Sample records for bilirubin udp-glucuronosyltransferase 1a1

  1. Bilirubin UDP-Glucuronosyltransferase 1A1 (UGT1A1) Gene Promoter Polymorphisms and HPRT, Glycophorin A, and Micronuclei Mutant Frequencies in Human Blood

    Energy Technology Data Exchange (ETDEWEB)

    Grant, D; Hall, I J; Eastmond, D; Jones, I M; Bell, D A


    A dinucleotide repeat polymorphism (5-, 6-, 7-, or 8-TA units) has been identified within the promoter region of UDP-glucuronosyltransferase 1A1 gene (UGT1A1). The 7-TA repeat allele has been associated with elevated serum bilirubin levels that cause a mild hyperbilirubinemia (Gilbert's syndrome). Studies suggest that promoter transcriptional activity of UGT1A1 is inversely related to the number of TA repeats and that unconjugated bilirubin concentration increases directly with the number of TA repeat elements. Because bilirubin is a known antioxidant, we hypothesized that UGT1A1 repeats associated with higher bilirubin may be protective against oxidative damage. We examined the effect of UGT1A1 genotype on somatic mutant frequency in the hypoxanthine-guanine phosphoribosyl-transferase (HPRT) gene in human lymphocytes and the glycophorin A (GPA) gene of red blood cells (both N0, NN mutants), and the frequency of lymphocyte micronuclei (both kinetochore (K) positive or micronuclei K negative) in 101 healthy smoking and nonsmoking individuals. As hypothesized, genotypes containing 7-TA and 8-TA displayed marginally lower GPA{_}NN mutant frequency relative to 5/5, 5/6, 6/6 genotypes (p<0.05). In contrast, our analysis showed that lower expressing UGT1A1 alleles (7-TA and 8-TA) were associated with modestly increased HPRT mutation frequency (p<0.05) while the same low expression genotypes were not significantly associated with micronuclei frequencies (K-positive or K-negative) when compared to high expression genotypes (5-TA and 6-TA). We found weak evidence that UGT1A1 genotypes containing 7-TA and 8-TA were associated with increased GPA{_}N0 mutant frequency relative to 5/5, 5/6, 6/6 genotypes (p<0.05). These data suggest that UGT1A1 genotype may modulate somatic mutation of some types, in some cell lineages, by a mechanism not involving bilirubin antioxidant activity. More detailed studies examining UGT1A1 promoter variation, oxidant/antioxidant balance and

  2. Glucose induces intestinal human UDP-glucuronosyltransferase (UGT) 1A1 to prevent neonatal hyperbilirubinemia. (United States)

    Aoshima, Naoya; Fujie, Yoshiko; Itoh, Tomoo; Tukey, Robert H; Fujiwara, Ryoichi


    Inadequate calorie intake or starvation has been suggested as a cause of neonatal jaundice, which can further cause permanent brain damage, kernicterus. This study experimentally investigated whether additional glucose treatments induce the bilirubin-metabolizing enzyme--UDP-glucuronosyltransferase (UGT) 1A1--to prevent the onset of neonatal hyperbilirubinemia. Neonatal humanized UGT1 (hUGT1) mice physiologically develop jaundice. In this study, UGT1A1 expression levels were determined in the liver and small intestine of neonatal hUGT1 mice that were orally treated with glucose. In the hUGT1 mice, glucose induced UGT1A1 in the small intestine, while it did not affect the expression of UGT1A1 in the liver. UGT1A1 was also induced in the human intestinal Caco-2 cells when the cells were cultured in the presence of glucose. Luciferase assays demonstrated that not only the proximal region (-1300/-7) of the UGT1A1 promoter, but also distal region (-6500/-4050) were responsible for the induction of UGT1A1 in the intestinal cells. Adequate calorie intake would lead to the sufficient expression of UGT1A1 in the small intestine to reduce serum bilirubin levels. Supplemental treatment of newborns with glucose solution can be a convenient and efficient method to treat neonatal jaundice while allowing continuous breastfeeding.

  3. Role of extrahepatic UDP-glucuronosyltransferase 1A1: advances in understanding breast milk-induced neonatal hyperbilirubinemia (United States)

    Fujiwara, Ryoichi; Maruo, Yoshihiro; Chen, Shujuan; Tukey, Robert H.


    Newborns commonly develop physiological hyperbilirubinemia (also known as jaundice). With increased bilirubin levels being observed in breast-fed infants, breast-feeding has been recognized as a contributing factor for the development of neonatal hyperbilirubinemia. Bilirubin undergoes selective metabolism by UDP-glucuronosyltransferase (UGT) 1A1 and becomes a water soluble glucuronide. Although several factors such as gestational age, dehydration and weight loss, and increased enterohepatic circulation have been associated with breast milk-induced jaundice (BMJ), deficiency in UGT1A1 expression is a known cause of BMJ. It is currently believed that unconjugated bilirubin is metabolized mainly in the liver. However, recent findings support the concept that extrahepatic tissues, such as small intestine and skin, contribute to bilirubin glucuronidation during the neonatal period. We will review the recent advances made towards understanding biological and molecular events impacting BMJ, especially regarding the role of extrahepatic UGT1A1 expression. PMID:26342858

  4. Impact of fatty acids on human UDP-glucuronosyltransferase 1A1 activity and its expression in neonatal hyperbilirubinemia. (United States)

    Shibuya, Ayako; Itoh, Tomoo; Tukey, Robert H; Fujiwara, Ryoichi


    While breast milk has been known as a cause of neonatal hyperbilirubinemia, the underlying mechanism of breast milk-induced jaundice has not been clarified. Here, the impact of fatty acids on human UDP-glucuronosyltransferase (UGT) 1A1--the sole enzyme that can metabolize bilirubin--were examined. Oleic acid, linoleic acid, and docosahexaenoic acid (DHA) strongly inhibited UGT1A1 activity. Forty-eight hours after a treatment with a lower concentration of DHA (10 mg/kg), total bilirubin significantly increased in neonatal hUGT1 mice, which are human neonatal jaundice models. In contrast, treatments with higher concentrations of fatty acids (0.1-10 g/kg) resulted in a decrease in serum bilirubin in hUGT1 mice. It was further demonstrated that the treatment with higher concentrations of fatty acids induced UGT1A1, possibly by activation of peroxisome proliferator-activated receptors. Our data indicates that activation of peroxisome proliferator-activated receptors would increase UGT1A1 expression, resulting in reduction of serum bilirubin levels in human infants.

  5. Importance of UDP-glucuronosyltransferase 1A1 expression in skin and its induction by UVB in neonatal hyperbilirubinemia. (United States)

    Sumida, Kyohei; Kawana, Makiko; Kouno, Emi; Itoh, Tomoo; Takano, Shuhei; Narawa, Tomoya; Tukey, Robert H; Fujiwara, Ryoichi


    UDP-glucuronosyltransferase (UGT) 1A1 is the sole enzyme that can metabolize bilirubin. Human infants physiologically develop hyperbilirubinemia as the result of inadequate expression of UGT1A1 in the liver. Although phototherapy using blue light is effective in preventing jaundice, sunlight has also been suggested, but without conclusive evidence, to reduce serum bilirubin levels. We investigated the mRNA expression pattern of human UGT1A1 in human skin, human skin keratinocyte (HaCaT) cells, and skin of humanized UGT1 mice. The effects of UVB irradiation on the expression of UGT1A1 in the HaCaT cells were also examined. Multiple UGT1A isoforms, including UGT1A1, were expressed in human skin and HaCaT cells. When HaCaT cells were treated with UVB-exposed tryptophan, UGT1A1 mRNA and activity were significantly induced. Treatment of the HaCaT cells with 6-formylindolo[3,2-b]carbazole, which is one of the tryptophan derivatives formed by UVB, resulted in an induction of UGT1A1 mRNA and activity. In neonates, the expression of UGT1A1 was greater in the skin; in adults, UGT1A1 was expressed mainly in the liver. Treatment of humanized UGT1 mice with UVB resulted in a reduction of serum bilirubin levels, along with increased UGT1A1 expression and activity in the skin. Our data revealed a protective role of UGT1A1 expressed in the skin against neonatal hyperbilirubinemia. Sunlight, a natural and free source of light, makes it possible to treat neonatal jaundice while allowing mothers to breast-feed neonates.

  6. High throughput screening assay for UDP-glucuronosyltransferase 1A1 glucuronidation profiling. (United States)

    Trubetskoy, O V; Finel, M; Kurkela, M; Fitzgerald, M; Peters, N R; Hoffman, F M; Trubetskoy, V S


    Development of high throughput screening (HTS) assays for evaluation of a compound's toxicity and potential for drug-drug interactions is a critical step towards production of better drug candidates and cost reduction in the drug development process. HTS assays for drug metabolism mediated by cytochrome P450s are now routinely used in compound library characterization and for computer modeling studies. However, development and application of HTS assays involving UDP-glucuronosyltransferases (UGTs) are lagging behind. Here we describe the development of a fluorescence-based HTS assay for UGT1A1 using recombinant enzyme and fluorescent substrate in the presence of an aqueous solution of PreserveX-QML (QBI Life Sciences, Madison, WI) polymeric micelles, acting as a stabilizer and a blocker of nonspecific interactions. The data include assay characteristics in 384-well plate format obtained with robotic liquid handling equipment and structures of hits (assay modifiers) obtained from the screening of a small molecule library at the University of Wisconsin HTS screening facility. The application of the assay for predicting UGT-related drug-drug interactions and building pharmacophore models, as well as the effects of polymeric micelles on the assay performance and compound promiscuity, is discussed.

  7. Accurate identification of UDP-glucuronosyltransferase 1A1 (UGT1A1) inhibitors using UGT1A1-overexpressing HeLa cells. (United States)

    Sun, Hua; Zhou, Xiaotong; Wu, Baojian


    1. UDP-glucuronosyltransferase 1A1 (UGT1A1) plays an irreplaceable role in detoxification of bilirubin and many drugs (e.g., SN-38). Here we aimed to explore the potential of UGT1A1-overexpressing HeLa cells (or HeLa1A1 cells) as a tool to accurately identify UGT1A1 inhibitors. 2. Determination of glucuronidation rates (β-estradiol and SN-38 as the substrates) was performed using HeLa1A1 cells and uridine diphosphoglucuronic acid (UDPGA)-supplemented cDNA expressed UGT1A1 enzyme (or microsomes). The inhibitory effects (IC50 values) of 20 structurally diverse compounds on the UGT1A1 activity were determined using HeLa1A1 cells and microsomal incubations. 3. In HeLa1A1 cells, the IC50 values for inhibition of β-estradiol glucuronidation by the tested compounds ranged from 0.33 to 94.6 µM. In the microsomal incubations, the IC50 values ranged from 0.47 to 155 µM. It was found that the IC50 values of all test compounds derived from the cells were well consistent with those from the microsomes (deviated by less than two-fold). Further, the IC50 values from the cells were strongly correlated with those from microsomes (r = 0.944, p HeLa cells were an appropriate tool to accurately depict the inhibition profiles of chemicals against UGT1A1.


    NARCIS (Netherlands)



    When membrane proteins are solubilized and subjected to purification procedures, the loss of lipids surrounding the protein often results in irreversible inactivation. We describe a procedure for the immunoaffinity purification of the membrane protein UDP-glucuronosyltransferase from human liver. Th

  9. Gene therapy with bilirubin-UDP-glucuronosyltransferase in the Gunn rat model of Crigler-Najjar syndrome type 1. (United States)

    Li, Q; Murphree, S S; Willer, S S; Bolli, R; French, B A


    Crigler-Najjar syndrome type 1 (CN type 1) is an autosomal recessive disorder characterized by nonhemolytic jaundice resulting from mutations to the gene encoding bilirubin-UDP-glucuronosyltransferase (UDPGT). The Gunn rat is an accurate animal model of this disease because the bilirubin-UDPGT gene in this strain carries a premature stop codon. The primary objective of this study was to complement this deficiency in vivo using liver-directed gene therapy. The efficiency of adenovirus type 5 (Ad5)-mediated gene transfer to the neonatal rat liver was first assessed by intravenous (i.v.) injection of an Ad5 vector carrying a nuclear-localized LacZ gene. An Ad5 vector expressing the cDNA encoding human bilirubin-UDPGT (Ad5/CMV/hUG-Br1) was then generated and injected i.v. into neonatal Gunn rats. Plasma samples were collected and bilirubin levels were determined at regular intervals. Although the mean level of bilirubin in homozygous Gunn rats 1-2 days after birth was already 14.5-fold higher than that of heterozygous siblings, treatment with Ad5/CMV/hUG-Br1 reduced plasma bilirubin to normal levels within 1 week. Plasma bilirubin in the treated homozygous rats remained normal for 4 weeks before gradually climbing to intermediate levels that were approximately half that of untreated homozygotes by 12 weeks. Administration of Ad5-mediated gene therapy to neonatal Gunn rats effectively complemented the deficiency in bilirubin-UDPGT, resulting in substantial reductions in plasma bilirubin over a 3-month period. The efficacy of Ad5-mediated gene therapy in neonates suggests that this approach might be effective against other hepatic disorders, including autosomal recessive deficiencies in lipid metabolism and vascular homeostasis.

  10. Induction of the UDP-Glucuronosyltransferase 1A1 during the Perinatal Period Can Cause Neurodevelopmental Toxicity. (United States)

    Hirashima, Rika; Michimae, Hirofumi; Takemoto, Hiroaki; Sasaki, Aya; Kobayashi, Yoshinori; Itoh, Tomoo; Tukey, Robert H; Fujiwara, Ryoichi


    Anticonvulsants can increase the risk of developing neurotoxicity in infants; however, the underlying mechanism has not been elucidated to date. Thyroxine [3,5,3',5'-l-tetraiodothyronine (T4)] plays crucial roles in the development of the central nervous system. In this study, we hypothesized that induction of UDP-glucuronosyltransferase 1A1 (UGT1A1)-an enzyme involved in the metabolism of T4-by anticonvulsants would reduce serum T4 levels and cause neurodevelopmental toxicity. Exposure of mice to phenytoin during both the prenatal and postnatal periods significantly induced UGT1A1 and decreased serum T4 levels on postnatal day 14. In the phenytoin-treated mice, the mRNA levels of synaptophysin and synapsin I in the hippocampus were lower than those in the control mice. The thickness of the external granule cell layer was greater in phenytoin-treated mice, indicating that induction of UGT1A1 during the perinatal period caused neurodevelopmental disorders. Exposure to phenytoin during only the postnatal period also caused these neurodevelopmental disorders. A T4 replacement attenuated the increase in thickness of the external granule cell layer, indicating that the reduced T4 was specifically associated with the phenytoin-induced neurodevelopmental disorder. In addition, these neurodevelopmental disorders were also found in the carbamazepine- and pregnenolone-16-α-carbonitrile-treated mice. Our study is the first to indicate that UGT1A1 can control neurodevelopment by regulating serum T4 levels.

  11. Developmental onset of bilirubin-induced neurotoxicity involves Toll-like receptor 2-dependent signaling in humanized UDP-glucuronosyltransferase1 mice. (United States)

    Yueh, Mei-Fei; Chen, Shujuan; Nguyen, Nghia; Tukey, Robert H


    Biological and signaling events that connect developmentally induced hyperbilirubinemia to bilirubin-induced neurological dysfunction (BIND) and CNS toxicity in humans are poorly understood. In mammals, UDP-glucuronosyltransferase 1A1 (UGT1A1) is the sole enzyme responsible for bilirubin glucuronidation, a rate-limiting step necessary for bilirubin metabolism and clearance. Humanized mice that express the entire UGT1 locus (hUGT1) and the UGT1A1 gene, develop neonatal hyperbilirubinemia, with 8-10% of hUGT1 mice succumbing to CNS damage, a phenotype that is presented by uncontrollable seizures. We demonstrate that neuroinflammation and reactive gliosis are prominent features of bilirubin brain toxicity, and a disturbed redox status resulting from activation of NADPH oxidase is an important contributing mechanism found in BIND. Using knock-out mice and primary brain cells, we connect a key pattern recognition receptor, Toll-like receptor 2 (TLR2), to hyperbilirubinemia-induced signaling. We illustrate a requirement for TLR2 signaling in regulating gliosis, proinflammatory mediators, and oxidative stress when neonatal mice encounter severe hyperbilirubinemia. TLR2-mediated gliosis strongly correlates with pronounced neuroinflammation in the CNS with up-regulation of TNFα, IL-1β, and IL-6, creating a pro-inflammatory CNS environment. Gene expression and immunohistochemistry staining show that hUGT1/Tlr2(-/-) mice fail to activate glial cells, proinflammatory cytokines, and stress response genes. In addition, bilirubin-induced apoptosis was significantly enhanced by blocking TLR2 signaling indicating its anti-apoptotic property. Consequently, a higher neonatal death rate (57.1%) in hUGT1/Tlr2(-/-) mice was observed when compared with hUGT1 mice (8.7%). These results suggest that TLR2 signaling and microglia neuroinflammation are linked to a repair and/or protection mode against BIND.

  12. Effects of variant UDP-glucuronosyltransferase 1A1 gene,glucose-6-phosphate dehydrogenase deficiency and thalassemia on cholelithiasis

    Institute of Scientific and Technical Information of China (English)

    Yang-Yang Huang; Ching-Shui Huang; Sien-Sing Yang; Min-Shung Lin; May-Jen Huang; Ching-Shan Huang


    AIM: To test the hypothesis that the variant UDPglucuronosyltransferase 1A1 (UGT1A1) gene, glucose-6-phosphate dehydrogenase (G6PD) deficiency, and thalassemia influence bilirubin metabolism and play a role in the development of cholelithiasis.METHODS: A total of 372 Taiwan Chinese with cholelithiasis who had undergone cholecystectomy and 293 healthy individuals were divided into case and control groups,respectively. PCR and restriction fragment length polymorphism were used to analyze the promoter area and nucleotides 211, 686, 1 091, and 1 456 of the UGT1A1 gene for all subjects and the gene variants for thalassemia and G6PD deficiency.RESULTS: Variation frequencies for the cholelithiasis patients were 16.1%, 25.8%, 5.4%, and 4.3% for A(TA)6TAA/A(TA)7TAA (6/7), heterozygosity within the coding region, compound heterozygosity, and homozygosity of the UGT1A1 gene, respectively. Comparing the case and control groups, a statistically significant difference in frequency was demonstrated for the homozygous variation of the UGT1A1 gene (P = 0.012, χ2 test), but not for the other variations. Further, no difference was demonstrated in a between-group comparison of the incidence of G6PD deficiency and thalassemia (2.7% vs 2.4% and 5.1% vs 5.1%, respectively). The bilirubin levels for the cholelithiasis patients with the homozygous variant-UGT1A1 gene were significantly different from the control analog (18.0±6.5 and 12.7±2.9 μmol/L, respectively; P<0.001, Student's ttest).CONCLUSION: Our results show that the homozygous variation in the UGT1A1 gene is a risk factor for the development of cholelithiasis in Taiwan Chinese.

  13. Effect of dietary eugenol on xenobiotic metabolism and mediation of UDP-glucuronosyltransferase and cytochrome P450 1A1 expression in rat liver. (United States)

    Iwano, Hidetomo; Ujita, Wakako; Nishikawa, Miyu; Ishii, Satomi; Inoue, Hiroki; Yokota, Hiroshi


    Xenobiotic-metabolizing enzymes (XMEs) play an important role in the elimination and detoxification of xenobiotics and drugs. A variety of natural dietary agents are known to protect against cancer by inducing XME. To elucidate the molecular mechanism of XME induction, we examined the effect of dietary eugenol (4-allyl-1-hydroxy-2-methoxybenzene) on xenobiotic metabolism. In this study, rats were administered dietary eugenol for 4 weeks to investigate the various effects of UDP-glucuronosyltransferase (UGT) and cytochrome P450 (CYP) expression. In rats administered dietary eugenol, expression levels of hepatic CYP1A 1 were reduced to 40% than of the controls, while expression of hepatic UGT1A6, UGT1A7 and UGT2B1 increased to 2-3 times than observed in the controls. Hepatic protein levels of UGT1A6 and 2B1 were also elevated in the eugenol-treated rats. These results suggest that the natural compound eugenol improves the xenobiotic-metabolizing systems that suppress and induce the expression of CYP1A1 and UGT, respectively.

  14. Gilbert's syndrome: High frequency of the (TA)7 TAA allele in India and its interaction with a novel CAT insertion in promoter of the gene for bilirubin UDP-glucuronosyltransferase 1 gene

    Institute of Scientific and Technical Information of China (English)

    Shabana Farheen; Sanghamitra Sengupta; Amal Santra; Suparna Pal; Gopal Krishna Dhali; Meenakshi Chakravorty; Partha P Majumder; Abhijit Chowdhury


    AIM: To identify the variants in UDP-glucuronosyltransferase 1 (UGT1A1) gene in Gilbert's syndrome (GS) and to estimate the association between homozygosity for TA insertion and GS in India, as well as the frequency of TA insertion and its impact among normal controls in India.METHODS: Ninety-five GS cases and 95 normal controls were selected. Liver function and other tests were done. The promoter and all 5 exons of UGT1A1 gene were resequenced. Functional assessment of a novel trinucleotide insertion was done byin silico analysis and by estimating UGT1A1 promoter activity carried out by luciferase reporter assay of appropriate constructs in Hep G2 cell line.RESULTS: Among the GS patients, 80% were homozygous for the TA insertion, which was several-fold higher than reports from other ethnic groups. The mean UCB level was elevated among individuals with only one copy of this insertion, which was not significantly different from those with two copies. Many new DNA variants in UGT1A1 gene were discovered, including a trinucleotide (CAT) insertion in the promoter found in a subset (10%) of GS patients, but not among normal controls. In-silico analysis showed marked changes in the DNA-folding of the promoter and functional analysis showed a 20-fold reduction in transcription efficiency of UGT1A1 gene resulting from this insertion, thereby significantly elevating the UCB level.CONCLUSION: The genetic epidemiology of GS is variable across ethnic groups and the epistatic interactions among UGT1A1 promoter variants modulate bilirubin glucuronidation.

  15. Human UDP-Glucuronosyltransferase 1A1 is the Primary Enzyme Responsible for the N-glucuronidation of N-hydroxy-PhIP in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Malfatti, M A; Felton, J S


    UDP-Glucuronosyltransferase 1A proteins (UGT1A) catalyze the glucuronidation of many endogenous and xenobiotic compounds including heterocyclic amines and their hydroxylated metabolites (the main topic of this study). Studies have shown that in humans UGT1A mediated glucuronidation is an important pathway in the detoxification of food-borne carcinogenic heterocyclic amines. The biotransformation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), the most mass abundant heterocyclic amine found in cooked meats, is highly dependent on cytochrome P4501A2 hydroxylation followed by UGT catalyzed glucuronidation of the N-hydroxy-PhIP reactive intermediate. To determine which UGT1A proteins are involved in the glucuronidation of N-hydroxy-PhIP, microsomal preparations from baculovirus infected insect cells that express all of the known functional human UGT1A isozymes (UGT1A1, -1A3, -1A4, -1A6, -1A7, -1A8, -1A9, -1A10) were exposed to N-hydroxy-PhIP and the reaction products were isolated by HPLC. All UGT1A proteins except UGT1A6 showed some degree of activity towards N-hydroxy-PhIP. The formation of both N-hydroxy-PhIP-N{sup 2}-glucuronide and N-hydroxy-PhIP-N3-glucuronide was both time and substrate concentration dependent in all the microsomal incubations that showed appreciable activity. UGT1A1 was the most efficient in converting N-hydroxy-PhIP to both conjugates producing 5 times more of the N{sup 2}-conjugate than UGT1A4, the next active UGT, and 286 times more than UGT1A7, the least active UGT. With an apparent Km of 52 {micro}M and a K{sub cat} of 114 min-1, UGT1A1 was also the most catalytically efficient in forming N-hydroxy-PhIP-N{sup 2}-glucuronide. Catalytic constants for UGT1A4, UGT1A8 and UGT1A9 were 52 min-1, 35 min{sup -1} and 3.7 min{sup -1}, respectively. The catalytic efficiency for N-hydroxy-PhIP-N3-glucuronide formation was 8, 10, and 6 times lower for UGT1A1, -1A4, and -1A8, respectively, when compared to the k{sub cat} values for N

  16. The Effect of UDP-glucuronosyltransferase 1A1 Expression on the Mutagenicity and Metabolism of the Cooked-Food Carcinogen 2-Amino-1-methyl-6-phenylimidazo[4-5,b]pyridine in CHO cells

    Energy Technology Data Exchange (ETDEWEB)

    Malfatti, M A; Wu, R W; Felton, J S


    UDP-glucuronosyltransferase proteins (UGT) catalyze the glucuronidation of both endogenous and xenobiotic compounds. In previous studies UGT1A1 has been implicated in the detoxification of certain food-borne-carcinogenic-heterocyclic amines. To determine the importance of UDP-glucuronosyltransferase 1A1 (UGT1A1) in the biotransformation of the cooked-food carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), genetically modified CHO cells that are nucleotide excision repair-deficient, and express cytochrome P4501A2 (UV5P3 cell line) were transfected with a cDNA plasmid of human UGT1A1 to establish the UDPglucuronosyltransferase 1A1 expressing 5P3hUGT1A1 cell line. Expression of the UGT1A1 gene was verified by screening neogene expressing clonal isolates (G-418 resistant) for their sensitivity to cell killing from PhIP exposure. Five of eleven clones were chosen for further analysis due to their resistance to cell killing. Western blot analysis was used to confirm the presence of the UGT1A1 and CYP1A2 proteins. All five clones displayed a 52 kDa protein band, which corresponded to a UGT1A1 control protein. Only four of the clones had a protein band that corresponded to the CYP1A2 control protein. Correct fragment size of the cDNAs in the remaining 4 clones was confirmed by RT-PCR and quantification of the mRNA product was accomplished by real-time RT-PCR. Expression of UGT1A1 in the transfected cells was 10{sup 4}-10{sup 5} fold higher relative to the UV5P3 parental cells. One clone (No.14) had a 10 fold higher increase in expression at 1.47 x 10{sup 5} over the other three clones. This clone was also the most active in converting N-hydroxy-PhIP to N-hydroxy-PhIP glucuronide conjugates in microsomal metabolism assays. Based on the D{sub 50} values, the cytotoxic effect of PhIP was decreased {approx}350 fold in the 5P3hUGT1A1 cells compared to the UV5P3 control cells. In addition no significant increase in mutation frequency was observed in the

  17. Role of UDP-Glucuronosyltransferase 1A1 in the Metabolism and Pharmacokinetics of Silymarin Flavonolignans in Patients with HCV and NAFLD

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    Ying Xie


    Full Text Available Silymarin is the most commonly used herbal medicine by patients with chronic liver disease. Silymarin flavonolignans undergo rapid first-pass metabolism primarily by glucuronidation. The aims of this investigation were: (1 to determine the association of UGT1A1*28 polymorphism with the area under the plasma concentration-time curves (AUCs for silybin A (SA and silybin B (SB; (2 to evaluate the effect of UGT1A1*28 polymorphism on the profile of flavonolignan glucuronide conjugates found in the plasma; and (3 to investigate the role of UGT1A1 enzyme kinetics on the pharmacokinetics of SA and SB. AUCs and metabolic ratios for thirty-three patients with chronic liver disease administered oral doses of silymarin were compared between different UGT1A1*28 genotypes. The AUCs, metabolic ratios, and the profiles of major SA and SB glucuronides did not differ significantly among the three UGT1A1 genotypes. In contrast, an increase in the proportion of sulfated flavonolignan conjugates in plasma was observed in subjects with UGT1A1*28/*28 genotype compared to subjects carrying wild type alleles. Differences in SA and SB in vitro intrinsic clearance estimates for UGTIA1 correlated inversely with SA and SB exposures observed in vivo indicating a major role for UGT1A1 in silymarin metabolism. In addition, a significant difference in the metabolic ratio observed between patients with NAFLD and HCV suggests that any effect of UGT1A1 polymorphism may be obscured by a greater effect of liver disease on the pharmacokinetics of silymarin. Taken together, these results suggest the presence of the UGT1A1*28 allele does not contribute significantly to a large inter-subject variability in the pharmacokinetics of silybin A and silybin B which may obscure the ability to detect beneficial effects of silymarin in patients with liver disease.

  18. Developmental hyperbilirubinemia and CNS toxicity in mice humanized with the UDP glucuronosyltransferase 1 (UGT1) locus. (United States)

    Fujiwara, Ryoichi; Nguyen, Nghia; Chen, Shujuan; Tukey, Robert H


    High levels of unconjugated bilirubin (UCB) in newborn children is associated with a reduction in hepatic UDP glucuronosyltransferase (UGT) 1A1 activity that can lead to CNS toxicity, brain damage, and even death. Little is known regarding those events that lead to UCB accumulation in brain tissue, and therefore, we sought to duplicate this condition in mice. The human UGT1 locus, encoding all 9-UGT1A genes including UGT1A1, was expressed in Ugt1(-/-) mice. Because the most common clinical condition associated with jaundice in adults is Gilbert's syndrome, which is characterized by an allelic polymorphism in the UGT1A1 promoter, hyperbilirubinemia was monitored in humanized UGT1 mice that expressed either the Gilbert's UGT1A1*28 allele [Tg(UGT1(A1*28))Ugt1(-/-) mice] or the normal UGT1A1*1 allele [Tg(UGT1(A1*1))Ugt1(-/-) mice]. Adult Tg(UGT1(A1*28))Ugt1(-/-) mice expressed elevated levels of total bilirubin (TB) compared with Tg(UGT1(A1*1))Ugt1(-/-) mice, confirming that the promoter polymorphism associated with the UGT1A1*28 allele contributes to hyperbilirubinemia in mice. However, TB accumulated to near toxic levels during neonatal development, a finding that is independent of the Gilbert's UGT1A1*28 promoter polymorphism. Whereas serum TB levels eventually returned to adult levels, TB clearance in neonatal mice was not associated with hepatic UGT1A1 expression. In approximately 10% of the humanized UGT1 mice, peak TB levels culminated in seizures followed by death. UCB deposition in brain tissue and the ensuing seizures were associated with developmental milestones and can be prevented by enhancing regulation of the UGT1A1 gene in neonatal mice.

  19. Variability of human hepatic UDP-glucuronosyltransferase activity

    NARCIS (Netherlands)

    Little, JM; Lester, R; Kuipers, F; Vonk, R; Mackenzie, PI; Drake, RR; Frame, L; Radominska-Pandya, A


    The availability of a unique series of liver samples from human subjects, both control patients (9) and those with liver disease (6; biliary atresia (2), retransplant, chronic tyrosinemia type I, tyrosinemia, Wilson's disease) allowed us to characterize human hepatic UDP-glucuronosyltransferases usi

  20. Efflux Transport Characterization of Resveratrol Glucuronides in UDP-Glucuronosyltransferase 1A1 Transfected HeLa Cells: Application of a Cellular Pharmacokinetic Model to Decipher the Contribution of Multidrug Resistance-Associated Protein 4. (United States)

    Wang, Shuai; Li, Feng; Quan, Enxi; Dong, Dong; Wu, Baojian


    Resveratrol undergoes extensive metabolism to form biologically active glucuronides in humans. However, the transport mechanisms for resveratrol glucuronides are not fully established. Here, we aimed to characterize the efflux transport of resveratrol glucuronides using UGT1A1-overexpressing HeLa cells (HeLa1A1 cells), and to determine the contribution of multidrug resistance-associated protein (MRP) 4 to cellular excretion of the glucuronides. Two glucuronide isomers [i.e., resveratrol 3-O-glucuronide (R3G) and resveratrol 4'-O-glucuronide (R4'G)] were excreted into the extracellular compartment after incubation of resveratrol (1-100 μM) with HeLa1A1 cells. The excretion rate was linearly related to the level of intracellular glucuronide, indicating that glucuronide efflux was a nonsaturable process. MK-571 (a dual inhibitor of UGT1A1 and MRPs) significantly decreased the excretion rates of R3G and R4'G while increasing their intracellular levels. Likewise, short-hairpin RNA (shRNA)-mediated silencing of MRP4 caused a significant reduction in glucuronide excretion but an elevation in glucuronide accumulation. Furthermore, β-glucuronidase expressed in the cells catalyzed the hydrolysis of the glucuronides back to the parent compound. A cellular pharmacokinetic model integrating resveratrol transport/metabolism with glucuronide hydrolysis/excretion was well fitted to the experimental data, allowing derivation of the efflux rate constant values in the absence or presence of shRNA targeting MRP4. It was found that a large percentage of glucuronide excretion (43%-46%) was attributed to MRP4. In conclusion, MRP4 participated in cellular excretion of R3G and R4'G. Integration of mechanistic pharmacokinetic modeling with transporter knockdown was a useful method to derive the contribution percentage of an exporter to overall glucuronide excretion.

  1. Cruciferous vegetable feeding alters UGT1A1 activity: diet- and genotype-dependent changes in serum bilirubin in a controlled feeding trial. (United States)

    Navarro, Sandi L; Peterson, Sabrina; Chen, Chu; Makar, Karen W; Schwarz, Yvonne; King, Irena B; Li, Shuying S; Li, Lin; Kestin, Mark; Lampe, Johanna W


    Chemoprevention by isothiocyanates from cruciferous vegetables occurs partly through up-regulation of phase II conjugating enzymes, such as UDP-glucuronosyltransferases (UGT). UGT1A1 glucuronidates bilirubin, estrogens, and several dietary carcinogens. The UGT1A1*28 polymorphism reduces transcription compared with the wild-type, resulting in decreased enzyme activity. Isothiocyanates are metabolized by glutathione S-transferases (GST); variants may alter isothiocyanate clearance such that response to crucifers may vary by genotype. We evaluated, in a randomized, controlled, crossover feeding trial in humans (n = 70), three test diets (single- and double-"dose" cruciferous and cruciferous plus apiaceous) compared with a fruit and vegetable-free basal diet. We measured serum bilirubin concentrations on days 0, 7, 11, and 14 of each 2-week feeding period to monitor UGT1A1 activity and determined effects of UGT1A1*28 and GSTM1/GSTT1-null variants on response. Aggregate bilirubin response to all vegetable-containing diets was statistically significantly lower compared with the basal diet (P cruciferous diets compared with basal (P cruciferous and cruciferous plus apiaceous compared with basal, and cruciferous plus apiaceous compared with single-dose cruciferous (P vegetable-containing diets compared with basal (P < 0.02 for all). Evaluation of the effects of diet stratified by GST genotype revealed some statistically significant genotypic differences; however, the magnitude was similar and not statistically significant between genotypes. These results may have implications for altering carcinogen metabolism through dietary intervention, particularly among UGT1A1*28/*28 individuals.

  2. Identification of UDP-glucuronosyltransferase isoforms responsible for leonurine glucuronidation in human liver and intestinal microsomes. (United States)

    Tan, Bo; Cai, Weimin; Zhang, Jinlian; Zhou, Ning; Ma, Guo; Yang, Ping; Zhu, Qing; Zhu, Yizhun


    Leonurine is a potent component of herbal medicine Herba leonuri. The detail information on leonurine metabolism in human has not been revealed so far. Two primary metabolites, leonurine O-glucuronide and demethylated leonurine, were observed and identified in pooled human liver microsomes (HLMs) and O-glucuronide is the predominant one. Among 12 recombinant human UDP-glucuronosyltransferases (UGTs), UGT1A1, UGT1A8, UGT1A9, and UGT1A10 showed catalyzing activity toward leonurine glucuronidation. The intrinsic clearance (CLint) of UGT1A1 was approximately 15-to 20-fold higher than that of UGT1A8, UGT1A9, and UGT1A10, respectively. Both chemical inhibition study and correlation study demonstrated that leonurine glucuronidation activities in HLMs had significant relationship with UGT1A1 activities. Leonurine glucuronide was the major metabolite in human liver microsomes. UGT1A1 was principal enzyme that responsible for leonurine glucuronidation in human liver and intestine microsomes.

  3. Interaction between oblongifolin C and UDP-glucuronosyltransferase isoforms in human liver and intestine microsomes. (United States)

    Gao, Cui; Shi, Rong; Wang, Tianming; Tan, Hongsheng; Xu, Hongxi; Ma, Yueming


    1. Oblongifolin C (OC) is a potential natural anticancer candidate, and its metabolic profile has not yet been established. 2. One major OC glucuronidation metabolite (OCG) has been identified in a pool of human liver microsomes (HLMs). Chemical inhibition experiments suggested that OCG was mainly formed by UGT1A. A screen of recombinant UDP-glucuronosyltransferase isoforms (UGTs) indicated that UGT1A1 primarily mediates OC conjugation, with minor contributions from UGT1A3 and UGT1A8. Enzyme kinetic studies showed that UGT1A1 was the main UGT isoform involved in OCG in HLMs. 3. Further investigation suggested that OC is a broad inhibitor of UGTs. Additionally, OC competitively inhibited UGT1A6 with a Ki value of 3.49 ± 0.57 μM, whereas non-competitively inhibited UGT1A10 with a Ki value of 2.12 ± 0.18 μM. 4. Understanding the interaction between OC and UGTs will greatly contribute to future investigations regarding the inter-individual differences in OC metabolism in clinical trials and potential drug-drug interactions.

  4. Development of UDP-glucuronosyltransferase activity toward digitoxigenin-monodigitoxoside in neonatal rats. (United States)

    Watkins, J B; Klaassen, C D


    Glucuronidation is low or undetectable in embryonic and early fetal tissues and changes to adult levels at rates depending on the acceptor, tissue, and species. Because other data indicate there may be a specific UDP-glucuronosyltransferase (GT) in the liver of adult rats that glucuronidates digitoxigenin-monodigitoxoside (DIG), the development of GT activity in neonatal rats toward DIG was compared with that of other acceptors. Conjugation of p-nitrophenol and 1-naphthol was higher at birth and decreased to adult levels by 20 days of age. Glucuronidation of chloramphenicol, morphine, valproic acid, and bilirubin increased from birth to adult activity by 20 days of age. Conjugation of phenolphthalein, estrone, and diethylstilbestrol was low in 1-day-old rats and higher than adult in 20-day-old animals. In contrast, glucuronidation of DIG was barely detectable (9% of adult) in 20-day-old rats. The concentration of UDP-glucuronic acid was 50% of adult levels at birth and increased to adult values by 10 days of age. Administration of 3-methylcholanthrene on days 6 to 9 after birth significantly stimulated GT activity toward 1-naphthol, p-nitrophenol, and morphine, whereas phenobarbital precociously increased conjugation of chloramphenicol, valproic acid, morphine, and diethylstilbestrol. Pregnenolone-16 alpha-carbonitrile enhanced the development of GT activity toward morphine, chloramphenicol, valproic acid, bilirubin, diethylstilbestrol, and estrone. Glucuronidation of DIG was not increased after 3-methylcholanthrene or phenobarbital, but could be induced after pregnenolone-16 alpha-carbonitrile to 7% of adult values in 10-day-old rats.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. New insights into the risk of phthalates: Inhibition of UDP-glucuronosyltransferases. (United States)

    Liu, Xin; Cao, Yun-Feng; Ran, Rui-Xue; Dong, Pei-Pei; Gonzalez, Frank J; Wu, Xue; Huang, Ting; Chen, Jian-Xin; Fu, Zhi-Wei; Li, Rong-Shan; Liu, Yong-Zhe; Sun, Hong-Zhi; Fang, Zhong-Ze


    Wide utilization of phthalates-containing products results in the significant exposure of humans to these compounds. Many adverse effects of phthalates have been documented in rodent models, but their effects in humans exposed to these chemicals remain unclear until more mechanistic studies on phthalate toxicities can be carried out. To provide new insights to predict the potential adverse effects of phthalates in humans, the recent study investigated the inhibition of representative phthalates di-n-octyl ortho-phthalate (DNOP) and diphenyl phthalate (DPhP) towards the important xenobiotic and endobiotic-metabolizing UDP-glucuronosyltransferases (UGTs). An in vitro UGTs incubation system was employed to study the inhibition of DNOP and DPhP towards UGT isoforms. DPhP and DNOP weakly inhibited the activities of UGT1A1, UGT1A7, and UGT1A8. 100 µM of DNOP inhibited the activities of UGT1A3, UGT1A9, and UGT2B7 by 41.8% (p [I]/Ki > 0.1, medium possibility; [I]/Ki > 1, high possibility), these studies predicted in vivo drug-drug interaction might occur when the plasma concentration of DPhP was above 0.089 µM. Taken together, this study reveales the potential for adverse effects of phthalates DNOP and DPhP as a result of UGT inhibition.

  6. Inhibition of UDP-Glucuronosyltransferases (UGTs) Activity by constituents of Schisandra chinensis. (United States)

    Song, Jin-Hui; Cui, Li; An, Li-Bin; Li, Wen-Tao; Fang, Zhong-Ze; Zhang, Yan-Yan; Dong, Pei-Pei; Wu, Xue; Wang, Li-Xuan; Gonzalez, Frank J; Sun, Xiao-Yu; Zhao, De-Wei


    Structure-activity relationship for the inhibition of Schisandra chinensis's ingredients toward (Uridine-Diphosphate) UDP-glucuronosyltransferases (UGTs) activity was performed in the present study. In vitro incubation system was employed to screen the inhibition capability of S. chinensis's ingredients, and in silico molecular docking method was carried out to explain possible mechanisms. At 100 μM of compounds, the activity of UGTs was inhibited by less than 90% by schisandrol A, schisandrol B, schisandrin, schisandrin C, schisantherin A, gomisin D, and gomisin G. Schisandrin A exerted strong inhibition toward UGT1A1 and UGT1A3, with the residual activity to be 7.9% and 0% of control activity. Schisanhenol exhibited strong inhibition toward UGT2B7, with the residual activity to be 7.9% of control activity. Gomisin J of 100 μM inhibited 91.8% and 93.1% of activity of UGT1A1 and UGT1A9, respectively. Molecular docking prediction indicated different hydrogen bonds interaction resulted in the different inhibition potential induced by subtle structure alteration among schisandrin A, schisandrin, and schisandrin C toward UGT1A1 and UGT1A3: schisandrin A > schisandrin > schisandrin C. The detailed inhibition kinetic evaluation showed the strong inhibition of gomisin J toward UGT1A9 with the inhibition kinetic parameter (Ki ) to be 0.7 μM. Based on the concentrations of gomisin J in the plasma of the rats given with S. chinensis, high herb-drug interaction existed between S. chinensis and drugs mainly undergoing UGT1A9-mediated metabolism. In conclusion, in silico-in vitro method was used to give the inhibition information and possible inhibition mechanism for S. chinensis's components toward UGTs, which guide the clinical application of S. chinensis.

  7. Polymorphisms of UDP-glucuronosyltransferase 1A7 are not involved in pancreatic diseases.

    NARCIS (Netherlands)

    Verlaan, M.; Drenth, J.P.H.; Truninger, K.; Koudova, M.; Schulz, H.U.; Bargetzi, M.; Kunzli, B.; Friess, H.; Cerny, M.; Kage, A.; Landt, O.; Morsche, R.H.M. te; Rosendahl, J.; Luck, W.; Nickel, R.; Halangk, J.; Macek Jr, M.; Jansen, J.B.M.J.; Witt, H.


    BACKGROUND: Xenobiotic mediated cellular injury is thought to play a major role in the pathogenesis of pancreatic diseases. Genetic variations that reduce the expression or activity of detoxifying phase II biotransformation enzymes such as the UDP-glucuronosyltransferases might be important in this

  8. UDP-glucuronosyltransferase expression in mouse liver is increased in obesity- and fasting-induced steatosis. (United States)

    Xu, Jialin; Kulkarni, Supriya R; Li, Liya; Slitt, Angela L


    UDP-glucuronosyltransferases (Ugt) catalyze phase II conjugation reactions with glucuronic acid, which enhances chemical polarity and the elimination from the body. Few studies have addressed whether Ugt expression and activity are affected by liver disease, such as steatosis. The purpose of this study was to determine whether steatosis induced by obesity or fasting could affect liver Ugt mRNA expression and activity. Male C57BL/6J and Lep(ob/ob) (ob/ob) mice were fed ad libitum or food was withheld for 24 h. In steatotic livers of ob/ob mice, Ugt1a1, -1a6, -1a9, -2a3, -3a1, and -3a2 mRNA expression increased. Fasting, which also induced steatosis, increased hepatic Ugt1a1, -1a6, -1a7, -1a9, -2b1, -2b5, -2a3, -3a1, and -3a2 mRNA expression in mouse liver. Likewise, acetaminophen glucuronidation increased by 47% in hepatic microsomes from ob/ob mice compared with that in C57BL/6J mice, but not after fasting. In both steatosis models, Ugt induction was accompanied by increased aryl hydrocarbon receptor, constitutive androstane receptor (CAR), peroxisome proliferator-activated receptor (PPAR)-α, pregnane X receptor, nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and peroxisome proliferator-activated receptor-γ coactivator-1α mRNA expression. In addition, fasting increased CAR, PPAR, and Nrf2 binding activity. The work points to hepatic triglyceride concentrations corresponding with nuclear receptor and Ugt expression. The findings indicate that steatosis significantly alters hepatic Ugt expression and activity, which could have a significant impact on determining circulating hormone levels, drug efficacy, and environmental chemical clearance.

  9. Genetic factors affecting gene transcription and catalytic activity of UDP-glucuronosyltransferases in human liver. (United States)

    Liu, Wanqing; Ramírez, Jacqueline; Gamazon, Eric R; Mirkov, Snezana; Chen, Peixian; Wu, Kehua; Sun, Chang; Cox, Nancy J; Cook, Edwin; Das, Soma; Ratain, Mark J


    The aim of this study was to discover cis- and trans-acting factors significantly affecting mRNA expression and catalytic activity of human hepatic UDP-glucuronosyltransferases (UGTs). Transcription levels of five major hepatic UGT1A (UGT1A1, UGT1A3, UGT1A4, UGT1A6 and UGT1A9) and five UGT2B (UGT2B4, UGT2B7, UGT2B10, UGT2B15 and UGT2B17) genes were quantified in human liver tissue samples (n = 125) using real-time PCR. Glucuronidation activities of 14 substrates were measured in 47 livers. We genotyped 167 tagSNPs (single-nucleotide polymorphisms) in UGT1A (n = 43) and UGT2B (n = 124), as well as the known functional UGT1A1*28 and UGT2B17 CNV (copy number variation) polymorphisms. Transcription levels of 15 transcription factors (TFs) known to regulate these UGTs were quantified. We found that UGT expression and activity were highly variable among the livers (median and range of coefficient of variations: 135%, 74-217% and 52%, 39-105%, respectively). CAR, PXR and ESR1 were found to be the most important trans-regulators of UGT transcription (median and range of correlation coefficients: 46%, 6-58%; 47%, 9-58%; and 52%, 24-75%, respectively). Hepatic UGT activities were mainly determined by UGT gene transcription levels. Twenty-one polymorphisms were significantly (FDR-adjusted P transcription and testosterone glucuronidation rate, in addition to that attributable to the UGT2B17 CNV. Our study discovered novel pharmacogenetic markers and provided detailed insight into the genetic network regulating hepatic UGTs.

  10. Expression and inducibility of UDP-glucuronosyltransferase 1As in MCF-7 human breast carcinoma cells. (United States)

    Hanioka, Nobumitsu; Iwabu, Hiroyuki; Hanafusa, Hiroyuki; Nakada, Shintaro; Narimatsu, Shizuo


    UDP-glucuronosyltransferases (UGTs) are conjugation enzymes, which are regulated in a tissue-specific manner by endogenous and environmental factors. In this study, we focused on UGT1A isoforms broadly expressed in hepatic and extrahepatic tissues and examined the expression and inducibility of UGT1As (UGT1A1 and UGT1A3-1A10) in MCF-7 cells (human breast carcinoma cell line). Reverse transcription polymerase chain reaction (RT-PCR) analysis demonstrated that UGT1A1, UGT1A6 and UGT1A9 mRNAs as well as the mRNAs of transcriptional regulators (AhR, aryl hydrocarbon receptor; Arnt, AhR nuclear translocator; ERα, oestrogen receptor α; ERβ, oestrogen receptor β; and GR, glucocorticoid receptor) are expressed in MCF-7 cells. UGT1A6 mRNA level in MCF-7 cells was significantly increased to 1.9 times by β-naphthoflavone (BNF), whereas UGT1A1 and UGT1A9 mRNA levels were not affected by BNF. There were no significant changes in the mRNAs of UGT1A1, UGT1A6 and UGT1A9 in MCF-7 cells by treatment with phenobarbital (PB) and dexamethasone (DEX) in MCF-7 cells. The kinetics of 7-ethyl-10-hydroxycamptothecin (SN-38), 5-hydroxytryptamine (5-HT) and 4-methylumbelliferone (4-MU) glucuronidation by microsomes from control and BNF-treated MCF-7 cells fitted with the Michaelis-Menten model, and the V(max) and CL(int) values were significantly increased to 7.5-8.5 times and 5.9-10.4 times by BNF treatment, respectively. These findings suggest that BNF induces UGT1A6 in MCF-7 cells and that the increase may be mediated by AhR but not pregnane X receptor (PXR)/constitutive androstane receptor (CAR). The information gained in this study should help predict and assess the toxicity of environmental chemicals.

  11. Effects of Dietary Components on Testosterone Metabolism via UDP-Glucuronosyltransferase


    Carl eJenkinson; Andrea ePetroczi; Declan P. Naughton


    The potential interference in testosterone metabolism through ingested substances has ramifications for: (i) a range of pathologies such as prostate cancer, (ii) medication contra-indications, (iii) disruption to the endocrine system, and (iv) potential confounding effects on doping tests. Conjugation of anabolic steroids during phase II metabolism, mainly driven by UDP-glucuronosyltransferase (UGT) 2B7, 2B15, and 2B17, has been shown to be impaired in vitro by a range of compounds including ...

  12. Induction of UDP-glucuronosyltransferase activities in Gunn, heterozygous, and Wistar rat livers by pregnenolone-16 alpha-carbonitrile. (United States)

    Watkins, J B; Klaassen, C D


    The effect of pregnenolone-16 alpha-carbonitrile (PCN) on UDP-glucuronosyltransferase (UDP-GT) activity was comprehensively examined in Wistar (JJ), heterozygous (Jj) and Gunn (jj) rats with eleven different acceptors for glucuronic acid. UDP-GT activity after 3-methylcholanthrene (3-MC) and phenobarbital (PB) treatment was studied in additional rats for comparative purposes. Conjugation of group-1 aglycones (1-naphthol and p-nitrophenol) was much lower in Gunn than in Wistar rats. PCN did not alter UDP-GT conjugation of these acceptors. UDP-GT activity toward group-1 aglycones was increased by 3-MC in Wistar and heterozygous rats but was not enhanced in Gunn rats by any inducer. Activity toward group-2 aglycones (morphine, chloramphenicol, valproic acid) was similar in control rats of all genotypes. PCN increased chloramphenicol conjugation, whereas PB enhanced the glucuronidation of all group-2 aglycones in Wistar, heterozygous, and Gunn rats. Conjugation of group-3 acceptors (bilirubin and digitoxigenin monodigitoxoside, DIG) was deficient in Gunn rats and was not inducible. PCN increased glucuronidation of bilirubin and DIG in Wistar and heterozygous rats. The concentration of UDP-glucuronic acid (UDPGA) in liver was similar in control animals of all genotypes and was increased in rats treated with 3-MC. The other inducers did not affect hepatic UDPGA levels. Thus, 3-MC, PB, and PCN induce UDP-GT activities toward different groups of acceptors of glucuronic acid. The results support the hypothesis that PCN induces a form of UDP-GT that preferentially conjugates the group-3 acceptors, bilirubin and DIG.

  13. Identification and preliminary characterization of UDP-glucuronosyltransferases catalyzing formation of ethyl glucuronide. (United States)

    Schwab, Nicole; Skopp, Gisela


    Ethyl glucuronide (EtG), a minor metabolite of ethanol, is used as a marker of alcohol consumption in a variety of clinical and forensic settings. At present there are very few studies of UDP-glucuronosyltransferases (UGT), responsible for catalyzing EtG formation, and the possible effect of nutritional components, e.g. flavonoids, which are extensively glucuronidated, on EtG formation has not been addressed at all. The following incubation conditions were optimized with regard to previously published conditions: buffer, substrate concentration, and incubation time. Isolation of EtG from the incubation mixture was also optimized. Recombinant UGT enzymes (UGT1A1, 1A3, 1A4, 1A6, 1A9, 2B7, 2B10, 2B15) were screened for their activity towards ethanol, and kinetic data were then established for all enzymes. It was decided to study the effect of the flavonoids quercetin and kaempferol on glucuronidation of ethanol. Isolation was by solid-phase extraction (SPE) to minimize matrix effects. Analysis was performed by liquid chromatography-tandem mass spectrometry (LC-MS-MS), with EtG-d5 as the internal standard. SPE was vital to avoid severe ion suppression after direct injection of the incubation solution. EtG formation was observed for all enzymes under investigation; their kinetics followed the Michaelis-Menten model, meaning the maximum reaction rate achieved at saturating substrate concentrations (V(max)) and the substrate concentration at which the reaction rate is half of V(max) (Michaelis-Menten constant, K(m)) could be calculated. The highest rate of glucuronidation was observed with UGT1A9 and 2B7. After co-incubation with both flavonoids, formation of EtG was significantly reduced for all enzymes except for UGT2B15, whose activity did not seem to be affected. Results reveal that multiple UGT isoforms are capable of catalyzing glucuronidation of ethanol; nevertheless, the effect of UGT polymorphism on glucuronidation of ethanol needs further study. Formation of Et

  14. Role of cytochrome P450 and UDP-glucuronosyltransferases in metabolic pathway of homoegonol in human liver microsomes. (United States)

    Kwon, Soon Sang; Kim, Ju Hyun; Jeong, Hyeon-Uk; Ahn, Kyung-Seop; Oh, Sei-Ryang; Lee, Hye Suk


    Homoegonol is being evaluated for the development of a new antiasthmatic drug. Based on a pharmacokinetic study of homoegonol in rats, homoegonol is almost completely eliminated via metabolism, but no study on its metabolism has been reported in animals and humans. Incubation of homoegonol in human liver microsomes in the presence of the reduced form of nicotinamide adenine dinucleotide phosphate and UDP-glucuronic acid resulted in the formation of five metabolites: 4-O-demethylhomoegonol (M1), hydroxyhomoegonol (M2 and M3), 4-O-demethylhomoegonol glucuronide (M4), and homoegonol glucuronide (M5). We characterized the cytochrome P450 (CYP) and UDP-glucuronosyltransferase (UGT) enzymes responsible for homoegonol metabolism using human liver microsomes, and cDNA-expressed CYP and UGT enzymes. CYP1A2 played a more prominent role than CYP3A4 and CYP2D6 in the 4-O-demethylation of homoegonol to M1. CYP3A4 was responsible for the hydroxylation of homoegonol to M2. The hydroxylation of homoegonol to M3 was insufficient to characterize CYP enzymes. Glucuronidation of homoegonol to M5 was mediated by UGT1A1, UGT1A3, UGT1A4, and UGT2B7 enzymes, whereas M4 was formed from 4-O-demethylhomoegonol by UGT1A1, UGT1A8, UGT1A10, and UGT2B15 enzymes.

  15. Effect of Honokiol on Cytochrome P450 and UDP-Glucuronosyltransferase Enzyme Activities in Human Liver Microsomes

    Directory of Open Access Journals (Sweden)

    Yong Yeon Cho


    Full Text Available Honokiol is a bioactive component isolated from the medicinal herbs Magnolia officinalis and Magnolia grandiflora that has antioxidative, anti-inflammatory, antithrombotic, and antitumor activities. The inhibitory potentials of honokiol on eight major human cytochrome P450 (CYP enzymes 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4, and four UDP-glucuronosyltransferases (UGTs 1A1, 1A4, 1A9, and 2B7 in human liver microsomes were investigated using liquid chromatography-tandem mass spectrometry. Honokiol strongly inhibited CYP1A2-mediated phenacetin O-deethylation, CYP2C8-mediated amodiaquine N-deethylation, CYP2C9-mediated diclofenac 4-hydroxylation, CYP2C19-mediated [S]-mephenytoin 4-hydroxylation, and UGT1A9-mediated propofol glucuronidation with Ki values of 1.2, 4.9, 0.54, 0.57, and 0.3 μM, respectively. Honokiol also moderately inhibited CYP2B6-mediated bupropion hydroxylation and CYP2D6-mediated bufuralol 1'-hydroxylation with Ki values of 17.5 and 12.0 μM, respectively. These in vitro results indicate that honokiol has the potential to cause pharmacokinetic drug interactions with other co-administered drugs metabolized by CYP1A2, CYP2C8, CYP2C9, CYP2C19, and UGT1A9.

  16. UDP-Glucuronosyltransferase Expression in Mouse Liver Is Increased in Obesity- and Fasting-Induced Steatosis


    Xu, Jialin; Kulkarni, Supriya R.; Li, Liya; Slitt, Angela L.


    UDP-glucuronosyltransferases (Ugt) catalyze phase II conjugation reactions with glucuronic acid, which enhances chemical polarity and the elimination from the body. Few studies have addressed whether Ugt expression and activity are affected by liver disease, such as steatosis. The purpose of this study was to determine whether steatosis induced by obesity or fasting could affect liver Ugt mRNA expression and activity. Male C57BL/6J and Lepob/ob (ob/ob) mice were fed ad libitum or food was wit...

  17. Intestinal excretion of unconjugated bilirubin in man and rats with inherited unconjugated hyperbilirubinemia

    NARCIS (Netherlands)

    Kotal, P; VanderVeere, CN; Sinaasappel, M; Elferink, RO; Vitek, L; Brodanova, M; Jansen, PLM; Fevery, J


    Patients with Crigler-Najjar syndrome and Gunn rats cannot form bilirubin glucuronides owing to a lack of bilirubin UDP-glucuronosyltransferase activity. Because increased serum and tissue bilirubin levels remain constant, an alternative excretory route has to substitute for this deficiency. Gunn ra

  18. Identification of the human UDP-glucuronosyltransferase isoforms involved in the glucuronidation of the phytochemical ferulic acid. (United States)

    Li, Xiaojun; Shang, Liang; Wu, Yaohua; Abbas, Suzanne; Li, Dong; Netter, Patrick; Ouzzine, Mohamed; Wang, Hui; Magdalou, Jacques


    Ferulic acid (FA), a member of the hydroxycinnamate family, is an abundant dietary antioxidant that may offer beneficial effects against cancer, cardiovascular disease, diabetes, osteoarthritis and Alzheimer's disease. In this study, evidence for sulfation and glucuronidation of FA was investigated upon incubation with human liver microsomes and cytosol. Two main glucuronides, M1 (ether O-glucuronide) and M2 (ester acylglucuronide), were formed with a similar affinity (apparent K(m) 3.53 and 5.15 mM, respectively). A phenol sulfoconjugate was also formed with a higher affinity (K(m) 0.53 mM). Identification of the UDP-glucuronosyltransferase (UGT) isoforms involved in FA glucuronidation was investigated with 12 human recombinant enzymes. FA was mainly glucuronidated by UGT1A isoforms and by UGT2B7. UGT1A4, 2B4, 2B15 and 2B17 failed to glucuronidate the substance. Examination of the kinetic constants revealed that FA was mainly glucuronidated by UGT1A1 at the two nucleophilic groups. UGT1A3 was able to glucuronidate these two positions with the same, but low, efficiency. UGT1A6 and 1A8 were involved in the formation of the ether glucuronide only, whereas UGT1A7, 1A10 and 2B7 preferentially glucuronidated the carboxyl group. Moreover, octyl gallate, a marker substrate of UGT1A1, competitively inhibited FA glucuronidation mediated by this isoform. Altogether, the results suggest that FA glucuronidation is primarily mediated by UGT1A1.

  19. Altered UDP-glucuronosyltransferase and sulfotransferase expression and function during progressive stages of human nonalcoholic fatty liver disease. (United States)

    Hardwick, Rhiannon N; Ferreira, Daniel W; More, Vijay R; Lake, April D; Lu, Zhenqiang; Manautou, Jose E; Slitt, Angela L; Cherrington, Nathan J


    The UDP-glucuronosyltransferases (UGTs) and sulfotransferases (SULTs) represent major phase II drug-metabolizing enzymes that are also responsible for maintaining cellular homeostasis by metabolism of several endogenous molecules. Perturbations in the expression or function of these enzymes can lead to metabolic disorders and improper management of xenobiotics and endobiotics. Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of liver damage ranging from steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. Because the liver plays a central role in the metabolism of xenobiotics, the purpose of the current study was to determine the effect of human NAFLD progression on the expression and function of UGTs and SULTs in normal, steatosis, NASH (fatty), and NASH (not fatty/cirrhosis) samples. We identified upregulation of UGT1A9, 2B10, and 3A1 and SULT1C4 mRNA in both stages of NASH, whereas UGT2A3, 2B15, and 2B28 and SULT1A1, 2B1, and 4A1 as well as 3'-phosphoadenosine-5'-phosphosulfate synthase 1 were increased in NASH (not fatty/cirrhosis) only. UGT1A9 and 1A6 and SULT1A1 and 2A1 protein levels were decreased in NASH; however, SULT1C4 was increased. Measurement of the glucuronidation and sulfonation of acetaminophen (APAP) revealed no alterations in glucuronidation; however, SULT activity was increased in steatosis compared with normal samples, but then decreased in NASH compared with steatosis. In conclusion, the expression of specific UGT and SULT isoforms appears to be differentially regulated, whereas sulfonation of APAP is disrupted during progression of NAFLD.

  20. Regulation of Sulfotransferase and UDP-Glucuronosyltransferase Gene Expression by the PPARs

    Directory of Open Access Journals (Sweden)

    Melissa Runge-Morris


    Full Text Available During phase II metabolism, a substrate is rendered more hydrophilic through the covalent attachment of an endogenous molecule. The cytosolic sulfotransferase (SULT and UDP-glucuronosyltransferase (UGT families of enzymes account for the majority of phase II metabolism in humans and animals. In general, phase II metabolism is considered to be a detoxication process, as sulfate and glucuronide conjugates are more amenable to excretion and elimination than are the parent substrates. However, certain products of phase II metabolism (e.g., unstable sulfate conjugates are genotoxic. Members of the nuclear receptor superfamily are particularly important regulators of SULT and UGT gene transcription. In metabolically active tissues, increasing evidence supports a major role for lipid-sensing transcription factors, such as peroxisome proliferator-activated receptors (PPARs, in the regulation of rodent and human SULT and UGT gene expression. This review summarizes current information regarding the regulation of these two major classes of phase II metabolizing enzyme by PPARs.

  1. Purification and characterization of a 4-hydroxybiphenyl UDP-glucuronosyltransferase from rat liver microsomes

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    Styczynski, B.; Green, M.; Coffman, B.; Puig, J.; Tephly, T. (Univ. of Iowa, Iowa City (United States))


    A phenobarbital-inducible rat liver microsomal UDP-glucuronosyltransferase (4-HBP UDPGT) which catalyzes the glucuronidation of 4-hydroxybiphenyl has been purified to homogeneity. The apparent subunit molecular weight of this protein is 52,500 as determined by SDS-PAGE. 4-HBP UDPGT was shown to react with 4-hydroxybiphenyl, p-nitrophenol and 4-methylumbelliferone, but did not react with morphine, testosteron or chloramphenicol. Upon treatment with Endoglycosidase H, the 4-HBP UDPGT underwent about a 2,000 dalton decrease in subunit molecular weight, suggesting that this protein in N-glycosylated. Western blot analysis has revealed immunorecognition of 4-HBP UDPGT by antibodies raised in rabbit against rat 3{alpha}- and 17{beta}-hydroxysteroid UDPGTs. Additionally, the authors have obtained the N-terminal amino acid sequence of 4-HBP UDPGT. These data provide evidence which suggests that this protein is different from another UDPGT previously shown to react with 4-hydroxybiphenyl, testosterone and chloramphenicol.

  2. In vitro characterization of glucuronidation of vanillin: identification of human UDP-glucuronosyltransferases and species differences. (United States)

    Yu, Jian; Han, Jing-Chun; Hua, Li-Min; Gao, Ya-Jie


    Vanillin is a food flavoring agent widely utilized in foods, beverages, drugs, and perfumes and has been demonstrated to exhibit multiple pharmacological activities. Given the importance of glucuronidation in the metabolism of vanillin, the UDP-glucuronosyltransferase conjugation pathway of vanillin was investigated in this study. Vanillin glucuronide was identified by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and a hydrolysis reaction catalyzed by β-glucuronidase. The kinetic study showed that vanillin glucuronidation by HLMs and HIMs followed Michaelis-Menten kinetics and the kinetic parameters were as follows: 134.9 ± 13.5 μM and 81.3 ± 11.3 μM for K(m) of HLMs and HIMs, 63.8 ± 2.0 nmol/min/mg pro and 13.4 ±2.0 nmol/min/mg pro for Vmax of HLMs and HIMs. All UDP-glucuronosyltransferase (UGT) isoforms except UGT1A4, 1A9, and 2B7 showed the capability to glucuronidate vanillin, and UGT1A6 exerted the higher V(max)/K(m) values than other UGT isoforms for the glucuronidation of vanillin when assuming expression of isoforms is similar in recombinant UGTs. Kinetic analysis using liver microsomes from six studied speices indicated that vanillin had highest affinity for the monkey liver microsomes enzyme (K(m)  = 25.6 ± 3.2 μM) and the lowest affinity for the mice liver microsomes enzyme (K(m)  = 149.1 ± 18.4 μM), and intrinsic clearance was in the following order: monkey > dog > minipig > mice > rat ~ human. These data collectively provided important information for understanding glucuronidation of vanillin.

  3. Quantitative Atlas of Cytochrome P450, UDP-Glucuronosyltransferase, and Transporter Proteins in Jejunum of Morbidly Obese Subjects. (United States)

    Miyauchi, Eisuke; Tachikawa, Masanori; Declèves, Xavier; Uchida, Yasuo; Bouillot, Jean-Luc; Poitou, Christine; Oppert, Jean-Michel; Mouly, Stéphane; Bergmann, Jean-François; Terasaki, Tetsuya; Scherrmann, Jean-Michel; Lloret-Linares, Célia


    Protein expression levels of drug-metabolizing enzymes and transporters in human jejunal tissues excised from morbidly obese subjects during gastric bypass surgery were evaluated using quantitative targeted absolute proteomics. Protein expression levels of 15 cytochrome P450 (CYP) enzymes, 10 UDP-glucuronosyltransferase (UGT) enzymes, and NADPH-P450 reductase (P450R) in microsomal fractions from 28 subjects and 49 transporters in plasma membrane fractions from 24 of the same subjects were determined using liquid chromatography-tandem mass spectrometry. Based on average values, UGT1A1, UGT2B15, UGT2B17, SGLT1, and GLUT2 exhibited high expression levels (over 10 fmol/μg protein), though UGT2B15 expression was detected at a high level in only one subject. CYP2C9, CYP2D6, CYP3A5, UGT1A6, P450R, ABCG2, GLUT5, PEPT1, MCT1, 4F2 cell-surface antigen heavy chain (4F2hc), LAT2, OSTα, and OSTβ showed intermediate levels (1-10 fmol/μg protein), and CYP1A1, CYP1A2, CYP1B1, CYP2C18, CYP2C19, CYP2J2, CYP3A7, CYP4A11, CYP51A1, UGT1A3, UGT1A4, UGT1A8, UGT2B4, ABCC1, ABCC4, ABCC5, ABCC6, ABCG8, TAUT, OATP2A1, OATP2B1, OATP3A1, OATP4A1, OCTN1, CNT2, PCFT, MCT4, GLUT4, and SLC22A18 showed low levels (less than 1 fmol/μg protein). The greatest interindividual difference (364-fold) was detected for UGT2B17. However, differences in expression levels of other quantified UGTs (except UGT2B15 and UGT2B17), CYPs (except CYP1A1 and CYP3A5), and P450R, and all quantified transporters, were within 10-fold. Expression levels of CYP1A2 and GLUT4 were significantly correlated with body-mass index. The levels of 4F2hc showed significant gender differences. Smokers showed increased levels of UGT1A1 and UGT1A3. These findings provide a basis for understanding the changes in molecular mechanisms of jejunal metabolism and transport, as well as their interindividual variability, in morbidly obese patients.

  4. Altered UDP-Glucuronosyltransferase and Sulfotransferase Expression and Function during Progressive Stages of Human Nonalcoholic Fatty Liver Disease


    Hardwick, Rhiannon N.; Ferreira, Daniel W.; More, Vijay R.; Lake, April D.; Lu, Zhenqiang; Manautou, Jose E.; Slitt, Angela L.; Cherrington, Nathan J


    The UDP-glucuronosyltransferases (UGTs) and sulfotransferases (SULTs) represent major phase II drug-metabolizing enzymes that are also responsible for maintaining cellular homeostasis by metabolism of several endogenous molecules. Perturbations in the expression or function of these enzymes can lead to metabolic disorders and improper management of xenobiotics and endobiotics. Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of liver damage ranging from steatosis to nonalcoholic...

  5. Serum bilirubin levels, UGT1A1 polymorphisms and risk for coronary artery disease. (United States)

    Lingenhel, Arno; Kollerits, Barbara; Schwaiger, Johannes P; Hunt, Steven C; Gress, Richard; Hopkins, Paul N; Schoenborn, Veit; Heid, Iris M; Kronenberg, Florian


    Low levels of the antioxidative serum bilirubin are associated with vascular aging and an increased risk for coronary artery disease (CAD). UGT1A1 is the major gene influencing bilirubin concentrations. Therefore, we investigated an association of bilirubin levels and two polymorphisms in the promoter of UGT1A1 (-53(TA-repeat) polymorphism and T-3279G) in 477 patients with premature, familial CAD and 619 age- and sex-matched controls. Bilirubin concentrations were significantly lower in cases than in controls (0.62+/-0.36 vs. 0.76+/-0.41 mg/dl for men, p=1.2 x 10(-10); and 0.42+/-0.29 vs. 0.55+/-0.23 mg/dl, p=1.9 x 10(-9) for women). Both polymorphisms showed a strong association with bilirubin levels with higher levels for homozygote carriers of the minor allele. These associations were most pronounced in male controls and patients (p=5.9 x 10(-26) and p=3.4 x 10(-16), respectively, for the -53(TA-repeat) polymorphism). Logistic regression analysis revealed low bilirubin levels but not the UGT1A1 polymorphisms to be significantly associated with CAD: OR (95% CI) 0.90 (0.86-0.94), p=2.6 x 10(-6) for men and 0.77 (0.68-0.87), p=3.2 x 10(-5) for women, respectively for each 0.1mg/dl increase of bilirubin. These results indicate that it is rather decreased bilirubin levels in general than the changes in the genetic variation of this gene that increase the risk for CAD.

  6. Structure–inhibition relationship of ginsenosides towards UDP-glucuronosyltransferases (UGTs)

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    Fang, Zhong-Ze [The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); Joint Center for Translational Medicine, Dalian Institute of Chemical Physics Chinese Academy of Sciences and The first Affiliated Hospital of Liaoning Medical University, No.457, Zhongshan Road, Dalian 116023 (China); Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892 (United States); Cao, Yun-Feng [Key Laboratory of Contraceptives and Devices Research(NPFPC),Shanghai Engineer and Technology Research Center of Reproductive Health Drug and Devices, Shanghai Institute of Planned Parenthood Research, Shanghai 200032 (China); Joint Center for Translational Medicine, Dalian Institute of Chemical Physics Chinese Academy of Sciences and The first Affiliated Hospital of Liaoning Medical University, No.457, Zhongshan Road, Dalian 116023 (China); Hu, Cui-Min [Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892 (United States); Hong, Mo; Sun, Xiao-Yu [Joint Center for Translational Medicine, Dalian Institute of Chemical Physics Chinese Academy of Sciences and The first Affiliated Hospital of Liaoning Medical University, No.457, Zhongshan Road, Dalian 116023 (China); Ge, Guang-Bo; Liu, Yong; Zhang, Yan-Yan; Yang, Ling [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 116023 Dalian (China); Sun, Hong-Zhi, E-mail: [The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China)


    The wide utilization of ginseng provides the high risk of herb–drug interaction (HDI) with many clinical drugs. The inhibition of ginsenosides towards drug-metabolizing enzymes (DMEs) has been regarded as an important reason for herb–drug interaction (HDI). Compared with the deep studies on the ginsenosides' inhibition towards cytochrome P450 (CYP), the inhibition of ginsenosides towards the important phase II enzymes UDP-glucuronosyltransferases (UGTs) remains to be unclear. The present study aims to evaluate the inhibition behavior of ginsenosides towards important UGT isoforms located in the liver and intestine using in vitro methods. The recombinant UGT isoform-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction was employed as in vitro probe reaction. The results showed that structure-dependent inhibition existed for the inhibition of ginsenosides towards UGT isoforms. To clarify the possibility of in vivo herb–drug interaction induced by this kind of inhibition, the ginsenoside Rg{sub 3} was selected as an example, and the inhibition kinetic type and parameters (K{sub i}) were determined. Rg{sub 3} competitively inhibited UGT1A7, 2B7 and 2B15-catalyzed 4-MU glucuronidation reaction, and exerted noncompetitive inhibition towards UGT1A8-catalyzed 4-MU glucuronidation. The inhibition parameters (K{sub i} values) were calculated to be 22.6, 7.9, 1.9, and 2.0 μM for UGT1A7, 1A8, 2B7 and 2B15. Using human maximum plasma concentration of Rg{sub 3} (400 ng/ml (0.5 μM)) after intramuscular injection of 60 mg Rg{sub 3}, the area under the plasma concentration-time curve (AUC) was extrapolated to increase by 2.2%, 6.3%, 26.3%, and 25% for the co-administered drugs completely undergoing the metabolism catalyzed by UGT1A7, 1A8, 2B7 and 2B15, respectively. All these results indicated that the ginsenosides' inhibition towards UGT isoforms might be an important reason for ginseng–drug interaction. - Highlights: ► Structure

  7. Chirality Influence of Zaltoprofen Towards UDP-Glucuronosyltransferases (UGTs) Inhibition Potential. (United States)

    Jia, Lin; Hu, Cuimin; Wang, Haina; Liu, Yongzhe; Liu, Xin; Zhang, Yan-Yan; Li, Wei; Wang, Li-Xuan; Cao, Yun-Feng; Fang, Zhong-Ze


    Zaltoprofen (ZLT) is a nonsteroidal antiinflammation drug, and has been clinically employed to treat rheumatoid arthritis, osteoarthritis, and other chronic inflammatory pain conditions. The present study aims to investigate the chirality influence of zaltoprofen towards the inhibition potential towards UDP-glucuronosyltransferases (UGTs) isoforms. In vitro a recombinant UGT isoforms-catalyzed 4-methylumbelliferone (4-MU) glucuronidation incubation system was employed to investigate the inhibition of (R)-zaltoprofen and (S)-zaltoprofen towards UGT isoforms. The inhibition difference capability was observed for the inhibition of (R)-zaltoprofen and (S)-zaltoprofen towards UGT1A8 and UGT2B7, but not for other tested UGT isoforms. (R)-zaltoprofen exhibited noncompetitive inhibition towards UGT1A8 and competitive inhibition towards UGT2B7. The inhibition kinetic parameters were calculated to be 35.3 μM and 19.2 μM for UGT1A8 and UGT2B7. (R)-zaltoprofen and (S)-zaltoprofen exhibited a different inhibition type towards UGT1A7. Based on the reported maximum plasma concentration of (R)-zaltoprofen in vivo, a high drug-drug interaction between (R)-zaltoprofen and the drugs mainly undergoing UGT1A7, UGT1A8, and UGT2B7-catalyzed glucuronidation was indicated.

  8. Glucuronidation of drugs and drug-induced toxicity in humanized UDP-glucuronosyltransferase 1 mice. (United States)

    Kutsuno, Yuki; Itoh, Tomoo; Tukey, Robert H; Fujiwara, Ryoichi


    UDP-glucuronosyltransferases (UGTs) are phase II drug-metabolizing enzymes that catalyze glucuronidation of various drugs. Although experimental rodents are used in preclinical studies to predict glucuronidation and toxicity of drugs in humans, species differences in glucuronidation and drug-induced toxicity have been reported. Humanized UGT1 mice in which the original Ugt1 locus was disrupted and replaced with the human UGT1 locus (hUGT1 mice) were recently developed. In this study, acyl-glucuronidations of etodolac, diclofenac, and ibuprofen in liver microsomes of hUGT1 mice were examined and compared with those of humans and regular mice. The kinetics of etodolac, diclofenac, and ibuprofen acyl-glucuronidation in hUGT1 mice were almost comparable to those in humans, rather than in mice. We further investigated the hepatotoxicity of ibuprofen in hUGT1 mice and regular mice by measuring serum alanine amino transferase (ALT) levels. Because ALT levels were increased at 6 hours after dosing in hUGT1 mice and at 24 hours after dosing in regular mice, the onset pattern of ibuprofen-induced liver toxicity in hUGT1 mice was different from that in regular mice. These data suggest that hUGT1 mice can be valuable tools for understanding glucuronidations of drugs and drug-induced toxicity in humans.

  9. Glucuronidation of zearalenone, zeranol and four metabolites in vitro: formation of glucuronides by various microsomes and human UDP-glucuronosyltransferase isoforms. (United States)

    Pfeiffer, Erika; Hildebrand, Andreas; Mikula, Hannes; Metzler, Manfred


    Glucuronidation constitutes an important pathway in the phase II metabolism of the mycotoxin zearalenone (ZEN) and the growth promotor α-zearalanol (α-ZAL, zeranol), but the enzymology of their formation is yet unknown. In the present study, ZEN, α-ZAL and four of their major phase I metabolites were glucuronidated in vitro using hepatic microsomes from steer, pig, rat and human, intestinal microsomes from humans, and eleven recombinant human UDP-glucuronosyltransferases (UGTs). After assigning chemical structures to the various glucuronides by using previously published information, the enzymatic activities of the various microsomes and UGT isoforms were determined together with the patterns of glucuronides generated. All six compounds were good substrates for all microsomes studied. With very few exceptions, glucuronidation occurred preferentially at the sterically unhindered phenolic 14-hydroxyl group. UGT1A1, 1A3 and 1A8 had the highest activities and gave rise to the phenolic glucuronide, whereas glucuronidation of the aliphatic hydroxyl group was mostly mediated by UGT2B7 with low activity. Based on these in vitro data, ZEN, α-ZAL and their metabolites must be expected to be readily glucuronidated both in the liver and intestine as well as in other extrahepatic organs of humans and various animal species.

  10. Inhibition of UDP-Glucuronosyltransferase (UGT) Isoforms by Arctiin and Arctigenin. (United States)

    Zhang, Hui; Zhao, Zhenying; Wang, Tao; Wang, Yijia; Cui, Xiao; Zhang, Huijuan; Fang, Zhong-Ze


    Arctiin is the major pharmacological ingredient of Fructus Arctii, and arctigenin is the metabolite of arctiin formed via the catalysis of human intestinal bacteria. The present study aims to investigate the inhibition profile of arctiin and arctigenin on important phase II drug-metabolizing enzymes UDP-glucuronosyltransferases (UGTs), indicating the possible herb-drug interaction. In vitro screening experiment showed that 100 μM of arctiin and arctigenin inhibited the activity of UGT1A3, 1A9, 2B7, and 2B15. Homology modeling-based in silico docking of arctiin and arctigenin into the activity cavity of UGT2B15 showed that hydrogen bonds and hydrophobic interactions contributed to the strong binding free energy of arctiin (-8.14 kcal/mol) and arctigenin (-8.43 kcal/mol) with UGT2B15. Inhibition kinetics study showed that arctiin and arctigenin exerted competitive and noncompetitive inhibition toward UGT2B15, respectively. The inhibition kinetic parameters (Ki ) were calculated to be 16.0 and 76.7 μM for the inhibition of UGT2B15 by arctiin and arctigenin, respectively. Based on the plasma concentration of arctiin and arctigenin after administration of 100 mg/kg of arctiin, the [I]/Ki values were calculated to be 0.3 and 0.007 for arctiin and arctigenin, respectively. Based on the inhibition evaluation standard ([I]/Ki   1, high possibility), arctiin might induce drug-drug interaction with medium possibility. Based on these results, clinical monitoring the utilization of Fructus Arctii is very important and necessary. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Endogenous Protein Interactome of Human UDP-Glucuronosyltransferases Exposed by Untargeted Proteomics (United States)

    Rouleau, Michèle; Audet-Delage, Yannick; Desjardins, Sylvie; Rouleau, Mélanie; Girard-Bock, Camille; Guillemette, Chantal


    The conjugative metabolism mediated by UDP-glucuronosyltransferase enzymes (UGTs) significantly influences the bioavailability and biological responses of endogenous molecule substrates and xenobiotics including drugs. UGTs participate in the regulation of cellular homeostasis by limiting stress induced by toxic molecules, and by controlling hormonal signaling networks. Glucuronidation is highly regulated at genomic, transcriptional, post-transcriptional and post-translational levels. However, the UGT protein interaction network, which is likely to influence glucuronidation, has received little attention. We investigated the endogenous protein interactome of human UGT1A enzymes in main drug metabolizing non-malignant tissues where UGT expression is most prevalent, using an unbiased proteomics approach. Mass spectrometry analysis of affinity-purified UGT1A enzymes and associated protein complexes in liver, kidney and intestine tissues revealed an intricate interactome linking UGT1A enzymes to multiple metabolic pathways. Several proteins of pharmacological importance such as transferases (including UGT2 enzymes), transporters and dehydrogenases were identified, upholding a potential coordinated cellular response to small lipophilic molecules and drugs. Furthermore, a significant cluster of functionally related enzymes involved in fatty acid β-oxidation, as well as in the glycolysis and glycogenolysis pathways were enriched in UGT1A enzymes complexes. Several partnerships were confirmed by co-immunoprecipitations and co-localization by confocal microscopy. An enhanced accumulation of lipid droplets in a kidney cell model overexpressing the UGT1A9 enzyme supported the presence of a functional interplay. Our work provides unprecedented evidence for a functional interaction between glucuronidation and bioenergetic metabolism. PMID:28217095

  12. New insights for the risk of bisphenol A: inhibition of UDP-glucuronosyltransferases (UGTs). (United States)

    Jiang, Hua-Mao; Fang, Zhong-Ze; Cao, Yun-Feng; Hu, Cui-Min; Sun, Xiao-Yu; Hong, Mo; Yang, Ling; Ge, Guang-Bo; Liu, Yong; Zhang, Yan-Yan; Dong, Qiang; Liu, Ren-Jie


    Bisphenol A (BPA), the important endocrine-disrupting chemical (EDC), has been reported to be able to induce various toxicity. The present study aims to understand the toxicity behavior of bisphenol A through evaluating the inhibition profile of bisphenol A towards UDP-glucuronosyltransferase (UGT) isoforms. In vitro recombinant UGTs-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction was employed as probe reaction for all the tested UGT isoforms. The results showed that bisphenol A exerted stronger inhibition towards UGT2B isoforms than UGT1A isoforms. Furthermore, the inhibition kinetic type and parameters (K(i)) were determined for the inhibition of bisphenol A towards UGT2B4, 2B7, 2B15, and 2B17. Bisphenol A exhibited the competitive inhibition towards UGT2B4, and noncompetitive inhibition towards UGT2B7, 2B15 and 2B17. The inhibition kinetic parameters (K(i)) were calculated to be 1.1, 32.6, 5.6, and 19.9 μM for UGT2B4, 2B7, 2B15 and 2B17, respectively. In combination with the in vivo concentration of bisphenol A, the elevation of exposure dose was predicted to increase by 29.1%, 1%, 5.7%, and 1.6% for UGT2B4, 2B7, 2B15, and 2B17, indicating the high influence of bisphenol A towards the in vivo UGT2B isofroms-mediated metabolism of xenobiotics and endogenous substances. All these data provide the supporting information for deeper understanding of toxicology of bisphenol A.

  13. Inactivation by UDP-glucuronosyltransferase enzymes: the end of androgen signaling. (United States)

    Chouinard, Sarah; Yueh, Mei-Fei; Tukey, Robert H; Giton, Frank; Fiet, Jean; Pelletier, Georges; Barbier, Olivier; Bélanger, Alain


    Conjugation by UDP-Glucuronosyltransferase (UGT) is the major pathway of androgen metabolism and elimination in the human. High concentrations of glucuronide conjugates of androsterone (ADT) and androstane-3alpha,17beta-diol (3alpha-diol) are present in circulation and several studies over the last 30 years have concluded that the serum levels of these metabolites might reflect the androgen metabolism in several tissues, including the liver and androgen target tissues. Three UGT2B enzymes are responsible for the conjugation of DHT and its metabolites ADT and 3alpha-diol: UGT2B7, B15 and B17. UGT2B7 is expressed in the liver and skin whereas UGT2B15 and B17 were found in the liver, prostate and skin. Very specific antibodies against each UGT2B enzyme have been obtained and used for immunohistochemical studies in the human prostate. It was shown that UGT2B17 is expressed in basal cells whereas UGT2B15 is only localized in luminal cells, where it inactivates DHT. By using LNCaP cells, we have also demonstrated that the expression and activity of UGT2B15 and B17 are modulated by several endogenous prostate factors including androgen. Finally, to study the physiological role of UGT2B enzymes, transgenic mice bearing the human UGT2B15 gene were recently obtained. A decrease in reproductive tissue weight from transgenic animals compared to those from control animals was observed. In conclusion, the conjugation by UGT2B7, B15 and B17, which represents a non-reversible step in androgen metabolism, is an important means by which androgens are regulated locally. It is also postulated that UGT enzymes protect the tissue from deleteriously high concentrations of active androgen.

  14. Sequential metabolism of sesamin by cytochrome P450 and UDP-glucuronosyltransferase in human liver. (United States)

    Yasuda, Kaori; Ikushiro, Shinichi; Kamakura, Masaki; Munetsuna, Eiji; Ohta, Miho; Sakaki, Toshiyuki


    Our previous study revealed that CYP2C9 played a central role in sesamin monocatecholization. In this study, we focused on the metabolism of sesamin monocatechol that was further converted into the dicatechol form by cytochrome P450 (P450) or the glucuronide by UDP-glucuronosyltransferase (UGT). Catecholization of sesamin monocatechol enhances its antioxidant activity, whereas glucuronidation strongly reduces its antioxidant activity. In human liver microsomes, the glucuronidation activity was much higher than the catecholization activity toward sesamin monocatechol. In contrast, in rat liver microsomes, catecholization is predominant over glucuronidation. In addition, rat liver produced two isomers of the glucuronide, whereas human liver produced only one glucuronide. These results suggest a significant species-based difference in the metabolism of sesamin between humans and rats. Kinetic studies using recombinant human UGT isoforms identified UGT2B7 as the most important UGT isoform for glucuronidation of sesamin monocatechol. In addition, a good correlation was observed between the glucuronidation activity and UGT2B7-specific activity in in vitro studies using 10 individual human liver microsomes. These results strongly suggest that UGT2B7 plays an important role in glucuronidation of sesamin monocatechol. Interindividual difference among the 10 human liver microsomes is approximately 2-fold. These results, together with our previous results on the metabolism of sesamin by human P450, suggest a small interindividual difference in sesamin metabolism. We observed the methylation activity toward sesamin monocatechol by catechol O-methyl transferase (COMT) in human liver cytosol. On the basis of these results, we concluded that CYP2C9, UGT2B7, and COMT played essential roles in the metabolism of sesamin in the human liver.

  15. Photoaffinity labeling of rat liver microsomal morphine UDP-glucuronosyltransferase by ( sup 3 H)flunitrazepam

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    Thomassin, J.; Tephly, T.R. (Univ. of Iowa, Iowa City (USA))


    Benzodiazepines have been shown to competitively inhibit morphine glucuronidation in rat and human hepatic microsomes. Flunitrazepam exerted a potent competitive inhibition of rat hepatic morphine UDP-glucuronosyltransferase (UDPGT) activity (Ki = 130 microM). It has no effect on the activity of p-nitrophenol, 17 beta-hydroxysteroid, 3 alpha-hydroxysteroid, or 4-hydroxybiphenyl UDPGTs. Because flunitrazepam is an effective photoaffinity label for benzodiazepine receptors, studied were performed in solubilized rat hepatic microsomes and with partially purified preparations of morphine UDPGT to determine the enhancement of flunitrazepam inhibition and binding to morphine UDPGT promoted by exposure to UV light. Under UV light, flunitrazepam inhibition was markedly enhanced. UV light exposure also led to a marked increase in binding of (3H)flunitrazepam to microsomal protein, which was protected substantially by preincubation with morphine. Testosterone, androsterone, and UDP-glucuronic acid did not protect against UV-enhanced flunitrazepam binding, and morphine did not reverse flunitrazepam binding once binding had occurred. As morphine UDPGT was purified, a good correlation was found between the increases in specific activity of morphine UDPGT and flunitrazepam binding to protein. Chromatofocusing chromatography showed that flunitrazepam bound only to fractions containing active morphine UDPGT, and no binding to 4-hydroxybiphenyl UDPGT was observed. Fluorography of a sodium dodecyl sulfate-polyacrylamide electrophoresis gel of solubilized hepatic microsomes that had been treated with (3H) flunitrazepam under UV light revealed a band with a monomeric molecular weight between 54,000 and 58,000. This monomeric molecular weight compares favorably with the reported monomeric molecular weight of homogeneous morphine UDPGT (56,000).

  16. Oligomerization of the UDP-glucuronosyltransferase 1A proteins: homo- and heterodimerization analysis by fluorescence resonance energy transfer and co-immunoprecipitation. (United States)

    Operaña, Theresa N; Tukey, Robert H


    UDP-glucuronosyltransferases (UGTs) are membrane-bound proteins localized to the endoplasmic reticulum and catalyze the formation of beta-d-glucopyranosiduronic acids (glucuronides) using UDP-glucuronic acid and acceptor substrates such as drugs, steroids, bile acids, xenobiotics, and dietary nutrients. Recent biochemical evidence indicates that the UGT proteins may oligomerize in the membrane, but conclusive evidence is still lacking. In the present study, we have used fluorescence resonance energy transfer (FRET) to study UGT1A oligomerization in live cells. This technique demonstrated that UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A7, UGT1A8, UGT1A9, and UGT1A10 self-oligomerize (homodimerize). Heterodimer interactions were also explored, and it was determined that UGT1A1 was capable of binding with UGT1A3, UGT1A4, UGT1A6, UGT1A7, UGT1A8, UGT1A9, and UGT1A10. In addition to the in vivo FRET analysis, UGT1A protein-protein interactions were demonstrated through co-immunoprecipitation experiments. Co-expression of hemagglutinin-tagged and cyan fluorescent protein-tagged UGT1A proteins, followed by immunoprecipitation with anti-hemagglutinin beads, illustrated the potential of each UGT1A protein to homodimerize. Co-immunoprecipitation results also confirmed that UGT1A1 was capable of forming heterodimer complexes with all of the UGT1A proteins, corroborating the FRET results in live cells. These preliminary studies suggest that the UGT1A family of proteins form oligomerized complexes in the membrane, a property that may influence function and substrate selectivity.

  17. Optimization of a UDP-glucuronosyltransferase assay for trout liver S9 fractions: Activity enhancement by alamethicin, a pore-forming peptide (United States)

    An existing assay for hepatic UDP-glucuronosyltransferase (UGT) activity was optimized for use with trout liver S9 fractions. Individual experiments were conducted to determine the time dependence of UGT activity as well as optimal levels of S9 protein, uridine 5’-diphosph...

  18. Effect of UDP-glucuronosyltransferase 1A8 polymorphism on raloxifene glucuronidation. (United States)

    Kokawa, Yuki; Kishi, Naoki; Jinno, Hideto; Tanaka-Kagawa, Toshiko; Narimatsu, Shizuo; Hanioka, Nobumitsu


    Raloxifene is an antiestrogen marketed for the treatment of osteoporosis. The major metabolic pathway of raloxifene is glucuronidation at 6- and/or 4'-positions, which is mainly catalyzed by UDP-glucuronosyltransferase 1A8 (UGT1A8) expressed in extrahepatic tissues such as the small intestine and colon. Two non-synonymous allelic variants, termed UGT1A8*2 (518C>G, A173G) and UGT1A8*3 (830G>A, C277Y), have been found in Caucasian, African-American and Asian populations. In this study, the effect of amino acid substitutions in UGT1A8 on raloxifene glucuronidation was studied using recombinant UGT1A8 enzymes of wild-type (UGT1A8.1) and variant UGT1A8 (UGT1A8.2 and UGT1A8.3) expressed in Sf9 cells. Raloxifene 6- and 4'-glucuronidation by UGT1A8.1 exhibited negative allosteric kinetics. The Km and Vmax values of UGT1A8.1 were 15.0 μM and 111 pmol/min/mg protein for 6-glucuronidation, and 9.35 μM and 232 pmol/min/mg protein for 4'-glucuronidation, respectively. The kinetics of raloxifene 6-glucuronidation by UGT1A8.2 was positive allosteric, whereas the kinetics of raloxifene 4'-glucuronidation was negative allosteric. The S50 value of raloxifene 6-glucuronidation was markedly low (1.2%) compared with the Km value of UGT1A8.1, and the Km value for raloxifene 4'-glucuronidation was 29% that of UGT1A8.1. The Vmax value for raloxifene 6-glucuronidation by UGT1A8.2 was comparable to that of UGT1A8.1, whereas the Vmax value for raloxifene 4'-glucuronidation was significantly lower (54%) than that of UGT1A8.1. The activities of raloxifene 6- and 4'-glucuronidation in UGT1A8.3 were markedly lower than those of UGT1A8.1. In mycophenolic acid glucuronidation, the kinetics by wild-type and variant UGT1A8s fitted the Michaelis-Menten model. The Km and Vmax values of UGT1A8.1 were 123 μM and 4820 pmol/min/mg protein, respectively. The Km and Vmax values of UGT1A8.2 were comparable to those of UGT1A8.1. The Km value of UGT1A8.3 was similar to that of UGT1A8.1, whereas the Vmax

  19. Unravelling the transcriptomic landscape of the major phase II UDP-glucuronosyltransferase drug metabolizing pathway using targeted RNA sequencing. (United States)

    Tourancheau, A; Margaillan, G; Rouleau, M; Gilbert, I; Villeneuve, L; Lévesque, E; Droit, A; Guillemette, C


    A comprehensive view of the human UDP-glucuronosyltransferase (UGT) transcriptome is a prerequisite to the establishment of an individual's UGT metabolic glucuronidation signature. Here, we uncover the transcriptome landscape of the 10 human UGT gene loci in normal and tumoral metabolic tissues by targeted RNA next-generation sequencing. Alignment on the human hg19 reference genome identifies 234 novel exon-exon junctions. We recover all previously known UGT1 and UGT2 enzyme-coding transcripts and identify over 130 structurally and functionally diverse novel UGT variants. We further expose a revised genomic structure of UGT loci and provide a comprehensive repertoire of transcripts for each UGT gene. Data also uncover a remodelling of the UGT transcriptome occurring in a tissue- and tumor-specific manner. The complex alternative splicing program regulating UGT expression and protein functions is likely critical in determining detoxification capacity of an organ and stress-related responses, with significant impact on drug responses and diseases.

  20. 尿苷二磷酸葡醛酸转移酶的研究进展%Progress of UDP-glucuronosyltransferases

    Institute of Scientific and Technical Information of China (English)



    UDP-glucuronosyltransferases (UGT) are the most important phase Ⅱ drug metabolizing enzyme, which can metabolize not only various endogenous substances, such as bilirubin, steroid hormones, thyroid hormones, bile acids and fat-soluble vitamins, but also many drugs, such as opioids, analgesics, NSAID and anticonvulsants. UGT plays an important role in drug absorbtion, metabolism, distribution and excretion. Furthermore, the inhibition or induction of UGT could not only result in serious drug-drug interactions, but also induce metabolic disorders of endogenous substances , for which evaluation of the inhibitory or induction effects of compounds on UGT is very important in clinic. This paper reviewed UGT in terms of its classification, tissue distribution, effect on drug absorption, gene polymorphism and related drug-drug interactions.%尿苷二磷酸葡醛酸转移酶(UGT)是体内最重要的Ⅱ相代谢酶,它可以参与许多内源性物质如胆红素、甾体激素、甲状腺激素、胆汁酸和脂溶性维生素等的代谢,在许多药物如阿片类药物、镇痛药、非甾体抗炎药和抗惊厥药等的代谢中也发挥着重要的作用.UGT在药物的吸收、分布、代谢和排泄中发挥重要作用.研究UGT特别是其基因多态性及其介导的药物-药物相互作用不仅可以指导临床用药,也可以揭示内源性物质代谢紊乱的机制.本文就UGT的分类、组织分布、对药物吸收的影响、基因多态性及其所介导的药物-药物相互作用进行综述.

  1. Characterization of niflumic acid as a selective inhibitor of human liver microsomal UDP-glucuronosyltransferase 1A9: application to the reaction phenotyping of acetaminophen glucuronidation. (United States)

    Miners, John O; Bowalgaha, Kushari; Elliot, David J; Baranczewski, Pawel; Knights, Kathleen M


    Enzyme selective inhibitors represent the most valuable experimental tool for reaction phenotyping. However, only a limited number of UDP-glucuronosyltransferase (UGT) enzyme-selective inhibitors have been identified to date. This study characterized the UGT enzyme selectivity of niflumic acid (NFA). It was demonstrated that 2.5 μM NFA is a highly selective inhibitor of recombinant and human liver microsomal UGT1A9 activity. Higher NFA concentrations (50-100 μM) inhibited UGT1A1 and UGT2B15 but had little effect on the activities of UGT1A3, UGT1A4, UGT1A6, UGT2B4, UGT2B7, and UGT2B17. NFA inhibited 4-methylumbelliferone and propofol (PRO) glucuronidation by recombinant UGT1A9 and PRO glucuronidation by human liver microsomes (HLM) according to a mixed (competitive-noncompetitive) mechanism, with K(i) values ranging from 0.10 to 0.40 μM. Likewise, NFA was a mixed or noncompetitive inhibitor of recombinant and human liver microsomal UGT1A1 (K(i) range 14-18 μM), whereas competitive inhibition (K(i) 62 μM) was observed with UGT2B15. NFA was subsequently applied to the reaction phenotyping of human liver microsomal acetaminophen (APAP) glucuronidation. Consistent with previous reports, APAP was glucuronidated by recombinant UGT1A1, UGT1A6, UGT1A9, and UGT2B15. NFA concentrations in the range of 2.5 to 100 μM inhibited APAP glucuronidation by UGT1A1, UGT1A9, and UGT2B15 but not by UGT1A6. The mean V(max) for APAP glucuronidation by HLM was reduced by 20, 35, and 40%, respectively, in the presence of 2.5, 50, and 100 μM NFA. Mean K(m) values decreased in parallel with V(max), although the magnitude of the decrease was smaller. Taken together, the NFA inhibition data suggest that UGT1A6 is the major enzyme involved in APAP glucuronidation.

  2. Traditional herbal formulas to as treatments for musculoskeletal disorders: Their inhibitory effects on the activities of human microsomal cytochrome p450s and udp-glucuronosyltransferases

    Directory of Open Access Journals (Sweden)

    Seong Eun Jin


    Abbreviation used: BPTSS: Bangpungtongseong-san, OJS: Ojeok-san, OYSGS: Oyaksungi-san, CYP450s: cytochrome P450s, UGTs: UDP-glucuronosyltransferases, MSDs: Musculoskeletal disorders, NSAIDs: nonsteroidal anti-inflammatory drugs, EOMCC: 7-ethoxy-methyloxy-3-cyanocoumarin, DBOMF: di(benzyloxymethoxyfluorescein, BOMCC: 7-benzyloxy-4-trifluoromethylcoumarin, HPLC: High-performance liquid chromatography, PDA: photo diode array, SEM: standard error of the mean, UDPGA: uridine 5'-diphosphoglucuronic acid.

  3. Mangifera indica L. extract and mangiferin modulate cytochrome P450 and UDP-glucuronosyltransferase enzymes in primary cultures of human hepatocytes. (United States)

    Rodeiro, Idania; José Gómez-Lechón, M; Perez, Gabriela; Hernandez, Ivones; Herrera, José Alfredo; Delgado, Rene; Castell, José V; Teresa Donato, M


    The aqueous stem bark extract of Mangifera indica L. (MSBE) has been reported to have antioxidant, anti-inflammatory and analgesic properties. In previous studies, we showed that MSBE and mangiferin, its main component, lower the activity of some cytochrome P-450 (P450) enzymes in rat hepatocytes and human liver microsomes. In the present study, the effects of MSBE and mangiferin on several P450 enzymes and UDP-glucuronosyltransferases (UGTs) in human-cultured hepatocytes have been examined. After hepatocytes underwent a 48-h treatment with sub-cytotoxic concentrations of the products (50-250 µg/mL), a concentration-dependent decrease of the activity of the five P450 enzymes measured (CYP1A2, 2A6, 2C9, 2D6 and 3A4) was observed. For all the activities, a reduction of at least 50% at the highest concentration (250 µg/mL) was observed. In addition, UGT activities diminished. MSBE considerably reduced UGT1A9 activity (about 60% at 250 µg/mL) and lesser effects on the other UGTs. In contrast, 250 µg/mL mangiferin had greater effects on UGT1A1 and 2B7 than on UGT1A9 (about 55% vs. 35% reduction, respectively). Quantification of specific mRNAs revealed reduced CYP3A4 and 3A5 mRNAs content, and an increase in CYP1A1, CYP1A2, UGT1A1 and UGT1A9 mRNAs. No remarkable effects on the CYP2A6, 2B6, 2C9, 2C19, 2D6 and 2E1 levels were observed. Our results suggest that the activity and/or expression of major P450 and UGT enzymes is modulated by MSBE and that potential herb-drugs interactions could arise after a combined intake of this extract with conventional medicines. Therefore, the potential safety risks of this natural product derived by altering the ADMET properties of co-administered drugs should be examined.

  4. UGT酶的遗传药理学研究进展%Progress in the pharmacogenomics of UDP-glucuronosyltransferase

    Institute of Scientific and Technical Information of China (English)

    郭栋; 庞良芳; 周宏灏


    尿苷二磷酸葡萄糖醛酸基转移酶(UDP-glucuronosyltransferase,UGT),是人体内重要的催化Ⅱ相结合反应的酶.UGT广泛分布于人体的肝、肾、胃肠道以及各种腺体组织,因其结构和细胞内分布的特殊性,对其研究落后于CYP450酶.近20年来随着实验技术的发展,越来越多的研究开始关注UGT.随着研究进展,UGT的底物在不断地扩展,包括有内源性激素、药物以及毒物.个体间、种族间葡萄糖醛酸化活性存在明显差异,UGT基因多态性是此现象的重要原因之一.对UGT基因多态性的研究日益增多,已经成立命名委员会.UGT按照序列相似性分两个大的亚家族,本文分别对其中主要参与药物代谢的UGT1 A和UGT2家族的某些成员的遗传药理学研究进展进行综述.%UDP-glucuronosyltransferase is an important enzyme involved in the phase II conjugation reaction. UGT is wildly expressed in human liver, kidney, stomach intestine tract and glandular organs. Because of the specificity of its structure and intra-cellular distribution, the study in UGT is lagged behind of the CYP450. Recent two decades, following the progress of the experiment technology, more and more research were focused on the UGT. Following these, the probe drug of UGT are enlarging, it involved in the metabolism of endogenous hormone, drugs and some kinds of toxicity. The polymorphisms of UGT gene were one of the most important reasons lead to the large inter-individual and inter-racial variability of the glucuronodiation activity. There are two subgroups, UGT1A and UGT2, depending on the similarity of the amino acid sequence. This paper reviews the current concept and new advances in the pharmacogenomics of UGT genes which have played an important role in drug metabolism.

  5. Isoform selectivity and kinetics of morphine 3- and 6-glucuronidation by human udp-glucuronosyltransferases: evidence for atypical glucuronidation kinetics by UGT2B7. (United States)

    Stone, Andrew N; Mackenzie, Peter I; Galetin, Aleksandra; Houston, J Brian; Miners, John O


    Morphine elimination involves UDP-glucuronosyltransferase (UGT) catalyzed conjugation with glucuronic acid to form morphine 3- and 6-glucuronides (M3G and M6G, respectively). It has been proposed that UGT2B7 is the major enzyme involved in these reactions, but there is evidence to suggest that other isoforms also catalyze morphine glucuronidation in man. Thus, we have characterized the selectivity and kinetics of M3G and M6G formation by recombinant human UGTs. UGT 1A1, 1A3, 1A6, 1A8, 1A9, 1A10, and 2B7 all catalyzed M3G formation, but only UGT2B7 formed M6G. The kinetics of M3G formation by the UGT1A family isoforms was consistent with a single enzyme Michaelis-Menten model, with apparent Km values ranging from 2.6 to 37.4 mM. In contrast, M3G and M6G formation by UGT2B7 exhibited atypical kinetics. The atypical kinetics may be described by a model with high- and low-affinity Km values (0.42 and 8.3 mM for M3G, and 0.97 and 7.4 mM for M6G) from fitting to a biphasic Michaelis-Menten model. However, a multisite model with an interaction between two identical binding sites in a negative cooperative manner provides a more realistic approach to modeling these data. According to this model, the respective binding affinities (Ks) for M3G and M6G were 1.76 and 1.41 mM, respectively. These data suggest that M6G formation may be used as a selective probe for UGT2B7 activity, and morphine glucuronidation by UGT2B7 appears to involve the simultaneous binding of two substrate molecules, highlighting the need for careful analysis of morphine glucuronidation kinetics in vitro.

  6. The UDP-glucuronosyltransferases of the blood-brain barrier: their role in drug metabolism and detoxication

    Directory of Open Access Journals (Sweden)

    Mohamed eOuzzine


    Full Text Available UDP-glucuronosyltransferases (UGTs form a multigenic family of membrane-bound enzymes expressed in various tissues, including brain. They catalyze the formation of β-Dglucuronides from structurally unrelated substances (drugs, other xenobiotics, as well as endogenous compounds by the linkage of glucuronic acid from the high energy donor, UDP-αD-glucuronic acid. In brain, UGTs actively participate to the overall protection of the tissue against the intrusion of potentially harmful lipophilic substances that are metabolized as hydrophilic glucuronides. These metabolites are generally inactive, except for important pharmacologically glucuronides such as morphine-6-glucuronide. UGTs are mainly expressed in endothelial cells and astrocytes of the blood brain barrier. They are also associated to brain interfaces devoid of blood-brain barrier, such as circumventricular organ, pineal gland, pituitary gland and neuro-olfactory tissues. Beside their key-role as a detoxication barrier, UGTs play a role in the steady-state of endogenous compounds, like steroids or dopamine that participate to the function of the brain. UGT isoforms of family 1A, 2A, 2B and 3A are expressed in brain tissues to various levels and are known to present distinct but overlapping substrate specificity. The importance of these enzyme species with regard to the formation of toxic, pharmacologically or physiologically relevant glucuronides in the brain will be discussed.

  7. Metabolic Disposition of Luteolin Is Mediated by the Interplay of UDP-Glucuronosyltransferases and Catechol-O-Methyltransferases in Rats. (United States)

    Wang, Liping; Chen, Qingwei; Zhu, Lijun; Li, Qiang; Zeng, Xuejun; Lu, Linlin; Hu, Ming; Wang, Xinchun; Liu, Zhongqiu


    Luteolin partially exerts its biologic effects via its metabolites catalyzed by UDP-glucuronosyltransferases (UGTs) and catechol-O-methyltransferases (COMTs). However, the interplay of UGTs and COMTs in mediating luteolin disposition has not been well clarified. In this study, we investigated the glucuronidation and methylation pathways of luteolin mediated by the interplay of UGTs and COMTs in vivo and in vitro. A total of nine luteolin metabolites was detected in rat plasma and bile by liquid chromatography-tandem mass spectrometry, namely, three glucuronides, two methylated metabolites, and four methylated glucuronides. Luteolin-3'-glucuronide (Lut-3'-G) exhibited the highest systemic exposure among these metabolites. Kinetics studies in rat liver S9 fractions suggested two pathways, as follows: 1) Luteolin was glucuronidated to luteolin-7-glucuronide, luteolin-4'-glucuronide, and Lut-3'-G by UGTs, and then Lut-7-G was methylated to chrysoeriol-7-glucuronide and diosmetin-7-glucuronide by COMTs. 2) Alternatively, luteolin was methylated to chrysoeriol and diosmetin by COMTs, and then chrysoeriol and diosmetin were glucuronidated by UGTs to their respective glucuronides. The methylation rate of luteolin was significantly increased by the absence of glucuronidation, whereas the glucuronidation rate was increased by the absence of methylation, but to a lesser extent. In conclusion, two pathways mediated by the interplay of UGTs and COMTs are probably involved in the metabolic disposition of luteolin. The glucuronidation and methylation of luteolin compensate for each other, although glucuronidation is the predominant pathway.

  8. Multiple UDP- Glucuronosyltransferases in Human Liver Microsomes Glucuronidate Both R- and S-7-Hydroxywarfarin into Two Metabolites (United States)

    Pugh, C. Preston; Pouncey, Dakota L; Hartman, Jessica H.; Nshimiyimana, Robert; Desrochers, Linda P.; Goodwin, Thomas E.; Boysen, Gunnar; Miller, Grover P.


    The widely used anticoagulant Coumadin (R/S-warfarin) undergoes oxidation by cytochromes P450 into hydroxywarfarins that subsequently become conjugated for excretion in urine. Hydroxywarfarins may modulate warfarin metabolism transcriptionally or through direct inhibition of cytochromes P450 and thus, UGT action toward hydroxywarfarin elimination may impact levels of the parent drugs and patient responses. Nevertheless, relatively little is known about conjugation by UDP-glucuronosyltransferases in warfarin metabolism. Herein, we identified probable conjugation sites, kinetic mechanisms and hepatic UGT isoforms involved in microsomal glucuronidation of R- and S-7-hydroxywarfarin. Both compounds underwent glucuronidation at C4 and C7 hydroxyl groups based on elution properties and spectral characteristics. Their formation demonstrated regio- and enantioselectivity by UGTs and resulted in either Michaelis-Menten or substrate inhibition kinetics. Glucuronidation at the C7 hydroxyl group occurred more readily than at the C4 group, and the reaction was overall more efficient for R-7-hydroxywarfarin due to higher affinity and rates of turnover. The use of these mechanisms and parameters to model in vivo clearance demonstrated that contributions of substrate inhibition would lead to underestimation of metabolic clearance than that predicted by Michaelis-Menten kinetics. Lastly, these processes were driven by multiple UGTs indicating redundancy in glucuronidation pathways and ultimately metabolic clearance of R- and S-7-hydroxywarfarin. PMID:25447818

  9. UDP-glucuronosyltransferase 2B7 C802T (His268Tyr) polymorphism in bladder cancer cases. (United States)

    Zimmermann, Anna; Blaszkewicz, Meinolf; Roth, Gerhard; Seidel, Thilo; Dietrich, Holger; Schutschkow, Olga; Bolt, Hermann M; Golka, Klaus


    A study of Chinese benzidine workers indicated elevated levels of UDP-glucuronosyltransferase (UGT) 2B7 T/T activity in carriers for development of bladder cancer. The present study was designed to investigate the possible impact of the presence of UGT2B7 genotype on bladder cancer risk in Caucasians. UGT2B7 polymorphism at locus C(802)T (His(268)Tyr) was detected using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-based procedure. The study group consisted of 211 bladder cancer cases and 210 controls suffering from different urological diseases, but without any history of cancer. Both groups were recruited from a Department of Urology located in a center of former chemical and rubber industries in Germany. Furthermore, 171 bladder cancer cases with a history of occupational exposure to aromatic amines surveyed for compensation due to an occupational disease were investigated. T/T genotype frequencies in bladder cancer cases, urological controls, and exposed patients appeared similar (27 vs. 35 vs. 25%). This study indicated that there were ethnic differences between Caucasian and Chinese general populations with respect to the UGT2B7 genotype. Furthermore, in contrast to an earlier investigation in benzidine-exposed Chinese bladder cancer patients, no relevant differences between bladder cancer patients and urological hospital controls were observed in Germany.

  10. Induction of digitoxigenin monodigitoxoside UDP-glucuronosyltransferase activity by glucocorticoids and other inducers of cytochrome P-450p in primary monolayer cultures of adult rat hepatocytes and in human liver. (United States)

    Schuetz, E G; Hazelton, G A; Hall, J; Watkins, P B; Klaassen, C D; Guzelian, P S


    We have recently proposed that glucocorticoids induce cytochrome P-450p, a liver microsomal hemoprotein originally isolated from rats treated with the antiglucocorticoid pregnenolone 16 alpha-carbonitrile (PCN), through a mechanism that involves a stereospecific recognition system clearly distinguishable from the classic glucocorticoid receptor (Schuetz, E. G., Wrighton, S. A., Barwick, J. L., and Guzelian, P. S. (1984) J. Biol. Chem. 259, 1999-2012). We now report that digitoxigenin monodigitoxoside UDP-glucuronosyltransferase (DIG UDP-glucuronosyltransferase), a liver microsomal enzyme activity induced by PCN in rats, is also inducible, as is P-450p, in primary monolayer cultures of adult rat hepatocytes. DIG UDP-glucuronosyltransferase activity closely resembled reported characteristics of induction of P-450p in its time course of induction, concentration-response relationships, exclusivity of induction by steroids with glucocorticoid properties, unusual rank order of potency of glucocorticoid agonists, unusually high ED50 for induction by glucocorticoids, enhanced induction rather than inhibition by anti-glucocorticoids in the presence of glucocorticoids, and finally, induction by nonsteroidal inducers of P-450p. DIG UDP-glucuronosyltransferase activity was also readily detected in human liver microsomes and was elevated in two patients who had received inducers of P-450p. We conclude that the liver enzymes controlled by the postulated PCN recognition system include not only P-450p but also one or more UDP-glucuronosyltransferases.

  11. Effect of a New Prokinetic Agent DA-9701 Formulated with Corydalis Tuber and Pharbitidis Semen on Cytochrome P450 and UDP-Glucuronosyltransferase Enzyme Activities in Human Liver Microsomes

    Directory of Open Access Journals (Sweden)

    Hye Young Ji


    Full Text Available DA-9701 is a new botanical drug composed of the extracts of Corydalis tuber and Pharbitidis semen, and it is used as an oral therapy for the treatment of functional dyspepsia in Korea. The inhibitory potentials of DA-9701 and its component herbs, Corydalis tuber and Pharbitidis semen, on the activities of seven major human cytochrome P450 (CYP enzymes and four UDP-glucuronosyltransferase (UGT enzymes in human liver microsomes were investigated using liquid chromatography-tandem mass spectrometry. DA-9701 and Corydalis tuber extract slightly inhibited UGT1A1-mediated etoposide glucuronidation, with 50% inhibitory concentration (IC50 values of 188 and 290 μg/mL, respectively. DA-9701 inhibited CYP2D6-catalyzed bufuralol 1′-hydroxylation with an inhibition constant (Ki value of 6.3 μg/mL in a noncompetitive manner. Corydalis tuber extract competitively inhibited CYP2D6-mediated bufuralol 1′-hydroxylation, with a Ki value of 3.7 μg/mL, whereas Pharbitidis semen extract showed no inhibition. The volume in which the dose could be diluted to generate an IC50 equivalent concentration (volume per dose index value of DA-9701 for inhibition of CYP2D6 activity was 1.16 L/dose, indicating that DA-9701 may not be a potent CYP2D6 inhibitor. Further clinical studies are warranted to evaluate the in vivo extent of the observed in vitro interactions.

  12. Interaction of periodate-oxidized UDP-glucuronic acid with recombinant human liver UDP-glucuronosyltransferase 1A6. (United States)

    Battaglia, E; Terrier, N; Mizeracka, M; Senay, C; Magdalou, J; Fournel-Gigleux, S; Radominska-Pandya, A


    Sodium periodate reacts with UDP-glucuronic acid (UDP-GlcUA) to generate a reactive derivative [periodate-oxidized UDP-GlcUA (o-UDP-GlcUA)]. The ability of this analog of UDP-GlcUA to inactivate and label the human recombinant UDP-glucuronosyltransferase (UGT) UGT1A6 via the UDP-GlcUA binding site was investigated. At an o-UDP-GlcUA concentration of 20 mM, the enzymatic activity of UGT1A6 was totally inactivated after 30 min of incubation at pH 7.4. Inhibition was irreversible, time-dependent, and concentration-dependent and exhibited pseudo-first order kinetics (kinact = 4.0 M-1.min-1). Cosubstrate protection with UDP-GlcUA was biphasic, with no protection in the first phase and almost total protection in the second phase, suggesting that at least 65% of the cross-linking occurs at the cosubstrate binding site. Partial inactivation by o-UDP-GlcUA led to a decrease in Vmax, suggesting that o-UDP-GlcUA can act as an active site-directed inhibitor. Furthermore, proteins, including the UGTs, from membrane fractions of a recombinant V79 cell line expressing the UGT1A6 enzyme and from rat liver microsomes were cross-linked by in situ periodate oxidation of [beta-32P]UDP-GlcUA. The present results suggest that periodate-oxidized UDP-GlcUA, which inactivates UGT1A6 by the possible formation of a Schiff base adduct with active site lysyl residues, can be used as a new affinity label for the UDP-GlcUA binding site.

  13. Cooperation of NAD(P)H:quinone oxidoreductase 1 and UDP-glucuronosyltransferases reduces menadione cytotoxicity in HEK293 cells. (United States)

    Nishiyama, Takahito; Izawa, Tadashi; Usami, Mami; Ohnuma, Tomokazu; Ogura, Kenichiro; Hiratsuka, Akira


    Previous studies have shown that NAD(P)H:quinone oxidoreductase 1 (NQO1) plays an important role in the detoxification of menadione (2-methyl-1,4-naphthoquinone, also known as vitamin K3). However, menadiol (2-methyl-1,4-naphthalenediol) formed from menadione by NQO1-mediated reduction continues to be an unstable substance, which undergoes the reformation of menadione with concomitant formation of reactive oxygen species (ROS). Hence, we focused on the roles of phase II enzymes, with particular attention to UDP-glucuronosyltransferases (UGTs), in the detoxification process of menadione. In this study, we established an HEK293 cell line stably expressing NQO1 (HEK293/NQO1) and HEK293/NQO1 cell lines with doxycycline (DOX)-regulated expression of UGT1A6 (HEK293/NQO1/UGT1A6) and UGT1A10 (HEK293/NQO1/UGT1A10), and evaluated the role of NQO1 and UGTs against menadione-induced cytotoxicity. Our results differed from those of previous studies. HEK293/NQO1 was the most sensitive cell line to menadione cytotoxicity among cell lines established in this study. These phenomena were also observed in HEK293/NQO1/UGT1A6 and HEK293/NQO1/UGT1A10 cells in which the expression of UGT was suppressed by DOX treatment. On the contrary, HEK293/NQO1/UGT1A6 and HEK293/NQO1/UGT1A10 cells without DOX treatment were resistant to menadione-induced cytotoxicity. These results demonstrated that NQO1 is not a detoxification enzyme for menadione and that UGT-mediated glucuronidation of menadiol is the most important detoxification process.

  14. Hepatic UDP-glucuronosyltransferase enzyme activity decreased during salt acclimation of sea lamprey juveniles from Minho river basin

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    Marta Candeias


    Full Text Available Sea lamprey (Petromyzon marinus L., 1758 is an anadromous species which migrates twice during its life cycle between freshwater and seawater. During downstream migration, the juveniles are subject to salinity changes ranging between 0 and 35. The aim of this study was to evaluate the influence of salinity in hepatic biomarkers of stress and biotransformation of juveniles from Minho river basin, Portugal, during trophic migration. Sampled juveniles (macrophthalmia were transported alive to the laboratory and maintained in 200 L tanks with LSS life support system. The specimens were separated in three groups of five pools (#8: i macrophthalmia, salinity 0 for 7 days; ii macrophthalmia, salinity 0 for 30 days and, iii macrophthalmia subjected to a salt gradient up to salinity 35, for 30 days. At final of the experiments the weight and the length of specimens were determined. Microsomes and cytosol obtained by centrifugation of liver homogenates were used for fluorimetric quantification of glutathione (GSH, glutathione disulphide (GSSG and malondialdehyde (MDA and, spectrophotometric determination of catalase (CTT1 and UDP-glucuronosyltransferase (UDPGT activities. Stats include ANOVA I and Duncan test. The results showed that salt exposure of the animals caused a decrease in the body weight and condition factor (K without changes the hepatic somatic index (p <0.05. It was also observed a decrease in the GSH/GSSG ratio and UDPGT activity, markers of oxidative stress and loss of biotransformation capacity of liver macrophthalmia (p <0.05. This disturbances may jeopardize the success of sea lamprey trophic migration, if occur a permanent or accidental exposure of juveniles to organic pollutants on the path to the sea. In addition, the salt exposure did not change the liver cytosolic MDA content (p <0.05. The significant increase in CTT1 activity may have contributed to prevent hepatic oxidative damages in the sea lamprey juveniles.

  15. Glucuronidation of edaravone by human liver and kidney microsomes: biphasic kinetics and identification of UGT1A9 as the major UDP-glucuronosyltransferase isoform. (United States)

    Ma, Liping; Sun, Jianguo; Peng, Ying; Zhang, Rong; Shao, Feng; Hu, Xiaoling; Zhu, Jianping; Wang, Xiaojin; Cheng, Xuefang; Zhu, Yinci; Wan, Ping; Feng, Dong; Wu, Hui; Wang, Guangji


    Edaravone was launched in Japan in 2001 and was the first neuroprotectant developed for the treatment of acute cerebral infarction. Edaravone is mainly eliminated as glucuronide conjugate in human urine (approximately 70%), but the mechanism involved in the elimination pathway remains unidentified. We investigated the glucuronidation of edaravone in human liver microsomes (HLM) and human kidney microsomes (HKM) and identified the major hepatic and renal UDP-glucuronosyltransferases (UGTs) involved. As we observed, edaravone glucuronidation in HLM and HKM exhibited biphasic kinetics. The intrinsic clearance of glucuronidation at high-affinity phase (CL(int1)) and low-affinity phase (CL(int2)) were 8.4 ± 3.3 and 1.3 ± 0.2 μl · min(-1) · mg(-1), respectively, for HLM and were 45.3 ± 8.2 and 1.8 ± 0.1 μl · min(-1) · mg(-1), respectively, for HKM. However, in microsomal incubations contained with 2% bovine serum albumin, CL(int1) and CL(int2) were 16.4 ± 1.2 and 3.7 ± 0.3 μl · min(-1) · mg(-1), respectively, for HLM and were 78.5 ± 3.9 and 3.6 ± 0.5 μl · min(-1) · mg(-1), respectively, for HKM. Screening with 12 recombinant UGTs indicated that eight UGTs (UGT1A1, UGT1A6, UGT1A7, UGT1A8, UGT1A9, UGT1A10, UGT2B7, and UGT2B17) produced a significant amount of glucuronide metabolite. Thus, six UGTs (UGT1A1, UGT1A6, UGT1A7, UGT1A9, UGT2B7, and UGT2B17) expressed in human liver or kidney were selected for kinetic studies. Among them, UGT1A9 exhibited the highest activity (CL(int1) = 42.4 ± 9.5 μl · min(-1) · mg(-1)), followed by UGT2B17 (CL(int) = 3.3 ± 0.4 μl · min(-1) · mg(-1)) and UGT1A7 (CL(int) = 1.7 ± 0.2 μl · min(-1) · mg(-1)). Inhibition study found that inhibitor of UGT1A9 (propofol) attenuated edaravone glucuronidation in HLM and HKM. In addition, edaravone glucuronidation in a panel of seven HLM was significantly correlated (r = 0.9340, p = 0.0021) with propofol glucuronidation. Results indicated that UGT1A9 was the main UGT isoform

  16. UDP-glucuronosyltransferase-mediated metabolic activation of the tobacco carcinogen 2-amino-9H-pyrido[2,3-b]indole. (United States)

    Tang, Yijin; LeMaster, David M; Nauwelaërs, Gwendoline; Gu, Dan; Langouët, Sophie; Turesky, Robert J


    2-Amino-9H-pyrido[2,3-b]indole (AαC) is a carcinogenic heterocyclic aromatic amine (HAA) that arises in tobacco smoke. UDP-glucuronosyltransferases (UGTs) are important enzymes that detoxicate many procarcinogens, including HAAs. UGTs compete with P450 enzymes, which bioactivate HAAs by N-hydroxylation of the exocyclic amine group; the resultant N-hydroxy-HAA metabolites form covalent adducts with DNA. We have characterized the UGT-catalyzed metabolic products of AαC and the genotoxic metabolite 2-hydroxyamino-9H-pyrido[2,3-b]indole (HONH-AαC) formed with human liver microsomes, recombinant human UGT isoforms, and human hepatocytes. The structures of the metabolites were elucidated by (1)H NMR and mass spectrometry. AαC and HONH-AαC underwent glucuronidation by UGTs to form, respectively, N(2)-(β-D-glucosidurony1)-2-amino-9H-pyrido[2,3-b]indole (AαC-N(2)-Gl) and N(2)-(β-D-glucosidurony1)-2-hydroxyamino-9H-pyrido[2,3-b]indole (AαC-HON(2)-Gl). HONH-AαC also underwent glucuronidation to form a novel O-linked glucuronide conjugate, O-(β-D-glucosidurony1)-2-hydroxyamino-9H-pyrido[2,3-b]indole (AαC-HN(2)-O-Gl). AαC-HN(2)-O-Gl is a biologically reactive metabolite and binds to calf thymus DNA (pH 5.0 or 7.0) to form the N-(deoxyguanosin-8-yl)-AαC adduct at 20-50-fold higher levels than the adduct levels formed with HONH-AαC. Major UGT isoforms were examined for their capacity to metabolize AαC and HONH-AαC. UGT1A4 was the most catalytically efficient enzyme (V(max)/K(m)) at forming AαC-N(2)-Gl (0.67 μl·min(-1)·mg of protein(-1)), and UGT1A9 was most catalytically efficient at forming AαC-HN-O-Gl (77.1 μl·min(-1)·mg of protein(-1)), whereas UGT1A1 was most efficient at forming AαC-HON(2)-Gl (5.0 μl·min(-1)·mg of protein(-1)). Human hepatocytes produced AαC-N(2)-Gl and AαC-HN(2)-O-Gl in abundant quantities, but AαC-HON(2)-Gl was a minor product. Thus, UGTs, usually important enzymes in the detoxication of many procarcinogens, serve as a

  17. In vitro glucuronidation of the primary metabolite of 10-chloromethyl-11-demethyl-12-oxo-calanolide A by human liver microsomes and its interactions with UDP-glucuronosyltransferase substrates. (United States)

    Liu, Xin; Sheng, Li; Zhao, Manman; Mi, Jiaqi; Liu, Zhihao; Li, Yan


    F18 (10-chloromethyl-11-demethyl-12-oxo-calanolide), an analog of (+)-Calanolide A, is a novel small-molecule nonnucleoside reverse transcriptase inhibitor for the therapy of human immunodeficiency virus (HIV) infection. M3, the most abundant primary metabolite of F18 in human liver microsomes (HLMs) and rat liver microsomes (RLMs), is mainly excreted in bile as a glucuronide conjugate in rats after oral administration. The aim of this study was to identify the UDP glucuronosyltransferase (UGT) isoforms involved in the glucuronidation of M3 by HLMs and recombinant human UGTs and investigate the metabolic interactions of M3 with the substrates of UGTs in HLMs. As a result, UGT1A1 was the major isozyme responsible for the glucuronidation of M3, followed by UGT1A4, UGT1A9 and UGT2B7. M3 exhibited significant inhibition against UGT1A9 and UGT2B7 in both HLMs and recombinant human UGTs. In addition, M3 inhibited UGT1A9 catalyzed mycophenolic acid (MPA) glucuronidation with Ki of 0.39 μM, and M3 also inhibited the glucuronidation of 3'-azido-3'-deoxythymidine (AZT) by a "mixed-type" mechanism with Ki of 16.8 μM. The results suggest that UGT1A1 provides the major contribution to M3 glucuronidation in vitro and M3 has the potential to interact with xenobiotics and endogenous chemicals that are UGT1A9 and UGT 2B7 substrates.

  18. Identification of Human UDP-Glucuronosyltransferase 1A4 as the Major Isozyme Responsible for the Glucuronidation of 20(S)-Protopanaxadiol in Human Liver Microsomes. (United States)

    Li, Jia; He, Chunyong; Fang, Lianxiang; Yang, Li; Wang, Zhengtao


    20(S)-protopanaxadiol (PPD), one of the representative aglycones of ginsenosides, has a broad spectrum of pharmacological activities. Although phase I metabolism has been investigated extensively, information regarding phase II metabolism of this compound remains to be elucidated. Here, a glucuronidated metabolite of PPD in human liver microsomes (HLMs) and rat liver microsomes (RLMs) was unambiguously identified as PPD-3-O-β-D-glucuronide by nuclear magnetic resonance spectroscopy and high resolution mass spectrometry. The chemical inhibition and recombinant human UDP-Glucuronosyltransferase (UGT) isoforms assay showed that the PPD glucuronidation was mainly catalyzed by UGT1A4 in HLM, whereas UGT1A3 showed weak catalytic activity. In conclusion, PPD-3-O-β-D-glucuronide was first identified as the principal glucuronidation metabolite of PPD in HLMs, which was catalyzed by UGT1A4.

  19. Coupling of UDP-glucuronosyltransferases and multidrug resistance-associated proteins is responsible for the intestinal disposition and poor bioavailability of emodin

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei; Feng, Qian; Li, Ye; Ye, Ling [Department of Pharmaceutics, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong (China); Hu, Ming, E-mail: [Department of Pharmaceutics, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong (China); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, 1441 Moursund Street, Houston, TX 77030 (United States); Liu, Zhongqiu, E-mail: [Department of Pharmaceutics, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong (China)


    Emodin is a poorly bioavailable but promising plant-derived anticancer drug candidate. The low oral bioavailability of emodin is due to its extensive glucuronidation in the intestine and liver. Caco-2 cell culture model was used to investigate the interplay between UDP-glucuronosyltransferases (UGTs) and efflux transporters in the intestinal disposition of emodin. Bidirectional transport assays of emodin at different concentrations were performed in the Caco-2 monolayers with or without multidrug resistance-associated protein (MRP) and breast cancer resistance protein (BCRP) efflux transporter chemical inhibitors. The bidirectional permeability of emodin and its glucuronide in the Caco-2 monolayers was determined. Emodin was rapidly metabolized to emodin glucuronide in Caco-2 cells. LTC4, a potent inhibitor of MRP2, decreased the efflux of emodin glucuronide and also substantially increased the intracellular glucuronide level in the basolateral-to-apical (B–A) direction. MK-571, chemical inhibitor of MRP2, MRP3, and MRP4, significantly reduced the efflux of glucuronide in the apical-to-basolateral (A–B) and B–A directions in a dose-dependent manner. However, dipyridamole, a BCRP chemical inhibitor demonstrated no effect on formation and efflux of emodin glucuronide in Caco-2 cells. In conclusion, UGT is a main metabolic pathway for emodin in the intestine, and the MRP family is composed of major efflux transporters responsible for the excretion of emodin glucuronide in the intestine. The coupling of UGTs and MRP efflux transporters causes the extensive metabolism, excretion, and low bioavailability of emodin. -- Highlights: ► Glucuronidation is the main reason for the poor oral bioavailability of emodin. ► Efflux transporters are involved in the excretion of emodin glucuronide. ► The intestine is the main organ for metabolism of emodin.

  20. The First Aspartic Acid of the DQxD Motif for Human UDP-Glucuronosyltransferase 1A10 Interacts with UDP-Glucuronic Acid during Catalysis (United States)

    Xiong, Yan; Patana, Anne-Sisko; Miley, Michael J.; Zielinska, Agnieszka K.; Bratton, Stacie M.; Miller, Grover P.; Goldman, Adrian; Finel, Moshe; Redinbo, Matt R.; Radominska-Pandya, Anna


    All UDP-glucuronosyltransferase enzymes (UGTs) share a common cofactor, UDP-glucuronic acid (UDP-GlcUA). The binding site for UDP-GlcUA is localized to the C-terminal domain of UGTs on the basis of amino acid sequence homology analysis and crystal structures of glycosyltransferases, including the C-terminal domain of human UGT2B7. We hypothesized that the 393DQMD-NAK399 region of human UGT1A10 interacts with the glucuronic acid moiety of UDP-GlcUA. Using site-directed mutagenesis and enzymatic analysis, we demonstrated that the D393A mutation abolished the glucuronidation activity of UGT1A10 toward all substrates. The effects of the alanine mutation at Q394, D396, and K399 on glucuronidation activities were substrate-dependent. Previously, we examined the importance of these residues in UGT2B7. Although D393 (D398 in UGT2B7) is similarly critical for UDP-GlcUA binding in both enzymes, the effects of Q394 (Q399 in UGT2B7) to Ala mutation on activity were significant but different between UGT1A10 and UGT2B7. A model of the UDP-GlcUA binding site suggests that the contribution of other residues to cosubstrate binding may explain these differences between UGT1A10 and UGT2B7. We thus postulate that D393 is critical for the binding of glucuronic acid and that proximal residues, e.g., Q394 (Q399 in UGT2B7), play a subtle role in cosubstrate binding in UGT1A10 and UGT2B7. Hence, this study provides important new information needed for the identification and understanding of the binding sites of UGTs, a major step forward in elucidating their molecular mechanism. PMID:18048489

  1. Herb–drug interaction prediction based on the high specific inhibition of andrographolide derivatives towards UDP-glucuronosyltransferase (UGT) 2B7

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Hai-Ying, E-mail: [The Fourth Affiliated Hospital of China Medical University, Shenyang 110032 (China); Sun, Dong-Xue [School of Traditional Chinese Medicine, Shenyang Pharmaceutical University, No. 103, Wenhua Road, Shenyang 110016 (China); Cao, Yun-Feng [The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road, Dalian 116023 (China); Ai, Chun-Zhi [Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road, Dalian 116023 (China); Qu, Yan-Qing [Thyroid Surgery, Yantaishan Hospital, Yantai, Shandong (China); Hu, Cui-Min [Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road, Dalian 116023 (China); Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC 20057 (United States); Jiang, Changtao [Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892 (United States); Dong, Pei-Pei [Academy of Integrative Medicine, Dalian Medical University, Dalian 116044 (China); Sun, Xiao-Yu; Hong, Mo [Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road, Dalian 116023 (China); Tanaka, Naoki; Gonzalez, Frank J. [Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892 (United States); and others


    Herb–drug interaction strongly limits the clinical application of herbs and drugs, and the inhibition of herbal components towards important drug-metabolizing enzymes (DMEs) has been regarded as one of the most important reasons. The present study aims to investigate the inhibition potential of andrographolide derivatives towards one of the most important phase II DMEs UDP-glucuronosyltransferases (UGTs). Recombinant UGT isoforms (except UGT1A4)-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction and UGT1A4-catalyzed trifluoperazine (TFP) glucuronidation were employed to firstly screen the andrographolide derivatives' inhibition potential. High specific inhibition of andrographolide derivatives towards UGT2B7 was observed. The inhibition type and parameters (K{sub i}) were determined for the compounds exhibiting strong inhibition capability towards UGT2B7, and human liver microsome (HLMs)-catalyzed zidovudine (AZT) glucuronidation probe reaction was used to furtherly confirm the inhibition behavior. In combination of inhibition parameters (K{sub i}) and in vivo concentration of andrographolide and dehydroandrographolide, the potential in vivo inhibition magnitude was predicted. Additionally, both the in vitro inhibition data and computational modeling results provide important information for the modification of andrographolide derivatives as selective inhibitors of UGT2B7. Taken together, data obtained from the present study indicated the potential herb–drug interaction between Andrographis paniculata and the drugs mainly undergoing UGT2B7-catalyzed metabolic elimination, and the andrographolide derivatives as potential candidates for the selective inhibitors of UGT2B7. - Highlights: • Specific inhibition of andrographolide derivatives towards UGT2B7. • Herb-drug interaction related withAndrographis paniculata. • Guidance for design of UGT2B7 specific inhibitors.

  2. The glucuronidation of R- and S-lorazepam: human liver microsomal kinetics, UDP-glucuronosyltransferase enzyme selectivity, and inhibition by drugs. (United States)

    Uchaipichat, Verawan; Suthisisang, Chuthamanee; Miners, John O


    The widely used hypnosedative-anxiolytic agent R,S-lorazepam is cleared predominantly by conjugation with glucuronic acid in humans, but the enantioselective glucuronidation of lorazepam has received little attention. The present study characterized the kinetics of the separate R and S enantiomers of lorazepam by human liver microsomes (HLMs) and by a panel of recombinant human UDP-glucuronosyltransferase (UGT) enzymes. Respective mean K(m) and V(max) values for R- and S-lorazepam glucuronidation by HLM were 29 ± 8.9 and 36 ± 10 µM, and 7.4 ± 1.9 and 10 ± 3.8 pmol/min ⋅ mg. Microsomal intrinsic clearances were not significantly different, suggesting the in vivo clearances of R- and S-lorazepam are likely to be similar. Both R- and S-lorazepam were glucuronidated by UGT2B4, 2B7, and 2B15, whereas R-lorazepam was additionally metabolized by the extrahepatic enzymes UGT1A7 and 1A10. Based on in vitro clearances and consideration of available in vivo and in vitro data, UGT2B15 is likely to play an important role in the glucuronidation of R- and S-lorazepam. However, the possible contribution of other enzymes and the low activities observed in vitro indicate that the lorazepam enantiomers are of limited use as substrate probes for UGT2B15. To identify potential drug-drug interactions, codeine, fluconazole, ketamine, ketoconazole, methadone, morphine, valproic acid, and zidovudine were screened as inhibitors of R- and S-lorazepam glucuronidation by HLM. In vitro-in vivo extrapolation suggested that, of these drugs, only ketoconazole had the potential to inhibit lorazepam clearance to a clinically significant extent.

  3. Effects of aqueous extract of Ruta graveolens and its ingredients on cytochrome P450, uridine diphosphate (UDP-glucuronosyltransferase, and reduced nicotinamide adenine dinucleotide (phosphate (NAD(PH-quinone oxidoreductase in mice

    Directory of Open Access Journals (Sweden)

    Yune-Fang Ueng


    Full Text Available Ruta graveolens (the common rue has been used for various therapeutic purposes, including relief of rheumatism and treatment of circulatory disorder. To elucidate the effects of rue on main drug-metabolizing enzymes, effects of an aqueous extract of the aerial part of rue and its ingredients on cytochrome P450 (P450/CYP, uridine diphosphate (UDP-glucuronosyltransferase, and reduced nicotinamide adenine dinucleotide (phosphate (NAD(PH:quinone oxidoreductase were studied in C57BL/6JNarl mice. Oral administration of rue extract to males increased hepatic Cyp1a and Cyp2b activities in a dose-dependent manner. Under a 7-day treatment regimen, rue extract (0.5 g/kg induced hepatic Cyp1a and Cyp2b activities and protein levels in males and females. This treatment increased hepatic UDP-glucuronosyltransferase activity only in males. However, NAD(PH:quinone oxidoreductase activity remained unchanged. Based on the contents of rutin and furanocoumarins of mouse dose of rue extract, rutin increased hepatic Cyp1a activity and the mixture of furanocoumarins (Fmix increased Cyp2b activities in males. The mixture of rutin and Fmix increased Cyp1a and Cyp2b activities. These results revealed that rutin and Fmix contributed at least in part to the P450 induction by rue.


    Directory of Open Access Journals (Sweden)

    Tatsuro Nakamura


    Full Text Available Our previous studies have demonstrated functional protein-protein interactions between cytochrome P450 (CYP 3A and UDP-glucuronosyltransferase (UGT. However, the role of carbohydrate chains of UGTs in the interaction with CYP is not well understood. To address this issue, we examined whether CYP3A1 modulates the function of UGT2B3 which lacks potential glycosylation sites. We also examined whether the introduction of N-glycosylation to UGT2B3 affects CYP3A-dependent modulation of UGT function. To introduce a potential glycosylation site into UGT2B3, Ser 316 of UGT2B3 was substituted with Asn by site-directed mutagenesis. A baculovirus-Sf-9 cell system for expressing CYP3A1 and UGT2B3/UGT2B3(S316N was established using a Bac-to-Bac system. Glycosylation of UGT2B3(S316N was demonstrated in this expression system. The microsomal activity of recombinant UGT was determined using 4-methylumbelliferone as a substrate. The effect of CYP3A1 co-expression on UGT function was examined by comparing the kinetic profiles between single (UGT alone and double expression (UGT plus CYP systems. The kinetics of the two expression systems fitted a Michaelis-Menten equation. When the 4-MU concentration was varied, co-expression of CYP3A1 lowered the Vmax of UGT2B3-mediated conjugation. Conversely, for UGT2B3(S316N, the Vmax in the dual expression system was higher than that in the single expression system. The data obtained demonstrate that the introduction of N-glycosylation to UGT2B3 alters its sensitivity to CYP3A1-dependent modulation while CYP3A1 enhanced UGT2B3(S316N activity, and wild-type UGT2B3 was suppressed by CYP3A1. These data suggest that N-glycosylation of UGT is one of the determinants regulating the interaction between CYP3A and UGT.

  5. Protein kinase Cα and Src kinase support human prostate-distributed dihydrotestosterone-metabolizing UDP-glucuronosyltransferase 2B15 activity. (United States)

    Chakraborty, Sunit K; Basu, Nikhil K; Jana, Sirsendu; Basu, Mousumi; Raychoudhuri, Amit; Owens, Ida S


    Because human prostate-distributed UDP-glucuronosyltransferase (UGT) 2B15 metabolizes 5α-dihydrotestosterone (DHT) and 3α-androstane-5α,17β-diol metabolite, we sought to determine whether 2B15 requires regulated phosphorylation similar to UGTs already analyzed. Reversible down-regulation of 2B15-transfected COS-1 cells following curcumin treatment and irreversible inhibition by calphostin C, bisindolylmaleimide, or röttlerin treatment versus activation by phorbol 12-myristate 13-acetate indicated that 2B15 undergoes PKC phosphorylation. Mutation of three predicted PKC and two tyrosine kinase sites in 2B15 caused 70-100 and 80-90% inactivation, respectively. Anti-UGT-1168 antibody trapped 2B15-His-containing co-immunoprecipitates of PKCα in 130-140- and >150-kDa complexes by gradient SDS-PAGE analysis. Complexes bound to WT 2B15-His remained intact during electrophoresis, whereas 2B15-His mutants at phosphorylation sites differentially dissociated. PKCα siRNA treatment inactivated >50% of COS-1 cell-expressed 2B15. In contrast, treatment of 2B15-transfected COS-1 cells with the Src-specific activator 1,25-dihydroxyvitamin D(3) enhanced activity; treatment with the Src-specific PP2 inhibitor or Src siRNA inhibited >50% of the activity. Solubilized 2B15-His-transfected Src-free fibroblasts subjected to in vitro [γ-(33)P]ATP-dependent phosphorylation by PKCα and/or Src, affinity purification, and SDS gel analysis revealed 2-fold more radiolabeling of 55-58-kDa 2B15-His by PKCα than by Src; labeling was additive for combined kinases. Collectively, the evidence indicates that 2B15 requires regulated phosphorylation by both PKCα and Src, which is consistent with the complexity of synthesis and metabolism of its major substrate, DHT. Whether basal cells import or synthesize testosterone for transport to luminal cells for reduction to DHT by 5α-steroid reductase 2, comparatively low-activity luminal cell 2B15 undergoes a complex pattern of regulated

  6. Cadmium and arsenic override NF-κB developmental regulation of the intestinal UGT1A1 gene and control of hyperbilirubinemia. (United States)

    Liu, Miao; Chen, Shujuan; Yueh, Mei-Fei; Fujiwara, Ryoichi; Konopnicki, Camille; Hao, Haiping; Tukey, Robert H


    Humanized UDP-glucuronosyltransferase (UGT)-1 (hUGT1) mice encode the UGT1 locus including the UGT1A1 gene. During neonatal development, delayed expression of the UGT1A1 gene leads to hyperbilirubinemia as determined by elevated levels of total serum bilirubin (TSB). We show in this report that the redox-sensitive NF-κB pathway is crucial for intestinal expression of the UGT1A1 gene and control of TSB levels. Targeted deletion of IKKβ in intestinal epithelial cells (hUGT1/Ikkβ(ΔIEC) mice) leads to greater neonatal accumulation of TSB than observed in control hUGT1/Ikkβ(F/F) mice. The elevation in TSB levels in hUGT1/Ikkβ(ΔIEC) mice correlates with a reduction in intestinal UGT1A1 expression. As TSB levels accumulate in hUGT1/Ikkβ(ΔIEC) mice during the neonatal period, the increase over that observed in hUGT1/Ikkβ(F/F) mice leads to weight loss, seizures and eventually death. Bilirubin accumulates in brain tissue from hUGT1/Ikkβ(ΔIEC) mice inducing an inflammatory state as shown by elevated TNFα, IL-1β and IL-6, all of which can be prevented by neonatal induction of hepatic or intestinal UGT1A1 and lowering of TSB levels. Altering the redox state of the intestines by oral administration of cadmium or arsenic to neonatal hUGT1/Ikkβ(F/F) and hUGT1/Ikkβ(ΔIEC) mice leads to induction of UGT1A1 and a dramatic reduction in TSB levels. Microarray analysis following arsenic treatment confirms upregulation of oxidation-reduction processes and lipid metabolism, indicative of membrane repair or synthesis. Our findings indicate that the redox state in intestinal epithelial cells during development is important in maintaining UGT1A1 gene expression and control of TSB levels.

  7. In vitro inhibitory effects of non-steroidal anti-inflammatory drugs on 4-methylumbelliferone glucuronidation in recombinant human UDP-glucuronosyltransferase 1A9--potent inhibition by niflumic acid. (United States)

    Mano, Yuji; Usui, Takashi; Kamimura, Hidetaka


    The inhibitory potencies of non-steroidal anti-inflammatory drugs (NSAIDs) on UDP-glucuronosyltransferase (UGT) 1A9 activity were investigated in recombinant human UGT1A9 using 4-methylumbelliferone (4-MU) as a substrate for glucuronidation. 4-MU glucuronidation (4-MUG) showed Michaelis-Menten kinetics with a Km value of 6.7 microM. The inhibitory effects of the following seven NSAIDs were investigated: acetaminophen, diclofenac, diflunisal, indomethacin, ketoprofen, naproxen and niflumic acid. Niflumic acid had the most potent inhibitory effect on 4-MUG with an IC50 value of 0.0341 microM. The IC50 values of diflunisal, diclofenac and indomethacin were 1.31, 24.2, and 34.1 microM, respectively, while acetaminophen, ketoprofen and naproxen showed less potent inhibition. Niflumic acid, diflunisal, diclofenac and indomethacin inhibited 4-MUG competitively with Ki values of 0.0275, 0.710, 53.3 and 69.9 microM, respectively, being similar to each IC50 value. In conclusion, of the seven NSAIDs investigated, niflumic acid was the most potent inhibitor of recombinant UGT1A9 via 4-MUG in a competitive manner.

  8. Exome-Wide Association Study Identifies New Low-Frequency and Rare UGT1A1 Coding Variants and UGT1A6 Coding Variants Influencing Serum Bilirubin in Elderly Subjects: A Strobe Compliant Article. (United States)

    Oussalah, Abderrahim; Bosco, Paolo; Anello, Guido; Spada, Rosario; Guéant-Rodriguez, Rosa-Maria; Chery, Céline; Rouyer, Pierre; Josse, Thomas; Romano, Antonino; Elia, Maurizzio; Bronowicki, Jean-Pierre; Guéant, Jean-Louis


    Genome-wide association studies (GWASs) have identified loci contributing to total serum bilirubin level. However, no exome-wide approaches have been performed to address this question. Using exome-wide approach, we assessed the influence of protein-coding variants on unconjugated, conjugated, and total serum bilirubin levels in a well-characterized cohort of 773 ambulatory elderly subjects from Italy. Coding variants were replicated in 227 elderly subjects from the same area. We identified 4 missense rare (minor allele frequency, MAF bilirubin level (P = 2.34 × 10(-34), P = 7.02 × 10(-34), and P = 8.27 × 10(-34)), as well as unconjugated, and conjugated bilirubin levels. We also identified UGT1A6 variants in association with total (rs6759892, p.Ser7Ala, P = 1.98 × 10(-26); rs2070959, p.Thr181Ala, P = 2.87 × 10(-27); and rs1105879, p.Arg184Ser, P = 3.27 × 10(-29)), unconjugated, and conjugated bilirubin levels. All UGT1A1 intronic variants (rs887829, rs6742078, and rs4148325) and UGT1A6 coding variants (rs6759892, rs2070959, and rs1105879) were significantly associated with gallstone-related cholecystectomy risk. The UGT1A6 variant rs2070959 (p.Thr181Ala) was associated with the highest risk of gallstone-related cholecystectomy (OR, 4.58; 95% CI, 1.58-13.28; P = 3.21 × 10(-3)). Using an exome-wide approach we identified coding variants on UGT1A1 and UGT1A6 genes in association with serum bilirubin level and hyperbilirubinemia risk in elderly subjects. UGT1A1 intronic single-nucleotide polymorphisms (SNPs) (rs6742078, rs887829, rs4148324) serve as proxy markers for the low-frequency and rare UGT1A1 variants, thereby providing mechanistic explanation to the relationship between UGT1A1 intronic SNPs and the UGT1A1 enzyme activity. UGT1A1 and UGT1A6 variants might be potentially associated with gallstone-related cholecystectomy risk.

  9. Bilirubin diglucuronide synthesis by a UDP-glucuronic acid-dependent enzyme system in rat liver microsomes. (United States)

    Blanckaert, N; Gollan, J; Schmid, R


    Incubation of rat liver homogenate or microsomal preparations with bilirubin or bilirubin monoglucuronide with (BMG) resulted in formation of bilirubin diglucuronide (BDG). Both synthesis of BMG and its conversion to BDG were critically dependent on the presence of UDP-glucuronic acid. Pretreatment of the animals with phenobarbital stimulated both reactions. When 33 microM bilirubin was incubated with microsomal preparations from phenobarbital-treated rats, 80-90% of the substrate was converted to bilirubin glucuronides; the reaction products consisted of almost equal amounts of BMG and BDG. When phenobarbital pretreatment was omitted or when the substrate concentration was increased to 164 microM bilirubin, proportionally more BMG and less BDG were formed. Homogenate and microsomes from homozygous Gunn rats neither synthesized BMG nor converted BMG to BDG. These findings in vitro suggest an explanation for the observations in vivo that, in conditions of excess bilirubin load or of genetically decreased bilirubin UDP glucuronosyltransferase (EC activity, proportionally more BMG and less BDG are excreted in bile. PMID:109837

  10. Glucuronidation of odorant molecules in the rat olfactory system: activity, expression and age-linked modifications of UDP-glucuronosyltransferase isoforms, UGT1A6 and UGT2A1, and relation to mitral cell activity. (United States)

    Leclerc, Séverine; Heydel, Jean-Marie; Amossé, Valérie; Gradinaru, Daniela; Cattarelli, Martine; Artur, Yves; Goudonnet, Hervé; Magdalou, Jacques; Netter, Patrick; Pelczar, Hélène; Minn, Alain


    The aim of the present study was to examine the glucuronidation of a series of odorant molecules by homogenates prepared either with rat olfactory mucosa, olfactory bulb or brain. Most of the odorant molecules tested were efficiently conjugated by olfactory mucosa, whereas olfactory bulb and brain homogenates displayed lower activities and glucuronidated only a few molecules. Important age-related changes in glucuronidation efficiency were observed in olfactory mucosa and bulb. Therefore, we studied changes in expression of two UDP-glucuronosyltransferase isoforms, UGT1A6 and UGT2A1, in 1-day, 1- and 2-week-, 3-, 12- and 24-month-old rats. UGT1A6 was expressed at the same transcriptional level in the olfactory mucosa, bulb and brain, throughout the life period studied. UGT2A1 mRNA was expressed in both olfactory mucosa and olfactory bulb, in accordance with previous results [Mol. Brain Res. 90 (2001) 83], but UGT2A1 transcriptional level was 400-4000 times higher than that of UGT1A6. Moreover, age-dependent variations in UGT2A1 mRNA expression were observed. As it has been suggested that drug metabolizing enzymes could participate in olfactory function, mitral cell electrical activity was recorded during exposure to different odorant molecules in young, adult and old animals. Age-related changes in the amplitude of response after stimulation with several odorant molecules were observed, and the highest responses were obtained with molecules that were not efficiently glucuronidated by olfactory mucosa. In conclusion, the present work presents new evidence of the involvement of UGT activity in some steps of the olfactory process.

  11. Estrogen receptor alpha, fos-related antigen-2, and c-Jun coordinately regulate human UDP glucuronosyltransferase 2B15 and 2B17 expression in response to 17beta-estradiol in MCF-7 cells. (United States)

    Hu, Dong Gui; Mackenzie, Peter I


    UDP-glucuronosyltransferase 2B15 and 2B17 expression is up-regulated by 17beta-estradiol in MCF-7 breast cancer cells, as assessed by quantitative real-time polymerase chain reaction. Using 5'-deletion mapping and site-directed mutagenesis, we demonstrate that 17beta-estradiol activation of UGT2B15 gene transcription is mediated by a 282-base pair fragment positioned -454 to -172 nucleotides from the translation start site. This region contains two putative activator protein-1 (AP-1) elements, one imperfect estrogen response element (ERE), and two consensus ERE half-sites. We propose that these five sites act as an estrogen response unit (ERU), because mutation in any site reduces activation of the UGT2B15 promoter by 17beta-estradiol. Despite the presence of two AP-1 elements, the UGT2B15 promoter is not responsive to the AP-1 activator phorbol 12-myristate 13-acetate. Although electrophoretic mobility shift assays (EMSA) indicate that the AP-1 proteins c-Jun and Fos-related antigen 2 (Fra-2) bound to the distal AP-1 site, binding of Jun or Fos family members to the proximal AP-1 site was not detected by EMSA. Chromatin immunoprecipitation assays showed a 17beta-estradiol-induced recruitment of estrogen receptor (ER) alpha, c-Jun, and Fra-2 to the 282-bp ERU. The involvement of these three transcription factors in the stimulation of UGT2B15 gene expression by 17beta-estradiol was confirmed by siRNA silencing experiments. Mutagenesis and siRNA experiments indicate that UGT2B17 expression is also regulated by 17beta-estradiol via the ERU, which is fully conserved in both promoters. Because UGT2B15 and UGT2B17 inactivate steroid hormones by glucuronidation, the regulation of their genes by 17beta-estradiol may maintain steroid hormone homeostasis and prevent excessive estrogen signaling activity.

  12. Differential effect of over-expressing UGT1A1 and CYP1A1 on xenobiotic assault in MCF-7 cells. (United States)

    Leung, Hau Y; Wang, Yun; Leung, Lai K


    Gene mutation has been considered as a major step of carcinogenesis. Some defective genes may induce spontaneous tumorigenesis, while others are required to interact with the environment to induce cancer. CYP1A1 and UGT1A1 are encoded for the respective phase I and II drug-metabolizing enzymes. Their expressions have been associated with breast cancer incidence in women, and some xenobiotics are substrates of these two enzymes. In the current study, cytochrome P450 (CYP) 1A1 and UDP-glucuronosyltransferase (UGT) 1A1 were over-expressed in the breast cancer MCF-7 cells, and potential interactions between these enzymes and estrogen or polycyclic aromatic hydrocarbon were evaluated. Compared with control cells (MCF-7(VEC)), reduced cell proliferation was seen in cells expressing UGT1A1 (MCF-7(UGT1A1)) under estradiol treatment. 7,12-Dimethylbenz[a]anthracene (DMBA) is an established breast cancer initiator in animal model. Over-expressing UGT1A1 reduced the binding of DMBA to DNA, and increased MCF-7(UGT1A1) intact cells under DMBA treatment was verified by comet assay. On the other hand, intensified DMBA binding and damages were observed in MCF-7(CYP1A1) cells. This study supported that UGT1A1 but not CYP1A1 expression could protect against xenobiotic assault.

  13. In vitro glucuronidation of Armillarisin A: UDP-glucuronosyltransferase 1A9 acts as a major contributor and significant species differences. (United States)

    Sun, Dongxue; Zhu, Liangliang; Xiao, Ling; Xia, Yangliu; Ge, Guangbo; Cao, Yunfeng; Wu, Yan; Yin, Jun; Yang, Ling


    1. This study is performed to investigate liver microsomal glucuronidation of Armillarisin A (A.A), an effective cholagogue drug, aiming at characterizing the involved UDP-glucuronosyltranferases (UGT) and revealing potential species differences. 2. A.A glucuronidation in human liver microsomes (HLM) generates one metabolite (M2) glucuronidated at the phenol hydroxyl group, obeying Michaelis-Menten kinetic model. Multiple isoforms including UGT1A1, 1A7, 1A9 and 2B15 can catalyze A.A glucuronidation. Kinetic assays and chemical inhibition studies both demonstrate that UGT1A9 is responsible for A.A glucuronidation in HLM. A.A glucuronidation in Cynomolgus monkey microsomes (CyLM) also follows Michaelis-Menten model, but can additionally catalyze the traced glucuronosyl substitution at the alcohol hydroxyl group (M1). The reactions in liver microsomes from Sprague-Dawley rats (RLM), ICR/CD-1 mouse (MLM), Beagle dog (DLM) all display biphasic kinetics and only M2 is detected. HLM, RLM and CyLM exhibit very similar catalytic activities towards A.A glucuronidation, with the intrinsic clearance values of respective 38, 37 and 37 μL/min/mg, which are much higher than MLM and DLM. 3. This in vitro study indicates that UGT1A9 acts as a major contributor to A.A glucuronidation in human liver, and the reaction displays large species differences.

  14. Bilirubin - urine (United States)

    Conjugated bilirubin - urine; Direct bilirubin - urine ... Bilirubin is not normally found in the urine. ... Increased levels of bilirubin in the urine may be due to: Biliary tract disease Cirrhosis Gallstones in the biliary tract Hepatitis Liver disease ...

  15. Bilirubin Test (United States)

    ... than females. African Americans routinely show lower bilirubin concentrations than non-African Americans. Strenuous exercise may increase bilirubin levels. Drugs that can decrease total bilirubin include barbiturates, caffeine, penicillin, and high doses of salicylates. The drug ...

  16. A humanized UGT1 mouse model expressing the UGT1A1*28 allele for assessing drug clearance by UGT1A1-dependent glucuronidation. (United States)

    Cai, Hongliang; Nguyen, Nghia; Peterkin, Vincent; Yang, Young-Sun; Hotz, Kathy; La Placa, Deirdre Beaton; Chen, Shujuan; Tukey, Robert H; Stevens, Jeffrey C


    Humanized mice that express the human UDP-glucuronosyltransferase (UGT) 1 locus have been developed in a Ugt1-null background as a model to improve predictions of human UGT1A-dependent drug clearance. Enzyme kinetic parameters (K(m) and V(max)) and pharmacokinetic properties of three probe drugs were compared using wild-type and humanized UGT1 mice that express the Gilbert's UGT1A1*28 allele [Tg(UGT1(A1*28)) Ugt1(-/-) mice]. The well characterized substrate for UGT1A1, 7-ethyl-10-hydroxy-camptothecin (SN-38), showed the greatest difference in parent drug exposure ( approximately 3-fold increase) and clearance ( approximately 3-fold decrease) in Tg(UGT1(A1*28)) Ugt1(-/-) mice after intravenous administration compared with wild-type and phenobarbital-treated animals. In contrast, the clearance of the UGT2B7 substrate (-)-17-allyl-4, 5alpha-epoxy-3, 14-dihydroxymorphinan-6-one (naloxone) was not altered in Tg(UGT1(A1*28)) Ugt1(-/-) mice. In addition, pharmacokinetic parameters with 1-(4-fluorophenyl)3(R)-[3-(4-fluorophenyl)-3(S)-hydroxypropyl]-4(S)-(4-hydroxyphenyl)-2-azetidinone (ezetimibe, Zetia; Merck & Co., Whitehouse Station, NJ), considered to be a major substrate for UGT1A1, showed small to no dependence on UGT1A1-directed glucuronidation. Enzyme kinetic parameters assessed for SN-38, ezetimibe, and naloxone using liver microsomes prepared from wild-type and Tg(UGT1(A1*28)) Ugt1(-/-) mice showed patterns consistent with the in vivo pharmacokinetic data. For SN-38 glucuronidation, V(max) decreased 5-fold in Tg(UGT1(A1*28)) Ugt1(-/-) mouse liver microsomes compared with microsomes prepared from wild-type mice, and decreased 10-fold compared with phenobarbital-treated Tg(UGT1(A1*28)) Ugt1(-/-) mice. These differences are consistent with SN-38 glucuronidation activities using HLMs isolated from individuals genotyped as UGT1A1*1 or UGT1A1*28. For ezetimibe and naloxone the differences in V(max) were minimal. Thus, Tg(UGT1(A1*28)) Ugt1(-/-) mice can serve as a

  17. Raloxifene glucuronidation in liver and intestinal microsomes of humans and monkeys: contribution of UGT1A1, UGT1A8 and UGT1A9. (United States)

    Kishi, Naoki; Takasuka, Akane; Kokawa, Yuki; Isobe, Takashi; Taguchi, Maho; Shigeyama, Masato; Murata, Mikio; Suno, Manabu; Hanioka, Nobumitsu


    1. Raloxifene is an antiestrogen that has been marketed for the treatment of osteoporosis, and is metabolized into 6- and 4'-glucuronides by UDP-glucuronosyltransferase (UGT) enzymes. In this study, the in vitro glucuronidation of raloxifene in humans and monkeys was examined using liver and intestinal microsomes and recombinant UGT enzymes (UGT1A1, UGT1A8 and UGT1A9). 2. Although the K(m) and CL(int) values for the 6-glucuronidation of liver and intestinal microsomes were similar between humans and monkeys, and species differences in Vmax values (liver microsomes, humans > monkeys; intestinal microsomes, humans monkeys) were observed, no significant differences were noted in the K(m) or S50, Vmax and CL(int) or CLmax values for the 4'-glucuronidation of liver and intestinal microsomes between humans and monkeys. 3. The activities of 6-glucuronidation in recombinant UGT enzymes were UGT1A1 > UGT1A8 >UGT1A9 for humans, and UGT1A8 > UGT1A1 > UGT1A9 for monkeys. The activities of 4'-glucuronidation were UGT1A8 > UGT1A1 > UGT1A9 in humans and monkeys. 4. These results demonstrated that the profiles for the hepatic and intestinal glucuronidation of raloxifene by microsomes were moderately different between humans and monkeys.

  18. Nrf2-Keap1 signaling pathway regulates human UGT1A1 expression in vitro and in transgenic UGT1 mice. (United States)

    Yueh, Mei-Fei; Tukey, Robert H


    The formation of beta-D-glucopyranosides (glucuronides) by the UDP-glucuronosyltransferases (UGTs) is a significant metabolic pathway that facilitates the elimination of small hydrophobic molecules such as drugs, dietary constituents, steroids, and bile acids. We elucidate here that an anti-oxidative response leads to induction of UGT1A1 through the Nrf2-Keap1 pathway. When human HepG2 cells were treated with the prooxidants tert-butylhydroquinone and beta-naphthoflavone, cellular UGT1A1 glucuronidation activities were increased. The induction of UGT1A1 proceeded following the overexpression of Nrf2 and was blocked following overexpression of Keap1, demonstrating that Keap1 suppresses Nrf2 activation of the UGT1A1 gene. Loss of function analysis for Nrf2 conducted by small interfering RNA revealed that induction of UGT1A1 was not seen in Nrf2 knock-out cells. To examine the contribution of oxidants toward the regulation of human UGT1A1 in vivo, transgenic mice bearing the human UGT1 locus (Tg-UGT1) were treated with tert-butylhydroquinone. Human UGT1A1 was markedly increased in small and large intestines as well as in liver. Gene mapping experiments including transfections of UGT1A1 reporter gene constructs into HepG2 cells coupled with functional analysis of Nrf2 expression and binding to anti-oxidant-response elements (ARE) resulted in identification of an ARE in the phenobarbital-response enhancer module region of the UGT1A1 gene. The ARE flanks the recently identified Ah receptor xenobiotic-responsive element. The results suggest that Nrf2-Keap1-dependent UGT1A1 induction by prooxidants might represent a key adaptive response to cellular oxidative stress that defends against a variety of environmental insults, including electrophile attacks and chemical carcinogenesis.

  19. Sulfation of fulvestrant by human liver cytosols and recombinant SULT1A1 and SULT1E1

    Directory of Open Access Journals (Sweden)

    Edavana VK


    Full Text Available Vineetha Koroth Edavana1, Xinfeng Yu1, Ishwori B Dhakal1, Suzanne Williams1, Baitang Ning2, Ian T Cook3, David Caldwell1, Charles N Falany3, Susan Kadlubar11Division of Medical Genetics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, USA; 2Division of Personalized Nutrition and Medicine, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, USA; 3Department of Pharmacology, University of Alabama, Birmingham, AL, USAAbstract: Fulvestrant (Faslodex™ is a pure antiestrogen that is approved to treat hormone receptor-positive metastatic breast cancer in postmenopausal women. Previous studies have demonstrated that fulvestrant metabolism in humans involves cytochromes P450 and UDP-glucuronosyltransferases (UGTs. To date, fulvestrant sulfation has not been characterized. This study examined fulvestrant sulfation with nine recombinant sulfotransferases and found that only SULT1A1 and SULT1E1 displayed catalytic activity toward this substrate, with Km of 4.2 ± 0.99 and 0.2 ± 0.16 µM, respectively. In vitro assays of 104 human liver cytosols revealed marked individual variability that was highly correlated with β-naphthol sulfation (SULT1A1 diagnostic substrate; r = 0.98, P < 0.0001, but not with 17ß-estradiol sulfation (SULT1E1 diagnostic substrate; r = 0.16, P = 0.10. Fulvestrant sulfation was correlated with both SULT1A1*1/2 genotype (P value = 0.023 and copy number (P < 0.0001. These studies suggest that factors influencing SULT1A1/1E1 tissue expression and/or enzymatic activity could influence the efficacy of fulvestrant therapy.Keywords: fulvestrant, sulfotransferase, genotype, copy number

  20. Cold stress initiates the Nrf2/UGT1A1/L-FABP signaling pathway in chickens. (United States)

    Chen, X Y; Li, R; Geng, Z Y


    Cold stress triggers an anti-oxidative response in animals regulated by Nrf2 (nuclear factor 2-like, NFE2L2) binding to deoxyribonucleic acid-regulatory sequences near stress-responsive genes. To identify chicken Nrf2-regulated genes, 3 genetically related experimental groups (EG) with 40 Huainan partridge chickens in each group were chosen. The chickens were maintained at 20°C environmental temperature from 5 wk of age. At 6 wk of age, 10 chickens from each EG were still maintained at 20°C as control, and the other 30 chickens from each EG were exposed to 6 ± 2°C. Liver samples were collected from the control and from chickens exposed to 6 ± 2°C for 12, 24, and 72 h for co-immuno-precipitation (CoIP) analysis. Chromatin immunoprecipitation (ChIP)-sequencing experiment in liver cells treated with Dimethyl fumarate (DMF) were carried out. A de novo motif was discovered which closely matched the core Nrf2 consensus binding motif. Genes involved in de novo motif discovery were further analyzed for their enrichment in the anti-oxidative response pathway and the lipid anabolism pathway. There were 14 genes found which are related to oxidative stress. To examine the downstream factors of the 14 responsive genes, one of them, UGT1A1 (UDP glucuronosyltransferase), was further analyzed by CoIP experiment and nano LC-ESI-MS/MS analysis. It was detected that fatty acid-binding protein (L-FABP, 127 AA) might be the potential UGT1A1 downstream interaction proteins. In conclusion, it is proposed that chickens under cold stress generate anti-oxidative stress and thus trigger the Nrf2/ARE signaling pathway, which further up-regulates the expression of L-FABP to inactivate lipid peroxidation of the cell membrane and promote fatty acid storage against the cold environment.

  1. Blood Test: Bilirubin (United States)

    ... Your 1- to 2-Year-Old Blood Test: Bilirubin KidsHealth > For Parents > Blood Test: Bilirubin A A A What's in this article? What ... Análisis de sangre: bilirrubina What It Is A bilirubin test measures the level of bilirubin (a byproduct ...

  2. The UGT1A1* allele and disease in childhood

    DEFF Research Database (Denmark)

    Padkær Petersen, Jesper

    Baggrund: Bilirubin er slutproduktet i hæms metabolisme. Ukonjugeret bilirubin er neuro-toksisk, men også en potent antioxidant af mulig klinisk relevans. Fortolkningen af observationelle bilirubin studier vanskeliggøres af potentiel revers kausalitet og adskillige tænkelige confoundere. En måde...... at adressere disse udfordringer på er at benytte UGT1A1*28 allelen som instrument variabel for bilirubin. Denne genetiske variation forklarer 18 % af alle variationer i serum bilirubin i kaukasiske populationer. Det er foreslået at UGT1A1*28 er en beskyttende antioxidativ genetisk adaptation, men den har også...... var UGT1A1*28 genotyper ikke associeret til akut respiratorisk sygdom, men en risikofaktor for varighed af respiratorisk sygdom Konklusion: Den manglende association mellem UGT1A1*28 genotyper og ALL hos børn indikerer at bilirubin ikke har nogen beskyttende antioxidant effekt mod denne sygdom. Den...

  3. Biology of Bilirubin Photoisomers. (United States)

    Hansen, Thor Willy Ruud


    Phototherapy is the main treatment for neonatal hyperbilirubinemia. In acute treatment of extreme hyperbilirubinemia, intensive phototherapy may have a role in 'detoxifying' the bilirubin molecule to more polar photoisomers, which should be less prone to crossing the blood-brain barrier, providing a 'brain-sparing' effect. This article reviews the biology of bilirubin isomers. Although there is evidence supporting the lower toxicity of bilirubin photoisomers, there are studies showing the opposite. There are methodologic weaknesses in most studies and better-designed experiments are needed. In an infant acutely threatened by bilirubin-induced brain damage, intensified phototherapy should be used expediently and aggressively.

  4. Bilirubin oxidation in brain. (United States)

    Hansen, T W


    Bilirubin is a product of heme catabolism which by virtue of its lipid solubility can cross the blood-brain barrier and enter the brain. Neonatal jaundice is a common transitional phenomenon which is due to the combination of increased heme catabolism and rate limitations as far as hepatic conjugation and biliary excretion of bilirubin. In the great majority of cases this is an innocuous condition, which is even posited to have some beneficial effects due to the ability of bilirubin to quench free oxygen radicals. However, because bilirubin is neurotoxic, hyperbilirubinemia in the newborn may exceptionally result in death in the neonatal period, or survival with severe neurological sequelae (kernicterus). Bilirubin enters the brain through an intact blood-brain barrier. Clearance of bilirubin from brain partly involves retro-transfer through the blood-brain barrier, and possibly also through the brain-CSF barrier into CSF. Work in our lab during the past 5 years has substantiated earlier work which had suggested that bilirubin may also be metabolized in brain. The responsible enzyme is found on the inner mitochondrial membrane, and oxidizes bilirubin at a rate of 100-300 pmol bilirubin/mg protein/minute. The enzyme activity is lower in the newborn compared with the mature animal, and is also lower in neurons compared with glia. Studies of different rat strains have documented genetic variability. The enzyme is cytochrome-c-dependent, but has as yet not been unequivocally identified. The rate of oxidation of bilirubin is such that this enzyme probably contributes meaningfully to the clearance of bilirubin from brain.

  5. Bilirubin measurements in neonates (United States)

    Newman, Gregory J.


    Infant Jaundice is a physiologic condition of elevated bilirubin in the tissue that affects nearly 60 percent of all term newborns and virtually 100 percent of premature infants. The high production of bilirubin in the newborn circulatory system and the inability of the immature liver to process and eliminate it case the condition. When the bilirubin levels rise, it starts to deposit in the baby's skin and in the brain. The deposits in the brain can cause neurologic impairment and death. The BiliCheck is a handheld, battery-powered device that measures the level of jaundice non-invasively using BioPhotonics at the point of care. The result is displayed on an LCD screen immediately, so physicians can now make treatment decision without waiting for results to return from the lab. The BiliCheck System has been marketed worldwide since April of 1998 and has received FDA clearance for use in the USA on pre-photo therapy infants in March of 1999.

  6. Serum bilirubin levels, polymorphisms and risk for coronary artery disease


    Lingenhel, Arno; Kollerits, Barbara; Johannes P. Schwaiger; Hunt, Steven C.; Gress, Richard; Hopkins, Paul N.; Schoenborn, Veit; Heid, Iris M; Kronenberg, Florian


    Serum bilirubin levels, UGT1A1 polymorphisms and risk for coronary artery disease correspondence: Corresponding author. Tel.: +43 512 9003 70560; fax: +43 512 9003 73560. (Kronenberg, Florian) (Kronenberg, Florian) Division of Genetic Epidemiology; Department of Medical Genetics, Molecular and Clinical Pharmacology; Innsbruck Medical University - AUSTRIA (Lingenhel, Arno) Division of Genetic Epidemiology; Depa...

  7. Bilirubin-albumin binding, bilirubin/albumin ratios, and free bilirubin levels : Where do we stand?

    NARCIS (Netherlands)

    Hulzebos, Christian V.; Dijk, Peter H.


    Treatment for unconjugated hyperbilirubinemia is predominantly based on one parameter, i.e., total serum bilirubin (TSB) levels. Yet, overt kernicterus has been reported in preterm infants at relatively low TSB levels, and it has been repeatedly shown that free unconjugated bilirubin (freeUCB) level

  8. Susceptibility to Exposure to Heterocyclic Amines from Cooked Food: Role of UDP-glucuronosyltransferases

    Energy Technology Data Exchange (ETDEWEB)

    Malfatti, M A; Felton, J S


    A number of carcinogenic heterocyclic amines (PhIP, MeIQx, and DiMeIQx) are produced from the condensation of creatinine, hexoses and amino acids during the cooking of meat (1). There are many variables that impact the production and subsequent ingestion of these compounds in our diet. Temperature, type of meat product, cooking method, doneness, and other factors affect the quantity of these carcinogens consumed by humans. Estimates of ingestion of these carcinogens are 1-20 ng/kg body weight per day (2). Human case control studies that correlate meat consumption from well-done cooking practices with cancer incidence indicate excess tumors for breast, colon, stomach, esophagus, and possibly prostate (3-5).

  9. Effects of dietary anticarcinogens and nonsteroidal anti-inflammatory drugs on rat gastrointestinal UDP-glucuronosyltransferases.

    NARCIS (Netherlands)

    Logt, E.M.J. van der; Roelofs, H.M.J.; Lieshout, E.M.M. van; Nagengast, F.M.; Peters, W.H.M.


    BACKGROUND: Dietary compounds or nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce cancer rates. Elevation of phase II detoxification enzymes might be one of the mechanisms leading to cancer prevention. We investigated the effects of dietary anticarcinogens and NSAIDs on rat gastrointestinal

  10. Optimized UDP-glucuronosyltransferase (UGT) activity assay for trout liver S9 fractions (United States)

    U.S. Environmental Protection Agency — This publication provides an optimized UGT assay for trout liver S9 fractions which can be used to perform in vitro-in vivo extrapolations of measured UGT activity....

  11. The Biological Effects of Bilirubin Photoisomers. (United States)

    Jasprova, Jana; Dal Ben, Matteo; Vianello, Eleonora; Goncharova, Iryna; Urbanova, Marie; Vyroubalova, Karolina; Gazzin, Silvia; Tiribelli, Claudio; Sticha, Martin; Cerna, Marcela; Vitek, Libor


    Although phototherapy was introduced as early as 1950's, the potential biological effects of bilirubin photoisomers (PI) generated during phototherapy remain unclear. The aim of our study was to isolate bilirubin PI in their pure forms and to assess their biological effects in vitro. The three major bilirubin PI (ZE- and EZ-bilirubin and Z-lumirubin) were prepared by photo-irradiation of unconjugated bilirubin. The individual photoproducts were chromatographically separated (TLC, HPLC), and their identities verified by mass spectrometry. The role of Z-lumirubin (the principle bilirubin PI) on the dissociation of bilirubin from albumin was tested by several methods: peroxidase, fluorescence quenching, and circular dichroism. The biological effects of major bilirubin PI (cell viability, expression of selected genes, cell cycle progression) were tested on the SH-SY5Y human neuroblastoma cell line. Lumirubin was found to have a binding site on human serum albumin, in the subdomain IB (or at a close distance to it); and thus, different from that of bilirubin. Its binding constant to albumin was much lower when compared with bilirubin, and lumirubin did not affect the level of unbound bilirubin (Bf). Compared to unconjugated bilirubin, bilirubin PI did not have any effect on either SH-SY5Y cell viability, the expression of genes involved in bilirubin metabolism or cell cycle progression, nor in modulation of the cell cycle phase. The principle bilirubin PI do not interfere with bilirubin albumin binding, and do not exert any toxic effect on human neuroblastoma cells.

  12. Quantitative imaging of bilirubin by photoacoustic microscopy (United States)

    Zhou, Yong; Zhang, Chi; Yao, Da-Kang; Wang, Lihong V.


    Noninvasive detection of both bilirubin concentration and its distribution is important for disease diagnosis. Here we implemented photoacoustic microscopy (PAM) to detect bilirubin distribution. We first demonstrate that our PAM system can measure the absorption spectra of bilirubin and blood. We also image bilirubin distributions in tissuemimicking samples, both without and with blood mixed. Our results show that PAM has the potential to quantitatively image bilirubin in vivo for clinical applications.

  13. Bilirubin-albumin binding, bilirubin/albumin ratios, and free bilirubin levels: where do we stand? (United States)

    Hulzebos, Christian V; Dijk, Peter H


    Treatment for unconjugated hyperbilirubinemia is predominantly based on one parameter, i.e., total serum bilirubin (TSB) levels. Yet, overt kernicterus has been reported in preterm infants at relatively low TSB levels, and it has been repeatedly shown that free unconjugated bilirubin (freeUCB) levels, or bilirubin/albumin (B/A) ratios for that matter, are more closely associated with bilirubin neurotoxicity. In this article, we review bilirubin-albumin binding, UCBfree levels, and B/A ratios in addition to TSB levels to individualize and optimize treatment especially in preterm infants. Methods to measure bilirubin-albumin binding or UCBfree are neither routinely performed in Western clinical laboratories nor incorporated in current management guidelines on unconjugated hyperbilirubinemia. For bilirubin-albumin binding, this seems justified because several of these methods have been challenged, and sufficiently powered prospective trials on the clinical benefits are lacking. Technological advances in the measurement of UCBfree may provide a convenient means for integrating UCBfree measurements into routine clinical management of jaundiced infants. A point-of-care method, as well as determination of UCBfree levels in various newborn populations, is desirable to learn more about variations in time and how various clinical pathophysiological conditions affect UCBfree levels. This will improve the estimation of approximate UCBfree levels associated with neurotoxicity. To delineate the role of UCBfree in the management of jaundiced (preterm) infants, trials are needed using UCBfree as treatment parameter. The additional use of the B/A ratio in jaundiced preterms has been evaluated in the Bilirubin Albumin Ratio Trial (BARTrial; Clinical Trials: ISRCTN74465643) but failed to demonstrate better neurodevelopmental outcome in preterm infants bilirubin toxicity. Yet, different methodologies for estimating these parameters exist, and sufficiently powered, prospective clinical

  14. Photoacoustic microscopy of bilirubin in tissue phantoms (United States)

    Zhou, Yong; Zhang, Chi; Yao, Da-Kang; Wang, Lihong V.


    Determining both bilirubin's concentration and its spatial distribution are important in disease diagnosis. Here, for the first time, we applied quantitative multiwavelength photoacoustic microscopy (PAM) to detect bilirubin concentration and distribution simultaneously. By measuring tissue-mimicking phantoms with different bilirubin concentrations, we showed that the root-mean-square error of prediction has reached 0.52 and 0.83 mg/dL for pure bilirubin and for blood-mixed bilirubin detection (with 100% oxygen saturation), respectively. We further demonstrated the capability of the PAM system to image bilirubin distribution both with and without blood. Finally, by underlaying bilirubin phantoms with mouse skins, we showed that bilirubin can be imaged with consistent accuracy down to >400 μm in depth. Our results show that PAM has potential for noninvasive bilirubin monitoring in vivo, as well as for further clinical applications.

  15. The Biological Effects of Bilirubin Photoisomers.

    Directory of Open Access Journals (Sweden)

    Jana Jasprova

    Full Text Available Although phototherapy was introduced as early as 1950's, the potential biological effects of bilirubin photoisomers (PI generated during phototherapy remain unclear. The aim of our study was to isolate bilirubin PI in their pure forms and to assess their biological effects in vitro. The three major bilirubin PI (ZE- and EZ-bilirubin and Z-lumirubin were prepared by photo-irradiation of unconjugated bilirubin. The individual photoproducts were chromatographically separated (TLC, HPLC, and their identities verified by mass spectrometry. The role of Z-lumirubin (the principle bilirubin PI on the dissociation of bilirubin from albumin was tested by several methods: peroxidase, fluorescence quenching, and circular dichroism. The biological effects of major bilirubin PI (cell viability, expression of selected genes, cell cycle progression were tested on the SH-SY5Y human neuroblastoma cell line. Lumirubin was found to have a binding site on human serum albumin, in the subdomain IB (or at a close distance to it; and thus, different from that of bilirubin. Its binding constant to albumin was much lower when compared with bilirubin, and lumirubin did not affect the level of unbound bilirubin (Bf. Compared to unconjugated bilirubin, bilirubin PI did not have any effect on either SH-SY5Y cell viability, the expression of genes involved in bilirubin metabolism or cell cycle progression, nor in modulation of the cell cycle phase. The principle bilirubin PI do not interfere with bilirubin albumin binding, and do not exert any toxic effect on human neuroblastoma cells.

  16. Disease: H00208 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available H00208 Hyperbilirubinemia; Crigler-Najjar syndrome, type I (CN1); Crigler-Najjar sy...dromes result in unconjugated hyperbilirubinemia caused by deficiency of which is involved in the detoxification of bilirubin by conjugation with glucu...ronic acid. Gilbert disease is a benign familial disorder characterized by low-grade chronic hyperbilirubine...sta E Hematologically important mutations: bilirubin UDP-glucuronosyltransferase gene mutations in Gilbert a

  17. Bilirubin Binding to PPARα Inhibits Lipid Accumulation. (United States)

    Stec, David E; John, Kezia; Trabbic, Christopher J; Luniwal, Amarjit; Hankins, Michael W; Baum, Justin; Hinds, Terry D


    Numerous clinical and population studies have demonstrated that increased serum bilirubin levels protect against cardiovascular and metabolic diseases such as obesity and diabetes. Bilirubin is a potent antioxidant, and the beneficial actions of moderate increases in plasma bilirubin have been thought to be due to the antioxidant effects of this bile pigment. In the present study, we found that bilirubin has a new function as a ligand for PPARα. We show that bilirubin can bind directly to PPARα and increase transcriptional activity. When we compared biliverdin, the precursor to bilirubin, on PPARα transcriptional activation to known PPARα ligands, WY 14,643 and fenofibrate, it showed that fenofibrate and biliverdin have similar activation properties. Treatment of 3T3-L1 adipocytes with biliverdin suppressed lipid accumulation and upregulated PPARα target genes. We treated wild-type and PPARα KO mice on a high fat diet with fenofibrate or bilirubin for seven days and found that both signal through PPARα dependent mechanisms. Furthermore, the effect of bilirubin on lowering glucose and reducing body fat percentage was blunted in PPARα KO mice. These data demonstrate a new function for bilirubin as an agonist of PPARα, which mediates the protection from adiposity afforded by moderate increases in bilirubin.

  18. Usefulness of the bilirubin/albumin ratio for predicting bilirubin-induced neurotoxicity in premature infants

    NARCIS (Netherlands)

    Hulzebos, C. V.; van Imhoff, D. E.; Bos, A. F.; Ahlfors, C. E.; Verkade, H. J.; Dijk, P. H.


    Unconjugated hyperbilirubinaemia occurs in almost all premature infants and is potentially neurotoxic. Treatment is based on total serum bilirubin (TSB), but treatment thresholds are not evidence based. Free bilirubin (Bf) - that is, not bound to albumin, seems a better parameter for bilirubin neuro

  19. Functionalized SBA-15 materials for bilirubin adsorption (United States)

    Tang, Tao; Zhao, Yanling; Xu, Yao; Wu, Dong; Xu, Jun; Deng, Feng


    To investigate the driving force for bilirubin adsorption on mesoporous materials, a comparative study was carried out between pure siliceous SBA-15 and three functionalized SBA-15 mesoporous materials: CH 3-SBA-15 (MS), NH 2-SBA-15 (AS), and CH 3/NH 2-SBA-15 (AMS) that were synthesized by one-pot method. The obtained materials exhibited large surface areas (553-810 m 2/g) and pore size (6.6-7.1 nm) demonstrated by XRD and N 2-ad/desorption analysis. The SEM images showed that the materials had similar fiberlike morphology. The functionalization extent was calculated according to 29Si MAS NMR spectra and it was close to the designed value (10%). The synthesized mesoporous materials were used as bilirubin adsorbents and showed higher bilirubin adsorption capacities than the commercial active carbon. The adsorption capacities of amine functionalized samples AMS and AS were larger than those of pure siliceous SBA-15 and MS, indicating that electrostatic interaction was the dominant driving force for bilirubin adsorption on mesoporous materials. Increasing the ionic strength of bilirubin solution by adding NaCl would decrease the bilirubin adsorption capacity of mesoporous material, which further demonstrated that the electrostatic interaction was the dominant driving force for bilirubin adsorption. In addition, the hydrophobic interaction provided by methyl groups could promote the bilirubin adsorption.

  20. A genome-wide association study of total bilirubin and cholelithiasis risk in sickle cell anemia.

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    Jacqueline N Milton

    Full Text Available Serum bilirubin levels have been associated with polymorphisms in the UGT1A1 promoter in normal populations and in patients with hemolytic anemias, including sickle cell anemia. When hemolysis occurs circulating heme increases, leading to elevated bilirubin levels and an increased incidence of cholelithiasis. We performed the first genome-wide association study (GWAS of bilirubin levels and cholelithiasis risk in a discovery cohort of 1,117 sickle cell anemia patients. We found 15 single nucleotide polymorphisms (SNPs associated with total bilirubin levels at the genome-wide significance level (p value <5 × 10(-8. SNPs in UGT1A1, UGT1A3, UGT1A6, UGT1A8 and UGT1A10, different isoforms within the UGT1A locus, were identified (most significant rs887829, p = 9.08 × 10(-25. All of these associations were validated in 4 independent sets of sickle cell anemia patients. We tested the association of the 15 SNPs with cholelithiasis in the discovery cohort and found a significant association (most significant p value 1.15 × 10(-4. These results confirm that the UGT1A region is the major regulator of bilirubin metabolism in African Americans with sickle cell anemia, similar to what is observed in other ethnicities.

  1. Glucuronidation of drugs in humanized UDP-glucuronosyltransferase 1 mice: Similarity with glucuronidation in human liver microsomes. (United States)

    Kutsuno, Yuki; Sumida, Kyohei; Itoh, Tomoo; Tukey, Robert H; Fujiwara, Ryoichi


    Uridine 5'-diphosphate-glucuronosyltransferases (UGTs) are phase II drug-metabolizing enzymes that catalyze glucuronidation of various endogenous and exogenous substrates. Among 19 functional human UGTs, UGT1A family enzymes largely contribute to the metabolism of clinically used drugs. While the UGT1A locus is conserved in mammals such as humans, mice, and rats, species differences in drug glucuronidation have been reported. Recently, humanized UGT1 mice in which the original Ugt1 locus was disrupted and replaced with the human UGT1 locus (hUGT1 mice) have been developed. To evaluate the usefulness of hUGT1 mice to predict human glucuronidation of drugs, UGT activities, and inhibitory effects on UGTs were examined in liver microsomes of hUGT1 mice as well as in those of wild-type mice and humans. Furosemide acyl-glucuronidation was sigmoidal and best fitted to the Hill equation in hUGT1 mice and human liver microsomes, while it was fitted to the substrate inhibition equation in mouse liver microsomes. Kinetic parameters of furosemide glucuronidation were very similar between hUGT1 mice and human liver microsomes. The kinetics of S-naproxen acyl-glucuronidation and inhibitory effects of compounds on furosemide glucuronidation in hUGT1 liver microsomes were also slightly, but similar to those in human liver microsomes, rather than in wild-type mice. While wild-type mice lack imipramine and trifluoperazine N-glucuronidation potential, hUGT1 mice showed comparable N-glucuronidation activity to that of humans. Our data indicate that hUGT1 mice are promising tools to predict not only in vivo human drug glucuronidation but also potential drug-drug interactions.

  2. Effect of the beta-glucuronidase inhibitor saccharolactone on glucuronidation by human tissue microsomes and recombinant UDP-glucuronosyltransferases. (United States)

    Oleson, Lauren; Court, Michael H


    Glucuronidation studies using microsomes and recombinant uridine diphosphoglucuronosyltransferases (UGTs) can be complicated by the presence of endogenous beta-glucuronidases, leading to underestimation of glucuronide formation rates. Saccharolactone is the most frequently used beta-glucuronidase inhibitor, although it is not clear whether this reagent should be added routinely to glucuronidation incubations. Here we have determined the effect of saccharolactone on eight different UGT probe activities using pooled human liver microsomes (pHLMs) and recombinant UGTs (rUGTs). Despite the use of buffered incubation solutions, it was necessary to adjust the pH of saccharolactone solutions to avoid effects (enhancement or inhibition) of lowered pH on UGT activity. Saccharolactone at concentrations ranging from 1 to 20 mM did not enhance any of the glucuronidation activities evaluated that could be considered consistent with inhibition of beta-glucuronidase. However, for most activities, higher saccharolactone concentrations resulted in a modest degree of inhibition. The greatest inhibitory effect was observed for glucuronidation of 5-hydroxytryptamine and estradiol by pHLMs, with a 35% decrease at 20 mM saccharolactone concentration. Endogenous beta-glucuronidase activities were also measured using various human tissue microsomes and rUGTs with estradiol-3-glucuronide and estradiol-17-glucuronide as substrates. Glucuronide hydrolysis was observed for pHLMs, lung microsomes and insect-cell expressed rUGTs, but not for kidney, intestinal or human embryonic kidney HEK293 microsomes. However, the extent of hydrolysis was relatively small, representing only 9-19% of the glucuronide formation rate measured in the same preparations. Consequently, these data do not support the routine inclusion of saccharolactone in glucuronidation incubations. If saccharolactone is used, concentrations should be titrated to achieve activity enhancement without inhibition.

  3. Bilirubin Oxidase Activity of Bacillus subtilis CotA


    Sakasegawa, S; Ishikawa, H.; Imamura, S.; Sakuraba, H.; Goda, S.; Ohshima, T.


    The spore coat protein CotA from Bacillus subtilis was previously identified as a laccase. We have now found that CotA also shows strong bilirubin oxidase activity and markedly higher affinity for bilirubin than conventional bilirubin oxidase. This is the first characterization of bilirubin oxidase activity in a bacterial protein.

  4. Intermolecular interactions in the bilirubin-cholate-silica system (United States)

    Vlasova, N. N.; Golovkova, L. P.; Severinovskaya, O. V.


    Bilirubin-cholate interactions in aqueous solutions were studied. The constants of binding of bilirubin with taurocholate dimers and taurodeoxycholate trimers were calculated. The adsorption of bilirubin and cholates on the surface of highly dispersed silica was studied. It was shown that taurine-conjugated cholates are poorly adsorbed from micellar solutions on the silica surface, the specific amount of bilirubin adsorbed decreases with increasing concentration of cholates in the solution, the affinity of free bilirubin for the silica surface is independent of the nature of the cholic acid, and that the affinity of cholate-bilirubin complexes for the silica surface is lower than the affinity of free bilirubin.

  5. Does bilirubin protect against developing diabetes mellitus? (United States)

    Breimer, Lars H; Mikhailidis, Dimitri P


    After 25 years of evaluating bilirubin as a possible protective agent in neonatal and cardiovascular disease, interest has moved on to a exploring a possible protective role in diabetes mellitus (DM). This review finds conflicting prospective data for a protective relationship though there are retrospective, case-controlled data, that can only show association, which is not causality. Only prospective studies can show causality. Also, it would appear that the underlying biochemical assumptions do not readily translate from the animal to the human setting. Given that many factors impact on circulating bilirubin levels, it is not surprising that a clear-cut answer is not available; the jury is still out. Any relationship between DM and bilirubin might relate to intermediates in bilirubin metabolism, including relationships involving the genes for the enzymes participating in those steps. Nevertheless, the pursuit of bilirubin in disease causation is opening new avenues for research and if it is established that serum bilirubin can predict risks, much will have been achieved. The answer may have to come from molecular genetic analyses.

  6. Supramolecular Complexes Formed in Systems Bile Salt-Bilirubin-Silica (United States)

    Vlasova, N. N.; Severinovskaya, O. V.; Golovkova, L. P.

    The formation of supramolecular complexes between bilirubin and primary micelles of bile salts has been studied. The association constants of bile salts and binding of bilirubin with these associates have been determined. The adsorption of bilirubin and bile salts from individual and mixed aqueous solutions onto hydrophobic silica surfaces has been investigated. The interaction of bilirubin with primary bile salt micelles and the strong retention in mixed micelles, which are supramolecular complexes, result in the adsorption of bilirubin in free state only.

  7. Inaccurate values for direct bilirubin with some commonly used direct bilirubin procedures. (United States)

    Chan, K M; Scott, M G; Wu, T W; Clouse, R E; Calvin, D R; Koenig, J; Lichti, D A; Ladenson, J H


    We compared five methods for the determination of total and direct bilirubins in serum samples from normal controls, subjects with Gilbert's syndrome, and serum pools containing about 50 and 150 mg of total bilirubin per liter. The Kodak Ektachem method and a diazotized sulfanilic acid method with 0.15 mmol/L sodium nitrite concentrations are the only methods that gave accurate direct bilirubin values, as judged by liquid-chromatographic results. The aca method that involved p-nitrobenzene diazonium tetrafluoroborate and another diazotized sulfanilic acid method with a higher concentration of sodium nitrite (0.8 mmol/L) yielded falsely high values for direct bilirubin, which could lead to clinical confusion. The more recently introduced diazotized sulfanilic acid method of the aca gave substantially better results than the p-nitrobenzene diazonium tetrafluoroborate method but was still inaccurate. Systematic investigation of these procedures revealed that the overestimation of direct bilirubin by the diazotized sulfanilic acid method was related to the amount of unconjugated bilirubin present and its ability to react as direct bilirubin in the presence of higher concentrations of sodium nitrite. Inherent properties of p-nitrobenzene diazonium tetrafluoroborate appeared to be responsible for inaccuracies in that method, which could not be corrected by varying reagent concentration or the reaction conditions.

  8. Can Excess Bilirubin Levels Cause Learning Difficulties? (United States)

    Pretorius, E.; Naude, H.; Becker, P. J.


    Examined learning problems in South African sample of 7- to 14-year-olds whose mothers reported excessively high infant bilirubin shortly after the child's birth. Found that this sample had lowered verbal ability with the majority also showing impaired short-term and long-term memory. Findings suggested that impaired formation of astrocytes…

  9. The effect of UGT1A1 promoter polymorphism in the development of hyperbilirubinemia and cholelithiasis in hemoglobinopathy patients.

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    Suad AlFadhli

    Full Text Available Present study was aimed to explore the effect of (TAn UGT1A1 gene promoter polymorphism on bilirubin metabolism, bilirubinaemia, predisposition to cholelithiasis and subsequent cholecystectomy, in Sickle-Cell Anemia (SCA and beta-Thalasemia major (bTH in Kuwaiti subjects compared to other population. This polymorphism was analyzed and correlated to total bilirubin and cholelithiasis in 270 age, gender, ethnically matched subjects (92 bTH, 116 SCA and 62 Controls using PCR, dHPLC, fragment analysis and direct sequencing. Four genotypes of UGT1A1 were detected in this study (TA6/6, TA6/7, TA6/8 and TA7/7. (TA6/8 was found only in four individuals; hence it was not included in the analysis. There was a statistically significant association of genotypes with serum total bilirubin levels in both bTH and SCA groups (p<0.001. Subjects with (TA7/7 had the highest total serum bilirubin level (178.7 ± 3.5 µmole/l. A significant association was observed between allele (TA7 and cholelithiasis development (p = 0.0001. The 40%, 67.5% and 100% of SCA with (TA6/6, (TA6/7 and (TA7/7 respectively developed cholelithiasis and were subsequently cholecystectomized. Our results confirm UGT1A1 (TA7 allele as one of the factors accounting for the hyperbilirubinemia and cholelithiasis observed in SCA and bTH.


    Directory of Open Access Journals (Sweden)

    Suresh Babu


    Full Text Available OBJECTIVE : To correlate Total Serum Bilirubin (TSB values to the clinical course of hyperbilirubinemia in newborns as this can be an indirect method of quality assurance in the laboratory. METHODS : An observational study of bilirubin values from 100 randomly selected case records of newborn jaundice for a period of 6 months. TSB values were determined by diazo reaction on venous blood samples on a semi auto analyzer. MS excel sheet used for statistical analysis. RESULTS : Clinical course of hyperbilirubinemia in all subjects correlated well to the reported TSB values in first to last zones corresponding to 15 mg /dL on 3rd day to 5th day of age. Zones 3, 4 and 5 varied from 7th day of birth, as phototherapy and recovery altered visual assessment of jaundice. One patient was expired with kernicterus had very high TSB value. The median bilirubin values trend downfall which correlated clinically to recovery from jaundice and 33% rapid decline in TSB also indicated the intervention by phototherapy. CONCLUSIONS : Bilirubin is one parameter with higher inter laboratory variability since its discovery till today. Hence more quality methods are to be developed to minimize this bias in clinical interpretation of reported bilirubin levels. Our study is an intermediary quality measure useful for both clinicians and lab personnel. This study can be adopted for retrospective quality evaluation and can be adopted for other parameters as well.

  11. Studies on bile acid and bilirubin in liver diseases Part 2. Clinical significance of serum bilirubin sulfate in various liver diseases


    石川, 泰祐


    The clinical significance of serum bilirubin sulfate, one of the direct bilirubin, was evaluated in various liver diseases with over 2 mg/dl of serum bilirubin concentration. The diagnosis included 25 cases of acute hepatitis, 8 cases of chronic hepatitis, 8 cases of liver cirrhosis and 16 cases of liver cirrhosis with hepatoma. Bilirubin sulfate was fractioned by Yonei's solvent partition method. The clinical significance of bilirubin sulfate was assessed by comparison of bilirubin sulfate w...

  12. Orlistat treatment increases fecal bilirubin excretion and decreases plasma bilirubin concentrations in hyperbilirubinemic Gunn rats

    NARCIS (Netherlands)

    Nishioka, T; Hafkamp, AM; Havinga, R; Van Lierop, PPE; Velvis, H; Verkade, HJ


    Objective To determine whether serum levels of unconjugated bilirubin (UCB) can be decreased by enhancing fecal fat excretion. Study design Gunn rats were fed a high-fat diet (control) or the same diet mixed with the lipase inhibitor orlistat. At regular intervals, plasma UCB concentrations were det

  13. Clinical significance of the UGT1A1*28 allele detection in HIV-infected patients

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    Veronika Kanestri


    Full Text Available Introduction: The UGT1A1*28 (rs8175347 polymorphism is associated with hyperbilirubinemia. The presence of 6 TA-repeats in the UGT1A1 gene promoter region corresponds to normal UGT1TA1 activity. A detection of 7 TA-repeats in hetero- or homozygous individuals [(TA6/(TA7 and (TA7/(TA7] is associated with lower UGT1TA1 activity, which may eventually result in the development of Gilbert syndrome and/or modified individual response to drugs metabolized by this enzyme. ATV contributes to the decreased levels of UGT1A1, which may lead to elevations of indirect bilirubin, jaundice and even to therapy discontinuation. We evaluated the prevalence of the UGT1A1*28 among HIV-infected patients and the dependence of the frequency and severity of AE during ATV treatment on individual genetic characteristics. Materials and Methods: 47 HIV-infected patients was screen for UGT1A1 genotype and the presence of UGT1A1*28. All patients received ATV in the HAART regimen for 48 weeks. Changes in the total, direct and indirect bilirubin, ALT, AST, GGT and jaundice were evaluated. Statistical analysis was performed using Microsoft Office Excel for Windows XP Professional 2007 and Biostat. Results: All patients were followed up in the AIDS Center (males 72.3%, median age 33 years, median CD4+ count-282 cells/µl (19.5%. HBV/HCV was in 36.2% patients. Ten patients had risk factors that could affect bilirubin turnover (chronic cholecystitis, biliary dyskinesia, etc.. Genotype (TA6/(TA6 was found in 42.6% patients, (TA6/(TA7-42.6% and (TA7/(TA7-14.9%. Overall prevalence of UGT1A1*28 was 57.4%, and homozygous allele frequency was 14.9%. G3/4 of indirect bilirubin were detected in 36.2% patients [(TA6/(TA6 in 10–20%, (TA6/(TA7-25-40%, (TA7/(TA7-72-86%], and significant jaundice in 10.6% [80% with (TA7/(TA7]. The OR for hyperbilirubinemia>40 µmol/L in patients with heterozygous UGT1A1*28 was increased 3 times over patients without this allele (OR 3.07, 95% CI 1.54–4.6 and

  14. Bilirubin dosage in cord blood: could it predict neonatal hyperbilirubinemia?

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    Adélia Jeha Nasser Bernaldo

    Full Text Available CONTEXT: With early discharge, many newborns have to be readmitted to hospital for hyperbilirubinemia to be treated, and this has been held responsible for the reappearance of kernicterus. OBJECTIVE: To evaluate whether bilirubin levels in cord blood could predict neonatal hyperbilirubinemia that would require treatment, in full-term newborns up to their third day of life. TYPE OF STUDY: Prospective study. SETTING: Neonatal Unit of Hospital Israelita Albert Einstein, São Paulo, Brazil. PARTICIPANTS: 380 full-term newborns considered normal: with or without ABO/Rh blood group incompatibility and without other complications. PROCEDURES: Blood was taken from the umbilical cord for analysis of conjugated, unconjugated and total bilirubin serum levels. The newborns were followed up until discharge, and unconjugated bilirubin that required phototherapy was compared to the cord bilirubin assay. Discriminant analysis was used to classify newborns: with or without risk of needing phototherapy by the third day of life. MAIN MEASUREMENTS: Bilirubin assay in cord blood; mother's and newborn's blood groups; phototherapy indication. RESULTS: The mean value for unconjugated bilirubin in cord blood was significantly higher in newborns whose unconjugated bilirubin required phototherapy. The presence of ABO blood group incompatibility was a significant variable in relation to unconjugated bilirubin that required phototherapy. The most useful cutoff point for unconjugated bilirubin in cord blood was 2.0 mg/100 ml. DISCUSSION: Cord blood could be collected, stored and used for further analysis of unconjugated bilirubin levels as a means for considering whether or not to discharge a moderately jaundiced child from hospital, in association with other resources. CONCLUSIONS: Blood incompatibility between mother and child was a predictor for the appearance of hyperbilirubinemia that required treatment. Considering a cutoff point of 2.0 mg/100 ml, it could be concluded

  15. Regioselective and stereospecific glucuronidation of trans- and cis-resveratrol in human. (United States)

    Aumont, V; Krisa, S; Battaglia, E; Netter, P; Richard, T; Mérillon, J M; Magdalou, J; Sabolovic, N


    Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a polyphenol present in wine, which has been reported to have anti-inflammatory, anti-platelet, and anti-carcinogenic effects. The glucuronidation of this compound and that of the cis-isomer also naturally present, has been investigated in human liver microsomes. Both isomers were actively glucuronidated. The reaction led to the formation of two glucuronides (3-O- and 4'-O-glucuronides), whose structure was characterized by LC-MS and proton NMR. Glucuronidation was regio- and stereoselective. It occurred at a faster rate with the cis-isomer and preferred the 3-position on both isomers. In addition, the glucuronidation of resveratrol was tested using several recombinant UDP-glucuronosyltransferase (UGT) isoforms. The reaction was catalyzed by UGT of the family 1A (UGT1A1, 1A6, 1A7, 1A9, 1A10). The bilirubin conjugating UGT1A1 was mainly involved in the 3-O-glucuronidation of trans-resveratrol, whereas the phenol conjugating UGT1A6 activity was restricted to cis-resveratrol. The UGT1A9 and 1A10 were active toward both isomers. The activity supported by UGT2B7 and UGT2B15 was very low and restricted to cis-resveratrol. UGT1A3, 1A4, 2B4, and 2B11 were unable to form resveratrol glucuronides.

  16. Regioselective glucuronidation of oxyresveratrol, a natural hydroxystilbene, by human liver and intestinal microsomes and recombinant UGTs. (United States)

    Hu, Nan; Mei, Mei; Ruan, Jianqing; Wu, Wenjin; Wang, Yitao; Yan, Ru


    Oxyresveratrol (OXY) is a natural hydroxystilbene that shows similar bioactivity but better water solubility than resveratrol. This study aims to characterize its glucuronidation kinetics in human liver (HLMs) and intestinal (HIMs) microsomes and identify the main UDP-glucuronosyltransferase (UGT) isoforms involved. Three and four mono-glucuronides of OXY were generated in HIMs and HLMs, respectively, with oxyresveratrol-2-O-β-D-glucuronosyl (G4) as the major metabolite in both organs. The kinetics of G4 formation fit a sigmoidal model in HLMs and biphasic kinetics in HIMs. Multiple UGT isoforms catalyzed G4 formation with the highest activity observed with UGT1A9 followed by UGT1A1. G4 formation by both isoforms followed substrate inhibition kinetics. Propofol (UGT1A9 inhibitor) effectively blocked G4 generation in HLMs (IC50 63.7 ± 11.6 µM), whereas the UGT1A1 inhibitor bilirubin only produced partial inhibition in HLMs and HIMs. These findings shed light on the metabolic mechanism of OXY and arouse awareness of drug interactions.

  17. The inverse association of incident cardiovascular disease with plasma bilirubin is unaffected by adiponectin

    NARCIS (Netherlands)

    Dullaart, Robin P. F.; Boersema, Jeltje; Lefrandt, Joop D.; Wolffenbuttel, Bruce H. R.; Bakker, Stephan J. L.


    Objective: Bilirubin may protect against atherosclerotic cardiovascular disease (CVD). The heme oxygenase pathway is crucial for bilirubin generation, and is stimulated by adiponectin. We tested the relationship of plasma bilirubin with adiponectin, and determined whether the association of incident

  18. Low-normal free thyroxine confers decreased serum bilirubin in type 2 diabetes mellitus

    NARCIS (Netherlands)

    Deetman, Petronella E.; Kwakernaak, Arjan J.; Bakker, Stephan J. L.; Dullaart, Robin P. F.


    Background: Bilirubin may confer cardiovascular protection because of its strong antioxidative properties. Both thyroid dysfunction and the diabetic state affect bilirubin metabolism. Here we tested whether low-normal thyroid function affects serum bilirubin among euthyroid subjects with and without

  19. Extreme Bilirubin Levels as a Causal Risk Factor for Symptomatic Gallstone Disease

    DEFF Research Database (Denmark)

    Stender, Stefan; Frikke-Schmidt, Ruth; Nordestgaard, Børge G


    In individuals without blockage of their bile ducts, levels of plasma bilirubin likely reflect levels of biliary bilirubin; higher biliary bilirubin levels may increase the risk of gallstone disease....

  20. Genetically elevated bilirubin and risk of ischaemic heart disease

    DEFF Research Database (Denmark)

    Stender, Stefan; Frikke-Schmidt, R; Nordestgaard, B G


    Elevated plasma levels of bilirubin, an endogenous antioxidant, have been associated with reduced risk of ischaemic heart disease (IHD) and myocardial infarction (MI). Whether this is a causal relationship remains unclear.......Elevated plasma levels of bilirubin, an endogenous antioxidant, have been associated with reduced risk of ischaemic heart disease (IHD) and myocardial infarction (MI). Whether this is a causal relationship remains unclear....

  1. Does bilirubin protect against hemochromatosis gene (HFE) related mortality?

    NARCIS (Netherlands)

    Alizadeh, Behrooz Z.; Njajou, Omer T.; Houwing-Duistermaat, Jeanine J.; de Jong, Gerard; Vergeer, Jeannette M.; Hofman, Albert; Pols, Huibert A.P.; van Duijn, Cornelia M.


    Serum bilirubin is an important antioxidant that is found at increased levels in hereditary hemochromatosis patients. We hypothesized that increased levels of serum bilirubin may play a protective role against oxidative stress induced by iron overload in carriers of mutations in the hereditary hemoc

  2. Conjugated bilirubin in neonates with glucose-6-phosphate dehydrogenase deficiency. (United States)

    Kaplan, M; Rubaltelli, F F; Hammerman, C; Vilei, M T; Leiter, C; Abramov, A; Muraca, M


    We used a system capable of measuring conjugated bilirubin and its monoconjugated and diconjugated fractions in serum to assess bilirubin conjugation in 29 glucose-6-phosphate dehydrogenase (G6PD)-deficient, term, male newborn infants and 35 control subjects; all had serum bilirubin levels > or = 256 mumol/L (15 mg/dI). The median value for diconjugated bilirubin was lower in the G6PD-deficient neonates than in control subjects (0.06 (range 0.00 to 1.84) vs 0.21 (range 0.00 to 1.02) mumol/L, p = 0.006). Diglucuronide was undetectable in 11 (38.9%) of the G6PD-deficient infants versus 3 (8.6%) of the control subjects (p = 0.015). These findings imply a partial defect of bilirubin conjugation not previously demonstrated in G6PD-deficient newborn infants.

  3. Trans-Cutaneous Bilirubinometery versus Serum Bilirubin in Neonatal Jaundice. (United States)

    Mahram, Manoochehr; Oveisi, Sonia; Jaberi, Najmeh


    Hyperbilirubinemia is a common problem in neonates and causes serious complications. Thus, serial measurements of bilirubin should be done. This assessment is done through two methods of laboratory measurement in serum sample and transcutaneous bilirubinometer. This descriptive study compared transcutaneous bilirubin assessment and laboratory serum bilirubin. Bilirubin level was assessed among 256 neonates admitted to the Qods Children's Hospital in Qazvin- Iran, because of neonatal indirect jaundice, through two methods of transcutaneous bilirubinometery from two sites of forehead and sternum and laboratory measurement of bilirubin in serum. The cases were non-hemolytic icteric term neonates weighing 2500 gram or more and had not received phototherapy or other treatments. Neonates with hemolytic forms of jaundice, sepsis and suspicious to metabolic disorders were excluded. Assessments by means of KJ-8000 transcutaneous bilirubinometer from two sites of forehead and sternum and through laboratory measurement of serum bilirubin were registered and analyzed. The results of the current study showed that there was a correlation of 0.82 between serum bilirubin and transcutaneous forehead bilirubin assessment and for the used device sensitivity of 0.844; specificity of 0.842, Youden Index of 0.709 and Shortest of 0.042 for a cut-off of 12.4 in bilirubin of participants. Furthermore, Likelihood Ratio positive and negative (LR) were 5.665 and 0.164, respectively and diagnostic Odds Ratio (LR+/LR-) was 34.56. Transcutaneous bilirubinometery can be considered as a reliable tool to assess bilirubin for the screening of neonatal jaundice in term neonates.

  4. Relationship between serum bilirubin levels and optic neuritis

    Institute of Scientific and Technical Information of China (English)

    DENG Juan; LIANG Xue-mei; ZHANG Xiu-lan; LING Shi-qi; YANG Ting-ting; LI Min; PENG Fu-hua


    Background Bilirubin is the end product of heme catabolism and has strong antioxidant properties.Serum bilirubin levels are reported to be reduced in patients with multiple sclerosis (MS) and neuromyelitis optica (NMO).The pathophysiology of optic neuritis (ON) resembles that of MS; however,the role of endogenous bilirubin in ON is unclear.The aim of this study is to measure serum bilirubin levels in patients with ON,and to investigate the correlation between ON and serum antioxidant status of bilirubin.Methods Serum levels of bilirubin were measured in 42 patients with ON,50 patients with multiple sclerosis (MS),48 patients with neuromyelitis optica (NMO) and 48 healthy control subjects.Results Serum total bilirubin (Tbil),direct bilirubin (Dbil) and indirect bilirubin (Ibil) levels in patients with ON were significantly lower than those in the healthy controls.However,no statistical significance was found between levels in the ON and MS,ON and NMO,and MS and NMO groups.In patients with ON,serum Tbil,Dbil,and Ibil levels were lower in those with recurrence or those with ON for a longer duration (>1 year).Moreover,Tbil,Dbil,and Ibil concentrations were lower in patients with papillitis than in those with retrobulbar type ON,but the differences were not statistically significant.Conclusions Low antioxidant status may exist in patients with ON.But serum levels of Tbil,Dbil,and Ibil did not correlate with clinical presentations,such as recurrence,duration of disease and subtypes of ON.Low antioxidant status already existed in MS or NMO patients before systemic symptoms appeared.

  5. Anti-genotoxic potential of bilirubin in vivo

    DEFF Research Database (Denmark)

    Wallner, Marlies; Antl, Nadja; Rittmannsberger, Barbara;


    The bile pigment bilirubin is a known antioxidant and is associated with protection from cancer and cardiovascular disease (CVD) when present in too strong concentrations. Unconjugated bilirubin (UCB) might also possess anti-genotoxic potential by preventing oxidative damage to DNA. Moderately...... elevated bilirubin levels are found in individuals with Gilbert syndrome and more severe in the hyperbilirubinemic Gunn rat model. This study was therefore aimed to assess the levels of oxidative damage to DNA in Gilbert syndrome subjects and Gunn rats compared to matched controls. Seventy-six individuals...

  6. Transcutaneous bilirubin nomograms in African neonates (United States)

    Mabogunje, Cecilia A.; Imosemi, Donald O.; Emokpae, Abieyuwa A.


    Background The use of transcutaneous bilirubin (TcB) as a screening tool, based on relevant population-specific nomogram, or proxy for total serum bilirubin (TSB) levels in assessing the risk of subsequent hyperbilirubinemia is supported by several clinical guidelines on the management of neonatal hyperbilirubinemia. However, while TcB has been found to significantly over-estimate TSB in neonates of African-American ancestry, with variations across TcB devices, no nomogram has been specifically reported for this racial group. This study therefore set out to develop TcB nomograms for healthy late pre-term and term black African neonates derived from two widely used bilirubinometers. Methods A retrospective analysis of 12,377 TcB measurements obtained from 6,373 neonates in the first postnatal week, over a period of 48 months using Bilichek and JM-103 bilirubinometers. TcB percentiles were computed from hour-specific TcB values and nomograms developed for each of the screening devices. Predictive ability of the 75th and 95th percentiles to detect significant hyperbilirubinemia was evaluated between 24–96 hours of age. The 95th percentile curve was compared with those from other populations. Results The velocity of TcB rise at 75th and 95th percentiles was generally higher with JM-103 than Bilichek. Both percentiles also peaked at higher TcB levels with JM-103. The 95th percentile for both instruments showed a downward trend as from approximately 114 hours. Both instruments had high negative predictive values across the selected time-epochs and lower discriminatory ability than reported in non-black populations. Conclusions The predictive utility of TcB as a potential screening tool varies across devices in black African neonates with or without risk of significant hyperbilirubinemia, and lower than levels reported in non-black populations. Equipment-specific nomograms should be considered for TcB monitoring in this racial population where TSB is not routinely

  7. The clinical syndrome of bilirubin-induced neurologic dysfunction. (United States)

    Bhutani, Vinod K; Johnson-Hamerman, Lois


    Clinicians have hypothesized a spectrum of minor neurologic manifestations, consistent with neuroanatomical reports and collectively termed as a "syndrome of bilirubin-induced neurologic dysfunction (BIND)," which can occur in the absence of classical kernicterus. The current review builds on these initial reports with a focus on clinical signs and symptoms that are assessed by standardized tools and manifest from neonatal age to childhood. These clinical manifestations are characterized by the following domains: (i) neuromotor signs; (ii) muscle tone abnormalities; (iii) hyperexcitable neonatal reflexes; (iv) variety of neurobehavior manifestations; (v) speech and language abnormalities; and (vi) evolving array of central processing abnormalities, such as sensorineural audiology and visuomotor dysfunctions. Concerns remain that the most vulnerable infants are likely to acquire BIND, either because their exposure to bilirubin is not identified as severe enough to need treatment or is prolonged but slightly below current threshold levels for intervention. Knowing that a total serum/plasma bilirubin (TB) level is not the most precise indicator of neurotoxicity, the role of expanded biomarkers or a "bilirubin panel" has yet to be validated in prospective studies. Future studies that correlate early "toxic" bilirubin exposure to long-term academic potential of children are needed to explore new insights into bilirubin's effect on the structural and functional maturation of an infant's neural network topology.

  8. Ibuprofen augments bilirubin toxicity in rat cortical neuronal culture. (United States)

    Berns, Monika; Toennessen, Margit; Koehne, Petra; Altmann, Rodica; Obladen, Michael


    Premature infants are at risk for bilirubin-associated brain damage. In cell cultures bilirubin causes neuronal apoptosis and necrosis. Ibuprofen is used to close the ductus arteriosus, and is often given when hyperbilirubinemia is at its maximum. Ibuprofen is known to interfere with bilirubin-albumin binding. We hypothesized that bilirubin toxicity to cultured rat embryonic cortical neurons is augmented by coincubation with ibuprofen. Incubation with ibuprofen above a concentration of 125 microg/mL reduced cell viability, measured by methylthiazole tetrazolium reduction, to 68% of controls (p < 0.05). Lactate dehydrogenase (LDH) release increased from 29 to 38% (p < 0.01). The vehicle solution did not affect cell viability. Coincubation with 10 microM unconjugated bilirubin (UCB)/human serum albumin in a molar ratio of 3:1 and 250 microg/mL ibuprofen caused additional loss of cell viability and increased LDH release (p < 0.01), DNA fragmentation, and activated caspase-3. Preincubation with the pan-caspase inhibitor z-val-ala-asp-fluoromethyl ketone abolished ibuprofen- and UCB-induced DNA fragmentation. The study demonstrates that bilirubin in low concentration of 10 microM reduces neuron viability and ibuprofen increases this effect. Apoptosis is the underlying cell death mechanism.

  9. Relationship between bilirubin free radical and formation of pigment gallstone

    Institute of Scientific and Technical Information of China (English)

    Xiang-Tao Liu; Jian Hu


    In this paper, we summarize the main progresses made inour group in the field of the mechanism of pigment gallstoneformation. It was found that after treetment with freeradicals, bilirubin (BR) was changed into free radical itself,and a semiquinone free radical and a superoxide free radicalbound with metal were recognized, which was detected byESR (electron spin resonance). By the meana of NMR(nuclear magnetic resonance) and IR (Infra-red spectra), itwas postulated that bilirubin polymerized through thereaction between the vinyl group and the hydroxyl groupunder the attack of free radicals. It was also found thatbilirubin free radical were liable to calcify in a kinetic study.Because of its chemical properties, bilirubin free radical wasshown to be cytotoxic to hepetocyte, which wasdemonstrated based on the following facts: induction ofphospholipid peroxidation (LPO), leakage of lactatedehydrogenase (LDH) and decrease of glutathione. As tothe mechanism of bilirubin-induced cytotoxicity, it waspostulated that the main target of bilirubin free radical wasthe cell membrane, including phospholipid and membranebound proteins, especially spectrin, a content ofcytoskeleton. Based on the results mentioned above, it wasdeduced that bilirubin free radical is the key factor thatinitiates and promotes the formation of pigment gallstone,which is consistent with other researches in recent years.

  10. Morphine glucuronidation and glucosidation represent complementary metabolic pathways that are both catalyzed by UDP-glucuronosyltransferase 2B7: kinetic, inhibition, and molecular modeling studies. (United States)

    Chau, Nuy; Elliot, David J; Lewis, Benjamin C; Burns, Kushari; Johnston, Martin R; Mackenzie, Peter I; Miners, John O


    Morphine 3-β-D-glucuronide (M3G) and morphine 6-β-D-glucuronide (M6G) are the major metabolites of morphine in humans. More recently, morphine-3-β-d-glucoside (M-3-glucoside) was identified in the urine of patients treated with morphine. Kinetic and inhibition studies using human liver microsomes (HLM) and recombinant UGTs as enzyme sources along with molecular modeling were used here to characterize the relationship between morphine glucuronidation and glucosidation. The M3G to M6G intrinsic clearance (C(Lint)) ratio (∼5.5) from HLM supplemented with UDP-glucuronic acid (UDP-GlcUA) alone was consistent with the relative formation of these metabolites in humans. The mean C(Lint) values observed for M-3-glucoside by incubations of HLM with UDP-glucose (UDP-Glc) as cofactor were approximately twice those for M6G formation. However, although the M3G-to-M6G C(Lint) ratio remained close to 5.5 when human liver microsomal kinetic studies were performed in the presence of a 1:1 mixture of cofactors, the mean C(Lint) value for M-3-glucoside formation was less than that of M6G. Studies with UGT enzyme-selective inhibitors and recombinant UGT enzymes, along with effects of BSA on morphine glycosidation kinetics, were consistent with a major role of UGT2B7 in both morphine glucuronidation and glucosidation. Molecular modeling identified key amino acids involved in the binding of UDP-GlcUA and UDP-Glc to UGT2B7. Mutagenesis of these residues abolished morphine glucuronidation and glucosidation. Overall, the data indicate that morphine glucuronidation and glucosidation occur as complementary metabolic pathways catalyzed by a common enzyme (UGT2B7). Glucuronidation is the dominant metabolic pathway because the binding affinity of UDP-GlcUA to UGT2B7 is higher than that of UDP-Glc.

  11. Induction of UDP-glucuronosyltransferase 2B15 gene expression by the major active metabolites of tamoxifen, 4-hydroxytamoxifen and endoxifen, in breast cancer cells. (United States)

    Chanawong, Apichaya; Hu, Dong Gui; Meech, Robyn; Mackenzie, Peter I; McKinnon, Ross A


    We previously reported upregulation of UGT2B15 by 17β-estradiol in breast cancer MCF7 cells via binding of the estrogen receptor α (ERα) to an estrogen response unit (ERU) in the proximal UGT2B15 promoter. In the present study, we show that this ERα-mediated upregulation was significantly reduced by two ER antagonists (fulvestrant and raloxifene) but was not affected by a third ER antagonist, 4-hydroxytamoxifen (4-OHTAM), a major active tamoxifen (TAM) metabolite. Furthermore, we found that, similar to 17β-estradiol, 4-OHTAM and endoxifen (another major active TAM metabolite) elevated UGT2B15 mRNA levels, and that this stimulation was significantly abrogated by fulvestrant. Further experiments using 4-OHTAM revealed a critical role for ERα in this regulation. Specifically; knockdown of ERα expression by anti-ERα small interfering RNA reduced the 4-OHTAM-mediated induction of UGT2B15 expression; 4-OHTAM activated the wild-type but not the ERU-mutated UGT2B15 promoter; and chromatin immunoprecipitation assays showed increased ERα occupancy at the UGT2B15 ERU in MCF7 cells upon exposure to 4-OHTAM. Together, these data indicate that both 17β-estradiol and the antiestrogen 4-OHTAM upregulate UGT2B15 in MCF7 cells via the same ERα-signaling pathway. This is consistent with previous observations that both 17β-estradiol and TAM upregulate a common set of genes in MCF7 cells via the ER-signaling pathway. As 4-OHTAM is a UGT2B15 substrate, the upregulation of UGT2B15 by 4-OHTAM in target breast cancer cells is likely to enhance local metabolism and inactivation of 4-OHTAM within the tumor. This represents a potential mechanism that may reduce TAM therapeutic efficacy or even contribute to the development of acquired TAM resistance.

  12. Blood-brain interfaces and bilirubin-induced neurological diseases. (United States)

    Ghersi-Egea, J F; Gazzin, S; Strazielle, N


    The endothelium of the brain microvessels and the choroid plexus epithelium form highly specialized cellular barriers referred to as blood-brain interfaces through which molecular exchanges take place between the blood and the neuropil or the cerebrospinal fluid, respectively. Within the brain, the ependyma and the pia-glia limitans modulate exchanges between the neuropil and the cerebrospinal fluid. All these interfaces are key elements of neuroprotection and fulfill trophic functions; both properties are critical to harmonious brain development and maturation. By analogy to hepatic bilirubin detoxification pathways, we review the transport and metabolic mechanisms which in all these interfaces may participate in the regulation of bilirubin cerebral bioavailability in physiologic conditions, both in adult and in developing brain. We specifically address the role of ABC and OATP transporters, glutathione-S-transferases, and the potential involvement of glucuronoconjugation and oxidative metabolic pathways. Regulatory mechanisms are explored which are involved in the induction of these pathways and represent potential pharmacological targets to prevent bilirubin accumulation into the brain. We then review the possible alteration of the neuroprotective and trophic barrier functions in the course of bilirubin-induced neurological dysfunctions resulting from hyperbilirubinemia. Finally, we highlight the role of the blood-brain and blood-CSF barriers in regulating the brain biodisposition of candidate drugs for the treatment or prevention of bilirubin-induced brain injury.

  13. Functional polyethersulfone particles for the removal of bilirubin. (United States)

    Jiang, Xin; Xiang, Tao; Xie, Yi; Wang, Rui; Zhao, Weifeng; Sun, Shudong; Zhao, Chang-Sheng


    In this study, polyethersulfone/poly (glycidyl methacrylate) particles are prepared via in situ cross-linked polymerization coupled with a phase inversion technique. The surfaces of these particles are then further modified by grafting amino groups using tetraethylenepentamine, dethylenetriamine, ethylenediamine, or 1,6-hexanediamine for the removal of bilirubin. The particles are characterized by Flourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. Batch adsorption experiments are performed to verify the adsorption capability, and the effect of bilirubin initial concentration, bovine serum albumin concentration, and solution ionic strength on the adsorption is also investigated. In addition, both adsorption kinetic and isotherm models are applied to analyze the adsorption process of bilirubin, and a particle column is used to further study the bilirubin removal ability.To prove that the method was a universal portal to prepare functional particles, polysulfone, polystyrene, and poly(vinylidene fluoride) based functional particles were also prepared and used for the removal of bilirubin. This study and the results indicated that the particles had a great potential to be used in hemoperfusion treatment for hyperbilirubinemia.

  14. Study on Removal of Bilirubin with Magnetic Affinity Separation Technique

    Institute of Scientific and Technical Information of China (English)

    张凤宝; 王淑兰; 徐辉; 张国亮


    An affinity adsorbent, Cibacron Blue 3GA immobilized magnetic polyvinyl alcohol (PVA) microspheres was used for bilirubin removal taking the advantage of easy separation of magnetic sorbent from the biosystem.Fe3 O4 superparamagnetic particles was synthesized with hydrothermal reaction of ferrous chloride (FeC12) and ferric chloride (FeCl3). Such magnetic particles are then encapsulated in biocompatible PVA to form magnetic polymer microspheres sized from 2 to 15 nm with hydroxyl groups on its surface. Cibacron Blue 3GA, a dye-ligand, was covalently coupled with the polyvinyl alcohol through the nucleophilic reaction between the chloride of its triazine ring and the hydroxyl groups of PVA molecules under alkaline condition. The affinity adsorbent carried 21.1μmol Cibacron Blue 3GA per gram magnetic polymer microspheres was used to remove unconjugated and conjugated bilirubin from the solution which was composed of bilirubin or bilirubin and protein. After the adsorption, the adsorbent loaded with bilirubin was removed easily in the magnetic field.

  15. Influence of hemoglobin on non-invasive optical bilirubin sensing (United States)

    Jiang, Jingying; Gong, Qiliang; Zou, Da; Xu, Kexin


    Since the abnormal metabolism of bilirubin could lead to diseases in the human body, especially the jaundice which is harmful to neonates. Traditional invasive measurements are difficult to be accepted by people because of pain and infection. Therefore, the real-time and non-invasive measurement of bilirubin is of great significance. However, the accuracy of currently transcutaneous bilirubinometry(TcB) is generally not high enough, and affected by many factors in the human skin, mostly by hemoglobin. In this talk, absorption spectra of hemoglobin and bilirubin have been collected and analyzed, then the Partial Least Squares (PLS) models have been built. By analyzing and comparing the Correlation and Root Mean Square Error of Prediction(RMSEP), the results show that the Correlation of bilirubin solution model is larger than that of the mixture solution added with hemoglobin, and its RMSEP value is smaller than that of mixture solution. Therefore, hemoglobin has influences on the non-invasive optical bilirubin sensing. In next step, it is necessary to investigate how to eliminate the influence.

  16. Mitochondrial targeting of bilirubin regulatory enzymes: An adaptive response to oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Muhsain, Siti Nur Fadzilah, E-mail: [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Faculty of Pharmacy, University Teknologi Mara (Malaysia); Lang, Matti A., E-mail: [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Abu-Bakar, A' edah, E-mail: [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia)


    The intracellular level of bilirubin (BR), an endogenous antioxidant that is cytotoxic at high concentrations, is tightly controlled within the optimal therapeutic range. We have recently described a concerted intracellular BR regulation by two microsomal enzymes: heme oxygenase 1 (HMOX1), essential for BR production and cytochrome P450 2A5 (CYP2A5), a BR oxidase. Herein, we describe targeting of these enzymes to hepatic mitochondria during oxidative stress. The kinetics of microsomal and mitochondrial BR oxidation were compared. Treatment of DBA/2J mice with 200 mg pyrazole/kg/day for 3 days increased hepatic intracellular protein carbonyl content and induced nucleo-translocation of Nrf2. HMOX1 and CYP2A5 proteins and activities were elevated in microsomes and mitoplasts but not the UGT1A1, a catalyst of BR glucuronidation. A CYP2A5 antibody inhibited 75% of microsomal BR oxidation. The inhibition was absent in control mitoplasts but elevated to 50% after treatment. An adrenodoxin reductase antibody did not inhibit microsomal BR oxidation but inhibited 50% of mitochondrial BR oxidation. Ascorbic acid inhibited 5% and 22% of the reaction in control and treated microsomes, respectively. In control mitoplasts the inhibition was 100%, which was reduced to 50% after treatment. Bilirubin affinity to mitochondrial and microsomal CYP2A5 enzyme is equally high. Lastly, the treatment neither released cytochrome c into cytoplasm nor dissipated membrane potential, indicating the absence of mitochondrial membrane damage. Collectively, the observations suggest that BR regulatory enzymes are recruited to mitochondria during oxidative stress and BR oxidation by mitochondrial CYP2A5 is supported by mitochondrial mono-oxygenase system. The induced recruitment potentially confers membrane protection. - Highlights: • Pyrazole induces oxidative stress in the mouse liver. • Pyrazole-induced oxidative stress induces mitochondrial targeting of key bilirubin regulatory enzymes, HMOX1

  17. Effect of pH and temperature on the binding of bilirubin to human erythrocyte membranes

    Indian Academy of Sciences (India)

    H Rashid; Mohammad K Ali; S Tayyab


    Effect of pH and temperature on the binding of bilirubin to human erythrocyte membranes was studied by incubating the membranes at different pH and temperatures and determining the bound bilirubin. At all pH values, the amount of membrane-bound bilirubin increased with the increase in bilirubin-to-albumin molar ratios (B/As), being highest at lower pH values in all cases. Further, linear increase in bound bilirubin with the increase in bilirubin concentration in the incubate was observed at a constant B/A and at all pH values. However, the slope value increased with the decrease in pH suggesting more bilirubin binding to membranes at lower pH values. Increase in bilirubin binding at lower pH can be explained on the basis of increased free bilirubin concentration as well as more conversion of bilirubin dianion to monoanion. Temperature dependence of bilirubin binding to membranes was observed within the temperature range of 7°–60°C, showing minimum binding at 27°C and 37°C which increased on either side. Increase in bilirubin binding at temperatures lower than 20°C and higher than 40°C can be ascribed to the change in membrane topography as well as bilirubin-albumin interaction.

  18. Studies on the molecular significance in the interaction of bilirubin with collagen. (United States)

    Nagarajan, Usharani; Gladstone Christopher, Jayakumar; Chandrasekaran, Bangaru; Jonnalagadda, Raghava Rao; Balachandran, Unni Nair; Kohsaku, Kawakami


    The present investigation is aimed to understand the physiological significance of bilirubin interaction with collagen. In human skin, collagen absorbs both free bilirubin and serum bound bilirubin from the human system. Interaction between bilirubin and collagen depends on time, temperature and concentration of bilirubin. There is an increase in the aggregation rate of collagen in the presence of biliruibin. At physiological condition, 125 nM of bilirubin is the maximum concentration absorbed by per mg of collagen molecule. Bilirubin accelerates the lateral growth of collagen fibrils by shifting its rate of nucleation. Moreover, collagen-bilirubin complex exhibit a tendency to undergo adsorption onto the surface of the fibroblast cells, showing detrimental effects on fibroblasts proliferations. Based on the collagen binding assays, the binding of bilirubin to collagen is found to be electrostatic in nature, which confirms binding between the amino acid fragment of α1 (I) region of collagen and carboxyl group of bilirubin. The biotinylated bilirubin derivatives show better binding to α1 (I) chain rather than α2 (I) chains which clearly designates that bilirubin shows greater affinity to α1 chains of collagen. This novel approach directs to reduce the occurrence of bilirubin in hyperbilirubinemia patients.

  19. Measurements of neonatal bilirubin and albumin concentrations: a need for improvement and quality control

    NARCIS (Netherlands)

    Imhoff, D.E. van; Dijk, P.H.; Weykamp, C.W.; Cobbaert, C.M.; Hulzebos, C.V.; Liem, K.D.


    Accurate and precise bilirubin and albumin measurements are essential for proper management of jaundiced neonates. Data hereon are lacking for Dutch laboratories. We aimed to determine variability of measurements of bilirubin and albumin concentrations typical for (preterm) neonates. Aqueous, human

  20. Measurements of neonatal bilirubin and albumin concentrations : a need for improvement and quality control

    NARCIS (Netherlands)

    van Imhoff, Deirdre E.; Dijk, Peter H.; Weykamp, Cas W.; Cobbaert, Christa M.; Hulzebos, Christian V.


    Accurate and precise bilirubin and albumin measurements are essential for proper management of jaundiced neonates. Data hereon are lacking for Dutch laboratories. We aimed to determine variability of measurements of bilirubin and albumin concentrations typical for (preterm) neonates. Aqueous, human


    NARCIS (Netherlands)



    Background/Aims: Hyperbilirubinemia associated with sepsis is frequently observed in humans. In this study, an experimental rat model was developed to study bilirubin metabolism and transport during endotoxemia. Methods: Rats were injected intravenously with a single bolus of lipopolysaccharide (1 m

  2. Plasma bilirubin and late graft failure in renal transplant recipients

    NARCIS (Netherlands)

    Deetman, Petronella E.; Zelle, Dorien M.; van der Heide, Jaap J. Homan; Navis, Gerjan J.; Gans, Reinold O. B.; Bakker, Stephan J. L.


    Exogenous bilirubin has been shown to protect against oxidative stress in ischemia-reperfusion injury. Oxidative stress has been implicated in the pathophysiology of chronic transplant dysfunction leading to late graft failure after renal transplantation. We prospectively investigated whether high e

  3. Nanofibrous polymeric beads from aramid fibers for efficient bilirubin removal. (United States)

    Peng, Zihang; Yang, Ye; Luo, Jiyue; Nie, Chuanxiong; Ma, Lang; Cheng, Chong; Zhao, Changsheng


    Polymer based hemoperfusion has been developed as an effective therapy to remove the extra bilirubin from patients. However, the currently applied materials suffer from either low removal efficiency or poor blood compatibility. In this study, we report the development of a new class of nanofibrous absorbent that exhibited high bilirubin removal efficiency and good blood compatibility. The Kevlar nanofiber was prepared by dissolving micron-sized Kevlar fiber in proper solvent, and the beads were prepared by dropping Kevlar nanofiber solutions into ethanol. Owing to the nanofiborous structure of the Kevlar nanofiber, the beads displayed porous structures and large specific areas, which would facilitate the adsorption of toxins. In the adsorption test, it was noticed that the beads possessed an adsorption capacity higher than 40 mg g(-1) towards bilirubin. In plasma mimetic solutions, the beads still showed high bilirubin removal efficiency. Furthermore, after incorporating with carbon nanotubes, the beads were found to have increased adsorption capacity for human degradation waste. Moreover, the beads showed excellent blood compatibility in terms of a low hemolysis ratio, prolonged clotting times, suppressed coagulant activation, limited platelet activation, and inhibited blood related inflammatory activation. Additionally, the beads showed good compatibility with endothelial cells. In general, the Kevlar nanofiber beads, which integrated with high adsorption capacity, good blood compatibility and low cytotoxicity, may have great potential for hemoperfusion and some other applications in biomedical fields.


    NARCIS (Netherlands)



    The association of unconjugated bilirubin (UCB) with amorphous calcium phosphate was studied in vitro. To this end UCB, solubilized in different micellar bile salt solutions, was incubated with freshly prepared calcium phosphate precipitate. It was demonstrated that amorphous calcium phosphate (ACP)

  5. Conformational changes in the bilirubin-human serum albumin complex at extreme alkaline pH

    DEFF Research Database (Denmark)

    Honoré, B; Frandsen, P C


    Light-absorption, c.d. and fluorescence of the bilirubin-albumin complex were investigated at extreme alkaline pH. Above pH 11.1 albumin binds the bilirubin molecule, twisted oppositely to the configuration at more neutral pH. On the basis of light-absorption it is shown that two alkaline...... between tryptophan-214 and bilirubin, and partly exposing the liganded bilirubin to the solvent. Udgivelsesdato: 1986-Jun-1...

  6. Clinical Significance of Serum Bilirubin Detection of Patient with Coronary Heart Disease

    Institute of Scientific and Technical Information of China (English)

    TAO Li; LUO Rui; ZHUANG Diankui


    Objective To explore the relation between serum bilirubin and coronary heart disease.Methods Compare the level of serum bilirubin among patients with coronary heart disease, patients with other disease and normal persons. Results The level of serum bilirubin of patients with coronary heart disease is higher than that of normal persons. Conclusion The reduction of density of serum bilirubin is one of the independent risk factors of coronary heart disease.

  7. Complete COL1A1 allele deletions in osteogenesis imperfecta

    NARCIS (Netherlands)

    van Dijk, Fleur S.; Huizer, Margriet; Kariminejad, Ariana; Marcelis, Carlo L.; Plomp, Astrid S.; Terhal, Paulien A.; Meijers-Heijboer, Hanne; Weiss, Marjan M.; van Rijn, Rick R.; Cobben, Jan M.; Pals, Gerard


    Purpose: To identify a molecular genetic cause in patients with a clinical diagnosis of osteogenesis imperfecta (OI) type I/IV. Methods: The authors performed multiplex ligation-dependent probe amplification analysis of the COL1A1 gene in a group of 106 index patients. Results: In four families with

  8. Interaction of bilirubin with Ag and Au ions: green synthesis of bilirubin-stabilized nanoparticles (United States)

    Shukla, Shashi P.; Roy, Mainak; Mukherjee, Poulomi; Tyagi, A. K.; Mukherjee, Tulsi; Adhikari, Soumyakanti


    We report a simple green chemistry to synthesize and stabilize monodispersed silver and gold nanoparticles sols by reducing aqueous solution of the respective metal salts in the presence of bilirubin (BR). No additional capping agent was used in the process of stabilization of the nanoparticles. As a completely new finding, we have observed that BR known to be toxic at higher concentration in one hand and conversely an antioxidant at physiological concentration reduces these metal ions to form the respective metal nanoparticles. Moreover, BR and its oxidized products also serve as capping agents to the nanoparticles. The particles were characterized by transmission electron microscopy. BR and its oxidized products capped nanoparticles are stable for months. The UV-Vis absorption spectra of the silver sol show the plasmon peak of symmetric spherical particles which was further reflected in the TEM images. The sizes of the silver particles were about 5 nm. These silver particles showed reasonably high antibacterial activity in Gram negative wild type E. coli. In the case of interaction of BR with gold ions, we could obtain cubic gold nanoparticles of average sizes 20-25 nm. Possible modes of anchorage of BR and/its oxidized products to silver nanoparticles were demonstrated by surface-enhanced resonance Raman spectroscopy (SERS) that in turn demonstrated the feasibility of using these nanoparticles as SERS substrates.

  9. Interaction of bilirubin with Ag and Au ions: green synthesis of bilirubin-stabilized nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, Shashi P. [Bhabha Atomic Research Centre, Radiation and Photochemistry Division (India); Roy, Mainak [Bhabha Atomic Research Centre, Chemistry Division (India); Mukherjee, Poulomi [Bhabha Atomic Research Centre, Nuclear Agriculture and Biotechnology Division (India); Tyagi, A. K. [Bhabha Atomic Research Centre, Chemistry Division (India); Mukherjee, Tulsi [Bhabha Atomic Research Centre, Chemistry Group (India); Adhikari, Soumyakanti, E-mail: [Bhabha Atomic Research Centre, Radiation and Photochemistry Division (India)


    We report a simple green chemistry to synthesize and stabilize monodispersed silver and gold nanoparticles sols by reducing aqueous solution of the respective metal salts in the presence of bilirubin (BR). No additional capping agent was used in the process of stabilization of the nanoparticles. As a completely new finding, we have observed that BR known to be toxic at higher concentration in one hand and conversely an antioxidant at physiological concentration reduces these metal ions to form the respective metal nanoparticles. Moreover, BR and its oxidized products also serve as capping agents to the nanoparticles. The particles were characterized by transmission electron microscopy. BR and its oxidized products capped nanoparticles are stable for months. The UV-Vis absorption spectra of the silver sol show the plasmon peak of symmetric spherical particles which was further reflected in the TEM images. The sizes of the silver particles were about 5 nm. These silver particles showed reasonably high antibacterial activity in Gram negative wild type E. coli. In the case of interaction of BR with gold ions, we could obtain cubic gold nanoparticles of average sizes 20-25 nm. Possible modes of anchorage of BR and/its oxidized products to silver nanoparticles were demonstrated by surface-enhanced resonance Raman spectroscopy (SERS) that in turn demonstrated the feasibility of using these nanoparticles as SERS substrates.

  10. Distant Determination of Bilirubin Distribution in Skin by Multi-Spectral Imaging (United States)

    Saknite, I.; Jakovels, D.; Spigulis, J.


    For mapping the bilirubin distribution in bruised skin the multi-spectral imaging technique was employed, which made it possible to observe temporal changes of the bilirubin content in skin photo-types II and III. The obtained results confirm the clinical potential of this technique for skin bilirubin diagnostics.

  11. Bilirubin binding with liver cystatin induced structural and functional changes. (United States)

    Mustafa, Mir Faisal; Bano, Bilqees


    Cysteine proteinases and their inhibitors play a significant role in the proteolytic environment of the cells. Inhibitors of cysteine proteinases regulate the activity of these enzymes helping in checking the degdration activity of cathepsins. The bilirubin secreated by liver cells can bind to cystatin present in the liver resulting in its functional inactivation, which may further lead to the increase in cathepsins level causing liver cirrhosis. In case of some pathophysiological conditions excess bilirubin gets accumulated e.g. in presence of Fasciola hepatica (liver fluke) in mammals and humans, leading to liver cirrhosis and possibly jaundice or normal blockade of bile duct causing increased level of bilirubin in blood. Protease-cystatin imbalance causes disease progression. In the present study, Bilirubin (BR) and liver cystatin interaction was studied to explore the cystatin inactivation and structural alteration. The binding interaction was studied by UV-absorption, FT-IR and fluorescence spectroscopy. The quenching of protein fluorescence confirmed the binding of BR with buffalo liver cystatin (BLC). Stern-Volmer analysis of BR-BLC system indicates the presence of static component in the quenching mechanism and the number of binding sites to be close to 1. The fluorescence data proved that the fluorescence quenching of liver cystatin by BR was the result of BR-cystatin complex formation. FTIR analysis of BR-Cystatin complex revealed change in the secondary structure due to perturbation in the microenvironment further confirmed by the decreased caseinolytic activity of BLC against papain. Fluorescence measurements also revealed quenching of fluorescence and shift in peak at different time intervals and at varying pH values. Photo-illumination of BR-cystatin complex causes change in the surrounding environment of liver cystatin as indicated by red-shift. The binding constant for BR-BLC complex was found to be 9.279 × 10(4) M(-1). The cystatin binding with

  12. Heme degradation and human disease: diversity is the soul of life. (United States)

    Shibahara, Shigeki; Kitamuro, Tomomi; Takahashi, Kazuhiro


    We all depend on molecular oxygen and heme for our life, as evident from the pigments in blood and daily wastes. About 80% of serum bilirubin is derived from hemoglobin of senescent erythrocytes, which have finished their mission of 120 days and have been phagocytized by macrophages in the reticuloendothelial system. Here we present an overview of the heme degradation processes and relevant disorders by focusing on heme oxygenase-1 (HO-1), a key enzyme in heme catabolism. HO-1 cleaves the porphyrin macrocycle of heme at the expense of molecular oxygen to release a linear tetrapyrrole biliverdin, carbon monoxide, and ferrous iron; biliverdin is rapidly reduced to bilirubin. Bilirubin is transported to the liver (hepatocytes), conjugated with glucuronic acid by bilirubin UDP-glucuronosyltransferase, and excreted into bile. Genetic diversity, a strategy in the host defense, is seen in the human ho-1 and UDP-glucuronosyltransferase genes. Moreover, striking interspecies variations are noted in the regulation of HO-1 expression by hypoxia, heat shock, or interferon-gamma, each of which mainly represses HO-1 expression in human cells. Implications of such a variety are discussed in relevance to the pathogenesis of severe malaria caused by Plasmodium falciparum, the most ancient foe of humans.

  13. Bilirubin exerts pro-angiogenic property through Akt-eNOS-dependent pathway. (United States)

    Ikeda, Yasumasa; Hamano, Hirofumi; Satoh, Akiho; Horinouchi, Yuya; Izawa-Ishizawa, Yuki; Kihira, Yoshitaka; Ishizawa, Keisuke; Aihara, Ken-Ichi; Tsuchiya, Koichiro; Tamaki, Toshiaki


    Low serum bilirubin levels are associated with the risk of cardiovascular diseases including peripheral artery disease. Bilirubin is known to exert its property such as antioxidant effect or the enhancement of flow-mediated vasodilation, however, bilirubin action on angiogenesis remains unclear. To investigate the molecular mechanism of bilirubin on angiogenic effect, we first employed C57BL/6J mice with unilateral hindlimb ischemia surgery and divided the mice into two groups (vehicle-treated group and bilirubin-treated group). The analysis of laser speckle blood flow demonstrated the enhancement of blood flow recovery in response to ischemia of mice with bilirubin treatment. The density of capillaries was significantly higher in ischemic-adductor muscles of bilirubin-treated mice. The phosphorylated levels of endothelial nitric oxide synthase (eNOS) and Akt were increased in ischemic skeletal muscles of mice with bilirubin treatment compared with vehicle treatment. In in vitro experiments by using human aortic endothelial cells, bilirubin augmented eNOS and Akt phosphorylation, cell proliferation, cell migration and tube formation. These bilirubin actions on endothelial cell activation were inhibited by LY294002, a phosphatidylinositol 3-kinase inhibitor. In conclusion, bilirubin promotes angiogenesis through endothelial cells activation via Akt-eNOS-dependent manner.

  14. Determination of bilirubin by thermal lens spectrometry and studies of its transport into hepatic cells (United States)

    Margon, A.; Terdoslavich, M.; Cocolo, A.; Decorti, G.; Passamonti, S.; Franko, M.


    The liver is responsible for clearance of bilirubin, the end product of heme catabolism, from the bloodstream. The main aim of our investigation was to determine the role of the carrier protein bilitranslocase in bilirubin uptake into the liver. Our experiments consisted of exposing cell cultures to bilirubin solutions under different conditions and measuring the uptake of bilirubin into the cells. However, since bilirubin is only slightly soluble in aqueous solution (pH 7.4), we had to use bilirubin concentrations that are far below the limit of detection of the commonly used techniques (e.g. LOD for HPLC with UV-Vis detection \\cong 10 μM). TLS showed up to be a suitable technique for investigation of bilirubin uptake with an LOD of 2 nM. Under basal conditions, bilirubin uptake did not occur. However, increase of cytosolic NADH due to catabolism of specific substrates (e.g. lactate or ethanol) seemed to trigger bilirubin uptake. Furthermore, bilirubin uptake was completely inhibited by addition of specific anti-bilitranslocase antibodies. We can thus infer that, under these conditions, bilitranslocase is the main bilirubin transporter.

  15. Photodamage of the cells in culture sensitized with bilirubin (United States)

    Kozlenkova, O. A.; Plavskaya, L. G.; Mikulich, A. V.; Leusenko, I. A.; Tretyakova, A. I.; Plavskii, V. Yu


    It has been shown that exposure to radiation of LED sources of light with an emission band maximum at about 465 and 520 nm having substantially identical damaging effects on animal cells in culture, that are in a logarithmic growth phase and preincubated with pigment. Photobiological effect is caused by photodynamic processes involving singlet oxygen generated by triplet excited sensitizer. Mono-exponential type dependence of cell survival on the energy dose indicates that it is bilirubin that acts as a sensitizer but not its photoproducts. The inclusion of bilirubin in the cells, where it is primarily localized in the mitochondria cells, it is accompanied by multiple amplification photochemical stability compared to pigment molecules bound with albumin

  16. A New Bilirubin Concentration Detection Method by Light Reflection

    CERN Document Server

    Subasilar, B


    A new and simple method of blood bilirubin detection through light reflection from skin is developed. The basic improvement over the existing methods is in the design of the light emitter and detector geometry which facilitates a two-stream plane parallel homogenous medium solution to the emitting-scatterig radiative transfer equation. The forward peak in the scattering phase function that is characteristic of water droplets and water filled media is accounted for through a proper method named delta-Eddington approximation.

  17. The Relationship of the Anti-Oxidant Bilirubin with Free Thyroxine Is Modified by Insulin Resistance in Euthyroid Subjects

    NARCIS (Netherlands)

    Deetman, Petronella E.; Bakker, Stephan J. L.; Kwakernaak, Arjan J.; Navis, Gerjan; Dullaart, Robin P. F.


    Background: The strong anti-oxidative properties of bilirubin largely explain its cardioprotective effects. Insulin resistance is featured by low circulating bilirubin. Thyroid hormone affects both bilirubin generation and its biliary transport, but it is unknown whether circulating bilirubin is ass

  18. Bilirubin: an endogenous molecule with antiviral activity in vitro.

    Directory of Open Access Journals (Sweden)

    Rosaria eSantangelo


    Full Text Available Bilirubin-IX-alpha (BR is the final product of heme metabolism through the heme oxygenase/biliverdin reductase (HO/BVR system. Previous papers reported on the microbicidal effects of the HO by-products biliverdin-IX-alpha, carbon monoxide and iron, through either direct or indirect mechanisms. In this paper the evidence of a virucidal effect of BR against human herpes simplex virus type 1 (HSV-1 and the enterovirus EV71 was provided. Bilirubin-IX-alpha, at concentrations 1-10 µM, close to those found in blood and tissues, significantly reduced HSV-1 and EV71 replication in Hep-2 and Vero cell lines, respectively. Bilirubin-IX-alpha inhibited viral infection of Hep-2 and Vero cells when given 2 hours before, concomitantly and 2 hours after viral infection. Furthermore, BR retained its antiviral activity even complexed with a saturating concentration of human serum-albumin. Moreover, 10 µM BR increased the formation of nitric oxide and the phosphorylation of JNK in Vero and Hep-2 cell lines, respectively, thus implying a role of these two pathways in the mechanism of antiviral activity of the bile pigment. In conclusion, these results support the antiviral effect of BR against HSV-1 and enterovirus in vitro, and put the basis for further basic and clinical studies to understand the real role of BR as an endogenous antiviral molecule.

  19. Molecularly Imprinted Quartz Crystal Microbalance Sensor (QCM for Bilirubin Detection

    Directory of Open Access Journals (Sweden)

    Çiğdem Çiçek


    Full Text Available This study aims the preparation of a QCM sensor for the detection of bilirubin in human plasma. Bilirubin-imprinted poly-(2-hydroxyethyl methacrylate-N-methacryloyl-l-tryptophan methyl ester (PHEMATrp nanofilm (MIP on the gold surface of a QCM chip was synthesized by the molecular imprinting technique. Meanwhile, the non-imprinted PHEMATrp (NIP nanofilm was synthesized by the same experimental technique to examine the imprinting effect. Characterization of MIP and NIP nanofilms on the QCM chip surface was achieved by atomic force microscopy (AFM, ellipsometry, Fourier transform infrared spectrophotometry-attenuated total reflectance (FTIR-ATR and contact angle measurements (CA. The observations indicated that the nanofilm was almost in a monolayer. Thereinafter, the imprinted and the non-imprinted QCM chips were connected to the QCM system to investigate kinetic and affinity properties. In order to examine the selectivity of the MIP-PHEMATrp nanofilm, competitive adsorption of bilirubin with cholesterol and estradiol was performed. Limit of detection (LOD and limit of quantitation (LOQ values were calculated as 0.45 μg/mL and 0.9 μg/mL, respectively.

  20. Spectroscopic studies on the interaction of bilirubin with liver cystatin. (United States)

    Shah, Aaliya; Bano, Bilqees


    Studies on the role of endogenous metabolites such as bilirubin and their interactions with biomolecules have attracted considerable attention over the past several years. In this work, the interaction of bilirubin (BR) with purified goat liver cystatin (LC) was studied using fluorescence and ultraviolet (UV) spectroscopy. The fluorescence data proved that the fluorescence quenching of liver cystatin by BR was the result of BR-cystatin complex formation. Stern-Volmer analysis of fluorescence quenching data showed the binding constant to be 9.27 x 10⁴ M⁻¹ and the number of binding sites to be close to unity. The conformation of the BR-cystatin complex was found to change upon varying the pH of the complex. The BR-cystatin complex was found to have reduced papain inhibitory activity. Photo-illumination of BR-cystatin complex causes perturbation in the micro-environment of goat liver cystatin as indicated by red-shift. This report summarizes our research efforts to reveal the mechanism of interaction of bilirubin with liver cystatin.

  1. Association between flavonoid-rich fruit and vegetable consumption and total serum bilirubin. (United States)

    Loprinzi, Paul D; Mahoney, Sara E


    Emerging work demonstrates that serum bilirubin is a novel biomarker implicated in cardiovascular and metabolic diseases. However, we have a limited understanding of the influence of flavonoid-rich fruit and vegetable consumption on bilirubin levels, which was the purpose of this study. Data from the 2003 to 2006 National Health and Nutrition Examination survey were used (n = 1783; 18-85 years of age), with analyses performed in 2014. Total serum bilirubin was measured from a blood sample. Using a food frequency questionnaire (FFQ), a flavonoid index variable was created summing the frequency of consumption of flavonoid-rich foods. After adjustments, greater consumption of flavonoid-rich fruits and vegetables was positively associated with bilirubin levels. Our findings suggest an association between flavonoid-rich fruit and vegetable consumption and bilirubin levels. If confirmed by prospective and experimental studies, then regular consumption of flavonoid-rich fruits and vegetables should be promoted to increase levels of bilirubin.

  2. Glucuronidation of thyroxine in human liver, jejunum, and kidney microsomes. (United States)

    Yamanaka, Hiroyuki; Nakajima, Miki; Katoh, Miki; Yokoi, Tsuyoshi


    Glucuronidation of thyroxine is a major metabolic pathway facilitating its excretion. In this study, we characterized the glucuronidation of thyroxine in human liver, jejunum, and kidney microsomes, and identified human UDP-glucuronosyltransferase (UGT) isoforms involved in the activity. Human jejunum microsomes showed a lower K(m) value (24.2 microM) than human liver (85.9 microM) and kidney (53.3 microM) microsomes did. Human kidney microsomes showed a lower V(max) value (22.6 pmol/min/mg) than human liver (133.4 pmol/min/mg) and jejunum (184.6 pmol/min/mg) microsomes did. By scaling-up, the in vivo clearances in liver, intestine, and kidney were estimated to be 1440, 702, and 79 microl/min/kg body weight, respectively. Recombinant human UGT1A8 (108.7 pmol/min/unit), UGT1A3 (91.6 pmol/min/unit), and UGT1A10 (47.3 pmol/min/unit) showed high, and UGT1A1 (26.0 pmol/min/unit) showed moderate thyroxine glucuronosyltransferase activity. The thyroxine glucuronosyltransferase activity in microsomes from 12 human livers was significantly correlated with bilirubin O-glucuronosyltransferase (r = 0.855, p microsomes was mainly catalyzed by UGT1A8 and UGT1A10 and to a lesser extent by UGT1A1, and the activity in human kidney microsomes was mainly catalyzed by UGT1A7, UGT1A9, and UGT1A10. The changes of activities of these UGT1A isoforms via inhibition and induction by administered drugs as well as genetic polymorphisms may be a causal factor of interindividual differences in the plasma thyroxine concentration.

  3. High preoperative bilirubin values protect against reperfusion injury after live donor liver transplantation. (United States)

    Spetzler, Vinzent N; Goldaracena, Nicolas; Kaths, Johann M; Marquez, Max; Selzner, Nazia; Cattral, Mark S; Greig, Paul D; Lilly, Les; McGilvray, Ian D; Levy, Gary A; Ghanekar, Anand; Renner, Eberhard L; Grant, David R; Selzner, Markus


    Heme Oxygenase-1 and its product biliverdin/bilirubin have been demonstrated to protect against ischemia/reperfusion injury (IRI). We investigated whether increased preoperative bilirubin values of transplant recipients decrease IRI. Preoperative bilirubin levels of live donor liver recipients were correlated to postoperative liver transaminase as a marker of IRI. Additionally, two recipient groups with pretransplant bilirubin levels >24 μmol/l (n = 348) and ≤24 μmol/l (n = 118) were compared. Post-transplant liver function, complications, length of hospital stay, and patient and graft survival were assessed. Preoperative bilirubin levels were negatively correlated to the postoperative increase in transaminases suggesting a protective effect against IRI. The maximal rise of ALT after transplantation in high versus low bilirubin patients was 288 (-210-2457) U/l vs. 375 (-11-2102) U/l, P = 0.006. Bilirubin remained a significant determining factor in a multivariate linear regression analysis. The MELD score and its individual components as a marker of severity of chronic liver disease were significantly higher in the high versus low bilirubin group (P bilirubin levels of liver recipients before live donor transplantation is associated with decreased postoperative IRI.

  4. Bilirubin Increases Insulin Sensitivity by Regulating Cholesterol Metabolism, Adipokines and PPARγ Levels. (United States)

    Liu, Jinfeng; Dong, Huansheng; Zhang, Yong; Cao, Mingjun; Song, Lili; Pan, Qingjie; Bulmer, Andrew; Adams, David B; Dong, Xiao; Wang, Hongjun


    Obesity can cause insulin resistance and type 2 diabetes. Moderate elevations in bilirubin levels have anti-diabetic effects. This study is aimed at determining the mechanisms by which bilirubin treatment reduces obesity and insulin resistance in a diet-induced obesity (DIO) mouse model. DIO mice were treated with bilirubin or vehicle for 14 days. Body weights, plasma glucose, and insulin tolerance tests were performed prior to, immediately, and 7 weeks post-treatment. Serum lipid, leptin, adiponectin, insulin, total and direct bilirubin levels were measured. Expression of factors involved in adipose metabolism including sterol regulatory element-binding protein (SREBP-1), insulin receptor (IR), and PPARγ in liver were measured by RT-PCR and Western blot. Compared to controls, bilirubin-treated mice exhibited reductions in body weight, blood glucose levels, total cholesterol (TC), leptin, total and direct bilirubin, and increases in adiponectin and expression of SREBP-1, IR, and PPARγ mRNA. The improved metabolic control achieved by bilirubin-treated mice was persistent: at two months after treatment termination, bilirubin-treated DIO mice remained insulin sensitive with lower leptin and higher adiponectin levels, together with increased PPARγ expression. These results indicate that bilirubin regulates cholesterol metabolism, adipokines and PPARγ levels, which likely contribute to increased insulin sensitivity and glucose tolerance in DIO mice.

  5. The kinetics of oxidation of bilirubin and ascorbic acid in solution (United States)

    Solomonov, A. V.; Rumyantsev, E. V.; Kochergin, B. A.; Antina, E. V.


    The results of a comparative study of the oxidation of bilirubin, ascorbic acid, and their mixture in aqueous solutions under the action of air oxygen and hydrogen peroxide are presented. The observed and true rate constants for the oxidation reactions were determined. It was shown that the oxidation of tetrapyrrole pigment occurred under these conditions bypassing the stage of biliverdin formation to monopyrrole products. Simultaneous oxidation of bilirubin and ascorbic acid was shown to be accompanied by the inhibition of ascorbic acid oxidation by bilirubin, whereas ascorbic acid itself activated the oxidation of bilirubin.

  6. Unconjugated bilirubin mediates heme oxygenase-1-induced vascular benefits in diabetic mice. (United States)

    Liu, Jian; Wang, Li; Tian, Xiao Yu; Liu, Limei; Wong, Wing Tak; Zhang, Yang; Han, Quan-Bin; Ho, Hing-Man; Wang, Nanping; Wong, Siu Ling; Chen, Zhen-Yu; Yu, Jun; Ng, Chi-Fai; Yao, Xiaoqiang; Huang, Yu


    Heme oxygenase-1 (HO-1) exerts vasoprotective effects. Such benefit in diabetic vasculopathy, however, remains unclear. We hypothesize that bilirubin mediates HO-1-induced vascular benefits in diabetes. Diabetic db/db mice were treated with hemin (HO-1 inducer) for 2 weeks, and aortas were isolated for functional and molecular assays. Nitric oxide (NO) production was measured in cultured endothelial cells. Hemin treatment augmented endothelium-dependent relaxations (EDRs) and elevated Akt and endothelial NO synthase (eNOS) phosphorylation in db/db mouse aortas, which were reversed by the HO-1 inhibitor SnMP or HO-1 silencing virus. Hemin treatment increased serum bilirubin, and ex vivo bilirubin treatment improved relaxations in diabetic mouse aortas, which was reversed by the Akt inhibitor. Biliverdin reductase silencing virus attenuated the effect of hemin. Chronic bilirubin treatment improved EDRs in db/db mouse aortas. Hemin and bilirubin reversed high glucose-induced reductions in Akt and eNOS phosphorylation and NO production. The effect of hemin but not bilirubin was inhibited by biliverdin reductase silencing virus. Furthermore, bilirubin augmented EDRs in renal arteries from diabetic patients. In summary, HO-1-induced restoration of endothelial function in diabetic mice is most likely mediated by bilirubin, which preserves NO bioavailability through the Akt/eNOS/NO cascade, suggesting bilirubin as a potential therapeutic target for clinical intervention of diabetic vasculopathy.

  7. 21 CFR 862.1113 - Bilirubin (total and unbound) in the neonate test system. (United States)


    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1113 Bilirubin (total and unbound) in the neonate test system....

  8. 21 CFR 862.1115 - Urinary bilirubin and its conjugates (nonquantitative) test system. (United States)


    ... HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1115 Urinary bilirubin and its conjugates (nonquantitative)...

  9. Bilirubin as an antioxidant: kinetic studies of the reaction of bilirubin with peroxyl radicals in solution, micelles, and lipid bilayers. (United States)

    Hatfield, Gillian L; Barclay, L Ross C


    Bilirubin (BR) showed very weak antioxidant activity in a nonpolar medium of styrene or cumene in chlorobenzene. In contrast, BR exhibited strong antioxidant activity in polar media such as aqueous lipid bilayers or SDS micelles/methyl linoleate (pH 7.4), where the rate with peroxyl radicals, k(inh) = 5.0 x 10(4) M(-)(1) s(-)(1), was comparable to that with vitamin E analogues, Trolox, or PMHC. An electron-transfer mechanism accounts for the effect of the medium on the antioxidant properties of BR.

  10. Biochemical measurement of bilirubin with an evanescent wave optical sensor (United States)

    Poscio, Patrick; Depeursinge, Christian D.; Emery, Y.; Parriaux, Olivier M.; Voirin, Guy


    Optical sensing techniques can be considered as powerful information sources on the biochemistry of tissue, blood, and physiological fluids. Various sensing modalities can be considered: spectroscopic determination of the fluorescence or optical absorption of the biological medium itself, or more generally, of a reagent in contact with the biological medium. The principle and realization of the optical sensor developed are based on the use of polished fibers: the cladding of a monomode fiber is removed on a longitudinal section. The device can then be inserted into an hypodermic needle for in-vivo measurements. Using this minute probe, local measurements of the tissue biochemistry or metabolic processes can be obtained. The sensing mechanism is based on the propagation of the evanescent wave in the tissues or reagent: the proximity of the fiber core allows the penetration of the model field tail into the sensed medium, with a uniquely defined field distribution. Single or multi-wavelength analysis of the light collected into the fiber yields the biochemical information. Here an example of this sensing technology is discussed. In-vitro measurement of bilirubin in gastric juice demonstrates that the evanescent wave optical sensor provides a sensitivity which matches the physiological concentrations. A device is proposed for in-vivo monitoring of bilirubin concentration in the gastro-oesophageal tract.

  11. Bilirubin inhibits iNOS expression and NO production in response to endotoxin in rats. (United States)

    Wang, Weizheng W; Smith, Darcey L H; Zucker, Stephen D


    The inducible isoform of heme oxygenase (HO), HO-1, has been shown to play an important role in attenuating tissue injury. Because HO-1 catalyzes the rate-limiting step in bilirubin synthesis, we examined the hypothesis that bilirubin is a key mediator of HO-1 cytoprotection, employing a rat model of endotoxemia. Bilirubin treatment resulted in improved survival and attenuated liver injury in response to lipopolysaccharide infusion. Serum levels of NO and tumor necrosis factor alpha, key mediators of endotoxemia, and hepatic inducible nitric oxide synthase (iNOS) expression were significantly lower in bilirubin-treated rodents versus control animals. Both intraperitoneal and local administration of bilirubin also was found to ameliorate hindpaw inflammation induced by the injection of lambda-carrageenan. Consistent with in vivo results, bilirubin significantly inhibited iNOS expression and suppressed NO production in lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophages. In contrast, bilirubin treatment induced a threefold increase in LPS-mediated prostaglandin synthesis in the absence of significant changes in cyclooxygenase expression or activity, suggesting that bilirubin enhances substrate availability for eicosanoid synthesis. Bilirubin had no effect on LPS-mediated activation of nuclear factor kappaB or p38 mitogen-activated protein kinase, consistent with a nuclear factor kappaB-independent mechanism of action. Taken together, these data support a cytoprotective role for bilirubin that is mediated, at least in part, through the inhibition of iNOS expression and, potentially, through stimulation of local prostaglandin E2 production. In conclusion, our findings suggest a role for bilirubin in mollifying tissue injury in response to inflammatory stimuli and support the possibility that the phenomenon of "jaundice of sepsis" represents an adaptive physiological response to endotoxemia. Supplementary material for this article can be found on the

  12. Copy number variation in sulfotransferase isoform 1A1 (SULT1A1 is significantly associated with enzymatic activity in Japanese subjects

    Directory of Open Access Journals (Sweden)

    Yu X


    Full Text Available Xinfeng Yu,1 Takahiro Kubota,2 Ishwori Dhakal,1 Setsuo Hasegawa,3 Suzanne Williams,1 Shogo Ozawa,4 Susan Kadlubar11Division of Medical Genetics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA; 2Chiba Institute of Science, Chiba, Japan; 3Sekino Clinical Pharmacology Clinic, Tokyo, Japan; 4Iwate Medical University, Iwate, JapanAbstract: Sulfotransferase isoform 1A1 (SULT1A1 plays a key role in the metabolism of a variety of endo- and xenobiotics and it's activity could influence response to drugs. Our previous studies have focused on the impact of genetic variants of SULT1A1 on enzymatic activity in Caucasians and African-Americans. However, the contribution of genetic variants to SULT1A1 activity in Asians has not been explored. In this study, we investigated the collective effects of both SULT1A1 copy number variants (CNVs and single nucleotide polymorphisms (SNPs in the promoter region, coding region, and 3´ untranslated region on SULT1A1 activity in Japanese subjects. SNPs in the SULT1A1 promoter and 3´ untranslated region were not associated with SULT1A1 activity (P > 0.05. SULT1A1*1/2 (Arg213His was marginally associated with SULT1A1 activity (P = 0.037. However, SULT1A1 CNVs were strongly associated with SULT1A1 activity (trend test P = 0.008 and accounted for 10% of the observed variability in activity for Japanese subjects. In conclusion, SULT1A1 CNVs play a pivotal role in determination of SULT1A1 activity in Japanese subjects, highlighting the influence of ethnic differences in SULT1A1 genetic variants on drug metabolism and therapeutic efficacy.Keywords: CNV, genotype, phenotype, SULT1A1, single nucleotide polymorphisms

  13. Stopped-flow studies of spectral changes in bilirubin-human serum albumin following an alkaline pH jump and following binding of bilirubin

    DEFF Research Database (Denmark)

    Honoré, B


    ). The changes were analyzed according to a scheme of consecutive unimolecular reactions. Spectral monitoring of a pH jump from 11.3 to 11.8 reveals that the bilirubin-albumin complex changes its structure in several steps. The UV absorption spectra show that 3.8 tyrosine residues ionize in the first step, 2.......5 in the second, none in the third, and 0.8 in the fourth and following steps. The visible absorption spectrum of bound bilirubin changes in the second, third, and fourth steps. The bilirubin spectra of the different bilirubin-albumin complexes occurring in the transition show a common isosbestic point at 445 nm...

  14. Clinical system model for monitoring the physiological status of jaundice by extracting bilirubin components from skin diffuse reflectance spectra (United States)

    Kumar, Alla S.; Clark, Joseph; Beyette, Fred R., Jr.


    Neonatal jaundice is a medical condition which occurs in newborns as a result of an imbalance between the production and elimination of bilirubin. The excess bilirubin in the blood stream diffuses into the surrounding tissue leading to a yellowing of the skin. As the bilirubin levels rise in the blood stream, there is a continuous exchange between the extra vascular bilirubin and bilirubin in the blood stream. Exposure to phototherapy alters the concentration of bilirubin in the vascular and extra vascular regions by causing bilirubin in the skin layers to be broken down. Thus, the relative concentration of extra vascular bilirubin is reduced leading to a diffusion of bilirubin out of the vascular region. Diffuse reflectance spectra from human skin contains physiological and structural information of the skin and nearby tissue. A diffuse reflectance spectrum must be captured before and after blanching in order to isolate the intravascular and extra vascular bilirubin. A new mathematical model is proposed with extra vascular bilirubin concentration taken into consideration along with other optical parameters in defining the diffuse reflectance spectrum from human skin. A nonlinear optimization algorithm has been adopted to extract the optical properties (including bilirubin concentration) from the skin reflectance spectrum. The new system model and nonlinear algorithm have been combined to enable extraction of Bilirubin concentrations within an average error of 10%.

  15. Ammonia-induced energy disorders interfere with bilirubin metabolism in hepatocytes. (United States)

    Wang, Qiongye; Wang, Yanfang; Yu, Zujiang; Li, Duolu; Jia, Bin; Li, Jingjing; Guan, Kelei; Zhou, Yubing; Chen, Yanling; Kan, Quancheng


    Hyperammonemia and jaundice are the most common clinical symptoms of hepatic failure. Decreasing the level of ammonia in the blood is often accompanied by a reduction in bilirubin in patients with hepatic failure. Previous studies have shown that hyperammonemia can cause bilirubin metabolism disorders, however it is unclear exactly how hyperammonemia interferes with bilirubin metabolism in hepatocytes. The purpose of the current study was to determine the mechanism or mechanisms by which hyperammonemia interferes with bilirubin metabolism in hepatocytes. Cell viability and apoptosis were analyzed in primary hepatocytes that had been exposed to ammonium chloride. Mitochondrial morphology and permeability were observed and analyzed, intermediates of the tricarboxylic acid (TCA) cycle were determined and changes in the expression of enzymes related to bilirubin metabolism were analyzed after ammonia exposure. Hyperammonemia inhibited cell growth, induced apoptosis, damaged the mitochondria and hindered the TCA cycle in hepatocytes. This led to a reduction in energy synthesis, eventually affecting the expression of enzymes related to bilirubin metabolism, which then caused further problems with bilirubin metabolism. These effects were significant, but could be reversed with the addition of adenosine triphosphate (ATP). This study demonstrates that ammonia can cause problems with bilirubin metabolism by interfering with energy synthesis.

  16. Relationship of Bilirubin Levels in Infancy to Later Intellectual Development. Interim Report No. 20. (United States)

    Rubin, Rosalyn A.; And Others

    The relationship of bilirubin (a red bile pigment that is sometimes found in the urine and occurs in the blood and tissues in jaundice) in infancy to later intellectual development was investigated in 241 infants with moderately elevated and high bilirubin levels. Ss were administered motor, psycholinguistic, and intelligence tests at age 8…

  17. Circulating Total Bilirubin and Risk of Incident Cardiovascular Disease in the General Population

    NARCIS (Netherlands)

    Kunutsor, Setor K.; Bakker, Stephan J. L.; Gansevoort, Ronald T.; Chowdhury, Rajiv; Dullaart, Robin P. F.


    OBJECTIVE: To assess the association of circulating total bilirubin and cardiovascular disease (CVD) risk in a new prospective study and to determine whether adding information on total bilirubin values to established cardiovascular risk factors is associated with improvement in prediction of CVD ri

  18. New Sorbent for Bilirubin Removal from Human Plasma: Albumin Immobilized Microporous Membranous PTFE Capillaries

    Institute of Scientific and Technical Information of China (English)

    Lei ZHANG; Gu JIN


    In this study, we developed a tailored capillary sorbent for bilirubin removal. For immobilized bioligand, capillaries were grafted with epoxy groups using RIGP. The HSA immobilized capillaries has a high affinity adsorption capacity (71.2 mg bilirubin/g polymer) and a shorter adsorption equilibrium time (about 60 min).

  19. Association of bilirubin and protein thiols in relation to copper and ceruloplasmin in hyperbilirubinemic patients

    Institute of Scientific and Technical Information of China (English)

    Mungli Prakash; Jeevan K Shetty; Roshan D'Souza; Suhasa Upadhya; Vijay Kumar


    Objective:Bilirubin is a double edged sword in biological system,acting as a toxic molecule and cytoprotecrant.Unconjugated bilirubin is proved to show antioxidant activity in vitro and in vivo.In the current work we tried to know the relationship between both conjugated and unconjugated bilirubin with copper and protein thiols in patients with hyperbilirnbinemia.Methods:Study was conducted on 56 hyperbilirubinemic cases and 56 healthy controls.Serum copper,ceruloplasmin,protein thiols,total bilirubin,conjugated and unconjugated bilirubin,unconjugated bilimbin/albumin ratio,total protein,albumin,AST,ALT and ALP were estimated.Results:There was significant increase in serum copper,total bilirubin,conjugated and unconjugated bilimbin.uriconjugated bilirubin/albumin ratio,AST,ALT,and ALP,and decrease in serum ceruloplasmin,protein thiols,total protein,and albumin in hyperbilimbinemic cases when compared to healthy controls.Conjugated bilimbin correlated positively with liver enzymes AST and ALP,and negatively with protein thials,total protein and albumin.Unconjugated bilirubin correlated positively with ALT.Protein thiols correlated negatively with copper and positively with ceruloplasmin,and also correlated negativelv with liver enzymes like AST,ALT and ALP,and positively with total protein and albumin.Conclusion:Combination of elevated levels of trace elements like copper and availability of reducing agent like bilimbin may prove deleterious by generating free radicals.


    Institute of Scientific and Technical Information of China (English)

    贲晓明; 秦玉明; 吴圣楣; 张惠民; 陈舜年; 夏振炜


    Objective Evaluate the sensitivity and reliability of visual evoked potential to flash ( FVEP ) in detecting bilirubin neurotoxicity and approach the risk parameters of bilirubin neurotoxicity in hyperbilirubinernia newborns. Methods Based on the successful establishment of animal models for acute bilirubin encephalopathy by intraperitoneal infusion of bilirubin with a dosage of 100~200μg /g body weight to 1-weekold guinea pigs, the F-VEP was recorded in animal models and human neonates with hyperbilirubinemia, and the sensitivity and reliability of F-VEP in detecting bilirubin neurotoxicity were evaluated. Results F-VEP features and its P1 latency significantly correlated to brain adenosine triphosphate (ATP) level, neurobehavioral and neuropathological changes in experimental bilirubin encephalopathy ; neonates with hyperbilirubinemia showed significant F-VEP changes characterized by absence of P1 or P1 latency prolonged in 1~7-dayold newborns, especially when the jaundice was caused by immunoincompatibility and infectious diseases. Conclusion F-VEP would be a good discriminator for bilirubin neurotoxicity, and can become a promising technique in monitoring bilirubin encephalopathy.

  1. Effect of bilirubin on triglyceride synthesis in streptozotocin-induced diabetic nephropathy. (United States)

    Xu, Jianwei; Lee, Eun Seong; Baek, Seon Ha; Ahn, Shin-Young; Kim, Sejoong; Na, Ki Young; Chae, Dong-Wan; Chin, Ho Jun


    We aimed to elucidate the effect of bilirubin on dyslipidemia and nephropathy in a diabetes mellitus (DM) type I animal model. Sprague-Dawley rats were separated into control, DM, and bilirubin-treated DM (Bil) groups. The Bil group was injected intraperitoneally with 60 mg/kg bilirubin 3 times per week and hepatoma cells were cultured with bilirubin at a concentration of 0.3 mg/dL. The Bil group showed lower serum creatinine levels 5 weeks after diabetes onset. Bilirubin treatment also decreased the amount of mesangial matrix, lowered the expression of renal collagen IV and transforming growth factor (TGF)-β1, and reduced the level of apoptosis in the kidney, compared to the DM group. These changes were accompanied by decreased tissue levels of hydrogen superoxide and NADPH oxidase subunit proteins. Bilirubin decreased serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), free fatty acids, and triglycerides (TGs), as well as the TG content in the liver tissues. Bilirubin suppressed protein expression of LXRα, SREBP-1, SCD-1, and FAS, factors involved in TG synthesis that were elevated in the livers of DM rats and hepatoma cells under high-glucose conditions. In conclusion, bilirubin attenuates renal dysfunction and dyslipidemia in diabetes by suppressing LXRα and SREBP-1 expression and oxidative stress.

  2. Purification, characterization and decolorization of bilirubin oxidase from Myrothecium verrucaria 3.2190 (United States)

    Myrothecium verrucaria 3.2190 is a nonligninolytic fungus that produces bilirubin oxidase. Both Myrothecium verrucaria and the extracellular bilirubin oxidase were tested for their ability to decolorize indigo carmine. The biosorption and biodegradation of the dye were detected during the process of...

  3. Multiple binding of bilirubin to human serum albumin and cobinding with laurate

    DEFF Research Database (Denmark)

    Sato, H; Honoré, B; Brodersen, R


    Numerical analysis of multiple binding of two ligands to one carrier has been accomplished, using the principle of several sets of acceptable binding constants, with bilirubin-laurate-albumin as an example. Binding of bilirubin to defatted human serum albumin was investigated by a spectroscopic m...

  4. Thyroid hormone uptake in cultured rat anterior pituitary cells: effects of energy status and bilirubin

    NARCIS (Netherlands)

    F.W.J.S. Wassen (Frank); E.P.C.M. Moerings (Ellis); H. van Toor (Hans); G. Hennemann; M.E. Everts (Maria)


    textabstractTransport of thyroxine (T(4)) into the liver is inhibited in fasting and by bilirubin, a compound often accumulating in the serum of critically ill patients. We tested the effects of chronic and acute energy deprivation, bilirubin and its precursor biliverdi

  5. Metabolism of bilirubin by human cytochrome P450 2A6

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Bakar, A' edah, E-mail: [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Arthur, Dionne M. [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide (Australia); Wikman, Anna S. [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Department of Pharmaceutical Biosciences, Uppsala University, SE-75123 Uppsala (Sweden); Rahnasto, Minna; Juvonen, Risto O.; Vepsäläinen, Jouko; Raunio, Hannu [School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, POB 1627, 70211 Kuopio (Finland); Ng, Jack C. [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide (Australia); Lang, Matti A. [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia)


    The mouse cytochrome P450 (CYP) 2A5 has recently been shown to function as hepatic “Bilirubin Oxidase” (Abu-Bakar, A., et al., 2011. Toxicol. Appl. Pharmacol. 257, 14–22). To date, no information is available on human CYP isoforms involvement in bilirubin metabolism. In this paper we provide novel evidence for human CYP2A6 metabolising the tetrapyrrole bilirubin. Incubation of bilirubin with recombinant yeast microsomes expressing the CYP2A6 showed that bilirubin inhibited CYP2A6-dependent coumarin 7-hydroxylase activity to almost 100% with an estimated K{sub i} of 2.23 μM. Metabolite screening by a high-performance liquid chromatography/electrospray ionisation mass spectrometry indicated that CYP2A6 oxidised bilirubin to biliverdin and to three other smaller products with m/z values of 301, 315 and 333. Molecular docking analyses indicated that bilirubin and its positively charged intermediate interacted with key amino acid residues at the enzyme's active site. They were stabilised at the site in a conformation favouring biliverdin formation. By contrast, the end product, biliverdin was less fitting to the active site with the critical central methylene bridge distanced from the CYP2A6 haem iron facilitating its release. Furthermore, bilirubin treatment of HepG2 cells increased the CYP2A6 protein and activity levels with no effect on the corresponding mRNA. Co-treatment with cycloheximide (CHX), a protein synthesis inhibitor, resulted in increased half-life of the CYP2A6 compared to cells treated only with CHX. Collectively, the observations indicate that the CYP2A6 may function as human “Bilirubin Oxidase” where bilirubin is potentially a substrate and a regulator of the enzyme. -- Highlights: ► Human CYP2A6 interacts with bilirubin with a high affinity. ► Bilirubin docking to the CYP2A6 active site is more stable than biliverdin docking. ► Recombinant CYP2A6 microsomes metabolised bilirubin to biliverdin. ► Bilirubin increased the hepatic

  6. Increased conjugated bilirubin is sufficient to initiate screening for biliary atresia

    DEFF Research Database (Denmark)

    Madsen, Stine Skipper; Kvist, Nina; Thorup, Jørgen


    cirrhosis. The Danish Health and Medicines Authority (DHMA) demands diagnostic evaluation of children with elevated level of serum bilirubin after two weeks of age. Biliary atresia has to be excluded if conjugated bilirubin level is above than 20 μmol/l, and/or more than 20% of total bilirubin......: During the period, 73 patients where operated with a portoenterostomy ad modum Kasai. Patients older than 84 days at the time of operation were excluded, 54 patients were available for analysis. Conjugated bilirubin in μmol/l and the percentage value were significantly above the DHMA threshold limit......: mean 129.7 μmol/l (42-334 μmol/l) and 73% (28-97%), respectively. CONCLUSION: The total amount of conjugated bilirubin above 20 μmol/l is sufficient to require further evaluation for biliary atresia. The percentage value is unnecessary and may cause confusion. FUNDING: none. TRIAL REGISTRATION...

  7. Increased large VLDL and small LDL particles are related to lower bilirubin in Type 2 diabetes mellitus

    NARCIS (Netherlands)

    Dullaart, Robin P F; de Vries, Rindert; Lefrandt, Joop D


    OBJECTIVES: Bilirubin may protect against atherosclerotic cardiovascular disease by virtue of its anti-oxidative properties, but lower bilirubin may also be associated to atherogenic lipoprotein abnormalities. We determined associations of plasma (apo)lipoproteins and lipoprotein subfractions in sub

  8. Primary Biliary Cirrhosis and Hemolytic Anemia Confusing Serum Bilirubin Levels

    Directory of Open Access Journals (Sweden)

    M Brackstone


    Full Text Available Hemolysis is observed in more than 50% of patients with cirrhosis. However, there has been little documention of the association of primary biliary cirrhosis with autoimmune hemolytic anemia. Two cases, found within a single practice, of primary biliary cirrhosis coexisting with autoimmune hemolysis and a third case coexisting with hereditary spherocytosis are presented. Anemia in such patients is commonly attributed to chronic disease, and hyperbilirubinemia is attributed to primary biliary cirrhosis. These patients were considered for liver transplantation until the diagnosis of a comorbid hemolytic process was established. This association may be more prevalent than previously recognized. A diagnosis of comorbid hemolysis must always be considered in context with anemia and serum bilirubin levels that rise out of proportion to the severity of the primary biliary cirrhosis.

  9. Bilirubin and Progression of Nephropathy in Type 2 Diabetes : A Post Hoc Analysis of RENAAL With Independent Replication in IDNT

    NARCIS (Netherlands)

    Riphagen, Ineke J.; Deetman, Petronella E.; Bakker, Stephan J. L.; Navis, Gerarda; Cooper, Mark E.; Lewis, Julia B.; de Zeeuw, Dick; Lambers Heerspink, Hiddo


    Bilirubin, a potent endogenous antioxidant, was found to protect against the development of diabetic nephropathy (DN) in rodents. In humans, cross-sectional studies found an inverse relation between bilirubin and DN. We prospectively investigated whether bilirubin is associated with progression of D

  10. Statins alter the hepatobiliary transport of unconjugated and conjugated bilirubin in sandwich-cultured rat hepatocytes. (United States)

    Szabó, Mónika; Veres, Zsuzsa; Bátai-Konczos, Attila; Kékesi, Orsolya; Kis, Emese; Szabó, Kitti; Jemnitz, Katalin


    Several studies have reported that statins occasionally cause impairment of liver functions characterized by elevated serum bilirubin levels, which might be due to altered function of the multidrug resistance-associated proteins (Mrp2/3). We aimed to study the modulation of the hepatobiliary transport of bilirubin by four statin derivatives, atorvastatin, fluvastatin, pravastatin, and rosuvastatin in sandwich-cultured rat hepatocytes. All statins except pravastatin significantly inhibited the uptake of bilirubin. The biliary efflux of bilirubin conjugates was increased by pravastatin and rosuvastatin concentration dependently. Rosuvastatin stimulated not only the Mrp2 mediated biliary, but the Mrp3 mediated sinusoidal elimination, resulting in decreased intracellular bilirubin accumulation. The significantly induced Mrp2/3 protein levels (ranging from 1.5 to 1.8-fold) accounted for the elevated efflux. Cell polarization, the formation of biliary network was also significantly increased by fluvastatin, pravastatin and rosuvastatin (151%, 216% and 275% of the control, respectively). The simultaneous inhibition of the uptake and the stimulation of the sinusoidal and canalicular elimination may explain, at least in part, the clinical observation of elevated serum bilirubin levels. In conclusion, our results suggest that in spite of the elevated serum bilirubin levels, the altered Mrp2 and Mrp3 functions by statins is probably not associated with hepatotoxic effects.

  11. [Haemolysis and turbidity influence on three analysis methods of quantitative determination of total and conjugated bilirubin on ADVIA 1650]. (United States)

    Gobert De Paepe, E; Munteanu, G; Schischmanoff, P O; Porquet, D


    Plasma bilirubin testing is crucial to prevent the occurrence of neonatal kernicterus. Haemolysis may occur during sampling and interfere with bilirubin determination. Moreover, lipidic infusions may induce plasma lipemia and also interfere with bilirubin measurement. We evaluated the interference of haemolysis and lipemia with three methods of total and direct bilirubin measurement adaptated on an Advia 1650 analyser (Siemens Medical Solutions Diagnostics) : Synermed (Sofibel), Bilirubin 2 (Siemens) and Bilirubin Auto FS (Diasys). The measurement of total bilirubin was little affected by haemolysis with all three methods. The Bilirubin 2 (Siemens) method was the less sensitive to haemolysis even at low bilirubin levels. The measurement of conjugated bilirubin was significantly altered by low heamoglobin concentrations for Bilirubin Auto FS(R) (30 microM or 0,192 g/100 mL haemoglobin) and for Synermed (60 microM or 0,484 g/100 mL haemoglobin). In marked contrast, we found no haemoglobin interference with the Direct Bilirubin 2 reagent which complied with the method validation criteria from the French Society for Biological Chemistry. The lipemia up to 2 g/L of Ivelip did not affect neither the measurement of total bilirubin for all three methods nor the measurement of conjugated bilirubin with the Diasys and Siemens reagents. However, we observed a strong interference starting at 0,5 g/L of Ivelip with the Synermed reagent. Our data suggest that both Siemens and Diasys methods allow to measure accurately total and conjugated bilirubin in hemolytic and lipemic samples, nevertheless, the Siemens methodology is less affected by these interferences.

  12. Intraperitoneal Bilirubin Administration Decreases Infarct Area in a Rat Coronary Ischemia/Reperfusion Model

    Directory of Open Access Journals (Sweden)

    Ron eBen-Amotz


    Full Text Available Bilirubin was previously considered a toxin byproduct of heme catabolism. However, a mounting body of evidence suggests that at physiological doses, bilirubin is a powerful antioxidant and anti-atherosclerotic agent. Recent clinical studies have shown that human beings with genetically-induced hyperbilirubinemia (Gilbert Syndrome are protected against coronary heart disease. The purpose of this study was to investigate whether administration of exogenous bilirubin to normal rats would convey similar protective effects in an experimental model of coronary ischemia. We hypothesized that intraperitoneal bilirubin administration 1 hour before injury would decrease infarct area and preserve left ventricular (LV systolic function when compared to non-treated rats. Coronary ischemia was induced by temporary (30 min ligation of the left anterior descending coronary artery in control or bilirubin treated rats, followed by a 1-hour period of reperfusion. LV function was estimated by measurements of fractional shortening and fractional area shortening using echocardiography. LV function decreased in both experimental groups after ischemia and reperfusion, although in bilirubin-treated rats fractional shortening was less depressed during the period of ischemia (18.8 vs 25.8%, p = 0.034. Infarct size was significantly reduced in the bilirubin treated group compared to the non-treated group (13.34% vs 25.5%, p = 0.0067. Based on the results of this study, bilirubin supplementation appears to provide significant decrease in infarct size although protective effects on LV function were noted only during the period of ischemia. This result also suggests that lipid soluble antioxidant bilirubin prevents the oxidation of cardiolipin and decreases the infarct size in the heart during ischemia.

  13. Relation of Pre-anthracycline Serum Bilirubin Levels to Left Ventricular Ejection Fraction After Chemotherapy. (United States)

    Vera, Trinity; D'Agostino, Ralph B; Jordan, Jennifer H; Whitlock, Matthew C; Meléndez, Giselle C; Lamar, Zanetta S; Porosnicu, Mercedes; Bonkovsky, Herbert L; Poole, Leslie B; Hundley, W Gregory


    Myocardial injury because of oxidative stress manifesting through reductions in left ventricular ejection fraction (LVEF) may occur after the administration of anthracycline-based chemotherapy (A-bC). We hypothesized that bilirubin, an effective endogenous antioxidant, may attenuate the reduction in LVEF that sometimes occurs after receipt of A-bC. We identified 751 consecutively treated patients with cancer who underwent a pre-A-bC LVEF measurement, exhibited a serum total bilirubin level bilirubin and LVEF changes. The LVEF decreased by 10.7 ± 13.7%, 8.9 ± 11.8%, and 7.7 ± 11.5% in group 1 (bilirubin at baseline ≤0.5 mg/dl), group 2 (bilirubin 0.6 to 0.8 mg/dl), and group 3 (bilirubin 0.9 to 1.9 mg/dl), respectively. More group 1 patients experienced >15% decrease in LVEF compared with those in group 3 (p = 0.039). After adjusting for age, coronary artery disease/myocardial infarction, diabetes mellitus, hematocrit, and the use of cardioactive medications, higher precancer treatment bilirubin levels and lesser total anthracycline doses were associated with LVEF preservation (p = 0.047 and 0.011, respectively). In patients treated with anthracyclines who subsequently develop symptoms associated with heart failure, pre-anthracycline treatment serum bilirubin levels inversely correlate with subsequent deterioration in post-cancer treatment LVEF. In conclusion, these results suggest that increased levels of circulating serum total bilirubin, an intrinsic antioxidant, may facilitate preservation of LVEF in patients receiving A-bC for cancer.

  14. Cobinding of bilirubin and laurate to human serum albumin: spectroscopic characterization of stoichiometric complexes

    DEFF Research Database (Denmark)

    Honoré, B; Sato, H; Brodersen, R


    Light absorption and CD spectra of bound bilirubin and albumin fluorescence spectra have been recorded from mixtures containing albumin, A, bilirubin, B, and laurate, L, in Tris-NaCl buffer at pH 8.2, 25 degrees C. Concentrations of the corresponding stoichiometric complexes, ABiLj, for i = 0....... Brodersen et al. (1987) Eur. J. Biochem. 169, 487-495). The results were utilized at the microscopic level to investigate ligand-induced conformational changes. When laurate was bound to AB, a decrease of the distance between Trp-214 and the bound bilirubin occurred, as measured according to Förster...

  15. Enhanced bilirubin binding to different mammalian erythrocytes in the presence of magnesium ions


    M. K. Ali; Siddiqui, M. U.; Tayyab, S.


    Effect of magnesium ions on the binding of bilirubin to erythrocytes of different mammalian species, namely, human, buffalo, goat and sheep was studied. Increase in the concentration of magnesium ions led to a gradual increase in the erythrocyte-bound bilirubin in both human and buffalo erythrocytes whereas in sheep and goat erythrocytes, the pronounced increase was found beyond 2.0 and 2.7 mM MgCl2 concentrations respectively. Percentage increase in erythrocyte-bound bilirubin was found high...

  16. Multiple secretoglobin 1A1 genes are differentially expressed in horses

    Directory of Open Access Journals (Sweden)

    Côté Olivier


    Full Text Available Abstract Background Secretoglobin 1A1 (SCGB 1A1, also called Clara cell secretory protein, is the most abundantly secreted protein of the airway. The SCGB1A1 gene has been characterized in mammals as a single copy in the genome. However, analysis of the equine genome suggested that horses might have multiple SCGB1A1 gene copies. Non-ciliated lung epithelial cells produce SCGB 1A1 during inhalation of noxious substances to counter airway inflammation. Airway fluid and lung tissue of horses with recurrent airway obstruction (RAO, a chronic inflammatory lung disease affecting mature horses similar to environmentally induced asthma of humans, have reduced total SCGB 1A1 concentration. Herein, we investigated whether horses have distinct expressed SCGB1A1 genes; whether the transcripts are differentially expressed in tissues and in inflammatory lung disease; and whether there is cell specific protein expression in tissues. Results We identified three SCGB1A1 gene copies on equine chromosome 12, contained within a 512-kilobase region. Bioinformatic analysis showed that SCGB1A1 genes differ from each other by 8 to 10 nucleotides, and that they code for different proteins. Transcripts were detected for SCGB1A1 and SCGB1A1A, but not for SCGB1A1P. The SCGB1A1P gene had most inter-individual variability and contained a non-sense mutation in many animals, suggesting that SCGB1A1P has evolved into a pseudogene. Analysis of SCGB1A1 and SCGB1A1A sequences by endpoint-limiting dilution PCR identified a consistent difference affecting 3 bp within exon 2, which served as a gene-specific “signature”. Assessment of gene- and organ-specific expression by semiquantitative RT-PCR of 33 tissues showed strong expression of SCGB1A1 and SCGB1A1A in lung, uterus, Fallopian tube and mammary gland, which correlated with detection of SCGB 1A1 protein by immunohistochemistry. Significantly altered expression of the ratio of SCGB1A1A to SCGB1A1 was detected in RAO

  17. Preparation of Aminated Macroporous Polyvinyl Alcohol Resins and Evaluation for Bilirubin Adsorption

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-chao; ZHANG Sheng-nan; HU Yue-han; XIE Hui; OU Lai-liang; YU Yao-ting; KONG De-ling; GU Han-qing


    In the present study we prepared macroporous polyvinyl alcohol beads. A series of bilirubin adsorbents were generated by immobilization of eight amine agents to the beads as ligands. The adsorption of bilirubin was evaluated by in vitro static and dynamic adsorption tests. The results show that these adsorbents have excellent adsorption efficiency and capacity. Among the eight ligands, trimethylamine (TMA), triethylamine (TEA) and 1,6- hexanediamine(HAD) showed the highest adsorption capacity. The adsorption equilibrium can be achieved in half an hour, and the adsorption percentage of bilirubin was up to 80%. Static electricity and hydrophobic interaction played the main role in bilirubin adsorption, and the adsorption was found to match the monolayer model. The excellent adsorption of these adsorbents indicates their potential in clinical treatment.

  18. Computational chemical analysis of unconjugated bilirubin anions and insights into pKa values clarification (United States)

    Vega-Hissi, Esteban G.; Estrada, Mario R.; Lavecchia, Martín J.; Pis Diez, Reinaldo


    The pKa, the negative logarithm of the acid dissociation equilibrium constant, of the carboxylic acid groups of unconjugated bilirubin in water is a discussed issue because there are quite different experimental values reported. Using quantum mechanical calculations we have studied the conformational behavior of unconjugated bilirubin species (in gas phase and in solution modeled implicitly and explicitly) to provide evidence that may clarify pKa values because of its pathophysiological relevance. Our results show that rotation of carboxylate group, which is not restricted, settles it in a suitable place to establish stronger interactions that stabilizes the monoanion and the dianion to be properly solvated, demonstrating that the rationalization used to justify the high pKa values of unconjugated bilirubin is inappropriate. Furthermore, low unconjugated bilirubin (UCB) pKa values were estimated from a linear regression analysis.

  19. Unilobar versus bilobar biliary drainage: effect on quality of life and bilirubin level reduction

    Directory of Open Access Journals (Sweden)

    Shivanand Gamanagatti


    Conclusion: Percutaneous biliary drainage provides good palliation of malignant obstructive jaundice. Partial-liver drainage achieved results as good as those after complete liver drainage with significant improvements in QOL and reduction of the bilirubin level.

  20. The effect of bilirubin on lipid peroxidation and antioxidant enzymes in cumene hydroperoxide-treated erythrocytes. (United States)

    Yeşilkaya, A; Yeğin, A; Ozdem, S; Aksu, T A


    Recently, it has been suggested that bilirubin may act as a potent biological chain-breaking antioxidant. To observe the effects of free bilirubin on antioxidant reactions in cumene hydroperoxide-treated erythrocytes (15 g hemoglobin/dl), we added bilirubin at four different concentrations (0.5, 1, 5, and 10 mg/dl). We measured the thiobarbituric acid-reactive substance and reduced glutathione levels, and some antioxidant enzyme activities, namely superoxide dismutase, catalase, and glucose-6-phosphate dehydrogenase. Thiobarbituric acid-reactive substance and chemiluminescent signals decreased during the incubation. Superoxide dismutase activities also decreased but not as much as in the control group. Glucose-6-phosphate dehydrogenase activities and reduced glutathione levels increased, but catalase activities remained the same as the control group. Our results suggest that bilirubin--in the concentrations we have used--partially prevented the oxidant effects of cumene hydroperoxide.

  1. Evaluation of oxidant and antioxidant status in term neonates: a plausible protective role of bilirubin. (United States)

    Shekeeb Shahab, M; Kumar, Praveen; Sharma, Neeraj; Narang, Anil; Prasad, Rajendra


    In vitro studies have shown unequivocally that bilirubin is an antioxidant. We hypothesized that bilirubin serves a physiological role of an antioxidant in vivo. To investigate the probable protective role of bilirubin in vivo, term babies with clinical jaundice were grouped into four categories-serum total bilirubin (STB) 200 mg/l, and kernicterus. Serum bilirubin, serum albumin, plasma glucose-6-phosphate dehydrogenase (G6PD), lipid peroxidation in blood cells, and reduced glutathione (GSH) content in whole blood were investigated. We also measured superoxide dismutase (SOD) and catalase in hemolysate and total plasma antioxidant capacity (TAC). Lipid peroxidation and antioxidant enzymes were significantly lower in babies with STB 200 mg/l and in babies with bilirubin encephalopathy. Elevated levels of MDA, SOD, and catalase and significantly decreased levels of reduced glutathione and total antioxidant capacity were observed in STB >200 mg/l group. Antioxidant enzymes were also significantly inhibited in bilirubin encephalopathy babies. Post phototherapy, MDA production and antioxidant levels were significantly increased whilst total antioxidant capacity and reduced glutathione were significantly decreased compared to pre-phototherapy values. Exchange transfusion resulted in reduced oxidative stress in subjects with encephalopathy, whereas no significant difference was observed in other babies with STB >200 mg/l. Taken together, the present study propounds that bilirubin acts as a physiological antioxidant till 200 mg/l concentration in full-term normal neonates. It is conjectured that beyond 200 mg/l, it can no longer be considered physiologic. However, the cause of pathological jaundice needs to be identified and treated. The present data documents that phototherapy also induces oxidative stress.

  2. Studies on The Adsorption Capacity for Bilirubin of The Adsorbent Chitosan-β-Cyclodextrin

    Institute of Scientific and Technical Information of China (English)


    The adsorbent crosslinked chitosan-β-cyclodextrin (β-CD) was prepared by the reaction of glutaraldehyde with chitosan and β-cyclodextrin. This type of adsorbent has high adsorption capacity for unconjugated bilirubin. The adsorption capacity was related to the β-CD content of the adsorbent; phosphate buffer concentration; temperature; pH value; ionic strength and the adsorbent beads. The results indicated that the chitosan-β-CD was a good adsorbent for unconjugated bilirubin with high capacity.

  3. Quantitative determination of cerebrospinal fluid bilirubin on a high throughput chemistry analyzer


    Said Ahmed, Degmo


    Background Subarachnoid hemorrhage is a condition with high rates of mortality and morbidity. The diagnosis requires an urgent cerebral computed tomography scan and also a lumbar puncture if the scan fails to demonstrate intracranial blood. In Sweden the cerebrospinal fluid (CSF) is analyzed by spectrophotometric scanning for the presence of hemoglobin and bilirubin. The aim of the study was to develop a quantitative diazo reagent based analysis of cerebrospinal fluid bilirubin as a replaceme...

  4. Successive determination of urinary bilirubin and creatinine employing simultaneous injection effective mixing flow analysis. (United States)

    Ponhong, Kraingkrai; Teshima, Norio; Grudpan, Kate; Vichapong, Jitlada; Motomizu, Shoji; Sakai, Tadao


    A novel four-channel simultaneous injection effective mixing flow analysis (SIEMA) system has been assembled for successive determination of bilirubin and creatinine in urinary samples. The chemical variables and physical parameters in the flow system were optimized for the enhancement of successive analytical performances. The interferences from urine matrices on the determination of bilirubin and creatinine were eliminated to dilute urine samples. The calibration graphs with the optimum conditions were achieved to be in 0.024-5.0 mg L(-1) for bilirubin and 2-100 mg L(-1) for creatinine. The relative standard deviations (RSDs) at 3 mg L(-1) of bilirubin and at 50 mg L(-1) of creatinine for 11 runs were 1.5 and 1.0%, respectively. The limits of detections (3σ of blank) for bilirubin and creatinine were 7 µg L(-1) and 0.6 mg L(-1), respectively. The sample throughput for stepwise detection was 22 h(-1). The proposed method was applied to the successive determination of bilirubin and creatinine in urine samples.

  5. Development of a System Model for Non-Invasive Quantification of Bilirubin in Jaundice Patients (United States)

    Alla, Suresh K.

    Neonatal jaundice is a medical condition which occurs in newborns as a result of an imbalance between the production and elimination of bilirubin. Excess bilirubin in the blood stream diffuses into the surrounding tissue leading to a yellowing of the skin. An optical system integrated with a signal processing system is used as a platform to noninvasively quantify bilirubin concentration through the measurement of diffuse skin reflectance. Initial studies have lead to the generation of a clinical analytical model for neonatal jaundice which generates spectral reflectance data for jaundiced skin with varying levels of bilirubin concentration in the tissue. The spectral database built using the clinical analytical model is then used as a test database to validate the signal processing system in real time. This evaluation forms the basis for understanding the translation of this research to human trials. The clinical analytical model and signal processing system have been successful validated on three spectral databases. First spectral database is constructed using a porcine model as a surrogate for neonatal skin tissue. Samples of pig skin were soaked in bilirubin solutions of varying concentrations to simulate jaundice skin conditions. The resulting skins samples were analyzed with our skin reflectance systems producing bilirubin concentration values that show a high correlation (R2 = 0.94) to concentration of the bilirubin solution that each porcine tissue sample is soaked in. The second spectral database is the spectral measurements collected on human volunteers to quantify the different chromophores and other physical properties of the tissue such a Hematocrit, Hemoglobin etc. The third spectral database is the spectral data collected at different time periods from the moment a bruise is induced.

  6. Serum total bilirubin levels and coronary heart disease--Causal association or epiphenomenon? (United States)

    Kunutsor, Setor K


    Observational epidemiological evidence supports a linear inverse and independent association between serum total bilirubin levels and coronary heart disease (CHD) risk, but whether this association is causal remains to be ascertained. A Mendelian randomization approach was employed to test whether serum total bilirubin is causally linked to CHD. The genetic variant rs6742078--well known to specifically modify levels of serum total bilirubin and accounting for up to 20% of the variance in circulating serum total bilirubin levels--was used as an instrumental variable. In pooled analysis of estimates reported from published genome-wide association studies, every copy of the T allele of rs6742078 was associated with 0.42 standard deviation (SD) higher levels of serum total bilirubin (95% confidence interval, 0.40 to 0.43). Based on combined data from the Coronary Artery Disease Genome wide Replication and Meta-analyses and the Coronary Artery Disease (C4D) Genetics Consortium involving a total of 36,763 CHD cases and 76,997 controls, the odds ratio for CHD per copy of the T allele was 1.01 (95% confidence interval, 0.99 to 1.04). The odds ratio of CHD for a 1 SD genetically elevated serum total bilirubin level was 1.03 (95% confidence interval, 0.98 to 1.09). The current findings casts doubt on a strong causal association of serum total bilirubin levels with CHD. The inverse associations demonstrated in observational studies may be driven by biases such as unmeasured confounding and/or reverse causation. However, further research in large-scale consortia is needed.

  7. Predictors of the change in bilirubin levels over twelve weeks of treatment with atazanavir

    LENUS (Irish Health Repository)

    Cotter, Aoife G


    AbstractObjectiveTo determine the factors associated with change in bilirubin concentration 12 weeks after the initiation of an atazanavir (ATV)-containing antiretroviral regimen.MethodsWe performed a retrospective case note review of all patients prescribed ATV between January 2004 and October 2007 in a cohort of HIV infected subjects. Data collected included baseline demographics, hepatitis B and C serology, current antiretroviral therapy, baseline and week 12 routine bloods. The primary endpoint was the change in bilirubin concentration at 12 weeks after start of ATV. Multvariable linear regression was performed to assess the relationships between the change in bilirubin and variables of interest. Results: Eighty-three ATV-treated patients were included in the analysis of whom 46 (60.5%) were hepatitis C antibody positive. The median (interquartile range) change in bilirubin by week 12 was 16 (4, 22) umol\\/L; only 1 patient developed grade 4 hyperbilirubinaemia at week 12. After controlling for baseline bilirubin levels, HCV seropositivity and baseline ALP were associated with a smaller change in bilirubin over the 12 weeks with a trend towards lower increases in those receiving tenofovir. Sensitivity analyses reported similar associations with methadone use and injection drug use, when these variables replaced HCV sero-positivity in the model. Conclusion: Patients with hepatitis C co-infection experience smaller changes in bilirubin upon exposure to ATV. Although the underlying mechanism for this association remains unclear, these data support the safe use of this drug in this patient setting. Further research into the clinical predictors of ATV-related hyperbilirubinaemia is warranted.

  8. Protein expression of CYP1A1, CYP1B1, ALDH1A1, and ALDH2 in young patients with oral squamous cell carcinoma. (United States)

    Kaminagakura, E; Caris, A; Coutinho-Camillo, C; Soares, F A; Takahama-Júnior, A; Kowalski, L P


    The purpose of this study was to evaluate the expression of the enzymes involved in the biotransformation of tobacco and alcohol. A study group of 41 young patients (≤40 years old) with oral squamous cell carcinoma (OSCC) was compared to 59 control subjects (≥50 years old) with tumours of similar clinical stages and topographies. The immunohistochemical expression of CYP1A1, CYP1B1, ALDH1A1, and ALDH2 was evaluated using the tissue microarray technique. There was a predominance of males, smokers, and alcohol drinkers in both groups. Most tumours were located in the tongue (43.9% vs. 50.8%), were well-differentiated (63.4% vs. 56.6%), and were in clinical stages III or IV (80.5% vs. 78.0%). No difference was observed in the expression of CYP1A1, ALDH1A1, or ALDH2 between the two groups. CYP1A1 and ALDH2 protein expression had no influence on the prognosis. The immunoexpression of CYP1B1 was significantly higher in the control group than in the young group (PCYP1B1 overexpression vs. protein underexpression (64% vs. 25%; PCYP1B1. Further studies involving other genes and proteins are necessary to complement the results of this research.

  9. Study on the Property of β -CDEP Supported by Methylated Polystyrene for Inclusion and Adsorption of Bilirubin

    Institute of Scientific and Technical Information of China (English)

    MAO LuYuan; SHEN HanXi; ZHUANG YunFeng; YANG Yong; FAN YunGe


    @@ How to utilize functional material to eliminate uncombined bilirubin is a key problem in the research of artificial hepatic supporter [1]. There have been reports on the utilization of cyclodextrin and its polymer as biomedical materials [2,3]. In this paper, it was studied that the property of cyclodextrin polymers (MPS-CDEP) synthesized by us for the inclusion and adsorption of bilirubin. Bilirubin is the degradation product of heme (ferriprotoporohyrin IX), which body contain, and structures of both as follows:

  10. The relationship of the anti-oxidant bilirubin with free thyroxine is modified by insulin resistance in euthyroid subjects.

    Directory of Open Access Journals (Sweden)

    Petronella E Deetman

    Full Text Available BACKGROUND: The strong anti-oxidative properties of bilirubin largely explain its cardioprotective effects. Insulin resistance is featured by low circulating bilirubin. Thyroid hormone affects both bilirubin generation and its biliary transport, but it is unknown whether circulating bilirubin is associated with thyroid function in euthyroid subjects. Aim is to determine relationships of bilirubin with TSH, free T4 and free T3 in euthyroid subjects without type 2 diabetes mellitus (T2DM, and to assess whether such a relationship would be modified by the degree of insulin resistance. METHODS: Total bilirubin, TSH, free T4, free T3, glucose, insulin, lipids and transaminases were measured in 1854 fasting euthyroid subjects without T2DM, recruited from the general population (PREVEND cohort. Insulin resistance was assessed by homeostasis model assessment. RESULTS: Bilirubin was positively related to free T4 (β = 0.116, P<0.001 and free T3 (β = 0.078, P = 0.001, but bilirubin was unrelated to TSH. The relationship of bilirubin with free T4 was modified by insulin resistance with a larger effect in more insulin resistant individuals (adjusted for age and sex: β = 0.043, P = 0.056 for interaction; additionally adjusted for smoking, alcohol intake, transaminases and total cholesterol (β = 0.044, P = 0.044 for interaction. The association of bilirubin with free T4 was also modified by high density lipoprotein cholesterol (age- and sex-adjusted: β = 0.040, P = 0.072. CONCLUSIONS: Low bilirubin relates to low free T4 in euthyroid non-diabetic subjects. Low normal free T4 may particularly confer low bilirubin in more insulin resistant individuals.

  11. Bilirubin modulated cytokines, growth factors and angiogenesis to improve cutaneous wound healing process in diabetic rats. (United States)

    Ram, Mahendra; Singh, Vishakha; Kumawat, Sanjay; Kant, Vinay; Tandan, Surendra Kumar; Kumar, Dinesh


    Bilirubin has shown cutaneous wound healing potential in some preliminary studies. Here we hypothesize that bilirubin facilitates wound healing in diabetic rats by modulating important healing factors/candidates and antioxidant parameters in a time-dependent manner. Diabetes was induced in male Wistar rats by streptozotocin. In all diabetic rats wounds were created under pentobarbitone anesthesia. All the rats were divided into two groups, of which one (control) was treated with ointment base and other with bilirubin ointment (0.3%). Wound closer measurement and tissue collection were done on days 3, 7, 14 and 19 post-wounding. The relative expressions of hypoxia inducible factor-1 alpha (HIF-1α), vascular endothelial growth factor (VEGF), stromal cell-derived factor-1 alpha (SDF-1α), transforming growth factor- beta1 (TGF-β1()), tumor necrosis factor-α (TNF-α) and interlukin-10 (IL-10) mRNA and proteins and the mRNA of interlukin-1 beta (IL-1β) and matrix metalloprteinase-9 (MMP-9) were determined in the wound tissues. CD-31 staining and collagen content were evaluated by immunohistochemistry and picrosirius red staining, respectively. Histopathological changes were assessed by H&E staining. The per cent wound closer was significantly higher from day 7 onwards in bilirubin-treated rats. HIF-1α, VEGF, SDF-1α, TGF-β1, IL-10 mRNA and protein levels were significantly higher on days 3, 7 and 14 in bilirubin-treated rats. The mRNA expression and protein level of TNF-α and the mRNA of IL-1β and MMP-9 were progressively and markedly reduced in bilirubin-treated rats. The collagen deposition and formation of blood vessels were greater in bilirubin-treated rats. Bilirubin markedly facilitated cutaneous wound healing in diabetic rats by modulating growth factors, cytokines, neovasculogenesis and collagen contents to the wound site. Topical application of bilirubin ointment might be of great use in cutaneous wound healing in diabetic patients.

  12. Amine-functionalized PVA-co-PE nanofibrous membrane as affinity membrane with high adsorption capacity for bilirubin. (United States)

    Wang, Wenwen; Zhang, Hao; Zhang, Zhifeng; Luo, Mengying; Wang, Yuedan; Liu, Qiongzhen; Chen, Yuanli; Li, Mufang; Wang, Dong


    In this study, poly(vinyl alcohol-co-ethylene) (PVA-co-PE) nanofibrous membrane was activated by sodium hydroxide and cyanuric chloride, and then the activated membranes were functionalized by 1,3-propanediamine, hexamethylenediamine and diethylenetriamine to be affinity membranes for bilirubin removal, respectively. The chemical structures and morphologies of membranes were investigated by SEM, FTIR and XPS. And the adsorption ability of different amine-functionalized nanofibrous membranes for bilirubin was characterized. Furthermore, the effects of temperature, initial concentration of bilirubin, NaCl concentration and BSA concentration on the adsorption capacity for bilirubin of diethylenetriamine-functionalized nanofibrous membrane were studied. Results indicated that the adsorption capacity for bilirubin of diethylenetriamine-functionalized nanofibrous membrane could reach 85mg/g membrane when the initial bilirubin concentration was 200mg/L while the adsorption capacity could be increased to 110mg/g membrane if the initial bilirubin concentration was more than 400mg/L. The dynamic adsorption of diethylenetriamine-functionalized nanofibrous membrane showed that the ligands of amine groups on the membrane surface could be used as far as possible by recirculating the plasma with certain flow rates. Therefore, the diethylenetriamine-functionalized PVA-co-PE nanofibrous membrane possessed high adsorption capacity for bilirubin and it can be candidate as affinity membrane for bilirubin removal.

  13. Bilirubin degradation in methanol induced by continuous UV-B irradiation: a UHPLC--ESI-MS study. (United States)

    Stanojević, J S; Zvezdanović, J B; Marković, D Z


    Degradation of bilirubin in aerobic methanol solution by continuous UV-B irradiation has been investigated in this work. The purpose of this study was to shed more light on bilirubin interaction with the UV-B component of natural sunlight, since bilirubin is a very efficient UV-B absorber located in the skin epidermis. The degradation products have been detected and studied by a combined method of Ultra High Performance Liquid Chromatography-Electrospray Ionization Mass Spectrometry (UHPLC-ESI-MS). Bilirubin, a toxic pigment which itself is a product of (hemoglobin) degradation in organisms, undergoes its own degradation under aerobic conditions of UV-B continuous irradiation (e.g. photooxidation) that can be partly self-sensitized. Two dipyrrolic structures have been identified as a result of the bilirubin degradation, not including the bilirubin derivative biliverdin whose increase in the irradiated system is synchronous with a time dynamics of bilirubin degradation. It appears that one of dipyrrolic products originates directly from bilirubin and biliverdin molecules, while the other one is probably connected to bilirubin self-sensitized degradation. The precursor role of biliverdin in the degradation process--related to the detected dipyrroles--has not been confirmed.

  14. Efficient voltammetric discrimination of free bilirubin from uric acid and ascorbic acid by a CVD nanographite-based microelectrode. (United States)

    Taurino, Irene; Van Hoof, Viviane; Magrez, Arnaud; Forró, László; De Micheli, Giovanni; Carrara, Sandro


    We report a novel electrochemical sensor based on nanographite grown on platinum microelectrodes for the determination of bilirubin in the presence of normal concentrations of albumin. The albumin is a protein with an intrinsic ability to bind the bilirubin therefore reducing the concentration of the free electroactive metabolite in human fluids. In addition, the proposed device permits the discrimination of free bilirubin from two interferents, uric acid and ascorbic acid, by the separation of their oxidation peaks in voltammetry. Preliminary measurements in human serum prove that the proposed nanostructured platform can be used to detect bilirubin.


    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  16. Lower Serum Bilirubin and Uric Acid Concentrations in Patients with Parkinson's Disease in China. (United States)

    Qin, Xiao-Ling; Zhang, Qing-Shan; Sun, Li; Hao, Meng-Wei; Hu, Zhao-Ting


    The objective of the study is to investigate the correlation between bilirubin and uric acid (UA) concentrations and symptoms of Parkinson's disease (PD) in Chinese population. A total of 425 PD patients and 460 controls were included in the current study. Patients were diagnosed by a neurologist and assessed using the Hoehn & Yahr (H&Y) scale. Venous blood samples were collected, and bilirubin and UA concentrations were analyzed. Compared to controls, indirect bilirubin (IBIL) and UA concentrations were lower in PD patients (P IBIL = 0.015, P UA = 0.000). Serum IBIL in different age subgroups and H&Y stage subgroups were also lower compared to the control group (P IBIL = 0.000, P UA = 0.000) but were not significantly different among these subgroups. Females in the control group had significantly lower serum IBIL and UA concentrations than males (P IBIL = 0.000, P UA = 0.000) and the PD group (P IBIL = 0.027, P UA = 0.000). In early PD (patients with bilirubin and UA concentrations lack the endogenous defense system to prevent peroxynitrite and other free radicals from damaging and destroying dopaminergic cells in the substantia nigra. Our results provide a basis for further investigation into the role of bilirubin in PD.

  17. Evaluation of region selective bilirubin-induced brain damage as a basis for a pharmacological treatment (United States)

    Dal Ben, Matteo; Bottin, Cristina; Zanconati, Fabrizio; Tiribelli, Claudio; Gazzin, Silvia


    The neurologic manifestations of neonatal hyperbilirubinemia in the central nervous system (CNS) exhibit high variations in the severity and appearance of motor, auditory and cognitive symptoms, which is suggestive of a still unexplained selective topography of bilirubin-induced damage. By applying the organotypic brain culture (OBC: preserving in vitro the cellular complexity, connection and architecture of the in vivo brain) technique to study hyperbilirubinemia, we mapped the regional target of bilirubin-induced damage, demonstrated a multifactorial toxic action of bilirubin, and used this information to evaluate the efficacy of drugs applicable to newborns to protect the brain. OBCs from 8-day-old rat pups showed a 2–13 fold higher sensitivity to bilirubin damage than 2-day-old preparations. The hippocampus, inferior colliculus and cerebral cortex were the only brain regions affected, presenting a mixed inflammatory-oxidative mechanism. Glutamate excitotoxicity was appreciable in only the hippocampus and inferior colliculus. Single drug treatment (indomethacin, curcumin, MgCl2) significantly improved cell viability in all regions, while the combined (cocktail) administration of the three drugs almost completely prevented damage in the most affected area (hippocampus). Our data may supports an innovative (complementary to phototherapy) approach for directly protecting the newborn brain from bilirubin neurotoxicity. PMID:28102362

  18. Cytochrome P450 2A5 and bilirubin: Mechanisms of gene regulation and cytoprotection

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sangsoo Daniel; Antenos, Monica [Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Squires, E. James [Department of Animal and Poultry Sciences, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Kirby, Gordon M., E-mail: [Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada)


    Bilirubin (BR) has recently been identified as the first endogenous substrate for cytochrome P450 2A5 (CYP2A5) and it has been suggested that CYP2A5 plays a major role in BR clearance as an alternative mechanism to BR conjugation by uridine-diphosphate glucuronyltransferase 1A1. This study investigated the mechanisms of Cyp2a5 gene regulation by BR and the cytoprotective role of CYP2A5 in BR hepatotoxicity. BR induced CYP2A5 expression at the mRNA and protein levels in a dose-dependent manner in primary mouse hepatocytes. BR treatment also caused nuclear translocation of Nuclear factor-E2 p45-related factor 2 (Nrf2) in hepatocytes. In reporter assays, BR treatment of primary hepatocytes transfected with a Cyp2a5 promoter-luciferase reporter construct resulted in a 2-fold induction of Cyp2a5 reporter activity. Furthermore, cotransfection of the hepatocytes with a Nrf2 expression vector without BR treatment resulted in an increase in Cyp2a5 reporter activity of approximately 2-fold and BR treatment of Nrf2 cotransfectants further increased reporter activity by 4-fold. In addition, site-directed mutation of the ARE in the reporter construct completely abolished both the BR- and Nrf2-mediated increases in reporter activity. The cytoprotective role of CYP2A5 against BR-mediated apoptosis was also examined in Hepa 1–6 cells that lack endogenous CYP2A5. Transient overexpression of CYP2A5 partially blocked BR-induced caspase-3 cleavage in Hepa 1–6 cells. Furthermore, in vitro degradation of BR was increased by microsomes from Hepa 1–6 cells overexpressing CYP2A5 compared to control cells transfected with an empty vector. Collectively, these results suggest that Nrf2-mediated CYP2A5 transactivation in response to BR may provide an additional mechanism for adaptive cytoprotection against BR hepatotoxicity. - Highlights: • The mechanism of Cyp2a5 gene regulation by BR was investigated. • The cytoprotective role of CYP2A5 in BR hepatotoxicity was determined. • BR

  19. Signal integration by the CYP1A1 promoter - a quantitative study

    NARCIS (Netherlands)

    Schulthess, P.; Löffler, A.; Vetter, S.; Kreft, L.; Schwarz, M.; Braeuning, A.; Blüthgen, N.


    Genes involved in detoxification of foreign compounds exhibit complex spatiotemporal expression patterns in liver. Cytochrome P450 1A1 (CYP1A1), for example, is restricted to the pericentral region of liver lobules in response to the interplay between aryl hydrocarbon receptor (AhR) and Wnt/β-cateni

  20. NOTCH-induced aldehyde dehydrogenase 1A1 deacetylation promotes breast cancer stem cells. (United States)

    Zhao, Di; Mo, Yan; Li, Meng-Tian; Zou, Shao-Wu; Cheng, Zhou-Li; Sun, Yi-Ping; Xiong, Yue; Guan, Kun-Liang; Lei, Qun-Ying


    High aldehyde dehydrogenase (ALDH) activity is a marker commonly used to isolate stem cells, particularly breast cancer stem cells (CSCs). Here, we determined that ALDH1A1 activity is inhibited by acetylation of lysine 353 (K353) and that acetyltransferase P300/CBP-associated factor (PCAF) and deacetylase sirtuin 2 (SIRT2) are responsible for regulating the acetylation state of ALDH1A1 K353. Evaluation of breast carcinoma tissues from patients revealed that cells with high ALDH1 activity have low ALDH1A1 acetylation and are capable of self-renewal. Acetylation of ALDH1A1 inhibited both the stem cell population and self-renewal properties in breast cancer. Moreover, NOTCH signaling activated ALDH1A1 through the induction of SIRT2, leading to ALDH1A1 deacetylation and enzymatic activation to promote breast CSCs. In breast cancer xenograft models, replacement of endogenous ALDH1A1 with an acetylation mimetic mutant inhibited tumorigenesis and tumor growth. Together, the results from our study reveal a function and mechanism of ALDH1A1 acetylation in regulating breast CSCs.

  1. Correlates of Cytochrome P450 1A1 Expression in Bottlenose Dolphin (Tursiops truncatus) Integument Biopsies

    NARCIS (Netherlands)

    Wilson, J.Y.; Wells, R.; Anguilar, A.; Borrell, A.; Tornero, V.; Reijnders, P.J.H.; Moore, M.


    Integument biopsy is a nondestructive method for sampling free-ranging cetaceans, which allows for the determination of both contaminant concentrations and biomarker responses. Cytochrome P450 1A1 (CYP1A1) expression is induced by polycyclic aromatic hydrocarbons and planar halogenated aromatic hydr

  2. Organic anion transporting polypeptide 1a1 null mice are sensitive to cholestatic liver injury. (United States)

    Zhang, Youcai; Csanaky, Iván L; Cheng, Xingguo; Lehman-McKeeman, Lois D; Klaassen, Curtis D


    Organic anion transporting polypeptide 1a1 (Oatp1a1) is predominantly expressed in livers of mice and is thought to transport bile acids (BAs) from blood into liver. Because Oatp1a1 expression is markedly decreased in mice after bile duct ligation (BDL). We hypothesized that Oatp1a1-null mice would be protected against liver injury during BDL-induced cholestasis due largely to reduced hepatic uptake of BAs. To evaluate this hypothesis, BDL surgeries were performed in both male wild-type (WT) and Oatp1a1-null mice. At 24 h after BDL, Oatp1a1-null mice showed higher serum alanine aminotransferase levels and more severe liver injury than WT mice, and all Oatp1a1-null mice died within 4 days after BDL, whereas all WT mice survived. At 24 h after BDL, surprisingly Oatp1a1-null mice had higher total BA concentrations in livers than WT mice, suggesting that loss of Oatp1a1 did not prevent BA accumulation in the liver. In addition, secondary BAs dramatically increased in serum of Oatp1a1-null BDL mice but not in WT BDL mice. Oatp1a1-null BDL mice had similar basolateral BA uptake (Na(+)-taurocholate cotransporting polypeptide and Oatp1b2) and BA-efflux (multidrug resistance-associated protein [Mrp]-3, Mrp4, and organic solute transporter α/β) transporters, as well as BA-synthetic enzyme (Cyp7a1) in livers as WT BDL mice. Hepatic expression of small heterodimer partner Cyp3a11, Cyp4a14, and Nqo1, which are target genes of farnesoid X receptor, pregnane X receptor, peroxisome proliferator-activated receptor alpha, and NF-E2-related factor 2, respectively, were increased in WT BDL mice but not in Oatp1a1-null BDL mice. These results demonstrate that loss of Oatp1a1 function exacerbates cholestatic liver injury in mice and suggest that Oatp1a1 plays a unique role in liver adaptive responses to obstructive cholestasis.

  3. Transport and metabolism at blood-brain interfaces and in neural cells: relevance to bilirubin-induced encephalopathy

    Directory of Open Access Journals (Sweden)

    Silvia eGazzin


    Full Text Available Bilirubin, the end-product of heme catabolism, circulates in non pathological plasma mostly as a protein-bound species. When bilirubin concentration builds up, the free fraction of the molecule increases. Unbound bilirubin then diffuses across blood-brain interfaces into the brain, where it accumulates and exerts neurotoxic effects. In this classical view of bilirubin neurotoxicity, blood-brain interfaces act merely as structural barriers impeding the penetration of the pigment-bound carrier protein, and neural cells are considered as passive targets of its toxicity. Yet, the role of blood-brain interfaces in the occurrence of bilirubin encephalopathy appears more complex than being simple barriers to the diffusion of bilirubin, and neural cells such as astrocytes and neurons can play an active role in controlling the balance between the neuroprotective and neurotoxic effects of bilirubin. This article reviews the emerging in vivo and in vitro data showing that transport and metabolic detoxification mechanisms at the blood-brain and blood-CSF barriers may modulate bilirubin flux across both cellular interfaces, and that these protective functions can be affected in chronic hyperbilirubinemia. Then the in vivo and in vitro arguments in favor of the physiological antioxidant function of intracerebral bilirubin are presented, as well as with the potential role of transporters such as ABCC-1 and metabolizing enzymes such as cytochromes P-450 in setting the cerebral cell- and structure-specific toxicity of bilirubin following hyperbilirubinemia. The relevance of these data to the pathophysiology of bilirubin-induced neurological diseases is discussed.

  4. Sensitizing effect of Z,Z-bilirubin IXα and its photoproducts on enzymes in model solutions (United States)

    Plavskii, V. Yu.; Mostovnikov, V. A.; Tret'yakova, A. I.; Mostovnikova, G. R.


    In model systems, we have studied side effects which may be induced by light during phototherapy of hyperbilirubinemia (jaundice) in newborn infants, with the aim of reducing the Z,Z-bilirubin IXα (Z,Z-BR IXα) level. We have shown that the sensitizing effect of Z,Z-BR IXα, localized at strong binding sites of the human serum albumin (HSA) macromolecule, is primarily directed at the amino acid residues of the carrier protein and does not involve the molecules of the enzyme (lactate dehydrogenase (LDH)) present in the buffer solution. The detected photodynamic damage to LDH is due to sensitization by bilirubin photoisomers, characterized by lower HSA association constants and located (in contrast to native Z,Z-BR IXα) on the surface of the HSA protein globule. Based on study of the spectral characteristics of the photoproducts of Z,Z-BR IXα and comparison of their accumulation kinetics in solution and the enzyme photo-inactivation kinetics, we concluded that the determining role in sensitized damage to LDH is played by lumirubin. The photosensitization effect depends on the wavelength of the radiation used for photoconversion of bilirubin. When (at the beginning of exposure) we make sure that identical numbers of photons are absorbed by the pigment in the different spectral ranges, the side effect is minimal for radiation corresponding to the long-wavelength edge of the bilirubin absorption band. We have shown that for a bilirubin/HSA concentration ratio >2 (when some of the pigment molecules are sorbed on the surface of the protein globule), the bilirubin can act as a photosensitizing agent for the enzyme present in solution. We discuss methods for reducing unfavorable side effects of light on the body of newborn infants during phototherapy of hyperbilirubinemia.

  5. Protein-encapsulated bilirubin: paving the way to a useful probe for singlet oxygen. (United States)

    Pimenta, Frederico M; Jensen, Jan K; Etzerodt, Michael; Ogilby, Peter R


    When dissolved in a bulk solvent, bilirubin efficiently removes singlet molecular oxygen, O2(a(1)Δg), through a combination of chemical reactions and by promoting the O2(a(1)Δg)→O2(X(3)Σg(-)) nonradiative transition to populate the ground state of oxygen. To elucidate how such processes can be exploited in the development of a biologically useful fluorescent probe for O2(a(1)Δg), pertinent photophysical and photochemical parameters of bilirubin encapsulated in a protein were determined. The motivation for studying a protein-encapsulated system reflects the ultimate desire to (a) use genetic engineering to localize the probe at a specific location in a living cell, and (b) provide a controlled environment around the chromophore/fluorophore. Surprisingly, explicit values of oxygen- and O2(a(1)Δg)-dependent parameters that characterize the behavior of a given chromophore/fluorophore encased in a protein are not generally available. To the end of quantifying the effects of such an encasing protein, a recently discovered bilirubin-binding protein isolated from a Japanese eel was used. The data show that this system indeed preferentially responds to O2(a(1)Δg) and not to the superoxide ion. However, this protein not only shields bilirubin such that the rate constants for interaction with O2(a(1)Δg) decrease relative to what is observed in a bulk solvent, but the fraction of the total O2(a(1)Δg)-bilirubin interaction that results in a chemical reaction between O2(a(1)Δg) and bilirubin also decreases appreciably. The rate constants thus obtained provide a useful starting point for the general design and development of reactive protein-encased fluorescent probes for O2(a(1)Δg).

  6. Quantitative assessment of the multiple processes responsible for bilirubin homeostasis in health and disease

    Directory of Open Access Journals (Sweden)

    Levitt DG


    Full Text Available David G Levitt,1 Michael D Levitt2 1Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA; 2Research Service, Veterans Affairs Medical Center, Minneapolis, MN, USAAbstract: Serum bilirubin measurements are commonly obtained for the evaluation of ill patients and to screen for liver disease in routine physical exams. An enormous research effort has identified the multiple mechanisms involved in the production and metabolism of conjugated (CB and unconjugated bilirubin (UB. While the qualitative effects of these mechanisms are well understood, their expected quantitative influence on serum bilirubin homeostasis has received less attention. In this review, each of the steps involved in bilirubin production, metabolism, hepatic cell uptake, and excretion is quantitatively examined. We then attempt to predict the expected effect of normal and defective function on serum UB and CB levels in health and disease states including hemolysis, extra- and intrahepatic cholestasis, hepatocellular diseases (eg, cirrhosis, hepatitis, and various congenital defects in bilirubin conjugation and secretion (eg, Gilbert's, Dubin–Johnson, Crigler–Najjar, Rotor syndromes. Novel aspects of this review include: 1 quantitative estimates of the free and total UB and CB in the plasma, hepatocyte, and bile; 2 detailed discussion of the important implications of the recently recognized role of the hepatic OATP transporters in the maintenance of CB homeostasis; 3 discussion of the differences between the standard diazo assay versus chromatographic measurement of CB and UB; 4 pharmacokinetic implications of the extremely high-affinity albumin binding of UB; 5 role of the enterohepatic circulation in physiologic jaundice of newborn and fasting hyperbilirubinemia; and 6 insights concerning the clinical interpretation of bilirubin measurements.Keywords: liver, conjugation, diazo, albumin, Rotor

  7. Aldehyde Dehydrogenase 1A1: Friend or Foe to Female Metabolism?

    Directory of Open Access Journals (Sweden)

    Jennifer M. Petrosino


    Full Text Available In this review, we summarize recent advances in understanding vitamin A-dependent regulation of sex-specific differences in metabolic diseases, inflammation, and certain cancers. We focus on the characterization of the aldehyde dehydrogenase-1 family of enzymes (ALDH1A1, ALDH1A2, ALDH1A3 that catalyze conversion of retinaldehyde to retinoic acid. Additionally, we propose a “horizontal transfer of signaling” from estrogen to retinoids through the action of ALDH1A1. Although estrogen does not directly influence expression of Aldh1a1, it has the ability to suppress Aldh1a2 and Aldh1a3, thereby establishing a female-specific mechanism for retinoic acid generation in target tissues. ALDH1A1 regulates adipogenesis, abdominal fat formation, glucose tolerance, and suppression of thermogenesis in adipocytes; in B cells, ALDH1A1 plays a protective role by inducing oncogene suppressors Rara and Pparg. Considering the conflicting responses of Aldh1a1 in a multitude of physiological processes, only tissue-specific regulation of Aldh1a1 can result in therapeutic effects. We have shown through successful implantation of tissue-specific Aldh1a1−/− preadipocytes that thermogenesis can be induced in wild-type adipose tissues to resolve diet-induced visceral obesity in females. We will briefly discuss the emerging role of ALDH1A1 in multiple myeloma, the regulation of reproduction, and immune responses, and conclude by discussing the role of ALDH1A1 in future therapeutic applications.

  8. Regression approach to non-invasive determination of bilirubin in neonatal blood (United States)

    Lysenko, S. A.; Kugeiko, M. M.


    A statistical ensemble of structural and biophysical parameters of neonatal skin was modeled based on experimental data. Diffuse scattering coefficients of the skin in the visible and infrared regions were calculated by applying a Monte-Carlo method to each realization of the ensemble. The potential accuracy of recovering the bilirubin concentration in dermis (which correlates closely with that in blood) was estimated from spatially resolved spectrometric measurements of diffuse scattering. The possibility to determine noninvasively the bilirubin concentration was shown by measurements of diffuse scattering at λ = 460, 500, and 660 nm at three source-detector separations under conditions of total variability of the skin biophysical parameters.

  9. Initial formation of zebrafish brain ventricles occurs independently of circulation and requires the nagie oko and snakehead/atp1a1a.1 gene products. (United States)

    Lowery, Laura Anne; Sive, Hazel


    The mechanisms by which the vertebrate brain develops its characteristic three-dimensional structure are poorly understood. The brain ventricles are a highly conserved system of cavities that form very early during brain morphogenesis and that are required for normal brain function. We have initiated a study of zebrafish brain ventricle development and show here that the neural tube expands into primary forebrain, midbrain and hindbrain ventricles rapidly, over a 4-hour window during mid-somitogenesis. Circulation is not required for initial ventricle formation, only for later expansion. Cell division rates in the neural tube surrounding the ventricles are higher than between ventricles and, consistently, cell division is required for normal ventricle development. Two zebrafish mutants that do not develop brain ventricles are snakehead and nagie oko. We show that snakehead is allelic to small heart, which has a mutation in the Na+K+ ATPase gene atp1a1a.1. The snakehead neural tube undergoes normal ventricle morphogenesis; however, the ventricles do not inflate, probably owing to impaired ion transport. By contrast, mutants in nagie oko, which was previously shown to encode a MAGUK family protein, fail to undergo ventricle morphogenesis. This correlates with an abnormal brain neuroepithelium, with no clear midline and disrupted junctional protein expression. This study defines three steps that are required for brain ventricle development and that occur independently of circulation: (1) morphogenesis of the neural tube, requiring nok function; (2) lumen inflation requiring atp1a1a.1 function; and (3) localized cell proliferation. We suggest that mechanisms of brain ventricle development are conserved throughout the vertebrates.

  10. Downregulation of Col1a1 induces differentiation in mouse spermatogonia

    Institute of Scientific and Technical Information of China (English)

    Sun-Hong Chen; Ding Li; Chen Xu


    Col1a1 (one of the subunit of collagen type Ⅰ) is a collagen,which belongs to a family of extracellular matrix (ECM) proteins that play an important role in cellular proliferation and differentiation.However,the role of Col1a1 in spermatogenesis,especially in the control of proliferation and differentiation of spermatogonial stem cells (SSCs),remains unknown.In this study,we explored effects of downregulation of Col1a1 on differentiation and proliferation of mouse spermatogonia.Loss-of-function study revealed that Oct4 and Plzf,markers of SSC self-renewal,were significantly decreased,whereas the expression of c-kit and haprin,hallmarks of SSC differentiation,was enhanced after Col1a1 knockdown.Cell cycle analyses indicated that two-thirds of spermatogonia were arrested in S phase after Col1a1 knockdown.In vivo experiments,DNA injection and electroporation of the testes showed that spermatogonia self-renewal ability was impaired remarkably with the loss-of-function of Col1a1.Our data suggest that silencing of Col1a1 can suppress spermatogonia self-renewal and promote spermatogonia differentiation.

  11. Association between CYP1A1m1 gene polymorphism and primary open-angle glaucoma. (United States)

    Costa, N B; Silva, C T X; Frare, A B; Silva, R E; Moura, K K V O


    The CYP1A1 gene is related to the generation of secondary metabolites that are capable of inducing DNA damage. The CYP1A1m1 polymorphism has been examined in many studies, and is located in a region near loci that have been linked to glaucoma, including the locus GLC1I. As a result, this polymorphism has been related to several diseases that are influenced by exposure to xenobiotic as well as primary open-angle glaucoma. We compared the prevalence of the CYP1A1m1 polymorphism in 152 Brazilian patients, 100 patients with primary open-angle glaucoma, and 52 normal controls using restriction fragment length polymorphism analysis. The frequency of the homozygous wild-type (w1/w1) CYP1A1 gene among patients with primary open-angle glaucoma (N = 100) was 16%, for genotype w1/m1, the frequency was 77%, and for m1/m1 it was 7%. Among the control group (N = 52), the frequency of the homozygous wild-type (w1/w1) CYP1A1 gene was 54%, the frequency of w1/m1 was 46%, and the frequency of m1/m1 was 0%. The presence of the CYP1A1m1 polymorphism may interfere with xenobiotic metabolism and exacerbate direct or indirect damage to the optic nerve. These CYP1A1m1 polymorphisms may be risk factors for primary open-angle glaucoma.

  12. Association between bilirubin and risk of Non-Alcoholic Fatty Liver Disease based on a prospective cohort study (United States)

    Tian, Jianbo; Zhong, Rong; Liu, Cheng; Tang, Yuhan; Gong, Jing; Chang, Jiang; Lou, Jiao; Ke, Juntao; Li, Jiaoyuan; Zhang, Yi; Yang, Yang; Zhu, Ying; Gong, Yajie; Xu, Yanyan; Liu, Peiyi; Yu, Xiao; Xiao, Lin; Du, Min; Yang, Ling; Yuan, Jing; Wang, Youjie; Chen, Weihong; Wei, Sheng; Liang, Yuan; Zhang, Xiaomin; He, Meian; Wu, Tangchun; Yao, Ping; Miao, Xiaoping


    The study aimed to assess the association between total, direct, and indirect bilirubin and nonalcoholic fatty live disease (NAFLD) risk given its high prevalence and serious clinical prognosis. Among 27,009 subjects who participated in a healthy screening program from the Dongfeng-Tongji cohort study in 2008, 8189 eligible subjects (aged 35–86 years; males, 43.95%) were ultimately enrolled. The incidence rates of NAFLD in 2013 were compared with respect to baseline bilirubin levels among subjects free of NAFLD, and the effect sizes were estimated by logistic regression analysis. During 5 years follow-up, we observed 1956 cases of newly developed NAFLD with the overall incidence of 23.88%. Direct bilirubin was presented to inversely associate with NAFLD risk. Compared with quartile 1 of direct bilirubin, the multivariable-adjusted ORs (95% CIs) for NAFLD of quartile 2 to 4 were 1.104 (0.867–1.187), 0.843 (0.719–0.989), and 0.768 (0.652–0.905), respectively, P for trend 0.002). Similarly, inverse effects of direct bilirubin on NAFLD incidence were also observed when stratified by sex and BMI. However, no significant associations were found between total, and indirect bilirubin and NAFLD risk. Direct bilirubin reduced NAFLD risk independent of possible confounders among middle-aged and elderly Chinese population, probably based on the endogenous antioxidation of bilirubin. PMID:27484402

  13. A relevance study on uterine leiomyoma and gene polymorphisms of CYP1A1 MspⅠand SULT1A1 Arg213His%CYP1A1基因MspⅠ位点和SULT1A1基因Arg213His位点多态性与子宫肌瘤的关联性研究

    Institute of Scientific and Technical Information of China (English)

    周超; 林林; 张英姿; 徐天和; 张磊磊


    目的 探讨细胞色素P450(cytochrome P450,CYP)1A1基因MspⅠ位点和硫酸氨基转移酶(sulfotransferase,SULT)1A1基因Arg213His位点多态性与鲁北地区汉族女性子宫肌瘤的关系.方法 采用聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)方法检测123例子宫肌瘤患者和123例健康对照组的CYP1A1基因MspⅠ位点的基因型和SULT1A1基因Arg213His位点的基因型,分析基因多态性与子宫肌瘤的关系.结果 子宫肌瘤组CYP1A1基因MspⅠ位点的基因型与对照组中的分布比较,差异无统计学意义(P=0.927);而子宫肌瘤组SULT1A1基因Arg213His位点的基因型与对照组中的分布比较,差异有统计学意义(P=0.011).CYP1A1基因MspⅠ位点和SULT1A1基因Arg213His位点多态性在子宫肌瘤的发生过程中的交互作用比较,差异有统计学意义(P=0.024).结论 CYP1A1基因MspⅠ位点多态性与鲁北地区汉族女性子宫肌瘤的易感性无显著相关;SULT1A1基因Arg213His位点多态性与鲁北地区汉族女性子宫肌瘤的发生有关,并增加了子宫肌瘤的患病风险;CYP1A1基因MspⅠ位点和SULT1A1基因Arg213His位点多态性在子宫肌瘤的发生过程中具有交互作用.

  14. Evaluation of the Predictive Value of Umbilical Cord Serum Bilirubin Level for the Development of Subsequent Hyperbilirubinemia in Term and Late-Preterm Neonates

    Directory of Open Access Journals (Sweden)

    Fariba Hemmati


    Conclusion: Based on the findings, UCS bilirubin level could not predict subsequent hyperbilirubinemia. Therefore, the best predictive marker for neonatal jaundice is the assessment of clinical risk factors and predischarge bilirubin level.

  15. Microchip capillary electrophoresis for frontal analysis of free bilirubin and study of its interaction with human serum albumin. (United States)

    Nie, Zhou; Fung, Ying Sing


    To meet the need for bedside monitoring of free bilirubin for neonates under critical conditions, a microfluidic chip was fabricated and tested for its coupling with CE/frontal analysis (FA) to determine free bilirubin and study of its binding interaction with HSA, which regulated its concentration in plasma. The poly(methyl methacrylate) (PMMA) multichannel chip was fabricated by CO2 laser ablation and bonded with a fused-silica separation capillary for CE/FA separation with UV detection. The chip was designed to allow a complete assay of four electrophoretic runs using preconditioned channels to speed up the determination of free bilirubin and to deliver quick results for bedside monitoring. Under optimized conditions, the linear working range for free bilirubin was from 10 to 200 micromol with RSDs from 2.1 to 5.0% for n=3, and the LOD at 9 micromol for S/N=3. From a binding study between bilirubin and HSA under FA condition, the second binding constant for bilirubin-HSA was determined as 1.07x10(5) L/mol and the number of binding sites per HSA as 3.46. The results enabled the calculation of free bilirubin for jaundiced infants based on the clinically significant level of total bilirubin, producing a range of 118.3-119.4 micromol/L. The developed method is shown to meet the clinical requirement with additional margin of protection to detect the early rising level of free bilirubin prior to jaundice condition. The low-cost microchip CE/FA device is shown to produce quick results with high potential to deliver a suitable bed-side monitoring method for bilirubin management in neonates.

  16. Circular dichroism study of the interaction between mutagens and bilirubin bound to different binding sites of serum albumins (United States)

    Orlov, Sergey; Goncharova, Iryna; Urbanová, Marie

    Although recent investigations have shown that bilirubin not only has a negative role in the organism but also exhibits significant antimutagenic properties, the mechanisms of interactions between bilirubin and mutagens are not clear. In this study, interaction between bilirubin bound to different binding sites of mammalian serum albumins with structural analogues of the mutagens 2-aminofluorene, 2,7-diaminofluorene and mutagen 2,4,7-trinitrofluorenone were investigated by circular dichroism and absorption spectroscopy. Homological human and bovine serum albumins were used as chiral matrices, which preferentially bind different conformers of bilirubin in the primary binding sites and make it observable by circular dichroism. These molecular systems approximated a real system for the study of mutagens in blood serum. Differences between the interaction of bilirubin bound to primary and to secondary binding sites of serum albumins with mutagens were shown. For bilirubin bound to secondary binding sites with low affinity, partial displacement and the formation of self-associates were observed in all studied mutagens. The associates of bilirubin bound to primary binding sites of serum albumins are formed with 2-aminofluorene and 2,4,7-trinitrofluorenone. It was proposed that 2,7-diaminofluorene does not interact with bilirubin bound to primary sites of human and bovine serum albumins due to the spatial hindrance of the albumins binding domains. The spatial arrangement of the bilirubin bound to serum albumin along with the studied mutagens was modelled using ligand docking, which revealed a possibility of an arrangement of the both bilirubin and 2-aminofluorene and 2,4,7-trinitrofluorenone in the primary binding site of human serum albumin.

  17. Effects of Teratogenic Drugs on CYP1A1 Activity in Differentiating Rat Embryo Cells. (United States)

    Tayeboon, Gh S; Ostad, S N; Nasri, S; Nili-Ahmadabadi, A; Tavakoli, F; Sabzevari, O


    CYP1A1, a P450 isoenzyme, is involved in the phase I xenobiotic metabolism including teratogen drugs. In the present study, the ability of teratogens to elevate the embryonic expression of CYP1A1 was examined. Micromass cell cultures prepared from day 13 rat embryo limb buds (LB). LB cells were cultivated and exposed for 5 days to retinoic acid (RA), hydrocortisone (HC), caffeine (CA) and quinine (QN). CYP1A1 protein expression and activity were measured using immunofluorescence staining and ethoxyresorufin O-deethylation (EROD) assay, respectively. The EROD activity increased significantly following LB cells exposure to RA and HC (pteratogens have potency to increase CYP1A1 activity.

  18. Preparation and adsorption property of aminated cross linking microbeads of GMA/EGDMA for bilirubin

    Indian Academy of Sciences (India)

    Zhiping Chen; Baojiao Gao; Xiaofeng Yang


    Cross linking microbeads with a controllable diameter were synthesized by suspension copolymerization of the monomer glycidyl methacrylate (GMA) and the cross linking agent ethylene glycol dimethylacrylate (EGDMA). By the ring-opening reaction of the epoxy groups, the microbeads GMA/EGDMA were modified with different aminating agents and resulting in the aminated microbeads. The morphology of the microbeads was characterized by SEM. The adsorption property of aminated microbeads for bilirubin was investigated, and the effects of various factors, such as the chemical structures of the aminating agents, pH values of the medium and the presence of bovine serum albumin in the adsorption medium, on the adsorption property were examined. The experimental results show that the aminated microbeads have strong adsorption ability for bilirubin, and the isotherm adsorption behaviour is fitted to Freundlich equation satisfactorily. The adsorption ability of the aminated microbeads modified with hexanediamine is stronger than that of others, and the longer the molecule of multi-ethylene multiamine, the weaker the adsorption ability for bilirubin. The pH value of the medium affects the adsorption ability greatly, as pH = 6, the adsorption ability is strongest. In the presence of BSA, the microbeads still have a higher adsorption capacity towards bilirubin.

  19. Deracemization of bilirubin as the marker of the chirality of micellar aggregates. (United States)

    Sorrenti, Alessandro; Altieri, Barbara; Ceccacci, Francesca; Di Profio, Pietro; Germani, Raimondo; Giansanti, Luisa; Savelli, Gianfranco; Mancini, Giovanna


    The deracemization of bilirubin in micellar aggregates of structurally correlated chiral surfactants was studied by circular dichroism experiments and exploited as the marker of the expression of chirality of the aggregates. The obtained results suggest that the hydrophobic interactions control the transfer of chirality from the monomers to the aggregates, and that different regions of the same aggregate might feature opposite enantiorecognition capabilities.

  20. Functionalized Magnetic Fe3O4-β-Cyclodextran Nanoparticles for Efficient Removal of Bilirubin. (United States)

    Han, Lulu; Chu, Simin; Wei, Houliang; Ren, Jun; Xu, Li; Jia, Lingyun


    Bilirubin (BR), as a lipophilic toxin, can binds and deposits in various tissues, especially the brain tissue, leading to hepatic coma and even death. Magnetic nanoparticles adsorbent modified by β-cyclodextran (Fe3O4-β-CD) was developed to remove the BR from the plasma. Fe3O4-β-CD nanoparticles was prepared through Schiff base reaction between the polyethylenimine (PEI)-modified Fe3O4 and aldehyde-functionalized β-CD, and characterized by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and dynamic light scattering (DLS). Under optimized conditions, the Fe3O4-β-CD adsorbent could adsorb 225.6 mg/g free BR in PBS and reach the adsorption equilibrium within 90 min mainly through hydrophobic interaction; Moreover, the adsorbent displayed better adsorption capability in a dialysis system for BSA-bound bilirubin, plasma bilirubin and total bile acid, and the removal rates of those were 66%, 31% and 41% respectively. Because of the advantages of fast separation and purification process, low preparation cost, good adsorption capability for plasma bilirubin, Fe3O4-β-CD may become an economical and promising absorbent of BR for clinical applications.

  1. Kinetics of oxidation of bilirubin and its protein complex by hydrogen peroxide in aqueous solutions (United States)

    Solomonov, A. V.; Rumyantsev, E. V.; Antina, E. V.


    A comparative study of oxidation reactions of bilirubin and its complex with albumin was carried out in aqueous solutions under the action of hydrogen peroxide and molecular oxygen at different pH values. Free radical oxidation of the pigment in both free and bound forms at pH 7.4 was shown not to lead to the formation of biliverdin, but to be associated with the decomposition of the tetrapyrrole chromophore into monopyrrolic products. The effective and true rate constants of the reactions under study were determined. It was assumed that one possible mechanism of the oxidation reaction is associated with the interaction of peroxyl radicals and protons of the NH groups of bilirubin molecules at the limiting stage with the formation of a highly reactive radical intermediate. The binding of bilirubin with albumin was found to result in a considerable reduction in the rate of the oxidation reaction associated with the kinetic manifestation of the protein protection effect. It was found that the autoxidation of bilirubin by molecular oxygen with the formation of biliverdin at the intermediate stage can be observed with an increase in the pH of solutions.

  2. Prognostic value of serum total bilirubin in patients with acute coronary syndrome after percutaneous coronary intervention

    Institute of Scientific and Technical Information of China (English)



    Objective To investigate the predictive value of serum total bilirubin (STB) level in patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI) .Methods A total of 1273 consecutive patients treated with PCI in cardiology department,First Affiliated Hospital of Zhengzhou University from June

  3. Surface modifying of microporous PTFE capillary for bilirubin removing from human plasma and its blood compatibility

    Energy Technology Data Exchange (ETDEWEB)

    Jin Gu [Department of Chemistry, University of Science and Technology of China, HeFei, 230026 (China)], E-mail:; Yao Qizhi; Zhang Shanzi [Department of Chemistry, University of Science and Technology of China, HeFei, 230026 (China); Zhang Lei [Department of Chemistry, University of Science and Technology of China, HeFei, 230026 (China); AnHui Entry Exit Inspection and Quarantine Bureau, HeFei, 230001 (China)


    In this study, human serum albumin (HSA) was covalently immobilized onto the inner surface of microporous poly(tetrafluoroethylene) (MPTFE) capillaries for direct bilirubin removal from human plasma. To obtain active binding sites for HSA, the MPTFE capillaries were chemically functionalized by using a coating of poly(vinyl alcohol) (PVA)-glycidyl methacrylate (GMA) copolymers. Characterization of grafted MPTFE capillaries was verified by XPS, Fourier transform infrared spectroscopy (FT-IR), scanning electronic microscopy (SEM). Non-specific adsorption on the PVA-GMA coated capillary remains low (< 0.38 mg bilirubin/g), and higher affinity adsorption capacity, of up to 73.6 mg bilirubin/g polymer was obtained after HSA is immobilized. Blood compatibility of the grafted MPTFE capillary was evaluated by SEM and platelet rich plasma (PRP) contacting experiments. The experimental data on blood compatibility indicated that PVA-coated and PVA-GMA-HSA coated PTFE capillary showed a sharp suppress on platelets adhesion. The proposed method has the potential of serving in bilirubin removal in clinical application.

  4. EKTACHEM bilirubin fraction Bc as a predictor of liver transplant rejection. (United States)

    Cox, C J; Valdiserri, R O; Zerbe, T R; Genter, J L


    Bilirubin fractions Bc and DELTA, not routinely available prior to the EKTACHEM Chemistry Analyzer and its slide methodology, were studied in an outpatient population of liver transplant recipients. A preliminary evaluation by the authors has shown that direct bilirubin (DBILI) levels in the normal range consist almost exclusively of DELTA (protein-bound conjugated bilirubin), while at elevated DBILI levels, an increasing amount of Bc (non-protein-bound conjugated bilirubin) is measured as well. The present study evaluated the clinical significance of Bc in the serum of 80 liver transplant recipients as a means of identifying episodes of rejection. Each patient was classified into rejection or nonrejection categories based on clinical status, liver biopsy results, and/or response to therapy. Eighteen patients were classified as experiencing an episode of rejection during the period of this study. Fourteen of these (77.8%) had Bc levels that ranged from 0.1 to 6.8 mg/dl. Sixty two patients were classified in the nonrejection category. Fourteen (22.6%) of these patients had Bc levels that ranged from 0.1 to 0.6 mg/dl. In our outpatient liver transplant recipients with Bc greater than or equal to 0.1 mg/dl, the relative risk of rejection (% of rejection patients with Bc/% of nonrejection patients with Bc) was 3.44. This value indicates that Bc determination may be a helpful adjunct in the assessment of rejection.

  5. 21 CFR 862.1110 - Bilirubin (total or direct) test system. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bilirubin (total or direct) test system. 862.1110 Section 862.1110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

  6. A pro-inflammatory glycoprotein biomarker is associated with lower bilirubin in metabolic syndrome

    NARCIS (Netherlands)

    Dullaart, Robin P. F.; Gruppen, Eke G.; Connelly, Margery A.; Lefrandt, Joop D.


    Objectives: Bilirubin exerts anti-oxidative and anti-inflammatory properties which may beneficially influence the development of cardio-metabolic disorders. A nuclear magnetic resonance (NMR) spectroscopy-based glycoprotein biomarker, designated GlycA, whose signal originates from several glycosylat

  7. β-Catenin-regulated ALDH1A1 is a target in ovarian cancer spheroids. (United States)

    Condello, S; Morgan, C A; Nagdas, S; Cao, L; Turek, J; Hurley, T D; Matei, D


    Cancer cells form three-dimensional (3D) multicellular aggregates (or spheroids) under non-adherent culture conditions. In ovarian cancer (OC), spheroids serve as a vehicle for cancer cell dissemination in the peritoneal cavity, protecting cells from environmental stress-induced anoikis. To identify new targetable molecules in OC spheroids, we investigated gene expression profiles and networks upregulated in 3D vs traditional monolayer culture conditions. We identified ALDH1A1, a cancer stem cell marker as being overexpressed in OC spheroids and directly connected to key elements of the β-catenin pathway. β-Catenin function and ALDH1A1 expression were increased in OC spheroids vs monolayers and in successive spheroid generations, suggesting that 3D aggregates are enriched in cells with stem cell characteristics. β-Catenin knockdown decreased ALDH1A1 expression levels and β-catenin co-immunoprecipitated with the ALDH1A1 promoter, suggesting that ALDH1A1 is a direct β-catenin target. Both short interfering RNA-mediated β-catenin knockdown and A37 ((ethyl-2-((4-oxo-3-(3-(pryrrolidin-1-yl)propyl)-3,4-dihydrobenzo [4,5]thioeno [3,2-d]pyrimidin-2-yl)thio)acetate)), a novel ALDH1A1 small-molecule enzymatic inhibitor described here for the first time, disrupted OC spheroid formation and cell viability (Pmodel. These data strongly support the role of β-catenin-regulated ALDH1A1 in the maintenance of OC spheroids and propose new ALDH1A1 inhibitors targeting this cell population.

  8. Role of CYP1A1 haplotypes in modulating susceptibility to coronary artery disease. (United States)

    Lakshmi, Sana Venkata Vijaya; Naushad, Shaik Mohammad; Saumya, Kankanala; Rao, Damera Seshagiri; Kutala, Vijay Kumar


    To investigate the role of cytochrome P450 1A1 (CYP1A1) haplotypes in modulating susceptibility to coronary artery disease (CAD), a case-control study was conducted by enrolling 352 CAD cases and 282 healthy controls. PCR-RFLP, multiplex PCR, competitive ELISA techniques were employed for the analysis of CYP1A1 [ml (T-->C), m2 (A-->G) and m4 (C-->A)] haplotypes, glutathione-S-transferase (GST)T1/GSTM1 null variants and plasma 8-oxo-2'deoxyguanosine (8-oxodG) respectively. Two CYP1A1 haplotypes, i.e. CAC and TGC showed independent association with CAD risk, while all-wild CYP1A1 haplotype i.e. TAC showed reduced risk for CAD. All the three variants showed mild linkage disequilibrium (D': 0.05 to 0.17). GSTT1 null variant also exerted independent association with CAD risk (OR: 2.53, 95% CI 1.55-4.12). Among the conventional risk factors, smoking showed synergetic interaction with CAC haplotype of CYP1A1 and GSTT1 null genotype in inflating CAD risk. High risk alleles of this pathway showed dose-dependent association with percentage of stenosis and number of vessels affected. Elevated 8-oxodG levels were observed in subjects with CYP1A1 CAC haplotype and GSTT1 null variant. Multiple linear regression model of these xenobiotic variants explained 36% variability in 8-oxodG levels. This study demonstrated the association of CYP1A1 haplotypes and GSTT1 null variant with CAD risk and this association was attributed to increased oxidative DNA damage.

  9. Assessment of duodenogastric reflux by combined continuous intragastric pH and bilirubin monitoring

    Institute of Scientific and Technical Information of China (English)

    Fei Dai; Jun Gong; Ru Zhang; Jin-Yan Luo; You-Ling Zhu; Xue-Qin Wang


    AIM: To assess the diagnostic value of a combination of continuous intragastric pH and bilirubin monitoring in the detection of duodenogastric reflux (DGR), and the effects of diet on the bilirubin absorbance.METHODS: 30 healthy volunteers were divided into twogroups: standard diet group (Group 1) 18 cases, free diet group (Group 2) 12 cases. Each subjects were subjected to simultaneous 24 hour intragastric pH and spectrophotometric bilirubin concentration monitoring (Bilitec 2000).RESULTS: There was no difference of preprandial phasebilirubin absorbance between two groups. The absorbanceof postprandial phase was significantly increased in group 2than group 1. There was no difference between preprandialphase and postprandial phase absorbance in group 1.Postprandial phase absorbance was significantly higher ingroup 2. In a comparison of bile reflux with intragastric pHduring night time, there were 4 types of reflux:Simultaneous increase in absorbance and pH in only 19.6%, increase in bilirubin with unchanged pH 33. 3 %, pHincrease with unchanged absorbance 36. 3 %, and bothunchanged in 10. 8 %. Linear regression analysis showed nocorrelation between percertage total time of pH < 4 aridpercentage total time of absortance > 0. 14, r=0.068, P<0.05.CONCLUSION: Because of the dietary effect, highabsorbance fluids or foods should be avoided in detection.Intrsgastric pH and bilirubin monitoring separately predictthe presence of duodenal (and/or pancreatic) reflux and bilereflux. They can not substitute for each other. The detectionof DGR is improved if the two parameters are combinedsimultanoously.

  10. Selective nonenzymatic bilirubin detection in blood samples using a Nafion/Mn-Cu sensor. (United States)

    Noh, Hui-Bog; Won, Mi-Sook; Shim, Yoon-Bo


    The specific detection of biological organics without the use of an enzyme is challenging, and it is crucial for analytical and clinical chemistry. We report specific nonenzymatic bilirubin detection through the catalytic oxidation of bilirubin molecule on the Nafion/Mn-Cu surface. The catalytic ability, true surface area, morphology, crystallinity, composition, and oxidation state of the sensor surface were assessed using voltammetry, coulometry, XPS, XRD, Brunauer-Emmett-Teller (BET), SEM, EDXS, and TOF-SIMS experiments. The results showed that the surface was composed of microporous Mn-Cu bimetallic crystal in flake shape with a large BET surface area (3.635 m(2)g(-1)), where the surface area and crystallinity mainly affected the sensor performance. Product analysis of the catalytic reaction on the sensor probe revealed a specific two-electron oxidation of dipyrromethane moiety to dipyrromethene in the bilirubin molecule. Experimental variables affecting the analysis of bilirubin were optimized in terms of probe composition, temperature, pH, and potential. At the optimized condition, the dynamic range was between 1.2 μM and 0.42 mM, which yielded the equation of ΔI (μA)=(1.03 ± 0.72)+(457.0 ± 4.03) [C] (mM) with 0.999 of correlation coefficient, and the detection limit was 25.0 ± 1.8 nM (n=5, k=3). The stability test, interference effects, and analysis of real clinical samples, human whole blood and certified serum samples were demonstrated to confirm the reliability of the proposed bilirubin sensor.

  11. Three-dimensionally porous graphene: A high-performance adsorbent for removal of albumin-bonded bilirubin. (United States)

    Ma, Chun Fang; Gao, Qiang; Xia, Kai Sheng; Huang, Zhi Yuan; Han, Bo; Zhou, Cheng Gang


    The development of bilirubin adsorbents with high adsorption efficiencies towards albumin-bonded bilirubin is still a considerable challenge. In this work, a three-dimensionally porous graphene (3D-pGR) has been fabricated through a simple carbon dioxide (CO2) activation of thermally exfoliated graphite oxide (EGO). Intriguingly, the resultant 3D-pGR material showed hierarchically micro-meso-macroporous structure, high specific surface area of up to 843m(2)g(-1), and large pore volume as high as 2.71cm(3)g(-1). Besides, the large planar π-configuration structure of 3D-pGR made it possible to compete effectively with albumin for bilirubin binding. Taking advantages of these fantastic characteristics, the 3D-pGR was demonstrated to be extraordinarily efficient for bilirubin removal from a bovine serum albumin (BSA)-rich solution. Under optimized conditions, the maximum adsorption capacity of 3D-pGR for BSA-bonded bilirubin was up to 126.1mgg(-1), which is not only significantly higher than the adsorption capacities of currently available adsorbents towards albumin-bonded bilirubin, but also superior to those of many reported adsorbents towards free bilirubin. In addition, the hemolysis assay of 3D-pGR indicated that this material had negligible hemolysis effect. Findings from this study may open up important new possibilities for removal of protein-bonded toxins.


    Sadler, Ryan A; Lamberski, Nadine; Christopher, Mary M


    Captive waterbuck ( Kobus ellipsiprymnus ) that appear clinically healthy have been noted to have high serum bilirubin concentrations compared with other ruminants; however, questions remain about the physiologic factors affecting bilirubin concentration and its potential association with underlying disease and icteric serum or mucous membranes. Serum bilirubin concentrations of healthy and diseased waterbuck housed at the San Diego Zoo Safari Park from 1989 to 2012 were retrospectively analyzed to determine any link between icteric serum, total bilirubin concentration (tBili), and disease entities in this species. Total bilirubin and direct (dBili) bilirubin concentrations and the prevalence of icteric serum were compared by subspecies, age group, and health status; associations with complete blood count and biochemical results and clinical diagnosis were assessed. No significant differences were found in tBili or dBili between Ellipsen (n = 32) and Defassa (n = 29) subspecies or in juveniles (n = 22) versus adults (n = 39). Clinically healthy waterbuck (n = 40) had significantly higher tBili (mean ± 2SD, 7.9 ± 1.2 mg/dl; P bilirubin (2.2-6.2 mg/dl). These results suggest healthy waterbuck have relatively high tBili and dBili compared with related species. Icteric serum may be seen in up to 15% of healthy animals in the absence of icteric tissues.

  13. The molecular basis for the broad substrate specificity of human sulfotransferase 1A1.

    Directory of Open Access Journals (Sweden)

    Ilana Berger

    Full Text Available Cytosolic sulfotransferases (SULTs are mammalian enzymes that detoxify a wide variety of chemicals through the addition of a sulfate group. Despite extensive research, the molecular basis for the broad specificity of SULTs is still not understood. Here, structural, protein engineering and kinetic approaches were employed to obtain deep understanding of the molecular basis for the broad specificity, catalytic activity and substrate inhibition of SULT1A1. We have determined five new structures of SULT1A1 in complex with different acceptors, and utilized a directed evolution approach to generate SULT1A1 mutants with enhanced thermostability and increased catalytic activity. We found that active site plasticity enables binding of different acceptors and identified dramatic structural changes in the SULT1A1 active site leading to the binding of a second acceptor molecule in a conserved yet non-productive manner. Our combined approach highlights the dominant role of SULT1A1 structural flexibility in controlling the specificity and activity of this enzyme.

  14. A novel stop codon mutation in exon 1 (558C>A) of the UGT1A1 gene in a Thai neonate with Crigler-Najjar syndrome type I. (United States)

    Wanlapakorn, N; Nilyanimit, P; Vorawandthanachai, T; Deesudjit, T; Dumrongpisutikul, N; Poovorawan, Y


    Human uridine 5'-diphosphate-glucuronosyltransferases play a critical role in detoxification by conjugating bilirubin with glucoronic acid. Impaired or reduced enzymatic activity causes a spectrum of clinical disorders such as Crigler-Najjar syndrome type I (CN1), Crigler-Najjar syndrome type II, and Gilbert's syndrome. CN1 is a severe form of unconjugated hyperbilirubinemia caused by homozygous or compound heterozygous mutations in the gene for uridine 5'-diphosphate glucuronosyltransferase 1 family, polypeptide A1 (UGT1A1), resulting in complete loss of enzyme function. Here, we report a novel homozygous mutation of UGT1A1 in a female Thai infant who was diagnosed with CN1, and her parents were found to be heterozygous carriers. The patient was homozygous for the c.558C>A mutation, which resulted in a premature stop codon in exon 1. Her asymptomatic parents were carriers of the nonsense c.558C>A mutation. Our result suggests an important role for homozygous c.558C>A mutations in the UGT1A1 gene in the development of severe unconjugated hyperbilirubinemia.

  15. Looking to the horizon: the role of bilirubin in the development and prevention of age-related chronic diseases. (United States)

    Wagner, Karl-Heinz; Wallner, Marlies; Mölzer, Christine; Gazzin, Silvia; Bulmer, Andrew Cameron; Tiribelli, Claudio; Vitek, Libor


    Bilirubin, the principal tetrapyrrole, bile pigment and catabolite of haem, is an emerging biomarker of disease resistance, which may be related to several recently documented biological functions. Initially believed to be toxic in infants, the perception of bilirubin has undergone a transformation: it is now considered to be a molecule that may promote health in adults. Data from the last decade demonstrate that mildly elevated serum bilirubin levels are strongly associated with reduced prevalence of chronic diseases, particularly cardiovascular diseases (CVDs), as well as CVD-related mortality and risk factors. Recent data also link bilirubin to other chronic diseases, including cancer and Type 2 diabetes mellitus, and to all-cause mortality. Therefore, there is evidence to suggest that bilirubin is a biomarker for reduced chronic disease prevalence and a predictor of all-cause mortality, which is of important clinical significance. In the present review, detailed information on the association between bilirubin and all-cause mortality, as well as the pathological conditions of CVD, cancer, diabetes and neurodegenerative diseases, is provided. The mechanistic background concerning how bilirubin and its metabolism may influence disease prevention and its clinical relevance is also discussed. Given that the search for novel biomarkers of these diseases, as well as for novel therapeutic modalities, is a key research objective for the near future, bilirubin represents a promising candidate, meeting the criteria of a biomarker, and should be considered more carefully in clinical practice as a molecule that might provide insights into disease resistance. Clearly, however, greater molecular insight is warranted to support and strengthen the conclusion that bilirubin can prevent disease, with future research directions also proposed.

  16. Bilirubin activates transcription of HIF-1α in human proximal tubular cells cultured in the physiologic oxygen content. (United States)

    Kim, Sung Gyun; Ahn, Shin-Young; Lee, Eun Seong; Kim, Sejoong; Na, Ki Young; Chae, Dong-Wan; Chin, Ho Jun


    The expression of hypoxia-inducible factor (HIF) is influenced by reactive oxygen species (ROS). Effect of bilirubin on HIF-1 expression in proximal tubular cells was investigated under physiological oxygen concentration, which is relative hypoxic condition mimicking oxygen content in the medulla of renal tissue. The human kidney (HK2) cells were cultured in 5% oxygen with or without bilirubin. HIF-1α protein expression was increased by bilirubin treatment at 0.01-0.2 mg/dL concentration. The messenger RNA expression of HIF-1α was increased by 1.69±0.05 folds in the cells cultured with 0.1 mg/dL bilirubin, compared to the control cells. The inhibitors of PI3K/mTOR, PI3K/AKT, and ERK 1/2 pathways did not attenuate increased HIF-1α expression by bilirubin. HIF-1α expression decreased by 10 µM exogenous hydrogen peroxide (H2O2); scavenger of ROS with or without bilirubin in the HK2 cells increased HIF-1α concentration more than that in the cells without bilirubin. Exogenous H2O2 decreased the phosphorylation of P70S6 kinase, which was completely reversed by bilirubin treatment. Knockdown of NOX4 gene by small interfering RNA (siRNA) increased HIF-1α mRNA expression. In coonclusion, bilirubin enhances HIF-1α transcription as well as the up-regulation of HIF-1α protein translation through the attenuation of ROS and subunits of NADPH oxidase.

  17. Bilirubin prevents acute DSS-induced colitis by inhibiting leukocyte infiltration and suppressing upregulation of inducible nitric oxide synthase. (United States)

    Zucker, Stephen D; Vogel, Megan E; Kindel, Tammy L; Smith, Darcey L H; Idelman, Gila; Avissar, Uri; Kakarlapudi, Ganesh; Masnovi, Michelle E


    Bilirubin is thought to exert anti-inflammatory effects by inhibiting vascular cell adhesion molecule-1 (VCAM-1)-dependent leukocyte migration and by suppressing the expression of inducible nitric oxide synthase (iNOS). As VCAM-1 and iNOS are important mediators of tissue injury in the dextran sodium sulfate (DSS) murine model of inflammatory colitis, we examined whether bilirubin prevents colonic injury in DSS-treated mice. Male C57BL/6 mice were administered 2.5% DSS in the drinking water for 7 days, while simultaneously receiving intraperitoneal injections of bilirubin (30 mg/kg) or potassium phosphate vehicle. Disease activity was monitored, peripheral blood counts and serum nitrate levels were determined, and intestinal specimens were analyzed for histological injury, leukocyte infiltration, and iNOS expression. The effect of bilirubin on IL-5 production by HSB-2 cells and on Jurkat cell transendothelial migration also was determined. DSS-treated mice that simultaneously received bilirubin lost less body weight, had lower serum nitrate levels, and exhibited reduced disease severity than vehicle-treated animals. Concordantly, histopathological analyses revealed that bilirubin-treated mice manifested significantly less colonic injury, including reduced infiltration of eosinophils, lymphocytes, and monocytes, and diminished iNOS expression. Bilirubin administration also was associated with decreased eosinophil and monocyte infiltration into the small intestine, with a corresponding increase in peripheral blood eosinophilia. Bilirubin prevented Jurkat migration but did not alter IL-5 production. In conclusion, bilirubin prevents DSS-induced colitis by inhibiting the migration of leukocytes across the vascular endothelium and by suppressing iNOS expression.

  18. Distribution of composite CYP1A1 genotypes in Africans, African-Americans and Caucasians. (United States)

    Garte, S J; Trachman, J; Crofts, F; Toniolo, P; Buxbaum, J; Bayo, S; Taioli, E


    We present the genotype distribution of the CYP1A1 gene in a sample of over 300 subjects of various ethnic origins. Genotypes are presented as composites of eight possible alleles, taking into account the three major polymorphisms, including a recently described African-American-specific MspI RFLP. A new nomenclature system is presented for clarifying the various haplotypes. Interesting interracial differences in allelic frequencies and admixture rates were observed for the three polymorphisms. Because of the importance of the CYP1A1 gene (which encodes the aromatic hydrocarbon hydroxylase) as a biomarker of genetic susceptibility to environmental carcinogens such as polycyclic aromatic hydrocarbons, these data may provide a useful reference for future studies of relationships between CYP1A1 genotype and disease susceptibility.

  19. Aldehyde dehydrogenase 1a1 mediates a GABA synthesis pathway in midbrain dopaminergic neurons. (United States)

    Kim, Jae-Ick; Ganesan, Subhashree; Luo, Sarah X; Wu, Yu-Wei; Park, Esther; Huang, Eric J; Chen, Lu; Ding, Jun B


    Midbrain dopamine neurons are an essential component of the basal ganglia circuitry, playing key roles in the control of fine movement and reward. Recently, it has been demonstrated that γ-aminobutyric acid (GABA), the chief inhibitory neurotransmitter, is co-released by dopamine neurons. Here, we show that GABA co-release in dopamine neurons does not use the conventional GABA-synthesizing enzymes, glutamate decarboxylases GAD65 and GAD67. Our experiments reveal an evolutionarily conserved GABA synthesis pathway mediated by aldehyde dehydrogenase 1a1 (ALDH1a1). Moreover, GABA co-release is modulated by ethanol (EtOH) at concentrations seen in blood alcohol after binge drinking, and diminished ALDH1a1 leads to enhanced alcohol consumption and preference. These findings provide insights into the functional role of GABA co-release in midbrain dopamine neurons, which may be essential for reward-based behavior and addiction.

  20. Mildly elevated serum bilirubin levels are negatively associated with carotid atherosclerosis among elderly persons.

    Directory of Open Access Journals (Sweden)

    Ryuichi Kawamoto

    Full Text Available Serum bilirubin may have a beneficial role in preventing oxidative changes in atherosclerosis. Limited information is available on whether serum total bilirubin is an independent confounding factor for carotid atherosclerosis {for example, intima-media thickness (IMT, plaque} measured noninvasively by B-mode ultrasonography only among elderly persons. The study subjects were 325 men aged 79 ± 8 (mean ± standard deviation years and 509 women aged 81 ± 8 years that were enrolled consecutively from patients aged ≥ 60 years in the medical department. Carotid IMT and plaque were derived via B-mode ultrasonography. Multiple linear regression analysis showed that in men age (β = 0.199, p = 0.002, smoking status (β = 0.154, p = 0.006, GGT (β = -0.139, p = 0.039, and GGT (β = -0.133, p = 0.022 were significantly and independently associated with carotid IMT, and in women age (β = 0.186, p < 0.001, systolic blood pressure (β = 0.104, p = 0.046, diastolic blood pressure (β = -0.148, p = 0.004, prevalence of antihypertensive medication (β = 0.126, p = 0.004, fasting plasma glucose (β = 0.135, p = 0.003, GGT (β = -0.104, p = 0.032, estimated glomerular filtration rate, serum bilirubin (β = -0.119, p = 0.006, and prevalence of cardiovascular disease (CVD (β = 0.103, p = 0.017 were also independently associated with carotid IMT. The odds ratios (ORs {95% confidence interval (CI} of increasing serum bilirubin category were negatively associated with carotid IMT ≥ 1.0 mm and plaque in both genders. Compared to subjects with a serum bilirubin of Quartile-1, the multivariate-OR (95% CI of carotid plaque was 0.25 (0.11-0.57 in the Quartile-4 male group, and 0.41 (0.21-0.78 in the Quartile-2 female group, 0.51 (0.26-0.98 in the Quartile-3 female group, and 0.46 (0.24-0.89 in the Quartile-4 female group. Our data demonstrated an independently negative association between serum bilirubin and carotid atherosclerosis in both genders.

  1. Inducible bilirubin oxidase: A novel function for the mouse cytochrome P450 2A5

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Bakar, A' edah, E-mail: [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Arthur, Dionne Maioha [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide (Australia); Aganovic, Simona [Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Centre, Box 578, S-751 23 Uppsala (Sweden); Ng, Jack C. [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide (Australia); Lang, Matti A. [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Centre, Box 578, S-751 23 Uppsala (Sweden)


    We have previously shown that bilirubin (BR), a breakdown product of haem, is a strong inhibitor and a high affinity substrate of the mouse cytochrome P450 2A5 (CYP2A5). The antioxidant BR, which is cytotoxic at high concentrations, is potentially useful in cellular protection against oxygen radicals if its intracellular levels can be strictly controlled. The mechanisms that regulate cellular BR levels are still obscure. In this paper we provide preliminary evidence for a novel function of CYP2A5 as hepatic 'BR oxidase'. A high-performance liquid chromatography/electrospray ionisation mass spectrometry screening showed that recombinant yeast microsomes expressing the CYP2A5 oxidise BR to biliverdin, as the main metabolite, and to three other smaller products with m/z values of 301, 315 and 333. The metabolic profile is significantly different from that of chemical oxidation of BR. In chemical oxidation the smaller products were the main metabolites. This suggests that the enzymatic reaction is selective, towards biliverdin production. Bilirubin treatment of primary hepatocytes increased the CYP2A5 protein and activity levels with no effect on the corresponding mRNA. Co-treatment with cycloheximide (CHX), a protein synthesis inhibitor, resulted in increased half-life of the CYP2A5 compared to cells treated only with CHX. Collectively, the observations suggest that the CYP2A5 is potentially an inducible 'BR oxidase' where BR may accelerate its own metabolism through stabilization of the CYP2A5 protein. It is possible that this metabolic pathway is potentially part of the machinery controlling intracellular BR levels in transient oxidative stress situations, in which high amounts of BR are produced. -- Highlights: Black-Right-Pointing-Pointer CYP2A5 metabolizes bilirubin to biliverdin and dipyrroles. Black-Right-Pointing-Pointer Bilirubin increased the hepatic CYP2A5 protein and activity levels. Black-Right-Pointing-Pointer Bilirubin does not

  2. Data of evolutionary structure change: 1BU1A-1OOTA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1BU1A-1OOTA 1BU1 1OOT A A -IIVVALYDYEAIHHEDLSFQKGDQMVVLEESGE---WW.../line> 1OOT A 1OOTA -19.135000228881836 0.26499998569488525 29.607999801635742 ...0.7739999890327454 0.5450000166893005 0.3240000009536743 tion>> 1OOT A 1OOTA WTGRV--NGREG

  3. Cytochrome P450 CYP1A1: wider roles in cancer progression and prevention

    Directory of Open Access Journals (Sweden)

    Tsatsakis Aristidis M


    Full Text Available Abstract CYP1A1 is one of the main cytochrome P450 enzymes, examined extensively for its capacity to activate compounds with carcinogenic properties. Continuous exposure to inhalation chemicals and environmental carcinogens is thought to increase the level of CYP1A1 expression in extrahepatic tissues, through the aryl hydrocarbon receptor (AhR. Although the latter has long been recognized as a ligand-induced transcription factor, which is responsible for the xenobiotic activating pathway of several phase I and phase II metabolizing enzymes, recent evidence suggests that the AhR is involved in various cell signaling pathways critical to cell cycle regulation and normal homeostasis. Disregulation of these pathways is implicated in tumor progression. In addition, it is becoming increasingly evident that CYP1A1 plays an important role in the detoxication of environmental carcinogens, as well as in the metabolic activation of dietary compounds with cancer preventative activity. Ultimately the contribution of CYP1A1 to cancer progression or prevention may depend on the balance of procarcinogen activation/detoxication and dietary natural product extrahepatic metabolism.

  4. ATP1A1-mediated Src signaling inhibits coronavirus entry into host cells

    NARCIS (Netherlands)

    C. Burkard (Christine); M.H. Verheije (Monique); B.L. Haagmans (Bart); F.J.M. van Kuppeveld (Frank ); P.J.M. Rottier (Peter); B.J. Bosch (Berend Jan); C.A.M. de Haan (Cornelis)


    textabstractIn addition to transporting ions, the multisubunit Na+,K+-ATPase also functions by relaying cardiotonic steroid (CTS)-binding- induced signals into cells. In this study, we analyzed the role of Na+,K+-ATPase and, in particular, of its ATP1A1 α subunit during coronavirus (CoV) infection.

  5. Effects of clinorotation on COL1A1- EGFP gene expression

    Institute of Scientific and Technical Information of China (English)

    DAI Zhongquan; LI Yinghui; DING Bai; ZHANG Yuguo; LIU Weiquan; LIU Pengpeng


    Bone-formation related gene plays a critical role in bone loss induced by space microgravity, however the exact mechanism is unclear. In this study, we aim to investigate the effect of microgravity on the activity of α 1(I) collagen (COL1A1) gene promoter and the expression of osteoblast-related genes. COL1A1 promoter was digested by restriction enzymes resulting in three DNA fragments. The fragments were ligated with the enhanced green fluorescent protein report gene, and subcloned into expression vectors. ROS17/2.8 cells transfected by these vectors were screened by G418, and enhanced green fluorescent protein (EGFP) positive colonies were isolated and cultured under clinostat condition. EGFP and Collagen type I expression level were detected by fluorescence intensity analysis and immunocytochemistry methods respectively. The results showed that the expression of EGFP and collagen type I was increased 24 h, 48 h after the cells were cultured under stimulated microgravity, illustrating that the activity of COL1A1 promoter might be increased. In conclusion, osteoblasts can compensatively increase the expression of type I collagen by enhancing the activity of COL1A1 promoter under short-term simulated microgravity conditions.

  6. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) increases bilirubin formation but hampers quantitative hepatic conversion of biliverdin to bilirubin in rats with wild-type AH receptor. (United States)

    Niittynen, Marjo; Simanainen, Ulla; Pohjanvirta, Raimo; Sankari, Satu; Tuomisto, Jouni T


    In haem degradation, haem oxygenase-1 (HO-1) first cleaves haem to biliverdin, which is reduced to bilirubin by biliverdin IXα reductase (BVR-A). The environmental pollutant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes hepatic accumulation of biliverdin in moderately TCDD-resistant line B (Kuopio) rats. Using line B and two TCDD-sensitive rat strains, the present study set out to probe the dose-response and biochemical mechanisms of this accumulation. At 28 days after exposure to 3-300 μg/kg TCDD in line B rats, already the lowest dose of TCDD tested, 3 μg/kg, affected serum bilirubin conjugates, and after doses ≥100 μg/kg, the liver content of bilirubin, biliverdin and their conjugates (collectively 'bile pigments') as well as HO-1 was elevated. BVR-A activity and serum bile acids were increased only by the doses of 100 and 300 μg/kg TCDD, respectively. Biliverdin conjugates correlated best with biliverdin suggesting it to be their immediate precursor. TCDD (100 μg/kg, 10 days) increased hepatic bilirubin and biliverdin levels also in TCDD-sensitive Long-Evans (Turku/AB; L-E) rats. Hepatic bilirubin and bile acids, but not biliverdin, were increased in feed-restricted L-E control rats. In TCDD-sensitive line C (Kuopio) rats, 10 μg/kg of TCDD increased the body-weight-normalized biliary excretion of bilirubin. Altogether, the results suggest that at acutely toxic doses, TCDD induces the formation of bilirubin in rats. However, concurrently, TCDD seems to hamper the quantitative conversion of biliverdin to bilirubin in line B and L-E rats' liver. Biliverdin conjugates are most likely formed as secondary products of biliverdin.


    Directory of Open Access Journals (Sweden)

    Marcela Capcarová


    Full Text Available The present study was designed to determinate the effect of propolis as a feed additive on the serum bilirubin and albumin content of female and male chickens. Broiler chickens hybrid Hubbard JV (n=500 were divided into five groups in each gender (control – C and four experimental groups E1 – E4. Experimental chickens received a propolis extract in feed mixture in various doses (E1 – 150 mg/kg; E2 – 450 mg/kg; E3 – 600 mg/kg; E4 – 800 mg/kg. The group that received feed without propolis addition served as the control. Contents of albumin and bilirubin were determined with spectrophotometer. Supplementation of the diet with propolis in the dose of 600 mg/kg significantly (P<0.05 increased albumin content in male chickens. Propolis addition to diets may be a source for antioxidant capacity in human and animals.

  8. Increased conjugated bilirubin is sufficient to initiate screening for biliary atresia

    DEFF Research Database (Denmark)

    Madsen, Stine Skipper; Kvist, Nina; Thorup, Jørgen


    . This percentage value has caused diagnostic trouble over the years. The objective of the present study was to investigate the possibility of changing the recommendations. METHODS: This was a retrospective analysis of the medical records of children operated for biliary atresia in the 1993-2012 period. RESULTS......: During the period, 73 patients where operated with a portoenterostomy ad modum Kasai. Patients older than 84 days at the time of operation were excluded, 54 patients were available for analysis. Conjugated bilirubin in μmol/l and the percentage value were significantly above the DHMA threshold limit......: mean 129.7 μmol/l (42-334 μmol/l) and 73% (28-97%), respectively. CONCLUSION: The total amount of conjugated bilirubin above 20 μmol/l is sufficient to require further evaluation for biliary atresia. The percentage value is unnecessary and may cause confusion. FUNDING: none. TRIAL REGISTRATION...

  9. Effects of OATP -C gene polymorphisms and low-dose rifampicin on serum bilirubin level

    Institute of Scientific and Technical Information of China (English)

    WeiZHANG; Yi-jingHE; QingLI; Hong-haoZHOU


    AIM OATP-C is a liver-specific organic anion uptake transporter and shows high affinity for bilirubin uptaking. Rifampicin has been identified as a potent inhibitor of OATP-C both in vitro and in vivo. This study was set to determine the allele frequencies of OATP-C*1a', OATP-C*1b, and OATP-C* 15 in Chinese population, and secondly, to quantitate the contribution of the OATP-C gene polymorphisms and low-dose rifampicin adminstration to the serum bilirubin level in vivo. METHODS Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and a novel tetreprimers method were used to identify OATP-C*1a, OATP-C*1b, and OATP-C*15 genotypes.

  10. Characterization of a Novel Mutation in SLC1A1 Associated with Schizophrenia (United States)

    Afshari, Parisa; Myles-Worsley, Marina; Cohen, Ori S.; Tiobech, Josepha; Faraone, Stephen V.; Byerley, William; Middleton, Frank A.


    We have recently described a hemi-deletion on chromosome 9p24.2 at the SLC1A1 gene locus and its co-segregation with schizophrenia in an extended Palauan pedigree. This finding represents a point of convergence for several pathophysiological models of schizophrenia. The present report sought to characterize the biological consequences of this hemi-deletion. Dual luciferase assays demonstrated that the partially deleted allele (lacking exon 1 and the native promoter) can drive expression of a 5′-truncated SLC1A1 using sequence upstream of exon 2 as a surrogate promoter. However, confocal microscopy and electrophysiological recordings demonstrate that the 5′-truncated SLC1A1 lacks normal membrane localization and glutamate transport ability. To identify downstream consequences of the hemi-deletion, we first used a themed qRT-PCR array to compare expression of 84 GABA and glutamate genes in RNA from peripheral blood leukocytes in deletion carriers (n = 11) versus noncarriers (n = 8) as well as deletion carriers with psychosis (n = 5) versus those without (n = 3). Then, targeted RNA-Seq (TREx) was used to quantify expression of 375 genes associated with neuropsychiatric disorders in HEK293 cells subjected to either knockdown of SLC1A1 or overexpression of full-length or 5′-truncated SLC1A1. Expression changes of several genes strongly implicated in schizophrenia pathophysiology were detected (e.g. SLC1A2, SLC1A3, SLC1A6, SLC7A11, GRIN2A, GRIA1 and DLX1). PMID:26380821

  11. The role of bilirubin in diabetes, metabolic syndrome, and cardiovascular diseases

    Directory of Open Access Journals (Sweden)

    Libor eVitek


    Full Text Available Bilirubin belongs to a phylogenetically old superfamily of tetrapyrrolic compounds, which have multiple biological functions. Although for decades they were believed to be only a waste product of the heme catabolic pathway at best, and a potentially toxic compound at worst; recent data has convincingly demonstrated that mildly elevated serum bilirubin levels are strongly associated with a lower prevalence of oxidative stress-mediated diseases. Indeed, serum bilirubin has been consistently shown to be negatively correlated to cardiovascular diseases (CVD, as well as to CVD-related diseases and risk factors such as arterial hypertension, diabetes mellitus, metabolic syndrome, and obesity. In addition, the clinical data are strongly supported by evidence arising from both in vitro and in vivo experimental studies. This data not only shows the protective effects of bilirubin per se; but addionally, of other products of the heme catabolic pathway such as biliverdin and carbon monoxide, as well as its key enzymes (heme oxygenase and biliverdin reductase; thus, further underlining the biological impacts of this pathway. In this review, detailed information on the experimental and clinical evidence between the heme catabolic pathway and CVD, and those related diseases such as diabetes, metabolic syndrome, and obesity is provided. All of these pathological conditions represent an important threat to human civilization, being the major killers in developed countries, with a steadily increasing prevalence. Thus, it is extremely important to search for novel markers of these diseases, as well as for novel therapeutic modalities to reverse this unfavorable situation. The heme catabolic pathway seems to fulfill the criteria for both diagnostic purposes as well as for potential therapeutical interventions.

  12. Influence of bilirubin and other antioxidants on nitrergic relaxation in the pig gastric fundus. (United States)

    Colpaert, E E; Lefebvre, R A


    1. The influence of several antioxidants (bilirubin, urate, ascorbate, alpha-tocopherol, glutathione (GSH), Cu/Zn superoxide dismutase (SOD) and the manganese SOD mimic EUK-8) on nitrergic relaxations induced by either exogenous nitric oxide (NO; 10(-5) M) or electrical field stimulation (4 Hz; 10 s and 3 min) was studied in the pig gastric fundus. 2. Ascorbate (5x10(-4) M), alpha-tocopherol (4x10(-4) M), SOD (300 - 1000 u ml(-1)) and EUK-8 (3x10(-4) M) did not influence the relaxations to exogenous NO. In the presence of GSH (5x10(-4) M), the short-lasting relaxation to NO became biphasic, potentiated and prolonged. Urate (4x10(-4) M) and bilirubin (2x10(-4) M) also potentiated the relaxant effect of NO. None of the antioxidants influenced the electrically evoked relaxations. 3. 6-Anilino-5,8-quinolinedione (LY83583; 10(-5) M) had no influence on nitrergic nerve stimulation but nearly abolished the relaxant response to exogenous NO. Urate and GSH completely prevented this inhibitory effect, while it was partially reversed by SOD and bilirubin. Ascorbate, alpha-tocopherol and EUK-8 were without effect. 4. Hydroquinone (10(-4) M) did not affect the electrically induced nitrergic relaxations, but markedly reduced NO-induced relaxations. The inhibition of exogenous NO by hydroquinone was completely prevented by urate and GSH. SOD and ascorbate afforded partial protection, while bilirubin, EUK-8 and alpha-tocopherol were ineffective. 5. Hydroxocobalamin (10(-4) M) inhibited relaxations to NO by 50%, but not the electrically induced responses. Full protection versus this inhibitory effect was obtained with urate, GSH and alpha-tocopherol. 6. These results strengthen the hypothesis that several endogenous antioxidant defense mechanisms, enzymatic as well as non-enzymatic, might play a role in the nitrergic neurotransmission process.

  13. Direct antioxidant properties of bilirubin andbiliverdin. Is there a role for biliverdin reductase?

    Directory of Open Access Journals (Sweden)

    Thomas eJansen


    Full Text Available Reactive oxygen species (ROS and signaling events are involved in the pathogenesis of endothelial dysfunction and represent a major contribution to vascular regulation. Molecular signaling is highly dependent on reactive oxygen species. But depending on the amount of ROS production it might have toxic or protective effects. Despite a large number of negative outcomes in large clinical trials (e.g. HOPE, HOPE-TOO, antioxidant molecules and agents are important players to influence the critical balance between production and elimination of RONS. However, chronic systemic antioxidant therapy lacks clinical efficacy, probably by interfering with important physiological redox signaling pathways. Therefore, it may be a much more promising attempt to induce intrinsic antioxidant pathways in order to increase the antioxidants not systemically but at the place of oxidative stress and complications. Among others, heme oxygenase (HO has been shown to be important for attenuating the overall production of ROS in a broad range of disease states through its ability to degrade heme and to produce carbon monoxide (CO, biliverdin/bilirubin, and the release of free iron with subsequent ferritin induction. With the present review we would like to highlight the important antioxidant role of the heme oxygenase system and especially discuss the contribution of the biliverdin, bilirubin and biliverdin reductase to these beneficial effects. The bilierdin reductase was reported to confer an antioxidant redox amplification cycle by which low, physiological bilirubin concentrations confer potent antioxidant protection via recycling of biliverdin from oxidized bilirubin by the biliverdin reductase, linking this sink for oxidants to the NADPH pool. To date the existence and role of this antioxidant redox cycle is still under debate and we present and discuss the pros and cons as well as our own findings on this topic.

  14. The antioxidant effect of free bilirubin on cumene-hydroperoxide treated human leukocytes. (United States)

    Yesilkaya, A; Altinayak, R; Korgun, D K


    To examine the antioxidant effect of bilirubin (BR) on leukocyte, we treated leukocytes obtained from healthy subjects with an oxidant and various concentrations of BR. High concentrations of BR decreased thiobarbituric acid reactive substances (TBARS) and catalase activities, increased superoxide dismutase (SOD) activity, but had no effect on glutathione (GSH) concentration. Our results showed that under physiological conditions, BR has an antioxidant effect only in high concentrations.

  15. Antioxidant potential of bilirubin-accelerated wound healing in streptozotocin-induced diabetic rats. (United States)

    Ram, Mahendra; Singh, Vishakha; Kumar, Dhirendra; Kumawat, Sanjay; Gopalakrishnan, Anu; Lingaraju, Madhu C; Gupta, Priyanka; Tandan, Surendra Kumar; Kumar, Dinesh


    Oxidative injury is markedly responsible for wound complications in diabetes mellitus. The biological actions of bilirubin may be relevant to prevent oxidant-mediated cell death, as bilirubin application at a low concentration scavenges reactive oxygen species. Hence, we hypothesized that topical bilirubin application might improve wound healing in diabetic rats. Diabetes was induced in adult male Wistar rats, which were divided into two groups, i.e., diabetic control and diabetic treated. Non-diabetic healthy rats were also taken as healthy control group. Wound area was measured on days 3, 7, 14, and 19 post-wounding. The levels of malondialdehyde (MDA) and reduced glutathione (GSH) and the activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) were estimated in the granulation tissue. There was a significant increase in percent wound closure in healthy control and diabetic treated rats on days 7, 14, and 19, as compared to diabetic control rats on days 7, 14, and 19. There was significant decrease in MDA levels on days 7, 14, and 19 in diabetic treated rats, as compared to diabetic control rats. Levels of GSH were significantly increased on days 3, 7, 14, and 19 in diabetic treated rats, as compared to diabetic control rats. GPx, SOD, and CAT activities were significantly higher on days 3, 7, and 14 in diabetic treated rats, as compared to diabetic control rats. The findings indicate that bilirubin is effective in reducing the oxidant status in wounds of diabetic rats which might have accelerated wound healing in these rats.

  16. Ternary complexes of albumin-Mn(II)-bilirubin and Electron Spin Resonance studies of gallstones

    CERN Document Server

    Chikvaidze, E N; Kirikashvili, I N; Mamniashvili, G I


    The stability of albumin-bilirubin complex was investigated depending on pH of solution. It was shown that the stability of complex increases in presence of Mn(II) ions. It was also investigated the paramagnetic composition of gallstones by the electron spin resonance (ESR) method. It turned out that all investigated gallstones contain a free bilirubin radical-the stable product of its radical oxidation. Accordingly the paramagnetic composition gallstones could be divided on three main types: cholesterol, brown pigment and black pigment stones. ESR spectra of cholesterol stones is singlet with g=2.003 and splitting between components 1.0 mT. At the same time the brown gallstones, besides aforementioned signal contain the ESR spectrum which is characteristics for Mn(II) ion complexes with inorganic compounds and, finally, in the black pigment stones it was found out Fe(III) and Cu(II) complexes with organic compounds and a singlet of bilirubin free radical. It is supposed that crystallization centers of gallst...

  17. Mildly elevated serum total bilirubin levels are negatively associated with carotid atherosclerosis among elderly persons with type 2 diabetes. (United States)

    Kawamoto, Ryuichi; Ninomiya, Daisuke; Hasegawa, Yoichi; Kasai, Yoshihisa; Kusunoki, Tomo; Ohtsuka, Nobuyuki; Kumagi, Teru; Abe, Masanori


    Diabetes is strongly associated with several mechanisms of tissue damage such as oxidative stress. Serum bilirubin may have a beneficial role in preventing oxidative changes in cardiovascular disease (CVD). Limited information is available on whether serum bilirubin is an independent confounding factor for carotid atherosclerosis among elderly persons with type 2 diabetes. The study subjects were 169 men aged 79 ± 8 (mean ± SD) years and 205 women aged 81 ± 8 years that were enrolled consecutively from patients in the medical department. Carotid intima-media thickness (IMT) and plaque were derived via B-mode ultrasonography. Multiple linear regression analysis showed that serum total bilirubin (β = -0.160) was significantly associated with carotid IMT. Compared to subjects with a serum total bilirubin of tertile-1 (0.13-0.58 mg/dL), the multivariate-adjusted odds ratio (95% confidence interval) of carotid IMT ≥1.0 mm including plaque and carotid plaque was 0.46 (0.23-0.93) and 0.32 (0.17-0.60) in the Tertile-3 group (0.87-1.93 mg/dL), respectively. Next, data were further stratified by gender, age, smoking status, medication and prevalence of CVD. There were no significant differences in serum total bilirubin levels between selected subgroups. Our data demonstrated a negative association between serum total bilirubin and carotid atherosclerosis among elderly persons with type 2 diabetes.

  18. Usefulness of serum bilirubin levels as a biomarker for long-term clinical outcomes after percutaneous coronary intervention. (United States)

    Kim, Hyun-Wook; Choi, Dong-Hyun; Lim, Leejin; Lee, Young-Min; Kang, Joon Tae; Chae, Seung Seok; Ki, Young-Jae; Song, Heesang; Koh, Young-Youp


    The aim of this study was to evaluate the prognostic value of serum total bilirubin on the development of adverse outcomes after percutaneous coronary intervention (PCI) besides high-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-B type natriuretic peptide (NT-proBNP). Serum total bilirubin, hs-cTnT, and NT-proBNP were analyzed in 372 patients who underwent PCI. The primary endpoint was cardiac death. There were 21 events of cardiac death during a mean of 25.8 months of follow-up. When the serum total bilirubin cut-off level (median value) was set to 0.58 mg/dL using the receiver operating characteristic curve, the sensitivity was 95.2 % and the specificity was 51.0 % for differentiating between the group with cardiac death and the group without cardiac death. Kaplan-Meier analysis revealed that the lower serum total bilirubin group (bilirubin group (≥0.58 mg/dL) (10.4 vs. 0.6 %, log-rank: P = 0.0001). In conclusion, low serum total bilirubin is a predictive marker for cardiac death after PCI.

  19. Does corticosteroid treatment cause prolonged recovery and increased total bilirubin level in severe ADAMTS-13-deficient TTP patient? (United States)

    Sayiner, Zeynel Abidin; Acik, Didar Yanardag; Yilmaz, Mehmet; Subari, Salih; Mete, Ayse Ozlem; Dai, M Sinan


    A 41-year-old female patient complaining of fatigue, headache, mild confusion, and rush on her lower extremities was admitted to our emergency department. Laboratory tests revealed that he had anemia, thrombocytopenia, and increased levels of indirect bilirubin and lactic dehydrogenase (LDH) in blood tests. Direct and indirect Coombs tests were negative, and fragmented erythrocytes were observed in peripheral blood smears. The patient was diagnosed with thrombotic thrombocytopenic purpura (TTP). The best supportive care was provided. Therapeutic plasma exchange (TPE) and 1 mg/kg methylprednisolone treatments were administered. On the 10th day of treatment, LDH level and fragmented red blood cells in peripheral blood smear were decreased, but his direct and indirect bilirubin levels increased despite the fact that he was treated with 1 mg/kg methylprednisolone and TPE. The patient had severe ADAMTS-13 deficiency. After discontinued steroids treatment, his bilirubin level normalized within 4 days. On the 4th day after bilirubin level normalized, vincristine treatment was administered. TPE was also continued. There was no consensus about the optimal schedule for discontinuing plasmapheresis therapy, and also we observed total bilirubin level improvement with discontinued corticosteroid treatment. In this case, corticosteroid treatment was linked with the increase of total bilirubin level in severe ADAMTS-13-deficient TTP patient.

  20. High serum total bilirubin as a protective factor against hip bone loss in healthy middle-aged men. (United States)

    Kim, Beom-Jun; Koh, Jung-Min; Ahn, Seong Hee; Lee, Seung Hun; Kim, Eun Hee; Bae, Sung Jin; Kim, Hong-Kyu; Choe, Jae Won; Kim, Ghi Su


    Bilirubin is known to have a physiologic role as an antioxidant that efficiently scavenges peroxyl radicals and suppresses oxidation, and oxidative stress has detrimental effects on bone metabolism. In the present study, we performed a 3-year longitudinal study of healthy middle-aged men, investigating the association between serum total bilirubin concentrations and annualized changes in bone mineral density (BMD). The study enrolled a total of 917 Korean men aged 40 years or older who had undergone comprehensive routine health examinations with an average follow-up interval of 3 years. BMD at proximal femur sites was measured with dual-energy X-ray absorptiometry using the same equipment at baseline and follow-up. The overall mean annualized rates of bone loss at the total femur, femoral neck, and trochanter were -0.25 %/year, -0.34 %/year, and -0.44 %/year, respectively. After adjustment for potential confounders, the rates of bone loss at all proximal femur sites were significantly attenuated in a dose-response fashion across increasing bilirubin concentrations (P = 0.006-0.046). Moreover, compared to subjects in the lowest bilirubin quartile category, those in the highest bilirubin quartile category showed significantly less bone loss at all proximal femur sites after adjustment for confounding factors (P = 0.010-0.048). This study provides the first clinical evidence that serum total bilirubin could be a protective marker against future bone loss, especially in subjects without liver diseases.

  1. CYP1A1 genetic polymorphisms and uterine leiomyoma risk: a meta-analysis (United States)

    Wang, Fen; Chen, Jiying; Wang, Lin; Ma, Yulan; Mayinuer, Niyazi


    Background: Some studies assessed the association between CYP1A1 MspI and Ile462Val polymorphisms and uterine leiomyoma (UL) risk. However, the results were controversial. We did this meta-analysis to determine the association between CYP1A1 MspI and Ile462Val polymorphisms and UL risk. Materials and methods: We searched databases containing PubMed, Springer Link, EMBASE, Chinese National Knowledge Infrastructure (CNKI) up to 11 October 2014. Pooled ORs and 95% CIs were used to assess the strength of the associations. Results: In total, 9 case-control studies with 2157 UL cases and 2197 healthy controls were included in this meta-analysis. CYP1A1 Ile462Val polymorphism was significantly associated with UL risk (OR = 2.29, 95% CI 1.75-2.99, P < 0.00001). In the subgroup analysis by race, significantly increased risks were found in the Asians (OR = 2.76, 95% CI 1.86-4.09, P < 0.00001) and Caucasians (OR = 1.87, 95% CI 1.30-2.68, P = 0.0007). However, MspI polymorphism was not significantly associated with UL risk (OR = 1.15, 95% CI 0.90-1.47, P = 0.27). In the subgroup analysis by race, no significant association was found in the Asians (OR = 1.15, 95% CI 0.86-1.54, P = 0.35). Conclusion: In summary, the results of the meta-analysis suggested that CYP1A1 Ile462Val polymorphism was significantly associated with UL risk. PMID:26064254

  2. Herbicide resistance of transgenic rice plants expressing human CYP1A1. (United States)

    Kawahigashi, Hiroyuki; Hirose, Sakiko; Ohkawa, Hideo; Ohkawa, Yasunobu


    Cytochrome P450 monooxygenases (P450s) metabolize herbicides to produce mainly non-phytotoxic metabolites. Although rice plants endogenously express multiple P450 enzymes, transgenic plants expressing other P450 isoforms might show improved herbicide resistance or reduce herbicide residues. Mammalian P450s metabolizing xenobiotics are reported to show a broad and overlapping substrate specificity towards lipophilic foreign chemicals, including herbicides. These P450s are ideal for enhancing xenobiotic metabolism in plants. A human P450, CYP1A1, metabolizes various herbicides with different structures and modes of herbicide action. We introduced human CYP1A1 into rice plants, and the transgenic rice plants showed broad cross-resistance towards various herbicides and metabolized them. The introduced CYP1A1 enhanced the metabolism of chlorotoluron and norflurazon. The herbicides were metabolized more rapidly in the transgenic rice plants than in non-transgenic controls. Transgenic rice plants expressing P450 might be useful for reducing concentrations of various chemicals in the environment.

  3. Relationship between CYP1A1 polymorphisms and invasion and metastasis of breast cancer

    Institute of Scientific and Technical Information of China (English)

    Hua Wang; Wen-Jian Wang


    Objective:To investigate the relationship betweenCYP1A1 genetic polymorphisms and the invasion and metastasis of breast cancer.Methods:TheCYP1A1 gene polymorphism(anT-C transversion at nucleotide position3801) was detected by the polymerase chain reaction and restriction fragment length polymorphism in80 cases with breast cancer and60 samples of normal breast tissue.The difference in genotypic distribution frequency between the groups, the correlation between the genotypes and the factors related to prognosis were analyzed.Results:The incidence of homozygous and variant genotypes had no difference between the breast cancer group and controls group(P=0.746).The proportion of variant genotype increased as clinical stage(P=0.006) advanced, as well as with increased numbers of lymph node metastases(P=0.010). Conclusions:In patients with breast cancer there is a correlation between theCYP1A1CC allele and some factors indicating poor prognosis, including more lymph node metastases as well as a more advanced clinical stage.

  4. Antagonism between Cry1Ac1 and Cyt1A1 toxins of bacillus thuringiensis (United States)

    del Rincon-Castro MC; Barajas-Huerta; Ibarra


    Most strains of the insecticidal bacterium Bacillus thuringiensis have a combination of different protoxins in their parasporal crystals. Some of the combinations clearly interact synergistically, like the toxins present in B. thuringiensis subsp. israelensis. In this paper we describe a novel joint activity of toxins from different strains of B. thuringiensis. In vitro bioassays in which we used pure, trypsin-activated Cry1Ac1 proteins from B. thuringiensis subsp. kurstaki, Cyt1A1 from B. thuringiensis subsp. israelensis, and Trichoplusia ni BTI-Tn5B1-4 cells revealed contrasting susceptibility characteristics. The 50% lethal concentrations (LC50s) were estimated to be 4,967 of Cry1Ac1 per ml of medium and 11.69 ng of Cyt1A1 per ml of medium. When mixtures of these toxins in different proportions were assayed, eight different LC50s were obtained. All of these LC50s were significantly higher than the expected LC50s of the mixtures. In addition, a series of bioassays were performed with late first-instar larvae of the cabbage looper and pure Cry1Ac1 and Cyt1A1 crystals, as well as two different combinations of the two toxins. The estimated mean LC50 of Cry1Ac1 was 2.46 ng/cm2 of diet, while Cyt1A1 crystals exhibited no toxicity, even at very high concentrations. The estimated mean LC50s of Cry1Ac1 crystals were 15.69 and 19.05 ng per cm2 of diet when these crystals were mixed with 100 and 1,000 ng of Cyt1A1 crystals per cm2 of diet, respectively. These results indicate that there is clear antagonism between the two toxins both in vitro and in vivo. Other joint-action analyses corroborated these results. Although this is the second report of antagonism between B. thuringiensis toxins, our evidence is the first evidence of antagonism between toxins from different subspecies of B. thuringiensis (B. thuringiensis subsp. kurstaki and B. thuringiensis subsp. israelensis) detected both in vivo and in vitro. Some possible explanations for this relationship are discussed.

  5. Analysis Of The Effects Of Marine Corps M1A1 Abram’s Tank Age On Operational Availability (United States)


    14. SUBJECT TERMS M1A1 Abrams MBT, Reliability Centered Maintenance (RCM), Operational Availability, Materiel Maintenance, Anniston Army Depot, Depot...Secretary of Defense for Logistics and Materiel Readiness [OUSD(L&MR)], 2011, p. 67). The United States Marine Corps (USMC) M1A1 Abrams Tank...C. USMC M1A1 MISSION The M1A1 Abrams MBT was designed primarily as an offensive weapon but is also an effective defensive weapon system. The

  6. Reduced inflammatory response in cigarette smoke exposed Mrp1/Mdr1a/1b deficient mice

    Directory of Open Access Journals (Sweden)

    Postma Dirkje S


    Full Text Available Abstract Background Tobacco smoke is the principal risk factor for chronic obstructive pulmonary disease (COPD, though the mechanisms of its toxicity are still unclear. The ABC transporters multidrug resistance-associated protein 1 (MRP1 and P-glycoprotein (P-gp/MDR1 extrude a wide variety of toxic substances across cellular membranes and are highly expressed in bronchial epithelium. Their impaired function may contribute to COPD development by diminished detoxification of noxious compounds in cigarette smoke. Methods We examined whether triple knock-out (TKO mice lacking the genes for Mrp1 and Mdr1a/1b are more susceptible to develop COPD features than their wild-type (WT littermates. TKO and WT mice (six per group were exposed to 2 cigarettes twice daily by nose-only exposure or room air for 6 months. Inflammatory infiltrates were analyzed in lung sections, cytokines and chemokines in whole lung homogenates, emphysema by mean linear intercept. Multiple linear regression analysis with an interaction term was used to establish the statistical significances of differences. Results TKO mice had lower levels of interleukin (IL-7, KC (mouse IL-8, IL-12p70, IL-17, TNF-alpha, G-CSF, GM-CSF and MIP-1-alpha than WT mice independent of smoke exposure (P P P Conclusion Mrp1/Mdr1a/1b knock-out mice have a reduced inflammatory response to cigarette smoke. In addition, the expression levels of several cytokines and chemokines were also lower in lungs of Mrp1/Mdr1a/1b knock-out mice independent of smoke exposure. Further studies are required to determine whether dysfunction of MRP1 and/or P-gp contribute to the pathogenesis of COPD.

  7. Wound healing genes and susceptibility to cutaneous leishmaniasis in Brazil: Role of COL1A1


    Almeida, Lucas; Oliveira, Joyce; Guimarães, Luiz Henrique; Carvalho, Edgar M.; Blackwell, Jenefer M.; Castellucci, Léa


    Previous studies have demonstrated a role for wound healing genes in resolution of cutaneous lesions caused by Leishmania spp. in both mice and humans, including the gene FLI1 encoding Friend leukaemia virus integration 1. Reduction of Fli1 expression in mice has been shown to result in up-regulation of collagen type I alpha 1 (Col1a1) and alpha 2 (Col1a2) genes and, conversely, in down-regulation of the matrix metalloproteinase 1 (Mmp1) gene, suggesting that Fli1 suppression is involved in a...

  8. CYP1A1 expression in breast milk cells of Japanese population

    Energy Technology Data Exchange (ETDEWEB)

    Yonemoto, Junzo; Shiizaki, Kazuhiro; Sone, Hideko; Morita, Masatosi [National Institute for Environmental Studies, Tsukuba (Japan); Uechi, Hiroto [Uechi Obstetrics and Gynecology Clinic, Utsunomiya (Japan); Masuzaki, Yuko; Koizumi, Atsuko; Matzumura, Toru [Metocean Environment Inc., Ohigawa (Japan)


    Dioxins are persistent, lipophilic compounds that are ubiquitous in the environment. Concern over the reproductive and developmental toxicity of dioxins has been growing since they have endocrine-disrupting properties and have adversely affected the health of offspring in experimental and epidemiological studies. Monitoring of maternal body burdens of dioxins and their biological responses to dioxin exposure is needed to estimate the potential health risk to their offspring. Breast milk has been used for monitoring dioxins in humans for decades. Breast milk has some advantages in exposure monitoring. Sampling is non-invasive, and dioxin levels are relatively high because of the high lipid content. It is assumed that mammary glands are exposed to a higher level of dioxins than other tissues since mammary glands synthesize and store milk fat. Breast milk contains leukocytes and exfoliated ductal epithelial cells. If these cells responded to dioxins and expressed CYP enzymes, a sensitive biomarker for dioxin exposure, they would be useful as biomarkers for dioxin exposure. In the present study, the expression of CYP enzymes in intact milk cells or cells cultured with TCDD was investigated. In addition, breast milk samples were collected from mothers within one week of childbearing, and the expression of CYP1A1 mRNA in milk cells was determined. The relationship between CYP1A1 mRNA expression in milk cells and dioxin levels in the cream layer of breast milk was analyzed.

  9. Bilirubin - blood (United States)

    ... Gastroenterology. In: Rennie JM, ed. Rennie and Robsertson's Textbook of Neonatology. 5th ed. Philadelphia, PA: Elsevier; 2012:chap 29. Pratt DS. Liver chemistry and function tests. In: Feldman M, Friedman LS, ...

  10. Identification of heme oxygenase-1 stimulators by a convenient ELISA-based bilirubin quantification assay. (United States)

    Rücker, Hannelore; Amslinger, Sabine


    The upregulation of heme oxygenase-1 (HO-1) has proven to be a useful tool for fighting inflammation. In order to identify new HO-1 inducers, an efficient screening method was developed which can provide new lead structures for drug research. We designed a simple ELISA-based HO-1 enzyme activity assay, which allows for the screening of 12 compounds in parallel in the setting of a 96-well plate. The well-established murine macrophage cell line RAW264.7 is used and only about 26µg of protein from whole cell lysates is needed for the analysis of HO-1 activity. The quantification of HO-1 activity is based on an indirect ELISA using the specific anti-bilirubin antibody 24G7 to quantify directly bilirubin in the whole cell lysate, applying a horseradish peroxidase-tagged antibody together with ortho-phenylenediamine and H2O2 for detection. The bilirubin is produced on the action of HO enzymes by converting their substrate heme to biliverdin and additional recombinant biliverdin reductase together with NADPH at pH 7.4 in buffer. This sensitive assay allows for the detection of 0.57-82pmol bilirubin per sample in whole cell lysates. Twenty-three small molecules, mainly natural products with an α,β-unsaturated carbonyl unit such as polyphenols, including flavonoids and chalcones, terpenes, an isothiocyanate, and the drug oltipraz were tested at typically 6 or 24h incubation with RAW264.7 cells. The activity of known HO-1 inducers was confirmed, while the chalcones cardamonin, flavokawain A, calythropsin, 2',3,4'-trihydroxy-4-methoxychalcone (THMC), and 2',4'-dihydroxy-3,4-dimethoxychalcone (DHDMC) were identified as new potent HO-1 inducers. The highest inductive power after 6h incubation was found at 10µM for DHDMC (6.1-fold), carnosol (3.9-fold), butein (3.1-fold), THMC (2.9-fold), and zerumbone (2.5-fold). Moreover, the time dependence of HO-1 protein production for DHDMC was compared to its enzyme activity, which was further evaluated in the presence of

  11. The Relationship between Serum Bilirubin and Elevated Fibrotic Indices among HBV Carriers: A Cross-Sectional Study of a Chinese Population

    Directory of Open Access Journals (Sweden)

    Min Du


    Full Text Available The study probed the association between bilirubin and hepatitis B virus (HBV infection and progression. A cross-sectional analysis of 28,500 middle aged and elderly Chinese participants was performed to analyze the differences of bilirubin in terms of hepatitis B surface antigen (HBsAg positive or negative and the correlation between bilirubin and severity of hepatic fibrosis estimated by non-invasive indices. Bilirubin was significantly higher in the HBsAg (+ group than the HBsAg (− group. Higher bilirubin levels were consistently associated with elevated liver fibrosis indices among HBsAg carriers. Compared with quartile 1 of total bilirubin (TBil, the multivariable-adjusted ORs (95% CIs for elevated fibrosis indices of quartile 4 were 2.24 (95% CIs, 1.57–3.21 estimated by fibrosis 4 score (FIB-4 and 2.22 (95% CIs, 1.60–3.08 estimated by aspartate transaminase to platelet ratio index (APRI. In addition, direct bilirubin (DBil had a stronger association with elevated liver fibrosis indices than did indirect bilirubin (IBil. Furthermore, the relationship between DBil and elevated fibrosis indices was more robust among participants who were female, overweight or had central fat distribution. These findings suggested that bilirubin levels, especially DBil, were independently associated with an increased risk of increased fibrosis indices.

  12. Molecular cloning, sequence identification and expression profile of domestic guinea pig (Cavia porcellus UGT1A1 gene

    Directory of Open Access Journals (Sweden)

    Yang Deming


    Full Text Available Domestic guinea pig is a model animal for human disease research. Uridine diphosphate glucuronosyltransferase 1 family, polypeptide A1 (UGT1A1 is an important human disease-related gene. In this study, the complete coding sequence of domestic guinea pig gene UGT1A1 was amplified by reverse transcription-polymerase chain reaction. The open reading frame of the domestic guinea pig UGT1A1 gene is 1602 bp in length and was found to encode a protein of 533 amino acids. Sequence analysis revealed that the UGT1A1 protein of domestic guinea pig shared high homology with the UGT1A1 proteins of degu (84%, damara mole-rat (84%, human (80%, northern white-cheeked gibbon (80%, Colobus angolensis palliatus (80% and golden snub-nosed monkey (79%. This gene contains five exons and four introns, as revealed by the computer-assisted analysis. The results also showed that the domestic guinea pig UGT1A1 gene had a close genetic relationship with the UGT1A1 gene of degu. The prediction of transmembrane helices showed that domestic guinea pig UGT1A1 might be a transmembrane protein. Expression profile analysis indicated that the domestic guinea pig UGT1A1 gene was differentially expressed in detected domestic guinea pig tissues. Our experiment laid a primary foundation for using the domestic guinea pig as a model animal to study the UGT1A1-related human diseases.

  13. Genetic polymorphisms of CYP1A1 and risk of leukemia: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Lu J


    Full Text Available Jun Lu,1,* Qian Zhao,1,2,* Ya-Jing Zhai,3 Hai-Rong He,1 Li-Hong Yang,1 Fan Gao,1 Rong-Sheng Zhou,4 Jie Zheng,1 Xian-Cang Ma1,51Clinical Research Center, The First Affiliated Hospital, Xi’an Jiaotong University, 2College of Pharmacy, Xi’an Medical University, 3Department of Pharmacy, The First Affiliated Hospital, Xi’an Jiaotong University, 4Department of Anesthesiology, The First Affiliated Hospital, Xi’an Jiaotong University, 5Department of Psychiatry, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, People’s Republic of China*These authors contributed equally to this workAbstract: The associations between CYP1A1 polymorphisms and risk of leukemia have been studied extensively, but the results have been inconsistent. Therefore, in this study, we performed a meta-analysis to clarify associations of three CYP1A1 polymorphisms (T3801C, A2455G, and C4887A with the risks of acute lymphoblastic leukemia (ALL, acute myeloid leukemia (AML, and chronic myeloid leukemia (CML. Medline, EMBASE, and China National Knowledge Infrastructure databases were searched to collect relevant studies published up to April 20, 2015. The extracted data were analyzed statistically, and pooled odds ratios with 95% confidence intervals were calculated to quantify the associations. Overall, 26 publications were included. Finally, T3801C was associated with an increased risk of AML in Asians under the dominant model. For A2455G, the risk of ALL was increased among Caucasians in the recessive model and the allele-contrast model; A2455G was also associated with an increased risk of CML among Caucasians under the recessive model, dominant model, and allele-contrast model. For C4887A, few of the included studies produced data. In conclusion, the results suggest that Asians carrying the T3801C C allele might have an increased risk of AML and that Caucasians with the A2455G GG genotype might have an increased risk of ALL. Further

  14. Phenotype refinement strengthens the association of AHR and CYP1A1 genotype with caffeine consumption. (United States)

    McMahon, George; Taylor, Amy E; Davey Smith, George; Munafò, Marcus R


    Two genetic loci, one in the cytochrome P450 1A1 (CYP1A1) and 1A2 (CYP1A2) gene region (rs2472297) and one near the aryl-hydrocarbon receptor (AHR) gene (rs6968865), have been associated with habitual caffeine consumption. We sought to establish whether a more refined and comprehensive assessment of caffeine consumption would provide stronger evidence of association, and whether a combined allelic score comprising these two variants would further strengthen the association. We used data from between 4,460 and 7,520 women in the Avon Longitudinal Study of Parents and Children, a longitudinal birth cohort based in the United Kingdom. Self-report data on coffee, tea and cola consumption (including consumption of decaffeinated drinks) were available at multiple time points. Both genotypes were individually associated with total caffeine consumption, and with coffee and tea consumption. There was no association with cola consumption, possibly due to low levels of consumption in this sample. There was also no association with measures of decaffeinated drink consumption, indicating that the observed association is most likely mediated via caffeine. The association was strengthened when a combined allelic score was used, accounting for up to 1.28% of phenotypic variance. This was not associated with potential confounders of observational association. A combined allelic score accounts for sufficient phenotypic variance in caffeine consumption that this may be useful in Mendelian randomization studies. Future studies may therefore be able to use this combined allelic score to explore causal effects of habitual caffeine consumption on health outcomes.

  15. 胆红素脑病与胆红素/血浆白蛋白比值关系探讨%The study of the relationship between bilirubin encephalopathy and bilirubin/albumin

    Institute of Scientific and Technical Information of China (English)

    刘新晖; 李贵南; 胡月圆; 张慧; 周勇


    目的 探讨胆红素脑病与血清胆红素/血浆白蛋白比值( B/A)的关系.方法 对2008年11月至2009年10月本院住院的高胆红素血症患儿进行回顾性总结,分为胆红素脑病组(病例组)与非胆红素脑病组(对照组),对住院期间的血清胆红素高峰值、血浆白蛋白以及B/A等因素之间的关系进行统计学分析.结果 共收集到2253例高胆红素血症患儿,其中88例诊断胆红素脑病.病例组B/A为(1.59±0.47),对照组B/A为(0.80±0.28),差异有统计学意义(t=474.537,P=0.000).B/A比值为0~1.0、1.1 ~2.0、2.1 ~3.0时,胆红素脑病发生率分别为0.5%、12.9%、69.2%.结论 胆红素脑病的发生与B/A比值有关,B/A越高,发生胆红素脑病的危险性越大.%Objective The relationship between the bilirubin encephalopathy and bilirubin/ albumin (B/A) is discussed. Methods Cases with hyperbilirubinemia in hospital from Dec 2008 to Oct 2009, assigned into bilirubin encephalopathy group and control group, the relationship among bilirubin peak, albumin and B/A were analyzed retrospectively. Results Of the 2253 babies with hyperbilirubinemia, A total of 88 babies developed bilirubin encephalopathy. The B/A value in bilirubin encephalopathy group was 1. 59 ±0. 47, and control group was 0. 80 ±0. 28, with significant differences between two groups (t = 474. 537, P = 0. 000). The incidence of bilirubin encephalopathy at different levels of B/A was different; 0 - 1. 0, 0. 5% ; 1. 1 -2.0, 12. 9% ; 2. 1 - 3. 0, 69. 2% . Conclusion The incidence of bilirubin encephalopathy is significantly associated with the levels of B/A.

  16. The association between indirect bilirubin levels and liver fibrosis due to chronic hepatitis C virus infection. (United States)

    Cengiz, Mustafa; Yılmaz, Guldal; Ozenirler, Seren


    We proposed to evaluate the association between serum indirect bilirubin levels and liver fibrosis in patients with chronic hepatitis C (CHC) genotype 1b. Biopsy proven CHC genotype 1b patients' demographics, clinical and histopathological characteristics were evaluated. Logistic regression analysis was done to evaluate the clinical, laboratory and demographic features of the histologically proven liver fibrosis in CHC patients. A total of 112 biopsy proven CHC genotype 1b patients were enrolled into the study. Liver fibrosis scores were measured by using Ishak fibrosis scores and were divided into two groups; fibrosis scores ≤ 2 were categorized as mild fibrosis, 82 patients (73.2%), whereas fibrosis scores >2 were categorized as advanced fibrosis group, 30 patients (26.8%). Patients with advanced fibrosis had lower indirect bilirubin levels than the mild fibrosis group (0.28 ± 0.02 mg/dl vs. 0.44 ± 0.032 mg/dl, pbilirubin level was negatively correlated with advanced fibrosis scores (r=-0.416 and pbilirubin level was an independent predicting factor of advanced liver fibrosis (OR: 0.001, 95% CI: 0.0-0.005, pbilirubin levels and advanced liver fibrosis caused by CHC genotype 1b.

  17. Method for Estimating Bilirubin Isomerization Efficiency in Phototherapy to Treat Neonatal Jaundice (United States)

    Lisenko, S. A.; Kugeiko, M. M.


    We propose a method for quantitative assessment of the efficacy of phototherapy to treat neonatal jaundice using the diffuse reflectance spectrum for the newborn's skin, based on the analytical dependence of the measured spectrum on the structural and morphological parameters of the skin, affecting the optical conditions in the medium, and an algorithm for rapid calculation of the bilirubin photoisomerization rate in the skin tissues as a function of the structural and morphological parameters of the skin and the wavelength of the exciting radiation. From the results of a numerical simulation of the process of radiation transport in the skin, we assess the stability of our method to variations in the scattering properties of the skin and the concentrations of its optically active chromophores (melanin, oxyhemoglobin, deoxyhemoglobin). We show that in order to achieve the maximum efficacy of phototherapy, we should use light from the range 484-496 nm. In this case, the intensity of the exciting radiation should be selected individually for each newborn according to the bilirubin photoisomerization rate characteristic for it.

  18. Effects of Calcium Ions on Thermodynamic Properties of Mixed Bilirubin/Cholesterol Monolayers (United States)

    Wu, Qiong; Tang, Yu-feng; Li, Ye-min; Xie, An-jian; Shen, Yu-hua; Zhu, Jin-miao; Li, Chuan-hao


    The mixed monolayer behavior of bilirubin/cholesterol was studied through surface pressure-area (π-A) isotherms on aqueous solutions containing various concentrations of calcium ions. Based on the data of π-A isotherms, the mean area per molecule, collapse pressure, surface compressibility modulus, excess molecular areas, free energy of mixing, and excess free energy of mixing of the monolayers on different subphases were calculated. The results show an expansion in the structure of the mixed monolayer with Ca2+ in subphase, and non-ideal mixing of the components at the air/water interface is observed with positive deviation from the additivity rule in the excess molecular areas. The miscibility between the components is weakened with the increase of concentration of Ca2+ in subphase. The facts indicate the presence of coordination between Ca2+ and the two components. The mixed monolayer, in which the molar ratio of bilirubin to cholesterol is 3:2, is more stable from a thermodynamic point of view on pure water. But the stable 3:2 stoichiometry complex is destroyed with the increase of the concentration of Ca2+ in subphase. Otherwise, the mixed monolayers have more thermodynamic stability at lower surface pressure on Ca2+ subphase.

  19. Bioelectrocatalytic mediatorless dioxygen reduction at carbon ceramic electrodes modified with bilirubin oxidase

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    Nogala, Wojciech; Celebanska, Anna; Szot, Katarzyna [Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw (Poland); Wittstock, Gunther, E-mail: gunther.wittstock@uni-oldenburg.d [Carl von Ossietzky University of Oldenburg, Faculty of Mathematics and Science, Center of Interface Science (CIS), Department of Pure and Applied Chemistry, D-26111 Oldenburg (Germany); Opallo, Marcin, E-mail: [Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw (Poland)


    Carbon ceramic electrodes were prepared by sol-gel processing of a hydrophobic precursor - methyltrimethoxysilane (MTMOS) - together with dispersed graphite microparticles according to a literature procedure. Bilirubin oxidase (BOx) was adsorbed on this electrode from buffer solution and this process was followed by atomic force microscopy (AFM). The electrodes exhibited efficient mediatorless electrocatalytic activity towards dioxygen reduction. The activity depends on the time of adsorption of the enzyme and the pH. The electrode remains active in neutral solution. The bioelectrocatalytic activity is further increased when a fraction of the carbon microparticles is replaced by sulfonated carbon nanoparticles (CNPs). This additive enhances the electrical communication between the enzyme and the electronic conductor. At pH 7 the carbon ceramic electrode modified with bilirubin oxidase retains ca. half of its highest activity. The role of the modified nanoparticles is confirmed by experiments in which a film embedded in a hydrophobic silicate matrix also exhibited efficient mediatorless biocatalytic dioxygen reduction. Scanning electrochemical microscopy (SECM) of the studied electrodes indicated a rather even distribution of the catalytic activity over the electrode surface.

  20. Spontaneous evolution in bilirubin levels predicts liver-related mortality in patients with alcoholic hepatitis.

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    Minjong Lee

    Full Text Available The accurate prognostic stratification of alcoholic hepatitis (AH is essential for individualized therapeutic decisions. The aim of this study was to develop a new prognostic model to predict liver-related mortality in Asian AH patients. We conducted a hospital-based, retrospective cohort study using 308 patients with AH between 1999 and 2011 (a derivation cohort and 106 patients with AH between 2005 and 2012 (a validation cohort. The Cox proportional hazards model was constructed to select significant predictors of liver-related death from the derivation cohort. A new prognostic model was internally validated using a bootstrap sampling method. The discriminative performance of this new model was compared with those of other prognostic models using a concordance index in the validation cohort. Bilirubin, prothrombin time, creatinine, potassium at admission, and a spontaneous change in bilirubin levels from day 0 to day 7 (SCBL were incorporated into a model for AH to grade the severity in an Asian patient cohort (MAGIC. For risk stratification, four risk groups were identified with cutoff scores of 29, 37, and 46 based on the different survival probabilities (P<0.001. In addition, MAGIC showed better discriminative performance for liver-related mortality than any other scoring system in the validation cohort. MAGIC can accurately predict liver-related mortality in Asian patients hospitalized for AH. Therefore, SCBL may help us decide whether patients with AH urgently require corticosteroid treatment.

  1. Photo-isomerization and oxidation of bilirubin in mammals is dependent on albumin binding. (United States)

    Goncharova, Iryna; Jašprová, Jana; Vítek, Libor; Urbanová, Marie


    The bilirubin (BR) photo-conversion in the human body is a protein-dependent process; an effective photo-isomerization of the potentially neurotoxic Z,Z-BR as well as its oxidation to biliverdin in the antioxidant redox cycle is possible only when BR is bound on serum albumin. We present a novel analytical concept in the study of linear tetrapyrroles metabolic processes based on an in-depth mapping of binding sites in the structure of human serum albumin (HSA). A combination of fluorescence spectroscopy, circular dichroism (CD) spectroscopy, and molecular modeling methods was used for recognition of the binding site for BR, its derivatives (mesobilirubin and bilirubin ditaurate), and the products of the photo-isomerization and oxidation (lumirubin, biliverdin, and xanthobilirubic acid) on HSA. The CD spectra and fluorescent quenching of the Trp-HSA were used to calculate the binding constants. The results of the CD displacement experiments performed with hemin were interpreted together with the findings of molecular docking performed on the pigment-HSA complexes. We estimated that Z,Z-BR and its metabolic products bind on two independent binding sites. Our findings support the existence of a reversible antioxidant redox cycle for BR and explain an additional pathway of the photo-isomerization process (increase of HSA binding capacity; the excess free [unbound] BR can be converted and also bound to HSA).

  2. Effects of Calcium Ions on Thermodynamic Properties of Mixed Bilirubin/Cholesterol Monolayers

    Institute of Scientific and Technical Information of China (English)

    Qiong Wu; Yu-feng Tang; Ye-min Li; An-jian Xie; Yu-hua Shen; Jin-miao Zhu; Chuan-hao Li


    The mixed monolayer behavior of bilirubin/cholesterol was studied through surface pressure-area (π-A) isotherms on aqueous solutions containing various concentrations of calcium ions.Based on the data of π-A isotherms,the mean area per molecule,collapse pressure,surface compressibility modulus,excess molecular areas,free energy of mixing,and excess free energy of mixing of the monolayers on different subphases were calculated.The results show an expansion in the structure of the mixed monolayer with Ca2+ in subphase, and non-ideal mixing of the components at the air/water interface is observed with positive deviation from the additivity rule in the excess molecular areas.The miscibility between the components is weakened with the increase of concentration of Ca2+ in subphase.The facts indicate the presence of coordination between Ca2+ and the two components.The mixed monolayer,in which the molar ratio of bilirubin to cholesterol is 3:2,is more stable from a thermodynamic point of view on pure water.But the stable 3:2 stoichiometry complex is destroyed with the increase of the concentration of Ca2+ in subphase.Otherwise,the mixed monolayers have more thermodynamic stability at lower surface pressure on Ca2+ subphase.

  3. Amplifying the fluorescence of bilirubin enables the real-time detection of heme oxygenase activity. (United States)

    Klemz, Roman; Mashreghi, Mir-Farzin; Spies, Claudia; Volk, Hans-Dieter; Kotsch, Katja


    Heme oxygenases (HO) are the rate-limiting enzymes in the degradation of heme to equimolar amounts of antioxidant bile pigments, the signaling molecule carbon monoxide, and ferric iron. The inducible form HO-1 confers protection on cells and tissues that mediates beneficial effects in many diseases. Consequently, measurement of the enzymatic activity is vital in the investigation of the regulatory role of HO. Here we report that the fluorescence characteristics of bilirubin in complex with serum albumin can be used for the real-time detection of HO activity in enzymatic kinetics measurements. We characterized the enzymatic activity of a truncated human HO-1 and measured the HO activity for various cell types and organs, in either the basal naive or the HO-1-induced state. The bilirubin-dependent increase in fluorescence over time monitored by this assay facilitates a very fast, sensitive, and reliable measurement of HO activity. Our approach offers the basis for a highly sensitive high-throughput screening, which provides, inter alia, the opportunity to discover new therapeutic HO-1-inducing agents.

  4. Heme oxygenase-1-derived bilirubin protects endothelial cells against high glucose-induced damage. (United States)

    He, Meihua; Nitti, Mariapaola; Piras, Sabrina; Furfaro, Anna Lisa; Traverso, Nicola; Pronzato, Maria Adelaide; Mann, Giovanni E


    Hyperglycemia and diabetes are associated with endothelial cell dysfunction arising from enhanced oxidative injury, leading to the progression of diabetic vascular pathologies. The redox-sensitive transcription factor nuclear factor-E2-related factor 2 (Nrf2) is a master regulator of antioxidant genes, such as heme oxygenase-1 (HO-1), involved in cellular defenses against oxidative stress. We have investigated the pathways involved in high glucose-induced activation of HO-1 in endothelial cells and examined the molecular mechanisms underlying cytoprotection. Elevated d-glucose increased intracellular generation of reactive oxygen species (ROS), leading to nuclear translocation of Nrf2 and HO-1 expression in bovine aortic endothelial cells, with no changes in cell viability. Superoxide scavenging and inhibition of endothelial nitric oxide synthase (eNOS) abrogated upregulation of HO-1 expression by elevated glucose. Inhibition of HO-1 increased the sensitivity of endothelial cells to high glucose-mediated damage, while addition of bilirubin restored cell viability. Our findings establish that exposure of endothelial cells to high glucose leads to activation of endogenous antioxidant defense genes via the Nrf2/ARE pathway. Upregulation of HO-1 provides cytoprotection against high glucose-induced oxidative stress through the antioxidant properties of bilirubin. Modulation of the Nrf2 pathway in the early stages of diabetes may thus protect against sustained damage by hyperglycemia during progression of the disease.


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    Full Text Available Bilirubin is the degradation product of heme, thebulk of which is derived from hemoglobin of senescenterythrocytes and hepatic hemoproteins. Bilirubin ispotentially toxic, but is normally rendered harmless bybinding to plasma albumin, and efficient hepatic clearance.Jaundice, (also known as icterus is a yellowishpigmentation of the skin, the conjunctival membranes overthe sclerae (whites of the eyes, and other mucousmembranes caused by hyperbilirubinemia (increased levelsof bilirubin in the blood. Complications of jaundiceinclude sepsis especially cholangitis, biliary cirrhosis,pancreatitis, coagulopathy, renal and liver failure.Treatment of rats with Phenylhydrazine 5 mg/ kg bodyweight for five days resulted in the development ofjaundice as BR level was found to be higher than 2 mg/dL.Bilirubin lowering potential of Benzoin ethyl alcoholextract was evaluated in temporarily jaundiced adultwistar rats. Treatment of these rats with Benzoin extractfor seven days reduced the BR level significantly to thenormal value. Whereas smaller dose (10mg/kg bodyweight resulted in the reduction in BR level from 2.51 ±0.02 to 0.90 ± 0.01 mg/dL, higher doses of 20 and 40mg/kg body weight were found to be more effective inreducing the bilirubin level from 2.54 ± 0.01 to 0.82 ±0.01 mg/dL and from 2.49±0.02 to 0.66±0.01 mg/dL,respectively. Therefore, Benzoin ethyl alcohol extract canbe used to reduce bilirubin concentration to a normal levelin jaundiced subjects.

  6. Lower carotid intima media thickness is predicted by higher serum bilirubin in both non-diabetic and Type 2 diabetic subjects

    NARCIS (Netherlands)

    Dullaart, Robin P. F.; Kappelle, Paul J.W.H.; de Vries, Rindert


    Background: Higher serum bilirubin levels may be implicated cardiovascular protection. It is unknown whether the impact of serum bilirubin on carotid artery intima media thickness (IMT), a marker of subclinical atherosclerosis, is different in diabetic subjects compared to non-diabetic subjects. We

  7. Thymoquinone, an active constituent of Nigella sativa seeds, binds with bilirubin and protects mice from hyperbilirubinemia and cyclophosphamide-induced hepatotoxicity. (United States)

    Laskar, Amaj A; Khan, Masood A; Rahmani, Arshad H; Fatima, Sana; Younus, Hina


    Some reports indicate that thymoquinone (TQ), the main constituent of Nigella sativa seeds, is hepatoprotective. The aim of this study was to determine whether TQ is able to bind directly to bilirubin, and whether TQ or liposomal formulation of TQ (Lip-TQ) can reduce cyclophosphamide (CYP)-induced liver toxicity, serum bilirubin level in mice. The binding of TQ with bilirubin was studied by UV-VIS, fluorescence and Near-UV CD spectroscopy. Inhibition of binding of bilirubin to erythrocytes by TQ was also examined. To increase the in vivo efficacy, Lip-TQ was prepared and used against CYP-induced toxicity. The protective role of TQ or Lip-TQ against CYP-induced toxicity was assessed by determining the liver function parameters, the levels of superoxide dismutase (SOD) and catalase (CAT), and histological studies. It was found that TQ binds to bilirubin and significantly inhibits the binding of bilirubin to erythrocytes. Lip-TQ (10 mg/kg) significantly reduced the levels of aspartate transaminase (AST) from 254 ± 48 to 66 ± 18 IU/L (P bilirubin from 2.8 ± 0.50 to 1.24 ± 0.30 mg/dl (P bilirubin in systemic circulation in disease conditions that lead to hyperbilirubinemia and liver toxicity and hence may be used as a supplement in the treatment of liver ailments.

  8. Osteoporosis and Related Genes: VDR, ESR And COL1A1

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    Sabriye Kocaturk Sel


    Full Text Available Osteoporosis is now considered as one of the major and growing health care problems around the world. Osteoporosis is the most prevalent metabolic bone disease among developed countries and it is defined as a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue with a consequent increase in bone fragility. Bone is a highly metabolically active tissue in which the processes of osteoblastic bone formation and osteoclastic bone resorption are continuous throughout life. Coupling of osteoblast and osteoclast action ensures that a normal bone structure is maintained. A loss of bone homeostasis may result in a decrease in bone mass leading to osteoporosis or in a defect in the mineralization of bone. Numerous genetic, hormonal, nutritional and life-style factors contribute to the acquisition and maintenance of bone mass. Among them, genetic variations explain as much as 50-80% of the variance for bone mineral density (BMD in the population. Many genes that could be related to osteoporosis have been studied and of them all Vitamin D receptor (VDR, estrogen receptor alpha (ESRα and collagen 1 alpha 1 chain (COL1A1 genes have been the most focused on. [Archives Medical Review Journal 2011; 20(4.000: 246-269

  9. Significance of total bilirubin/albumin in predicting bilirubin neurotoxicity%新生儿总胆红素与白蛋白比值对预测胆红素神经毒性的临床意义

    Institute of Scientific and Technical Information of China (English)

    陈清; 苏卫东; 瞿尔力; 黄育丹; 邓秀睿


    目的 探讨新生儿血清总胆红素/白蛋白在预测胆红素神经毒性方面的临床意义.方法 选择2007年5月至2010年8月住院治疗的高胆红素血症新生儿83例,检测其血清总胆红素和白蛋白等,并计算血清总胆红素/白蛋白,同时根据脑干听觉诱发电位(BAEP)的检测结果分为BAEP正常组和BAEP异常组,并对比观察.结果 BAEP异常组27例,BAEP正常组56例,BAEP 异常组的血清总胆红素、血清总胆红素/白蛋白均显著高于BAEP正常组[(356.50±59.23)μmol/L比(318.70±55.12)μmol/L、(5.02±0.49)×10-3比(4.56±0.43)×10-3],差异有统计学意义(P0.05).结论 血清总胆红素/白蛋白较血清总胆红素更能反映高胆红素血症新生儿血中游离胆红素的水平,可作为评估胆红素神经毒性危险因素的指标之一.%Objective To investigate the significance of total bilirubin/albumin in predicting bilirubin neurotoxicity.Methods Eighty-three cases with hyperbilirubinemia who treated from May 2007 to August 2010 were selected,the serum total bilirubin and albumin were detected and total bilirubin/albumin was calculated.According to brainstem auditory evoked potential(BAEP)results,the patients were divided into normal BAEP group and abnormal BAEP group and compared.Results There were 27 cases of abnormal BAEP group and 56 cases of normal BAEP group.Total bilirubin and total bilirubin/albumin in abnormal BAEP group were higher than those in normal BAEP group[(356.50±59.23)μmol/L vs.(318.70±55.12)μmol/L,(5.02±0.49)×10-3 vs.(4.56±0.43)×10-3],the differences were significant (P0.05).Conclusion Total bilirubin/albumin can reflect serum unconjugated bilirubin level of neonatus with hyperbilirubinemia better than total bilirubin,and it can can be taken as one index to evaluate the risk factors of bilirubin neurotoxicity.

  10. The Indian origin of paternal haplogroup R1a1* substantiates the autochthonous origin of Brahmins and the caste system. (United States)

    Sharma, Swarkar; Rai, Ekta; Sharma, Prithviraj; Jena, Mamata; Singh, Shweta; Darvishi, Katayoon; Bhat, Audesh K; Bhanwer, A J S; Tiwari, Pramod Kumar; Bamezai, Rameshwar N K


    Many major rival models of the origin of the Hindu caste system co-exist despite extensive studies, each with associated genetic evidences. One of the major factors that has still kept the origin of the Indian caste system obscure is the unresolved question of the origin of Y-haplogroup R1a1*, at times associated with a male-mediated major genetic influx from Central Asia or Eurasia, which has contributed to the higher castes in India. Y-haplogroup R1a1* has a widespread distribution and high frequency across Eurasia, Central Asia and the Indian subcontinent, with scanty reports of its ancestral (R*, R1* and R1a*) and derived lineages (R1a1a, R1a1b and R1a1c). To resolve these issues, we screened 621 Y-chromosomes (of Brahmins occupying the upper-most caste position and schedule castes/tribals occupying the lower-most positions) with 55 Y-chromosomal binary markers and seven Y-microsatellite markers and compiled an extensive dataset of 2809 Y-chromosomes (681 Brahmins, and 2128 tribals and schedule castes) for conclusions. A peculiar observation of the highest frequency (up to 72.22%) of Y-haplogroup R1a1* in Brahmins hinted at its presence as a founder lineage for this caste group. Further, observation of R1a1* in different tribal population groups, existence of Y-haplogroup R1a* in ancestors and extended phylogenetic analyses of the pooled dataset of 530 Indians, 224 Pakistanis and 276 Central Asians and Eurasians bearing the R1a1* haplogroup supported the autochthonous origin of R1a1 lineage in India and a tribal link to Indian Brahmins. However, it is important to discover novel Y-chromosomal binary marker(s) for a higher resolution of R1a1* and confirm the present conclusions.

  11. Mice Deficient in the Gene for Cytochrome P450 (CYP)1A1 Are More Susceptible Than Wild-Type to Hyperoxic Lung Injury: Evidence for Protective Role of CYP1A1 Against Oxidative Stress (United States)

    Wang, Lihua; Wang, Gangduo; Couroucli, Xanthi I.; Shivanna, Binoy; Welty, Stephen E.; Barrios, Roberto; Khan,  M. Firoze; Nebert, Daniel W.; Roberts, L. Jackson; Moorthy, Bhagavatula


    Hyperoxia contributes to acute lung injury in diseases such as acute respiratory distress syndrome in adults and bronchopulmonary dysplasia in premature infants. Cytochrome P450 (CYP)1A1 has been shown to modulate hyperoxic lung injury. The mechanistic role(s) of CYP1A1 in hyperoxic lung injury in vivo is not known. In this investigation, we hypothesized that Cyp1a1(–/–) mice would be more susceptible to hyperoxic lung injury than wild-type (WT) mice, and that the protective role of CYP1A1 is in part due to CYP1A1-mediated decrease in the levels of reactive oxygen species-mediated lipid hydroperoxides, e.g., F2-isoprostanes/isofurans, leading to attenuation of oxidative damage. Eight- to ten-week-old male WT (C57BL/6J) or Cyp1a1(–/–) mice were exposed to hyperoxia (>95% O2) or room air for 24–72 h. The Cyp1a1(–/–) mice were more susceptible to oxygen-mediated lung damage and inflammation than WT mice, as evidenced by increased lung weight/body weight ratio, lung injury, neutrophil infiltration, and augmented expression of IL-6. Hyperoxia for 24–48 h induced CYP1A expression at the mRNA, protein, and enzyme levels in liver and lung of WT mice. Pulmonary F2-isoprostane and isofuran levels were elevated in WT mice after hyperoxia for 24 h. On the other hand, Cyp1a1(–/–) mice showed higher levels after 48–72 h of hyperoxia exposure compared to WT mice. Our results support the hypothesis that CYP1A1 protects against hyperoxic lung injury by decreasing oxidative stress. Future research could lead to the development of novel strategies for prevention and/or treatment of acute lung injury. PMID:24893714

  12. Subtle bilirubin-induced neurodevelopmental dysfunction (BIND) in the term and late preterm infant : Does it exist?

    NARCIS (Netherlands)

    Lunsing, Roelineke J.


    Subtle bilirubin-induced neurological dysfunction (BIND) is defined as disturbances in sensory and sensorimotor integration, central auditory processing, coordination, and muscle tone in the absence of the classical findings of kernicterus. This review is restricted to the (sensori)motor signs of BI

  13. Evaluation of Treatment Thresholds for Unconjugated Hyperbilirubinemia in Preterm Infants: Effects on Serum Bilirubin and on Hearing Loss?

    NARCIS (Netherlands)

    Hulzebos, C.V.; Dommelen, P. van; Verkerk, P.H.; Dijk, P.H.; Straaten, H.L.M. van


    Background:Severe unconjugated hyperbilirubinemia may cause deafness. In the Netherlands, 25% lower total serum bilirubin (TSB) treatment thresholds were recently implemented for preterm infants.Objective:To determine the rate of hearing loss in jaundiced preterms treated at high or at low TSB thres

  14. [Postpartal serum bilirubin levels in the newborn after induction of labour with "prostaglandin cap" or oxytocin (author's transl)]. (United States)

    Grünberger, W; Coradello, H; Huber, J; Husslein, P


    In the course of a prospective study the development of Serum bilirubine levels was controlled in 90 neonates. In 30 cases labour had been induced by means of intravenous oxytocin infusion, in a further 30 cases by means of local peri-cervical prostaglandine E2 (PGE2)-application. The control group consisted of 30 children, with spontaneous onset of labour. Anamnesis, duration of gravidity, course of labour and method of delivery were the same in all groups; the neonates were all treated the same. The serum bilirubine was determined fotometrically with the Greiner Selective Analyzer GSA II on the 1st, 3rd and 5th post partum day and the results assessed by the multivariant analysis according to Newman-Keuls. No differences were found between the PGE2- and the control group, the bilirubine values of the oxytocin groups were significantly higher (p less than 0.001). Icteric neonates with serum bilirubine values of greater than 12 mg% were found more than double as often in the oxytocin group than in the PGE2- group (7:3). The results indicate, that for labour induction by pharmaceuticals, local application of PGE2 by means of a portio cap should be favored over intravenous oxytocin administration.

  15. Benzo(a)pyrene induces hepatic AKR1A1 mRNA expression in tilapia fish (Oreochromis niloticus). (United States)

    Osorio-Yáñez, Citlalli; García-Tavera, José Luis; Pérez-Núñez, Maria Teresa; Poblete-Naredo, Irais; Muñoz, Balam; Barron-Vivanco, Briscia S; Rothenberg, Stephen J; Zapata-Pérez, Omar; Albores, Arnulfo


    AKR1A1 or aldehyde reductase is a member of the aldo-keto reductases superfamily that is evolutionarily conserved among species. AKR1A1 is one of the five AKRs (AKR1A1 and 1C1-1C4) implicated in the metabolic benzo(a)pyrene (BaP) activation to reactive BaP 7,8-dione. BaP is a polycyclic aromatic hydrocarbon (PAH) widely distributed in aquatic ecosystems and its metabolic activation is necessary to produce its toxic effects. Although the presence of AKR1A1 in fish has been reported, its tissue distribution in tilapia (Oreochromis niloticus) and AKR1A1 inducibility by BaP are not known yet. Moreover, cytochrome P4501A (CYP1A) mRNA expression in fish has been used as a PAH biomarker of effect. Therefore, BaP effects on AKR1A1 and CYP1A gene expressions in tilapia, a species of commercial interest, were investigated by real-time RT-PCR. A partial AKR1A1 cDNA was identified, sequenced and compared with AKR1A1 reported sequences in the GenBank DNA database. Constitutive AKR1A1 mRNA expression was detected mainly in liver, similarly to that of CYP1A. BaP exposure resulted in statistically significant AKR1A1 and CYP1A mRNA induction in liver (20- and 120-fold, respectively) at 24 h. On the other hand, ethoxyquin (EQ) was used as control inducer for AKR1A1 mRNA. Interestingly, EQ also induced CYP1A mRNA levels in tilapia liver. Our results suggest that teleost AKR1A1, in addition to CYP1A, are inducible by BaP. The mechanism of AKR1A1 induction by BaP and its role in fish susceptibility to BaP toxic effects remains to be elucidated.

  16. The Research of Bilirubin Levels in Neonatal Cerebrospinal Fluid in the Diagnosis of Bilirubin Encephalopathy%新生儿脑脊液胆红素在胆红素脑病诊断中的研究

    Institute of Scientific and Technical Information of China (English)

    孙路璐; 金玉莲; 刘光辉; 张健; 郑洪


    Objective To investigate the value of concentration of bilirubin in cerebrospinal fluid for early diagnosis of neonatal bilirubin encephalopathy.Methods 34 cases with bilirubin encephalopathy and 37 cases with non-bilirubin encephalopathy as control group were chosen from February 2011 to October 2012.The concentrations of unconjugated bilirubin in cerebrospinal fluid and unconjugated bilirubin in serum of two groups were compared.According to the ROC curve,their critical value,sensitivity,specificity,positive predictive value and negative predictive value in the diagnosis of bilirubin encephalopathy were analyzed.Results The unconjugated bilirubin in cerebrospinal fluid in the bilirubin encephalopathy group (13.88 ± 5.03)μmol/L was significant higher than that in the control group (5.83 ± 4.30)μmol/L(P < 0.01),there was statistical significance in difference (P < 0.01).The area under curve of unconjugated bilirubin in cerebrospinal fluid(0.909) was larger than that of unconjugated bilirubin in serum(0.692),according to the ROC curve.When the critical value was 9.55 μmol/L,the sensitivity and specificity of unconjugated bilirubin in cerebrospinal fluid in the diagnosis of neonatal bilirubin encephalopathy were 86.7% and 93.9%,respectively.Conclusion Unconjugated bilirubin in cerebros-pinal fluid value was a good indicator for predicting bilirubin encephalopathy and it was helpful to provide information for rational clinical treatment of hyperbilirubinemia.%目的 探讨高胆红素血症新生儿脑脊液未结合胆红素水平对胆红素脑病的早期诊断价值.方法 以2011年2月-2012年10月入院的34例胆红素脑病患儿(病例组)和37例单纯高胆红素血症患儿(对照组)为研究对象,比较两组脑脊液及血清未结合胆红素水平,并绘制ROC曲线,计算脑脊液未结合胆红素及血清未结合胆红素水平在诊断胆红素脑病中的临界值、灵敏度、特异度、阳性预

  17. The Evolving Landscape of Neurotoxicity by Unconjugated Bilirubin: Role of Glial Cells and Inflammation

    Directory of Open Access Journals (Sweden)

    Dora eBrites


    Full Text Available Unconjugated hyperbilirubinemia is a common condition in the first week of postnatal life. Although generally harmless, some neonates may develop very high levels of unconjugated bilirubin (UCB, which may surpass the protective mechanisms of the brain at preventing UCB accumulation. In this case, both short-term and long-term neurodevelopmental disabilities, such as acute and chronic UCB encephalopathy, known as kernicterus, or more subtle alterations designed as bilirubin-induced neurological dysfunction (BIND may be produced. There is a tremendous variability in babies’ vulnerability towards UCB for reasons not yet explained, but preterm birth, sepsis, hypoxia and haemolytic disease are comprised as risk factors. Therefore, UCB levels and neurological abnormalities are not strictly correlated. Even nowadays, the mechanisms of UCB neurotoxicity are still unclear, as are specific biomarkers, and little is known about lasting sequelae attributable to hyperbilirubinemia. On autopsy, UCB was shown to be within neurons, neuronal processes and microglia, and to produce loss of neurons, demyelination and gliosis. In isolated cell cultures, UCB was shown to impair neuronal arborization and to induce the release of proinflammatory cytokines from microglia and astrocytes. However, cell dependent-sensitivity to UCB toxicity and the role of each nerve cell type remain understood. This review provides a comprehensive insight into cell susceptibilities and molecular targets of UCB in neurons, astrocytes, and oligodendrocytes, and on phenotypic and functional responses of microglia to UCB. Interplay among glia elements and cross-talk with neurons, with a special emphasis in the UCB-induced immunostimulation, and the role of sepsis in BIND pathogenesis are highlighted. New and interesting data on the anti-inflammatory and antioxidant activities of different pharmacological agents are also presented, as novel and promising additional therapeutic approaches to

  18. Dysfunction of organic anion transporting polypeptide 1a1 alters intestinal bacteria and bile acid metabolism in mice.

    Directory of Open Access Journals (Sweden)

    Youcai Zhang

    Full Text Available Organic anion transporting polypeptide 1a1 (Oatp1a1 is predominantly expressed in liver and is able to transport bile acids (BAs in vitro. Male Oatp1a1-null mice have increased concentrations of taurodeoxycholic acid (TDCA, a secondary BA generated by intestinal bacteria, in both serum and livers. Therefore, in the present study, BA concentrations and intestinal bacteria in wild-type (WT and Oatp1a1-null mice were quantified to investigate whether the increase of secondary BAs in Oatp1a1-null mice is due to alterations in intestinal bacteria. The data demonstrate that Oatp1a1-null mice : (1 have similar bile flow and BA concentrations in bile as WT mice; (2 have a markedly different BA composition in the intestinal contents, with a decrease in conjugated BAs and an increase in unconjugated BAs; (3 have BAs in the feces that are more deconjugated, desulfated, 7-dehydroxylated, 3-epimerized, and oxidized, but less 7-epimerized; (4 have 10-fold more bacteria in the small intestine, and 2-fold more bacteria in the large intestine which is majorly due to a 200% increase in Bacteroides and a 30% reduction in Firmicutes; and (5 have a different urinary excretion of bacteria-related metabolites than WT mice. In conclusion, the present study for the first time established that lack of a liver transporter (Oatp1a1 markedly alters the intestinal environment in mice, namely the bacteria composition.

  19. Effects of Bilirubin on Alveolar Macrophages in Rats with Emphysema and Expression of iNOS and NO in Them

    Institute of Scientific and Technical Information of China (English)

    李建强; 赵卉; 宋满景; 徐永健; 张珍祥


    To explore the effects of bilirubin on alveolar macrophages (AM) and expression of iNOS and NO in them in emphysema model, the rats were pretreated with bilirubin before exposed to smoke. AM were isolated from bronchoalveolar lavage fluid (BALF) and cultured. Pathological microscopic examination of AM and immunohistochemical analysis of iNOS were performed. Nitric oxide (NO) content in the samples was determined by nitrate reductase technique. The results showed both alveoli and alveolar septum appeared normal in size and shape in normal group. AM showed kidney-shaped nucleus and were rich in Golgi complexes and primary lysosomes in the cytoplasm. The inner membrane of mitochondrion was continuous. Most cristae of the mitochondria were intact. In model group, the alveoli were expanded, ruptured and bullaes were formed. Both the population and sizes of AM increased significantly. Secondary lysosomes were rich in the cytoplasm. Deformation and pyknosis of the nucleus, swelling of the mitochondrions and rupture of the inner mitochondrial membrane could also be seen. At high magnification, most of the mitochondrial cristae were broken, or completely lost at certain points. In bilirubin group, alveoli partly expanded and the population of AM also increased, with morphological changes being slighter than that in model group. Both NO contents and expression of iNOS in model group were higher than those in normal group (P<0.05). In bilirubin group the two indice were lower than those in model group (P<0.05). Our findings suggested that high expression of iNOS and high NO content in AM accelerate the development of emphysema associated with smoking in rats. Bilirubin may exert protective effects on AM and retards the development of emphysema in rats.

  20. Transcutaneous bilirubin--comparing the accuracy of BiliChek(R) and JM 103(R) in a regional postnatal unit.

    LENUS (Irish Health Repository)

    Qualter, Yvonne M


    OBJECTIVE: Transcutaneous bilirubin (TcB) has the potential to reduce serum bilirubin sampling. During a recent survey on the use of TcB in postnatal units in the Republic of Ireland, we identified that only 58% of the 19 units were using TcB and that only two devices were in use, the BiliChek(R) and JM 103(R). We aimed to evaluate and compare these two devices in a regional postnatal unit. METHODS: To evaluate and compare the accuracy of the BiliChek(R) and JM 103(R), we studied simultaneous TcB and total serum bilirubin (TSB) measurements from a population of jaundiced term and near term infants. We evaluated each device with regard to correlation with TSB and potential to safely reduce serum bilirubin testing. RESULTS: Both TcB devices strongly correlated with TSB (r = 0.88 for BiliChek(R) and r = 0.70 for JM 103(R). The BiliChek(R) and JM 103(R) were accurate up to cut-off values of 200 mumol\\/L and 180 mumol\\/L, respectively. Using Bhutani\\'s nomogram, 100% sensitivity was achieved using the 75th percentile for BiliChek(R) and the 40th percentile for JM 103(R). CONCLUSION: Both TcB devices correlated closely with moderately increased TSB levels and are suitable screening tools to identify jaundiced infants that require a serum bilirubin, with upper limit cut-off values. Both devices reduced the need for TSB levels. We found the BiliChek(R) slightly more accurate than the JM 103(R) for our study population. TcB however, is not in widespread use.

  1. Serum Bilirubin and 6-min Walk Distance as Prognostic Predictors for Inoperable Chronic Thromboembolic Pulmonary Hypertension: A Prospective Cohort Study

    Institute of Scientific and Technical Information of China (English)

    Juan-Ni Gong; Zhen-Guo Zhai; Yuan-Hua Yang; Yan Liu; Song Gu; Tu-Guang Kuang; Wan-Mu Xie


    Background: Inoperable chronic thromboembolic pulmonary hypertension (CTEPH) is a severe clinical syndrome characterized by right cardiac failure and possibly subsequent liver dysfunction.However, whether serum markers of liver dysfunction can predict prognosis in inoperable CTEPH patients has not been determined.Our study aimed to evaluate the potential role of liver function markers (such as serum levels of transaminase, bilirubin, and gamma-glutamyl transpeptidase [GGT]) combined with 6-min walk test in the prediction of prognosis in patients with inoperable CTEPH.Methods: From June 2005 to May 2013, 77 consecutive patients with inoperable CTEPH without confounding co-morbidities were recruited for this prospective cohort study.Baseline clinical characteristics and 6-min walk distance (6MWD) results were collected.Serum biomarkers of liver function, including levels of aspartate aminotransferase, alanine aminotransferase, GGT, uric acid, and serum bilirubin, were also determined at enrollment.All-cause mortality was recorded during the follow-up period.Results: During the follow-up, 22 patients (29%) died.Cox regression analyses demonstrated that increased serum concentration of total bilirubin (hazard ratio [HR] =7.755, P < 0.001), elevated N-terminal of the prohormone brain natriuretic peptide (HR =1.001, P =0.001), decreased 6MWD (HR =0.990, P < 0.001), increased central venous pressure (HR =1.074, P =0.040), and higher pulmonary vascular resistance (HR =1.001, P =0.018) were associated with an increased risk of mortality.Serum concentrations of total bilirubin (HR =4.755, P =0.007) and 6MWD (HR =0.994, P =0.017) were independent prognostic predictors for CTEPH patients.Patients with hyperbilirubinemia (≥23.7 μ mol/L) had markedly worse survival than those with normobilirubinemia.Conclusion: Elevated serum bilirubin and decreased 6MWD are potential predictors for poor prognosis in inoperable CTEPH.

  2. NAD+ Attenuates Bilirubin-Induced Hyperexcitation in the Ventral Cochlear Nucleus by Inhibiting Excitatory Neurotransmission and Neuronal Excitability (United States)

    Liang, Min; Yin, Xin-Lu; Wang, Lu-Yang; Yin, Wei-Hai; Song, Ning-Ying; Shi, Hai-Bo; Li, Chun-Yan; Yin, Shan-Kai


    Nicotinamide adenine dinucleotide (NAD+) is an important molecule with extensive biological functions in various cellular processes, including protection against cell injuries. However, little is known regarding the roles of NAD+ in neuronal excitation and excitotoxicity associated with many neurodegenerative disorders and diseases. Using patch-clamp recordings, we studied its potential effects on principal neurons in the ventral cochlear nucleus (VCN), which is particularly vulnerable to bilirubin excitotoxicity. We found that NAD+ effectively decreased the size of evoked excitatory postsynaptic currents (eEPSCs), increased paired-pulse ratio (PPR) and reversed the effect of bilirubin on eEPSCs, implicating its inhibitory effects on the presynaptic release probability (Pr). Moreover, NAD+ not only decreased the basal frequency of miniature EPSCs (mEPSCs), but also reversed bilirubin-induced increases in the frequency of mEPSCs without affecting their amplitude under either condition. Furthermore, we found that NAD+ decreased the frequency of spontaneous firing of VCN neurons as well as bilirubin-induced increases in firing frequency. Whole-cell current-clamp recordings showed that NAD+ could directly decrease the intrinsic excitability of VCN neurons in the presence of synaptic blockers, suggesting NAD+ exerts its actions in both presynaptic and postsynaptic loci. Consistent with these observations, we found that the latency of the first postsynaptic spike triggered by high-frequency train stimulation of presynaptic afferents (i.e., the auditory nerve) was prolonged by NAD+. These results collectively indicate that NAD+ suppresses presynaptic transmitter release and postsynaptic excitability, jointly weakening excitatory neurotransmission. Our findings provide a basis for the exploration of NAD+ for the prevention and treatment of bilirubin encephalopathy and excitotoxicity associated with other neurological disorders. PMID:28217084

  3. Genistein decreases basal hepatic cytochrome P450 1A1 protein expression and activity in Swiss Webster mice. (United States)

    Froyen, Erik B; Steinberg, Francene M


    Soy consumption has been associated with risk reduction for chronic diseases such as cancer. One proposed mechanism for cancer prevention by soy is through decreasing cytochrome P450 1A1 (Cyp1a1) activity. However, it is not known with certainty which soy components modulate Cyp1a1, or the characteristics or mechanisms involved in the responses after short-term (<20 days) dietary treatment without concomitant carcinogen-mediated induction. Therefore, the objective was to test the hypothesis that physiologic concentrations of dietary genistein and/or daidzein will decrease basal hepatic Cyp1a1 protein expression and activity in male and female Swiss Webster mice via inhibiting the bindings of aryl hydrocarbon receptor (AhR)-AhR nuclear translocator (ARNT) and estrogen receptor-α to the Cyp1a1 promoter region xenobiotic response element. The mice were fed the AIN-93G diet supplemented with 1500 mg/kg of genistein or daidzein for up to 1 week. Genistein, but not daidzein, significantly decreased basal hepatic microsomal Cyp1a1 protein expression and activity. AhR protein expression was not altered. Molecular mechanisms were investigated in Hepa-1c1c7 cells treated with 5 μmol/L purified aglycones genistein, daidzein, or equol. Cells treated with genistein exhibited inhibitions in ARNT and estrogen receptor-α bindings to the Cyp1a1 promoter region. This study demonstrated that genistein consumption reduced constitutive hepatic Cyp1a1 protein expression and activity, thereby contributing to the understanding of how soy isoflavone aglycones modulate cytochrome P450 biotransformation enzymes.

  4. The effect of knockout of sulfotransferases 1a1 and 1d1 and of transgenic human sulfotransferases 1A1/1A2 on the formation of DNA adducts from furfuryl alcohol in mouse models. (United States)

    Sachse, Benjamin; Meinl, Walter; Glatt, Hansruedi; Monien, Bernhard H


    Furfuryl alcohol is a rodent carcinogen present in numerous foodstuffs. Sulfotransferases (SULTs) convert furfuryl alcohol into the DNA reactive and mutagenic 2-sulfoxymethylfuran. Sensitive techniques for the isotope-dilution ultra performance liquid chromatography-tandem mass spectrometry quantification of resulting DNA adducts, e.g. N (2)-((furan-2-yl)methyl)-2'-deoxyguanosine (N (2)-MF-dG), were developed. To better understand the contribution of specific SULT forms to the genotoxicity of furfuryl alcohol in vivo, we studied the tissue distribution of N (2)-MF-dG in different mouse models. Earlier mutagenicity studies with Salmonella typhimurium strains expressing different human and murine SULT forms indicated that human SULT1A1 and murine Sult1a1 and 1d1 catalyze furfuryl alcohol sulfo conjugation most effectively. Here, we used three mouse lines to study the bioactivation of furfuryl alcohol by murine SULTs, FVB/N wild-type (wt) mice and two genetically modified models lacking either murine Sult1a1 or Sult1d1. The animals received a single dose of furfuryl alcohol, and the levels of the DNA adducts were determined in liver, kidney, lung, colon and small intestine. The effect of Sult1d1 gene disruption on the genotoxicity of furfuryl alcohol was moderate and limited to kidney and small intestine. In contrast, the absence of functional Sult1a1 had a massive influence on the adduct levels, which were lowered by 33-73% in all tissues of the female Sult1a1 null mice compared with the wt animals. The detection of high N (2)-MF-dG levels in a humanized mouse line expressing hSULT1A1/1A2 instead of endogeneous Sult1a1 and Sult1d1 supports the hypothesis that furfuryl alcohol is converted to the mutagenic 2-sulfoxymethylfuran also in humans.

  5. Genotype frequencies of polymorphic GSTM1, GSTT1, and cytochrome P450 CYP1A1 in Mexicans. (United States)

    Montero, Regina; Araujo, Antonio; Carranza, Paloma; Mejía-Loza, Vanessa; Serrano, Luis; Albores, Arnulfo; Salinas, Juan E; Camacho-Carranza, Rafael


    The genotype frequencies of three metabolic polymorphisms were determined in a sample of a typical community in central Mexico. CYP1A1*3, GSTM1, and GSTT1 polymorphisms were studied in 150 donors born in Mexico and with Mexican ascendants; with respect to ethnicity the subjects can be considered Mestizos. PCR reactions were used to amplify specific fragments of the selected genes from genomic DNA. An unexpected 56.7% frequency of the CYP1A1*3 allele (which depends on the presence of a Val residue in the 462 position of the enzyme, instead of Ile) was found, the highest described for open populations of different ethnic origins (i.e., Caucasian, Asian, African, or African American). The GSTM1 null genotype was found with a frequency of 42.6%, which is not different from other ethnicities, whereas the GSTT1 null genotype had a frequency of 9.3%, one of the lowest described for any ethnic group but comparable to the frequency found in India (9.7%). The frequency of the combined genotype CYP1A1*3/*3 and the GSTM1 null allele is one of the highest observed to date (or perhaps the highest): 13.7% among all the ethnicities studied, including Caucasians and Asians, whereas the combination of CYP1A1*3/*3 with the GSTT1 null allele reached only 2.8%. The GSTM1 null allele combined with the GSTT1 null allele, on the other hand, has one of the lowest frequencies described, 4.24%, comparable to the frequencies found in African Americans and Indians. Finally, the combined CYP1A1*3/*3, GSTM1 null allele, and GSTT1 null allele genotype could not be found in the sample studied; it is assumed that the frequency of carriers of these combined genotypes is less than 1%. CYP1A1*3 and CYP1A1*2 polymorphisms were also evaluated in 50 residents in a community of northern Mexico; the CYP1A1*3 frequency was 54%, similar to that found in the other community studied, and the CYP1A1*2 frequency was 40%, which is high compared to Caucasians and Asians but comparable to the frequency found in

  6. Relationship of tobacco smoking, CYP1A1, GSTM1 gene polymorphism and esophageal cancer in Xi'an

    Institute of Scientific and Technical Information of China (English)

    An-Hui Wang; Chang-Sheng Sun; Liang-Shou Li; Jiu-Yi Huang; Qing-Shu Chen


    AIM: To analyze the association of tobacco smoking,polymorphism of CYP1A1 (7th exon ) and GSTM1 genotypeand esophageal cancer(EC) in Xi'an.METHODS: A hospital based case-control study, withmolecular epidemiological method, was carried out.Polymorphism of CYP1A1 and GSTM1 of samples from 127EC cases and 101 controls were detected by PCR method.RESULTS: There were no significant difference of age andgender between cases and controls. Tobacco smokingwas the main risk factor(OR= 1.97 ;95% Cl = 1.12-3.48)for EC in Xi'an. The proportions of CYP1A1 lle/lle, lle/Val and Val/Val gene types in cases and controls was19.7%, 45.7%, 34.6% and 30.7%, 47.5%, 21.8%respectively( P= 0.049). Individuals with CYP1A1 Val/Valgenotype compared to those with CYP1A1 lle/llegenotype had higher risk for EC increased (OR = 2.48,95% Cl = 1.12-5.54). The proportions of GSTM1 deletiongenotype in cases and controls were 58.3% and 43.6%(OR= 1.81, 95%Cl = 1.03-3.18, P = 0.028). Analysis ofgene-environment interaction showed that tobaccosmoking and CYP1A1 Val/Val genotype; tobacco smokingand GSTM1 deletion genotype had synergism interactionrespectively. Analysis of gene-gene interaction did notfind synergistic interaction between these two genes. Butin GSTM1 deletion group, there was significant differenceof distribution of CYP1A1 genotype between cases andcontrols (P=0.011).CONCLUSION: CYP1A1 Val/Val and GSrM1 deletiongenotypes are genetic susceptibility biomarkers for EC. Therisk increases, when person with CYP1A1 Val/Val and/orGSTM1 deletion genotype. And these two-metabolic enzymesseem to have interactions with tobacco smoking, in which themechanism still needs further study.

  7. Combination effect of cytochrome P450 1A1 gene polymorphisms on uterine leiomyoma: A case-control study (United States)

    Salimi, Saeedeh; Sajadian, Mojtaba; Khodamian, Maryam; Yazdi, Atefeh; Rezaee, Soodabeh; Mohammadpour-Gharehbagh, Abbas; Mokhtari, Mojgan; Yaghmaie, Minoo


    Uterine leiomyoma (UL) is an estrogen-dependent neoplasm of the uterus, and estrogen metabolizing enzymes affect its progression. This study aimed to evaluate the association between two single-nucleotide polymorphisms of cytochrome P450 1A1 (CYP1A1) gene and UL risk. The study consisted of 105 patients with UL and 112 healthy women as controls. Ile462Val (A/G) and Asp449Asp (T/C) polymorphisms of CYP1A1 gene were analyzed by DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism methods, respectively. The findings indicated no association between Ile462Val (A/G) and Asp449Asp (T/C) polymorphisms of CYP1A1 gene and UL (p < 0.05). However, the combination effect of TT/AG genotypes of the Asp449Asp (T/C) and Ile462Val (A/G) polymorphisms was associated with 4.3-fold higher risk of UL. In addition, haplotype analysis revealed that TG haplotype of the Asp449Asp (T/C) and Ile462Val (A/G) polymorphisms could increase the UL risk nearly 4.9-fold. Asp449Asp (T/C) and Ile462Val (A/G) polymorphisms of CYP1A1 gene were not associated with UL susceptibility; however, the combination of the TT/AG genotypes and TG haplotype could increase the UL risk.

  8. Induction of CYP1A1 and CYP2E1 in rat liver by histamine: binding and kinetic studies. (United States)

    Dávila-Borja, Víctor M; Belmont, Javier A; Espinosa, J Javier; Moreno-Sánchez, Rafael; Albores, Arnulfo; Montero, Regina D


    Histamine (HA) may bind to cytochrome P450 (CYP450) in rat liver microsomes. The CYP450-HA complex seems to regulate some cellular processes such as proliferation. In the present work, it is shown that HA increases the activity and protein level of CYP1A1 and CYP2E1, in vivo. CYP1A1 is associated with polycyclic aromatic hydrocarbon-mediated carcinogenesis and CYP2E1 with liver damage by oxidative stress. Studies of enzyme kinetics and binding with rat liver microsomes and supersomes were carried out to determine whether HA is a substrate of CYP1A1 and/or CYP2E1. The lack of NADPH oxidation in the presence of HA showed that it is not a substrate for CYP1A1. Activity measurements using the O-dealkylation of ethoxyresorufin indicated that HA is a mixed-type inhibitor of CYP1A1 in both microsomes and supersomes. On the other hand, HA induced a significant NADPH oxidation catalyzed by CYP2E1 supersomes, strongly suggesting that HA is a substrate for this isoform. Furthermore, HA is consumed in the presence of CYP2E1-induced microsomes and supersomes, as determined by o-phtalaldehyde complexes with HA by HPLC. The present findings may contribute to understand better the physiological function of CYP450 in relation with inflammation and other physiological processes in which HA may have a relevant role.

  9. Induction of CYP1A1 in rat liver after ingestion of mussels contaminated by Erika fuel oils

    Energy Technology Data Exchange (ETDEWEB)

    Chaty, Sylvie; Rodius, Francois; Vasseur, Paule [Universite de Metz: CNRS UMR 7146, Lab., Interactions Ecotoxicite, Biodiversite, Ecosystemes, Metz (France); Lanhers, Marie-Claire; Burnel, Daniel [Universite de Nancy I, Faculte de Medecine, Vandoeuvre-les-Nancy (France)


    Polycyclic aromatic hydrocarbons (PAH) are known to be specific inducers of CYP1A1 expression in vertebrates. CYP1A1 induction has been widely studied in mammal cell cultures or in vivo, in conditions of exposure to single PAH chemicals. Here, we studied the possible transfer of PAH to rats via the food chain in environmentally-relevant conditions. Rats were fed for 2 days with PAH-contaminated mussels sampled on coasts polluted by the Erika oil-tanker wreck. CYP1A1 expression was investigated by measuring mRNA levels and EROD enzymatic activity over the 84 h following the last ingestion. CYP1A1 expression in treated rats was compared to controls fed with mussels free from PAH contamination. The results showed that ingestion of PAH-contaminated mussels induced CYP1A1 mRNA and EROD activity. Increase of transcriptional level and of EROD activity was transient with a peak within 12 h and a return to basal levels within 36 h. (orig.)

  10. A non-canonical function of eukaryotic elongation factor 1A1: regulation of interleukin-6 expression. (United States)

    Schulz, Ingo; Engel, Claudia; Niestroj, André J; Kehlen, Astrid; Rahfeld, Jens-Ulrich; Kleinschmidt, Martin; Lehmann, Karola; Roßner, Steffen; Demuth, Hans-Ulrich


    Interleukin-6 is one of the most prominent triggers of inflammatory processes. We have shown recently that heteroarylketones (HAKs) interfere with stimulated interleukin-6 expression in astrocytes by suppression of STAT3 phosphorylation at serine 727. Surprisingly, this effect is not based on the inhibition of STAT3-relevant kinases. Therefore, we here used the structurally modified HAK compound biotin-HAK-3 in a reverse chemical approach to identify the relevant molecular target in UV-mediated cross-linking experiments. Employing streptavidin-specific 2D-immunoblotting followed by mass spectrometry we identified nine proteins putatively interacting with biotin-HAK-3. After co-immunoprecipitation, co-immunofluorescence, surface plasmon resonance analyses and RNAi-mediated knock-down, the eukaryotic elongation factor 1A1 (eEF1A1) was verified as the relevant target of HAK bioactivity. eEF1A1 forms complexes with STAT3 and PKCδ, which are crucial for STAT3(S727) phosphorylation and for NF-κB/STAT3-enhanced interleukin-6 expression. Furthermore, the intracellular HAK accumulation is strongly dependent on eEF1A1 expression. Taken together, the results reveal a novel molecular mechanism for a non-canonical role of eEF1A1 in signal transduction via direct modulation of kinase-dependent phosphorylation events.

  11. Excessive bilirubin elevation in a patient with hereditary spherocytosis and intrahepatic cholestasis. (United States)

    Wree, A; Canbay, A; Müller-Beissenhirtz, H; Dechêne, A; Gerken, G; Dührsen, U; Lammert, F; Nückel, H


    Hereditary spherocytosis is a common hemolytic anemia with an estimated incidence of 1 / 2500 births. It is caused by a molecular defect in one or more of the proteins of the red blood cell cytoskeleton. Mutations in the ABCB11 gene, encoding the bile salt export pump, can entail progressive familial intrahepatic cholestasis and benign recurred intrahepatic cholestasis. A 18 year old Turkish patient with hereditary spherocytosis was admitted to hospital with pruritus and severe jaundice. Ultrasound examination presented stones in gallbladder and bile duct. After endoscopic retrograde cholangiography with extraction of small bile duct stones abdominal pain resolved and liver enzymes normalized within a few days, but bilirubin and bile acids remained highly elevated. Liver biopsy revealed a severe canalicular cholestasis. Genetic analysis showed the compound heterozygous variants ABCB11 A 444V and 3084A > G. Treatment with ursodesoxycholic acid and intermittent therapy with prednisone reduced pruritus and jaundice with concomitant improvement of blood test. Here we report the first case of a patient with combined hereditary spherocytosis and compound heterozygous ABCB11 gene variants predisposing to intrahepatic cholestasis. Therefore, patients with hemolytic disorders should be investigated for bile acid transporter diseases in case of hyperbilirubinemia and severe cholestasis.

  12. Analysis of binding ability of two tetramethylpyridylporphyrins to albumin and its complex with bilirubin (United States)

    Solomonov, Alexey V.; Shipitsyna, Maria K.; Vashurin, Arthur S.; Rumyantsev, Evgeniy V.; Timin, Alexander S.; Ivanov, Sergey P.


    An interaction between 5,10,15,20-tetrakis-(N-methyl-x-pyridyl)porphyrins, x = 2; 4 (TMPyPs) with bovine serum albumin (BSA) and its bilirubin (BR) complex was investigated by UV-Viz and fluorescence spectroscopy under imitated physiological conditions involving molecular docking studies. The parameters of forming intermolecular complexes (binding constants, quenching rate constants, quenching sphere radius etc.) were determined. It was showed that the interaction between proteins and TMPyPs occurs via static quenching of protein fluorescence and has predominantly hydrophobic and electrostatic character. It was revealed that obtained complexes are relatively stable, but in the case of TMPyP4 binding with proteins occurs better than TMPyP2. Nevertheless, both TMPyPs have better binding ability with free protein compared to BRBSA at the same time. The influence of TMPyPs on the conformational changes in protein molecules was studied using synchronous fluorescence spectroscopy. It was found that there is no competition of BR with TMPyPs for binging sites on protein molecule and BR displacement does not occur. Molecular docking calculations have showed that TMPyPs can bind with albumin via tryptophan residue in the hydrophilic binding site of protein molecule but it is not one possible interaction way.

  13. Decolorization and biodegradation of remazol brilliant blue R by bilirubin oxidase. (United States)

    Liu, Youxun; Huang, Juan; Zhang, Xiaoyu


    The dye-decolorizing potential of bilirubin oxidase (BOX) was demonstrated for an anthraquinone dye, remazol brilliant blue R (RBBR). The dye was decolorized 40% within 4 h by the BOX alone, whereas it was more efficient in the presence of 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), showing 91.5% decolorization within 25 min. The effects of operational parameters on decolorization were examined. The results showed that the decolorization efficiency decreased with increasing RBBR concentration, and a marked inhibition effect was exhibited when the dye concentrations were above 100 mg l(-1). The optimum temperature for enzymatic decolorization was 40 degrees C. BOX showed efficient decolorization of the dye with a wide pH range of 5-8.5. The maximum decolorization activity occurred at pH 8 with ABTS and at pH 5 without ABTS. Analysis of RBBR ultraviolet and visible (UV-VIS) spectra after BOX treatment indicated that the decolorization of RBBR was due to biodegradation. Our results suggested that ABTS can serve as an electron mediator to facilitate the oxidation of RBBR, and the BOX-ABTS mediator-involved dye decolorization mechanism was similar to that of laccase. Operation over a wide range of pH and efficient decolorization suggested that the BOX can be used to decolorize synthetic dyes from effluents, especially for anthraquinonic dyes.

  14. Bilirubin oxidation end products directly alter K+ channels important in the regulation of vascular tone. (United States)

    Hou, Shangwei; Xu, Rong; Clark, Joseph F; Wurster, William L; Heinemann, Stefan H; Hoshi, Toshinori


    The exact etiology of delayed cerebral vasospasm following cerebral hemorrhage is not clear, but a family of compounds termed 'bilirubin oxidation end products (BOXes)' derived from heme has been implicated. As proper regulation of vascular smooth muscle tone involves large-conductance Ca(2+)- and voltage-dependent Slo1 K(+) (BK, maxiK, K(Ca)1.1) channels, we examined whether BOXes altered functional properties of the channel. Electrophysiological measurements of Slo1 channels heterologously expressed in a human cell line and of native mouse BK channels in isolated cerebral myocytes showed that BOXes markedly diminished open probability. Biophysically, BOXes specifically stabilized the conformations of the channel with its ion conduction gate closed. The results of chemical amino-acid modifications and molecular mutagenesis together suggest that two specific lysine residues in the structural element linking the transmembrane ion-permeation domain to the carboxyl cytosolic domain of the Slo1 channel are critical in determining the sensitivity of the channel to BOXes. Inhibition of Slo1 BK channels by BOXes may contribute to the development of delayed cerebral vasospasm following brain hemorrhage.

  15. Sixth hour transcutaneous bilirubin predicting significant hyperbilirubinemia in ABO incompatible neonates

    Institute of Scientific and Technical Information of China (English)

    Ramesh Y Bhat; Pavan CG Kumar


    Background: Neonates with ABO hemolytic disease are at greater risk for developing significant hyperbilirubinemia. We aimed to determine whether sixth hour transcutaneous bilirubin (TcB) could predict such a risk. Methods: TcB measurements were obtained at the 6th hour of life in blood group A or B neonates born to blood group O, rhesus factor compatible mothers. Subsequent hyperbilirubinemia was monitored and considered significant if a neonate required phototherapy/exchange transfusion. The predictive role of sixth hour TcB was estimated. Results: Of 144 ABO incompatible neonates, 41(OA, 24; O-B, 17) had significant hyperbilirubinemia. Mean sixth hour TcB was significantly higher among neonates who developed significant hyperbilirubinemia than those who did not (5.83±1.35 mg/dL vs. 3.65±0.96 mg/dL, P4 mg/dL had the highest sensitivity of 93.5% and >6 mg/dL had the highest specifi city of 99%. Area under receiver operating characteristic curve was 0.898. Conclusion: Sixth hour TcB predicts subsequent significant hyperbilirubinemia in ABO incompatible neonates.

  16. Bilirubin oxidase based enzymatic air-breathing cathode: Operation under pristine and contaminated conditions. (United States)

    Santoro, Carlo; Babanova, Sofia; Erable, Benjamin; Schuler, Andrew; Atanassov, Plamen


    The performance of bilirubin oxidase (BOx) based air breathing cathode was constantly monitored over 45 days. The effect of electrolyte composition on the cathode oxygen reduction reaction (ORR) output was investigated. Particularly, deactivation of the electrocatalytic activity of the enzyme in phosphate buffer saline (PBS) solution and in activated sludge (AS) was evaluated. The greatest drop in current density was observed during the first 3 days of constant operation with a decrease of ~60 μA cm(-2) day(-1). The rate of decrease slowed to ~10 μA cm(-2) day(-1) (day 3 to 9) and then to ~1.5 μA cm(-2)day(-1) thereafter (day 9 to 45). Despite the constant decrease in output, the BOx cathode generated residual current after 45 days operations with an open circuit potential (OCP) of 475 mV vs. Ag/AgCl. Enzyme deactivation was also studied in AS to simulate an environment close to the real waste operation with pollutants, solid particles and bacteria. The presence of low-molecular weight soluble contaminants was identified as the main reason for an immediate enzymatic deactivation within few hours of cathode operation. The presence of solid particles and bacteria does not affect the natural degradation of the enzyme.

  17. Characterization of erythrosine B binding to bovine serum albumin and bilirubin displacement. (United States)

    Mathavan, Vinodaran M K; Boh, Boon Kim; Tayyab, Saad


    The interaction of crythrosine B (ErB), a commonly used dye for coloring foods and drinks, with bovine scrum albumin (BSA) was investigated both in the absence and presence of bilirubin (BR) using absorption and absorption difference spectroscopy. ErB binding to BSA was reflected from a significant red shift of 11 nm in the absorption maximum of ErB (527 nm) with the change in absorbance at lamdamax. Analysis of absorption difference spectroscopic titration results of BSA with increasing concentrations of ErB3 using Benesi-Hildebrand equation gave the association constant, K as 6.9 x 10(4) M(-1). BR displacing action of ErB was revealed by a significant blue shift in the absorption maximum, accompanied by a decrease in absorbance difference at lamdamax in the difference spectrum of BR-BSA complex upon addition of increasing concentrations of ErB. This was further substantiated by fluorescence spectroscopy, as addition of increasing concentrations of ErB to BR-BSA complex caused a significant decrease in fluoresccnce at 510 nm. The results suggest that ErB binds to a site in the vicinity of BR binding site on BSA. Therefore, intake of ErB may increase the risk of hyperbilirubinemia in the healthy subjects.

  18. Is bilirubin able to affect the cell cycle in Gunn rat brain? - An in vivo and in vitro study -


    Robert, Maria Celeste


    The hyperbilirubinemic jj Gunn rat is a well established animal model for Crigler-Najjar type I Syndrome and neonatal jaundice. Similarly to humans, they present neurological deficits and what is more a marked cerebellar hypoplasia with a prominent loss and degeneration of Purkinje cells and granule neurons. Since high levels of bilirubin have been proven to arrest the cell cycle progression, we addressed the question if the cerebellar hypoplasia observed in the hyperbilirubinemic Gunn rat co...

  19. Effect of bilirubin on expression and localization of PGP and Mrp1 in the central nervous system


    Gazzin, Silvia


    INTRODUZIONE A basse concentrazioni la bilirubina non coniugata (unconjugated bilirubin, UCB) prodotta dalla degradazione dell’emoglobina, sembra essere un potente anti-ossidante, mentre è estremamente dannosa ad alte concentrazioni, causando encefalopatia nei neonati con severo ittero. Il 70% dei bambini che presentano kernittero muoiono entro sette giorni di vita, mentre il 30% dei sopravvissuti manifesta irreversibili conseguenze come sordità, ritardo mentale e danni cerebrali perman...

  20. Analysis of observed values of glucose, creatinine, bilirubin and ALT examinations in Blood(Serum,Plasma) in hospital population


    Soni, Heratkumar D.; Kapadia, Manisha P.; Modi, Kamal R.; Patel, Shaileshkumar M.; Saxena, Puneet


    Objectives: Find reference range by Hoffman's method and compare it with published reference range in standard textbooks.Method: Observed values (results) of glucose (FBS, RBS and PP2BS), creatinine, bilirubin (total and direct) and ALT were collected from LIS of biochemistry section of New civil hospital surat laboratory services. Data were analysed using computarised hoffman's method as described by Alex K, Claudiu B and David WS2. Reference range derived by computarised hoffman's method we...

  1. The Effects of Field Massage Technique on Bilirubin Level and the Number of Defecations in Preterm Infants

    Directory of Open Access Journals (Sweden)

    Soheila Karbandi


    Full Text Available Background: Hyperbilirubinemia is a common physiological problem in approximately 80% of preterm infants during the first week after birth. Increase in bowel movements reduces enterohepatic circulation and increases bilirubin excretion. Aim: This study aimed to evaluate the effects of Field massage technique on bilirubin level and the number of defecations in preterm infants Method: This clinical trial was performed on 80 preterm infants aged 30-36 weeks, who were hospitalized in neonatal intensive care units of Qaem, Imam Reza, and Ommolbanin hospitals of Mashhad, Iran, in 2011. The enrolled infants were randomized into intervention and control groups. The control group received the routine care, and the intervention group received a 15-minute massage twice a day (morning and evening, for five consecutive days. Field massage technique was applied by the researcher. The number of defecations and cutaneous bilirubin level were recorded on a daily basis until the sixth day after birth. Independent t-test and Mann-Whitney U test were performed to analyze the data, using SPSS version 14. Results: The mean age of the intervention and control groups was 17.2±4.5 and 17.1±4.5 hours, respectively. The mean level of cutaneous bilirubin in the intervention and control groups on the first and sixth days were not significantly different (10.7±1.5, 10.8±1.4, 13.4±2.0, and 13.4±2.6, respectively; the first day: P=0.67, the sixth day: P=0.98. The number of defecations on the fourth (P=0.01, fifth (P

  2. Inverse association between serum total bilirubin levels and diabetic peripheral neuropathy in patients with type 2 diabetes. (United States)

    Kim, Eun Sook; Lee, Sung Won; Mo, Eun Young; Moon, Sung Dae; Han, Je Ho


    Several studies have suggested that bilirubin, a potent innate antioxidant, plays a protective role against cardiovascular and microvascular disease. This study investigated the association between serum concentrations of total bilirubin (TB) and the presence of diabetic peripheral neuropathy (DPN) in Korean diabetic patients. This cross-sectional study involved 1207 patients aged more than 30 years with type 2 diabetes. DPN was assessed according to clinical symptoms and physical examinations using Michigan Neuropathy Screening Instrument examination score, 10-g monofilament sensation, and current perception threshold. The subjects were stratified into gender-specific tertiles based on TB values, and the relationship between the TB values and DPN was analyzed. Compared with patients within the lowest TB tertile, those with higher TB levels consisted of patients with shorter duration of diabetes, lower HbA1c, better renal function, and less autonomic neuropathy, retinopathy, and albuminuria. Serum TB levels were inversely associated with DPN. In multivariate analysis for the development of DPN after adjusting for potential confounding factors including retinopathy, albuminuria, and autonomic neuropathy, the TB levels were inversely associated with the presence of DPN, both as a continuous variable [odds ratio (OR) per log standard deviation (SD) 0.79; 95% confidence interval (CI) 0.65-0.97; P = 0.022] and when categorized in tertiles (the highest vs. the lowest tertile; OR 0.63; 95% CI 0.40-0.99; P = 0.046). Low serum bilirubin levels are significantly associated with DPN, independently of classic risk factors and other microvascular complications. Further investigation is necessary to determine whether serum bilirubin has a prognostic significance on DPN.

  3. Studies on preparing and adsorption property of grafting terpolymer microbeads of PEI-GMA/AM/MBA for bilirubin. (United States)

    Gao, Baojiao; Lei, Haibo; Jiang, Liding; Zhu, Yong


    Crosslinking copolymer microbeads with a diameter range of 100-150 microm were synthesized by suspension copolymerization of glycidyl methacrylate (GMA), acrylamide (AM) and N,N'-methylene bisacrylamide (MBA). Subsequently, polyethyleneimine (PEI) was grafted on the surfaces of the terpolymer microbeads GMA/AM/MBA via the ring-opening reaction of the epoxy groups, and the grafting microbeads PEI-GMA/AM/MBA were prepared. In this paper, the adsorption property of the grafting microbeads for bilirubin was mainly investigated, and the effects of various factors, such as pH value, ionic strength and grafting degree of PEI on the surface of grafting microbeads and the adsorption capacity of the grafting microbeads for bilirubin were examined. The batch adsorption experiment results show that by right of the action of grafted polyamine macromolecules PEI, the grafting microbeads PEI-GMA/AM/MBA have quite strong adsorption ability for bilirubin; the isotherm adsorption conforms to Freundlich equation. The pH value of the medium affects the adsorption capacity greatly, As in the nearly neutral solutions with pH 6, the grafting microbeads have the strongest adsorption ability for bilirubin, whereas in acidic and basic solutions their adsorption ability is weak. The ionic strength hardly affects the adsorption ability of the grafting microbeads. The grafting degree of PEI on the surfaces of the grafting microbeads also has a great effect on the adsorption capacity, and higher the grafting degree of PEI on the surface of the microbead PEI-GMA/AM/MBA, the stronger is the adsorption ability of the microbeads.

  4. Prognostic significance of pretreatment serum levels of albumin, LDH and total bilirubin in patients with non-metastatic breast cancer. (United States)

    Liu, Xiaoan; Meng, Qing H; Ye, Yuanqing; Hildebrandt, Michelle A T; Gu, Jian; Wu, Xifeng


    Liver function tests (LFTs) have been reported as independent predictors of non-liver disease-related morbidity and mortality in general population and cancer patients. In this study, we evaluated the relationship between pretreatment serum LFTs and overall survival (OS) in non-metastatic Caucasian breast cancer patients. Seven LFTs, including albumin, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase (LDH), total bilirubin and total protein, were measured in pretreatment serum from 2425 female Caucasian patients with newly diagnosed, histologically confirmed non-metastatic invasive breast cancer. Multivariate Cox model was used to estimate hazard ratio (HR) and 95% confidence interval (CI) for the association of individual LFTs with 5-year OS while adjusting for age, smoking status, pathological characteristics and treatment regimen. We found that serum albumin, LDH and total bilirubin were significantly associated with 5-year OS in multivariate Cox analyses. Patients with higher albumin level exhibited 45% reduced risk of death (HR = 0.55, 95% CI: 0.40-0.75) compared with those with lower albumin level. Patients with higher total bilirubin level had a nearly 40% reduction in the risk of death (HR = 0.62, 95% CI: 0.45-0.85) and patients with higher LDH levels had a 1.42-fold increased risk of death (HR = 1.42, 95% CI: 1.08-1.88). Furthermore, cumulative analysis showed a significant dose-response trend of significantly increasing risk of death with increasing number of unfavorable LFT levels. Our result highlighted the potential of using pretreatment serum levels of albumin, LDH and total bilirubin as prognostic factors for OS in patients with non-metastatic breast cancer.


    Institute of Scientific and Technical Information of China (English)

    WU Xiao-lin; GU Ming-min; CUI Bing; LI Xi-hua; LU Zhen-yu; WANG Zhu-gang; YUAN Wen-tao; SONG Huai-dong


    Objective To detect the peculiar mutation in a Chinese family with osteogenesis imperfecta,COL1A1 and COL1A2 being analysed. Methods A genome screen was undertaken covering COL1A1 at 17q21-22 and COL1A2 at 7q22.1. The Linkage ( Version 5.1 ) was used for 2-point analysis. DNA sequencing was used to screen and identify the mutation. Results A linkage to the markers on chromosome 17q21-22 was observed. Sequence analysis of COL1A1 revealed a splicing mutation ( IVS8-2A > G) that converted the 3' end of intron 8 from AG to GG. Conclusion This mutation ( IVS 8-2A > G) is novel, and has not yet been registered in the Human Type Ⅰ and Type Ⅲ Collagen Mutations Database.

  6. The antagonistic effect of antipsychotic drugs on a HEK293 cell line stably expressing human alpha(1A1)-adrenoceptors

    DEFF Research Database (Denmark)

    Nourian, Zahra; Mulvany, Michael J; Nielsen, Karsten Bork


    challenged with phenylephrine (EC(50)=1.61x10(-8) M). From Schild analysis, prazosin, sertindole, risperidone, and haloperidol caused a concentration-dependent, rightward shift of the cumulative concentration-response curves for phenylephrine in cells expressing human recombinant alpha(1A1)-adrenoceptors...... human alpha(1A1)-adrenoceptors in competition binding studies confirmed much higher antagonist affinity of sertindole and risperidone than haloperidol for these receptors. In summary, it can be concluded that there is an approximately 10-fold higher adrenoceptor affinity of risperidone and sertindole...... for human alpha(1A1)-adrenoceptors compared to haloperidol. These findings are consistent with the observation that risperidone and sertindole have a higher incidence of orthostatic hypotension than haloperidol....

  7. Research Advances. Image Pinpoints All 5 Million Atoms in Viral Coat; Bilirubin, "Animals-Only" Pigment, Found in Plants; New Evidence Shows Humans Make Salicylic Acid (United States)

    King, Angela G.


    Recent "firsts" in chemical research: image of a viral capsid pinpointing 5 million atoms; isolation and identification of an "animal" pigment, bilirubin, from a plant source; evidence that humans make salicylic acid.

  8. Improvement of enzymatic saccharification yield in Arabidopsis thaliana by ectopic expression of the rice SUB1A-1 transcription factor

    Directory of Open Access Journals (Sweden)

    Lizeth Núñez-López


    Full Text Available Saccharification of polysaccharides releases monosaccharides that can be used by ethanol-producing microorganisms in biofuel production. To improve plant biomass as a raw material for saccharification, factors controlling the accumulation and structure of carbohydrates must be identified. Rice SUB1A-1 is a transcription factor that represses the turnover of starch and postpones energy-consuming growth processes under submergence stress. Arabidopsis was employed to test if heterologous expression of SUB1A-1 or SUB1C-1 (a related gene can be used to improve saccharification. Cellulolytic and amylolytic enzymatic treatments confirmed that SUB1A-1 transgenics had better saccharification yield than wild-type (Col-0, mainly from accumulated starch. This improved saccharification yield was developmentally controlled; when compared to Col-0, young transgenic vegetative plants yielded 200–300% more glucose, adult vegetative plants yielded 40–90% more glucose and plants in reproductive stage had no difference in yield. We measured photosynthetic parameters, starch granule microstructure, and transcript abundance of genes involved in starch degradation (SEX4, GWD1, juvenile transition (SPL3-5 and meristematic identity (FUL, SOC1 but found no differences to Col-0, indicating that starch accumulation may be controlled by down-regulation of CONSTANS and FLOWERING LOCUS T by SUB1A-1 as previously reported. SUB1A-1 transgenics also offered less resistance to deformation than wild-type concomitant to up-regulation of AtEXP2 expansin and BGL2 glucan-1,3,-beta-glucosidase. We conclude that heterologous SUB1A-1 expression can improve saccharification yield and softness, two traits needed in bioethanol production.

  9. Investigation of the potential modulatory effect of biliverdin, carbon monoxide and bilirubin on nitrergic neurotransmission in the pig gastric fundus. (United States)

    Colpaert, Erwin E; Timmermans, Jean-Pierre; Lefebvre, Romain A


    In porcine gastric fundus, we have investigated the colocalization of the bile pigment biosynthetic enzymes heme oxygenase-2 and biliverdin reductase with neuronal nitric oxide synthase (nNOS), the effect of carbon monoxide (CO) on fundic circular smooth muscle and the possible modulatory effect of the bile pigments biliverdin and bilirubin on CO-mediated relaxations and on nitrergic relaxation. Heme oxygenase-2 and biliverdin reductase immunoreactivity was present in all nNOS containing myenteric neurons. CO induced a concentration-dependent relaxation of fundic circular smooth muscle strips, which was completely blocked by the specific guanylate cyclase inhibitor 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one (ODQ). 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1), biliverdin and bilirubin strongly enhanced the amplitude of the CO-induced relaxation. Tin protoporphyrin had no effect on electrically induced nitrergic relaxation, but spectrophotometric analysis learned that incubation of porcine gastric fundus circular muscle strips with tin protoporphyrin did not influence heme oxygenase activity. In conclusion, our data suggest that nitrergic neurons in the pig gastric fundus are able to produce biliverdin and bilirubin, and that these agents potentiate the relaxant effect of CO, which is formed concomitantly with biliverdin by heme oxygenase-2.

  10. Interaction between maternal passive smoking during pregnancy and CYP1A1 and GSTs polymorphisms on spontaneous preterm delivery.

    Directory of Open Access Journals (Sweden)

    Yi-Juan Luo

    Full Text Available OBJECTIVE: The present study aimed to examine the association between maternal passive smoking during pregnancy and the risk of spontaneous PTD and to explore the potential interaction of the single or joint gene polymorphism of CYP1A1 and GSTs with maternal passive smoking on the risk of spontaneous PTD. METHOD: We investigated whether the association between maternal passive smoking and PTD can be modified by 2 metabolic genes, i.e. cytochrome P4501A1 (CYP1A1 and glutathione S-transferases (GSTs, in a case-control study with 198 spontaneous preterm and 524 term deliveries in Shenzhen and Foshan, China. We used logistic regression to test gene-passive smoking interaction, adjusting for maternal socio-demographics and prepregnancy body mass index. RESULTS: Overall, maternal passive smoking during pregnancy was associated with higher risk of PTD (adjusted odds ratio = 2.20 [95% confidence interval: 1.56-3.12]. This association was modified by CYP1A1 and GSTs together, but not by any single genotype. For cross-categories of CYP1A1 Msp I and GSTs, maternal passive smoking was associated with higher risk of PTD among those women with CYP1A1 "TC/CC"+ GSTs "null", but not among women with other genotypes; and this interaction was significant (OR = 2.66 [95% CI: 1.19-5.97]; P-value: 0.017. For cross-categories of CYP1A1 BsrD I and GSTs, maternal passive smoking was associated with higher risk of PTD only among those women with CYP1A1"AG/GG"+ GSTs "null", but not among women with other genotypes; and this interaction was significant (OR = 3.00 [95% CI: 1.17-7.74]; P-value: 0.023. CONCLUSIONS: Our findings suggest that the combined genotypes of CYP1A1 and GSTs can help to identify vulnerable pregnant women who are subject to high risk of spontaneous PTD due to passive smoking.

  11. Human serum albumin-stabilized gold nanoclusters act as an electron transfer bridge supporting specific electrocatalysis of bilirubin useful for biosensing applications. (United States)

    Santhosh, Mallesh; Chinnadayyala, Somasekhar R; Singh, Naveen K; Goswami, Pranab


    Human serum albumin (HSA)-stabilized Au18 nanoclusters (AuNCs) were synthesized and chemically immobilized on an Indium tin oxide (ITO) plate. The assembly process was characterized by advanced electrochemical and spectroscopic techniques. The bare ITO electrode generated three irreversible oxidation peaks, whereas the HSA-AuNC-modified electrode produced a pair of redox peaks for bilirubin at a formal potential of 0.27V (vs. Ag/AgCl). However, the native HSA protein immobilized on the ITO electrode failed to produce any redox peak for bilirubin. The results indicate that the AuNCs present in HSA act as electron transfer bridge between bilirubin and the ITO plate. Docking studies of AuNC with HSA revealed that the best docked structure of the nanocluster is located around the vicinity of the bilirubin binding site, with an orientation that allows specific oxidation. When the HSA-AuNC-modified electrode was employed for the detection of bilirubin using chronoamperometry at 0.3V (vs. Ag/AgCl), a steady-state current response against bilirubin in the range of 0.2μM to 7μM, with a sensitivity of 0.34μAμM(-1) and limit of detection of 86.32nM at S/N 3, was obtained. The bioelectrode was successfully applied to measure the bilirubin content in spiked serum samples. The results indicate the feasibility of using HSA-AuNC as a biorecognition element for the detection of serum bilirubin levels using an electrochemical technique.

  12. Selective and sensitive detection of free bilirubin in blood serum using human serum albumin stabilized gold nanoclusters as fluorometric and colorimetric probe. (United States)

    Santhosh, Mallesh; Chinnadayyala, Somasekhar R; Kakoti, Ankana; Goswami, Pranab


    We report here a fluorescence quenching based non-enzymatic method for sensitive and reliable detection of free bilirubin in blood serum samples using human serum albumin (HSA) stabilized gold nanoclusters (HSA-AuNCs) as fluorescent probe. The fluorescence of the nanoclusters was strongly quenched by bilirubin in a concentration dependent manner by virtue of the inherent specific interaction between bilirubin and HSA. A strong binding constant of 0.55×10(6) L mole(-1) between the HSA-AuNC and bilirubin was discerned. The nano clusters each with size ~1.0 nm (in diameter) and a core of Au18 were homogeneously distributed in HSA molecules as revealed from the respective high resolution transmission electron microscopic and mass spectroscopic studies. The fluorescence quenching phenomena which obeyed a simple static quenching mechanism, was utilized for interference free detection of bilirubin with minimum detection limit (DL) of 248±12 nM (S/N=3). The fluorescence response of HSA-AuNCs against bilirubin was practically unaltered over a wide pH (6-9) and temperature (25-50 °C) range. Additionally, peroxidase-like catalytic activity of these nanoclusters was exploited for colorimetric detection of bilirubin in serum sample with a DL of 200±19 nM by following the decrease in absorbance (at λ440 nm) of the reaction and its rate constant (Kp) of 2.57±0.63 mL μg(-1) min(-1). Both these fluorometric and colorimetric methods have been successfully used for detection of free bilirubin in blood serum samples.



    Reddy, MR; Swathi; Sangamitra; Pratap Rao; Sugunakar; Mohd. Nasir


    INTRODUCTION Hyperbilirubinemia invariably occurs in the newborns and is discerned as clinical jaundice in nearly 50% of infants. It is a cause of concern not only for the parents but also for the paediatricians. Bilirubin production is 2-3 times higher in normal term newborns compared with adults. The colour in jaundice usually results from accumulation of unconjugated, non-polar, lipid soluble, bilirubin pigment in the skin which is formed from haemoglobin by the action of h...

  14. Bilirubin-induced neural impairment: a special focus on myelination, age-related windows of susceptibility and associated co-morbidities. (United States)

    Brites, Dora; Fernandes, Adelaide


    Bilirubin-induced neurologic dysfunction (BIND) and classical kernicterus are clinical manifestations of moderate to severe hyperbilirubinemia whenever bilirubin levels exceed the capacity of the brain defensive mechanisms in preventing its entrance and cytotoxicity. In such circumstances and depending on the associated co-morbidities, bilirubin accumulation may lead to short- or long-term neurodevelopmental disabilities, which may include deficits in auditory, cognitive, and motor processing. Neuronal cell death, astrocytic reactivity, and microglia activation are part of the bilirubin-induced pathogenesis. Less understood is how abnormal growth and maturation of oligodendrocytes may impact on brain development, affecting the formation of myelin tracts. Based on in-vitro and in-vivo models, as well as in clinical cases presented here, we propose the existence of impaired myelination by bilirubin with long-term sequelae, mainly in pre-term infants. Sensitive time-windows are highlighted and centered on the different developmental-dependent impairments determined by bilirubin, and the influence of sepsis and hypoxia is reviewed.

  15. Biliverdin reductase/bilirubin mediates the anti-apoptotic effect of hypoxia in pulmonary arterial smooth muscle cells through ERK1/2 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Song, Shasha [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Wang, Shuang [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Biopharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081 (China); Ma, Jun; Yao, Lan; Xing, Hao; Zhang, Lei; Liao, Lin [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Zhu, Daling, E-mail: [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical, University (Daqing), Daqing 163319 (China); Biopharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081 (China)


    Inhibition of pulmonary arterial smooth muscle cell (PASMC) apoptosis induced by hypoxia plays an important role in pulmonary arterial remodeling leading to aggravate hypoxic pulmonary arterial hypertension. However, the mechanisms of hypoxia acting on PASMC apoptosis remain exclusive. Biliverdin reductase (BVR) has many essential biologic roles in physiological and pathological processes. Nevertheless, it is unclear whether the hypoxia-induced inhibition on PASMC apoptosis is mediated by BVR. In the present work, we found BVR majorly localized in PASMCs and was up-regulated in levels of protein and mRNA by hypoxia. Then we studied the contribution of BVR to anti-apoptotic response of hypoxia in PASMCs. Our results showed that siBVR, blocking generation of bilirubin, reversed the effect of hypoxia on enhancing cell survival and apoptotic protein (Bcl-2, procasepase-9, procasepase-3) expression, preventing nuclear shrinkage, DNA fragmentation and mitochondrial depolarization in starved PASMCs, which were recovered by exogenous bilirubin. Moreover, the inhibitory effect of bilirubin on PASMC apoptosis under hypoxic condition was blocked by the inhibitor of ERK1/2 pathway. Taken together, our data indicate that BVR contributes to the inhibitory process of hypoxia on PASMC apoptosis, which is mediated by bilirubin through ERK1/2 pathway. Highlights: • BVR expresses in PASMC and is up-regulated by hypoxia in protein and mRNA levels. • BVR/bilirubin contribute to the inhibitive process of hypoxia on PASMC apoptosis. • Bilirubin protects PASMC from apoptosis under hypoxia via ERK1/2 pathway.

  16. Flood monitoring and damage assessment in Thailand using multi-temporal HJ-1A/1B and MODIS images (United States)

    Zhou, S. L.; Zhang, W. C.


    Flood is one of the most serious natural disasters in South Asia. How to monitor floods and assess damage caused is the most urgent problem for the government and disaster experts. With the advances of remote sensing, images acquired before the beginning of disaster to the very end or after the disaster from Earth-observing satellites benefit the decision making for reduction and protection of disaster dramatically. By using multi-temporal HJ-1A/1B and MODIS remote sensing data, applicability of different algorithms for flood monitoring and damage assessing was investigated in 2011 Thailand floods. Three different algorithms were adopted to monitor flood disaster events with water indices. Comparisons on the flood disaster monitoring and damage assessing by means of HJ-1A/1B and MODIS images suggested that multi-temporal HJ-1A/1B is much useful for the purpose, which demonstrated with the analysis of the thresholds estimated and problems in data post-processing. The variations of the inundated areas in the process of 2011 Thailand floods revealed were presented in this paper, and the damage caused by flooding was evaluated in three aspects, the population in the inundated region, the inundated information of different provinces and land use areas. Compared with MODIS, HJ-1A/1B images can provide more rapid and accurate flood extent and damage assessment for the disaster prevention, damage mitigation and disaster relief.

  17. Interaction models of CYP1A1, GSTM1 polymorphisms and tobacco smoking in intestinal gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Jing Shen; Run-Tian Wang; Yao-Chu Xu; Li-Wei Wang; Xin-Ru Wang


    AIM: To explore the interaction models of the cytochrome P-450 (CYP) 1A1 Valv ariant and glutathione S-transferase (GST)M1 null polymorphisms with tobacco smoking in the occurrence of intestinal gastric cancer.METHODS: A community-based case-control study was conducted in Yangzhong. Subjects included 114 intestinal types of gastric cancer with endoscopic and pathological diagnosis during January 1997 and December 1998, and 693 controls selected from their spouse, siblings or siblingsin-law who had no history of digestive system cancer.Logistic regression was used to estimate the interaction models.RESULTS: The frequency of the CYP1A1 Val variant allele in cases did not differ from that in controls. The OR of GSTM1 null genotype was 2.0 (95% confidence interval [95%CI]: 1.2-3.1, P<0.01). It showed a significant type 2 form of interaction model when both CYP1A1 Val variant allele and former tobacco smoking existed (i.e., among the multiplicative effects, the disease risk is increased by the tobacco exposure alone but not by the CYP1A1 variant alone). The interaction index γ was 2.8, and OReg (95%CI)was 5.0 (1.9-13.4). GSTM1 null genotype and former tobacco smoking were significant in a type 4 interaction model (i.e.,the disease risk is increased by GSTM1 null genotype or tobacco exposure alone among the multiplicative effects).The interaction index γ and OReg (95%CI) were 3.4 and 8.4 (3.4-20.9), respectively.CONCLUSION: Different interaction models of CYP1A1 Val variant allele and GSTM1 null genotype with tobacco smoking will contribute to understanding carcinogenic mechanism, but there is a need to further investigate in larger scale studies.

  18. Increased CYP1A1 expression in human exfoliated urothelial cells of cigarette smokers compared to non-smokers

    Energy Technology Data Exchange (ETDEWEB)

    Doerrenhaus, Angelika; Roos, Peter H. [Institute for Occupational Physiology at the University Dortmund, Dortmund (Germany); Mueller, Tina [Institute for Occupational Physiology at the University Dortmund, Dortmund (Germany); University Dortmund, Department of Statistics, Mathematical Statistics with Applications in Biometrics, Dortmund (Germany)


    Polycyclic aromatic hydrocarbons, arylamines and nitrosamines, constituents of cigarette smoke, are known inducers of bladder cancer. The biochemical response of the target tissue, the bladder urothelium, following inhalation of cigarette smoke has not been studied so far. We used exfoliated transitional urothelial cells from human urine samples to analyze effects of smoking on induction of the cytochrome P450 enzyme CYP1A1. Samples of 40 subjects, including male and female smokers and non-smokers, were examined. A prerequisite for the immunofluorescence microscopic analysis of the cells was the enrichment of the urothelial cell population. This was achieved by a new method which is based on magnetic cell sorting exploiting specific binding of immobilized Griffonia simplicifolia lectin to the surface of urothelial cells. Immunostaining of the final cell preparation with a monoclonal antibody to CYP1A1 showed that about 6% of the urothelial cells of non-smokers stained positive for CYP1A1. However, this fraction of positive cells was more than 44% of the urothelial cells in samples from cigarette smokers. In spite of the individual variation, the difference was statistically significant. There were no gender-related differences in the portion of CYP1A1 expressing urothelial cells of smokers and non-smokers. In essence, we show for the first time that human urothelial cells respond to cigarette smoking by induction of CYP1A1. The approach opens new fields of mechanistic and biomarker research with respect to the pathogenetic processes of cancer development in the human bladder. (orig.)

  19. Strong Inhibition of Celastrol Towards UDP-Glucuronosyl Transferase (UGT 1A6 and 2B7 Indicating Potential Risk of UGT-Based Herb-Drug Interaction

    Directory of Open Access Journals (Sweden)

    Qi Wang


    Full Text Available Celastrol, a quinone methide triterpene isolated from Tripterygium wilfordii Hook F., has various biochemical and pharmacological activities, and is now being developed as a promising anti-tumor agent. Inhibitory activity of compounds towards UDP-glucuronosyltransferase (UGT is an important cause of clinical drug-drug interactions and herb-drug interactions. The aim of the present study is to investigate the inhibition of celastrol towards two important UDP-glucuronosyltransferase (UGT isoforms UGT1A6 and UGT2B7. Recombinant UGT isoforms and non-specific substrate 4-methylumbelliferone (4-MU were used. The results showed that celastrol strongly inhibited the UGT1A6 and 2B7-mediated 4-MU glucuronidation reaction, with 0.9 ± 0.1% and 1.8 ± 0.2% residual 4-MU glucuronidation activity at 100 μM of celastrol, respectively. Furthermore, inhibition kinetic study (Dixon plot and Lineweaver-Burk plot demonstrated that celastrol noncompetitively inhibited the UGT1A1-mediated 4-MU glucuronidation, and competitively inhibited UGT2B7-catalyzed 4-MU glucuronidation. The inhibition kinetic parameters (Ki were calculated to be 0.49 μM and 0.045 μM for UGT1A6 and UGT2B7, respectively. At the therapeutic concentration of celastrol for anti-tumor utilization, the possibility of celastrol-drug interaction and celastrol-containing herbs-drug interaction were strongly indicated. However, given the complicated nature of herbs, these results should be viewed with more caution.

  20. Heme Degradation by Heme Oxygenase Protects Mitochondria but Induces ER Stress via Formed Bilirubin

    Directory of Open Access Journals (Sweden)

    Andrea Müllebner


    Full Text Available Heme oxygenase (HO, in conjunction with biliverdin reductase, degrades heme to carbon monoxide, ferrous iron and bilirubin (BR; the latter is a potent antioxidant. The induced isoform HO-1 has evoked intense research interest, especially because it manifests anti-inflammatory and anti-apoptotic effects relieving acute cell stress. The mechanisms by which HO mediates the described effects are not completely clear. However, the degradation of heme, a strong pro-oxidant, and the generation of BR are considered to play key roles. The aim of this study was to determine the effects of BR on vital functions of hepatocytes focusing on mitochondria and the endoplasmic reticulum (ER. The affinity of BR to proteins is a known challenge for its exact quantification. We consider two major consequences of this affinity, namely possible analytical errors in the determination of HO activity, and biological effects of BR due to direct interaction with protein function. In order to overcome analytical bias we applied a polynomial correction accounting for the loss of BR due to its adsorption to proteins. To identify potential intracellular targets of BR we used an in vitro approach involving hepatocytes and isolated mitochondria. After verification that the hepatocytes possess HO activity at a similar level as liver tissue by using our improved post-extraction spectroscopic assay, we elucidated the effects of increased HO activity and the formed BR on mitochondrial function and the ER stress response. Our data show that BR may compromise cellular metabolism and proliferation via induction of ER stress. ER and mitochondria respond differently to elevated levels of BR and HO-activity. Mitochondria are susceptible to hemin, but active HO protects them against hemin-induced toxicity. BR at slightly elevated levels induces a stress response at the ER, resulting in a decreased proliferative and metabolic activity of hepatocytes. However, the proteins that are targeted

  1. Spectrofluorimetric quantification of bilirubin using yttrium-norfloxacin complex as a fluorescence probe in serum samples

    Energy Technology Data Exchange (ETDEWEB)

    Kamruzzaman, Mohammad; Alam, Al-Mahmnur [Department of Chemistry, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Hak Lee, Sang, E-mail: [Department of Chemistry, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Ho Kim, Young, E-mail: [Research Institute of Advanced Energy Technology, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Kim, Gyu-Man [School of Mechanical Engineering, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Hyub Oh, Sang [Center for Gas Analysis, Korea Research Institute of Standards and Science, Daejeon 305-600 (Korea, Republic of)


    A simple and sensitive spectrofluorimetric method was developed to determine trace amounts of bilirubin (BR) using yttrium (Y{sup 3+})-norfloxacin (NFLX) complex as a fluorescence (FL) probe. NFLX can form a stable binary complex with Y{sup 3+} and markedly enhances the weak FL signal of the NFLX. The FL intensity of the Y{sup 3+}-NFLX complex decreased significantly in the presence of BR in a buffer solution at pH=7.2. Under optimal conditions, the FL intensity decreased according to the BR concentration and showed a good linear relationship in the range of 0.03-2.3 {mu}g mL{sup -1} of BR with a correlation coefficient of 0.9988. The limit of detection for the determination of BR was 2.8 ng mL{sup -1} with a relative standard deviation (RSD) of 1.55% for five replicate determination of 0.05 {mu}g mL{sup -1} BR. The presented method offers higher sensitivity with simple instrumentation and was applied successfully in detecting BR at low concentrations. Highlights: Black-Right-Pointing-Pointer Weak FL signal of NFLX was enhanced at 419 nm by forming binary complex with Y{sup 3+}. Black-Right-Pointing-Pointer The FL intensity of Y{sup 3+}-NFLX complex was quenched markedly in the presence of ATP. Black-Right-Pointing-Pointer NFLX can transfer energy to Y{sup 3+} and BR and form the Y{sup 3+}-NFLX-ATP ternary complex. Black-Right-Pointing-Pointer The reduced FL intensity of the system was correlated with the concentration of BR. Black-Right-Pointing-Pointer The method is applied to determine BR at low concentration (2.8 ng mL{sup -1}) in serum.

  2. Study on correlation among three kinds of bilirubin detection method%三种胆红素检测方法相关性研究

    Institute of Scientific and Technical Information of China (English)

    李守卫; 姚强


    目的 探讨三种胆红素检测方法的相关性.方法 选取生后7d内目测存在黄疸的住院新生儿50例,抽取血清标本用生化法测定血清总胆红素值,并同步以微量法和经皮法测定胆红素值,分别计算经皮胆红素值(TcB)与静脉血总胆红素值、末梢微量血胆红素值、静脉血总胆红素值之间的相关系数、检验其统计学意义.结果 末梢微量血胆红素检测法、经皮胆红素检测法分别与静脉血生化法均有很好的相关性(r=0.948、0.935,均P<0.01),并且末梢微量血胆红素检测法与静脉血生化法相关性更好.结论 采用微量血测定法检测胆红素值,不失为一种操作简便、结果可靠的方法.%Objective To explore which operation and the accuracy of the detection method is better by exploring the correlation among three bilirubin detection methods.Methods 50 hospitalized neonates within 7 days after birth with visual jaundice were randomly selected.The total serum bilirubin level was measured by the routine laboratory method.At the same time,the serum bilirubin level was measured by bilirubin analyzer for capillary blood and transcutaneous bilirubin(TcB) measurement,then calculated the linear correlation coefficient of TcB level and TSB level,capillary blood bilirubin level and TSB level respectively to analyze their statistical significance,and get the linear regression model at last.Results Close correlation is existed between the capillary blood bilirubin measurement and the routine laboratory method,also the transcutaneous bilirubin measurement and the routine laboratory method.Moreover,the former is better than the later.Conclusion Capillary blood bilirubin is reliable in measuring serum bilirubin level of newborns.

  3. Trans-activation of Col1a1 Promoter by Osterix During Osteocyte Differentiation%转录因子Osterix对成骨细胞Col1a1基因的反式激活作用

    Institute of Scientific and Technical Information of China (English)

    潘秋辉; 马纪; 于永春; 孙奋勇


    Osterix(Osx)是一种具有锌指结构的转录因子,对骨形成十分重要.但到目前为止,直接接受Osterix调控的靶基因尚不清楚.用骨形态发生蛋白2(bone morphogenetic protein 2,BMP2)诱导原代培养小鼠成骨细胞的骨分化,定量RT-PCR检测Ⅰ型胶原蛋白(collagen Ⅰ a 1,Col1a1)与Osx的转录水平.结果发现,二者的转录时相具有相同的变化模式.为了确定二者之间的关系,采用腺病毒表达系统在原代成骨细胞中过表达Osx.数据表明,Osx能够明显上调Col1a1的转录水平.用EMSA(electromobility shift assay)检测这些过表达Osx基因的成骨细胞核抽提物,迁移条带的出现表明,Osx能够直接与Col1a1的启动子相结合.结果提示,在原代培养的成骨细胞中,Osterix通过直接与启动子相结合,调控Col1a1基因的转录.

  4. CYP1A1 MspI基因多态性与乳腺癌关系的Meta分析%Meta-analysis on Genetic Polymorphism of CYP1A1 MspI and the Risk of Breast Cancer

    Institute of Scientific and Technical Information of China (English)

    徐小乐; 靳雅丽; 沈月平


    目的探讨CYP1A1 MspI基因多态性与乳腺癌的关系.方法以乳腺癌组与对照组人群基因型分布的OR值为效应指标,根据一致性检验的结果,选择固定效应模型或随机效应模型对OR进行合并,并进行偏倚评估.结果共查到符合要求的国外文献10篇,病例和对照数分别为3708、5471例.经过异质性检验,10项结果存在异质性(q=17.7898,P=0.037),通过随机效应模型估计,以CYP1A1 MspI野生纯合子为参比组,携带有杂合子或突变纯合子的妇女发生乳腺癌的合并OR为0.95 (95%CI:0.82~1.11).结论 CYP1A1 Msp I基因多态性与乳腺癌易感性无关.

  5. Characterization of the Ala62Pro polymorphic variant of human cytochrome P450 1A1 using recombinant protein expression

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Heon; Kang, Sukmo [College of Veterinary Medicine, BK21plus Program for Creative Veterinary Science Research, and Research Institute for Veterinary Science, Seoul National University, Seoul (Korea, Republic of); Dong, Mi Sook [School of Life Sciences and Biotechnology, Korea University, Seoul (Korea, Republic of); Park, Jung-Duck [College of Medicine, Chung-Ang University, Seoul (Korea, Republic of); Park, Jinseo; Rhee, Sangkee [College of Agriculture of Life Science, Seoul National University, Seoul (Korea, Republic of); Ryu, Doug-Young, E-mail: [College of Veterinary Medicine, BK21plus Program for Creative Veterinary Science Research, and Research Institute for Veterinary Science, Seoul National University, Seoul (Korea, Republic of)


    Cytochrome P450 (CYP) 1A1 is a heme-containing enzyme involved in detoxification of hydrophobic pollutants. Its Ala62Pro variant has been identified previously. Ala62 is located in α-helix A of CYP1A1. Residues such as Pro and Gly are α-helix breakers. In this study, the Ala62Pro variant was characterized using heterologous expression. E. coli expressing the Ala62Pro variant, and the purified variant protein, had lower CYP (i.e. holoenzyme) contents than their wild-type (WT) equivalents. The CYP variant from E. coli and mammalian cells exhibited lower 7-ethoxyresorufin O-dealkylation (EROD) and benzo[a]pyrene hydroxylation activities than the WT. Enhanced supplementation of a heme precursor during E. coli culture did not increase CYP content in E. coli expressing the variant, but did for the WT. As for Ala62Pro, E. coli expressing an Ala62Gly variant had a lower CYP content than the WT counterpart, but substitution of Ala62 with α-helix-compatible residues such as Ser and Val partially recovered the level of CYP produced. Microsomes from mammalian cells expressing Ala62Pro and Ala62Gly variants exhibited lower EROD activities than those expressing the WT or Ala62Val variant. A region harboring α-helix A has interactions with another region containing heme-interacting residues. Site-directed mutagenesis analyses suggest the importance of interactions between the two regions on holoenzyme expression. Together, these findings suggest that the Ala62Pro substitution leads to changes in protein characteristics and function of CYP1A1 via structural disturbance of the region where the residue is located. - Highlights: • Ala62 is located in α-helix A of the carcinogen-metabolizing enzyme CYP1A1. • Pro acts as an α-helix breaker. • A variant protein of CYP1A1, Ala62Pro, had lower heme content than the wild-type. • The variant of CYP1A1 had lower enzyme activities than the wild-type.

  6. Comparison of different methods in detection of neonatal bilirubin%不同方法对新生儿胆红素测定的比较

    Institute of Scientific and Technical Information of China (English)

    符宝铭; 韦蓉; 石明芳; 杨广林; 闫芳; 黄战; 周春浪; 欧珊


    Objective: To explore the differences of neonatal bilirubin detection with different methods, find a good method to monitor the dynamic changes of neonatal bilirubin. Methods; Three methods including automatic biochemical analyzer (biochemical method) , trace bilirubin analyzer (micromethod) and percutaneous bilirubin meter (percutaneous method) were used to detect the bilirubin levels of 90 neonates, then the differences were compared; micromethod and percutaneous method both were used to monitor the bilirubin levels of 392 normal full - term neonates at 1 ~7 days after birth dynamically, then the difference was compared. Results; There was no significant difference in measured value of bilirubin between micromethod and biochemical method ( P > 0. 05 ) ; when the level of bilirubin was less than 200 junol/L and within 201 -300 uJnol/L, there was no significant difference in measured value of bilirubin between percutaneous method and biochemical method (P >0.05); when the level of bilirubin was more than 300 jtmol/L, there was significant difference in measured value of bilirubin between percutaneous method and biochemical method (P < 0. 05) ; there was significant difference in measured value of bilirubin in neonates at 1 -7 days after birth between micromethod and percutaneous method (P <0. 05) . Conclusion; Micromethod is accurate and easy to operate in detection of neonatal bilirubin, which is superior to biochemical method and percutaneous method in dynamic monitoring of neonatal bilirubin.%目的:探讨不同方法对新生儿胆红素测定的差异,以寻找监测新生儿胆红素动态变化的好方法.方法:应用3种测定方法:全自动生化分析仪(生化法)、微量胆红素测定仪(微量法)、经皮测胆仪(经皮法)对90例新生儿进行胆红素测定并比较其差异,用微量法和经皮法同时对392例正常足月新生儿生后1~7天胆红素进行动态监测并比较其差异.结果:微量法胆红素测定值与生

  7. 一成骨不全家系的COL1A1基因突变检测%Mutation Detection of COL1A1 Gene in a Pedigree with Osteogenesis Imperfecta

    Institute of Scientific and Technical Information of China (English)

    秦炜; 何隽祥; 施瑾; 邢清和; 高建军; 钱学庆; 刘壮俊; 舒安利; 贺林


    成骨不全(Osteogenesis imperfecta,OI)是一种由于Ⅰ型胶原形成障碍,导致骨脆性增强为主要症状的常染色体显性遗传性疾病.临床上主要表现为骨质脆弱、蓝巩膜、耳聋和中等程度的关节畸形等症状.成骨不全基因分别定位于17q21.31-q22和7q22.1,其致病基因分别为COL1A1和COL1A2.对一常染色体显性遗传的成骨不全家系进行连锁分析,在COL1A1遗传位点发现紧密连锁(LOD=9.31;θ=.00).突变检测发现在COL1A1基因第26内含子5′端剪接位点处存在一由GT转换为AT的致病突变,该突变引起的异常剪接是导致成骨不全的致病原因之一.%Osteogenesis imperfecta(OI)is heritable bone fragility,which is inherited as an autosomal dominant trait clinical presentation.Clinical symptom,in general,is dominantly inherited OI with blue sclerae,hearing loss and mild-moderate skeletal deformity.Genetic loci of OI have been mapped to17q21.31-q22 and 7q22.1,in which COL1A1 and COL1A2 are known to be the causal genes.In this work,we performed linkage analysis in a kindred with autosomal dominant hereditary OI.A tight linkage to the markers on chromosome 17q21.31-q22 (maximum two-point lod score:9.31 at θ=.00) was observed.Sequence analysis of COL1A1 revealed a single-base mutation that converted the consensus sequence at the 5′end of intron 26 from GT to AT to form an abnormal splicing site leading to OI.

  8. Akt1 is essential for postnatal mammary gland development, function, and the expression of Btn1a1.

    Directory of Open Access Journals (Sweden)

    Jessica LaRocca

    Full Text Available Akt1, a serine-threonine protein kinase member of the PKB/Akt gene family, plays critical roles in the regulation of multiple cellular processes, and has previously been implicated in lactation and breast cancer development. In this study, we utilized Akt1+/+ and Akt1-/- C57/Bl6 female mice to assess the role that Akt1 plays in normal mammary gland postnatal development and function. We examined postnatal morphology at multiple time points, and analyzed gene and protein expression changes that persist into adulthood. Akt1 deficiency resulted in several mammary gland developmental defects, including ductal outgrowth and defective terminal end bud formation. Adult Akt1-/- mammary gland composition remained altered, exhibiting fewer alveolar buds coupled with increased epithelial cell apoptosis. Microarray analysis revealed that Akt1 deficiency altered expression of genes involved in numerous biological processes in the mammary gland, including organismal development, cell death, and tissue morphology. Of particular importance, a significant decrease in expression of Btn1a1, a gene involved in milk lipid secretion, was observed in Akt1-/- mammary glands. Additionally, pseudopregnant Akt1-/- females failed to induce Btn1a1 expression in response to hormonal stimulation compared to their wild-type counterparts. Retroviral-mediated shRNA knockdown of Akt1 and Btn1a1 in MCF-7 human breast epithelial further illustrated the importance of Akt1 in mammary epithelial cell proliferation, as well as in the regulation of Btn1a1 and subsequent expression of ß-casein, a gene that encodes for milk protein. Overall these findings provide mechanistic insight into the role of Akt1 in mammary morphogenesis and function.

  9. Role of CYP1A1 in modulating the vascular and blood pressure benefits of omega-3 polyunsaturated fatty acids. (United States)

    Agbor, Larry N; Wiest, Elani F; Rothe, Michael; Schunck, Wolf-Hagen; Walker, Mary K


    The mechanisms that mediate the cardiovascular protective effects of omega 3 (n-3) polyunsaturated fatty acids (PUFAs) have not been fully elucidated. Cytochrome P450 1A1 efficiently metabolizes n-3 PUFAs to potent vasodilators. Thus, we hypothesized that dietary n-3 PUFAs increase nitric oxide (NO)-dependent blood pressure regulation and vasodilation in a CYP1A1-dependent manner. CYP1A1 wild-type (WT) and knockout (KO) mice were fed an n-3 or n-6 PUFA-enriched diet for 8 weeks and were analyzed for tissue fatty acids and metabolites, NO-dependent blood pressure regulation, NO-dependent vasodilation of acetylcholine (ACh) in mesenteric resistance arterioles, and endothelial NO synthase (eNOS) and phospho-Ser1177-eNOS expression in the aorta. All mice fed the n-3 PUFA diet showed significantly higher levels of n-3 PUFAs and their metabolites, and significantly lower levels of n-6 PUFAs and their metabolites. In addition, KO mice on the n-3 PUFA diet accumulated significantly higher levels of n-3 PUFAs in the aorta and kidney without a parallel increase in the levels of their metabolites. Moreover, KO mice exhibited significantly less NO-dependent regulation of blood pressure on the n-3 PUFA diet and significantly less NO-dependent, ACh-mediated vasodilation in mesenteric arterioles on both diets. Finally, the n-3 PUFA diet significantly increased aortic phospho-Ser1177-eNOS/eNOS ratio in the WT compared with KO mice. These data demonstrate that CYP1A1 contributes to eNOS activation, NO bioavailability, and NO-dependent blood pressure regulation mediated by dietary n-3 PUFAs.

  10. Polymorphisms of GSTM1 and CYP1A1 genes and their genetic susceptibility to prostate cancer in Chinese men

    Institute of Scientific and Technical Information of China (English)


    Background Variation in prostate cancer incidence between different racial groups has been well documented,for which genetic polymorphisms are hypothesized to be an explanation.We evaluated the association between polymorphisms in the cytochrome P-450 CYP1A1(CYP1A1)and glutathione S-transferase M1(GSTM1)genes and genetic susceptibility to prostate cancer in Chinese men.Methods Two hundred and eight prostate cancer patients and 230 age matched controls were enrolled in this study.All DNA samples from peripheral blood lymphocytes were genotyped for common genetic polymorphisms of the CYP1A1 and GSTM1 genes using the oligonucleotide microarray(DNA chip)technique and the polymorphism results confirmed by sequencing.The different polymorphisms in prostate cancer patients were also analyzed according to age at diagnosis,prostate specific antigen level,cancer stage and grade(Gleason score).Results The prevalence of the GSTM1(0/0)genotype was significantly higher in prostate cancer patients(58.2%)than in controls(41.7%,P<0.05).Further analysis demonstrated that the prostate cancer patients with a GSTM1(0/0)genotype were younger than those with the GSTM1(+/+)genotype(P=0.024).No significant differences in the frequency distributions of CYP1A1 polymorphisms were observed between prostate cancer patients and controls.Conclusion GSTM1(0/0)gene polymorphism may be linked to prostate cancer risk and early age of onset in Chinese.

  11. 1,25-Dihydroxyvitamin D3 inhibition of col1a1 promoter expression in calvariae from neonatal transgenic mice (United States)

    Bedalov, A.; Salvatori, R.; Dodig, M.; Kapural, B.; Pavlin, D.; Kream, B. E.; Clark, S. H.; Woody, C. O.; Rowe, D. W.; Lichtler, A. C.


    We studied the effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) on organ cultures of transgenic mouse calvariae containing segments of the Col1a1 promoter extending to -3518, -2297, -1997, -1794, -1763, and -1719 bp upstream of the transcription start site fused to the chloramphenicol acetyltransferase (CAT) reporter gene. 1,25(OH)2D3 had a dose-dependent inhibitory effect on the expression of the -3518 bp promoter construct (ColCAT3.6), with maximal inhibition of about 50% at 10 nM. This level of inhibition was consistent with the previously observed effect on the endogenous Col1a1 gene in bone cell models. All of the shorter constructs were also inhibited by 10 nM 1,25(OH)2D3, suggesting that the sequences required for 1, 25(OH)2D3 inhibition are downstream of -1719 bp. The inhibitory effect of 1,25(OH)2D3 on transgene mRNA was maintained in the presence of the protein synthesis inhibitor cycloheximide, suggesting that the inhibitory effect on Col1a1 gene transcription does not require de novo protein synthesis. We also examined the in vivo effect of 1,25(OH)2D3 treatment of transgenic mice on ColCAT activity, and found that 48 h treatment caused a dose-dependent inhibition of CAT activity in calvariae comparable to that observed in organ cultures. In conclusion, we demonstrated that 1,25(OH)2D3 inhibits Col1A1 promoter activity in transgenic mouse calvariae, both in vivo and in vitro. The results indicate that there is a 1, 25(OH)2D3 responsive element downstream of -1719 bp. The inhibitory effect does not require new protein synthesis.

  12. Family-Based Association Testing of OCD-associated SNPs of SLC1A1 in an autism sample. (United States)

    Brune, Camille W; Kim, Soo-Jeong; Hanna, Gregory L; Courchesne, Eric; Lord, Catherine; Leventhal, Bennett L; Cook, Edwin H


    Reports identified the neuronal glutamate transporter gene, SLC1A1 (OMIM 133550, chromosome 9p24), as a positional and functional candidate gene for obsessive-compulsive disorder (OCD). The presence of obsessions and compulsions similar to OCD in autism, the identification of this region in a genome-wide linkage analysis of individuals with autism spectrum disorders (ASDs), and the hypothesized role of glutamate in ASDs make SLC1A1 a candidate gene for ASD as well. To test for association between SLC1A1 and autism, we typed three single nucleotide polymorphisms (SNPs, rs301430, rs301979, rs301434) previously associated with OCD in 86 strictly defined trios with autism. Family-Based Association Tests (FBAT) with additive and recessive models were used to check for association. Additionally, an rs301430-rs301979 haplotype identified for OCD was investigated. FBAT revealed nominally significant association between autism and one SNP under a recessive model. The G allele of rs301979 was undertransmitted (equivalent to overtransmission of the C allele under a dominant model) to individuals with autism (Z=-2.47, P=0.01). The G allele was also undertransmitted in the T-G haplotype under the recessive model (Z=-2.41, P=0.02). Both findings were also observed in the male-only sample. However, they did not withstand correction for multiple comparisons.

  13. Polymorphic variation of CYP1A1 and CYP1B1 genes in a Haryana population. (United States)

    Giri, Shiv Kumar; Yadav, Anita; Kumar, Anil; Dev, Kapil; Gulati, Sachin; Gupta, Ranjan; Aggarwal, Neeraj; Gautam, Sanjeev Kumar


    Cytochrome P450 (CYP) 1A1 and CYP1B1 are important phase I xenobiotic metabolizing enzymes involved in the metabolism of numbers of toxins, endogenous hormones, and pharmaceutical drugs. Polymorphisms in these phase I genes can alter enzyme activity and are known to be associated with cancer susceptibility related to environmental toxins and hormone exposure. Their genotypes may also display ethnicity-dependent population frequencies. The present study was aimed to determine the frequencies of commonly known functional polymorphisms of CYP1A1 and CYP1B1 genes in a Haryana state population of North India. The allelic frequency of CYP1A1 polymorphism m1 (MspI) was 29.65% and m2 (Ile(462)Val) was 24.85%. The frequency of CYP1B1 polymorphism m1 (Val(432)Leu) was 45.85% and m2 (Asn(453)Ser) was 16.2%. We observed inter- and intra-ethnic variation in the frequency distribution of these polymorphisms. Analysis of polymorphisms in these genes might help in predicting the risk of cancer. Our results emphasize the need for more such studies in high-risk populations.

  14. Deficient expression of aldehyde dehydrogenase 1A1 is consistent with increased sensitivity of Gorlin syndrome patients to radiation carcinogenesis. (United States)

    Wright, Aaron T; Magnaldo, Thierry; Sontag, Ryan L; Anderson, Lindsey N; Sadler, Natalie C; Piehowski, Paul D; Gache, Yannick; Weber, Thomas J


    Human phenotypes that are highly susceptible to radiation carcinogenesis have been identified. Sensitive phenotypes often display robust regulation of molecular features that modify biological response, which can facilitate identification of the pathways/networks that contribute to pathophysiological outcomes. Here we interrogate primary dermal fibroblasts isolated from Gorlin syndrome patients (GDFs), who display a pronounced inducible tumorigenic response to radiation, in comparison to normal human dermal fibroblasts (NHDFs). Our approach exploits newly developed thiol reactive probes to define changes in protein thiol profiles in live cell studies, which minimizes artifacts associated with cell lysis. Redox probes revealed deficient expression of an apparent 55 kDa protein thiol in GDFs from independent Gorlin syndrome patients, compared with NHDFs. Proteomics tentatively identified this protein as aldehyde dehydrogenase 1A1 (ALDH1A1), a key enzyme regulating retinoic acid synthesis, and ALDH1A1 protein deficiency in GDFs was confirmed by Western blot. A number of additional protein thiol differences in GDFs were identified, including radiation responsive annexin family members and lamin A/C. Collectively, candidates identified in our study have plausible implications for radiation health effects and cancer susceptibility.

  15. Screening and analysis of a new mutation of COL1A1 gene in a family with osteogenesis imperfecta%一个成骨不全家系COL1A1基因的突变筛查

    Institute of Scientific and Technical Information of China (English)

    白雪; 李克秋; 任秀智; 何晓波; 王毅; 官士珍; 景亚青; 李光


    Objective To investigate mutation of COL1A1 gene and analyze the relationship between genotype and clinical phenotype in a family with osteogenesis imperfecta (OI).Methods The family history of an OI pedigree,along with clinical data,was collected.Blood samples from the proband and his families,as well as 50 normal controls,were collected.Mutation of COL1A1 gene was screened using PCR-high resolution melting (PCR-HRM) and validated by sequencing.Results PCR-HRM method showed an abnormal result in proband COL1A1 33_34 exons,which Tm was 87.7℃,in contrast to the normal control (wt) Tm of 87.9 ℃ ± 0.06℃.There was a significant difference between the proband and the normal control with the standardization curve and the difference curves.DNA sequencing showed that COL1A1 gene exons 33_34 has lost a C base (c.2321delC),which resulted in a frameshift mutation and caused an premature termination codon (UAA) at amino acid 334,i.e.,p.Pro774LeufsX334.The father and grandfather of the proband,both suffered from OI,were verified to be heterozygous for the same mutation.The same mutation was not found in 50 normal controls.Database search confirmed this to be a novel mutation.Pedigree analysis suggested that it has an autosomal dominant inheritance.The proband and patients from the family were clinically diagnosed as OI type Ⅰ.Conclusion The study has identified a novel mutation of COL1A1 gene,c.2321delC.This frameshift mutation has caused a premature stop codon and reduced collagen type Ⅰ synthesis,characterized by a lighter OI clinical phenotype.%目的 筛查1个成骨不全(osteogenesis imperfecta,OI)家系中COL1A1基因的突变,并分析基因型与临床表型的关系.方法 收集先证者及家系成员临床资料,采集先证者、随诊家属及50名正常对照的外周血标本,应用PCR-高分辨率熔解曲线(high resolution melting,HRM)分析筛查COL1A1基因突变,基因测序确定突变位点.结果 PCR-HRM分析显示,先证者COL1A1

  16. Hop (Humulus lupulus L.) Extract and 6-Prenylnaringenin Induce P450 1A1 Catalyzed Estrogen 2-Hydroxylation (United States)


    Humulus lupulus L. (hops) is a popular botanical dietary supplement used by women as a sleep aid and for postmenopausal symptom relief. In addition to its efficacy for menopausal symptoms, hops can also modulate the chemical estrogen carcinogenesis pathway and potentially protect women from breast cancer. In the present study, an enriched hop extract and the key bioactive compounds [6-prenylnarigenin (6-PN), 8-prenylnarigenin (8-PN), isoxanthohumol (IX), and xanthohumol (XH)] were tested for their effects on estrogen metabolism in breast cells (MCF-10A and MCF-7). The methoxyestrones (2-/4-MeOE1) were analyzed as biomarkers for the nontoxic P450 1A1 catalyzed 2-hydroxylation and the genotoxic P450 1B1 catalyzed 4-hydroxylation pathways, respectively. The results indicated that the hop extract and 6-PN preferentially induced the 2-hydroxylation pathway in both cell lines. 8-PN only showed slight up-regulation of metabolism in MCF-7 cells, whereas IX and XH did not have significant effects in either cell line. To further explore the influence of hops and its bioactive marker compounds on P450 1A1/1B1, mRNA expression and ethoxyresorufin O-dealkylase (EROD) activity were measured. The results correlated with the metabolism data and showed that hop extract and 6-PN preferentially enhanced P450 1A1 mRNA expression and increased P450 1A1/1B1 activity. The aryl hydrocarbon receptor (AhR) activation by the isolated compounds was tested using xenobiotic response element (XRE) luciferase construct transfected cells. 6-PN was found to be an AhR agonist that significantly induced XRE activation and inhibited 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced XRE activity. 6-PN mediated induction of EROD activity was also inhibited by the AhR antagonist CH223191. These data show that the hop extract and 6-PN preferentially enhance the nontoxic estrogen 2-hydroxylation pathway through AhR mediated up-regulation of P450 1A1, which further emphasizes the importance of

  17. Relationship between polymorphisms of CYP1A1, CYP1B1 genes and susceptibility to recurrent abortion%CYP1A1和CYP1B1基因多态性与RPL易感性

    Institute of Scientific and Technical Information of China (English)

    朱壮彦; 赵富玺; 富晓敏; 穆雅琴; 畅学艳


    Objective To investigate the relationship between polymorphisms of CYP1A1 and CYP lBlgenes and the susceptibility to recurrent pregnancy loss(RPL). Methods The Mspl polymorphism of CYP1A1 and the polymorphism in exon 3 codon 432(C-G of CYP1B1) were detected with the methods of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and allele specific-PCR (AS-PCR) in a case-control study including 81 cases of RPL and 98 healthy controls. Results There was no significant correlation between Mspl polymorphism and RPL susceptibility (x2 =0. 335 ,P =0. 846). There were significant differences in the genotype distributions or allele frequencies of CYP1B1 L432V polymorphism between the two groups (x2 = 7. 467 , P = 0. 024;x2 = 9. 129, P = 0. 003). Compared with wild-type C/C,the susceptibility of recurrent abortion with the genotypes of homozygotic mutation G/G and heterozygotic mutation C/G were increased by 2. 620 and 1. 954 times,respectively. Compared with allele C,the risk of recurrent abortion with allele G was increased by 2. 038. Conclusion The gene polymorphism of CYP1B1 in exon 3 condon 432 (C-G) might be a genetic risk factor of RPL and the allelic polymorphism of CYP1B1 L432V increases the risk of recurrent abortion. The results do not show that polymorphism of Mspl is associated with the susceptibility of RPL.%目的 探讨CYP1A1、CYP1B1基因多态性与复发性流产(RPL)遗传易感性关系,为预防和治疗该病提供新靶点.方法 本研究采用等位基因特异性PCR (As-PCR)和聚合酶链反应-限制性片断长度多态性(PCRRFLP)方法,针对CYP1A1基因MspI酶切位点和CYP1B1 L432V多态位点,检测81例患有原因不明RPL病例组和98名有生育史健康女性对照组之间差异.结果 RPL组和对照组CYP1A1 MspI位点3种基因型m1/m1、m1/m2、m2/m2分布频率差异无统计学意义(x2=0.335,P>0.05);CYP1B1 L432V多态位点3种基因型C/C、C/G、G/G在病例组和对照组分

  18. Inhibition of cholesterol crystallization under bilirubin deconjugation: partial characterization of mechanisms whereby infected bile accelerates pigment stone formation. (United States)

    Nakai, Kuniharu; Tazuma, Susumu; Nishioka, Tomoji; Chayama, Kazuaki


    Pigment gallstones have been reported to be closely associated with biliary tract infection. We previously reported that addition of unconjugated bilirubin (UCB), which is deconjugated by beta-glucuronidase in infected bile, could enhance cholesterol crystal formation in supersaturated model bile (MB). The present study evaluated the effect of beta-glucuronidase on the processes of pigment gallstone formation and cholesterol crystallization. Supersaturated MB (taurocholate/lecithin/cholesterol at 71:18:11, a total lipid concentration of 10.0 g/dl and a cholesterol saturation index (CSI) of 2.0) and native rat bile were mixed at a ratio of 3:1. Then, mixed bile was incubated with or without beta-glucuronidase and changes of the following parameters were investigated over time: (1) the UCB/total bilirubin ratio; (2) cholesterol crystal formation; (3) the precipitate weight and the cholesterol concentration in the precipitate and supernatant; and (4) the lipid distribution of vesicles in the supernatant. Compared with beta-glucuronidase-free bile, (1) beta-glucuronidase-containing bile showed a significant increase of the UCB/total bilirubin ratio, (2) as well as a significantly longer nucleation time (96+/-17.0 vs. 114+/-20.0) and fewer cholesterol crystals. (3) The precipitate weight and the cholesterol concentration in the precipitate were significantly increased, while the cholesterol concentration in supernatant was decreased. (4) When mixed bile was incubated with beta-glucuronidase, the cholesterol concentration in the vesicles was lower than in bile without beta-glucuronidase. The precipitate weight and the cholesterol concentration in the precipitate was increased by incubation with beta-glucuronidase, while cholesterol concentration was decreased in the supernatant (especially in the vesicles). This means that bile vesicles were more stable and it was more difficult for cholesterol crystals to form. Thus, the presence of beta-glucuronidase may inhibit the

  19. Crossed beam reaction of the cyano radical, CN(X 2Σ+), with methylacetylene, CH3CCH (X 1A1): Observation of cyanopropyne, CH3CCCN (X 1A1), and cyanoallene, H2CCCHCN (X 1A') (United States)

    Huang, L. C. L.; Balucani, N.; Lee, Y. T.; Kaiser, R. I.; Osamura, Y.


    The chemical dynamics to form cyanopropyne, CH3CCCN (X 1A1), and cyanoallene, H2CCCHCN (X 1A'), via the neutral-neutral reaction of the cyano radical, CN (X 2Σ+), with methylacetylene, CH3CCH (X 1A1), is investigated under single collision conditions in a crossed molecular beam experiment at a collision energy of 24.7 kJ mol-1. The laboratory angular distribution and time-of-flight spectra of the C4H3N products are recorded at m/e=65, 64, 63, and 62. The reaction of d3-methylacetylene, CD3CCH (X 1A1), with CN radicals yields reactive scattering signal at m/e=68 and m/e=67 demonstrating that two distinct H(D) atom loss channels are open. Forward-convolution fitting of the laboratory data reveal that the reaction dynamics are indirect and governed by an initial attack of the CN radical to the π electron density of the β carbon atom of the methylacetylene molecule to form a long lived CH3CCHCN collision complex. The latter decomposes via two channels, i.e., H atom loss from the CH3 group to yield cyanoallene, and H atom loss from the acetylenic carbon atom to form cyanopropyne. The explicit identification of the CN vs H exchange channel and two distinct product isomers cyanoallene and cyanopropyne strongly suggests the title reaction as a potential route to form these isomers in dark molecular clouds, the outflow of dying carbon stars, hot molecular cores, as well as the atmosphere of hydrocarbon rich planets and satellites such as the Saturnian moon Titan.

  20. 关于胆红素升高的实验室检测与临床%Detection of bilirubin: from laboratory to clinical practice

    Institute of Scientific and Technical Information of China (English)



    Jaundice (abnormal elevation of bilirubin) is common in clinical practice.At present bilirubin is detected by measuring total bilirubin (TB) and direct bilirubin (DB) in hospital.Indirect bilirubin (IB) is the difference of TB and DB.Direct bilirubin reflects mainly the conjugated bilirubin but they are not all equivalent.Indirect bilirubin and unconjugated bilirubin are the same condition.In clinical practice,the proportion of DB (or IB) in TB is more significant than their level of elevation.The cause of jaundice could be roughly determined by analyzing the proportion of DB (or IB) in TB.The methodology and quality of bilirubin detection are quite different in hospitals in our country.The proportion of DB aud IB in TB in detection of bilirubin is also quite different in hospitals.It leads to a big puzzle to the diagnosis and differential diagnosis of jaundice for clinical doctors.It is suggested that the quality control of bilirubin detection should be strengthened in laboratory in hospital.On the bases of strict quality control of bilirubin detection,proper adjustment of the proportion of DB and IB as to make it consistiug with clinical practice and pathogenesis of diseases,and making the proportion stable for long time are also suggested.%黄疸即胆红素异常升高在临床上很常见.目前医院检测胆红素通常测定血中的总胆红素和直接胆红素,而以总胆红素减去直接胆红素得到间接胆红素的数值.直接胆红素主要反映结合胆红素,但二者并不完全等同.与此类似,间接胆红素主要反映非结合胆红素.在临床上,对黄疸的诊断和鉴别诊断,直接胆红素(或间接胆红素)占总胆红素的比例较之胆红素升高的幅度更有意义.通过分析直接或间接胆红素的比例,往往可以对黄疸的原因做出大致的诊断和鉴别诊断.但目前各家医院检测胆红素的方法和水平差别较大,不同疾病状态下所测出的直接或间接胆红素的比


    Directory of Open Access Journals (Sweden)



    Full Text Available INTRODUCTION Hyperbilirubinemia invariably occurs in the newborns and is discerned as clinical jaundice in nearly 50% of infants. It is a cause of concern not only for the parents but also for the paediatricians. Bilirubin production is 2-3 times higher in normal term newborns compared with adults. The colour in jaundice usually results from accumulation of unconjugated, non-polar, lipid soluble, bilirubin pigment in the skin which is formed from haemoglobin by the action of heme oxygenase, biliverdin reductase and non-enzymatic reducing agents in the reticulo-endothelial cells. AIMS & OBJECTIVE To determine hour specific serum bilirubin (22-26 hrs which will predict, subsequent significant hyperbilirubinemia in healthy term newborns. MATERIALS & METHODS A total of 250 healthy full term newborns were enrolled into the study. First bilirubin estimation (TSB 1 was estimated at 22- 26 hrs. The neonates were followed up clinically every 12 hrs for 72 hrs (till discharge. Second bilirubin estimation (TSB S was done whenever clinical suspicion of jaundice was present (usually at 72 hours. Depending upon the TSB 1 value, the infants were evaluated by using two available protocols (Arbitrary cut off value of 5 mg/dl and average value of 4.06 mg%. Sensitivity, specificity, negative and positive predictive values and likelihood ratio of the test were calculated. P-value was used to determine the level of significance. RESULTS Of 250 neonates included in the study, 13 neonates developed hyperbilirubinemia and were subjected to phototherapy. No infants with average bilirubin value of ≤4.06 mg% developed subsequent hyperbilirubinemia. However, 2 infants with arbitrary cut off value of ≤5 mg/dl developed hyperbilirubinemia. There was significant difference in TSB I value of neonates who subsequently did and those who did not developed significant hyperbilirubinemia (P-value-<0.01. The negative predictive value to these two applied protocol is very high

  2. Evaluating the role of indirect bilirubin, urobilinogen and Shine AND Lal index as an alternative screening tool for beta thalassemia minor

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    Ridham A. Khanderia


    Methods: The present study was conducted on 100 (n=100 subjects in blood bank, department of pathology, government medical college Rajkot, Gujarat, India. In first group 50 subjects (Thalassemia minor were selected while in second group 50 (n2=50 normal individuals from hospital staff were selected. Complete-haemogram, serum-direct, indirect and total bilirubin, urine urobilinogen and their sensitivity and specificity were calculated. Results: Of the 50 cases in test group, 41 had higher Indirect Bilirubin level (>0.7 mg/dl, 35 had high urobilinogen level (>1 mg/dl. In control group out of 50 cases, 3 had high indirect bilirubin levels, 4 had high urobilinogen levels. Indirect-bilirubin had sensitivity of 82%, specificity of 94%. Urobilinogen showed sensitivity of 70% and specificity of 92%. Conclusion: Indirect bilirubin and urine-urobilinogen is a valuable, cost-effective screening test for beta-thalassemia-trait with sensitivity and specificity comparable to RBC indices. [Int J Res Med Sci 2015; 3(3.000: 730-737

  3. Bilirubin isomer distribution in jaundiced neonates during phototherapy with LED light centered at 497 nm (turquoise) vs. 459 nm (blue)

    DEFF Research Database (Denmark)

    Ebbesen, Finn; Madsen, Poul H; Vandborg, Pernille K;


    of jaundiced neonates after 24 h of therapy with narrow-band (LED) light centered at 497 nm (turquoise) vs. 459 nm (blue), of essentially equal irradiance. MATERIALS: Eighty-three neonates (≥33 wk gestational age) with uncomplicated hyperbilirubinemia were included in the study. Forty neonates were exposed...... to light centered at 497 nm and 43 infants with light centered at 459 nm. Irradiances were 5.2 × 10(15) and 5.1 × 10(15) photons/cm(2)/s, respectively. RESULTS: After 24 h of treatment no significant differences in serum concentrations of total bilirubin isomers and Z,Z-bilirubin were observed between...... the 2 groups. Interestingly, concentrations of Z,E-bilirubin, and thus also total bilirubin isomers formed during therapy, were highest for infants receiving light centered at 459 nm, while the concentration of E,Z-bilirubin was highest for those receiving light centered at 497 nm. No significant...

  4. CYP1A1, GSTM1, GSTT1 and TP53 Polymorphisms and Risk of Gallbladder Cancer in Bolivians. (United States)

    Sakai, Kazuaki; Loza, Ernesto; Roig, Guido Villa-Gomez; Nozaki, Ryoko; Asai, Takao; Ikoma, Toshikazu; Tsuchiya, Yasuo; Kiyohara, Chikako; Yamamoto, Masaharu; Nakamura, Kazutoshi


    The Plurinational State of Bolivia (Bolivia) has a high incidence rate of gallbladder cancer (GBC). However, the genetic and environmental risk factors for GBC development are not well understood. We aimed to assess whether or not cytochrome P450 (CYP1A1), glutathione S-transferase mu 1 (GSTM1), theta 1 (GSTT1) and tumor suppressor protein p53 (TP53) genetic polymorphisms modulate GBC susceptibility in Bolivians. This case-control study covered 32 patients with GBC and 86 healthy subjects. GBC was diagnosed on the basis of histological analysis of tissues at the Instituto de Gastroenterologia Boliviano-Japones (IGBJ); the healthy subjects were members of the staff at the IGBJ. Distributions of the CYP1A1 rs1048943 and TP53 rs1042522 polymorphisms were assayed using PCR-restriction fragment length polymorphism assay. GSTM1 and GSTT1 deletion polymorphisms were detected by a multiplex PCR assay. The frequency of the GSTM1 null genotype was significantly higher in GBC patients than in the healthy subjects (odds ratio [OR], 2.35; 95% confidence interval [CI], 1.03-5.37; age-adjusted OR, 3.53; 95% CI, 1.29-9.66; age- and sex-adjusted OR, 3.40; 95% CI, 1.24-9.34). No significant differences were observed in the frequencies of CYP1A1, GSTT1, or TP53 polymorphisms between the two groups. The GSTM1 null genotype was associated with increased GBC risk in Bolivians. Additional studies with larger control and case populations are warranted to confirm the association between the GSTM1 deletion polymorphism and GBC risk suggested in the present study.

  5. Transcriptional repression of the Dspp gene leads to dentinogenesis imperfecta phenotype in Col1a1-Trps1 transgenic mice. (United States)

    Napierala, Dobrawa; Sun, Yao; Maciejewska, Izabela; Bertin, Terry K; Dawson, Brian; D'Souza, Rena; Qin, Chunlin; Lee, Brendan


    Dentinogenesis imperfecta (DGI) is a hereditary defect of dentin, a calcified tissue that is the most abundant component of teeth. Most commonly, DGI is manifested as a part of osteogenesis imperfecta (OI) or the phenotype is restricted to dental findings only. In the latter case, DGI is caused by mutations in the DSPP gene, which codes for dentin sialoprotein (DSP) and dentin phosphoprotein (DPP). Although these two proteins together constitute the majority of noncollagenous proteins of the dentin, little is known about their transcriptional regulation. Here we demonstrate that mice overexpressing the Trps1 transcription factor (Col1a1-Trps1 mice) in dentin-producing cells, odontoblasts, present with severe defects of dentin formation that resemble DGI. Combined micro-computed tomography (µCT) and histological analyses revealed tooth fragility due to severe hypomineralization of dentin and a diminished dentin layer with irregular mineralization in Col1a1-Trps1 mice. Biochemical analyses of noncollagenous dentin matrix proteins demonstrated decreased levels of both DSP and DPP proteins in Col1a1-Trps1 mice. On the molecular level, we demonstrated that sustained high levels of Trps1 in odontoblasts lead to dramatic decrease of Dspp expression as a result of direct inhibition of the Dspp promoter by Trps1. During tooth development Trps1 is highly expressed in preodontoblasts, but in mature odontoblasts secreting matrix its expression significantly decreases, which suggests a Trps1 role in odontoblast development. In these studies we identified Trps1 as a potent inhibitor of Dspp expression and the subsequent mineralization of dentin. Thus, we provide novel insights into mechanisms of transcriptional dysregulation that leads to DGI.

  6. ALDH1A1 mRNA expression in association with prognosis of triple-negative breast cancer. (United States)

    Liu, Yan; Baglia, Michelle; Zheng, Ying; Blot, William; Bao, Ping-Ping; Cai, Hui; Nechuta, Sarah; Zheng, Wei; Cai, Qiuyin; Shu, Xiao Ou


    ALDH1 is a crucial element in the retinoic acid signaling pathway regulating the self-renewal and differentiation of normal stem cells, and may play an important role in cancer progression. However, research on ALDH1 gene expression and breast cancer prognosis has yielded conflicting results. We evaluated the association between tumor tissue ALDH1A1/ALDH1A3 mRNA expression and triple-negative breast cancer (TNBC) prognosis in the Shanghai Breast Cancer Survival Study (SBCSS, N=463), Nashville Breast Health Study (NBHS, N=86), and Southern Community Cohort Study (SCCS, N=47). Gene expression was measured in RNA isolated from breast cancer tissues. In the SBCSS, higher ALDH1A1 mRNA level was associated with improved disease-free (HR=0.87, 95% CI: 0.80-0.95, per log unit change) and overall survival (HR=0.85, 95% CI: 0.78-0.93 per log unit change) independent of age at diagnosis, TNM stage and treatment. We replicated the findings for overall survival in the NBHS and SCCS (HR = 0.27, 95% CI: 0.10-0.73) and for disease-free survival by a meta-analysis of four publicly-available gene expression datasets (HR = 0.86, 95% CI: 0.76-0.97). No significant association was found for ALDH1A3.Our study suggests high expression of ALDH1A1 mRNA in tumor tissues may be an independent predictor of a favorable TNBC outcome.

  7. The role of genes AMPD1, CNB and COL1A1 in the propensity to employment rowing.

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    Kozyrev A.V.


    Full Text Available The question of the frequency distribution of polymorphic alleles of genes AMPD1, CNB and COL1A1. In the experiment, was attended by athletes, rowers qualifications at the age of 21 to 28 years, and people without experience of regular sport at the age of 20 to 22 years. Established that certain combinations of alleles can be recommended as a diagnostic complex genetic markers to assess the propensity to develop and display of strength, endurance and speed. It is shown that upon receipt of positive results may conduct a successful selection in rowing, the implementation of the individualization of the training process and improve its efficiency.

  8. UGT1A1 gene polymorphism: Impact on toxicity and efficacy of irinotecan-based regimens in metastatic colorectal cancer

    Institute of Scientific and Technical Information of China (English)

    Christoph Schulz; Volker Heinemann; Andreas Schalhorn; Nikolas Moosmann; Thomas Zwingers; Stefan Boeck; Clemens Giessen; Hans-Joachim Stemmler


    AIM: To investigate the correlation between uridine diphosphate glucuronosyl transferase 1A1 ( UGT1A1) gene polymorphisms and irinotecan-associated side effects and parameters of drug efficacy in patients with metastatic colorectal cancer (mCRC) receiving a lowdose weekly irinotecan chemotherapeutic regimen.METHODS: Genotypes were retrospectively evaluated by gene scan analysis on the ABI 310 sequencer of the TATAA box in the promoter region of the UGT1A1 gene in blood samples from 105 patients who had received 1st line irinotecan-based chemotherapy for mCRC.RESULTS: The distribution of the genotypes was as follows: wild type genotype (WT) ( 6/6) 39.0%,heterozygous genotype ( 6/7) 49.5%, and homozygous genotype ( 7/7) 9.5%. The overall response rate (OR) was similar between patients carrying the ( 6/7, 7/7) or the WT genotype ( 6/6) (44.3% vs 43.2%, P = 0.75).Neither time to progression [(TTP) 8.1 vs 8.2 mo, P = 0.97] nor overall survival [(OS) 21.2 vs 18.9 mo, P = 0.73] differed significantly in patients who carried the ( 6/6) when compared to the ( 6/7, 7/7) genotype. No significant differences in toxicity were observed: Grade 3 and 4 delayed diarrhoea [( 6/7, 7/7) vs ( 6/6); 13.0% vs 6.2%, P =0.08], treatment delays [( 6/7, 7/7) vs ( 6/6); 25.1% vs 19.3%, P = 0.24] or dose reductions [( 6/7, 7/7) vs ( 6/6); 21.5% vs 27.2%, P = 0.07].CONCLUSION: This analysis demonstrates the nonsignificant influence of the UGT1A1 gene polymorphism on efficacy and rate of irinotecan-associated toxicity in mCRC patients receiving low-dose irinotecan based chemotherapy.

  9. Crossed beam reaction of cyano radicals with hydrocarbon molecules. I. Chemical dynamics of cyanobenzene (C6H5CN; X 1A1) and perdeutero cyanobenzene (C6D5CN; X 1A1) formation from reaction of CN(X 2Σ+) with benzene C6H6(X 1A1g), and d6-benzene C6D6(X 1A1g) (United States)

    Balucani, N.; Asvany, O.; Chang, A. H. H.; Lin, S. H.; Lee, Y. T.; Kaiser, R. I.; Bettinger, H. F.; Schleyer, P. v. R.; Schaefer, H. F.


    The chemical reaction dynamics to form cyanobenzene C6H5CN(X 1A1), and perdeutero cyanobenzene C6D5CN(X 1A1) via the neutral-neutral reaction of the cyano radical CN(X 2Σ+), with benzene C6H6(X 1A1g) and perdeutero benzene C6D6(X 1A1g), were investigated in crossed molecular beam experiments at collision energies between 19.5 and 34.4 kJ mol-1. The laboratory angular distributions and time-of-flight spectra of the products were recorded at mass to charge ratios m/e=103-98 and 108-98, respectively. Forward-convolution fitting of our experimental data together with electronic structure calculations (B3LYP/6-311+G**) indicate that the reaction is without entrance barrier and governed by an initial attack of the CN radical on the carbon side to the aromatic π electron density of the benzene molecule to form a Cs symmetric C6H6CN(C6D6CN) complex. At all collision energies, the center-of-mass angular distributions are forward-backward symmetric and peak at π/2. This shape documents that the decomposing intermediate has a lifetime longer than its rotational period. The H/D atom is emitted almost perpendicular to the C6H5CN plane, giving preferentially sideways scattering. This experimental finding can be rationalized in light of the electronic structure calculations depicting a H-C-C angle of 101.2° in the exit transition state. The latter is found to be tight and located about 32.8 kJ mol-1 above the products. Our experimentally determined reaction exothermicity of 80-95 kJ mol-1 is in good agreement with the theoretically calculated one of 94.6 kJ mol-1. Neither the C6H6CN adduct nor the stable iso cyanobenzene isomer C6H5NC were found to contribute to the scattering signal. The experimental identification of cyanobenzene gives a strong background for the title reaction to be included with more confidence in reaction networks modeling the chemistry in dark, molecular clouds, outflow of dying carbon stars, hot molecular cores, as well as the atmosphere of hydrocarbon

  10. Osteogenesis imperfecta type I: Molecular heterogeneity for COL1A1 null alleles of type I collagen

    Energy Technology Data Exchange (ETDEWEB)

    Willing, M.C.; Deschenes, S.P.; Pitts, S.H.; Arikat, H.; Roberts, E.J.; Scott, D.A.; Slayton, R.L. [Univ. of Iowa, Iowa City, IA (United States); Byers, P.H. [Univ. of Washington, Seattle, WA (United States)


    Osteogenesis imperfecta (OI) type I is the mildest form of inherited brittle-bone disease. Dermal fibroblasts from most affected individuals produce about half the usual amount of type I procollagen, as a result of a COL1A1 {open_quotes}null{close_quotes} allele. Using PCR amplification of genomic DNA from affected individuals, followed by denaturing gradient gel electrophoresis (DGGE) and SSCP, we identified seven different COL1A1 gene mutations in eight unrelated families with OI type I. Three families have single nucleotide substitutions that alter 5{prime} donor splice sites; two of these unrelated families have the same mutation. One family has a point mutation, in an exon, that creates a premature termination codon, and four have small deletions or insertions, within exons, that create translational frameshifts and new termination codons downstream of the mutation sites. Each mutation leads to both marked reduction in steady-state levels of mRNA from the mutant allele and a quantitative decrease in type I procollagen production. Our data demonstrate that different molecular mechanisms that have the same effect on type I collagen production result in the same clinical phenotype. 58 refs., 4 figs., 1 tab.

  11. ALDH1A1 provides a source of meiosis-inducing retinoic acid in mouse fetal ovaries. (United States)

    Bowles, Josephine; Feng, Chun-Wei; Miles, Kim; Ineson, Jessica; Spiller, Cassy; Koopman, Peter


    Substantial evidence exists that during fetal ovarian development in mammals, retinoic acid (RA) induces germ cells to express the pre-meiotic marker Stra8 and enter meiosis, and that these effects are prevented in the fetal testis by the RA-degrading P450 enzyme CYP26B1. Nonetheless, the role of RA has been disputed principally because germ cells in embryos lacking two major RA-synthesizing enzymes, ALDH1A2 and ALDH1A3, remain able to enter meiosis. Here we show that a third RA-synthesizing enzyme, ALDH1A1, is expressed in fetal ovaries, providing a likely source of RA in the absence of ALDH1A2 and ALDH1A3. In ovaries lacking ALDH1A1, the onset of germ cell meiosis is delayed. Our data resolve the conundrum posed by conflicting published data sets and reconfirm the model that meiosis is triggered by endogenous RA in the developing ovary.

  12. Associations of CYP1A1 gene polymorphisms and risk of breast cancer in Indian women: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Eloisa Singian


    Full Text Available Reported associations of CYP1A1 polymorphisms with breast cancer have been inconsistent. In this meta-analysis examining breast cancer associations of three CYP1A1 polymorphisms (M1, M2 and M4 among Indian women may yield information that may be of clinical and epidemiological use for this particular demography. We searched MEDLINE using PubMed and Embase for association studies. From seven published case-control studies, we estimated overall associations and applied subgroup analysis to explore differential effects. All three polymorphisms exhibited overall increased risk, significant in M1 (OR 1.61-1.65, p = 0.04 and M4 (OR 2.02-3.92, p = 0.02-0.04. Differential effects were observed only in the M1 polymorphism where M1 effects were significant in South Indians (OR 2.20-4.34, p < 0.0001 but not the North population, who were at reduced risk (OR 0.64-0.77, p = 0.03-0.55. These populations were not materially different in regard to M2 and M4 as did the women stratified by menopausal status. In this meta-analysis, M1 and M4 effects may render Indian women susceptible, but may be limited by heterogeneity of the studies. Differential effects of the M1 polymorphism in breast cancer render South Indians susceptible compared to those in the North.

  13. Prenatal diagnosis of Crigler-Najjar syndrome type I by single-strand conformation polymorphism (SSCP). (United States)

    Francoual, Jeanne; Trioche, Pascale; Mokrani, Chahnez; Seboui, Hassen; Khrouf, Naïma; Chalas, Jacqueline; Clement, Marina; Capel, Liliane; Tachdjian, Gérard; Labrune, Philippe


    Crigler-Najjar syndrome type I (CN-I) is a rare and severe inherited disorder of bilirubin metabolism, caused by the total deficiency of bilirubin-UDP-glucuronosyltransferase (UGT) activity. Enzymatic diagnosis cannot be performed in chorionic villi or amniocytes as UGT is not active in these tissues. The cloning of the UGT1 gene and the identification of disease-causing mutations have led to the possibility of performing DNA-based diagnosis. Here we report DNA-based prenatal diagnosis of CN-I in two Tunisian families in whom CN-I patients were diagnosed. As we had previously shown that CN-I was, in Tunisia, associated with homozygosity for the Q357R mutation within the UGT1 gene, we were able to detect this mutation in both families and to show that it was easily recognized by single-strand conformation polymorphism (SSCP) analysis. In both cases, SSCP analysis of fetal DNA showed that the fetus was heterozygous for the Q357R mutation. In one family, the pregnancy was carried to term and a healthy baby was born, whereas, in the other family, the pregnancy is still continuing. Thus the prenatal diagnosis of CN-I is possible, provided disease-causing mutations have been identified. SSCP analysis of DNA prepared either from amniocytes or from chorionic villi is a simple, reliable and fast method for prenatal diagnosis.

  14. Bilirubin Oxidase from Myrothecium verrucaria Physically Absorbed on Graphite Electrodes. Insights into the Alternative Resting Form and the Sources of Activity Loss (United States)

    Tasca, Federico; Farias, Diego; Castro, Carmen; Acuna-Rougier, Cristina; Antiochia, Riccarda


    The oxygen reduction reaction is one of the most important chemical processes in energy converting systems and living organisms. Mediator-less, direct electro-catalytic reduction of oxygen to water was achieved on spectrographite electrodes modified by physical adsorption of bilirubin oxidases from Myrothecium verrucaria. The existence of an alternative resting form of the enzyme is validated. The effect on the catalytic cycle of temperature, pH and the presence of halogens in the buffer was investigated. Previous results on the electrochemistry of bilirubin oxidase and on the impact of the presence of halogens are reviewed and reinterpreted. PMID:26196288

  15. 非结合胆红素/白蛋白比值与脑干诱发电位相关性及对胆红素脑损伤预测价值%Correlation and predictive value between non conjugated bilirubin/albumin ratio and brain stem evoked potential in predicting bilirubin brain damage

    Institute of Scientific and Technical Information of China (English)

    扈志银; 郑小亮; 户振军


    目的:研究新生儿非结合胆红素/白蛋白比值与ABR相关性及对胆红素脑损伤的预测价值,为防治提供临床依据. 方法:以2013年1月至2014年12月在庆阳市妇幼保健院新生儿病房收住的113例足月高胆红素血症患儿为观察对象,检查血清总胆红素、非结合胆红素水平、计算总胆红素/白蛋白(B/A)、非结合胆红素/白蛋白(UCB/A)比值, ABR,并监测其伴随疾病. 结果:观察时间内,113例高胆红素血症的足月新生儿中合并胆红素脑病31例,无胆红素脑病患儿82例. 分析了B/A、UCB/A及ABR诊断胆红素脑病的灵敏度、特异性及Youden指数. 提示UCB/A及ABR作为诊断胆红素脑病的指标有一定价值. 结论:UCB/A值与ABR对胆红素脑损伤有诊断价值,可作为目前临床检测新生儿胆红素脑损伤的方法.%Objective:To study the predictive value of neonatal bilirubin/albumin ratio with ABR correlation to bilirubin brain damage in order to provide the clinical basis for the prevention and control. Methods:113 cases of full-term neonatal hyperbilirubinemia in Qingyang maternal and child care from Jan 2013 to Dec 2014 were checked levels of the serum total bilirubin and the combination of bilirubin, calculates ratio of total bilirubin/albumin(B/A) and the combination of bilirubin/albumin(UCB/A), ABR and its associated with disease. Results: In the observation period, there were 31 cases of bilirubin encephalopathy and no bilirubin encephalopathy of 82 cases. The sensitivity and specificity of B/A, UCB/A, ABR and Youden index in the diagnosis of neonatal hyperbilirubinemia were analyzed. Conclusion:UCB/A value and ABR have diagnostic value to the bilirubin brain damage, which can be used as a method to detect neonatal bilirubin brain injury at present.

  16. Characterization of the structural determinants required for potent mechanism-based inhibition of human cytochrome P450 1A1 by cannabidiol. (United States)

    Yamaori, Satoshi; Okushima, Yoshimi; Yamamoto, Ikuo; Watanabe, Kazuhito


    We previously demonstrated that cannabidiol (CBD) was a potent mechanism-based inhibitor of human cytochrome P450 1A1 (CYP1A1). However, the moiety of CBD that contributes to the potent mechanism-based inhibition of human CYP1A1 remains unknown. Thus, the effects of compounds structurally related to CBD on CYP1A1 activity were examined with recombinant human CYP1A1 in order to characterize the structural requirements for potent inactivation by CBD. When preincubated in the presence of NADPH for 20min, olivetol, which corresponds to the pentylresorcinol moiety of CBD, enhanced the inhibition of the 7-ethoxyresorufin O-deethylase activity of CYP1A1. In contrast, d-limonene, which corresponds to the terpene moiety of CBD, failed to inhibit CYP1A1 activity in a metabolism-dependent manner. Pentylbenzene, which lacks two free phenolic hydroxyl groups, also did not enhance CYP1A1 inhibition. On the other hand, preincubation of the CBD-2'-monomethyl ether (CBDM) and CBD-2',6'-dimethyl ether (CBDD) enhanced the inhibition of CYP1A1 activity. Inhibition by cannabidivarin (CBDV), which possessed a propyl side chain, was strongly potentiated by its preincubation. Orcinol, which has a methyl group, augmented CYP1A1 inhibition, whereas its derivative without an alkyl side chain, resorcinol, did not exhibit any metabolism-dependent inhibition. The preincubation of CBD-hydroxyquinone did not markedly enhance CYP1A1 inhibition. We further confirmed that olivetol, CBDM, CBDD, CBDV, and orcinol, as well as CBD (kinact=0.215min(-1)), inactivated CYP1A1 activity; their kinact values were 0.154, 0.0638, 0.0643, 0.226, and 0.0353min(-1), respectively. These results suggest that the methylresorcinol structure in CBD may have structurally important roles in the inactivation of CYP1A1.

  17. Correlation of Polymorphisms of UDP-Glucuronosyltransferase 1A7 Gene to Genetic Susceptibility of Lung Cancer%尿苷二磷酸葡糖醛酸转移酶1A7基因多态与肺癌遗传易感性的关系

    Institute of Scientific and Technical Information of China (English)

    冯飞跃; 周彤; 潘凯枫; 张联; 林东昕; 梁刚; 吕文富; 缪小平; 于春媛; 谭文; 周翊峰; 孙瞳; 康滨


    背景与目的:代谢酶尿苷二磷酸葡糖醛酸转移酶1A7(UDP-glucuronosyltcansferase,UGT1A7)可催化香烟中的致癌物质苯并[α]芘、亚硝胺NNK和杂环胺PhIP与葡糖醛酸结合使之失活,在解毒机制中起重要作用.本实验旨在研究UGT1A7基因多态与肺癌易感性的关系.方法:以聚合酶链反应-变性高效液相色谱(DHPLC)技术和聚合酶链反应-限制性片段长度多态性方法,分析317例正常对照和312例肺癌患者外周血淋巴细胞基因组DNA,UGT1A7 129~131和208位点多态基因型分布,及其与肺癌风险的关系.结果:与携带UGT1A7*1/*1基因型个体比较,携带UGT1A7*3/*1基因型的个体患肺腺癌的风险增高1.80倍(校正的OR为1.80;95%CI 1.03~3.12),携带UGT1A7*3基因型的个体患肺腺癌的风险增高1.59倍(校正的OR为1.59,95%CI 0.96~2.63).UGT1A7多态与肺鳞癌风险不相关.结论:UGT1A7基因多态可能是中国人肺癌遗传易感性因素.

  18. Adjusting CA19-9 values to predict malignancy in obstructive jaundice: Influence of bilirubin and C-reactive protein

    Institute of Scientific and Technical Information of China (English)

    Gaetano La Greca; Maria Sofia; Rosario Lombardo; Saverio Latteri; Agostino Ricotta; Stefano Puleo; Domenico Russello


    AIM:To find a possible relationship between inflammation and CA19-9 tumor marker by analyzing data from patients with benign jaundice (BJ) and malignant jaundice (MJ).METHODS:All patients admitted for obstructive jaundice,in the period 2005-2009,were prospectively enrolled in the study,obtaining a total of 102 patients.On admission,all patients underwent complete standard blood test examinations including C-reactive protein (CRP),bilirubin,CA19-9.Patients were considered eligible for the study when they presented obstructive jaundice confirmed by instrumental examinations and increased serum bilirubin levels (total bilirubin > 2.0 mg/dL).The standard cut-off level for CA19-9 was 32 U/mL,whereas for CRP this was 1.5 mg/L.The CA19-9 level was adjusted by dividing it by the value of serum bilirubin or by the CRP value.The patients were divided into 2 groups,MJ and BJ,and after the adjustment a comparison between the 2 groups of patients was performed.Sensitivity,specificity and positive predictive values were calculated before and after the adjustment.RESULTS:Of the 102 patients,51 were affected by BJ and 51 by MJ.Pathologic CA19-9 levels were found in 71.7% of the patients.In the group of 51 BJ patients there were 29 (56.9%) males and 22 (43.1%) females with a median age of 66 years (range 24-96 years),whereas in the MJ group there were 24 (47%) males and 27 (53%) females,with a mean age of 70 years (range 30-92 years).Pathologic CA19-9 serum level was found in 82.3% of MJ.CRP levels were pathologic in 66.6% of the patients with BJ and in 49% with MJ.Bilirubin and CA19-9 average levels were significantly higher in MJ compared with BJ (P =0.000 and P =0.02),while the CRP level was significantly higher in BJ (P =0.000).Considering a CA19-9 cut-off level of 32 U/mL,82.3% in the MJ group and 54.9% in the BJ group were positive for CA19-9 (P =0.002).A CA19-9 cut-off of 100 U/mL increases the difference between the two groups:35.3% in BJ and 68.6

  19. Dietary Lecithin Decreases Skeletal Muscle COL1A1 and COL3A1 Gene Expression in Finisher Gilts

    Directory of Open Access Journals (Sweden)

    Henny Akit


    Full Text Available The purpose of this study was to investigate the effect of dietary lecithin on skeletal muscle gene expression of collagen precursors and enzymes involved in collagen synthesis and degradation. Finisher gilts with an average start weight of 55.9 ± 2.22 kg were fed diets containing either 0, 4, 20 or 80 g/kg soybean lecithin prior to harvest for six weeks and the rectus abdominis muscle gene expression profile was analyzed by quantitative real-time PCR. Lecithin treatment down-regulated Type I (α1 procollagen (COL1A1 and Type III (α1 procollagen (COL3A1 mRNA expression ( p < 0.05, respectively, indicating a decrease in the precursors for collagen synthesis. The α-subunit of prolyl 4-hydroxylase (P4H mRNA expression also tended to be down-regulated ( p = 0.056, indicating a decrease in collagen synthesis. Decreased matrix metalloproteinase-1 (MMP-1 mRNA expression may reflect a positive regulatory response to the reduced collagen synthesis in muscle from the pigs fed lecithin ( p = 0.035. Lecithin had no effect on tissue inhibitor metalloproteinase-1 (TIMP-1, matrix metalloproteinase-13 (MMP-13 and lysyl oxidase mRNA expression. In conclusion, lecithin down-regulated COL1A1 and COL3A1 as well as tended to down-regulate α-subunit P4H expression. However, determination of muscle collagen content and solubility are required to support the gene functions.

  20. Genetic polymorphisms in CYP1A1, CYP1B1 and COMT genes in Greenlandic Inuit and Europeans

    Directory of Open Access Journals (Sweden)

    Mandana Ghisari


    Full Text Available Background. The Indigenous Arctic population is of Asian descent, and their genetic background is different from the Caucasian populations. Relatively little is known about the specific genetic polymorphisms in genes involved in the activation and detoxification mechanisms of environmental contaminants in Inuit and its relation to health risk. The Greenlandic Inuit are highly exposed to legacy persistent organic pollutants (POPs such as polychlorinated biphenyls (PCBs and organochlorine pesticides (OCPs, and an elucidation of gene–environment interactions in relation to health risks is needed. Objectives. The aim of this study was to determine and compare the genotype and allele frequencies of the cytochrome P450 CYP1A1 Ile462Val (rs1048943, CYP1B1 Leu432Val (rs1056836 and catechol-O-methyltransferase COMT Val158Met (rs4680 in Greenlandic Inuit (n=254 and Europeans (n=262 and explore the possible relation between the genotypes and serum levels of POPs. Results. The genotype and allele frequency distributions of the three genetic polymorphisms differed significantly between the Inuit and Europeans. For Inuit, the genotype distribution was more similar to those reported for Asian populations. We observed a significant difference in serum polychlorinated biphenyl (CB-153 and the pesticide 1,1-dichloro-2,2-bis(p-chlorophenyl-ethylene (p,p′-DDE levels between Inuit and Europeans, and for Inuit also associations between the POP levels and genotypes for CYP1A1, CYP1B1 and COMT. Conclusion. Our data provide new information on gene polymorphisms in Greenlandic Inuit that might support evaluation of susceptibility to environmental contaminants and warrant further studies.

  1. Agrobacterium-mediated transformation of Ananas comosus with CYP1A1%根癌农杆菌介导CYP1A1转化菠萝的研究

    Institute of Scientific and Technical Information of China (English)

    何业华; 吴会桃; 罗吉; 方少秋; 马均; 卢敏; 彭兵; 伍成厚


    将菠萝(Ananas comosus)愈伤组织经含有植物表达重组质粒(pUHA1-CYP1A1)的根癌农杆菌(LBA4404菌株)侵染后,在MS+3.0 mg/L BA+2.0 mg/L NAA+100 μmol/L AS+8 g/L agar上共培养3 d,转入选择培养基(MS+3.0 mg/L BA+2.0 mg/L NAA+20 mg/L Km+400 mg/L Carb+8 g/L agar)上培养约10 d后开始分化出不定芽;28 d后将绿色的抗Km不定芽转入MS+2.0 mg/L NAA+30 mg/L Km+300 mg/L Carb+8 g/L agar上再进行连续2轮选择,随后将绿芽转入MS+1.0 mg/L IBA+30 mg/L Km+8 g/L agar上生根,共获得95株Km抗性植株,转化率0.12%~2.69%.对其中部分的抗Km植株进行PCR检测,PCR阳性植株率达64.29%.经Southern杂交进一步证实,CYP1A1已整合到菠萝基因中.以琼脂为培养基凝固剂、共培养基中添加AS、增加选择次数和逐渐增加新一轮选择培养基中的Km质量浓度等是根癌农杆菌介导菠萝愈伤组织获得转基因植株的重要条件.

  2. Energy change in the formation of conjugated bilirubin: A possible responsive mechanism for liver cell pathology Cambio energético durante la conjugación de la bilirrubina: un posible mecanismo de lesión hepatocelular

    Directory of Open Access Journals (Sweden)

    V. Wiwanitkit


    Full Text Available Bilirubin is formed when red blood cells die and their hemoglobin is broken down within the macrophages into heme and globins. In the liver, bilirubin is conjugated with UDP-glucuronate, making it water-soluble diglucuronide. Concerning this conjugation, a molecule of bilirubin reacts with two molecules of glucoronic acid. However, the nature of this energy-consuming reaction in the formation of conjugated bilirubin has never been reported, and this can be important for its potential implication in hyperbilirubinemia. In this work, the author calculated the energy required by conjugated-bilirubin formation per molecule. The energy required for complex formation is -22 kCal/mol. The nature of this energy-producing reaction can be a good explanation. Increased energy delivery in conjugated hyperbilirubinemia in liver disease might be a responsive mechanism to hepatic damage.

  3. Increasing the catalytic activity of Bilirubin oxidase from Bacillus pumilus: Importance of host strain and chaperones proteins. (United States)

    Gounel, Sébastien; Rouhana, Jad; Stines-Chaumeil, Claire; Cadet, Marine; Mano, Nicolas


    Aggregation of recombinant proteins into inclusion bodies (IBs) is the main problem of the expression of multicopper oxidase in Escherichia coli. It is usually attributed to inefficient folding of proteins due to the lack of copper and/or unavailability of chaperone proteins. The general strategies reported to overcome this issue have been focused on increasing the intracellular copper concentration. Here we report a complementary method to optimize the expression in E. coli of a promising Bilirubin oxidase (BOD) isolated from Bacillus pumilus. First, as this BOD has a disulfide bridge, we switched E.coli strain from BL21 (DE3) to Origami B (DE3), known to promote the formation of disulfide bridges in the bacterial cytoplasm. In a second step, we investigate the effect of co-expression of chaperone proteins on the protein production and specific activity. Our strategy allowed increasing the final amount of enzyme by 858% and its catalytic rate constant by 83%.

  4. Indicators of inflammation and cellular damage in chronic asymptomatic or oligosymptomatic alcoholics: correlation with alteration of bilirubin and hepatic and pancreatic enzymes

    Directory of Open Access Journals (Sweden)

    Borini Paulo


    Full Text Available Biochemical and hematimetric indicators of inflammation and cell damage were correlated with bilirubin and hepatic and pancreatic enzymes in 30 chronic male alcoholics admitted into psychiatric hospital for detoxification and treatment of alcoholism. Aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, and total bilirubin were altered, respectively, in 90%, 63%, 87%, 23% and 23% of the cases. None of the indicators of inflammation (lactic dehydrogenase, altered in 16% of the cases; alpha-1 globulin, 24%; alpha-2 globulin, 88%; leucocyte counts, 28% was correlated with alterations of bilirubin or liver enzymes. Lactic dehydrogenase was poorly sensitive for detection of hepatocytic or muscular damage. Alterations of alpha-globulins seemed to have been due more to alcohol metabolism-induced increase of lipoproteins than to inflammation. Among indicators of cell damage, serum iron, increased in 40% of the cases, seemed to be related to liver damage while creatine phosphokinase, increased in 84% of the cases, related to muscle damage. Hyperamylasemia was found in 20% of the cases and significantly correlated with levels of bilirubin, alkaline phosphatase and gamma-glutamyltransferase. It was indicated that injuries of liver, pancreas, salivary glands, and muscle occurred in asymptomatic or oligosymptomatic chronic alcoholics.

  5. 用于清除胆红素的磁性亲和分离方法%Study on Removal of Bilirubin with Magnetic Affinity Separation Technique

    Institute of Scientific and Technical Information of China (English)

    徐辉; 张国亮; 张凤宝; 王淑兰


    An affinity adsorbent, Cibacron Blue 3GA immobilized magnetic polyvinyl alcohol (PVA) microsphereswas used for bilirubin removal taking the advantage of easy separation of magnetic sorbent from the biosystem.Fe3 O4 superparamagnetic particles was synthesized with hydrothermal reaction of ferrous chloride (FeCl2) and ferricchloride (FeCl3). Such magnetic particles are then encapsulated in biocompatible PVA to form magnetic polymermicrospheres sized from 2 to 15 nm with hydroxyl groups on its surface. Cibacron Blue 3GA, a dye-ligand, wascovalently coupled with the polyvinyl alcohol through the nucleophilic reaction between the chloride of its triazinering and the hydroxyl groups of PVA molecules under alkaline condition. The affinity adsorbent carried 21.1 μmolCibacron Blue 3GA per gram magnetic polymer microspheres was used to remove unconjugated and conjugatedbilirubin from the solution which was composed of bilirubin or bilirubin and protein. After the adsorption, theadsorbent loaded with bilirubin was removed easily in the magnetic field.

  6. 新生儿胆红素脑病发病机制与临床评价%Pathogenesis and clinical evaluation of bilirubin encephalopathy in newborn infant

    Institute of Scientific and Technical Information of China (English)



    @@ 新生儿时期严重的高胆红素血症,特别是生后1周内发生的严重高胆红素血症常易导致急性神经系统功能障碍,即急性胆红素脑病(Acute bilirubin encephalopathy,ABE).

  7. Effect of preoperative biliary drainage on surgical results after pancreaticoduodenectomy in patients with distal common bile duct cancer:Focused on the rate of decrease in serum bilirubin

    Institute of Scientific and Technical Information of China (English)

    Yun Mee Choi; Seok-Hwan Shin; Kyung Rae Kim; Ze-Hong Woo; Eung-Ho Cho; Keon-Young Lee; Seung-Ik Ahn; Sun Keun Choi; Sei Joong Kim; Yoon Seok Hut; Young Up Cho; Kee-Chun Hang


    AIM:To examine if the rate of decrease in serum bilirubin after preoperative biliary drainagecan be used as a predicting factor for surgical complications and postoperative recovery after pancreaticoduodenectomy in patients with distal common bile duct cancer.METHODS:A retrospective study was performed in 49 consecutive patients who underwent pancreaticoduodenectomy for distal common bile duct cancer.Potential risk factors were compared between the complicated and uncomplicated groups.Also,the rates of decrease in serum bilirubin were compared pre-and postoperatively.RESULTS:Preoperative biliary drainage (PBD) was performed in 40 patients (81.6%).Postoperative morbidity and mortality rates were 46.9% (23/49) and 6.1% (3/49),respectively.The presence or absence of PBD was not different between the complicated and uncomplicated groups.In patients with PBD,neither the absolute level nor the rate of decrease in serum bilirubin was significantly different.Patients with rapid decrease preoperatively showed faster decrease during the first postoperative week (5.5±4.4 μmol/L vs-1.7±9.9μmol/L,P=0.004).CONCLUSION:PBD does not affect the surgical outcome of pancreaticoduodenectomy in patients with distal common bile duct cancer.There is a certain group of patients with a compromised hepatic excretory function,which is represented by the slow rate of decrease in serum bilirubin after PBD.

  8. High sensitive C-reactive protein and serum amyloid A are inversely related to serum bilirubin : effect-modification by metabolic syndrome

    NARCIS (Netherlands)

    Deetman, Petronella E.; Bakker, Stephan J. L.; Dullaart, Robin P. F.


    Background: Bilirubin has been implicated in cardiovascular protection by virtue of its anti-inflammatory and anti-oxidative properties. The metabolic syndrome is featured by enhanced low-grade systemic inflammation and oxidative stress. Serum amyloid A (SAA) impairs anti-oxidative properties of hig

  9. 新生儿胆红素脑病脑脊液胆红素及脑干听觉诱发电位检测的临床意义%The clinical significance of cerebrospinal fluid bilirubin and brainstem auditory evoked potential tests in neonatal bilirubin encephalopathy

    Institute of Scientific and Technical Information of China (English)

    李先红; 张健; 查萍; 王丽丽; 孔萤; 孙璐路; 郑洪


    Objective To explore the clinical significance of cerebrospinal fluid bilirubin level and brainstem auditory evoked poten -tial in neonatal bilirubin encephalopathy .Methods All the cases with hyperbilirubinemia were selected from July 2011 to July 2013 in our department,and were divided into the bilirubin encephalopathy group (44 cases) and the non-bilirubin encephalopathy group (79 cases).Ce-rebrospinal fluid ,serum bilirubin level and brainstem auditory evoked potential ( BAEP ) changes were compared between the two groups of children .Results The cerebrospinal fluid bilirubin level in bilirubin encephalopathy group was higher than that of non -bilirubin encephalopa-thy group [(11.0 +3.9) tendency/L vs (7.4 +4.0) tendency/L],and the difference was statistically significant (P<0.01).The inci-dence of abnormal BAEP (61.4%) in bilirubin encephalopathy group was higher than that of non-bilirubin encephalopathy group (16.5%), and the difference was statistically significant (P<0.01).Conclusion Cerebrospinal fluid bilirubin can be used as a reliable indicator for bilirubin encephalopathy in the early diagnosis ,and newborn infants with bilirubin encephalopathy accompanied by higher incidence of hearing damage require early intervention treatment .%目的:探讨新生儿胆红素脑病脑脊液胆红素水平及脑干听觉诱发电位(BAEP)检查的临床意义。方法选取高胆红素血症新生儿为研究对象,分为胆红素脑病组(44例)和非胆红素脑病组(79例),比较两组患儿脑脊液、血清胆红素水平以及BAEP变化。结果胆红素脑病组患儿脑脊液胆红素水平高于非胆红素脑病组[(11.0±3.9) mol/L VS (7.4±4.0) mol/L],差异有统计学意义(P<0.05);胆红素脑病组BAEP异常发生率(61.4%)高于非胆红素脑病组(16.5%),差异有统计学意义(P<0.01)。结论脑脊液胆红素水平检测可作为新生儿胆红素脑病早期诊断的可

  10. Co-Electrodeposition of Bilirubin Oxidase with Redox Polymer through Ligand Substitution for Use as an Oxygen Reduction Cathode

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hyo Sul; Kang, Chan [Chonbuk National University, Jeonju (Korea, Republic of)


    The water soluble redox polymer, poly(N-vinylimidazole) complexed with Os(4,4'-dichloro-2,2'-bipyridine){sub 2}Cl]{sup +} (PVI-[Os(dCl-bpy){sub 2}Cl]{sup +}), was electrodeposited on the surface of a glassy carbon electrode by applying cycles of alternating square wave potentials between 0.2 V (2 s) and 0.7 V (2 s) to the electrode in a solution containing the redox polymer. The coordinating anionic ligand, Cl- of the osmium complex, became labile in the reduced state of the complex and was substituted by the imidazole of the PVI chain. The ligand substitution reactions resulted in crosslinking between the PVI chains, which made the redox polymer water insoluble and caused it to be deposited on the electrode surface. The deposited film was still electrically conducting and the continuous electrodeposition of the redox polymer was possible. When cycles of square wave potentials were applied to the electrode in a solution of bilirubin oxidase and the redox polymer, the enzyme was co-electrodeposited with the redox polymer, because the enzymes could be bound to the metal complexes through the ligand exchange reactions. The electrode with the film of the PVI-[Os(dCl-bpy){sub 2}Cl]{sup +} redox polymer and the co-electrodeposited bilirubin oxidase was employed for the reduction of O{sub 2} and a large increase of the currents was observed due to the electrocatalytic O{sub 2} reduction with a half wave potential at 0.42 V vs. Ag/AgCl.

  11. Bilirubin scavenges chloramines and inhibits myeloperoxidase-induced protein/lipid oxidation in physiologically relevant hyperbilirubinemic serum. (United States)

    Boon, A C; Hawkins, C L; Coombes, J S; Wagner, K H; Bulmer, A C


    Hypochlorous acid (HOCl), an oxidant produced by myeloperoxidase (MPO), induces protein and lipid oxidation, which is implicated in the pathogenesis of atherosclerosis. Individuals with mildly elevated bilirubin concentrations (i.e., Gilbert syndrome; GS) are protected from atherosclerosis, cardiovascular disease, and related mortality. We aimed to investigate whether exogenous/endogenous unconjugated bilirubin (UCB), at physiological concentrations, can protect proteins/lipids from oxidation induced by reagent and enzymatically generated HOCl. Serum/plasma samples supplemented with exogenous UCB (≤250µM) were assessed for their susceptibility to HOCl and MPO/H2O2/Cl(-) oxidation, by measuring chloramine, protein carbonyl, and malondialdehyde (MDA) formation. Serum/plasma samples from hyperbilirubinemic Gunn rats and humans with GS were also exposed to MPO/H2O2/Cl(-) to: (1) validate in vitro data and (2) determine the relevance of endogenously elevated UCB in preventing protein and lipid oxidation. Exogenous UCB dose-dependently (P<0.05) inhibited HOCl and MPO/H2O2/Cl(-)-induced chloramine formation. Albumin-bound UCB efficiently and specifically (3.9-125µM; P<0.05) scavenged taurine, glycine, and N-α-acetyllysine chloramines. These results were translated into Gunn rat and GS serum/plasma, which showed significantly (P<0.01) reduced chloramine formation after MPO-induced oxidation. Protein carbonyl and MDA formation was also reduced after MPO oxidation in plasma supplemented with UCB (P<0.05; 25 and 50µM, respectively). Significant inhibition of protein and lipid oxidation was demonstrated within the physiological range of UCB, providing a hypothetical link to protection from atherosclerosis in hyperbilirubinemic individuals. These data demonstrate a novel and physiologically relevant mechanism whereby UCB could inhibit protein and lipid modification by quenching chloramines induced by MPO-induced HOCl.

  12. Heterozygous mutation of eEF1A1b resulted in spermatogenesis arrest and infertility in male tilapia, Oreochromis niloticus (United States)

    Chen, Jinlin; Jiang, Dongneng; Tan, Dejie; Fan, Zheng; Wei, Yingying; Li, Minghui; Wang, Deshou


    Eukaryotic elongation factor 1 alpha (eEF1A) is an essential component of the translational apparatus. In the present study, eEF1A1b was isolated from the Nile tilapia. Real-time PCR and Western blot revealed that eEF1A1b was expressed highly in the testis from 90 dah (days after hatching) onwards. In situ hybridization and immunohistochemistry analyses showed that eEF1A1b was highly expressed in the spermatogonia of the testis. CRISPR/Cas9 mediated mutation of eEF1A1b resulted in spermatogenesis arrest and infertility in the F0 XY fish. Consistently, heterozygous mutation of eEF1A1b (eEF1A1b+/−) resulted in an absence of spermatocytes at 90 dah, very few spermatocytes, spermatids and spermatozoa at 180 dah, and decreased Cyp11b2 and serum 11-ketotestosterone level at both stages. Further examination of the fertilization capacity of the sperm indicated that the eEF1A1b+/− XY fish were infertile due to abnormal spermiogenesis. Transcriptomic analyses of the eEF1A1b+/− testis from 180 dah XY fish revealed that key elements involved in spermatogenesis, steroidogenesis and sperm motility were significantly down-regulated compared with the control XY. Transgenic overexpression of eEF1A1b rescued the spermatogenesis arrest phenotype of the eEF1A1b+/− testis. Taken together, our data suggested that eEF1A1b is crucial for spermatogenesis and male fertility in the Nile tilapia. PMID:28266557

  13. Epigenetic Determinants of CYP1A1 Induction by the Aryl Hydrocarbon Receptor Agonist 3,3',4,4',5-Pentachlorobiphenyl (PCB 126

    Directory of Open Access Journals (Sweden)

    Sabine U. Vorrink


    Full Text Available Many enzymes involved in xenobiotic metabolism, including cytochrome P450 (CYP 1A1, are regulated by the aryl hydrocarbon receptor (AhR. 3,3',4,4',5-Penta chlorobiphenyl (PCB 126 is a potent ligand for AhR and can thus induce the expression of CYP1A1. Interestingly, we observed that human carcinoma cell lines derived from different types of epithelial cells displayed divergent degrees of CYP1A1 induction after exposure to PCB 126. Since epigenetic mechanisms are known to be involved in cell type-specific gene expression, we sought to assess the epigenetic determinants of CYP1A1 induction in these carcinoma cell lines. In contrast to HepG2 hepatocarcinoma cells, HeLa cervical carcinoma cells showed significantly lower levels of CYP1A1 mRNA expression following PCB 126 exposure. Our results show that the two cell lines maintained differences in the chromatin architecture along the CYP1A1 promoter region. Furthermore, treatment with the epigenetic modifiers, trichostatin A (TSA and 5-aza-2'-deoxycytidine (5-Aza-dC, significantly increased the expression of CYP1A1 after PCB 126 treatment in HeLa cells. However, we did not observe apparent differences in methylation levels or specific location of CpG DNA methylation between the two cell lines in the analyzed CYP1A1 promoter region. Taken together, our findings suggest that the differences in CYP1A1 expression between HepG2 and HeLa cells are due to differences in the chromatin architecture of the CYP1A1 promoter and thus establish a role of epigenetic regulation in cell-specific CYP1A1 expression.

  14. 血清胆红素与代谢综合征的相关性研究%Relationship Between Serum Bilirubin and Metabolic Syndrome

    Institute of Scientific and Technical Information of China (English)

    韩硕; 张壬; 金元哲


    Objective] To explore the correlation between serum bilirubin and metabolic syndrome (MS) .[Methods] A total of 2 ,125 participants in our survey of atherosclerosis and related diseases were recruited to complete questionnaire ,physical examinations and laboratory tests .They were divided into metabolic syndrome (MS) and non‐metabolic syndrome (NMS) groups according to the International Diabetes Federation (IDF) diag‐nostic criteria for MS .And the correlations were analyzed for MS and serum total bilirubin ,direct bilirubin and in‐direct bilirubin .[Results] Their age range was 35~64 years .With an overall incidence rate of MS of 36 .1% ,it was higher in females than males (43 .5% vs 18 .4% ,P <0 .01) .Direct bilirubin was higher in MS group than that in NMS group [(2 .07 ± 0 .86) vs (2 .29 ± 0 .96)μmol/L ,P <0 .01] .With a rising number of MS composi‐tion factors ,bilirubin levels decreased .Among MS individuals ,serum total bilirubin and direct bilirubin levels were higher in males than those in females ( P<0 .05) .Logistic regression analysis showed that a low direct bili‐rubin level was more susceptible to MS .[Conclusion]Serum bilirubin may be associated with MS and direct biliru‐bin has greater correlations with MS .Individuals with lower serum direct bilirubin levels are more susceptible to MS .%【目的】研究血清胆红素与代谢综合征(MS)的相关性。【方法】对参与辽宁省沈阳市城区动脉硬化及其相关疾病调查的居民进行问卷调查、体格检查和实验室检查,依据国际糖尿病联盟诊断标准将其分为MS组及非代谢综合征(NMS)组。分析受试者血清总胆红素(TBIL)、直接胆红素(DBIL)及间接胆红素(IBIL)与MS的相关性。【结果】共纳入2125名35~64周岁居民,MS的总发生率为36.1%,女性高于男性(43.5%vs18.4%,P<0.01)。MS组DBIL浓度低于NMS组[(2.07±0.86)μmol/Lvs(2.29±0.96

  15. Relationship between serum bilirubin and diabetic kideny disease in patients with type 2 diabetes%2型糖尿病患者血清胆红素水平与糖尿病肾病关系的研究

    Institute of Scientific and Technical Information of China (English)

    陈宇; 周永华; 韩晓骏; 严冲; 苏如婷; 李小飞


    目的 探讨2型糖尿病(type 2 diabetes mellitus,T2DM)患者血清胆红素水平与糖尿病肾病(diabetickidney disease,DKD)之间的关系.方法 789例T2DM患者,按照24小时尿白蛋白定量分为正常尿白蛋白组(尿白蛋白300 mg),并以168例正常成人作为对照组,观察各组之间血清胆红素的差异,探讨血清胆红素水平与DKD的关系.结果 T2DM患者血清总胆红素、直接胆红素和间接胆红素水平均低于正常对照组(P0.05);临床尿白蛋白组的总胆红素、直接胆红素以及间接胆红素均低于其他两组(P0.05;r=-0.106,P0.05;r=0.12,P<0.05.结论 胆红素可能是T2DM患者肾脏的保护性因子.糖尿病早期采取积极的抗氧化治疗对防止DKD的发生发展有重要意义.%Objective To approach the relationship between serum bilirubin level and diabetic kideny disease in patients with type 2 diabetes mellitus(T2DM).Methods 789 T2DM patients were classified into normoalbuminuria group (urinary albumin excretion less than 30 mg per 24 h), microalbuminuria group (urinary albumin excretion range from 30 to 300 mg per 24 h) and macroalbuminuria group (urinary albumin excretion more than 300 mg per 24 h) according to the degree of urinary albumin excretion.We chose 168 healthy adults randomly as the control group.The difference in serum bilirubin among groups and the correlation between serum bilirubin and diabetic nephropathy were analyzed.Results T2DM group had higher levels of serum total bilirubin, direct bilirubin and unconjugated bilirubin significantly than those of the control group ( P <0.01 or P <0.05).The total bilirubin and unconjugated bilirubin levels of the microalbuminuria group were lower compared with those of the normoalbuminuria group ( P <0.01, P < 0.05), while there was no significant difference in the direct bilirubin (P >0.05).Compared with the other two groups, the macroalbuminuria group had lower serum total bilirubin, direct bilirubin as well as

  16. Antimutagenic properties of Mangifera indica L. stem bark extract and evaluation of its effects on hepatic CYP1A1. (United States)

    Morffi, Janet; Rodeiro, Idania; Hernández, Sandra Luz; González, Leonora; Herrera, Jose; Espinosa-Aguirre, J Javier


    Mangifera indica stem bark extract (MSBE) is a Cuban natural product which has shown strong antioxidant properties. In this work, the antimutagenic effect of MSBE was tested against 10 well-known mutagens/carcinogens in the Ames test in the absence or presence of metabolic fraction (S9). The chemical mutagens tested included: cyclophosphamide, mitomycin C, bleomycin, cisplatin, dimethylnitrosamine (DMNA), benzo[a]pyrene (BP), 2-acetylaminofluorene (2-AAF), sodium azide, 1-nitropyrene (1-NP) and picrolonic acid. Protective effects of the extract were also evaluated by comparing the efficiency of S9 fraction obtained from rats treated during 28 days with oral doses of MSBE (50-500 mg/kg) with that obtained from rats treated with vehicle (control) to activate bleomycin and cyclophosphamide in the Ames test. MSBE concentrations between 50 and 500 μg/plate significantly reduced the mutagenicity mediated by all the chemicals tested with the exception of sodium azide. Higher mutagenicity was found when bleomycin and cyclophosphamide (CP) were activated by control S9 than by MSBE S9. In addition, inhibition of CYP1A1 microsomal activity was observed in the presence of MSBE (10-20 μg/ml). We can conclude that besides its potent antioxidant activity previously reported, MSBE may also exert a chemoprotective effect due to its capacity to inhibit CYP activity.

  17. Genotyping by"cold single-strand conformation polymorphism" of the UGT1A1 promoter polymorphism in Mexican mestizos. (United States)

    Arámbula, Eliakym; Vaca, Gerardo


    Since no data have previously been reported concerning both the (TA) n polymorphism at the promoter of the UGT1A1 gene in the Mexican population and the use of single-strand conformation polymorphism (SSCP) for the detection of such polymorphism, genotyping by SSCP in 375 G-6-PD normal (Group A) and 81 G-6-PD-deficient (Group B) mestizos belonging to 14 states was carried out. Allele frequencies for (TA)6 and (TA)7 repeats were 0.654 and 0.334, respectively, in Group A and 0.685 and 0.315 in Group B; in the former group, the (TA)5 allele was also observed with a frequency of 0.012. The frequencies of the genotype (TA)7/(TA)7 were 10.1% (Group A) and 8.6% (Group B). The (TA)7/(TA)8 genotype was also observed in a patient with unconjugated hyperbilirubinemia. Due to the importance of its potential medical implications, the observed high frequency (10%) of the (TA)7/(TA)7 genotype is stressed. Genotyping by SSCP of the (TA) n polymorphism is an adequate methodological option.

  18. Influence of curcumin on cyclosporin-induced reduction of biliary bilirubin and cholesterol excretion and on biliary excretion of cyclosporin and its metabolites. (United States)

    Deters, M; Siegers, C; Hänsel, W; Schneider, K P; Hennighausen, G


    We investigated the ability of curcumin, which can be extracted from different Curcuma species, to prevent cyclosporin-induced reduction of biliary bilirubin and cholesterol excretion, and its influence on biliary excretion of cyclosporin (CS) and its metabolites in the bile fistula model in rats. I.v. injection of curcumin (25 and 50 mg/kg) after 30 min increased dose-dependently basal bile flow (30 microliters/kg/min) up to 200%, biliary bilirubin excretion (3000 pmol/kg/min) up to 150%, and biliary cholesterol excretion (22 nmol/kg/min) up to 113%. CS (30 mg/kg) reduced bile flow to 66% and biliary excretion of bilirubin and of cholesterol to 33% of the basal value 30 min after i.v. injection. I.v. administration of curcumin (25 and 50 mg/kg) 30 min after CS increased bile flow dose dependently again to 130% for 1 hour and biliary excretion of cholesterol and of bilirubin to 100% of the basal value for 30 and 150 min, respectively. Injection of curcumin 15 min before CS prevented the CS-induced drop of bile flow at 50 mg/kg and reduction of biliary bilirubin excretion already at 25 mg/kg until the end of the experiment (180 min). The CS-induced reduction of biliary cholesterol excretion, however, was not prevented by curcumin. Finally, the biliary excretions of CS (1200 ng/kg/min) and its metabolites (1200 ng/kg/min) were slightly reduced by curcumin at a dose of 50 mg/kg (to 83% of the initial values). The clinical importance of these controversial effects remains to be shown.

  19. 胆红素对凝血功能检测结果的影响%Influence of bilirubin on the coagulation function test results

    Institute of Scientific and Technical Information of China (English)



    目的:探讨不同胆红素浓度对血浆凝血酶原时间(PT)和活化部分凝血活酶时间(APTT)检测结果的影响.方法:对含有不同总胆红素浓度的质控血浆进行血浆凝血酶原时间和活化部分凝血活酶时间指标测定,比较不同浓度的胆红素对上述指标的影响.结果:随着血浆总胆红素浓度的升高,PT、APTT检测结果升高,胆红素水平低于20 μmol/L时,对血浆PT、APTT测定结果影响的差异无统计学意义(P>0.05),当胆红素浓度高于41 μmol/L时,APTT检测结果显著高于对照血浆水平(P0.05).When the bilirubin concentration was more than 41 μmol/L,the APTT test result was significantly higher than the controlled plasma level(P<0.05).When the bilirubin concentration was more than 62 μ mol/L,the PT test result was significantly higher than the controlled plasma level(P<0.05).Conclusion:When the bilirubin level is less than 20 μ mol/L,the influence on the coagulation function test results is not big.However the plasma bilirubin concentration is significantly increased,it has distraction on the PT and APTT test results.When simply because of elevated bilirubin levels lead to PT, APTT results abnormal increase,it could be used the regression equation for correction to provide more accurate detection results in clinic.

  20. Conjugated bilirubin affects cytokine profiles in hepatitis A virus infection by modulating function of signal transducer and activator of transcription factors. (United States)

    Castro-García, Flor P; Corral-Jara, Karla F; Escobedo-Melendez, Griselda; Sandoval-Hernandez, Monserrat A; Rosenstein, Yvonne; Roman, Sonia; Panduro, Arturo; Fierro, Nora A


    Hepatitis A virus (HAV) infection is the major cause of acute liver failure in paediatric patients. The clinical spectrum of infection is variable, and liver injury is determined by altered hepatic enzyme function and bilirubin concentration. We recently reported differences in cytokine profiles between distinct HAV-induced clinical courses, and bilirubin has been recognized as a potential immune-modulator. However, how bilirubin may affect cytokine profiles underlying the variability in the course of infection has not been determined. Herein, we used a transcription factor (TF) binding site identification approach to retrospectively analyse cytokine expression in HAV-infected children and to predict the entire set of TFs associated with the expression of specific cytokine profiles. The results suggested that modulation of the activity of signal transducers and activators of transcription proteins (STATs) may play a central role during HAV infection. This led us to compare the degree of STAT phosphorylation in peripheral blood lymphoid cells (PBLCs) from paediatric patients with distinct levels of conjugated bilirubin (CB). Low CB levels in sera were associated with increased STAT-1 and STAT-5 phosphorylation. A positive correlation was observed between the serum interleukin-6 (IL-6) content and CB values, whereas higher levels of CB correlated with reduced serum IL-8 values and with a reduction in the proportion of PBLCs positive for STAT-5 phosphorylation. When CB was used to stimulate patients' PBLCs in vitro, the levels of IL-6 and tumour necrosis factor-α were increased. The data showed that bilirubin plays a role in STAT function and affects cytokine profile expression during HAV infection.

  1. UGT1A1*28 genotype and irinotecan dosage in patients with metastatic colorectal cancer: a Dutch Colorectal Cancer Group study.

    NARCIS (Netherlands)

    Kweekel, D.M.; Gelderblom, H.; Straaten, T Van der; Antonini, N.F.; Punt, C.J.A.; Guchelaar, H.J.


    The aim of the study was to investigate the associations between UGT1A1(*)28 genotype and (1) response rates, (2) febrile neutropenia and (3) dose intensity in patients with metastatic colorectal cancer treated with irinotecan. UGT1A1(*)28 genotype was determined in 218 patients receiving irinotecan

  2. Inhibition of 17β-estradiol activation by CYP1A1: genotype- and regioselective inhibition by St. John's Wort and several natural polyphenols. (United States)

    Schwarz, Dieter; Kisselev, Pyotr; Schunck, Wolf-Hagen; Roots, Ivar


    Several epidemiological studies associate certain CYP1A1 genotypes, alone or in combination, with an increased risk of estrogen-related cancers. Previously we demonstrated that metabolic activation of estrogens by CYP1A1 is a genotype-dependent reaction with the CYP1A1.2 (Ile462Val) variant being the most efficient catalyst (Kisselev et al.). To answer the question whether genotype-dependent inhibition of activation of estrogens by CYP1A1 could also contribute, we studied the inhibition of hydroxylation activity of the most common allelic variants of human CYP1A1 towards 17β-estradiol. We expressed and purified CYP1A1.1 (wild-type), CYP1A1.2 (Ile462Val), and CYP1A1.4 (Thr461Asn) and performed inhibition assays by natural polyphenols of our diet and drugs of NADPH-dependent estradiol hydroxylation in reconstituted CYP1A1 systems. From the polyphenols studied, a St. John's Wort (Hypericum perforatum) extract, some of its main single constituents hypericin, pseudohypericin, and quercetin, as well as the flavonols kaempferol, myricetin and the phytoestrogens resveratrol and tetramethyl-stilbene exhibited strong inhibition. For the St. John's Wort extract and its single constituents hypericin, pseudohypericin, and quercetin, inhibition exhibited a remarkable dependency on the CYP1A1 genotype. Whereas (wild-type) CYP1A1.1 was most inhibited by the whole crude extract, the variant CYP1A1.2 (Ile462Val) was significantly stronger inhibited by the constituents in its pure form: IC₅₀ values for 2-hydroxylation was more than two times lower compared with the wild-type enzyme and the variant CYP1A1.4 (Thr461Asn). Besides this, the inhibition exhibited a remarkable regioselectivity. The data suggest that risk of estrogen-mediated diseases might be not only influenced by CYP1A1 genotype-dependent activation but also its inhibition by natural polyphenols of our diet and drugs.

  3. Association of genetic variants of xenobiotic and estrogen metabolism pathway (CYP1A1 and CYP1B1) with gallbladder cancer susceptibility. (United States)

    Sharma, Kiran Lata; Agarwal, Akash; Misra, Sanjeev; Kumar, Ashok; Kumar, Vijay; Mittal, Balraj


    Gallbladder carcinoma is a highly aggressive cancer with female predominance. Interindividual differences in the effectiveness of the activation/detoxification of environmental carcinogens and endogenous estrogens may play a crucial role in cancer susceptibility. The present study included 410 patients with carcinoma of the gallbladder (GBC) and 230 healthy subjects. This study examined association of CYP1A1-MspI, CYP1A1-Ile462Val, and CYP1B1-Val432Leu with GBC susceptibility. CYP1A1-MspI [CC] and CYP1A1-Ile462Val [iso/val] genotypes were found to be significantly associated with GBC (p=0.006 and p=0.03, respectively), as compared to healthy controls, while CYP1B1-Val432Leu was not associated with GBC. The CYP1A1 haplotype [C-val] showed a significant association with GBC (p=0.006). On stratification based on gender, the CYP1A1-MspI [CC] genotype showed an increased risk of GBC in females (p=0.018). In case-only analysis, tobacco users with CYP1A1-MspI [CT] genotypes were at a higher risk of GBC (p=0.008). Subdividing the GBC patients on the basis of gallstone status, the CYP1A1 haplotype [C-val] imparted a higher risk in patients without stones when compared to controls (p=0.001). The results remained significant even after applying Bonferroni correction. Multivariate analysis revealed an increased risk of CYP1A1 iso/val and val/val genotypes in GBC patients having BMI >25 (p=0.021). The CYP1A1 polymorphisms may confer increased risk of GBC, probably due to impaired xenobiotic or hormone metabolism through a gallstone-independent pathway.

  4. A method distinguishing expressed vs. null mutations of the Col1A1 gene in osteogenesis imperfecta

    Energy Technology Data Exchange (ETDEWEB)

    Redford-Badwal, D.A.; Stover, M.L.; McKinstry, M. [and others


    Osteogenesis imperfecta (OI) is a heterogeneous group of heritable disorders of bone characterized by increased susceptibility to fracture. Most of the causative mutations were identified in patients with the lethal form of the disease. Attention is now shifting to the milder forms of OI where glycine substitutions and null producing mutations have been found. Single amino acid substitutions can be identified by RT/PCR of total cellular RNA, but this approach does not work well for null mutations since the defective transcript does not accumulate in the cytoplasm. We have altered our RNA extraction method to separate RNA from the nuclear and cytoplasmic compartments of cultured fibroblasts. Standard methods of mutation identification (RT/PCR followed by SSCP) is applied to each RNA fraction. DNA from an abnormal band on the SSCP gel is eluted and amplified by PCR for cloning and sequencing. Using this approach we have identified an Asp to Asn change in exon 50 (type II OI) and a Gly to Arg in exon 11 (type I OI) of the COL1A1 gene. These changes were found in both nuclear and cytoplasmic compartments. These putative mutations are currently being confirmed by protein studies. In contrast, three patients with mild OI associated with reduced {proportional_to}(I)mRNA, had distinguishing SSCP bands present in the nuclear but not the cytoplasmic compartment. In one case a frame shift mutation was observed, while the other two revealed polymorphisms. The compartmentalization of the mutant allele has directed us to look elsewhere in the transcript for the causative mutation. This approach to mutation identification is capable of distinguishing these fundamentally different types of mutations and allows for preferential cloning and sequencing of the abnormal allele.

  5. 新生儿胆红素脑病33例临床分析%A retrospective study of neonatal severe bilirubin encephalopathy in 33 newborns

    Institute of Scientific and Technical Information of China (English)

    徐瑞峰; 吴珠明; 高红霞; 易彬


    目的 探讨新生儿胆红素脑病的病因及临床特点.方法 选择2006年1月至2010年1月我院新生儿科收治的重症新生儿高胆红素血症患儿,分为胆红素脑病组(脑病组)与非胆红素脑病组(非脑病组),比较两组患儿病因、临床特征、胆红素水平、胆红素/白蛋白比值(B/A)以及治疗转归.结果 脑病组黄疸病因以溶血性因素占首位(48.5%),其次是感染因素(24.2%);非脑病组黄疸病因主要为溶血(69.7%).脑病组总胆红素、B/A比值、入院日龄和黄疸持续时间均大于非脑病组[( 555.2±113.9) μmol/L比(431.3±62.3)μmol/L,(0.87±0.17)比(0.67±0.11),(129.5±60.7)h比(53.0±22.6)h,(81.6±39.6)h比(34.2±15.8)h,P均<0.001].胆红素脑病警告期与痉挛期患儿入院日龄、血清胆红素及B/A比值差异无统计学意义(P>0.05).85%的胆红素脑病患儿预后不良.结论 溶血与感染是新生儿胆红素脑病的主要原因,总胆红素浓度过高和干预延迟是引起胆红素脑病的高危因素.%Objective To investigate the etiology and clinical features of neonatal bilirubin encephalopathy. Methods To select severe hyperbilirubinemia infant admitted in Gansu Provincial Maternity and Children's Hospital from January 2006 to January 2010, assigned into encephalopathy group and non-encephalopathy group, comparing their clinical characteristics, bilirubin level, bilirubin/ albumin ratio (B/A) and outcome. Results The main etiology of neonatal bilirubin encephalopathy is hemolytic (48. 5% ) , followed by infection (24. 2% ) ; but the etiology of non-encephalopathy is mainly for hemolysis, accounted for 69. 7%. Total bilirubin, B/A ratio, admission day and jaundice duration of Encephalopathy group are larger than them in non-encephalopathy group, the difference was statistically significant, (555. 2 ±113. 9) μmol/Lvs. (431. 3 ±62. 3) |xmol/L, (0.87 ±0.17) us. (0.67 ±0. 11) , (129.5 ±60.7) h ts. (53.0 ±22.6) h and (81.6 ±39.6) h

  6. 新生儿胆红素脑病脑脊液总胆红素及颅脑MRI检查的临床意义%Clinical Significance of Cerebrospinal Fluid Bilirubin and Craniocerebral Magnetic Resonance Imaging Measurements in Newborns with Bilirubin Encephalopathy

    Institute of Scientific and Technical Information of China (English)

    李先红; 张健; 郑洪; 孔萤; 孙路璐; 刘光辉


    Objective To explore the clinical significance of changes in cerebrospinal fluid bilirubin levels and craniocerebral magnetic resonance imaging (MRI)features in newborns with bilir-ubin encephalopathy. Methods Total bilirubin levels in serum and cerebrospinal fluid were determined using vanadate oxidation method with automatic biochemical analyzer in 44 newborns with bilirubin encephalopathy (bilirubin encephalopathy group)and 79 newborns without bilirubin enceph-alopathy (non-bilirubin encephalopathy group).In addition,craniocerebral MRI was performed in both groups. Results Total bilirubin levels in serum and cerebrospinal fluid in bilirubin encephalopathy group were significantly higher than those in non-bilirubin encephalopathy group (P<0.01).In bilirubin enceph-alopathy group,MRI showed symmetrical high signal intensity in the globus pallidus on T1WI in 33 newborns,abnormal signal in lateral side of posterior limb of internal capsule in the right basal ganglion region in 1 newborn,high signal intensity in the head of the right caudate nucleus on T1WI in 1 newborn, abnormal signal in the lateral ventricle in 3 newborns,abnormal signal in the bilateral frontal lobes in 1 newborn, short T1T2 signal in the torcular herophili in 1 newborn,and normal signal in 4 newborns. In non-bilirubin encephalopathy group,MRI showed symmetrical high signal intensity in the globus pallidus on T1WI in 3 newborns, abnormal signal in the right side of top occipital in 1 newborn, and normal signal in 75 newborns. The incidence of symmetrical high T1WI signal intensity in the globus pallidus in bilirubin encephalopathy group was significantly higher than that in non-bilirubin encephalopathy group (P<0.01).Conclusion Cerebrospinal fluid bilirubin can be used as a reliable indicator for the early diagnosis of bilirubin encephalopathy. The symmetrical high signal intensity in the globus pallidus on T1WI is the main feature of bilirubin encephalopathy in newborns. Regular fol-low-up and

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