1
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Basiglio CL, Crocenzi FA, Sánchez Pozzi EJ, Roma MG. Oxidative Stress and Localization Status of Hepatocellular Transporters: Impact on Bile Secretion and Role of Signaling Pathways. Antioxid Redox Signal 2021; 35:808-831. [PMID: 34293961 DOI: 10.1089/ars.2021.0021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Significance: Most hepatopathies are primarily or secondarily cholestatic in nature. Oxidative stress (OS) is a frequent trait among them, and impairs the machinery to generate bile by triggering endocytic internalization of hepatocellular transporters, thus causing cholestasis. This is critical, since it leads to accelerated transporter degradation, which could explain the common post-transcriptional downregulation of transporter expression in human cholestatic diseases. Recent Advances: The mechanisms involved in OS-induced hepatocellular transporter internalization are being revealed. Filamentous actin (F-actin) cytoskeleton disorganization and/or detachment of crosslinking actin proteins that afford transporter stability have been characterized as causal factors. Activation of redox-sensitive signaling pathways leading to changes in phosphorylation status of these structures is involved, including Ca2+-mediated activation of "classical" and "novel" protein kinase C (PKC) isoforms or redox-signaling cascades downstream of NADPH oxidase. Critical Issues: Despite the well-known occurrence of hepatocellular transporter internalization in human hepatopathies, the cholestatic implications of this phenomenon have been overlooked. Accordingly, no specific treatment has been established in the clinical practice for its prevention/reversion. Future Directions: We need to improve our knowledge on the pro-oxidant triggering factors and the multiple signaling pathways that mediate this oxidative injury in each cholestatic hepatopathy, so as to envisage tailor-made therapeutic strategies for each case. Meanwhile, administration of antioxidants or heme oxygenase-1 induction to elevate the hepatocellular levels of the endogenous scavenger bilirubin are promising alternatives that need to be re-evaluated and implemented. They may complement current treatments in cholestasis aimed to enhance transcriptional carrier expression, by providing membrane stability to the newly synthesized carriers. Antioxid. Redox Signal. 35, 808-831.
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Affiliation(s)
- Cecilia L Basiglio
- Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas, CONICET, U.N.R., Rosario, Argentina
| | - Fernando A Crocenzi
- Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas, CONICET, U.N.R., Rosario, Argentina
| | - Enrique J Sánchez Pozzi
- Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas, CONICET, U.N.R., Rosario, Argentina
| | - Marcelo G Roma
- Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas, CONICET, U.N.R., Rosario, Argentina
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2
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Xiong K, Cai J, Liu P, Wang J, Zhao S, Xu L, Yang Y, Liu J, Ma A. Lactobacillus casei Alleviated the Abnormal Increase of Cholestasis-Related Liver Indices During Tuberculosis Treatment: A Post Hoc Analysis of Randomized Controlled Trial. Mol Nutr Food Res 2021; 65:e2100108. [PMID: 33864432 DOI: 10.1002/mnfr.202100108] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/30/2021] [Indexed: 12/17/2022]
Abstract
SCOPE Probiotics are promising in mitigating drug-induced liver injury in animal experiments. However, the clinical evidence is absent. The objective is to investigate the effect of adjunctive Lactobacillus casei on tuberculosis-drug-induced liver injury. METHODS AND RESULTS A post hoc analysis is conducted for a previous randomized controlled trial. The trial is registered at the Chinese Clinical Trial Registry (No. ChiCTR-IOR-17013210). Four hundred twenty nine patients are allocated to receive standard tuberculosis therapy alone (control group), or together with 1 × 1010 colony-forming units (CFU) per day (low-dose group), or 2 × 1010 CFU per day of L. casei (high-dose group) during tuberculosis treatment. The L. casei supplementation significantly reduced the incidence of the abnormal increase of cholestasis-related liver indices including alkaline phosphatase (p = 0.024) and bilirubin (p = 0.013). Plasma lipopolysaccharide (p = 0.02), intestinal permeability biomarkers including zonula occludens-1 (p = 0.001) and intestinal fatty acid binding protein (p = 0.002) are significantly reduced. The gut microbiota composition is dramatically altered with a reduction of Bacteroidetes (p < 0.001) and a corresponding increase of Actinobacteria (p < 0.001) and Firmicutes (p = 0.003). CONCLUSIONS L. casei supplementation is beneficial for suppressing abnormally elevated cholestasis-related liver indices during tuberculosis treatment, which may be related to its modification on blood lipopolysaccharide, intestinal barrier function, and gut microbiota.
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Affiliation(s)
- Ke Xiong
- School of Public Health, Institute of Nutrition and Health, Qingdao University, Qingdao, Shandong, 266021, China
| | - Jing Cai
- School of Public Health, Institute of Nutrition and Health, Qingdao University, Qingdao, Shandong, 266021, China
| | - Peiying Liu
- Linyi People's Hospital, Linyi, Shandong, 276000, China
| | - Jinyu Wang
- School of Public Health, Institute of Nutrition and Health, Qingdao University, Qingdao, Shandong, 266021, China
| | | | - Lei Xu
- School of Public Health, Institute of Nutrition and Health, Qingdao University, Qingdao, Shandong, 266021, China
| | - Yang Yang
- School of Public Health, Institute of Nutrition and Health, Qingdao University, Qingdao, Shandong, 266021, China
| | - Jiahong Liu
- Qingdao Central Hospital, Qingdao, Shandong, 266042, China
| | - Aiguo Ma
- School of Public Health, Institute of Nutrition and Health, Qingdao University, Qingdao, Shandong, 266021, China
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3
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Shani V, Safory H, Szargel R, Wang N, Cohen T, Elghani FA, Hamza H, Savyon M, Radzishevsky I, Shaulov L, Rott R, Lim KL, Ross CA, Bandopadhyay R, Zhang H, Engelender S. Physiological and pathological roles of LRRK2 in the nuclear envelope integrity. Hum Mol Genet 2020; 28:3982-3996. [PMID: 31626293 DOI: 10.1093/hmg/ddz245] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 09/12/2019] [Accepted: 10/03/2019] [Indexed: 01/28/2023] Open
Abstract
Mutations in LRRK2 cause autosomal dominant and sporadic Parkinson's disease, but the mechanisms involved in LRRK2 toxicity in PD are yet to be fully understood. We found that LRRK2 translocates to the nucleus by binding to seven in absentia homolog (SIAH-1), and in the nucleus it directly interacts with lamin A/C, independent of its kinase activity. LRRK2 knockdown caused nuclear lamina abnormalities and nuclear disruption. LRRK2 disease mutations mostly abolish the interaction with lamin A/C and, similar to LRRK2 knockdown, cause disorganization of lamin A/C and leakage of nuclear proteins. Dopaminergic neurons of LRRK2 G2019S transgenic and LRRK2 -/- mice display decreased circularity of the nuclear lamina and leakage of the nuclear protein 53BP1 to the cytosol. Dopaminergic nigral and cortical neurons of both LRRK2 G2019S and idiopathic PD patients exhibit abnormalities of the nuclear lamina. Our data indicate that LRRK2 plays an essential role in maintaining nuclear envelope integrity. Disruption of this function by disease mutations suggests a novel phosphorylation-independent loss-of-function mechanism that may synergize with other neurotoxic effects caused by LRRK2 mutations.
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Affiliation(s)
- Vered Shani
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Hazem Safory
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Raymonde Szargel
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ninghan Wang
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - Tsipora Cohen
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Fatimah Abd Elghani
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Haya Hamza
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Mor Savyon
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Inna Radzishevsky
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Lihi Shaulov
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ruth Rott
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Kah-Leong Lim
- Department of Physiology, National University of Singapore, Singapore, Singapore
| | - Christopher A Ross
- Department of Psychiatry, The Johns Hopkins Medical School, Baltimore, MD, USA
| | | | - Hui Zhang
- Department of Neuroscience, Thomas Jefferson University, Philadelphia, PA, USA
| | - Simone Engelender
- Dept. of Biochemistry, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
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4
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Corpechot C, Barbu V, Chazouillères O, Broué P, Girard M, Roquelaure B, Chrétien Y, Dong C, Lascols O, Housset C, Jéru I. Genetic contribution of ABCC2 to Dubin-Johnson syndrome and inherited cholestatic disorders. Liver Int 2020; 40:163-174. [PMID: 31544333 DOI: 10.1111/liv.14260] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 08/27/2019] [Accepted: 09/10/2019] [Indexed: 01/18/2023]
Abstract
BACKGROUND AND AIMS The ABCC2 gene is implicated in Dubin-Johnson syndrome (DJS), a rare autosomal recessive liver disorder. The primary aim of this study was to determine the diagnostic value of ABCC2 genetic testing in the largest cohort of DJS reported to date. The high number of patients with cholestatic manifestations in this series prompted us to evaluate the genetic contribution of rare, potentially pathogenic ABCC2 variants to other inherited cholestatic disorders. METHODS The cohort study included 32 patients with clinical DJS diagnosis, and 372 patients referred for the following disorders: low phospholipid-associated cholelithiasis (LPAC) syndrome, intrahepatic cholestasis of pregnancy (ICP) and benign recurrent intrahepatic cholestasis (BRIC). ABCC2 was screened by next-generation sequencing. RESULTS Most patients with clinical DJS had positive genetic diagnosis (n = 30; 94%), with a great diversity of point mutations and copy number variations in ABCC2. Strikingly, eight (27%) of these patients showed transient cholestatic features at presentation: four neonatal cholestasis, two ICP, one contraceptive-induced cholestasis and one sporadic cholestasis. Conversely, the frequency of rare, heterozygous, potentially pathogenic ABCC2 variants in patients with LPAC, ICP or BRIC did not differ significantly from that of the general population. CONCLUSIONS This large series reveals that DJS is a highly homogeneous Mendelian disorder involving a large spectrum of ABCC2 variants. Genetic testing is crucial to establish early DJS diagnosis in patients with atypical presentations, such as neonatal cholestasis. This study also provides no evidence for the contribution of rare, potentially pathogenic ABCC2 variants to other inherited cholestatic disorders.
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Affiliation(s)
- Christophe Corpechot
- Centre de Référence des Maladies Inflammatoires des Voies Biliaires et des Hépatites Auto-Immunes (MIVB-H), Filière de Santé des Maladies Rares du Foie de l'enfant et de l'adulte (FILFOIE), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, Paris, France.,INSERM, Centre de Recherche Saint-Antoine (CRSA), Institut Hospitalo-Universitaire de Cardio-métabolisme et Nutrition (ICAN), Sorbonne Université, Paris, France
| | - Véronique Barbu
- INSERM, Centre de Recherche Saint-Antoine (CRSA), Institut Hospitalo-Universitaire de Cardio-métabolisme et Nutrition (ICAN), Sorbonne Université, Paris, France.,Laboratoire Commun de Biologie et Génétique Moléculaires, Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, Paris, France
| | - Olivier Chazouillères
- Centre de Référence des Maladies Inflammatoires des Voies Biliaires et des Hépatites Auto-Immunes (MIVB-H), Filière de Santé des Maladies Rares du Foie de l'enfant et de l'adulte (FILFOIE), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, Paris, France.,INSERM, Centre de Recherche Saint-Antoine (CRSA), Institut Hospitalo-Universitaire de Cardio-métabolisme et Nutrition (ICAN), Sorbonne Université, Paris, France
| | - Pierre Broué
- Centres de compétences maladies rares du foie de l'enfant et Centre de référence constitutif maladies héréditaires du métabolisme, Hépatologie Pédiatrique et Maladies Héréditaires du Métabolisme, Hôpitaux de Toulouse, Hôpital des Enfants, Toulouse, France
| | - Muriel Girard
- Service d'Hépato-Gastroentérologie et Nutrition Pédiatrique, Assistance Publique-Hôpitaux de Paris, Hôpital Necker Enfants-Malades, Paris, France.,INSERM U1151, Institut Necker Enfants-Malades, Université Paris Descartes, Paris, France
| | - Bertrand Roquelaure
- Service d'Hépato-Gastroentérologie et Nutrition Pédiatrique, Assistance Publique-Hôpitaux de Marseille, Hôpital de la Timone Enfants, Marseille, France
| | - Yves Chrétien
- Centre de Référence des Maladies Inflammatoires des Voies Biliaires et des Hépatites Auto-Immunes (MIVB-H), Filière de Santé des Maladies Rares du Foie de l'enfant et de l'adulte (FILFOIE), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, Paris, France
| | - Catherine Dong
- Centre de Référence des Maladies Inflammatoires des Voies Biliaires et des Hépatites Auto-Immunes (MIVB-H), Filière de Santé des Maladies Rares du Foie de l'enfant et de l'adulte (FILFOIE), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, Paris, France
| | - Olivier Lascols
- INSERM, Centre de Recherche Saint-Antoine (CRSA), Institut Hospitalo-Universitaire de Cardio-métabolisme et Nutrition (ICAN), Sorbonne Université, Paris, France.,Laboratoire Commun de Biologie et Génétique Moléculaires, Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, Paris, France
| | - Chantal Housset
- Centre de Référence des Maladies Inflammatoires des Voies Biliaires et des Hépatites Auto-Immunes (MIVB-H), Filière de Santé des Maladies Rares du Foie de l'enfant et de l'adulte (FILFOIE), Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, Paris, France.,INSERM, Centre de Recherche Saint-Antoine (CRSA), Institut Hospitalo-Universitaire de Cardio-métabolisme et Nutrition (ICAN), Sorbonne Université, Paris, France
| | - Isabelle Jéru
- INSERM, Centre de Recherche Saint-Antoine (CRSA), Institut Hospitalo-Universitaire de Cardio-métabolisme et Nutrition (ICAN), Sorbonne Université, Paris, France.,Laboratoire Commun de Biologie et Génétique Moléculaires, Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Antoine, Paris, France
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5
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Anticholestatic mechanisms of ursodeoxycholic acid in lipopolysaccharide-induced cholestasis. Biochem Pharmacol 2019; 168:48-56. [DOI: 10.1016/j.bcp.2019.06.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 06/10/2019] [Indexed: 12/14/2022]
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6
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Prasnicka A, Lastuvkova H, Alaei Faradonbeh F, Cermanova J, Hroch M, Mokry J, Dolezelova E, Pavek P, Zizalova K, Vitek L, Nachtigal P, Micuda S. Iron overload reduces synthesis and elimination of bile acids in rat liver. Sci Rep 2019; 9:9780. [PMID: 31278332 PMCID: PMC6611795 DOI: 10.1038/s41598-019-46150-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 06/21/2019] [Indexed: 12/15/2022] Open
Abstract
Excessive iron accumulation in the liver, which accompanies certain genetic or metabolic diseases, impairs bile acids (BA) synthesis, but the influence of iron on the complex process of BA homeostasis is unknown. Thus, we evaluated the effect of iron overload (IO) on BA turnover in rats. Compared with control rats, IO (8 intraperitoneal doses of 100 mg/kg every other day) significantly decreased bile flow as a consequence of decreased biliary BA secretion. This decrease was associated with reduced expression of Cyp7a1, the rate limiting enzyme in the conversion of cholesterol to BA, and decreased expression of Bsep, the transporter responsible for BA efflux into bile. However, IO did not change net BA content in faeces in response to increased intestinal conversion of BA into hyodeoxycholic acid. In addition, IO increased plasma cholesterol concentrations, which corresponded with reduced Cyp7a1 expression and increased expression of Hmgcr, the rate-limiting enzyme in de novo cholesterol synthesis. In summary, this study describes the mechanisms impairing synthesis, biliary secretion and intestinal processing of BA during IO. Altered elimination pathways for BA and cholesterol may interfere with the pathophysiology of liver damage accompanying liver diseases with excessive iron deposition.
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Affiliation(s)
- Alena Prasnicka
- Department of Pharmacology, Charles University, Faculty of Medicine in Hradec Kralove, Hradec Kralove, Czech Republic.,Department of Biological and Medical Sciences, Charles University, Faculty of Pharmacy in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Hana Lastuvkova
- Department of Pharmacology, Charles University, Faculty of Medicine in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Fatemeh Alaei Faradonbeh
- Department of Pharmacology, Charles University, Faculty of Medicine in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Jolana Cermanova
- Department of Pharmacology, Charles University, Faculty of Medicine in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Milos Hroch
- Department of Medical Biochemistry, Charles University, Faculty of Medicine in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Jaroslav Mokry
- Department of Histology and Embryology, Charles University, Faculty of Medicine in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Eva Dolezelova
- Department of Biological and Medical Sciences, Charles University, Faculty of Pharmacy in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Petr Pavek
- Department of Pharmacology and Toxicology, Charles University, Faculty of Pharmacy in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Katerina Zizalova
- Department of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Libor Vitek
- Department of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Petr Nachtigal
- Department of Biological and Medical Sciences, Charles University, Faculty of Pharmacy in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Stanislav Micuda
- Department of Pharmacology, Charles University, Faculty of Medicine in Hradec Kralove, Hradec Kralove, Czech Republic.
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7
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Roma MG, Barosso IR, Miszczuk GS, Crocenzi FA, Pozzi EJS. Dynamic Localization of Hepatocellular Transporters: Role in Biliary Excretion and Impairment in Cholestasis. Curr Med Chem 2019; 26:1113-1154. [DOI: 10.2174/0929867325666171205153204] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/06/2017] [Accepted: 09/07/2017] [Indexed: 12/25/2022]
Abstract
Bile flow generation is driven by the vectorial transfer of osmotically active compounds from sinusoidal blood into a confined space, the bile canaliculus. Hence, localization of hepatocellular transporters relevant to bile formation is crucial for bile secretion. Hepatocellular transporters are localized either in the plasma membrane or in recycling endosomes, from where they can be relocated to the plasma membrane on demand, or endocytosed when the demand decreases. The balance between endocytic internalization/ exocytic targeting to/from this recycling compartment is therefore the main determinant of the hepatic capability to generate bile, and to dispose endo- and xenobiotics. Furthermore, the exacerbated endocytic internalization is a common pathomechanisms in both experimental and human cholestasis; this results in bile secretory failure and, eventually, posttranslational transporter downregulation by increased degradation. This review summarizes the proposed structural mechanisms accounting for this pathological condition (e.g., alteration of function, localization or expression of F-actin or F-actin/transporter cross-linking proteins, and switch to membrane microdomains where they can be readily endocytosed), and the mediators implicated (e.g., triggering of “cholestatic” signaling transduction pathways). Lastly, we discussed the efficacy to counteract the cholestatic failure induced by transporter internalization of a number of therapeutic experimental approaches based upon the use of compounds that trigger exocytic targetting of canalicular transporters (e.g., cAMP, tauroursodeoxycholate). This therapeutics may complement treatments aimed to transcriptionally improve transporter expression, by affording proper localization and membrane stability to the de novo synthesized transporters.
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Affiliation(s)
- Marcelo G. Roma
- Instituto de Fisiologia Experimental (IFISE) - Facultad de Ciencias Bioquimicas y Farmaceuticas (CONICET - U.N.R.), S2002LRL, Rosario, Argentina
| | - Ismael R. Barosso
- Instituto de Fisiologia Experimental (IFISE) - Facultad de Ciencias Bioquimicas y Farmaceuticas (CONICET - U.N.R.), S2002LRL, Rosario, Argentina
| | - Gisel S. Miszczuk
- Instituto de Fisiologia Experimental (IFISE) - Facultad de Ciencias Bioquimicas y Farmaceuticas (CONICET - U.N.R.), S2002LRL, Rosario, Argentina
| | - Fernando A. Crocenzi
- Instituto de Fisiologia Experimental (IFISE) - Facultad de Ciencias Bioquimicas y Farmaceuticas (CONICET - U.N.R.), S2002LRL, Rosario, Argentina
| | - Enrique J. Sánchez Pozzi
- Instituto de Fisiologia Experimental (IFISE) - Facultad de Ciencias Bioquimicas y Farmaceuticas (CONICET - U.N.R.), S2002LRL, Rosario, Argentina
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8
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EGFP transgene: a useful tool to track transplanted bone marrow mononuclear cell contribution to peripheral remyelination. Transgenic Res 2018; 27:135-153. [DOI: 10.1007/s11248-018-0062-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 02/01/2018] [Indexed: 12/14/2022]
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9
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Li J, Zhang J, Zhao YL, Huang HY, Wang YZ. Comprehensive Quality Assessment Based Specific Chemical Profiles for Geographic and Tissue Variation in Gentiana rigescens Using HPLC and FTIR Method Combined with Principal Component Analysis. Front Chem 2017; 5:125. [PMID: 29312929 PMCID: PMC5743669 DOI: 10.3389/fchem.2017.00125] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Accepted: 12/12/2017] [Indexed: 12/19/2022] Open
Abstract
Roots, stems, leaves, and flowers of Longdan (Gentiana rigescens Franch. ex Hemsl) were collected from six geographic origins of Yunnan Province (n = 240) to implement the quality assessment based on contents of gentiopicroside, loganic acid, sweroside and swertiamarin and chemical profile using HPLC-DAD and FTIR method combined with principal component analysis (PCA). The content of gentiopicroside (major iridoid glycoside) was the highest in G. rigescens, regardless of tissue and geographic origin. The level of swertiamarin was the lowest, even unable to be detected in samples from Kunming and Qujing. Significant correlations (p < 0.05) between gentiopicroside, loganic acid, sweroside, and swertiamarin were found at inter- or intra-tissues, which were highly depended on geographic origins, indicating the influence of environmental conditions on the conversion and transport of secondary metabolites in G. rigescens. Furthermore, samples were reasonably classified as three clusters along large producing areas where have similar climate conditions, characterized by carbohydrates, phenols, benzoates, terpenoids, aliphatic alcohols, aromatic hydrocarbons, and so forth. The present work provided global information on the chemical profile and contents of major iridoid glycosides in G. rigescens originated from six different origins, which is helpful for controlling quality of herbal medicines systematically.
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Affiliation(s)
- Jie Li
- Institute of Medicinal Plants, Yunnan Academy of Agricultural Sciences, Kunming, China.,College of Traditional Chinese Medicine, Yunnan University of Traditional Chinese Medicine, Kunming, China
| | - Ji Zhang
- Institute of Medicinal Plants, Yunnan Academy of Agricultural Sciences, Kunming, China
| | - Yan-Li Zhao
- Institute of Medicinal Plants, Yunnan Academy of Agricultural Sciences, Kunming, China
| | - Heng-Yu Huang
- College of Traditional Chinese Medicine, Yunnan University of Traditional Chinese Medicine, Kunming, China
| | - Yuan-Zhong Wang
- Institute of Medicinal Plants, Yunnan Academy of Agricultural Sciences, Kunming, China
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10
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Szargel R, Shani V, Abd Elghani F, Mekies LN, Liani E, Rott R, Engelender S. The PINK1, synphilin-1 and SIAH-1 complex constitutes a novel mitophagy pathway. Hum Mol Genet 2016; 25:3476-3490. [DOI: 10.1093/hmg/ddw189] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023] Open
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11
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Chiellini F, Dinucci D, Bartoli C, Piras AM, Chiellini E. Intracellular Fate Investigation of Bio-Eliminable Polymeric Nanoparticles by Confocal Laser Scanning Microscopy. J BIOACT COMPAT POL 2016. [DOI: 10.1177/0883911507084821] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This is a study of the in vitro cytotoxicity and intracellular fate of poly[(glycylglycinemethacrylamide)-co-N-(2-hydroxypropylmethacrylamide y)] bio-eliminable polymer samples and relative nanoparticles in Balb/c 3T3 cloned A31 mouse embryo fibroblasts cell line by using Confocal Laser Scanning Microscopy (CLSM). Nanoparticles were prepared by co-precipitating the polymers with fluorescein labeled human serum albumin (HSA-FITC) as the fluorescent probe and as the model protein drug. The toxicity of the polymers containing 25, 50 and 100%, respectively, of (glycylglycinemethacrylamide) x (GGMA) was investigated in terms of cytoskeleton morphology by exposing cells to various concentrations of polymers for 24 h. Under normal culture conditions, fibroblast cells exhibit characteristic spreading and shape, however, when the cell cultures were subjected to chemical, metabolic or physical stress, their morphology changed reducing their visibility. The polymers with the lower glycine content exert a lower toxicity even at high concentrations [8.5mg/mL]. The cellular uptake of nanoparticles was determined by incubating fibroblasts with HSA-FITC loaded particles and HSA-FITC alone at three different time points. The results indicate that nanoparticles were up-taken by the cells in a time dependent fashion. Preliminary evaluation of the intracellular fate of the prepared nanoparticles indicate their possible lysosomal escape.
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Affiliation(s)
- Federica Chiellini
- Laboratory of Bioactive Polymeric Materials for Biomedical and Environmental Applications (BIOlab), UdR INSTM Department of Chemistry & Industrial Chemistry, University of Pisa Via Livornese 1291, 56010 S. Piero a Grado (Pisa), Italy
| | - Dinuccio Dinucci
- Laboratory of Bioactive Polymeric Materials for Biomedical and Environmental Applications (BIOlab), UdR INSTM Department of Chemistry & Industrial Chemistry, University of Pisa Via Livornese 1291, 56010 S. Piero a Grado (Pisa), Italy
| | - Cristina Bartoli
- Laboratory of Bioactive Polymeric Materials for Biomedical and Environmental Applications (BIOlab), UdR INSTM Department of Chemistry & Industrial Chemistry, University of Pisa Via Livornese 1291, 56010 S. Piero a Grado (Pisa), Italy
| | - Anna Maria Piras
- Laboratory of Bioactive Polymeric Materials for Biomedical and Environmental Applications (BIOlab), UdR INSTM Department of Chemistry & Industrial Chemistry, University of Pisa Via Livornese 1291, 56010 S. Piero a Grado (Pisa), Italy
| | - Emo Chiellini
- Laboratory of Bioactive Polymeric Materials for Biomedical and Environmental Applications (BIOlab), UdR INSTM Department of Chemistry & Industrial Chemistry, University of Pisa Via Livornese 1291, 56010 S. Piero a Grado (Pisa), Italy,
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12
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Migocka-Patrzałek M, Makowiecka A, Nowak D, Mazur AJ, Hofmann WA, Malicka-Błaszkiewicz M. β- and γ-Actins in the nucleus of human melanoma A375 cells. Histochem Cell Biol 2015; 144:417-28. [PMID: 26239425 PMCID: PMC4628621 DOI: 10.1007/s00418-015-1349-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/14/2015] [Indexed: 11/13/2022]
Abstract
Actin is a highly conserved protein that is expressed in all eukaryotic cells and has essential functions in the cytoplasm and the nucleus. Nuclear actin is involved in transcription by all three RNA polymerases, chromatin remodelling, RNA processing, intranuclear transport, nuclear export and in maintenance of the nuclear architecture. The nuclear actin level and polymerization state are important factors regulating nuclear processes such as transcription. Our study shows that, in contrast to the cytoplasm, the majority of endogenous nuclear actin is unpolymerized in human melanoma A375 cells. Most mammalian cells express the two non-muscle β- and γ-actin isoforms that differ in only four amino acids. Despite their sequence similarity, studies analysing the cytoplasmic functions of these isoforms demonstrated that β- and γ-actins show differences in localization and function. However, little is known about the involvement of the individual actin isoforms in nuclear processes. Here, we used the human melanoma A375 cell line to analyse actin isoforms in regard to their nuclear localization. We show that both β- and γ-non-muscle actin isoforms are present in nuclei of these cells. Immunolocalization studies demonstrate that both isoforms co-localize with RNA polymerase II and hnRNP U. However, we observe differences in the ratio of cytoplasmic to nuclear actin distribution between the isoforms. We show that β-actin has a significantly higher nucleus-to-cytoplasm ratio than γ-actin.
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Affiliation(s)
- Marta Migocka-Patrzałek
- Department of Animal Developmental Biology, Institute of Experimental Biology, Faculty of Biological Sciences, University of Wroclaw, Sienkiewicza 21, 50-335, Wroclaw, Poland.
- Department of Cell Pathology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland.
- Department of Physiology and Biophysics, University at Buffalo State University of New York, Buffalo, NY, USA.
| | - Aleksandra Makowiecka
- Department of Cell Pathology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Dorota Nowak
- Department of Cell Pathology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Antonina J Mazur
- Department of Cell Pathology, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Wilma A Hofmann
- Department of Physiology and Biophysics, University at Buffalo State University of New York, Buffalo, NY, USA
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13
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Zinchuk V, Grossenbacher-Zinchuk O. Quantitative colocalization analysis of fluorescence microscopy images. CURRENT PROTOCOLS IN CELL BIOLOGY 2014; 62:4.19.1-4.19.14. [PMID: 24610126 DOI: 10.1002/0471143030.cb0419s62] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Colocalization is an important finding in many cell biological studies. This unit describes a protocol for quantitative evaluation of fluorescence microscopy images with colocalization based on calculation of a number of specialized coefficients. Images of double-stained sections are first subjected to background correction, and then various coefficients are calculated. Meanings of the coefficients and a guide to interpretation of the results of calculations based on the use of linguistic variables are given. Success in colocalization studies depends on the quality of images analyzed, proper preparation of the images for coefficients calculations, and correct interpretation of results obtained. This protocol helps ensure reliability of colocalization coefficient calculations.
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Affiliation(s)
- Vadim Zinchuk
- Department of Neurobiology and Anatomy, Kochi University, Faculty of Medicine, Japan
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14
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Cressman AM, Petrovic V, Piquette-Miller M. Inflammation-mediated changes in drug transporter expression/activity: implications for therapeutic drug response. Expert Rev Clin Pharmacol 2014; 5:69-89. [DOI: 10.1586/ecp.11.66] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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15
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Aida K, Hayashi H, Inamura K, Mizuno T, Sugiyama Y. Differential Roles of Ubiquitination in the Degradation Mechanism of Cell Surface–Resident Bile Salt Export Pump and Multidrug Resistance–Associated Protein 2. Mol Pharmacol 2013; 85:482-91. [DOI: 10.1124/mol.113.091090] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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16
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YANG KYUNGHEE, KÖCK KATHLEEN, SEDYKH ALEXANDER, TROPSHA ALEXANDER, BROUWER KIML. An updated review on drug-induced cholestasis: mechanisms and investigation of physicochemical properties and pharmacokinetic parameters. J Pharm Sci 2013; 102:3037-57. [PMID: 23653385 PMCID: PMC4369767 DOI: 10.1002/jps.23584] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 04/13/2013] [Accepted: 04/16/2013] [Indexed: 12/15/2022]
Abstract
Drug-induced cholestasis is an important form of acquired liver disease and is associated with significant morbidity and mortality. Bile acids are key signaling molecules, but they can exert toxic responses when they accumulate in hepatocytes. This review focuses on the physiological mechanisms of drug-induced cholestasis associated with altered bile acid homeostasis due to direct (e.g., bile acid transporter inhibition) or indirect (e.g., activation of nuclear receptors, altered function/expression of bile acid transporters) processes. Mechanistic information about the effects of a drug on bile acid homeostasis is important when evaluating the cholestatic potential of a compound, but experimental data often are not available. The relationship between physicochemical properties, pharmacokinetic parameters, and inhibition of the bile salt export pump among 77 cholestatic drugs with different pathophysiological mechanisms of cholestasis (i.e., impaired formation of bile vs. physical obstruction of bile flow) was investigated. The utility of in silico models to obtain mechanistic information about the impact of compounds on bile acid homeostasis to aid in predicting the cholestatic potential of drugs is highlighted.
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Affiliation(s)
- KYUNGHEE YANG
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - KATHLEEN KÖCK
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - ALEXANDER SEDYKH
- Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - ALEXANDER TROPSHA
- Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - KIM L.R. BROUWER
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
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17
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Biosynthesis and trafficking of the bile salt export pump, BSEP: therapeutic implications of BSEP mutations. Mol Aspects Med 2013; 37:3-14. [PMID: 23685087 DOI: 10.1016/j.mam.2013.05.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/25/2013] [Accepted: 05/07/2013] [Indexed: 12/17/2022]
Abstract
The bile salt export pump (BSEP, ABCB11) is the primary transporter of bile acids from the hepatocyte to the biliary system. This rate-limiting step in bile formation is essential to the formation of bile salt dependent bile flow, the enterohepatic circulation of bile acids, and the digestion of dietary fats. Mutations in BSEP are associated with cholestatic diseases such as progressive familial intrahepatic cholestasis type 2 (PFIC2), benign recurrent intrahepatic cholestasis type 2 (BRIC2), drug-induced cholestasis, and intrahepatic cholestasis of pregnancy. Development of clinical therapies for these conditions necessitates a clear understanding of the cell biology of biosynthesis, trafficking, and transcriptional and translational regulation of BSEP. This chapter will focus on the molecular and cell biological aspects of this critical hepatic membrane transporter.
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18
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The bile salt export pump (BSEP) in health and disease. Clin Res Hepatol Gastroenterol 2012; 36:536-53. [PMID: 22795478 DOI: 10.1016/j.clinre.2012.06.006] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 05/29/2012] [Accepted: 06/06/2012] [Indexed: 02/04/2023]
Abstract
The bile salt export pump (BSEP) is the major transporter for the secretion of bile acids from hepatocytes into bile in humans. Mutations of BSEP are associated with cholestatic liver diseases of varying severity including progressive familial intrahepatic cholestasis type 2 (PFIC-2), benign recurrent intrahepatic cholestasis type 2 (BRIC-2) and genetic polymorphisms are linked to intrahepatic cholestasis of pregnancy (ICP) and drug-induced liver injury (DILI). Detailed analysis of these diseases has considerably increased our knowledge about physiology and pathophysiology of bile secretion in humans. This review focuses on expression, localization, and function, short- and long-term regulation of BSEP as well as diseases association and treatment options for BSEP-associated diseases.
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19
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Harris HJ, Clerte C, Farquhar MJ, Goodall M, Hu K, Rassam P, Dosset P, Wilson GK, Balfe P, Ijzendoorn SC, Milhiet PE, McKeating JA. Hepatoma polarization limits CD81 and hepatitis C virus dynamics. Cell Microbiol 2012; 15:430-45. [PMID: 23126643 PMCID: PMC3599488 DOI: 10.1111/cmi.12047] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 09/08/2012] [Accepted: 09/27/2012] [Indexed: 12/12/2022]
Abstract
Many viruses target the polarized epithelial apex during host invasion. In contrast, hepatitis C virus (HCV) engages receptors at the basal surface of hepatocytes in the polarized liver parenchyma. Hepatocyte polarization limits HCV entry by undefined mechanism(s). Given the recent reports highlighting a role for receptor mobility in pathogen entry, we studied the effect(s) of hepatocyte polarization on viral receptor and HCV pseudoparticle (HCVpp) dynamics using real-time fluorescence recovery after photobleaching and single particle tracking. Hepatoma polarization reduced CD81 and HCVpp dynamics at the basal membrane. Since cell polarization is accompanied by changes in the actin cytoskeleton and CD81 links to actin via its C-terminus, we studied the dynamics of a mutant CD81 lacking a C-terminal tail (CD81(ΔC)) and its effect(s) on HCVpp mobility and infection. CD81(ΔC) showed an increased frequency of confined trajectories and a reduction of Brownian diffusing molecules compared to wild-type protein in non-polarized cells. However, these changes were notobserved in polarized cells. HCVpp showed a significant reduction in Brownian diffusion and infection of CD81(ΔC) expressing non-polarized cells. In summary, these data highlight the dynamic nature of CD81 and demonstrate a role for CD81 lateral diffusion to regulate HCV infection in a polarization-dependent manner.
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Affiliation(s)
- H J Harris
- School of Immunity and Infection, University of Birmingham, Birmingham, UK
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20
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Hirsova P, Karlasova G, Dolezelova E, Cermanova J, Zagorova M, Kadova Z, Hroch M, Sispera L, Tomsik P, Lenicek M, Vitek L, Pavek P, Kucera O, Cervinkova Z, Micuda S. Cholestatic effect of epigallocatechin gallate in rats is mediated via decreased expression of Mrp2. Toxicology 2012; 303:9-15. [PMID: 23146761 DOI: 10.1016/j.tox.2012.10.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 10/02/2012] [Accepted: 10/09/2012] [Indexed: 12/22/2022]
Abstract
Epigallocatechin gallate (EGCG) has been shown to be protective in various experimental models of liver injury, although opposite effects have also been reported. Since its effect on biliary physiology has not been thoroughly investigated, the present study evaluated effect of EGCG on bile flow and bile acid homeostasis in rats. Compared to controls, EGCG treatment decreased bile flow by 23%. Hepatic paracellular permeability and biliary bile acid excretion were not altered by EGCG administration, but biliary glutathione excretion was reduced by 70%. Accordingly, the main glutathione transporter on the hepatocyte canalicular membrane, multidrug resistance-associated protein 2 (Mrp2), was significantly decreased at the protein level. EGCG administration also doubled plasma bile acid levels compared to controls. While protein levels of the main hepatic bile acid transporters were unchanged, the rate-limiting enzyme in the bile acid synthesis, Cyp7a1, was significantly increased by EGCG. Enhanced bile acid synthesis in these animals was also confirmed by a 2-fold increase in plasma marker 7α-hydroxy-4-cholesten-3-one. In contrast, EGCG markedly downregulated major bile acid transporters (Asbt and Ostα) and regulatory molecules (Shp and Fgf15) in the ileum. When EGCG was coadministered with ethinylestradiol, a potent cholestatic agent, it did not show any additional effect on the induced cholestasis. This study shows ability of EGCG to raise plasma bile acid concentrations, mainly through Cyp7a1 upregulation, and to decrease bile production through reduction in Mrp2-mediated bile acid-independent bile flow. In conclusion, our data demonstrate that under certain conditions EGCG may induce cholestasis.
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Affiliation(s)
- Petra Hirsova
- Department of Pharmacology, Faculty of Medicine in Hradec Kralove, Charles University in Prague, Simkova 870, 500 38 Hradec Kralove, Czech Republic
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21
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Hanzel CE, Almeira Gubiani MF, Verstraeten SV. Endosomes and lysosomes are involved in early steps of Tl(III)-mediated apoptosis in rat pheochromocytoma (PC12) cells. Arch Toxicol 2012; 86:1667-80. [PMID: 22669516 DOI: 10.1007/s00204-012-0878-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 05/23/2012] [Indexed: 10/28/2022]
Abstract
The mechanisms that mediate thallium (Tl) toxicity are still not completely understood. The exposure of rat pheochromocytoma (PC12) cells to Tl(I) or Tl(III) activates both mitochondrial (Tl(I) and Tl(III)) and extrinsic (Tl(III)) pathways of apoptosis. In this work we evaluated the hypothesis that the effects of Tl(III) may be mediated by the damage to lysosomes, where it might be incorporated following the route of iron uptake. PC12 cells exposed for 3 h to 100 μM Tl(III) presented marked endosomal acidification, effect that was absent when cells were incubated in a serum-free medium and that was fully recovered when the latter was supplemented with transferrin. After 6 h of incubation the colocalization of cathepsins D and B with the lysosomal marker Lamp-1 was decreased together with an increase in the total activity of the enzymes. A permanent damage to lysosomes after 18 h of exposure was evidenced from the impairment of acridine orange uptake. Cathepsin D caused the cleavage of pro-apoptotic protein BID that is involved in the activation of the intrinsic pathway of apoptosis. Supporting that, BID cleavage and the activation of caspase 3 by Tl(III) were fully prevented when cells were preincubated with cathepsin D inhibitor (pepstatin A) and only partially prevented when cathepsin B inhibitor (E64d) was used. None of these inhibitors affected BID cleavage or caspase 3 activation in Tl(I)-treated cells. Together, experimental results support the role of Tl(III) uptake by the acidic cell compartments and their involvement in the early steps of Tl(III)-mediated PC12 cells apoptosis.
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Affiliation(s)
- Cecilia E Hanzel
- Department of Biological Chemistry, IQUIFIB (UBA-CONICET), School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
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22
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Han WQ, Xia M, Zhang C, Zhang F, Xu M, Li NJ, Li PL. SNARE-mediated rapid lysosome fusion in membrane raft clustering and dysfunction of bovine coronary arterial endothelium. Am J Physiol Heart Circ Physiol 2011; 301:H2028-37. [PMID: 21926345 DOI: 10.1152/ajpheart.00581.2011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The present study attempted to evaluate whether soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) mediate lysosome fusion in response to death receptor activation and contribute to membrane raft (MR) clustering and consequent endothelial dysfunction in coronary arterial endothelial cells. By immunohistochemical analysis, vesicle-associated membrane proteins 2 (VAMP-2, vesicle-SNAREs) were found to be abundantly expressed in the endothelium of bovine coronary arteries. Direct lysosome fusion monitoring by N-(3-triethylammoniumpropyl)-4-[4-(dibutylamino)styryl]pyridinium dibromide (FM1-43) quenching demonstrated that the inhibition of VAMP-2 with tetanus toxin or specific small interfering ribonucleic acid (siRNA) almost completely blocked lysosome fusion to plasma membrane induced by Fas ligand (FasL), a well-known MR clustering stimulator. The involvement of SNAREs was further confirmed by an increased interaction of VAMP-2 with a target-SNARE protein syntaxin-4 after FasL stimulation in coimmunoprecipitation analysis. Also, the inhibition of VAMP-2 with tetanus toxin or VAMP-2 siRNA abolished FasL-induced MR clustering, its colocalization with a NADPH oxidase unit gp91(phox), and increased superoxide production. Finally, FasL-induced impairment of endothelium-dependent vasodilation was reversed by the treatment of bovine coronary arteries with tetanus toxin or VAMP-2 siRNA. VAMP-2 is critical to lysosome fusion in MR clustering, and this VAMP-2-mediated lysosome-MR signalosomes contribute to redox regulation of coronary endothelial function.
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Affiliation(s)
- Wei-Qing Han
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298, USA
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23
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Zinchuk V, Grossenbacher‐Zinchuk O. Quantitative Colocalization Analysis of Confocal Fluorescence Microscopy Images. ACTA ACUST UNITED AC 2011; Chapter 4:Unit4.19. [DOI: 10.1002/0471143030.cb0419s52] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Vadim Zinchuk
- Department of Anatomy and Cell Biology, Kochi University Faculty of Medicine Japan
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24
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Stieger B. The role of the sodium-taurocholate cotransporting polypeptide (NTCP) and of the bile salt export pump (BSEP) in physiology and pathophysiology of bile formation. Handb Exp Pharmacol 2011:205-59. [PMID: 21103971 DOI: 10.1007/978-3-642-14541-4_5] [Citation(s) in RCA: 198] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Bile formation is an important function of the liver. Bile salts are a major constituent of bile and are secreted by hepatocytes into bile and delivered into the small intestine, where they assist in fat digestion. In the small intestine, bile salts are almost quantitatively reclaimed and transported back via the portal circulation to the liver. In the liver, hepatocytes take up bile salts and secrete them again into bile for ongoing enterohepatic circulation. Uptake of bile salts into hepatocytes occurs largely in a sodium-dependent manner by the sodium taurocholate cotransporting polypeptide NTCP. The transport properties of NTCP have been extensively characterized. It is an electrogenic member of the solute carrier family of transporters (SLC10A1) and transports predominantly bile salts and sulfated compounds, but is also able to mediate transport of additional substrates, such as thyroid hormones, drugs and toxins. It is highly regulated under physiologic and pathophysiologic conditions. Regulation of NTCP copes with changes of bile salt load to hepatocytes and prevents entry of cytotoxic bile salts during liver disease. Canalicular export of bile salts is mediated by the ATP-binding cassette transporter bile salt export pump BSEP (ABCB11). BSEP constitutes the rate limiting step of hepatocellular bile salt transport and drives enterohepatic circulation of bile salts. It is extensively regulated to keep intracellular bile salt levels low under normal and pathophysiologic situations. Mutations in the BSEP gene lead to severe progressive familial intrahepatic cholestasis. The substrates of BSEP are practically restricted to bile salts and their metabolites. It is, however, subject to inhibition by endogenous metabolites or by drugs. A sustained inhibition will lead to acquired cholestasis, which can end in liver injury.
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Affiliation(s)
- Bruno Stieger
- Division of Clinical Pharmacology and Toxicology, University Hospital, 8091, Zurich, Switzerland.
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25
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Bianchi MG, Gatti R, Torielli L, Padoani G, Gazzola GC, Bussolati O. The glutamate transporter excitatory amino acid carrier 1 associates with the actin-binding protein alpha-adducin. Neuroscience 2010; 169:584-95. [PMID: 20493242 DOI: 10.1016/j.neuroscience.2010.05.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 04/26/2010] [Accepted: 05/14/2010] [Indexed: 11/28/2022]
Abstract
Excitatory amino acid carrier 1 (EAAC1) belongs to the family of the Na(+)-dependent glutamate carriers. Although the association between defective EAAC1 function and neurologic disease has been repeatedly studied, EAAC1 regulation is not yet fully understood. We have reported that in C6 glioma cells both the activity and membrane targeting of EAAC1 require the integrity of actin cytoskeleton. Here we show that, in the same model, EAAC1 partially co-localizes with actin filaments at the level of cell processes. Moreover, perinuclear spots in which EAAC1 co-localizes with the actin binding protein alpha-adducin are observed in some cells and, consistently, faint co-immunoprecipitation bands between EAAC1 and alpha-adducin are detected. Co-localization and partial co-immunoprecipitation of EAAC1 and adducin are still detectable after cell treatment with phorbol esters, a condition that leads to a protein kinase C (PKC)-dependent increase of EAAC1 expression on the membrane and to the phosphorylation of adducin. A co-immunoprecipitation band was also detected in protein extracts of rat hippocampus. The amount of adducin co-immunoprecipitated with EAAC1 increases after the treatment of C6 cells with retinoic acid, a differentiating agent that induces EAAC1 overexpression in this cell model. Moreover, in clones of C6 cells transfected with a hemagglutinin (HA)-tagged adducin, the bands of EAAC1 immunoprecipitated by an anti-HA antiserum were proportional to EAAC1 expression. These results suggest the existence of a pool of EAAC1 transporters associated with the actin binding protein alpha-adducin in a PKC-insensitive manner.
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Affiliation(s)
- M G Bianchi
- Unit of General and Clinical Pathology, Department of Experimental Medicine, University of Parma, Parma, Italy
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26
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Brcakova E, Fuksa L, Cermanova J, Kolouchova G, Hroch M, Hirsova P, Martinkova J, Staud F, Micuda S. Alteration of methotrexate biliary and renal elimination during extrahepatic and intrahepatic cholestasis in rats. Biol Pharm Bull 2010; 32:1978-85. [PMID: 19952415 DOI: 10.1248/bpb.32.1978] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Methotrexate (MTX), an important anticancer and immunosuppressive agent, has been suggested for the treatment of primary biliary cirrhosis. However, the drug's pharmacodynamics and toxicity is dependent on its concentrations in plasma which in turn are directly related to MTX's elimination in the liver and kidney. Therefore, the aim of this study was to evaluate changes in MTX biliary and renal excretion during either intrahepatic or obstructive cholestasis in rats. The steady state pharmacokinetic parameters of MTX were evaluated in rats one (BDO1) or seven (BDO7) days after bile duct obstruction (BDO) or 18 h after administration of lipopolysaccharide (LPS). In comparison to the respective control groups, biliary and total clearances of MTX were decreased to 12% and 49% in the BDO1 group, to 5% and 56% in the BDO7 animals, and to 42% and 43% in the LPS group, respectively. Renal clearance of MTX was unchanged in BDO groups, but decreased to 23% of controls in the LPS animals. The serum biochemistry and expression of main hepatic MTX transporters (Mrp2, Mrp3, Mrp4, Bcrp, Oatp1a1, Oatp1a4 and Oatp1b2) confirmed the pathological cholestatic changes in the liver and partly elucidated the cause of changes in MTX pharmacokinetic parameters. In conclusion, this study is the first describing marked alteration of MTX hepatic and renal elimination induced by cholestasis in rats. Moreover, the reported changes in MTX pharmacokinetics and respective transporter expression suggest important mechanistic differences between the two widely used cholestatic models.
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Affiliation(s)
- Eva Brcakova
- Department of Pharmacology, Faculty of Medicine in Hradec Kralove, Charles University in Prague
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27
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Klaassen CD, Aleksunes LM. Xenobiotic, bile acid, and cholesterol transporters: function and regulation. Pharmacol Rev 2010; 62:1-96. [PMID: 20103563 PMCID: PMC2835398 DOI: 10.1124/pr.109.002014] [Citation(s) in RCA: 548] [Impact Index Per Article: 39.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Transporters influence the disposition of chemicals within the body by participating in absorption, distribution, and elimination. Transporters of the solute carrier family (SLC) comprise a variety of proteins, including organic cation transporters (OCT) 1 to 3, organic cation/carnitine transporters (OCTN) 1 to 3, organic anion transporters (OAT) 1 to 7, various organic anion transporting polypeptide isoforms, sodium taurocholate cotransporting polypeptide, apical sodium-dependent bile acid transporter, peptide transporters (PEPT) 1 and 2, concentrative nucleoside transporters (CNT) 1 to 3, equilibrative nucleoside transporter (ENT) 1 to 3, and multidrug and toxin extrusion transporters (MATE) 1 and 2, which mediate the uptake (except MATEs) of organic anions and cations as well as peptides and nucleosides. Efflux transporters of the ATP-binding cassette superfamily, such as ATP-binding cassette transporter A1 (ABCA1), multidrug resistance proteins (MDR) 1 and 2, bile salt export pump, multidrug resistance-associated proteins (MRP) 1 to 9, breast cancer resistance protein, and ATP-binding cassette subfamily G members 5 and 8, are responsible for the unidirectional export of endogenous and exogenous substances. Other efflux transporters [ATPase copper-transporting beta polypeptide (ATP7B) and ATPase class I type 8B member 1 (ATP8B1) as well as organic solute transporters (OST) alpha and beta] also play major roles in the transport of some endogenous chemicals across biological membranes. This review article provides a comprehensive overview of these transporters (both rodent and human) with regard to tissue distribution, subcellular localization, and substrate preferences. Because uptake and efflux transporters are expressed in multiple cell types, the roles of transporters in a variety of tissues, including the liver, kidneys, intestine, brain, heart, placenta, mammary glands, immune cells, and testes are discussed. Attention is also placed upon a variety of regulatory factors that influence transporter expression and function, including transcriptional activation and post-translational modifications as well as subcellular trafficking. Sex differences, ontogeny, and pharmacological and toxicological regulation of transporters are also addressed. Transporters are important transmembrane proteins that mediate the cellular entry and exit of a wide range of substrates throughout the body and thereby play important roles in human physiology, pharmacology, pathology, and toxicology.
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Affiliation(s)
- Curtis D Klaassen
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160-7417, USA.
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Sánchez Pozzi EJ, Roma MG. Putative role for actin organization status in the dynamic localization of canalicular carriers under oxidative stress conditions. Am J Physiol Gastrointest Liver Physiol 2009; 296:G969. [PMID: 19332616 DOI: 10.1152/ajpgi.00019.2009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Mulder J, Karpen SJ, Tietge UJF, Kuipers F. Nuclear receptors: mediators and modifiers of inflammation-induced cholestasis. FRONT BIOSCI-LANDMRK 2009; 14:2599-630. [PMID: 19273222 PMCID: PMC4085779 DOI: 10.2741/3400] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Inflammation-induced cholestasis (IIC) is a frequently occurring phenomenon. A central role in its pathogenesis is played by nuclear receptors (NRs). These ligand-activated transcription factors not only regulate basal expression of hepatobiliary transport systems, but also mediate adaptive responses to inflammation and possess anti-inflammatory characteristics. The latter two functions may be exploited in the search for new treatments for IIC as well as for cholestasis in general. Current knowledge of the pathogenesis of IIC and the dual role NRs in this process are reviewed. Special interest is given to the use of NRs as potential targets for intervention.
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Affiliation(s)
- Jaap Mulder
- Department of Pediatrics Center for Liver, Digestive and Metabolic Diseases, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
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Lively S, Brown IR. The extracellular matrix protein SC1/hevin localizes to excitatory synapses following status epilepticus in the rat lithium-pilocarpine seizure model. J Neurosci Res 2008; 86:2895-905. [PMID: 18488994 DOI: 10.1002/jnr.21735] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The epileptic brain is characterized by increased susceptibility to neuronal hyperexcitability. The rat lithium-pilocarpine model, which mimics many features of temporal lobe epilepsy, has been used to study processes leading to the development of recurrent seizures. After a prolonged seizure episode, termed status epilepticus (SE), neural changes occur during a period known as epileptogenesis and include neuronal cell death, reactive gliosis, axonal sprouting, and synaptogenesis. Extracellular matrix adhesion molecules are important regulators of synaptogenesis and axonal sprouting resulting from SE. SC1, also known as hevin, is an antiadhesive extracellular matrix molecule that localizes to synapses in the mammalian brain. In this study, the distribution of SC1 protein in neurons following SE was examined using the lithium-pilocarpine model. SC1 protein levels in neuronal cell bodies showed a transient decrease at 1 day post-SE, which coincided with an increase of SC1 in the synapse-rich neuropil that was identified with the synaptic marker synaptophysin. Immunoelectron microscopy confirmed the decrease of SC1 signal in neurons at 1 day post-SE and showed that SC1 remained localized to postsynaptic elements throughout the seizure time course. Increased colocalization of SC1 was detected with the excitatory synaptic markers vesicular glutamate transporter 1 (VGLUT1), AMPA receptor subunit GluR1, and N-methyl-D-aspartate receptor subunit NR1, but not with the inhibitory synaptic markers vesicular gamma-aminobutyric acid (GABA) transporter (VGAT) and GABA(A) receptor subunit beta2 (GABA(A) beta2), which could reflect enhanced association of SC1 with excitatory synapses. These findings suggest that SC1 may be involved in synaptic modifications underlying epileptogenesis.
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Affiliation(s)
- Starlee Lively
- Center for the Neurobiology of Stress, University of Toronto at Scarborough, Toronto, Ontario, Canada
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Wang L, Oka N, Tropak M, Callahan J, Lee J, Wilson G, Redington A, Caldarone CA. Remote ischemic preconditioning elaborates a transferable blood-borne effector that protects mitochondrial structure and function and preserves myocardial performance after neonatal cardioplegic arrest. J Thorac Cardiovasc Surg 2008; 136:335-42. [DOI: 10.1016/j.jtcvs.2007.12.055] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Revised: 10/24/2007] [Accepted: 12/18/2007] [Indexed: 10/22/2022]
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Zinchuk V, Zinchuk O. Quantitative Colocalization Analysis of Confocal Fluorescence Microscopy Images. ACTA ACUST UNITED AC 2008; Chapter 4:Unit 4.19. [DOI: 10.1002/0471143030.cb0419s39] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Vadim Zinchuk
- Department of Anatomy and Cell Biology, Kochi University, Faculty of Medicine Japan
| | - Olga Zinchuk
- Institute of Anatomy, University of Berne, CH‐3000 Berne Switzerland
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Abstract
OBJECTIVES The present study was aimed at evaluation of in vivo biliary and renal excretion of rhodamine 123 (Rho123), a P-glycoprotein (P-gp) substrate, in rats during either acute or chronic cholestasis induced by bile duct obstruction (BDO). METHODS The Rho123 clearance study was performed either one (BDO1) or seven (BDO7) days after BDO. Bile flow was reconstituted, and bile and urine were collected after steady-state plasma concentration of Rho123 was attained. Tissue expression of P-gp was evaluated by quantitative immunohistochemistry, and immunoblotting. RESULTS Significant up-regulation of the liver P-gp protein was observed in acute and chronic cholestasis. Primary periportal location of P-gp was enlarged also to pericentral areas. In the kidneys, immunohistochemistry showed pancellular increase in P-gp after 1 day of BDO, which subsided after 7 days of BDO. Nevertheless, biliary and renal clearances (CL(Bile) and CL(R)) of Rho123 did not reflect the induction of P-gp expression. While CL(Bile) was reduced one day after cholestasis and restored on the seventh day, the CL(R) was preserved in BDO1 group and reduced in BDO7 group without change in glomerular filtration rate. In parallel, biliary and renal clearances of conjugated bilirubin were significantly reduced in both cholestatic groups compared with controls. CONCLUSION These findings suggest that extrahepatic cholestasis causes time-dependent changes in elimination of Rho123 which do not exactly reflect alteration of P-gp expression in the rat liver and kidney. These data may help to explain impaired elimination of P-gp substrates after short-term cholestasis that may commonly occur in clinical practice.
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Inhibition of mitochondrial remodeling by cyclosporine A preserves myocardial performance in a neonatal rabbit model of cardioplegic arrest. J Thorac Cardiovasc Surg 2008; 135:585-93. [PMID: 18329475 DOI: 10.1016/j.jtcvs.2007.09.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Revised: 09/12/2007] [Accepted: 09/24/2007] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Mitochondrial permeability transition pore opening is associated with apoptotic signaling and alterations in mitochondrial structure and function. We tested whether inhibition of mitochondrial permeability transition pore opening with cyclosporine A preserved mitochondrial structure and function after cardioplegic arrest and whether this preservation is associated with improved myocardial performance. METHODS Langendorff-perfused neonatal rabbit hearts were perfused for 30 minutes with Krebs-Henseleit buffer (CCP; n = 6) or Krebs-Henseleit buffer containing 2 mumol/L of cyclosporine A (CCP+CsA; n = 6) followed by 60 minutes of normothermic crystalloid cardioplegia (CCP) and 60 minutes of reperfusion. Control hearts (non-CCP; n = 6) were constantly perfused for 150 minutes without cardioplegic arrest. RESULTS In comparison with non-CCP, CCP was associated with Bax translocation to the mitochondria, cytochrome c release, and greater frequency of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive myocytes These changes were also associated with deficits in isolated mitochondrial oxygen consumption at complex I. CsA pretreatment minimized or prevented all these findings. Myocardial performance (systolic pressure, maximum positive and negative dP/dt, and elevated left ventricular end-diastolic pressure) at 5, 15, 30, and 60 minutes after reperfusion was diminished in CCP hearts when compared with non-CPB, and these deficits could be minimized with cyclosporine A pretreatment. (P < .05 all comparisons) CONCLUSIONS Cyclosporine A prevents apoptosis-related mitochondrial permeabilization and dysfunction after cardioplegic arrest. This protection is associated with improved myocardial performance. Prevention of mitochondrial permeability transition pore opening is a valuable target for mitochondrial (and myocardial) preservation after neonatal cardioplegic arrest.
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Lively S, Brown IR. Localization of the extracellular matrix protein SC1 coincides with synaptogenesis during rat postnatal development. Neurochem Res 2008; 33:1692-700. [PMID: 18335312 DOI: 10.1007/s11064-008-9606-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Accepted: 01/23/2008] [Indexed: 12/12/2022]
Abstract
SC1 is an extracellular matrix protein that belongs to the SPARC family of matricellular molecules. This anti-adhesive protein localizes to synapses in the adult rat brain and has been postulated to modulate synapse shape. In this study, increased levels of SC1 were detected from postnatal days 10-20, with a peak at postnatal day 15, a period of intense synaptogenesis. During this time, increased colocalization of SC1 with the synaptic marker synaptophysin was observed in synapse-rich regions of the cerebellum and the cerebral cortex. These findings indicate that the pattern of SC1 localization coincided with synaptogenesis during rat postnatal development.
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Affiliation(s)
- Starlee Lively
- Center for the Neurobiology of Stress, University of Toronto at Scarborough, 1265 Military Trail, Toronto, ON, Canada, M1C 1A4
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Oka N, Wang L, Mi W, Zhu W, Honjo O, Caldarone CA. Cyclosporine A prevents apoptosis-related mitochondrial dysfunction after neonatal cardioplegic arrest. J Thorac Cardiovasc Surg 2008; 135:123-30, 130.e1-2. [PMID: 18179928 DOI: 10.1016/j.jtcvs.2007.05.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Revised: 04/27/2007] [Accepted: 05/02/2007] [Indexed: 12/01/2022]
Abstract
OBJECTIVE Mitochondrial permeability transition pore opening plays a critical role in mediating the mitochondrial response to ischemia/reperfusion injury and initiation of apoptosis. We tested whether inhibition of mitochondrial permeability transition pore opening with cyclosporine A prevented apoptosis-related alterations in mitochondrial structure and function after cardioplegic arrest. METHODS Newborn piglets (age approximately 14 days) underwent cardiopulmonary bypass, cardioplegic arrest (60 minutes), weaning from bypass, and 6-hour reperfusion. Comparison was made among cold crystalloid cardioplegia (n = 5), cold crystalloid cardioplegia with cyclosporine A pretreatment (n = 5), and noncardiopulmonary bypass (n = 5) groups. RESULTS Early apoptosis signaling events (Bax translocation to the mitochondria) were prominent in cold crystalloid cardioplegia and prevented in cold crystalloid cardioplegia + cyclosporine A myocardium. Mitochondrial release of cytochrome c, determined by Western blot of cytosolic fractions and confocal quantitative colocalization analysis, was also prominent in cold crystalloid cardioplegia but prevented in cold crystalloid cardioplegia + cyclosporine A myocardium. Electron microscopy of isolated mitochondria demonstrated subjective alterations in mitochondrial architecture in cold crystalloid cardioplegia mitochondria, which were prevented by cyclosporine A. Deficiency of isolated mitochondrial oxygen consumption at Complex I was present in cold crystalloid cardioplegia mitochondria and prevented by cyclosporine A (P < .01). The frequency of deoxyuride-5'-triphosphate biotin nick end labeling-positive myocytes was diminished in cold crystalloid cardioplegia + cyclosporine A myocardium (P < .05). Mitochondrial resistance to calcium-mediated mitochondrial permeability transition pore opening was not different in cold crystalloid cardioplegia and noncardiopulmonary bypass mitochondria, suggesting that calcium overload is not solely responsible for the observed deficits in mitochondrial function. CONCLUSIONS Cyclosporine A pretreatment prevents postcardioplegia alterations in mitochondrial structure and function in a clinically relevant model of neonatal cardiac surgery. Prevention of mitochondrial permeability transition pore opening and apoptosis signaling events (Bax translocation and mitochondrial permeabilization) are associated with superior mitochondrial preservation.
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Affiliation(s)
- Norihiko Oka
- Division of Cardiovascular Surgery, the Hospital for Sick Children, University of Toronto, Ontario, Canada
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Zinchuk V, Zinchuk O, Okada T. Quantitative colocalization analysis of multicolor confocal immunofluorescence microscopy images: pushing pixels to explore biological phenomena. Acta Histochem Cytochem 2007; 40:101-11. [PMID: 17898874 PMCID: PMC1993886 DOI: 10.1267/ahc.07002] [Citation(s) in RCA: 324] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Accepted: 06/08/2007] [Indexed: 11/22/2022] Open
Abstract
Quantitative colocalization analysis is an advanced digital imaging tool to examine antigens of interest in immunofluorescence images obtained using confocal microscopes. It employs specialized algorithms to estimate the degree of overlap of fluorescence signals and thus enables acquiring important new information not otherwise obtainable using qualitative approaches alone. As raw confocal images have high levels of background, they should be prepared to become suitable for reliable calculation of colocalization coefficients by correcting it. We provide concise theoretical basis of quantitative colocalization analysis, discuss its limitations, and describe proper use of the technique. The use of quantitative colocalization analysis is demonstrated by studying bile salt export pump and multidrug resistance associated protein 2 in the liver and major basic protein and platelet activating factor receptor antigens in conjunctiva. The review is focused on the applicability and correct interpretation of the results of colocalization coefficients calculations.
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Affiliation(s)
- Vadim Zinchuk
- Department of Anatomy and Cell Biology, Kochi University Faculty of Medicine
| | - Olga Zinchuk
- Department of Ophthalmology, Kochi University Faculty of Medicine, Okoh-cho, Nankoku, Kochi 783–8505, Japan
| | - Teruhiko Okada
- Department of Anatomy and Cell Biology, Kochi University Faculty of Medicine
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Zinchuk V, Zinchuk O, Akimaru K, Moriya F, Okada T. Ethanol consumption alters expression and colocalization of bile salt export pump and multidrug resistance protein 2 in the rat. Histochem Cell Biol 2007; 127:503-12. [PMID: 17384956 DOI: 10.1007/s00418-007-0277-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/07/2007] [Indexed: 02/01/2023]
Abstract
Chronic ethanol consumption elicits detrimental changes of liver metabolism. By employing a 12-week-long feeding regimen, we investigated the effects of chronic ethanol consumption on the expression and localization of bile salt export pump (Bsep), a major canalicular exporter of bile salts, and multidrug resistance protein 2 (Mrp2), a canalicular organic anion transporter, in the rat liver. RT-PCR, confocal immunofluorescence microscopy, immunoblotting, and quantitative colocalization analysis were used to examine their gene and protein expression, and changes in the distribution of antigenic sites. Bsep mRNA was upregulated, while Mrp2 mRNA responded by downregulation. In agreement with mRNA, the expression of Bsep protein increased, while the expression of Mrp2 protein responded with a decrease, suggesting that the expression of both of them is transcriptionally regulated. Confocal immunofluorescence microscopy showed disruption of the colocalization of Bsep and Mrp2 proteins at the hepatocyte canalicular membrane and their relocation intracellularly. Quantitative colocalization analysis of Bsep and Mrp2 proteins revealed a steady decrease in the degree of colocalization and Mrp2 expression, indicating that although the properties of both transporters are affected, Mrp2 is altered more. These findings provide evidence that ethanol alters Bsep and Mrp2 canalicular transporters in the rat liver, at both the mRNA and protein levels. Mrp2 shows deeper involvement. Eight weeks appears to be a critical time point in this process.
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Affiliation(s)
- Vadim Zinchuk
- Department of Anatomy and Cell Biology, Kochi University Faculty of Medicine, Kohasu, Okoh-cho, Nankoku, Kochi, 783-8505, Japan.
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Chen S, Brown IR. Translocation of constitutively expressed heat shock protein Hsc70 to synapse-enriched areas of the cerebral cortex after hyperthermic stress. J Neurosci Res 2007; 85:402-9. [PMID: 17203483 DOI: 10.1002/jnr.21124] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hsp70 is a multi-gene family composed of stress-inducible members (Hsp70) and other members that are constitutively expressed (Hsc70). The heat shock proteins Hsp70 and Hsc70 exhibit similar molecular structure and biochemical functions. Constitutively expressed Hsc70 is enriched in the mammalian nervous system compared with non-neural tissues and present at high levels in neuronal cell bodies. After thermal stress, Hsc70 is translocated to synapse-enriched areas of the cerebral cortex where it associates with Hsp40 to form a complex that can refold denaturated proteins. These results suggest that the heat shock response in the nervous system involves not only the synthesis of stress-inducible Hsps but also the translocation of constitutively expressed Hsc70 to synapse-enriched areas where it could participate in neuroprotective mechanisms that preserved synaptic function during times of stress.
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Affiliation(s)
- Sheng Chen
- Centre for the Neurobiology of Stress, University of Toronto at Scarborough, Ontario, Canada
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40
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Fleming EH, Kolokoltsov AA, Davey RA, Nichols JE, Roberts NJ. Respiratory syncytial virus F envelope protein associates with lipid rafts without a requirement for other virus proteins. J Virol 2006; 80:12160-70. [PMID: 17005642 PMCID: PMC1676292 DOI: 10.1128/jvi.00643-06] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Accepted: 09/15/2006] [Indexed: 01/16/2023] Open
Abstract
Like many enveloped viruses, human respiratory syncytial virus (RSV) assembles at and buds from lipid rafts. Translocation of the envelope proteins to these membrane subdomains is essential for production of infectious virus, but the targeting mechanism is poorly understood and it is not known if other virus proteins are required. Here we demonstrate that F protein of RSV intrinsically targets to lipid rafts without a requirement for any other virus protein, including the SH and G envelope proteins. Recombinant virus deficient in SH and G but retaining F protein expression was used to demonstrate that F protein still localized in rafts in both A549 and HEp-2 cells. Expression of a recombinant F gene by use of plasmid vectors demonstrated that F contains its own targeting domain and localized to rafts in the absence of other virus proteins. The domain responsible for translocation was then mapped. Unlike most other virus envelope proteins, F is unusual since the target signal is not contained within the cytoplasmic domain nor did it involve fatty acid modified residues. Furthermore, exchange of the transmembrane domain with that of the vesicular stomatitis virus G protein, a nonraft protein, did not alter F protein raft localization. Taken together, these data suggest that domains present in the extracellular portion of the protein are responsible for lipid raft targeting of the RSV F protein.
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Affiliation(s)
- Elisa H Fleming
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555-0435, USA
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Stieger B, Meier Y, Meier PJ. The bile salt export pump. Pflugers Arch 2006; 453:611-20. [PMID: 17051391 DOI: 10.1007/s00424-006-0152-8] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Accepted: 08/08/2006] [Indexed: 12/20/2022]
Abstract
Canalicular secretion of bile salts mediated by the bile salt export pump Bsep constitutes the major driving force for the generation of bile flow. Bsep is a member of the B-family of the super family of ATP-binding cassette transporters and is classified as ABCB11. Bsep has a narrow substrate specificity, which is largely restricted to bile salts. Bsep is extensively regulated at the transcriptional and posttranscriptional level, which directly modulates canalicular bile formation. Pathophysiological alterations of Bsep by either inherited mutations or acquired processes such as inhibition by drugs or disease-related down regulation may lead to a wide spectrum of mild to severe forms of liver disease. Furthermore, many genetic variants of Bsep are known, some of which potentially render individuals susceptible to acquired forms of liver disease.
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Affiliation(s)
- Bruno Stieger
- Department of Medicine, Institute of Clinical Pharmacology and Toxicology, University Hospital, Zürich, Switzerland.
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Dombrowski F, Stieger B, Beuers U. Tauroursodeoxycholic acid inserts the bile salt export pump into canalicular membranes of cholestatic rat liver. J Transl Med 2006; 86:166-74. [PMID: 16344857 DOI: 10.1038/labinvest.3700371] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Ursodeoxycholic acid exerts anticholestatic effects in chronic cholestatic liver disease in humans as well as in experimental animal models of cholestasis. Its taurine conjugate, TUDCA, was recently shown to stimulate insertion of the apical conjugate export pump, Mrp2 (ABCC2), into canalicular membranes of rat hepatocytes made cholestatic by exposure to taurolithocholic acid (TLCA). The aim of this immunoelectronmicroscopic study was to test whether TLCA and TUDCA modulate the canalicular density of the other key apical transporter, the bile salt export pump, Bsep (ABCB11), in a similar way. Immunoelectronmicroscopic analysis of Bsep density on canalicular membranes, microvilli, and pericanalicular area of hepatocytes was performed in rat liver tissue prepared after liver perfusion with bile acids or carrier medium only. TLCA (10 micromol/l for 50 min) decreased Bsep density in canalicular membranes to 31% of controls (P<0.05) when bile flow was reduced to 35% of controls (P<0.05). Concomitantly, Bsep density in a 1 microm pericanalicular zone increased to 202% (P<0.05) indicating effective retrieval of Bsep from the canalicular membrane induced by TLCA. Coadministration of TUDCA (25 micromol/l) led to a 3.2-fold increase of Bsep density in canalicular membranes equal to control liver (P<0.05 vs TLCA) in association with a 3.8-fold increase of bile flow (P<0.05 vs TLCA). Stimulation of apical membrane insertion of key transporters like the bile salt export pump, Bsep, and-as previously shown-the conjugate export pump, Mrp2, may contribute to the anticholestatic action of UDCA amides in cholestatic conditions.
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Affiliation(s)
- Frank Dombrowski
- Department of Pathology, University of Magdeburg, Magdeburg, Germany
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