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Boczki P, Colombo M, Weiner J, Rapöhn I, Lacher M, Kiess W, Hanschkow M, Körner A, Landgraf K. Inhibition of AHCY impedes proliferation and differentiation of mouse and human adipocyte progenitor cells. Adipocyte 2024; 13:2290218. [PMID: 38064408 PMCID: PMC10732623 DOI: 10.1080/21623945.2023.2290218] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
S-adenosyl-homocysteine-hydrolase (AHCY) plays an important role in the methionine cycle regulating cellular methylation levels. AHCY has been reported to influence proliferation and differentiation processes in different cell types, e.g. in cancer cells and mouse embryonic stem cells. In the development of adipose tissue, both the proliferation and differentiation of adipocyte progenitor cells (APCs) are important processes, which in the context of obesity are often dysregulated. To assess whether AHCY might also be involved in cell proliferation and differentiation of APCs, we investigated the effect of reduced AHCY activity on human and mouse APCs in vitro. We show that the inhibition of AHCY using adenosine dialdehyde (AdOx) and the knockdown of AHCY using gene-specific siRNAs reduced APC proliferation and number. Inhibition of AHCY further reduced APC differentiation into mature adipocytes and the expression of adipogenic differentiation markers. Global DNA methylation profiling in human APCs revealed that inhibition of AHCY is associated with alterations in CpG methylation levels of genes involved in fat cell differentiation and pathways related to cellular growth. Our findings suggest that AHCY is necessary for the maintenance of APC proliferation and differentiation and inhibition of AHCY alters DNA methylation processes leading to a dysregulation of the expression of genes involved in the regulation of these processes.
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Affiliation(s)
- Paula Boczki
- Center for Pediatric Research Leipzig (CPL), Hospital for Children & Adolescents, University of Leipzig, Leipzig, Germany
| | - Marco Colombo
- Center for Pediatric Research Leipzig (CPL), Hospital for Children & Adolescents, University of Leipzig, Leipzig, Germany
| | - Juliane Weiner
- Medical Department III - Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany
| | - Inka Rapöhn
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Leipzig, Germany
| | - Martin Lacher
- Department of Pediatric Surgery, University of Leipzig, Leipzig, Germany
| | - Wieland Kiess
- Center for Pediatric Research Leipzig (CPL), Hospital for Children & Adolescents, University of Leipzig, Leipzig, Germany
| | - Martha Hanschkow
- Center for Pediatric Research Leipzig (CPL), Hospital for Children & Adolescents, University of Leipzig, Leipzig, Germany
| | - Antje Körner
- Center for Pediatric Research Leipzig (CPL), Hospital for Children & Adolescents, University of Leipzig, Leipzig, Germany
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Leipzig, Germany
| | - Kathrin Landgraf
- Center for Pediatric Research Leipzig (CPL), Hospital for Children & Adolescents, University of Leipzig, Leipzig, Germany
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Jiang Q, Lan S, Tan F, Liang Y, Guo Z, Hou Y, Zhang H, Wu G, Liu Z. Adenosylhomocysteinase plays multiple roles in maintaining the identity and pluripotency of mouse embryonic stem cells†. Biol Reprod 2024; 110:450-464. [PMID: 38035769 DOI: 10.1093/biolre/ioad165] [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: 07/20/2023] [Revised: 10/25/2023] [Accepted: 11/30/2023] [Indexed: 12/02/2023] Open
Abstract
Adenosylhomocysteinase (AHCY), a key enzyme in the methionine cycle, is essential for the development of embryos and the maintenance of mouse embryonic stem cells (mESCs). However, the precise underlying mechanism of Ahcy in regulating pluripotency remains unclear. As the only enzyme that can hydrolyze S-adenosylhomocysteine in mammals, AHCY plays a critical role in the metabolic homeostasis, epigenetic remodeling, and transcriptional regulation. Here, we identified Ahcy as a direct target of OCT4 and unveiled that AHCY regulates the self-renewal and differentiation potency of mESCs through multiple mechanisms. Our study demonstrated that AHCY is required for the metabolic homeostasis of mESCs. We revealed the dual role of Ahcy in both transcriptional activation and inhibition, which is accomplished via the maintenance of H3K4me3 and H3K27me3, respectively. We found that Ahcy is required for H3K4me3-dependent transcriptional activation in mESCs. We also demonstrated that AHCY interacts with polycomb repressive complex 2 (PRC2), thereby maintaining the pluripotency of mESCs by sustaining the H3K27me3-regulated transcriptional repression of related genes. These results reveal a previously unrecognized OCT4-AHCY-PRC2 axis in the regulation of mESCs' pluripotency and provide insights into the interplay between transcriptional factors, cellular metabolism, chromatin dynamics and pluripotency regulation.
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Affiliation(s)
- Qi Jiang
- College of Life Science, Northeast Agricultural University, Harbin, China
- Basic Research Department, Guangzhou National Laboratory, Guangzhou, China
- Key Laboratory of Animal Cellular and Genetic Engineering of Heilongjiang Province, College of Life Science, Northeast Agricultural University, Harbin, China
| | - Shubing Lan
- Basic Research Department, Guangzhou National Laboratory, Guangzhou, China
| | - Fancheng Tan
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Xiamen, China
| | - Yiping Liang
- Basic Research Department, Guangzhou National Laboratory, Guangzhou, China
| | - Zhencheng Guo
- Basic Research Department, Guangzhou National Laboratory, Guangzhou, China
| | - Yanlin Hou
- Basic Research Department, Guangzhou National Laboratory, Guangzhou, China
| | - Hui Zhang
- Basic Research Department, Guangzhou National Laboratory, Guangzhou, China
- The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Guangming Wu
- Basic Research Department, Guangzhou National Laboratory, Guangzhou, China
- Department of Obstetrics and Gynecology, Guangdong Provincial Key Laboratory of Major Obstetric Diseases, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Zhonghua Liu
- College of Life Science, Northeast Agricultural University, Harbin, China
- Key Laboratory of Animal Cellular and Genetic Engineering of Heilongjiang Province, College of Life Science, Northeast Agricultural University, Harbin, China
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3
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Nakanishi M, Hino M, Nomoto H. Trypanosoma brucei proliferates normally even after losing all S-adenosylhomocysteine hydrolase genes. Biochem Biophys Res Commun 2023; 686:149152. [PMID: 37926042 DOI: 10.1016/j.bbrc.2023.149152] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 09/29/2023] [Accepted: 10/23/2023] [Indexed: 11/07/2023]
Abstract
S-adenosylhomocysteine (SAH) hydrolase is the enzyme responsible for breaking down SAH into adenosine and homocysteine. It has long been believed that a deficiency of this enzyme leads to SAH accumulation, subsequently inhibiting methyltransferases responsible for nucleic acids and proteins, which severely affects cell proliferation. To investigate whether targeting this enzyme could be a viable strategy to combat Trypanosoma brucei, the causative agent of human African trypanosomiasis, we created a null mutant of the SAH hydrolase gene in T. brucei using the Cre/loxP system and conducted a phenotype analysis. Surprisingly, the null mutant, where all five SAH hydrolase gene loci were deleted, exhibited normal proliferation despite the observed SAH accumulation. These findings suggest that inhibiting SAH hydrolase may not be an effective approach to suppressing T. brucei proliferation, making the enzyme a less promising target for antitrypanosome drug development.
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Affiliation(s)
- Masayuki Nakanishi
- Laboratory of Biochemistry, School of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime, 790-8578, Japan.
| | - Mami Hino
- Laboratory of Biochemistry, School of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime, 790-8578, Japan.
| | - Hiroshi Nomoto
- Laboratory of Biochemistry, School of Pharmaceutical Sciences, Matsuyama University, Matsuyama, Ehime, 790-8578, Japan.
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4
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Pavičić I, Rokić F, Vugrek O. Effects of S-Adenosylhomocysteine Hydrolase Downregulation on Wnt Signaling Pathway in SW480 Cells. Int J Mol Sci 2023; 24:16102. [PMID: 38003292 PMCID: PMC10671441 DOI: 10.3390/ijms242216102] [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: 09/13/2023] [Revised: 10/31/2023] [Accepted: 11/03/2023] [Indexed: 11/26/2023] Open
Abstract
S-adenosylhomocysteine hydrolase (AHCY) deficiency results mainly in hypermethioninemia, developmental delay, and is potentially fatal. In order to shed new light on molecular aspects of AHCY deficiency, in particular any changes at transcriptome level, we enabled knockdown of AHCY expression in the colon cancer cell line SW480 to simulate the environment occurring in AHCY deficient individuals. The SW480 cell line is well known for elevated AHCY expression, and thereby represents a suitable model system, in particular as AHCY expression is regulated by MYC, which, on the other hand, is involved in Wnt signaling and the regulation of Wnt-related genes, such as the β-catenin co-transcription factor LEF1 (lymphoid enhancer-binding factor 1). We selected LEF1 as a potential target to investigate its association with S-adenosylhomocysteine hydrolase deficiency. This decision was prompted by our analysis of RNA-Seq data, which revealed significant changes in the expression of genes related to the Wnt signaling pathway and genes involved in processes responsible for epithelial-mesenchymal transition (EMT) and cell proliferation. Notably, LEF1 emerged as a common factor in these processes, showing increased expression both on mRNA and protein levels. Additionally, we show alterations in interconnected signaling pathways linked to LEF1, causing gene expression changes with broad effects on cell cycle regulation, tumor microenvironment, and implications to cell invasion and metastasis. In summary, we provide a new link between AHCY deficiency and LEF1 serving as a mediator of changes to the Wnt signaling pathway, thereby indicating potential connections of AHCY expression and cancer cell phenotype, as Wnt signaling is frequently associated with cancer development, including colorectal cancer (CRC).
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Affiliation(s)
| | | | - Oliver Vugrek
- Laboratory for Advanced Genomics, Divison of Molecular Medicine, Institute Ruđer Bošković, Bijenička Cesta 54, 10000 Zagreb, Croatia; (I.P.); (F.R.)
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You Y, Chen X, Chen Y, Pang J, Chen Q, Liu Q, Xue H, Zeng Y, Xiao J, Mi J, Tang Y, Ling W. Epigenetic modulation of Drp1-mediated mitochondrial fission by inhibition of S-adenosylhomocysteine hydrolase promotes vascular senescence and atherosclerosis. Redox Biol 2023; 65:102828. [PMID: 37517319 PMCID: PMC10400927 DOI: 10.1016/j.redox.2023.102828] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 07/24/2023] [Indexed: 08/01/2023] Open
Abstract
AIMS Vascular senescence, which is closely related to epigenetic regulation, is an early pathological condition in cardiovascular diseases including atherosclerosis. Inhibition of S-adenosylhomocysteine hydrolase (SAHH) and the consequent increase of S-adenosylhomocysteine (SAH), a potent inhibitor of DNA methyltransferase, has been associated with an elevated risk of cardiovascular diseases. This study aimed to investigate whether the inhibition of SAHH accelerates vascular senescence and the development of atherosclerosis. METHODS AND RESULTS The case-control study related to vascular aging showed that increased levels of plasma SAH were positively associated with the risk of vascular aging, with an odds ratio (OR) of 3.90 (95% CI, 1.17-13.02). Elevated pulse wave velocity, impaired endothelium-dependent relaxation response, and increased senescence-associated β-galactosidase staining were observed in the artery of SAHH+/- mice at 32 weeks of age. Additionally, elevated expression of p16, p21, and p53, fission morphology of mitochondria, and over-upregulated expression of Drp1 were observed in vascular endothelial cells with SAHH inhibition in vitro and in vivo. Further downregulation of Drp1 using siRNA or its specific inhibitor, mdivi-1, restored the abnormal mitochondrial morphology and rescued the phenotypes of vascular senescence. Furthermore, inhibition of SAHH in APOE-/- mice promoted vascular senescence and atherosclerosis progression, which was attenuated by mdivi-1 treatment. Mechanistically, hypomethylation over the promoter region of DRP1 and downregulation of DNMT1 were demonstrated with SAHH inhibition in HUVECs. CONCLUSIONS SAHH inhibition epigenetically upregulates Drp1 expression through repressing DNA methylation in endothelial cells, leading to vascular senescence and atherosclerosis. These results identify SAHH or SAH as a potential therapeutic target for vascular senescence and cardiovascular diseases.
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Affiliation(s)
- Yiran You
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Xu Chen
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, USA
| | - Yu Chen
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Juan Pang
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Qian Chen
- Department of Cardiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, People's Republic of China; School of Public Health and Management, Ningxia Medical University, Yinchuan, People's Republic of China
| | - Qiannan Liu
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Hongliang Xue
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Yupeng Zeng
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Jinghe Xiao
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Jiaxin Mi
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Yi Tang
- Department of Nutrition, The First People's Hospital of Zhaoqing, Zhaoqing, China
| | - Wenhua Ling
- Department of Nutrition, School of Public Health, Sun Yat-Sen University, Guangzhou, People's Republic of China; School of Public Health and Management, Ningxia Medical University, Yinchuan, People's Republic of China; Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Guangzhou, People's Republic of China.
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6
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Vande Voorde J, Steven RT, Najumudeen AK, Ford CA, Dexter A, Gonzalez-Fernandez A, Nikula CJ, Xiang Y, Ford L, Maneta Stavrakaki S, Gilroy K, Zeiger LB, Pennel K, Hatthakarnkul P, Elia EA, Nasif A, Murta T, Manoli E, Mason S, Gillespie M, Lannagan TRM, Vlahov N, Ridgway RA, Nixon C, Raven A, Mills M, Athineos D, Kanellos G, Nourse C, Gay DM, Hughes M, Burton A, Yan B, Sellers K, Wu V, De Ridder K, Shokry E, Huerta Uribe A, Clark W, Clark G, Kirschner K, Thienpont B, Li VSW, Maddocks ODK, Barry ST, Goodwin RJA, Kinross J, Edwards J, Yuneva MO, Sumpton D, Takats Z, Campbell AD, Bunch J, Sansom OJ. Metabolic profiling stratifies colorectal cancer and reveals adenosylhomocysteinase as a therapeutic target. Nat Metab 2023; 5:1303-1318. [PMID: 37580540 PMCID: PMC10447251 DOI: 10.1038/s42255-023-00857-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [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] [Received: 02/24/2022] [Accepted: 07/06/2023] [Indexed: 08/16/2023]
Abstract
The genomic landscape of colorectal cancer (CRC) is shaped by inactivating mutations in tumour suppressors such as APC, and oncogenic mutations such as mutant KRAS. Here we used genetically engineered mouse models, and multimodal mass spectrometry-based metabolomics to study the impact of common genetic drivers of CRC on the metabolic landscape of the intestine. We show that untargeted metabolic profiling can be applied to stratify intestinal tissues according to underlying genetic alterations, and use mass spectrometry imaging to identify tumour, stromal and normal adjacent tissues. By identifying ions that drive variation between normal and transformed tissues, we found dysregulation of the methionine cycle to be a hallmark of APC-deficient CRC. Loss of Apc in the mouse intestine was found to be sufficient to drive expression of one of its enzymes, adenosylhomocysteinase (AHCY), which was also found to be transcriptionally upregulated in human CRC. Targeting of AHCY function impaired growth of APC-deficient organoids in vitro, and prevented the characteristic hyperproliferative/crypt progenitor phenotype driven by acute deletion of Apc in vivo, even in the context of mutant Kras. Finally, pharmacological inhibition of AHCY reduced intestinal tumour burden in ApcMin/+ mice indicating its potential as a metabolic drug target in CRC.
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Affiliation(s)
| | | | | | | | | | | | | | - Yuchen Xiang
- Department of Metabolism Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
| | - Lauren Ford
- Department of Metabolism Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
| | - Stefania Maneta Stavrakaki
- Department of Metabolism Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
| | | | - Lucas B Zeiger
- Cancer Research UK Beatson Institute, Glasgow, UK
- School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Kathryn Pennel
- School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | | | | | | | | | - Eftychios Manoli
- Department of Metabolism Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
| | - Sam Mason
- Department of Metabolism Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
| | - Michael Gillespie
- Cancer Research UK Beatson Institute, Glasgow, UK
- School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | | | | | | | - Colin Nixon
- Cancer Research UK Beatson Institute, Glasgow, UK
| | | | - Megan Mills
- Cancer Research UK Beatson Institute, Glasgow, UK
| | | | | | - Craig Nourse
- School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - David M Gay
- Cancer Research UK Beatson Institute, Glasgow, UK
- School of Cancer Sciences, University of Glasgow, Glasgow, UK
- Københavns Universitet, BRIC, Copenhagen, Denmark
| | - Mark Hughes
- Cancer Research UK Beatson Institute, Glasgow, UK
| | - Amy Burton
- National Physical Laboratory, London, UK
| | - Bin Yan
- National Physical Laboratory, London, UK
| | - Katherine Sellers
- The Francis Crick Institute, London, UK
- Rheos Medicines, Cambridge, MA, USA
| | - Vincen Wu
- Department of Metabolism Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
| | - Kobe De Ridder
- Department of Human Genetics, University of Leuven, KU Leuven, Leuven, Belgium
| | - Engy Shokry
- Cancer Research UK Beatson Institute, Glasgow, UK
| | | | | | - Graeme Clark
- Cancer Research UK Beatson Institute, Glasgow, UK
| | | | - Bernard Thienpont
- Department of Human Genetics, University of Leuven, KU Leuven, Leuven, Belgium
| | | | | | - Simon T Barry
- Bioscience, Early Oncology, AstraZeneca, Cambridge, UK
| | - Richard J A Goodwin
- Imaging and Data Analytics, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Cambridge, UK
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - James Kinross
- Department of Metabolism Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
| | - Joanne Edwards
- School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | | | | | - Zoltan Takats
- Department of Metabolism Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
- Biological Mass Spectrometry, Rosalind Franklin Institute, Didcot, UK
| | | | - Josephine Bunch
- National Physical Laboratory, London, UK
- Department of Metabolism Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
- Biological Mass Spectrometry, Rosalind Franklin Institute, Didcot, UK
| | - Owen J Sansom
- Cancer Research UK Beatson Institute, Glasgow, UK.
- School of Cancer Sciences, University of Glasgow, Glasgow, UK.
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7
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Dai X, Liu S, Cheng L, Huang T, Guo H, Wang D, Xia M, Ling W, Xiao Y. Betaine Supplementation Attenuates S-Adenosylhomocysteine Hydrolase-Deficiency-Accelerated Atherosclerosis in Apolipoprotein E-Deficient Mice. Nutrients 2022; 14:nu14030718. [PMID: 35277077 PMCID: PMC8840105 DOI: 10.3390/nu14030718] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/25/2022] [Accepted: 02/06/2022] [Indexed: 12/25/2022] Open
Abstract
S-adenosylhomocysteine (SAH) is a risk factor of cardiovascular diseases and atherosclerosis. However, the causal association between SAH and atherosclerosis is still uncertain. In the present study, heterozygous SAH hydrolase (SAHH+/−) knockout mice were bred with apolipoprotein E-deficient mice to produce ApoE−/−/SAHH+/− mice. At 8 weeks of age, these mice were fed on AIN-93G diets added with or without betaine (4 g betaine/100 g diet) for 8 weeks. Compared with ApoE−/−/SAHHWT mice, SAHH deficiency caused an accumulation of plasma SAH concentration and a decrease in S-adenosylmethionine (SAM)/SAH ratio as well as plasma homocysteine levels. Betaine supplementation lowered SAH levels and increased SAM/SAH ratio and homocysteine levels in ApoE−/−/SAHH+/− mice. Furthermore, SAHH deficiency promoted the development of atherosclerosis, which was reduced by betaine supplementation. The atheroprotective effects of betaine on SAHH-deficiency-promoted atherosclerosis were associated with inhibition of NFκB inflammation signaling pathway and inhibition of proliferation and migration of smooth muscle cells. In conclusion, our results suggest that betaine supplementation lowered plasma SAH levels and protected against SAHH-deficiency-promoted atherosclerosis through repressing inflammation and proliferation and migration of smooth muscle cells.
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Affiliation(s)
- Xin Dai
- Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen 518107, China; (X.D.); (S.L.); (L.C.); (T.H.)
| | - Si Liu
- Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen 518107, China; (X.D.); (S.L.); (L.C.); (T.H.)
| | - Lokyu Cheng
- Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen 518107, China; (X.D.); (S.L.); (L.C.); (T.H.)
| | - Ting Huang
- Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen 518107, China; (X.D.); (S.L.); (L.C.); (T.H.)
| | - Honghui Guo
- Department of Nutrition, School of Public Health, Guangdong Medical University, Dongguan 523808, China;
| | - Dongliang Wang
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China; (D.W.); (M.X.); (W.L.)
| | - Min Xia
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China; (D.W.); (M.X.); (W.L.)
| | - Wenhua Ling
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China; (D.W.); (M.X.); (W.L.)
| | - Yunjun Xiao
- Guangdong Provincial Key Laboratory of Digestive Cancer Research, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen 518107, China; (X.D.); (S.L.); (L.C.); (T.H.)
- Correspondence: ; Tel.: +86-138-0989-0750
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8
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Gupta A, Storey KB. Coordinated expression of Jumonji and AHCY under OCT transcription factor control to regulate gene methylation in wood frogs during anoxia. Gene 2021; 788:145671. [PMID: 33887369 DOI: 10.1016/j.gene.2021.145671] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 04/05/2021] [Accepted: 04/15/2021] [Indexed: 12/17/2022]
Abstract
Wood frogs (Rana sylvatica) can survive extended periods of whole body freezing. Freezing imparts multiple stresses on cells that include anoxia and dehydration, but these can also be experienced as independent stresses. Under anoxia stress, energy metabolism is suppressed, and pro-survival pathways are prioritized to differentially regulate some transcription factors including OCT1 and OCT4. Jumonji C domain proteins (JMJD1A and JMJD2C) are hypoxia responsive demethylases whose expression is accelerated by OCT1 and OCT4 which act to demethylate genes related to the methionine cycle. The responses by these factors to 24 h anoxia exposure and 4 h aerobic recovery was analyzed in liver and skeletal muscle of wood frogs to assess their involvement in metabolic adaptation to oxygen limitation. Immunoblot results showed a decrease in JMJD1A levels under anoxia in liver and muscle, but an increase was observed in JMJD2C demethylase protein in anoxic skeletal muscle. Protein levels of adenosylhomocysteinase (AHCY) and methionine adenosyl transferase (MAT), enzymes of the methionine cycle, also showed an increase in the reoxygenated liver, whereas the levels decreased in muscle. A transcription factor ELISA showed a decrease in DNA binding by OCT1 in the reoxygenated liver and anoxic skeletal muscle, and transcript levels also showed tissue specific gene expression. The present study provides the first analysis of the role of the OCT1 transcription factor, associated proteins, and lysine demethylases in mediating responses to anoxia by wood frog tissues.
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Affiliation(s)
- Aakriti Gupta
- Department of Biology, Carleton University, Ottawa K1S 5B6, Canada
| | - Kenneth B Storey
- Department of Biology, Carleton University, Ottawa K1S 5B6, Canada.
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9
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Maclean KN, Jiang H, Phinney WN, Mclagan BM, Roede JR, Stabler SP. Derangement of hepatic polyamine, folate, and methionine cycle metabolism in cystathionine beta-synthase-deficient homocystinuria in the presence and absence of treatment: Possible implications for pathogenesis. Mol Genet Metab 2021; 132:128-138. [PMID: 33483253 DOI: 10.1016/j.ymgme.2021.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/04/2021] [Accepted: 01/05/2021] [Indexed: 11/22/2022]
Abstract
Cystathionine beta-synthase deficient homocystinuria (HCU) is a life-threatening disorder of sulfur metabolism. Our knowledge of the metabolic changes induced in HCU are based almost exclusively on data derived from plasma. In the present study, we present a comprehensive analysis on the effects of HCU upon the hepatic metabolites and enzyme expression levels of the methionine-folate cycles in a mouse model of HCU. HCU induced a 10-fold increase in hepatic total homocysteine and in contrast to plasma, this metabolite was only lowered by approximately 20% by betaine treatment indicating that this toxic metabolite remains unacceptably elevated. Hepatic methionine, S-adenosylmethionine, S-adenosylhomocysteine, N-acetlymethionine, N-formylmethionine, methionine sulfoxide, S-methylcysteine, serine, N-acetylserine, taurocyamine and N-acetyltaurine levels were also significantly increased by HCU while cysteine, N-acetylcysteine and hypotaurine were all significantly decreased. In terms of polyamine metabolism, HCU significantly decreased spermine and spermidine levels while increasing 5'-methylthioadenosine. Betaine treatment restored normal spermine and spermidine levels but further increased 5'-methylthioadenosine. HCU induced a 2-fold induction in expression of both S-adenosylhomocysteine hydrolase and methylenetetrahydrofolate reductase. Induction of this latter enzyme was accompanied by a 10-fold accumulation of its product, 5-methyl-tetrahydrofolate, with the potential to significantly perturb one‑carbon metabolism. Expression of the cytoplasmic isoform of serine hydroxymethyltransferase was unaffected by HCU but the mitochondrial isoform was repressed indicating differential regulation of one‑carbon metabolism in different sub-cellular compartments. All HCU-induced changes in enzyme expression were completely reversed by either betaine or taurine treatment. Collectively, our data show significant alterations of polyamine, folate and methionine cycle metabolism in HCU hepatic tissues that in some cases, differ significantly from those observed in plasma, and have the potential to contribute to multiple aspects of pathogenesis.
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Affiliation(s)
- Kenneth N Maclean
- Departments of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| | - Hua Jiang
- Departments of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Whitney N Phinney
- Medicine and University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Bailey M Mclagan
- Departments of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - James R Roede
- Pharmaceutical Sciences, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Sally P Stabler
- Medicine and University of Colorado School of Medicine, Aurora, CO 80045, USA
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10
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Greco CM, Cervantes M, Fustin JM, Ito K, Ceglia N, Samad M, Shi J, Koronowski KB, Forne I, Ranjit S, Gaucher J, Kinouchi K, Kojima R, Gratton E, Li W, Baldi P, Imhof A, Okamura H, Sassone-Corsi P. S-adenosyl-l-homocysteine hydrolase links methionine metabolism to the circadian clock and chromatin remodeling. Sci Adv 2020; 6:eabc5629. [PMID: 33328229 PMCID: PMC7744083 DOI: 10.1126/sciadv.abc5629] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 10/30/2020] [Indexed: 05/03/2023]
Abstract
Circadian gene expression driven by transcription activators CLOCK and BMAL1 is intimately associated with dynamic chromatin remodeling. However, how cellular metabolism directs circadian chromatin remodeling is virtually unexplored. We report that the S-adenosylhomocysteine (SAH) hydrolyzing enzyme adenosylhomocysteinase (AHCY) cyclically associates to CLOCK-BMAL1 at chromatin sites and promotes circadian transcriptional activity. SAH is a potent feedback inhibitor of S-adenosylmethionine (SAM)-dependent methyltransferases, and timely hydrolysis of SAH by AHCY is critical to sustain methylation reactions. We show that AHCY is essential for cyclic H3K4 trimethylation, genome-wide recruitment of BMAL1 to chromatin, and subsequent circadian transcription. Depletion or targeted pharmacological inhibition of AHCY in mammalian cells markedly decreases the amplitude of circadian gene expression. In mice, pharmacological inhibition of AHCY in the hypothalamus alters circadian locomotor activity and rhythmic transcription within the suprachiasmatic nucleus. These results reveal a previously unappreciated connection between cellular metabolism, chromatin dynamics, and circadian regulation.
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Affiliation(s)
- Carolina Magdalen Greco
- Center for Epigenetics and Metabolism; U1233 INSERM; Department of Biological Chemistry, School of Medicine, University of California, Irvine (UCI), Irvine, CA, USA.
| | - Marlene Cervantes
- Center for Epigenetics and Metabolism; U1233 INSERM; Department of Biological Chemistry, School of Medicine, University of California, Irvine (UCI), Irvine, CA, USA
| | - Jean-Michel Fustin
- Graduate School of Pharmaceutical Sciences, Department of Systems Biology, Kyoto University, Kyoto 606-8501, Japan
| | - Kakeru Ito
- Graduate School of Pharmaceutical Sciences, Department of Systems Biology, Kyoto University, Kyoto 606-8501, Japan
| | - Nicholas Ceglia
- Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California Irvine (UCI), Irvine, CA, USA
| | - Muntaha Samad
- Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California Irvine (UCI), Irvine, CA, USA
| | - Jiejun Shi
- Department of Biological Chemistry, School of Medicine, University of California Irvine (UCI), Irvine, CA, USA
- Division of Biostatistics, Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Kevin Brian Koronowski
- Center for Epigenetics and Metabolism; U1233 INSERM; Department of Biological Chemistry, School of Medicine, University of California, Irvine (UCI), Irvine, CA, USA
| | - Ignasi Forne
- Biomedical Center, Protein Analysis Unit, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
| | - Suman Ranjit
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine (UCI), Irvine, CA, USA
| | - Jonathan Gaucher
- Center for Epigenetics and Metabolism; U1233 INSERM; Department of Biological Chemistry, School of Medicine, University of California, Irvine (UCI), Irvine, CA, USA
| | - Kenichiro Kinouchi
- Center for Epigenetics and Metabolism; U1233 INSERM; Department of Biological Chemistry, School of Medicine, University of California, Irvine (UCI), Irvine, CA, USA
| | - Rika Kojima
- Graduate School of Pharmaceutical Sciences, Department of Systems Biology, Kyoto University, Kyoto 606-8501, Japan
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine (UCI), Irvine, CA, USA
| | - Wei Li
- Department of Biological Chemistry, School of Medicine, University of California Irvine (UCI), Irvine, CA, USA
- Division of Biostatistics, Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Pierre Baldi
- Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California Irvine (UCI), Irvine, CA, USA
| | - Axel Imhof
- Biomedical Center, Protein Analysis Unit, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Strasse 9, 82152 Planegg-Martinsried, Germany
| | - Hitoshi Okamura
- Graduate School of Pharmaceutical Sciences, Department of Systems Biology, Kyoto University, Kyoto 606-8501, Japan
| | - Paolo Sassone-Corsi
- Center for Epigenetics and Metabolism; U1233 INSERM; Department of Biological Chemistry, School of Medicine, University of California, Irvine (UCI), Irvine, CA, USA.
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11
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Li X, Bu S, Pan RR, Zhou C, Qu K, Ying X, Zhong J, Xiao J, Yuan Q, Zhang S, Tipton L, Wang Y, Deng Y, Duan S. The values of AHCY and CBS promoter methylation on the diagnosis of cerebral infarction in Chinese Han population. BMC Med Genomics 2020; 13:163. [PMID: 33138824 PMCID: PMC7607831 DOI: 10.1186/s12920-020-00798-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 09/16/2020] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND The goal of our study is to investigate whether the methylation levels of AHCY and CBS promoters are related to the risk of cerebral infarction by detecting the methylation level of AHCY and CBS genes. METHODS We extracted peripheral venous blood from 152 patients with cerebral infarction and 152 gender- and age-matched healthy controls, and determined methylation levels of AHCY and CBS promoters using quantitative methylation-specific polymerase chain reaction. We used the percentage of methylation reference (PMR) to indicate gene methylation level. RESULTS We compared the promoter methylation levels of two genes (AHCY and CBS) in peripheral blood DNA between the cerebral infarction case group and the control group. Our study showed no significant difference in AHCY promoter methylation between case and control. Subgroup analysis by gender showed that the methylation level of AHCY in males in the case group was lower than that in the control group, but the difference was not statistically significant in females. In a subgroup analysis by age, there was no significant difference in the AHCY methylation level between the case and control in the young group (≤44 years old). However, the level of AHCY gene methylation in the middle-aged group (45-59 years old) was significantly higher and the aged group (≥60 years old) was significantly lower than that in the control groups. However, CBS promoter methylation levels were significantly lower in the case group than in the control group (median PMR: 70.20% vs 104.10%, P = 3.71E-10). In addition, the CBS methylation levels of males and females in the case group were significantly lower than those in the control group (male: 64.33% vs 105%, P = 2.667E-08; female: 78.05% vs 102.8%, P = 0.003). We also found that the CBS levels in the young (23-44), middle-aged (45-59), and older (60-90) groups were significantly lower than those in the control group (young group: 69.97% vs 114.71%; P = 0.015; middle-aged group: 56.04% vs 91.71%; P = 6.744E-06; older group: 81.6% vs 119.35%; P = 2.644E-04). Our ROC curve analysis of CBS hypomethylation showed an area under the curve of 0.713, a sensitivity of 67.4%, and a specificity of 74.0%. CONCLUSION Our study suggests that hypomethylation of the CBS promoter may be closely related to the risk of cerebral infarction and may be used as a non-invasive diagnostic biomarker for cerebral infarction.
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Affiliation(s)
- Xiaodong Li
- Department of Neurology, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, 450006, Henan, China
| | - Shufang Bu
- Department of Neurology, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, 450006, Henan, China
| | - Ran Ran Pan
- School of Medicine, Ningbo University, Ningbo, Zhejiang, 315211, China
| | - Cong Zhou
- School of Medicine, Ningbo University, Ningbo, Zhejiang, 315211, China
| | - Kun Qu
- Department of Neurology, the 960th of Hospital of PLA, Zibo, 255330, Shandong, China
| | - Xiuru Ying
- School of Medicine, Ningbo University, Ningbo, Zhejiang, 315211, China
| | - Jie Zhong
- School of Medicine, Ningbo University, Ningbo, Zhejiang, 315211, China
| | - Jianhao Xiao
- Department of Neurology, the Second Affiliated Hospital, Zhengzhou University, Zhengzhou, 450014, Henan, China
| | - Qian Yuan
- Department of Neurology, the Second Affiliated Hospital, Zhengzhou University, Zhengzhou, 450014, Henan, China
| | - Simiao Zhang
- Department of Neurology, the Second Affiliated Hospital, Zhengzhou University, Zhengzhou, 450014, Henan, China
| | - Laura Tipton
- Bioinformatics Core, Department of Complementary and Integrative Medicine and John A. Burns School of Medicine, University of Hawai'i, Honolulu, HI, 96822, USA
| | - Yunliang Wang
- Department of Neurology, the Second Affiliated Hospital, Zhengzhou University, Zhengzhou, 450014, Henan, China.
| | - Youping Deng
- Bioinformatics Core, Department of Complementary and Integrative Medicine and John A. Burns School of Medicine, University of Hawai'i, Honolulu, HI, 96822, USA.
| | - Shiwei Duan
- School of Medicine, Ningbo University, Ningbo, Zhejiang, 315211, China.
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12
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Alegre S, Pascual J, Trotta A, Angeleri M, Rahikainen M, Brosche M, Moffatt B, Kangasjärvi S. Evolutionary conservation and post-translational control of S-adenosyl-L-homocysteine hydrolase in land plants. PLoS One 2020; 15:e0227466. [PMID: 32678822 PMCID: PMC7367456 DOI: 10.1371/journal.pone.0227466] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 06/30/2020] [Indexed: 02/01/2023] Open
Abstract
Trans-methylation reactions are intrinsic to cellular metabolism in all living organisms. In land plants, a range of substrate-specific methyltransferases catalyze the methylation of DNA, RNA, proteins, cell wall components and numerous species-specific metabolites, thereby providing means for growth and acclimation in various terrestrial habitats. Trans-methylation reactions consume vast amounts of S-adenosyl-L-methionine (SAM) as a methyl donor in several cellular compartments. The inhibitory reaction by-product, S-adenosyl-L-homocysteine (SAH), is continuously removed by SAH hydrolase (SAHH), which essentially maintains trans-methylation reactions in all living cells. Here we report on the evolutionary conservation and post-translational control of SAHH in land plants. We provide evidence suggesting that SAHH forms oligomeric protein complexes in phylogenetically divergent land plants and that the predominant protein complex is composed by a tetramer of the enzyme. Analysis of light-stress-induced adjustments of SAHH in Arabidopsis thaliana and Physcomitrella patens further suggests that regulatory actions may take place on the levels of protein complex formation and phosphorylation of this metabolically central enzyme. Collectively, these data suggest that plant adaptation to terrestrial environments involved evolution of regulatory mechanisms that adjust the trans-methylation machinery in response to environmental cues.
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Affiliation(s)
- Sara Alegre
- Department of Biochemistry, Molecular Plant Biology, University of Turku, Turku, Finland
| | - Jesús Pascual
- Department of Biochemistry, Molecular Plant Biology, University of Turku, Turku, Finland
| | - Andrea Trotta
- Department of Biochemistry, Molecular Plant Biology, University of Turku, Turku, Finland
- Institute of Biosciences and Bioresources, National Research Council of Italy, Sesto Fiorentino, Firenze, Italy
| | - Martina Angeleri
- Department of Biochemistry, Molecular Plant Biology, University of Turku, Turku, Finland
| | - Moona Rahikainen
- Department of Biochemistry, Molecular Plant Biology, University of Turku, Turku, Finland
| | - Mikael Brosche
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Barbara Moffatt
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
| | - Saijaliisa Kangasjärvi
- Department of Biochemistry, Molecular Plant Biology, University of Turku, Turku, Finland
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13
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Akpa CA, Kleo K, Oker E, Tomaszewski N, Messerschmidt C, López C, Wagener R, Oehl-Huber K, Dettmer K, Schoeler A, Lenze D, Oefner PJ, Beule D, Siebert R, Capper D, Dimitrova L, Hummel M. Acquired resistance to DZNep-mediated apoptosis is associated with copy number gains of AHCY in a B-cell lymphoma model. BMC Cancer 2020; 20:427. [PMID: 32408898 PMCID: PMC7227222 DOI: 10.1186/s12885-020-06937-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 05/07/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Enhancer of zeste homolog 2 (EZH2) is considered an important driver of tumor development and progression by its histone modifying capabilities. Inhibition of EZH2 activity is thought to be a potent treatment option for eligible cancer patients with an aberrant EZH2 expression profile, thus the indirect EZH2 inhibitor 3-Deazaneplanocin A (DZNep) is currently under evaluation for its clinical utility. Although DZNep blocks proliferation and induces apoptosis in different tumor types including lymphomas, acquired resistance to DZNep may limit its clinical application. METHODS To investigate possible mechanisms of acquired DZNep resistance in B-cell lymphomas, we generated a DZNep-resistant clone from a previously DZNep-sensitive B-cell lymphoma cell line by long-term treatment with increasing concentrations of DZNep (ranging from 200 to 2000 nM) and compared the molecular profiles of resistant and wild-type clones. This comparison was done using molecular techniques such as flow cytometry, copy number variation assay (OncoScan and TaqMan assays), fluorescence in situ hybridization, Western blot, immunohistochemistry and metabolomics analysis. RESULTS Whole exome sequencing did not indicate the acquisition of biologically meaningful single nucleotide variants. Analysis of copy number alterations, however, demonstrated among other acquired imbalances an amplification (about 30 times) of the S-adenosyl-L-homocysteine hydrolase (AHCY) gene in the resistant clone. AHCY is a direct target of DZNep and is critically involved in the biological methylation process, where it catalyzes the reversible hydrolysis of S-adenosyl-L-homocysteine to L-homocysteine and adenosine. The amplification of the AHCY gene is paralleled by strong overexpression of AHCY at both the transcriptional and protein level, and persists upon culturing the resistant clone in a DZNep-free medium. CONCLUSIONS This study reveals one possible molecular mechanism how B-cell lymphomas can acquire resistance to DZNep, and proposes AHCY as a potential biomarker for investigation during the administration of EZH2-targeted therapy with DZNep.
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Affiliation(s)
- Chidimma Agatha Akpa
- Department of Experimental Hematopathology, Institute of Pathology, Charité Medical University, Berlin, Charitéplatz 1, 10117, Berlin, Germany.
- Berlin School of Integrative Oncology, Charité - Medical University of Berlin, Berlin, Germany.
| | - Karsten Kleo
- Department of Experimental Hematopathology, Institute of Pathology, Charité Medical University, Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Elisabeth Oker
- Department of Experimental Hematopathology, Institute of Pathology, Charité Medical University, Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Nancy Tomaszewski
- Department of Experimental Hematopathology, Institute of Pathology, Charité Medical University, Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | | | - Cristina López
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, Ulm, Germany
| | - Rabea Wagener
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, Ulm, Germany
| | - Kathrin Oehl-Huber
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, Ulm, Germany
| | - Katja Dettmer
- Institute of Functional Genomics, University of Regensburg, Regensburg, Germany
| | - Anne Schoeler
- Department of Neuropathology, Charité, Medical University of Berlin, corporate member of Free University Berlin, Humboldt-University Berlin, and Berlin Institute of Health, Berlin, Germany
- German Cancer Consortium (DKTK); Partner Site Berlin, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Dido Lenze
- Department of Experimental Hematopathology, Institute of Pathology, Charité Medical University, Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Peter J Oefner
- Berlin School of Integrative Oncology, Charité - Medical University of Berlin, Berlin, Germany
| | - Dieter Beule
- Berlin Institute of Health, Charité Core Unit Bioinformatics, Berlin, Germany
| | - Reiner Siebert
- Institute of Human Genetics, Ulm University and Ulm University Medical Center, Ulm, Germany
| | - David Capper
- Berlin School of Integrative Oncology, Charité - Medical University of Berlin, Berlin, Germany
- Department of Neuropathology, Charité, Medical University of Berlin, corporate member of Free University Berlin, Humboldt-University Berlin, and Berlin Institute of Health, Berlin, Germany
- German Cancer Consortium (DKTK); Partner Site Berlin, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Lora Dimitrova
- Department of Experimental Hematopathology, Institute of Pathology, Charité Medical University, Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Michael Hummel
- Department of Experimental Hematopathology, Institute of Pathology, Charité Medical University, Berlin, Charitéplatz 1, 10117, Berlin, Germany
- Berlin School of Integrative Oncology, Charité - Medical University of Berlin, Berlin, Germany
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14
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Abstract
Psychotropic Psilocybe mushrooms biosynthesize their principal natural product psilocybin in five steps, among them a phosphotransfer and two methyltransfer reactions, which consume one equivalent of 5'-adenosine triphosphate (ATP) and two equivalents of S-adenosyl-l-methionine (SAM). This short but co-substrate-intensive pathway requires nucleoside cofactor salvage to maintain high psilocybin production rates. We characterized the adenosine kinase (AdoK) and S-adenosyl-l-homocysteine (SAH) hydrolase (SahH) of Psilocybe cubensis. Both enzymes are directly or indirectly involved in regenerating SAM. qRT-PCR expression analysis revealed an induced expression of the genes in the fungal primordia and carpophores. A one-pot in vitro reaction with the N-methyltransferase PsiM of the psilocybin pathway demonstrates a concerted action with SahH to facilitate biosynthesis by removal of accumulating SAH.
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Affiliation(s)
- Richard Demmler
- Department Pharmaceutical MicrobiologyHans-Knöll-InstituteFriedrich-Schiller-UniversitätBeutenbergstrasse 11a07745JenaGermany
| | - Janis Fricke
- Department Pharmaceutical MicrobiologyHans-Knöll-InstituteFriedrich-Schiller-UniversitätBeutenbergstrasse 11a07745JenaGermany
| | - Sebastian Dörner
- Department Pharmaceutical MicrobiologyHans-Knöll-InstituteFriedrich-Schiller-UniversitätBeutenbergstrasse 11a07745JenaGermany
| | - Markus Gressler
- Department Pharmaceutical MicrobiologyHans-Knöll-InstituteFriedrich-Schiller-UniversitätBeutenbergstrasse 11a07745JenaGermany
| | - Dirk Hoffmeister
- Department Pharmaceutical MicrobiologyHans-Knöll-InstituteFriedrich-Schiller-UniversitätBeutenbergstrasse 11a07745JenaGermany
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15
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Liang Q, Ou M, Ren Y, Yao Z, Hu R, Li J, Liu Y, Wang W. Molecular cloning, characterization and expression analysis of S- adenosyl- L-homocysteine hydrolase (SAHH) during the pathogenic infection of Litopenaeus vannamei by Vibrio alginolyticus. Fish Shellfish Immunol 2019; 88:284-292. [PMID: 30849500 DOI: 10.1016/j.fsi.2019.02.058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 02/22/2019] [Accepted: 02/25/2019] [Indexed: 06/09/2023]
Abstract
SAHH is an enzyme, playing a significant role in the catalyzation of the S-adenosyl homocysteine (SAH) into homocysteine (Hcy) and adenosine (Ado). However, little is known information of the enzyme in crustaceans. In the present study, SAHH cDNA was cloned from Litopenaeus vannamei (LvSAHH). The full length of the LvSAHH was found, containing a 5' UTR of 119 bp, an ORF of 1236 bp and a 3' UTR of 549 bp. The LvSAHH gene encoded a polypeptide of 411 amino acids with an estimated molecular mass of 45.55 kD and a predicted isoelectronic point (pI) of 5.63. Comparison of the deduced amino acid sequence showed that LvSAHH has high identity (70 %-82%) with other known species. qRT-PCR analysis revealed that LvSAHH mRNA was broadly expressed in all of the examined tissues, while the highest expression level was observed in muscle, followed by the expression in stomach, gill, pleopod, hepatopancreas, heart, eye and intestine. Subcellular localization analysis revealed that LvSAHH was predominantly localized in the cytoplasm and nucleus. LvSAHH mRNA expression levels in hepatopancreas and gill were significantly up-regulated from 6 to 48 h after V. alginolyticus injection and reached the highest level (15-fold and 8-fold, p < 0.01) at 24 h, respectively. Additionally, the Toll-like receptors (TLR) and interleukins-16 (IL-16) were detected in hepatopancreas and gill of LvSAHH-knockdown SAHH. LvRack1, LvToll1, LvToll2, LvToll3 and LvIL-16 transcripts were decreased significantly in LvSAHH-knockdown shrimp at 24 h post V. alginolyticus stimulation in hepatopancreas and gill. But LvToll3 was no significant difference in gill. In summary, these results indicated that LvSAHH may play a regulatory role in the invertebrate innate immune defense by regulating TLR and IL-16 expression.
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Affiliation(s)
- QingJian Liang
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China
| | - MuFei Ou
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China
| | - YingHao Ren
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China
| | - ZeNa Yao
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China
| | - Rui Hu
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China
| | - JieZhen Li
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China
| | - Yuan Liu
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China
| | - Weina Wang
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China.
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16
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Aranda S, Alcaine-Colet A, Blanco E, Borràs E, Caillot C, Sabidó E, Di Croce L. Chromatin capture links the metabolic enzyme AHCY to stem cell proliferation. Sci Adv 2019; 5:eaav2448. [PMID: 30854431 PMCID: PMC6402848 DOI: 10.1126/sciadv.aav2448] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 01/28/2019] [Indexed: 05/19/2023]
Abstract
Profiling the chromatin-bound proteome (chromatome) in a simple, direct, and reliable manner might be key to uncovering the role of yet uncharacterized chromatin factors in physiology and disease. Here, we have designed an experimental strategy to survey the chromatome of proliferating cells by using the DNA-mediated chromatin pull-down (Dm-ChP) technology. Our approach provides a global view of cellular chromatome under normal physiological conditions and enables the identification of chromatin-bound proteins de novo. Integrating Dm-ChP with genomic and functional data, we have discovered an unexpected chromatin function for adenosylhomocysteinase, a major one-carbon pathway metabolic enzyme, in gene activation. Our study reveals a new regulatory axis between the metabolic state of pluripotent cells, ribosomal protein production, and cell division during the early phase of embryo development, in which the metabolic flux of methylation reactions is favored in a local milieu.
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Affiliation(s)
- Sergi Aranda
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
- Corresponding author. (S.A.); (L.D.C.)
| | - Anna Alcaine-Colet
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Enrique Blanco
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Eva Borràs
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Claire Caillot
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Eduard Sabidó
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Luciano Di Croce
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Pg. Lluis Companys 23, Barcelona 08010, Spain
- Corresponding author. (S.A.); (L.D.C.)
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17
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Zeng L, Sun S, Han D, Liu Y, Liu H, Feng H, Wang Y. Long non-coding RNA H19/SAHH axis epigenetically regulates odontogenic differentiation of human dental pulp stem cells. Cell Signal 2018; 52:65-73. [PMID: 30165103 DOI: 10.1016/j.cellsig.2018.08.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/03/2018] [Accepted: 08/25/2018] [Indexed: 12/22/2022]
Abstract
Long noncoding RNAs (lncRNAs) are emerging as important regulators in molecular processes and may play vital roles in odontogenic differentiation of human dental pulp stem cells (hDPSCs). However, their functions remain to be elucidated. As lncRNA H19 is one of the most classical lncRNA, which plays essential roles in cellular differentiation, thus we explored the effects and mechanisms of H19 in odontogenic differentiation of hDPSCs. Stable overexpression and knockdown of H19 in hDPSCs were constructed using recombinant lentiviruses containing H19 and short hairpin-H19 expression cassettes, respectively. Alkaline phosphatase (ALP) assay, Alizarin red staining assay, von kossa staining, quantitative polymerase chain reaction (qPCR), Western blot analysis, and immunofluorescent staining results indicated that overexpression of H19 in hDPSCs positively regulates the odontogenic differentiation of hDPSCs, while knockdown of H19 in hDPSCs inhibits odontogenic differentiation of hDPSCs. Further, we found that H19 promotes the odontogenic differentiation of hDPSCs through S-adenosylhomocysteine hydrolase (SAHH) epigenetically regulates the methylation and expression of distal-less homeobox (DLX3) gene. Herein, for the first time, we determined that H19/SAHH axis epigentically regulates odontogenic differentiaiton of hDPSCs by inhibiting the DNA methyltransferase 3B (DNMT3B)-mediated methylation of DLX3. Our findings provide a new insight into how H19/SAHH axis play its role in odontogenic differentiation of hDPSCs, and would be helpful in developing therapeutic approaches for dentin regeneration based on stem cells.
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Affiliation(s)
- Li Zeng
- Department Prosthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, PR China
| | - Shichen Sun
- Department Prosthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, PR China
| | - Dong Han
- Department Prosthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, PR China
| | - Yang Liu
- Department Prosthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, PR China
| | - Haochen Liu
- Department Prosthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, PR China
| | - Hailan Feng
- Department Prosthodontics, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, PR China.
| | - Yixiang Wang
- Central Laboratory, Peking University School and Hospital of Stomatology, PR China.
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Fu Y, Wang W, Li X, Liu Y, Niu Y, Zhang B, Nie J, Pan B, Wang R, Yang J. LncRNA H19 interacts with S-adenosylhomocysteine hydrolase to regulate LINE-1 Methylation in human lung-derived cells exposed to Benzo[a]pyrene. Chemosphere 2018; 207:84-90. [PMID: 29772428 DOI: 10.1016/j.chemosphere.2018.05.048] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/04/2018] [Accepted: 05/08/2018] [Indexed: 06/08/2023]
Abstract
Benzo [a]pyrene (BaP) have been demonstrated to induce lung cancer risk in humans and many different animal models, with aberrant gene methylation as one of the epigenetic errors; however, the molecular mechanisms remain unclear. Here, we used three types of human lung-derived cells with BaP exposure as a model and attempted to investigate the long non-coding RNA (lncRNA) H19/S-adenosylhomocysteine hydrolase (SAHH) pathway that regulates gene methylation in vitro exposure to BaP. Results showed that compared to the controls, BaP-treated cells H19 expressions were increased in a dose- and time-dependent manner, whereas SAHH protein expressions were decreased. Indeed, H19 binds to and attenuates SAHH expressions and activity, and this interaction will be enhanced by BaP. However, suppression of H19 exaggerates SAHH protein expression and activity exposed to BaP. Although BaP-treated cells H19 single knockdown expectedly increased long interspersed nuclear elements-1 (LINE-1) methylation and inhibited benzo [a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE) -DNA adducts formation with altering SAHH protein expressions and activity, the double knockdown restored methylation to the control level and exacerbated BPDE-DNA adducts formation. Overall, our results uncover a H19/SAHH circuit involving gene-methylation alterations by carcinogen BaP.
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Affiliation(s)
- Ye Fu
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, China
| | - Wubin Wang
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, China
| | - Xuejing Li
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, China
| | - Yanli Liu
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, China
| | - Yingying Niu
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, China
| | - Bin Zhang
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, China
| | - Jisheng Nie
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, China
| | - Baolong Pan
- General Hospital of Taiyuan Iron & Steel (Group) Co., Ltd, Taiyuan 030008, China
| | - Ruisheng Wang
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, China
| | - Jin Yang
- Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, China.
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Tang Z, Qiu H, Luo L, Liu N, Zhong J, Kang K, Gou D. miR-34b Modulates Skeletal Muscle Cell Proliferation and Differentiation. J Cell Biochem 2017; 118:4285-4295. [PMID: 28422320 DOI: 10.1002/jcb.26079] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/18/2017] [Indexed: 12/22/2022]
Abstract
Myogenesis involves myoblast proliferation and differentiation to myocytes, followed by fusion and hypertrophy to form myotubes during muscle development. Increasing evidence showed that microRNAs (miRNAs) play important roles in the regulation of myogenesis. We have previously revealed that miR-34b is steadily increased during this process. This miRNA regulates differentiation in various cell types, though its function in myogenesis remains to be elucidated. In this study, we show that miR-34b represses muscle cell proliferation and promotes myotube formation. Our quantitative iTRAQ-based proteomic analysis reveals 97 proteins are regulated by miR-34b in mouse myoblast C2C12. We identified that miR-34b targets 14-3-3 protein gamma, adenosylhomocysteinase and nucleolin by binding to their 3'UTR. Further analysis of these proteins expression patterns show that nucleolin is a cognate target of miR-34b during myogenic differentiation. Here, we proved that a moderate reduction of nucleolin in cells enhanced the myotube formation. However, nucleolin is required for myogenesis, as cells with low levels of nucleolin reduced cell proliferation rate and are unable to differentiate. Our data demonstrated that nucleolin regulates myogenesis in a protein-abundance-dependent manner. J. Cell. Biochem. 118: 4285-4295, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Zhixiong Tang
- Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences, Shenzhen University, Shenzhen, Guangdong, 518060, China
| | - Huiling Qiu
- Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences, Shenzhen University, Shenzhen, Guangdong, 518060, China
- Biomedical Engineering, Health and Environmental Engineering, Shenzhen Technology University, Shenzhen, Guangdong, 518000, China
| | - Lan Luo
- Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences, Shenzhen University, Shenzhen, Guangdong, 518060, China
| | - Nian Liu
- Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences, Shenzhen University, Shenzhen, Guangdong, 518060, China
| | - Jiasheng Zhong
- Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences, Shenzhen University, Shenzhen, Guangdong, 518060, China
| | - Kang Kang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Shenzhen University Health Sciences Center, Shenzhen, 518000, China
| | - Deming Gou
- Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences, Shenzhen University, Shenzhen, Guangdong, 518060, China
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20
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Brzezinski K, Czyrko J, Sliwiak J, Nalewajko-Sieliwoniuk E, Jaskolski M, Nocek B, Dauter Z. S-adenosyl-L-homocysteine hydrolase from a hyperthermophile (Thermotoga maritima) is expressed in Escherichia coli in inactive form - Biochemical and structural studies. Int J Biol Macromol 2017; 104:584-596. [PMID: 28629859 PMCID: PMC7888557 DOI: 10.1016/j.ijbiomac.2017.06.065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [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: 03/30/2017] [Revised: 06/12/2017] [Accepted: 06/13/2017] [Indexed: 11/26/2022]
Abstract
Thermotoga maritima is a hyperthermophilic bacterium but its genome encodes a number of archaeal proteins including S-adenosyl-L-homocysteine hydrolase (SAHase), which regulates cellular methylation reactions. The question of proper folding and activity of proteins of extremophilic origin is an intriguing problem. When expressed in E.coli and purified (as a homotetramer) at room temperature, the hyperthermophilic SAHase from T.maritima was inactive. ITC study indicated that the protein undergoes heat-induced conformational changes, and enzymatic activity assays demonstrated that these changes are required to attain enzymatic activity. To explain the mechanism of thermal activation, two crystal structures of the inactive form of T. maritima SAHase (iTmSAHase) were determined for an incomplete binary complex with the reduced cofactor (NADH), and in a mixture of binary complexes with NADH and with adenosine. In contrast to active SAHases, in iTmSAHase only two of the four subunits contain a bound cofactor, predominantly in its non-reactive, reduced state. Moreover, the closed-like conformation of the cofactor-containing subunits precludes substrate delivery to the active site. The two other subunits cannot be involved in the enzymatic reaction either; although they have an open-like conformation, they do not contain the cofactor, whose binding site may be occupied by an adenosine molecule. The results suggest that this enzyme, when expressed in mesophilic cells, is arrested in the activity-incompatible conformation revealed by its crystal structures.
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Affiliation(s)
- Krzysztof Brzezinski
- Institute of Chemistry, University of Bialystok, Ciolkowskiego 1K, 15-245 Bialystok, Poland.
| | - Justyna Czyrko
- Institute of Chemistry, University of Bialystok, Ciolkowskiego 1K, 15-245 Bialystok, Poland
| | - Joanna Sliwiak
- Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | | | - Mariusz Jaskolski
- Center for Biocrystallographic Research, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland; Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, Umultowska 89b, 61-614 Poznan, Poland
| | - Boguslaw Nocek
- Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Zbigniew Dauter
- Synchrotron Radiation Research Section, MCL, National Cancer Institute, Argonne National Laboratory, Argonne, IL 60439, USA
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21
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Grbeša I, Kalo A, Belužić R, Kovačević L, Lepur A, Rokić F, Hochberg H, Kanter I, Simunović V, Muńoz-Torres PM, Shav-Tal Y, Vugrek O. Mutations in S-adenosylhomocysteine hydrolase (AHCY) affect its nucleocytoplasmic distribution and capability to interact with S-adenosylhomocysteine hydrolase-like 1 protein. Eur J Cell Biol 2017. [PMID: 28647132 DOI: 10.1016/j.ejcb.2017.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
S-adenosylhomocysteine hydrolase (AHCY) is thought to be located at the sites of ongoing AdoMet-dependent methylation, presumably in the cell nucleus. Endogenous AHCY is located both in cytoplasm and the nucleus. Little is known regarding mechanisms that drive its subcellular distribution, and even less is known on how mutations causing AHCY deficiency affect its intracellular dynamics. Using fluorescence microscopy and GFP-tagged AHCY constructs we show significant differences in the intensity ratio between nuclei and cytoplasm for mutant proteins when compared with wild type AHCY. Interestingly, nuclear export of AHCY is not affected by leptomycin B. Systematic deletions showed that AHCY has two regions, located at both sides of the protein, that contribute to its nuclear localization, implying the interaction with various proteins. In order to evaluate protein interactions in vivo we engaged in bimolecular fluorescence complementation (BiFC) based studies. We investigated previously assumed interaction with AHCY-like-1 protein (AHCYL1), a paralog of AHCY. Indeed, significant interaction between both proteins exists. Additionally, silencing AHCYL1 leads to moderate inhibition of nuclear export of endogenous AHCY.
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Affiliation(s)
- Ivana Grbeša
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia; The Mina & Everard Goodman Faculty of Life Sciences and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Alon Kalo
- The Mina & Everard Goodman Faculty of Life Sciences and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Robert Belužić
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Lucija Kovačević
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Adriana Lepur
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Filip Rokić
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Hodaya Hochberg
- The Mina & Everard Goodman Faculty of Life Sciences and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Itamar Kanter
- The Mina & Everard Goodman Faculty of Life Sciences and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Vesna Simunović
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Pau Marc Muńoz-Torres
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Yaron Shav-Tal
- The Mina & Everard Goodman Faculty of Life Sciences and Institute of Nanotechnology, Bar-Ilan University, Ramat Gan 52900, Israel
| | - Oliver Vugrek
- Laboratory for Advanced Genomics, Department of Molecular Medicine, Ruđer Bošković Institute, 10000 Zagreb, Croatia.
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Zhou J, Yang L, Zhong T, Mueller M, Men Y, Zhang N, Xie J, Giang K, Chung H, Sun X, Lu L, Carmichael GG, Taylor HS, Huang Y. H19 lncRNA alters DNA methylation genome wide by regulating S-adenosylhomocysteine hydrolase. Nat Commun 2015; 6:10221. [PMID: 26687445 PMCID: PMC4703905 DOI: 10.1038/ncomms10221] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [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: 06/29/2015] [Accepted: 11/16/2015] [Indexed: 02/05/2023] Open
Abstract
DNA methylation is essential for mammalian development and physiology. Here we report that the developmentally regulated H19 lncRNA binds to and inhibits S-adenosylhomocysteine hydrolase (SAHH), the only mammalian enzyme capable of hydrolysing S-adenosylhomocysteine (SAH). SAH is a potent feedback inhibitor of S-adenosylmethionine (SAM)-dependent methyltransferases that methylate diverse cellular components, including DNA, RNA, proteins, lipids and neurotransmitters. We show that H19 knockdown activates SAHH, leading to increased DNMT3B-mediated methylation of an lncRNA-encoding gene Nctc1 within the Igf2-H19-Nctc1 locus. Genome-wide methylation profiling reveals methylation changes at numerous gene loci consistent with SAHH modulation by H19. Our results uncover an unanticipated regulatory circuit involving broad epigenetic alterations by a single abundantly expressed lncRNA that may underlie gene methylation dynamics of development and diseases and suggest that this mode of regulation may extend to other cellular components.
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Affiliation(s)
- Jichun Zhou
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Department of Surgical Oncology, Affiliated Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310016, China
| | - Lihua Yang
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Department of Obstetrics and Gynecology, Tianjin Renmin Hospital, Tianjin 300000, China
| | - Tianyu Zhong
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Department of Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi 341000, China
| | - Martin Mueller
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Department of Obstetrics and Gynecology, University Hospital, Bern 3012, Switzerland
| | - Yi Men
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Department of Head and Neck Surgery, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China
| | - Na Zhang
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
| | - Juanke Xie
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
- Reproductive Medical Center, Henan Provincial People's Hospital, Zhengzhou, Henan 450003, China
| | - Karolyn Giang
- Zymo Research Corporation, Irvine, California 92614, USA
| | - Hunter Chung
- Zymo Research Corporation, Irvine, California 92614, USA
| | - Xueguang Sun
- Zymo Research Corporation, Irvine, California 92614, USA
| | - Lingeng Lu
- Department of Chronic Diseases Epidemiology, Yale School of Public Health, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Gordon G Carmichael
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
| | - Hugh S Taylor
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
| | - Yingqun Huang
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut 06510, USA
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Stender S, Chakrabarti RS, Xing C, Gotway G, Cohen JC, Hobbs HH. Adult-onset liver disease and hepatocellular carcinoma in S-adenosylhomocysteine hydrolase deficiency. Mol Genet Metab 2015; 116:269-74. [PMID: 26527160 PMCID: PMC4733618 DOI: 10.1016/j.ymgme.2015.10.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [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: 09/08/2015] [Revised: 10/23/2015] [Accepted: 10/23/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND The etiology of liver disease remains elusive in some adults presenting with severe hepatic dysfunction. METHODS AND RESULTS Here we describe a woman of Pakistani descent who had elevated aminotransferases at age 23. She developed muscle weakness in her mid-20s, and was diagnosed with hepatocellular carcinoma at age 29. She died without a diagnosis at age 32 after having a liver transplant. Exome sequencing revealed that she was homozygous for a missense mutation (R49H) in AHCY, the gene encoding S-adenosylhomocysteine (SAH) hydrolase. SAH hydrolase catalyzes the final step in conversion of methionine to homocysteine and inactivating mutations in this enzyme cause a rare autosomal recessive disorder, SAH hydrolase deficiency, that typically presents in infancy. An asymptomatic 7-year old son of the proband is also homozygous for the AHCY-R49H mutation and has elevated serum aminotransferase levels, as well as markedly elevated serum levels of SAH, S-adenosylmethionine (SAM), and methionine, which are hallmarks of SAH hydrolase deficiency. CONCLUSION This report reveals several new aspects of SAH hydrolase deficiency. Affected women with SAH hydrolase deficiency can give birth to healthy children. SAH hydrolase deficiency can remain asymptomatic in childhood, and the disorder can be associated with early onset hepatocellular carcinoma. The measurement of serum amino acids should be considered in patients with liver disease or hepatocellular carcinoma of unknown etiology.
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Affiliation(s)
- Stefan Stender
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, United States; McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, United States.
| | - Rima S Chakrabarti
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, United States; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, United States.
| | - Chao Xing
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, United States.
| | - Garrett Gotway
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States.
| | - Jonathan C Cohen
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, United States.
| | - Helen H Hobbs
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, United States; McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, United States; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, United States.
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24
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He P, Zhao L, Zhu L, Weinman EJ, De Giorgio R, Koval M, Srinivasan S, Yun CC. Restoration of Na+/H+ exchanger NHE3-containing macrocomplexes ameliorates diabetes-associated fluid loss. J Clin Invest 2015; 125:3519-31. [PMID: 26258413 DOI: 10.1172/jci79552] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 06/25/2015] [Indexed: 01/19/2023] Open
Abstract
Diarrhea is one of the troublesome complications of diabetes, and the underlying causes of this problem are complex. Here, we investigated whether altered electrolyte transport contributes to diabetic diarrhea. We found that the expression of Na+/H+ exchanger NHE3 and several scaffold proteins, including NHE3 regulatory factors (NHERFs), inositol trisphosphate (IP₃) receptor-binding protein released with IP₃ (IRBIT), and ezrin, was decreased in the intestinal brush border membrane (BBM) of mice with streptozotocin-induced diabetes. Treatment of diabetic mice with insulin restored intestinal NHE3 activity and fluid absorption. Molecular analysis revealed that NHE3, NHERF1, IRBIT, and ezrin form macrocomplexes, which are perturbed under diabetic conditions, and insulin administration reconstituted these macrocomplexes and restored NHE3 expression in the BBM. Silencing of NHERF1 or IRBIT prevented NHE3 trafficking to the BBM and insulin-dependent NHE3 activation. IRBIT facilitated the interaction of NHE3 with NHERF1 via protein kinase D2-dependent phosphorylation. Insulin stimulated ezrin phosphorylation, which enhanced the interaction of ezrin with NHERF1, IRBIT, and NHE3. Additionally, oral administration of lysophosphatidic acid (LPA) increased NHE3 activity and fluid absorption in diabetic mice via an insulin-independent pathway. Together, these findings indicate the importance of NHE3 in diabetic diarrhea and suggest LPA administration as a potential therapeutic strategy for management of diabetic diarrhea.
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Nakao A, Suzuki H, Ueno H, Iwasaki H, Setsuta T, Kashima A, Sunada S. Discovery and structural analyses of S-adenosyl-L-homocysteine hydrolase inhibitors based on non-adenosine analogs. Bioorg Med Chem 2015; 23:4952-4969. [PMID: 26037610 DOI: 10.1016/j.bmc.2015.05.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 05/09/2015] [Accepted: 05/11/2015] [Indexed: 11/17/2022]
Abstract
Optimization of a new series of S-adenosyl-L-homocysteine hydrolase (AdoHcyase) inhibitors based on non-adenosine analogs led to very potent compounds 14n, 18a, and 18b with IC50 values of 13 ± 3, 5.0 ± 2.0, and 8.5 ± 3.1 nM, respectively. An X-ray crystal structure of AdoHcyase with NAD(+) and 18a showed a novel open form co-crystal structure. 18a in the co-crystals formed intramolecular eight membered ring hydrogen bond formations. A single crystal X-ray structure of 14n also showed an intramolecular eight-membered ring hydrogen bond interaction.
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Affiliation(s)
- Akira Nakao
- Research Division, Mitsubishi Tanabe Pharma Corporation, 1000, Kamoshida-cho, Aoba-ku, Yokohama 227-0033, Japan.
| | - Hiroko Suzuki
- Research Division, Mitsubishi Tanabe Pharma Corporation, 1000, Kamoshida-cho, Aoba-ku, Yokohama 227-0033, Japan
| | - Hiroaki Ueno
- Research Division, Mitsubishi Tanabe Pharma Corporation, 1000, Kamoshida-cho, Aoba-ku, Yokohama 227-0033, Japan
| | - Hiroshi Iwasaki
- Research Division, Mitsubishi Tanabe Pharma Corporation, 1000, Kamoshida-cho, Aoba-ku, Yokohama 227-0033, Japan
| | - Tomofumi Setsuta
- Research Division, Mitsubishi Tanabe Pharma Corporation, 1000, Kamoshida-cho, Aoba-ku, Yokohama 227-0033, Japan
| | - Akiko Kashima
- Research Division, Mitsubishi Tanabe Pharma Corporation, 1000, Kamoshida-cho, Aoba-ku, Yokohama 227-0033, Japan
| | - Shinji Sunada
- Research Division, Mitsubishi Tanabe Pharma Corporation, 1000, Kamoshida-cho, Aoba-ku, Yokohama 227-0033, Japan
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Kalani A, Kamat PK, Givvimani S, Brown K, Metreveli N, Tyagi SC, Tyagi N. Nutri-epigenetics ameliorates blood-brain barrier damage and neurodegeneration in hyperhomocysteinemia: role of folic acid. J Mol Neurosci 2014; 52:202-15. [PMID: 24122186 DOI: 10.1007/s12031-013-0122-5] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Accepted: 09/10/2013] [Indexed: 01/01/2023]
Abstract
Epigenetic mechanisms underlying nutrition (nutrition epigenetics) are important in understanding human health. Nutritional supplements, for example folic acid, a cofactor in one-carbon metabolism, regulate epigenetic alterations and may play an important role in the maintenance of neuronal integrity. Folic acid also ameliorates hyperhomocysteinemia, which is a consequence of elevated levels of homocysteine. Hyperhomocysteinemia induces oxidative stress that may epigenetically mediate cerebrovascular remodeling and leads to neurodegeneration; however, the mechanisms behind such alterations remain unclear. Therefore, the present study was designed to observe the protective effects of folic acid against hyperhomocysteinemia-induced epigenetic and molecular alterations leading to neurotoxic cascades. To test this hypothesis, we employed 8-weeks-old male wild-type (WT) cystathionine-beta-synthase heterozygote knockout methionine-fed (CBS+/− + Met), WT, and CBS+/− + Met mice supplemented with folic acid (FA) [WT + FA and CBS+/− + Met + FA, respectively, 0.0057-μg g−1 day−1 dose in drinking water/4 weeks]. Hyperhomocysteinemia in CBS+/− + Met mouse brain was accompanied by a decrease in methylenetetrahydrofolate reductase and an increase in S-adenosylhomocysteine hydrolase expression, symptoms of oxidative stress, upregulation of DNA methyltransferases, rise in matrix metalloproteinases, a drop in the tissue inhibitors of metalloproteinases, decreased expression of tight junction proteins, increased permeability of the blood-brain barrier, neurodegeneration, and synaptotoxicity. Supplementation of folic acid to CBS+/− + Met mouse brain led to a decrease in the homocysteine level and rescued pathogenic and epigenetic alterations, showing its protective efficacy against homocysteine-induced neurotoxicity.
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Plouviez S, Faure B, Le Guen D, Lallier FH, Bierne N, Jollivet D. A new barrier to dispersal trapped old genetic clines that escaped the Easter Microplate tension zone of the Pacific vent mussels. PLoS One 2013; 8:e81555. [PMID: 24312557 PMCID: PMC3846894 DOI: 10.1371/journal.pone.0081555] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 10/21/2013] [Indexed: 11/23/2022] Open
Abstract
Comparative phylogeography of deep-sea hydrothermal vent species has uncovered several genetic breaks between populations inhabiting northern and southern latitudes of the East Pacific Rise. However, the geographic width and position of genetic clines are variable among species. In this report, we further characterize the position and strength of barriers to gene flow between populations of the deep-sea vent mussel Bathymodiolus thermophilus. Eight allozyme loci and DNA sequences of four nuclear genes were added to previously published sequences of the cytochrome c oxidase subunit I gene. Our data confirm the presence of two barriers to gene flow, one located at the Easter Microplate (between 21°33′S and 31°S) recently described as a hybrid zone, and the second positioned between 7°25′S and 14°S with each affecting different loci. Coalescence analysis indicates a single vicariant event at the origin of divergence between clades for all nuclear loci, although the clines are now spatially discordant. We thus hypothesize that the Easter Microplate barrier has recently been relaxed after a long period of isolation and that some genetic clines have escaped the barrier and moved northward where they have subsequently been trapped by a reinforcing barrier to gene flow between 7°25′S and 14°S.
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Affiliation(s)
- Sophie Plouviez
- Université Pierre et Marie Curie-Paris 6, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France
- CNRS UMR 7144, Station Biologique de Roscoff, Roscoff, France
- Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University, Beaufort, North Carolina, United States of America
- * E-mail:
| | - Baptiste Faure
- Université Pierre et Marie Curie-Paris 6, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France
- CNRS UMR 7144, Station Biologique de Roscoff, Roscoff, France
- Université Montpellier 2, Montpellier, France
- CNRS UMR 5554, Institut des Sciences de l’Evolution, Station Méditerranéenne de l’Environnement Littoral, Sète, France
| | - Dominique Le Guen
- Université Pierre et Marie Curie-Paris 6, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France
- CNRS UMR 7144, Station Biologique de Roscoff, Roscoff, France
| | - François H. Lallier
- Université Pierre et Marie Curie-Paris 6, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France
- CNRS UMR 7144, Station Biologique de Roscoff, Roscoff, France
| | - Nicolas Bierne
- Université Montpellier 2, Montpellier, France
- CNRS UMR 5554, Institut des Sciences de l’Evolution, Station Méditerranéenne de l’Environnement Littoral, Sète, France
| | - Didier Jollivet
- Université Pierre et Marie Curie-Paris 6, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France
- CNRS UMR 7144, Station Biologique de Roscoff, Roscoff, France
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Zhou LT, Jia S, Wan PJ, Kong Y, Guo WC, Ahmat T, Li GQ. RNA interference of a putative S-adenosyl-L-homocysteine hydrolase gene affects larval performance in Leptinotarsa decemlineata (Say). J Insect Physiol 2013; 59:1049-1056. [PMID: 23973411 DOI: 10.1016/j.jinsphys.2013.08.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 08/02/2013] [Accepted: 08/02/2013] [Indexed: 06/02/2023]
Abstract
In Leptinotarsa decemlineata, juvenile hormones (JHs) play primary roles in the regulation of metamorphosis, reproduction and diapause. In JH biosynthetic pathway in insect corpora allata, methylation of farnesoic acid or JH acid using S-adenosyl-L-methionine generates a potent feedback inhibitor S-adenosyl-L-homocysteine (AdoHcy). Rapid removal of AdoHcy is hypothesized to be essential for JH synthesis. AdoHcy hydrolase (SAHase) is the only eukaryotic enzyme catalyzing the removal. In the present paper, we firstly cloned a putative LdSAHase gene from L. decemlineata. The cDNA consists of 1806 bp and encodes a 525 amino acid protein. LdSAHase was expressed in all developmental stages. The gene had the highest and the lowest level of transcription respectively in the 3rd- and 4th-instars' heads that contain corpora allata, which was positively correlated with JH titer in the haemolymph and the mRNA level of a JH early-inducible gene, the Krüppel homolog 1 gene (Kr-h1). Secondly, dietary ingestion of bacterially-expressed LdSAHase-dsRNA significantly decreased LdSAHase and LdKr-h1 mRNA levels, reduced JH titer, and caused the death of the larvae, and the failure of pupation and adult emergence. After continuous exposure for 12 days, 42% of the larvae died, 65% of the prepupae failed to pupate and 100% of the pupae failed to emerge. Moreover, RNAi-mediated LdSAHase knockdown also reduced larval developing time, and decreased larval weight. Lastly, application of JH analogue pyriproxyfen to LdSAHase-dsRNA-exposed larvae did not greatly increase LdSAHase expression level and JH content, but up-regulated LdKr-h1 mRNA level. Expectedly, pyriproxyfen application could partially rescue the negative effects on the survival and the development. Thus, our results support the hypothesis that SAHase plays a critical role in JH biosynthesis in insects.
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Affiliation(s)
- Li-Tao Zhou
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
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Cañizares MC, Lozano-Durán R, Canto T, Bejarano ER, Bisaro DM, Navas-Castillo J, Moriones E. Effects of the crinivirus coat protein-interacting plant protein SAHH on post-transcriptional RNA silencing and its suppression. Mol Plant Microbe Interact 2013; 26:1004-15. [PMID: 23697374 DOI: 10.1094/mpmi-02-13-0037-r] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
In plants, post-transcriptional gene silencing (PTGS) is a sequence-specific mechanism of RNA degradation induced by double-stranded RNA (dsRNA), which is processed into small interfering RNAs (siRNAs). siRNAs are methylated and, thereby, stabilized by the activity of the S-adenosylmethionine-dependent RNA methyltransferase HEN1. PTGS is amplified by host-encoded RNA-dependent RNA polymerases (RDR), which generate dsRNA that is processed into secondary siRNAs. To counteract this RNA silencing-mediated response of the host, plant viruses express proteins with silencing suppression activity. Here, we report that the coat protein (CP) of crinivirus (family Closteroviridae, genus Crinivirus) Tomato chlorosis virus, a known suppressor of silencing, interacts with S-adenosylhomocysteine hydrolase (SAHH), a plant protein essential for sustaining the methyl cycle and S-adenosylmethionine-dependent methyltransferase activity. Our results show that, by contributing to an increased accumulation of secondary siRNAs generated by the action of RDR6, SAHH enhances local RNA silencing. Although downregulation of SAHH prevents local silencing, it enhances the spread of systemic silencing. Our results also show that SAHH is important in the suppression of local RNA silencing not only by the crinivirus Tomato chlorosis virus CP but also by the multifunctional helper component-proteinase of the potyvirus Potato virus Y.
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Affiliation(s)
- M Carmen Cañizares
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-Consejo Superior de Investigaciones Científicas IHSM-UMA-CSIC, Estación Experimental La Mayora, Málaga, Spain
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Planque C, Dairou J, Noll C, Bui LC, Ripoll C, Guedj F, Delabar JM, Janel N. Mice deficient in cystathionine beta synthase display increased Dyrk1A and SAHH activities in brain. J Mol Neurosci 2013; 50:1-6. [PMID: 22700376 DOI: 10.1007/s12031-012-9835-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [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: 05/08/2012] [Accepted: 06/05/2012] [Indexed: 02/07/2023]
Abstract
Hyperhomocysteinemia is associated with brain disease. However, biological actions linking hyperhomocysteinemia to neuronal abnormalities are not well understood. We recently found a relationship between Dyrk1A protein expression, a serine/threonine kinase that might be responsible for cognitive functions in Down's syndrome, and hepatic S-adenosylhomocysteine hydrolase (SAHH) activity, which plays a key role in S-adenosylmethionine-dependent methylation reactions. Considering the role of methylation and Dyrk1A in cognitive functions, the aim of this study was to investigate the relationship between Dyrk1A and SAHH activity in brain of hyperhomocysteinemic mice. We found an increase in Dyrk1A protein expression and activity in brain of hyperhomocysteinemic mice, concomitant with an increased SAHH activity. The effect of overexpression of protein Dyrk1A on SAHH activity was confirmed in brain of Dyrk1A transgenic mice, and additionally we found a positive correlation between Dyrk1A and SAHH activity. These observations suggest a potential effect of Dyrk1A on brain phenotypes linked to hyperhomocysteinemia.
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Affiliation(s)
- Chris Planque
- Unit of Functional and Adaptative Biology, University of Paris Diderot, Sorbonne Paris Cité, EAC-CNRS 4413, 75013 Paris, France
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Zheng D, Zhang S, Zhou X, Wang C, Xiang P, Zheng Q, Xu JR. The FgHOG1 pathway regulates hyphal growth, stress responses, and plant infection in Fusarium graminearum. PLoS One 2012; 7:e49495. [PMID: 23166686 PMCID: PMC3498113 DOI: 10.1371/journal.pone.0049495] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 10/09/2012] [Indexed: 11/18/2022] Open
Abstract
Fusarium head blight (FHB) caused by Fusarium graminearum is a destructive disease of wheat and barley worldwide. In a previous study of systematic characterization of protein kinase genes in F. graminearum, mutants of three putative components of the osmoregulation MAP kinase pathway were found to have distinct colony morphology and hyphal growth defects on PDA plates. Because the osmoregulation pathway is not known to regulate aerial hyphal growth and branching, in this study we further characterized the functions of the FgHog1 pathway in growth, pathogenesis, and development. The Fghog1, Fgpbs2, and Fgssk2 mutants were all reduced in growth rate, aerial hyphal growth, and hyphal branching angle. These mutants were not only hypersensitive to osmotic stress but also had increased sensitivity to oxidative, cytoplasm membrane, and cell wall stresses. The activation of FgHog1 was blocked in the Fgpbs2 and Fgssk2 mutants, indicating the sequential activation of FgSsk2-FgPbs2-FgHog1 cascade. Interestingly, the FgHog1 MAPK pathway mutants appeared to be sensitive to certain compounds present in PDA. They were female sterile but retained male fertility. We also used the metabolomics profiling approach to identify compatible solutes that were accumulated in the wild type but not in the Fghog1 deletion mutant. Overall, our results indicate that the FgSsk2-FgPbs2-FgHog1 MAPK cascade is important for regulating hyphal growth, branching, plant infection, and hyperosmotic and general stress responses in F. graminearum.
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Affiliation(s)
- Dawei Zheng
- NWAFU-PU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Shijie Zhang
- NWAFU-PU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Xiaoying Zhou
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
- * E-mail: (XZ); (JX)
| | - Chenfang Wang
- NWAFU-PU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Ping Xiang
- NWAFU-PU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Qian Zheng
- NWAFU-PU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Jin-Rong Xu
- NWAFU-PU Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
- * E-mail: (XZ); (JX)
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Jeong W, Kim J, Ahn SE, Lee SI, Bazer FW, Han JY, Song G. AHCYL1 is mediated by estrogen-induced ERK1/2 MAPK cell signaling and microRNA regulation to effect functional aspects of the avian oviduct. PLoS One 2012; 7:e49204. [PMID: 23145124 PMCID: PMC3492294 DOI: 10.1371/journal.pone.0049204] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 10/07/2012] [Indexed: 12/18/2022] Open
Abstract
S-adenosylhomocysteine hydrolase-like protein 1 (AHCYL1), also known as IP(3) receptor-binding protein released with IP(3) (IRBIT), regulates IP(3)-induced Ca(2+) release into the cytoplasm of cells. AHCYL1 is a critical regulator of early developmental stages in zebrafish, but little is known about the function of AHCYL1 or hormonal regulation of expression of the AHCYL1 gene in avian species. Therefore, we investigated differential expression profiles of the AHCYL1 gene in various adult organs and in oviducts from estrogen-treated chickens. Chicken AHCYL1 encodes for a protein of 540 amino acids that is highly conserved and has considerable homology to mammalian AHCYL1 proteins (>94% identity). AHCYL1 mRNA was expressed abundantly in various organs of chickens. Further, the synthetic estrogen agonist induced AHCYL1 mRNA and protein predominantly in luminal and glandular epithelial cells of the chick oviduct. In addition, estrogen activated AHCYL1 through the ERK1/2 signal transduction cascade and that activated expression of AHCYL1 regulated genes affecting oviduct development in chicks as well as calcium release in epithelial cells of the oviduct. Also, microRNAs, miR-124a, miR-1669, miR-1710 and miR-1782 influenced AHCYL1 expression in vitro via its 3'-UTR which suggests that post-transcriptional events are involved in the regulation of AHCYL1 expression in the chick oviduct. In conclusion, these results indicate that AHCYL1 is a novel estrogen-stimulated gene expressed in epithelial cells of the chicken oviduct that likely affects growth, development and calcium metabolism of the mature oviduct of hens via an estrogen-mediated ERK1/2 MAPK cell signaling pathway.
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Affiliation(s)
- Wooyoung Jeong
- WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
| | - Jinyoung Kim
- WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
| | - Suzie E. Ahn
- WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
| | - Sang In Lee
- WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
| | - Fuller W. Bazer
- WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
- Center for Animal Biotechnology and Genomics and Department of Animal Science, Texas A&M University, College Station, Texas, United States of America
| | - Jae Yong Han
- WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
| | - Gwonhwa Song
- WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea
- * E-mail:
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Honzík T, Magner M, Krijt J, Sokolová J, Vugrek O, Belužić R, Barić I, Hansíkova H, Elleder M, Veselá K, Bauerová L, Ondrušková N, Ješina P, Zeman J, Kožich V. Clinical picture of S-adenosylhomocysteine hydrolase deficiency resembles phosphomannomutase 2 deficiency. Mol Genet Metab 2012; 107:611-3. [PMID: 22959829 DOI: 10.1016/j.ymgme.2012.08.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 08/14/2012] [Accepted: 08/14/2012] [Indexed: 10/28/2022]
Abstract
We report on the seventh known patient with S-adenosylhomocysteine hydrolase (SAHH) deficiency presenting at birth with features resembling phosphomannomutase 2 (PMM2-CDG Ia) deficiency. Plasma methionine and total homocysteine levels were normal at 2 months and increased only after the 8th month of age. SAHH deficiency was confirmed at 4.5 years of age by showing decreased SAHH activity (11% in both erythrocytes and fibroblasts), and compound heterozygosity for a known mutation c.145C>T (p.R49C) and a novel variant c.211G>A (p.G71S) in the AHCY gene. Retrospective analysis of clinical features revealed striking similarities between SAHH deficiency and the PMM2-CDG Ia.
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Affiliation(s)
- Tomáš Honzík
- First Faculty of Medicine, Institute of Inherited Metabolic Disorders, Charles University in Prague and General University Hospital in Prague, Czech Republic
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Chang KH, Chen YC, Wu YR, Lee WF, Chen CM. Downregulation of genes involved in metabolism and oxidative stress in the peripheral leukocytes of Huntington's disease patients. PLoS One 2012; 7:e46492. [PMID: 23029535 PMCID: PMC3459918 DOI: 10.1371/journal.pone.0046492] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 09/05/2012] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Huntington's disease (HD) is caused by expanded CAG repeats encoding a polyglutamine tract in the huntingtin (HTT) protein. A number of differentially-expressed protein molecules have been identified in striatum of HD animal models. Here we examined if the expression changes could be visualized in the peripheral leukocytes of HD patients and pre-symptomatic HD (PreHD) carriers. METHODS AND FINDINGS The expression levels of 17 candidate genes that differentially expressed in striatum between transgenic HD and wild-type mice in literature were measured in the peripheral leukocytes of 4 PreHD carriers, 16 HD patients and 20 healthy controls. Four genes majorly involved in metabolism and oxidative stress response, including AHCY1, ACO2, OXCT1 and CAP1, demonstrated consistent downregulation in peripheral leukocytes of both PreHD carriers and HD patients, while UCP2 was only down-regulated in HD patients. CONCLUSION These results provide potential peripheral biomarkers to indicate disease onset in preclinical stage, and to monitor the efficacy of early treatment. Further studies of a large series of preHD carriers and symptomatic HD patients will be warranted to verify the findings and examine if these markers correlate with clinical features.
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Affiliation(s)
| | | | | | | | - Chiung-Mei Chen
- Department of Neurology, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taipei, Taiwan
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Tehlivets O, Malanovic N, Visram M, Pavkov-Keller T, Keller W. S-adenosyl-L-homocysteine hydrolase and methylation disorders: yeast as a model system. Biochim Biophys Acta Mol Basis Dis 2012; 1832:204-15. [PMID: 23017368 PMCID: PMC3787734 DOI: 10.1016/j.bbadis.2012.09.007] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 09/14/2012] [Accepted: 09/18/2012] [Indexed: 12/14/2022]
Abstract
S-adenosyl-L-methionine (AdoMet)-dependent methylation is central to the regulation of many biological processes: more than 50 AdoMet-dependent methyltransferases methylate a broad spectrum of cellular compounds including nucleic acids, proteins and lipids. Common to all AdoMet-dependent methyltransferase reactions is the release of the strong product inhibitor S-adenosyl-L-homocysteine (AdoHcy), as a by-product of the reaction. S-adenosyl-L-homocysteine hydrolase is the only eukaryotic enzyme capable of reversible AdoHcy hydrolysis to adenosine and homocysteine and, thus, relief from AdoHcy inhibition. Impaired S-adenosyl-L-homocysteine hydrolase activity in humans results in AdoHcy accumulation and severe pathological consequences. Hyperhomocysteinemia, which is characterized by elevated levels of homocysteine in blood, also exhibits a similar phenotype of AdoHcy accumulation due to the reversal of the direction of the S-adenosyl-L-homocysteine hydrolase reaction. Inhibition of S-adenosyl-L-homocysteine hydrolase is also linked to antiviral effects. In this review the advantages of yeast as an experimental system to understand pathologies associated with AdoHcy accumulation will be discussed.
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Affiliation(s)
- Oksana Tehlivets
- Institute of Molecular Biosciences, University of Graz, Graz, Austria.
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Ouyang B, Fei Z, Joung JG, Kolenovsky A, Koh C, Nowak J, Caplan A, Keller WA, Cui Y, Cutler AJ, Tsang EWT. Transcriptome profiling and methyl homeostasis of an Arabidopsis mutant deficient in S-adenosylhomocysteine hydrolase1 (SAHH1). Plant Mol Biol 2012; 79:315-31. [PMID: 22555436 DOI: 10.1007/s11103-012-9914-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 04/11/2012] [Indexed: 05/10/2023]
Abstract
Transcriptome profiling was conducted to detect genes whose expression is significantly changed in an Arabidopsis mutant deficient in S-adenosylhomocysteine hydrolase1 (SAHH1) during early seedling development when mutant phenotypes could be clearly observed. A total of 2,040 differentially expressed genes were identified, representing approximately 6.7% of the 30,385 DNA oligonucleotide targets on the microarray. Among these differential expressed genes, many were mapped to pathways essential to plant growth and development including those of primary, secondary and hormone metabolisms. A significant proportion of up-regulated genes encoded transposable elements which were mapped to the centromeric and pericentromeric regions of the Arabidopsis chromosomes that were analyzed. A number of down-regulated genes were found to be involved in root hair formation, which might have contributed to the root hair defective phenotype of the mutant. Analysis of genes encoding transposable elements and those associating with root hair development indicated that these genes were highly co-expressed during seedling development. Despite SAHH1 deficiency, the expression of genes encoding methyltransferase remained largely unchanged in the sahh1 mutant. Bisulfite sequencing analysis of the transposable elements and the FWA gene revealed that their sequences in the mutant were deficient of 5-methylcytosines. Analysis of mutant genomic DNA using restriction endonucleases that were unable to cut methylated DNA suggested a genome-wide hypomethylation had occurred in the mutant. These results indicated that SAHH1 plays a critical role in methyl homeostasis, and its deficiency is a major contributing factor to the change of global gene expression, metabolic pathways and activation of transposable elements in the sahh1 mutant.
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Affiliation(s)
- Bo Ouyang
- Plant Biotechnology Institute, National Research Council of Canada (NRC), 110 Gymnasium Place, Saskatoon, SK, S7N 0W9, Canada
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Lee S, Doxey AC, McConkey BJ, Moffatt BA. Nuclear targeting of methyl-recycling enzymes in Arabidopsis thaliana is mediated by specific protein interactions. Mol Plant 2012; 5:231-48. [PMID: 21976714 DOI: 10.1093/mp/ssr083] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Numerous transmethylation reactions are required for normal plant growth and development. S-adenosylhomocysteine hydrolase (SAHH) and adenosine kinase (ADK) act coordinately to recycle the by-product of these reactions, S-adenosylhomocysteine (SAH) that would otherwise competitively inhibit methyltransferase (MT) activities. Here, we report on investigations to understand how the SAH produced in the nucleus is metabolized by SAHH and ADK. Localization analyses using green fluorescent fusion proteins demonstrated that both enzymes are capable of localizing to the cytoplasm and the nucleus, although no obvious nuclear localization signal was found in their sequences. Deletion analysis revealed that a 41-amino-acid segment of SAHH (Gly(150)-Lys(190)) is required for nuclear targeting of this enzyme. This segment is surface exposed, shows unique sequence conservation patterns in plant SAHHs, and possesses additional features of protein-protein interaction motifs. ADK and SAHH interact in Arabidopsis via this segment and also interact with an mRNA cap MT. We propose that the targeting of this complex is directed by the nuclear localization signal of the MT; other MTs may similarly target SAHH/ADK to other subcellular compartments to ensure uninterrupted transmethylation.
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Affiliation(s)
- Sanghyun Lee
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
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Yang X, Xie Y, Raja P, Li S, Wolf JN, Shen Q, Bisaro DM, Zhou X. Suppression of methylation-mediated transcriptional gene silencing by βC1-SAHH protein interaction during geminivirus-betasatellite infection. PLoS Pathog 2011; 7:e1002329. [PMID: 22028660 PMCID: PMC3197609 DOI: 10.1371/journal.ppat.1002329] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 09/06/2011] [Indexed: 12/23/2022] Open
Abstract
DNA methylation is a fundamental epigenetic modification that regulates gene expression and represses endogenous transposons and invading DNA viruses. As a counter-defense, the geminiviruses encode proteins that inhibit methylation and transcriptional gene silencing (TGS). Some geminiviruses have acquired a betasatellite called DNA β. This study presents evidence that suppression of methylation-mediated TGS by the sole betasatellite-encoded protein, βC1, is crucial to the association of Tomato yellow leaf curl China virus (TYLCCNV) with its betasatellite (TYLCCNB). We show that TYLCCNB complements Beet curly top virus (BCTV) L2- mutants deficient for methylation inhibition and TGS suppression, and that cytosine methylation levels in BCTV and TYLCCNV genomes, as well as the host genome, are substantially reduced by TYLCCNB or βC1 expression. We also demonstrate that while TYLCCNB or βC1 expression can reverse TGS, TYLCCNV by itself is ineffective. Thus its AC2/AL2 protein, known to have suppression activity in other geminiviruses, is likely a natural mutant in this respect. A yeast two-hybrid screen of candidate proteins, followed by bimolecular fluorescence complementation analysis, revealed that βC1 interacts with S-adenosyl homocysteine hydrolase (SAHH), a methyl cycle enzyme required for TGS. We further demonstrate that βC1 protein inhibits SAHH activity in vitro. That βC1 and other geminivirus proteins target the methyl cycle suggests that limiting its product, S-adenosyl methionine, may be a common viral strategy for methylation interference. We propose that inhibition of methylation and TGS by βC1 stabilizes geminivirus/betasatellite complexes. Plants employ repressive viral genome methylation as an epigenetic defense against geminiviruses, and geminiviruses respond by elaborating proteins that inhibit methylation and transcriptional gene silencing (TGS). Some geminiviruses have acquired a satellite called DNA β (betasatellite), which depends on the helper virus for replication and spread within and between hosts. In return, the sole betasatellite encoded protein, βC1, encodes a pathogenicity factor that enhances viral replication and is responsible for inducing disease symptoms. Geminivirus/betasatellite complexes are common and cause significant losses of food and fiber crops. Here, we explore the molecular basis of the association between Tomato yellow leaf curl China virus (TYLCCNV) and its betasatellite (TYLCCNB). We show that TYLCCNV by itself is unable to reverse TGS. However, co-inoculation of TYLCCNB, or expression of βC1 protein, results in reduced methylation of both the helper virus and host genome, and reversal of TGS directed against a transgene and an endogenous locus. We also present evidence that βC1 accomplishes this by interacting with and inhibiting the activity of S-adenosyl homocysteine hydrolase (SAHH), an enzyme needed to maintain the methyl cycle that generates the methyltransferase co-factor S-adenosyl methionine. Thus, we propose that inhibition of methylation-mediated TGS by βC1 drives geminivirus/betasatellite association.
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Affiliation(s)
- Xiuling Yang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Yan Xie
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Priya Raja
- Department of Molecular Genetics, Plant Biotechnology Center, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Sizhun Li
- Department of Molecular Genetics, Plant Biotechnology Center, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Jamie N. Wolf
- Department of Molecular Genetics, Plant Biotechnology Center, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Qingtang Shen
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - David M. Bisaro
- Department of Molecular Genetics, Plant Biotechnology Center, and Center for RNA Biology, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (XZ);
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
- * E-mail: (XZ);
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Grubbs R, Vugrek O, Deisch J, Wagner C, Stabler S, Allen R, Barić I, Rados M, Mudd SH. S-adenosylhomocysteine hydrolase deficiency: two siblings with fetal hydrops and fatal outcomes. J Inherit Metab Dis 2010; 33:705-13. [PMID: 20852937 DOI: 10.1007/s10545-010-9171-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Revised: 06/17/2010] [Accepted: 07/05/2010] [Indexed: 10/19/2022]
Abstract
This paper reports the clinical and metabolic findings in two sibling sisters born with fetal hydrops and eventually found to have deficient S-adenosylhomocysteine hydrolase (AHCY) activity due to compound heterozygosity for two novel mutations, c.145C>T; p.Arg49Cys and c.257A>G; p.Asp86Gly. Clinically, the major abnormalities in addition to fetal hydrops (very likely due to impaired synthetic liver function) were severe hypotonia/myopathy, feeding problems, and respiratory failure. Metabolic abnormalities included elevated plasma S-adenosylhomocysteine, S-adenosylmethionine, and methionine, with hypoalbuminemia, coagulopathies, and serum transaminase elevation. The older sister died at age 25 days, but the definitive diagnosis was made only retrospectively. The underlying genetic abnormality was diagnosed in the second sister, but treatment by means of dietary methionine restriction and supplementation with phosphatidylcholine and creatine did not prevent her death at age 122 days. These cases extend the experience with AHCY deficiency in humans, based until now on only the four patients previously identified, and suggest that the deficiency in question may be a cause of fetal hydrops and developmental abnormalities of the brain.
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Ishihara M, Kusakabe Y, Ohsumichi T, Tanaka N, Nakanishi M, Kitade Y, Nakamura KT. Crystallization of mouse S-adenosyl-L-homocysteine hydrolase. Acta Crystallogr Sect F Struct Biol Cryst Commun 2010; 66:313-5. [PMID: 20208169 PMCID: PMC2833045 DOI: 10.1107/s1744309110000771] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Accepted: 01/07/2010] [Indexed: 11/10/2022]
Abstract
S-adenosyl-L-homocysteine hydrolase (SAHH; EC 3.3.1.1) catalyzes the reversible hydrolysis of S-adenosyl-L-homocysteine to adenosine and L-homocysteine. For crystallographic investigations, mouse SAHH (MmSAHH) was overexpressed in bacterial cells and crystallized using the hanging-drop vapour-diffusion method in the presence of the reaction product adenosine. X-ray diffraction data to 1.55 A resolution were collected from an orthorhombic crystal form belonging to space group I222 with unit-cell parameters a = 100.64, b = 104.44, c = 177.31 A. Structural analysis by molecular replacement is in progress.
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Affiliation(s)
| | | | | | | | - Masayuki Nakanishi
- College of Pharmaceutical Sciences, Matsuyama University, Ehime 790-8578, Japan
| | - Yukio Kitade
- Faculty of Engineering, Gifu University, Gifu 501-1193, Japan
- Center for Emerging Infectious Diseases, Gifu University, Gifu 501-1193, Japan
- Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1193, Japan
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Baubec T, Dinh HQ, Pecinka A, Rakic B, Rozhon W, Wohlrab B, von Haeseler A, Scheid OM. Cooperation of multiple chromatin modifications can generate unanticipated stability of epigenetic States in Arabidopsis. Plant Cell 2010; 22:34-47. [PMID: 20097869 PMCID: PMC2828703 DOI: 10.1105/tpc.109.072819] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Revised: 12/15/2009] [Accepted: 12/29/2009] [Indexed: 05/18/2023]
Abstract
Epigenetic changes of gene expression can potentially be reversed by developmental programs, genetic manipulation, or pharmacological interference. However, a case of transcriptional gene silencing, originally observed in tetraploid Arabidopsis thaliana plants, created an epiallele resistant to many mutations or inhibitor treatments that activate many other suppressed genes. This raised the question about the molecular basis of this extreme stability. A combination of forward and reverse genetics and drug application provides evidence for an epigenetic double lock that is only alleviated upon the simultaneous removal of both DNA methylation and histone methylation. Therefore, the cooperation of multiple chromatin modifications can generate unanticipated stability of epigenetic states and contributes to heritable diversity of gene expression patterns.
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Affiliation(s)
- Tuncay Baubec
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Huy Q. Dinh
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, 1030 Vienna, Austria
- Center for Integrative Bioinformatics Vienna, Max F. Perutz Laboratories, University of Vienna, 1030 Vienna, Austria
| | - Ales Pecinka
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Branislava Rakic
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Wilfried Rozhon
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Bonnie Wohlrab
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Arndt von Haeseler
- Center for Integrative Bioinformatics Vienna, Max F. Perutz Laboratories, University of Vienna, 1030 Vienna, Austria
| | - Ortrun Mittelsten Scheid
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, 1030 Vienna, Austria
- Address correspondence to
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Abstract
During the last decade much important new information relating to the metabolic pathway from methionine to homocysteine has been gained. Interest has been stimulated by the discovery of two novel disorders, glycine N-methyltransferase deficiency and S-adenosylhomocysteine hydrolase deficiency. Another disorder in this pathway, methionine adenosyltransferase deficiency, has been increasingly detected, thanks to the expansion of newborn screening programmes by tandem mass spectrometry technology. These significant steps allow important insight into the pathogenesis of these three disorders, as well as into the mechanisms of damage to various organs (liver, brain, muscle) and point to the relevance of these disorders for crucial biological processes such as methylation, transsulfuration or carcinogenesis in mammals, the pathogenesis of numerous pathological conditions, in particular those associated with hyperhomocysteinaemia, the action and possible toxicity of some drugs or consequences of nutritional variations. This review summarizes current knowledge of three inherited disorders in this metabolic pathway and draws attention to their much broader significance for human health and understanding of important biological processes.
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Affiliation(s)
- Ivo Barić
- Department of Pediatrics, University Hospital Center and School of Medicine, Zagreb, Croatia.
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Penyalver R, Oger PM, Su S, Alvarez B, Salcedo CI, López MM, Farrand SK. The S-adenosyl-L-homocysteine hydrolase gene ahcY of Agrobacterium radiobacter K84 is required for optimal growth, antibiotic production, and biocontrol of crown gall disease. Mol Plant Microbe Interact 2009; 22:713-724. [PMID: 19445596 DOI: 10.1094/mpmi-22-6-0713] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Agrobacterium radiobacter K84 is a commercial agent used worldwide to control crown gall disease caused by pathogenic isolates of A. tumefaciens. More than 2,000 transposon insertion derivatives of strain K84 were screened by a standardized greenhouse bioassay to identify mutants defective in biocontrol. Three mutants affected in biocontrol properties were identified. All three mutants displayed normal levels of attachment to tomato seed and root colonization. One of these mutants, M19-164, exhibited partial biocontrol and did not produce detectable levels of agrocin 84. In this mutant, the transposon is located in the agn locus of pAgK84, which codes for agrocin 84 biosynthesis. The second mutant, M19-158, also exhibited partial biocontrol and produced reduced amounts of agrocin 84 as a result of a mutation in a chromosomal gene of unknown function. The third mutant, M9-22, failed to biocontrol, was impaired in both growth in minimal medium and siderophore production, and failed to produce detectable levels of agrocin 84. The chromosomal gene ahcY, which encodes S-adenosyl-l-homocysteine hydrolase, was disrupted in this mutant. Expression of a functional copy of ahcY in M9-22 restored all of the altered phenotypes. The fact that all identified biocontrol mutants exhibited a partial or total defect in production of agrocin 84 indicates that this antibiotic is required for optimum biocontrol. This study also identified two chromosomally encoded genes required for agrocin 84 production. That a mutation in ahcY abolishes biocontrol suggests that the intracellular ratio of S-adenosyl-l-methionine to S-adenosyl-l-homocysteine is an important factor for agrocin 84 biosynthesis. Finally, we demonstrate that the ahcY gene in strain K84 is also required for optimal growth as well as for antibiotic production and biocontrol of crown gall disease.
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Affiliation(s)
- Ramón Penyalver
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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Godge MR, Kumar D, Kumar PP. Arabidopsis HOG1 gene and its petunia homolog PETCBP act as key regulators of yield parameters. Plant Cell Rep 2008; 27:1497-1507. [PMID: 18592247 DOI: 10.1007/s00299-008-0576-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Revised: 06/06/2008] [Accepted: 06/15/2008] [Indexed: 05/26/2023]
Abstract
Plant hormones influence the key parameters that contribute to crop yield, including biomass, branching and seed number. We tested manipulation of cytokinin signaling as an avenue for influencing these growth parameters. Here we report a full-length cDNA coding for a cytokinin binding protein, Petunia cytokinin binding protein (PETCBP) from Petunia hybrida cv. Mitchell. PETCBP encodes for a protein that exhibits high sequence similarity to S-adenosyl-L-homocysteine hydrolase (SAHH). Transgenic petunia plants expressing this gene in antisense orientation displayed profuse branching, delayed flowering and delayed shoot bud induction from leaf explants in vitro. Homologs were also isolated from Arabidopsis thaliana homology-dependent gene silencing 1 (HOG1) and Orzya sativa (OsCBP). Arabidopsis HOG1 showed high affinity cytokinin binding activity and modified plant architecture similar to PETCBP. Transgenic Arabidopsis plants overexpressing HOG1 showed early flowering with a significantly reduced plant biomass and number of leaves. In contrast, profuse branching, delayed flowering, increased leaf size and higher seed yield were the major phenotypes observed in the antisense suppression lines. These results suggest that genetic manipulation of this cytokinin binding protein or its orthologs could be used for improving crop biomass and seed yield.
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Affiliation(s)
- Mandar R Godge
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore, 117543, Singapore
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46
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Malanovic N, Streith I, Wolinski H, Rechberger G, Kohlwein SD, Tehlivets O. S-adenosyl-L-homocysteine hydrolase, key enzyme of methylation metabolism, regulates phosphatidylcholine synthesis and triacylglycerol homeostasis in yeast: implications for homocysteine as a risk factor of atherosclerosis. J Biol Chem 2008; 283:23989-99. [PMID: 18591246 PMCID: PMC3259781 DOI: 10.1074/jbc.m800830200] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 06/30/2008] [Indexed: 11/06/2022] Open
Abstract
In eukaryotes, S-adenosyl-L-homocysteine hydrolase (Sah1) offers a single way for degradation of S-adenosyl-L-homocysteine, a product and potent competitive inhibitor of S-adenosyl-L-methionine (AdoMet)-dependent methyltransferases. De novo phosphatidylcholine (PC) synthesis requires three AdoMet-dependent methylation steps. Here we show that down-regulation of SAH1 expression in yeast leads to accumulation of S-adenosyl-L-homocysteine and decreased de novo PC synthesis in vivo. This decrease is accompanied by an increase in triacylglycerol (TG) levels, demonstrating that Sah1-regulated methylation has a major impact on cellular lipid homeostasis. TG accumulation is also observed in cho2 and opi3 mutants defective in methylation of phosphatidylethanolamine to PC, confirming that PC de novo synthesis and TG synthesis are metabolically coupled through the efficiency of the phospholipid methylation reaction. Indeed, because both types of lipids share phosphatidic acid as a precursor, we find in cells with down-regulated Sah1 activity major alterations in the expression of the INO1 gene as well as in the localization of Opi1, a negative regulatory factor of phospholipid synthesis, which binds and is retained in the endoplasmic reticulum membrane by phosphatidic acid in conjunction with VAMP/synaptobrevin-associated protein, Scs2. The addition of homocysteine, by the reversal of the Sah1-catalyzed reaction, also leads to TG accumulation in yeast, providing an attractive model for the role of homocysteine as a risk factor of atherosclerosis in humans.
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Affiliation(s)
| | | | | | | | | | - Oksana Tehlivets
- Institute of Molecular Biosciences, University of Graz, A-8010 Graz,
Austria
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47
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Li CH, Yu N, Jiang SM, Shangguan XX, Wang LJ, Chen XY. Down-regulation of S-adenosyl-L: -homocysteine hydrolase reveals a role of cytokinin in promoting transmethylation reactions. Planta 2008; 228:125-36. [PMID: 18350315 DOI: 10.1007/s00425-008-0724-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2007] [Revised: 02/03/2008] [Accepted: 02/28/2008] [Indexed: 05/10/2023]
Abstract
S-adenosyl-L: -homocysteine hydrolase (SAHH) is a key enzyme for maintenance of cellular transmethylation potential. Although a cytokinin-binding activity had been hypothesized for SAHH, the relation between cytokinin and transmethylation reactions has not been elucidated. Here we show that, of the two Arabidopsis thaliana SAHH genes, AtSAHH1 has a much higher expression level than AtSAHH2. A T-DNA insertion mutant of AtSAHH1 (sahh1-1) and the RNA interference (RNAi) plants (dsAtSAHH2) accumulated a higher level of cytokinins, exhibited phenotypic changes similar to those of cytokinin-overproducers, and their global DNA methylation status was reduced. On the other hand, cytokinins positively regulate the transmethylation pathway genes, including AtSAHH1, AtADK1 (for adenosine kinase), and this regulation involves the cytokinin activity. Furthermore, expression of three cytosine DNA methyltransferase genes examined was inducible by cytokinin treatment. Unlike adenine and adenosine which are SAHH inhibitors, the adenine-type cytokinins have no effect on SAHH activity at protein level. Changing of endogenous cytokinin levels by transgene expression resulted in alterations of DNA methylation status in the sahh1-1 background, suggesting that cytokinins promote DNA methylation, at least under transmethylation stringent conditions. These data demonstrate that the phytohormone cytokinin plays a role in promoting transmethylation reactions, including DNA methylation.
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Affiliation(s)
- Chun-Hong Li
- National Key Laboratory of Plant Molecular Genetics, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032, Shanghai, People's Republic of China
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48
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Jordan ND, West JP, Bottley A, Sheikh M, Furner I. Transcript profiling of the hypomethylated hog1 mutant of Arabidopsis. Plant Mol Biol 2007; 65:571-86. [PMID: 17786563 DOI: 10.1007/s11103-007-9221-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Accepted: 08/08/2007] [Indexed: 05/17/2023]
Abstract
Transcript profiling was used to look for genes that differ in expression between the SAH hydrolase deficient and hypomethylated hog1-1 mutant and the parental (HOG1) line. This analysis identified a subset of gene transcripts that were up-regulated in hog1-1 plants. The majority of these transcripts were from genes located in the pericentromeric heterochromatin. About a third of the genes are annotated as transposons or having transposon homology. Subsequent experiments using Northern blots, RT-PCR and real-time RT-PCR confirmed the up-regulation of 19 of the genes and identified a set of molecular probes for genes that are up-regulated in the hog1-1 background. Six (of six genes tested) of the hog1-1 up-regulated genes are also up-regulated in the hypomethylated ddm1 mutant, three in the hypomethylated met1 mutant and three in the dcl3 mutant. The results suggest that the hypomethylation in the mutant lines may have a causal role in the up-regulation of these transcripts.
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Abstract
The S-adenosylhomocysteine hydrolase from the apicomplexan Cryptosporidium parvum (CpSAHH) has been characterized. CpSAHH is a single-copy, intronless gene of 1479 bp encoding a protein of 493 amino acids with a molecular mass of 55.6 kDa. Reverse transcriptase-polymerase chain reaction analysis confirmed that CpSAHH is expressed both in intracellular stages (in C. parvum-infected HCT-8 cells 24 h after infection) and in sporozoites. CpSAHH was expressed in Escherichia coli TB1 cells as a fusion with maltose-binding protein. The recombinant fusion was cleaved by Factor Xa and the enzymatic activity of both the fusion protein and the purified separated CpSAHH was measured. The enzymatic activity of CpSAHH was inhibited by d-eritadenine, S-DHPA and Ara-A.
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Affiliation(s)
- Vlasta Ctrnáctá
- Department of Tropical Medicine, 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic.
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50
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Hermes M, Osswald H, Kloor D. Role of S-adenosylhomocysteine hydrolase in adenosine-induced apoptosis in HepG2 cells. Exp Cell Res 2007; 313:264-83. [PMID: 17097637 DOI: 10.1016/j.yexcr.2006.10.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [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: 07/13/2006] [Revised: 10/06/2006] [Accepted: 10/10/2006] [Indexed: 12/18/2022]
Abstract
Adenosine has been shown to initiate apoptosis through different mechanisms: (i) activation of adenosine receptors, (ii) intracellular conversion to AMP and stimulation of AMP-activated kinase, (iii) conversion to S-adenosylhomocysteine (AdoHcy), which is an inhibitor of S-adenosylmethionine (AdoMet)-dependent methyltransferases. Since the pathways involved are still not completely understood, we further investigated the role of AdoHcy hydrolase in adenosine-induced apoptosis. In HepG2 cells, adenosine induced caspase-like activity and DNA fragmentation, a marker of apoptosis. These effects were potentiated by co-incubation with homocysteine or adenosine deaminase inhibitor, pentostatin, and were mimicked by inhibition of AdoHcy hydrolase by adenosine-2',3'-dialdehyde (Adox). Adenosine-induced effects were significantly inhibited by dipyridamole, an inhibitor of adenosine transporter, whereas inhibitors of adenosine kinase did not affect adenosine-induced changes. Various adenosine receptor agonists and AICAR, an activator of AMP-activated kinase, did not mimic the effect of adenosine. Thus, adenosine-induced apoptosis is likely due to intracellular action of AdoHcy and independent of AMP-activated kinase and adenosine receptors. Because elevated AdoHcy levels are associated with reduced mRNA methylation, we studied mRNA expression in Adox-treated cells by microarray analysis. Since several p53-target genes and other apoptosis-related genes were up-regulated by Adox, we conclude that AdoHcy is involved in adenosine-induced apoptosis by altering gene expression.
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Affiliation(s)
- Marina Hermes
- Department of Pharmacology and Toxicology, Faculty of Medicine, University of Tuebingen, Wilhelmstrasse 56, D-72074 Tuebingen, Germany
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