1
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Gazzin S, Bellarosa C, Tiribelli C. Molecular events in brain bilirubin toxicity revisited. Pediatr Res 2024; 95:1734-1740. [PMID: 38378754 DOI: 10.1038/s41390-024-03084-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/17/2024] [Accepted: 01/28/2024] [Indexed: 02/22/2024]
Abstract
The mechanisms involved in bilirubin neurotoxicity are still far from being fully elucidated. Several different events concur to damage mainly the neurons among which inflammation and alteration of the redox state play a major role. An imbalance of cellular calcium homeostasis has been recently described to be associated with toxic concentrations of bilirubin, and this disequilibrium may in turn elicit an inflammatory reaction. The different and age-dependent sensitivity to bilirubin damage must also be considered in describing the dramatic clinical picture of bilirubin-induced neurological damage (BIND) formerly known as kernicterus spectrum disorder (KSD). This review aims to critically address what is known and what is not in the molecular events of bilirubin neurotoxicity to provide hints for a better diagnosis and more successful treatments. Part of these concepts have been presented at the 38th Annual Audrey K. Brown Kernicterus Symposium of Pediatric American Society, Washington DC, May 1, 2023.
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Affiliation(s)
- Silvia Gazzin
- Liver-Brain Unit "Rita Moretti", Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, ss14, Km 163.5, Basovizza, 34149, Trieste, Italy
| | - Cristina Bellarosa
- Liver-Brain Unit "Rita Moretti", Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, ss14, Km 163.5, Basovizza, 34149, Trieste, Italy
| | - Claudio Tiribelli
- Liver-Brain Unit "Rita Moretti", Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, ss14, Km 163.5, Basovizza, 34149, Trieste, Italy.
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2
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Jiang JL, Zhou YY, Zhong WW, Luo LY, Liu SY, Xie XY, Mu MY, Jiang ZG, Xue Y, Zhang J, He YH. Uridine diphosphate glucuronosyltransferase 1A1 prevents the progression of liver injury. World J Gastroenterol 2024; 30:1189-1212. [PMID: 38577195 PMCID: PMC10989491 DOI: 10.3748/wjg.v30.i9.1189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/02/2024] [Accepted: 01/29/2024] [Indexed: 03/06/2024] Open
Abstract
BACKGROUND Uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) plays a crucial role in metabolizing and detoxifying endogenous and exogenous substances. However, its contribution to the progression of liver damage remains unclear. AIM To determine the role and mechanism of UGT1A1 in liver damage progression. METHODS We investigated the relationship between UGT1A1 expression and liver injury through clinical research. Additionally, the impact and mechanism of UGT1A1 on the progression of liver injury was analyzed through a mouse model study. RESULTS Patients with UGT1A1 gene mutations showed varying degrees of liver damage, while patients with acute-on-chronic liver failure (ACLF) exhibited relatively reduced levels of UGT1A1 protein in the liver as compared to patients with chronic hepatitis. This suggests that low UGT1A1 levels may be associated with the progression of liver damage. In mouse models of liver injury induced by carbon tetrachloride (CCl4) and concanavalin A (ConA), the hepatic levels of UGT1A1 protein were found to be increased. In mice with lipopolysaccharide or liver steatosis-mediated liver-injury progression, the hepatic protein levels of UGT1A1 were decreased, which is consistent with the observations in patients with ACLF. UGT1A1 knockout exacerbated CCl4- and ConA-induced liver injury, hepatocyte apoptosis and necroptosis in mice, intensified hepatocyte endoplasmic reticulum (ER) stress and oxidative stress, and disrupted lipid metabolism. CONCLUSION UGT1A1 is upregulated as a compensatory response during liver injury, and interference with this upregulation process may worsen liver injury. UGT1A1 reduces ER stress, oxidative stress, and lipid metabolism disorder, thereby mitigating hepatocyte apoptosis and necroptosis.
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Affiliation(s)
- Jin-Lian Jiang
- Department of Infectious Diseases, Affiliated Hospital of Zunyi Medical University, Zunyi 563000, Guizhou Province, China
| | - Yi-Yang Zhou
- Department of Infectious Diseases, Affiliated Hospital of Zunyi Medical University, Zunyi 563000, Guizhou Province, China
| | - Wei-Wei Zhong
- Department of Infectious Diseases, Jingmen Central Hospital, Jingmen 448000, Hubei Province, China
| | - Lin-Yan Luo
- Department of Respiratory Medicine, Anshun People’s Hospital, Anshun 561099, Guizhou Province, China
| | - Si-Ying Liu
- Department of Infectious Diseases, Affiliated Hospital of Zunyi Medical University, Zunyi 563000, Guizhou Province, China
| | - Xiao-Yu Xie
- Department of General Practice, Affiliated Hospital of Zunyi Medical University, Zunyi 563000, Guizhou Province, China
| | - Mao-Yuan Mu
- Department of Intervention Radiology, Affiliated Hospital of Zunyi Medical University, Zunyi 563000, Guizhou Province, China
| | - Zhi-Gang Jiang
- School of Public Health, Zunyi Medical University, Zunyi 563099, Guizhou Province, China
| | - Yuan Xue
- Department of Liver Diseases, Third People’s Hospital of Changzhou, Changzhou 213000, Jiangsu Province, China
| | - Jian Zhang
- Department of Digestion, Dafang County People’s Hospital, Bijie 551600, Guizhou Province, China
| | - Yi-Huai He
- Department of Infectious Diseases, Affiliated Hospital of Zunyi Medical University, Zunyi 563000, Guizhou Province, China
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Llido JP, Fioriti E, Pascut D, Giuffrè M, Bottin C, Zanconati F, Tiribelli C, Gazzin S. Bilirubin-Induced Transcriptomic Imprinting in Neonatal Hyperbilirubinemia. BIOLOGY 2023; 12:834. [PMID: 37372119 DOI: 10.3390/biology12060834] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/01/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023]
Abstract
Recent findings indicated aberrant epigenetic control of the central nervous system (CNS) development in hyperbilirubinemic Gunn rats as an additional cause of cerebellar hypoplasia, the landmark of bilirubin neurotoxicity in rodents. Because the symptoms in severely hyperbilirubinemic human neonates suggest other regions as privileged targets of bilirubin neurotoxicity, we expanded the study of the potential impact of bilirubin on the control of postnatal brain development to regions correlating with human symptoms. Histology, transcriptomic, gene correlation, and behavioral studies were performed. The histology revealed widespread perturbation 9 days after birth, restoring in adulthood. At the genetic level, regional differences were noticed. Bilirubin affected synaptogenesis, repair, differentiation, energy, extracellular matrix development, etc., with transient alterations in the hippocampus (memory, learning, and cognition) and inferior colliculi (auditory functions) but permanent changes in the parietal cortex. Behavioral tests confirmed the presence of a permanent motor disability. The data correlate well both with the clinic description of neonatal bilirubin-induced neurotoxicity, as well as with the neurologic syndromes reported in adults that suffered neonatal hyperbilirubinemia. The results pave the way for better deciphering the neurotoxic features of bilirubin and evaluating deeply the efficacy of new therapeutic approaches against the acute and long-lasting sequels of bilirubin neurotoxicity.
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Affiliation(s)
- John Paul Llido
- Liver Brain Unit "Rita Moretti", Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, 34149 Basovizza, Italy
- Department of Science and Technology, Philippine Council for Health Research and Development, Bicutan, Taguig City 1631, Philippines
- Department of Life Sciences, University of Trieste, 34139 Trieste, Italy
| | - Emanuela Fioriti
- Liver Brain Unit "Rita Moretti", Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, 34149 Basovizza, Italy
| | - Devis Pascut
- Liver Cancer Unit, Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, 34149 Basovizza, Italy
| | - Mauro Giuffrè
- Department of Medical, Surgical and Health Sciences, University of Trieste, 34149 Trieste, Italy
- Department of Internal Medicine, Yale School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Cristina Bottin
- Department of Medical, Surgical and Health Sciences, University of Trieste, 34149 Trieste, Italy
| | - Fabrizio Zanconati
- Department of Medical, Surgical and Health Sciences, University of Trieste, 34149 Trieste, Italy
| | - Claudio Tiribelli
- Liver Brain Unit "Rita Moretti", Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, 34149 Basovizza, Italy
| | - Silvia Gazzin
- Liver Brain Unit "Rita Moretti", Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, 34149 Basovizza, Italy
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Models of bilirubin neurological damage: lessons learned and new challenges. Pediatr Res 2022:10.1038/s41390-022-02351-x. [PMID: 36302856 DOI: 10.1038/s41390-022-02351-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 09/26/2022] [Accepted: 10/03/2022] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Jaundice (icterus) is the visible manifestation of the accumulation of bilirubin in the tissue and is indicative of potential toxicity to the brain. Since its very first description more than 2000 years ago, many efforts have been undertaken to understand the molecular determinants of bilirubin toxicity to neuronal cells to reduce the risk of neurological sequelae through the use of available chemicals and in vitro, ex vivo, in vivo, and clinical models. Although several studies have been performed, important questions remain unanswered, such as the reasons for regional sensitivity and the interplay with brain development. The number of new molecular effects identified has increased further, which has added even more complexity to the understanding of the condition. As new research challenges emerged, so does the need to establish solid models of prematurity. METHODS This review critically summarizes the key mechanisms of severe neonatal hyperbilirubinemia and the use of the available models and technologies for translational research. IMPACT We critically review the conceptual dogmas and models used for studying bilirubin-induced neurotoxicity. We point out the pitfalls and translational gaps, and suggest new clinical research challenges. We hope to inform researchers on the pro and cons of the models used, and to help direct their experimental focus in a most translational research.
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Pranty AI, Shumka S, Adjaye J. Bilirubin-Induced Neurological Damage: Current and Emerging iPSC-Derived Brain Organoid Models. Cells 2022; 11:2647. [PMID: 36078055 PMCID: PMC9454749 DOI: 10.3390/cells11172647] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/04/2022] [Accepted: 08/17/2022] [Indexed: 11/16/2022] Open
Abstract
Bilirubin-induced neurological damage (BIND) has been a subject of studies for decades, yet the molecular mechanisms at the core of this damage remain largely unknown. Throughout the years, many in vivo chronic bilirubin encephalopathy models, such as the Gunn rat and transgenic mice, have further elucidated the molecular basis of bilirubin neurotoxicity as well as the correlations between high levels of unconjugated bilirubin (UCB) and brain damage. Regardless of being invaluable, these models cannot accurately recapitulate the human brain and liver system; therefore, establishing a physiologically recapitulating in vitro model has become a prerequisite to unveil the breadth of complexities that accompany the detrimental effects of UCB on the liver and developing human brain. Stem-cell-derived 3D brain organoid models offer a promising platform as they bear more resemblance to the human brain system compared to existing models. This review provides an explicit picture of the current state of the art, advancements, and challenges faced by the various models as well as the possibilities of using stem-cell-derived 3D organoids as an efficient tool to be included in research, drug screening, and therapeutic strategies for future clinical applications.
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Affiliation(s)
| | | | - James Adjaye
- Institute for Stem Cell Research and Regenerative Medicine, Faculty of Medicine, Heinrich-Heine University, Moorenstrasse 5, 40225 Dusseldorf, Germany
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Normalizing hyperactivity of the Gunn rat with bilirubin-induced neurological disorders via ketanserin. Pediatr Res 2022; 91:556-564. [PMID: 33790408 DOI: 10.1038/s41390-021-01446-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/28/2021] [Accepted: 02/08/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Severe neonatal hyperbilirubinemia has been known to cause the clinical syndrome of kernicterus and a milder one the syndrome of bilirubin-induced neurologic dysfunction (BIND). BIND clinically manifests itself after the neonatal period as developmental delay, cognitive impairment, and related behavioral and psychiatric disorders. The complete picture of BIND is not clear. METHODS The Gunn rat is a mutant strain of the Wistar rat with the BIND phenotype, and it demonstrates abnormal behavior. We investigated serotonergic dysfunction in Gunn rats by pharmacological analyses and ex vivo neurochemical analyses. RESULTS Ketanserin, the 5-HT2AR antagonist, normalizes hyperlocomotion of Gunn rats. Both serotonin and its metabolites in the frontal cortex of Gunn rats were higher in concentrations than in control Wistar rats. The 5-HT2AR mRNA expression was downregulated without alteration of the protein abundance in the Gunn rat frontal cortex. The TPH2 protein level in the Gunn rat raphe region was significantly higher than that in the Wistar rat. CONCLUSIONS It would be of value to be able to postulate that a therapeutic strategy for BIND disorders would be the restoration of brain regions affected by the serotonergic dysfunction to normal operation to prevent before or to normalize after onset of BIND manifestations. IMPACT We demonstrated serotonergic dysregulation underlying hyperlocomotion in Gunn rats. This finding suggests that a therapeutic strategy for bilirubin-induced neurologic dysfunction (BIND) would be the restoration of brain regions affected by the serotonergic dysfunction to normal operation to prevent before or to normalize after the onset of the BIND manifestations. Ketanserin normalizes hyperlocomotion of Gunn rats. To our knowledge, this is the first study to demonstrate a hyperlocomotion link to serotonergic dysregulation in Gunn rats.
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Kitchen ST, Tang N, He M, Ly E, Mooney SM, Bearer CF. Bilirubin inhibits lipid raft dependent functions of L1 cell adhesion molecule in rat pup cerebellar granule neurons. Pediatr Res 2021; 89:1389-1395. [PMID: 32937649 PMCID: PMC9323028 DOI: 10.1038/s41390-020-01156-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/07/2020] [Accepted: 09/01/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND The mechanism of bilirubin neurotoxicity is poorly understood. We hypothesize that bilirubin inhibits the function of lipid rafts (LR), microdomains of the plasma membrane critical for signal transduction. To test this hypothesis, we measured the effect of free bilirubin (Bf) between 7.6 and 122.5 nM on LR-dependent functions of L1 cell adhesion molecule (L1). METHODS Cerebellar granule neurons (CGN) were plated on poly-L-lysine overnight, and neurite length was determined after 1 h treatment with L1 alone or L1 and bilirubin. L1 activation of ERK1/2 was measured in CGN in the presence or absence of bilirubin. The effect of bilirubin on L1 distribution in LR was quantitated, and the localization of bilirubin to LR was determined. RESULTS The addition of bilirubin to CGN treated with L1 significantly decreased neurite length compared to L1 alone. L1 activation of ERK1/2 was inhibited by bilirubin. Bilirubin redistributed L1 into LR. Bilirubin was associated only with LR-containing fractions of a sucrose density gradient. CONCLUSION Bf significantly inhibits LR-dependent functions of L1 and are found only associated with LR, suggesting one mechanism by which bilirubin may exert neurotoxicity is through the dysfunction of protein-LR interactions. IMPACT This article establishes lipid rafts as a target for the neurotoxic effects of bilirubin. This article provides clear evidence toward establishing one mechanism of bilirubin neurotoxicity, where little is understood. This article paves the way for future investigation into lipid raft dependent functions, and its role in neurodevelopmental outcome.
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Affiliation(s)
- Spencer T. Kitchen
- Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio, 44106
| | - Ningfeng Tang
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, Maryland, 21201
| | - Min He
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, 21218
| | - Eric Ly
- Division of Neonatology, University of Maryland School of Medicine, Baltimore, Maryland, 21201
| | - Sandra M. Mooney
- Department of Nutrition, University of North Carolina School of Public Health, Chapel Hill, North Carolina, 27514
| | - Cynthia F. Bearer
- Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio, 44106,Corresponding author: Cynthia F. Bearer, M.D., Ph.D., Department of Pediatrics, 2109 Adelbert Rd, 8th floor, Cleveland, OH 44106, Tel. (410) 328-6003, Fax. (410) 328-1076,
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8
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Gazzin S, Dal Ben M, Montrone M, Jayanti S, Lorenzon A, Bramante A, Bottin C, Moretti R, Tiribelli C. Curcumin Prevents Cerebellar Hypoplasia and Restores the Behavior in Hyperbilirubinemic Gunn Rat by a Pleiotropic Effect on the Molecular Effectors of Brain Damage. Int J Mol Sci 2020; 22:ijms22010299. [PMID: 33396688 PMCID: PMC7795686 DOI: 10.3390/ijms22010299] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/23/2020] [Accepted: 12/25/2020] [Indexed: 01/08/2023] Open
Abstract
Bilirubin toxicity to the central nervous system (CNS) is responsible for severe and permanent neurologic damage, resulting in hearing loss, cognitive, and movement impairment. Timely and effective management of severe neonatal hyperbilirubinemia by phototherapy or exchange transfusion is crucial for avoiding permanent neurological consequences, but these therapies are not always possible, particularly in low-income countries. To explore alternative options, we investigated a pharmaceutical approach focused on protecting the CNS from pigment toxicity, independently from serum bilirubin level. To this goal, we tested the ability of curcumin, a nutraceutical already used with relevant results in animal models as well as in clinics in other diseases, in the Gunn rat, the spontaneous model of neonatal hyperbilirubinemia. Curcumin treatment fully abolished the landmark cerebellar hypoplasia of Gunn rat, restoring the histological features, and reverting the behavioral abnormalities present in the hyperbilirubinemic rat. The protection was mediated by a multi-target action on the main bilirubin-induced pathological mechanism ongoing CNS damage (inflammation, redox imbalance, and glutamate neurotoxicity). If confirmed by independent studies, the result suggests the potential of curcumin as an alternative/complementary approach to bilirubin-induced brain damage in the clinical scenario.
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Affiliation(s)
- Silvia Gazzin
- Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, ss14, Km 163.5, Basovizza, 34149 Trieste, Italy; (M.D.B.); (M.M.); (S.J.); (C.T.)
- Correspondence:
| | - Matteo Dal Ben
- Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, ss14, Km 163.5, Basovizza, 34149 Trieste, Italy; (M.D.B.); (M.M.); (S.J.); (C.T.)
| | - Michele Montrone
- Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, ss14, Km 163.5, Basovizza, 34149 Trieste, Italy; (M.D.B.); (M.M.); (S.J.); (C.T.)
| | - Sri Jayanti
- Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, ss14, Km 163.5, Basovizza, 34149 Trieste, Italy; (M.D.B.); (M.M.); (S.J.); (C.T.)
| | - Andrea Lorenzon
- SPF Animal Facility, CBM Scarl, Bldg. Q2, AREA Science Park, ss14, Km 163.5, Basovizza, 34149 Trieste, Italy; (A.L.); (A.B.)
| | - Alessandra Bramante
- SPF Animal Facility, CBM Scarl, Bldg. Q2, AREA Science Park, ss14, Km 163.5, Basovizza, 34149 Trieste, Italy; (A.L.); (A.B.)
| | - Cristina Bottin
- Department of Medical Sciences, Ospedale di Cattinara, University of Trieste, Strada di Fiume 447, 34149 Trieste, Italy;
| | - Rita Moretti
- Neurology Clinic, Department of Medical, Surgical, and Health Sciences, University of Trieste, Strada di Fiume 447, 34149 Trieste, Italy;
| | - Claudio Tiribelli
- Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, ss14, Km 163.5, Basovizza, 34149 Trieste, Italy; (M.D.B.); (M.M.); (S.J.); (C.T.)
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Hansen TWR, Wong RJ, Stevenson DK. Molecular Physiology and Pathophysiology of Bilirubin Handling by the Blood, Liver, Intestine, and Brain in the Newborn. Physiol Rev 2020; 100:1291-1346. [PMID: 32401177 DOI: 10.1152/physrev.00004.2019] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Bilirubin is the end product of heme catabolism formed during a process that involves oxidation-reduction reactions and conserves iron body stores. Unconjugated hyperbilirubinemia is common in newborn infants, but rare later in life. The basic physiology of bilirubin metabolism, such as production, transport, and excretion, has been well described. However, in the neonate, numerous variables related to nutrition, ethnicity, and genetic variants at several metabolic steps may be superimposed on the normal physiological hyperbilirubinemia that occurs in the first week of life and results in bilirubin levels that may be toxic to the brain. Bilirubin exists in several isomeric forms that differ in their polarities and is considered a physiologically important antioxidant. Here we review the chemistry of the bilirubin molecule and its metabolism in the body with a particular focus on the processes that impact the newborn infant, and how differences relative to older children and adults contribute to the risk of developing both acute and long-term neurological sequelae in the newborn infant. The final section deals with the interplay between the brain and bilirubin and its entry, clearance, and accumulation. We conclude with a discussion of the current state of knowledge regarding the mechanism(s) of bilirubin neurotoxicity.
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Affiliation(s)
- Thor W R Hansen
- Division of Paediatric and Adolescent Medicine, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; and Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - Ronald J Wong
- Division of Paediatric and Adolescent Medicine, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; and Department of Pediatrics, Stanford University School of Medicine, Stanford, California
| | - David K Stevenson
- Division of Paediatric and Adolescent Medicine, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; and Department of Pediatrics, Stanford University School of Medicine, Stanford, California
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10
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Bilirubin disrupts calcium homeostasis in neonatal hippocampal neurons: a new pathway of neurotoxicity. Arch Toxicol 2020; 94:845-855. [DOI: 10.1007/s00204-020-02659-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 02/03/2020] [Indexed: 12/22/2022]
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11
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Experimental models assessing bilirubin neurotoxicity. Pediatr Res 2020; 87:17-25. [PMID: 31493769 DOI: 10.1038/s41390-019-0570-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/29/2019] [Accepted: 08/16/2019] [Indexed: 02/08/2023]
Abstract
The molecular and cellular events leading to bilirubin-induced neurotoxicity, the mechanisms regulating liver and intestine expression in neonates, and alternative pathways of bilirubin catabolism remain incompletely defined. To answer these questions, researchers have developed a number of model systems to closely recapitulate the main characteristics of the disease, ranging from tissue cultures to engineered mouse models. In the present review we describe in vitro, ex vivo, and in vivo models developed to study bilirubin metabolism and neurotoxicity, with a special focus on the use of engineered animal models. In addition, we discussed the most recent studies related to potential therapeutic approaches to treat neonatal hyperbilirubinemia, ranging from anti-inflammatory drugs, activation of nuclear receptor pathways, blockade of bilirubin catabolism, and stimulation of alternative bilirubin-disposal pathways.
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Bilirubin-Induced Oxidative Stress Leads to DNA Damage in the Cerebellum of Hyperbilirubinemic Neonatal Mice and Activates DNA Double-Strand Break Repair Pathways in Human Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:1801243. [PMID: 30598724 PMCID: PMC6287157 DOI: 10.1155/2018/1801243] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 09/19/2018] [Accepted: 10/02/2018] [Indexed: 12/27/2022]
Abstract
Unconjugated bilirubin is considered a potent antioxidant when present at moderate levels. However, at high concentrations, it produces severe neurological damage and death associated with kernicterus due to oxidative stress and other mechanisms. While it is widely recognized that oxidative stress by different toxic insults results in severe damage to cellular macromolecules, especially to DNA, no data are available either on DNA damage in the brain triggered by hyperbilirubinemia during the neonatal period or on the activation of DNA repair mechanisms. Here, using a mouse model of neonatal hyperbilirubinemia, we demonstrated that DNA damage occurs in vivo in the cerebellum, the brain region most affected by bilirubin toxicity. We studied the mechanisms associated with potential toxic action of bilirubin on DNA in in vitro models, which showed significant increases in DNA damage when neuronal and nonneuronal cells were treated with 140 nM of free bilirubin (Bf), as determined by γH2AX Western blot and immunofluorescence analyses. Cotreatment of cells with N-acetyl-cysteine, a potent oxidative-stress inhibitor, prevented DNA damage by bilirubin, supporting the concept that DNA damage was caused by bilirubin-induced oxidative stress. Bilirubin treatment also activated the main DNA repair pathways through homologous recombination (HR) and nonhomologous end joining (NHEJ), which may be adaptive responses to repair bilirubin-induced DNA damage. Since DNA damage may be another important factor contributing to neuronal death and bilirubin encephalopathy, these results contribute to the understanding of the mechanisms associated with bilirubin toxicity and may be of relevance in neonates affected with severe hyperbilirubinemia.
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Bortolussi G, Muro AF. Advances in understanding disease mechanisms and potential treatments for Crigler–Najjar syndrome. Expert Opin Orphan Drugs 2018. [DOI: 10.1080/21678707.2018.1495558] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Giulia Bortolussi
- Mouse Molecular Genetics Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Andrés Fernando Muro
- Mouse Molecular Genetics Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
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14
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Vodret S, Bortolussi G, Iaconcig A, Martinelli E, Tiribelli C, Muro AF. Attenuation of neuro-inflammation improves survival and neurodegeneration in a mouse model of severe neonatal hyperbilirubinemia. Brain Behav Immun 2018; 70:166-178. [PMID: 29458193 DOI: 10.1016/j.bbi.2018.02.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/06/2018] [Accepted: 02/15/2018] [Indexed: 01/21/2023] Open
Abstract
All pre-term newborns and a high proportion of term newborns develop neonatal jaundice. Neonatal jaundice is usually a benign condition and self-resolves within few days after birth. However, a combination of unfavorable complications may lead to acute hyperbilirubinemia. Excessive hyperbilirubinemia may be toxic for the developing nervous system leading to severe neurological damage and death by kernicterus. Survivors show irreversible neurological deficits such as motor, sensitive and cognitive abnormalities. Current therapies rely on the use of phototherapy and, in unresponsive cases, exchange transfusion, which is performed only in specialized centers. During bilirubin-induced neurotoxicity different molecular pathways are activated, ranging from oxidative stress to endoplasmic reticulum (ER) stress response and inflammation, but the contribution of each pathway in the development of the disease still requires further investigation. Thus, to increase our understanding of the pathophysiology of bilirubin neurotoxicity, encephalopathy and kernicterus, we pharmacologically modulated neurodegeneration and neuroinflammation in a lethal mouse model of neonatal hyperbilirubinemia. Treatment of mutant mice with minocycline, a second-generation tetracycline with anti-inflammatory and neuroprotective properties, resulted in a dose-dependent rescue of lethality, due to reduction of neurodegeneration and neuroinflammation, without affecting plasma bilirubin levels. In particular, rescued mice showed normal motor-coordination capabilities and behavior, as determined by the accelerating rotarod and open field tests, respectively. From the molecular point of view, rescued mice showed a dose-dependent reduction in apoptosis of cerebellar neurons and improvement of dendritic arborization of Purkinje cells. Moreover, we observed a decrease of bilirubin-induced M1 microglia activation at the sites of damage with a reduction in oxidative and ER stress markers in these cells. Collectively, these data indicate that neurodegeneration and neuro-inflammation are key factors of bilirubin-induced neonatal lethality and neuro-behavioral abnormalities. We propose that the application of pharmacological treatments having anti-inflammatory and neuroprotective effects, to be used in combination with the current treatments, may significantly improve the management of acute neonatal hyperbilirubinemia, protecting from bilirubin-induced neurological damage and death.
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Affiliation(s)
- Simone Vodret
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano, 99, 34149 Trieste, Italy
| | - Giulia Bortolussi
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano, 99, 34149 Trieste, Italy.
| | - Alessandra Iaconcig
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano, 99, 34149 Trieste, Italy
| | - Elena Martinelli
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano, 99, 34149 Trieste, Italy
| | - Claudio Tiribelli
- Centro Studi Fegato, Fondazione Italiana Fegato, AREA Science Park, Campus Basovizza, Trieste, Italy
| | - Andrés F Muro
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano, 99, 34149 Trieste, Italy.
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15
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Feng J, Li M, Wei Q, Li S, Song S, Hua Z. Unconjugated bilirubin induces pyroptosis in cultured rat cortical astrocytes. J Neuroinflammation 2018; 15:23. [PMID: 29357878 PMCID: PMC5776766 DOI: 10.1186/s12974-018-1064-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 01/12/2018] [Indexed: 02/07/2023] Open
Abstract
Background Bilirubin-induced neurological dysfunction (BIND), a severe complication of extreme neonatal hyperbilirubinemia, could develop into permanent neurodevelopmental impairments. Several studies have demonstrated that inflammation and nerve cell death play important roles in bilirubin-induced neurotoxicity; however, the underlying mechanism remains unidentified. Methods The present study was intended to investigate whether pyroptosis, a highly inflammatory form of programmed cell death, participated in the bilirubin-mediated toxicity on cultured rat cortical astrocytes. Further, VX-765, a potent and selective competitive drug, was used to inhibit the activation of caspase-1. The effects of VX-765 on astrocytes treated with bilirubin, including the cell viability, morphological changes of the cell membrane and nucleus, and the production of pro-inflammation cytokines, were observed. Results Stimulation of the astrocytes with unconjugated bilirubin (UCB) at the conditions mimicking those of jaundiced newborns significantly increased the activation of caspase-1. Further, caspase-1 activation was inhibited by treatment with VX-765. Compared with UCB-treated astrocytes, the relative cell viability of VX-765-pretreated astrocytes was improved; meanwhile, the formation of plasma membrane pores was prevented, as measured by lactate dehydrogenase release, trypan blue staining, and ethidium bromide (EtBr) uptake. Moreover, DNA fragmentation was partly attenuated and the release of IL-1β and IL-18 was apparently decreased. Conclusion Pyroptosis is involved in the process of UCB-induced rat cortical astrocytes’ injury in vitro and may be the missing link of cell death and inflammatory response exacerbating UCB-related neurotoxicity. More importantly, the depression of caspase-1 activation, the core link of pyroptosis, attenuated UCB-induced cellular dysfunction and cytokine release, which might shed light on a new therapeutic approach to BIND.
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Affiliation(s)
- Jie Feng
- Department of Neonatology, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014, China.,Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Chongqing, 400014, China.,China International Science and Technology Cooperation base of Child development and Critical Disorders, Chongqing, China
| | - Mengwen Li
- Department of Neonatology, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014, China.,Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Chongqing, 400014, China.,China International Science and Technology Cooperation base of Child development and Critical Disorders, Chongqing, China
| | - Qian Wei
- Department of Neonatology, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014, China.,Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Chongqing, 400014, China.,China International Science and Technology Cooperation base of Child development and Critical Disorders, Chongqing, China
| | - Shengjun Li
- Department of Neonatology, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014, China.,China International Science and Technology Cooperation base of Child development and Critical Disorders, Chongqing, China
| | - Sijie Song
- Department of Neonatology, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014, China.,China International Science and Technology Cooperation base of Child development and Critical Disorders, Chongqing, China
| | - Ziyu Hua
- Department of Neonatology, Children's Hospital of Chongqing Medical University, Chongqing, 400014, China. .,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, 400014, China. .,Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, 400014, China. .,China International Science and Technology Cooperation base of Child development and Critical Disorders, Chongqing, China.
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16
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Vodret S, Bortolussi G, Jašprová J, Vitek L, Muro AF. Inflammatory signature of cerebellar neurodegeneration during neonatal hyperbilirubinemia in Ugt1 -/- mouse model. J Neuroinflammation 2017; 14:64. [PMID: 28340583 PMCID: PMC5366125 DOI: 10.1186/s12974-017-0838-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 03/12/2017] [Indexed: 12/14/2022] Open
Abstract
Background Severe hyperbilirubinemia is toxic during central nervous system development. Prolonged and uncontrolled high levels of unconjugated bilirubin lead to bilirubin-induced neurological damage and eventually death by kernicterus. Bilirubin neurotoxicity is characterized by a wide array of neurological deficits, including irreversible abnormalities in motor, sensitive and cognitive functions, due to bilirubin accumulation in the brain. Despite the abundant literature documenting the in vitro and in vivo toxic effects of bilirubin, it is unclear which molecular and cellular events actually characterize bilirubin-induced neurodegeneration in vivo. Methods We used a mouse model of neonatal hyperbilirubinemia to temporally and spatially define the response of the developing cerebellum to the bilirubin insult. Results We showed that the exposure of developing cerebellum to sustained bilirubin levels induces the activation of oxidative stress, ER stress and inflammatory markers at the early stages of the disease onset. In particular, we identified TNFα and NFKβ as key mediators of bilirubin-induced inflammatory response. Moreover, we reported that M1 type microglia is increasingly activated during disease progression. Failure to counteract this overwhelming stress condition resulted in the induction of the apoptotic pathway and the generation of the glial scar. Finally, bilirubin induced the autophagy pathway in the stages preceding death of the animals. Conclusions This study demonstrates that inflammation is a key contributor to bilirubin damage that cooperates with ER stress in the onset of neurotoxicity. Pharmacological modulation of the inflammatory pathway may be a potential intervention target to ameliorate neonatal lethality in Ugt1-/- mice. Electronic supplementary material The online version of this article (doi:10.1186/s12974-017-0838-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Simone Vodret
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano, 99, 34149, Trieste, Italy
| | - Giulia Bortolussi
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano, 99, 34149, Trieste, Italy.
| | - Jana Jašprová
- Institute of Medical Biochemistry and Laboratory Medicine, First Faculty of Medicine, Charles University, 120 00, Prague, Czech Republic
| | - Libor Vitek
- Institute of Medical Biochemistry and Laboratory Medicine, First Faculty of Medicine, Charles University, 120 00, Prague, Czech Republic.,Fourth Department of Internal Medicine, First Faculty of Medicine, Charles University, 120 00, Prague, Czech Republic
| | - Andrés F Muro
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano, 99, 34149, Trieste, Italy.
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17
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Yueh MF, Chen S, Nguyen N, Tukey RH. Developmental, Genetic, Dietary, and Xenobiotic Influences on Neonatal Hyperbilirubinemia. Mol Pharmacol 2017; 91:545-553. [PMID: 28283555 DOI: 10.1124/mol.116.107524] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 03/07/2017] [Indexed: 01/08/2023] Open
Abstract
Hyperbilirubinemia, caused by the accumulation of unconjugated bilirubin, is one of the most common clinical diagnoses in both premature and term newborns. Owing to the fact that bilirubin is metabolized solely through glucuronidation by UDP-glucuronosyltransferase (UGT) 1A1, it is now known that immaturity of UGT1A1, in combination with the overproduction of bilirubin during the developmental stage, acts as a bottleneck to bilirubin elimination and predisposes the infant to high total serum bilirubin levels. Although neonatal jaundice is mostly benign, excessively high levels of serum bilirubin in a small percentage of newborns can cause bilirubin-induced neurologic dysfunction, potentially leading to permanent brain damage, a condition known as kernicterus Although a large portion of hyperbilirubinemia cases in newborns are associated with hemolytic diseases, we emphasize here the impaired ability of UGT1A1 to eliminate bilirubin that contributes to hyperbilirubinemia-induced neurotoxicity in the developmental stage. As a series of hereditary UGT1A1 mutations have been identified that are associated with UGT1A1 deficiency, new evidence has verified that delayed expression of UGT1A1 during the early stages of neonatal development is a tightly controlled event involving coordinated intrahepatic and extrahepatic regulation. This review recapitulates the progress that has been made in recent years in understanding the causes and physiopathology of severe hyperbilirubinemia, investigating molecular mechanisms underlying bilirubin-induced encephalopathy, and searching for potential therapies for treating pathologic hyperbilirubinemia. Several animal models have been developed to make it possible to examine bilirubin-induced neurotoxicity from multiple directions. Moreover, environmental factors that may alleviate or worsen the condition of hyperbilirubinemia are discussed.
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Affiliation(s)
- Mei-Fei Yueh
- Laboratory of Environmental Toxicology, Department of Pharmacology, University of California, San Diego, La Jolla, California
| | - Shujuan Chen
- Laboratory of Environmental Toxicology, Department of Pharmacology, University of California, San Diego, La Jolla, California
| | - Nghia Nguyen
- Laboratory of Environmental Toxicology, Department of Pharmacology, University of California, San Diego, La Jolla, California
| | - Robert H Tukey
- Laboratory of Environmental Toxicology, Department of Pharmacology, University of California, San Diego, La Jolla, California
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18
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Dal Ben M, Bottin C, Zanconati F, Tiribelli C, Gazzin S. Evaluation of region selective bilirubin-induced brain damage as a basis for a pharmacological treatment. Sci Rep 2017; 7:41032. [PMID: 28102362 PMCID: PMC5244479 DOI: 10.1038/srep41032] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 12/14/2016] [Indexed: 12/20/2022] Open
Abstract
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.
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Affiliation(s)
- Matteo Dal Ben
- Italian Liver Foundation (Fondazione Italiana Fegato), AREA Science Park, Trieste, Italy
| | - Cristina Bottin
- Department of Medical Sciences (Dipartimento di Scienze Mediche), Ospedale di Cattinara, Univestità degli Studi di Trieste, Trieste, Italy
| | - Fabrizio Zanconati
- Department of Medical Sciences (Dipartimento di Scienze Mediche), Ospedale di Cattinara, Univestità degli Studi di Trieste, Trieste, Italy
| | - Claudio Tiribelli
- Italian Liver Foundation (Fondazione Italiana Fegato), AREA Science Park, Trieste, Italy
| | - Silvia Gazzin
- Italian Liver Foundation (Fondazione Italiana Fegato), AREA Science Park, Trieste, Italy
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19
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Manni I, Di Rocco G, Fusco S, Leone L, Barbati SA, Carapella CM, Grassi C, Piaggio G, Toietta G. Monitoring the Response of Hyperbilirubinemia in the Mouse Brain by In Vivo Bioluminescence Imaging. Int J Mol Sci 2016; 18:ijms18010050. [PMID: 28036021 PMCID: PMC5297685 DOI: 10.3390/ijms18010050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 12/18/2016] [Accepted: 12/22/2016] [Indexed: 01/02/2023] Open
Abstract
Increased levels of unconjugated bilirubin are neurotoxic, but the mechanism leading to neurological damage has not been completely elucidated. Innovative strategies of investigation are needed to more precisely define this pathological process. By longitudinal in vivo bioluminescence imaging, we noninvasively visualized the brain response to hyperbilirubinemia in the MITO-Luc mouse, in which light emission is restricted to the regions of active cell proliferation. We assessed that acute hyperbilirubinemia promotes bioluminescence in the brain region, indicating an increment in the cell proliferation rate. Immunohistochemical detection in brain sections of cells positive for both luciferase and the microglial marker allograft inflammatory factor 1 suggests proliferation of microglial cells. In addition, we demonstrated that brain induction of bioluminescence was altered by pharmacological displacement of bilirubin from its albumin binding sites and by modulation of the blood-brain barrier permeability, all pivotal factors in the development of bilirubin-induced neurologic dysfunction. We also determined that treatment with minocycline, an antibiotic with anti-inflammatory and neuroprotective properties, or administration of bevacizumab, an anti-vascular endothelial growth factor antibody, blunts bilirubin-induced bioluminescence. Overall the study supports the use of the MITO-Luc mouse as a valuable tool for the rapid response monitoring of drugs aiming at preventing acute bilirubin-induced neurological dysfunction.
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Affiliation(s)
- Isabella Manni
- Department of Research, Advanced Diagnostic, and Technological Innovation, Regina Elena National Cancer Institute, 00144 Rome, Italy.
| | - Giuliana Di Rocco
- Department of Research, Advanced Diagnostic, and Technological Innovation, Regina Elena National Cancer Institute, 00144 Rome, Italy.
| | - Salvatore Fusco
- Institute of Human Physiology, Medical School, Università Cattolica del Sacro Cuore, 00168 Rome, Italy.
| | - Lucia Leone
- Institute of Human Physiology, Medical School, Università Cattolica del Sacro Cuore, 00168 Rome, Italy.
| | - Saviana Antonella Barbati
- Institute of Human Physiology, Medical School, Università Cattolica del Sacro Cuore, 00168 Rome, Italy.
| | | | - Claudio Grassi
- Institute of Human Physiology, Medical School, Università Cattolica del Sacro Cuore, 00168 Rome, Italy.
| | - Giulia Piaggio
- Department of Research, Advanced Diagnostic, and Technological Innovation, Regina Elena National Cancer Institute, 00144 Rome, Italy.
| | - Gabriele Toietta
- Department of Research, Advanced Diagnostic, and Technological Innovation, Regina Elena National Cancer Institute, 00144 Rome, Italy.
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20
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Abstract
Bilirubin-induced neurotoxicity in preterm neonates remains a clinical concern. Multiple cellular and molecular cascades likely underlie bilirubin-induced neuronal injury, including plasma membrane perturbations, excitotoxicity, neuroinflammation, oxidative stress, and cell cycle arrest. Preterm newborns are particularly vulnerable secondary to central nervous system immaturity and concurrent adverse clinical conditions that may potentiate bilirubin toxicity. Acute bilirubin encephalopathy in preterm neonates may be subtle and manifest primarily as recurrent symptomatic apneic events. Low-bilirubin kernicterus continues to be reported in preterm neonates, and although multifactorial in nature, is often associated with marked hypoalbuminemia.
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Affiliation(s)
- Jon F Watchko
- Division of Newborn Medicine, Department of Pediatrics, Magee-Womens Hospital, Children's Hospital of Pittsburgh, Magee-Womens Research Institute, University of Pittsburgh School of Medicine, 300 Halket Street, Pittsburgh, PA 15213, USA.
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21
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Impairment of enzymatic antioxidant defenses is associated with bilirubin-induced neuronal cell death in the cerebellum of Ugt1 KO mice. Cell Death Dis 2015; 6:e1739. [PMID: 25950469 PMCID: PMC4669693 DOI: 10.1038/cddis.2015.113] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 03/16/2015] [Accepted: 03/18/2015] [Indexed: 01/14/2023]
Abstract
Severe hyperbilirubinemia is toxic during central nervous system development. Prolonged and uncontrolled high levels of unconjugated bilirubin lead to bilirubin-induced encephalopathy and eventually death by kernicterus. Despite extensive studies, the molecular and cellular mechanisms of bilirubin toxicity are still poorly defined. To fill this gap, we investigated the molecular processes underlying neuronal injury in a mouse model of severe neonatal jaundice, which develops hyperbilirubinemia as a consequence of a null mutation in the Ugt1 gene. These mutant mice show cerebellar abnormalities and hypoplasia, neuronal cell death and die shortly after birth because of bilirubin neurotoxicity. To identify protein changes associated with bilirubin-induced cell death, we performed proteomic analysis of cerebella from Ugt1 mutant and wild-type mice. Proteomic data pointed-out to oxidoreductase activities or antioxidant processes as important intracellular mechanisms altered during bilirubin-induced neurotoxicity. In particular, they revealed that down-representation of DJ-1, superoxide dismutase, peroxiredoxins 2 and 6 was associated with hyperbilirubinemia in the cerebellum of mutant mice. Interestingly, the reduction in protein levels seems to result from post-translational mechanisms because we did not detect significant quantitative differences in the corresponding mRNAs. We also observed an increase in neuro-specific enolase 2 both in the cerebellum and in the serum of mutant mice, supporting its potential use as a biomarker of bilirubin-induced neurological damage. In conclusion, our data show that different protective mechanisms fail to contrast oxidative burst in bilirubin-affected brain regions, ultimately leading to neurodegeneration.
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22
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Stanford JA, Shuler JM, Fowler SC, Stanford KG, Ma D, Bittel DC, Le Pichon JB, Shapiro SM. Hyperactivity in the Gunn rat model of neonatal jaundice: age-related attenuation and emergence of gait deficits. Pediatr Res 2015; 77:434-9. [PMID: 25518009 PMCID: PMC4346430 DOI: 10.1038/pr.2014.199] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Accepted: 09/26/2014] [Indexed: 12/18/2022]
Abstract
BACKGROUND Neonatal jaundice resulting from elevated unconjugated bilirubin occurs in 60-80% of newborn infants. Although mild jaundice is generally considered harmless, little is known about its long-term consequences. Recent studies have linked mild bilirubin-induced neurological dysfunction (BIND) with a range of neurological syndromes, including attention-deficit hyperactivity disorder. The goal of this study was to measure BIND across the lifespan in the Gunn rat model of BIND. METHODS Using a sensitive force plate actometer, we measured locomotor activity and gait in jaundiced (jj) Gunn rats versus their nonjaundiced (Nj) littermates. Data were analyzed for young adult (3-4 mo), early middle-aged (9-10 mo), and late middle-aged (17-20 mo) male rats. RESULTS jj rats exhibited lower body weights at all ages and a hyperactivity that resolved at 17-20 mo of age. Increased propulsive force and gait velocity accompanied hyperactivity during locomotor bouts at 9-10 mo in jj rats. Stride length did not differ between the two groups at this age. Hyperactivity normalized, and gait deficits, including decreased stride length, propulsive force, and gait velocity, emerged in the 17-20-mo-old jj rats. CONCLUSION These results demonstrate that, in aging, hyperactivity decreases with the onset of gait deficits in the Gunn rat model of BIND.
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Affiliation(s)
- John A. Stanford
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA,Corresponding Author: John A. Stanford, Ph.D., Department of Molecular & Integrative Physiology, Mailstop 3051, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, phone: 913-588-7416, fax: 913-588-5677,
| | - Jeffrey M. Shuler
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Stephen C. Fowler
- Department of Pharmacology & Toxicology, University of Kansas, Lawrence, KS, USA
| | - Kimberly G. Stanford
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Delin Ma
- Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Douglas C. Bittel
- The Ward Family Heart Center, Children’s Mercy Hospital, Kansas City, MO, USA
| | - Jean-Baptiste Le Pichon
- Department of Neurology, Children’s Mercy Hospital, Kansas City, MO, USA,Departments of Neurology and Pediatrics, University of Kansas Medical Center, Kansas City, KS, USA,Department of Pediatrics, University of Missouri-Kansas City, Kansas City, MO, USA
| | - Steven M. Shapiro
- Department of Neurology, Children’s Mercy Hospital, Kansas City, MO, USA,Departments of Neurology and Pediatrics, University of Kansas Medical Center, Kansas City, KS, USA,Department of Pediatrics, University of Missouri-Kansas City, Kansas City, MO, USA
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Watchko JF, Painter MJ, Panigrahy A. Are the neuromotor disabilities of bilirubin-induced neurologic dysfunction disorders related to the cerebellum and its connections? Semin Fetal Neonatal Med 2015; 20:47-51. [PMID: 25547431 DOI: 10.1016/j.siny.2014.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Investigators have hypothesized a range of subcortical neuropathology in the genesis of bilirubin-induced neurologic dysfunction (BIND). The current review builds on this speculation with a specific focus on the cerebellum and its connections in the development of the subtle neuromotor disabilities of BIND. The focus on the cerebellum derives from the following observations: (i) the cerebellum is vulnerable to bilirubin-induced injury; perhaps the most vulnerable region within the central nervous system; (ii) infants with cerebellar injury exhibit a neuromotor phenotype similar to BIND; and (iii) the cerebellum has extensive bidirectional circuitry projections to motor and non-motor regions of the brainstem and cerebral cortex that impact a variety of neurobehaviors. Future study using advanced magnetic resonance neuroimaging techniques have the potential to shed new insights into bilirubin's effect on neural network topology via both structural and functional brain connectivity measurements.
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Affiliation(s)
- Jon F Watchko
- Division of Newborn Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Michael J Painter
- Division of Pediatric Neurology, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Ashok Panigrahy
- Department of Pediatric Radiology, Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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Watchko JF, Maisels MJ. The enigma of low bilirubin kernicterus in premature infants: why does it still occur, and is it preventable? Semin Perinatol 2014; 38:397-406. [PMID: 25267279 DOI: 10.1053/j.semperi.2014.08.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Low bilirubin kernicterus in preterm neonates, though rare, remains an unpredictable and refractory form of brain injury. Hypoalbuminemia, co-morbid CNS insult(s), infection, and inflammation are contributing causes that, in many cases, appear to interact in potentiating bilirubin neurotoxicity. Despite compulsive attention to serum bilirubin levels, and clinical and laboratory indices of neurotoxicity risk, low bilirubin kernicterus continues to be seen in contemporary NICUs. While efforts to refine and improve current treatment guidelines are certainly needed, such revision(s) will also have to take into account the risks and benefits of any intervention, including phototherapy.
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Affiliation(s)
- Jon F Watchko
- Division of Newborn Medicine, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA.
| | - M Jeffrey Maisels
- Division of Newborn Medicine, Department of Pediatrics, Oakland University William Beaumont School of Medicine, Beaumont Children's Hospital, Royal Oak, MI
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26
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Bastos LFS, Godin AM, Zhang Y, Jarussophon S, Ferreira BCS, Machado RR, Maier SF, Konishi Y, de Freitas RP, Fiebich BL, Watkins LR, Coelho MM, Moraes MFD. A minocycline derivative reduces nerve injury-induced allodynia, LPS-induced prostaglandin E2 microglial production and signaling via toll-like receptors 2 and 4. Neurosci Lett 2013; 543:157-62. [PMID: 23523650 DOI: 10.1016/j.neulet.2013.03.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 03/03/2013] [Accepted: 03/05/2013] [Indexed: 11/19/2022]
Abstract
Many studies have shown that minocycline, an antibacterial tetracycline, suppresses experimental pain. While minocycline's positive effects on pain resolution suggest that clinical use of such drugs may prove beneficial, minocycline's antibiotic actions and divalent cation (Ca(2+); Mg(2+)) chelating effects detract from its potential utility. Thus, we tested the antiallodynic effect induced by a non-antibacterial, non-chelating minocycline derivative in a model of neuropathic pain and performed an initial investigation of its anti-inflammatory effects in vitro. Intraperitoneal minocycline (100mg/kg) and 12S-hydroxy-1,12-pyrazolinominocycline (PMIN; 23.75 mg/kg, 47.50mg/kg or 95.00 mg/kg) reduce the mechanical allodynia induced by chronic constriction injury of mouse sciatic nerve. PMIN reduces the LPS-induced production of PGE2 by primary microglial cell cultures. Human embryonic kidney cells were transfected to express human toll-like receptors 2 and 4, and the signaling via both receptors stimulated with PAM3CSK4 or LPS (respectively) was affected either by minocycline or PMIN. Importantly, these treatments did not affect the cell viability, as assessed by MTT test. Altogether, these results reinforce the evidence that the anti-inflammatory and experimental pain suppressive effects induced by tetracyclines are neither necessarily linked to antibacterial nor to Ca(2+) chelating activities. This study supports the evaluation of the potential usefulness of PMIN in the management of neuropathic pain, as its lack of antibacterial and Ca(2+) chelating activities might confer greater safety over conventional tetracyclines.
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Affiliation(s)
- Leandro F S Bastos
- Núcleo de Neurociências (NNC), Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Bloco A4, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
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