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Ma JT, Xia S, Zhang BK, Luo F, Guo L, Yang Y, Gong H, Yan M. The pharmacology and mechanisms of traditional Chinese medicine in promoting liver regeneration: A new therapeutic option. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 116:154893. [PMID: 37236047 DOI: 10.1016/j.phymed.2023.154893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/04/2023] [Accepted: 05/17/2023] [Indexed: 05/28/2023]
Abstract
BACKGROUND The liver is renowned for its remarkable regenerative capacity to restore its structure, size and function after various types of liver injury. However, in patients with end-stage liver disease, the regenerative capacity is inhibited and liver transplantation is the only option. Considering the limitations of liver transplantation, promoting liver regeneration is suggested as a new therapeutic strategy for liver disease. Traditional Chinese medicine (TCM) has a long history of preventing and treating various liver diseases, and some of them have been proven to be effective in promoting liver regeneration, suggesting the therapeutic potential in liver diseases. PURPOSE This review aims to summarize the molecular mechanisms of liver regeneration and the pro-regenerative activity and mechanism of TCM formulas, extracts and active ingredients. METHODS We conducted a systematic search in PubMed, Web of Science and the Cochrane Library databases using "TCM", "liver regeneration" or their synonyms as keywords, and classified and summarized the retrieved literature. The PRISMA guidelines were followed. RESULTS Forty-one research articles met the themes of this review and previous critical studies were also reviewed to provide essential background information. Current evidences indicate that various TCM formulas, extracts and active ingredients have the effect on stimulating liver regeneration through modulating JAK/STAT, Hippo, PI3K/Akt and other signaling pathways. Besides, the mechanisms of liver regeneration, the limitation of existing studies and the application prospect of TCM to promote liver regeneration are also outlined and discussed in this review. CONCLUSION This review supports TCM as new potential therapeutic options for promoting liver regeneration and repair of the failing liver, although extensive pharmacokinetic and toxicological studies, as well as elaborate clinical trials, are still needed to demonstrate safety and efficacy.
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Affiliation(s)
- Jia-Ting Ma
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Changsha, China
| | - Shuang Xia
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Changsha, China
| | - Bi-Kui Zhang
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Changsha, China
| | - Fen Luo
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Changsha, China
| | - Lin Guo
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Changsha, China
| | - Yan Yang
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Changsha, China
| | - Hui Gong
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Changsha, China.
| | - Miao Yan
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China; Institute of Clinical Pharmacy, Central South University, Changsha, China; International Research Center for Precision Medicine, Transformative Technology and Software Services, Changsha, China.
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Hu S, Cao C, Poddar M, Delgado E, Singh S, Singh-Varma A, Stolz DB, Bell A, Monga SP. Hepatocyte β-catenin loss is compensated by Insulin-mTORC1 activation to promote liver regeneration. Hepatology 2023; 77:1593-1611. [PMID: 35862186 PMCID: PMC9859954 DOI: 10.1002/hep.32680] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/13/2022] [Accepted: 07/16/2022] [Indexed: 01/25/2023]
Abstract
BACKGROUND AND AIMS Liver regeneration (LR) following partial hepatectomy (PH) occurs via activation of various signaling pathways. Disruption of a single pathway can be compensated by activation of another pathway to continue LR. The Wnt-β-catenin pathway is activated early during LR and conditional hepatocyte loss of β-catenin delays LR. Here, we study mechanism of LR in the absence of hepatocyte-β-catenin. APPROACH AND RESULTS Eight-week-old hepatocyte-specific Ctnnb1 knockout mice (β-catenin ΔHC ) were subjected to PH. These animals exhibited decreased hepatocyte proliferation at 40-120 h and decreased cumulative 14-day BrdU labeling of <40%, but all mice survived, suggesting compensation. Insulin-mediated mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) activation was uniquely identified in the β-catenin ΔHC mice at 72-96 h after PH. Deletion of hepatocyte regulatory-associated protein of mTOR (Raptor), a critical mTORC1 partner, in the β-catenin ΔHC mice led to progressive hepatic injury and mortality by 30 dys. PH on early stage nonmorbid Raptor ΔHC -β-catenin ΔHC mice led to lethality by 12 h. Raptor ΔHC mice showed progressive hepatic injury and spontaneous LR with β-catenin activation but died by 40 days. PH on early stage nonmorbid Raptor ΔHC mice was lethal by 48 h. Temporal inhibition of insulin receptor and mTORC1 in β-catenin ΔHC or controls after PH was achieved by administration of linsitinib at 48 h or rapamycin at 60 h post-PH and completely prevented LR leading to lethality by 12-14 days. CONCLUSIONS Insulin-mTORC1 activation compensates for β-catenin loss to enable LR after PH. mTORC1 signaling in hepatocytes itself is critical to both homeostasis and LR and is only partially compensated by β-catenin activation. Dual inhibition of β-catenin and mTOR may have notable untoward hepatotoxic side effects.
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Affiliation(s)
- Shikai Hu
- School of Medicine, Tsinghua University, Beijing, China
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
| | - Catherine Cao
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
| | - Minakshi Poddar
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
| | - Evan Delgado
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
- Pittsburgh Liver Research Center, University of Pittsburgh Medical Center and University of Pittsburgh School of Medicine, Pittsburgh, PA USA
| | - Sucha Singh
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
| | - Anya Singh-Varma
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
| | - Donna Beer Stolz
- Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA USA
| | - Aaron Bell
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
- Pittsburgh Liver Research Center, University of Pittsburgh Medical Center and University of Pittsburgh School of Medicine, Pittsburgh, PA USA
| | - Satdarshan P. Monga
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
- Pittsburgh Liver Research Center, University of Pittsburgh Medical Center and University of Pittsburgh School of Medicine, Pittsburgh, PA USA
- Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA USA
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Liver regeneration after partial hepatectomy is improved in the absence of aryl hydrocarbon receptor. Sci Rep 2022; 12:15446. [PMID: 36104446 PMCID: PMC9474532 DOI: 10.1038/s41598-022-19733-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 09/02/2022] [Indexed: 11/19/2022] Open
Abstract
The liver is among the few organs having the ability to self-regenerate in response to a severe damage compromising its functionality. The Aryl hydrocarbon receptor (Ahr) is a transcription factor relevant for the detoxification of xenobiotics but also largely important for liver development and homeostasis. Hence, liver cell differentiation is developmentally modulated by Ahr through the controlled expression of pluripotency and stemness-inducing genes. Here, 2/3 partial hepatectomy (PH) was used as a clinically relevant approach to induce liver regeneration in Ahr-expressing (Ahr+/+) and Ahr-null (Ahr−/−) mice. Ahr expression and activity were early induced after 2/3 PH to be gradually downmodulated latter during regeneration. Ahr−/− mice triggered liver regeneration much faster than AhR+/+ animals, although both reached full regeneration at the latest times. At initial stages after PHx, earlier regenerating Ahr−/− livers had upregulation of cell proliferation markers and increased activation of signalling pathways related to stemness such as Hippo-YAP and Wnt/β-catenin, concomitantly with the induction of pro-inflammatory cytokines TNFa, IL6 and p65. These phenotypes, together with the improved metabolic adaptation of Ahr−/− mice after PHx and their induced sustained cell proliferation, could likely result from the expansion of undifferentiated stem cells residing in the liver expressing OCT4, SOX2, KLF4 and NANOG. We propose that Ahr needs to be induced early during regeneration to fine-tune liver regrowth to physiological values. Since Ahr deficiency did not result in liver overgrowth, its transient pharmacological inhibition could serve to improve liver regeneration in hepatectomized and transplanted patients and in those exposed to damaging liver toxins and carcinogens.
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Zhang B, Lv D, Chen Y, Nie W, Jiao Y, Zhang J, Zhou X, Wu X, Chen S, Ma T. Aquaporin-9 facilitates liver regeneration following hepatectomy. Redox Biol 2022; 50:102246. [PMID: 35086002 PMCID: PMC8802049 DOI: 10.1016/j.redox.2022.102246] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/06/2022] [Accepted: 01/19/2022] [Indexed: 12/12/2022] Open
Abstract
Aquaporin-9 (AQP9) is an aquaglyceroporin strongly expressed in the basolateral membrane of hepatocytes facing the sinusoids. AQP9 is permeable to hydrogen peroxide (H2O2) and glycerol as well as to water. Here, we report impaired liver regeneration in AQP9−/− mice which involves altered steady-state H2O2 concentration and glucose metabolism in hepatocytes. AQP9−/− mice showed remarkably delayed liver regeneration and increased mortality following 70% or 90% partial hepatectomy. Compared to AQP9+/+ littermates, AQP9−/− mice showed significantly greater hepatic H2O2 concentration and more severe liver injury. Fluorescence measurements indicated impaired H2O2 transport across plasma membrane of primary cultured hepatocytes from AQP9−/− mice, supporting the hypothesis that AQP9 deficiency results in H2O2 accumulation and oxidative injury in regenerating liver because of reduced export of intracellular H2O2 from hepatocytes. The H2O2 overload in AQP9−/− hepatocytes reduced PI3K-Akt and insulin signaling, inhibited autophagy and promoted apoptosis, resulting in impaired proliferation and increased cell death. In addition, hepatocytes from AQP9−/− mice had low liver glycerol and high blood glycerol levels, suggesting decreased glycerol uptake and gluconeogenesis in AQP9−/− hepatocytes. Adeno-associated virus (AAV)-mediated expression of hepatic expression of aquaglyceroporins AQP9 and AQP3 in AQP9−/− mice, but not water-selective channel AQP4, fully rescued the impaired liver regeneration phenotype as well as the oxidative injury and abnormal glucose metabolism. Our data revealed a pivotal role of AQP9 in liver regeneration by regulating hepatocyte H2O2 homeostasis and glucose metabolism, suggesting AQP9 as a novel target to enhance liver regeneration following injury, surgical resection or transplantation. AQP9 mediates H2O2 and glycerol transport across hepatocytes plasma membrane AQP9−/− mice exhibit retained liver regeneration and higher mortality after PH Elevated H2O2 and reduced glucose levels appear in AQP9−/− regenerating liver Replacement of aquaglyceroporin rescued impaired AQP9−/− mouse liver regeneration AQP9 may become a novel target to improve liver regeneration
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Hodson L, Gunn PJ. The regulation of hepatic fatty acid synthesis and partitioning: the effect of nutritional state. Nat Rev Endocrinol 2019; 15:689-700. [PMID: 31554932 DOI: 10.1038/s41574-019-0256-9] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is an increasing global public health burden. NAFLD is strongly associated with type 2 diabetes mellitus, obesity and cardiovascular disease and begins with intrahepatic triacylglycerol accumulation. Under healthy conditions, the liver regulates lipid metabolism to meet systemic energy needs in the fed and fasted states. The processes of fatty acid uptake, fatty acid synthesis and the intracellular partitioning of fatty acids into storage, oxidation and secretion pathways are tightly regulated. When one or more of these processes becomes dysregulated, excess lipid accumulation can occur. Although genetic and environmental factors have been implicated in the development of NAFLD, it remains unclear why an imbalance in these pathways begins. The regulation of fatty acid partitioning occurs at several points, including during triacylglycerol synthesis, lipid droplet formation and lipolysis. These processes are influenced by enzyme function, intake of dietary fats and sugars and whole-body metabolism, and are further affected by the presence of obesity or insulin resistance. Insight into how the liver controls fatty acid metabolism in health and how these processes might be affected in disease would offer the potential for new therapeutic treatments for NAFLD to be developed.
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Affiliation(s)
- Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Headington, Oxford, UK.
- Oxford NIHR Biomedical Research Centre, Churchill Hospital, Headington, Oxford, UK.
| | - Pippa J Gunn
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Headington, Oxford, UK
- Oxford NIHR Biomedical Research Centre, Churchill Hospital, Headington, Oxford, UK
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Wan H, Li J, Liao H, Liao M, Luo L, Xu L, Yuan K, Zeng Y. Nicotinamide induces liver regeneration and improves liver function by activating SIRT1. Mol Med Rep 2018; 19:555-562. [PMID: 30483782 DOI: 10.3892/mmr.2018.9688] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 09/21/2018] [Indexed: 02/05/2023] Open
Affiliation(s)
- Hai‑Feng Wan
- Department of Liver Surgery, Liver Transplantation Division, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Jia‑Xin Li
- Department of Liver Surgery, Liver Transplantation Division, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Hao‑Tian Liao
- Department of Liver Surgery, Liver Transplantation Division, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Ming‑Heng Liao
- Department of Liver Surgery, Liver Transplantation Division, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Lin Luo
- Department of Liver Surgery, Liver Transplantation Division, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Lin Xu
- Laboratory of Liver Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Ke‑Fei Yuan
- Department of Liver Surgery, Liver Transplantation Division, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Yong Zeng
- Department of Liver Surgery, Liver Transplantation Division, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
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Brosch M, Kattler K, Herrmann A, von Schönfels W, Nordström K, Seehofer D, Damm G, Becker T, Zeissig S, Nehring S, Reichel F, Moser V, Thangapandi RV, Stickel F, Baretton G, Röcken C, Muders M, Matz-Soja M, Krawczak M, Gasparoni G, Hartmann H, Dahl A, Schafmayer C, Walter J, Hampe J. Epigenomic map of human liver reveals principles of zonated morphogenic and metabolic control. Nat Commun 2018; 9:4150. [PMID: 30297808 PMCID: PMC6175862 DOI: 10.1038/s41467-018-06611-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 09/14/2018] [Indexed: 12/21/2022] Open
Abstract
A deeper epigenomic understanding of spatial organization of cells in human tissues is an important challenge. Here we report the first combined positional analysis of transcriptomes and methylomes across three micro-dissected zones (pericentral, intermediate and periportal) of human liver. We identify pronounced anti-correlated transcriptional and methylation gradients including a core of 271 genes controlling zonated metabolic and morphogen networks and observe a prominent porto-central gradient of DNA methylation at binding sites of 46 transcription factors. The gradient includes an epigenetic and transcriptional Wnt signature supporting the concept of a pericentral hepatocyte regeneration pathway under steady-state conditions. While donors with non-alcoholic fatty liver disease show consistent gene expression differences corresponding to the severity of the disease across all zones, the relative zonated gene expression and DNA methylation patterns remain unchanged. Overall our data provide a wealth of new positional insights into zonal networks controlled by epigenetic and transcriptional gradients in human liver. Spatial mapping of genomic programs in tissue cells is an important step in the understanding of organ function and disease. Here, the authors provide a spatially resolved epigenomic and transcriptomic map of human liver and show porto-central gradients in metabolic and morphogen networks and transcription factor binding sites as a basis to better understand liver regeneration and function.
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Affiliation(s)
- Mario Brosch
- Medical Department 1, University Hospital Dresden, Technische Universität Dresden (TU Dresden), Dresden, Germany.,Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden (TU Dresden), Dresden, Germany
| | - Kathrin Kattler
- Department of Genetics and Epigenetics, Universität des Saarlandes, Saarbrücken, Germany
| | - Alexander Herrmann
- Medical Department 1, University Hospital Dresden, Technische Universität Dresden (TU Dresden), Dresden, Germany.,Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden (TU Dresden), Dresden, Germany
| | - Witigo von Schönfels
- Department of Visceral Surgery, University Hospital Schleswig-Holstein, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Karl Nordström
- Department of Genetics and Epigenetics, Universität des Saarlandes, Saarbrücken, Germany
| | - Daniel Seehofer
- Department of Hepatobiliary Surgery and Visceral Transplantation, University of Leipzig, Leipzig, Germany
| | - Georg Damm
- Department of Hepatobiliary Surgery and Visceral Transplantation, University of Leipzig, Leipzig, Germany
| | - Thomas Becker
- Department of Visceral Surgery, University Hospital Schleswig-Holstein, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Sebastian Zeissig
- Medical Department 1, University Hospital Dresden, Technische Universität Dresden (TU Dresden), Dresden, Germany
| | - Sophie Nehring
- Medical Department 1, University Hospital Dresden, Technische Universität Dresden (TU Dresden), Dresden, Germany
| | - Fabian Reichel
- Medical Department 1, University Hospital Dresden, Technische Universität Dresden (TU Dresden), Dresden, Germany
| | - Vincent Moser
- Medical Department 1, University Hospital Dresden, Technische Universität Dresden (TU Dresden), Dresden, Germany
| | - Raghavan Veera Thangapandi
- Medical Department 1, University Hospital Dresden, Technische Universität Dresden (TU Dresden), Dresden, Germany
| | - Felix Stickel
- Department of Gastroenterology, University of Zürich, Zürich, Switzerland
| | - Gustavo Baretton
- Institute of Pathology, University Hospital Dresden, Technische Universität Dresden (TU Dresden), Dresden, Germany
| | - Christoph Röcken
- Institute of Pathology, University Hospital Schleswig-Holstein, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Michael Muders
- Institute of Pathology, University Hospital Dresden, Technische Universität Dresden (TU Dresden), Dresden, Germany
| | - Madlen Matz-Soja
- Rudolf-Schönheimer-Institute for Biochemistry, University of Leipzig, Leipzig, Germany
| | - Michael Krawczak
- Institute of Medical Informatics and Statistics, Christian-Albrechts University, Kiel, Germany
| | - Gilles Gasparoni
- Department of Genetics and Epigenetics, Universität des Saarlandes, Saarbrücken, Germany
| | - Hella Hartmann
- Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden (TU Dresden), Dresden, Germany
| | - Andreas Dahl
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden (TU Dresden), Dresden, Germany
| | - Clemens Schafmayer
- Department of Visceral Surgery, University Hospital Schleswig-Holstein, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Jörn Walter
- Department of Genetics and Epigenetics, Universität des Saarlandes, Saarbrücken, Germany
| | - Jochen Hampe
- Medical Department 1, University Hospital Dresden, Technische Universität Dresden (TU Dresden), Dresden, Germany. .,Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden (TU Dresden), Dresden, Germany.
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Jia C, Yang H, Dai C, Xu F, Peng S, Zhao Y, Zhao C, Zhao L. Expression of hypoxia inducible factor-1α and its correlation with phosphoenolpyruvate carboxykinase after portal vein ligation in rats. Life Sci 2017; 190:97-102. [DOI: 10.1016/j.lfs.2017.09.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 08/28/2017] [Accepted: 09/06/2017] [Indexed: 02/06/2023]
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Fülöp A, Szijártó A, Harsányi L, Budai A, Pekli D, Korsós D, Horváth I, Kovács N, Karlinger K, Máthé D, Szigeti K. Demonstration of metabolic and cellular effects of portal vein ligation using multi-modal PET/MRI measurements in healthy rat liver. PLoS One 2014; 9:e90760. [PMID: 24599299 PMCID: PMC3944348 DOI: 10.1371/journal.pone.0090760] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 02/03/2014] [Indexed: 01/07/2023] Open
Abstract
Objectives In the early recognition of portal vein ligation (PVL) induced tumor progression, positron emission tomography and magnetic resonance imaging (PET/MRI) could improve diagnostic accuracy of conventionally used methods. It is unknown how PVL affects metabolic patterns of tumor free hepatic tissues. The aim of this preliminary study is to evaluate the effect of PVL on glucose metabolism, using PET/MRI imaging in healthy rat liver. Materials and Methods Male Wistar rats (n = 30) underwent PVL. 2-deoxy-2-(18F)fluoro-D-glucose (FDG) PET/MRI imaging (nanoScan PET/MRI) and morphological/histological examination were performed before (Day 0) and 1, 2, 3, and 7 days after PVL. Dynamic PET data were collected and the standardized uptake values (SUV) for ligated and non-ligated liver lobes were calculated in relation to cardiac left ventricle (SUVVOI/SUVCLV) and mean liver SUV (SUVVOI/SUVLiver). Results PVL induced atrophy of ligated lobes, while non-ligated liver tissue showed compensatory hypertrophy. Dynamic PET scan revealed altered FDG kinetics in both ligated and non-ligated liver lobes. SUVVOI/SUVCLV significantly increased in both groups of lobes, with a maximal value at the 2nd postoperative day and returned near to the baseline 7 days after the ligation. After PVL, ligated liver lobes showed significantly higher tracer uptake compared to the non-ligated lobes (significantly higher SUVVOI/SUVLiver values were observed at postoperative day 1, 2 and 3). The homogenous tracer biodistribution observed before PVL reappeared by 7th postoperative day. Conclusion The observed alterations in FDG uptake dynamics should be taken into account during the assessment of PET data until the PVL induced atrophic and regenerative processes are completed.
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Affiliation(s)
- András Fülöp
- 1st Department of Surgery, Semmelweis University, Budapest, Hungary
- * E-mail:
| | - Attila Szijártó
- 1st Department of Surgery, Semmelweis University, Budapest, Hungary
| | - László Harsányi
- 1st Department of Surgery, Semmelweis University, Budapest, Hungary
| | - András Budai
- 1st Department of Surgery, Semmelweis University, Budapest, Hungary
| | - Damján Pekli
- 1st Department of Surgery, Semmelweis University, Budapest, Hungary
| | - Diána Korsós
- 1st Department of Surgery, Semmelweis University, Budapest, Hungary
| | - Ildikó Horváth
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Noémi Kovács
- CROmed Translational Research Centers, Budapest, Hungary
| | - Kinga Karlinger
- Department of Radiology and Oncotherapy, Semmelweis University, Budapest, Hungary
| | - Domokos Máthé
- CROmed Translational Research Centers, Budapest, Hungary
| | - Krisztián Szigeti
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
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Elucidating the metabolic regulation of liver regeneration. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 184:309-21. [PMID: 24139945 DOI: 10.1016/j.ajpath.2013.04.034] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 03/26/2013] [Accepted: 04/01/2013] [Indexed: 02/08/2023]
Abstract
The regenerative capability of liver is well known, and the mechanisms that regulate liver regeneration are extensively studied. Such analyses have defined general principles that govern the hepatic regenerative response and implicated specific extracellular and intracellular signals as regulated during and essential for normal liver regeneration. Nevertheless, the most proximal events that stimulate liver regeneration and the distal signals that terminate this process remain incompletely understood. Recent data suggest that the metabolic response to hepatic insufficiency might be the proximal signal that initiates regenerative hepatocellular proliferation. This review provides an overview of the data in support of a metabolic model of liver regeneration and reflects on the clinical implications and areas for further study suggested by these findings.
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Tajima T, Goda N, Fujiki N, Hishiki T, Nishiyama Y, Senoo-Matsuda N, Shimazu M, Soga T, Yoshimura Y, Johnson RS, Suematsu M. HIF-1alpha is necessary to support gluconeogenesis during liver regeneration. Biochem Biophys Res Commun 2009; 387:789-94. [PMID: 19643083 DOI: 10.1016/j.bbrc.2009.07.115] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Accepted: 07/23/2009] [Indexed: 01/17/2023]
Abstract
Coordinated recovery of hepatic glucose metabolism is prerequisite for normal liver regeneration. To examine roles of hypoxia inducible factor-1alpha (HIF-1alpha) for hepatic glucose homeostasis during the reparative process, we inactivated the gene in hepatocytes in vivo. Following partial hepatectomy (PH), recovery of residual liver weight was initially retarded in the mutant mice by down-regulation of hepatocyte proliferation, but occurred comparably between the mutant and control mice at 72h after PH. At this time point, the mutant mice showed lowered blood glucose levels with enhanced accumulation of glycogen in the liver. The mutant mice exhibited impairment of hepatic gluconeogenesis as assessed by alanine tolerance test. This appeared to result from reduced expression of PGK-1 and PEPCK since 3-PG, PEP and malate were accumulated to greater extents in the regenerated liver. In conclusion, these findings provide evidence for roles of HIF-1alpha in the regulation of gluconeogenesis under liver regeneration.
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Affiliation(s)
- Toshihide Tajima
- Department of Obstetrics & Gynecology, Keio University, Shinjuku-ku, Tokyo, Japan
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Ferri D, Moro L, Mastrodonato M, Capuano F, Marra E, Liquori GE, Greco M. Ultrastructural zonal heterogeneity of hepatocytes and mitochondria within the hepatic acinus during liver regeneration after partial hepatectomy. Biol Cell 2005; 97:277-88. [PMID: 15762849 DOI: 10.1042/bc20040154] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND INFORMATION Partial hepatectomy (70%) induces cell proliferation until the original mass of the liver is restored. In the first 24 h after partial hepatectomy, drastic changes in the metabolism of the remaining liver have been shown to occur. To evaluate changes in hepatocyte ultrastructure within the hepatic acinus during the liver regenerative process, we investigated, by light and electron microscopy observations on specimens taken 0 h, 24 h and 96 h after partial hepatectomy, the hepatocyte structure and ultrastructure in the periportal and pericentral area of the hepatic acinus, with a particular emphasis on mitochondria ultrastructure. Moreover, some biochemical events that could affect the mitochondria ultrastructure and function were investigated. RESULTS We found that, 24 h after partial hepatectomy, mitochondria with altered ultrastructure were preferentially localized in the periportal area. Periportal hepatocytes showed also an increase in the number of peroxisomes, free ribosomes, lysosomes and autophagosomes. Altered mitochondria showed swelling, an ultrastructural index of increased membrane permeability, a reduction in the number of cristae, and a rarefied, often vacuoled, matrix. Consistently, an increase in the mitochondrial oxidized/reduced glutathione ratio was found as well as calcium release from mitochondria in a manner inhibited by cyclosporin A. Interestingly, light and electron microscopy analysis showed that the hepatocytes in the periportal area were the cells with the major structural attributes to proliferate. At 96 h after partial hepatectomy, the preferential zonation of altered mitochondria was lost and the normal mitochondrial membrane permeability properties were restored. CONCLUSIONS We suggest that 24 h after partial hepatectomy, a preferential zonation of altered mitochondria in the periportal hepatocytes could be involved in the changes of metabolic and functional heterogeneity of the hepatocytes within the hepatic acinus during the regenerative process.
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Affiliation(s)
- Domenico Ferri
- Department of Zoology, Laboratory of Histology and Comparative Anatomy, University of Bari, Via Amendola 165/A, 70126 Bari, Italy
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13
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Skrtic S, Carlsson L, Ljungberg A, Lindén D, Michalik L, Wahli W, Oscarsson J. Decreased expression of peroxisome proliferator-activated receptor alpha and liver fatty acid binding protein after partial hepatectomy of rats and mice. Liver Int 2005; 25:33-40. [PMID: 15698396 DOI: 10.1111/j.1478-3231.2004.0998.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
BACKGROUND AIMS Marked changes in metabolism, including liver steatosis and hypoglycemia, occur after partial hepatectomy. Peroxisome proliferator-activated receptor alpha (PPAR alpha) is a nuclear hormone receptor that is activated by fatty acids and involved in hepatic fatty acid metabolism and regeneration. Liver fatty acid binding protein (LFABP) is an abundant protein in liver cytosol whose expression is regulated by PPAR alpha. It is involved in fatty acid uptake and diffusion and in PPAR alpha signaling. The aim of this study was to investigate the expression of PPAR alpha and LFABP during liver regeneration. METHODS Male Sprague-Dawley rats and male C57 Bl/6 mice were subjected to 2/3 hepatectomy and LFABP and PPAR alpha mRNA and protein levels were measured at different time points after surgery. The effect of partial hepatectomy was followed during 48 h in rats and 72 h in mice. RESULTS PPAR alpha mRNA and protein levels were decreased 26 h after hepatectomy of rats. The LFABP mRNA and protein levels paralleled those of PPAR alpha and were also decreased 26 h after hepatectomy. In mice, the mRNA level was decreased after 36 and 72 h after hepatectomy. In this case, LFABP mRNA levels decreased more slowly after partial hepatectomy than in rats. CONCLUSIONS A marked decrease in PPAR alpha expression may be important for changed gene expression, e.g. LFABP, and metabolic changes, such as hypoglycemia, during liver regeneration.
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Affiliation(s)
- Stanko Skrtic
- Research Center for Endocrinology and Metabolism, Sahlgrenska Unbiversity Hospital, Göteborg University, SE-413 45 Göteborg, Sweden.
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14
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Affiliation(s)
- Thomas Kietzmann
- Institut fur Biochemie und Molekulare Zellbiologie, Universitat Gottingen, Germany
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15
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Roth U, Jungermann K, Kietzmann T. Activation of glucokinase gene expression by hepatic nuclear factor 4alpha in primary hepatocytes. Biochem J 2002; 365:223-8. [PMID: 11950391 PMCID: PMC1222650 DOI: 10.1042/bj20020340] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2002] [Revised: 04/04/2002] [Accepted: 04/12/2002] [Indexed: 12/19/2022]
Abstract
Glucokinase (GK) is a key enzyme for glucose utilization in liver and shows a higher expression in the perivenous zone. In primary rat hepatocytes, the GK gene expression was activated by HNF (hepatic nuclear factor)-4alpha via the sequence -52/-39 of the GK promoter. Venous pO2 enhanced HNF-4 levels and HNF-4 binding to the GK-HNF-4 element. Thus, HNF-4alpha could play the role of a regulator for zonated GK expression.
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Affiliation(s)
- Ulrike Roth
- Institut für Biochemie und Molekulare Zellbiologie, Georg-August-Universität Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany
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16
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Moriyama M, Nishisako M, Ueda J, Kannan Y, Ohta M, Sugano T. Changes in fructose-induced production of glucose in the rat liver following partial hepatectomy. Arch Biochem Biophys 1999; 371:53-62. [PMID: 10525289 DOI: 10.1006/abbi.1999.1422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The fructose-induced production of glucose in the liver after partial hepatectomy (PH) was evaluated by using the liver-perfusion system. There was no significant difference in plasma glucose level between hepatectomized (HX) and sham-operated (SO) rats at 24 h after surgery, and, thereafter, almost similar levels were obtained in both groups. However, the level of serum free fatty acids (FFA) was significantly higher in HX rats than that in SO rats at 24 and 48 h after surgery. When both groups of rats were given fructose by gavage, the increment of plasma glucose was significantly larger in HX rats than in SO rats. Lactate infusion failed to increase the rate of glucose production in perfused livers of both HX and SO rats and there was no significant difference in the activity of hepatic phosphoenolpyruvate carboxykinase. By contrast, fructose infusion elicited a large increase in glucose production in the perfused livers of HX rats at 24 and 48 h after PH. The increase was closely associated with not the change in fructose 2,6-bisphosphate levels but the increment of the intracellular levels of citrate. Treatment of octanoate or oleate, which supplies acetyl-CoA via fatty acid oxidation, mimicked the fructose-induced increase in glucose production in SO rats with a concomitant increase in hepatic levels of citrate. These results suggest that the oxidation of FFA may play an important role in glucose production induced by fructose administration during the early phase of liver regeneration.
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Affiliation(s)
- M Moriyama
- College of Agriculture, Osaka Prefecture University, Sakai, Osaka, 599-8531, Japan.
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17
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Thermostable hepatocyte growth factor and energy metabolism in rats after partial hepatectomy. Bull Exp Biol Med 1999. [DOI: 10.1007/bf02432798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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18
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Yasmineh WG, Beyer HS, Caspers JI, Theologides A. Effect of food intake on the activity of liver enzymes in partially hepatectomized rats treated with tumor necrosis factor. Biochem Pharmacol 1995; 50:1309-12. [PMID: 7488250 DOI: 10.1016/0006-2952(95)00265-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
After partial hepatectomy (PHx), there are significant changes in the activity of a number of enzymes in the regenerating rat liver. Administration of low doses of recombinant human tumor necrosis factor-alpha (rHu-TNF) to normal rats induces similar changes in some of the enzymes but not in others. Because certain observations suggest that TNF may play a dominant role in liver regeneration, we speculated that the discrepancies in enzyme activities may be due to the decrease in food intake caused by PHx. Accordingly, the activities of eleven liver enzymes of 70% PHx rats additionally treated i.p. with rHu-TNF (20-50 micrograms/kg/day for 3-4 days) were compared with those of (i) PHx controls fed ad lib., and (ii) PHx controls pair-fed the same amount of food. When pair-fed controls were used, the discrepancies in the activities of the enzymes that are affected by fasting tended to disappear, suggesting that the decrease in the food intake was responsible for the differences.
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Affiliation(s)
- W G Yasmineh
- Department of Laboratory Medicine and Pathology, University Hospital, Minneapolis, MN 55455, USA
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19
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Haber BA, Chin S, Chuang E, Buikhuisen W, Naji A, Taub R. High levels of glucose-6-phosphatase gene and protein expression reflect an adaptive response in proliferating liver and diabetes. J Clin Invest 1995; 95:832-41. [PMID: 7860767 PMCID: PMC295564 DOI: 10.1172/jci117733] [Citation(s) in RCA: 112] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The regenerating liver after partial hepatectomy is one of the few physiologic models of cellular proliferation in the adult animal. During hepatic regeneration, the animal is able to maintain metabolic homeostasis despite the acute loss of two thirds of hepatic tissue. In examining the molecular mechanisms regulating hepatic regeneration, we isolated novel immediate-early genes that are rapidly induced as the remnant liver undergoes the transition from its normal quiescent state into the G1 phase of the cell cycle. One of the most rapidly and highly induced genes which we initially termed RL-1, encodes rat glucose-6-phosphatase (rG6Pase). G6Pase mRNA peaks at 30 min and 36-48 h after hepatectomy correlating with the first and second rounds of cell division. This finding is compatible with studies that showed that G6Pase enzyme activity increases during liver regeneration. However, the increase in G6Pase mRNA is much more dramatic, indicating that it is a more sensitive indicator of this regulation. G6Pase gene expression peaks in the perinatal time period in the liver and remains elevated during the first month of life. The expression of the G6Pase gene is also dramatically elevated in BB diabetic rats, again higher than the enzyme elevation, and its relative induction after partial hepatectomy is blunted in these animals. Insulin treatment of partially hepatectomized diabetic animals downregulates the expression of G6Pase mRNA. Using specific antibodies against G6Pase, we detect a 36-kD G6Pase protein, and its level is elevated in regenerating and diabetic livers. The pattern of G6Pase mRNA expression appears to reflect similar changes in insulin and glucagon levels which accompany diabetes and hepatic proliferation. The elevation of G6Pase expression in these conditions is indicative of its importance as a regulator of glucose homeostasis in normal and abnormal physiologic states.
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Affiliation(s)
- B A Haber
- Department of Genetics, Children's Hospital of Philadelphia, Pennsylvania
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20
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Van Noorden CJ, Jonges GN. Heterogeneity of kinetic parameters of enzymes in situ in rat liver lobules. Histochem Cell Biol 1995; 103:93-101. [PMID: 7634157 DOI: 10.1007/bf01454005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In the present review, metabolic compartmentation in liver lobules is discussed as being dynamic and more complex than thus far assumed on the basis of numbers of mRNA or protein molecules or the capacity (zero-order activity) of enzymes. Isoenzyme distribution patterns and local kinetic parameters of enzymes may vary over the different zones of liver lobules. As a consequence, metabolic fluxes in vivo at physiological substrate concentrations may be completely different from those that are assumed on the basis of the number of molecules or the capacity of enzymes present in zones of liver lobules. For a more correct estimation of the levels of metabolic processes in the different compartments of liver tissue, local kinetic parameters and substrate concentrations have to be determined to calculate local metabolic fluxes. Direct measurements of metabolic fluxes in vivo with the use of noninvasive techniques is a promising alternative and the techniques will become increasingly important in future metabolic research.
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Affiliation(s)
- C J Van Noorden
- Academic Medical Centre, University of Amsterdam, Laboratory of Cell Biology and Histology, The Netherlands
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21
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Christ B, Nath A, Heinrich PC, Jungermann K. Inhibition by recombinant human interleukin-6 of the glucagon-dependent induction of phosphoenolpyruvate carboxykinase and of the insulin-dependent induction of glucokinase gene expression in cultured rat hepatocytes: regulation of gene transcription and messenger RNA degradation. Hepatology 1994; 20:1577-83. [PMID: 7527006 DOI: 10.1002/hep.1840200629] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The influence of recombinant human interleukin-6, the major mediator of the inflammatory response in liver, on the glucagon- and insulin-dependent induction of the phosphoenolpyruvate carboxykinase and glucokinase gene, respectively, was monitored on the level of gene transcription, mRNA abundance and enzyme activity in cultured rat hepatocytes. As control markers of the interleukin-6-induced acute-phase response the mRNA levels of the acute phase proteins alpha 2-macroglobulin and beta-fibrinogen were determined. In cultured rat hepatocytes, recombinant human interleukin-6, added simultaneously with glucagon and insulin, lowered the maximal increase in glucagon-induced phosphoenolpyruvate carboxykinase mRNA levels after 2 hr and the maximal increase in glucokinase mRNA levels after 3 hr to about 30%, respectively. It inhibited the glucagon-induced increase in phosphoenolpyruvate carboxykinase gene transcription and phosphoenolpyruvate carboxykinase enzyme activity, as well as the insulin-induced increases in glucokinase gene transcription and glucokinase enzyme activity. Recombinant human interleukin-6 increased the mRNA levels of the acute-phase proteins alpha 2-macroglobulin and beta-fibrinogen gradually over 4 to 6 hr. Recombinant human interleukin-6, added 2 hr after glucagon or 3 hr after insulin at the maximum of the hormone-induced enzyme mRNA levels, almost doubled the decay rate of phosphoenolpyruvate carboxykinase mRNA and glucokinase mRNA. The results show that interleukin-6 induced the expression of inflammatory proteins and simultaneously inhibited the hormone-induced expression of enzymes of intermediary metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- B Christ
- Institute for Biochemistry and Molecular Cell Biology, Georg-August-Universität, Göttingen, Germany
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22
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Wehmeyer N, Gunderson H, Nauman J, Savage S, Hartzell C. Determination of the glycogen synthesis pathway by 13C nuclear magnetic resonance analysis. Metabolism 1994; 43:38-43. [PMID: 8289673 DOI: 10.1016/0026-0495(94)90155-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The level of hepatic glycogen synthesized directly from glucose was measured in rats with [1-13C]glucose. The nuclear magnetic resonance (NMR) spectrum of glucose was used to measure the distribution of the 13C label from C1 to the other carbons. Female Sprague-Dawley rats were surgically implanted with catheters in the left carotid artery and the right jugular vein, followed by a 3-day recovery period and a 24-hour fast to deplete liver glycogen. A 2-hour infusion of the fasted animal with [1-13C]glucose was immediately followed by the removal of blood and liver tissue. The liver was divided into the right, left, caudate, and medial lobes, and then freeze-clamped in liquid nitrogen and stored at -80 degrees C. The 13C NMR glucose spectra were obtained from glycogen that was isolated from each liver lobe and hydrolyzed to glucose with amyloglucosidase. Spectra were obtained at 50.3 MHz in a narrow-bore Gemini 200-MHz NMR spectrometer (Varian, Palo Alto, CA). The distribution of 13C onto glucose carbons was measured from these spectra, and the percent direct pathway was calculated to be 29% +/- 2.5%. Metabolic variation for the synthesis of glycogen within the liver was determined by measuring the direct pathway contribution in each of the four liver lobes. Percent direct pathway values were similar (P > .05) in right (35% +/- 4.9%), left (26% +/- 5.1%), medial (25% +/- 4.9%), and caudate (27% +/- 5.6%) lobes. For some of the animals, the direct pathway was determined by infusion with [6-13C]glucose.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- N Wehmeyer
- Department of Chemistry, Northern Arizona University, Flagstaff 86011
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23
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Lindfeldt J, Ahrén B, Holmin T. Glucose homeostasis after peri-arterial hepatic denervation in partially hepatectomized rats. RESEARCH IN EXPERIMENTAL MEDICINE. ZEITSCHRIFT FUR DIE GESAMTE EXPERIMENTELLE MEDIZIN EINSCHLIESSLICH EXPERIMENTELLER CHIRURGIE 1993; 193:397-405. [PMID: 8122045 DOI: 10.1007/bf02576248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Peri-arterial hepatic denervation did not change the low basal plasma glucose levels on the 1st post-operative day in partially hepatectomized animals. On the 2nd post-operative day, the denervated animals had significantly higher basal plasma glucose levels than innervated animals. Basal plasma insulin levels were similar in both resected groups, suggesting a relative hyperinsulinemia in the innervated group. Basal plasma glucagon levels were similar in all groups on the 1st post-operative day, but were significantly raised on the 2nd post-operative day in the two resected groups. After i.v. glucose (0.5 g/kg b.w.) on the 1st post-operative day, or glucagon (10 micrograms/kg b.w.) on the 2nd post-operative day, the absolute increments and eliminations of glucose and insulin were similar in all groups. We conclude that the hypoglycemia observed after partial hepatectomy is not only due to the evident loss of glycogen stores, but is also mediated by mechanisms dependent on the peri-arterial hepatic nerves, possibly through an effect on basal plasma insulin levels.
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Affiliation(s)
- J Lindfeldt
- Department of Surgery, Lund University, Sweden
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24
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25
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Gardemann A, Püschel GP, Jungermann K. Nervous control of liver metabolism and hemodynamics. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 207:399-411. [PMID: 1633798 DOI: 10.1111/j.1432-1033.1992.tb17063.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- A Gardemann
- Institut für Biochemie, Georg-August-Universität Göttingen, Federal Republic of Germany
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26
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Milland J, Schreiber G. Transcriptional activity of the phosphoenolpyruvate carboxykinase gene decreases in regenerating rat liver. FEBS Lett 1991; 279:184-6. [PMID: 2001729 DOI: 10.1016/0014-5793(91)80144-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Rat cytosolic phosphoenolpyruvate carboxykinase (PEPCK) gene expression and enzyme activity in liver were studied in rats fasted for 12 hours before and after partial hepatectomy, sham operation or no operation. Transcriptional activity and mRNA levels decreased in regenerating liver compared to sham-operated and unoperated controls. In contrast, PEPCK enzyme activity in regenerating liver was similar to that in the livers of sham-operated and unoperated controls. Since all the animals were fasted the decrease in transcription is probably caused by some factor other than insulin, the known repressor of PEPCK gene expression.
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Affiliation(s)
- J Milland
- Russel Grimwade School of Biochemistry, University of Melbourne, Parkville, Australia
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27
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Wimmer M, Luttringer C, Colombi M. The development of the acinar heterotopic pattern of phosphoenolpyruvate carboxykinase activity in the newborn rat. HISTOCHEMISTRY 1990; 94:55-9. [PMID: 2351561 DOI: 10.1007/bf00266790] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The postnatal appearance of phosphoenolpyruvate carboxykinase activity (PEPCK) and acinar heterotopy was investigated in newborn rats aged 2 h, 12 h, 24 h and 3 days, as well as in juvenile rats aged 25 days. The livers showed an almost homogeneous distribution of activity along the sinusoidal length at the beginning of extrauterine life where energy needs are greatest. Compared to rats aged 2 h, the PEPCK activity was higher in the livers from rats aged 12 h. The increase in activity was most pronounced in the intermediary zone. After 24 h of extrauterine life the activity decreased again creating a homogeneous acinar activity pattern. By day 3 activity had increased in the periportal zone, while decreasing in the perivenous zone, resulting in a periportal to perivenous gradient. By day 25 total activity had reached highest values both in males and females, due to a relatively high perivenous activity. The more prominent acinar gradient corresponded approximately to the one seen in adult animals.
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Affiliation(s)
- M Wimmer
- Anatomisches Institut der Universität Basel, Switzerland
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28
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Tosh D, Alberti KG, Agius L. Clofibrate induces carnitine acyltransferases in periportal and perivenous zones of rat liver and does not disturb the acinar zonation of gluconeogenesis. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 992:245-50. [PMID: 2775785 DOI: 10.1016/0304-4165(89)90081-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Clofibrate induces hypertrophy and hyperplasia and marked changes in the activities of various enzymes in rat liver. We examined the effects of treatment of rats with clofibrate on enzyme induction and on rates of metabolic flux in hepatocytes isolated from the periportal and perivenous zones of the liver. Clofibrate induced the activities of carnitine acetyltransferase (90-fold), carnitine palmitoyltransferase (3-fold) and NADP-linked malic enzyme (3-fold) to the same level in periportal as in perivenous hepatocytes, suggesting that these enzymes were induced uniformly throughout the liver acinus. Increased rates of palmitate metabolism and ketogenesis after clofibrate treatment were associated with: a more oxidised mitochondrial redox state; diminished responsiveness to glucagon and loss of periportal/perivenous zonation. Despite the marked liver enlargement and hyperplasia caused by clofibrate, the normal periportal/perivenous zonation of alanine aminotransferase and gluconeogenesis was preserved in livers of clofibrate-treated rats, indicating that clofibrate-induced hyperplasia does not disrupt the normal acinar zonation of these metabolic functions.
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Affiliation(s)
- D Tosh
- Department of Medicine, University of Newcastle upon Tyne, U.K
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29
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Athari A, Unthan-Fechner K, Schwartz P, Probst I. Adult rat hepatocyte microcarrier culture. Comparison to the conventional dish culture system. IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY : JOURNAL OF THE TISSUE CULTURE ASSOCIATION 1988; 24:1085-91. [PMID: 3056897 DOI: 10.1007/bf02620809] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A technique has been devised to attach adult rat hepatocytes to collagen-coated dextran microcarriers. Cells were cultured serum-free for 2 d and their viability, enzyme activities, glucose metabolism, and hormone responsiveness were compared to data obtained from conventional dish cell culture. The two different culture methods showed no difference in cell viability and morphology. Microcarrier-cultured cells exhibited hormone responsiveness comparable to dish cultures; glycolysis could be activated three-fold by the sole addition of insulin, and gluconeogenesis was increased by 40 to 50% by glucagon. During the 48-h culture glucokinase and phosphoenolpyruvate carboxykinase activities declined at a similar rate in both culture systems. Long-term culture with 0.1 microM insulin prevented the decrease of glucokinase activity. Insulin responsiveness (activation of glycolysis) was still pronounced after 48 h in culture. The microcarrier technique establishes a new in vitro liver system in which acute and long-term hormonal actions can be investigated using the technical advantages of a suspension culture.
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Affiliation(s)
- A Athari
- Institute für Biochemie, Universität Göttingen, FRG
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30
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Gebhardt R, Burger HJ, Heini H, Schreiber KL, Mecke D. Alterations of hepatic enzyme levels and of the acinar distribution of glutamine synthetase in response to experimental liver injury in the rat. Hepatology 1988; 8:822-30. [PMID: 2899050 DOI: 10.1002/hep.1840080421] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Glutamine synthetase shows a striking heterogeneous distribution in normal rat liver as consistently revealed by immunohistochemistry using a specific antiserum against the rat liver enzyme or a cross-reacting antiserum. The effects of zonal liver injury induced by allylformate or CCl4 on this distribution and on the activity of glutamine synthetase as well as of enzymes with different acinar distribution were investigated. Treatment with allylformate or CCl4 at appropriate concentrations led to severe hepatocyte necrosis in the periportal and perivenous zone, respectively, as revealed by histological examination and by the levels of serum marker enzymes. Exposure to allylformate (50 to 100 microliter per kg) for less than 1 day did not change the distribution and activity of glutamine synthetase but reduced the specific activities of the urea cycle enzymes. In contrast, treatment with CCl4 (1,000 microliter per kg) strongly reduced the activity and the acinar region covered by glutamine synthetase but not, for instance, the activities of the urea cycle enzymes. These results in conjunction with the data obtained for other enzymes indicate that a short exposure to these hepatotoxins affects different enzyme activities in close accord with their preferential acinar localization. During prolonged exposure this initial response was often modified due to adaptation. In the case of glutamine synthetase, however, no adaptive appearance of glutamine synthetase in other parts of the acinus could be detected even if the cell population originally expressing this phenotype was destroyed. This extremely inflexible distribution suggests that glutamine synthetase expression is a matter of cell differentiation rather than of modulation by nutritional and hormonal factors (or their acinar gradients) as found for many other hepatic enzymes.
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Affiliation(s)
- R Gebhardt
- Physiologische-chemisches Institut, Universität Tübingen, Federal Republic of Germany
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31
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Klinger W, Devereux T, Fouts JR. Functional and structural zonal hepatocyte heterogeneity--dynamics and ontogenic development. EXPERIMENTAL PATHOLOGY 1988; 35:69-91. [PMID: 3066639 DOI: 10.1016/s0232-1513(88)80100-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- W Klinger
- Institute of Pharmacology and Toxicology, Friedrich Schiller University, Jena, G.D.R
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32
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Fischer G, Ruschenburg I, Eigenbrodt E, Katz N. Decrease in glucokinase and glucose-6-phosphatase and increase in hexokinase in putative preneoplastic lesions of rat liver. J Cancer Res Clin Oncol 1987; 113:430-6. [PMID: 3040765 DOI: 10.1007/bf00390036] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Preneoplastic liver lesions were produced in female Wistar rats by oral administration of 2-acetylaminofluorene for 165 days succeeded by a carcinogen-free standard diet up to 420 days. During the treatment numerous altered hepatic foci (AHF) and hyperplastic nodules (HN) were detected histochemically by a focal decrease or lack of adenosine-5-triphosphatase and glucose-6-phosphatase (G-6-Pase) activities. In addition, the immunohistochemically demonstrable amount of L-type pyruvate kinase was clearly reduced. The histochemically demonstrated decrease of G-6-Pase was substantiated by microbiochemical determination of the enzyme activity in microdissected material. Moreover, during the experimental period a continuous decrease in glucokinase and an increase in hexokinase was detected microbiochemically within AHF and HN. These alterations indicate a shift in the carbohydrate metabolism from gluconeogenesis to glucose utilization and pentose-phosphate-pathway for biosynthesis of nucleic acids. Beside other oncofetal markers, HK may be used as indicator of the early stages of liver carcinogenesis.
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Jungermann K. Metabolic zonation of liver parenchyma: significance for the regulation of glycogen metabolism, gluconeogenesis, and glycolysis. DIABETES/METABOLISM REVIEWS 1987; 3:269-93. [PMID: 3552523 DOI: 10.1002/dmr.5610030112] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Van Noorden CJ, Frederiks WM, Aronson DC, Marx F, Bosch K, Jonges GN, Vogels IM, James J. Changes in the acinar distribution of some enzymes involved in carbohydrate metabolism in rat liver parenchyma after experimentally induced cholestasis. VIRCHOWS ARCHIV. B, CELL PATHOLOGY INCLUDING MOLECULAR PATHOLOGY 1986; 52:501-11. [PMID: 2884772 DOI: 10.1007/bf02889989] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Extrahepatic cholestasis induced by ligation and transsection of the common bile duct caused a change in the parenchyma/stroma relationship in rat liver. Two weeks after ligation, the periportal zones of the parenchyma were progressively invaded by expanding bile ductules with surrounding connective tissue diverging from the portal areas. Parenchymal disarray developed and small clumps of hepatocytes or isolated hepatocytes were scattered within the expanded portal areas. These cells showed normal activity of lactate, succinate and glutamate dehydrogenase and may, therefore, be considered to be functionally active. After cholestasis the remainder of the liver parenchyma showed adaptational changes with respect to glucose homeostasis, as demonstrated by histochemical means. Glycogen stores disappeared completely whereas glycogen phosphorylase activity increased about ten fold. The increased glycogen phosphorylase activity and glycogen depletion indicate a greater glycogenolytic capacity in liver parenchyma after bile duct ligation to maintain as far as possible a normal plasma glucose concentration. The parenchymal distribution pattern of glucose-6-phosphatase activity did not change significantly after bile duct ligation. The isolated hepatocytes within the expanded portal tracts showed a high activity of this enzyme whereas the pericentral parenchyma was only moderately active. The distribution patterns of glucose-6-phosphate dehydrogenase and lactate dehydrogenase activity in the liver parenchyma were also largely unchanged after bile duct ligation, but the histochemical reaction for glucose-6-phosphate dehydrogenase activity demonstrated infiltration of the remainder of the parenchyma by non-parenchymal cells, possibly Küpffer cells and leucocytes as part of an inflammatory reaction. Under normal conditions the mitochondrial enzymes succinate and glutamate dehydrogenase show an opposite heterogenous distribution pattern in liver parenchyma. Following cholestasis both enzymes became uniformly distributed. The underlying regulatory mechanism for these different changes in distribution patterns of enzyme activities is not yet understood.
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Zieve L, Anderson WR, Lyftogt C, Draves K. Hepatic regenerative enzyme activity after pericentral and periportal lobular toxic injury. Toxicol Appl Pharmacol 1986; 86:147-58. [PMID: 3787616 DOI: 10.1016/0041-008x(86)90045-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Pericentral and periportal liver injuries involving less than 50% of the parenchyma were produced with acetaminophen and allyl alcohol, respectively. Doses were selected to produce comparable peak serum malate dehydrogenase, sorbitol dehydrogenase, and SGPT activities. The regenerative response was assessed by serial measurements of hepatic thymidine kinase (TK) activity and ornithine decarboxylase (ODC) activity. The initial responses reflected in ODC activity were more or less similar. However, the ultimate regenerative response reflected by TK activity was almost three times as great after periportal injury as after pericentral injury, after allowing for differences in the extent of necrosis. Histologic examination also showed greater mitotic and tissue reparative responses after periportal injury. These results suggest that the concept of hepatocellular heterogeneity applies to the regenerative response of liver cells as well as the metabolic functions previously identified.
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Christ B, Probst I, Jungermann K. Antagonistic regulation of the glucose/glucose 6-phosphate cycle by insulin and glucagon in cultured hepatocytes. Biochem J 1986; 238:185-91. [PMID: 3026341 PMCID: PMC1147114 DOI: 10.1042/bj2380185] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Flux through the glucose/glucose 6-phosphate cycle in cultured hepatocytes was measured with radiochemical techniques. Utilization of [2-3H]glucose was taken as a measure of glucokinase flux. Liberation of [14C]glucose from [U-14C]glycogen and from [U-14C]lactate, as well as the difference between the utilization of [2-3H]glucose and of [U-14C]glucose, were taken as measures of glucose-6-phosphatase flux. At constant 5 mM-glucose and 2 mM-lactate concentrations insulin increased glucokinase flux by 35%; it decreased glucose-6-phosphatase flux from glycogen by 50%, from lactate by 15% and reverse flux from external glucose by 65%, i.e. overall by 40%. Glucagon had essentially no effect on glucokinase flux; it enhanced glucose-6-phosphatase flux from glycogen by 700%, from lactate by 45% and reverse flux from external glucose by 20%, i.e. overall by 110%. At constant glucose concentrations cellular glucose 6-phosphate concentrations were essentially not altered by insulin, but were increased by glucagon by 230%. In conclusion, under basic conditions without added hormones the glucose/glucose 6-phosphate cycle showed only a minor net glucose uptake, of 0.03 mumol/min per g of hepatocytes; this flux was increased by insulin to a net glucose uptake of 0.21 mumol/min per g and reversed by glucagon to a net glucose release of 0.22 mumol/min per g. Since the glucose 6-phosphate concentrations after hormone treatment did not correlate with the glucose-6-phosphatase flux, it is suggested that the hormones influenced the enzyme activity directly.
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Schofield PS, Kerbey AL, Sugden MC. Hepatic pyruvate metabolism during liver regeneration after partial hepatectomy in the rat. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1986; 18:453-8. [PMID: 3709932 DOI: 10.1016/0020-711x(86)90188-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Hepatic pyruvate kinase (PK) and pyruvate dehydrogenase (PDHa) specific activities were decreased after partial hepatectomy or sham operation. The decreases were more marked and sustained after partial hepatectomy. These activity changes ensure that hepatic carbon flux after partial hepatectomy is predominantly in the direction of gluconeogenesis. The decrease in PK specific activity observed after partial hepatectomy was associated with a decreased PK activation ratio (activity measured at 0.15 mM PEP: activity measured at 5.0 mM PEP), and hepatic concentrations of PEP were increased. The low hepatic PDHa activity observed at the first day after partial hepatectomy occurred concomitantly with an increased fatty acid concentration. PDHa activity increased after inhibition of lipolysis. The results indicate that carbohydrate utilization is unimportant for hepatic energy supply during liver regeneration. There was no evidence that the control of PK or PDH in the regenerative liver after partial hepatectomy differed from that observed in the liver of the unoperated rat.
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Miethke H, Wittig B, Nath A, Jungermann K. Gluconeogenic-glycolytic capacities and metabolic zonation in liver of rats with streptozotocin, non-ketotic as compared to alloxan, ketotic diabetes. HISTOCHEMISTRY 1986; 85:483-9. [PMID: 3023262 DOI: 10.1007/bf00508430] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Activities (mumol X min-1 X g liver) and zonal distributions of key enzymes of carbohydrate metabolism were studied in livers of streptozotocin-diabetic rats and compared to the values in alloxan-diabetes. Streptozotocin led to a non-ketotic diabetes with blood glucose being increased by more than fivefold but ketone bodies being in the normal range, while alloxan produced a ketotic diabetes with blood glucose, acetoacetate and beta-hydroxybutyrate being elevated by more than fivefold. Portal insulin was decreased to about 20% in streptozotocin- and more drastically to about 7% in alloxan-diabetes. Conversely, portal glucagon was increased in the two states to about 250% and 180%, respectively. The glucogenic key enzyme phosphoenolpyruvate carboxykinase (PEPCK) was enhanced in streptozotocin- and alloxan-diabetes to over 300%, while the glycolytic pyruvate kinase L (PKL) was lowered to 65% and 80%, respectively. The normal periportal to perivenous gradient of PEPCK of about 3:1, as measured in microdissected tissue samples, was maintained with elevated activities in the two zones. The normal periportal to perivenous gradient of PKL of 1:1.7 was diminished with lowered activities in the two zones. The glucogenic glucose-6-phosphatase (G6Pase) was increased in streptozotocin- and alloxan-diabetes to 130% and 140%, respectively, while the glucose utilizing glucokinase (GK) was decreased to 60% and 50%, respectively. The normal periportal to perivenous gradient of G6Pase, demonstrated histochemically, remained unaffected. Carnitine palmitoyltransferase (CPT) was increased to over 190% and acetyl-CoA carboxylase (ACC) was decreased to 60% in streptozotocin, non-ketotic diabetes, while the two enzymes were altered more drastically to 400% and 50%, respectively, in alloxan, ketotic diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)
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Van Noorden CJ, Vogels IM, Fronik G, Houtkooper JM, James J. Ploidy class-dependent metabolic changes in rat hepatocytes after partial hepatectomy. Exp Cell Res 1985; 161:551-7. [PMID: 2415377 DOI: 10.1016/0014-4827(85)90110-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Glucose-6-phosphate dehydrogenase (G6PDH), succinate dehydrogenase (SDH) activity and the single-stranded RNA (ssRNA) content of isolated hepatocytes of different ploidy classes from adult male rats have been studied after partial hepatectomy using quantitative cytochemical means. The SDH activity and ssRNA content in all classes of hepatocytes are decreased during the first hours after operation followed by an increase above control values. The increase of both SDH activity and ssRNA content is significant only in the mononuclear diploid (MD) cells but not in the hepatocytes of higher ploidy classes and is related with the mitotic wave at 32 h after hepatectomy. After the mitotic wave, the values quickly return to normal levels. The G6PDH activity does not show any significant change in hepatocytes other than MD cells. In MD cells the G6PDH activity is elevated on a highly significant level up to a maximum value of 3.5 times the control value at 48 h after operation. The G6PDH activity in MD cells is returned to normal values within 14 days after operation. It is concluded that: 1. The MD cells show a distinct metabolic behaviour due to their function as stem cells of liver parenchyma and retain at least some of their fetal characteristics. 2. G6PDH activity is not a transformation-linked discriminant for neoplastic metabolism.
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Wittig B, Zierz S, Gubernatis G, Nath A, Jungermann K. Glucostat capacity and metabolic zonation in rat liver after portocaval anastomosis. BIOLOGICAL CHEMISTRY HOPPE-SEYLER 1985; 366:713-22. [PMID: 2998414 DOI: 10.1515/bchm3.1985.366.2.713] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The activities and zonal distribution of key enzymes of carbohydrate metabolism were studied in livers of rats after end-to-side portocaval anastomosis. Sham-operated control animals with the same periods of interruption of hepatic blood supply as the shunted animals were pair-fed. The following alterations were observed: Food uptake was reduced to about 20% at the first postoperational day; it was then increased continuously to about 70% at day 8. Body weight, after a small 10% postoperational decrease, remained unaltered, but liver weight was lowered to 55% at day 8 and then stayed constant. The total glycogen reserves of the liver (g X 100 g body weight-1) were reduced, after a transient fall to about 10% at day 1-4, to about 25%. The total activity of the glucogenic phosphoenolpyruvate carboxykinase (mumol . min-1 X 100 g body weight-1) was diminished, after a transient increase to 190% and 150% at day 1 and 2 respectively, to about 55% from day 8 onwards. The total activity of the glucogenic glucose-6-phosphatase was lowered without a transient rise to about 30%. The total activities of the glycolytic pyruvate kinase isoenzyme L and glucokinase were decreased continuously to about 40% at day 8; that of the citrate cycle enzyme succinate dehydrogenase was lowered parallel with liver weight to 55%. The transient decrease of the glycogen reserves and the intermediate increase of the phosphoenolpyruvate carboxykinase capacity were due to the operational stress, since they were observed also in the sham-operated control animals. All other alterations, the decrease of liver weight and of the capacities of both gluconeogenic and glycolytic key enzymes, were specific for the portocaval anastomosis. The normal periportal to perivenous gradient of phosphoenolpyruvate carboxykinase of about 3.5:1, as measured in microdissected tissue samples, remained the same with specific activities reduced to about 80% each in the two zones. The normal periportal to perivenous gradient of pyruvate kinase L of about 1:1.7 was equalized with levels lowered to 35% and 23%, respectively, in the two zones. The normal periportal to perivenous gradients of glucose-6-phosphatase and succinate dehydrogenase, demonstrated histochemically, were essentially maintained with perivenous bridging occurring transiently at day 4 and 8.(ABSTRACT TRUNCATED AT 400 WORDS)
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Miethke H, Wittig B, Nath A, Zierz S, Jungermann K. Metabolic zonation in liver of diabetic rats. Zonal distribution of phosphoenolpyruvate carboxykinase, pyruvate kinase, glucose-6-phosphatase and succinate dehydrogenase. BIOLOGICAL CHEMISTRY HOPPE-SEYLER 1985; 366:493-501. [PMID: 2988584 DOI: 10.1515/bchm3.1985.366.1.493] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The activities and zonal distribution of key enzymes of carbohydrate metabolism were studied in livers of diabetic rats. 48 h after alloxan treatment the following alterations were observed, intermediate values being reached after 24 h: Blood glucose, acetoacetate and beta-hydroxybutyrate were increased to more than 500%; liver glycogen was reduced to about 10%. Portal vein insulin was reduced to below 10%, portal glucagon was increased to almost 200%. The glucogenic enzymes phosphoenolpyruvate carboxykinase and glucose-6-phosphatase were enhanced to 320% and 150%, respectively. The glycolytic enzymes glucokinase and pyruvate kinase L (differentiated from the M2 isoenzyme with a specific anti-L-antibody) were lowered to 50% and 75%, respectively. The citrate cycle enzyme succinate dehydrogenase remained unchanged. The normal periportal to perivenous gradient of phosphoenolpyruvate carboxykinase of about 3:1, as measured in microdissected tissue samples, was enhanced to about 4:1 with activities elevated to 230% and 190%, respectively, in the two zones. The normal periportal to perivenous gradient of pyruvate kinase L of about 1:1.7, as determined with the microdissection technique, was reduced to about 1:1.4 with levels lowered to 55% and 45%, respectively, in the two zones. The even zonal distribution of pyruvate kinase M2 remained unaltered.(ABSTRACT TRUNCATED AT 250 WORDS)
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Chatzipanagiotou S, Nath A, Vogt B, Jungermann K. Alteration in the capacities as well as in the zonal and cellular distributions of pyruvate kinase L and M2 in regenerating rat liver. BIOLOGICAL CHEMISTRY HOPPE-SEYLER 1985; 366:271-80. [PMID: 4005043 DOI: 10.1515/bchm3.1985.366.1.271] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Pyruvate kinase L (PKL), the glucoregulatory isoenzyme of adult parenchymal cells, and M2 (PKM2), the isoenzyme of proliferating and non-parenchymal cells, were measured, using a specific anti-PKL antibody for differentiation, in total liver homogenates, in isolated parenchymal and non-parenchymal cells as well as in microdissected periportal and perivenous liver tissue from regenerating rat liver after two-thirds partial hepatectomy. Moreover, the zonal distribution of PKL was studied using immunohistochemical techniques. In total liver homogenates PKL activity per g liver decreased after partial hepatectomy, while PKM2 increased. Total PKL activity per 100 g body weight was restored to preoperational levels much more slowly than liver weight. During liver regeneration parenchymal cells acquired high PKM2 besides PKL activity. The isoenzyme outfit of non-parenchymal cells remained unchanged. Microdissection studies showed that PKL lost its normal perivenous to periportal gradient after partial hepatectomy and became evenly distributed within the liver acinus. PKM2 did not retain its even distribution, it became predominant in the periportal zone. Immunohistochemical staining revealed that after partial hepatectomy PKL was present in all parenchymal cells in an atypical non-zonal heterogeneous distribution. Normal specific activities as well as zonal and cellular distributions of both pyruvate kinase isoenzymes were restored 14-21 d after partial hepatectomy. During regeneration after 2/3 partial hepatectomy the liver loses its glucostat function as corroborated in this study by the decrease of the glycolytic capacity via the glucoregulatory PKL; this change of function is accompanied by a loss of PKL-zonation. This finding corroborates the view that zonation of carbohydrate-metabolizing enzymes is required only when the liver functions as a glucostat. The increase of PKM2 and the appearance of a zonal PKM2 heterogeneity are in line with the pattern of hepatocyte proliferation after partial hepatectomy.
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Jungermann K. [Metabolic zonation of liver parenchyma. Regulation of the glucostat of the liver]. THE SCIENCE OF NATURE - NATURWISSENSCHAFTEN 1985; 72:76-84. [PMID: 3990823 DOI: 10.1007/bf00508136] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The liver is the glucostat of the organism. It removes glucose when offered in excess as after a normal meal via glycogen synthesis and glycolysis; it provides glucose when needed as in between meals. Hepatocytes from the periportal (afferent) and perivenous (efferent) zones of the liver parenchyma differ in their enzyme content and subcellular structures. Therefore the model of "metabolic zonation" proposes different functions for the two zones. Glucose release is predominantly located in the periportal and glucose uptake in the perivenous zone. The non-zonal, homogeneous and the zonal heterogeneous organization of antagonistic pathways are compared to a narrow country road and a divided highway, respectively, which would allow traffic to proceed at a given time in only one or in both directions, respectively. The highway, corresponding to the model of metabolic zonation, is certainly more efficient than a narrow country road.
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Siverio JM, Torres NV, Meléndez-Hevia E. Activities of L-lactate and glycerol phosphate production rates in vitro from glucose 6-phosphate in regenerating rat liver. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1985; 17:1015-7. [PMID: 4065405 DOI: 10.1016/0020-711x(85)90248-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Activities of L-lactate and glycerol phosphate production in vitro were assayed in regenerating rat liver at different times after partial hepatectomy and were compared with activities of sham operated controls. Results show an oscillatory shift in these activities with smallest values for both L-lactate and glycerol phosphate production rates at 20 hr, these being 80% and 50%, respectively of normal values, and with highest values at 42 hr where these rates were 150% and 125%, respectively, both recovering their original state 60 hr after surgery. From these data it is concluded that in regenerating liver there are changes in the ability of the glycolysis system to produce L-lactate and glycerol phosphate.
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Francavilla A, Di Leo A, Wu SQ, Ove P, Van Thiel D, Sciascia C, Starzl TE. Discordance between glucokinase activity and insulin and glucagon receptor changes occurring during liver regeneration in the rat. Horm Metab Res 1984; 16 Suppl 1:47-50. [PMID: 6099817 PMCID: PMC2962606 DOI: 10.1055/s-2007-1014896] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
During regeneration of rat livers following 70% hepatectomy, insulin binding sites on hepatocyte plasma membranes are increased after 24-48 hours, glucagon binding sites are reduced on days 2-8, and the resultant insulin/glucagon binding ratio is markedly increased. An apparent paradox was the finding of a depression of the activity of an insulin associated enzyme, glucokinase, at a time when the number of insulin binding sites was increased.
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Andersen B, Zierz S, Jungermann K. Alteration in zonation of succinate dehydrogenase, phosphoenolpyruvate carboxykinase and glucose-6-phosphatase in regenerating rat liver. HISTOCHEMISTRY 1984; 80:97-101. [PMID: 6321405 DOI: 10.1007/bf00492778] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Parenchymal activities (mumol . min-1 . g liver-1) and distributions of mitochondrial succinate dehydrogenase, cytosolic phosphoenolpyruvate carboxykinase and microsomal glucose-6-phosphatase were studied in regenerating rat liver after two thirds partial hepatectomy. Succinate dehydrogenase activity remained constant with a slight and transient increase for a few hours after operation. The typical periportal localization was changed to an almost even distribution from 8 h to 7 days; it was fully restored after 14 days. Phosphoenolpyruvate carboxykinase activity was increased by 1.8 fold 24 h after surgery; it remained enhanced until about 72 h. The normal periportal to perivenous enzyme gradient was diminished or replaced by a homogeneous distribution between 8 h and 7 days; the zonal heterogeneity was regained after 14 days. Glucose-6-phosphatase activity remained constant after partial hepatectomy. The normal periportal maximum was lost between 4 h and 36 h; the activity became more equally distributed and was even shifted towards the perivenous zone. After 48 h the zonal distribution was reestablished. The results indicate that after partial hepatectomy the gluconeogenic capacity of the liver remnant is increased and that this increase is accompanied by a loss of the normal heterogeneity which is typical for the glucostat function of the organ. They reveal in addition that the three enzymes, representing three different subcellular compartments, change their zonal heterogeneity individually rather than synchronously.
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Fischer W, Wagle SR, Katz NR. Altered distribution of hexokinase and glucokinase between parenchymal and nonparenchymal cells of rat liver after methapyrilene intoxication. Biochem Biophys Res Commun 1983; 115:1090-5. [PMID: 6626220 DOI: 10.1016/s0006-291x(83)80047-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The cell number as well as the hexokinase and glucokinase activity of liver parenchymal and nonparenchymal cells were studied in methapyrilene treated rats. The number of nonparenchymal cells was doubled after treatment with methapyrilene for two weeks while that of hepatocytes remained constant. The hexokinase activity was increased fourfold in the nonparenchymal cell fraction while it was unchanged in the parenchymal cells. The glucokinase activity was decreased in the hepatocytes to one third. Hence, the increased hexokinase activity was due to a proliferation of nonparenchymal cells rather than to a toxic dedifferentiation of hepatocytes.
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Fischer W, Fischer G, Katz NR. Inversion of the metabolic zonation of rat liver parenchyma by methapyrilene treatment. Pharmacol Biochem Behav 1983; 18 Suppl 1:421-4. [PMID: 6314382 DOI: 10.1016/0091-3057(83)90210-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Treatment with the antihistaminic agent methapyrilene led to a decrease of glucose-6-phosphatase activity and to an increase of glucose phosphorylating activity in the periportal zone of the liver acinus. However, the glucogenic capacity was maintained by a compensatory elevation of glucose-6-phosphatase and simultaneous reduction of hexokinase and glucokinase in the perivenous zone. The normal metabolic zonation with a glucogenic periportal and a glycolytic perivenous zone was not abolished but inverted by these alterations.
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Probst I, Schwartz P, Jungermann K. Induction in primary culture of 'gluconeogenic' and 'glycolytic' hepatocytes resembling periportal and perivenous cells. EUROPEAN JOURNAL OF BIOCHEMISTRY 1982; 126:271-8. [PMID: 6751822 DOI: 10.1111/j.1432-1033.1982.tb06775.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Adult rat hepatocytes were kept in primary culture for 48 h under different hormonal conditions to induce an enzyme pattern which with respect to carbohydrate metabolism approximated that of periportal and perivenous hepatocytes in vivo. 1. Glucagon-treated cells compared with control cells possessed a lower activity of glucokinase, a 4.5-fold higher activity of phosphoenolpyruvate carboxykinase and unchanged levels of glucose-6-phosphatase, phosphofructokinase, fructose-bisphosphatase and pyruvate kinase; they resembled in a first approximation the periportal cell type and are called for simplicity 'periportal'. Inversely, insulin-treated cells compared with control cells contained a 2.2-fold higher activity of glucokinase, a slightly decreased activity of phosphoenolpyruvate carboxykinase, increased activities of phosphofructokinase and pyruvate kinase and unaltered levels of glucose-6-phosphatase and fructose-bisphosphatase; they resembled perivenous cells and are called simply 'perivenous'. Gluconeogenesis and glycolysis were studied under various substrate and hormone concentrations. 2. Physiological concentrations of glucose (5 mM) and lactate (2 mM) gave about 80% saturation of gluconeogenesis from lactate and less than 15% saturation of glycolysis at a simultaneous 40% inhibition of the glycolytic rate by lactate. 3. Comparison of the two cell types showed that under identical assay conditions (5 mM glucose, 2 mM lactate, 0.5 nM insulin, 0.1 muM dexamethasone) gluconeogenesis was 1.5-fold faster in the 'periportal' cells and glycolysis was 2.4-fold faster in the 'perivenous' cells. 4. Metabolic rates were under short-term hormonal control. Insulin increased glycolysis three fold in both cell types with a half-maximal effect at about 0.4 nM, but did not influence the gluconeogenic rate. Glucagon inhibited glycolysis by 70% with a half-maximal effect at about 0.1 nM. Gluconeogenesis was stimulated by glucagon (half-maximal dose: 0.5 nM) 1.8-fold only in 'periportal' cells containing high phosphoenolpyruvate carboxykinase activity, not in the 'perivenous' cells with a low level of this enzyme. 5. A comparison of the two cell types showed that with maximally stimulating hormone concentrations gluconeogenesis was threefold faster in 'periportal' cells and glycolysis was eightfold faster in 'perivenous' cells. The results support the view that periportal and perivenous hepatocytes in vivo catalyse gluconeogenesis and glycolysis at inverse rates.
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Abstract
Hepatocytes from the periportal (afferent) and perivenous (efferent) zones of the liver parenchyma differ in their enzyme content and subcellular structures. Therefore, different functions are proposed for the two zones. (a) Oxidative energy metabolism, beta-oxidation, amino acid catabolism, ureagenesis from amino acids, gluconeogenesis, bile acid, and bilirubin excretion and oxidation protection are preferentially located in the periportal zone. (b) Glycolysis, liponeogenesis, ureagenesis from ammonia, and biotransformation are predominantly situated in the perivenous zone. Heterogeneity in the synthesis of plasma proteins also appears to exist. The heterogeneous expression of the genome in hepatocytes is apparently caused by the periportal to perivenous gradient in oxygen and hormone concentrations, and by a different autonomic innervation of the parenchymal zones.
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