Downregulation of methyltransferase Dnmt2 results in condition-dependent telomere shortening and senescence or apoptosis in mouse fibroblasts

Anna Lewinska; Jagoda Adamczyk-Grochala; Ewa Kwasniewicz; Maciej Wnuk

doi:10.1002/jcp.25848

Downregulation of methyltransferase Dnmt2 results in condition-dependent telomere shortening and senescence or apoptosis in mouse fibroblasts

J Cell Physiol. 2017 Dec;232(12):3714-3726. doi: 10.1002/jcp.25848. Epub 2017 Apr 27.

Authors

Anna Lewinska¹, Jagoda Adamczyk-Grochala¹, Ewa Kwasniewicz¹, Maciej Wnuk²

Affiliations

¹ Laboratory of Cell Biology, University of Rzeszow, Kolbuszowa, Poland.
² Department of Genetics, University of Rzeszow, Kolbuszowa, Poland.

PMID: 28177119
DOI: 10.1002/jcp.25848

Abstract

Dnmt2 is a highly conserved methyltransferase of uncertain biological function(s). As Dnmt2 was considered as a driver of fruit fly longevity and a modulator of stress response, we decided to evaluate the role of Dnmt2 during stress-induced premature senescence in NIH3T3 mouse fibroblasts. Stable knockdown of Dnmt2 resulted in hydrogen peroxide-mediated sensitivity and apoptosis, whereas in the control conditions, senescence was induced. Cellular senescence was accompanied by elevated levels of p53 and p21, decreased telomere length and telomerase activity, increased production of reactive oxygen species and protein carbonylation, and DNA damage. Dnmt2 silencing also promoted global DNA and RNA hypermethylation, and upregulation of methyltransferases, namely Dnmt1, Dnmt3a, and Dnmt3b. Taken together, we show for the first time that Dnmt2 may promote lifespan in the control conditions and survival during stress conditions in mouse fibroblasts.

Keywords: Dnmt2; apoptosis; genetic instability; senescence; telomere length.

MeSH terms

Animals
Apoptosis* / drug effects
CRISPR-Cas Systems
Cell Proliferation
Cellular Senescence* / drug effects
Cyclin-Dependent Kinase Inhibitor p21 / genetics
Cyclin-Dependent Kinase Inhibitor p21 / metabolism
DNA (Cytosine-5-)-Methyltransferase 1
DNA (Cytosine-5-)-Methyltransferases / genetics
DNA (Cytosine-5-)-Methyltransferases / metabolism*
DNA Methylation
DNA Methyltransferase 3A
DNA Methyltransferase 3B
Down-Regulation
Epigenesis, Genetic
Fibroblasts / drug effects
Fibroblasts / enzymology*
Fibroblasts / pathology
Gene Expression Regulation, Enzymologic
Gene Knockdown Techniques
Genomic Instability
Hydrogen Peroxide / toxicity
Mice
NIH 3T3 Cells
Oxidative Stress / drug effects
Reactive Oxygen Species / metabolism
Signal Transduction
Telomerase / genetics
Telomerase / metabolism
Telomere Shortening* / drug effects
Transfection
Tumor Suppressor Protein p53 / genetics
Tumor Suppressor Protein p53 / metabolism

Substances

Cdkn1a protein, mouse
Cyclin-Dependent Kinase Inhibitor p21
Dnmt3a protein, mouse
Reactive Oxygen Species
Tumor Suppressor Protein p53
Hydrogen Peroxide
Dnmt2 protein, mouse
DNA (Cytosine-5-)-Methyltransferase 1
DNA (Cytosine-5-)-Methyltransferases
DNA Methyltransferase 3A
Dnmt1 protein, mouse
Telomerase