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Patil V, Cuenin C, Chung F, Aguilera JR, Fernandez-Jimenez N, Romero-Garmendia I, Bilbao JR, Cahais V, Rothwell J, Herceg Z. Human mitochondrial DNA is extensively methylated in a non-CpG context. Nucleic Acids Res 2019; 47:10072-10085. [PMID: 31665742 PMCID: PMC6821263 DOI: 10.1093/nar/gkz762] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [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: 05/03/2019] [Revised: 08/19/2019] [Accepted: 08/23/2019] [Indexed: 12/30/2022] Open
Abstract
Mitochondrial dysfunction plays critical roles in cancer development and related therapeutic response; however, exact molecular mechanisms remain unclear. Recently, alongside the discovery of mitochondrial-specific DNA methyltransferases, global and site-specific methylation of the mitochondrial genome has been described. Investigation of any functional consequences however remains unclear and debated due to insufficient evidence of the quantitative degree and frequency of mitochondrial DNA (mtDNA) methylation. This study uses WGBS to provide the first quantitative report of mtDNA methylation at single base pair resolution. The data show that mitochondrial genomes are extensively methylated predominantly at non-CpG sites. Importantly, these methylation patterns display notable differences between normal and cancer cells. Furthermore, knockdown of DNA methyltransferase enzymes resulted in a marked global reduction of mtDNA methylation levels, indicating these enzymes may be associated with the establishment and/or maintenance of mtDNA methylation. DNMT3B knockdown cells displayed a comparatively pronounced global reduction in mtDNA methylation with concomitant increases in gene expression, suggesting a potential functional link between methylation and gene expression. Together these results demonstrate reproducible, non-random methylation patterns of mtDNA and challenge the notion that mtDNA is lowly methylated. This study discusses key differences in methodology that suggest future investigations must allow for techniques that assess both CpG and non-CpG methylation.
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Affiliation(s)
- Vibha Patil
- Epigenetics Group, International Agency for Research on Cancer (IARC), 69372 Lyon Cedex 08, France
| | - Cyrille Cuenin
- Epigenetics Group, International Agency for Research on Cancer (IARC), 69372 Lyon Cedex 08, France
| | - Felicia Chung
- Epigenetics Group, International Agency for Research on Cancer (IARC), 69372 Lyon Cedex 08, France
| | | | - Nora Fernandez-Jimenez
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country (UPV/EHU), Biocruces-Bizkaia Health Research Institute, Leioa, Basque Country 48940, Spain
| | - Irati Romero-Garmendia
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country (UPV/EHU), Biocruces-Bizkaia Health Research Institute, Leioa, Basque Country 48940, Spain
| | - Jose Ramon Bilbao
- Department of Genetics, Physical Anthropology and Animal Physiology, University of the Basque Country (UPV/EHU), Biocruces-Bizkaia Health Research Institute, Leioa, Basque Country 48940, Spain
| | - Vincent Cahais
- Epigenetics Group, International Agency for Research on Cancer (IARC), 69372 Lyon Cedex 08, France
| | - Joseph Rothwell
- Nutritional Epidemiology Group, International Agency for Research on Cancer (IARC), 69372 Lyon Cedex 08, France
| | - Zdenko Herceg
- Epigenetics Group, International Agency for Research on Cancer (IARC), 69372 Lyon Cedex 08, France
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Gutierrez OL, Ocampo CL, Aguilera JR, Luna J, Sumano LH. Pharmacokinetics of disodium-fosfomycin in mongrel dogs. Res Vet Sci 2007; 85:156-61. [PMID: 17910966 DOI: 10.1016/j.rvsc.2007.08.011] [Citation(s) in RCA: 14] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Revised: 06/12/2007] [Accepted: 08/21/2007] [Indexed: 11/25/2022]
Abstract
Pharmacokinetic variables of fosfomycin were determined after administration of buffered disodium-fosfomycin intravenously (IV), intramuscularly (IM), subcutaneously (SC) and orally (PO), in mongrel dogs, at 40 and 80 mg/kgday for three days. Renal integrity was also assessed by measuring key serum variables. Day 1, day 2 and day 3 plasma concentration vs. time profiles were undistinguishable, but there appears to be a lineal increase in serum concentrations vs. time with the dose. A non-accumulative kinetic behavior was observed after three days with both doses and most pharmacokinetic variables remain unaltered. Considering a MIC range from 1 mirog/mL to 16 microg/mL of fosfomycin in serum for sensitive bacteria, and a negligible plasma protein binding of fosfomycin (<0.5%), useful plasma concentrations can only be achieved after the SC injection of 80 mg/kg every 12h, having a C(max)=18.96+/-0.3 microg/mL; a T(1/2beta)=2.09+/-0.06 microg/mL and a bioavailability of 84-85%. No alterations were observed in serum variables of kidney-related biochemical values.
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Affiliation(s)
- O L Gutierrez
- Departamento de Fisiología y Farmacología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de Mexico, Avenida Universidad 3000, Coyoacán, Mexico City 04510, Mexico
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