestasis of pregnancy. Finally, we observe substantial genetic pleiotropy for multiple metabolic pathways and illustrate the importance of careful instrument selection in Mendelian randomization analysis, revealing a putative causal relationship between acetone and hypertension. Our publicly available results provide a foundational resource for the community to examine the role of metabolism across diverse diseases.

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.

Intrahepatic cholestasis of pregnancy and theory of inheritance of the disease. Literature review

Intrahepatic cholestasis during pregnancy is associated with a higher risk of prenatal and maternal complications. There are several new publications and guidelines on the detection and thresholds of intrahepatic cholestasis during pregnancy. However, the genetic background of this disease has rarely been investigated. This is a comprehensive review of the roles of genes in intrahepatic cholestasis during pregnancy.

Intrahepatic cholestasis of pregnancy - Diagnosis and management: A consensus statement of the Society of Obstetric Medicine of Australia and New Zealand (SOMANZ): Executive summary

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy liver disease, characterised by pruritus and increased total serum bile acids (TSBA), Australian incidence 0.6-0.7%. ICP is diagnosed by non-fasting TSBA ≥19 μmol/L in a pregnant woman with pruritus without rash without a known pre-existing liver disorder. Peak TSBA ≥40 and ≥100 μmol/L identify severe and very severe disease respectively, associated with spontaneous preterm birth when severe, and with stillbirth, when very severe. Benefit-vs-risk for iatrogenic preterm birth in ICP remains uncertain. Ursodeoxycholic acid remains the best pharmacotherapy preterm, improving perinatal outcome and reducing pruritus, although it has not been shown to reduce stillbirth.

Fluorescence-based methods for studying activity and drug-drug interactions of hepatic solute carrier and ATP binding cassette proteins involved in ADME-Tox

In humans, approximately 70% of drugs are eliminated through the liver. This process is governed by the concerted action of membrane transporters and metabolic enzymes. Transporters mediating hepatocellular uptake of drugs belong to the SLC (Solute carrier) superfamily of transporters. Drug efflux either toward the portal vein or into the bile is mainly mediated by active transporters of the ABC (ATP Binding Cassette) family. Alteration in the function and/or expression of liver transporters due to mutations, disease conditions, or co-administration of drugs or food components can result in altered pharmacokinetics. On the other hand, drugs or food components interacting with liver transporters may also interfere with liver function (e.g., bile acid homeostasis) and may even cause liver toxicity. Accordingly, certain transporters of the liver should be investigated already at an early stage of drug development. Most frequently radioactive probes are applied in these drug-transporter interaction tests. However, fluorescent probes are cost-effective and sensitive alternatives to radioligands, and are gaining wider application in drug-transporter interaction tests. In our review, we summarize our current understanding about hepatocyte ABC and SLC transporters affected by drug interactions. We provide an update of the available fluorescent and fluorogenic/activable probes applicable in in vitro or in vivo testing of these ABC and SLC transporters, including near-infrared transporter probes especially suitable for in vivo imaging. Furthermore, our review gives a comprehensive overview of the available fluorescence-based methods, not directly relying on the transport of the probe, suitable for the investigation of hepatic ABC or SLC-type drug transporters.