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  1. Article ; Online: Molecular markers associated with cognitive impairment in centenarians.

    Stevnsner, Tinna / Sanchez-Roman, Ines

    Aging

    2022  Volume 14, Issue 10, Page(s) 4191–4192

    MeSH term(s) Aged, 80 and over ; Centenarians ; Cognition ; Cognitive Dysfunction/epidemiology ; Cognitive Dysfunction/genetics ; Humans ; Mental Status and Dementia Tests
    Language English
    Publishing date 2022-05-18
    Publishing country United States
    Document type Journal Article
    ISSN 1945-4589
    ISSN (online) 1945-4589
    DOI 10.18632/aging.204094
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Measuring the Activity of DNA Repair Enzymes in Isolated Mitochondria.

    Ferrando, Beatriz / Møller, Ian Max / Stevnsner, Tinna

    Methods in molecular biology (Clifton, N.J.)

    2021  Volume 2363, Page(s) 321–334

    Abstract: Nuclear, mitochondrial and plastidic DNA is constantly exposed to conditions, such as ultraviolet radiation or reactive oxygen species, which will induce chemical modifications to the nucleotides. Unless repaired, these modifications can lead to ... ...

    Abstract Nuclear, mitochondrial and plastidic DNA is constantly exposed to conditions, such as ultraviolet radiation or reactive oxygen species, which will induce chemical modifications to the nucleotides. Unless repaired, these modifications can lead to mutations, so the nucleus, mitochondria and plastids each contains a number of DNA repair systems. We here describe assays for measuring the enzyme activities associated with the base-excision repair pathway in potato tuber mitochondria. As the name implies, this pathway involves removing a modified base and replacing it with an undamaged base. Activity of each of the enzymes involved, DNA glycosylase, apurinic/apyrimidinic endonuclease, DNA polymerase and DNA ligase can be measured by incubating a mitochondrial extract with a specifically designed oligonucleotide. After incubation, the reaction mixture is separated on a polyacrylamide gel, and the amounts of specific products formed is estimated by autoradiography, which makes it possible to calculate the enzymatic activity.
    MeSH term(s) DNA Glycosylases/genetics ; DNA Glycosylases/metabolism ; DNA Repair ; DNA Repair Enzymes/genetics ; DNA, Mitochondrial ; DNA-(Apurinic or Apyrimidinic Site) Lyase/genetics ; DNA-(Apurinic or Apyrimidinic Site) Lyase/metabolism ; Mitochondria/genetics ; Mitochondria/metabolism ; Ultraviolet Rays
    Chemical Substances DNA, Mitochondrial ; DNA Glycosylases (EC 3.2.2.-) ; DNA-(Apurinic or Apyrimidinic Site) Lyase (EC 4.2.99.18) ; DNA Repair Enzymes (EC 6.5.1.-)
    Language English
    Publishing date 2021-01-11
    Publishing country United States
    Document type Journal Article
    ISSN 1940-6029
    ISSN (online) 1940-6029
    DOI 10.1007/978-1-0716-1653-6_21
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Phosphorylation of the Human DNA Glycosylase NEIL2 Is Affected by Oxidative Stress and Modulates Its Activity.

    Myrup Holst, Camilla / Brøndum Andersen, Nanna / Thinggaard, Vibeke / Tilken, Mine / Lautrup, Sofie / Tesauro, Cinzia / Stevnsner, Tinna

    Antioxidants (Basel, Switzerland)

    2023  Volume 12, Issue 2

    Abstract: The DNA glycosylase NEIL2 plays a central role in maintaining genome integrity, in particular during oxidative stress, by recognizing oxidized base lesions and initiating repair of these via the base excision repair (BER) pathway. Post-translational ... ...

    Abstract The DNA glycosylase NEIL2 plays a central role in maintaining genome integrity, in particular during oxidative stress, by recognizing oxidized base lesions and initiating repair of these via the base excision repair (BER) pathway. Post-translational modifications are important molecular switches that regulate and coordinate the BER pathway, and thereby enable a rapid and fine-tuned response to DNA damage. Here, we report for the first time that human NEIL2 is regulated by phosphorylation. We demonstrate that NEIL2 is phosphorylated by the two kinases cyclin-dependent kinase 5 (CDK5) and protein kinase C (PKC) in vitro and in human SH-SY5Y neuroblastoma cells. The phosphorylation of NEIL2 by PKC causes a substantial reduction in NEIL2 repair activity, while CDK5 does not directly alter the enzymatic activity of NEIL2 in vitro, suggesting distinct modes of regulating NEIL2 function by the two kinases. Interestingly, we show a rapid dephosphorylation of NEIL2 in response to oxidative stress in SH-SY5Y cells. This points to phosphorylation as an important modulator of NEIL2 function in this cellular model, not least during oxidative stress.
    Language English
    Publishing date 2023-02-02
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2704216-9
    ISSN 2076-3921
    ISSN 2076-3921
    DOI 10.3390/antiox12020355
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Phosphorylation of the Human DNA Glycosylase NEIL2 Is Affected by Oxidative Stress and Modulates Its Activity

    Myrup Holst, Camilla / Brøndum Andersen, Nanna / Thinggaard, Vibeke / Tilken, Mine / Lautrup, Sofie / Tesauro, Cinzia / Stevnsner, Tinna

    Antioxidants. 2023 Feb. 02, v. 12, no. 2

    2023  

    Abstract: The DNA glycosylase NEIL2 plays a central role in maintaining genome integrity, in particular during oxidative stress, by recognizing oxidized base lesions and initiating repair of these via the base excision repair (BER) pathway. Post-translational ... ...

    Abstract The DNA glycosylase NEIL2 plays a central role in maintaining genome integrity, in particular during oxidative stress, by recognizing oxidized base lesions and initiating repair of these via the base excision repair (BER) pathway. Post-translational modifications are important molecular switches that regulate and coordinate the BER pathway, and thereby enable a rapid and fine-tuned response to DNA damage. Here, we report for the first time that human NEIL2 is regulated by phosphorylation. We demonstrate that NEIL2 is phosphorylated by the two kinases cyclin-dependent kinase 5 (CDK5) and protein kinase C (PKC) in vitro and in human SH-SY5Y neuroblastoma cells. The phosphorylation of NEIL2 by PKC causes a substantial reduction in NEIL2 repair activity, while CDK5 does not directly alter the enzymatic activity of NEIL2 in vitro, suggesting distinct modes of regulating NEIL2 function by the two kinases. Interestingly, we show a rapid dephosphorylation of NEIL2 in response to oxidative stress in SH-SY5Y cells. This points to phosphorylation as an important modulator of NEIL2 function in this cellular model, not least during oxidative stress.
    Keywords DNA damage ; DNA glycosylases ; DNA repair ; cyclin-dependent kinase ; dephosphorylation ; enzyme activity ; genome ; humans ; models ; oxidation ; oxidative stress ; phosphorylation ; protein kinase C
    Language English
    Dates of publication 2023-0202
    Publishing place Multidisciplinary Digital Publishing Institute
    Document type Article ; Online
    ZDB-ID 2704216-9
    ISSN 2076-3921
    ISSN 2076-3921
    DOI 10.3390/antiox12020355
    Database NAL-Catalogue (AGRICOLA)

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  5. Article ; Online: Bowhead NEIL1: molecular cloning, characterization, and enzymatic properties.

    Holm, Signe / Larsen, Rikke Møller / Holst, Camilla Myrup / Heide-Jørgensen, Mads Peter / Steffensen, John Fleng / Stevnsner, Tinna / Larsen, Knud

    Biochimie

    2022  Volume 206, Page(s) 136–149

    Abstract: Nei Like DNA Glycosylase 1 (NEIL1) is a DNA glycosylase, which specifically processes oxidative DNA damage by initiating base excision repair. NEIL1 recognizes and removes bases, primarily oxidized pyrimidines, which have been damaged by endogenous ... ...

    Abstract Nei Like DNA Glycosylase 1 (NEIL1) is a DNA glycosylase, which specifically processes oxidative DNA damage by initiating base excision repair. NEIL1 recognizes and removes bases, primarily oxidized pyrimidines, which have been damaged by endogenous oxidation or exogenous mutagenic agents. NEIL1 functions through a combined glycosylase/AP (apurinic/apyrimidinic)-lyase activity, whereby it cleaves the N-glycosylic bond between the DNA backbone and the damaged base via its glycosylase activity and hydrolysis of the DNA backbone through beta-delta elimination due to its AP-lyase activity. In our study we investigated our hypothesis proposing that the cancer resistance of the bowhead whale can be associated with a better DNA repair with NEIL1 being upregulated or more active. Here, we report the molecular cloning and characterization of three transcript variants of bowhead whale NEIL1 of which two were homologous to human transcripts. In addition, a novel NEIL1 transcript variant was found. A differential expression of NEIL mRNA was detected in bowhead eye, liver, kidney, and muscle. The A-to-I editing of NEIL1 mRNA was shown to be conserved in the bowhead and two adenosines in the 242Lys codon were subjected to editing. A mass spectroscopy analysis of liver and eye tissue failed to demonstrate the existence of a NEIL1 isoform originating from RNA editing. Recombinant bowhead and human NEIL1 were expressed in E. coli and assayed for enzymatic activity. Both bowhead and human recombinant NEIL1 catalyzed, with similar efficiency, the removal of a 5-hydroxyuracil lesion in a DNA bubble structure. Hence, these results do not support our hypothesis but do not refute the hypothesis either.
    MeSH term(s) Animals ; Humans ; Bowhead Whale/genetics ; Bowhead Whale/metabolism ; Escherichia coli/genetics ; Escherichia coli/metabolism ; DNA Repair ; DNA Glycosylases/genetics ; DNA Glycosylases/chemistry ; DNA Glycosylases/metabolism ; Cloning, Molecular ; DNA ; RNA, Messenger ; Lyases/metabolism ; Escherichia coli Proteins/genetics ; Deoxyribonuclease (Pyrimidine Dimer)/genetics ; Deoxyribonuclease (Pyrimidine Dimer)/metabolism
    Chemical Substances DNA Glycosylases (EC 3.2.2.-) ; DNA (9007-49-2) ; RNA, Messenger ; Lyases (EC 4.-) ; NEIL1 protein, human (EC 3.2.2.-) ; Nei protein, E coli (EC 3.1.25.1) ; Escherichia coli Proteins ; Deoxyribonuclease (Pyrimidine Dimer) (EC 3.1.25.1)
    Language English
    Publishing date 2022-11-02
    Publishing country France
    Document type Journal Article
    ZDB-ID 120345-9
    ISSN 1638-6183 ; 0300-9084
    ISSN (online) 1638-6183
    ISSN 0300-9084
    DOI 10.1016/j.biochi.2022.10.014
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: The role of aging and brain-derived neurotrophic factor signaling in expression of base excision repair genes in the human brain.

    Lautrup, Sofie / Myrup Holst, Camilla / Yde, Anne / Asmussen, Stine / Thinggaard, Vibeke / Larsen, Knud / Laursen, Lisbeth Schmidt / Richner, Mette / Vaegter, Christian B / Prieto, G Aleph / Berchtold, Nicole / Cotman, Carl W / Stevnsner, Tinna

    Aging cell

    2023  Volume 22, Issue 9, Page(s) e13905

    Abstract: DNA damage is a central contributor to the aging process. In the brain, a major threat to the DNA is the considerable amount of reactive oxygen species produced, which can inflict oxidative DNA damage. This type of damage is removed by the base excision ... ...

    Abstract DNA damage is a central contributor to the aging process. In the brain, a major threat to the DNA is the considerable amount of reactive oxygen species produced, which can inflict oxidative DNA damage. This type of damage is removed by the base excision repair (BER) pathway, an essential DNA repair mechanism, which contributes to genome stability in the brain. Despite the crucial role of the BER pathway, insights into how this pathway is affected by aging in the human brain and the underlying regulatory mechanisms are very limited. By microarray analysis of four cortical brain regions from humans aged 20-99 years (n = 57), we show that the expression of core BER genes is largely downregulated during aging across brain regions. Moreover, we find that expression of many BER genes correlates positively with the expression of the neurotrophin brain-derived neurotrophic factor (BDNF) in the human brain. In line with this, we identify binding sites for the BDNF-activated transcription factor, cyclic-AMP response element-binding protein (CREB), in the promoter of most BER genes and confirm the ability of BDNF to regulate several BER genes by BDNF treatment of mouse primary hippocampal neurons. Together, these findings uncover the transcriptional landscape of BER genes during aging of the brain and suggest BDNF as an important regulator of BER in the human brain.
    MeSH term(s) Animals ; Humans ; Mice ; Aging/genetics ; Aging/metabolism ; Brain/metabolism ; Brain-Derived Neurotrophic Factor/genetics ; Brain-Derived Neurotrophic Factor/metabolism ; DNA Repair/genetics ; Signal Transduction/genetics
    Chemical Substances Brain-Derived Neurotrophic Factor ; BDNF protein, human (7171WSG8A2)
    Language English
    Publishing date 2023-06-19
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2113083-8
    ISSN 1474-9726 ; 1474-9718
    ISSN (online) 1474-9726
    ISSN 1474-9718
    DOI 10.1111/acel.13905
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: Role of Estrogen and Other Sex Hormones in Brain Aging. Neuroprotection and DNA Repair.

    Zárate, Sandra / Stevnsner, Tinna / Gredilla, Ricardo

    Frontiers in aging neuroscience

    2017  Volume 9, Page(s) 430

    Abstract: Aging is an inevitable biological process characterized by a progressive decline in physiological function and increased susceptibility to disease. The detrimental effects of aging are observed in all tissues, the brain being the most important one due ... ...

    Abstract Aging is an inevitable biological process characterized by a progressive decline in physiological function and increased susceptibility to disease. The detrimental effects of aging are observed in all tissues, the brain being the most important one due to its main role in the homeostasis of the organism. As our knowledge about the underlying mechanisms of brain aging increases, potential approaches to preserve brain function rise significantly. Accumulating evidence suggests that loss of genomic maintenance may contribute to aging, especially in the central nervous system (CNS) owing to its low DNA repair capacity. Sex hormones, particularly estrogens, possess potent antioxidant properties and play important roles in maintaining normal reproductive and non-reproductive functions. They exert neuroprotective actions and their loss during aging and natural or surgical menopause is associated with mitochondrial dysfunction, neuroinflammation, synaptic decline, cognitive impairment and increased risk of age-related disorders. Moreover, loss of sex hormones has been suggested to promote an accelerated aging phenotype eventually leading to the development of brain hypometabolism, a feature often observed in menopausal women and prodromal Alzheimer's disease (AD). Although data on the relation between sex hormones and DNA repair mechanisms in the brain is still limited, various investigations have linked sex hormone levels with different DNA repair enzymes. Here, we review estrogen anti-aging and neuroprotective mechanisms, which are currently an area of intense study, together with the effect they may have on the DNA repair capacity in the brain.
    Language English
    Publishing date 2017-12-22
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2558898-9
    ISSN 1663-4365
    ISSN 1663-4365
    DOI 10.3389/fnagi.2017.00430
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Endothelin-1 induces a strong pressor effect in ball pythons (Python regius).

    Jensen, Maja Fuhlendorff / Nedergaard, Signe / Nielsen, Hang Nguyen / Skovgaard, Nini / Stevnsner, Tinna V / Wang, Tobias

    Comparative biochemistry and physiology. Part A, Molecular & integrative physiology

    2019  Volume 241, Page(s) 110620

    Abstract: Endothelin-1 (ET-1) is a very potent vasoactive peptide released from endothelial cells, and ET-1 plays an important role in the maintenance and regulation of blood pressure in mammals. ET-1 signaling is mediated by two receptors: ... ...

    Abstract Endothelin-1 (ET-1) is a very potent vasoactive peptide released from endothelial cells, and ET-1 plays an important role in the maintenance and regulation of blood pressure in mammals. ET-1 signaling is mediated by two receptors: ET
    MeSH term(s) Animals ; Blood Pressure/drug effects ; Boidae/physiology ; Endothelin Receptor Antagonists/pharmacology ; Endothelin-1/pharmacology ; Mesenteric Arteries/drug effects ; Nitric Oxide/metabolism ; Pulmonary Artery/drug effects ; Receptors, Endothelin/chemistry ; Receptors, Endothelin/genetics ; Receptors, Endothelin/metabolism ; Vasoconstriction/drug effects ; Vasodilation/drug effects
    Chemical Substances Endothelin Receptor Antagonists ; Endothelin-1 ; Receptors, Endothelin ; Nitric Oxide (31C4KY9ESH)
    Language English
    Publishing date 2019-11-23
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 121246-1
    ISSN 1531-4332 ; 0300-9629 ; 1095-6433
    ISSN (online) 1531-4332
    ISSN 0300-9629 ; 1095-6433
    DOI 10.1016/j.cbpa.2019.110620
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: The Caenorhabditis elegans Werner syndrome protein participates in DNA damage checkpoint and DNA repair in response to CPT-induced double-strand breaks.

    Hyun, Moonjung / Choi, Seoyun / Stevnsner, Tinna / Ahn, Byungchan

    Cellular signalling

    2016  Volume 28, Issue 3, Page(s) 214–223

    Abstract: The RecQ helicases play roles in maintenance of genomic stability in species ranging from Escherichia coli to humans and interact with proteins involved in DNA metabolic pathways such as DNA repair, recombination, and replication. Our previous studies ... ...

    Abstract The RecQ helicases play roles in maintenance of genomic stability in species ranging from Escherichia coli to humans and interact with proteins involved in DNA metabolic pathways such as DNA repair, recombination, and replication. Our previous studies found that the Caenorhabditis elegans WRN-1 RecQ protein (a human WRN ortholog) exhibits ATP-dependent 3'-5' helicase activity and that the WRN-1 helicase is stimulated by RPA-1 on a long forked DNA duplex. However, the role of WRN-1 in response to S-phase associated with DSBs is unclear. We found that WRN-1 is involved in the checkpoint response to DSBs after CPT, inducing cell cycle arrest, is recruited to DSBs by RPA-1 and functions upstream of ATL-1 and ATM-1 for CHK-1 phosphorylation in the S-phase checkpoint. In addition, WRN-1 and RPA-1 recruitments to the DSBs require MRE-11, suggesting that DSB processing controlled by MRE-11 is important for WRN-1 at DSBs. The repair of CPT-induced DSBs is greatly reduced in the absence of WRN-1. These observations suggest that WRN-1 functions downstream of RPA-1 and upstream of CHK-1 in the DSB checkpoint pathway and is also required for the repair of DSB.
    MeSH term(s) Animals ; Caenorhabditis elegans/metabolism ; Caenorhabditis elegans Proteins/antagonists & inhibitors ; Caenorhabditis elegans Proteins/genetics ; Caenorhabditis elegans Proteins/metabolism ; Camptothecin/toxicity ; Checkpoint Kinase 1 ; Comet Assay ; DNA Breaks, Double-Stranded/drug effects ; DNA Helicases/genetics ; DNA Helicases/metabolism ; DNA Repair ; Mutagenesis ; Protein Kinases/chemistry ; Protein Kinases/genetics ; Protein Kinases/metabolism ; RNA Interference ; Replication Protein A/antagonists & inhibitors ; Replication Protein A/genetics ; Replication Protein A/metabolism ; S Phase Cell Cycle Checkpoints/drug effects
    Chemical Substances Caenorhabditis elegans Proteins ; Replication Protein A ; mre-11 protein, C elegans ; Protein Kinases (EC 2.7.-) ; Checkpoint Kinase 1 (EC 2.7.11.1) ; chk-1 protein, C elegans (EC 2.7.11.1) ; DNA Helicases (EC 3.6.4.-) ; WRN-1 protein, C elegans (EC 5.99.-) ; Camptothecin (XT3Z54Z28A)
    Language English
    Publishing date 2016-03
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1002702-6
    ISSN 1873-3913 ; 0898-6568
    ISSN (online) 1873-3913
    ISSN 0898-6568
    DOI 10.1016/j.cellsig.2015.12.006
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Mitochondrial base excision repair assays.

    Gredilla, Ricardo / Stevnsner, Tinna

    Methods in molecular biology (Clifton, N.J.)

    2012  Volume 920, Page(s) 289–304

    Abstract: Mitochondrial DNA (mtDNA) is constantly exposed to oxidative injury. Due to its location close to the main site of reactive oxygen species, the inner mitochondrial membrane, mtDNA is more susceptible than nuclear DNA to oxidative damage. The accumulation ...

    Abstract Mitochondrial DNA (mtDNA) is constantly exposed to oxidative injury. Due to its location close to the main site of reactive oxygen species, the inner mitochondrial membrane, mtDNA is more susceptible than nuclear DNA to oxidative damage. The accumulation of DNA damage is thought to be particularly deleterious in post-mitotic cells, including neurons, and to play a critical role in the aging process and in a variety of diseases. Thus, efficient mtDNA repair is important for the maintenance of genomic integrity and a healthy life. The base excision repair (BER) mechanism was the first to be described in mitochondria, and consequently it is the best known. This chapter outlines protocols for isolating mitochondria from mammalian cells in culture and from rodent tissues including liver and brain. It also covers the isolation of synaptic mitochondria. BER takes place in four distinct steps, and protocols describing in vitro assays for measuring these enzymatic steps in lysates of isolated mitochondria are included.
    MeSH term(s) Animals ; Brain/cytology ; Cell Fractionation/methods ; Cells, Cultured ; DNA Glycosylases/metabolism ; DNA Polymerase gamma ; DNA Repair ; DNA-(Apurinic or Apyrimidinic Site) Lyase/metabolism ; DNA-Directed DNA Polymerase/metabolism ; Denaturing Gradient Gel Electrophoresis ; Liver/cytology ; Mice ; Mitochondria/genetics ; Mitochondrial Proteins/metabolism ; Nuclear Proteins/metabolism ; Synapses/metabolism
    Chemical Substances Mitochondrial Proteins ; Nuclear Proteins ; DNA Polymerase gamma (EC 2.7.7.7) ; DNA-Directed DNA Polymerase (EC 2.7.7.7) ; DNA Glycosylases (EC 3.2.2.-) ; DNA-(Apurinic or Apyrimidinic Site) Lyase (EC 4.2.99.18)
    Language English
    Publishing date 2012
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1940-6029
    ISSN (online) 1940-6029
    DOI 10.1007/978-1-61779-998-3_20
    Database MEDical Literature Analysis and Retrieval System OnLINE

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