Discovery of glycocholic acid and taurochenodeoxycholic acid as phenotypic biomarkers in cholangiocarcinoma

Decoding TGR5: A comprehensive review of its impact on cerebral diseases

Currently, unraveling the enigmatic realm of drug targets for cerebral disorders poses a formidable challenge. Takeda G protein-coupled receptor 5 (TGR5), also known as G protein-coupled bile acid receptor 1, is a specific bile acid receptor. Widely distributed across various tissues, TGR5 orchestrates a myriad of biological functions encompassing inflammation, energy metabolism, fatty acid metabolism, immune responses, cellular proliferation, apoptosis, and beyond. Alongside its well-documented implications in liver diseases, obesity, type 2 diabetes, tumors, and cardiovascular diseases, a growing body of evidence accentuates the pivotal role of TGR5 in cerebral diseases. Thus, this comprehensive review aimed to scrutinize the current insights into the pathological mechanisms involving TGR5 in cerebral diseases, while contemplating its potential as a promising therapeutic target for cerebral diseases.

Identification of molecular subtypes based on bile acid metabolism in cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma is a highly heterogeneous tumor with bile acid metabolism involving in its development. The aim of this study was to characterize bile acid metabolism and identify specific subtypes to better stratify cholangiocarcinoma patients for individualized treatment and prognostic assessment.

METHODS

A total of 30 bile acids were quantified using the ultra-performance liquid chromatography tandem mass spectrometry. Using Consensus clustering, the molecular subtypes related to bile acid metabolism were identified. The prognosis, clinicopathologic characteristics, immune landscape, and therapeutic response were compared between these subtypes. The single-cell RNA sequencing (scRNA-seq) analysis and preliminary cell experiment were also conducted to verify our findings.

RESULTS

The altered bile acid profile and genetic variation of bile acid metabolism-related genes in cholangiocarcinoma were demonstrated. The cholangiocarcinoma was categorized into bile acid metabolism-active and -inactive subtypes with different prognoses, clinicopathologic characteristics, tumor microenvironments (TME) and therapeutic responses. This categorization was reproducible and predictable. Specifically, the bile acid metabolism-active subtype showed a poor prognosis with an immunosuppressive microenvironment and an inactive response to immunotherapy, while the bile acid metabolism-inactive subtype showed the opposite characteristics. Moreover, the scRNA-seq revealed that immunotherapy altered bile acid metabolism in TME of cholangiocarcinoma. Finally, a prognostic signature related to bile acid metabolism was developed, which exhibited strong power for prognostic assessment of cholangiocarcinoma. Consistently, these results were verified by immunohistochemistry, cell proliferation, migration, and apoptosis assays.

CONCLUSION

In conclusion, a novel cholangiocarcinoma classification based on bile acid metabolism was established. This classification was significant for the estimation of TME and prognosis.

A novel model to study mechanisms of cholestasis in human cholangiocytes reveals a role for the SIPR2 pathway

BACKGROUND

Ductular reactivity is central to the pathophysiology of cholangiopathies. Mechanisms underlying the reactive phenotype activation by exogenous inflammatory mediators and bile acids are poorly understood.

METHODS

Using human extrahepatic cholangiocyte organoids (ECOs) we developed an injury model emulating the cholestatic microenvironment with exposure to inflammatory mediators and various pathogenic bile acids. Moreover, we explored roles for the bile acid activated Sphingosine-1-phosphate receptor 2 (S1PR2) and potential beneficial effects of therapeutic bile acids UDCA and norUDCA.

RESULTS

Synergistic exposure to bile acids (taurocholic acid, glycocholic acid, glycochenodeoxycholic acid) and TNF-α for 24 hours induced a reactive state as measured by ECO diameter, proliferation, lactate dehydrogenase activity and reactive phenotype markers. While NorUDCA and UDCA treatments given 8 hours after injury induction both suppressed reactive phenotype activation and most injury parameters, proliferation was improved by NorUDCA only. Extrahepatic cholangiocyte organoid stimulation with S1PR2 agonist sphingosine-1-phosphate reproduced the cholangiocyte reactive state and upregulated S1PR2 downstream mediators; these effects were suppressed by S1PR2 antagonist JET-013 (JET), downstream mediator extracellular signal-regulated kinase 1/2 inhibitor, and by norUDCA or UDCA treatments. JET also partially suppressed reactive phenotype after bile acid injury.

CONCLUSIONS

We developed a novel model to study the reactive cholangiocyte state in response to pathological stimuli in cholestasis and demonstrated a contributory role of S1PR2 signaling in both injury and NorUDCA/UDCA treatments. This model is a valuable tool to further explore the pathophysiology of human cholangiopathies.

Effect of feeding a dried distillers' grains with solubles diet on the metabolism of the intestinal wall in Guanling crossbred cattle: a preliminary assessment

Dried distillers' grains with solubles (DDGS)-based diets are nutritious and can improve the inflammations and intestinal immunity in livestock. However, there is limited research examining the effect of feeding DDGS-based diets on changes in intestinal metabolites and related pathways in livestock. In this study, six Guanling crossbred cattle (Guizhou Guanling Yellow cattle × Simmental cattle) were selected and divided into a basal diet (BD) group and an experimental group fed with DDGS replacing 25% of the daily ration concentrates (DDGS) (n=3), respectively. Fresh jejunum (J), ileum (I) and cecum (C) tissues were collected for metabolomic analysis. Differential metabolites and metabolic pathways were explored by means of univariate and multivariate statistical analysis. In comparison to the J-BD group, 123 differential metabolites (VIP > 1, p < 0.05) were identified in the J-DDGS group, which (top 20) were mainly divided into superclasses, including lipids and lipid-like molecules, organic acids and derivatives, and organoheterocyclic compounds. Compared with the I-BD group, 47 differential metabolites were obtained in the I-DDGS group, which were mainly divided into superclasses, including lipids and lipid-like molecules and organic acids and derivatives. The C-DDGS vs. C-BD comparison revealed 88 differential metabolites, which were mainly divided into superclasses, including lipids and lipid-like molecules, organic oxygen compounds, and nucleosides. A total of 34 significant metabolic pathways were found (p < 0.05, -log(p) > 1.3). Among them, 3 significant pathways were significantly enriched in the J-DDGS group, 11 significant pathways were significantly enriched in the I-DDGS group, and 20 significant pathways were significantly enriched in the C-DDGS group. Importantly, primary bile acid biosynthesis, linoleic acid metabolism, and arachidonic acid metabolism correlated with intestinal inflammation and immunity by regulating gut microbiota, prostaglandin synthesis, and cell signaling. The data suggest that DDGS-fed cattle unregulated three metabolic pathways mentioned above and that a DDGS-based diet was able to maintain a balance of these three metabolic pathways, thus resulting in improvement of intestinal inflammation and enhanced immunity in cattle. In conclusion, the DDGS diet has the potential to improve intestinal inflammation and enhance the immunity of Guanling crossbred cattle by regulating the metabolic patterns of lipids and lipid-like molecules, organic acids and derivatives, and related metabolic pathways. These results allude to potential metabolic regulatory mechanisms of DDGS diets and also provide a theoretical basis for the application of DDGS in livestock feed.

Molecular Biomarkers in Cholangiocarcinoma: Focus on Bile

Hepatobiliary system cancers have demonstrated an increasing incidence rate in the past years. Without the presence of early symptoms, the majority of such cancers manifest with a set of similar symptoms, such as cholestasis resulting in posthepatic icterus. Differential diagnosis of hepatobiliary cancers is required for the therapy selection, however, the similarity of the symptoms complicates diagnostics. Thus, the search for molecular markers is of high interest for such patients. Cholangiocarcinoma (CCA) is characterized by a poor prognosis due to a low resectability rate, which occurs because this disease is frequently beyond the limits of surgical therapy at the time of diagnosis. The CCA is diagnosed by the combination of clinical/biochemical features, radiological methods, and non-specific serum tumor biomarkers, although invasive examination is still needed. The main disadvantage is limited specificity and sensitivity, which complicates early diagnostics. Therefore, prognostic and predictive biomarkers are still lacking and urgently needed for early diagnosis. In contrast to serum, bile is more accessible to identify biliary disease due to its simpler composition. Moreover, bile can contain higher concentrations of tumor biomarkers due to its direct contact with the tumor. It is known that the composition of the main bile component - bile acids, may vary during different diseases of the biliary tract. This review summarizes the recent developments in the current research on the diagnostic biomarkers for CCA in serum and bile and provides an overview of the methods of bile acids analysis.

The Role of Bile Acids in Pancreatic Cancer

Bile acids are well known to promote the digestion and absorption of fat, and at the same time, they play an important role in lipid and glucose metabolism. More studies have found that bile acids such as ursodeoxycholic acid also have anti-inflammatory and immune-regulating effects. Bile acids have been extensively studied in biliary and intestinal tumors but less in pancreatic cancer. Patients with pancreatic cancer, especially pancreatic head cancer, are often accompanied by biliary obstruction and elevated bile acids caused by tumors. Elevated total bile acid levels in pancreatic cancer patients usually have a poor prognosis. There has been controversy over whether elevated bile acids are harmful or beneficial to pancreatic cancer. Still, there is no doubt that bile acids are important for the occurrence and development of pancreatic cancer. This article summarizes the research on bile acid as a biomarker and regulation of the occurrence, development and chemoresistance of pancreatic cancer, hoping to provide some inspiration for future research.

Alteration of serum bile acids in non-small cell lung cancer identified by a validated LC-MS/MS method

BACKGROUND

Bile acids (BA) are important metabolites and serve as signaling molecules, which are involve in multiple cancer-related signaling pathways.

METHODS

A validated LC-MS/MS approach was applied in a case-control study with 220 non-small cell lung cancer (NSCLC) patients and 244 matched healthy controls. The concentrations of seven common types of BAs in serum were determined and compared. Subgroup analyses based on demographic factor, lifestyle, pathologic types and tumor stage were conducted. Machine learning analysis was performed for NSCLC classification.

RESULTS

Serum levels of primary BAs, including cholic acid (CA), taurocholic acid (TCA) and glycocholic acid (GCA), were upregulated, while lithocholic acid (LCA), a type of secondary BA, was downregulated in NSCLC patients compared with healthy controls in overall analysis. Higher level of chenodeoxycholic acid (CDCA) and lower level of ursodeoxycholic acid (UDCA) were observed in female, elder, overweight patients, as well as patients without alcohol use in comparison with controls. CDCA and CA levels were higher only in lung adenocarcinoma (LUAD), and UDCA and DCA levels were lower only in squamous cell carcinoma (LUSC), while the concentrations of TCA, GCA, and LCA were altered prevalently in LUAD and LUSC patients. For discrimination of NSCLC from healthy people, the area under the receiver operating characteristics (ROC) curve of the models through support vector machine (SVM) approach was 0.91 (95% CI 0.88-0.94) in the training set and 0.84 (95% CI 0.78-0.91) in the validation set, respectively.

CONCLUSIONS

Serum BAs were altered in NSCLC patients compared with controls, among which primary BAs were elevated and secondary BAs were decreased. Moreover, distinct patterns of BA alterations were revealed between LUAD patients and LUSC patients.

Plasma Bile Acid Profiling and Modulation of Secreted Mucin 5AC in Cholangiocarcinoma

Studies investigating the potential role of circulating bile acids (BAs) as diagnostic biomarkers for cholangiocarcinoma (CCA) are sparse and existing data do not adjust for confounding variables. Furthermore, the mechanism by which BAs affect the expression of the oncogenic mucin 5AC (MUC5AC) has never been investigated. We performed a case-control study to characterise the profile of circulating BAs in patients with CCA (n = 68) and benign biliary disease (BBD, n = 48) with a validated liquid chromatography-tandem mass spectrometry technique. Odd ratios (OR) for CCA associations were calculated with multivariable logistic regression models based on a directed acyclic graph structure learning algorithm. The most promising BAs were then tested in an in vitro study to investigate their interplay in modulating MUC5AC expression. The total concentration of BAs was markedly higher in patients with CCA compared with BBD controls and accompanied by a shift in BAs profile toward a higher proportion of primary conjugated BAs (OR = 1.50, CI: 1.14 to 1.96, p = 0.003), especially taurochenodeoxycholic acid (TCDCA, OR = 42.29, CI: 3.54 to 504.63, p = 0.003) after multiple adjustments. Western blot analysis of secreted MUC5AC in human primary cholangiocytes treated with primary conjugated BAs or with TCDCA alone allowed us to identify a novel 230 kDa isoform, possibly representing a post-translationally modified MUC5AC specie.

Relevance of Bile Acids in Cholangiocarcinoma Pathogenesis: Critical Revision and Future Directions

Cholangiocarcinoma (CCA), a highly heterogeneous cancer, is the second most common type of primary liver cancer. It is characterized by resistance to therapy and poor prognosis, with a 5-year survival rate lower than 20%. The pathogenesis of CCA is complex and multifactorial, and in recent years, bile acids (BAs) have been implicated in CCA development and prognosis. BAs belong to a category of amphipathic compounds that hold significant importance as signaling molecules and inflammatory agents. They possess the ability to activate transcriptional factors and cellular signaling pathways, thereby governing the regulation of lipid, glucose, and energy metabolism in diverse human disorders. These disorders encompass chronic liver diseases among other conditions. In this review, we provided an update on the current knowledge on the molecular mechanisms involving BAs in cholangiocarcinogenesis. Additionally, we analyzed the role of gut and biliary microbiota in CCA pathogenesis. Future research is required to better understand how to modulate BA activity and, possibly, identify new therapeutic strategies.

Research progress of bile biomarkers and their immunoregulatory role in biliary tract cancers

Biliary tract cancers (BTCs), including cholangiocarcinoma and gallbladder carcinoma, originate from the biliary epithelium and have a poor prognosis. Surgery is the only choice for cure in the early stage of disease. However, most patients are diagnosed in the advanced stage and lose the chance for surgery. Early diagnosis could significantly improve the prognosis of patients. Bile has complex components and is in direct contact with biliary tract tumors. Bile components are closely related to the occurrence and development of biliary tract tumors and may be applied as biomarkers for BTCs. Meanwhile, arising evidence has confirmed the immunoregulatory role of bile components. In this review, we aim to summarize and discuss the relationship between bile components and biliary tract cancers and their ability as biomarkers for BTCs, highlighting the role of bile components in regulating immune response, and their promising application prospects.

Data-driven identification of plasma metabolite clusters and metabolites of interest for potential detection of early-stage non-small cell lung cancer cases versus cancer-free controls

BACKGROUND

Metabolomics is a potential means for biofluid-based lung cancer detection. We conducted a non-targeted, data-driven assessment of plasma from early-stage non-small cell lung cancer (ES-NSCLC) cases versus cancer-free controls (CFC) to explore and identify the classes of metabolites for further targeted metabolomics biomarker development.

METHODS

Plasma from 250 ES-NSCLC cases and 250 CFCs underwent ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) in positive and negative electrospray ionization (ESI) modes. Molecular feature extraction, formula generation, and find-by-ion tools annotated metabolic entities. Analysis was restricted to endogenous metabolites present in ≥ 80% of samples. Unsupervised hierarchical cluster analysis identified clusters of metabolites. The metabolites with the strongest correlation with the principal component of each cluster were included in logistic regression modeling to assess discriminatory performance with and without adjustment for clinical covariates.

RESULTS

A total of 1900 UHPLC-QTOF-MS assessments identified 1667 and 2032 endogenous metabolites in the ESI-positive and ESI-negative modes, respectively. After data filtration, 676 metabolites remained, and 12 clusters of metabolites were identified from each ESI mode. Multivariable logistic regression using the representative metabolite from each cluster revealed effective classification of cases from controls with overall diagnostic accuracy of 91% (ESI positive) and 94% (ESI negative). Metabolites of interest identified for further targeted analysis include the following: 1b, 3a, 12a-trihydroxy-5b-cholanoic acid, pyridoxamine 5'-phosphate, sphinganine 1-phosphate, gamma-CEHC, 20-carboxy-leukotriene B4, isodesmosine, and 18-hydroxycortisol.

CONCLUSIONS

Plasma-based metabolomic detection of early-stage NSCLC appears feasible. Further metabolomics studies targeting phospholipid, steroid, and fatty acid metabolism are warranted to further develop noninvasive metabolomics-based detection of early-stage NSCLC.

Diagnosis Biomarkers of Cholangiocarcinoma in Human Bile: An Evidence-Based Study

Simple Summary

A liquid biopsy has the characteristics of low trauma and easy acquisition in the diagnosis of cholangiocarcinoma. Many researchers try to find diagnostic or prognostic biomarkers of CCA through blood, urine, bile and other body fluids. Due to the close proximity of bile to the lesion and the stable nature, bile gradually comes into people’s view. The evaluation of human bile diagnostic biomarkers is not only to the benefit of screening more suitable clinical markers but also of exploring the pathological changes of the disease.

Abstract

Cholangiocarcinoma (CCA) is a multifactorial malignant tumor of the biliary tract, and the incidence of CCA is increasing in recent years. At present, the diagnosis of CCA mainly depends on imaging and invasive examination, with limited specificity and sensitivity and late detection. The early diagnosis of CCA always faces the dilemma of lacking specific diagnostic biomarkers. Non-invasive methods to assess the degree of CAA have been developed throughout the last decades. Among the many specimens looking for CCA biomarkers, bile has gotten a lot of attention lately. This paper mainly summarizes the recent developments in the current research on the diagnostic biomarkers for CCA in human bile at the levels of the gene, protein, metabolite, extracellular vesicles and volatile organic compounds.

Comparative and mechanistic study of pharmacodynamic difference in anti-breast cancer activity between water and liquor extracts of Xiaojin Pills

ETHNOPHARMACOLOGICAL RELEVANCE

Xiaojin Pills was first recorded during the Qing Dynasty and have a history of nearly 300 years. It is the first choice among Chinese patent medicines for the clinical treatment of diseases of the mammary glands in contemporary traditional Chinese medicine. It was also widely used in the treatment of breast cancer, lung cancer, thyroid cancer, and other malignant tumors. Its initial administration method was "taken orally after soaking with Chinese baijiu"; however, the method was changed to "taken orally with water" within the last 40 years. There is no scientific evidence for the difference in efficacy against breast cancer between the two methods of administration.

AIM OF THE STUDY

In vitro and in vivo experiments were carried out to confirm the therapeutic advantages of the liquor extract of Xiaojin Pills to improve the efficacy against breast cancer, and the mechanism was explained in terms of metabolomics and molecular biology.

MATERIALS AND METHODS

In vitro, a cell counting kit-8 cell activity assay and flow cytometry were used to detect the activity and apoptosis of MCF-7 breast cancer cells. In vivo, pharmacodynamic evaluation was performed by constructing a heterotopic transplantation model of breast cancer in BALB/c-nu mice. TUNEL staining was used to observe the apoptosis of cells in tumor tissues. The expression of proteins associated with the phosphoinositide 3-kinase (PI3K)/Akt pathway in BALB/c-nu mice tissue was investigated by metabolomics analysis, immunohistochemistry and western blotting.

RESULTS

CCK-8 assay showed that the IC₅₀ of XJP-L for the inhibition of the activity of MCF-7 cells was less than that of XJP-W at different times. Flow cytometry assay suggested that the apoptosis rate in the XJP-L group was higher than that in the normal control group (p < 0.01). Animal experiment results indicated that both XJP-W group and XJP-L group reduced the volume and quality of the tumor after administration, and the reduction was more significant in the XJP-L group (p < 0.01). Metabolomics analysis results demonstrated that there are about 26 different metabolites have been screened in the serum metabolites between the liquor and water extract, mainly involved in glycerophospholipid, glutamic acid, aspartic acid, nitrogen and pyrimidine metabolism. In addition, immunohistochemistry and WB results showed that compared with the model group, the protein expression of PTEN, AKT, BAX and in tumor tissues of XJP-L and XJP-W groups both exhibited an upward trend, while the expression of BCL-2, p-PI3K and p-AKT exhibited a downward trend, which was much more obvious in XJP-L group.

CONCLUSIONS

This study demonstrates that the liquor extract of Xiaojin Pills had a stronger anti-breast cancer effect than that of the water extract. The PI3K/Akt signaling pathway might play an important role in the mechanism of the liquor extract of Xiaojin Pills and thus improve the efficacy against breast cancer.

Combination of molecular docking and liver transcription sequencing analysis for the evaluation of salt-processed psoraleae fructus-induced hepatotoxicity in ovariectomized mice

ETHNOPHARMACOLOGICAL RELEVANCE

Salt-processed Psoraleae fructus (SPF) is widely used as a phytoestrogen-like agent in the treatment of osteoporosis. However, SPF-associated hepatotoxicity is a known health hazard. Cholestasis is often associated with SPF-induced hepatotoxicity. Notably, clinical liver injury is a common side effect of SPF in the treatment of osteoporosis; however, the exact mechanism underlying this phenomenon is unclear.

AIM OF THE STUDY

To evaluate SPF-induced hepatotoxicity in an ovariectomized murine model of estrogen deficiency and examine the mechanisms underlying this process.

MATERIALS AND METHODS

To explore the molecular mechanism of SPF-induced cholestatic liver injury, different concentrations of SPF (5 and 10 g/kg) were intragastrically administered to ovariectomized and non-ovariectomized female ICR mice for 30 days.

RESULTS

SPF-treated mice showed noticeably swollen hepatocytes, dilated bile ducts, and elevated levels of serum biochemical markers. Compared to ovariectomized mice, these changes were more prominent in non-ovariectomized mice. According to the sequence data, a total of 6689 mRNAs were identified. Compared with the control group, 1814 differentially expressed mRNAs were identified in the group treated with high SPF doses (SPHD), including 939 upregulated and 875 downregulated mRNAs. Molecular docking and Western blot experiments showed that liver injury was closely related to the estrogen levels. Compared with the negative control group, the expression levels of FXR, Mrp2, CYP7a1, BSEP, SULT1E1, HNF4a, and Nrf2 decreased in the estradiol-treated (E2), low-dose SPF-treated (SPLD), and SPHD groups. Interestingly, the expression levels of FXR, CYP7a1, SULT1E1, and HNF4α were significantly higher in the ovariectomized groups than in the non-ovariectomized groups (#P < 0.05; ###P < 0.001).

CONCLUSIONS

Overall, this study demonstrates that SPF downregulates key enzymes involved in cholesterol and bile acid biosyntheses, posing a risk for cholestatic liver injury. SPF also regulates the FXR-SULT1E signaling pathway via HNF4α, which is an important causative factor of cholestasis. Moreover, the severity of liver damage was significantly lower in the ovariectomized groups than in the non-ovariectomized group. These results suggest that the estrogen level is the most critical factor determining liver injury.

Importance of Bile Composition for Diagnosis of Biliary Obstructions

Determination of the cause of a biliary obstruction is often inconclusive from serum analysis alone without further clinical tests. To this end, serum markers as well as the composition of bile of 74 patients with biliary obstructions were determined to improve the diagnoses. The samples were collected from the patients during an endoscopic retrograde cholangiopancreatography (ERCP). The concentration of eight bile salts, specifically sodium cholate, sodium glycocholate, sodium taurocholate, sodium glycodeoxycholate, sodium chenodeoxycholate, sodium glycochenodeoxycholate, sodium taurodeoxycholate, and sodium taurochenodeoxycholate as well as bile cholesterol were determined by HPLC-MS. Serum alanine aminotransferase (ALT), aspartate transaminase (AST), and bilirubin were measured before the ERCP. The aim was to determine a diagnostic factor and gain insights into the influence of serum bilirubin as well as bile salts on diseases. Ratios of conjugated/unconjugated, primary/secondary, and taurine/glycine conjugated bile salts were determined to facilitate the comparison to literature data. Receiver operating characteristic (ROC) curves were determined, and the cut-off values were calculated by determining the point closest to (0,1). It was found that serum bilirubin was a good indicator of the type of biliary obstruction; it was able to differentiate between benign obstructions such as choledocholithiasis (at the concentration of >11 µmol/L) and malignant changes such as pancreatic neoplasms or cholangiocarcinoma (at the concentration of >59 µmol/L). In addition, it was shown that conjugated/unconjugated bile salts confirm the presence of an obstruction. With lower levels of conjugated/unconjugated bile salts the possibility for inflammation and, thus, neoplasms increase.

Bile Acid Regulates the Colonization and Dissemination of Candida albicans from the Gastrointestinal Tract by Controlling Host Defense System and Microbiota

Candida albicans (CA), a commensal and opportunistic eukaryotic organism, frequently inhabits the gastrointestinal (GI) tract and causes life-threatening infections. Antibiotic-induced gut dysbiosis is a major risk factor for increased CA colonization and dissemination from the GI tract. We identified a significant increase of taurocholic acid (TCA), a major bile acid in antibiotic-treated mice susceptible to CA infection. In vivo findings indicate that administration of TCA through drinking water is sufficient to induce colonization and dissemination of CA in wild-type and immunosuppressed mice. Treatment with TCA significantly reduced mRNA expression of immune genes ang4 and Cxcr3 in the colon. In addition, TCA significantly decreased the relative abundance of three culturable species of commensal bacteria, Turicibacter sanguinis, Lactobacillus johnsonii, and Clostridium celatum, in both cecal contents and mucosal scrapings from the colon. Taken together, our results indicate that TCA promotes fungal colonization and dissemination of CA from the GI tract by controlling the host defense system and intestinal microbiota that play a critical role in regulating CA in the intestine.

Biliary Strictures and Cholangiocarcinoma - Untangling a Diagnostic Conundrum

Cholangiocarcinoma is an uncommon and highly aggressive biliary tract malignancy with few manifestations until late disease stages. Diagnosis is currently achieved through a combination of clinical, biochemical, radiological and histological techniques. A number of reported cancer biomarkers have the potential to be incorporated into diagnostic pathways, but all lack sufficient sensitivity and specificity limiting their possible use in screening and early diagnosis. The limitations of standard serum markers such as CA19-9, CA125 and CEA have driven researchers to identify multiple novel biomarkers, yet their clinical translation has been slow with a general requirement for further validation in larger patient cohorts. We review recent advances in the diagnostic pathway for suspected CCA as well as emerging diagnostic biomarkers for early detection, with a particular focus on non-invasive approaches.

Serum Bile Acid Profiles Improve Clinical Prediction of Nonalcoholic Fatty Liver in T2DM patients

Background: The present study aimed to assess the ability of serum bile acid profiles to predict the development of nonalcoholic fatty liver (NAFL) in type 2 diabetes mellitus (T2DM) patients. Methods: Using targeted ultraperformance liquid chromatography (UPLC) coupled with triple quadrupole mass spectrometry (TQ/MS), we compared serum bile acid levels in T2DM patients with NAFL (n = 30) and age- and sex-matched T2DM patients without NAFL (n = 36) at the first time. Second, an independent cohort study of T2DM patients with NAFL (n = 17) and age- and sex-matched T2DM patients without NAFL (n = 20) was used to validate the results. The incremental benefits of serum biomarkers, clinical variables alone, or with biomarkers were then evaluated using receiver operating characteristic (ROC) curves and decision curve analysis. The area under the curve (AUC), integrated discrimination improvement (IDI), and net reclassification improvement (NRI) were used to evaluate the biomarker predictive abilities. Results: The serum bile acid profiles in T2DM patients with NAFL were significantly different from T2DM patients without NAFL, as characterized by the significant elevation of LCA, TLCA, TUDCA, CDCA-24G, and TCDCA, which may be potential biomarkers for the identification of NAFL in T2DM patients. Based on the improvement in AUC, IDI, and NRI, the addition of 5 bile acids to a model with clinical variables statistically improved its predictive value. Similar results were found in the validation cohort. Conclusions: These results highlight that the detected biomarkers may contribute to the progression of NAFL in T2DM patients, and these biomarkers particularly in combination may help in the diagnosis of NAFL and allow earlier intervention in T2DM patients.

Taurochenodeoxycholic acid inhibits the proliferation and invasion of gastric cancer and induces its apoptosis

Taurochenodeoxycholic acid (TCDCA) is the principal ingredient of Compound Shougong Powder. Despite traditional Chinese medicine (TCM) research demonstrates that Compound Shougong Powder can restrict tumor growth, whether TCDCA exerts a role in suppressing cancer as the major ingredient of Compound Shougong Powder remains unknown. This study aims to clarify the regulatory mechanism of TCDCA on gastric cancer. Gastric cancer cells SGC-7901 were cultured to investigate the effects of TCDCA on proliferation and apoptosis. Furthermore, a subcutaneously implanted tumor model was established using SGC-7901 cells in BALB/C nude mice and tumor volume was measured under low and high dose treatment of TCDCA. Cell proliferation, apoptosis, and invasion were subjected to 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay, flow cytometry, and transwell assay. Differentially expressed genes were screened by transcriptome sequencing. Nude mouse tumorigenicity assay was initiated to identify the effect of TCDCA on both tumor volume and weight, and the expression of candidate genes screened by transcriptome sequencing was determined by real-time fluorescence quantification (qPCR) and Western blot. The experiments revealed that TCDCA could significantly inhibit the proliferation and invasion of gastric cancer cells and induce apoptosis of these cells. Meanwhile, test findings via in vivo indicated that TCDCA severely diminished the volume and weight of tumors. This study first demonstrated that TCDCA inhibited the proliferation and invasion of gastric cancer and induced apoptosis, which is expected to serve as an experimental basis for the application of TCM in tumor therapeutic options. PRACTICAL APPLICATIONS: Through this study, the inhibitory effect of Taurochenodeoxycholic acid on gastric cancer can be clarified, which provides a new research basis for the application of traditional Chinese medicine (TCM) and TCM monomer in cancer. In addition, this study can further promote the research and application of Chinese traditional medicine, which has important application value and economic benefits.

The role of bile acid subtypes in the diagnosis of cholangiocarcinoma

OBJECTIVES

To find the potential biomarkers of cholangiocarcinoma, form a biomarker package, evaluate its efficiency, and validate it.

METHODS

R software was used to analyze the differential expression of mRNAs between cholangiocarcinoma and adjacent nontumorous tissues, obtained from The Cancer Genome Atlas (TCGA), and enrich the KEGG pathway. Metabo-Profile Inc. performed the comprehensive bile acid profiling and quantitation. The training set concluded 20 cholangiocarcinoma and 20 nontumorous volunteers. Receiver operating characteristic (ROC) curve and accompanying area under the curve (AUC) was calculated. The top four bile acids formed a new biomarker package. The validation set included 15 cholangiocarcinoma and 15 nontumorous, and the sensitivity and specificity of the new biomarker package were tested.

RESULTS

Gene expression of 36 cholangiocarcinoma and nine adjacent nontumorous tissues was obtained in January 2020. Totally 9887 differential genes were eligible (logFC ≥ 1 or ≤ -1, P < 0.05, and adjust P < 0.01). GO analysis showed that 20 KEGG pathways were enriched, including primary bile acid biosynthesis and bile secretion. Comprehensive bile acid profiling and quantitation showed 15 differential bile acid types, and the ROC-AUC was between 0.953 and 0.750. HDCA, isoLCA, bCDCA, and DCA were selected to form a biomarker package. The Logit (p = cholangiocarcinoma) = 7.898 - 3.70*(1isoLCA) - 0.444*(bCDCA) + 0.415*(HDCA) + 0.041*DCA. Its ROC-AUC was 0.944. In the validation set, the sensitivity was 0.933 and the specificity was 0.867.

CONCLUSION

Bile acid types package was efficient to distinguish nontumorous population and cholangiocarcinoma. The difference might be associated to the downregulation of primary bile acid biosynthesis and bile secretion pathway of cholangiocarcinoma.

Analysis of bile acid profile in plasma to differentiate cholangiocarcinoma from benign biliary diseases and healthy controls

Bile acids (BAs) are currently considered as causative agents for Cholangiocarcinoma (CCA). However, the profile of circulating BAs in CCA have not been well characterized. The aim of this study was to describe the alterations of BAs metabolism in patients with CCA compared to benign biliary diseases (BBD) and healthy controls (HC), and to discover the specific BAs as biomarkers for CCA diagnosis. The concentrations of 15 BAs in plasma were measured in a total of 329 subjects, including patients with BBD, CCA, gallbladder cancer (GC), hepatocellular carcinoma (HCC), and healthy subjects, using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Binary logistic regression analysis was used to build a diagnostic model for CCA. An imbalance in the ratio of conjugated to unconjugated BAs was observed in CCA patients compared to BBD and HC groups, with higher conjugated BAs and lower unconjugated BAs. A panel of 2 BA metabolites consisting of CDCA and TCDCA showed high diagnostic performance for CCA versus BBD and CCA versus HC, with higher AUC, sensitivity and specificity than carbohydrate antigen 19-9 (CA 199), clinically employed CCA biomarker. Importantly, HCC and GC samples were also included to confirm specificity of the BA biomarkers for CCA diagnosis. In summary, specific changes in plasma concentrations of BAs may serve as diagnostic biomarkers for distinguishing CCA from BBD and HC, with higher performance than CA199.

Discovery of Gut Bacteria Specific to Alzheimer's Associated Diseases is a Clue to Understanding Disease Etiology: Meta-Analysis of Population-Based Data on Human Gut Metagenomics and Metabolomics

Alzheimer's disease (AD)-associated sequence (ADAS) of cultured fecal bacteria was discovered in human gut targeted screening. This study provides important information to expand our current understanding of the structure/activity relationship of ADAS and putative inhibitors/activators that are potentially involved in ADAS appearance/disappearance. The NCBI database analysis revealed that ADAS presents at a large proportion in American Indian Oklahoman (C&A) with a high prevalence of obesity/diabetes and in colorectal cancer (CRC) patients from the US and China. An Oklahoman non-native group (NNI) showed no ADAS. Comparison of two large US populations reveals that ADAS is more frequent in individuals aged ≥66 and in females. Prevalence and levels of fecal metabolites are altered in the C&A and CRC groups versus controls. Biogenic amines (histamine, tryptamine, tyramine, phenylethylamine, cadaverine, putrescine, agmatine, spermidine) that present in food and are produced by gut microbiota are significantly higher in C&A (e.g., histamine/histidine 95-fold) versus NNI (histamine/histidine 16-fold). The majority of these bio-amines are cytotoxic at concentrations found in food. Inositol phosphate signaling implicated in AD is altered in C&A and CRC. Tryptamine stimulated accumulation of inositol phosphate. The seizure-eliciting tryptamine induced cytoplasmic vacuolization and vesiculation with cell fragmentation. Present additions of ADAS-carriers at different ages including infants led to an ADAS-comprising human sample size of 2,830 from 27 studies from four continents (North America, Australia, Asia, Europe). Levels of food-derived monoamine oxidase inhibitors and anti-bacterial compounds, the potential modulators of ADAS-bacteria growth and biogenic amine production, were altered in C&A versus NNI. ADAS is attributable to potentially modifiable risk factors of AD associated diseases.

Effect of Lactobacillus plantarum HT121 on serum lipid profile, gut microbiota, and liver transcriptome and metabolomics in a high-cholesterol diet-induced hypercholesterolemia rat model

OBJECTIVES

The aim of this study was to evaluate effect of Lactobacillus plantarum HT121 on serum lipid profile, gut microbiota, and liver transcriptome and metabolomics.

METHODS

L. plantarum HT121 was selected by screening of acid and bile salt tolerance and cholesterol assimilation assay. Sprague Dawley rats were randomly divided into three groups and fed the respective diets for 7 wk: normal chow diet (NCD), high-cholesterol diet (HCD), and high-cholesterol diet plus L. plantarum HT121 (HT121). After 7 wk, blood lipid profile was measured by enzyme-linked immunosorbent assay, gut microbiota was determined by 16 S rRNA sequencing, gene expression, and bile acids in liver were detected by transcriptome and metabolomics, respectively.

RESULTS

L. plantarum HT121 feeding decreased serum triacylglycerols (TGs), total cholesterol (TC), and low-density lipoprotein (LDL), and increased serum high-density lipoprotein levels. HT121 treatment increased the α-diversity in the HT121 group to a level close to that in the NCD group, and restored the genera of Adlercreutzia, Mucispirillum, Ruminococcus, Clostridium, Blautia, Roseburia, and Akkermansia to levels similar to those in the NCD group. Furthermore, the high-cholesterol diet decreased taurocholic acid (TCA) and increased taurochenodeoxycholic acid (TCDCA) and glycocholic acid (GCA) in the liver; all these changes were reversed by HT121 treatment, bringing the levels close to those in the NCD group. Finally, HT121 treatment increased expression of bile secretion-related genes Cyp7 a1 in rat liver, which was positively correlated with TG, Clostridium, and GCA. Spearman's correlation analysis showed that TGs, TC, and LDL were positively correlated with the relative abundance of genera of Blautia, Clostridium, and Roseburia, and levels of bile acid glycocholic acid, and inversely correlated with the relative abundance of Ruminococcus and Mucispirillum.

CONCLUSIONS

L. plantarum HT121 can improve serum lipid profiles in a high-fat diet-induced rat model, which may be attributed to alteration in gut microbiota and bile acid metabolism.

Biliary Microbiota and Bile Acid Composition in Cholelithiasis

Background

A functional interplay between BAs and microbial composition in gut is a well-documented phenomenon. In bile, this phenomenon is far less studied, and with this report, we describe the interactions between the BAs and microbiota in this complex biological matrix. Methodology. Thirty-seven gallstone disease patients of which twenty-one with Opisthorchis felineus infection were enrolled in the study. The bile samples were obtained during laparoscopic cholecystectomy for gallstone disease operative treatment. Common bile acid composition was measured by LC-MS/MS. Gallbladder microbiota were previously analyzed with 16S rRNA gene sequencing on Illumina MiSeq platform. The associations between bile acid composition and microbiota were analyzed.

Results

Bile acid signature and Opisthorchis felineus infection status exert influence on beta-diversity of bile microbial community. Direct correlations were found between taurocholic acid, taurochenodeoxycholic acid concentrations, and alpha-diversity of bile microbiota. Taurocholic acid and taurochenodeoxycholic acid both show positive associations with the presence of Chitinophagaceae family, Microbacterium and Lutibacterium genera, and Prevotella intermedia. Also, direct associations were identified for taurocholic acid concentration and the presence of Actinomycetales and Bacteroidales orders, Lautropia genus, Jeotgalicoccus psychrophilus, and Haemophilus parainfluenzae as well as for taurochenodeoxycholic acid and Acetobacteraceae family and Sphingomonas genus. There were no differences in bile acid concentrations between O. felineus-infected and noninfected patients. Conclusions/Significance. Associations between diversity, taxonomic profile of bile microbiota, and bile acid levels were evidenced in patients with cholelithiasis. Increase of taurochenodeoxycholic acid and taurocholic acid concentration correlates with bile microbiota alpha-diversity and appearance of opportunistic pathogens.

Metabolomics identified new biomarkers for the precise diagnosis of pancreatic cancer and associated tissue metastasis

Pancreatic cancer (PC) is one of the most aggressive malignancies with high mortality due to a complex and latent pathogenesis leading to the severe lack of early diagnosis methods. To improve clinical diagnosis and enhance therapeutic outcome, we employed the newly developed precision-targeted metabolomics method to identify and validate metabolite biomarkers from the plasma samples of patients with pancreatic cancer that can sensitively and efficiently diagnose the onsite progression of the disease. Many differential metabolites have the capacity to markedly distinguish patients with pancreatic cancer (n = 60) from healthy controls (n = 60). To further enhance the specificity and selectivity of metabolite biomarkers, a dozen tumor tissues from PC patients and paired normal tissues were used to clinically validate the biomarker performance. We eventually verified five new metabolite biomarkers in plasma (creatine, inosine, beta-sitosterol, sphinganine and glycocholic acid), which can be used to readily diagnose pancreatic cancer in a clinical setting. Excitingly, we proposed a panel biomarker by integrating these five individual metabolites into one pattern, demonstrating much higher accuracy and specificity to precisely diagnose pancreatic cancer than conventional biomarkers (CA125, CA19-9, CA242 and CEA); moreover, this plasma panel biomarker used for PC diagnosis is also quite convenient to implement in clinical practice. Using the same metabolomics method, we characterized succinic acid and gluconic acid as having a great capability to monitor the progression and metastasis of pancreatic cancer at different stages. Taken together, this metabolomics method was used to identify and validate metabolite biomarkers that can precisely and sensitively diagnose the onsite progression and metastasis of pancreatic cancer in a clinical setting. Furthermore, such effort should leave clinicians with the correct time frame to facilitate early and efficient therapeutic interventions, which could largely improve the five-year survival rate of PC patients by significantly lowering clinical mortality.

Bile Acid Receptor Therapeutics Effects on Chronic Liver Diseases

In the past ten years, our understanding of the importance of bile acids has expanded from fat absorption and glucose/lipid/energy homeostasis into potential therapeutic targets for amelioration of chronic cholestatic liver diseases. The discovery of important bile acid signaling mechanisms, as well as their role in metabolism, has increased the interest in bile acid/bile acid receptor research development. Bile acid levels and speciation are dysregulated during liver injury/damage resulting in cytotoxicity, inflammation, and fibrosis. An increasing focus to target bile acid receptors, responsible for bile acid synthesis and circulation, such as Farnesoid X receptor and apical sodium-dependent bile acid transporter to reduce bile acid synthesis have resulted in clinical trials for treatment of previously untreatable chronic liver diseases such as non-alcoholic steatohepatitis and primary sclerosing cholangitis. This review focuses on current bile acid receptor mediators and their effects on parenchymal and non-parenchymal cells. Attention will also be brought to the gut/liver axis during chronic liver damage and its treatment with bile acid receptor modulators. Overall, these studies lend evidence to the importance of bile acids and their receptors on liver disease establishment and progression.

Identification of key genes and pathways associated with cholangiocarcinoma development based on weighted gene correlation network analysis

Background

As the most frequently occurred tumor in biliary tract, cholangiocarcinoma (CCA) is mainly characterized by its late diagnosis and poor outcome. It is therefore urgent to identify specific genes and pathways associated with its progression and prognosis.

Materials and Methods

The differentially expressed genes in The Cancer Genome Atlas were analyzed to build the co-expression network by Weighted gene co-expression network analysis (WGCNA). Gene ontology (GO) as well as Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted for the selected genes. Module-clinical trait relationships were analyzed to explore the association with clinicopathological parameters. Log-rank tests and cox regression were used to identify the prognosis-related genes.

Results

The most related modules with CCA development were tan module containing 181 genes and salmon module with 148 genes. GO analysis suggested enrichment terms of digestion, hormone transport and secretion, epithelial cell proliferation, signal release, fibroblast activation, response to acid chemical, wnt, Nicotinamide adenine dinucleotide phosphate metabolism. KEGG analysis demonstrated 15 significantly altered pathways including glutathione metabolism, wnt, central carbon metabolism, mTOR, pancreatic secretion, protein digestion, axon guidance, retinol metabolism, insulin secretion, salivary secretion, fat digestion. Key genes of SOX2, KIT, PRSS56, WNT9A, SLC4A4, PRRG4, PANX2, PIR, RASSF8, MFSD4A, INS, RNF39, IL1R2, CST1, and PPP3CA might be potential prognostic markers for CCA, of which RNF39 and PRSS56 also showed significant correlation with clinical stage.

Discussion

Differentially expressed genes and key modules contributing to CCA development were identified by WGCNA. Our results offer novel insights into the characteristics in the etiology, prognosis, and treatment of CCA.

Diagnosis of hepatocellular carcinoma using a novel anti-glycocholic acid monoclonal antibody-based method

Glycocholic acid (GCA) is a novel identified biomarker for hepatocellular carcinoma (HCC). However, clinical pathological study of GCA has not been extensive due to the limited availability of anti-GCA monoclonal antibodies (mAbs) and restricted detection methods. In the present study, using human GCA conjugated with bovine serum albumin as the immunogen to immunize BALB/c mice, a novel anti-GCA mAb was generated and characterized. The isotypes of heavy chain and light chain of anti-GCA mAb were examined to be IgG2a and κ, respectively, with a high affinity constant (2.6×10⁸ mol/l). The anti-GCA mAb binds GCA with high specificity and sensitivity, and the 50% inhibitory rate was 77.09 ng/ml. The present study also established a rapid, sensitive and efficient indirect competitive ELISA analysis using this anti-GCA mAb to detect the level of GCA produced by different HCC cell lines. Therefore, the present study may successfully develop a novel method for early HCC diagnosis, and also provide insights for further research and treatment of HCC.