Peroxisome Proliferator-Activated Receptor-γ Prevents Cholesterol Gallstone Formation in C57bl Mice by Regulating Bile Acid Synthesis and Enterohepatic Circulation

Trans-ancestry genome-wide association meta-analysis of gallstone disease

Gallstone disease is a highly prevalent and costly gastrointestinal disease. Yet, genetic variation in susceptibility to gallstone disease and its implication in metabolic regulatory pathways remain to be explored. We report a trans-ancestry genome-wide association meta-analysis of gallstone disease including 88,063 cases and 1,490,087 controls in the UK Biobank, FinnGen, Biobank Japan, and Million Veteran Program. We identified 91 (37 novel) risk loci across the meta-analysis and found replication in statistically compelling signals in the All of Us Research Program. A polygenic risk score constructed from trans-ancestry lead variants was positively associated with liver chemistry and alpha-1-antitrypsin deficiency and negatively associated with total cholesterol and low-density lipoprotein levels among trans-ancestry and European ancestry groups in the Penn Medicine BioBank. Cross-trait colocalization analysis between risk loci and 44 liver, metabolic, renal, and inflammatory traits yielded 350 significant colocalizations as well as 97 significant colocalizations and 65 prioritized genes from expression quantitative trait loci from eight tissues. These findings broaden our understanding of the genetic architecture of gallstone disease.

Proteomics and metabolomics analyses of urine for investigation of gallstone disease in a high-altitude area

BACKGROUND

The incidence of gallstones is high in Qinghai Province. However, the molecular mechanisms underlying the development of gallstones remain unclear.

METHODS

In this study, we collected urine samples from 30 patients with gallstones and 30 healthy controls. The urine samples were analysed using multi-omics platforms. Proteomics analysis was conducted using data-independent acquisition, whereas metabolomics analysis was performed using liquid chromatography-mass spectrometry (LC-MS).

RESULTS

Among the patients with gallstones, we identified 49 down-regulated and 185 up-regulated differentially expressed proteins as well as 195 up-regulated and 189 down-regulated differentially expressed metabolites. Six pathways were significantly enriched: glycosaminoglycan degradation, arginine and proline metabolism, histidine metabolism, pantothenate and coenzyme A biosynthesis, drug metabolism-other enzymes, and the pentose phosphate pathway. Notably, 10 differentially expressed proteins and metabolites showed excellent predictive performance and were selected as potential biomarkers.

CONCLUSION

The findings of our metabolomics and proteomics analyses provide new insights into novel biomarkers for patients with cholelithiasis in high-altitude areas.

Raspberry Ketone Attenuates Hepatic Fibrogenesis and Inflammation via Regulating the Crosstalk of FXR and PGC-1α Signaling

Hepatic fibrosis is a compensatory response to chronic liver injury and inflammation, and dietary intervention is recommended as one of the fundamental prevention strategies. Raspberry ketone (RK) is an aromatic compound first isolated from raspberry and widely used to prepare food flavors. The current study investigated the hepatoprotection and potential mechanism of RK against hepatic fibrosis. In vitro, hepatic stellate cell (HSC) activation was stimulated with TGF-β and cultured with RK, farnesoid X receptor (FXR), or peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) agonist or inhibitor, respectively. In vivo, C57BL/6 mice were injected intraperitoneally with thioacetamide (TAA) at 100/200 mg/kg from the first to the fifth week. Mice were intragastrically administrated with RK or Cur once a day from the second to the fifth week. In activated HSCs, RK inhibited extracellular matrix (ECM) accumulation, inflammation, and epithelial-mesenchymal transition (EMT) process. RK both activated FXR/PGC-1α and regulated their crosstalk, which were verified by their inhibitors and agonists. Deficiency of FXR or PGC-1α also attenuated the effect of RK on the reverse of activated HSCs. RK also decreased serum ALT/AST levels, liver histopathological change, ECM accumulation, inflammation, and EMT in mice caused by TAA. Double activation of FXR/PGC-1α might be the key targets for RK against hepatic fibrosis. Above all, these discoveries supported the potential of RK as a novel candidate for the dietary intervention of hepatic fibrosis.

Comprehensive analysis of differential long non-coding RNA and messenger RNA expression in cholelithiasis using high-throughput sequencing and bioinformatics

Background

The etiology of gallstone disease (GSD) has not been fully elucidated. Consequently, the primary objective of this study was to scrutinize and provisionally authenticate the distinctive expression profiles of long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) in GSD.

Methods

RiboNucleic Acid (RNA) sequencing was used on four paired human gallbladder samples for the purpose of this study. Differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) were identified and subjected to analysis of their biological functions. The Pearson's correlation coefficients between DElncRNAs and DEmRNAs were computed to construct a co-expression network delineating their associations. Furthermore, both cis- and trans-regulatory networks of selected lncRNAs were established and visualized. Additionally, a competing endogenous RNA (ceRNA) regulatory network was constructed. To validate the RNA-sequencing data, we performed a Quantitative Real-time Polymerase Chain Reaction (RT-qPCR) on 10 paired human gallbladder samples, assessing the expressions of the top 4 DEmRNAs and DElncRNAs in gallstone and control samples.

Results

A total of 934 DEmRNAs and 304DElncRNAs were successfully identified. Functional enrichment analysis indicated a predominant involvement in metabolic-related biological functions. Correlation analysis revealed a strong association between the expressions of 597 DEmRNAs and 194 DElncRNAs. Subsequently, both a cis-lncRNA-mRNA and a trans-lncRNA-Transcription Factor (TF)-mRNA regulatory network were meticulously constructed. Additionally, a ceRNA network, comprising of 24 DElncRNAs, 201 DEmRNAs, and 120 predicted miRNAs, was established. Furthermore, using RT-qPCR, we observed significant upregulation of AC004692.4, HECW1-IT1, SFRP4, and COMP, while LINC01564, SLC26A3, RP1-27K12.2, and GSTA2 exhibited marked downregulation in gallstone samples. Importantly, these findings were consistent with the sequencing.

Conclusion

We conducted a screening process to identify DElncRNAs and DEmRNAs in GSD. This approach contributes to a deeper understanding of the genetic factors involved in the etiology of gallstones.

The role of peroxisome proliferator-activated receptors in the regulation of bile acid metabolism

Bile acids are synthesized from cholesterol in the liver. Dysregulation of bile acid homeostasis, characterized by excessive accumulation in the liver, gallbladder and blood, can lead to hepatocellular damage and the development of cholestatic liver disease. Nuclear receptors play a crucial role in the control of bile acid metabolism by efficiently regulating bile acid synthesis and transport in the liver. Among these receptors, peroxisome proliferator-activated receptor (PPAR), a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily, controls the expression of genes involved in adipogenesis, lipid metabolism, inflammation and glucose homeostasis and has emerged as a potential therapeutic target for the treatment of the metabolic syndrome in the past two decades. Emerging evidence suggests that PPAR activation holds promise as a therapeutic target for cholestatic liver disease, as it affects both bile acid production and transport. This review provides a comprehensive overview of recent advances in elucidating the role of PPAR in the regulation of bile acid metabolism, highlighting the current position of PPAR agonists in the treatment of primary biliary cholangitis. By summarizing the specific regulatory effects of PPAR on bile acids, this review contributes to the exploration of novel therapeutic strategies for cholestatic liver diseases.

Chaihu Shugan prevents cholesterol gallstone formation by ameliorating the microbiota dysbiosis and metabolic disturbance in mice

Introduction: Cholesterol gallstone (CGS) is a biliary tract disorder requiring treatment in approximately 20% of patients. The efficacy of Chaihu Shugan in preventing CGS recurrence after successful treatment remains uncertain. Methods: We examined the in vivo preventive efficacy of Chaihu Shugan using a CGS mouse model and used multi-omics to study the interplay between gut microbiota, metabolism, and gene expression. Results: The intestinal microbiota was severely dysregulated during the formation of CGS, showing a marked decrease in the abundance of beneficial microbiota, especially Lactobacillus and Akkermansia. Chaihu Shugan prevented CGS formation by restoring the composition of the gut microbiota and reversing the metabolic disturbances caused by dysbiosis. This preventive effect of Chaihu Shugan was paralleled by changes in the expression of metabolism-related genes in the liver. A network pharmacology analysis of Chaihu Shugan revealed that obacunone may be the key active metabolite in regulating bile acid metabolism. Multi-omics and correlation analyses elucidated the interplay between gut microbiota, metabolism, and gene alterations in the dose-dependent effect of Chaihu Shugan. Conclusion: Our data show that Chaihu Shugan can prevent CGS and indicate its mechanisms of action.

De novo mutation loci and clinical analysis in a child with sodium taurocholate cotransport polypeptide deficiency: A case report

BACKGROUND

Sodium taurocholate cotransport polypeptide (NTCP) deficiency disease is a genetic metabolic disorder due to mutations in the SLC10A1 gene and impaired bile acid salt uptake by the basolateral membrane transport protein NTCP in hepatocytes. A variety of clinical manifestations and genetic mutation loci have been reported for this disease. However, specific therapeutic measures are lacking, and the long-term effects are unknown.

CASE SUMMARY

An infant with elevated bile acids and behavioral neurodevelopmental delay failed to respond to bile acid-lowering therapy. Genetic testing for metabolic liver disease revealed that the child had NTCP deficiency due to the SLC10A1 mutation: c.422dupA (p.Y141X), which is a novel mutation site. The current follow-up revealed a gradual decrease in bile acid levels after 1 year of age, but the child still had behavioral neurodevelopmental delays.

CONCLUSION

The clinical manifestations, genetic characteristics, treatment and long-term prognosis due to NTCP deficiency remain poorly defined and need to be further confirmed by more studies and reports.

High-Fat Diet Alleviates Neuroinflammation and Metabolic Disorders of APP/PS1 Mice and the Intervention With Chinese Medicine

Alzheimer's disease (AD) is a progressive neurodegenerative disease caused by the complex interaction of multiple mechanisms. Recent studies examining the effect of high-fat diet (HFD) on the AD phenotype have demonstrated a significant influence on both inflammation and cognition. However, different studies on the effect of high-fat diet on AD pathology have reported conflicting conclusions. To explore the involvement of HFD in AD, we investigated phenotypic and metabolic changes in an AD mouse model in response to HFD. The results indicated there was no significant effect on Aβ levels or contextual memory due to HFD treatment. Of note, HFD did moderate neuroinflammation, despite spurring inflammation and increasing cholesterol levels in the periphery. In addition, diet affected gut microbiota symbiosis, altering the production of bacterial metabolites. HFD created a favorable microenvironment for bile acid alteration and arachidonic acid metabolism in APP/PS1 mice, which may be related to the observed improvement in LXR/PPAR expression. Our previous research demonstrated that Huanglian Jiedu decoction (HLJDD) significantly ameliorated impaired learning and memory. Furthermore, HLJDD may globally suppress inflammation and lipid accumulation to relieve cognitive impairment after HFD intervention. It was difficult to define the effect of HFD on AD progression because the results were influenced by confounding factors and biases. Although there was still obvious damage in AD mice treated with HFD, there was no deterioration and there was even a slight remission of neuroinflammation. Moreover, HLJDD represents a potential AD drug based on its anti-inflammatory and lipid-lowering effects.

Pioglitazone prevents cholesterol gallstone formation through the regulation of cholesterol homeostasis in guinea pigs with a lithogenic diet

Background

The cholesterol gallstones diseases (CGD) is highly correlated with metabolic syndrome and type 2 diabetes. The present study aimed to investigate preventive effects of pioglitazone (PIO), an antidiabetic drug, on the CGD in guinea pigs fed with a lithogenic diet (LD).

Methods

The guinea pigs were fed with the LD for 8 weeks. All guinea pigs were grouped as follows: low fat diet; LD; LD plus PIO (4 mg/kg); LD plus PIO (8 mg/kg); LD plus ezetimibe (EZE) (2 mg/kg). Gallbladder stones were observed using microscopy. The profile of biliary composition, and blood glucose, insulin and lipid were analyzed. The liver or ileum was harvested for determinations of hydroxyl-methyl-glutaryl-CoA reductase (HMGCR), sterol regulatory element-binding proteins 2 (SREBP2), 7α-hydroxylase (CYP7A1), adenosine triphosphate-binding cassette (ABC) sterol transporters G5 and G8 (ABCG5, ABCG8), bile salt export pump (BSEP), Niemann-Pick C1-Like 1 (NPC1L1) and acetyl-coenzyme A cholesterol acyltransferase (ACAT2) by Western blot. The gallbladders were used for histological examination.

Results

The LD successfully induced gallstone. Both pioglitazone and ezetimibe prevented gallstone formation, as well as hepatic and cholecystic damages. Pioglitazone significantly decreased HMGCR and SREBP2, but increased CYP7A1, ABCG5, ABCG8, and BSEP in the liver. Pioglitazone also remarkably decreased NPC1L1 and ACAT2, while increased ABCG5/8 in the intestine. The beneficial alterations of cholesterol and bile acids in the bile, as well as profile of glucose, insulin and lipid in the blood were found in the guinea pigs treated with pioglitazone.

Conclusion

Pioglitazone has a noticeable benefit towards the CGD, which is involved in changes of synthesis, transformation, absorption, and transportation of cholesterol.