Unconjugated bilirubin alleviates experimental ulcerative colitis by regulating intestinal barrier function and immune inflammation

BACKGROUND Unconjugated bilirubin(UCB) is generally considered toxic but has gained recent prominence for its anti-inflammatory properties. However, the effects of it on the interaction between intestinal flora and organisms and how it influences immune responses remain unresolved.AIM To investigate the role of UCB in intestinal barrier function and immune inflammation in mice with dextran-sulfate-sodium-induced colitis.METHODS Acute colitis was induced by 3%(w/v) dextran sulfate sodium salt in drinking water for 6 d followed by untreated water for 2 d. Concurrently, mice with colitis were administered 0.2 mL UCB(400 μmol/L) by intra-gastric gavage for 7 d.Disease activity index(DAI) was monitored daily. Mice were sacrificed at the end of the experiment. The length of the colon and weight of the spleen were recorded. Serum level of D-lactate, intestinal digestive proteases activity, and changes to the gut flora were analyzed. In addition, colonic specimens were analyzed by histology and for expression of inflammatory markers and proteins.RESULTS Mice treated with UCB had significantly relieved severity of colitis, including lower DAI, longer colon length, and lower spleen weight(colon length: 4.92 ±0.09 cm vs 3.9 ± 0.15 cm; spleen weight: 0.33 ± 0.04 vs 0.74 ± 0.04, P < 0.001). UCB administration inactivated digestive proteases(chymotrypsin: 18.70 ± 0.69 U/g vs44.81 ± 8.60 U/g; trypsin: 1.52 ± 0.23 U/g vs 9.05 ± 1.77 U/g, P < 0.01), increased expression of tight junction(0.99 ± 0.05 vs 0.57 ± 0.03, P < 0.001), decreased serum level of D-lactate(31.76 ± 3.37 μmol/L vs 54.25 ± 1.45 μmol/L, P < 0.001), and lowered histopathological score(4 ± 0.57 vs 7 ± 0.57, P < 0.001) and activity of myeloperoxidase(46.79 ± 2.57 U/g vs 110.32 ± 19.19 U/g, P < 0.001). UCB also regulated the intestinal microbiota, inhibited expression of tumor necrosis factor(TNF) α and interleukin 1β(TNF-α: 52.61 ± 7.81 pg/mg vs 105.04 ± 11.92 pg/mg,interleukin 1β: 13.43 ± 1.68 vs 32.41 ± 4.62 pg/mg, P < 0.001), decreased expression of Toll-like receptor 4(0.61 ± 0.09 vs 1.07 ± 0.03, P < 0.001) and myeloid differentiation primary response gene 88(0.73 ± 0.08 vs 1.01 ± 0.07, P <0.05), and increased expression of TNF-receptor-associated factor 6(0.79 ± 0.02 vs0.43 ± 0.09 P < 0.05) and inhibitor of kappa B α(0.93 ± 0.07 vs 0.72 ± 0.07, P < 0.05)in the colon.CONCLUSION UCB can protect intestinal barrier function, regulate normal intestinal homeostasis, and suppress inflammation via the Toll-like receptor 4/nuclear factor-κB signaling pathway.

A NEW TEST IN ANTENATAL MONITORING-THE EVALUATION OF SALIVARY UNCONJUGATED ESTRIOL MEASUREMENT

A new unconjugated saliva estriol （SE3） determination by radioimmunoassay（3H-E3） was used to monitor 497 fetuses of late pregnancies, including 280 high-risk and217 normal pregnant women. The normal pregnant SE3 values had been established by themeasurement of 1378 cases from 20 to 41 weeks of gestation. The results of SE3 assaysrevealed that 1. In prenatal prediction of fetal well-being, the total false negative andfalse positive rates were 2.0% and 0.6%, respectively, the correct rate which was similarto that of serum free E3 （SFE3） values was 97.4%, and was significantly higher thanthat of overnight 12-hour urine E3/C analyses as formerly reported. 2. There were 8 fetaldeathe in 11 cases with low SE3 levels. No perinatal death occurred in the 486 cases withnormal SE3 values, except one fetus who died of nuchal cord strangulation. It is highlyimportant that the saliva specimen be correctly collected and the technique ofmeasurement of SE3 be carefully carried out. Our observations suggest that the clinicaluse of SE3 assays are scientific, reliable, and it is more practicable than that of SFE3 as-says. The determination of SFE3 can be replaced by SE3 test for assessing fetal-placentalwell-being.

Construction of remote cyano-substituted quaternary carbon centers via nickel-catalyzed migratory hydrocyanation of unconjugated dienes

The transition-metal-catalyzed migratory functionalization has emerged as a robust protocol for the building of C–C bonds remote from the“initiation”position.However,a similar strategy for the construction of quaternary carbon centers is still underdeveloped and only a limited number of reports exist.Herein,we report a nickel-catalyzed migratory hydrocyanation of unconjugated dienes to construct remote cyano-substituted quaternary carbon centers.This transformation features exceptional regioselectivity,mild reaction conditions,broad substrate scope and high yields.The synthetic utility of this method has been highlighted by a series of product derivatizations,and the potential of this transformation has been extended to synthesize TRPV1 antagonist and the key intermediate in the total synthesis of quebrachamine.Density functional theory(DFT)studies unveiled that the specific catalytic pocket assumed a significant role in the selective formation of cyano-substituted quaternary carbon centers.

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

AIM： To identify the variants in U rase 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 by in silico analysis and by estimating UGT1A1 promoter activity carried out by ludferase 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 interactions among UGT1A1 groups and the epistatic promoter variants modulate bilirubin glucuronidation.

Gilbert’s syndrome coexisting with hereditary spherocytosis might not be rare: Six case reports

BACKGROUND Both Gilbert's syndrome(GS)and hereditary spherocytosis(HS)are common genetic disorders.However,comorbidity of GS with HS has always been considered a rare phenomenon,and it can impede accurate diagnoses in the presence of isolated unconjugated hyperbilirubinemia.CASE SUMMARY In a study on Levitt’s carbon monoxide(CO)breath test for the differential diagnosis of isolated hyperbilirubinemia,we found six GS patients with HS in 6 mo.The patients,including five males and one female,aged 25-58 years,were from four families and generally in good health.Their chronic fluctuating jaundice and/or hyperbilirubinemia had been diagnosed as simple constitutional jaundice for 6-30 years.Liver function tests showed isolated unconjugated hyperbilirubinemia with serum total bilirubin ranging from 20.7-75.4μmol/L.Blood hemoglobin was normal in five cases,and slightly decreased in one(11.5 g/dL).Overt hemolytic signs were absent,while erythrocyte lifespan determined by the newly developed Levitt’s CO breath test was significantly short(15-50 d),definitely demonstrating the presence of hemolysis.Given that their unconjugated hyperbilirubinemia compared inappropriately with hemolytic severity,as indicated by the hemoglobin level,further combined genetic tests for both UGT1A1 and hereditary erythrocyte deficiencies were conducted.These tests confirmed,at last,the coexistence of GS with HS.CONCLUSION Comorbidity of GS and HS might not be uncommon in isolated unconjugated hyperbilirubinemia.While CO breath test would sensitively detect the hemolysis,the discordance between the hyperbilirubinemia and hemoglobin level could strongly indicate the coexistence of GS and HS.

The therapeutic efficiency of ursodeoxycholic acid on Gilbert syndrome complicated by aplastic anemia: a series of case reports

Objective:To reduce the potential risk in aplastic anemia patients complicated with Gilbert syndrome,and find an effective treatment for the unconjugated hyperbilirubinemia.Material and Methods:The mutation of UGT1A1 gene was identified first via sequencing in patients with Gilbert syndrome complicated by aplastic anemia.Before the treatment for aplastic anemia,bilirubin and phenobarbitone tests were conducted.Patients were then treated for their primary disease and given ursodeoxycholic acid(UDCA)either with or without phenobarbitone.Results:The clinical practice of UDCA,which can alleviate increased bilirubin levels,did not affect the key treatments for aplastic anemia.Conclusions:These results indicate that Gilbert syndrome should be addressed when treating aplastic anemia.Furthermore,abnormal bilirubin levels can be controlled effectively by the UDCA treatment.

Ursodeoxycholic acid as adjuvant treatment to phototherapy for neonatal hyperbilirubinemia:a systematic review and meta‑analysis

Background Neonatal hyperbilirubinemia is observed in most newborns,and 5–15%of neonates require phototherapy.Phototherapy is efective but often prolongs hospitalization and has both short-term and potential long-term harms.The aim of this systematic review and meta-analysis was to evaluate the role of ursodeoxycholic acid(UDCA)combined with phototherapy in neonatal hyperbilirubinemia.Methods A literature search was conducted on September 1,2021;590 studies were screened,and 17 full texts were assessed by two authors.We included randomized controlled trials with or without placebo intervention.Primary outcomes were changes in total bilirubin levels at 24 hours and phototherapy duration.We calculated mean diferences with 95%confdence intervals(CI).Results Six studies with 880 neonates were included.Of these studies,only two used a placebo-controlled double-blinded design.The overall risk of bias was high in one and moderate in four of the included studies.The mean decrease in the total bilirubin level during the frst 24 hours was 2.06 mg/dL(95%CI 0.82–3.30;six studies)greater in the UDCA treatment group.The phototherapy duration was 19.7 hours(95%CI 10.4–29.1;fve studies)shorter in the UDCA treatment group.Conclusions We found low-quality evidence that UDCA as an adjuvant to phototherapy seems to decrease total bilirubin faster and shorten phototherapy duration compared to standard treatment.Further studies are needed to confrm the efcacy,acute and long-term outcomes,and safety before implementing UDCA as an adjuvant to phototherapy in neonatal hyperbilirubinemia.