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Duncan AW. Pathological polyploidy and liver repair failure in RAD51-deficient mice. Hepatology 2024:01515467-990000000-00828. [PMID: 38546299 DOI: 10.1097/hep.0000000000000871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 03/15/2024] [Indexed: 04/25/2024]
Affiliation(s)
- Andrew W Duncan
- Department of Pathology, Pittsburgh Liver Research Center, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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2
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Wilson SR, Duncan AW. The Ploidy State as a Determinant of Hepatocyte Proliferation. Semin Liver Dis 2023; 43:460-471. [PMID: 37967885 PMCID: PMC10862383 DOI: 10.1055/a-2211-2144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2023]
Abstract
The liver's unique chromosomal variations, including polyploidy and aneuploidy, influence hepatocyte identity and function. Among the most well-studied mammalian polyploid cells, hepatocytes exhibit a dynamic interplay between diploid and polyploid states. The ploidy state is dynamic as hepatocytes move through the "ploidy conveyor," undergoing ploidy reversal and re-polyploidization during proliferation. Both diploid and polyploid hepatocytes actively contribute to proliferation, with diploids demonstrating an enhanced proliferative capacity. This enhanced potential positions diploid hepatocytes as primary drivers of liver proliferation in multiple contexts, including homeostasis, regeneration and repopulation, compensatory proliferation following injury, and oncogenic proliferation. This review discusses the influence of ploidy variations on cellular activity. It presents a model for ploidy-associated hepatocyte proliferation, offering a deeper understanding of liver health and disease with the potential to uncover novel treatment approaches.
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Affiliation(s)
- Sierra R. Wilson
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Andrew W. Duncan
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
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3
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Xu L, Paine AC, Barbeau DJ, Alencastro F, Duncan AW, McElroy AK. Limiting viral replication in hepatocytes alters Rift Valley fever virus disease manifestations. J Virol 2023; 97:e0085323. [PMID: 37695055 PMCID: PMC10537571 DOI: 10.1128/jvi.00853-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 07/13/2023] [Indexed: 09/12/2023] Open
Abstract
Rift Valley fever virus (RVFV) causes mild to severe disease in humans and livestock. Outbreaks of RVFV have been reported throughout Africa and have spread outside Africa since 2000, calling for urgent worldwide attention to this emerging virus. RVFV directly infects the liver, and elevated transaminases are a hallmark of severe RVFV infection. However, the specific contribution of viral replication in hepatocytes to pathogenesis of RVFV remains undefined. To address this, we generated a recombinant miRNA-targeted virus, RVFVmiR-122, to limit hepatocellular replication. MicroRNAs are evolutionarily conserved non-coding RNAs that regulate mRNA expression by targeting them for degradation. RVFVmiR-122 includes an insertion of four target sequences of the liver-specific miR-122. In contrast to control RVFVmiR-184, which contains four target sequences of mosquito-specific miR-184, RVFVmiR-122 has restricted replication in vitro in primary mouse hepatocytes. RVFVmiR-122-infected C57BL/6 mice survived acute hepatitis and instead developed late-onset encephalitis. This difference in clinical outcome was eliminated in Mir-122 KO mice, confirming the specificity of the finding. Interestingly, C57BL/6 mice infected with higher doses of RVFVmiR-122 had a higher survival rate which was correlated with faster clearance of virus from the liver, suggesting a role for activation of host immunity in the phenotype. Together, our data demonstrate that miR-122 can specifically restrict the replication of RVFVmiR-122 in liver tissue both in vitro and in vivo, and this restriction alters the clinical course of disease following RVFVmiR-122 infection. IMPORTANCE Rift Valley fever virus (RVFV) is a hemorrhagic fever virus that causes outbreaks in humans and livestock throughout Africa and has spread to continents outside Africa since 2000. However, no commercial vaccine or treatment is currently available for human use against RVFV. Although the liver has been demonstrated as a key target of RVFV, the contribution of viral replication in hepatocytes to overall RVFV pathogenesis is less well defined. In this study we addressed this question by using a recombinant miRNA-targeted virus with restricted replication in hepatocytes. We gained a better understanding of how this individual cell type contributes to the development of disease caused by RVFV. Techniques used in this study provide an innovative tool to the RVFV field that could be applied to study the consequences of limited RVFV replication in other target cells.
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Affiliation(s)
- Lingqing Xu
- Department of Pediatrics, Division of Pediatric Infectious Disease, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Alden C. Paine
- Department of Pediatrics, Division of Pediatric Infectious Disease, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Dominique J. Barbeau
- Department of Pediatrics, Division of Pediatric Infectious Disease, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Frances Alencastro
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Andrew W. Duncan
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Anita K. McElroy
- Department of Pediatrics, Division of Pediatric Infectious Disease, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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4
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Roy N, Alencastro F, Roseman BA, Wilson SR, Delgado ER, May MC, Bhushan B, Bello FM, Jurczak MJ, Shiva S, Locker J, Gingras S, Duncan AW. Dysregulation of Lipid and Glucose Homeostasis in Hepatocyte-Specific SLC25A34 Knockout Mice. Am J Pathol 2022; 192:1259-1281. [PMID: 35718058 PMCID: PMC9472157 DOI: 10.1016/j.ajpath.2022.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/18/2022] [Accepted: 06/08/2022] [Indexed: 10/18/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is an epidemic affecting 30% of the US population. It is characterized by insulin resistance, and by defective lipid metabolism and mitochondrial dysfunction in the liver. SLC25A34 is a major repressive target of miR-122, a miR that has a central role in NAFLD and liver cancer. However, little is known about the function of SLC25A34. To investigate SLC25A34 in vitro, mitochondrial respiration and bioenergetics were examined using hepatocytes depleted of Slc25a34 or overexpressing Slc25a34. To test the function of SLC25A34 in vivo, a hepatocyte-specific knockout mouse was generated, and loss of SLC25A34 was assessed in mice maintained on a chow diet and a fast-food diet (FFD), a model for NAFLD. Hepatocytes depleted of Slc25a34 displayed increased mitochondrial biogenesis, lipid synthesis, and ADP/ATP ratio; Slc25a34 overexpression had the opposite effect. In the knockout model on chow diet, SLC25A34 loss modestly affected liver function (altered glucose metabolism was the most pronounced defect). RNA-sequencing revealed changes in metabolic processes, especially fatty acid metabolism. After 2 months on FFD, knockouts had a more severe phenotype, with increased lipid content and impaired glucose tolerance, which was attenuated after longer FFD feeding (6 months). This work thus presents a novel model for studying SLC25A34 in vivo in which SLC25A34 plays a role in mitochondrial respiration and bioenergetics during NAFLD.
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Affiliation(s)
- Nairita Roy
- Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; McGowan Institute for Regenerative Medicine, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Pittsburgh Liver Research Center, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Frances Alencastro
- Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; McGowan Institute for Regenerative Medicine, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Pittsburgh Liver Research Center, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Bayley A Roseman
- Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; McGowan Institute for Regenerative Medicine, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Pittsburgh Liver Research Center, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Sierra R Wilson
- Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; McGowan Institute for Regenerative Medicine, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Pittsburgh Liver Research Center, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Evan R Delgado
- Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; McGowan Institute for Regenerative Medicine, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Pittsburgh Liver Research Center, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Meredith C May
- Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; McGowan Institute for Regenerative Medicine, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Pittsburgh Liver Research Center, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Bharat Bhushan
- Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Pittsburgh Liver Research Center, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Fiona M Bello
- Pittsburgh Liver Research Center, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Medicine, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Michael J Jurczak
- Pittsburgh Liver Research Center, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Medicine, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Sruti Shiva
- Departments of Pharmacology and Chemical Biology, Vascular Medicine Institute, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Joseph Locker
- Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Pittsburgh Liver Research Center, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Sebastien Gingras
- Department of Immunology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Andrew W Duncan
- Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; McGowan Institute for Regenerative Medicine, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Pittsburgh Liver Research Center, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Bioengineering, School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania.
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5
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Wang H, Lu J, Alencastro F, Roberts A, Fiedor J, Carroll P, Eisenman RN, Ranganathan S, Torbenson M, Duncan AW, Prochownik EV. Coordinated Cross-Talk Between the Myc and Mlx Networks in Liver Regeneration and Neoplasia. Cell Mol Gastroenterol Hepatol 2022; 13:1785-1804. [PMID: 35259493 PMCID: PMC9046243 DOI: 10.1016/j.jcmgh.2022.02.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 01/26/2023]
Abstract
BACKGROUND & AIMS The c-Myc (Myc) Basic helix-loop-helix leucine zipper (bHLH-ZIP) transcription factor is deregulated in most cancers. In association with Max, Myc controls target genes that supervise metabolism, ribosome biogenesis, translation, and proliferation. This Myc network crosstalks with the Mlx network, which consists of the Myc-like proteins MondoA and ChREBP, and Max-like Mlx. Together, this extended Myc network regulates both common and distinct gene targets. Here, we studied the consequence of Myc and/or Mlx ablation in the liver, particularly those pertaining to hepatocyte proliferation, metabolism, and spontaneous tumorigenesis. METHODS We examined the ability of hepatocytes lacking Mlx (MlxKO) or Myc+Mlx (double KO [DKO]) to repopulate the liver over an extended period of time in a murine model of type I tyrosinemia. We also compared this and other relevant behaviors, phenotypes, and transcriptomes of the livers with those from previously characterized MycKO, ChrebpKO, and MycKO × ChrebpKO mice. RESULTS Hepatocyte regenerative potential deteriorated as the Extended Myc Network was progressively dismantled. Genes and pathways dysregulated in MlxKO and DKO hepatocytes included those pertaining to translation, mitochondrial function, and hepatic steatosis resembling nonalcoholic fatty liver disease. The Myc and Mlx Networks were shown to crosstalk, with the latter playing a disproportionate role in target gene regulation. All cohorts also developed steatosis and molecular evidence of early steatohepatitis. Finally, MlxKO and DKO mice showed extensive hepatic adenomatosis. CONCLUSIONS In addition to showing cooperation between the Myc and Mlx Networks, this study showed the latter to be more important in maintaining proliferative, metabolic, and translational homeostasis, while concurrently serving as a suppressor of benign tumorigenesis. GEO accession numbers: GSE181371, GSE130178, and GSE114634.
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Affiliation(s)
- Huabo Wang
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Jie Lu
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Frances Alencastro
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; McGowan Institute for Regenerative Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Alexander Roberts
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Julia Fiedor
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Patrick Carroll
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Robert N Eisenman
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | | | - Michael Torbenson
- Department of Laboratory Medicine and Pathology, The Mayo Clinic, Rochester, Minnesota
| | - Andrew W Duncan
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; McGowan Institute for Regenerative Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Edward V Prochownik
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania; Hillman Comprehensive Cancer Center, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; Department of Microbiology and Molecular Genetics, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
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6
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Jackson LE, Kulkarni S, Wang H, Lu J, Dolezal JM, Bharathi SS, Ranganathan S, Patel MS, Deshpande R, Alencastro F, Wendell SG, Goetzman ES, Duncan AW, Prochownik EV. Correction: Genetic Dissociation of Glycolysis and the TCA Cycle Affects Neither Normal nor Neoplastic Proliferation. Cancer Res 2022; 82:944. [PMID: 35247896 DOI: 10.1158/0008-5472.can-21-4295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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7
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Ayoob JC, Boyce RD, Livshits S, Bruno TC, Delgoffe GM, Galson DL, Duncan AW, Atkinson JM, Oesterreich S, Evans S, Alikhani M, Baker TA, Pratt S, DeHaan KJ, Chen Y, Boone DN. Getting to YES: The Evolution of the University of Pittsburgh Medical Center Hillman Cancer Center Youth Enjoy Science (YES) Academy. J STEM Outreach 2022; 5:10.15695/jstem/v5i2.02. [PMID: 36910569 PMCID: PMC9997544 DOI: 10.15695/jstem/v5i2.02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The University of Pittsburgh Medical Center Hillman Cancer Center Academy (Hillman Academy) has the primary goal of reaching high school students from underrepresented and disadvantaged backgrounds and guiding them through a cutting-edge research and professional development experience that positions them for success in STEM. With this focus, the Hillman Academy has provided nearly 300 authentic mentored research internship opportunities to 239 students from diverse backgrounds over the past 13 years most of whom matriculated into STEM majors in higher education. These efforts have helped shape a more diverse generation of future scientists and clinicians, who will enrich these fields with their unique perspectives and lived experiences. In this paper, we describe our program and the strategies that led to its growth into a National Institutes of Health Youth Enjoy Science-funded program including our unique multi-site structure, tiered mentoring platform, multifaceted recruitment approach, professional and academic development activities, and a special highlight of a set of projects with Deaf and Hard of Hearing students. We also share student survey data from the past six years that indicate satisfaction with the program, self-perceived gains in key areas of scientific development, awareness of careers in STEM, and an increased desire to pursue advanced degrees in STEM.
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Affiliation(s)
- Joseph C Ayoob
- University of Pittsburgh School of Medicine, Department of Computational and Systems Biology
| | - Richard D Boyce
- University of Pittsburgh School of Medicine, Department of Biomedical Informatics
| | - Solomon Livshits
- University of Pittsburgh School of Medicine, Department of Biomedical Informatics
| | - Tullia C Bruno
- University of Pittsburgh School of Medicine, Department of Immunology (Tumor Microenvironment Center and Cancer Immunology and Immunotherapy Program).,UPMC Hillman Cancer Center
| | - Greg M Delgoffe
- University of Pittsburgh School of Medicine, Department of Immunology (Tumor Microenvironment Center and Cancer Immunology and Immunotherapy Program).,UPMC Hillman Cancer Center
| | - Deborah L Galson
- University of Pittsburgh School of Medicine, Department of Medicine (Division of Hematology/Oncology, McGowan Institute for Regenerative Medicine).,UPMC Hillman Cancer Center
| | - Andrew W Duncan
- University of Pittsburgh School of Medicine, Department of Pathology (McGowan Institute for Regenerative Medicine).,University of Pittsburgh School of Medicine, Department of Bioengineering.,UPMC Hillman Cancer Center
| | - Jennifer M Atkinson
- University of Pittsburgh School of Medicine, Department of Pharmacology and Chemical Biology.,Women's Cancer Research Center, Magee Women's Research Institute.,UPMC Hillman Cancer Center
| | - Steffi Oesterreich
- University of Pittsburgh School of Medicine, Department of Pharmacology and Chemical Biology.,Women's Cancer Research Center, Magee Women's Research Institute.,UPMC Hillman Cancer Center
| | - Steve Evans
- University of Pittsburgh School of Medicine, Department of Surgery
| | - Malihe Alikhani
- University of Pittsburgh, School of Computing and Information, Department of Computer Science
| | - Tobias A Baker
- University of Pittsburgh School of Medicine, Department of Biomedical Informatics
| | - Sheila Pratt
- University of Pittsburgh, School of Health and Rehabilitation Sciences, Department of Communication Science and Disorders
| | | | - Yuanyuan Chen
- University of Pittsburgh School of Medicine, Department of Ophthalmology
| | - David N Boone
- University of Pittsburgh School of Medicine, Department of Biomedical Informatics.,UPMC Hillman Cancer Center
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Wilson SR, Duncan AW. Single-Cell DNA Sequencing Reveals Chromosomal Diversity in HCC and a Novel Model of HCC Evolution. Gastroenterology 2022; 162:46-48. [PMID: 34626601 PMCID: PMC8981166 DOI: 10.1053/j.gastro.2021.09.065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 09/28/2021] [Indexed: 01/03/2023]
Affiliation(s)
- Sierra R. Wilson
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Andrew W. Duncan
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
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Barajas JM, Lin CH, Sun HL, Alencastro F, Zhu AC, Aljuhani M, Navari L, Yilmaz SA, Yu L, Corps K, He C, Duncan AW, Ghoshal K. METTL3 Regulates Liver Homeostasis, Hepatocyte Ploidy, and Circadian Rhythm-Controlled Gene Expression in Mice. Am J Pathol 2022; 192:56-71. [PMID: 34599880 PMCID: PMC8759040 DOI: 10.1016/j.ajpath.2021.09.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/19/2021] [Accepted: 09/15/2021] [Indexed: 01/03/2023]
Abstract
N6-methyladenosine (m6A), the most abundant internal modifier of mRNAs installed by the methyltransferase 13 (METTL3) at the (G/A)(m6A)C motif, plays a critical role in the regulation of gene expression. METTL3 is essential for embryonic development, and its dysregulation is linked to various diseases. However, the role of METTL3 in liver biology is largely unknown. In this study, METTL3 function was unraveled in mice depleted of Mettl3 in neonatal livers (Mettl3fl/fl; Alb-Cre). Liver-specific Mettl3 knockout (M3LKO) mice exhibited global decrease in m6A on polyadenylated RNAs and pathologic features associated with nonalcoholic fatty liver disease (eg, hepatocyte ballooning, ductular reaction, microsteatosis, pleomorphic nuclei, DNA damage, foci of altered hepatocytes, focal lobular and portal inflammation, and elevated serum alanine transaminase/alkaline phosphatase levels). Mettl3-depleted hepatocytes were highly proliferative, with decreased numbers of binucleate hepatocytes and increased nuclear polyploidy. M3LKO livers were characterized by reduced m6A and expression of several key metabolic transcripts regulated by circadian rhythm and decreased nuclear protein levels of the core clock transcription factors BMAL1 and CLOCK. A significant decrease in total Bmal1 and Clock mRNAs but an increase in their nuclear levels were observed in M3LKO livers, suggesting impaired nuclear export. Consistent with the phenotype, methylated (m6A) RNA immunoprecipitation coupled with sequencing and RNA sequencing revealed transcriptome-wide loss of m6A markers and alterations in abundance of mRNAs involved in metabolism in M3LKO. Collectively, METTL3 and m6A modifications are critical regulators of liver homeostasis and function.
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Affiliation(s)
- Juan M Barajas
- Department of Pathology, The Ohio State University, Columbus, Ohio
| | - Cho-Hao Lin
- Department of Pathology, The Ohio State University, Columbus, Ohio; Comprehensive Cancer Center, College of Medicine, The Ohio State University, Columbus, Ohio
| | - Hui-Lung Sun
- Department of Biochemistry and Molecular Biology and Institute for Biophysical Dynamics, Howard Hughes Medical Institute, University of Chicago, Chicago, Illinois
| | - Frances Alencastro
- Department of Pathology, Pittsburgh Liver Research Center, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pennsylvania
| | - Allen C Zhu
- Department of Biochemistry and Molecular Biology and Institute for Biophysical Dynamics, Howard Hughes Medical Institute, University of Chicago, Chicago, Illinois
| | - Mona Aljuhani
- Department of Pathology, The Ohio State University, Columbus, Ohio
| | - Ladan Navari
- Comprehensive Cancer Center, College of Medicine, The Ohio State University, Columbus, Ohio
| | - Selen A Yilmaz
- Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio
| | - Lianbo Yu
- Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio
| | - Kara Corps
- Department of Veterinary Biosciences, The Ohio State University, Columbus, Ohio
| | - Chuan He
- Department of Biochemistry and Molecular Biology and Institute for Biophysical Dynamics, Howard Hughes Medical Institute, University of Chicago, Chicago, Illinois
| | - Andrew W Duncan
- Department of Pathology, Pittsburgh Liver Research Center, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pennsylvania.
| | - Kalpana Ghoshal
- Department of Pathology, The Ohio State University, Columbus, Ohio; Comprehensive Cancer Center, College of Medicine, The Ohio State University, Columbus, Ohio.
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10
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Ma J, Tan X, Kwon Y, Delgado ER, Zarnegar A, DeFrances MC, Duncan AW, Zarnegar R. A Novel Humanized Model of NASH and Its Treatment With META4, A Potent Agonist of MET. Cell Mol Gastroenterol Hepatol 2021; 13:565-582. [PMID: 34756982 PMCID: PMC8688725 DOI: 10.1016/j.jcmgh.2021.10.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 10/12/2021] [Accepted: 10/13/2021] [Indexed: 12/10/2022]
Abstract
BACKGROUND & AIMS Nonalcoholic fatty liver disease is a frequent cause of hepatic dysfunction and is now a global epidemic. This ailment can progress to an advanced form called nonalcoholic steatohepatitis (NASH) and end-stage liver disease. Currently, the molecular basis of NASH pathogenesis is poorly understood, and no effective therapies exist to treat NASH. These shortcomings are due to the paucity of experimental NASH models directly relevant to humans. METHODS We used chimeric mice with humanized liver to investigate nonalcoholic fatty liver disease in a relevant model. We carried out histologic, biochemical, and molecular approaches including RNA-Seq. For comparison, we used side-by-side human NASH samples. RESULTS Herein, we describe a "humanized" model of NASH using transplantation of human hepatocytes into fumarylacetoacetate hydrolase-deficient mice. Once fed a high-fat diet, these mice develop NAFLD faithfully, recapitulating human NASH at the histologic, cellular, biochemical, and molecular levels. Our RNA-Seq analyses uncovered that a variety of important signaling pathways that govern liver homeostasis are profoundly deregulated in both humanized and human NASH livers. Notably, we made the novel discovery that hepatocyte growth factor (HGF) function is compromised in human and humanized NASH at several levels including a significant increase in the expression of the HGF antagonists known as NK1/NK2 and marked decrease in HGF activator. Based on these observations, we generated a potent, human-specific, and stable agonist of human MET that we have named META4 (Metaphor) and used it in the humanized NASH model to restore HGF function. CONCLUSIONS Our studies revealed that the humanized NASH model recapitulates human NASH and uncovered that HGF-MET function is impaired in this disease. We show that restoring HGF-MET function by META4 therapy ameliorates NASH and reinstates normal liver function in the humanized NASH model. Our results show that the HGF-MET signaling pathway is a dominant regulator of hepatic homeostasis.
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Affiliation(s)
- Jihong Ma
- The Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania 15261
| | - Xinping Tan
- The Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania 15261
| | - Yongkook Kwon
- The Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania 15261
| | - Evan R. Delgado
- The Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania 15261,Pittsburgh Liver Research Center, School of Medicine, Pittsburgh, Pennsylvania,McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Arman Zarnegar
- The Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania 15261
| | - Marie C. DeFrances
- The Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania 15261,Pittsburgh Liver Research Center, School of Medicine, Pittsburgh, Pennsylvania,McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Andrew W. Duncan
- The Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania 15261,Pittsburgh Liver Research Center, School of Medicine, Pittsburgh, Pennsylvania,McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Reza Zarnegar
- The Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania 15261,Pittsburgh Liver Research Center, School of Medicine, Pittsburgh, Pennsylvania,McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania,Correspondence Address correspondence to: Prof Reza Zarnegar, University of Pittsburgh, Department of Pathology, 200 Lothrop St, Pittsburgh, Pennsylvania 15261. tel: (412) 648-8657; fax: (412) 648-1916.
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Takeishi K, Collin de l'Hortet A, Wang Y, Handa K, Guzman-Lepe J, Matsubara K, Morita K, Jang S, Haep N, Florentino RM, Yuan F, Fukumitsu K, Tobita K, Sun W, Franks J, Delgado ER, Shapiro EM, Fraunhoffer NA, Duncan AW, Yagi H, Mashimo T, Fox IJ, Soto-Gutierrez A. Assembly and Function of a Bioengineered Human Liver for Transplantation Generated Solely from Induced Pluripotent Stem Cells. Cell Rep 2021; 31:107711. [PMID: 32492423 DOI: 10.1016/j.celrep.2020.107711] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/17/2019] [Accepted: 05/08/2020] [Indexed: 12/22/2022] Open
Abstract
The availability of an autologous transplantable auxiliary liver would dramatically affect the treatment of liver disease. Assembly and function in vivo of a bioengineered human liver derived from induced pluripotent stem cells (iPSCs) has not been previously described. By improving methods for liver decellularization, recellularization, and differentiation of different liver cellular lineages of human iPSCs in an organ-like environment, we generated functional engineered human mini livers and performed transplantation in a rat model. Whereas previous studies recellularized liver scaffolds largely with rodent hepatocytes, we repopulated not only the parenchyma with human iPSC-hepatocytes but also the vascular system with human iPS-endothelial cells, and the bile duct network with human iPSC-biliary epithelial cells. The regenerated human iPSC-derived mini liver containing multiple cell types was tested in vivo and remained functional for 4 days after auxiliary liver transplantation in immunocompromised, engineered (IL2rg-/-) rats.
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Affiliation(s)
- Kazuki Takeishi
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | | | - Yang Wang
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Hepatobiliary Surgery, Peking University People's Hospital, Beijing 100044, China
| | - Kan Handa
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Jorge Guzman-Lepe
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Kentaro Matsubara
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Kazutoyo Morita
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Sae Jang
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Nils Haep
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Rodrigo M Florentino
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Physiology and Biophysics, Universidade Federal de Minas Gerais, Belo Horizonte 31270-010, Brazil
| | - Fangchao Yuan
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
| | - Ken Fukumitsu
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Kimimasa Tobita
- Department of Bioengineering and Department of Developmental Biology, University of Pittsburgh, Pittsburgh, PA 15201, USA
| | - Wendell Sun
- LifeCell Corporation, Branchburg, NJ 08876, USA
| | - Jonathan Franks
- Center for Biologic Imaging, University of Pittsburgh Medical School, Pittsburgh, PA 15261, USA
| | - Evan R Delgado
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219-3110, USA; Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Erik M Shapiro
- Department of Radiology, Michigan State University, East Lansing, MI 48824, USA
| | - Nicolas A Fraunhoffer
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Facultad de Ciencias de la Salud, Carrera de Medicina, Universidad Maimónides, Ciudad Autónoma de Buenos Aires and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires, Buenos Aires 1001, Argentina
| | - Andrew W Duncan
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219-3110, USA; Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Hiroshi Yagi
- Department of Surgery, School of Medicine, Keio University, Tokyo 160-8582, Japan
| | - Tomoji Mashimo
- Division of Animal Genetics, Laboratory Animal Research Center, Institute of Medical Science, University of Tokyo, Tokyo 158-8557, Japan
| | - Ira J Fox
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219-3110, USA; Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Surgery, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Alejandro Soto-Gutierrez
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219-3110, USA; Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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12
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Delgado ER, Erickson HL, Tao J, Monga SP, Duncan AW, Anakk S. Scaffolding Protein IQGAP1 Is Dispensable, but Its Overexpression Promotes Hepatocellular Carcinoma via YAP1 Signaling. Mol Cell Biol 2021; 41:e00596-20. [PMID: 33526450 PMCID: PMC8088129 DOI: 10.1128/mcb.00596-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/21/2020] [Accepted: 01/14/2021] [Indexed: 12/13/2022] Open
Abstract
IQ motif-containing GTPase-activating protein 1 (IQGAP1) is a ubiquitously expressed scaffolding protein that is overexpressed in a number of cancers, including liver cancer, and is associated with protumorigenic processes, such as cell proliferation, motility, and adhesion. IQGAP1 can integrate multiple signaling pathways and could be an effective antitumor target. Therefore, we examined the role of IQGAP1 in tumor initiation and promotion during liver carcinogenesis. We found that ectopic overexpression of IQGAP1 in the liver is not sufficient to initiate tumorigenesis. Moreover, we report that the tumor burden and cell proliferation in the diethylnitrosamine-induced liver carcinogenesis model in Iqgap1-/- mice may be driven by MET signaling. In contrast, IQGAP1 overexpression enhanced YAP activation and subsequent NUAK2 expression to accelerate and promote hepatocellular carcinoma (HCC) in a clinically relevant model expressing activated (S45Y) β-catenin and MET. Here, increasing IQGAP1 expression in vivo does not alter β-catenin or MET activation; instead, it promotes YAP activity. Overall, we demonstrate that although IQGAP1 expression is not required for HCC development, the gain of IQGAP1 function promotes the rapid onset and increased liver carcinogenesis. Our results show that an adequate amount of IQGAP1 scaffold is necessary to maintain the quiescent status of the liver.
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Affiliation(s)
- Evan R Delgado
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Hanna L Erickson
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Junyan Tao
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Satdarshan P Monga
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Andrew W Duncan
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Sayeepriyadarshini Anakk
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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Abstract
Hepatocytes are the primary functional cells of the liver that perform essential roles in homeostasis, regeneration, and injury. Most mammalian somatic cells are diploid and contain pairs of each chromosome, but there are also polyploid cells containing additional sets of chromosomes. Hepatocytes are among the best described polyploid cells, with polyploids comprising more than 25 and 90% of the hepatocyte population in humans and mice, respectively. Cellular and molecular mechanisms that regulate hepatic polyploidy have been uncovered, and in recent years, diploid and polyploid hepatocytes have been shown to perform specialized functions. Diploid hepatocytes accelerate liver regeneration induced by resection and may accelerate compensatory regeneration after acute injury. Polyploid hepatocytes protect the liver from tumor initiation in hepatocellular carcinoma and promote adaptation to tyrosinemia-induced chronic injury. This review describes how ploidy variations influence cellular activity and presents a model for context-specific functions for diploid and polyploid hepatocytes.
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Affiliation(s)
- Patrick D Wilkinson
- Division of Genetics, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Andrew W Duncan
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
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Abstract
Polyploidy, a balanced amplification of the genome, is common in the liver. The function of hepatic polyploidy is not entirely clear, but growing evidence shows that polyploidy can protect the liver from tumor formation. In this issue of EMBO Reports, Sladky and colleagues identify the PIDDosome as a polyploidy sensor that regulates liver cancer (Sladky et al, 2020b).
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Affiliation(s)
- Andrew W Duncan
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA, USA
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Xue Y, Bhushan B, Mars WM, Bowen W, Tao J, Orr A, Stoops J, Yu Y, Luo J, Duncan AW, Michalopoulos GK. Phosphorylated Ezrin (Thr567) Regulates Hippo Pathway and Yes-Associated Protein (Yap) in Liver. Am J Pathol 2020; 190:1427-1437. [PMID: 32289287 PMCID: PMC10069283 DOI: 10.1016/j.ajpath.2020.03.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 02/20/2020] [Accepted: 03/26/2020] [Indexed: 12/18/2022]
Abstract
The activation of CD81 [the portal of entry of hepatitis C virus (HCV)] by agonistic antibody results in phosphorylation of Ezrin via Syk kinase and is associated with inactivation of the Hippo pathway and increase in yes-associated protein (Yap1). The opposite occurs when glypican-3 or E2 protein of HCV binds to CD81. Hepatocyte-specific glypican-3 transgenic mice have decreased levels of phosphorylated (p)-Ezrin (Thr567) and Yap, increased Hippo activity, and suppressed liver regeneration. The role of Ezrin in these processes has been speculated, but not proved. We show that Ezrin has a direct role in the regulation of Hippo pathway and Yap. Forced expression of plasmids expressing mutant Ezrin (T567D) that mimics p-Ezrin (Thr567) suppressed Hippo activity and activated Yap signaling in hepatocytes in vivo and enhanced activation of pathways of β-catenin and leucine rich repeat containing G protein-coupled receptor 4 (LGR4) and LGR5 receptors. Hepatoma cell lines JM1 and JM2 have decreased CD81 expression and Hippo activity and up-regulated p-Ezrin (T567). NSC668394, a p-Ezrin (Thr567) antagonist, significantly decreased hepatoma cell proliferation. We additionally show that p-Ezrin (T567) is controlled by epidermal growth factor receptor and MET. Ezrin phosphorylation, mediated by CD81-associated Syk kinase, is directly involved in regulation of Hippo pathway, Yap levels, and growth of normal and neoplastic hepatocytes. The finding has mechanistic and potentially therapeutic applications in hepatocyte growth biology, hepatocellular carcinoma, and HCV pathogenesis.
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Affiliation(s)
- Yuhua Xue
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Bharat Bhushan
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Wendy M Mars
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - William Bowen
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Junyan Tao
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Anne Orr
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - John Stoops
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Yanping Yu
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jianhua Luo
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Andrew W Duncan
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
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16
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Borges FK, Bhandari M, Guerra-Farfan E, Patel A, Sigamani A, Umer M, Tiboni ME, Villar-Casares MDM, Tandon V, Tomas-Hernandez J, Teixidor-Serra J, Avram VRA, Winemaker M, Ramokgopa MT, Szczeklik W, Landoni G, Wang CY, Begum D, Neary JD, Adili A, Sancheti PK, Lawendy AR, Balaguer-Castro M, Ślęczka P, Jenkinson RJ, Nur AN, Wood GCA, Feibel RJ, McMahon SJ, Sigamani A, Popova E, Biccard BM, Moppett IK, Forget P, Landais P, McGillion MH, Vincent J, Balasubramanian K, Harvey V, Garcia-Sanchez Y, Pettit SM, Gauthier LP, Guyatt GH, Conen D, Garg AX, Bangdiwala SI, Belley-Cote EP, Marcucci M, Lamy A, Whitlock R, Le Manach Y, Fergusson DA, Yusuf S, Devereaux PJ, Veevaete L, le Polain de Waroux B, Lavand'homme P, Cornu O, Tribak K, Yombi JC, Touil N, Reul M, Bhutia JT, Clinckaert C, De Clippeleir D, Reul M, Patel A, Tandon V, Gauthier LP, Avram VRA, Winemaker M, de Beer J, Simpson DL, Worster A, Alvarado KA, Gregus KK, Lawrence KH, Leong DP, Joseph PG, Magloire P, Deheshi B, Bisland S, Wood TJ, Tushinski DM, Wilson DAJ, Kearon C, Le Manach Y, Adili A, Tiboni ME, Neary JD, Cowan DD, Khanna V, Zaki A, Farrell JC, MacDonald AM, Conen D, Wong SCW, Karbassi A, Wright DS, Shanthanna H, Coughlin R, Khan M, Wikkerink S, Quraishi FA, Lawendy AR, Kishta W, Schemitsch E, Carey T, Macleod MD, Sanders DW, Vasarhelyi E, Bartley D, Dresser GK, Tieszer C, Jenkinson RJ, Shadowitz S, Lee JS, Choi S, Kreder HJ, Nousiainen M, Kunz MR, Tuazon R, Shrikumar M, Ravi B, Wasserstein D, Stephen DJG, Nam D, Henry PDG, Wood GCA, Mann SM, Jaeger MT, Sivilotti MLA, Smith CA, Frank CC, Grant H, Ploeg L, Yach JD, Harrison MM, Campbell AR, Bicknell RT, Bardana DD, Feibel RJ, McIlquham K, Gallant C, Halman S, Thiruganasambandamoorth V, Ruggiero S, Hadden WJ, Chen BPJ, Coupal SA, McMahon SJ, McLean LM, Shirali HR, Haider SY, Smith CA, Watts E, Santone DJ, Koo K, Yee AJ, Oyenubi AN, Nauth A, Schemitsch EH, Daniels TR, Ward SE, Hall JA, Ahn H, Whelan DB, Atrey A, Khoshbin A, Puskas D, Droll K, Cullinan C, Payendeh J, Lefrancois T, Mozzon L, Marion T, Jacka MJ, Greene J, Menon M, Stiegelmahr R, Dillane D, Irwin M, Beaupre L, Coles CP, Trask K, MacDonald S, Trenholm JAI, Oxner W, Richardson CG, Dehghan N, Sadoughi M, Sharma A, White NJ, Olivieri L, Hunt SB, Turgeon TR, Bohm ER, Tran S, Giilck SM, Hupel T, Guy P, O'Brien PJ, Duncan AW, Crawford GA, Zhou J, Zhao Y, Liu Y, Shan L, Wu A, Muñoz JM, Chaudier P, Douplat M, Fessy MH, Piriou V, Louboutin L, David JS, Friggeri A, Beroud S, Fayet JM, Landais P, Leung FKL, Fang CX, Yee DKH, Sancheti PK, Pradhan CV, Patil AA, Puram CP, Borate MP, Kudrimoti KB, Adhye BA, Dongre HV, John B, Abraham V, Pandey RA, Rajkumar A, George PE, Sigamani A, Stephen M, Chandran N, Ashraf M, Georgekutty AM, Sulthan AS, Adinarayanan S, Sharma D, Barnawal SP, Swaminathan S, Bidkar PU, Mishra SK, Menon J, M N, K VZ, Hiremath SA, NC M, Jawali A, Gnanadurai KR, George CE, Maddipati T, KP MKP, Sharma V, Farooque K, Malhotra R, Mittal S, Sawhney C, Gupta B, Mathur P, Gamangati S, Tripathy V, Menon PH, Dhillon MS, Chouhan DK, Patil S, Narayan R, Lal P, Bilchod PN, Singh SU, Gattu UV, Dashputra RP, Rahate PV, Turiel M, De Blasio G, Accetta R, Perazzo P, Stella D, Bonadies M, Colombo C, Fozzato S, Pino F, Morelli I, Colnaghi E, Salini V, Denaro G, Beretta L, Placella G, Giardina G, Binda M, Marcato A, Guzzetti L, Piccirillo F, Cecconi M, Khor HM, Lai HY, Kumar CS, Chee KH, Loh PS, Tan KM, Singh S, Foo LL, Prakasam K, Chaw SH, Lee ML, Ngim JHL, Boon HW, Chin II, Kleinlugtenbelt YV, Landman EBM, Flikweert ER, Roerdink HW, Brokelman RB, Elskamp-Meijerman HF, Horst MR, Cobben JHMG, Umer M, Begum D, Anjum A, Hashmi PM, Ahmed T, Rashid HU, Khattak MJ, Rashid RH, Lakdawala RH, Noordin S, Juman NM, Khan RI, Riaz MM, Bokhari SS, Almas A, Wahab H, Ali A, Khan HN, Khan EK, Nur AN, Janjua KA, Orakzai SH, Khan AS, Mustafa KJ, Sohail MA, Umar M, Khan SA, Ashraf M, Khan MK, Shiraz M, Furgan A, Ślęczka P, Dąbek P, Kumoń A, Satora W, Ambroży W, Święch M, Rycombel J, Grzelak A, Gucwa J, Machala W, Ramokgopa MT, Firth GB, Karera M, Fourtounas M, Singh V, Biscardi A, Iqbal MN, Campbell RJ, Maluleke ML, Moller C, Nhlapo L, Maqungo S, Flint M, Nejthardt MB, Chetty S, Naidoo R, Guerra-Farfan E, Tomas-Hernandez J, Garcia-Sanchez Y, Garrido Clua M, Molero-Garcia V, Minguell-Monyart J, Teixidor-Serra J, Villar-Casares MDM, Selga Marsa J, Porcel-Vazquez JA, Andres-Peiro JV, Aguilar M, Mestre-Torres J, Colomina MJ, Guilabert P, Paños Gozalo ML, Abarca L, Martin N, Usua G, Martinez-Ripol P, Gonzalez Posada MA, Lalueza-Broto P, Sanchez-Raya J, Nuñez Camarena J, Fraguas-Castany A, Balaguer-Castro M, Torner P, Jornet-Gibert M, Serrano-Sanz J, Cámara-Cabrera J, Salomó-Domènech M, Yela-Verdú C, Peig-Font A, Ricol L, Carreras-Castañer A, Martínez-Sañudo L, Herranz S, Feijoo-Massó C, Sianes-Gallén M, Castillón P, Bernaus M, Quintas S, Gómez O, Salvador J, Abarca J, Estrada C, Novellas M, Torra M, Dealbert A, Macho O, Ivanov A, Valldosera E, Arroyo M, Pey B, Yuste A, Mateo L, De Caso J, Anaya R, Higa-Sansone JL, Millan A, Baños V, Herrera-Mateo S, Aguado HJ, Martinez-Municio G, León R, Santiago-Maniega S, Zabalza A, Labrador G, Guerado E, Cruz E, Cano JR, Bogallo JM, Sa-ngasoongsong P, Kulachote N, Sirisreetreerux N, Pengrung N, Chalacheewa T, Arnuntasupakul V, Yingchoncharoen T, Naratreekoon B, Kadry MA, Thayaparan S, Abdlaziz I, Aframian A, Imbuldeniya A, Bentoumi S, Omran S, Vizcaychipi MP, Correia P, Patil S, Haire K, Mayor ASE, Dillingham S, Nicholson L, Elnaggar M, John J, Nanjayan SK, Parker MJ, O'Sullivan S, Marmor MT, Matityahu A, McClellan RT, Comstock C, Ding A, Toogood P, Slobogean G, Joseph K, O'Toole R, Sciadini M, Ryan SP, Clark ME, Cassidy C, Balonov K, Bergese SD, Phieffer LS, Gonzalez Zacarias AA, Marcantonio AJ, Devereaux PJ, Bhandari M, Borges FK, Balasubramanian K, Bangdiwala SI, Harvey V, McGillion MH, Pettit SM, Vincent J, Vincent J, Harvey V, Dragic-Taylor S, Maxwell C, Molnar S, Pettit SM, Wells JR, Forget P, Borges FK, Landais P, Sigamani A, Landoni G, Wang CY, Szczeklik W, Biccard BM, Popova E, Moppett IK, Lamy A, Whitlock R, Ofori SN, Yang SS, Wang MK, Duceppe E, Spence J, Vasquez JP, Marcano-Fernández F, Conen D, Ham H, Tiboni ME, Prada C, Yung TCH, Sanz Pérez I, Neary JD, Bosch MJ, Prystajecky MR, Chowdhury C, Khan JS, Belley-Cote EP, Stella SF, Marcucci M, Heidary B, Tran A, Wawrzycka-Adamczyk K, Chen YCP, Tandon V, González-Osuna A, Patel A, Biedroń G, Wludarczyk A, Lefebvre M, Ernst JA, Staffhorst B, Woodfine JD, Alwafi EM, Mrkobrada M, Parlow S, Roberts R, McAlister F, Sackett D, Wright J. Accelerated surgery versus standard care in hip fracture (HIP ATTACK): an international, randomised, controlled trial. Lancet 2020; 395:698-708. [PMID: 32050090 DOI: 10.1016/s0140-6736(20)30058-1] [Citation(s) in RCA: 163] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/06/2020] [Accepted: 01/07/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND Observational studies have suggested that accelerated surgery is associated with improved outcomes in patients with a hip fracture. The HIP ATTACK trial assessed whether accelerated surgery could reduce mortality and major complications. METHODS HIP ATTACK was an international, randomised, controlled trial done at 69 hospitals in 17 countries. Patients with a hip fracture that required surgery and were aged 45 years or older were eligible. Research personnel randomly assigned patients (1:1) through a central computerised randomisation system using randomly varying block sizes to either accelerated surgery (goal of surgery within 6 h of diagnosis) or standard care. The coprimary outcomes were mortality and a composite of major complications (ie, mortality and non-fatal myocardial infarction, stroke, venous thromboembolism, sepsis, pneumonia, life-threatening bleeding, and major bleeding) at 90 days after randomisation. Patients, health-care providers, and study staff were aware of treatment assignment, but outcome adjudicators were masked to treatment allocation. Patients were analysed according to the intention-to-treat principle. This study is registered at ClinicalTrials.gov (NCT02027896). FINDINGS Between March 14, 2014, and May 24, 2019, 27 701 patients were screened, of whom 7780 were eligible. 2970 of these were enrolled and randomly assigned to receive accelerated surgery (n=1487) or standard care (n=1483). The median time from hip fracture diagnosis to surgery was 6 h (IQR 4-9) in the accelerated-surgery group and 24 h (10-42) in the standard-care group (p<0·0001). 140 (9%) patients assigned to accelerated surgery and 154 (10%) assigned to standard care died, with a hazard ratio (HR) of 0·91 (95% CI 0·72 to 1·14) and absolute risk reduction (ARR) of 1% (-1 to 3; p=0·40). Major complications occurred in 321 (22%) patients assigned to accelerated surgery and 331 (22%) assigned to standard care, with an HR of 0·97 (0·83 to 1·13) and an ARR of 1% (-2 to 4; p=0·71). INTERPRETATION Among patients with a hip fracture, accelerated surgery did not significantly lower the risk of mortality or a composite of major complications compared with standard care. FUNDING Canadian Institutes of Health Research.
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Stahl EC, Delgado ER, Alencastro F, LoPresti ST, Wilkinson PD, Roy N, Haschak MJ, Skillen CD, Monga SP, Duncan AW, Brown BN. Inflammation and Ectopic Fat Deposition in the Aging Murine Liver Is Influenced by CCR2. Am J Pathol 2019; 190:372-387. [PMID: 31843499 DOI: 10.1016/j.ajpath.2019.10.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 10/02/2019] [Accepted: 10/22/2019] [Indexed: 02/08/2023]
Abstract
Aging is associated with inflammation and metabolic syndrome, which manifests in the liver as nonalcoholic fatty liver disease (NAFLD). NAFLD can range in severity from steatosis to fibrotic steatohepatitis and is a major cause of hepatic morbidity. However, the pathogenesis of NAFLD in naturally aged animals is unclear. Herein, we performed a comprehensive study of lipid content and inflammatory signature of livers in 19-month-old aged female mice. These animals exhibited increased body and liver weight, hepatic triglycerides, and inflammatory gene expression compared with 3-month-old young controls. The aged mice also had a significant increase in F4/80+ hepatic macrophages, which coexpressed CD11b, suggesting a circulating monocyte origin. A global knockout of the receptor for monocyte chemoattractant protein (CCR2) prevented excess steatosis and inflammation in aging livers but did not reduce the number of CD11b+ macrophages, suggesting changes in macrophage accumulation precede or are independent from chemokine (C-C motif) ligand-CCR2 signaling in the development of age-related NAFLD. RNA sequencing further elucidated complex changes in inflammatory and metabolic gene expression in the aging liver. In conclusion, we report a previously unknown accumulation of CD11b+ macrophages in aged livers with robust inflammatory and metabolic transcriptomic changes. A better understanding of the hallmarks of aging in the liver will be crucial in the development of preventive measures and treatments for end-stage liver disease in elderly patients.
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Affiliation(s)
- Elizabeth C Stahl
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Evan R Delgado
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Frances Alencastro
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Samuel T LoPresti
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Bioengineering Department, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Patrick D Wilkinson
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Nairita Roy
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Martin J Haschak
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Bioengineering Department, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Clint D Skillen
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Satdarshan P Monga
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Andrew W Duncan
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Pathology, University of Pittsburgh School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania.
| | - Bryan N Brown
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Bioengineering Department, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania; Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania.
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18
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Gliozzi ML, Espiritu EB, Shipman KE, Rbaibi Y, Long KR, Roy N, Duncan AW, Lazzara MJ, Hukriede NA, Baty CJ, Weisz OA. Effects of Proximal Tubule Shortening on Protein Excretion in a Lowe Syndrome Model. J Am Soc Nephrol 2019; 31:67-83. [PMID: 31676724 DOI: 10.1681/asn.2019020125] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 09/24/2019] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Lowe syndrome (LS) is an X-linked recessive disorder caused by mutations in OCRL, which encodes the enzyme OCRL. Symptoms of LS include proximal tubule (PT) dysfunction typically characterized by low molecular weight proteinuria, renal tubular acidosis (RTA), aminoaciduria, and hypercalciuria. How mutant OCRL causes these symptoms isn't clear. METHODS We examined the effect of deleting OCRL on endocytic traffic and cell division in newly created human PT CRISPR/Cas9 OCRL knockout cells, multiple PT cell lines treated with OCRL-targeting siRNA, and in orcl-mutant zebrafish. RESULTS OCRL-depleted human cells proliferated more slowly and about 10% of them were multinucleated compared with fewer than 2% of matched control cells. Heterologous expression of wild-type, but not phosphatase-deficient, OCRL prevented the accumulation of multinucleated cells after acute knockdown of OCRL but could not rescue the phenotype in stably edited knockout cell lines. Mathematic modeling confirmed that reduced PT length can account for the urinary excretion profile in LS. Both ocrl mutant zebrafish and zebrafish injected with ocrl morpholino showed truncated expression of megalin along the pronephric kidney, consistent with a shortened S1 segment. CONCLUSIONS Our data suggest a unifying model to explain how loss of OCRL results in tubular proteinuria as well as the other commonly observed renal manifestations of LS. We hypothesize that defective cell division during kidney development and/or repair compromises PT length and impairs kidney function in LS patients.
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Affiliation(s)
| | | | | | | | | | - Nairita Roy
- Department of Pathology, McGowan Institute for Regenerative Medicine, and Pittsburgh Liver Research Center, Pittsburgh, Pennsylvania
| | - Andrew W Duncan
- Department of Pathology, McGowan Institute for Regenerative Medicine, and Pittsburgh Liver Research Center, Pittsburgh, Pennsylvania
| | - Matthew J Lazzara
- Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia; and
| | - Neil A Hukriede
- Department of Developmental Biology, and.,Center for Critical Care Nephrology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | | | - Ora A Weisz
- Renal-Electrolyte Division, Department of Medicine,
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19
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Wilkinson PD, Delgado ER, Alencastro F, Leek MP, Roy N, Weirich MP, Stahl EC, Otero PA, Chen MI, Brown WK, Oertel M, Duncan AW. Polyploidy in Liver Regeneration and Adaptation to Chronic Injury. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.369.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Nairita Roy
- PathologyUniversity of PittsburghPittsburghPA
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20
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Wilkinson PD, Alencastro F, Delgado ER, Leek MP, Weirich MP, Otero PA, Roy N, Brown WK, Oertel M, Duncan AW. Polyploid Hepatocytes Facilitate Adaptation and Regeneration to Chronic Liver Injury. Am J Pathol 2019; 189:1241-1255. [PMID: 30928253 DOI: 10.1016/j.ajpath.2019.02.008] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 01/29/2019] [Accepted: 02/25/2019] [Indexed: 01/10/2023]
Abstract
The liver contains diploid and polyploid hepatocytes (tetraploid, octaploid, etc.), with polyploids comprising ≥90% of the hepatocyte population in adult mice. Polyploid hepatocytes form multipolar spindles in mitosis, which lead to chromosome gains/losses and random aneuploidy. The effect of aneuploidy on liver function is unclear, and the degree of liver aneuploidy is debated, with reports showing aneuploidy affects 5% to 60% of hepatocytes. To study relationships among liver polyploidy, aneuploidy, and adaptation, mice lacking E2f7 and E2f8 in the liver (LKO), which have a polyploidization defect, were used. Polyploids were reduced fourfold in LKO livers, and LKO hepatocytes remained predominantly diploid after extensive proliferation. Moreover, nearly all LKO hepatocytes were euploid compared with control hepatocytes, suggesting polyploid hepatocytes are required for production of aneuploid progeny. To determine whether reduced polyploidy impairs adaptation, LKO mice were bred onto a tyrosinemia background, a disease model whereby the liver can develop disease-resistant, regenerative nodules. Although tyrosinemic LKO mice were more susceptible to morbidities and death associated with tyrosinemia-induced liver failure, they developed regenerating nodules similar to control mice. Analyses revealed that nodules in the tyrosinemic livers were generated by aneuploidy and inactivating mutations. In summary, we identified new roles for polyploid hepatocytes and demonstrated that they are required for the formation of aneuploid progeny and can facilitate adaptation to chronic liver disease.
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Affiliation(s)
- Patrick D Wilkinson
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Frances Alencastro
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Evan R Delgado
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Madeleine P Leek
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Matthew P Weirich
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - P Anthony Otero
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Nairita Roy
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Whitney K Brown
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Michael Oertel
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Andrew W Duncan
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania.
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21
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Wilkinson PD, Delgado ER, Alencastro F, Leek MP, Roy N, Weirich MP, Stahl EC, Otero PA, Chen MI, Brown WK, Duncan AW. The Polyploid State Restricts Hepatocyte Proliferation and Liver Regeneration in Mice. Hepatology 2019; 69:1242-1258. [PMID: 30244478 PMCID: PMC6532408 DOI: 10.1002/hep.30286] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 09/16/2018] [Indexed: 12/12/2022]
Abstract
The liver contains a mixture of hepatocytes with diploid or polyploid (tetraploid, octaploid, etc.) nuclear content. Polyploid hepatocytes are commonly found in adult mammals, representing ~90% of the entire hepatic pool in rodents. The cellular and molecular mechanisms that regulate polyploidization have been well characterized; however, it is unclear whether diploid and polyploid hepatocytes function similarly in multiple contexts. Answering this question has been challenging because proliferating hepatocytes can increase or decrease ploidy, and animal models with healthy diploid-only livers have not been available. Mice lacking E2f7 and E2f8 in the liver (liver-specific E2f7/E2f8 knockout; LKO) were recently reported to have a polyploidization defect, but were otherwise healthy. Herein, livers from LKO mice were rigorously characterized, demonstrating a 20-fold increase in diploid hepatocytes and maintenance of the diploid state even after extensive proliferation. Livers from LKO mice maintained normal function, but became highly tumorigenic when challenged with tumor-promoting stimuli, suggesting that tumors in LKO mice were driven, at least in part, by diploid hepatocytes capable of rapid proliferation. Indeed, hepatocytes from LKO mice proliferate faster and out-compete control hepatocytes, especially in competitive repopulation studies. In addition, diploid or polyploid hepatocytes from wild-type (WT) mice were examined to eliminate potentially confounding effects associated with E2f7/E2f8 deficiency. WT diploid cells also showed a proliferative advantage, entering and progressing through the cell cycle faster than polyploid cells, both in vitro and during liver regeneration (LR). Diploid and polyploid hepatocytes responded similarly to hepatic mitogens, indicating that proliferation kinetics are unrelated to differential response to growth stimuli. Conclusion: Diploid hepatocytes proliferate faster than polyploids, suggesting that the polyploid state functions as a growth suppressor to restrict proliferation by the majority of hepatocytes.
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Affiliation(s)
- Patrick D. Wilkinson
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Evan R. Delgado
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Frances Alencastro
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Madeleine P. Leek
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Nairita Roy
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Matthew P. Weirich
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Elizabeth C. Stahl
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - P. Anthony Otero
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Maelee I. Chen
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Whitney K. Brown
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Andrew W. Duncan
- Department of Pathology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
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22
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Wang H, Dolezal JM, Kulkarni S, Lu J, Mandel J, Jackson LE, Alencastro F, Duncan AW, Prochownik EV. Myc and ChREBP transcription factors cooperatively regulate normal and neoplastic hepatocyte proliferation in mice. J Biol Chem 2018; 293:14740-14757. [PMID: 30087120 DOI: 10.1074/jbc.ra118.004099] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 08/02/2018] [Indexed: 12/31/2022] Open
Abstract
Analogous to the c-Myc (Myc)/Max family of bHLH-ZIP transcription factors, there exists a parallel regulatory network of structurally and functionally related proteins with Myc-like functions. Two related Myc-like paralogs, termed MondoA and MondoB/carbohydrate response element-binding protein (ChREBP), up-regulate gene expression in heterodimeric association with the bHLH-ZIP Max-like factor Mlx. Myc is necessary to support liver cancer growth, but not for normal hepatocyte proliferation. Here, we investigated ChREBP's role in these processes and its relationship to Myc. Unlike Myc loss, ChREBP loss conferred a proliferative disadvantage to normal murine hepatocytes, as did the combined loss of ChREBP and Myc. Moreover, hepatoblastomas (HBs) originating in myc-/-, chrebp-/-, or myc-/-/chrebp-/- backgrounds grew significantly more slowly. Metabolic studies on livers and HBs in all three genetic backgrounds revealed marked differences in oxidative phosphorylation, fatty acid β-oxidation (FAO), and pyruvate dehydrogenase activity. RNA-Seq of livers and HBs suggested seven distinct mechanisms of Myc-ChREBP target gene regulation. Gene ontology analysis indicated that many transcripts deregulated in the chrebp-/- background encode enzymes functioning in glycolysis, the TCA cycle, and β- and ω-FAO, whereas those dysregulated in the myc-/- background encode enzymes functioning in glycolysis, glutaminolysis, and sterol biosynthesis. In the myc-/-/chrebp-/- background, additional deregulated transcripts included those involved in peroxisomal β- and α-FAO. Finally, we observed that Myc and ChREBP cooperatively up-regulated virtually all ribosomal protein genes. Our findings define the individual and cooperative proliferative, metabolic, and transcriptional roles for the "Extended Myc Network" under both normal and neoplastic conditions.
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Affiliation(s)
- Huabo Wang
- From the Division of Hematology/Oncology, Children's Hospital of Pittsburgh of UPMC
| | - James M Dolezal
- From the Division of Hematology/Oncology, Children's Hospital of Pittsburgh of UPMC
| | - Sucheta Kulkarni
- From the Division of Hematology/Oncology, Children's Hospital of Pittsburgh of UPMC
| | - Jie Lu
- From the Division of Hematology/Oncology, Children's Hospital of Pittsburgh of UPMC
| | - Jordan Mandel
- From the Division of Hematology/Oncology, Children's Hospital of Pittsburgh of UPMC
| | - Laura E Jackson
- From the Division of Hematology/Oncology, Children's Hospital of Pittsburgh of UPMC
| | | | | | - Edward V Prochownik
- From the Division of Hematology/Oncology, Children's Hospital of Pittsburgh of UPMC, .,the Pittsburgh Liver Center.,the Hillman Cancer Center of UPMC, and.,the Department of Microbiology and Molecular Genetics, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15224
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23
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Stahl E, LoPresti S, Delgado E, Alencastro F, Wilkinson P, Duncan AW, Brown BN. Age‐induced Hepatic Steatosis and Inflammation of Murine Livers is Influenced by MCP‐1. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.150.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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24
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Edmunds LR, Otero PA, Sharma L, D'Souza S, Dolezal JM, David S, Lu J, Lamm L, Basantani M, Zhang P, Sipula IJ, Li L, Zeng X, Ding Y, Ding F, Beck ME, Vockley J, Monga SPS, Kershaw EE, O'Doherty RM, Kratz LE, Yates NA, Goetzman EP, Scott D, Duncan AW, Prochownik EV. Abnormal lipid processing but normal long-term repopulation potential of myc-/- hepatocytes. Oncotarget 2017; 7:30379-95. [PMID: 27105497 PMCID: PMC5058687 DOI: 10.18632/oncotarget.8856] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 04/09/2016] [Indexed: 01/03/2023] Open
Abstract
Establishing c-Myc's (Myc) role in liver regeneration has proven difficult particularly since the traditional model of partial hepatectomy may provoke an insufficiently demanding proliferative stress. We used a model of hereditary tyrosinemia whereby the affected parenchyma can be gradually replaced by transplanted hepatocytes, which replicate 50-100-fold, over several months. Prior to transplantation, livers from myc−/− (KO) mice were smaller in young animals and larger in older animals relative to myc+/+ (WT) counterparts. KO mice also consumed more oxygen, produced more CO2 and generated more heat. Although WT and KO hepatocytes showed few mitochondrial structural differences, the latter demonstrated defective electron transport chain function. RNAseq revealed differences in transcripts encoding ribosomal subunits, cytochrome p450 members and enzymes for triglyceride and sterol biosynthesis. KO hepatocytes also accumulated neutral lipids. WT and KO hepatocytes repopulated recipient tyrosinemic livers equally well although the latter were associated with a pro-inflammatory hepatic environment that correlated with worsening lipid accumulation, its extracellular deposition and parenchymal oxidative damage. Our results show Myc to be dispensable for sustained in vivo hepatocyte proliferation but necessary for maintaining normal lipid homeostasis. myc−/− livers resemble those encountered in non-alcoholic fatty liver disease and, under sustained proliferative stress, gradually acquire the features of non-alcoholic steatohepatitis.
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Affiliation(s)
- Lia R Edmunds
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center, Pittsburgh, PA, USA.,Department of Molecular Genetics and Developmental Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - P Anthony Otero
- Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Lokendra Sharma
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center, Pittsburgh, PA, USA.,Biotechnology Program, Center for Biological Sciences, Central University of Bihar, Bihar, India
| | - Sonia D'Souza
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - James M Dolezal
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Sherin David
- Department of Molecular Genetics and Developmental Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jie Lu
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Lauren Lamm
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Mahesh Basantani
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Pili Zhang
- Division of Endocrinology, Diabetes and Bone Disease, Department of Medicine, Mt. Sinai School of Medicine, New York, NY, USA
| | - Ian J Sipula
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Lucy Li
- Division of Endocrinology, Diabetes and Bone Disease, Department of Medicine, Mt. Sinai School of Medicine, New York, NY, USA
| | - Xuemei Zeng
- Biomedical Mass Spectrometry Center, University of Pittsburgh Schools of the Health Sciences, Pittsburgh, PA, USA
| | - Ying Ding
- Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Fei Ding
- Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Megan E Beck
- Division of Medical Genetics, Children's Hospital of UPMC, The University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Jerry Vockley
- Division of Medical Genetics, Children's Hospital of UPMC, The University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Satdarshan P S Monga
- Department of Pathology, Division of Experimental Pathology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Erin E Kershaw
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Robert M O'Doherty
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Lisa E Kratz
- Laboratory of Biochemical Genetics Kennedy Krieger Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nathan A Yates
- Biomedical Mass Spectrometry Center, University of Pittsburgh Schools of the Health Sciences, Pittsburgh, PA, USA.,Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Eric P Goetzman
- Division of Medical Genetics, Children's Hospital of UPMC, The University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Donald Scott
- Division of Endocrinology, Diabetes and Bone Disease, Department of Medicine, Mt. Sinai School of Medicine, New York, NY, USA
| | - Andrew W Duncan
- Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Edward V Prochownik
- Division of Hematology/Oncology, Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center, Pittsburgh, PA, USA.,Department of Molecular Genetics and Developmental Biology, University of Pittsburgh, Pittsburgh, PA, USA.,The University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
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25
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Jackson LE, Kulkarni S, Wang H, Lu J, Dolezal JM, Bharathi SS, Ranganathan S, Patel MS, Deshpande R, Alencastro F, Wendell SG, Goetzman ES, Duncan AW, Prochownik EV. Genetic Dissociation of Glycolysis and the TCA Cycle Affects Neither Normal nor Neoplastic Proliferation. Cancer Res 2017; 77:5795-5807. [PMID: 28883002 DOI: 10.1158/0008-5472.can-17-1325] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 07/19/2017] [Accepted: 09/01/2017] [Indexed: 12/25/2022]
Abstract
Rapidly proliferating cells increase glycolysis at the expense of oxidative phosphorylation (oxphos) to generate sufficient levels of glycolytic intermediates for use as anabolic substrates. The pyruvate dehydrogenase complex (PDC) is a critical mitochondrial enzyme that catalyzes pyruvate's conversion to acetyl coenzyme A (AcCoA), thereby connecting these two pathways in response to complex energetic, enzymatic, and metabolic cues. Here we utilized a mouse model of hepatocyte-specific PDC inactivation to determine the need for this metabolic link during normal hepatocyte regeneration and malignant transformation. In PDC "knockout" (KO) animals, the long-term regenerative potential of hepatocytes was unimpaired, and growth of aggressive experimental hepatoblastomas was only modestly slowed in the face of 80%-90% reductions in AcCoA and significant alterations in the levels of key tricarboxylic acid (TCA) cycle intermediates and amino acids. Overall, oxphos activity in KO livers and hepatoblastoma was comparable with that of control counterparts, with evidence that metabolic substrate abnormalities were compensated for by increased mitochondrial mass. These findings demonstrate that the biochemical link between glycolysis and the TCA cycle can be completely severed without affecting normal or neoplastic proliferation, even under the most demanding circumstances. Cancer Res; 77(21); 5795-807. ©2017 AACR.
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Affiliation(s)
- Laura E Jackson
- Division of Neonatology, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Sucheta Kulkarni
- Division of Hematology/Oncology, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Huabo Wang
- Division of Hematology/Oncology, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Jie Lu
- Division of Hematology/Oncology, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - James M Dolezal
- Division of Hematology/Oncology, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Sivakama S Bharathi
- Division of Medical Genetics, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Sarangarajan Ranganathan
- Department of Pathology, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Mulchand S Patel
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, New York
| | - Rahul Deshpande
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Frances Alencastro
- Department of Pathology, The McGowan Institute for Regenerative Medicine and The Pittsburgh Liver Research Center, The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Stacy G Wendell
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Eric S Goetzman
- Division of Medical Genetics, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Andrew W Duncan
- Department of Pathology, The McGowan Institute for Regenerative Medicine and The Pittsburgh Liver Research Center, The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Edward V Prochownik
- Division of Hematology/Oncology, Department of Pediatrics, Children's Hospital of Pittsburgh of The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania. .,Department of Microbiology and Molecular Genetics, The University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.,The University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania
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26
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Hsu SH, Delgado ER, Otero PA, Teng KY, Kutay H, Meehan KM, Moroney JB, Monga JK, Hand NJ, Friedman JR, Ghoshal K, Duncan AW. MicroRNA-122 regulates polyploidization in the murine liver. Hepatology 2016; 64:599-615. [PMID: 27016325 PMCID: PMC4956491 DOI: 10.1002/hep.28573] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 03/14/2016] [Indexed: 12/17/2022]
Abstract
UNLABELLED A defining feature of the mammalian liver is polyploidy, a numerical change in the entire complement of chromosomes. The first step of polyploidization involves cell division with failed cytokinesis. Although polyploidy is common, affecting ∼90% of hepatocytes in mice and 50% in humans, the specialized role played by polyploid cells in liver homeostasis and disease remains poorly understood. The goal of this study was to identify novel signals that regulate polyploidization, and we focused on microRNAs (miRNAs). First, to test whether miRNAs could regulate hepatic polyploidy, we examined livers from Dicer1 liver-specific knockout mice, which are devoid of mature miRNAs. Loss of miRNAs resulted in a 3-fold reduction in binucleate hepatocytes, indicating that miRNAs regulate polyploidization. Second, we surveyed age-dependent expression of miRNAs in wild-type mice and identified a subset of miRNAs, including miR-122, that is differentially expressed at 2-3 weeks, a period when extensive polyploidization occurs. Next, we examined Mir122 knockout mice and observed profound, lifelong depletion of polyploid hepatocytes, proving that miR-122 is required for complete hepatic polyploidization. Moreover, the polyploidy defect in Mir122 knockout mice was ameliorated by adenovirus-mediated overexpression of miR-122, underscoring the critical role miR-122 plays in polyploidization. Finally, we identified direct targets of miR-122 (Cux1, Rhoa, Iqgap1, Mapre1, Nedd4l, and Slc25a34) that regulate cytokinesis. Inhibition of each target induced cytokinesis failure and promoted hepatic binucleation. CONCLUSION Among the different signals that have been associated with hepatic polyploidy, miR-122 is the first liver-specific signal identified; our data demonstrate that miR-122 is both necessary and sufficient in liver polyploidization, and these studies will serve as the foundation for future work investigating miR-122 in liver maturation, homeostasis, and disease. (Hepatology 2016;64:599-615).
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Affiliation(s)
- Shu-hao Hsu
- Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Evan R. Delgado
- Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - P. Anthony Otero
- Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Kun-yu Teng
- Department of Pathology, The Ohio State University, 646C MRF Bldg., 420 W. 12th Ave., Columbus, OH 43210
| | - Huban Kutay
- Department of Pathology, The Ohio State University, 646C MRF Bldg., 420 W. 12th Ave., Columbus, OH 43210
| | - Kolin M. Meehan
- Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Justin B. Moroney
- Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Jappmann K. Monga
- Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
| | - Nicholas J. Hand
- Children’s Hospital of Philadelphia Research Institute, Department of Pediatrics, Division of Gastroenterology, Hepatology and Nutrition. 3615 Civic Center Blvd., Philadelphia, PA 19104
| | - Joshua R. Friedman
- Children’s Hospital of Philadelphia Research Institute, Department of Pediatrics, Division of Gastroenterology, Hepatology and Nutrition. 3615 Civic Center Blvd., Philadelphia, PA 19104
| | - Kalpana Ghoshal
- Department of Pathology, The Ohio State University, 646C MRF Bldg., 420 W. 12th Ave., Columbus, OH 43210
| | - Andrew W. Duncan
- Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219
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Edmunds LR, Sharma L, Otero PA, D'Souza S, Dolezal JM, Zeng X, Ding Y, Ding F, Beck ME, Kratz LE, Vockley J, Goetzman E, Scott D, Yates N, Duncan AW, Prochownik EV. Abstract B25: Novel hepatic phenotypes caused by conditional c-Myc deletion. Mol Cancer Res 2016. [DOI: 10.1158/1557-3125.metca15-b25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The transcription factor c-Myc (hereafter Myc) is among the most frequently deregulated oncoproteins. Inhibition of Myc triggers proliferative arrest of transformed cells and promotes tumor regression and/or apoptosis. Myc is also developmentally necessary and myc-/- embryos die at E9.5-10.5. However, Myc's role in the maintenance of specific tissues has been shown to be of variable importance and necessity. For example, several studies of Myc's role in promoting liver regeneration following partial hepatectomy (PH) have given conflicting results, although all show Myc to be generally dispensable for this function. We have used a conditional murine knockout (KO) model of Myc to study its role in liver regeneration. By employing a mycfl/fl;Alb-Cre+ model in which loss of Myc occurs perinatally, we studied non-oncogenic liver proliferation and metabolism in the absence of Myc signaling.
We employed basic metabolic benchmarks of liver function including measurements of triglyceride levels, oxidative phosphorylation, and TCA cycle and electron transport chain function. At the molecular level, RNAseq was performed on isolated hepatocytes and the mitochondrial proteome was evaluated by both differential and unbiased mass spectrometry. At the time of active Myc excision, myc-/- mice had a significantly lower liver: body weight ratios relative to myc+/+ controls. However, this was reversed in older mice and was associated with the hepatic accumulation of neutral lipids, cholesterol and increased fatty acid β-oxidation in myc-/- mice. RNAseq on hepatocytes and Ingenuity Pathway analyses showed differences in 105 transcripts (q<0.05), the major pathways encoding ribosomal proteins, members of the cytochrome p450 family and enzymes involved in cholesterol and bile metabolism. These findings correlated with abnormalities in fatty acid and sterol metabolism and storage in liver samples.
PH may provide an insufficiently sustained proliferative challenge to allow adequate evaluation of Myc's potential role in liver regeneration. We therefore utilized a mouse model of hereditary tyrosinemia in which knockout of the gene encoding fumarylacetoacetate hydrolase (FAH) leads to hepatocellular death that can be rescued by the infusion of fah+/+ hepatocytes, which expand and eventually replace the fah-/- recipient hepatocytes. FAH-deficient animals could be rescued equally well by both myc+/+ and myc-/- hepatocytes. However, livers from the latter group showed excessive neutral lipid accumulation and fibrosis, reminiscent of non-alcoholic steatohepatitis (NASH). Taken together, our results provide unequivocal evidence that Myc is dispensable for long-term hepatic regeneration but is necessary to maintain proper lipid and steroid metabolism. In Myc's absence the excessive accumulation of these intermediates predisposes to the development of a relatively mild pathology mimicking non-alcoholic fatty liver disease, which under the duress of chronic proliferation, progresses to a more severe NASH-like picture of end-stage liver disease. Our studies thus reveal a heretofore unappreciated role for Myc in hepatic metabolic homeostasis.
Citation Format: Lia R. Edmunds, Lokendra Sharma, Peter Anthony Otero, Sonia D'Souza, James M. Dolezal, Xuemei Zeng, Ying Ding, Fei Ding, Megan E. Beck, Lisa E. Kratz, Jerry Vockley, Eric Goetzman, Donald Scott, Nathan Yates, Andrew W. Duncan, Edward V. Prochownik. Novel hepatic phenotypes caused by conditional c-Myc deletion. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr B25.
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Affiliation(s)
- Lia R. Edmunds
- 1Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA,
| | - Lokendra Sharma
- 2Center for Biological Sciences, Central University of Bihar, Bihar, India,
| | | | - Sonia D'Souza
- 1Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA,
| | | | - Xuemei Zeng
- 3University of Pittsburgh School of Medicine, Pittsburgh, PA,
| | - Ying Ding
- 3University of Pittsburgh School of Medicine, Pittsburgh, PA,
| | - Fei Ding
- 3University of Pittsburgh School of Medicine, Pittsburgh, PA,
| | - Megan E. Beck
- 1Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA,
| | | | - Jerry Vockley
- 1Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA,
| | - Eric Goetzman
- 1Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA,
| | | | - Nathan Yates
- 3University of Pittsburgh School of Medicine, Pittsburgh, PA,
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Abstract
The composition of the liver changes dramatically with age. Hepatocytes in young individuals are relatively small and uniform in size. In contrast, adult hepatocytes vary considerably in cell and nuclear size, number of nuclei per cell and DNA content per nucleus (1, 2). Many of these striking age-associated morphological changes are attributed to hepatic polyploidy, a numerical change in the entire complement of chromosomes. Polyploid hepatocytes were recognized over a century ago, but it is unclear whether these cells play a specialized role in liver homeostasis, regeneration or disease. Despite our limited understanding of the physiological role of polyploid hepatocytes, nearly a dozen genes have been implicated in the regulation of polyploidy (2). Notably, Chantal Desdouets’ group previously demonstrated a critical role for insulin in the generation of binucleate polyploid hepatocytes in rats (3). Motivated by these early findings, Gentric, Celton-Morizur, Desdouets and colleagues rationalized that liver diseases frequently associated with dysregulated insulin signaling could have an abnormal ploidy spectrum. Indeed, in recent work the authors identified a connection between abnormal hepatic polyploidy and nonalcoholic fatty liver disease (NAFLD)
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Affiliation(s)
- Shu-Hao Hsu
- Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Andrew W Duncan
- Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA
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Kurinna S, Stratton SA, Coban Z, Schumacher JM, Grompe M, Duncan AW, Barton MC. p53 regulates a mitotic transcription program and determines ploidy in normal mouse liver. Hepatology 2013; 57:2004-13. [PMID: 23300120 PMCID: PMC3632650 DOI: 10.1002/hep.26233] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2012] [Accepted: 11/28/2012] [Indexed: 12/11/2022]
Abstract
UNLABELLED Functions of p53 during mitosis reportedly include prevention of polyploidy and transmission of aberrant chromosomes. However, whether p53 plays these roles during genomic surveillance in vivo and, if so, whether this is done via direct or indirect means remain unknown. The ability of normal, mature hepatocytes to respond to stimuli, reenter the cell cycle, and regenerate liver mass offers an ideal setting to assess mitosis in vivo. In quiescent liver, normally high ploidy levels in adult mice increased with loss of p53. Following partial hepatectomy, p53(-/-) hepatocytes exhibited early entry into the cell cycle and prolonged proliferation with an increased number of polyploid mitoses. Ploidy levels increased during regeneration of both wild-type (WT) and p53(-/-) hepatocytes, but only WT hepatocytes were able to dynamically resolve ploidy levels and return to normal by the end of regeneration. We identified multiple cell cycle and mitotic regulators, including Foxm1, Aurka, Lats2, Plk2, and Plk4, as directly regulated by chromatin interactions of p53 in vivo. Over a time course of regeneration, direct and indirect regulation of expression by p53 is mediated in a gene-specific manner. CONCLUSION Our results show that p53 plays a role in mitotic fidelity and ploidy resolution in hepatocytes of normal and regenerative liver.
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Affiliation(s)
- Svitlana Kurinna
- Department of Biochemistry and Molecular Biology, UT MD Anderson Cancer Center, Houston, TX
| | - Sabrina A. Stratton
- Department of Biochemistry and Molecular Biology, UT MD Anderson Cancer Center, Houston, TX
| | - Zeynep Coban
- Department of Biochemistry and Molecular Biology, UT MD Anderson Cancer Center, Houston, TX,Center for Cancer Epigenetics, UT MD Anderson Cancer Center, Houston, TX,Graduate program in Genes and Development, University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX
| | - Jill M. Schumacher
- Center for Cancer Epigenetics, UT MD Anderson Cancer Center, Houston, TX,Department of Genetics, UT MD Anderson Cancer Center, Houston, TX,Graduate program in Genes and Development, University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX
| | - Markus Grompe
- Oregon Stem Cell Center, Papé Family Pediatric Research Institute, Oregon Health & Science University, Portland, OR, 97239 USA
| | - Andrew W. Duncan
- Oregon Stem Cell Center, Papé Family Pediatric Research Institute, Oregon Health & Science University, Portland, OR, 97239 USA,Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Michelle Craig Barton
- Department of Biochemistry and Molecular Biology, UT MD Anderson Cancer Center, Houston, TX,Center for Stem Cell and Developmental Biology, UT MD Anderson Cancer Center, Houston, TX,Center for Cancer Epigenetics, UT MD Anderson Cancer Center, Houston, TX,Graduate program in Genes and Development, University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX
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Abstract
Polyploidy has been described in the liver for over 100 years. The frequency of polyploid hepatocytes varies by age and species, but up to 90% of mouse hepatocytes and approximately 50% of human hepatocytes are polyploid. In addition to alterations in the entire complement of chromosomes, variations in chromosome copy number have been recently described. Aneuploidy in the liver is pervasive, affecting 60% of hepatocytes in mice and 30-90% of hepatocytes in humans. Polyploidy and aneuploidy in the liver are closely linked, and the ploidy conveyor model describes this relationship. Diploid hepatocytes undergo failed cytokinesis to generate polyploid cells. Proliferating polyploid hepatocytes, which form multipolar spindles during cell division, generate reduced ploidy progeny (e.g., diploid hepatocytes from tetraploids or octaploids) and/or aneuploid daughters. New evidence suggests that random hepatic aneuploidy can promote adaptation to liver injury. For instance, in response to chronic liver damage, subsets of aneuploid hepatocytes that are differentially resistant to the injury remain healthy, regenerate the liver and restore function. Future work is required to elucidate the mechanisms regulating dynamic chromosome changes in the liver and to understand how these processes impact normal and abnormal liver function.
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Affiliation(s)
- Andrew W Duncan
- Department of Pathology, McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219, United States.
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31
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Duncan AW, Hanlon Newell AE, Bi W, Finegold MJ, Olson SB, Beaudet AL, Grompe M. Aneuploidy as a mechanism for stress-induced liver adaptation. J Clin Invest 2012; 122:3307-15. [PMID: 22863619 DOI: 10.1172/jci64026] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 06/28/2012] [Indexed: 02/06/2023] Open
Abstract
Over half of the mature hepatocytes in mice and humans are aneuploid and yet retain full ability to undergo mitosis. This observation has raised the question of whether this unusual somatic genetic variation evolved as an adaptive mechanism in response to hepatic injury. According to this model, hepatotoxic insults select for hepatocytes with specific numerical chromosome abnormalities, rendering them differentially resistant to injury. To test this hypothesis, we utilized a strain of mice heterozygous for a mutation in the homogentisic acid dioxygenase (Hgd) gene located on chromosome 16. Loss of the remaining Hgd allele protects from fumarylacetoacetate hydrolase (Fah) deficiency, a genetic liver disease model. When adult mice heterozygous for Hgd and lacking Fah were exposed to chronic liver damage, injury-resistant nodules consisting of Hgd-null hepatocytes rapidly emerged. To determine whether aneuploidy played a role in this phenomenon, array comparative genomic hybridization (aCGH) and metaphase karyotyping were performed. Strikingly, loss of chromosome 16 was dramatically enriched in all mice that became completely resistant to tyrosinemia-induced hepatic injury. The frequency of chromosome 16-specific aneuploidy was approximately 50%. This result indicates that selection of a specific aneuploid karyotype can result in the adaptation of hepatocytes to chronic liver injury. The extent to which aneuploidy promotes hepatic adaptation in humans remains under investigation.
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Affiliation(s)
- Andrew W Duncan
- Oregon Stem Cell Center, Papé Family Pediatric Research Institute, Portland, OR, USA.
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Duncan AW, Hanlon Newell AE, Smith L, Wilson EM, Olson SB, Thayer MJ, Strom SC, Grompe M. Frequent aneuploidy among normal human hepatocytes. Gastroenterology 2012; 142:25-8. [PMID: 22057114 PMCID: PMC3244538 DOI: 10.1053/j.gastro.2011.10.029] [Citation(s) in RCA: 153] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 10/03/2011] [Accepted: 10/15/2011] [Indexed: 12/11/2022]
Abstract
Murine hepatocytes become polyploid and then undergo ploidy reversal and become aneuploid in a dynamic process called the ploidy conveyor. Although polyploidization occurs in some types of human cells, the degree of aneuploidy in human hepatocytes is not known. We isolated hepatocytes derived from healthy human liver samples and determined chromosome number and identity using traditional karyotyping and fluorescence in situ hybridization. Similar to murine hepatocytes, human hepatocytes are highly aneuploid. Moreover, imaging studies revealed multipolar spindles and chromosome segregation defects in dividing human hepatocytes. Aneuploidy therefore does not necessarily predispose liver cells to transformation but might promote genetic diversity among hepatocytes.
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Affiliation(s)
- Andrew W Duncan
- Oregon Stem Cell Center, Papé Family Pediatric Research Institute, Oregon Health & Science University, Portland, Oregon, USA.
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Dorrell C, Erker L, Schug J, Kopp JL, Canaday PS, Fox AJ, Smirnova O, Duncan AW, Finegold MJ, Sander M, Kaestner KH, Grompe M. Prospective isolation of a bipotential clonogenic liver progenitor cell in adult mice. Genes Dev 2011; 25:1193-203. [PMID: 21632826 DOI: 10.1101/gad.2029411] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The molecular identification of adult hepatic stem/progenitor cells has been hampered by the lack of truly specific markers. To isolate putative adult liver progenitor cells, we used cell surface-marking antibodies, including MIC1-1C3, to isolate subpopulations of liver cells from normal adult mice or those undergoing an oval cell response and tested their capacity to form bilineage colonies in vitro. Robust clonogenic activity was found to be restricted to a subset of biliary duct cells antigenically defined as CD45(-)/CD11b(-)/CD31(-)/MIC1-1C3(+)/CD133(+)/CD26(-), at a frequency of one of 34 or one of 25 in normal or oval cell injury livers, respectively. Gene expression analyses revealed that Sox9 was expressed exclusively in this subpopulation of normal liver cells and was highly enriched relative to other cell fractions in injured livers. In vivo lineage tracing using Sox9creER(T2)-R26R(YFP) mice revealed that the cells that proliferate during progenitor-driven liver regeneration are progeny of Sox9-expressing precursors. A comprehensive array-based comparison of gene expression in progenitor-enriched and progenitor-depleted cells from both normal and DDC (3,5-diethoxycarbonyl-1,4-dihydrocollidine or diethyl1,4-dihydro-2,4,6-trimethyl-3,5-pyridinedicarboxylate)-treated livers revealed new potential regulators of liver progenitors.
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Affiliation(s)
- Craig Dorrell
- Oregon Stem Cell Center, Oregon Health and Science University, Portland, USA
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34
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Duncan AW, Mawson JB, LeBlanc JG, Potts JE, Duncan WJ. Imaging of a carotid aneurysm in two patients following extracorporeal membrane oxygenation therapy. Pediatr Cardiol 2009; 30:1000-2. [PMID: 19471993 DOI: 10.1007/s00246-009-9462-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Revised: 03/31/2009] [Accepted: 04/18/2009] [Indexed: 10/20/2022]
Abstract
Following extracorporeal membrane oxygenation (ECMO), two patients subsequently developed carotid aneurysms at the site of cannulation. Given the invasive nature of ECMO, vascular ultrasound and/or computerized tomographic imaging should be considered to rule out cannulation-site complications post-ECMO.
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Affiliation(s)
- Andrew W Duncan
- Division of Cardiology, British Columbia Children's Hospital and The University of British Columbia, 1F Clinic, Vancouver, BC V6H 3V4, Canada
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35
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Duncan AW, Hickey RD, Paulk NK, Culberson AJ, Olson SB, Finegold MJ, Grompe M. Ploidy reductions in murine fusion-derived hepatocytes. PLoS Genet 2009; 5:e1000385. [PMID: 19229314 PMCID: PMC2636893 DOI: 10.1371/journal.pgen.1000385] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Accepted: 01/20/2009] [Indexed: 12/12/2022] Open
Abstract
We previously showed that fusion between hepatocytes lacking a crucial liver enzyme, fumarylacetoacetate hydrolase (FAH), and wild-type blood cells resulted in hepatocyte reprogramming. FAH expression was restored in hybrid hepatocytes and, upon in vivo expansion, ameliorated the effects of FAH deficiency. Here, we show that fusion-derived polyploid hepatocytes can undergo ploidy reductions to generate daughter cells with one-half chromosomal content. Fusion hybrids are, by definition, at least tetraploid. We demonstrate reduction to diploid chromosome content by multiple methods. First, cytogenetic analysis of fusion-derived hepatocytes reveals a population of diploid cells. Secondly, we demonstrate marker segregation using ß-galactosidase and the Y-chromosome. Approximately 2–5% of fusion-derived FAH-positive nodules were negative for one or more markers, as expected during ploidy reduction. Next, using a reporter system in which ß-galactosidase is expressed exclusively in fusion-derived hepatocytes, we identify a subpopulation of diploid cells expressing ß-galactosidase and FAH. Finally, we track marker segregation specifically in fusion-derived hepatocytes with diploid DNA content. Hemizygous markers were lost by ≥50% of Fah-positive cells. Since fusion-derived hepatocytes are minimally tetraploid, the existence of diploid hepatocytes demonstrates that fusion-derived cells can undergo ploidy reduction. Moreover, the high degree of marker loss in diploid daughter cells suggests that chromosomes/markers are lost in a non-random fashion. Thus, we propose that ploidy reductions lead to the generation of genetically diverse daughter cells with about 50% reduction in nuclear content. The generation of such daughter cells increases liver diversity, which may increase the likelihood of oncogenesis. The liver comprises many different types of cells, including hepatocytes. Hepatocytes perform numerous physiological functions, such as detoxification, metabolism, and protein synthesis. Hepatocytes have the ability to fuse with blood cells, generating hybrid hepatocytes that contain nuclei from both fusion partners. In cases of genetic liver disease, fusion between diseased hepatocytes and normal blood cells can result in the formation of hybrid hepatocytes that function normally. In this series of experiments, we show that fusion hepatocytes produce daughter cells with one-half the amount of DNA found in the parental fusion hepatocyte. Furthermore, we show that the daughter cells are genetically distinct from each other. The increase in genetic diversity within the liver could give rise to hepatocytes lacking proper growth control, potentially resulting in tumor formation and cancer.
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Affiliation(s)
- Andrew W Duncan
- Oregon Stem Cell Center, Oregon Health and Science University, Portland, Oregon, United States of America.
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36
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Shine NP, Coates HL, Lannigan FJ, Duncan AW. Adenotonsillar surgery in morbidly obese children: routine elective admission of all patients to the intensive care unit is unnecessary. Anaesth Intensive Care 2007; 34:724-30. [PMID: 17183889 DOI: 10.1177/0310057x0603400607] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Morbidly obese children undergoing adenotonsillectomy, often with co-morbid obstructive sleep apnoea, may be considered at a higher risk of postoperative respiratory compromise. This retrospective study aimed to assess the frequency and severity of postoperative respiratory complications in these patients and to identify preoperative risks factors for such morbidity. Medical and nursing chart review of all consecutive elective post-adenotonsillectomy admissions of morbidly obese children (defined as >95th centile for body mass index adjusted for age and gender) to our intensive care unit over a 30-month period was performed. A total of 26 morbidly obese children were identified. The majority (14/26) had an uncomplicated recovery following surgery. Of those cases that required postoperative intervention, 10 patients required supplemental oxygen with or without suctioning and/or repositioning alone, whilst two required continuous positive airway pressure therapy. No patient required re-intubation. An oxygen saturation nadir of < 70% and the presence of more than one central apnoea, noted on preoperative overnight polysomnography, were associated with postoperative respiratory complications requiring intervention. Although the intervention group were younger, more obese and had a higher respiratory disturbance index, none of these factors were statistically significant. Routine admission to the paediatric intensive care unit of all morbidly obese children undergoing adenotonsillectomy may be unnecessary, once a suitable high level of nursing is available in an alternative setting, to administer simple positional and suctioning intervention and to perform regular patient observation. Special consideration should be given to the postoperative nursing environment for those patients with a SaO2 nadir < 70% noted preoperatively, indicating the presence of a significant central disease component.
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Affiliation(s)
- N P Shine
- Department of Paediatric Otolaryngology, Princess Margaret Hospital, Perth, Western Australia, Australia
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37
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Kitsos CM, Sankar U, Illario M, Colomer-Font JM, Duncan AW, Ribar TJ, Reya T, Means AR. Calmodulin-dependent protein kinase IV regulates hematopoietic stem cell maintenance. J Biol Chem 2005; 280:33101-8. [PMID: 16020540 DOI: 10.1074/jbc.m505208200] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The hematopoietic stem cell (HSC) gives rise to all mature, terminally differentiated cells of the blood. Here we show that calmodulin-dependent protein kinase IV (CaMKIV) is present in c-Kit+ ScaI+ Lin(-/low) hematopoietic progenitor cells (KLS cells) and that its absence results in hematopoietic failure, characterized by a diminished KLS cell population and by an inability of these cells to reconstitute blood cells upon serial transplantation. KLS cell failure in the absence of CaMKIV is correlated with increased apoptosis and proliferation of these cells in vivo and in vitro. In turn, these cell biological defects are correlated with decreases in CREB-serine 133 phosphorylation as well as in CREB-binding protein (CBP) and Bcl-2 levels. Re-expression of CaMKIV in Camk4-/- KLS cells results in the rescue of the proliferation defects in vitro as well as in the restoration of CBP and Bcl-2 to wild type levels. These studies show that CaMKIV is a regulator of HSC homeostasis and suggest that its effects may be in part mediated via regulation of CBP and Bcl-2.
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Affiliation(s)
- Christine M Kitsos
- Department of Pharmacology and Cancer Biology, Duke University, Medical Center, Durham, North Carolina 27715, USA
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Duncan AW, Rattis FM, DiMascio LN, Congdon KL, Pazianos G, Zhao C, Yoon K, Cook JM, Willert K, Gaiano N, Reya T. Integration of Notch and Wnt signaling in hematopoietic stem cell maintenance. Nat Immunol 2005; 6:314-22. [PMID: 15665828 DOI: 10.1038/ni1164] [Citation(s) in RCA: 567] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2004] [Accepted: 12/30/2004] [Indexed: 01/06/2023]
Abstract
A fundamental question in hematopoietic stem cell (HSC) biology is how self-renewal is controlled. Here we show that the molecular regulation of two critical elements of self-renewal, inhibition of differentiation and induction of proliferation, can be uncoupled, and we identify Notch signaling as a key factor in inhibiting differentiation. Using transgenic Notch reporter mice, we found that Notch signaling was active in HSCs in vivo and downregulated as HSCs differentiated. Inhibition of Notch signaling led to accelerated differentiation of HSCs in vitro and depletion of HSCs in vivo. Finally, intact Notch signaling was required for Wnt-mediated maintenance of undifferentiated HSCs but not for survival or entry into the cell cycle in vitro. These data suggest that Notch signaling has a dominant function in inhibiting differentiation and provide a model for how HSCs may integrate multiple signals to maintain the stem cell state.
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Affiliation(s)
- Andrew W Duncan
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
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Shann FA, Duncan AW, Brandstater B. Prolonged per-laryngeal endotracheal intubation in children: 40 years on. Anaesth Intensive Care 2003; 31:664-6; discussion 663-4. [PMID: 14719429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Because tracheostomy has a very high complication rate in small children, prolonged mechanical ventilation was not performed satisfactorily in infants until a technique was developed that allowed prolonged per-laryngeal endotracheal intubation in children. Plastic polyvinyl chloride endotracheal tubes were introduced in the 1950s; they soften at body temperature, and are much less likely to cause subglottic stenosis than endotracheal tubes made from metal or rubber. The first account of prolonged per-laryngeal intubation of infants using polyvinyl chloride tubes was written by Dr Bernard Brandstater, and this remarkable document is reproduced here. It sets out all the important principles of endotracheal intubation in children: the tube must fit easily through the cricoid ring, it must be firmly fixed in place with the tip in the mid trachea, meticulous humidification and suction are essential, and the tube should be changed only if there are signs of obstruction.
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Affiliation(s)
- F A Shann
- Intensive Care Unit, Royal Children's Hospital, Melbourne, Victoria
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40
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Willert K, Brown JD, Danenberg E, Duncan AW, Weissman IL, Reya T, Yates JR, Nusse R. Wnt proteins are lipid-modified and can act as stem cell growth factors. Nature 2003; 423:448-52. [PMID: 12717451 DOI: 10.1038/nature01611] [Citation(s) in RCA: 1607] [Impact Index Per Article: 76.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2003] [Accepted: 03/20/2003] [Indexed: 12/13/2022]
Abstract
Wnt signalling is involved in numerous events in animal development, including the proliferation of stem cells and the specification of the neural crest. Wnt proteins are potentially important reagents in expanding specific cell types, but in contrast to other developmental signalling molecules such as hedgehog proteins and the bone morphogenetic proteins, Wnt proteins have never been isolated in an active form. Although Wnt proteins are secreted from cells, secretion is usually inefficient and previous attempts to characterize Wnt proteins have been hampered by their high degree of insolubility. Here we have isolated active Wnt molecules, including the product of the mouse Wnt3a gene. By mass spectrometry, we found the proteins to be palmitoylated on a conserved cysteine. Enzymatic removal of the palmitate or site-directed and natural mutations of the modified cysteine result in loss of activity, and indicate that the lipid is important for signalling. The purified Wnt3a protein induces self-renewal of haematopoietic stem cells, signifying its potential use in tissue engineering.
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Affiliation(s)
- Karl Willert
- Howard Hughes Medical Institute and Department of Developmental Biology, Stanford University School of Medicine, Stanford, California 94305, USA
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Reya T, Duncan AW, Ailles L, Domen J, Scherer DC, Willert K, Hintz L, Nusse R, Weissman IL. A role for Wnt signalling in self-renewal of haematopoietic stem cells. Nature 2003; 423:409-14. [PMID: 12717450 DOI: 10.1038/nature01593] [Citation(s) in RCA: 1527] [Impact Index Per Article: 72.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2002] [Accepted: 03/27/2003] [Indexed: 01/12/2023]
Abstract
Haematopoietic stem cells (HSCs) have the ability to renew themselves and to give rise to all lineages of the blood; however, the signals that regulate HSC self-renewal remain unclear. Here we show that the Wnt signalling pathway has an important role in this process. Overexpression of activated beta-catenin expands the pool of HSCs in long-term cultures by both phenotype and function. Furthermore, HSCs in their normal microenvironment activate a LEF-1/TCF reporter, which indicates that HCSs respond to Wnt signalling in vivo. To demonstrate the physiological significance of this pathway for HSC proliferation we show that the ectopic expression of axin or a frizzled ligand-binding domain, inhibitors of the Wnt signalling pathway, leads to inhibition of HSC growth in vitro and reduced reconstitution in vivo. Furthermore, activation of Wnt signalling in HSCs induces increased expression of HoxB4 and Notch1, genes previously implicated in self-renewal of HSCs. We conclude that the Wnt signalling pathway is critical for normal HSC homeostasis in vitro and in vivo, and provide insight into a potential molecular hierarchy of regulation of HSC development.
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Affiliation(s)
- Tannishtha Reya
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA.
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Abstract
The Rac/Rho-specific guanine nucleotide exchange factor, Vav-1, is a key component of the T-cell antigen receptor (TCR)-linked signaling machinery. Here we have used somatic cell gene-targeting technology to generate a Vav-1-deficient Jurkat T-cell line. The J.Vav1 cell line exhibits dramatic defects in TCR-dependent interleukin (IL)-2 promoter activation, accompanied by significant reductions in the activities of the NFAT(IL-2), NFkappaB, AP-1 and REAP transcription factors that bind to the IL-2 promoter region. In contrast, loss of Vav-1 had variable effects on early TCR-stimulated signaling events. J.Vav1 cells display a selective defect in sustained Ca(2+) signaling during TCR stimulation, and complementation of this abnormality by exogenously introduced Vav-1 is dependent on the Vav-1 calponin homology domain. While JNK activation was severely impaired, the stimulation of Ras, ERK and protein kinase C-theta activities, as well as the mobilization of lipid rafts, appeared normal in the J.Vav1 cells. Finally, evidence is presented to suggest that the alternative Vav family members, Vav-2 and Vav-3, are activated during TCR ligation, and partially compensate for the loss of Vav-1 in Jurkat T cells.
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Affiliation(s)
- Youjia Cao
- Department of Pharmacology and Cancer Biology and Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA
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Abstract
The aim of this article is to provide an up to date review of second malignant neoplasms (SMN's) following treatment for childhood cancer, referring to their incidence, the role of genetic factors, and how the primary malignancy and treatment received influence the type, site and prognosis of SMN's. The role of genetic factors will be discussed as far as they impact upon a predisposition to later development of SMN's. The primary malignancies that have important associations with SMN's will then be discussed, in particular Hodgkin's disease, retinoblastoma and acute lymphoblastic leukaemia. The important second malignancies will be highlighted, including tumours of the CNS and thyroid, osteosarcoma, secondary acute myeloid leukaemia and melanoma. Emphasis will be put upon identifying which patients are most likely to suffer from these tumours. An important part of the article are case histories. These are provided in combination with illustrations as a useful adjunct to the text, with a particular emphasis on radiological features, diagnosis and screening. Finally, the important but different roles of causal agents, in particular chemotherapy and radiotherapy are highlighted.
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Affiliation(s)
- J Moppett
- Department of Paediatric Oncology, Bristol Royal Hospital for Sick Children, St. Michael's Hill, BS2 8BJ, Bristol, UK
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Moppett J, Oakhill A, Duncan AW. Erratum to “Second malignancies in children: the usual suspects?”. Eur J Radiol 2001. [DOI: 10.1016/s0720-048x(01)00342-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Testican is a highly conserved, differentially expressed gene product of unknown function. Since testican is expressed by human endothelial cells and includes a signal sequence, it was our hypothesis that testican protein would be present in blood. We have developed chicken antibodies specific for testican sequence near the N-terminal and identified a 130-kDa form of testican in human plasma. This is much larger than the calculated molecular weight of the encoded polypeptide, suggesting glycosylation of this plasma protein, and large forms of recombinant testican produced in culture were found to include chondroitin sulfate. The 130-kDa form of testican is unstable in plasma. It is converted to smaller stable forms by separable plasma factors that can be blocked by certain serine protease inhibitors. Testican size conversion may be important in its functional activation or decay. One testican domain has strong homology to thyropin-type cysteine protease-inhibitors. Thus, testican may have a function related to protease inhibition in the blood.
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Affiliation(s)
- M A BaSalamah
- Pathology & Laboratory Medicine Department, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7525, USA
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46
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Abstract
OBJECTIVE Difficulties in measuring insulin sensitivity prevent the identification of insulin-resistant individuals in the general population. Therefore, we compared fasting insulin, homeostasis model assessment (HOMA), insulin-to-glucose ratio, Bennett index, and a score based on weighted combinations of fasting insulin, BMI, and fasting triglycerides with the euglycemic insulin clamp to determine the most appropriate method for assessing insulin resistance in the general population. RESEARCH DESIGN AND METHODS Family history of diabetes, BMI, blood pressure, waist and hip circumference, fasting lipids, glucose, insulin, liver enzymes, and insulin sensitivity index (ISI) using the euglycemic insulin clamp were obtained for 178 normoglycemic individuals aged 25-68 years. Product-moment correlations were used to examine the association between ISI and various surrogate measurements of insulin sensitivity. Regression models were used to devise weights for each variable and to identify cutoff points for individual components of the score. A bootstrap procedure was used to identify the most useful predictors of ISI. RESULTS Correlation coefficients between ISI and fasting insulin, HOMA, insulin-to-glucose ratio, and the Bennett index were similar in magnitude. The variables that best predicted insulin sensitivity were fasting insulin and fasting triglycerides. The use of a score based on Mffm/I = exp[2.63 - 0.28ln(insulin) - 0.31ln(TAG)] rather than the use of fasting insulin alone resulted in a higher sensitivity and a maintained specificity when predicting insulin sensitivity. CONCLUSIONS A weighted combination of two routine laboratory measurements, i.e., fasting insulin and triglycerides, provides a simple means of screening for insulin resistance in the general population.
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Affiliation(s)
- K A McAuley
- Department of Human Nutrition, Otago University, Dunedin, New Zealand.
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Affiliation(s)
- A W Duncan
- Department of Radiology, Bristol Royal Hospital for Sick Children, St. Michael's Hill, Bristol BS2 8BJ, UK
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48
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Abstract
The aim of this article is to provide an up to date review of second malignant neoplasms (SMN's) following treatment for childhood cancer, referring to their incidence, the role of genetic factors, and how the primary malignancy and treatment received influence the type, site and prognosis of SMN's. The role of genetic factors will be discussed as far as they impact upon a predisposition to later development of SMN's. The primary malignancies that have important associations with SMN's will then be discussed, in particular Hodgkin's disease, retinoblastoma and acute lymphoblastic leukaemia. The important second malignancies will be highlighted, including tumours of the CNS and thyroid, osteosarcoma, secondary acute myeloid leukaemia and melanoma. Emphasis will be put upon identifying which patients are most likely to suffer from these tumours. An important part of the article are case histories. These are provided in combination with illustrations as a useful adjunct to the text, with a particular emphasis on radiological features, diagnosis and screening. Finally, the important but different roles of causal agents, in particular chemotherapy and radiotherapy are highlighted.
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Affiliation(s)
- J Moppett
- Department of Paediatric Oncology, Bristol Royal Hospital for Sick Children, St. Michael's Hill, Bristol BS2 8BJ, UK
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Affiliation(s)
- A W Duncan
- Consultant Paediatric Radiologist Clinical Senior Lecturer in Paediatric Radiology University of Bristol Bristol Royal Hospital for Sick Children St. Michael's Hill BS2 8BJ, Bristol, UK
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Abstract
Testican is a putative extracellular heparan/ chondroitin sulfate proteoglycan of unknown function that is expressed in a variety of human tissues at widely different levels but is most abundant in the brain. In mice, testican mRNA has been detected only in brain and it is therefore likely to have an important function in the central nervous system. RNA blot analysis reveals the relative intensity of testican in various regions of the human brain. Levels of testican message are most pronounced in the thalamus, hippocampus, occipital lobe, nucleus accumbens, temporal lobe, and caudate nucleus, with somewhat lower levels in the cerebral cortex, medulla oblongata, frontal lobe, amygdala, putamen, spinal cord, substantia nigra, and cerebellum. In situ hybridization reveals the cellular distribution of the mRNA within these areas to be highest in neurons and in choroid plexus epithelium, and moderately lower in ependymal cells lining the ventricles and in vascular endothelial cells. Testican mRNA is not detected in oligodendrocytes or in most astrocytes. However, astrocytes in regions of reactive gliosis do express testican mRNA. These findings, along with a cysteine-rich pattern similarity to neurocan, brevican, versican, and other proteoglycans found in brain, suggest that testican may be a part of the specialized extracellular matrix of the brain.
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Affiliation(s)
- H S Marr
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 27599-7525, USA
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