Unique bile acid profiles in the bile ducts of patients with primary sclerosing cholangitis.

BACKGROUND: The relationship between primary sclerosing cholangitis (PSC) and biliary bile acids (BAs) remains unclear. Although a few studies have compared PSC biliary BAs with other diseases, they did not exclude the influence of cholestasis, which affects the composition of BAs. We compared biliary BAs and microbiota among patients with PSC, controls without cholestasis, and controls with cholestasis, based on the hypothesis that alterations in BAs underlie the pathophysiology of PSC. METHODS: Bile samples were obtained using endoscopic retrograde cholangiopancreatography from patients with PSC (n = 14), non-hepato-pancreato-biliary patients without cholestasis (n = 15), and patients with cholestasis (n = 13). RESULTS: The BA profiles showed that patients with PSC and cholestasis controls had significantly lower secondary BAs than non-cholestasis controls, as expected, whereas the ratio of cholic acid/chenodeoxycholic acid in patients with PSC was significantly lower despite cholestasis, and the ratio of (cholic acid + deoxycholic acid)/(chenodeoxycholic acid + lithocholic acid) in patients with PSC was significantly lower than that in the controls with or without cholestasis. The BA ratio in the bile of patients with PSC showed a similar trend in the serum. Moreover, there were correlations between the alteration of BAs and clinical data that differed from those of the cholestasis controls. Biliary microbiota did not differ among the groups. CONCLUSIONS: Patients with PSC showed characteristic biliary and serum BA compositions that were different from those in other groups. These findings suggest that the BA synthesis system in patients with PSC differs from that in controls and patients with other cholestatic diseases. Our approach to assessing BAs provides insights into the pathophysiology of PSC.

Primary 12α-Hydroxylated Bile Acids Lower Hepatic Iron Concentration in Rats.

BACKGROUND: Primary 12α-hydroxylated bile acids (12αOH BAs) enhance intestinal iron uptake due to their ability ex vivo to chelate iron. However, no information is available on their role in vivo, especially in the liver. OBJECTIVES: To investigate the effects and mechanisms of primary 12αOH BAs on hepatic iron concentration in vivo. METHODS: Male Wistar King A Hokkaido male rats (WKAH/HkmSlc) rats aged 4-5 weeks were fed a control diet or a diet with cholic acid (CA; 0.5 g/kg diet), the primary 12αOH BA, for 2 weeks (Study 1) or 13 weeks (Study 2). In Study 3, rats fed the same diets were given drinking water either alone or containing vancomycin (200 mg/L) for 6 weeks. The variables measured included food intake (Studies 1-3), bile acid profiles (Studies 1 and 3), hepatic iron concentration (Studies 1-3), fecal iron excretion (Studies 1 and 2), iron-related liver gene expression (Studies 2 and 3), and plasma iron-related factors (Studies 2 and 3). RESULTS: In Study 1, CA feed reduced the hepatic iron concentration (-16%; P = 0.005) without changing food intake or fecal iron excretion. In Study 2, we found a significant increase in the aortic plasma concentration of lipocalin 2 (LCN2; +65%; P < 0.001), an iron-trafficking protein. In Study 3, we observed no effect of vancomycin treatment on the CA-induced reduction of hepatic iron concentration (-32%; P < 0.001), accompanied by increased plasma LCN2 concentration (+72%; P = 0.003), in the CA-fed rats despite a drastic reduction in the secondary 12αOH BA concentration (-94%; P < 0.001) in the aortic plasma. CONCLUSIONS: Primary 12αOH BAs reduced the hepatic iron concentration in rats. LCN2 may be responsible for the hepatic iron-lowering effect of primary 12αOH BAs by transporting iron out of the liver.

A novel voltammetric approach to the detection of primary bile acids in serum samples.

An innovative voltammetric approach to the detection of cholic and chenodeoxycholic acids is presented. These two primary bile acids are important biomarkers of liver function in humans and are involved in many physiological processes in the human body. Herein we describe a way to reproducibly convert the hard-to-detect bile acid molecule into an easily detectable derivative in situ using 0.1 M HClO4 in acetonitrile (water content 0.55%). Under these conditions the bile acids are dehydrated and the resulting alkenes can be subsequently oxidized electrochemically on polished boron-doped diamond electrode under unchanged conditions at approximately +1.2 V vs. Ag/AgNO3 in acetonitrile. After optimization, differential pulse voltammetry provides competitive limits of detection of 0.5 µM and 1.0 µM for cholic and chenodeoxycholic acid, respectively, with a linear course of calibration dependency to the minimum of 80 µM. The method was applied for detection of cholic and chenodeoxycholic acids in artificial and human serum samples using single solid phase extraction on C-18 cartridge for preliminary separation of the analytes. High recoveries of 80-90% were consistently obtained by the proposed voltammetric method and reference HPLC with fluorescence detection for human serum samples, confirming good selectivity for real-life samples.

Fetal coenzyme Q10 deficiency in intrahepatic cholestasis of pregnancy.

AIM: Intrahepatic cholestasis of pregnancy (ICP) is considered a high-risk condition because it may have serious consequences for the fetus health. ICP is characterized by the accumulation of bile acids in maternal serum which contribute to an imbalance between the production of reactive oxygen species and the antioxidant defenses increasing the oxidative stress experienced by the fetus. Previously, it was reported a significant decrease in plasma coenzyme Q10 (CoQ10) in women with ICP. CoQ10 is a redox substance integrated in the mitochondrial respiratory chain and is recognized as a potent antioxidant playing an intrinsic role against oxidative damage. The objective of the present study was to investigate the levels of CoQ10 in umbilical cord blood during normal pregnancy and in those complicated with ICP, all of them compared to the maternal ones. METHODS: CoQ10 levels and bile acid levels in maternal and umbilical cord blood levels during normal pregnancies (n=23) and in those complicated with ICP (n=13), were investigated. RESULTS: A significant decrease in neonate CoQ10 levels corrected by cholesterol (0.105±0.010 vs. 0.069±0.011, P<0.05, normal pregnancy vs. ICP, respectively), together with an increase of total serum bile acids (2.10±0.02 vs. 7.60±2.30, P<0.05, normal pregnancy vs. ICP, respectively) was observed. CONCLUSIONS: A fetus from an ICP mother is exposed to a greater risk derived from oxidative damage. The recognition of CoQ10 deficiency is important since it could be the starting point for a new and safe intervention strategy which can establish CoQ10 as a promising candidate to prevent the risk of oxidative stress.

Metabolism of fatty acids and bile acids in plasma is associated with overactive bladder in males: potential biomarkers and targets for novel treatments in a metabolomics analysis.

OBJECTIVES: The present study was conducted to identify metabolites using a metabolomics approach and investigate the relationship between these metabolites and urgency as a major symptom of overactive bladder (OAB). PATIENTS AND METHODS: In 47 male participants without any apparent neurological disease, OAB was defined as an urgency score on the International Prostate Symptom Score of 2 and higher (OAB group, n = 26), while patients with a score of 1 or 0 were placed in a control group (n = 21). A comprehensive study on plasma metabolites was conducted, and metabolites were compared between the OAB and control groups. RESULTS: Age was significantly higher in the OAB group, while prostate volume did not differ between the groups. A 24-h bladder diary revealed that nocturnal urine volume, 24-h micturition frequency, nocturnal micturition frequency, and the nocturnal index were significantly higher in the OAB group, whereas maximum voided volume was significantly lower in this group. The metabolomics analysis identified 79 metabolites from the plasma of participants. The multivariate analysis showed that increases in the fatty acids (22:1), erucic acid and palmitoleic acid, and a decrease in cholic acid correlated with incidence of male OAB. A decrease in acylcarnitine (18:2)-3 and an increase in cis-11-eicosenoic acid also appeared to be associated with OAB in males. CONCLUSIONS: OAB in males may occur through the abnormal metabolism of fatty acids and bile acids. Further studies on these pathways will contribute to the detection of new biomarkers and development of potential targets for novel treatments.

Effects of theabrownin on serum metabolites and gut microbiome in rats with a high-sugar diet.

Evidence has proven that the gut microbiota is an important environmental factor contributing to obesity by altering host energy harvest and storage. We performed a high-throughput 16S rDNA sequencing association study and serum metabolomics profiling in rats with a high-sugar diet. Our studies revealed that the high sugar diet reduced the diversity of cecal microorganisms, while the combination of theabrownin and the high sugar diet increased the diversity of cecal microorganisms and promoted reproduction of Alloprevotella, Coprostanoligenes_group, Bacteroides, Prevotellaceae_NK3B31_group, Desulfovibrio, Intestinimonas, Alistipes, Bifidobacterium, Phascolarctobacterium, Ruminococcaceae_UCG-010 and Staphylococcus. The combination also inhibited the growth of Lactobacillus, Prevotellaceae_Ga6A1_group and Tyzzerella. The Firmicutes/Bacteroidetes (F/B) ratio can be significantly reduced after the intervention of theabrownin in high sugar diet rats, and the reproduction of Bacteroides acidifaciens (BA) and Staphylococcus saprophyticus subsp. saprophyticus can be promoted. We found that the obesity-associated gut microbial species were linked to the changes in circulating metabolites. Serum levels of deoxycholic acid, cholic acid, 1H-indole-3-acetic acid, 3-indole acrylic acid and melatonin were negatively correlated with BA and Staphylococcus saprophyticus subsp. saprophyticus, but positively correlated with Lactobacillus murinus, Leptum and Gut_metagenome. 2-Hydroxy-6-methylpyridin-3-carboxylic acid, l-homoserine, and 1,7-dimethylxanthine were positively correlated with BA and Staphylococcus saprophyticus subsp. saprophyticus, but negatively correlated with Lactobacillus murinus, Leptum, and Gut_metagenome. In a high sugar diet mode, theabrownin reduced the body weight and triglycerides and improved insulin resistance mainly by targeting the reproduction of intestinal microorganisms such as BA, Staphylococcus saprophyticus subsp. saprophyticus, Lactobacillus murinus, Leptum, Gut_metagenome and so on. A strong correlation between cecal microorganisms and serum metabolites, obesity and insulin resistance was observed. Theabrownin has high potential in reducing the risk of cardiovascular diseases such as diabetes and obesity.

Determination of cholic acid in body fluids by ß­cyclodextrin-modified N-doped carbon dot fluorescent probes.

An easy, dependable, and sensitive cholic acid activity experiment was designed based on ß­cyclodextrin-modified carbon dot (ß­CD-CD) nanoprobes with specific host-guest recognizing ability and photoelectron transfer capability. The ß­CD-CD nanoprobes were characterized by infrared, ultraviolet-visible, and fluorescence spectroscopy and transmission electron microscopy. The fluorescence of the probes under optimized conditions linearly responded to cholic acid concentration from 0 to 650 µmol·L-1 with a detection limit of 25 nmol·L-1. The probes also performed well in detecting cholic acid in serum and urine samples with an average recovery rate of 97.1%-103.4%. Thus, this study provides a reliable, rapid, and easy method of cholic acid detection in body fluids that can be potentially applied in medical studies.

The cholic acid extension study in Zellweger spectrum disorders: Results and implications for therapy.

INTRODUCTION: Currently, no therapies are available for Zellweger spectrum disorders (ZSDs), a group of genetic metabolic disorders characterised by a deficiency of functional peroxisomes. In a previous study, we showed that oral cholic acid (CA) treatment can suppress bile acid synthesis in ZSD patients and, thereby, decrease plasma levels of toxic C27 -bile acid intermediates, one of the biochemical abnormalities in these patients. However, no effect on clinically relevant outcome measures could be observed after 9 months of CA treatment. It was noted that, in patients with advanced liver disease, caution is needed because of possible hepatotoxicity. METHODS: An extension study of the previously conducted pretest-posttest design study was conducted including 17 patients with a ZSD. All patients received oral CA for an additional period of 12 months, encompassing a total of 21 months of treatment. Multiple clinically relevant parameters and markers for bile acid synthesis were assessed after 15 and 21 months of treatment. RESULTS: Bile acid synthesis was still suppressed after 21 months of CA treatment, accompanied with reduced levels of C27 -bile acid intermediates in plasma. These levels significantly increased again after discontinuation of CA. No significant changes were found in liver tests, liver elasticity, coagulation parameters, fat-soluble vitamin levels or body weight. CONCLUSIONS: Although CA treatment did lead to reduced levels of toxic C27 -bile acid intermediates in ZSD patients without severe liver fibrosis or cirrhosis, no improvement of clinically relevant parameters was observed after 21 months of treatment. We discuss the implications for CA therapy in ZSD based on these results.

Lipid-lowering effect of bergamot polyphenolic fraction: role of pancreatic cholesterol ester hydrolase.

Bergamot polyphenolic fraction (BPF) has been shown to positively modulate several mechanisms involved in metabolic syndrome, suggesting its use in therapy. In particular, it is able to induce a significant amelioration of serum lipid profile in hyperlipemic patients at different levels. The purpose of our study was to investigate the effect of BPF on cholesterol absorption physiologically mediated by pancreatic cholesterol ester hydrolase (pCEH). An in vitro activity assay was performed to study the effect of BPF on pCEH, whereas the rate of cholesterol absorption was evaluated through in vivo studies. In particular, male, Sprague-Dawley rats (200–225 g) were fed either normal chow or chow supplemented with 0.5% cholic acid, 5.5% peanut oil, and varying amounts of cholesterol (0 to 1.5%). BPF (10 mg/Kg) was daily administrated by means of a gastric gavage to animals fed with lipid supplemented diet for 4 weeks and, at the end of the study, plasma lipids and liver cholesteryl esters were measured in all experimental groups. Our results show that BPF was able to inhibit pCEH activity and this effect was confirmed, in vivo, via detection of lymphatic cholesteryl ester in rats fed with a cholesterol-rich diet. This evidence clarifies a further mechanism responsible for the hypolipemic properties of BPF previously observed in humans, confirming its beneficial effect in the therapy of hypercholesterolemia and in the treatment of metabolic syndrome.

A Metabolomic and Lipidomic Serum Signature from Nonhuman Primates Administered with a Promising Radiation Countermeasure, Gamma-Tocotrienol.

The development of radiation countermeasures for acute radiation syndrome (ARS) has been underway for the past six decades, leading to the identification of multiple classes of radiation countermeasures. However, to date, only two growth factors (Neupogen and Neulasta) have been approved by the United States Food and Drug Administration (US FDA) for the mitigation of hematopoietic acute radiation syndrome (H-ARS). No radioprotector for ARS has been approved by the FDA yet. Gamma-tocotrienol (GT3) has been demonstrated to have radioprotective efficacy in murine as well as nonhuman primate (NHP) models. Currently, GT3 is under advanced development as a radioprotector that can be administered prior to radiation exposure. We are studying this agent for its safety profile and efficacy using the NHP model. In this study, we analyzed global metabolomic and lipidomic changes using ultra-performance liquid chromatography (UPLC) quadrupole time-of-flight mass spectrometry (QTOF-MS) in serum samples of NHPs administered GT3. Our study, using 12 NHPs, demonstrates that alterations in metabolites manifest only 24 h after GT3 administration. Furthermore, metabolic changes are associated with transient increase in the bioavailability of antioxidants, including lactic acid and cholic acid and anti-inflammatory metabolites 3 deoxyvitamin D3, and docosahexaenoic acid. Taken together, our results show that the administration of GT3 to NHPs causes metabolic shifts that would provide an overall advantage to combat radiation injury. This initial assessment also highlights the utility of metabolomics and lipidomics to determine the underlying physiological mechanisms involved in the radioprotective efficacy of GT3.

Pharmacometabolomics in Endogenous Drugs: A New Approach for Predicting the Individualized Pharmacokinetics of Cholic Acid.

The evaluation of individual variability in endogenous drugs' metabolism and disposition is a very challenging task. We developed and validated a metabotype to pharmacokinetics (PK) matching approach by taking cholic acid as an example to predict the individualized PK of endogenous drugs. The stable isotope-labeled cholic acid was selected as the substitute analyte of cholic acid to ensure the accurate measurement of blood concentration. First, large-scale metabolite profiling studies were performed on the predose urine samples of 28 rats. Then, to examine the individualized PK of deuterium 4-cholic acid (d4-cholic acid) in these rats, we determined its plasma concentrations and calculated the differential AUC values. Subsequently, we conducted a two-stage partial least-squares analysis in which 31 baseline metabolites were screened initially for predicting the individualized AUC values of d4-cholic acid using the data of predose urine metabolites. Finally, network biology analysis was applied to give the biological interpretation of the individual variances in cholic acid metabolism and disposition, and the result further narrowed the selection of baseline metabolites from 31 to 2 (sarcosine and S-adenosyl-l-homocysteine) for such prediction. Collectively, this pharmacometabolomics research provided a new strategy for predicting individualized PK of endogenous drugs.

Sensitivity and Specificity of Biochemical Tests for Diagnosis of Intrahepatic Cholestasis of Pregnancy.

BACKGROUND AND AIM: Intrahepatic cholestasis of pregnancy (ICP) is linked with increased risk of fetal complications. An accurate diagnostic test is needed to diagnose this disorder on time. We aimed to assess sensitivity and specificity of laboratory tests used for diagnosis of intrahepatic cholestasis of pregnancy and determine more reliable cut-off values of transaminases. MATERIAL AND METHODS: Sixty one symptomatic patients with ICP and 29 healthy pregnant women were included in the retrospective analysis. RESULTS: ICP patients had higher total bile acids (TBA) levels than healthy women (32 vs. 6; P < 0.0001) due to increase in cholic acid (CA) and chenodeoxycholic acid (CDCA). CA/CDCA ratio was significantly higher in ICP patients compared to healthy pregnant women (1.13 vs. 0.68; P < 0.00002). TBA, CA, CDCA and CA/CDCA ratio demonstrate the following sensitivity (94%, 96%, 89%, 71.9%) and specificity (63%, 63%, 59%, 79.3%, respectively) for ICP diagnosis. Lowering cut-off values for ALT (31 U/L) and AST (30 U/L) resulted only in minimal increase of sensitivity to 92.2% vs. 90.1% for ALT and to 92.2%, vs. 90.6% for AST. CONCLUSION: The present study did not reveal any single specific and sensitive marker for reliable diagnosis of ICP. Establishment of lower cut-off values for transaminases activity might only minimally increase the accuracy of diagnosing ICP.

Cholic acid therapy in Zellweger spectrum disorders.

INTRODUCTION: Zellweger spectrum disorders (ZSDs) are characterized by a failure in peroxisome formation, caused by autosomal recessive mutations in different PEX genes. At least some of the progressive and irreversible clinical abnormalities in patients with a ZSD, particularly liver dysfunction, are likely caused by the accumulation of toxic bile acid intermediates. We investigated whether cholic acid supplementation can suppress bile acid synthesis, reduce accumulation of toxic bile acid intermediates and improve liver function in these patients. METHODS: An open label, pretest-posttest design study was conducted including 19 patients with a ZSD. Participants were followed longitudinally during a period of 2.5 years prior to the start of the intervention. Subsequently, all patients received oral cholic acid and were followed during 9 months of treatment. Bile acids, peroxisomal metabolites, liver function and liver stiffness were measured at baseline and 4, 12 and 36 weeks after start of cholic acid treatment. RESULTS: During cholic acid treatment, bile acid synthesis decreased in the majority of patients. Reduced levels of bile acid intermediates were found in plasma and excretion of bile acid intermediates in urine was diminished. In patients with advanced liver disease (n = 4), cholic acid treatment resulted in increased levels of plasma transaminases, bilirubin and cholic acid with only a minor reduction in bile acid intermediates. CONCLUSIONS: Oral cholic acid therapy can be used in the majority of patients with a ZSD, leading to at least partial suppression of bile acid synthesis. However, caution is needed in patients with advanced liver disease due to possible hepatotoxic effects.

Bile acids promote diethylnitrosamine-induced hepatocellular carcinoma via increased inflammatory signaling.

Hepatocellular carcinoma (HCC) is the most common hepatic malignancy and the third leading cause of cancer related deaths. Previous studies have implicated bile acids in pathogenesis of HCC, but the mechanisms are not known. We investigated the mechanisms of HCC tumor promotion by bile acids the diethylnitrosamine (DEN)-initiation-cholic acid (CA)-induced tumor promotion protocol in mice. The data show that 0.2% CA treatment resulted in threefold increase in number and size of DEN-induced liver tumors. All tumors observed in DEN-treated mice were well-differentiated HCCs. The HCCs observed in DEN-treated CA-fed mice exhibited extensive CD3-, CD20-, and CD45-positive inflammatory cell aggregates. Microarray-based global gene expression studies combined with Ingenuity Pathway Analysis revealed significant activation of NF-κB and Nanog in the DEN-treated 0.2% CA-fed livers. Further studies showed significantly higher TNF-α and IL-1ß mRNA, a marked increase in total and phosphorylated-p65 and phosphorylated IκBα (degradation form) in livers of DEN-treated 0.2% CA-fed mice. Treatment of primary mouse hepatocytes with various bile acids showed significant induction of stemness genes including Nanog, KLF4, Sox2, and Oct4. Quantification of total and 20 specific bile acids in liver, and serum revealed a tumor-associated bile acid signature. Finally, quantification of total serum bile acids in normal, cirrhotic, and HCC human samples revealed increased bile acids in serum of cirrhotic and HCC patients. Taken together, these data indicate that bile acids are mechanistically involved pathogenesis of HCC and may promote HCC formation via activation of inflammatory signaling.

Fluorescent molecularly imprinted polymers based on 1,8-naphthalimide derivatives for efficiently recognition of cholic acid.

Fluorescent molecularly imprinted polymers (MIPs) have attracted increasing attentions in recent years due to their high selectivity and sensitivity for target molecules. In this study, two cholic acid imprinted fluorescent polymers, i.e., MIP1 and MIP2, were prepared using 4-dimethylamino-N-allylnaphthalimide (F1) and 4-piperazinyl-N-allylnaphthalimide (F2) as the fluorescent functional monomers, respectively. The fluorescence intensity of MIP1 decreased linearly with the increase of the template concentration in the range of 1.50-120.0 µM, while the fluorescence intensity of MIP2 increased linearly with the increase of the template concentration in the range of 0.40-110.0 µM. The detection limits of MIP1 and MIP2 for cholic acid were 0.42 and 0.083 µM, respectively. The mechanisms of the fluorescence responsive of the imprinted polymers were discussed. The results of fluorescence measurement and binding experiments demonstrated that both imprinted polymers have high recognition abilities and binding affinities for the template. The imprinted polymers have been successfully applied to the determination of cholic acid in human serums. The present study indicated that 1,8-naphthalimide can be used as a modular building block for design and construction of various fluorogenic molecularly imprinted materials for practical sensing and separation.

Cardiomyopathy reverses with recovery of liver injury, cholestasis and cholanemia in mouse model of biliary fibrosis.

BACKGROUND: Triggers and exacerbants of cirrhotic cardiomyopathy (CC) are poorly understood, limiting treatment options in patients with chronic liver diseases. Liver transplantation alone reverses some features of CC, but the physiology behind this effect has never been studied. AIMS: We aimed to determine whether reversal of liver injury and fibrosis in mouse affects cardiac parameters. The second aim was to determine whether cardiomyopathy can be induced by specifically increasing systemic bile acid (BA) levels. METHODS: 6-8 week old male C57BL6J mice were fed either chow (n = 5) or 3,5-diethoxycarbonyl-1,4-dihydroxychollidine (DDC) (n = 10) for 3 weeks. At the end of 3 weeks, half the mice in the DDC fed group were randomized to chow (the reversed [REV] group). Serial ECHOs and electrocardiographic analysis was conducted weekly for 6 weeks followed by liver tissue and serum studies. Hearts were analysed for key components of function and cell signalling. Cardiac physiological and molecular parameters were similarly analysed in Abcb11(-/-) mice (n = 5/grp) fed 0.5% cholic acid supplemented diet for 1 week. RESULTS: Mice in the REV group showed normalization of biochemical markers of liver injury with resolution of electrocardiographic and ECHO aberrations. Catecholamine resistance seen in DDC group resolved in the REV group. Cardiac recovery was accompanied by normalization of cardiac troponin-T2 as well as resolution of cardiac stress response at RNA level. Cardiovascular physiological and molecular parameters correlated with degree of cholanemia. Cardiomyopathy was reproduced in cholanemic BA fed Abcb11(-/-) mice. CONCLUSIONS: Cardiomyopathy resolves with resolution of liver injury, is associated with cholanaemia, and can be induced by BA feeding.

Pore size--a key property for selective toxin removal in blood purification.

PURPOSE: Extracorporeal blood purification systems based on combined membrane/adsorption technologies are used in acute liver failure to replace detoxification as well as to remove inflammatory mediators in sepsis patients. In addition to coating and chemical modification of the surface, pore size significantly controls the selectivity of adsorption materials. METHODS: This study addresses the adsorption of albumin bound liver toxins, cytokines, and representative plasma compounds on three adsorbents which differ only in pore size distribution. All three adsorbents are based on hydrophobic poly(styrene-divinylbenzene) copolymer matrices and have mean pore sizes of 15, 30, and 100 nm. RESULTS: The pores of adsorbents act as molecular sieves and prevent the entry of molecules that are larger than their molecular cut-off. The results of this study reveal that adsorbents based on styrene-divinylbenzene polymers with 15 nm pores are suitable for cytokine removal, and the same adsorbents with 30-40 nm pores are the best choice for the removal of albumin-bound toxins in the case of liver failure. Adsorbents with very large pores lack selectivity which leads to uncontrolled adsorption of all plasma proteins. Therefore, hydrophobic adsorbents with large pores offer inadequate plasma compatibility and do not fulfill the requirements for blood purification. CONCLUSIONS: Biocompatibility and efficiency of adsorbents used for blood purification can improved by fine tuning of adsorbent surface pore distributions.

Development of a highly sensitive MIP based-QCM nanosensor for selective determination of cholic acid level in body fluids.

Determination of cholic acid is very important and necessary in body fluids due to its both pharmaceutical and clinical significance. In this study, a quartz crystal microbalance (QCM) nanosensor, which is imprinted cholic acid, has been developed for the assignation of cholic acid. The cholic acid selective memories have been generated on QCM electrode surface by using molecularly imprinted polymer (MIP) based on methacryloylamidohistidine-copper (II) (MAH-Cu(II)) pre-organized monomer. The cholic acid imprinted nanosensor was characterized by atomic force microscopy (AFM) and then analytical performance of the cholic acid imprinted QCM nanosensor was studied. The detection limit was found to be 0.0065µM with linear range of 0.01-1,000 µM. Moreover, the high value of Langmuir constant (b) (7.3*10(5)) obtained by Langmuir graph showed that the cholic acid imprinted nanosensor had quite strong binding sites affinity. At the last step of this procedure, cholic acid levels in body fluids were determined by the prepared imprinted QCM nanosensor.

Vertical sleeve gastrectomy reduces hepatic steatosis while increasing serum bile acids in a weight-loss-independent manner.

OBJECTIVE: Our objective was to investigate the role of bile acids in hepatic steatosis reduction after vertical sleeve gastrectomy (VSG). DESIGN AND METHODS: High fat diet (HFD)-induced obese C57Bl/6 mice were randomized to VSG, Sham operation (Sham), Sham operation with pair feeding to VSG (Sham-PF), or nonsurgical controls (Naïve). All mice were on HFD until sacrifice. Mice were observed postsurgery and data for body weight, body composition, metabolic parameters, serum bile acid level and composition were collected. Further hepatic gene expression by mRNA-seq and RT-PCR analysis was assessed. RESULTS: VSG and Sham-PF mice lost equal weight postsurgery while VSG mice had the lowest hepatic triglyceride content at sacrifice. The VSG mice had elevated serum bile acid levels that positively correlated with maximal weight loss. Serum bile composition in the VSG group had increased cholic and tauroursodeoxycholic acid. These bile acid composition changes in VSG mice explained observed downregulation of hepatic lipogenic and bile acid synthetic genes. CONCLUSION: VSG in obese mice results in greater hepatic steatosis reduction than seen with caloric restriction alone. VSG surgery increases serum bile acids that correlate with weight lost postsurgery and changes serum bile composition that could explain suppression of hepatic genes responsible for lipogenesis.

Evaluation of serum bile acid profiles as biomarkers of liver injury in rodents.

Bile acids (BAs) have been studied as potential biomarkers of drug-induced liver injury. However, the relationship between levels of individual BAs and specific forms of liver injury remains to be fully understood. Thus, we set out to evaluate cholic acid (CA), glycocholic acid (GCA), and taurocholic acid (TCA) as potential biomarkers of liver injury in rodent toxicity studies. We have developed a sensitive liquid chromatography-tandem mass spectrometry (LC/MS/MS) assay applicable to rat and mouse serum and evaluated levels of the individual BAs in comparison with the classical biomarkers of hepatotoxicity (alanine aminotransferase [ALT], aspartate aminotransferase [AST], glutamate dehydrogenase (GLDH), alkaline phosphatase, total bilirubin, gamma-glutamyl transferase, and total BAs) and histopathology findings in animals treated with model toxicants. The pattern of changes in the individual BAs varied with different forms of liver injury. Animals with histopathologic signs of hepatocellular necrosis showed increases in all 3 BAs tested, as well as increases in ALT, AST, GLDH, and total BAs. Animals with histopathologic signs of bile duct hyperplasia (BDH) displayed increases in only conjugated BAs (GCA and TCA), a pattern not observed with the other toxicants. Because BDH is detectable only via histopathology, our results indicate the potential diagnostic value of examining individual BAs levels in serum as biomarkers capable of differentiating specific forms of liver injury in rodent toxicity studies.