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Ascanelli C, Dahir R, Wilson CH. Manipulating Myc for reparative regeneration. Front Cell Dev Biol 2024; 12:1357589. [PMID: 38577503 PMCID: PMC10991803 DOI: 10.3389/fcell.2024.1357589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/15/2024] [Indexed: 04/06/2024] Open
Abstract
The Myc family of proto-oncogenes is a key node for the signal transduction of external pro-proliferative signals to the cellular processes required for development, tissue homoeostasis maintenance, and regeneration across evolution. The tight regulation of Myc synthesis and activity is essential for restricting its oncogenic potential. In this review, we highlight the central role that Myc plays in regeneration across the animal kingdom (from Cnidaria to echinoderms to Chordata) and how Myc could be employed to unlock the regenerative potential of non-regenerative tissues in humans for therapeutic purposes. Mastering the fine balance of harnessing the ability of Myc to promote transcription without triggering oncogenesis may open the door to many exciting opportunities for therapeutic development across a wide array of diseases.
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Affiliation(s)
| | | | - Catherine H. Wilson
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
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Wei R, Teng Y, Han C, Wei S, Li L, Liu H, Hu S, Kang B, Xu H. Multi-omics reveals goose fatty liver formation from metabolic reprogramming. Front Vet Sci 2024; 11:1122904. [PMID: 38348107 PMCID: PMC10859500 DOI: 10.3389/fvets.2024.1122904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 01/08/2024] [Indexed: 02/15/2024] Open
Abstract
To comprehensively provide insight into goose fatty liver formation, we performed an integrative analysis of the liver transcriptome, lipidome, and amino acid metabolome, as well as peripheral adipose tissue transcriptome analysis using samples collected from the overfed geese and normally fed geese. Transcriptome analysis showed that liver metabolism pathways were mainly enriched in glucolipid metabolism, amino acid metabolism, inflammation response, and cell cycle; peripheral adipose tissue and the liver cooperatively regulated liver lipid accumulation during overfeeding. Liver lipidome patterns obviously changed after overfeeding, and 157 different lipids were yielded. In the liver amino acid metabolome, the level of Lys increased after overfeeding. In summary, this is the first study describing goose fatty liver formation from an integrative analysis of transcriptome, lipidome, and amino acid metabolome, which will provide a whole new dimension to understanding the mechanism of goose fatty liver formation.
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Affiliation(s)
- Rongxue Wei
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Yongqiang Teng
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Chunchun Han
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Shouhai Wei
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Liang Li
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Hehe Liu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Shenqiang Hu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Bo Kang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Hengyong Xu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Livestock and Poultry Multi-Omics, Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
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3
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Katz LS, Brill G, Wang P, Lambertini L, Zhang P, Haldeman JM, Liu H, Newgard CB, Stewart AF, Garcia-Ocaña A, Scott DK. Transcriptional activation of the Myc gene by glucose in β-cells requires a ChREBP-dependent 3-D chromatin interaction between the Myc and Pvt1 genes. Mol Metab 2024; 79:101848. [PMID: 38042369 PMCID: PMC10714240 DOI: 10.1016/j.molmet.2023.101848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 11/14/2023] [Accepted: 11/28/2023] [Indexed: 12/04/2023] Open
Abstract
OBJECTIVE All forms of diabetes result from insufficient functional β-cell mass. Thus, achieving the therapeutic goal of expanding β-cell mass requires a better mechanistic understanding of how β-cells proliferate. Glucose is a natural β-cell mitogen that mediates its effects in part through the glucose-responsive transcription factor, carbohydrate response element binding protein (ChREBP) and the anabolic transcription factor, MYC. However, mechanistic details by which glucose activates Myc at the transcriptional level are poorly understood. METHODS Here, siRNA was used to test the role of ChREBP in the glucose response of MYC, ChIP and ChIPseq to identify potential regulatory binding sites, chromatin conformation capture to identify DNA/DNA interactions, and an adenovirus was constructed to expresses x-dCas9 and an sgRNA that specifically disrupts the recruitment of ChREBP to a specific targeted ChoRE. RESULTS We found that ChREBP is essential for glucose-mediated transcriptional induction of Myc, and for increases in Myc mRNA and protein abundance. Further, ChIPseq revealed that the carbohydrate response element (ChoRE) nearest to the Myc transcriptional start site (TSS) is immediately upstream of the gene encoding the lncRNA, Pvt1, 60,000 bp downstream of the Myc gene. Chromatin Conformation Capture (3C) confirmed a glucose-dependent interaction between these two sites. Transduction with an adenovirus expressing x-dCas9 and an sgRNA specifically targeting the highly conserved Pvt1 ChoRE, attenuates ChREBP recruitment, decreases Myc-Pvt1 DNA/DNA interaction, and decreases expression of the Pvt1 and Myc genes in response to glucose. Importantly, isolated and dispersed rat islet cells transduced with the ChoRE-disrupting adenovirus also display specific decreases in ChREBP-dependent, glucose-mediated expression of Pvt1 and Myc, as well as decreased glucose-stimulated β-cell proliferation. CONCLUSIONS The mitogenic glucose response of Myc is mediated via glucose-dependent recruitment of ChREBP to the promoter of the Pvt1 gene and subsequent DNA looping with the Myc promoter.
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Affiliation(s)
- Liora S Katz
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA
| | - Gabriel Brill
- Pharmacologic Sciences Department, Stony Brook University, Stony Brook, NY, USA(5)
| | - Peng Wang
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA
| | - Luca Lambertini
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA
| | - Pili Zhang
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA
| | | | - Hongtao Liu
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA
| | | | - Andrew F Stewart
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA
| | - Adolfo Garcia-Ocaña
- Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope, 1500 E Duarte Rd, Duarte, CA 91010, USA
| | - Donald K Scott
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA.
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Krishnamurthy KA, Rutten MGS, Hoogerland JA, van Dijk TH, Bos T, Koehorst M, de Vries MP, Kloosterhuis NJ, Havinga H, Schomakers BV, van Weeghel M, Wolters JC, Bakker BM, Oosterveer MH. Hepatic ChREBP orchestrates intrahepatic carbohydrate metabolism to limit hepatic glucose 6-phosphate and glycogen accumulation in a mouse model for acute Glycogen Storage Disease type Ib. Mol Metab 2024; 79:101838. [PMID: 37995884 PMCID: PMC10716006 DOI: 10.1016/j.molmet.2023.101838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 11/13/2023] [Indexed: 11/25/2023] Open
Abstract
OBJECTIVE Carbohydrate Response Element Binding Protein (ChREBP) is a glucose 6-phosphate (G6P)-sensitive transcription factor that acts as a metabolic switch to maintain intracellular glucose and phosphate homeostasis. Hepatic ChREBP is well-known for its regulatory role in glycolysis, the pentose phosphate pathway, and de novo lipogenesis. The physiological role of ChREBP in hepatic glycogen metabolism and blood glucose regulation has not been assessed in detail, and ChREBP's contribution to carbohydrate flux adaptations in hepatic Glycogen Storage Disease type 1 (GSD I) requires further investigation. METHODS The current study aimed to investigate the role of ChREBP as a regulator of glycogen metabolism in response to hepatic G6P accumulation, using a model for acute hepatic GSD type Ib. The immediate biochemical and regulatory responses to hepatic G6P accumulation were evaluated upon G6P transporter inhibition by the chlorogenic acid S4048 in mice that were either treated with a short hairpin RNA (shRNA) directed against ChREBP (shChREBP) or a scrambled shRNA (shSCR). Complementary stable isotope experiments were performed to quantify hepatic carbohydrate fluxes in vivo. RESULTS ShChREBP treatment normalized the S4048-mediated induction of hepatic ChREBP target genes to levels observed in vehicle- and shSCR-treated controls. In parallel, hepatic shChREBP treatment in S4048-infused mice resulted in a more pronounced accumulation of hepatic glycogen and further reduction of blood glucose levels compared to shSCR treatment. Hepatic ChREBP knockdown modestly increased glucokinase (GCK) flux in S4048-treated mice while it enhanced UDP-glucose turnover as well as glycogen synthase and phosphorylase fluxes. Hepatic GCK mRNA and protein levels were induced by shChREBP treatment in both vehicle- and S4048-treated mice, while glycogen synthase 2 (GYS2) and glycogen phosphorylase (PYGL) mRNA and protein levels were reduced. Finally, knockdown of hepatic ChREBP expression reduced starch domain binding protein 1 (STBD1) mRNA and protein levels while it inhibited acid alpha-glucosidase (GAA) activity, suggesting reduced capacity for lysosomal glycogen breakdown. CONCLUSIONS Our data show that ChREBP activation controls hepatic glycogen and blood glucose levels in acute hepatic GSD Ib through concomitant regulation of glucose phosphorylation, glycogenesis, and glycogenolysis. ChREBP-mediated control of GCK enzyme levels aligns with corresponding adaptations in GCK flux. In contrast, ChREBP activation in response to acute hepatic GSD Ib exerts opposite effects on GYS2/PYGL enzyme levels and their corresponding fluxes, indicating that GYS2/PYGL expression levels are not limiting to their respective fluxes under these conditions.
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Affiliation(s)
- K A Krishnamurthy
- Laboratory of Pediatrics, University of Groningen, University Medical Center Groningen, The Netherlands
| | - M G S Rutten
- Laboratory of Pediatrics, University of Groningen, University Medical Center Groningen, The Netherlands
| | - J A Hoogerland
- Laboratory of Pediatrics, University of Groningen, University Medical Center Groningen, The Netherlands
| | - T H van Dijk
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, The Netherlands
| | - T Bos
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, The Netherlands
| | - M Koehorst
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, The Netherlands
| | - M P de Vries
- Laboratory of Pediatrics, University of Groningen, University Medical Center Groningen, The Netherlands; Interfaculty Mass Spectrometry Center, University of Groningen, University Medical Center Groningen, The Netherlands
| | - N J Kloosterhuis
- Laboratory of Pediatrics, University of Groningen, University Medical Center Groningen, The Netherlands
| | - H Havinga
- Laboratory of Pediatrics, University of Groningen, University Medical Center Groningen, The Netherlands
| | - B V Schomakers
- Laboratory Genetic Metabolic Diseases, UMC Amsterdam, The Netherlands; Core Facility Metabolomics, UMC Amsterdam, The Netherlands
| | - M van Weeghel
- Laboratory Genetic Metabolic Diseases, UMC Amsterdam, The Netherlands; Core Facility Metabolomics, UMC Amsterdam, The Netherlands
| | - J C Wolters
- Laboratory of Pediatrics, University of Groningen, University Medical Center Groningen, The Netherlands; Interfaculty Mass Spectrometry Center, University of Groningen, University Medical Center Groningen, The Netherlands
| | - B M Bakker
- Laboratory of Pediatrics, University of Groningen, University Medical Center Groningen, The Netherlands
| | - M H Oosterveer
- Laboratory of Pediatrics, University of Groningen, University Medical Center Groningen, The Netherlands; Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, The Netherlands.
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5
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Wang H, Stevens T, Lu J, Roberts A, Land CV, Muzumdar R, Gong Z, Vockley J, Prochownik EV. The Myc-Like Mlx Network Impacts Aging and Metabolism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.26.568749. [PMID: 38076995 PMCID: PMC10705233 DOI: 10.1101/2023.11.26.568749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
The "Mlx" and "Myc" Networks share many common gene targets. Just as Myc's activity depends upon its heterodimerization with Max, the Mlx Network requires that the Max-like factor Mlx associate with the Myc-like factors MondoA or ChREBP. We show here that body-wide Mlx inactivation, like that of Myc, accelerates numerous aging-related phenotypes pertaining to body habitus and metabolism. The deregulation of numerous aging-related Myc target gene sets is also accelerated. Among other functions, these gene sets often regulate ribosomal and mitochondrial structure and function, genomic stability and aging. Whereas "MycKO" mice have an extended lifespan because of a lower cancer incidence, "MlxKO" mice have normal lifespans and a somewhat higher cancer incidence. Like Myc, Mlx, MondoA and ChREBP expression and that of their target genes, deteriorate with age in both mice and humans, underscoring the importance of life-long and balanced cross-talk between the two Networks to maintain normal aging.
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Affiliation(s)
- Huabo Wang
- Division of Hematology/Oncology, UPMC Children’s Hospital of Pittsburgh
| | - Taylor Stevens
- Division of Hematology/Oncology, UPMC Children’s Hospital of Pittsburgh
| | - Jie Lu
- Division of Hematology/Oncology, UPMC Children’s Hospital of Pittsburgh
| | - Alexander Roberts
- Division of Hematology/Oncology, UPMC Children’s Hospital of Pittsburgh
| | | | - Radhika Muzumdar
- Division of Endocrinology, UPMC Children’s Hospital of Pittsburgh
| | - Zhenwei Gong
- Division of Endocrinology, UPMC Children’s Hospital of Pittsburgh
| | - Jerry Vockley
- Division of Medical Genetics, UPMC Children’s Hospital of Pittsburgh
| | - Edward V. Prochownik
- Division of Hematology/Oncology, UPMC Children’s Hospital of Pittsburgh
- The Department of Microbiology and Molecular Genetics, UPMC
- The Hillman Cancer Center of UPMC
- The Pittsburgh Liver Research Center, UPMC, Pittsburgh, PA. 15224
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6
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Wang H, Lu J, Stevens T, Roberts A, Mandel J, Avula R, Ma B, Wu Y, Wang J, Land CV, Finkel T, Vockley JE, Airik M, Airik R, Muzumdar R, Gong Z, Torbenson MS, Prochownik EV. Premature aging and reduced cancer incidence associated with near-complete body-wide Myc inactivation. Cell Rep 2023; 42:112830. [PMID: 37481724 PMCID: PMC10591215 DOI: 10.1016/j.celrep.2023.112830] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 05/18/2023] [Accepted: 07/03/2023] [Indexed: 07/25/2023] Open
Abstract
MYC proto-oncogene dysregulation alters metabolism, translation, and other functions in ways that support tumor induction and maintenance. Although Myc+/- mice are healthier and longer-lived than control mice, the long-term ramifications of more complete Myc loss remain unknown. We now describe the chronic consequences of body-wide Myc inactivation initiated postnatally. "MycKO" mice acquire numerous features of premature aging, including altered body composition and habitus, metabolic dysfunction, hepatic steatosis, and dysregulation of gene sets involved in functions that normally deteriorate with aging. Yet, MycKO mice have extended lifespans that correlate with a 3- to 4-fold lower lifetime cancer incidence. Aging tissues from normal mice and humans also downregulate Myc and gradually alter many of the same Myc target gene sets seen in MycKO mice. Normal aging and its associated cancer predisposition are thus highly linked via Myc.
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Affiliation(s)
- Huabo Wang
- Division of Hematology/Oncology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Jie Lu
- Division of Hematology/Oncology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Taylor Stevens
- Division of Hematology/Oncology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Alexander Roberts
- Division of Hematology/Oncology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Jordan Mandel
- Division of Hematology/Oncology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Raghunandan Avula
- Division of Hematology/Oncology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA; The University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Bingwei Ma
- Tongji University School of Medicine, Shanghai, China
| | - Yijen Wu
- Department of Developmental Biology, The University of Pittsburgh, Pittsburgh, PA, USA
| | - Jinglin Wang
- Division of Hematology/Oncology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA; Central South University, Xiangya School of Medicine, Changsha, Hunan 410013, P.R. China
| | - Clinton Van't Land
- Division of Medical Genetics, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Toren Finkel
- Division of Cardiology, The Department of Internal Medicine and the UPMC Aging Institute, Pittsburgh, PA 15224, USA
| | - Jerry E Vockley
- Division of Medical Genetics, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Merlin Airik
- Division of Nephrology, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Rannar Airik
- Division of Nephrology, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Radhika Muzumdar
- Division of Endocrinology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Zhenwei Gong
- Division of Endocrinology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Michel S Torbenson
- Division of Laboratory Medicine and Pathology, The Mayo Clinic, Rochester, MN 55905, USA
| | - Edward V Prochownik
- Division of Hematology/Oncology, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA; Department of Microbiology and Molecular Genetics, UPMC, Pittsburgh, PA 15261, USA; Hillman Cancer Center of UPMC, Pittsburgh, PA 15232, USA; Pittsburgh Liver Research Center, UPMC, Pittsburgh, PA 15261, USA.
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7
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Prochownik EV, Wang H. Lessons in aging from Myc knockout mouse models. Front Cell Dev Biol 2023; 11:1244321. [PMID: 37621775 PMCID: PMC10446843 DOI: 10.3389/fcell.2023.1244321] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 07/31/2023] [Indexed: 08/26/2023] Open
Abstract
Despite MYC being among the most intensively studied oncogenes, its role in normal development has not been determined as Myc-/- mice do not survival beyond mid-gestation. Myc ± mice live longer than their wild-type counterparts and are slower to accumulate many age-related phenotypes. However, Myc haplo-insufficiency likely conceals other important phenotypes as many high-affinity Myc targets genes continue to be regulated normally. By delaying Myc inactivation until after birth it has recently been possible to study the consequences of its near-complete total body loss and thus to infer its normal function. Against expectation, these "MycKO" mice lived significantly longer than control wild-type mice but manifested a marked premature aging phenotype. This seemingly paradoxical behavior was potentially explained by a >3-fold lower lifetime incidence of cancer, normally the most common cause of death in mice and often Myc-driven. Myc loss accelerated the accumulation of numerous "Aging Hallmarks", including the loss of mitochondrial and ribosomal structural and functional integrity, the generation of reactive oxygen species, the acquisition of genotoxic damage, the detrimental rewiring of metabolism and the onset of senescence. In both mice and humans, normal aging in many tissues was accompaniued by the downregulation of Myc and the loss of Myc target gene regulation. Unlike most mouse models of premature aging, which are based on monogenic disorders of DNA damage recognition and repair, the MycKO mouse model directly impacts most Aging Hallmarks and may therefore more faithfully replicate the normal aging process of both mice and humans. It further establishes that the strong association between aging and cancer can be genetically separated and is maintained by a single gene.
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Affiliation(s)
- Edward V. Prochownik
- Division of Hematology/Oncology, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, United States
- The Department of Microbiology and Molecular Genetics, UPMC, Pittsburgh, PA, United States
- The Hillman Cancer Center of UPMC, Pittsburgh, PA, United States
- The Pittsburgh Liver Research Center, UPMC, Pittsburgh, PA, United States
| | - Huabo Wang
- Division of Hematology/Oncology, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA, United States
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8
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Illi B, Nasi S. Myc beyond Cancer: Regulation of Mammalian Tissue Regeneration. PATHOPHYSIOLOGY 2023; 30:346-365. [PMID: 37606389 PMCID: PMC10443299 DOI: 10.3390/pathophysiology30030027] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/28/2023] [Accepted: 07/31/2023] [Indexed: 08/23/2023] Open
Abstract
Myc is one of the most well-known oncogenes driving tumorigenesis in a wide variety of tissues. From the brain to blood, its deregulation derails physiological pathways that grant the correct functioning of the cell. Its action is carried out at the gene expression level, where Myc governs basically every aspect of transcription. Indeed, in addition to its role as a canonical, chromatin-bound transcription factor, Myc rules RNA polymerase II (RNAPII) transcriptional pause-release, elongation and termination and mRNA capping. For this reason, it is evident that minimal perturbations of Myc function mirror malignant cell behavior and, consistently, a large body of literature mainly focuses on Myc malfunctioning. In healthy cells, Myc controls molecular mechanisms involved in pivotal functions, such as cell cycle (and proliferation thereof), apoptosis, metabolism and cell size, angiogenesis, differentiation and stem cell self-renewal. In this latter regard, Myc has been found to also regulate tissue regeneration, a hot topic in the research fields of aging and regenerative medicine. Indeed, Myc appears to have a role in wound healing, in peripheral nerves and in liver, pancreas and even heart recovery. Herein, we discuss the state of the art of Myc's role in tissue regeneration, giving an overview of its potent action beyond cancer.
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Affiliation(s)
- Barbara Illi
- Institute of Molecular Biology and Pathology, National Research Council, c/o Department of Biology and Biotechnology “Charles Darwin”, Sapienza University of Rome, 00185 Rome, Italy
| | - Sergio Nasi
- Institute of Molecular Biology and Pathology, National Research Council, c/o Department of Biology and Biotechnology “Charles Darwin”, Sapienza University of Rome, 00185 Rome, Italy
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9
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Wang H, Stevens T, Lu J, Airik M, Airik R, Prochownik EV. Disruption of Multiple Overlapping Functions Following Stepwise Inactivation of the Extended Myc Network. Cells 2022; 11:cells11244087. [PMID: 36552851 PMCID: PMC9777503 DOI: 10.3390/cells11244087] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022] Open
Abstract
Myc, a member of the "Myc Network" of bHLH-ZIP transcription factors, supervises proliferation, metabolism, and translation. It also engages in crosstalk with the related "Mlx Network" to co-regulate overlapping genes and functions. We investigated the consequences of stepwise conditional inactivation of Myc and Mlx in primary and SV40 T-antigen-immortalized murine embryonic fibroblasts (MEFs). Myc-knockout (MycKO) and Myc × Mlx "double KO" (DKO)-but not MlxKO-primary MEFs showed rapid growth arrest and displayed features of accelerated aging and senescence. However, DKO MEFs soon resumed proliferating, indicating that durable growth arrest requires an intact Mlx network. All three KO MEF groups deregulated multiple genes and functions pertaining to aging, senescence, and DNA damage recognition/repair. Immortalized KO MEFs proliferated in Myc's absence while demonstrating variable degrees of widespread genomic instability and sensitivity to genotoxic agents. Finally, compared to primary MycKO MEFs, DKO MEFs selectively downregulated numerous gene sets associated with the p53 and retinoblastoma (Rb) pathways and G2/M arrest. Thus, the reversal of primary MycKO MEF growth arrest by either Mlx loss or SV40 T-antigen immortalization appears to involve inactivation of the p53 and/or Rb pathways.
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Affiliation(s)
- Huabo Wang
- Division of Hematology/Oncology, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Taylor Stevens
- Division of Hematology/Oncology, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Jie Lu
- Division of Hematology/Oncology, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Merlin Airik
- Division of Nephrology, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
| | - Rannar Airik
- Division of Nephrology, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
- Department of Developmental Biology, The University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Edward V. Prochownik
- Division of Hematology/Oncology, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, PA 15224, USA
- The Department of Microbiology and Molecular Genetics, The University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA
- The UPMC Hillman Comprehensive Cancer Center, Pittsburgh, PA 25232, USA
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Correspondence: ; Tel.: +1-412-692-6795
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10
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Regulation of Normal and Neoplastic Proliferation and Metabolism by the Extended Myc Network. Cells 2022; 11:cells11243974. [PMID: 36552737 PMCID: PMC9777120 DOI: 10.3390/cells11243974] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 11/30/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022] Open
Abstract
The Myc Network, comprising a small assemblage of bHLH-ZIP transcription factors, regulates many hundreds to thousands of genes involved in proliferation, energy metabolism, translation and other activities. A structurally and functionally related set of factors known as the Mlx Network also supervises some of these same functions via the regulation of a more limited but overlapping transcriptional repertoire. Target gene co-regulation by these two Networks is the result of their sharing of three members that suppress target gene expression as well as by the ability of both Network's members to cross-bind one another's consensus DNA sites. The two Networks also differ in that the Mlx Network's control over transcription is positively regulated by several glycolytic pathway intermediates and other metabolites. These distinctive properties, functions and tissue expression patterns potentially allow for sensitive control of gene regulation in ways that are differentially responsive to environmental and metabolic cues while allowing for them to be both rapid and of limited duration. This review explores how such control might occur. It further discusses how the actual functional dependencies of the Myc and Mlx Networks rely upon cellular context and how they may differ between normal and neoplastic cells. Finally, consideration is given to how future studies may permit a more refined understanding of the functional interrelationships between the two Networks.
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