1
|
Fidler E, Dwyer K, Ansari A. Ssu72: a versatile protein with functions in transcription and beyond. Front Mol Biosci 2024; 11:1332878. [PMID: 38304578 PMCID: PMC10830811 DOI: 10.3389/fmolb.2024.1332878] [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: 11/03/2023] [Accepted: 01/08/2024] [Indexed: 02/03/2024] Open
Abstract
Eukaryotic transcription is a complex process involving a vast network of protein and RNA factors that influence gene expression. The main player in transcription is the RNA polymerase that synthesizes the RNA from the DNA template. RNA polymerase II (RNAPII) transcribes all protein coding genes and some noncoding RNAs in eukaryotic cells. The polymerase is aided by interacting partners that shuttle it along the gene for initiation, elongation and termination of transcription. One of the many factors that assist RNAPII in transcription of genes is Ssu72. It is a carboxy-terminal-domain (CTD)-phosphatase that plays pleiotropic roles in the transcription cycle. It is essential for cell viability in Saccharomyces cerevisiae, the organism in which it was discovered. The homologues of Ssu72 have been identified in humans, mice, plants, flies, and fungi thereby suggesting the evolutionarily conserved nature of the protein. Recent studies have implicated the factor beyond the confines of transcription in homeostasis and diseases.
Collapse
Affiliation(s)
| | | | - Athar Ansari
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
| |
Collapse
|
2
|
Romualdo GR, Heidor R, Bacil GP, Moreno FS, Barbisan LF. Past, present, and future of chemically induced hepatocarcinogenesis rodent models: Perspectives concerning classic and new cancer hallmarks. Life Sci 2023; 330:121994. [PMID: 37543357 DOI: 10.1016/j.lfs.2023.121994] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/25/2023] [Accepted: 07/29/2023] [Indexed: 08/07/2023]
Abstract
Hepatocellular carcinoma (HCC), the main primary liver cancer, accounts for 5 % of all incident cases and 8.4 % of all cancer-related deaths worldwide. HCC displays a spectrum of environmental risk factors (viral chronic infections, aflatoxin exposure, alcoholic- and nonalcoholic fatty liver diseases) that result in molecular complexity and heterogeneity, contributing to a rising epidemiological burden, poor prognosis, and non-satisfactory treatment options. The emergence of HCC (i.e., hepatocarcinogenesis) is a multistep and complex process that addresses many (epi)genetic alterations and phenotypic traits, the so-called cancer hallmarks. "Polymorphic microbiomes", "epigenetic reprogramming", "senescent cells" and "unlocking phenotypic plasticity" are trending hallmarks/enabling features in cancer biology. As the main molecular drivers of HCC are still undruggable, chemically induced in vivo models of hepatocarcinogenesis are useful tools in preclinical research. Thus, this narrative review aimed at recapitulating the basic features of chemically induced rodent models of hepatocarcinogenesis, eliciting their permanent translational value regarding the "classic" and the "new" cancer hallmarks/enabling features. We gathered state-of-art preclinical evidence on non-cirrhotic, inflammation-, alcoholic liver disease- and nonalcoholic fatty liver-associated HCC models, demonstrating that these bioassays indeed express the recently added hallmarks, as well as reflect the interplay between classical and new cancer traits. Our review demonstrated that these protocols remain valuable for translational preclinical application, as they recapitulate trending features of cancer science. Further "omics-based" approaches are warranted while multimodel investigations are encouraged in order to avoid "model-biased" responses.
Collapse
Affiliation(s)
- Guilherme Ribeiro Romualdo
- São Paulo State University (UNESP), Botucatu Medical School, Experimental Research Unit (UNIPEX), Multimodel Drug Screening Platform - Laboratory of Chemically Induced and Experimental Carcinogenesis (MDSP-LCQE), Botucatu, SP, Brazil; São Paulo State University (UNESP), Biosciences Institute, Department of Structural and Functional Biology, Laboratory of Chemically Induced and Experimental Carcinogenesis (LCQE), Botucatu, SP, Brazil; São Paulo State University (UNESP), Botucatu Medical School, Botucatu, SP, Brazil
| | - Renato Heidor
- University of São Paulo (USP), Faculty of Pharmaceutical Sciences, Department of Food and Experimental Nutrition, Laboratory of Diet, Nutrition, and Cancer, São Paulo, SP, Brazil
| | - Gabriel Prata Bacil
- São Paulo State University (UNESP), Biosciences Institute, Department of Structural and Functional Biology, Laboratory of Chemically Induced and Experimental Carcinogenesis (LCQE), Botucatu, SP, Brazil; São Paulo State University (UNESP), Botucatu Medical School, Botucatu, SP, Brazil
| | - Fernando Salvador Moreno
- University of São Paulo (USP), Faculty of Pharmaceutical Sciences, Department of Food and Experimental Nutrition, Laboratory of Diet, Nutrition, and Cancer, São Paulo, SP, Brazil
| | - Luís Fernando Barbisan
- São Paulo State University (UNESP), Botucatu Medical School, Experimental Research Unit (UNIPEX), Multimodel Drug Screening Platform - Laboratory of Chemically Induced and Experimental Carcinogenesis (MDSP-LCQE), Botucatu, SP, Brazil; São Paulo State University (UNESP), Biosciences Institute, Department of Structural and Functional Biology, Laboratory of Chemically Induced and Experimental Carcinogenesis (LCQE), Botucatu, SP, Brazil; São Paulo State University (UNESP), Botucatu Medical School, Botucatu, SP, Brazil.
| |
Collapse
|
3
|
Nie T, Lu J, Zhang H, Mao L. Latest advances in the regulatory genes of adipocyte thermogenesis. Front Endocrinol (Lausanne) 2023; 14:1250487. [PMID: 37680891 PMCID: PMC10482227 DOI: 10.3389/fendo.2023.1250487] [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: 06/30/2023] [Accepted: 08/07/2023] [Indexed: 09/09/2023] Open
Abstract
An energy imbalance cause obesity: more energy intake or less energy expenditure, or both. Obesity could be the origin of many metabolic disorders, such as type 2 diabetes and cardiovascular disease. UCP1 (uncoupling protein1), which is highly and exclusively expressed in the thermogenic adipocytes, including beige and brown adipocytes, can dissipate proton motive force into heat without producing ATP to increase energy expenditure. It is an attractive strategy to combat obesity and its related metabolic disorders by increasing non-shivering adipocyte thermogenesis. Adipocyte thermogenesis has recently been reported to be regulated by several new genes. This work provided novel and potential targets to activate adipocyte thermogenesis and resist obesity, such as secreted proteins ADISSP and EMC10, enzyme SSU72, etc. In this review, we have summarized the latest research on adipocyte thermogenesis regulation to shed more light on this topic.
Collapse
Affiliation(s)
- Tao Nie
- School of Basic Medicine, Hubei University of Arts and Science, Xiangyang, China
| | - Jinli Lu
- Scientific Research Center, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, China
| | - Hua Zhang
- Department of Medical Iconography, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Liufeng Mao
- Scientific Research Center, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, China
| |
Collapse
|
4
|
Kim MH, Lee CW. Phosphatase Ssu72 Is Essential for Homeostatic Balance Between CD4 + T Cell Lineages. Immune Netw 2023; 23:e12. [PMID: 37179750 PMCID: PMC10166661 DOI: 10.4110/in.2023.23.e12] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 12/01/2022] [Accepted: 12/21/2022] [Indexed: 05/15/2023] Open
Abstract
Ssu72, a dual-specificity protein phosphatase, not only participates in transcription biogenesis, but also affects pathophysiological functions in a tissue-specific manner. Recently, it has been shown that Ssu72 is required for T cell differentiation and function by controlling multiple immune receptor-mediated signals, including TCR and several cytokine receptor signaling pathways. Ssu72 deficiency in T cells is associated with impaired fine-tuning of receptor-mediated signaling and a defect in CD4+ T cell homeostasis, resulting in immune-mediated diseases. However, the mechanism by which Ssu72 in T cells integrates the pathophysiology of multiple immune-mediated diseases is still poorly elucidated. In this review, we will focus on the immunoregulatory mechanism of Ssu72 phosphatase in CD4+ T cell differentiation, activation, and phenotypic function. We will also discuss the current understanding of the correlation between Ssu72 in T cells and pathological functions which suggests that Ssu72 might be a therapeutic target in autoimmune disorders and other diseases.
Collapse
Affiliation(s)
- Min-Hee Kim
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon 16419, Korea
| | - Chang-Woo Lee
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon 16419, Korea
- SKKU Institute for Convergence, Sungkyunkwan University, Suwon 16419, Korea
| |
Collapse
|
5
|
Ssu72 phosphatase is essential for thermogenic adaptation by regulating cytosolic translation. Nat Commun 2023; 14:1097. [PMID: 36841836 PMCID: PMC9968297 DOI: 10.1038/s41467-023-36836-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 02/20/2023] [Indexed: 02/27/2023] Open
Abstract
Brown adipose tissue (BAT) plays a pivotal role in maintaining body temperature and energy homeostasis. BAT dysfunction is associated with impaired metabolic health. Here, we show that Ssu72 phosphatase is essential for mRNA translation of genes required for thermogenesis in BAT. Ssu72 is found to be highly expressed in BAT among adipose tissue depots, and the expression level of Ssu72 is increased upon acute cold exposure. Mice lacking adipocyte Ssu72 exhibit cold intolerance during acute cold exposure. Mechanistically, Ssu72 deficiency alters cytosolic mRNA translation program through hyperphosphorylation of eIF2α and reduces translation of mitochondrial oxidative phosphorylation (OXPHOS) subunits, resulting in mitochondrial dysfunction and defective thermogenesis in BAT. In addition, metabolic dysfunction in Ssu72-deficient BAT returns to almost normal after restoring Ssu72 expression. In summary, our findings demonstrate that cold-responsive Ssu72 phosphatase is involved in cytosolic translation of key thermogenic effectors via dephosphorylation of eIF2α in brown adipocytes, providing insights into metabolic benefits of Ssu72.
Collapse
|
6
|
Yoon JS, Lee CW. Protein phosphatases regulate the liver microenvironment in the development of hepatocellular carcinoma. Exp Mol Med 2022; 54:1799-1813. [PMID: 36380016 PMCID: PMC9722691 DOI: 10.1038/s12276-022-00883-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 08/31/2022] [Accepted: 09/01/2022] [Indexed: 11/16/2022] Open
Abstract
The liver is a complicated heterogeneous organ composed of different cells. Parenchymal cells called hepatocytes and various nonparenchymal cells, including immune cells and stromal cells, are distributed in liver lobules with hepatic architecture. They interact with each other to compose the liver microenvironment and determine its characteristics. Although the liver microenvironment maintains liver homeostasis and function under healthy conditions, it also shows proinflammatory and profibrogenic characteristics that can induce the progression of hepatitis and hepatic fibrosis, eventually changing to a protumoral microenvironment that contributes to the development of hepatocellular carcinoma (HCC). According to recent studies, phosphatases are involved in liver diseases and HCC development by regulating protein phosphorylation in intracellular signaling pathways and changing the activities and characteristics of liver cells. Therefore, this review aims to highlight the importance of protein phosphatases in HCC development and in the regulation of the cellular components in the liver microenvironment and to show their significance as therapeutic targets.
Collapse
Affiliation(s)
- Joon-Sup Yoon
- grid.264381.a0000 0001 2181 989XDepartment of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, 16419 Republic of Korea
| | - Chang-Woo Lee
- grid.264381.a0000 0001 2181 989XDepartment of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, 16419 Republic of Korea ,grid.264381.a0000 0001 2181 989XDepartment of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, 06351 Republic of Korea
| |
Collapse
|
7
|
Kim JY, Choi H, Kim HJ, Jee Y, Noh M, Lee MO. Polyploidization of Hepatocytes: Insights into the Pathogenesis of Liver Diseases. Biomol Ther (Seoul) 2022; 30:391-398. [PMID: 35790893 PMCID: PMC9424332 DOI: 10.4062/biomolther.2022.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 05/27/2022] [Accepted: 05/28/2022] [Indexed: 11/26/2022] Open
Abstract
Polyploidization is a process by which cells are induced to possess more than two sets of chromosomes. Although polyploidization is not frequent in mammals, it is closely associated with development and differentiation of specific tissues and organs. The liver is one of the mammalian organs that displays ploidy dynamics in physiological homeostasis during its development. The ratio of polyploid hepatocytes increases significantly in response to hepatic injury from aging, viral infection, iron overload, surgical resection, or metabolic overload, such as that from non-alcoholic fatty liver diseases (NAFLDs). One of the unique features of NAFLD is the marked heterogeneity of hepatocyte nuclear size, which is strongly associated with an adverse liver-related outcome, such as hepatocellular carcinoma, liver transplantation, and liver-related death. Thus, hepatic polyploidization has been suggested as a potential driver in the progression of NAFLDs that are involved in the control of the multiple pathogenicity of the diseases. However, the importance of polyploidy in diverse pathophysiological contexts remains elusive. Recently, several studies reported successful improvement of symptoms of NAFLDs by reducing pathological polyploidy or by controlling cell cycle progression in animal models, suggesting that better understanding the mechanisms of pathological hepatic polyploidy may provide insights into the treatment of hepatic disorders.
Collapse
Affiliation(s)
- Ju-Yeon Kim
- College of Pharmacy, Seoul National University, Seoul 00826, Republic of Korea
| | - Haena Choi
- College of Pharmacy, Seoul National University, Seoul 00826, Republic of Korea
| | - Hyeon-Ji Kim
- College of Pharmacy, Seoul National University, Seoul 00826, Republic of Korea
- Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 00826, Republic of Korea
| | - Yelin Jee
- College of Pharmacy, Seoul National University, Seoul 00826, Republic of Korea
| | - Minsoo Noh
- College of Pharmacy, Seoul National University, Seoul 00826, Republic of Korea
- Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 00826, Republic of Korea
| | - Mi-Ock Lee
- College of Pharmacy, Seoul National University, Seoul 00826, Republic of Korea
- Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 00826, Republic of Korea
- Bio-MAX institute, Seoul National University, Seoul 08826, Republic of Korea
| |
Collapse
|
8
|
Kim HS, Yoon JS, Jeon Y, Park EJ, Lee JK, Chen S, Lee H, Park JY, Go H, Lee CW. Ssu72-HNF4α signaling axis classify the transition from steatohepatitis to hepatocellular carcinoma. Cell Death Differ 2022; 29:600-613. [PMID: 34616001 PMCID: PMC8901687 DOI: 10.1038/s41418-021-00877-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 09/08/2021] [Accepted: 09/15/2021] [Indexed: 11/09/2022] Open
Abstract
Growing evidence suggests a mechanistic link between steatohepatitis and hepatocellular carcinoma (HCC). However, the lack of representative animal models hampers efforts to understand pathophysiological mechanisms underlying steatohepatitis-related HCC. We found that liver-specific deletion of Ssu72 phosphatase in mice, leads to a high incidence of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis, but not HCC. However, loss of Ssu72 drastically increased the probability of HCC developing, as well as the population of hepatic progenitors, in various chemical and metabolic syndrome-induced HCC models. Importantly, hepatic Ssu72 loss resulted in the induction of mature hepatocyte-to-progenitor cell conversion, by dedifferentiation orchestrated by Ssu72-mediated hypo-phosphorylation of hepatocyte nuclear factor 4α (HNF4α), a master regulator of hepatocyte function. Our findings suggest that Ssu72-mediated HNF4α transcription contributes to the progression of steatohepatitis-associated HCC by regulating the dedifferentiation potential of hepatocytes. Thus, targeting the Ssu72-mediated HNF4α signaling that underlies the pathogenesis of steatohepatitis-associated HCC development could be a novel therapeutic intervention for steatohepatitis-associated HCC.
Collapse
Affiliation(s)
- Hyun-Soo Kim
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, South Korea.
| | - Joon-Sup Yoon
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Yoon Jeon
- Research Institute, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang, South Korea
| | - Eun-Ji Park
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Jin-Kwan Lee
- Research Institute, Curogen Technology, Suwon, South Korea
| | - Si Chen
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Ho Lee
- Research Institute, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang, South Korea
| | - Jee Young Park
- Department of Pathology, Kyungpook National University Medical Center, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Heounjeong Go
- Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Chang-Woo Lee
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, South Korea.
- Research Institute, Curogen Technology, Suwon, South Korea.
| |
Collapse
|
9
|
Kim JY, Yang IS, Kim HJ, Yoon JY, Han YH, Seong JK, Lee MO. RORα contributes to the maintenance of genome ploidy in the liver of mice with diet-induced nonalcoholic steatohepatitis. Am J Physiol Endocrinol Metab 2022; 322:E118-E131. [PMID: 34894722 DOI: 10.1152/ajpendo.00309.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Hepatic polyploidization is closely linked to the progression of nonalcoholic fatty liver disease (NAFLD); however, the underlying molecular mechanism is not clearly understood. In this study, we demonstrated the role of retinoic acid-related orphan receptor α (RORα) in the maintenance of genomic integrity, particularly in the pathogenesis of NAFLD, using the high-fat diet (HFD)-fed liver-specific RORα knockout (RORα-LKO) mouse model. First, we observed that the loss of hepatic retinoic acid receptor-related orphan receptor α (RORα) accelerated hepatocyte nuclear polyploidization after HFD feeding. In 70% partial hepatectomy experiments, enrichment of hepatocyte polyploidy was more obvious in the RORα-LKO animals, which was accompanied by early progression to the S phase and blockade of the G2/M transition, suggesting a potential role of RORα in suppressing hepatocyte polyploidization in the regenerating liver. An analysis of a publicly available RNA sequencing (RNA-seq) and chromatin immunoprecipitation-seq dataset, together with the Search Tool of the Retrieval of Interacting Genes/Proteins database resource, revealed that DNA endoreplication was the top-enriched biological process Gene Ontology term. Furthermore, we found that E2f7 and E2f8, which encode key transcription factors for DNA endoreplication, were the downstream targets of RORα-induced transcriptional repression. Finally, we showed that the administration of JC1-40, an RORα activator (5 mg/kg body wt), significantly reduced hepatic nuclear polyploidization in the HFD-fed mice. Together, our observations suggest that the RORα-induced suppression of hepatic polyploidization may provide new insights into the pathological polyploidy of NAFLD and may contribute to the development of therapeutic strategies for the treatment of NAFLD.NEW & NOTEWORTHY It has been reported that hepatic polyploidization is closely linked to the progression of NAFLD. Here, we showed that the genetic depletion of hepatic RORα in mice accelerated hepatocyte polyploidization after high-fat diet feeding. The mechanism could be the RORα-mediated repression of E2f7 and E2f8, key transcription factors for DNA endoreplication. Thus, preservation of genome integrity by RORα could provide a new insight for developing therapeutics against the disease.
Collapse
Affiliation(s)
- Ju-Yeon Kim
- College of Pharmacy, Seoul National University, Seoul, South Korea
| | - In Sook Yang
- College of Veterinary Medicine, Seoul National University, Seoul, South Korea
| | - Hyeon-Ji Kim
- College of Pharmacy, Seoul National University, Seoul, South Korea
- Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, South Korea
| | - Jae-Yeun Yoon
- College of Pharmacy, Seoul National University, Seoul, South Korea
| | - Yong-Hyun Han
- College of Pharmacy, Kangwon National University, Chuncheon, South Korea
| | - Je Kyung Seong
- College of Veterinary Medicine, Seoul National University, Seoul, South Korea
- Research Institute of Veterinary Science, Seoul National University, Seoul, South Korea
- Korea Mouse Phenotyping Center, Seoul National University, Seoul, South Korea
| | - Mi-Ock Lee
- College of Pharmacy, Seoul National University, Seoul, South Korea
- Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, South Korea
- Bio-MAX Institute, Seoul National University, Seoul, South Korea
- Korea Mouse Phenotyping Center, Seoul National University, Seoul, South Korea
| |
Collapse
|
10
|
Lee JK, Koo SY, Nam HM, Lee JB, Ko J, Kim KM, Park EJ, Kim TJ, Lee H, Go H, Lee CW. Ssu72 is a T-cell receptor-responsive modifier that is indispensable for regulatory T cells. Cell Mol Immunol 2021; 18:1395-1411. [PMID: 33850312 PMCID: PMC8166877 DOI: 10.1038/s41423-021-00671-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 03/03/2021] [Indexed: 12/11/2022] Open
Abstract
The homeostatic balance between effector T cells and regulatory T cells (Tregs) is crucial for adaptive immunity; however, epigenetic programs that inhibit phosphorylation to regulate Treg development, peripheral expression, and suppressive activity are elusive. Here, we found that the Ssu72 phosphatase is activated by various T-cell receptor signaling pathways, including the T-cell receptor and IL-2R pathways, and localizes at the cell membrane. Deletion of Ssu72 in T cells disrupts CD4+ T-cell differentiation into Tregs in the periphery via the production of high levels of the effector cytokines IL-2 and IFNγ, which induce CD4+ T-cell activation and differentiation into effector cell lineages. We also found a close correlation between downregulation of Ssu72 and severe defects in mucosal tolerance in patients. Interestingly, Ssu72 forms a complex with PLCγ1, which is an essential effector molecule for T-cell receptor signaling as well as Treg development and function. Ssu72 deficiency impairs PLCγ1 downstream signaling and results in failure of Foxp3 induction. Thus, our studies show that the Ssu72-mediated cytokine response coordinates the differentiation and function of Treg cells in the periphery.
Collapse
Affiliation(s)
- Jin-Kwan Lee
- Research Institute, Curogen Technology, Suwon, South Korea
| | - Seo-Young Koo
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Hye-Mi Nam
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, South Korea
- MOGAM Institute for Biomedical Research, Gyeonggi, South Korea
| | - Jee-Boong Lee
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Jiwon Ko
- Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
- Asan Institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Kyung-Mo Kim
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Eun-Ji Park
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Tae Jin Kim
- Department of Immunology, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Ho Lee
- Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy, Research Institute, National Cancer Center, Gyeonggi, South Korea.
| | - Heounjeong Go
- Asan Institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
| | - Chang-Woo Lee
- Research Institute, Curogen Technology, Suwon, South Korea.
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon, South Korea.
| |
Collapse
|
11
|
Hwang S, Kim MH, Lee CW. Ssu72 Dual-Specific Protein Phosphatase: From Gene to Diseases. Int J Mol Sci 2021; 22:3791. [PMID: 33917542 PMCID: PMC8038829 DOI: 10.3390/ijms22073791] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 12/22/2022] Open
Abstract
More than 70% of eukaryotic proteins are regulated by phosphorylation. However, the mechanism of dephosphorylation that counteracts phosphorylation is less studied. Phosphatases are classified into 104 distinct groups based on substrate-specific features and the sequence homologies in their catalytic domains. Among them, dual-specificity phosphatases (DUSPs) that dephosphorylate both phosphoserine/threonine and phosphotyrosine are important for cellular homeostasis. Ssu72 is a newly studied phosphatase with dual specificity that can dephosphorylate both phosphoserine/threonine and phosphotyrosine. It is important for cell-growth signaling, metabolism, and immune activation. Ssu72 was initially identified as a phosphatase for the Ser5 and Ser7 residues of the C-terminal domain of RNA polymerase II. It prefers the cis configuration of the serine-proline motif within its substrate and regulates Pin1, different from other phosphatases. It has recently been reported that Ssu72 can regulate sister chromatid cohesion and the separation of duplicated chromosomes during the cell cycle. Furthermore, Ssu72 appears to be involved in the regulation of T cell receptor signaling, telomere regulation, and even hepatocyte homeostasis in response to a variety of stress and damage signals. In this review, we aim to summarize various functions of the Ssu72 phosphatase, their implications in diseases, and potential therapeutic indications.
Collapse
Affiliation(s)
- Soeun Hwang
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon 16419, Korea; (S.H.); (M.-H.K.)
| | - Min-Hee Kim
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon 16419, Korea; (S.H.); (M.-H.K.)
| | - Chang-Woo Lee
- Department of Molecular Cell Biology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Suwon 16419, Korea; (S.H.); (M.-H.K.)
- SKKU Institute for Convergence, Sungkyunkwan University, Suwon 16419, Korea
- Curogen Technology, Suwon 16419, Korea
| |
Collapse
|
12
|
Liu C, Zhang W, Xing W. Diverse and conserved roles of the protein Ssu72 in eukaryotes: from yeast to higher organisms. Curr Genet 2020; 67:195-206. [PMID: 33244642 DOI: 10.1007/s00294-020-01132-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 11/04/2020] [Accepted: 11/06/2020] [Indexed: 01/21/2023]
Abstract
Gene transcription is a complex biological process that involves a set of factors, enzymes and nucleotides. Ssu72 plays a crucial role in every step of gene transcription. RNA polymerase II (RNAPII) occupies an important position in the synthesis of mRNAs. The largest subunit of RNAPII, Rpb1, harbors its C-terminal domain (CTD), which participates in the initiation, elongation and termination of transcription. The CTD consists of heptad repeats of the consensus motif Tyr1-Ser2-Pro3-Thr4-Ser5-Pro6-Ser7 and is highly conserved among different species. The CTD is flexible in structure and undergoes conformational changes in response to serine phosphorylation and proline isomerization, which are regulated by specific kinases/phosphatases and isomerases, respectively. Ssu72 is a CTD phosphatase with catalytic activity against phosphorylated Ser5 and Ser7. The isomerization of Pro6 affects the binding of Ssu72 to its substrate. Ssu72 can also indirectly change the phosphorylation status of Ser2. In addition, Ssu72 is a member of the 3'-end cleavage and polyadenylation factor (CPF) complex. Together with other CPF components, Ssu72 regulates the 3'-end processing of premature mRNA. Recent studies have revealed other roles of Ssu72, including its roles in balancing phosphate homeostasis and controlling chromosome behaviors, which should be further explored. In conclusion, the protein Ssu72 is an enzyme worthy of attention, not confined to its role in gene transcription.
Collapse
Affiliation(s)
- Changfu Liu
- Department of Interventional Treatment, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China
| | - Weihao Zhang
- Department of Interventional Treatment, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China
| | - Wenge Xing
- Department of Interventional Treatment, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China.
| |
Collapse
|
13
|
Abstract
Polyploidy (or whole-genome duplication) is the condition of having more than two basic sets of chromosomes. Polyploidization is well tolerated in many species and can lead to specific biological functions. In mammals, programmed polyploidization takes place during development in certain tissues, such as the heart and placenta, and is considered a feature of differentiation. However, unscheduled polyploidization can cause genomic instability and has been observed in pathological conditions, such as cancer. Polyploidy of the liver parenchyma was first described more than 100 years ago. The liver is one of the few mammalian organs that display changes in polyploidy during homeostasis, regeneration and in response to damage. In the human liver, approximately 30% of hepatocytes are polyploid. The polyploidy of hepatocytes results from both nuclear polyploidy (an increase in the amount of DNA per nucleus) and cellular polyploidy (an increase in the number of nuclei per cell). In this Review, we discuss the regulation of polyploidy in liver development and pathophysiology. We also provide an overview of current knowledge about the mechanisms of hepatocyte polyploidization, its biological importance and the fate of polyploid hepatocytes during liver tumorigenesis.
Collapse
|
14
|
Song L, Zhang JG, Zheng L, Feng X, Hou J, Zhang HL, Liu SF. Establishment of rat liver cancer cell lines with different metastatic potential. Sci Rep 2020; 10:8329. [PMID: 32433581 PMCID: PMC7239898 DOI: 10.1038/s41598-020-65338-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/23/2020] [Indexed: 12/28/2022] Open
Abstract
The gloomy outcome of liver cancer is mainly due to the high rates of metastasis and recurrence, even after curative resection for early stage liver cancer. Our study was conducted to find the animal model suitable for the study of liver cancer metastasis. In our study, two liver cancer cells were obtained from N-nitrosodiethylamine (DEN) and N-nitrosomorpholine (NMOR) induced rats, and they were cultivated, screened and cloning cultivated. Bionomics of cells was analyzed. The results show that 2 cells had different metastatic potentiality. They were named Wrh-f2 and Wrh-s2, and they have the characteristics of Hepatocellular carcinoma cells. The bionomics of 2 cells showed: (1) The chromosome karyotype analysis showed that the mode of Wrh-f2 was 80–83 and Wrh-s2 was 55–57; (2) AFP positive cytoplasmic staining was observed in Wrh-f2 and Wrh-s2. Cytokeratin (CK) 7 and CK8 positive staining was present in Wrh-f2. CK8 positive staining was present in Wrh-s2; (3) The numbers of Wrh-f2 and Wrh-s2 that passed through the Transwells were 98 ± 12 and 55 ± 15;(4) Wrh-f2 had the significant higher colony formation (78%) than Wrh-s2(8%) (P < 0.01). (5) The animal models generated solid tumours when 2 cells were inoculated to nude mouse and rat. And Wrh-f2 developed stable pulmonary metastasis. The established cell lines with different metastatic potential showed obvious advantages over liver cancer in mimicking the biological properties of malignant liver cancer tumors. It provided a suitable model for the mechanism of liver cancer metastasis in vivo and in vitro.
Collapse
Affiliation(s)
- Lei Song
- Department of Laboratory Animal Science of Hebei Medical University, Heibei Key Laboratory of Laboratory Animals, Shijiazhuang, 050017, Hebei, China.,Institute of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin, 300193, China
| | - Jian-Gang Zhang
- Department of Pathology, The Third Hospital of Xingtai, Xingtai, 054000, Hebei, China
| | - Long Zheng
- Department of Laboratory Animal Science of Hebei Medical University, Heibei Key Laboratory of Laboratory Animals, Shijiazhuang, 050017, Hebei, China
| | - Xu Feng
- Department of Laboratory Animal Science of Hebei Medical University, Heibei Key Laboratory of Laboratory Animals, Shijiazhuang, 050017, Hebei, China
| | - Jie Hou
- Department of Laboratory Animal Science of Hebei Medical University, Heibei Key Laboratory of Laboratory Animals, Shijiazhuang, 050017, Hebei, China
| | - Huan-Ling Zhang
- Department of Laboratory Animal Science of Hebei Medical University, Heibei Key Laboratory of Laboratory Animals, Shijiazhuang, 050017, Hebei, China.
| | - Shu-Feng Liu
- Department of Laboratory Animal Science of Hebei Medical University, Heibei Key Laboratory of Laboratory Animals, Shijiazhuang, 050017, Hebei, China.
| |
Collapse
|
15
|
Abstract
Polyploid cells contain more than two homologous sets of chromosomes. The original observations of liver polyploidy date back to the 1940s, but functional roles for polyploid cells are still unclear. Liver polyploidy may influence regeneration, stress response, and cancer, although little evidence has established direct causal links between polyploidy and these biological phenotypes. In this review, we will introduce broad concepts about polyploidy including its distribution in nature and how polyploids form in normal and pathological situations. Then we will examine recent discoveries that have begun to clarify functionality and disease relevance of liver polyploidy. Finally, we will discuss implications and future directions of research about polyploidy in the liver.
Collapse
Affiliation(s)
- Shuyuan Zhang
- a Children's Research Institute, Departments of Pediatrics and Internal Medicine, Center for Regenerative Science and Medicine , University of Texas Southwestern Medical Center , Dallas , USA
| | - Yu-Hsuan Lin
- a Children's Research Institute, Departments of Pediatrics and Internal Medicine, Center for Regenerative Science and Medicine , University of Texas Southwestern Medical Center , Dallas , USA
| | - Branden Tarlow
- b Department of Internal Medicine , University of Texas Southwestern Medical Center , Dallas , TX , USA
| | - Hao Zhu
- a Children's Research Institute, Departments of Pediatrics and Internal Medicine, Center for Regenerative Science and Medicine , University of Texas Southwestern Medical Center , Dallas , USA
| |
Collapse
|
16
|
Manolopoulou M, Matlock BK, Nlandu-Khodo S, Simmons AJ, Lau KS, Phillips-Mignemi M, Ivanova A, Alford CE, Flaherty DK, Gewin LS. Novel kidney dissociation protocol and image-based flow cytometry facilitate improved analysis of injured proximal tubules. Am J Physiol Renal Physiol 2019; 316:F847-F855. [PMID: 30759021 PMCID: PMC6580245 DOI: 10.1152/ajprenal.00354.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 02/08/2019] [Accepted: 02/11/2019] [Indexed: 12/16/2022] Open
Abstract
Flow cytometry studies on injured kidney tubules are complicated by the low yield of nucleated single cells. Furthermore, cell-specific responses such as cell cycle dynamics in vivo have conventionally relied on indirect immunohistochemistry and proximal tubule markers that may be downregulated in injury. Here, we report a new tissue dissociation protocol for the kidney with an early fixation step that greatly enhances the yield of single cells. Genetic labeling of the proximal tubule with either mT/mG "tomato" or R26Fucci2aR (Fucci) cell cycle reporter mice allows us to follow proximal tubule-specific changes in cell cycle after renal injury. Image-based flow cytometry (FlowSight) enables gating of the cell cycle and concurrent visualization of the cells with bright field and fluorescence. We used the Fucci mouse in conjunction with FlowSight to identify a discrete polyploid population in proximal tubules after aristolochic acid injury. The tissue dissociation protocol in conjunction with genetic labeling and image-based flow cytometry is a tool that can improve our understanding of any discrete cell population after injury.
Collapse
Affiliation(s)
- Marika Manolopoulou
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Brittany K Matlock
- Flow Cytometry Shared Resource, Vanderbilt Vaccine Center, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Stellor Nlandu-Khodo
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Alan J Simmons
- Epithelial Biology Center, Vanderbilt University Medical Center , Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University , Nashville, Tennessee
| | - Ken S Lau
- Epithelial Biology Center, Vanderbilt University Medical Center , Nashville, Tennessee
- Center for Quantitative Sciences, Vanderbilt University Medical Center , Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University , Nashville, Tennessee
- Program in Chemical and Physical Biology, Vanderbilt University , Nashville, Tennessee
| | - Melanie Phillips-Mignemi
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Alla Ivanova
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Catherine E Alford
- Department of Pathology and Laboratory Medicine, Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee
| | - David K Flaherty
- Flow Cytometry Shared Resource, Vanderbilt Vaccine Center, Vanderbilt University Medical Center , Nashville, Tennessee
| | - Leslie S Gewin
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center , Nashville, Tennessee
- Department of Medicine, Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University , Nashville, Tennessee
| |
Collapse
|
17
|
Escandell JM, Carvalho ES, Gallo-Fernandez M, Reis CC, Matmati S, Luís IM, Abreu IA, Coulon S, Ferreira MG. Ssu72 phosphatase is a conserved telomere replication terminator. EMBO J 2019; 38:embj.2018100476. [PMID: 30796050 PMCID: PMC6443209 DOI: 10.15252/embj.2018100476] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 01/21/2019] [Accepted: 01/28/2019] [Indexed: 01/31/2023] Open
Abstract
Telomeres, the protective ends of eukaryotic chromosomes, are replicated through concerted actions of conventional DNA polymerases and elongated by telomerase, but the regulation of this process is not fully understood. Telomere replication requires (Ctc1/Cdc13)‐Stn1‐Ten1, a telomeric ssDNA‐binding complex homologous to RPA. Here, we show that the evolutionarily conserved phosphatase Ssu72 is responsible for terminating the cycle of telomere replication in fission yeast. Ssu72 controls the recruitment of Stn1 to telomeres by regulating Stn1 phosphorylation at Ser74, a residue located within its conserved OB‐fold domain. Consequently, ssu72∆ mutants are defective in telomere replication and exhibit long 3′‐ssDNA overhangs, indicative of defective lagging‐strand DNA synthesis. We also show that hSSU72 regulates telomerase activation in human cells by controlling recruitment of hSTN1 to telomeres. These results reveal a previously unknown yet conserved role for the phosphatase SSU72, whereby this enzyme controls telomere homeostasis by activating lagging‐strand DNA synthesis, thus terminating the cycle of telomere replication.
Collapse
Affiliation(s)
| | | | | | - Clara C Reis
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Samah Matmati
- Equipe Labellisée Ligue, CRCM, CNRS, Inserm, Institut Paoli-Calmettes, Aix-Marseille University, Marseille, France
| | - Inês Matias Luís
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Isabel A Abreu
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Stéphane Coulon
- Equipe Labellisée Ligue, CRCM, CNRS, Inserm, Institut Paoli-Calmettes, Aix-Marseille University, Marseille, France
| | - Miguel Godinho Ferreira
- Instituto Gulbenkian de Ciência, Oeiras, Portugal .,Institute for Research on Cancer and Aging of Nice (IRCAN), INSERM U1081 UMR7284, CNRS, Nice, France
| |
Collapse
|
18
|
Medina-Castellanos E, Villalobos-Escobedo JM, Riquelme M, Read ND, Abreu-Goodger C, Herrera-Estrella A. Danger signals activate a putative innate immune system during regeneration in a filamentous fungus. PLoS Genet 2018; 14:e1007390. [PMID: 30500812 PMCID: PMC6291166 DOI: 10.1371/journal.pgen.1007390] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 12/12/2018] [Accepted: 10/19/2018] [Indexed: 01/24/2023] Open
Abstract
The ability to respond to injury is a biological process shared by organisms of different kingdoms that can even result in complete regeneration of a part or structure that was lost. Due to their immobility, multicellular fungi are prey to various predators and are therefore constantly exposed to mechanical damage. Nevertheless, our current knowledge of how fungi respond to injury is scarce. Here we show that activation of injury responses and hyphal regeneration in the filamentous fungus Trichoderma atroviride relies on the detection of two danger or alarm signals. As an early response to injury, we detected a transient increase in cytosolic free calcium ([Ca2+]c) that was promoted by extracellular ATP, and which is likely regulated by a mechanism of calcium-induced calcium-release. In addition, we demonstrate that the mitogen activated protein kinase Tmk1 plays a key role in hyphal regeneration. Calcium- and Tmk1-mediated signaling cascades activated major transcriptional changes early following injury, including induction of a set of regeneration associated genes related to cell signaling, stress responses, transcription regulation, ribosome biogenesis/translation, replication and DNA repair. Interestingly, we uncovered the activation of a putative fungal innate immune response, including the involvement of HET domain genes, known to participate in programmed cell death. Our work shows that fungi and animals share danger-signals, signaling cascades, and the activation of the expression of genes related to immunity after injury, which are likely the result of convergent evolution.
Collapse
Affiliation(s)
- Elizabeth Medina-Castellanos
- Laboratorio Nacional de Genómica para la Biodiversidad-Unidad de Genómica Avanzada, Cinvestav, Libramiento Norte Carretera Irapuato-León, Irapuato, Gto, Mexico
| | - José Manuel Villalobos-Escobedo
- Laboratorio Nacional de Genómica para la Biodiversidad-Unidad de Genómica Avanzada, Cinvestav, Libramiento Norte Carretera Irapuato-León, Irapuato, Gto, Mexico
| | - Meritxell Riquelme
- Department of Microbiology, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Carretera Ensenada-Tijuana No. 3918, Ensenada, Baja California, Mexico
| | - Nick D. Read
- Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, University of Manchester, Manchester, United Kingdom
| | - Cei Abreu-Goodger
- Laboratorio Nacional de Genómica para la Biodiversidad-Unidad de Genómica Avanzada, Cinvestav, Libramiento Norte Carretera Irapuato-León, Irapuato, Gto, Mexico
| | - Alfredo Herrera-Estrella
- Laboratorio Nacional de Genómica para la Biodiversidad-Unidad de Genómica Avanzada, Cinvestav, Libramiento Norte Carretera Irapuato-León, Irapuato, Gto, Mexico
| |
Collapse
|
19
|
Abstract
Polyploid cells, which contain multiple copies of the typically diploid genome, are widespread in plants and animals. Polyploidization can be developmentally programmed or stress induced, and arises from either cell-cell fusion or a process known as endoreplication, in which cells replicate their DNA but either fail to complete cytokinesis or to progress through M phase entirely. Polyploidization offers cells several potential fitness benefits, including the ability to increase cell size and biomass production without disrupting cell and tissue structure, and allowing improved cell longevity through higher tolerance to genomic stress and apoptotic signals. Accordingly, recent studies have uncovered crucial roles for polyploidization in compensatory cell growth during tissue regeneration in the heart, liver, epidermis and intestine. Here, we review current knowledge of the molecular pathways that generate polyploidy and discuss how polyploidization is used in tissue repair and regeneration.
Collapse
Affiliation(s)
| | - Bruce A Edgar
- Huntsman Cancer Institute, Salt Lake City, UT 84112, USA
| |
Collapse
|
20
|
Mohib M, Afnan K, Paran TZ, Khan S, Sarker J, Hasan N, Hasan I, Sagor AT. Beneficial Role of Citrus Fruit Polyphenols Against Hepatic Dysfunctions: A Review. J Diet Suppl 2017. [DOI: 10.1080/19390211.2017.1330301] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Mohabbulla Mohib
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisboa, Portugal
| | - Kazi Afnan
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| | - Tasfiq Zaman Paran
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| | - Salma Khan
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| | - Juthika Sarker
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| | - Nahid Hasan
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| | - Istiaque Hasan
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| | - Abu Taher Sagor
- Department of Pharmaceutical Sciences, North South University, Dhaka, Bangladesh
| |
Collapse
|
21
|
Wang MJ, Chen F, Lau JTY, Hu YP. Hepatocyte polyploidization and its association with pathophysiological processes. Cell Death Dis 2017; 8:e2805. [PMID: 28518148 PMCID: PMC5520697 DOI: 10.1038/cddis.2017.167] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 03/01/2017] [Accepted: 03/14/2017] [Indexed: 12/14/2022]
Abstract
A characteristic cellular feature of the mammalian liver is the progressive polyploidization of the hepatocytes, where individual cells acquire more than two sets of chromosomes. Polyploidization results from cytokinesis failure that takes place progressively during the course of postnatal development. The proportion of polyploidy also increases with the aging process or with cellular stress such as surgical resection, toxic stimulation, metabolic overload, or oxidative damage, to involve as much as 90% of the hepatocytes in mice and 40% in humans. Hepatocyte polyploidization is generally considered an indicator of terminal differentiation and cellular senescence, and related to the dysfunction of insulin and p53/p21 signaling pathways. Interestingly, the high prevalence of hepatocyte polyploidization in the aged mouse liver can be reversed when the senescent hepatocytes are serially transplanted into young mouse livers. Here we review the current knowledge on the mechanism of hepatocytes polyploidization during postnatal growth, aging, and liver diseases. The biologic significance of polyploidization in senescent reversal, within the context of new ways to think of liver aging and liver diseases is considered.
Collapse
Affiliation(s)
- Min-Jun Wang
- Department of Cell Biology, Center for Stem Cell and Medicine, Second Military Medical University, Shanghai 200433, China
| | - Fei Chen
- Department of Cell Biology, Center for Stem Cell and Medicine, Second Military Medical University, Shanghai 200433, China
| | - Joseph T Y Lau
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
| | - Yi-Ping Hu
- Department of Cell Biology, Center for Stem Cell and Medicine, Second Military Medical University, Shanghai 200433, China
| |
Collapse
|
22
|
Kim HS, Fernandes G, Lee CW. Protein Phosphatases Involved in Regulating Mitosis: Facts and Hypotheses. Mol Cells 2016; 39:654-62. [PMID: 27669825 PMCID: PMC5050529 DOI: 10.14348/molcells.2016.0214] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 09/19/2016] [Accepted: 09/19/2016] [Indexed: 12/19/2022] Open
Abstract
Almost all eukaryotic proteins are subject to post-translational modifications during mitosis and cell cycle, and in particular, reversible phosphorylation being a key event. The recent use of high-throughput experimental analyses has revealed that more than 70% of all eukaryotic proteins are regulated by phosphorylation; however, the mechanism of dephosphorylation, counteracting phosphorylation, is relatively unknown. Recent discoveries have shown that many of the protein phosphatases are involved in the temporal and spatial control of mitotic events, such as mitotic entry, mitotic spindle assembly, chromosome architecture changes and cohesion, and mitotic exit. This implies that certain phosphatases are tightly regulated for timely dephosphorylation of key mitotic phosphoproteins and are essential for control of various mitotic processes. This review describes the physiological and pathological roles of mitotic phosphatases, as well as the versatile role of various protein phosphatases in several mitotic events.
Collapse
Affiliation(s)
- Hyun-Soo Kim
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 16419,
Korea
| | - Gary Fernandes
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 16419,
Korea
| | - Chang-Woo Lee
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 16419,
Korea
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351,
Korea
| |
Collapse
|