A protective antiarrhythmic role of ursodeoxycholic acid in an in vitro rat model of the cholestatic fetal heart

The gut microbiota and its role in the development of cardiovascular disease

INTRODUCTION

The pathophysiology of cardiovascular diseases encompasses a complex interplay of genetic and environmental risk factors. Even if traditional risk factors are treated to target, there remains a residual risk.

AREAS COVERED

This manuscript reviews the potential role of gut microbiota in the development of cardiovascular disease, and as potential target. A systematic search was conducted until 30 October 2024 on PubMed (MEDLINE), using the MeSH terms [Gut microbiota] + [Dysbiosis] + [Cardiovascular] + [TMAO] + [bile acids] + [short-chain fatty acids].

EXPERT OPINION

The term dysbiosis implies changes in equilibrium, with modifications in the composition and functionality of microbiota and a series of additional factors: reduced diversity and uniformity of microorganisms; reduced short-chain fatty acid-producing bacteria; increased gut permeability; release of metabolites, such as trimethylamine N-oxide, betaine, phenylalanine, tryptophan-kynurenine, phenylacetylglutamine, and lipopolysaccharides; and reduced secondary bile acid excretion, leading to inflammation, oxidative stress, and endothelial dysfunction and facilitating the onset of pathological conditions, including obesity, hypertension, diabetes, atherosclerosis, and heart failure. Attempts to restore gut microbiota balance through different interventions, mainly changes in diet, have been shown to positively affect individual components and metabolites and reduce the risk of cardiovascular disease. In addition, probiotics and prebiotics are potentially useful. Fecal microbiota transplantation is a promising therapy.

Protective effect of UDCA against IL-11- induced cardiac fibrosis is mediated by TGR5 signalling

Introduction

Cardiac fibrosis occurs in a wide range of cardiac diseases and is characterised by the transdifferentiation of cardiac fibroblasts into myofibroblasts these cells produce large quantities of extracellular matrix, resulting in myocardial scar. The profibrotic process is multi-factorial, meaning identification of effective treatments has been limited. The antifibrotic effect of the bile acid ursodeoxycholic acid (UDCA) is established in cases of liver fibrosis however its mechanism and role in cardiac fibrosis is less well understood.

Methods

In this study, we used cellular models of cardiac fibrosis and living myocardial slices to characterise the macroscopic and cellular responses of the myocardium to UDCA treatment. We complemented this approach by conducting RNA-seq on cardiac fibroblasts isolated from dilated cardiomyopathy patients. This allowed us to gain insights into the mechanism of action and explore whether the IL-11 and TGFβ/WWP2 profibrotic networks are influenced by UDCA. Finally, we used fibroblasts from a TGR5 KO mouse to confirm the mechanism of action.

Results and discussion

We found that UDCA reduced myofibroblast markers in rat and human fibroblasts and in living myocardial slices, indicating its antifibrotic action. Furthermore, we demonstrated that the treatment of UDCA successfully reversed the profibrotic IL-11 and TGFβ/WWP2 gene networks. We also show that TGR5 is the most highly expressed UDCA receptor in cardiac fibroblasts. Utilising cells isolated from a TGR5 knock-out mouse, we identified that the antifibrotic effect of UDCA is attenuated in the KO fibroblasts. This study combines cellular studies with RNA-seq and state-of-the-art living myocardial slices to offer new perspectives on cardiac fibrosis. Our data confirm that TGR5 agonists, such as UDCA, offer a unique pathway of action for the treatment of cardiac fibrosis. Medicines for cardiac fibrosis have been slow to clinic and have the potential to be used in the treatment of multiple cardiac diseases. UDCA is well tolerated in the treatment of other diseases, indicating it is an excellent candidate for further in-human trials.

The Cardiomyocyte in Cirrhosis: Pathogenic Mechanisms Underlying Cirrhotic Cardiomyopathy

Cirrhotic cardiomyopathy is defined as systolic and diastolic dysfunction in patients with cirrhosis, in the absence of any primary heart disease. These changes are mainly due to the malfunction or abnormalities of cardiomyocytes. Similar to non-cirrhotic heart failure, cardiomyocytes in cirrhotic cardiomyopathy demonstrate a variety of abnormalities: from the cell membrane to the cytosol and nucleus. At the cell membrane level, biophysical plasma membrane fluidity, and membrane-bound receptors such as the beta-adrenergic, muscarinic and cannabinoid receptors are abnormal either functionally or structurally. Other changes include ion channels such as L-type calcium channels, potassium channels, and sodium transporters. In the cytosol, calcium release and uptake processes are dysfunctional and the myofilaments such as myosin heavy chain and titin, are either functionally abnormal or have structural alterations. Like the fibrotic liver, the heart in cirrhosis also shows fibrotic changes such as a collagen isoform switch from more compliant collagen III to stiffer collagen I which also impacts diastolic function. Other abnormalities include the secondary messenger cyclic adenosine monophosphate, cyclic guanosine monophosphate, and their downstream effectors such as protein kinase A and G-proteins. Finally, other changes such as excessive apoptosis of cardiomyocytes also play a critical role in the pathogenesis of cirrhotic cardiomyopathy. The present review aims to summarize these changes and review their critical role in the pathogenesis of cirrhotic cardiomyopathy.

Meta-analyses in cholestatic pregnancy: The outstanding clinical questions

Reports of adverse pregnancy outcomes associated with maternal pruritus and liver impairment have circulated since the 1800s, yet the precise diagnosis and management of intrahepatic cholestasis of pregnancy have varied markedly. Recent evidence, including that from individual participant data meta-analyses, has provided an evidence that brings us closer to standardised, and optimal, management of the condition. Based upon increased adverse perinatal outcomes with higher bile acid concentrations, disease management should be according to severity (defined by peak bile acid concentration) in order to recommend appropriate gestation of birth. Similarly, the reduced spontaneous preterm birth rate for patients receiving ursodeoxycholic acid treatment suggests potential benefit for the treatment of patients with moderate-severe disease.

Effect of Maternal Ursodeoxycholic Acid Treatment on Fetal Atrioventricular Conduction in Patients with Intrahepatic Cholestasis of Pregnancy

INTRODUCTION

The aim of this study was, first, to investigate the difference in fetal atrioventricular conduction in patients with and without intrahepatic cholestasis of pregnancy (ICP) by measuring the fetal PR interval; second, to evaluate the altering effect of ursodeoxycholic acid (UDCA) treatment on the fetal PR interval in ICP patients.

METHODS

The study consisted of 42 ICP patients and 48 healthy pregnant women. Fetal echocardiography was performed to measure the mechanical PR interval. The fetal PR interval and the clinical characteristics were compared between the two groups. The effect of UDCA treatment on the fetal PR interval in ICP patients was evaluated.

RESULTS

In ICP patients, significantly longer fetal PR intervals were observed than in the control group (123.21 ± 8.54 vs. 115.13 ± 5.95 ms, p < 0.001). In the ICP group, there was a positive correlation between the fetal PR interval and maternal fasting total bile acid (TBA) levels (r = 0.514, p = 0.001). After 1 week of treatment with UDCA in patients with ICP, the PR interval was shorter than before, although the reduction was not statistically significant (120.98 ± 6.70 vs. 123.21 ± 8.54 ms, p = 0.095). In patients with severe ICP (TBA >40 mmol/L, n = 10), a significant reduction in the fetal PR interval was observed after treatment with UDCA (127.5 ms [IQR, 118.0-134.75] before vs. 122 ms [IQR, 109.5-126.5] after, p = 0.037).

CONCLUSION

Fetal PR interval increased in ICP patients in correlation with maternal serum TBA concentration. Treatment with UDCA may have limited positive effects on the fetal AV conduction system. The beneficial effects of UDCA on the fetal PR interval may be more pronounced in patients with higher bile acid levels.

Bile acid metabolism in health and ageing-related diseases

Bile acids (BAs) have surpassed their traditional roles as lipid solubilizers and regulators of BA homeostasis to emerge as important signalling molecules. Recent research has revealed a connection between microbial dysbiosis and metabolism disruption of BAs, which in turn impacts ageing-related diseases. The human BAs pool is primarily composed of primary BAs and their conjugates, with a smaller proportion consisting of secondary BAs. These different BAs exert complex effects on health and ageing-related diseases through several key nuclear receptors, such as farnesoid X receptor and Takeda G protein-coupled receptor 5. However, the underlying molecular mechanisms of these effects are still debated. Therefore, the modulation of signalling pathways by regulating synthesis and composition of BAs represents an interesting and novel direction for potential therapies of ageing-related diseases. This review provides an overview of synthesis and transportion of BAs in the healthy body, emphasizing its dependence on microbial community metabolic capacity. Additionally, the review also explores how ageing and ageing-related diseases affect metabolism and composition of BAs. Understanding BA metabolism network and the impact of their nuclear receptors, such as farnesoid X receptor and G protein-coupled receptor 5 agonists, paves the way for developing therapeutic agents for targeting BA metabolism in various ageing-related diseases, such as metabolic disorder, hepatic injury, cardiovascular disease, renal damage and neurodegenerative disease.

Fetal PR Interval in Pregnancies with Intrahepatic Cholestasis of Pregnancy: A Case-Control Study

OBJECTIVE

 This study had three purposes: first, to explore differences in fetal cardiac function in patients with and without intrahepatic cholestasis of pregnancy (ICP) based on PR interval (the interval between the beginning of the atrial contraction and the beginning of the ventricular contraction). Second, to explore a potential correlation between PR interval and bile acid levels in pregnant women with ICP. Third, to study changes in PR interval of fetuses from pregnant women with ICP after administration of ursodeoxycholic acid (UDCA).

STUDY DESIGN

 This was a prospective observational case-control study. ICP was defined as palmar plantar pruritus of nocturnal predominance for more than 1 week associated with a total bile acid level >10 μmol/L. Control cases were women with pregnancies scheduled for induction or elective cesarean section at term.

RESULTS

 One hundred and ten women with ICP and 72 controls were included in the study. Median gestational age at inclusion was 35.9 weeks. Median PR interval was significantly longer in fetuses of women with ICP (122 vs. 102 ms, p < 0.001). There was a significant correlation between bile acid levels and PR interval (rho = 0.723, p < 0.001). In 22 fetuses, the median PR interval decreased significantly following UDCA administration (134 vs. 118 ms, p = 0.004).

CONCLUSION

 PR interval is longer in fetuses of women with ICP. PR interval was significantly correlated with bile acid levels, and administration of UDCA significantly reduced PR interval.

KEY POINTS

· Differences in fetal cardiac function in patients with and without intrahepatic cholestasis.. · PR interval and bile acid levels in pregnant women with intrahepatic cholestasis.. · Changes in PR interval of fetuses from pregnant women with ICP after use of UDCA..

Role of the microbiota-gut-heart axis between bile acids and cardiovascular disease

Bile acid (BA) receptors (e.g., farnesoid X-activated receptor, muscarinic receptor) are expressed in cardiomyocytes, endothelial cells, and vascular smooth muscle cells, indicating the relevance of BAs to cardiovascular disease (CVD). Hydrophobic BAs are cardiotoxic, while hydrophilic BAs are cardioprotective. For example, fetal cardiac insufficiency in maternal intrahepatic cholestasis during pregnancy, and the degree of fetal cardiac abnormality, is closely related to the level of hydrophobic BAs in maternal blood and infant blood. However, ursodeoxycholic acid (the most hydrophilic BA) can reverse/prevent these detrimental effects of increased levels of hydrophobic BAs on the heart. The gut microbiota (GM) and GM metabolites (especially secondary BAs) have crucial roles in hypertension, atherosclerosis, unstable angina, and heart failure. Herein, we describe the relationship between CVD and the GM at the BA level. We combine the concept of the "microbiota-gut-heart axis" (MGHA) and postulate the role and mechanism of BAs in CVD development. In addition, the strategies for treating CVD with BAs under the MGHA are proposed.

Maternal and neonatal outcomes of intrahepatic cholestasis of pregnancy after in vitro fertilization

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) is an idiopathic disease of pregnancy. Little is known about how it specifically affects pregnancies resulting from in vitro fertilization (IVF). Our aim is to evaluate the impact of IVF on the perinatal outcomes of ICP.

METHODS

A retrospective study of 242 patients with intrahepatic cholestasis of pregnancy, comprising 36 conceived through IVF and 206 spontaneous conceptions (SC), enrolled between 2019 and 2021 was carried out. Data were analyzed from the medical archives of the Huazhong University of Science and Technology, Tongji Hospital.

RESULTS

Numerical values of transaminases (ALT, alanine aminotransferase; AST, aspartate aminotransferase) and serum total bile acid (TBA) are significantly lower in the IVF group than that in the spontaneous conceived group (p < 0.05). The incidence of gestational diabetes mellitus (GDM) was higher in the IVF group than in SC group (30.6% vs. 16%, p = 0.037). The cesarean section (CS) rates are higher in the IVF group (97.2% vs. 85.4%, p = 0.023). On the other hand, the prevalence of premature rupture of membranes (PROM) was higher in the SC group (10.7%) while none was reported in the IVF-ICP group. Other maternal comorbidities and neonatal outcomes were similar between the two groups.

CONCLUSION

ICP patients who underwent IVF are more likely to suffer from GDM. Therefore, monitoring and management of blood glucose should be strengthened during pregnancy. Fortunately, IVF does not seem to worsen the progression or outlook of ICP, so sticking to standard management practices is recommended.

Cardiac complications caused by biliary diseases: A review of clinical manifestations, pathogenesis and treatment strategies of cholecardia syndrome

Gallbladder and biliary diseases (GBDs) are one of the most common digestive diseases. The connections between GBDs and several organs other than the liver have gradually surfaced accompanied by the changes in people's diet structure and the continuous improvement of medical diagnosis technology. Among them, cholecardia syndrome that takes the heart as the important target of GBDs complications has been paid close attention. However, there are still no systematic report about its corresponding clinical manifestations and pathogenesis. This review summarized recent reported types of cholecardia syndrome and found that arrhythmia, myocardial injury, acute coronary syndrome and heart failure are common in the general population. Besides, the clinical diagnosis rate of intrahepatic cholestasis of pregnancy (ICP) and Alagille syndrome associated with gene mutation is also increasing. Accordingly, the underlying pathogenesis including abnormal secretion of bile acid, gene mutation, translocation and deletion (JAG1, NOTCH2, ABCG5/8 and CYP7A1), nerve reflex and autonomic neuropathy were further revealed. Finally, the potential treatment measures and clinical medication represented by ursodeoxycholic acid were summarized to provide assistance for clinical diagnosis and treatment.

EASL Clinical Practice Guidelines on the management of liver diseases in pregnancy

Liver diseases in pregnancy comprise both gestational liver disorders and acute and chronic hepatic disorders occurring coincidentally in pregnancy. Whether related to pregnancy or pre-existing, liver diseases in pregnancy are associated with a significant risk of maternal and fetal morbidity and mortality. Thus, the European Association for the Study of Liver Disease invited a panel of experts to develop clinical practice guidelines aimed at providing recommendations, based on the best available evidence, for the management of liver disease in pregnancy for hepatologists, gastroenterologists, obstetric physicians, general physicians, obstetricians, specialists in training and other healthcare professionals who provide care for this patient population.

Intrahepatic cholestasis of pregnancy and fetal cardiac dysfunction: a systematic review and meta-analysis

OBJECTIVE

Intrahepatic cholestasis of pregnancy is associated with adverse perinatal outcomes. Fetal cardiac dysfunction may be 1 part of the pathophysiology of pregnancies complicated by intrahepatic cholestasis of pregnancy. This systematic review and meta-analysis aimed to evaluate the association between intrahepatic cholestasis of pregnancy and fetal cardiac dysfunction.

DATA SOURCES

Systematic searches were performed on the databases of Medline, Embase, and Cochrane Library (up to March 2, 2023) for studies evaluating fetal cardiac function in pregnancies complicated by intrahepatic cholestasis of pregnancy in addition to the reference lists of included studies.

STUDY ELIGIBILITY CRITERIA

Studies were eligible for inclusion if they assessed the fetal cardiac function by fetal echocardiography in women with intrahepatic cholestasis of pregnancy (mild or severe) and compared with fetuses of healthy pregnant women. The studies published in English were included.

METHODS

The quality of the retrieved studies was assessed using the Newcastle-Ottawa Scale. Data on fetal myocardial performance index, E wave/A wave peak velocities ratio, and PR interval were pooled for the meta-analysis using random-effects models. The results were presented as weighted mean differences and 95% confidence intervals. This meta-analysis was registered with the International Prospective Register of Systematic Reviews (registration number: CRD42022334801).

RESULTS

A total of 14 studies were included in this qualitative analysis. Of note, 10 studies that reported data on fetal myocardial performance index, E wave/A wave peak velocities ratio, and PR interval were included in the quantitative analysis and showed a significant association between intrahepatic cholestasis of pregnancy and fetal cardiac dysfunction. Significantly higher fetal left ventricular myocardial performance index values (weighted mean difference, 0.10; 95% confidence interval, 0.04-0.16) and longer fetal PR intervals (weighted mean difference, 10.10 ms; 95% confidence interval, 7.34-12.86) were revealed in pregnancies complicated by intrahepatic cholestasis of pregnancy. Compared with the situation in pregnancies complicated by mild intrahepatic cholestasis of pregnancy, PR intervals were even longer in pregnancies complicated by severe intrahepatic cholestasis of pregnancy (weighted mean difference, 5.98 ms; 95% confidence interval, 0.20-11.77). There was no significant difference in fetal E wave/A wave peak velocities ratio between the group with intrahepatic cholestasis of pregnancy and the healthy pregnant group (weighted mean difference, 0.01; 95% confidence interval, -0.03 to 0.05).

CONCLUSION

Our findings supported the idea that intrahepatic cholestasis of pregnancy is associated with overall impaired fetal myocardial performance and impaired fetal cardiac conduction system. However, current evidence about the association between fetal cardiac dysfunction and intrahepatic cholestasis of pregnancy-induced stillbirth is lacking. Further studies are needed to reveal the relationship between fetal cardiac dysfunction and adverse perinatal outcomes in pregnancies complicated by intrahepatic cholestasis of pregnancy.

Stress regulation of WFS1 and PERK-p-eIF2α-ATF4 signaling pathway in placental tissue cells of intrahepatic cholestasis of pregnancy

INTRODUCTION

The placental tissue stress of intrahepatic cholestasis of pregnancy (ICP) is activated by ERS under hypoxia condition. PERK signaling pathway is the key pathway for UPR regulation, and is first to activated during ERS. WFS1, as an important regulatory gene of UPR pathway, participates in ERS regulation. The purpose of our study is to explore the expression level and mutual regulation mechanisms of WFS1 and PERK-mediated UPR pathway in ICP placental tissue cell under stress.

METHODS

Blood and placenta samples were obtained from the ICP patients and ethinylestradiol (EE)-induced intrahepatic cholestasis pregnant rats. IHC and WB were used to detect the expression of WFS1, key factors of PERK pathway (GRP78, PERK, eIF2a, P-eIF2α, ATF4) and placental stress peptides (CRH, UCN). Furthermore, qPCR was carried out to detect mRNA expression of above indicators.

RESULTS

The expression levels of WFS1 and key factors of PERK pathway were significantly increased in severe ICP placental tissues. Moreover, qPCR and WB showed that relative mRNA and protein expression levels of WFS1 and key factors of PERK pathways in placenta tissues of severe ICP and EE-induced intrahepatic cholestasis pregnant rats were higher than those in control group to varying degrees, while CRH and UCN were descended. Meanwhile, after WFS1-siRNA targeted silencing of the WFS1 gene, the protein expression levels of PERK, P-eIF2α, ATF4 were significantly increased, while CRH and UCN protein were significantly decreased.

DISCUSSION

Our study revealed that the activation of WFS1 and PERK-p-eIF2α-ATF4 signaling pathway may contribute to stress regulation in placental tissue cells of intrahepatic cholestasis of pregnancy, thereby avoiding adverse pregnancy outcomes.

The Interaction of Gut Microbiota and Heart Failure with Preserved Ejection Fraction: From Mechanism to Potential Therapies

Heart failure with preserved ejection fraction (HFpEF) is a disease for which there is no definite and effective treatment, and the number of patients is more than 50% of heart failure (HF) patients. Gut microbiota (GMB) is a general term for a group of microbiota living in humans' intestinal tracts, which has been proved to be related to cardiovascular diseases, including HFpEF. In HFpEF patients, the composition of GMB is significantly changed, and there has been a tendency toward dysbacteriosis. Metabolites of GMB, such as trimethylamine N-oxide (TMAO), short-chain fatty acids (SCFAs) and bile acids (BAs) mediate various pathophysiological mechanisms of HFpEF. GMB is a crucial influential factor in inflammation, which is considered to be one of the main causes of HFpEF. The role of GMB in its important comorbidity-metabolic syndrome-also mediates HFpEF. Moreover, HF would aggravate intestinal barrier impairment and microbial translocation, further promoting the disease progression. In view of these mechanisms, drugs targeting GMB may be one of the effective ways to treat HFpEF. This review focuses on the interaction of GMB and HFpEF and analyzes potential therapies.

Guidelines for assessment of cardiac electrophysiology and arrhythmias in small animals

Cardiac arrhythmias are a major cause of morbidity and mortality worldwide. Although recent advances in cell-based models, including human-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM), are contributing to our understanding of electrophysiology and arrhythmia mechanisms, preclinical animal studies of cardiovascular disease remain a mainstay. Over the past several decades, animal models of cardiovascular disease have advanced our understanding of pathological remodeling, arrhythmia mechanisms, and drug effects and have led to major improvements in pacing and defibrillation therapies. There exist a variety of methodological approaches for the assessment of cardiac electrophysiology and a plethora of parameters may be assessed with each approach. This guidelines article will provide an overview of the strengths and limitations of several common techniques used to assess electrophysiology and arrhythmia mechanisms at the whole animal, whole heart, and tissue level with a focus on small animal models. We also define key electrophysiological parameters that should be assessed, along with their physiological underpinnings, and the best methods with which to assess these parameters.

Gut microbiota, dysbiosis and atrial fibrillation. Arrhythmogenic mechanisms and potential clinical implications

Recent preclinical and observational cohort studies have implicated imbalances in gut microbiota composition as a contributor to atrial fibrillation (AF). The gut microbiota is a complex and dynamic ecosystem containing trillions of microorganisms, which produces bioactive metabolites influencing host health and disease development. In addition to host-specific determinants, lifestyle-related factors such as diet and drugs are important determinants of the gut microbiota composition. In this review, we discuss the evidence suggesting a potential bidirectional association between AF and gut microbiota, identifying gut microbiota-derived metabolites as possible regulators of the AF substrate. We summarize the effect of gut microbiota on the development and progression of AF risk factors, including heart failure, hypertension, obesity, and coronary artery disease. We also discuss the potential anti-arrhythmic effects of pharmacological and diet-induced modifications of gut microbiota composition, which may modulate and prevent the progression to AF. Finally, we highlight important gaps in knowledge and areas requiring future investigation. Although data supporting a direct relationship between gut microbiota and AF are very limited at the present time, emerging preclinical and clinical research dealing with mechanistic interactions between gut microbiota and AF is important as it may lead to new insights into AF pathophysiology and the discovery of novel therapeutic targets for AF.

Pregnancy-Associated Liver Diseases

The liver disorders unique to pregnancy include hyperemesis gravidarum, intrahepatic cholestasis of pregnancy, acute fatty liver of pregnancy, and preeclampsia-associated hepatic impairment, specifically hemolysis, elevated liver enzymes, and low platelet count syndrome (HELLP). Their importance lies in the significant maternal and fetal/neonatal morbidity and mortality. Expeditious diagnosis and clinical evaluation is critical to ensure timely, appropriate care and minimize risks to the pregnant woman and her fetus/baby. A multidisciplinary approach is essential, including midwives, maternal-fetal-medicine specialists, anesthetists, neonatologists, and hepatologists.

Intrahepatic cholestasis of pregnancy - Time to redefine the reference range of total serum bile acids: A cross-sectional study

Objective

To establish pregnancy‐specific reference ranges for fasting and postprandial total serum bile acid (TSBA) concentrations.

Design

Cross‐sectional study.

Setting

Tertiary‐care university hospital.

Population

Healthy pregnant women at term admitted to the Obstetrics Department over a period of 1 year. Exclusion criteria were an established diagnosis of intrahepatic cholestasis of pregnancy (ICP) or any coexisting condition of increased risk for ICP.

Methods

Both fasting (after 8–14 h of fasting) and postprandial (2 h after meal) TSBA concentrations were measured in 612 women (with 528 fasting samples and 377 postprandial samples) by automated enzymatic spectrophotometric assay.

Main outcome measures

Fasting and postprandial TSBA concentrations in 612 women.

Results

Reference intervals of 4.4–14.1 μmol/L for fasting TSBA and 4.7–20.2 μmol/L for postprandial TSBA were established. The postprandial values were significantly higher than the fasting values, with a median increase of 1.0 μmol/L (p < 0.0001). A correlation between fasting TSBA concentrations and postprandial concentrations was found, as well as correlations with fetal sex, parity and assisted reproductive technologies. A seasonal pattern was noticed for both fasting and postprandial TSBA, with the highest values measured in the winter season (p < 0.01 and 0.02, respectively)

Conclusions

Normal pregnancy is associated with mild hypercholanaemia, and therefore a higher threshold should be considered for the diagnosis of ICP. We suggest using the upper reference limits observed in our healthy pregnant population (14 μmol/L for fasting TSBA and 20 μmol/L for postprandial TSBA). As the fasting measurement is more specific for the diagnosis, and the postprandial measurement is essential for the assessment of severity, it is recommended to measure both values rather than use random sampling.

Tweetable abstract

Normal pregnancy is associated with mild hypercholanaemia, a higher threshold should be considered for the diagnosis of ICP.

Normal pregnancy is associated with mild hypercholanaemia, a higher threshold should be considered for the diagnosis of ICP.

Linked article: This article is commented on by Ovadia et al., pp. 1897–1898. in this issue. To view this minicommentary visit https://doi.org/10.1111/1471‐0528.17171

Pathogenic Mechanisms Underlying Cirrhotic Cardiomyopathy

Cardiac dysfunction associated with cirrhosis in the absence of preexisting heart disease is a condition known as cirrhotic cardiomyopathy (CCM). Cardiac abnormalities consist of enlargement of cardiac chambers, attenuated systolic and diastolic contractile responses to stress stimuli, and repolarization changes. CCM may contribute to cardiovascular morbidity and mortality after liver transplantation and other major surgeries, and also to the pathogenesis of hepatorenal syndrome. The underlying mechanisms of CCM are poorly understood and as such medical therapy is an area of unmet medical need. The present review focuses on the pathogenic mechanisms responsible for development of CCM. The two major concurrent mechanistic pathways are the inflammatory phenotype due to portal hypertension, and protein/lipid synthetic/metabolic defects due to cirrhosis and liver insufficiency. The inflammatory phenotype arises from intestinal congestion due to portal hypertension, resulting in bacteria/endotoxin translocation into the systemic circulation. The cytokine storm associated with inflammation, particularly TNFα acting via NFκB depresses cardiac function. They also stimulate two evanescent gases, nitric oxide and carbon monoxide which produce cardiodepression by cGMP. Inflammation also stimulates the endocannabinoid CB-1 pathway. These systems inhibit the stimulatory beta-adrenergic contractile pathway. The liver insufficiency of cirrhosis is associated with defective synthesis or metabolism of several substances including proteins and lipids/lipoproteins. The protein defects including titin and collagen contribute to diastolic dysfunction. Other protein abnormalities such as a switch of myosin heavy chain isoforms result in systolic dysfunction. Lipid biochemical changes at the cardiac sarcolemmal plasma membrane result in increased cholesterol:phospholipid ratio and decreased membrane fluidity. Final common pathway changes involve abnormal cardiomyocyte intracellular ion kinetics, particularly calcium. In conclusion, cirrhotic cardiomyopathy is caused by two pathways of cellular and molecular dysfunction/damage due to hepatic insufficiency and portal hypertension.

The Role of Bile Acids in Cardiovascular Diseases: from Mechanisms to Clinical Implications

Bile acids (BAs), key regulators in the metabolic network, are not only involved in lipid digestion and absorption but also serve as potential therapeutic targets for metabolic disorders. Studies have shown that cardiac dysfunction is associated with abnormal BA metabolic pathways. As ligands for several nuclear receptors and membrane receptors, BAs systematically regulate the homeostasis of metabolism and participate in cardiovascular diseases (CVDs), such as myocardial infarction, diabetic cardiomyopathy, atherosclerosis, arrhythmia, and heart failure. However, the molecular mechanism by which BAs trigger CVDs remains controversial. Therefore, the regulation of BA signal transduction by modulating the synthesis and composition of BAs is an interesting and novel direction for potential therapies for CVDs. Here, we mainly summarized the metabolism of BAs and their role in cardiomyocytes and noncardiomyocytes in CVDs. Moreover, we comprehensively discussed the clinical prospects of BAs in CVDs and analyzed the clinical diagnostic and application value of BAs. The latest development prospects of BAs in the field of new drug development are also prospected. We aimed to elucidate the underlying mechanism of BAs treatment in CVDs, and the relationship between BAs and CVDs may provide new avenues for the prevention and treatment of these diseases.

Alpha-1 Antitrypsin Z Variant (AAT PI*Z) as a Risk Factor for Intrahepatic Cholestasis of Pregnancy

Background: Intrahepatic cholestasis of pregnancy (ICP; prevalence 0.2–15.6%) is the most common pregnancy-related liver disorder. It may have serious consequences for a pregnancy, including increased risk of preterm delivery, meconium staining of amniotic fluid, fetal bradycardia, distress, and fetal demise. In cases of high bile acids (>100μmol/L), patients have 10-fold increase in the risk of stillbirth. Biophysical methods of fetal monitoring, such as cardiotocography, ultrasonography, or Doppler have been proven unreliable for risk prediction in the course of intrahepatic cholestasis. Therefore, we believe extensive research for more specific, especially early, markers should be carried out. By analogy with cholestasis in children with inherited alpha-1 antitrypsin deficiency (AATD), we hypothesized the SERPINA1 Z pathogenic variant might be related to a higher risk of cholestasis in pregnancy. This study aimed to investigate the most common AATD variants (Z and S SERPINA1 alleles) in a group of cholestatic pregnant women.

Results: The Z carrier frequency was calculated to be 6.8%, which is much higher compared to the general population [2.3%; the Chi-squared test with Yates correction is 6.8774 (p=0.008)].

Conclusion: Increased prevalence of SERPINA1 PI*Z variant in a group of women with intrahepatic cholestasis may suggest a possible genetic origin of a higher risk of intrahepatic cholestasis in pregnancy.

Ursodeoxycholic acid in intrahepatic cholestasis of pregnancy: a systematic review and individual participant data meta-analysis

BACKGROUND

Ursodeoxycholic acid is commonly used to treat intrahepatic cholestasis of pregnancy, yet its largest trial detected minimal benefit for a composite outcome (stillbirth, preterm birth, and neonatal unit admission). We aimed to examine whether ursodeoxycholic acid affects specific adverse perinatal outcomes.

METHODS

In this systematic review and individual participant data meta-analysis, we searched PubMed, Web of Science, Embase, MEDLINE, CINAHL, Global Health, MIDIRS, and Cochrane without language restrictions for relevant articles published between database inception, and Jan 1, 2020, using search terms referencing intrahepatic cholestasis of pregnancy, ursodeoxycholic acid, and perinatal outcomes. Eligible studies had 30 or more study participants and reported on at least one individual with intrahepatic cholestasis of pregnancy and bile acid concentrations of 40 μmol/L or more. We also included two unpublished cohort studies. Individual participant data were collected from the authors of selected studies. The primary outcome was the prevalence of stillbirth, for which we anticipated there would be insufficient data to achieve statistical power. Therefore, we included a composite of stillbirth and preterm birth as a main secondary outcome. A mixed-effects meta-analysis was done using multi-level modelling and adjusting for bile acid concentration, parity, and multifetal pregnancy. Individual participant data analyses were done for all studies and in different subgroups, which were produced by limiting analyses to randomised controlled trials only, singleton pregnancies only, or two-arm studies only. This study is registered with PROSPERO, CRD42019131495.

FINDINGS

The authors of the 85 studies fulfilling our inclusion criteria were contacted. Individual participant data from 6974 women in 34 studies were included in the meta-analysis, of whom 4726 (67·8%) took ursodeoxycholic acid. Stillbirth occurred in 35 (0·7%) of 5097 fetuses among women with intrahepatic cholestasis of pregnancy treated with ursodeoxycholic acid and in 12 (0·6%) of 2038 fetuses among women with intrahepatic cholestasis of pregnancy not treated with ursodeoxycholic acid (adjusted odds ratio [aOR] 1·04, 95% CI 0·35-3·07; p=0·95). Ursodeoxycholic acid treatment also had no effect on the prevalence of stillbirth when considering only randomised controlled trials (aOR 0·29, 95% CI 0·04-2·42; p=0·25). Ursodeoxycholic acid treatment had no effect on the prevalence of the composite outcome in all studies (aOR 1·28, 95% CI 0·86-1·91; p=0·22), but was associated with a reduced composite outcome when considering only randomised controlled trials (0·60, 0·39-0·91; p=0·016).

INTERPRETATION

Ursodeoxycholic acid treatment had no significant effect on the prevalence of stillbirth in women with intrahepatic cholestasis of pregnancy, but our analysis was probably limited by the low overall event rate. However, when considering only randomised controlled trials, ursodeoxycholic acid was associated with a reduction in stillbirth in combination with preterm birth, providing evidence for the clinical benefit of antenatal ursodeoxycholic acid treatment.

FUNDING

Tommy's, the Wellcome Trust, ICP Support, and the National Institute for Health Research.

Left atrial fibrosis progression detected by LGE-MRI after ablation of atrial fibrillation

BACKGROUND

Left atrial (LA) fibrosis is thought to be a substrate for atrial fibrillation (AF) and can be quantified by late gadolinium enhancement magnetic resonance imaging (LGE-MRI). Fibrosis formation in LA is a dynamic process and may either progress or regress following AF ablation. We examined the impact of postablation progression in LA fibrosis on AF recurrence.

METHODS

LA enhancement in LGE-MRI was quantified in 127 consecutive patients who underwent first time AF ablation. Serial LGE-MRIs were done prior to AF ablation, 3 months postablation and at least 12 months after second LGE-MRI. Transient postablation lesion (TL) was defined as atrial enhancement caused by ablation lesions that was detected on the first (3 month) but not on the second postablation LGE-MRI. New fibrosis (NF) was defined as atrial enhancement detected on the most recent LGE-MRI, at least 15 months after the ablation procedure. AF recurrence and its correlation with TL and NF was assessed in all patients during the follow-up period.

RESULTS

An increase of 1% NF increased the chance of postablation AF recurrence by 3% (hazard ratio [HR] 1.03, 95% CI 1-1.06, P = .05). TL had no significant impact on recurrence (P = .057). After adjusting for cardiovascular risk factors, HR increased as NF became greater. Greater volume of NF (≥21%) corresponded with lower arrhythmia-free survival (37% vs 62%, P = .01).

CONCLUSION

NF formation postablation of AF is a novel marker of long-term procedural outcome. Extensive NF is associated with significantly higher risk of atrial arrhythmia recurrence.

Fetal cardiac dysfunction in intrahepatic cholestasis of pregnancy is associated with elevated serum bile acid concentrations

BACKGROUND & AIMS

Intrahepatic cholestasis of pregnancy (ICP) is associated with an increased risk of stillbirth. This study aimed to assess the relationship between bile acid concentrations and fetal cardiac dysfunction in patients with ICP who were or were not treated with ursodeoxycholic acid (UDCA).

METHODS

Bile acid profiles and NT-proBNP, a marker of ventricular dysfunction, were assayed in umbilical venous serum from 15 controls and 76 ICP cases (36 untreated, 40 UDCA-treated). Fetal electrocardiogram traces were obtained from 43 controls and 48 ICP cases (26 untreated, 22 UDCA-treated). PR interval length and heart rate variability (HRV) parameters were measured in 2 behavioral states (quiet and active sleep).

RESULTS

In untreated ICP, fetal total serum bile acid (TSBA) concentrations (r = 0.49, p = 0.019), hydrophobicity index (r = 0.20, p = 0.039), glycocholate concentrations (r = 0.56, p = 0.007) and taurocholate concentrations (r = 0.44, p = 0.039) positively correlated with fetal NT-proBNP. Maternal TSBA (r = 0.40, p = 0.026) and alanine aminotransferase (r = 0.40, p = 0.046) also positively correlated with fetal NT-proBNP. There were no significant correlations between maternal or fetal serum bile acid concentrations and fetal HRV parameters or NT-proBNP concentrations in the UDCA-treated cohort. Fetal PR interval length positively correlated with maternal TSBA in untreated (r = 0.46, p = 0.027) and UDCA-treated ICP (r = 0.54, p = 0.026). Measures of HRV in active sleep and quiet sleep were significantly higher in untreated ICP cases than controls. HRV values in UDCA-treated cases did not differ from controls.

CONCLUSIONS

Elevated fetal and maternal serum bile acid concentrations in untreated ICP are associated with an abnormal fetal cardiac phenotype characterized by increased NT-proBNP concentration, PR interval length and HRV. UDCA treatment partially attenuates this phenotype.

LAY SUMMARY

The risk of stillbirth in intrahepatic cholestasis of pregnancy (ICP) is linked to the level of bile acids in the mother which are thought to disrupt the baby's heart rhythm. We found that babies of women with untreated ICP have abnormally functioning hearts compared to those without ICP, and the degree of abnormality is closely linked to the level of harmful bile acids in the mother and baby's blood. Babies of women with ICP who received treatment with the drug UDCA do not have the same level of abnormality in their hearts, suggesting that UDCA could be a beneficial treatment in some ICP cases, although further clinical trials are needed to confirm this.

Overview of bile acid signaling in the cardiovascular system

Bile acids (BAs) are classically known to play a vital role in the metabolism of lipids and in absorption. It is now well established that BAs act as signaling molecules, activating different receptors (such as farnesoid X receptor, vitamin D receptor, Takeda G-protein-coupled receptor 5, sphingosine-1-phosphate, muscarinic receptors, and big potassium channels) and participating in the regulation of energy homeostasis and lipid and glucose metabolism. In addition, increased BAs can impair cardiovascular function in liver cirrhosis. Approximately 50% of patients with cirrhosis develop cirrhotic cardiomyopathy. Exposure to high concentrations of hydrophobic BAs has been shown to be related to adverse effects with respect to vascular tension, endothelial function, arrhythmias, coronary atherosclerotic heart disease, and heart failure. The BAs in the serum BA pool have relevant through their hydrophobicity, and the lipophilic BAs are more harmful to the heart. Interestingly, ursodeoxycholic acid is a hydrophilic BA, and it is used as a therapeutic drug to reverse and protect the harmful cardiac effects caused by hydrophobic elevated BAs. In order to elucidate the mechanism of BAs and cardiovascular function, abundant experiments have been conducted in vitro and in vivo. The aim of this review was to explore the mechanism of BAs in the cardiovascular system.

Prolonged ursodeoxycholic acid administration reduces acute ischaemia-induced arrhythmias in adult rat hearts

Acute myocardial ischaemia and reperfusion (I-R) are major causes of ventricular arrhythmias in patients with a history of coronary artery disease. Ursodeoxycholic acid (UDCA) has previously been shown to be antiarrhythmic in fetal hearts. This study was performed to investigate if UDCA protects against ischaemia-induced and reperfusion-induced arrhythmias in the adult myocardium, and compares the effect of acute (perfusion only) versus prolonged (2 weeks pre-treatment plus perfusion) UDCA administration. Langendorff-perfused adult Sprague-Dawley rat hearts were subjected to acute regional ischaemia by ligation of the left anterior descending artery (10 min), followed by reperfusion (2 min), and arrhythmia incidence quantified. Prolonged UDCA administration reduced the incidence of acute ischaemia-induced arrhythmias (p = 0.028), with a reduction in number of ventricular ectopic beats during the ischaemic phase compared with acute treatment (10 ± 3 vs 58 ± 15, p = 0.036). No antiarrhythmic effect was observed in the acute UDCA administration group. Neither acute nor prolonged UDCA treatment altered the incidence of reperfusion arrhythmias. The antiarrhythmic effect of UDCA may be partially mediated by an increase in cardiac wavelength, due to the attenuation of conduction velocity slowing (p = 0.03), and the preservation of Connexin43 phosphorylation during acute ischaemia (p = 0.0027). The potential antiarrhythmic effects of prolonged UDCA administration merit further investigation.

Enzymatic quantification of total serum bile acids as a monitoring strategy for women with intrahepatic cholestasis of pregnancy receiving ursodeoxycholic acid treatment: a cohort study

OBJECTIVE

To evaluate enzymatic total serum bile acid quantification as a monitoring strategy for women with intrahepatic cholestasis of pregnancy (ICP) treated with ursodeoxycholic acid (UDCA).

DESIGN

Cohort.

SETTING

One UK university hospital.

POPULATION

29 ICP cases treated with UDCA.

METHODS

Serial samples were collected prospectively throughout gestation. Total serum bile acids were measured enzymatically and individual bile acids by high-performance liquid chromatography-tandem mass spectrometry. Data were log-transformed and analysed with random effects generalised least square regression.

MAIN OUTCOME MEASURES

The relationship between enzymatic total bile acid measurements and individual bile acid concentrations after UDCA treatment.

RESULTS

In untreated women, cholic acid was the principal bile acid (51%) and UDCA concentrations were <0.5%, whereas UDCA constituted 60% (IQR 43-69) of serum bile acids following treatment and cholic acid fell to <20%. Changes in the total bile acid measurement reflected similar alterations in the concentrations of the pathologically elevated bile acids, e.g. a two-fold increase in enzymatic total bile acids is accompanied by approximately a two-fold increase in cholic acid and chenodeoxycholic acid at most UDCA doses (P < 0.001). Most of the effects of UDCA on cholic acid occur in the first week of treatment (60% relative reduction, P = 0.025, 95% CI 0.2-0.9, from 10 micromol/l (4.7-17.6) to 3.5 micromol/l (1.4-7.5).

CONCLUSION

Ursodeoxycholic acid becomes the main component of the bile acid measurement after treatment. Enzymatic total bile acid assays are good predictors of both cholic acid and chenodeoxycholic acid, the primary bile acids that are raised prior to treatment.

TWEETABLE ABSTRACT

Ursodeoxycholic acid constitutes approximately 60% of the bile acid measurement and reduces pathological cholic acid in treated women.

Ursodeoxycholic acid inhibits uptake and vasoconstrictor effects of taurocholate in human placenta

Intrahepatic cholestasis of pregnancy (ICP) causes increased transfer of maternal bile acids to the fetus and an increased incidence of sudden fetal death. Treatment includes ursodeoxycholic acid (UDCA), but it is not clear if UDCA protects the fetus. This study explores the placental transport of the bile acid taurocholate (TC) by the organic anion-transporting polypeptide, (OATP)4A1, its effects on the placental proteome and vascular function, and how these are modified by UDCA. Various methodological approaches including placental villous fragments and Xenopus laevis oocytes were used to investigate UDCA transport. Placental perfusions and myography investigated the effect of TC on vasculature. The effects of acute TC exposure on placental tissue were investigated using quantitative proteomics. UDCA inhibited OATP4A1 activity in placental villous fragments and oocytes. TC induced vasoconstriction in placental and rat vasculature, which was attenuated by UDCA. Quantitative proteomic analysis of villous fragments showed direct effects of TC on multiple placental pathways, including oxidative stress and autophagy. The effects of TC on the placental proteome and vasculature demonstrate how bile acids may cause fetal distress in ICP. UDCA inhibition of OATP4A1 suggests it will protect the mother and fetus against the vascular effects of TC by inhibiting its cellular uptake. UDCA may protect the fetus in ICP by inhibiting OATP4A1-mediated bile acid transfer and TC-induced placental vasoconstriction. Understanding the physiologic mechanisms of UDCA may allow better therapeutic interventions to be designed specifically for the fetus in the future.-Lofthouse, E. M., Torrens, C., Manousopoulou, A., Nahar, M., Cleal, J. K., O'Kelly, I. M., Sengers, B. G., Garbis, S. D., Lewis, R. M. Ursodeoxycholic acid inhibits uptake and vasoconstrictor effects of taurocholate in human placenta.

TGR5 activation ameliorates hyperglycemia-induced cardiac hypertrophy in H9c2 cells

Left ventricular hypertrophy is an independent risk factor in diabetic patients. TGR5 is shown to express in hearts, but its functional role in diabetes-induced cardiac hypertrophy remained unclear. The current study investigated the role of TGR5 on high glucose-induced hypertrophy of H9C2 cells. After incubation with a high level of glucose, H9C2 cells showed hypertrophic responses. Activation of TGR5 by lithocholic acid (LCA) ameliorated cell hypertrophy and enhanced SERCA2a and phosphorylated phospholamban (PLN) expression in H9C2 cells. Triamterene inhibited these effects at an effective dose to block TGR5. However, LCA failed to modify the free radical elevation induced by high-glucose in the H9c2 cells. Moreover, PKA inhibitors, but not an Epac blocker, markedly improved hyperglycemia-induced hypertrophy and attenuated the increased SERCA2a expression by LCA; it also attenuated the phosphorylated PLN and SERCA2a protein expression levels in high glucose-treated H9C2 cells. In conclusion, TGR5 activation stimulated protein kinase A (PKA) to enhance PLN phosphorylation, which activated SERCA2a to remove Ca²⁺ from cytosol to sarcoplasmic reticulum in addition to the reduction of calcineurin/NFAT pathway signaling to ameliorate the hyperglycemia-induced cardiac hypertrophy shown in cardiomyocytes. TGR5 may service as a new target in the control of diabetic cardiomyopathy.

Biliary transporter gene mutations in severe intrahepatic cholestasis of pregnancy: Diagnostic and management implications

BACKGROUND AND AIMS

Clinical syndromes associated with biallelic mutations of bile acid (BA) transporters usually present in childhood. Subtle mutations may underlie intrahepatic cholestasis of pregnancy (ICP) and oral contraceptive steroid (OCS) induced cholestasis. In five women with identified genetic mutations of such transporters, with eight observed pregnancies complicated by ICP, we examined relationships between transporter mutations, clinical phenotypes, and treatment outcomes.

METHODS

Gene mutation analysis for BA transporter deficiencies was performed using Next Generation/Sanger sequencing, with analysis for gene deletions/duplications.

RESULTS

Intrahepatic cholestasis of pregnancy was early-onset (9-32 weeks gestation) and severe (peak BA 74-370 μmol/L), with premature delivery (28⁺¹ -37⁰ weeks gestation) in 7/8 pregnancies, in utero passage of meconium in 4/8, but overall good perinatal outcomes, with no stillbirths. There was generally no response to ursodeoxycholic acid and variable responses to rifampicin and chelation therapies; naso-biliary drainage appeared effective in 2/2 episodes persisting post-partum in each of the two sisters. Episodic jaundice occurring spontaneously or provoked by non-specific infections, and OCS-induced cholestasis, had previously occurred in 3/5 women. Two cases showed biallelic heterozygosity for several ABCB11 mutations, one was homozygous for an ABCB4 mutation and a fourth case was heterozygous for another ABCB4 mutation.

CONCLUSIONS

Early-onset or recurrent ICP, especially with previous spontaneous or OCS-induced episodes of cholestasis and/or familial cholestasis, may be attributable to transporter mutations, including biallelic mutations of one or more transporters. Response to standard therapies for ICP is often incomplete; BA sequestering therapy or naso-biliary drainage may be effective. Optimized management can produce good outcomes despite premature birth and evidence of fetal compromise.

Overview of Bile Acids Signaling and Perspective on the Signal of Ursodeoxycholic Acid, the Most Hydrophilic Bile Acid, in the Heart

Bile acids (BA) are classically known as an important agent in lipid absorption and cholesterol metabolism. Nowadays, their role in glucose regulation and energy homeostasis are widely reported. BAs are involved in various cellular signaling pathways, such as protein kinase cascades, cyclic AMP (cAMP) synthesis, and calcium mobilization. They are ligands for several nuclear hormone receptors, including farnesoid X-receptor (FXR). Recently, BAs have been shown to bind to muscarinic receptor and Takeda G-protein-coupled receptor 5 (TGR5), both G-protein-coupled receptor (GPCR), independent of the nuclear hormone receptors. Moreover, BA signals have also been elucidated in other nonclassical BA pathways, such as sphingosine-1-posphate and BK (large conductance calcium- and voltage activated potassium) channels. Hydrophobic BAs have been proven to affect heart rate and its contraction. Elevated BAs are associated with arrhythmias in adults and fetal heart, and altered ratios of primary and secondary bile acid are reported in chronic heart failure patients. Meanwhile, in patients with liver cirrhosis, cardiac dysfunction has been strongly linked to the increase in serum bile acid concentrations. In contrast, the most hydrophilic BA, known as ursodeoxycholic acid (UDCA), has been found to be beneficial in improving peripheral blood flow in chronic heart failure patients and in protecting the heart against reperfusion injury. This review provides an overview of BA signaling, with the main emphasis on past and present perspectives on UDCA signals in the heart.

Waveform analysis of the fetal ECG in labor in patients with intrahepatic cholestasis of pregnancy

AIM

Intrahepatic cholestasis of pregnancy (ICP) is reported to be associated with an increased risk of sudden fetal death. The possible mechanism is thought to be cardiac arrhythmia. Prolonged QT interval of the electrocardiogram (ECG) is associated with arrhytmogenic events. The aim of the study was to compare the fetal ECG QT interval during labor in pregnancies complicated with ICP to healthy controls.

METHODS

The fetal ECG and QT interval was reviewed retrospectively. The intrapartum QT interval was measured in 61 fetuses born to mothers with ICP and in a control group of similar size. The corrected QT interval (QTc) was calculated using Bazett's formula: QT/√RR. The occurrence of ST segment depression was also included in the analysis.

RESULTS

The groups were similar regarding to maternal age, parity, BMI, gestational age and smoking habits. The rate of labor induction was significantly higher in ICP patients (P < 0.001). The QTc at the beginning and the end of recording was analyzed and there were no significant differences in these values between the ICP patients and healthy controls (P = 0.467). Most ICP patients used ursodeoxycholic acid (UDCA) for mediation. We analyzed separately patients who had elevated liver enzymes before labor. No significant differences in the QTc were noted in these patients either. Nor were there any significant ST depressions in ICP patients.

CONCLUSIONS

The etiology of adverse perinatal outcome and even sudden fetal death in ICP is still controversial. No differences in QTc intervals and ST waveforms during labor were found in our study material.

Bile acids and their respective conjugates elicit different responses in neonatal cardiomyocytes: role of Gi protein, muscarinic receptors and TGR5

Bile acids are recognised as bioactive signalling molecules. While they are known to influence arrhythmia susceptibility in cholestasis, there is limited knowledge about the underlying mechanisms. To delineate mechanisms underlying fetal heart rhythm disturbances in cholestatic pregnancy, we used FRET microscopy to monitor cAMP release and contraction measurements in isolated rodent neonatal cardiomyocytes. The unconjugated bile acids CDCA, DCA and UDCA and, to a lesser extent, CA were found to be relatively potent agonists for the GPBAR1 (TGR5) receptor and elicit cAMP release, whereas all glyco- and tauro- conjugated bile acids are weak agonists. The bile acid-induced cAMP production does not lead to an increase in contraction rate, and seems to be mediated by the RI isoform of adenylate cyclase, unlike adrenaline-dependent release which is mediated by the RII isoform. In contrast, bile acids elicited slowing of neonatal cardiomyocyte contraction indicating that other signalling pathways are involved. The conjugated bile acids were found to be partial agonists of the muscarinic M_2, but not sphingosin-1-phosphate-2, receptors, and act partially through the G_i pathway. Furthermore, the contraction slowing effect of unconjugated bile acids may also relate to cytotoxicity at higher concentrations.

Heart and bile acids - Clinical consequences of altered bile acid metabolism

Cardiac dysfunction has an increased prevalence in diseases complicated by liver cirrhosis such as primary biliary cholangitis and primary sclerosing cholangitis. This observation has led to research into the association between abnormalities in bile acid metabolism and cardiac pathology. Approximately 50% of liver cirrhosis cases develop cirrhotic cardiomyopathy. Bile acids are directly implicated in this, causing QT interval prolongation, cardiac hypertrophy, cardiomyocyte apoptosis and abnormal haemodynamics of the heart. Elevated maternal serum bile acids in intrahepatic cholestasis of pregnancy, a disorder which causes an impaired feto-maternal bile acid gradient, have been associated with fatal fetal arrhythmias. The hydrophobicity of individual bile acids in the serum bile acid pool is of relevance, with relatively lipophilic bile acids having a more harmful effect on the heart. Ursodeoxycholic acid can reverse or protect against these detrimental cardiac effects of elevated bile acids.

Ursodeoxycholic acid protects cardiomyocytes against cobalt chloride induced hypoxia by regulating transcriptional mediator of cells stress hypoxia inducible factor 1α and p53 protein

In hepatocytes, ursodeoxycholic acid (UDCA) activates cell signalling pathways such as p53, intracellular calcium ([Ca²⁺ ]_i ), and sphingosine-1-phosphate (S1P)-receptor via Gα_i -coupled-receptor. Recently, UDCA has been shown to protect the heart against hypoxia-reoxygenation injury. However, it is not clear whether UDCA cardioprotection against hypoxia acts through a transcriptional mediator of cells stress, HIF-1α and p53. Therefore, in here, we aimed to investigate whether UDCA could protect cardiomyocytes (CMs) against hypoxia by regulating expression of HIF-1α, p53, [Ca²⁺ ]_i , and S1P-Gα_i -coupled-receptor. Cardiomyocytes were isolated from newborn rats (0-2 days), and hypoxia was induced by using cobalt chloride (CoCl₂ ). Cardiomyocytes were treated with UDCA and cotreated with either FTY720 (S1P-receptor agonist) or pertussis toxin (PTX; Gα_i inhibitor). Cells were subjected for proliferation assay, beating frequency, QuantiGene Plex assay, western blot, immunofluorescence, and calcium imaging. Our findings showed that UDCA counteracted the effects of CoCl₂ on cell viability, beating frequency, HIF-1α, and p53 protein expression. We found that these cardioprotection effects of UDCA were similar to FTY720, S1P agonist. Furthermore, we observed that UDCA protects CMs against CoCl₂ -induced [Ca²⁺ ]_i dynamic alteration. Pharmacological inhibition of the Gα_i -sensitive receptor did not abolish the cardioprotection of UDCA against CoCl₂ detrimental effects, except for cell viability and [Ca²⁺ ]_i . Pertussis toxin is partially effective in inhibiting UDCA protection against CoCl₂ effects on CM cell viability. Interestingly, PTX fully inhibits UDCA cardioprotection on CoCl₂ -induced [Ca²⁺ ]_i dynamic changes. We conclude that UDCA cardioprotection against CoCl₂ -induced hypoxia is similar to FTY720, and its actions are not fully mediated by the Gα_i -coupled protein sensitive pathways. Ursodeoxycholic acid is the most hydrophilic bile acid and is currently used to treat liver diseases. Recently, UDCA is shown to have a cardioprotection effects; however, the mechanism of UDCA cardioprotection is still poorly understood. The current data generated were the first to show that UDCA is able to inhibit the activation of HIF-1α and p53 protein during CoCl₂ -induced hypoxia in cardiomyocytes. This study provides an insight of UDCA mechanism in protecting cardiomyocytes against hypoxia.

Bile acids and cardiovascular function in cirrhosis

Cirrhotic cardiomyopathy and the hyperdynamic syndrome are clinically important complications of cirrhosis, but their exact pathogenesis is still partly unknown. Experimental models have proven the cardiotoxic effects of bile acids and recent studies of their varied receptor-mediated functions offer new insight into their involvement in cardiovascular dysfunction in cirrhosis. Bile acid receptors such as farnesoid X-activated receptor and TGR5 are currently under investigation as potential therapeutic targets in a variety of pathological conditions. These receptors have also recently been identified in cardiomyocytes, vascular endothelial cells and smooth muscle cells where they seem to play an important role in cellular metabolism. Chronic cholestasis leading to abnormal levels of circulating bile acids alters the normal signalling pathways and contributes to the development of profound cardiovascular disturbances. This review summarizes the evidence regarding the role of bile acids and their receptors in the generation of cardiovascular dysfunction in cirrhosis.

Ursodeoxycholic acid prevents ventricular conduction slowing and arrhythmia by restoring T-type calcium current in fetuses during cholestasis

Background

Increased maternal serum bile acid concentrations in intrahepatic cholestasis of pregnancy (ICP) are associated with fetal cardiac arrhythmias. Ursodeoxycholic acid (UDCA) has been shown to demonstrate anti-arrhythmic properties via preventing ICP-associated cardiac conduction slowing and development of reentrant arrhythmias, although the cellular mechanism is still being elucidated.

Methods

High-resolution fluorescent optical mapping of electrical activity and electrocardiogram measurements were used to characterize effects of UDCA on one-day-old neonatal and adult female Langendorff-perfused rat hearts. ICP was modelled by perfusion of taurocholic acid (TC, 400μM). Whole-cell calcium currents were recorded from neonatal rat and human fetal cardiomyocytes.

Results

TC significantly prolonged the PR interval by 11.0±3.5% (P<0.05) and slowed ventricular conduction velocity (CV) by 38.9±5.1% (P<0.05) exclusively in neonatal and not in maternal hearts. A similar CV decline was observed with the selective T-type calcium current (I_Ca,T) blocker mibefradil 1μM (23.0±6.2%, P<0.05), but not with the L-type calcium current (I_Ca,L) blocker nifedipine 1μM (6.9±6.6%, NS). The sodium channel blocker lidocaine (30μM) reduced CV by 60.4±4.5% (P<0.05). UDCA co-treatment was protective against CV slowing induced by TC and mibefradil, but not against lidocaine. UDCA prevented the TC-induced reduction in the I_Ca,T density in both isolated human fetal (−10.2±1.5 versus −5.5±0.9 pA/pF, P<0.05) and neonatal rat ventricular myocytes (−22.3±1.1 versus −9.6±0.8 pA/pF, P<0.0001), whereas UDCA had limited efficacy on the I_Ca,L.

Conclusion

Our findings demonstrate that I_Ca,T plays a significant role in ICP-associated fetal cardiac conduction slowing and arrhythmogenesis, and is an important component of the fetus-specific anti-arrhythmic activity of UDCA.

Bile acids and gestation

There are numerous profound maternal physiological changes that occur from conception onwards and adapt throughout gestation in order to support a healthy pregnancy. By the time of late gestation, when circulating pregnancy hormones are at their highest concentrations, maternal adaptations include relative hyperlipidemia, hypercholanemia and insulin resistance. Bile acids have now been established as key regulators of metabolism, and their role in gestational changes in metabolism is becoming apparent. Bile acid homeostasis is tightly regulated by the nuclear receptor FXR, which has been shown to have reduced activity during pregnancy. This review focuses on the gestational alterations in bile acid homeostasis that occur in normal pregnancy, which in some women can become pathological, leading to the development of intrahepatic cholestasis of pregnancy. As well as their important role in maternal metabolic health, we will review bile acid metabolism in the feto-placental unit.

Intrahepatic Cholestasis of Pregnancy in Women With Twin Pregnancy

The aim of the present work was to determine maternal and fetal outcomes of intrahepatic cholestasis of pregnancy (ICP) in twin pregnancies. All twin pregnancies delivered above 28 gestational weeks in West China Second University Hospital from January 2013 to May 2015 were included. Data on maternal demographics and obstetric complications together with fetal outcomes were collected. The risk of adverse maternal and fetal outcomes were determined in relation to ICP by crude odds ratios (OR) and adjusted ORs (aOR) with 95% confidence intervals (CI). Subgroup analysis concentrated on the effect of assisted reproductive technology (ART), ICP severity, and onset time. A total of 1,472 twin pregnancies were included, of which 362 were cholestasis patients and 677 were conceived by ART. Higher rates of preeclampsia (aOR 1.96; 95% CI 1.35, 2.85), meconium-stained amniotic fluid (aOR 3.10; 95% CI 2.10, 4.61), and preterm deliveries (aOR 3.20; 95% CI 2.35, 4.37) were observed in ICP patients. Subgroup analysis revealed higher incidences of adverse outcomes in severe and early onset ICP groups. In conclusion, adverse maternal and fetal outcomes were strongly associated with ICP in twin patients. Active management and close antenatal monitoring are needed, especially in the early onset and severe groups.

Bile acids evoke placental inflammation by activating Gpbar1/NF-κB pathway in intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a cholestatic disorder with potentially deleterious consequences for fetuses. Although a clear correlation between the elevated levels of maternal serum bile acids and deficient fetal outcome has been established in clinical practice, the underlying mechanisms remain elusive. Herein, we report that bile acids induce NF-κB pathway activation via G protein-coupled bile acid receptor 1 (Gpbar1), with consequent upregulation of inflammatory genes in trophoblasts, leading to aberrant leukocyte infiltration and inflammation in placenta. Ursodeoxycholic acid (UDCA), a drug used clinically to treat ICP, competes with other bile acids for binding with Gpbar1 and thus inhibits bile acid-induced inflammatory response in trophoblasts and improves fetal survival in pregnant rats with obstructive cholestasis. Notably, inhibition of NF-κB by andrographolide is more effective than UDCA in benefiting placentas and fetuses. Thus, anti-inflammation therapy targeting Gpbar1/NF-κB pathway could be effective in suppressing bile acid-induced inflammation and alleviating ICP-associated fetal disorders.

Pregnancy and liver disease

Pregnancy associated liver diseases affect up to 3% of pregnant women and are the most frequent cause of liver dysfunction in pregnancy. When severe, they are associated with significant morbidity and mortality for both mother and infant. A rapid evaluation to distinguish them from non-pregnancy related liver dysfunction is essential, in order to facilitate appropriate management. Liver disease unrelated to pregnancy can present de novo in pregnancy, or pregnancy can occur in women with preexisting liver pathology (Table 1). Research and subsequent advances in medical care have resulted in improved but still not satisfactory maternal and fetal outcomes. In this review we provide an overview of the liver diseases specific to the pregnant state and an update on their pathogenesis, treatment and outcomes. The risks of pregnancy in women with pre-existent liver pathology is detailed and recent advances in our understanding of specific risks and outcomes are discussed.

The pathophysiology of intrahepatic cholestasis of pregnancy

A number of liver disorders are specific to pregnancy. Amongst these, intrahepatic cholestasis of pregnancy (ICP), also known as obstetric cholestasis (OC), is the commonest, affecting approximately 1 in 140 UK pregnancies. Patients commonly present in the third trimester with severe pruritus and deranged serum liver tests; bile acids are elevated, in severe cases >40 μmol/L. Although the disease is considered relatively benign for the mother, increased rates of adverse fetal outcomes, including stillbirth, are associated with ICP. As our knowledge of the mechanisms underlying bile acid homeostasis has advanced in the last 15 years our understanding of ICP has grown, in particular with respect to genetic influences on susceptibility to the disease, the role of reproductive hormones and their metabolites and the possible identity of the pruritic agents. In this review, we will describe recent advances in the understanding of this condition with a particular emphasis on how aspects of genetic and reproductive hormone involvement in pathophysiology have been elucidated. We also review recent developments regarding our knowledge of placental and fetal pathophysiology and the long-term health consequences for the mother and child.

The protective effect of ursodeoxycholic acid in an in vitro model of the human fetal heart occurs via targeting cardiac fibroblasts

Bile acids are elevated in the blood of women with intrahepatic cholestasis of pregnancy (ICP) and this may lead to fetal arrhythmia, fetal hypoxia and potentially fetal death in utero. The bile acid taurocholic acid (TC) causes abnormal calcium dynamics and contraction in neonatal rat cardiomyocytes. Ursodeoxycholic acid (UDCA), a drug clinically used to treat ICP, prevents adverse effects of TC. During development, the fetus is in a state of relative hypoxia. Although this is essential for the development of the heart and vasculature, resident fibroblasts can transiently differentiate into myofibroblasts and form gap junctions with cardiomyocytes in vitro, resulting in cardiomyocyte depolarization. We expanded on previously published work using an in vitro hypoxia model to investigate the differentiation of human fetal fibroblasts into myofibroblasts. Recent evidence shows that potassium channels are involved in maintaining the membrane potential of ventricular fibroblasts and that ATP-dependent potassium (KATP) channel subunits are expressed in cultured fibroblasts. KATP channels are a valuable target as they are thought to have a cardioprotective role during ischaemic and hypoxic conditions. We investigated whether UDCA could modulate fibroblast membrane potential. We established the isolation and culture of human fetal cardiomyocytes and fibroblasts to investigate the effect of hypoxia, TC and UDCA on human fetal cardiac cells. UDCA hyperpolarized myofibroblasts and prevented TC-induced depolarisation, possibly through the activation of KATP channels that are expressed in cultured fibroblasts. Also, similar to the rat model, UDCA can counteract TC-induced calcium abnormalities in human fetal cultures of cardiomyocytes and myofibroblasts. Under normoxic conditions, we found a higher number of myofibroblasts in cultures derived from human fetal hearts compared to cells isolated from neonatal rat hearts, indicating a possible increased number of myofibroblasts in human fetal hearts. Hypoxia further increased the number of human fetal and rat neonatal myofibroblasts. However, chronically administered UDCA reduced the number of myofibroblasts and prevented hypoxia-induced depolarisation. In conclusion, our results show that the protective effect of UDCA involves both the reduction of fibroblast differentiation into myofibroblasts, and hyperpolarisation of myofibroblasts, most likely through the stimulation of potassium channels, i.e. KATP channels. This could be important in validating UDCA as an antifibrotic and antiarrhythmic drug for treatment of failing hearts and fetal arrhythmia.

Immunological basis in the pathogenesis of intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy poses a great risk to both maternal and fetal health. Despite extensive research, much of the pathogenesis of this disorder is unknown. The increase in bile acids observed in patients with intrahepatic cholestasis of pregnancy has been noted to cause a change in the immune system from the normally mediated TH2 response to one that is more oriented towards TH1. In this literature review, we have critically reviewed the current literature regarding the changes in the immune system and the potential effects of immunological changes in the management of the patient. The current treatment, ursodeoxycholic acid, is also discussed along with potential combination therapies and future directions for research.

Perinatal outcomes with intrahepatic cholestasis of pregnancy in twin pregnancies

OBJECTIVE

To describe perinatal outcomes of twin pregnancies complicated by intrahepatic cholestasis of pregnancy (ICP).

METHODS

We conducted a retrospective cohort study of women delivered at a large tertiary obstetric center in Shanghai, China from January 2006 to May 2014. Delivery data were abstracted from medical records of all twin gestations delivered at the hospital.

RESULTS

A total of 129/1922(6.7%) twin and 1190/92 273 singleton (1.3%) pregnancies were complicated by ICP. An increased risk of stillbirth among twin pregnancies was observed (3.9% and 0.8% in the ICP and non-ICP groups, respectively; aOR 5.75, 95% CI 2.00-16.6). Stillbirths with ICP and twins occurred between 33 and 35 weeks gestation compared to 36-38 weeks gestation among singletons. ICP in twins was also associated with an increased risk of preterm birth (<37 weeks) with an aOR of 4.17 (95% CI 2.47-7.04) and an aOR of 1.89 (95% CI 1.26-2.85) for delivery <35 weeks. Twin pregnancies complicated by ICP also had increased meconium staining of amniotic fluid and lower birth weight.

CONCLUSIONS

Twin pregnancies with ICP have significantly increased risks of adverse perinatal outcomes including stillbirth and preterm birth. Stillbirth occurs at an earlier gestational age in twin gestation compared to singletons, suggesting that earlier scheduled delivery should be considered in these women.

Acetylation mediates Cx43 reduction caused by electrical stimulation

Communication between cardiomyocytes depends upon gap junctions (GJ). Previous studies have demonstrated that electrical stimulation induces GJ remodeling and modifies histone acetylase (HAT) and deacetylase (HDAC) activities, although these two results have not been linked. The aim of this work was to establish whether electrical stimulation modulates GJ-mediated cardiac cell-cell communication by acetylation-dependent mechanisms. Field stimulation of HL-1 cardiomyocytes at 0.5 Hz for 24 h significantly reduced connexin43 (Cx43) expression and cell-cell communication. HDAC activity was down-regulated whereas HAT activity was not modified resulting in increased acetylation of Cx43. Consistent with a post-translational mechanism, we did not observe a reduction in Cx43 mRNA in electrically stimulated cells, while the proteasomal inhibitor MG132 maintained Cx43 expression. Further, the treatment of paced cells with the HAT inhibitor Anacardic Acid maintained both the levels of Cx43 and cell-cell communication. Finally, we observed increased acetylation of Cx43 in the left ventricles of dogs subjected to chronic tachypacing as a model of abnormal ventricular activation. In conclusion, our findings suggest that altered electrical activity can regulate cardiomyocyte communication by influencing the acetylation status of Cx43.

Past, present and perspectives of Manipur traditional medicine: A major health care system available for rural population in the North-East India

BACKGROUND

Traditional health care practices are still being followed extensively in Manipur, North-East India. This is the major or the only medical facility available in some rural areas of Manipur. Cross cultural ethno-pharmacological survey was conducted to document traditional health care practices by Maiba-Maibi (male-female traditional health care practitioners of Manipur).

MATERIALS AND METHODS

All together 59 traditional practitioners belonging to 12 ethnic communities in nine districts of the Manipur state were interviewed. A predesigned questionnaire was used for interviews, which included queries for type of ailments treating, symptoms, bioresources used, method of preparation, dosage forms, formulation, unit doses. The entire interviews were done in the residence of respective Maiba-Maibi, their patient handing and preparation of medicinal formulations were documented in written and audio-visual format.

RESULTS

The survey recorded traditional knowledge on 949 formulations used for 66 human ailments. Five hundred forty six plant products, 42 animal products and 22 organic/inorganic materials were found to be used in these 949 formulations. Five plant species - Zingiber officinale (Zingiberaceae), Cocos nucifera (Arecaceae), Oroxylum indicum (Bignonaceae), Curcuma longa (Zingiberaceae) and Allium sativum (Liliaceae) used by maximum number of Maiba and Maibi in maximum number of formulations.

RECOMMENDATION

This particular method of documentation keeps traditional knowledge alive. The WHO estimated perspective of traditional medicine across the world. These observations support therapeutic worth of Manipur Traditional medicines (MTM). Having generated a large database in course of this survey, next focus targeted for the scientific justification of MTM with an aim to develop commercially viable products.

Atrial Fibrillation and Fibrosis: Beyond the Cardiomyocyte Centric View

Atrial fibrillation (AF) associated with fibrosis is characterized by the appearance of interstitial myofibroblasts. These cells are responsible for the uncontrolled deposition of the extracellular matrix, which pathologically separate cardiomyocyte bundles. The enhanced fibrosis is thought to contribute to arrhythmias “indirectly” because a collagenous septum is a passive substrate for propagation, resulting in impulse conduction block and/or zigzag conduction. However, the emerging results demonstrate that myofibroblasts in vitro also promote arrhythmogenesis due to direct implications upon cardiomyocyte electrophysiology. This electrical interference may be considered beneficial as it resolves any conduction blocks; however, the passive properties of myofibroblasts might cause a delay in impulse propagation, thus promoting AF due to discontinuous slow conduction. Moreover, low-polarized myofibroblasts reduce, via cell-density dependence, the fast driving inward current for cardiac impulse conduction, therefore resulting in arrhythmogenic uniformly slow propagation. Critically, the subsequent reduction in cardiomyocytes resting membrane potential in vitro significantly increases the likelihood of ectopic activity. Myofibroblast densities and the degree of coupling at cellular border zones also impact upon this likelihood. By considering future in vivo studies, which identify myofibroblasts “per se” as a novel targets for cardiac arrhythmias, this review aims to describe the implications of noncardiomyocyte view in the context of AF.