Role of CETP, PCSK-9, and CYP7-alpha in cholesterol metabolism: Potential targets for natural products in managing hypercholesterolemia

Cardiovascular diseases (CVDs) are a leading cause of mortality worldwide, primarily affecting the heart and blood vessels, with atherosclerosis being a major contributing factor to their onset. Epidemiological and clinical studies have linked high levels of low-density lipoprotein (LDL) emanating from distorted cholesterol homeostasis as its major predisposing factor. Cholesterol homeostasis, which involves maintaining the balance in body cholesterol level, is mediated by several proteins or receptors, transcription factors, and even genes, regulating cholesterol influx (through dietary intake or de novo synthesis) and efflux (by their conversion to bile acids). Previous knowledge about CVDs management has evolved around modulating these receptors' activities through synthetic small molecules/antibodies, with limited interest in natural products. The central roles of the cholesteryl ester transfer protein (CETP), proprotein convertase subtilisin/kexin type 9 (PCSK9), and cytochrome P450 family 7 subfamily A member 1 (CYP7A1), among other proteins or receptors, have fostered growing scientific interests in understanding more on their regulatory activities and potential as drug targets. We present up-to-date knowledge on the contributions of CETP, PCSK9, and CYP7A1 toward CVDs, highlighting the clinical successes and failures of small molecules/antibodies to modulate their activities. In recommendation for a new direction to improve cardiovascular health, we have presented recent findings on natural products (including functional food, plant extracts, phytochemicals, bioactive peptides, and therapeutic carbohydrates) that also modulate the activities of CETP, PCSK-9, and CYP7A1, and emphasized the need for more research efforts redirected toward unraveling more on natural products potentials even at clinical trial level for CVD management.

Multi-biobank Mendelian randomization analyses identify opposing pathways in plasma low-density lipoprotein-cholesterol lowering and gallstone disease

Plasma low-density lipoprotein (LDL)-cholesterol is positively associated with coronary artery disease risk while biliary cholesterol promotes gallstone formation. Different plasma LDL-cholesterol lowering pathways may have distinct effects on biliary cholesterol and thereby gallstone disease risk. We conducted a Mendelian randomization (MR) study using data from the UK Biobank (30,547 gallstone disease cases/336,742 controls), FinnGen (34,461 cases/301,383 controls) and Biobank Japan (9,305 cases/168,253 controls). We first performed drug-target MR analyses substantiated by colocalization to investigate the effects of plasma LDL-cholesterol lowering therapies on gallstone disease risk. We then performed clustered MR analyses and pathway analyses to identify distinct mechanisms underlying the association of plasma LDL-cholesterol with gallstone disease risk. For a 1-standard deviation reduction in plasma LDL-cholesterol, genetic mimics of statins were associated with lower gallstone disease risk (odds ratio 0.72 [95% confidence interval 0.62, 0.83]), but genetic mimics of PCSK9 inhibitors and targeting apolipoprotein B were associated with higher risk (1.11 [1.03, 1.19] and 1.23 [1.13, 1.35]). The association for statins was supported by colocalization (posterior probability 98.7%). Clustered MR analyses identified variant clusters showing opposing associations of plasma LDL-cholesterol with gallstone disease risk, with some evidence for ancestry-and sex-specific associations. Among variants lowering plasma LDL-cholesterol, those associated with lower gallstone disease risk were mapped to glycosphingolipid biosynthesis pathway, while those associated with higher risk were mapped to pathways relating to plasma lipoprotein assembly, remodelling, and clearance and ATP-binding cassette transporters. This MR study provides genetic evidence that different plasma LDL-cholesterol lowering pathways have opposing effects on gallstone disease risk.

Changes in bile acid subtypes and improvements in lipid metabolism and atherosclerotic cardiovascular disease risk: the Preventing Overweight Using Novel Dietary Strategies (POUNDS Lost) trial

BACKGROUND

Distinct circulating bile acid (BA) subtypes may play roles in regulating lipid homeostasis and atherosclerosis.

OBJECTIVES

We investigated whether changes in circulating BA subtypes induced by weight-loss dietary interventions were associated with improved lipid profiles and atherosclerotic cardiovascular disease (ASCVD) risk estimates.

METHODS

This study included adults with overweight or obesity (n = 536) who participated in a randomized weight-loss dietary intervention trial. Circulating primary and secondary unconjugated BAs and their taurine-/glycine-conjugates were measured at baseline and 6 mo after the weight-loss diet intervention. The ASCVD risk estimates were calculated using the validated equations.

RESULTS

At baseline, higher concentrations of specific BA subtypes were related to higher concentrations of atherogenic very low-density lipoprotein lipid subtypes and ASCVD risk estimates. Weight-loss diet-induced decreases in primary BAs were related to larger reductions in triglycerides and total cholesterol [every 1 standard deviation (SD) decrease of glycocholate, glycochenodeoxycholate, or taurochenodeoxycholate was related to β (standard error) -3.3 (1.3), -3.4 (1.3), or -3.8 (1.3) mg/dL, respectively; PFDR < 0.05 for all]. Greater decreases in specific secondary BA subtypes were also associated with improved lipid metabolism at 6 mo; there was β -4.0 (1.1) mg/dL per 1-SD decrease of glycoursodeoxycholate (PFDR =0.003) for changes in low-density lipoprotein cholesterol. We found significant interactions (P-interaction < 0.05) between dietary fat intake and changes in BA subtypes on changes in ASCVD risk estimates; decreases in primary and secondary BAs (such as conjugated cholate or deoxycholate) were significantly associated with improved ASCVD risk after consuming a high-fat diet, but not after consuming a low-fat diet.

CONCLUSIONS

Decreases in distinct BA subtypes were associated with improved lipid profiles and ASCVD risk estimates, highlighting the importance of changes in circulating BA subtypes as significant factors linked to improved lipid metabolism and ASCVD risk estimates in response to weight-loss dietary interventions. Habitual dietary fat intake may modify the associations of changes in BAs with ASCVD risk. This trial was registered at clinicaltrials.gov as NCT00072995.

Resistance to Cholesterol Gallstone Disease: Hepatic Cholesterol Metabolism

Cholesterol gallstone disease (CGD) is one of the most common digestive diseases, and it is closely associated with hepatic cholesterol metabolism. Cholesterol gallstones may be caused by abnormal hepatic cholesterol metabolism, such as excessive cholesterol biosynthesis within the liver, interfering with the uptake or export of cholesterol in the liver, and abnormal hepatic cholesterol esterification. In this review, we begin with a brief overview of the clinical diagnosis and treatment of gallstone disease (GSD). Then, we briefly describe the major processes of hepatic cholesterol metabolism and summarize the key molecular expression changes of hepatic cholesterol metabolism in patients with gallstones. We review and analyze the recent advances in elucidating the relationships between these key molecules and CGD, and some targets significantly impacting on CGD via hepatic cholesterol metabolism are also listed. We also provide a significant discussion on the relationship between CGD and nonalcoholic fatty liver disease (NAFLD). Finally, the new discoveries of some therapeutic strategies associated with hepatic cholesterol metabolism to prevent and treat CGD are summarized.

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.

Atherosclerotic plaque vulnerability quantification system for clinical and biological interpretability

Acute myocardial infarction dominates coronary artery disease mortality. Identifying bio-signatures for plaque destabilization and rupture is important for preventing the transition from coronary stability to instability and the occurrence of thrombosis events. This computational systems biology study enrolled 2,235 samples from 22 independent bulks cohorts and 14 samples from two single-cell cohorts. A machine-learning integrative program containing nine learners was developed to generate a warning classifier linked to atherosclerotic plaque vulnerability signature (APVS). The classifier displays the reliable performance and robustness for distinguishing ST-elevation myocardial infarction from chronic coronary syndrome at presentation, and revealed higher accuracy to 33 pathogenic biomarkers. We also developed an APVS-based quantification system (APVSLevel) for comprehensively quantifying atherosclerotic plaque vulnerability, empowering early-warning capabilities, and accurate assessment of atherosclerosis severity. It unraveled the multidimensional dysregulated mechanisms at high resolution. This study provides a potential tool for macro-level differential diagnosis and evaluation of subtle genetic pathological changes in atherosclerosis.

Impact of gallstone disease on the risk of stroke and coronary artery disease: evidence from prospective observational studies and genetic analyses

BACKGROUND

Despite epidemiological evidence associating gallstone disease (GSD) with cardiovascular disease (CVD), a dilemma remains on the role of cholecystectomy in modifying the risk of CVD. We aimed to characterize the phenotypic and genetic relationships between GSD and two CVD events - stroke and coronary artery disease (CAD).

METHODS

We first performed a meta-analysis of cohort studies to quantify an overall phenotypic association between GSD and CVD. We then investigated the genetic relationship leveraging the largest genome-wide genetic summary statistics. We finally examined the phenotypic association using the comprehensive data from UK Biobank (UKB).

RESULTS

An overall significant effect of GSD on CVD was found in meta-analysis (relative risk [RR] = 1.26, 95% confidence interval [CI] = 1.19-1.34). Genetically, a positive shared genetic basis was observed for GSD with stroke ([Formula: see text]=0.16, P = 6.00 × 10-4) and CAD ([Formula: see text]=0.27, P = 2.27 × 10-15), corroborated by local signals. The shared genetic architecture was largely explained by the multiple pleiotropic loci identified in cross-phenotype association study and the shared gene-tissue pairs detected by transcriptome-wide association study, but not a causal relationship (GSD to CVD) examined through Mendelian randomization (MR) (GSD-stroke: odds ratio [OR] = 1.00, 95%CI = 0.97-1.03; GSD-CAD: OR = 1.01, 95%CI = 0.98-1.04). After a careful adjustment of confounders or considering lag time using UKB data, no significant phenotypic effect of GSD on CVD was detected (GSD-stroke: hazard ratio [HR] = 0.95, 95%CI = 0.83-1.09; GSD-CAD: HR = 0.98, 95%CI = 0.91-1.06), further supporting MR findings.

CONCLUSIONS

Our work demonstrates a phenotypic and genetic relationship between GSD and CVD, highlighting a shared biological mechanism rather than a direct causal effect. These findings may provide insight into clinical and public health applications.

Glutaredoxin 1 regulates cholesterol metabolism and gallstone formation by influencing protein S-glutathionylation

OBJECTIVE

Cholesterol gallstone disease (CGD) is closely related to cholesterol metabolic disorder. Glutaredoxin-1 (Glrx1) and Glrx1-related protein S-glutathionylation are increasingly being observed to drive various physiological and pathological processes, especially in metabolic diseases such as diabetes, obesity and fatty liver. However, Glrx1 has been minimally explored in cholesterol metabolism and gallstone disease.

METHODS

We first investigated whether Glrx1 plays a role in gallstone formation in lithogenic diet-fed mice using immunoblotting and quantitative real-time PCR. Then a whole-body Glrx1-deficient (Glrx1^-/-) mice and hepatic-specific Glrx1-overexpressing (AAV8-TBG-Glrx1) mice were generated, in which we analyzed the effects of Glrx1 on lipid metabolism upon LGD feeding. Quantitative proteomic analysis and immunoprecipitation (IP) of glutathionylated proteins were performed.

RESULTS

We found that protein S-glutathionylation was markedly decreased and the deglutathionylating enzyme Glrx1 was greatly increased in the liver of lithogenic diet-fed mice. Glrx1^-/- mice were protected from gallstone disease induced by a lithogenic diet because their biliary cholesterol and cholesterol saturation index (CSI) were reduced. Conversely, AAV8-TBG-Glrx1 mice showed greater gallstone progression with increased cholesterol secretion and CSI. Further studies showed that Glrx1-overexpressing greatly induced bile acid levels and/or composition to increase intestinal cholesterol absorption by upregulating Cyp8b1. In addition, liquid chromatography-mass spectrometry and IP analysis revealed that Glrx1 also affected the function of asialoglycoprotein receptor 1 (ASGR1) by mediating its deglutathionylation, thereby altering the expression of LXRα and controlling cholesterol secretion.

CONCLUSION

Our findings present novel roles of Glrx1 and Glrx1-regulated protein S-glutathionylation in gallstone formation through the targeting of cholesterol metabolism. Our data advises Glrx1 significantly increased gallstone formation by simultaneously increase bile-acid-dependent cholesterol absorption and ASGR1- LXRα-dependent cholesterol efflux. Our work suggests the potential effects of inhibiting Glrx1 activity to treat cholelithiasis.

Human Hepatocyte Nuclear Factors (HNF1 and LXRb) Regulate CYP7A1 in HIV-Infected Black South African Women with Gallstone Disease: A Preliminary Study

Female sex, high estrogen levels, aging, obesity, and dyslipidemia are some of the risk factors associated with gallstone formation. HIV-infected patients on combination antiretroviral therapy (cART) are more prone to hypercholesterolemia. Bile acid synthesis is initiated by cholesterol 7-alpha hydroxylase (CYP7A1) and regulated by hepatocyte nuclear factors (HNF1α, HNF4α, and LXRb). The aim of this study was to evaluate the expression of HNF1α, HNF4α, LXRb, and miRNAs (HNF4α specific: miR-194-5p and miR-122^*_1) that regulate CYP7A1 transcription in HIV-infected Black South African women on cART and presenting with gallstones relative to HIV-negative patients with gallstone disease. Females (n = 96) presenting with gallstone disease were stratified based on HIV status. The gene expression of CYP7A1, HNF1α, HNF4α, LXRb, miR-194-5p, and miR-122^*_1 was determined using RT-qPCR. Messenger RNA and miRNA levels were reported as fold change expressed as 2^-ΔΔCt (RQ min; RQ max). Fold changes >2 and <0.5 were considered significant. HIV-infected females were older in age (p = 0.0267) and displayed higher low-density lipoprotein cholesterol (LDL-c) (p = 0.0419), CYP7A1 [2.078-fold (RQ min: 1.278; RQ max: 3.381)], LXRb [2.595-fold (RQ min: 2.001; RQ max: 3.000)], and HNF1α [3.428 (RQ min: 1.806; RQ max: 6.507] levels. HNF4α [0.642-fold (RQ min: 0.266; RQ max: 1.55)], miR-194-5p [0.527-fold (RQ min: 0.37; RQ max: 0.752)], and miR-122*_1 [0.595-fold (RQ min: 0.332; RQ max: 1.066)] levels were lower in HIV-infected females. In conclusion, HIV-infected women with gallstone disease displayed higher LDL-c levels and increased bile acid synthesis, which was evidenced by the elevated expression of CYP7A1, HNF1α, and LXRb. This could have been further influenced by cART and aging.

Metabolomic and transcriptomic studies of improvements in myocardial infarction due to Pycr1 deletion

Myocardial infarction (MI) remains a major challenge to cardiovascular health worldwide, with poor healing leaving a direct impact on patients' quality of life and survival. Metabolic abnormalities after MI are receiving increasing attention. Our previous studies showed that enhancing proline catabolism ameliorates hypoxic damage to myocardial cells; therefore, we sought to determine whether reducing the synthesis of endogenous proline also affects MI. We analysed GEO datasets associated with MI and western blot of mouse heart tissue in an MI model to demonstrate pyrroline-5-carboxylate reductase 1 (Pycr1) expression level after MI. We constructed Pycr1 KO mice by CRISPR/Cas9 technology to explore the effect of Pycr1 gene KO after MI using transcriptomic and metabolomic techniques. In this study, we found reduced mRNA and protein expression levels of Pycr1 in the hearts of mice after MI. We observed that Pycr1 gene KO has a protective effect against MI, reducing the area of MI and improving heart function. Using transcriptomics approaches, we found 215 upregulated genes and 247 downregulated genes after KO of the Pycr1 gene, indicating that unsaturated fatty acid metabolism was affected at the transcriptional level. Metabolomics results revealed elevated content for 141 metabolites and decreased content for 90 metabolites, among which the levels of fatty acids, glycerol phospholipids, bile acids, and other metabolites increased significantly. The changes in these metabolites may be related to the protective effect of Pycr1 KO on the heart after MI. Pycr1 gene KO has a protective effect against MI and our research will lay a solid foundation for the development of future Pycr1-related drug targets.

Gallstone disease and the risk of cardiac mortality in patients with acute coronary syndrome

Background

Gallstone disease is a common gastrointestinal disorder, which has previously been reported to be associated with the incidence of cardiovascular disease. We aimed to investigate the association between gallstone disease and long-term outcomes in patients with acute coronary syndrome (ACS).

Materials and methods

A total of consecutive 13,975 ACS patients were included in this analysis. Gallstone disease in our study included both gallstones and cholecystectomy. The primary endpoint was cardiac mortality. The secondary outcome was all-cause mortality. Relative risks were estimated using Cox proportional hazards regression.

Results

During a median follow-up period of 2.96 years, 518 (4.2%) patients without gallstone disease and 62 (3.6%) patients in those with gallstone disease suffered cardiac death. After multivariable adjustment for established risk factors, subjects with gallstone disease had decreased risks of both cardiac mortality and all-cause mortality [hazard rate ratios (HR) = 0.72, 95% CI: 0.55-0.95 and HR = 0.75, 95% CI: 0.62-0.90, respectively]. In patients with performed cholecystectomy, the associations between gallstones and risks for cardiac mortality and all-cause mortality turned out to be non-significant. HRs varied across subgroups depending on the presence of selected established risk factors.

Conclusion

Presence of gallstone disease was associated with a significantly decreased risk of follow-up mortality in patients with ACS.

Research progress on the immune microenvironment of the gallbladder in patients with cholesterol gallstones

Cholesterol gallstones are very common in hepatobiliary surgery and have been studied to a certain extent by doctors worldwide for decades. However, the mechanism of cholesterol gallstone formation is not fully understood, so there is currently no completely effective drug for the treatment and prevention of cholesterol gallstones. The formation and development of cholesterol gallstones are caused by a variety of genetic and environmental factors, among which genetic susceptibility, intestinal microflora disorders, impaired gallbladder motility, and immune disorders are important in the pathogenesis of cholesterol gallstones. This review focuses on recent advances in these mechanisms. We also discuss some new targets that may be effective in the treatment and prevention of cholesterol gallstones, which may be hot areas in the future.

Modulation of Bile Acid Metabolism to Improve Plasma Lipid and Lipoprotein Profiles

New drugs targeting bile acid metabolism are currently being evaluated in clinical studies for their potential to treat cholestatic liver diseases, non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). Changes in bile acid metabolism, however, translate into an alteration of plasma cholesterol and triglyceride concentrations, which may also affect cardiovascular outcomes in such patients. This review attempts to gain insight into this matter and improve our understanding of the interactions between bile acid and lipid metabolism. Bile acid sequestrants (BAS), which bind bile acids in the intestine and promote their faecal excretion, have long been used in the clinic to reduce LDL cholesterol and, thereby, atherosclerotic cardiovascular disease (ASCVD) risk. However, BAS modestly but consistently increase plasma triglycerides, which is considered a causal risk factor for ASCVD. Like BAS, inhibitors of the apical sodium-dependent bile acid transporter (ASBTi’s) reduce intestinal bile acid absorption. ASBTi’s show effects that are quite similar to those obtained with BAS, which is anticipated when considering that accelerated faecal loss of bile acids is compensated by an increased hepatic synthesis of bile acids from cholesterol. Oppositely, treatment with farnesoid X receptor agonists, resulting in inhibition of bile acid synthesis, appears to be associated with increased LDL cholesterol. In conclusion, the increasing efforts to employ drugs that intervene in bile acid metabolism and signalling pathways for the treatment of metabolic diseases such as NAFLD warrants reinforcing interactions between the bile acid and lipid and lipoprotein research fields. This review may be considered as the first step in this process.

Mechanisms of traditional Chinese medicine in modulating gut microbiota metabolites-mediated lipid metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

The gut microbiome plays an important role in advancing the process of host lipid metabolism directly or indirectly. Traditional Chinese medicine (TCM) can improve the intestinal environment by intervening with gut microbiota metabolites to potentially regulate lipid levels. However, the underlying mechanisms remain unclear. Therefore, we examined the current databases to search for studies related to influence of TCM on the gut microbiota metabolites-mediated lipid metabolism.

AIM OF THE STUDY

This paper aims to review the TCM that could regulate lipid metabolism mediated by microbial metabolites and their pharmacological targets and provides perspectives for future investigation.

METHODS

Electronic databases including PubMed, Web of Science, EMBASE, the Cochrane Library, Chinese Biological Medicine Database, and China National Knowledge Infrastructure were searched up to April 2021 to identify eligible studies.

RESULTS

A total of 30 active compounds, five Chinese herbal formulae, and three proprietary Chinese medicines were included in this review. We found that TCM can effectively improve lipid metabolism by increasing short chain fatty acids (SCFA) levels, regulating bile acid (BA) metabolism, reducing the production of trimethylamine N-oxide (TMAO), alleviating the release of inflammatory factors, and altering branched-chain amino acids (BCAA) biosynthesis. This process is accompanied by changes in the structure of the gut microbiota, blood lipids, and expression of lipid metabolism genes.

CONCLUSION

In summary, studies on the regulation of lipid metabolism by microbial metabolites in TCM will provide a new approach for better management of dyslipidemia, which may facilitate future clinical treatments.

Associations of CD14 variants with the triglyceride levels and risk of myocardial infarction in an Eastern Chinese Han population

BACKGROUND

CD14 is crucial in the progression of myocardial infarction (MI). Several studies have explored the association between the risk of MI and the CD14 C-260 T polymorphism, but have reported inconsistent results.

METHODS

This study analyzed the association of the CD14 C-260 T polymorphism with susceptibility to MI. Totally, 240 MI patients and 298 normal subjects were included. The association between MI risk and the target polymorphism was assessed using 95% confidence intervals and odds ratios obtained through logistic regression.

RESULTS

The T allele of the CD14 C-260 T polymorphism was linked with an elevated risk of MI in Chinese Han people; subgroup analysis indicated that this effect was associated with smoking, male gender, and hypertension. In addition, the data revealed that different genotype carriers of the CD14 C-260 T polymorphism showed significantly distinct TG levels in MI patients.

CONCLUSION

Totally, the T allele of the CD14 C-260 T polymorphism is associated with an elevated risk of MI.

Causal relationship from coffee consumption to diseases and mortality: a review of observational and Mendelian randomization studies including cardiometabolic diseases, cancer, gallstones and other diseases

PURPOSE

High coffee consumption is associated with low risk of mortality and morbidity, but the causality remains unclear. This review aims to discuss findings from observational studies on coffee consumption in context of Mendelian randomization studies.

METHODS

The PubMed database was searched for all Mendelian randomization studies on coffee consumption and corresponding observational studies.

RESULTS

High coffee consumption is associated with low risk of all-cause and cardiovascular mortality in observational studies (HRs of 0.85-0.90 vs. no/low consumers), with no support of causality in Mendelian randomization studies. Moderate/high consumption is associated with low risk of cardiometabolic diseases, including ischemic heart disease (HRs of 0.85-0.90 vs. no/low consumption), stroke (HRs of approximately 0.80 vs. no/low consumption), type 2 diabetes (HRs of approximately 0.70 vs. no/low consumption) and obesity in observational studies, but not in Mendelian randomization studies. High consumption is associated with low risk of endometrial cancer and melanoma and high risk of lung cancer in observational studies, but with high risk of colorectal cancer in Mendelian randomization studies. In observational and Mendelian randomization studies, high coffee consumption is associated with low risk of gallstones (HRs of 0.55-0.70 for high vs. no/low self-reported and 0.81 (0.69-0.96) for highest vs. lowest genetic consumption).

CONCLUSION

High coffee consumption is associated with low risk of mortality, cardiometabolic diseases, some cancers and gallstones in observational studies, with no evidence to support causality from Mendelian randomization studies for most diseases except gallstones.

A common variant in CCDC93 protects against myocardial infarction and cardiovascular mortality by regulating endosomal trafficking of low-density lipoprotein receptor

AIMS

Genome-wide association studies have previously identified INSIG2 as a candidate gene for plasma low-density lipoprotein cholesterol (LDL-c). However, we suspect a role for CCDC93 in the same locus because of its involvement in the recycling of the LDL-receptor (LDLR).

METHODS AND RESULTS

Characterization of the INSIG2 locus was followed by studies in over 107 000 individuals from the general population, the Copenhagen General Population Study and the Copenhagen City Heart Study, for associations of genetic variants with plasma lipids levels, with risk of myocardial infarction (MI) and with cardiovascular mortality. CCDC93 was furthermore studied in cells and mice. The lead variant of the INSIG2 locus (rs10490626) is not associated with changes in the expression of nearby genes but is a part of a genetic block, which excludes INSIG2. This block includes a coding variant in CCDC93 p.Pro228Leu, which is in strong linkage disequilibrium with rs10490626 (r2 > 0.96). In the general population, separately and combined, CCDC93 p.Pro228Leu is dose-dependently associated with lower LDL-c (P-trend 2.5 × 10-6 to 8.0 × 10-9), with lower risk of MI (P-trend 0.04-0.002) and lower risk of cardiovascular mortality (P-trend 0.005-0.004). These results were validated for LDL-c, risk of both coronary artery disease and MI in meta-analyses including from 194 000 to >700 000 participants. The variant is shown to increase CCDC93 protein stability, while overexpression of human CCDC93 decreases plasma LDL-c in mice. Conversely, CCDC93 ablation reduces LDL uptake as a result of reduced LDLR levels at the cell membrane.

CONCLUSION

This study provides evidence that a common variant in CCDC93, encoding a protein involved in recycling of the LDLR, is associated with lower LDL-c levels, lower risk of MI and cardiovascular mortality.

The Use of Defatted Tenebrio molitor Larvae Meal as a Main Protein Source Is Supported in European Sea Bass (Dicentrarchus labrax) by Data on Growth Performance, Lipid Metabolism, and Flesh Quality

Objective

This study aims to determine the maximal inclusion level of defatted (d-) Tenebrio molitor larvae meal (TM) able to replace dietary fishmeal (FM) without compromising growth performance, general metabolism, and flesh quality traits in European sea bass, and to evaluate the major underlying physiological mechanisms.

Materials and Methods

Fish (55 ± 2 g) were fed with diets containing increasing levels of dTM: 0, 40, 80 and 100% (CTRL, TM40, TM80, and TM100, respectively) to replace FM. After 10 weeks of feeding, the growth performance, nutrient and energy balance, intestinal integrity, plasma metabolites and the expression of genes related to growth and nutrient metabolism, in liver and muscle were determined. The fatty acids (FA) profile, textural properties and color were also evaluated in muscle.

Results

Protein and lipids digestibility remained unaltered up to 80% dTM inclusion. Growth performance parameters were similar among dietary treatments. The dTM inclusion increased the hepatosomatic index in fish fed TM100. Muscle eicosapentaenoic acid, docosahexaenoic acid and n-3 long-chain polyunsaturated FA levels were maintained up to 80% dTM inclusion, but total cholesterol and non-esterified FA increased with dietary dTM inclusion. In liver, the expression of elongation of very long-chain FA protein 6 (elovl6) and FA desaturase 2 (fads2) did not change in fish fed TM40 and TM80, but elovl6 decreased whilst fads2 increased in fish fed TM100 when compared to those fed CTRL. The expression of cholesterol 7 alpha-monooxygenase (cyp7a1) decreased with dietary dTM inclusion. In muscle, the expression of myoblast determination protein-2 (myod2) decreased in fish fed TM80 and TM100.

Conclusion

It is feasible to substitute dietary FM by dTM up to 80% in European sea bass without detrimental effects on nutrient digestibility, growth performance and associated genetic pathways, whilst assuring fillet nutritional value for human consumption.

Association of Low Plasma Transthyretin Concentration With Risk of Heart Failure in the General Population

Importance

Several lines of evidence support low plasma transthyretin concentration as an in vivo biomarker of transthyretin tetramer instability, a prerequisite for the development of both wild-type transthyretin cardiac amyloidosis (ATTRwt) and hereditary transthyretin cardiac amyloidosis (ATTRm). Both ATTRm and ATTRwt cardiac amyloidosis may manifest as heart failure (HF). However, whether low plasma transthyretin concentration confers increased risk of incident HF in the general population is unknown.

Objective

To evaluate whether low plasma transthyretin concentration is associated with incident HF in the general population.

Design, Setting, and Participants

This study included data from 2 similar prospective cohort studies of the Danish general population, the Copenhagen General Population Study (CGPS; n = 9582) and the Copenhagen City Heart Study (CCHS; n = 7385). Using these data, first, whether low concentration of plasma transthyretin was associated with increased risk of incident HF was tested. Second, whether genetic variants in TTR associated with increasing tetramer instability were associated with lower transthyretin concentration and with higher risk of HF was tested. Data were collected from November 2003 to March 2017 in the CGPS and from November 1991 to June 1994 in the CCHS; participants from both studies were observed for survival time end points until March 2017. Data were analyzed from March to June 2019.

Exposures

Transthyretin concentration at or below the 5th percentile, between the 5th and 95th percentile (reference), and greater than the 95th percentile; genetic variants in TTR.

Main Outcome and Measure

Incident HF identified using the Danish National Patient Registry.

Results

Of 9582 individuals in the CGPS, 5077 (53.0%) were women, and the median (interquartile range [IQR]) age was 56 (47-65) years. Of 7385 individuals in the CCHS, 4452 (60.3%) were women, and the median (IQR) age was 59 (46-70) years. During a median (IQR) follow-up of 12.6 (12.3-12.9) years and 21.7 (11.6-23.8) years, 441 individuals (4.6%) in the CGPS and 1122 individuals (15.2%) in the CCHS, respectively, developed HF. Baseline plasma transthyretin concentrations at or below the 5th percentile were associated with incident HF (CGPS: hazard ratio [HR], 1.6; 95% CI, 1.1-2.4; CCHS: HR, 1.4; 95% CI, 1.1-1.7). Risk of HF was highest in men with low transthyretin levels. Compared with p.T139M, a transthyretin-stabilizing variant, TTR genotype was associated with stepwise lower transthyretin concentrations for wild-type TTR (-16.5%), p.G26S (-18.1%), and heterozygotes for other variants (p.V142I, p.H110N, and p.D119N; -30.8%) (P for trend <.001). The corresponding HRs for incident HF were 1.14 (95% CI, 0.57-2.28), 1.29 (95% CI, 0.64-2.61), and 2.04 (95% CI, 0.54-7.67), respectively (P for trend = .04).

Conclusions and Relevance

In this study, lower plasma and genetically determined transthyretin concentrations were associated with a higher risk of incident HF, suggesting a potential mechanistic association between low transthyretin concentration as a marker of tetramer instability and incident HF in the general population.

Maternal plasma folate concentration is positively associated with serum total cholesterol and low-density lipoprotein across the three trimesters of pregnancy

Increased first-trimester low-density lipoprotein (LDL-C) concentration has been associated with adverse pregnancy outcomes, such as gestational diabetes. The B vitamins folate, B-6, and total B-12 are key for the methyl group-dependent endogenous synthesis of phosphatidylcholine, which is needed for lipoprotein synthesis, e.g., very low-density lipoprotein (VLDL), the precursor of circulating LDL-C. Maternal B-vitamin concentration usually declines across trimesters. Whether changes in maternal B-vitamin concentrations are associated with total cholesterol (TC), triglycerides (TG), and lipoprotein concentrations is unknown. Therefore, we explored the association between plasma folate, vitamin B-6 in the form of pyridoxal 5′-phosphate (PLP), and total B-12 with serum TC, LDL-C, HDL-C, and TG concentrations across trimesters. This secondary analysis used data of a prospective pregnancy cohort study included apparently healthy adult women (n = 179) from Rio de Janeiro, Brazil. The biomarkers were measured in fasting blood samples collected at 5–13, 20–26, and 30–36 weeks of gestation. The associations between B vitamins and lipid concentrations across trimesters were explored using linear mixed-effect models. Among B vitamins, only plasma folate was positively associated with TC (β = 0.244, 95% CI 0.034–0.454) and LDL-C (β = 0.193, 95% CI 0.028–0.357) concentrations. The positive relationship of maternal folate and TC and LDL-C concentrations may indicate the importance of folate as a methyl donor for lipoprotein synthesis during pregnancy.

Farnesoid X Receptor Agonists as Therapeutic Target for Cardiometabolic Diseases

Cardiometabolic diseases are characterized as a combination of multiple risk factors for cardiovascular disease (CVD) and metabolic diseases including diabetes mellitus and dyslipidemia. Cardiometabolic diseases are closely associated with cell glucose and lipid metabolism, inflammatory response and mitochondrial function. Farnesoid X Receptor (FXR), a metabolic nuclear receptor, are found to be activated by primary BAs such as chenodeoxycholic acid (CDCA), cholic acid (CA) and synthetic agonists such as obeticholic acid (OCA). FXR plays crucial roles in regulating cholesterol homeostasis, lipid metabolism, glucose metabolism, and intestinal microorganism. Recently, emerging evidence suggests that FXR agonists are functional for metabolic syndrome and cardiovascular diseases and are considered as a potential therapeutic agent. This review will discuss the pathological mechanism of cardiometabolic disease and reviews the potential mechanisms of FXR agonists in the treatment of cardiometabolic disease.

Capsaicin—the major bioactive ingredient of chili peppers: bio-efficacy and delivery systems

The mechanisms of bio-efficacy of capsaicin and delivery systems with enhanced bioavailability were reviewed.

Coffee intake protects against symptomatic gallstone disease in the general population: a Mendelian randomization study

BACKGROUND AND OBJECTIVES

Coffee intake is associated with low risk of symptomatic gallstone disease (GSD). We tested the hypothesis that high coffee intake causally protects against symptomatic GSD using a Mendelian randomization design.

METHODS

First, we tested whether high coffee intake was associated with low risk of GSD in 104 493 individuals from the general population. Mean follow-up was 8 years (range: <1-13 years). Secondly, we tested whether two genetic variants near CYP1A1/A2 (rs2472297) and AHR (rs4410790), combined as an allele score, were associated with higher coffee intake measured as a continuous variable. Thirdly, we tested whether the allele score was associated with lower risk of GSD in 114 220 individuals including 7294 gallstone events. Mean follow-up was 38 years (range: <1-40 years).

RESULTS

In observational analysis, those with coffee intake of >6 cups daily had 23% lower risk of GSD compared to individuals without coffee intake [hazard ratio (HR) = 0.77 (95% confidence interval: 0.61-0.94)]. In genetic analysis, there was a stepwise higher coffee intake of up to 41% (caffeine per day) in individuals with 4 (highest) versus 0 (lowest) coffee intake alleles (P for trend = 3 x 10^-178 ) and a corresponding stepwise lower risk of GSD up to 19%[HR = 0.81 (0.69-0.96)]. The estimated observational odds ratio for GSD for a one cup per day higher coffee intake was 0.97 (0.96-0.98), equal to 3% lower risk. The corresponding genetic odds ratio was 0.89 (0.83-0.95), equal to 11% lower risk.

CONCLUSION

High coffee intake is associated observationally with low risk of GSD, and with genetic evidence to support a causal relationship.

Genetic contributions to NAFLD: leveraging shared genetics to uncover systems biology

Nonalcoholic fatty liver disease (NAFLD) affects around a quarter of the global population, paralleling worldwide increases in obesity and metabolic syndrome. NAFLD arises in the context of systemic metabolic dysfunction that concomitantly amplifies the risk of cardiovascular disease and diabetes. These interrelated conditions have long been recognized to have a heritable component, and advances using unbiased association studies followed by functional characterization have created a paradigm for unravelling the genetic architecture of these conditions. A novel perspective is to characterize the shared genetic basis of NAFLD and other related disorders. This information on shared genetic risks and their biological overlap should in future enable the development of precision medicine approaches through better patient stratification, and enable the identification of preventive and therapeutic strategies. In this Review, we discuss current knowledge of the genetic basis of NAFLD and of possible pleiotropy between NAFLD and other liver diseases as well as other related metabolic disorders. We also discuss evidence of causality in NAFLD and other related diseases and the translational significance of such evidence, and future challenges from the study of genetic pleiotropy.

Rare Diseases Related with Lipoprotein Metabolism

Rare diseases are gathering increasing attention in last few years, not only for its effects on innovation scientific research, but also for its propounding influence on common diseases. One of the most famous milestones made by Michael Brown and Joseph Goldstein in metabolism field is the discovery of the defective gene in familial hypercholesterolemia, a rare human genetic disease manifested with extreme high level of serum cholesterol (Goldstein JL, Brown MS, Proc Natl Acad Sci USA 70:2804-2808, 1973; Brown MS, Dana SE, Goldstein JL, J Biol Chem 249:789-796, 1974). Follow-up work including decoding the gene function, mapping-related pathways, and screening therapeutic targets are all based on the primary finding (Goldstein JL, Brown MS Arterioscler Thromb Vasc Biol 29:431-438, 2009). A series of succession win the two brilliant scientists the 1985 Nobel Prize, and bring about statins widely used for lipid management and decreasing cardiovascular disease risks. Translating the clinical extreme phenotypes into laboratory bench work has turned out to be the first important step in the paradigm conducting translational and precise medical research. Here we review the main categories of rare disorders related with lipoprotein metabolism, aiming to strengthen the notion that human rare inheritable genetic diseases would be the window to know ourselves better, to treat someone more efficiently, and to lead a healthy life longer. Few rare diseases related with lipoprotein metabolism were clustered into six sections based on changes in lipid profile, namely, hyper- or hypocholesterolemia, hypo- or hyperalphalipoproteinemia, abetalipoproteinemia, hypobetalipoproteinemia, and sphingolipid metabolism diseases. Each section consists of a brief introduction, followed by a summary of well-known disease-causing genes in one table, and supplemented with one or two diseases as example for detailed description. Here we aimed to raise more attention on rare lipoprotein metabolism diseases, calling for more work from basic research and clinical trials.

Genes Potentially Associated with Familial Hypercholesterolemia

This review addresses the contribution of some genes to the phenotype of familial hypercholesterolemia. At present, it is known that the pathogenesis of this disease involves not only a pathological variant of low-density lipoprotein receptor and its ligands (apolipoprotein B, proprotein convertase subtilisin/kexin type 9 or low-density lipoprotein receptor adaptor protein 1), but also lipids, including sphingolipids, fatty acids, and sterols. The genetic cause of familial hypercholesterolemia is unknown in 20%–40% of the cases. The genes STAP1 (signal transducing adaptor family member 1), CYP7A1 (cytochrome P450 family 7 subfamily A member 1), LIPA (lipase A, lysosomal acid type), ABCG5 (ATP binding cassette subfamily G member 5), ABCG8 (ATP binding cassette subfamily G member 8), and PNPLA5 (patatin like phospholipase domain containing 5), which can cause aberrations of lipid metabolism, are being evaluated as new targets for the diagnosis and personalized management of familial hypercholesterolemia.

Identification and Replication of Six Loci Associated With Gallstone Disease

Gallstone disease is a common complex disease that confers a substantial economic burden on society. The genetic underpinnings of gallstone disease remain incompletely understood. We aimed to identify genetic associations with gallstone disease using publicly available data from the UK Biobank and two large Danish cohorts. We extracted genetic associations with gallstone disease from the Global Biobank Engine (GBE), an online browser of genome-wide associations in UK Biobank participants (14,940 cases and 322,268 controls). Significant associations (P < 5 × 10^-8 ) were retested in two Copenhagen cohorts (comprising 1,522 cases and 18,266 controls). In the Copenhagen cohorts, we also tested whether a genetic risk score was associated with gallstone disease and whether individual gallstone loci were associated with plasma levels of lipids, lipoproteins, and liver enzymes. We identified 19 loci to be associated with gallstone disease in the GBE. Of these, 12 were replicated in the Copenhagen cohorts, including six previously unknown loci (in hepatocyte nuclear factor 4 alpha [HNF4A], fucosyltransferase 2, serpin family A member 1 [SERPINA1], jumonji domain containing 1C, AC074212.3, and solute carrier family 10A member 2 [SLC10A2]) and six known loci (in adenosine triphosphate binding cassette subfamily G member 8 [ABCG8], sulfotransferase family 2A member 1, cytochrome P450 7A1, transmembrane 4 L six family member 4, ABCB4, and tetratricopeptide repeat domain 39B). Five of the gallstone associations are protein-altering variants, and three (HNF4A p.Thr139Ile, SERPINA1 p.Glu366Lys, and SLC10A2 p.Pro290Ser) conferred per-allele odds ratios for gallstone disease of 1.30-1.36. Individuals with a genetic risk score >2.5 (prevalence 1%) had a 5-fold increased risk of gallstones compared to those with a score <1.0 (11%). Of the 19 lithogenic loci, 11 and ten exhibited distinct patterns of association with plasma levels of lipids and liver enzymes, respectively. Conclusion: We identified six susceptibility loci for gallstone disease.

Genome-wide association meta-analysis yields 20 loci associated with gallstone disease

Gallstones are responsible for one of the most common diseases in the Western world and are commonly treated with cholecystectomy. We perform a meta-analysis of two genome-wide association studies of gallstone disease in Iceland and the UK, totaling 27,174 cases and 736,838 controls, uncovering 21 novel gallstone-associated variants at 20 loci. Two distinct low frequency missense variants in SLC10A2, encoding the apical sodium-dependent bile acid transporter (ASBT), associate with an increased risk of gallstone disease (Pro290Ser: OR = 1.36 [1.25-1.49], P = 2.1 × 10-12, MAF = 1%; Val98Ile: OR = 1.15 [1.10-1.20], P = 1.8 × 10-10, MAF = 4%). We demonstrate that lower bile acid transport by ASBT is accompanied by greater risk of gallstone disease and highlight the role of the intestinal compartment of the enterohepatic circulation of bile acids in gallstone disease susceptibility. Additionally, two low frequency missense variants in SERPINA1 and HNF4A and 17 common variants represent novel associations with gallstone disease.