Bile acid excess induces cardiomyopathy and metabolic dysfunctions in the heart

Cardiac dysfunction in patients with cirrhosis and acute decompensation

The prevalence of cirrhotic cardiomyopathy (CCM) has been reported as high as 60%-70% in patients with liver cirrhosis and is associated with various negative outcomes. There has been a growing understanding of CCM over recent years. Indeed, the development of imaging techniques has enabled new diagnostic criteria to be proposed by the Cirrhotic Cardiomyopathy Consortium. However, important unanswered questions remain over pathophysiological mechanisms, optimal diagnostic modalities and potential treatment options. While there has been an increasing volume of literature evaluating CCM, there is a lack of clarity on its implications in acute decompensation, acute-on-chronic liver failure and following interventions such as transjugular intrahepatic portosystemic shunt insertion and liver transplantation. This review aims to summarise the literature in these challenging domains and suggest where future research should focus. We conclude that systemic inflammation and structural myocardial changes are likely to be crucial in the pathophysiology of the disease, but the relative contribution of different components remains elusive. Furthermore, future studies need to use standardised diagnostic criteria for CCM as well as incorporate newer imaging techniques assessing both myocardial structure and function. Finally, while specific treatments are currently lacking, therapeutics targeting systemic inflammation, microbial dysbiosis and bacterial translocation are promising targets and warrant further research.

Targeted next-generation sequencing panel to investigate antiplatelet adverse reactions in acute coronary syndrome patients undergoing percutaneous coronary intervention with stenting

Antiplatelet therapy, the gold standard of care for patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI), is one of the therapeutic approaches most associated with the development of adverse drug reactions (ADRs). Although numerous studies have shown that pharmacological intervention based on a limited number of high-evidence variants (primarily CYP2C19*2 and *3) can reduce the incidence of major adverse cardiovascular events (MACEs), ADRs still occur at variable rates (10.1 % in our case) despite personalized therapy. This study aimed to identify novel genetic variants associated with the endpoint of MACEs 12 months after PCI by designing and analyzing a targeted gene panel. We sequenced 244 ACS-PCI-stent patients (109 with event and 135 without event) and 99 controls without structural cardiovascular disease and performed an association analysis to search for unexpected genetic variants. No single nucleotide polymorphisms reached genomic significance after correction, but three novel variants, including ABCA1 (rs2472434), KLB (rs17618244), and ZNF335 (rs3827066), may play a role in MACEs in ACS patients. These genetic variants are involved in regulating high-density lipoprotein levels and cholesterol deposition, and as they are regulatory variants, they may affect the expression of nearby lipid metabolism-related genes. Our findings suggest new targets (both at the gene and pathway levels) that may increase susceptibility to MACEs, but further research is needed to clarify the role and impact of the identified variants before these findings can be incorporated into the therapeutic decision-making process.

Broadcasters, receivers, functional groups of metabolites, and the link to heart failure by revealing metabolomic network connectivity

BACKGROUND AND OBJECTIVE

Blood-based small molecule metabolites offer easy accessibility and hold significant potential for insights into health processes, the impact of lifestyle, and genetic variation on disease, enabling precise risk prevention. In a prospective study with records of heart failure (HF) incidence, we present metabolite profiling data from individuals without HF at baseline.

METHODS

We uncovered the interconnectivity of metabolites using data-driven and causal networks augmented with polygenic factors. Exploring the networks, we identified metabolite broadcasters, receivers, mediators, and subnetworks corresponding to functional classes of metabolites, and provided insights into the link between metabolomic architecture and regulation in health. We incorporated the network structure into the identification of metabolites associated with HF to control the effect of confounding metabolites.

RESULTS

We identified metabolites associated with higher and lower risk of HF incidence, such as glycine, ureidopropionic and glycocholic acids, and LPC 18:2. These associations were not confounded by the other metabolites due to uncovering the connectivity among metabolites and adjusting each association for the confounding metabolites. Examples of our findings include the direct influence of asparagine on glycine, both of which were inversely associated with HF. These two metabolites were influenced by polygenic factors and only essential amino acids, which are not synthesized in the human body and are obtained directly from the diet.

CONCLUSION

Metabolites may play a critical role in linking genetic background and lifestyle factors to HF incidence. Revealing the underlying connectivity of metabolites associated with HF strengthens the findings and facilitates studying complex conditions like HF.

Serum bile acid profiles are associated with heart failure with preserved ejection fraction in patients with metabolic dysfunction-associated fatty liver disease: An exploratory study

AIM

To analyse the association between serum bile acid (BA) profile and heart failure (HF) with preserved ejection fraction (HFpEF) in patients with metabolic dysfunction-associated fatty liver disease (MAFLD).

METHODS

We enrolled 163 individuals with biopsy-proven MAFLD undergoing transthoracic echocardiography for any indication. HFpEF was defined as left ventricular ejection fraction >50% with at least one echocardiographic feature of HF (left ventricular diastolic dysfunction, abnormal left atrial size) and at least one HF sign or symptom. Serum levels of 38 BAs were analysed using ultra-performance liquid chromatography coupled with tandem mass spectrometry.

RESULTS

Among the 163 patients enrolled (mean age 47.0 ± 12.8 years, 39.3% female), 52 (31.9%) and 43 (26.4%) met the HFpEF and pre-HFpEF criteria, and 38 serum BAs were detected. Serum ursodeoxycholic acid (UDCA) and hyocholic acid (HCA) species were lower in patients with HFpEF and achieved statistical significance after correction for multiple comparisons. Furthermore, decreases in glycoursodeoxycholic acid and tauroursodeoxycholic acid were associated with HF status.

CONCLUSIONS

In this exploratory study, specific UDCA and HCA species were associated with HFpEF status in adults with biopsy-confirmed MAFLD.

Bile Acids and Bilirubin Role in Oxidative Stress and Inflammation in Cardiovascular Diseases

Bile acids (BAs) and bilirubin, primarily known for their role in lipid metabolism and as heme catabolite, respectively, have been found to have diverse effects on various physiological processes, including oxidative stress and inflammation. Indeed, accumulating evidence showed that the interplay between BAs and bilirubin in these processes involves intricate regulatory mechanisms mediated by specific receptors and signaling pathways under certain conditions and in specific contexts. Oxidative stress plays a significant role in the development and progression of cardiovascular diseases (CVDs) due to its role in inflammation, endothelial dysfunction, hypertension, and other risk factors. In the cardiovascular (CV) system, recent studies have suggested that BAs and bilirubin have some opposite effects related to oxidative and inflammatory mechanisms, but this area of research is still under investigation. This review aims to introduce BAs and bilirubin from a biochemical and physiological point of view, emphasizing their potential protective or detrimental effects on CVDs. Moreover, clinical studies that have assessed the association between BAs/bilirubin and CVD were examined in depth to better interpret the possible link between them.

Coronary Microvascular Dysfunction in Acute Cholestasis-Induced Liver Injury

BACKGROUND

Previous studies have shown cardiac abnormalities in acute liver injury, suggesting a potential role in the associated high mortality.

METHODS

We designed an experimental study exploring the short-term effects of acute cholestasis-induced liver injury on cardiac function and structure in a rodent bile duct ligation (BDL) model to elucidate the potential interplay. Thirty-seven male Sprague-Dawley rats were subjected to BDL surgery (n = 28) or served as sham-operated (n = 9) controls. Transthoracic echocardiography, Doppler evaluation of the left anterior descending coronary artery, and myocardial contrast echocardiography were performed at rest and during adenosine and dobutamine stress 5 days after BDL. Immunohistochemical staining of myocardial tissue samples for hypoxia and inflammation as well as serum analysis were performed.

RESULTS

BDL animals exhibited acute liver injury with elevated transaminases, bilirubin, and total circulating bile acids (TBA) 5 days after BDL (TBA control: 0.81 ± 2.54 µmol/L vs. BDL: 127.52 ± 57.03 µmol/L; p < 0.001). Concurrently, cardiac function was significantly impaired, characterized by reduced cardiac output (CO) and global longitudinal strain (GLS) in the echocardiography at rest and under pharmacological stress (CO rest control: 120.6 ± 24.3 mL/min vs. BDL 102.5 ± 16.6 mL/min, p = 0.041; GLS rest control: -24.05 ± 3.8% vs. BDL: -18.5 ± 5.1%, p = 0.01). Myocardial perfusion analysis revealed a reduced myocardial blood flow at rest and a decreased coronary flow velocity reserve (CFVR) under dobutamine stress in the BDL animals (CFVR control: 2.1 ± 0.6 vs. BDL: 1.7 ± 0.5 p = 0.047). Immunofluorescence staining indicated myocardial hypoxia and increased neutrophil infiltration.

CONCLUSIONS

In summary, acute cholestasis-induced liver injury can lead to impaired cardiac function mediated by coronary microvascular dysfunction, suggesting that major adverse cardiac events may contribute to the mortality of acute liver failure. This may be due to endothelial dysfunction and direct bile acid signaling.

WITHDRAWN: Broadcasters, receivers, functional groups of metabolites and the link to heart failure using polygenic factors

The full text of this preprint has been withdrawn, as it was submitted in error. Therefore, the authors do not wish this work to be cited as a reference. Questions should be directed to the corresponding author.

WITHDRAWN: Broadcasters, receivers, functional groups of metabolites and the link to heart failure using polygenic factors

The full text of this preprint has been withdrawn, as it was submitted in error. Therefore, the authors do not wish this work to be cited as a reference. Questions should be directed to the corresponding author.

[Cirrhotic cardiomyopathy – Clinically fact or academic curiosity? Review: Part 1: definition, epidemiology, pathology and clinical manifestations]

Severe cirrhosis affecting myocardial function provokes a syndrome called Cirrhotic Cardiomyopathy, defined as cardiac disfunction associated with hepatic cirrhosis in the absence of other known cardiac disease. The prevalence is variable according different groups of investigation owing to the latent or subclinical course until a stressful situation unmask it such as surgery, hemorrhage, infection, hepatic transplant or transjugular intrahepatic porto-systemic shunt. We aimed to review the definition, pathology, pathophysiology, clinical manifestations, diagnostic criteria, images, clinical relevance, pharmacological treatment and hepatic transplantation.

Ginsenoside Rb1, Compound K and 20(S)-Protopanaxadiol Attenuate High-Fat Diet-Induced Hyperlipidemia in Rats via Modulation of Gut Microbiota and Bile Acid Metabolism

Hyperlipidemia, characterized by elevated serum lipid concentrations resulting from lipid metabolism dysfunction, represents a prevalent global health concern. Ginsenoside Rb1, compound K (CK), and 20(S)-protopanaxadiol (PPD), bioactive constituents derived from Panax ginseng, have shown promise in mitigating lipid metabolism disorders. However, the comparative efficacy and underlying mechanisms of these compounds in hyperlipidemia prevention remain inadequately explored. This study investigates the impact of ginsenoside Rb1, CK, and PPD supplementation on hyperlipidemia in rats induced by a high-fat diet. Our findings demonstrate that ginsenoside Rb1 significantly decreased body weight and body weight gain, ameliorated hepatic steatosis, and improved dyslipidemia in HFD-fed rats, outperforming CK and PPD. Moreover, ginsenoside Rb1, CK, and PPD distinctly modified gut microbiota composition and function. Ginsenoside Rb1 increased the relative abundance of Blautia and Eubacterium, while PPD elevated Akkermansia levels. Both CK and PPD increased Prevotella and Bacteroides, whereas Clostridium-sensu-stricto and Lactobacillus were reduced following treatment with all three compounds. Notably, only ginsenoside Rb1 enhanced lipid metabolism by modulating the PPARγ/ACC/FAS signaling pathway and promoting fatty acid β-oxidation. Additionally, all three ginsenosides markedly improved bile acid enterohepatic circulation via the FXR/CYP7A1 pathway, reducing hepatic and serum total bile acids and modulating bile acid pool composition by decreasing primary/unconjugated bile acids (CA, CDCA, and β-MCA) and increasing conjugated bile acids (TCDCA, GCDCA, GDCA, and TUDCA), correlated with gut microbiota changes. In conclusion, our results suggest that ginsenoside Rb1, CK, and PPD supplementation offer promising prebiotic interventions for managing HFD-induced hyperlipidemia in rats, with ginsenoside Rb1 demonstrating superior efficacy.

Cardiovascular diseases and the heart-gut cross talk

The purpose of this narrative review is to provide a comprehensive overview of current research on heart-gut cross talk and its implications for cardiovascular disease. To uncover relevant preclinical and clinical research examining heart-gut cross talk, a thorough literature search was undertaken utilising electronic databases. The chosen publications were critically examined, and major findings were synthesised to offer a thorough perspective on the subject. We want to synthesise the most recent study findings, explain the underlying mechanisms, and provide potential treatment techniques. By exploring bidirectional connection between the heart and the gut, we shed light on novel future options for the prevention and treatment of cardiovascular diseases. The heart-gut cross talk is an exciting field of study with implications for cardiovascular disease. Understanding the complex connection between the heart and the gastrointestinal tract may lead to the development of novel therapeutic targets and therapies for the prevention and management of cardiovascular diseases. Future research should concentrate on identifying the specific processes driving this crosstalk as well as assessing the efficacy of therapies targeting the gut microbiota and the gut-brain axis in improving cardiovascular outcomes.

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.

Cardiomyopathy in cirrhosis: From pathophysiology to clinical care

Cirrhotic cardiomyopathy (CCM) is defined as systolic or diastolic dysfunction in the absence of prior heart disease or another identifiable cause in patients with cirrhosis, in whom it is an important determinant of outcome. Its underlying pathogenic/pathophysiological mechanisms are rooted in two distinct pathways: 1) factors associated with portal hypertension, hyperdynamic circulation, gut bacterial/endotoxin translocation and the resultant inflammatory phenotype; 2) hepatocellular insufficiency with altered synthesis or metabolism of substances such as proteins, lipids, carbohydrates, bile acids and hormones. Different criteria have been proposed to diagnose CCM; the first in 2005 by the World Congress of Gastroenterology, and more recently in 2019 by the Cirrhotic Cardiomyopathy Consortium. These criteria mainly utilised echocardiographic evaluation, with the latter refining the evaluation of diastolic function and integrating global longitudinal strain into the evaluation of systolic function, an important addition since the haemodynamic changes that occur in advanced cirrhosis may lead to overestimation of systolic function by left ventricular ejection fraction. Advances in cardiac imaging, such as cardiac magnetic resonance imaging and the incorporation of an exercise challenge, may help further refine the diagnosis of CCM. Over recent years, CCM has been shown to contribute to increased mortality and morbidity after major interventions, such as liver transplantation and transjugular intrahepatic portosystemic shunt insertion, and to play a pathophysiologic role in the genesis of hepatorenal syndrome. In this review, we discuss the pathogenesis/pathophysiology of CCM, its clinical implications, and the role of cardiac imaging modalities including MRI. We also compare diagnostic criteria and review the potential diagnostic role of electrocardiographic QT prolongation. At present, no definitive medical therapy exists, but some promising potential treatment strategies for CCM are reviewed.

Integrated metabolomics and proteomics reveal biomarkers associated with hemodialysis in end-stage kidney disease

Background: We hypothesize that the poor survival outcomes of end-stage kidney disease (ESKD) patients undergoing hemodialysis are associated with a low filtering efficiency and selectivity. The current gold standard criteria using single or several markers show an inability to predict or disclose the treatment effect and disease progression accurately. Methods: We performed an integrated mass spectrometry-based metabolomic and proteomic workflow capable of detecting and quantifying circulating small molecules and proteins in the serum of ESKD patients. Markers linked to cardiovascular disease (CVD) were validated on human induced pluripotent stem cell (iPSC)-derived cardiomyocytes. Results: We identified dozens of elevated molecules in the serum of patients compared with healthy controls. Surprisingly, many metabolites, including lipids, remained at an elevated blood concentration despite dialysis. These molecules and their associated physical interaction networks are correlated with clinical complications in chronic kidney disease. This study confirmed two uremic toxins associated with CVD, a major risk for patients with ESKD. Conclusion: The retained molecules and metabolite-protein interaction network address a knowledge gap of candidate uremic toxins associated with clinical complications in patients undergoing dialysis, providing mechanistic insights and potential drug discovery strategies for ESKD.

The role of the gut microbiota and bile acids in heart failure: A review

Heart failure (HF) is the terminal manifestation of various cardiovascular diseases. Recently, accumulating evidence has demonstrated that gut microbiota are involved in the development of various cardiovascular diseases. Gut microbiota and their metabolites might play a pivotal role in the development of HF. However, previous studies have rarely described the complex role of gut microbiota and their metabolites in HF. In this review, we mainly discussed bile acids (BAs), the metabolites of gut microbiota. We explained the mechanisms by which BAs are involved in the pathogenesis of HF. We also discussed the use of gut microbiota and BAs for treating HF in Chinese medicine, highlighting the advantages of Chinese medicine in treating HF.

Broadcasters, receivers, functional groups of metabolites and the link to heart failure progression using polygenic factors

In a prospective study with records of heart failure (HF) incidence, we present metabolite profiling data from individuals without HF at baseline. We uncovered the interconnectivity of metabolites using data-driven and causal networks augmented with polygenic factors. Exploring the networks, we identified metabolite broadcasters, receivers, mediators, and subnetworks corresponding to functional classes of metabolites, and provided insights into the link between metabolomic architecture and regulation in health. We incorporated the network structure into the identification of metabolites associated with HF to control the effect of confounding metabolites. We identified metabolites associated with higher or lower risk of HF incidence, the associations that were not confounded by the other metabolites, such as glycine, ureidopropionic and glycocholic acids, and LPC 18:2. We revealed the underlying relationships of the findings. For example, asparagine directly influenced glycine, and both were inversely associated with HF. These two metabolites were influenced by polygenic factors and only essential amino acids which are not synthesized in the human body and come directly from the diet. Metabolites may play a critical role in linking genetic background and lifestyle factors to HF progression. Revealing the underlying connectivity of metabolites associated with HF strengthens the findings and facilitates a mechanistic understanding of HF progression.

Polygenic risk scores point toward potential genetic mechanisms of type 2 myocardial infarction in people with HIV

BACKGROUND

People with human immunodeficiency virus (HIV) infection (PWH) are at higher risk of myocardial infarction (MI) than those without HIV. About half of MIs in PWH are type 2 (T2MI), resulting from mismatch between myocardial oxygen supply and demand, in contrast to type 1 MI (T1MI), which is due to primary plaque rupture or coronary thrombosis. Despite worse survival and rising incidence in the general population, evidence-based treatment recommendations for T2MI are lacking. We used polygenic risk scores (PRS) to explore genetic mechanisms of T2MI compared to T1MI in PWH.

METHODS

We derived 115 PRS for MI-related traits in 9541 PWH enrolled in the Centers for AIDS Research Network of Integrated Clinical Systems cohort with adjudicated T1MI and T2MI. We applied multivariate logistic regression analyses to determine the association with T1MI and T2MI. Based on initial findings, we performed gene set enrichment analysis of the top variants composing PRS associated with T2MI.

RESULTS

We found that T1MI was strongly associated with PRS for cardiovascular disease, lipid profiles, and metabolic traits. In contrast, PRS for alcohol dependence and cholecystitis, significantly enriched in energy metabolism pathways, were predictive of T2MI risk. The association remained after the adjustment for actual alcohol consumption.

CONCLUSIONS

We demonstrate distinct genetic traits associated with T1MI and T2MI among PWH further highlighting their etiological differences and supporting the role of energy regulation in T2MI pathogenesis.

Cirrhotic Cardiomyopathy Following Bile Duct Ligation in Rats-A Matter of Time?

Cirrhotic patients often suffer from cirrhotic cardiomyopathy (CCM). Previous animal models of CCM were inconsistent concerning the time and mechanism of injury; thus, the temporal dynamics and cardiac vulnerability were studied in more detail. Rats underwent bile duct ligation (BDL) and a second surgery 28 days later. Cardiac function was assessed by conductance catheter and echocardiography. Histology, gene expression, and serum parameters were analyzed. A chronotropic incompetence (P_d31 < 0.001) and impaired contractility at rest and a reduced contractile reserve (P_d31 = 0.03, P_dob-d31 < 0.001) were seen 31 days after BDL with increased creatine (P_d35, P_d42, and P_d56 < 0.05) and transaminases (P_d31 < 0.001). A total of 56 days after BDL, myocardial fibrosis was seen (P_d56 < 0.001) accompanied by macrophage infiltration (CD68: P_group < 0.001) and systemic inflammation (TNFα: P_group < 0.001, white blood cell count: P_group < 0.001). Myocardial expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) was increased after 31 (P_d31 < 0.001) and decreased after 42 (P_d42 < 0.001) and 56 days (P_d56 < 0.001). Caspase-3 expression was increased 31 and 56 days after BDL (P_d31 = 0.005; P_d56 = 0.005). Structural changes in the myocardium were seen after 8 weeks. After the second surgery (second hit), transient myocardial insufficiency with secondary organ dysfunction was seen, characterized by reduced contractility and contractile reserve.

Pathological bile acid concentrations in chronic cholestasis cause adipose mitochondrial defects

Background & Aims

Although fat loss is observed in patients with cholestasis, how chronically elevated bile acids (BAs) impact white and brown fat depots remains obscure.

Methods

To determine the direct effect of pathological levels of BAs on lipid accumulation and mitochondrial function, primary white and brown adipocyte cultures along with fat depots from two separate mouse models of cholestatic liver diseases, namely (i) genetic deletion of farnesoid X receptor (Fxr); small heterodimer (Shp) double knockout (DKO) and (ii) injury by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC), were used.

Results

As expected, cholestatic mice accumulate high systemic BA levels and exhibit fat loss. Here, we demonstrate that chronic exposure to pathological BA levels results in mitochondrial dysfunction and defective thermogenesis. Consistently, both DKO and DDC-fed mice exhibit lower body temperature. Importantly, thermoneutral (30 °C) housing of the cholestatic DKO mice rescues the decrease in brown fat mass, and the expression of genes responsible for lipogenesis and regulation of mitochondrial function. To overcome systemic effects, primary adipocyte cultures were treated with pathological BA concentrations. Mitochondrial permeability and respiration analysis revealed that BA overload is sufficient to reduce mitochondrial function in primary adipocytes, which is not as a result of cytotoxicity. Instead, we found robust reductions in uncoupling protein 1 (Ucp1), PR domain containing 16 (Prdm16), and deiodinase, iodothyronine, type II (Dio2) transcripts in brown adipocytes upon treatment with chenodeoxycholic acid, whereas taurocholic acid led to the suppression of Dio2 transcript. This BA-mediated decrease in transcripts was alleviated by pharmacological activation of UCP1.

Conclusions

High concentrations of BAs cause defective thermogenesis by reducing the expression of crucial regulators of mitochondrial function, including UCP1, which may explain the clinical features of hypothermia and fat loss observed in patients with cholestatic liver diseases.

Impact and Implications

We uncover a detrimental effect of chronic bile acid overload on adipose mitochondrial function. Pathological concentration of different BAs reduces the expression of distinct genes involved in energy expenditure, which can be mitigated with pharmacological UCP1 activation.

Elevated bile acids are associated with left ventricular structural changes in biliary atresia

BACKGROUND

In children with biliary atresia (BA), pathologic structural changes within the heart, which define cirrhotic cardiomyopathy, are associated with adverse perioperative outcomes. Despite their clinical relevance, little is known about the pathogenesis and triggers of pathologic remodeling. Bile acid excess causes cardiomyopathy in experimental cirrhosis, but its role in BA is poorly understood.

METHODS

Echocardiographic parameters of left ventricular (LV) geometry [LV mass (LVM), LVM indexed to height, left atrial volume indexed to BSA (LAVI), and LV internal diameter (LVID)] were correlated with circulating serum bile acid concentrations in 40 children (52% female) with BA listed for transplantation. A receiver-operating characteristic curve was generated to determine optimal threshold values of bile acids to detect pathologic changes in LV geometry using Youden index. Paraffin-embedded human heart tissue was separately analyzed by immunohistochemistry for the presence of bile acid-sensing Takeda G-protein-coupled membrane receptor type 5.

RESULTS

In the cohort, 52% (21/40) of children had abnormal LV geometry; the optimal bile acid concentration to detect this abnormality with 70% sensitivity and 64% specificity was 152 µmol/L (C-statistics=0.68). Children with bile acid concentrations >152 µmol/L had ∼8-fold increased odds of detecting abnormalities in LVM, LVM index, left atrial volume index, and LV internal diameter. Serum bile acids positively correlated with LVM, LVM index, and LV internal diameter. Separately, Takeda G-protein-coupled membrane receptor type 5 protein was detected in myocardial vasculature and cardiomyocytes on immunohistochemistry.

CONCLUSION

This association highlights the unique role of bile acids as one of the targetable potential triggers for myocardial structural changes in BA.

Emerging Roles of Gut Microbial Modulation of Bile Acid Composition in the Etiology of Cardiovascular Diseases

Despite advances in preventive measures and treatment options, cardiovascular disease (CVD) remains the number one cause of death globally. Recent research has challenged the traditional risk factor profile and highlights the potential contribution of non-traditional factors in CVD, such as the gut microbiota and its metabolites. Disturbances in the gut microbiota have been repeatedly associated with CVD, including atherosclerosis and hypertension. Mechanistic studies support a causal role of microbiota-derived metabolites in disease development, such as short-chain fatty acids, trimethylamine-N-oxide, and bile acids, with the latter being elaborately discussed in this review. Bile acids represent a class of cholesterol derivatives that is essential for intestinal absorption of lipids and fat-soluble vitamins, plays an important role in cholesterol turnover and, as more recently discovered, acts as a group of signaling molecules that exerts hormonal functions throughout the body. Studies have shown mediating roles of bile acids in the control of lipid metabolism, immunity, and heart function. Consequently, a picture has emerged of bile acids acting as integrators and modulators of cardiometabolic pathways, highlighting their potential as therapeutic targets in CVD. In this review, we provide an overview of alterations in the gut microbiota and bile acid metabolism found in CVD patients, describe the molecular mechanisms through which bile acids may modulate CVD risk, and discuss potential bile-acid-based treatment strategies in relation to CVD.

The potential of tailoring the gut microbiome to prevent and treat cardiometabolic disease

Despite milestones in preventive measures and treatment, cardiovascular disease (CVD) remains associated with a high burden of morbidity and mortality. The protracted nature of the development and progression of CVD motivates the identification of early and complementary targets that might explain and alleviate any residual risk in treated patients. The gut microbiota has emerged as a sentinel between our inner milieu and outer environment and relays a modified risk associated with these factors to the host. Accordingly, numerous mechanistic studies in animal models support a causal role of the gut microbiome in CVD via specific microbial or shared microbiota-host metabolites and have identified converging mammalian targets for these signals. Similarly, large-scale cohort studies have repeatedly reported perturbations of the gut microbial community in CVD, supporting the translational potential of targeting this ecological niche, but the move from bench to bedside has not been smooth. In this Review, we provide an overview of the current evidence on the interconnectedness of the gut microbiome and CVD against the noisy backdrop of highly prevalent confounders in advanced CVD, such as increased metabolic burden and polypharmacy. We further aim to conceptualize the molecular mechanisms at the centre of these associations and identify actionable gut microbiome-based targets, while contextualizing the current knowledge within the clinical scenario and emphasizing the limitations of the field that need to be overcome.

The impact of subchronic ozone exposure on serum metabolome and the mechanisms of abnormal bile acid and arachidonic acid metabolisms in the liver

Ambient ozone (O₃) pollution can induce respiratory and cardiovascular toxicity. However, its impact on the metabolome and the underlying mechanisms remain unclear. This study first investigated the serum metabolite changes in rats exposed to 0.5 ppm O₃ for 3 months using untargeted metabolomic approach. Results showed chronic ozone exposure significantly altered the serum levels of 34 metabolites with potential increased risk of digestive, respiratory and cardiovascular disease. Moreover, bile acid synthesis and secretion, and arachidonic acid (AA) metabolism became the most prominent affected metabolic pathways after O₃ exposure. Further studies on the mechanisms found that the elevated serum toxic bile acid was not due to the increased biosynthesis in the liver, but the reduced reuptake from the portal vein to hepatocytes owing to repressed Ntcp and Oatp1a1, and the decreased bile acid efflux in hepatocytes as a results of inhibited Bsep, Ostalpha and Ostbeta. Meanwhile, decreased expressions of detoxification enzyme of SULT2A1 and the important regulators of FXR, PXR and HNF4α also contributed to the abnormal bile acids. In addition, O₃ promoted the conversion of AA into thromboxane A2 (TXA2) and 20-hydroxyarachidonic acid (20-HETE) in the liver by up-regulation of Fads2, Cyp4a and Tbxas1 which resulting in decreased AA and linoleic acid (LA), and increased thromboxane B2 (TXB2) and 20-HETE in the serum. Furthermore, apparent hepatic chronic inflammation, fibrosis and abnormal function were found in ozone-exposed rats. These results indicated chronic ozone exposure could alter serum metabolites by interfering their metabolism in the liver, and inducing liver injury to aggravate metabolic disorders.

Beyond Varices: Complications of Cirrhotic Portal Hypertension in Pediatrics

Complications of cirrhotic portal hypertension (PHTN) in children are broad and include clinical manifestations ranging from variceal hemorrhage, hepatic encephalopathy (HE), ascites, spontaneous bacterial peritonitis (SBP), and hepatorenal syndrome (HRS) to less common conditions such as hepatopulmonary syndrome, portopulmonary hypertension, and cirrhotic cardiomyopathy. The approaches to the diagnosis and management of these complications have become standard of practice in adults with cirrhosis with many guidance statements available. However, there is limited literature on the diagnosis and management of these complications of PHTN in children with much of the current guidance available focused on variceal hemorrhage. The aim of this review is to summarize the current literature in adults who experience these complications of cirrhotic PHTN beyond variceal hemorrhage and present the available literature in children, with a focus on diagnosis, management, and liver transplant decision making in children with cirrhosis who develop ascites, SBP, HRS, HE, and cardiopulmonary complications.

Cholestyramine resin administration alleviated cerebral ischemic injury in obese mice by improving gut dysbiosis and modulating the bile acid profile

Obesity is a risk factor for cerebrovascular diseases. Accumulating evidence has revealed that gut dysbiosis plays an important role in the pathophysiology of cerebrovascular diseases. However, little is known about the role of gut dysbiosis in stroke in obesity. In this study, we established a rodent middle cerebral artery occlusion (MCAO) model to investigate whether obesity-induced gut dysbiosis exacerbates cerebral ischemic injury and the role of the bile salt sequestrant cholestyramine resin (CR) in gut microbiota and stroke outcome in obese mice. Long-term 45% high-fat diet (HFD) diet (8 weeks) induced an obesity phenotype and caused gut dysbiosis, resulting in a larger infarct volume and higher serum levels of inflammatory cytokines after stroke, compared to those in the lean counterparts. LC-MS/MS and GC analysis revealed that obese mice with stroke developed an obviously perturbed bile acid (BA) profile characterized by higher levels of deoxycholic acid and its conjugated forms, and lower levels of butyrate in the cecal content. CR administration improved the obesity-induced dysbiotic microbiome, attenuated ischemic brain injury and modulated the stroke-perturbed BA profile. Furthermore, fecal microbiota transplantation (FMT) experiments revealed that the impact of obesity on stroke and the neuroprotective effects of CR were mediated by gut microbiota. In conclusion, Obesity induces gut dysbiosis, worsens stroke outcomes, and perturbs the BA profile. The dysbiotic microbiome is an important linkage between obesity and stroke. CR confers metabolic benefits and neuroprotective effects in obesity, perhaps by modulating gut microbial composition and BA metabolism.

Plasma Metabolomics Reveals Systemic Metabolic Alterations of Subclinical and Clinical Hypothyroidism

CONTEXT

Clinical hypothyroidism (CH) and subclinical hypothyroidism (SCH) have been linked to various metabolic comorbidities but the underlying metabolic alterations remain unclear. Metabolomics may provide metabolic insights into the pathophysiology of hypothyroidism.

OBJECTIVE

We explored metabolic alterations in SCH and CH and identify potential metabolite biomarkers for the discrimination of SCH and CH from euthyroid individuals.

METHODS

Plasma samples from a cohort of 126 human subjects, including 45 patients with CH, 41 patients with SCH, and 40 euthyroid controls, were analyzed by high-resolution mass spectrometry-based metabolomics. Data were processed by multivariate principal components analysis and orthogonal partial least squares discriminant analysis. Correlation analysis was performed by a Multivariate Linear Regression analysis. Unbiased Variable selection in R algorithm and 3 machine learning models were utilized to develop prediction models based on potential metabolite biomarkers.

RESULTS

The plasma metabolomic patterns in SCH and CH groups were significantly different from those of control groups, while metabolite alterations between SCH and CH groups were dramatically similar. Pathway enrichment analysis found that SCH and CH had a significant impact on primary bile acid biosynthesis, steroid hormone biosynthesis, lysine degradation, tryptophan metabolism, and purine metabolism. Significant associations for 65 metabolites were found with levels of thyrotropin, free thyroxine, thyroid peroxidase antibody, or thyroglobulin antibody. We successfully selected and validated 17 metabolic biomarkers to differentiate 3 groups.

CONCLUSION

SCH and CH have significantly altered metabolic patterns associated with hypothyroidism, and metabolomics coupled with machine learning algorithms can be used to develop diagnostic models based on selected metabolites.

Intestinal Flora Derived Metabolites Affect the Occurrence and Development of Cardiovascular Disease

In recent years, increasing evidence has shown that the gut microbiota and their metabolites play a pivotal role in human health and diseases, especially the cardiovascular diseases (CVDs). Intestinal flora imbalance (changes in the composition and function of intestinal flora) accelerates the progression of CVDs. The intestinal flora breaks down the food ingested by the host into a series of metabolically active products, including trimethylamine N-Oxide (TMAO), short-chain fatty acids (SCFAs), primary and secondary bile acids, tryptophan and indole derivatives, phenylacetylglutamine (PAGln) and branched chain amino acids (BCAA). These metabolites participate in the occurrence and development of CVDs via abnormally activating these signaling pathways more swiftly when the gut barrier integrity is broken down. This review focuses on the production and metabolism of TMAO and SCFAs. At the same time, we summarize the roles of intestinal flora metabolites in the occurrence and development of coronary heart disease and hypertension, pulmonary hypertension and other CVDs. The theories of "gut-lung axis" and "gut-heart axis" are provided, aiming to explore the potential targets for the treatment of CVDs based on the roles of the intestinal flora in the CVDs.

Effects of elevated bile acid levels on fetal myocardium in intrahepatic cholestasis of pregnancy, a retrospective study from a neonatal perspective

AIM

Intrahepatic cholestasis of pregnancy (ICP) is a liver disease which may lead to a sudden fetal death.Previous studies have suggested that the fetal accident may be related to their cardiac dysfunction.However,the relationship between fetal cardiac dysfunction and their maternal bile acid levels is not clear.This objective was to clarify the relationship from a neonatal perspective and to furtherly make clear the aftereffect by analyzing the cardiac parameters of the older neonates.

METHODS

In this case-control study,patients and their neonates,managed between 10 September 2018 and 30 June 2021 at a Chinese university hospital center,were divided into severe ICP group,mild ICP group and control gestational group.The maternal bile acid levels and the cardiac paramerers of one-day-old neonates and five-day-old neonates were analyzed,respectively.

RESULTS

The specific-myocardial enzyme(CK-MB) and left ventricular fraction shortening(FS) of neonates showed significant difference between ICP group and control group, and were meaningfully correlated with maternal bile acid levels.However,There was no significant difference in cardiac injury parameters of older neonates between the ICP group and control group.

CONCLUSIONS

The elevated maternal bile acid levels can lead to fetal myocardial injury and the injury can be recovered after removel from high concentrations of bile acid.

Gut microbiota in sarcopenia and heart failure

Sarcopenia is common in aging and in patients with heart failure (HF) who may experience worse outcomes. Patients with muscle wasting are more likely to experience falls and can have serious complications when undergoing cardiac procedures. While intensive nutritional support and exercise rehabilitation can help reverse some of these changes, they are often under-prescribed in a timely manner, and we have limited insights into who would benefit. Mechanistic links between gut microbial metabolites (GMM) have been identified and may contribute to adverse clinical outcomes in patients with cardio-renal diseases and aging. This review will examine the emerging evidence for the influence of the gut microbiome-derived metabolites and notable signaling pathways involved in both sarcopenia and HF, especially those linked to dietary intake and mitochondrial metabolism. This provides a unique opportunity to gain mechanistic and clinical insights into developing novel therapeutic strategies that target these GMM pathways or through tailored nutritional modulation to prevent progressive muscle wasting in elderly patients with heart failure.

Maternal and Fetal Bile Acid Homeostasis Regulated by Sulfated Progesterone Metabolites through FXR Signaling Pathway in a Pregnant Sow Model

Abnormally elevated circulating bile acids (BA) during pregnancy endanger fetal survival and offspring health; however, the pathology and underlying mechanisms are poorly understood. A total of nineteen pregnant sows were randomly assigned to day 60 of gestation, day 90 of gestation (G60, G90), and the farrowing day (L0), to investigate the intercorrelation of reproductive hormone, including estradiol, progesterone and sulfated progesterone metabolites (PMSs), and BA in the peripheral blood of mother and fetuses during pregnancy. All data were analyzed by Student's t-test or one-way ANOVA of GraphPad Prism and further compared by using the Student-Newman-Keuls test. Correlation analysis was also carried out using the CORR procedure of SAS to study the relationship between PMSs and BA levels in both maternal and fetal serum at G60, G90, and L0. Allopregnanolone sulphate (PM4S) and epiallopregnanolone sulphate (PM5S) were firstly identified in the maternal and fetal peripheral blood of pregnant sows by using newly developed ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) methods. Correlation analysis showed that pregnancy-associated maternal BA homeostasis was correlated with maternal serum PM4S levels, whereas fetal BA homeostasis was correlated with fetal serum PM5S levels. The antagonist activity role of PM5S on farnesoid X receptor (FXR)-mediated BA homeostasis and fibroblast growth factor 19 (FGF19) were confirmed in the PM5S and FXR activator co-treated pig primary hepatocytes model, and the antagonist role of PM4S on FXR-mediated BA homeostasis and FGF19 were also identified in the PM4S-treated pig primary hepatocytes model. Together with the high relative expression of FGF19 in pig hepatocytes, the pregnant sow is a promising animal model to investigate the pathogenesis of cholestasis during pregnancy.

Features of Cirrhotic Cardiomyopathy Early in the Lives of Infants With Biliary Atresia Correlate With Outcomes Following Kasai Portoenterostomy

Cirrhotic cardiomyopathy (CCM), detected during two-dimensional echocardiography (2DE), is prevalent in patients with biliary atresia (BA) awaiting transplant. Whether CCM occurs early in the lives of infants with BA is unknown. The aim of this study was to explore the incidence and consequence of CCM in patients with BA, focusing on the earliest ages when 2DE was performed. A cohort of 78 patients with BA at a single center underwent 2DE (median age = 132 days) during the first year of life. Left ventricular mass index (LVMI) to upper limit of normal (ULN) ratio ≥ 1.0 was present in 60% of patients who never underwent Kasai portoenterostomy (KPE; n = 15), 49% with nondraining KPE (n = 41), and 21% with draining KPE (n = 19). Patients with a draining KPE (median age at 2DE = 72 days) had a lower LVMI/ULN ratio (0.75 [interquartile range [IQR] 0.70, 0.91]) compared to those with a nondraining KPE (0.99 [IQR 0.78, 1.17] median age of 141 days; P = 0.012). In those whose 2DE was performed within 7 days of KPE (n = 19, median age of 61 days), the LVMI/ULN ratio was lower in those with a future draining KPE (0.73 [IQR 0.66, 0.75]) compared to the group with a future nondraining KPE (1.03 [IQR 0.88, 1.08], P = 0.002). Logistic regression modeling revealed LVMI/ULN ratio ≥ 1.0 as a predictor of KPE outcome, with an odds ratio of 16.7 (95% confidence interval 1.36-204; P = 0.028) for a future nondraining KPE compared to those with a LVMI/ULN ratio < 1.0. Conclusion: 2DE early in the lives of patients with BA revealed features of CCM that correlated with future outcomes. If validated in a multicenter study, this could lead to 2DE as a useful clinical tool in the care of infants with BA.

The Role of Bile Acids in the Human Body and in the Development of Diseases

Bile acids are specific and quantitatively important organic components of bile, which are synthesized by hepatocytes from cholesterol and are involved in the osmotic process that ensures the outflow of bile. Bile acids include many varieties of amphipathic acid steroids. These are molecules that play a major role in the digestion of fats and the intestinal absorption of hydrophobic compounds and are also involved in the regulation of many functions of the liver, cholangiocytes, and extrahepatic tissues, acting essentially as hormones. The biological effects are realized through variable membrane or nuclear receptors. Hepatic synthesis, intestinal modifications, intestinal peristalsis and permeability, and receptor activity can affect the quantitative and qualitative bile acids composition significantly leading to extrahepatic pathologies. The complexity of bile acids receptors and the effects of cross-activations makes interpretation of the results of the studies rather difficult. In spite, this is a very perspective direction for pharmacology.

Bile Acid Detection Techniques and Bile Acid-Related Diseases

Bile acid is a derivative of cholinergic acid (steroidal parent nucleus) that plays an important role in digestion, absorption, and metabolism. In recent years, bile acids have been identified as signaling molecules that regulate self-metabolism, lipid metabolism, energy balance, and glucose metabolism. The detection of fine changes in bile acids caused by metabolism, disease, or individual differences has become a research hotspot. At present, there are many related techniques, such as enzyme analysis, immunoassays, and chromatography, that are used for bile acid detection. These methods have been applied in clinical practice and laboratory research to varying degrees. However, mainstream detection technology is constantly updated and replaced with the passage of time, proffering new detection technologies. Previously, gas chromatography (GS) and gas chromatography-mass spectrometry (GC-MS) were the most commonly used for bile acid detection. In recent years, high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) has developed rapidly and has gradually become the mainstream bile acid sample separation and detection technology. In this review, the basic principles, development and progress of technology, applicability, advantages, and disadvantages of various detection techniques are discussed and the changes in bile acids caused by related diseases are summarized.

Clinical Nomogram to Predict Major Adverse Cardiac Events in Acute Myocardial Infarction Patients within 1 Year of Percutaneous Coronary Intervention

The purpose of this study was to summarize the clinical characteristics and risk factors of major adverse cardiovascular events (MACEs) in patients who had had acute myocardial infarction (AMI) within 1 year of percutaneous coronary intervention (PCI). A total of 421 AMI patients who were treated with PCI and experienced MACEs within 1 year of their admission were included in this retrospective study. In addition, patients were matched for age, sex, and presentation with 561 patients after AMI who had not had MACEs. The clinical characteristics and risk factors for MACEs within 1 year in AMI patients were investigated, to develop a nomogram for MACEs based on univariate and multivariate analyses. The C statistic was used to assess the discriminative performance of the nomogram. In addition, calibration curve and decision curve analyses were conducted to validate the calibration performance and utility, respectively, of the nomogram. After univariate and multivariate analyses, a nomogram was constructed based on age (odds ratio (OR): 1.030; 95% confidence interval (CI): 1.014–1.047), diabetes mellitus (OR: 1.667; 95% CI: 1.151–2.415), low-density lipoprotein cholesterol (OR: 1.332; 95% CI: 1.134–1.565), uric acid (OR: 1.003; 95% CI: 1.001–1.005), lipoprotein (a) (OR: 1.003; 95% CI: 1.002–1.003), left ventricular ejection fraction (OR: 0.929; 95% CI: 0.905–0.954), Syntax score (OR: 1.075; 95% CI: 1.053–1.097), and hypersensitive troponin T (OR: 1.002; 95% CI: 1.002–1.003). The C statistic was 0.814. The calibration curve showed good concordance of the nomogram, while decision curve analysis demonstrated satisfactory positive net benefits. We developed a convenient, practical, and effective prediction model for predicting MACEs in AMI patients within 1 year of PCI. To ensure generalizability, this model requires external validation.

Facilitating a high-quality dietary pattern induces shared microbial responses linking diet quality, blood pressure, and microbial sterol metabolism in caregiver-child dyads

Low-resource individuals are at increased risk of obesity and cardiovascular disease (CVD), partially attributable to poor dietary patterns and dysfunctional microbiota. Dietary patterns in childhood play critical roles in physiological development and are shaped by caregivers, making caregiver-child dyads attractive targets for dietary interventions to reduce metabolic disease risk. Herein, we targeted low-resource caregiver-child dyads for a 10-week, randomized, controlled, multifaceted lifestyle intervention including: nutrition and physical activity education, produce harvesting, cooking demonstrations, nutrition counseling, and kinetic activites; to evaluate its effects on dietary patterns, CVD risk factors, and microbiome composition. Subjects in the lifestyle intervention group improved total diet quality, increased whole grain intake, decreased energy intake, and enhanced fecal elimination of the microbe-derived metabolite lithocholic acid (LCA) in contrast to control subjects. Microbiomes were highly personalized, similar within dyads, and altered by lifestyle intervention. Differential modeling of microbiome composition identified taxa associated with total diet quality, whole grain intake, and LCA elimination including recognized fiber-degrading bacteria such as Subdoligranulum, and bile acid metabolizing organisms like Bifidobacterium. Inclusion of taxa identified in diet and metabolite modeling within blood pressure models improved prediction accuracy of microbiome-blood pressure associations. Importantly, microbiota-blood pressure relationships were shared between dyads, implying shared host-microbiota responses to lifestyle intervention. Overall, these outcomes provide insight into mechanisms by which dietary interventions impact the gut-cardiovascular axis to reduce future CVD risk. Registered at clinicaltrials.gov: NCT05367674.

Biliary cirrhosis-induced cardiac abnormality in rats: Interaction between Farnesoid-X-activated receptors and the cardiac uncoupling proteins 2 and 3

OBJECTIVES

This study aimed to evaluate the relationship between Farnesoid-X-activated receptors (FXR) as nuclear regulators of the antioxidant defense system as well as cardiac mitochondrial carrier proteins of UCP2 and UCP3 in cardiac damage induced by cirrhosis.

MATERIALS AND METHODS

Twenty-two male Wistar rats (200-250 g) were randomly divided into 3 experimental groups, including a control group (n=6), a sham-operated group (n=8), and a bile duct ligated (BDL) group (n=8). Four weeks after surgical intervention, biochemical assessment (AST, ALT, GGT, LDH, and ALP), histological observation, and molecular evaluation (FXR, UCP2, UCP3, BNP, Caspase3, and GAPDH) using real-time RT-PCR were performed.

RESULTS

Compared with the sham-operation group, the BDL group showed a significant rise in liver enzymes of AST, ALT, GGT, LDH, and ALP. Defined fibrotic and necrotic bundles and thick reticulin fibers were also found in BDL liver tissue. Besides liver morphological alterations, left ventricles of BDL ones were also associated with defined cardiomyocyte hypertrophy, myofiber vacuolization, and clear pigmentation. Findings showed a significant up-regulation of cardiac Brain Natriuretic Peptide (BNP) along with marked down-regulation in hepatic FXR, cardiac FXR, and cardiac UCP2 and UCP3. However, the expression of caspase 3 in the cardiac tissue was not affected by BDL operation during 4 weeks.

CONCLUSION

Expression of FXR as an upstream regulator of cellular redox status, besides the non-enzymatic ROS buffering defense system of cardiac UCPs, has a pivotal role in the pathogenesis of cirrhotic-induced cardiac abnormality in rats.

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.

Intermittent Fasting Enhances Right Ventricular Function in Preclinical Pulmonary Arterial Hypertension

Background Intermittent fasting (IF) confers pleiotropic cardiovascular benefits including restructuring of the gut microbiome and augmentation of cellular metabolism. Pulmonary arterial hypertension (PAH) is a rare and lethal disease characterized by right ventricular (RV) mitochondrial dysfunction and resultant lipotoxicity and microbiome dysbiosis. However, the effects of IF on RV function in PAH are unexplored. Therefore, we investigated how IF altered gut microbiota composition, RV function, and survival in the monocrotaline model of PAH. Methods and Results Male Sprague Dawley rats were randomly allocated into 3 groups: control, monocrotaline-ad libitum feeding, and monocrotaline-IF (every other day feeding). Echocardiography and invasive hemodynamics showed IF improved RV systolic and diastolic function despite no significant change in PAH severity. IF prevented premature mortality (30% mortality rate in monocrotaline-ad libitum versus 0% in monocrotaline-IF rats, P=0.04). IF decreased RV cardiomyocyte hypertrophy and reduced RV fibrosis. IF prevented RV lipid accrual on Oil Red O staining and ceramide accumulation as determined by metabolomics. IF mitigated the reduction in jejunum villi length and goblet cell abundance when compared with monocrotaline-ad libitum. The 16S ribosomal RNA gene sequencing demonstrated IF changed the gut microbiome. In particular, there was increased abundance of Lactobacillus in monocrotaline-IF rats. Metabolomics profiling revealed IF decreased RV levels of microbiome metabolites including bile acids, aromatic amino acid metabolites, and gamma-glutamylated amino acids. Conclusions IF directly enhanced RV function and restructured the gut microbiome. These results suggest IF may be a non-pharmacological approach to combat RV dysfunction, a currently untreatable and lethal consequence of PAH.

The gut-cardiovascular connection: new era for cardiovascular therapy

Our gut microbiome is constituted by trillions of microorganisms including bacteria, archaea and eukaryotic microbes. Nowadays, gut microbiome has been gradually recognized as a new organ system that systemically and biochemically interact with the host. Accumulating evidence suggests that the imbalanced gut microbiome contributes to the dysregulation of immune system and the disruption of cardiovascular homeostasis. Specific microbiome profiles and altered intestinal permeability are often observed in the pathophysiology of cardiovascular diseases. Gut-derived metabolites, toxins, peptides and immune cell-derived cytokines play pivotal roles in the induction of inflammation and the pathogenesis of dysfunction of heart and vasculature. Impaired crosstalk between gut microbiome and multiple organ systems, such as gut-vascular, heart-gut, gut-liver and brain-gut axes, are associated with higher cardiovascular risks. Medications and strategies that restore healthy gut microbiome might therefore represent novel therapeutic options to lower the incidence of cardiovascular and metabolic disorders.

Mechanistic insights into the pathophysiology of cirrhotic cardiomyopathy

Myocardial dysfunction in end stage cirrhotic liver disease, termed cirrhotic cardiomyopathy, is a long known, but little understood comorbidity seen in ∼50% of adults and children who present for liver transplantation. Structural, functional, hemodynamic and electrocardiographic aberrations that occur in the heart as a direct consequence of a damaged liver, is associated with multi-organ failure and increased mortality and morbidity in patients undergoing surgical procedures such as porto-systemic shunt placement and liver transplantation. Despite its clinical significance and rapid advances in science and pharmacotherapy, there is yet no specific treatment for this disease. This may be due to a lack of understanding of the pathogenesis and mechanisms behind how a cirrhotic liver causes cardiac pathology. This review will focus specifically on insights into the molecular mechanisms that drive this liver-heart interaction. Deeper understanding of the etio-pathogenesis of cirrhotic cardiomyopathy will allow us to design and test treatments that can be targeted to prevent and/or reverse this co-morbid consequence of liver failure and improve health care delivery and outcomes in patients with cirrhosis.

Redox-Dependent Effects in the Physiopathological Role of Bile Acids

Bile acids (BA) are recognized by their role in nutrient absorption. However, there is growing evidence that BA also have endocrine and metabolic functions. Besides, the steroidal-derived structure gives BA a toxic potential over the biological membrane. Thus, cholestatic disorders, characterized by elevated BA on the liver and serum, are a significant cause of liver transplant and extrahepatic complications, such as skeletal muscle, central nervous system (CNS), heart, and placenta. Further, the BA have an essential role in cellular damage, mediating processes such as membrane disruption, mitochondrial dysfunction, and the generation of reactive oxygen species (ROS) and oxidative stress. The purpose of this review is to describe the BA and their role on hepatic and extrahepatic complications in cholestatic diseases, focusing on the association between BA and the generation of oxidative stress that mediates tissue damage.

Intestinal-derived FGF15 protects against deleterious effects of vertical sleeve gastrectomy in mice

Bariatric surgeries such as the Vertical Sleeve Gastrectomy (VSG) are invasive but provide the most effective improvements in obesity and Type 2 diabetes. We hypothesized a potential role for the gut hormone Fibroblast-Growth Factor 15/19 which is increased after VSG and pharmacologically can improve energy homeostasis and glucose handling. We generated intestinal-specific FGF15 knockout (FGF15^INT-KO) mice which were maintained on high-fat diet. FGF15^INT-KO mice lost more weight after VSG as a result of increased lean tissue loss. FGF15^INT-KO mice also lost more bone density and bone marrow adipose tissue after VSG. The effect of VSG to improve glucose tolerance was also absent in FGF15^INT-KO. VSG resulted in increased plasma bile acid levels but were considerably higher in VSG-FGF15^INT-KO mice. These data point to an important role after VSG for intestinal FGF15 to protect the organism from deleterious effects of VSG potentially by limiting the increase in circulating bile acids.

The mechanisms that mediate the effects of weight loss surgeries such as vertical sleeve gastrectomy (VSG) are incompletely understood. Here the authors show that intestinal FGF15 is necessary to improve glucose tolerance and to prevent the loss of muscle and bone mass after VSG, potentially via protection against bile acid toxicity.

Exercise Training Attenuates Cirrhotic Cardiomyopathy

Cirrhotic cardiomyopathy is a condition where liver cirrhosis is associated with cardiac dysfunction. Triggers and blockers of cirrhotic cardiomyopathy are poorly understood, which might compromise the prognosis of chronic liver disease patients. We tested whether exercise training would reduce liver damage induced by thioacetamide and prevent liver cirrhosis-associated cardiomyopathy. Wistar rats were divided into three groups: control, thioacetamide (TAA), or TAA plus exercise. Thioacetamide increased liver weight and serum alanine aminotransferase and aspartate aminotransferase levels. Also, TAA treatment was involved with hepatic nodule formation, fibrotic septa, inflammatory infiltration, and hepatocyte necrosis. The exercise group presented with a reduction in liver injury status. We found that liver injury was associated with disordered cardiac hypertrophy as well as diastolic and systolic dysfunction. Exercise training attenuated cirrhosis-associated cardiac remodeling and diastolic dysfunction and prevented systolic impairment. These results provided insights that exercise training can mitigate cirrhotic cardiomyopathy phenotype. Graphical Abstract Exercise training attenuated liver injury as well as cirrhosis-associated cardiac remodeling and diastolic dysfunction and prevented systolic impairment.

Bile Acids, Liver Cirrhosis, and Extrahepatic Vascular Dysfunction

The bile acid pool with its individual bile acids (BA) is modulated in the enterohepatic circulation by the liver as the primary site of synthesis, the motility of the gallbladder and of the intestinal tract, as well as by bacterial enzymes in the intestine. The nuclear receptor farnesoid X receptor (FXR) and Gpbar1 (TGR5) are important set screws in this process. Bile acids have a vasodilatory effect, at least according to in vitro studies. The present review examines the question of the extent to which the increase in bile acids in plasma could be responsible for the hyperdynamic circulatory disturbance of liver cirrhosis and whether modulation of the bile acid pool, for example, via administration of ursodeoxycholic acid (UDCA) or via modulation of the dysbiosis present in liver cirrhosis could influence the hemodynamic disorder of liver cirrhosis. According to our analysis, the evidence for this is limited. Long-term studies on this question are lacking.

Chenodeoxycholic and deoxycholic acids induced positive inotropic and negative chronotropic effects on rat heart

Bile acids are endogenous amphiphilic steroids from the metabolites of cholesterol. Studies showed that they might contribute to the pathogenesis of cardiopathy in cholestatic liver diseases. Chenodeoxycholic acid (CDCA) and deoxycholic acid (DCA) is associated with colon cancer, gallstones, and gastrointestinal disorders. However, little information is available regarding their cardiac effects. Here, we reported that CDCA (100 μM) and DCA (100 μM) significantly increased the left ventricular developed pressure of the isolated rat hearts to 122.3 ± 5.6% and 145.1 ± 13.7%, and the maximal rate of the pressure development rising and descending (± dP/dtmax) to 103.4 ± 17.6% and 124.4 ± 37.7% of the basal levels, respectively. They decreased the heart rate and prolonged the RR, QRS, and QT intervals of Langendorff-perfused hearts in a concentration-dependent manner. Moreover, CDCA and DCA increased the developed tension of left ventricular muscle and the cytosolic Ca2+ concentrations in left ventricular myocytes; these functions positively coordinated with their inotropic effects on hearts. Additionally, CDCA (150 μM) and DCA (100 μM) decreased the sinoatrial node beating rate to 80.6 ± 3.0% and 79.7 ± 0.9% of the basal rate (334.2 ± 10.7 bpm), respectively. These results were consistent with their chronotropic effects. In conclusion, CDCA and DCA induced positive inotropic effects by elevating the Ca2+ in left ventricular myocytes. They exerted negative chronotropic effects by lowering the pace of the sinoatrial node in rat heart. These results indicated that the potential role of bile acids in cardiopathy related to cholestasis.

Microbiota and Metabolites as Factors Influencing Blood Pressure Regulation

The study of microbes has rapidly expanded in recent years due to a surge in our understanding that humans host a plethora of commensal microbes, which reside in their bodies and depending upon their composition, contribute to either normal physiology or pathophysiology. This article provides a general foundation for learning about host-commensal microbial interactions as an emerging area of research. The article is divided into two sections. The first section is dedicated to introducing commensal microbiota and its known effects on the host. The second section is on metabolites, which are biochemicals that the host and the microbes use for bi-directional communication with each other. Together, the sections review what is known about how microbes interact with the host to impact cardiovascular physiology, especially blood pressure regulation. © 2021 American Physiological Society. Compr Physiol 11:1731-1757, 2021.