Search Results (363)

Intrahepatic cholestasis of pregnancy (ICP) is characterized by the onset of pruritus and elevated serum transaminases and bile acids (BA). The key enzyme in BA synthesis is CYP7A1, and its functions are regulated by various nuclear receptors. The goal of this study is to evaluate the association between CYP7A1, NR1H1, RXRA, and PPARA gene variants and risk of ICP. Five single nucleotide variants (SNVs), rs3808607 (CYP7A1), rs56163822 (NR1H4), rs1800206 (PPARA), rs749759, and rs11381416 (NR2B1), were genotyped in a group of 96 ICP and 211 controls. The T allele of the CYP7A1 (rs3808607) variant may be a protective factor against ICP risk (OR = 0.697, 95% CI: 0.495–0.981, p = 0.038). Genetic model analysis showed that rs3808607 was associated with decreased risk of ICP under dominant (OR = 0.55, 95% CI: 0.32–3.16, p = 0.032, AIC = 380.9) and log-additive models (OR = 0.71, 95% CI: 0.51–1.00, p = 0.046, AIC = 381.4). The A insertion in the rs11381416 NR2B1 variant was associated with the degree of elevation in the liver function tests TBA (34.3 vs. 18.8 μmol/L, p = 0.002), ALT (397.0 vs. 213.0 IU/L, p = 0.017), and AST (186.0 vs. 114.4 IU/L, p = 0.032) in ICP women. Results indicate an association between the CYP7A1 rs3808607 and the risk of ICP and the association of the rs11381416 of the NR2B1 receptor with higher values of liver function tests in women with ICP. A better understanding of the cooperation of proteins involved in BA metabolism may have important therapeutic implications in ICP and other hepatobiliary diseases. Full article

Metabolic dysfunction-associated steatohepatitis (MASH) represents a critical hepatic manifestation within the broader spectrum of metabolic syndrome. The pathogenesis of MASH is characterized by disruptions in lipid metabolism, inflammation, and fibrosis. Bile acids and their receptors are integral to the progression of MASH, primarily through their regulatory influence on the metabolic networks of the gut–liver axis. This review offers a comprehensive and systematic examination of the molecular mechanisms underlying bile acid biosynthesis, metabolic dysregulation, and receptor signaling anomalies in MASH. Furthermore, it explores the translational potential of these insights into clinical therapies. Bile acids and their receptors emerge as pivotal therapeutic targets for MASH. Future research should focus on an in-depth analysis of dynamic regulatory mechanisms and the optimization of multi-target combination therapies, thereby paving the way for significant clinical advancements. Full article

Familial hypercholesterolemia (FH) is a genetic disorder marked by significantly elevated levels of low-density lipoprotein cholesterol (LDL-C) since childhood, substantially increasing the risk of premature atherosclerosis and cardiovascular disease. While dysfunction of hepatic LDL-C receptors is the main underlying cause, the gastrointestinal tract plays a key role in cholesterol homeostasis and represents an important therapeutic target. Inhibition of intestinal cholesterol absorption has emerged as an effective strategy in the management of pediatric FH, particularly in patients for whom statins may not be the ideal first-line treatment. Ezetimibe, an inhibitor of the Niemann-Pick C1-like 1 (NPC1L1) protein, has been shown to reduce LDL-C levels in children with FH, with a greater efficacy observed when used in combination with statins. Bile acid sequestrants also enhance cholesterol excretion but are often limited by gastrointestinal side effects, while dietary interventions, such as phytosterol supplementation and fiber-enriched diets, provide additional benefits in lowering LDL-C and are generally well tolerated. Emerging therapies, including microbiota-targeted strategies and novel cholesterol absorption inhibitors, show promise for expanding future treatment options. This review explores the mechanisms of intestinal cholesterol absorption and their relevance to pediatric FH. We examine key pathways, including dietary cholesterol uptake through NPC1L1, bile acid reabsorption, and cholesterol efflux mediated by ATP-binding cassette transporters, while also discussing clinical and experimental evidence on pharmacological and dietary interventions that modulate these pathways. A deeper understanding of cholesterol metabolism, the emerging role of the gut microbiota, and innovative therapeutic agents can support the development of more effective and personalized approaches to the treatment of children with FH. Full article

Background: Dyslipidemia and distorted fatty acid (FA) metabolism are frequent biochemical abnormalities associated with anorexia nervosa (AN). Gut microbiota is supposed to play an important role in the etiopathogenesis of AN. Apart from the digestive function of bile acids (BAs), these compounds have multiple metabolic functions due to the activation of specific receptors. Objective/aims: The aims of the study were to investigate biochemical measures, including plasma lipids (lipoproteins, respectively), fatty acid (FA) patterns, and the profile of plasma Bas, in AN patients and healthy controls (CON). Methods: Plasma phospholipid FA and BAs profiles were analyzed in 39 women with a restrictive type of AN (AN-R; median age 17 years) and in 35 CON women (median age 20 years). Results: Compared to CON, AN had an increased concentration of HDL-C, increased content of palmitic acid, and decreased proportion of linoleic acid. Moreover, AN had a drop in the level of the sum of PUFAn-6 and increased delta 9 desaturase activity for stearic acid. In AN, we found decreased levels of plasma tauroursodeoxycholic acid (TUDCA). In AN, concentrations of 22:5n-6, 16:0, 20:3n-6 and fat mass index were predic-tors of HDL-C levels (R² = 0.43). Conclusions: Patients with AN-R had an increased concentration of HDL-C, decreased levels of total PUFA n-6, and increased activity of D9D for stearic acid. Furthermore, AN exerted decreased levels of TUDCA. Therefore, a decreased level of TUDCA could potentially serve as a marker of AN. Full article

Non-alcoholic fatty liver disease (NAFLD) is a common metabolic condition characterized by hepatic lipid deposits, insulin resistance, and inflammation which may progress to non-alcoholic steatohepatitis (NASH) and fibrosis. Protein kinases play an important role in NAFLD development by regulating metabolic and inflammatory pathways. Mitogen-activated protein kinases (MAPKs), protein kinase C (PKC), AMP-activated protein kinase (AMPK), phosphoinositide 3-kinase (PI3K)/AKT, and mechanistic target of rapamycin (mTOR) are all involved in NAFLD and NASH progression. Emerging evidence indicates that Farnesoid X Receptor (FXR) agonists have therapeutic potential by modulating bile acid metabolism, lipid balance, and inflammatory responses. This review examines the mechanistic interplay between FXR agonists and important protein kinases in NAFLD and NASH. FXR agonists activate AMPK, which promotes fatty acid oxidation and reduces hepatic steatosis. They also regulate MAPK signaling, which reduces c-Jun NH2-terminal kinase (JNK)- and p38 MAPK-mediated inflammation. Furthermore, FXR agonists activate the PI3K/AKT pathway, enhancing insulin sensitivity and modulating mTOR signaling to reduce hepatic fibrosis. Clinical studies in NAFLD/NASH indicate that FXR agonists confer metabolic and anti-inflammatory benefits, although optimizing efficacy and minimizing adverse effects remain challenging. Future studies should focus on combination therapies targeting FXR alongside specific kinases to improve therapeutic outcomes. This review highlights the potential of FXR agonists to modulate protein kinase signaling, opening new avenues for targeted NAFLD/NASH therapy. Full article

Over the past decades, bile acids have been recognized as important signaling molecules with significant roles in metabolic health and disease. Many of their beneficial effects are mediated through the activation of the Takeda G protein-coupled receptor 5 (TGR5), a G protein-coupled receptor ubiquitously expressed in both humans and animals. Upon activation, TGR5 stimulates adenylate cyclase, leading to increased cyclic adenosine monophosphate (cAMP) levels and subsequent activation of protein kinase A (PKA). PKA then phosphorylates and activates several downstream signaling pathways, including exchange protein directly activated by cAMP (EPAC), extracellular signal-regulated kinase 1/2 (ERK1/2), and protein kinase B (AKT). Through these pathways, TGR5 acts as a key molecular link between bile acid signaling and the regulation of energy metabolism. TGR5 activation has been associated with body weight loss in obese models, primarily by reducing food intake, enhancing thermogenesis in adipose tissue and muscle to increase energy expenditure, and improving insulin secretion. This review highlights recent advances in our understanding of TGR5 biology and critically examines its therapeutic potential, limitations, and controversies in the context of energy metabolism, offering new perspectives and opportunities for treating metabolic disorders. Full article

Cancer is hallmarked by uncontrolled cell proliferation and enhanced cell survival, driven by a complex interplay of factors—including genetic and epigenetic changes—that disrupt metabolic and signaling pathways and impair organelle function. While the roles of mitochondria and the endoplasmic reticulum in cancer are widely recognized, emerging research is now drawing attention to the involvement of peroxisomes in tumor biology. Peroxisomes are essential for lipid metabolism, including fatty acid α- and β-oxidation, the synthesis of docosahexaenoic acid, bile acids, and ether lipids, as well as maintaining redox balance. Despite their critical functions, the role of peroxisomes in oncogenesis remains inadequately explored. Prostate cancer (PCa), the second most common cancer in men worldwide, exhibits a unique metabolic profile compared to other solid tumors. In contrast to the glycolysis-driven Warburg effect, primary PCa relies primarily on lipogenesis and oxidative phosphorylation. Peroxisomes are intricately involved in the metabolic adaptations of PCa, influencing both disease progression and therapy resistance. Key alterations in peroxisomal activity in PCa include the increased oxidation of branched-chain fatty acids, upregulation of α-methylacyl coenzyme A racemase (a prominent PCa biomarker), and downregulation of 1-alkyl-glycerone-3-phosphate synthase and catalase. This review critically examines the role of peroxisomes in PCa metabolism, progression, and therapeutic response, exploring their potential as biomarkers and targets for therapy. We also consider their relationship with androgen receptor signaling. A deeper understanding of peroxisome biology in PCa could pave the way for new therapies to improve patient outcomes. Full article

Metabolic dysregulation involving glucose and lipids is closely associated with chronic diseases such as type 2 diabetes mellitus. Emerging evidence highlights the regulatory role of bile acid (BA)–gut microbiota interactions in these metabolic disorders. The gut microbiota orchestrates the biotransformation of primary BAs into bioactive secondary BAs, which function as endocrine signaling molecules by activating the nuclear farnesoid X receptor (FXR) and G protein-coupled membrane receptor (TGR5), forming a communication network essential for metabolic homeostasis. BAs also reciprocally modulate gut microbiota composition. This BA–gut microbiota co-metabolism has emerged as a promising therapeutic target for lipid metabolism disorders. This comprehensive review examines the bidirectional interplay between gut microbiota and BA metabolism, focusing on microbial transformation of BAs, host–microbial co-regulatory pathways and mechanisms of BA metabolism, and the therapeutic implications of modulating the gut microbiota–BA axis in addressing glucose and lipid metabolism disorders. The synthesis of current evidence aims to elucidate the intricate crosstalk between microbial ecology and host metabolism mediated by BA signaling pathways, thereby exploring novel therapeutic intervention strategies. Full article

Nuclear receptors are proteins located in the nucleus that are involved in gene transcription and play an important role in regulating metabolism and inflammation. Systemic metabolic abnormalities and chronic inflammation in diabetic patients are associated with gene expression and activity of bile acid metabolism, lipid and carbohydrate metabolism, energy expenditure, and inflammation regulated by nuclear receptors. As a major metabolic organ, the nuclear receptor regulation signal of the liver is the key to regulating the dialog between the liver and other organs. In this review, we discuss the newly discovered role of hepatic nuclear receptor signaling in diabetes metabolism and inflammation and focus on recent advances in drug research targeting nuclear receptors in diabetes, including the use of traditional Chinese medicine. Full article

Elderly individuals infected with SARS-CoV-2 are at higher risk of developing cytokine storms and severe outcomes, yet specific biomarkers remain unclear. In this study, we investigated the alteration of primary bile acid metabolism in elderly patients with severe COVID-19 using untargeted metabolomics (n = 31), followed by targeted metabolomics to compare patients with disease progression (n = 16) to those without (n = 48). Significant reductions in chenodeoxycholic acid (CDCA) and glycochenodeoxycholic acid (GCDCA) levels were identified in severe cases, with GCDCA levels at admission correlating strongly with peak inflammatory markers. In vitro, CDCA, GCDCA, and their receptors, Farnesoid X Receptor (FXR) and Takeda G-protein-coupled receptor 5 (TGR5), effectively inhibited the inflammatory response induced by SARS-CoV-2. NOD-like receptor pathway, activated by SARS-CoV-2, may modulate inflammatory cytokines under the treatment of CDCA, GCDCA, and TGR5. CDCA and GCDCA levels at admission predicted disease progression, suggesting their potential as biomarkers for severe COVID-19 in the elderly and highlighting their regulatory role in inflammation, pointing to new therapeutic avenues. Full article

Tan sheep outperform Dorper sheep in meat-quality traits, including muscle fiber characteristics and fatty acid composition, while Dorper sheep excel in carcass weight. However, the molecular mechanisms underlying these breed-specific traits, especially gut microbiota–bile acid (BA) interactions, remain poorly understood. As host–microbiota co-metabolites, BAs are converted by colonic microbiota via bile salt hydrolase (BSH) and dehydroxylases into secondary BAs, which activate BA receptors to regulate host lipid and glucose metabolism. This study analyzed colonic BA profiles in 8-month-old Tan and Dorper sheep, integrating microbiome and longissimus dorsi muscle transcriptome data to investigate the gut–muscle axis in meat-quality and carcass trait regulation. Results showed that Tan sheep had 1.6-fold higher secondary BA deoxycholic acid (DHCA) levels than Dorper sheep (p < 0.05), whereas Dorper sheep accumulated conjugated primary BAs glycocholic acid (GCA) and tauro-α-muricholic acid (p < 0.05). Tan sheep exhibited downregulated hepatic BA synthesis genes, including cholesterol 7α-hydroxylase (CYP7A1) and 27-hydroxylase (CYP27A1), alongside upregulated transport genes such as bile salt export pump (BSEP), sodium taurocholate cotransporting polypeptide (NTCP), and ATP-binding cassette subfamily B member 4 (ABCB4), with elevated gut BSH activity (p < 0.05). DHCA was strongly correlated with g_Ruminococcaceae_UCG-014, ENSOARG00000001393, and ENSOARG00000016726, muscle fiber density, diameter, and linoleic acid (C18:2n6t) (|r| > 0.5, p < 0.05). In contrast, GCA was significantly associated with g_Lachnoclostridium_10, g_Rikenellaceae_RC9_gut_group, ENSOARG0000001232, carcass weight, and net meat weight (|r| > 0.5, p < 0.05). In conclusion, breed-specific colonic BA profiles were shaped by host–microbiota interactions, with DHCA potentially promoting meat quality in Tan sheep via regulation of muscle fiber development and fatty acid deposition, and GCA influencing carcass traits in Dorper sheep. This study provides novel insights into the gut microbiota–bile acid axis in modulating ruminant phenotypic traits. Full article

Objective: Yinchenhao decoction (YCHD), a classical herbal formula comprising Artemisia capillaris, Gardenia jasminoides, and Rheum palmatum, has been clinically used for over 1000 years to treat cholestasis. However, its mechanism of action remains undefined. This study aimed to elucidate YCHD’s therapeutic mechanisms against cholestasis, with a focus on the gut microbiota-mediated regulation of the farnesoid X receptor (FXR)–fibroblast growth factor 15 (FGF15) pathway. Methods: An alpha-naphthyl isothiocyanate (ANIT)-induced cholestasis mouse model was established. Mice received YCHD (3/9 g/kg) for 7 days. 16S rRNA sequencing, targeted LC/MS (bile acid (BA) quantification), untargeted GC/MS (fecal metabolite detection), qPCR/Western blot (FXR pathway analysis), fecal microbiota transplantation (FMT), and antibiotic depletion were employed to dissect the gut–liver axis interactions. Results: YCHD alleviated cholestatic liver injury by reducing serum biomarkers, restoring BA homeostasis via FXR-FGF15 activation, and suppressing hepatic Cyp7a1-mediated BA synthesis. It remodeled gut microbiota, enriched FXR-activating secondary BAs (CDCA, DCA, CA), and restored the intestinal barrier integrity. Antibiotic cocktail abolished YCHD’s efficacy, while FMT from YCHD-treated mice enhanced its therapeutic effects, confirming microbiota dependency. Conclusions: YCHD mitigates cholestasis through gut microbiota-driven FXR activation and direct hepatobiliary regulation. These findings bridge traditional medicine and modern pharmacology, highlighting microbiome modulation as a therapeutic strategy for cholestatic liver diseases. Full article

Bile acids (BAs), essential for lipid metabolism and fat-soluble vitamin absorption, also act as signaling molecules that regulate immune homeostasis. This review focuses on the roles of four key BA-activated receptors, farnesoid X receptor (FXR), G protein-coupled bile acid receptor 1 (GPBAR1), liver X receptors (LXRs), and vitamin D receptor (VDR), in modulating the functions of monocytes-macrophages, and dendritic cells (DCs). The biological synthesis, transport, and metabolism of BAs were discussed and highlighted the feedback mechanisms regulating the synthesis and enterohepatic circulation of BAs. Each receptor’s role in shaping immune responses is detailed, including their function in inflammation, apoptosis, phagocytosis, and pathogen clearance. FXR and GPBAR1 activation generally exhibits anti-inflammatory effects, while LXR and VDR modulate a more nuanced interplay between immune responses and lipid homeostasis. We also explored the cross-talk between BA-activated receptors and Toll-like receptors, providing a comprehensive understanding of the complex interplay between BA signaling and innate immunity. This review culminates by highlighting the therapeutic potential of targeting these receptors for the treatment of inflammatory and autoimmune diseases. Full article

Peroxisome proliferator-activated receptor α (PPARα, encoded by NR1C1) and farnesoid X receptor (FXR, encoded by NR1H4) are the two prominent nutrient-sensing nuclear receptors essential for maintaining hepatic metabolism during fasting and fed states, respectively. These nuclear receptors comprehensively regulate the transcription of numerous genes involved in fatty acid oxidation (FAO), ketogenesis, bile acid (BA) biosynthesis, and other metabolic processes critical for liver energy homeostasis. These receptors have been shown to have opposite impacts on autophagy, which is triggered by PPARα activation but inhibited by FXR activation. Recent studies have further revealed that liver-specific genetic ablation of key autophagic genes tremendously impairs the activation of these nuclear receptors, thereby profoundly affecting hepatic metabolism in both fasting and feeding states. This review explores the roles and mechanisms of PPARα and FXR in regulating liver metabolism and autophagy, highlighting the necessity of basal autophagic activity in ensuring the proper signaling of these nutrient-sensing nuclear receptors. Finally, we examine the potential therapeutic strategies that leverage the interplay between PPARα, FXR, and autophagy for the treatment of metabolic liver disorders. We also delve into the clinical implications of this complex relationship, emphasizing its significance for translational medicine and future therapeutic interventions. Full article

Background: Type 2 diabetes mellitus (T2DM), characterized by impaired glucose homeostasis, represents a significant threat to public health. Bile acids (BAs), as key metabolic regulators, play an essential role in glucose metabolism. Recent advances in high-resolution metabolomics have revealed that various BA species are closely linked to T2DM pathogenesis and play a critical role in maintaining glucose homeostasis. Understanding the underlying mechanisms by which BAs modulate glucose metabolism provides valuable insights for the prevention and treatment of T2DM. Methods/Results: This review describes the roles of diverse BA species in regulating glucose metabolism and comprehensively summarizes the relationship of unconjugated and conjugated BAs with T2DM in population studies. Furthermore, we discuss BA-targeted therapeutic approaches for T2DM, highlighting the urgent need for developing tissue-restricted modulators of BA receptors and advancing the clinical translation of novel beneficial BAs. Conclusion: Deeply understanding the role of BAs played in the pathogenesis and progression of T2DM will facilitate the development of potential therapeutic agents. Full article