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Stem Cell Reports Nov 2023UGT1A1 (UDP glucuronosyltransferase family 1 member A1) is the primary enzyme required for bilirubin conjugation, which is essential for preventing hyperbilirubinemia....
UGT1A1 (UDP glucuronosyltransferase family 1 member A1) is the primary enzyme required for bilirubin conjugation, which is essential for preventing hyperbilirubinemia. Animal models lack key human organic anion transporting polypeptides with distinct epigenetic control over bilirubin metabolism, necessitating a human model to interrogate the regulatory mechanism behind UGT1A1 function. Here, we use induced pluripotent stem cells to develop human liver organoids that can emulate conjugation failure phenotype. Bilirubin conjugation assays, chromatin immunoprecipitation, and transcriptome analysis elucidated the role of glucocorticoid antagonism in UGT1A1 activation. This antagonism prevents the binding of transcriptional repressor MECP2 at the expense of NRF2 with associated off-target effects. Therefore, we introduced functional GULO (L-gulonolactone oxidase) in human organoids to augment intracellular ascorbate for NRF2 reactivation. This engineered organoid conjugated more bilirubin and protected against hyperbilirubinemia when transplanted in immunosuppressed Crigler-Najjar syndrome rat model. Collectively, we demonstrate that our organoid system serves as a manipulatable model for interrogating hyperbilirubinemia and potential therapeutic development.
Topics: Humans; Animals; Rats; Bilirubin; NF-E2-Related Factor 2; Liver; Crigler-Najjar Syndrome; Hyperbilirubinemia; Glucuronosyltransferase; Pluripotent Stem Cells
PubMed: 37832542
DOI: 10.1016/j.stemcr.2023.09.006 -
Scandinavian Journal of Medicine &... Dec 2023Bilirubin was supposed to have cardio-metabolic protective role by signaling functions. Indeed, mild hyperbilirubinemia has immunosuppressive and endocrine activities...
INTRODUCTION
Bilirubin was supposed to have cardio-metabolic protective role by signaling functions. Indeed, mild hyperbilirubinemia has immunosuppressive and endocrine activities and may offer protection against oxidative stress-mediated diseases. Gilbert syndrome (GS) has been hypothesized to provide cardio-metabolic benefits.
OBJECTIVE
To investigate the prevalence of hyperbilirubinemia and its cardio-metabolic effects in a cohort of elite Italian athletes engaged in different sports disciplines.
METHODS
We enrolled 1492 elite athletes (age 25.8 ± 5.1) practising different disciplines (power, skills, endurance, and mixed) underwent blood, echocardiographic, and exercise tests. GS was diagnosed per exclusionem in athletes with isolated asymptomatic unconjugated hyperbilirubinemia.
RESULTS
GS was highlighted in 91 athletes (6%; globally 9% male and 2.4% female); 82% were males (p < 0.0001) showing higher indirect bilirubin (0.53 ± 0.4 vs. 0.36 ± 0.24 mg/dL in females, p < 0.0001). GS athletes had fewer platelets (201 ± 35 vs. 214 ± 41, p = 0.01), higher iron (male: 124 ± 44 vs. 100.9 ± 34 mcg/dL, p < 0.0001; female: 143.3 ± 35 vs. 99.9 ± 42 mcg/dL, p < 0.0001), and lower erythrocyte sedimentation rate, (1.93 ± 0.9 vs. 2.80 ± 2.7 mm/H, p = 0.03). At multivariate analysis, male (OR 3.89, p = 0.001) and iron (OR 3.47, p = 0.001) were independently associated with GS. No significant differences were found in cardiac remodeling, heart rate, blood pressure, arrhythmias, or power capacity at stress test. Endurance athletes (313) presented higher total (p = 0.003) and indirect bilirubin (p = 0.001).
CONCLUSION
Bilirubin has several metabolic effects (including immunosuppressive and endocrine) and plays a role in regulating antioxidant pathways exercise-related with hematological consequences but seems not to affect significantly cardiovascular remodeling. Endurance athletes present higher bilirubin concentrations, likely as an adaptive mechanism to counteract increased oxidative stress.
Topics: Humans; Male; Female; Young Adult; Adult; Hyperbilirubinemia; Gilbert Disease; Bilirubin; Athletes; Iron
PubMed: 37650311
DOI: 10.1111/sms.14481 -
Zhonghua Gan Zang Bing Za Zhi =... Oct 2021Gilbert's syndrome is a kind of benign inherited disease of bilirubin binding disorder, mainly due to the homozygous polymorphism A(TA)7TAA in the promoter of the gene...
Gilbert's syndrome is a kind of benign inherited disease of bilirubin binding disorder, mainly due to the homozygous polymorphism A(TA)7TAA in the promoter of the gene for uridine diphosphate -glucuronosyltransferase 1A1 (UGT1A1), which is a TA insertion into the promoter, designated as UGT1A1*28, with UGT activity reduction to 30% of the normal value. Therefore, circulating fat-soluble unconjugated bilirubin cannot be converted into water-soluble conjugated bilirubin, leading to unconjugated hyperbilirubinemia. Bilirubin has a strong affinity for erythrocyte phospholipids, which interferes with membrane composition and dynamics, resulting in increased erythrocytes fragility, easy rupture, and gradual shortening of survival time. However, there are no obvious sign of hemolysis or abnormal iron metabolism, erythrocytes and bone marrow morphology. A small amount of chronic hemolysis stimulates extramedullary (normal bone marrow morphology) hematopoiesis, ensuing compensatory increase in circulating erythrocytes and hemoglobin. Hyperbilirubinemia may also weaken gastrointestinal motility, increase passive diffusion and absorption across the intestinal mucosal epithelium by 1.5 to 2 times, thereby aggravating or worsening hyperbilirubinemia mainly with unconjugated bilirubin circulation, which indicates that there is a causal relationship between the circulating bilirubin concentration and rapid erythrocytes turnover and hemolysis rate in patients with Gilbert's syndrome. Interestingly, bilirubin also has significant antioxidant and anti-mutagenic activities, and the potential health benefits of mild hyperbilirubinemia in Gilbert's syndrome include reduced prevalence of cardiovascular disease, type 2 diabetes mellitus (and related risk factors), certain cancers, and cardiovascular-related and all-cause mortality. Exogenous bilirubin and biliverdin supplements in intestinal epithelial cells can be absorbed and may increase circulating concentration of these antioxidant compounds. With this information, we hope to raise awareness of the potentially harmful and beneficial effects of benign hyperbilirubinemia, and explore and develop beneficial medical interventions.
Topics: Bilirubin; Diabetes Mellitus, Type 2; Friends; Gilbert Disease; Glucuronosyltransferase; Humans; Hyperbilirubinemia
PubMed: 34814402
DOI: 10.3760/cma.j.cn501113-20200212-00041 -
Hepatology Communications Oct 2023Gilbert syndrome (GS) is genotypically predetermined by UGT1A1*28 homozygosity in Europeans and is phenotypically defined by hyperbilirubinemia using total bilirubin...
BACKGROUND AND AIMS
Gilbert syndrome (GS) is genotypically predetermined by UGT1A1*28 homozygosity in Europeans and is phenotypically defined by hyperbilirubinemia using total bilirubin (TB) cutoff ≥1mg/dL (17 μmol/L). The prevalence of illnesses associated with GS and hypobilirubinemia has never been studied prospectively. As TB varies with UGT1A1*28 genotyping, sex, and age, we propose stratified definitions of TB reference intervals and report the prevalence of illnesses and adjusted 15 years survival.
METHODS
UK Biobank with apparently healthy liver participants (middle-aged, n=138,125) were analyzed after the exclusion of of nonhealthy individuals. The stratified TB was classified as GS when TB >90th centile; <10th centile indicated hypobilirubinemia, and between the 10th and 90th centile was normobilirubinemia. We compared the prevalence and survival rates of 54 illnesses using odds ratio (OR), logistic regression, and Cox models adjusted for confounders, and causality by Mendelian randomizations.
RESULTS
In women, we identified 10% (7,741/76,809) of GS versus 3.7% (2,819/76,809) using the historical cutoff of ≥1 mg/dL (P<0.0001). When GS and hypobilirubinemia participants were compared with normobilirubinemia, after adjustment and Mendelian randomizations, only cholelithiasis prevalence was significantly higher (OR=1.50; 95% CI [1.3-1.7], P=0.001) in men with GS compared with normobilirubinemia and in causal association with bilirubin (P=0.04). No adjusted survival was significantly associated with GS or hypobilirubinemia.
CONCLUSIONS
In middle-aged Europeans, the stratified TB demonstrates a careless GS underestimation in women when using the standard unisex 1 mg/dL cutoff. The prevalence of illnesses is different in GS and hypobilirubinemia as well as survivals before adjusting for confounding factors. With the exception of cholelithiasis in men, these differences were no more significant after adjustment and Mendelian randomization.
Topics: Male; Middle Aged; Female; Humans; Adolescent; Gilbert Disease; Bilirubin; Hyperbilirubinemia; Liver; Healthy Volunteers
PubMed: 37738404
DOI: 10.1097/HC9.0000000000000245 -
Frontiers in Pharmacology 2021Unconjugated bilirubin (UCB) is more than the final product of heme catabolism. Mildly elevated systemic bilirubin concentrations, such as in Gilbert syndrome (GS),...
Unconjugated bilirubin (UCB) is more than the final product of heme catabolism. Mildly elevated systemic bilirubin concentrations, such as in Gilbert syndrome (GS), protect against various oxidative stress-mediated and metabolic diseases, including cardiovascular disease, type 2 diabetes mellitus, metabolic syndrome, cancer, and age-related disease. The Gunn rat is an animal model of hereditary hyperbilirubinemia widely used in assessing the effect of high serum bilirubin concentration in various organs. The present work aims to understand if life-long hyperbilirubinemia and bilirubin-priming might contribute to protection against atherosclerosis and diabetic nephropathy (DN) at the cellular level. Primary aortic endothelial cells and podocytes obtained from hyperbilirubinemic homozygous jj and normobilirubinemic heterozygous Nj Gunn rats were exposed to Palmitic Acid (PA) and Angiotensin II (Ang II), respectively, and the effects on cell viability and the activation of damage-related metabolic pathways evaluated. Results were validated on immortalized H5V and HK2 cells exposed to damage after UCB pretreatment. In both primary cell models, cells obtained from jj Gunn rats showed as significantly higher than Nj Gunn rats at any dose of the toxic agent. Reduction in CHOP expression and IL-6 release was observed in jj primary aortic endothelial cells exposed to PA compared to Nj cells. The same occurred on H5V pretreated with Unconjugated bilirubin. Upon Ang II treatment, primary podocytes from jj Gunn rats showed lower DNA fragmentation, cleaved caspase-3, and cleaved PARP induction than primary podocytes from Nj Gunn rats. In HK2 cells, the induction by Ang II of HIF-1α and LOXl2 was significantly reduced by UCB pretreatment. Our data suggest that in models of atherosclerosis and DN life-long hyperbilirubinemia exposure or bilirubin-priming significantly contribute to decrease the injury by enhancing thecellular defensive response.
PubMed: 33776779
DOI: 10.3389/fphar.2021.646953 -
Journal of the American Heart... Feb 2024Transthyretin cardiac amyloidosis (ATTR-CA) is a progressive and ultimately fatal cardiomyopathy. Biomarkers reflecting multiorgan dysfunction are of increasing...
BACKGROUND
Transthyretin cardiac amyloidosis (ATTR-CA) is a progressive and ultimately fatal cardiomyopathy. Biomarkers reflecting multiorgan dysfunction are of increasing importance in patients with heart failure; however, their significance in ATTR-CA remains largely unknown. The aims of this study were to characterize the multifaceted nature of ATTR-CA using blood biomarkers and assess the association between blood biomarkers and prognosis.
METHODS AND RESULTS
This is a retrospective cohort study of 2566 consecutive patients diagnosed with ATTR-CA between 2007 and 2023. Anemia (39%), high urea (52%), hyperbilirubinemia (18%), increased alkaline phosphatase (16%), increased CRP (C-reactive protein; 27%), and increased troponin (98.2%) were common findings in the overall population, whereas hyponatremia (6%) and hypoalbuminemia (2%) were less common. These abnormalities were most common in patients with p.(V142I) hereditary ATTR-CA, and became more prevalent as the severity of cardiac disease increased. Multivariable Cox regression analysis demonstrated that anemia (hazard ratio [HR], 1.19 [95% CI, 1.04-1.37]; =0.01), high urea (HR, 1.23 [95% CI, 1.04-1.45]; =0.01), hyperbilirubinemia (HR, 1.32 [95% CI, 1.13-1.57; =0.001), increased alkaline phosphatase (HR, 1.20 [95% CI, 1.01-1.42; =0.04), hyponatremia (HR, 1.65 [95% CI, 1.28-2.11]; <0.001), and troponin-T >56 ng/L (HR, 1.72 [95% CI, 1.46-2.03]; <0.001) were all independently associated with mortality in the overall population. The association between biomarkers and mortality varied across the spectrum of genotypes and left ventricular ejection fraction, with anemia remining independently associated with mortality in p.(V142I) hereditary ATTR-CA (HR, 1.58 [95% CI, 1.17-2.12]; =0.003) and in a subgroup of the overall population with a left ventricular ejection fraction ≤40% (HR, 1.39 [95% CI, 1.08-1.81]; =0.01).
CONCLUSIONS
Cardiac and noncardiac biomarker abnormalities were common and reflect the complex and multifaceted nature of ATTR-CA, with a wide range of biomarkers remaining independently associated with mortality. Clinical trials are needed to investigate whether biomarker abnormalities represent modifiable risk factors that if specifically targeted could improve outcomes.
Topics: Humans; Prealbumin; Cardiomyopathies; Amyloid Neuropathies, Familial; Stroke Volume; Retrospective Studies; Alkaline Phosphatase; Hyponatremia; Ventricular Function, Left; Prognosis; Biomarkers; Anemia; Hyperbilirubinemia; Urea
PubMed: 38314569
DOI: 10.1161/JAHA.123.033094 -
Case Reports in Gastroenterology 2022A 42-year-old man with no relevant past medical history presented with intermittent mild icterus and no signs of chronic liver disease. Laboratory tests were notable for...
A 42-year-old man with no relevant past medical history presented with intermittent mild icterus and no signs of chronic liver disease. Laboratory tests were notable for hyperbilirubinemia (total 7.97 mg/dL, direct 5.37 mg/dL), bilirubinuria, no signs of hemolysis, normal liver tests and lipids profile. Abdominal ultrasound was unremarkable. A panel of chronic liver diseases was negative except for increased serum (147.4 μg/dL) and urinary (179 μg/24 h) copper, with normal ceruloplasmin. No other Leipzig criteria for Wilson's disease were found, including a negative test for gene mutations (by exome sequencing). Total urinary coproporphyrin was normal with predominance of isomer I (86% of total urinary coproporphyrin output). Clinical and laboratorial profile was compatible with Dubin-Johnson syndrome; however, exome sequencing and search for deletions in the gene (encoding MRP2) only found a heterozygous potentially pathogenic variant (c.1483A>G - p.Lys495Glu). Additional extended molecular analysis of genes implicated in bilirubin metabolism found a homozygous deletion of a region encompassing exons 4-16 of gene (encoding OATP1B3) and all exons (encoding OATP1B1), thereby establishing Rotor syndrome diagnosis. Rotor and Dubin-Johnson syndromes are rare autosomal recessive liver diseases characterized by chronic conjugated hyperbilirubinemia, caused by the absence of the hepatic function OATP1B1/B3 (leading to impaired hepatic bilirubin reuptake and storage) and MRP2 transporters (leading to impaired hepatic bilirubin excretion), respectively. We report a case of compound hereditary hyperbilirubinemia with a misleading presentation with special focus on its diagnosis, particularly the advantage of extensive unbiased genetic testing by dedicated laboratories. With this case, we aim to highlight the necessity of establishing a diagnosis, reassuring the patient, and avoiding unnecessary invasive and costly diagnostic procedures.
PubMed: 36157610
DOI: 10.1159/000525517 -
The American Journal of Gastroenterology Aug 2019
Review
Topics: Bilirubin; Cholestasis; Diagnosis, Differential; Gilbert Disease; Humans; Hyperbilirubinemia; Jaundice; Jaundice, Obstructive; Liver Cirrhosis; Liver Function Tests; Non-alcoholic Fatty Liver Disease
PubMed: 31318706
DOI: 10.14309/ajg.0000000000000336 -
Expert Opinion on Biological Therapy Feb 2023
Topics: Humans; Crigler-Najjar Syndrome; Genetic Therapy
PubMed: 36579791
DOI: 10.1080/14712598.2022.2160237 -
Clinical Pharmacology and Therapeutics Sep 2019Observational epidemiological studies showed that mild hyperbilirubinemia has beneficial effects on the prevention of cardiovascular disease, type 2 diabetes mellitus,... (Review)
Review
Observational epidemiological studies showed that mild hyperbilirubinemia has beneficial effects on the prevention of cardiovascular disease, type 2 diabetes mellitus, and metabolic syndrome. In mammals, bilirubin plays a major role as a potent antioxidant. Uridine 5'-diphospho-glucuronosyl transferase (UGT)1A1 variants coding for bilirubin UDP-glucuronosyl transferase resulting in mild hyperbilirubinemia (as in Gilbert syndrome (GS)) may confer a strong genetic advantage. Strategies to boost bioavailability of bilirubin or to mimic GS represent an attractive approach to prevent many oxidative stress and inflammation-mediated diseases. Even a tiny, micromolar increase in serum bilirubin concentrations substantially decreases the risk of oxidative stress-mediated diseases. There are several possible ways to achieve this, including lifestyle changes, changes in dietary patterns, regular physical activities, or use of chemical drug or of specific plant products either in the form of regular food items or nutraceuticals. Further basic and experimental research is required to fully uncover this promising therapeutic field.
Topics: Age Factors; Bilirubin; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Gilbert Disease; Glucuronosyltransferase; Humans; Hyperbilirubinemia; Inflammation Mediators; Life Style; Metabolic Syndrome; Oxidative Stress; Severity of Illness Index; Sex Factors
PubMed: 30588615
DOI: 10.1002/cpt.1341