Functional metabolomics characterizes the contribution of farnesoid X receptor in pyrrolizidine alkaloid-induced hepatic sinusoidal obstruction syndrome.

Consumption of herbal products containing pyrrolizidine alkaloids (PAs) is one of the major causes for hepatic sinusoidal obstruction syndrome (HSOS), a deadly liver disease. However, the crucial metabolic variation and biomarkers which can reflect these changes remain amphibious and thus to result in a lack of effective prevention, diagnosis and treatments against this disease. The aim of the study was to determine the impact of HSOS caused by PA exposure, and to translate metabolomics-derived biomarkers to the mechanism. In present study, cholic acid species (namely, cholic acid, taurine conjugated-cholic acid, and glycine conjugated-cholic acid) were identified as the candidate biomarkers (area under the ROC curve 0.968 [95% CI 0.908-0.994], sensitivity 83.87%, specificity 96.55%) for PA-HSOS using two independent cohorts of patients with PA-HSOS. The increased primary bile acid biosynthesis and decreased liver expression of farnesoid X receptor (FXR, which is known to inhibit bile acid biosynthesis in hepatocytes) were highlighted in PA-HSOS patients. Furtherly, a murine PA-HSOS model induced by senecionine (50 mg/kg, p.o.), a hepatotoxic PA, showed increased biosynthesis of cholic acid species via inhibition of hepatic FXR-SHP singling and treatment with the FXR agonist obeticholic acid restored the cholic acid species to the normal levels and protected mice from senecionine-induced HSOS. This work elucidates that increased levels of cholic acid species can serve as diagnostic biomarkers in PA-HSOS and targeting FXR may represent a therapeutic strategy for treating PA-HSOS in clinics.

The role of bile acids in carcinogenesis.

Bile acids are soluble derivatives of cholesterol produced in the liver that subsequently undergo bacterial transformation yielding a diverse array of metabolites. The bulk of bile acid synthesis takes place in the liver yielding primary bile acids; however, other tissues have also the capacity to generate bile acids (e.g. ovaries). Hepatic bile acids are then transported to bile and are subsequently released into the intestines. In the large intestine, a fraction of primary bile acids is converted to secondary bile acids by gut bacteria. The majority of the intestinal bile acids undergo reuptake and return to the liver. A small fraction of secondary and primary bile acids remains in the circulation and exert receptor-mediated and pure chemical effects (e.g. acidic bile in oesophageal cancer) on cancer cells. In this review, we assess how changes to bile acid biosynthesis, bile acid flux and local bile acid concentration modulate the behavior of different cancers. Here, we present in-depth the involvement of bile acids in oesophageal, gastric, hepatocellular, pancreatic, colorectal, breast, prostate, ovarian cancer. Previous studies often used bile acids in supraphysiological concentration, sometimes in concentrations 1000 times higher than the highest reported tissue or serum concentrations likely eliciting unspecific effects, a practice that we advocate against in this review. Furthermore, we show that, although bile acids were classically considered as pro-carcinogenic agents (e.g. oesophageal cancer), the dogma that switch, as lower concentrations of bile acids that correspond to their serum or tissue reference concentration possess anticancer activity in a subset of cancers. Differences in the response of cancers to bile acids lie in the differential expression of bile acid receptors between cancers (e.g. FXR vs. TGR5). UDCA, a bile acid that is sold as a generic medication against cholestasis or biliary surge, and its conjugates were identified with almost purely anticancer features suggesting a possibility for drug repurposing. Taken together, bile acids were considered as tumor inducers or tumor promoter molecules; nevertheless, in certain cancers, like breast cancer, bile acids in their reference concentrations may act as tumor suppressors suggesting a Janus-faced nature of bile acids in carcinogenesis.

Plasma metabolomic profiles reveal sex- and maturation-dependent metabolic strategies in sea lamprey (Petromyzon marinus).

INTRODUCTION: Adult sea lamprey (Petromyzon marinus) cease feeding and migrate to spawning streams where males build nests, undergo final sexual maturation, and subsequently produce and release large quantities of bile acid pheromones that attract mature females. These animals are predicted to rearrange their metabolic pathways drastically to support their reproductive strategies, presenting advantageous opportunities to examine how sex and the maturation processes affect metabolism. OBJECTIVES: The objective is to investigate the metabolic differences between sexes and maturation states in sea lamprey that support changes in physiological functions. METHODS: We compared plasma metabolomes of spawning and prespawning sea lamprey in both sexes using both non-targeted and targeted metabolomics approaches using UPLC/MS-MS with electrospray ionization in both positive and negative modes. The data were processed using Progenesis QI, Compound Discoverer and XCMS softwares for alignment, peak picking, and deconvolution of the peaks. Principle component analyses (PCA) and partial least squares discriminant analyses (PLS-DA) were performed using SIMCA and Metaboanalyst softwares to identify discriminating features, followed by fragmentation matching with extensive database search and pathway mapping. RESULTS: The pheromonal bile acid biosynthesis was upregulated significantly in males compared to females. Spermiating males further upregulated bile acid biosynthesis by altering amino acid metabolisms, upregulating cofactors and nucleotide metabolisms, but downregulating carbohydrate and energy metabolisms. CONCLUSION: Plasma metabolomes are sex- and maturation-dependent and reflect the special metabolic demands at each life stage and reproductive strategy.

Planar bile acids in health and disease.

Bile acids are the amphipathic primary end-products of cholesterol metabolism that aid in digestion as well as participate in signal transduction in several hepatic and enteric pathways. Despite the reputation of bile acids as signaling molecules implicated in disease states such as cancer and diabetes, there remain numerous bile acid species that are weakly characterized in either physiological or pathological conditions. This review presents one such group: the flat or planar bile acids, a set of bile acids found in humans during infancy and occurring again during certain diseases. As their name implies, these molecules are structurally distinct from the typical human bile acids, retaining the planar structure of their cholesterol predecessor instead of bending or twisting at the A ring. This review defines these species of bile acids in detail and describes their presence in infancy, gestation, and in disease. The large gaps in research regarding the flat bile acids are highlighted and all available experimental knowledge collected as far as 60years ago is summarized. Further, the potential for these molecules as endogenous biomarkers of liver disease and injury is discussed. Finally, the flat bile salts found in humans are compared to the ancestral and evolutionary older bile salts, which similarly have a flat steroidal structure, as mechanisms of flat bile acid biosynthesis are explored.

Integration of Multi-Omics, Histological, and Biochemical Analysis Reveals the Toxic Responses of Nile Tilapia Liver to Chronic Microcystin-LR Exposure.

Microcystin-LR (MC-LR) is a cyanobacterial metabolite produced during cyanobacterial blooms and is toxic to aquatic animals, and the liver is the main targeted organ of MC-LR. To comprehensively understand the toxicity mechanism of chronic exposure to environmental levels of MC-LR on the liver of fish, juvenile Nile tilapia were exposed to 0 µg/L (control), 1 µg/L (M1), 3 µg/L (M3), 10 µg/L (M10), and 30 µg/L (M30) MC-LR for 60 days. Then, the liver hepatotoxicity induced by MC-LR exposure was systematically evaluated via histological and biochemical determinations, and the underlying mechanisms were explored through combining analysis of biochemical parameters, multi-omics (transcriptome and metabolome), and gene expression. The results exhibited that chronic MC-LR exposure caused slight liver minor structural damage and lipid accumulation in the M10 group, while resulting in serious histological damage and lipid accumulation in the M30 group, indicating obvious hepatotoxicity, which was confirmed by increased toxicity indexes (i.e., AST, ALT, and AKP). Transcriptomic and metabolomic analysis revealed that chronic MC-LR exposure induced extensive changes in gene expression and metabolites in six typical pathways, including oxidative stress, apoptosis, autophagy, amino acid metabolism, primary bile acid biosynthesis, and lipid metabolism. Taken together, chronic MC-LR exposure induced oxidative stress, apoptosis, and autophagy, inhibited primary bile acid biosynthesis, and caused fatty deposition in the liver of Nile tilapia.

VSV infection and LPS treatment alter serum bile acid profiles, bile acid biosynthesis, and bile acid receptors in mice.

Pathogen infections remain a significant public health problem worldwide. Accumulating evidence regarding the crosstalk between bile acid (BA) metabolism and immune response reveals that BA metabolism regulates host immunity and microbial pathogenesis, making it an attractive target for disease prevention and infection control. However, the effect of infection on circulating BA profiles, the biosynthesis-related enzymes, and their receptors remains to be depicted. Here, we investigated the effect of viral (vesicular stomatitis virus, VSV) and bacterial (lipopolysaccharide, LPS) infections on BA metabolism and signaling. Infection models were successfully established by intraperitoneally injecting VSV and LPS, respectively. VSV and LPS injection significantly changed the circulating BA profiles, with highly increased levels of taurine-conjugated BAs and significant decreases in unconjugated BAs. Consistent with the decreased levels of circulating cholic acid (CA) and chenodeoxycholic acid (CDCA), the expression of BA biosynthesis-related rate-limiting enzymes (Cyp7a1, Cyp27a1, Cyp8b1, and Hsd3b7) were significantly reduced. Furthermore, hepatic and pulmonary BA receptors (BARs) expression varied in different infection models. LPS treatment had an extensive impact on tested hepatic and pulmonary BARs, resulting in the upregulation of TGR5, S1PR2, and VDR, while VSV infection only promoted VDR expression. Our study provides insights into the involvement of BA metabolism in the pathophysiology of infection, which may provide potential clues for targeting BA metabolism and BAR signaling to boost innate immunity and control infection. IMPORTANCE: This study focuses on the crosstalk between bile acid (BA) metabolism and immune response in VSV infection and LPS treatment models and depicts the effect of infection on circulating BA profiles, the biosynthesis-related enzymes, and their receptors. These findings provide insights into the effect of infection on BA metabolism and signaling, adding a more comprehensive understanding to the relationship between infection, BA metabolism and immune responses.

The anticancer activity of bile acids in drug discovery and development.

Bile acids (BAs) constitute essential components of cholesterol metabolites that are synthesized in the liver, stored in the gallbladder, and excreted into the intestine through the biliary system. They play a crucial role in nutrient absorption, lipid and glucose regulation, and the maintenance of metabolic homeostasis. In additional, BAs have demonstrated the ability to attenuate disease progression such as diabetes, metabolic disorders, heart disease, and respiratory ailments. Intriguingly, recent research has offered exciting evidence to unveil their potential antitumor properties against various cancer cell types including tamoxifen-resistant breast cancer, oral squamous cell carcinoma, cholangiocarcinoma, gastric cancer, colon cancer, hepatocellular carcinoma, prostate cancer, gallbladder cancer, neuroblastoma, and others. Up to date, multiple laboratories have synthesized novel BA derivatives to develop potential drug candidates. These derivatives have exhibited the capacity to induce cell death in individual cancer cell types and display promising anti-tumor activities. This review extensively elucidates the anticancer activity of natural BAs and synthetic derivatives in cancer cells, their associated signaling pathways, and therapeutic strategies. Understanding of BAs and their derivatives activities and action mechanisms will evidently assist anticancer drug discovery and devise novel treatment.

The mitochondrial translocator protein (TSPO, 18 kDa): A key multifunctional molecule in liver diseases.

Translocator protein (TSPO, 18 kDa), previously known as peripheral-type benzodiazepine receptor, is an evolutionarily conserved and tryptophan-rich 169-amino-acid protein located on the outer mitochondrial membrane. TSPO plays a crucial role in various fundamental physiological functions and cellular processes. Its expression is altered in pathological conditions, thus rendering TSPO a potential tool for diagnostic imaging and an appealing therapeutic target. The investigation of synthetic TSPO ligands as both agonists and antagonists has provided valuable insights into the regulatory mechanisms and functional properties of TSPO. Recently, accumulating evidence has highlighted the significance of TSPO in liver diseases. However, a comprehensive summary of TSPO function in the normal liver and diverse liver diseases is lacking. This review aims to provide an overview of recent advances in understanding TSPO function in both normal liver cells and various liver diseases, with a particular emphasis on its involvement in liver fibrosis and inflammation and addresses the existing knowledge gaps in the field that require further investigation.

Integration of pharmacodynamics, network pharmacology and metabolomics to elucidate effect and mechanism of Artemisia capillaris Thunb. in the treatment of jaundice.

ETHNOPHARMACOLOGICAL RELEVANCE: As one of the most commonly used herbs, Artemisia capillaris Thunb. (ACT) display favorable effect in the treatment of jaundice. However, mechanism of ACT in the treatment of jaundice remains unclear at present, which limits its development and application. AIM OF THE STUDY: To investigate effect and mechanism of Artemisia capillaris Thunb. (ACT) in the treatment of jaundice using pharmacodynamics, network pharmacology and metabolomics. METHODS: Effect of ACT in treating jaundice was evaluated by biochemical assays and pathological observation using the α-naphthyl isothiocyanate (ANIT)-induced mice. Jaundice-relieving mechanism of ACT was investigated by integration of network pharmacology and metabolomics. RESULTS: After the mice with jaundice were administrated ACT extract for 9 days, compared to that of the model group, serum D-BIL, T-BIL and ALP levels of the mice in the low, medium, high dose of ACT group decreased by 39.81%, 15.30% and 16.92%; 48.06%, 42.54% and 36.91%; 26.90%, 12.34% and 16.90%, respectively. The pathologic study indicated that ACT improved the symptoms of liver injury of the mice with jaundice. The network of herb (i.e., ACT)-components-targets-disease (i.e., jaundice) was established, which consisted of 17 components classified in flavonoids, chromones, organic acids, terpenoids, and 234 targets related to treatment of jaundice. Metabolomics analysis showed that, compared to that in the model group, level of 8 differential metabolites were upregulated and level of 29 differential metabolites were downregulated in the mice liver in the ACT group, respectively. The main metabolic pathways involved in treatment of jaundice by ACT were pantothenate and CoA biosynthesis, glutathione metabolism, biosynthesis of unsaturated fatty acids, primary bile acid biosynthesis in the liver, respectively. The integrated analysis of network pharmacology and metabolomics showed that 3α,7α,12α a-Trihydroxy-5ß-cholanate, glycocholate, taurocholate, pantetheine 4'-phosphate, and d-4'-phosphopantothenate were the potential biomarkers for treatment of jaundice, and AKR1C4, ALDH2 and HSD11B were the potential drug targets in the treatment of jaundice by ACT. CONCLUSION: The study based on metabolomics and network pharmacology indicated that ACT can display favorable jaundice-relieving effect by its multiple components regulating multiple biomarkers, multiple targets and multiple pathways, and may be a rational therapy for the treatment of jaundice.

Investigation of dichlorodiphenyltrichloroethane (DDT) on xenobiotic enzyme disruption and metabolomic bile acid biosynthesis in DDT-sprayed areas using wild rats.

Dichlorodiphenyltrichloroethane (DDT) is an organochlorine insecticide used worldwide. Several studies have reported the toxic effects of DDT and its metabolites on steroid hormone biosynthesis; however, its environmental effects are not well understood. This study examined wild rats collected in DDT-sprayed areas of South Africa and quantified plasma metabolites using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS). Fold change analysis of the metabolome revealed the effect of DDT on bile acid biosynthesis. Gene expression of the related enzyme in rat liver samples was also quantified. Significant association was found between DDT and gene expression levels related to constitutive androstane receptor mediated enzymes, such as Cyp2b1 in rat livers. However, our results could not fully demonstrate that enzymes related to bile acid biosynthesis were strongly affected by DDT. The correlation between DDT concentration and gene expression involved in steroid hormone synthesis in testis was also evaluated; however, no significant correlation was found. The disturbance of metabolic enzymes occurred in rat liver in the target area. Our results suggest that DDT exposure affects gene expression in wild rats living in DDT-sprayed areas. Therefore, there is a need for DDT toxicity evaluation in mammals living in DDT-sprayed areas. We could not find an effective biomarker that could reflect the mechanism of DDT exposure; however, this approach can provide new insights for future research to evaluate DDT effects in sprayed areas.

An integrative analysis of lipidomics and transcriptomics in various mouse brain regions in response to real-ambient PM2.5 exposure.

Exposure to Fine particulate matter (PM2.5) has been associated with various neurological disorders. However, the underlying mechanisms of PM2.5-induced adverse effects on the brain are still not fully defined. Multi-omics analyses could offer novel insights into the mechanisms of PM2.5-induced brain dysfunction. In this study, a real-ambient PM2.5 exposure system was applied to male C57BL/6 mice for 16 weeks, and lipidomics and transcriptomics analysis were performed in four brain regions. The findings revealed that PM2.5 exposure led to 548, 283, 304, and 174 differentially expressed genes (DEGs), as well as 184, 89, 228, and 49 distinctive lipids in the hippocampus, striatum, cerebellum, and olfactory bulb, respectively. Additionally, in most brain regions, PM2.5-induced DEGs were mainly involved in neuroactive ligand-receptor interaction, cytokine-cytokine receptor interaction, and calcium signaling pathway, while PM2.5-altered lipidomic profile were primarily enriched in retrograde endocannabinoid signaling and biosynthesis of unsaturated fatty acids. Importantly, mRNA-lipid correlation networks revealed that PM2.5-altered lipids and DEGs were obviously enriched in pathways involving in bile acid biosynthesis, De novo fatty acid biosynthesis, and saturated fatty acids beta-oxidation in brain regions. Furthermore, multi-omics analyses revealed that the hippocampus was the most sensitive part to PM2.5 exposure. Specifically, dysregulation of Pla2g1b, Pla2g, Alox12, Alox15, and Gpx4 induced by PM2.5 were closely correlated to the disruption of alpha-linolenic acid, arachidonic acid and linoleic acid metabolism in the hippocampus. In summary, our findings highlight differential lipidomic and transcriptional signatures of various brain regions by real-ambient PM2.5 exposure, which will advance our understanding of potential mechanisms of PM2.5-induecd neurotoxicity.

Liquid Chromatography-Tandem Mass Spectrometry-Based Metabolomics Analysis of Indigo Naturalis Treatment of Ulcerative Colitis in Mice.

Ulcerative colitis (UC), often known as UC, is an inflammatory disease of the intestines that has frequent and long-lasting flare-ups. It is unknown precisely how the traditional Chinese drug Indigo Naturalis (IN) heals inflammatory bowel disease, despite its long-standing use in China and Japan. Finding new metabolite biomarkers linked to UC could improve our understanding of the disease, speed up the diagnostic process, and provide insight into how certain drugs work to treat the condition. Our work is designed to use a metabolomic method to analyze potential alterations in endogenous substances and their impact on metabolic pathways in a mouse model of UC. To determine which biomarkers and metabolisms are more frequently connected with IN's effects on UC, liquid chromatography-tandem mass spectrometry analysis of the serum metabolomics of UC mice and normal mice was performed. The outcomes demonstrated that IN boosted the health of UC mice and reduced the severity of their metabolic dysfunction. In the UC model, it was also found that IN changed the way 17 biomarkers and 3 metabolisms functioned.

The Cerebrospinal Fluid Profile of Cholesterol Metabolites in Parkinson's Disease and Their Association With Disease State and Clinical Features.

Disordered cholesterol metabolism is linked to neurodegeneration. In this study we investigated the profile of cholesterol metabolites found in the cerebrospinal fluid (CSF) of Parkinson's disease (PD) patients. When adjustments were made for confounding variables of age and sex, 7α,(25R)26-dihydroxycholesterol and a second oxysterol 7α,x,y-trihydroxycholest-4-en-3-one (7α,x,y-triHCO), whose exact structure is unknown, were found to be significantly elevated in PD CSF. The likely location of the additional hydroxy groups on the second oxysterol are on the sterol side-chain. We found that CSF 7α-hydroxycholesterol levels correlated positively with depression in PD patients, while two presumptively identified cholestenoic acids correlated negatively with depression.

A case of Cerebrotendinous Xanthomatosis with spinal cord involvement and without tendon xanthomas: identification of a new mutation of the CYP27A1 gene.

Cerebrotendinous Xanthomatosis (CTX) is an autosomal recessive defect of the alternative pathway of bile acid biosynthesis, due to the deficiency of mitochondrial cytochrome P450 sterol 27-hydroxylase enzyme encoded by CYP27A1. The deficit of sterol 27-hydroxylase raises cholestanol in plasma and tissues of affected patients. Although there is a marked variability of signs, symptoms, severity and age of onset, the main clinical manifestations of CTX include chronic diarrhea, bilateral cataract, tendon xanthomas and neurological dysfunction. Herein, we report the clinical, biochemical and molecular characterization of a Caucasian female affected by CTX diagnosed at 28 years. The patient's clinical history revealed neurological and behavioral manifestations already at fifth year of life, following by bilateral cataract and chronic diarrhea without xanthomas. At diagnosis, an involvement of the cervical spinal cord was also observed on MRI. Sterols profile analysis in plasma and red blood cell membranes showed very high cholestanol levels. CYP27A1 sequencing revealed a new variant (e.g., c.850_854delinsCTC) at homozygous status. The follow-up after 5 months of chenodeoxycholic acid treatment showed a decrease of plasma cholestanol of 64%. After 1 year, the patient showed normalization of bowel function, reduction of risk of falls, improvement of cognitive function although brain and spine MRI and other instrumental examinations remained unchanged. This case highlights the variability of the CTX phenotype that makes it difficult to reach an early diagnosis. Biochemical and/or molecular screening of CTX should be taken into account to early start the pharmacological treatment limiting neurological damages.

Comparative Analysis of the Effects of Long-Term 3,5-diiodothyronine Treatment on the Murine Hepatic Proteome and Transcriptome Under Conditions of Normal Diet and High-Fat Diet.

Background: The thyroid hormone (TH) metabolite 3,5-diiodothyronine (3,5-T2) is considered as a potential drug for treatment of nonalcoholic fatty liver disease (NAFLD) based on its prominent antisteatotic effects in murine models of obesity without the detrimental thyromimetic side effects known for classical TH. To expand our understanding of its mode of action, we comprehensively characterized the effects of 3,5-T2 on hepatic gene expression in a diet-induced murine model of obesity by a combined liver proteome and transcriptome analysis. Materials and Methods: Male C57BL/6 mice fed high-fat diet (HFD) to induce NAFLD or standard diet (SD) as control were treated with 2.5 µg/g body weight 3,5-T2 or saline for 4 weeks. We performed mass spectrometry analyses and integrated those proteome data with earlier published microarray-based transcriptome data from the same animals. In addition, concentrations of several sex steroids in serum and different tissues were determined by gas chromatography-tandem mass spectrometry. Results: We observed limited concordance between transcripts and proteins exhibiting differential abundance under 3,5-T2 treatment, which was only partially explainable by methodological reasons and might, therefore, reflect noncanonical post-transcriptional events. The treatment affected the levels of more and partially different proteins under HFD as compared with SD, demonstrating response modulation by the hepatic lipid load. The hepatic physiological signatures of 3,5-T2 treatment inferable from the omics data comprised the reduction of oxidative stress and alteration of apolipoprotein profiles, both due to decreased liver fat content. In addition, induction of several classical TH target genes and genes involved in the biosynthesis of cholesterol, bile acids (BAs), and male sex steroids was observed. The latter finding was supported by hepatic sex steroid measurements. Conclusion: While confirming the beneficial hepatic liver fat reduction by 3,5-T2 treatment, our data suggest that besides the well-known induction of fatty acid oxidation the stimulation of cholesterol- and BA synthesis with subsequent excretion of the latter through bile might represent a further important mechanism in this context. The obvious intensified male sex steroid exposition of the liver in 3,5-T2-treated HFD animals can be predicted to cause enhanced hepatic "masculinization," with not yet clear but potentially detrimental physiological consequences.

Protective effect of picroside I against hepatic fibrosis in mice via sphingolipid metabolism, bile acid biosynthesis, and PPAR signaling pathway.

Picroside I, a hepatoprotectant isolated from Picrorhiza kurroa Royle ex Benth and P. scrophulariiflora Pennell, can reduce liver injury in humans and animals. However, its anti-fibrosis effect remains elusive. This work aimed to explore the mechanism underlying the hepatoprotective effect of picroside I against hepatic fibrosis. Male mice (12 mice per group) were randomly divided into six groups: the control group; the model group, which received thioacetamide (TAA); the positive group, which received TAA + S-(5'-adenosyl)-l-methionine (SAMe, 10 mg/kg); the low-dose group, which received TAA + picroside I (25 mg/kg); the middle-dose group, which received TAA + picroside I (50 mg/kg); and the high-dose group, which received TAA + picroside I (75 mg/kg). Serum biochemical indicators were detected, and histological evaluation was performed. Metabolomics and proteomic analyses were conducted via liquid-chromatography coupled with tandem mass spectrometry (LC-MS/MS). Data showed that picroside I could decrease the serum levels of alanine transaminase (ALT), aspartate transaminase (AST), collagen type IV (CIV), N-terminal peptide of type III procollagen (PIIINP), laminin (LN), and hyaluronic acid (HA) and reduced fibrosis area. Picroside I altered metabolomic profiles, including energy, lipid, and glutathione (GSH) metabolism, in ice with fibrosis. Additionally, 25 differentially expressed proteins in the picroside I high-dose-treated group were reversed relative to in the model group. These proteins were involved in the sphingolipid signaling pathway, primary bile acid biosynthesis, and peroxisome proliferator-activated receptor (PPAR) signaling pathway. Moreover, this study revealed how picroside I could protect against TAA-induced liver fibrosis in mice. Results indicated that picroside I can serve as a candidate drug for hepatic fibrosis.

Formation and metabolism of oxysterols and cholestenoic acids found in the mouse circulation: Lessons learnt from deuterium-enrichment experiments and the CYP46A1 transgenic mouse.

While the presence and abundance of the major oxysterols and cholestenoic acids in the circulation is well established, minor cholesterol metabolites may also have biological importance and be of value to investigate. In this study by observing the metabolism of deuterium-labelled cholesterol in the pdgfbret/ret mouse, a mouse model with increased vascular permeability in brain, and by studying the sterol content of plasma from the CYP46A1 transgenic mouse overexpressing the human cholesterol 24S-hydroxylase enzyme we have been able to identify a number of minor cholesterol metabolites found in the circulation, make approximate-quantitative measurements and postulate pathways for their formation. These "proof of principle" data may have relevance when using mouse models to mimic human disease and in respect of the increasing possibility of treating human neurodegenerative diseases with pharmaceuticals designed to enhance the activity of CYP46A1 or by adeno-associated virus delivery of CYP46A1.

Transcriptome analysis to assess the cholestatic hepatotoxicity induced by Polygoni Multiflori Radix: Up-regulation of key enzymes of cholesterol and bile acid biosynthesis.

Polygoni Multiflori Radix (PMR) has been commonly used as a tonic in China for centuries. However, PMR-associated hepatotoxicity is becoming a safety issue. Cholestasis often occurs in PMR-induced hepatotoxicity in clinical medicine, but the exact mechanism is not completely understood. An RNA-Seq method was employed, in the present study, to explore the molecular mechanism of cholestatic liver injury induced by PMR, characterized by the hepatic transcriptional response in rats exposed to 1 and 20 g/kg PMR for 90 days. Pathological changes seen in rat livers exposed to PMR included increased bile ducts in portal areas and biliary epithelial cell hyperplasia, which were accompanied by the elevation of serum biochemistries. Dose-dependent increases in the expression of 14 transcripts encoding enzymes involved in the cholesterol biosynthetic pathway were identified. Furthermore, cholesterol 7-alpha hydroxylase (Cyp7a1), a rate-limiting enzyme in the synthesis of bile acids (BAs) from cholesterol, was found to be upregulated by PMR treatment. Protein analysis by western blot suggested that expression of 3-hydroxy-3-methylglutaryl CoA reductase (Hmgcr) and Cyp7a1 were increased in a dose-dependent manner. Collectively, the present study demonstrates that PMR upregulates key enzymes for biosynthesis of cholesterol and BA, which poses the risk of cholestatic liver injury. SIGNIFICANCE: To the best of our knowledge, this is the first transcriptome analysis to highlight the main molecular changes occurring in rats chronic exposed to PMR. We have identified 39 specific differentially expressed genes (DEGs) that were present in various comparisons. A total of 14 of these altered gene transcripts were associated with cholesterol biosynthesis. Another factor of great importance in our opinion seemed to be the enhancement of bile acid (BA) biosynthesis, which were closely linked to cholesterol biosynthesis or metabolism. Our findings suggested that the disturbance on balance of BA formation and elimination might lead to a BA overload in hepatocytes, thereby resulting in liver injury.

Bile acid analysis in human disorders of bile acid biosynthesis.

Bile acids facilitate the absorption of lipids in the gut, but are also needed to maintain cholesterol homeostasis, induce bile flow, excrete toxic substances and regulate energy metabolism by acting as signaling molecules. Bile acid biosynthesis is a complex process distributed across many cellular organelles and requires at least 17 enzymes in addition to different metabolite transport proteins to synthesize the two primary bile acids, cholic acid and chenodeoxycholic acid. Disorders of bile acid synthesis can present from the neonatal period to adulthood and have very diverse clinical symptoms ranging from cholestatic liver disease to neuropsychiatric symptoms and spastic paraplegias. This review describes the different bile acid synthesis pathways followed by a summary of the current knowledge on hereditary disorders of human bile acid biosynthesis with a special focus on diagnostic bile acid profiling using mass spectrometry.

Extract of Rhus verniciflua stokes protects the diet-induced hyperlipidemia in mice.

Rhus verniciflua stokes (RVS) is a popular medicinal plant in oriental medicines which is commonly used to resolve extravasated blood. To elucidate the molecular mechanism of the role of RVS extracts on the regulation of lipid and cholesterol biosynthesis, we investigated whether RVS extract protect the hyperlipidemia in western diet-induced C57BL6/J mice. Mice fed a western diet and additionally RVS extracts was administered orally at a dose of 0.1 or 1 g/kg/day for 2 weeks respectively. Group with higher dose of RVS extract showed a significantly decreased body weight compared with western diet fed mice groups. And total cholesterol, LDL-cholesterol levels and fatty liver formation were also improved especially in group of mice fed western diet supplemented high dose RVS extracts. Next, synthesis of hepatic bile acids were significantly increased in RVS extract fed groups. Furthermore, RVS extracts significantly increase promoter activity of Cyp7a1 via up-regulate the transcriptional expression level of LXRα. Our data suggest that RVS extracts could be a potent therapeutic ingredient for prevent a hyperlipidemia via increase of bile acids biosynthesis.