Abstract 265: Assessment Of Oxidative DNA Double Strand Break And Repair In Cardiomyocytes

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Bo Ye ◽  
Ning Hou ◽  
Lu Xiao ◽  
Haodong Xu ◽  
Faqian Li
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Dna Damage ◽  
Dna Repair ◽  
Stress Responses ◽  
Strand Break ◽  
Neonatal Rat ◽  
Rat Cardiomyocytes ◽  
Repair Protein ◽  
Dna Repair Protein

Backgrounds: DNA damage occurs in cardiomyocytes during normal cellular metabolism and is significantly increased under cardiac stresses. How cardiomyocytes repair their DNA damage, especially DNA double strand breaks (DSBs), remains undetermined. We assessed DSBs caused by oxidative stress. More importantly, we investigated the spatiotemporal dynamics of DNA repair protein assembly/disassembly in DNA damage sites. Methods: Cultured neonatal rat cardiomyocytes were treated with different doses of hydrogen peroxide (H2O2) for 30 minutes to assess DNA damage response (DDR). To investigate the dynamics of DDR, cells were treated with 200 uM H2O2 and followed up to 72 hours. DSBs were evaluated by counting DNA damage foci after staining with antibody against histone H2AX phosphorylation at serine 139 (g-H2AX). The dynamics and posttranslational modification of DNA repair proteins were determined by Western blotting, immunolabeling, and confocal microscopy. Result: g-H2AX was proportionally increased to H2O2 dosage. Discrete nuclear g-H2AX foci were seen 30 minutes after hydrogen peroxide treatment with 50 uM, but became pannuclear when H2O2 was above 400 uM. At 200 uM of hydrogen peroxide, g-H2AX started to increase at 15 minutes and reached to highest levels at 60 minutes with up to 70 nuclear foci, started to decline at 2 hours, and returned to basal levels at 24 hours. DDR transducer kinase, ataxia telangiectasia mutated (ATM) was activated at 5 minutes with increased phosphorylation at serine 1981 (pATM) which started to decrease at 24 hours, but remained elevated up to 48 hours. Another DDR transducer kinase, ATM and Rad3-related (ATR) showed a biphasic activation at 30 minutes and 8 hours. ATM and ATR colocalized with g-H2AX. DNA damage mediator proteins such as MRN complex and p53BP1 were also recruited to sites of DNA damage at g-H2AX foci. Conclusions: DSBs and their repair have emerged as a new frontier of stress responses. Newly developed methods for studying g-H2AX and DNA repair protein dynamics can be explored to investigate DDR to oxidative stress in cardiomyocytes.

scholarly journals ROS induces NETosis by oxidizing DNA and initiating DNA repair

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Dhia Azzouz ◽  
Meraj A. Khan ◽  
Nades Palaniyar
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Polymerase Activity ◽  
Neutrophil Activation ◽  
Neutrophil Extracellular Trap ◽  
Nuclear Antigen ◽  
Chromatin Decondensation ◽  
Genome Wide ◽  
Repair Protein ◽  
Dna Repair Protein

AbstractReactive oxygen species (ROS) are essential for neutrophil extracellular trap (NET) formation or NETosis. Nevertheless, how ROS induces NETosis is unknown. Neutrophil activation induces excess ROS production and a meaningless genome-wide transcription to facilitate chromatin decondensation. Here we show that the induction of NADPH oxidase-dependent NETosis leads to extensive DNA damage, and the subsequent translocation of proliferating cell nuclear antigen (PCNA), a key DNA repair protein, stored in the cytoplasm into the nucleus. During the activation of NETosis (e.g., by phorbol myristate acetate, Escherichia coli LPS, Staphylococcus aureus (RN4220), or Pseudomonas aeruginosa), preventing the DNA-repair-complex assembly leading to nick formation that decondenses chromatin causes the suppression of NETosis (e.g., by inhibitors to, or knockdown of, Apurinic endonuclease APE1, poly ADP ribose polymerase PARP, and DNA ligase). The remaining repair steps involving polymerase activity and PCNA interactions with DNA polymerases β/δ do not suppress agonist-induced NETosis. Therefore, excess ROS produced during neutrophil activation induces NETosis by inducing extensive DNA damage (e.g., oxidising guanine to 8-oxoguanine), and the subsequent DNA repair pathway, leading to chromatin decondensation.

Motor Coordination in Space: An Analysis of the Effects of Microgravity on XRCCI DNA Repair Protein Function

2020 ◽  
Author(s):  
Vishruth Nagam
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Protein Function ◽  
Motor Coordination ◽  
Strand Break ◽  
Single Strand Break ◽  
Single Strand Break Repair ◽  
Repair Protein ◽  
Mature Neurons ◽  
Microgravity Conditions

Abstract While in space, astronauts have been known to face exposure to stressors that may increase susceptibility to DNA damage. If DNA repair proteins are defective or nonexistent, DNA mutations may accumulate, causing increasingly abnormal function as one ages [1]. The DNA single-strand break repair protein XRCC1 is important for cerebellar neurogenesis and interneuron development [2]. According to previous studies, a deficiency of XRCC1 can lead to an increase in DNA damage, in mature neurons, and ataxia (a progressive loss of motor coordination) [2]. I propose to address how XRCC1’s efficiency can change in microgravity conditions. This experiment’s relevance is underscored by the importance of motor coordination and physical fitness for astronauts; determining the potential effects of microgravity on XRCC1 is crucial for future space exploration.

scholarly journals Werner Helicase Control of Human Papillomavirus 16 E1-E2 DNA Replication Is Regulated by SIRT1 Deacetylation

mBio ◽  
2019 ◽  
Vol 10 (2) ◽  
Author(s):  
Dipon Das ◽  
Molly L. Bristol ◽  
Nathan W. Smith ◽  
Claire D. James ◽  
Xu Wang ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Life Cycle ◽  
Dna Replication ◽  
Homologous Recombination ◽  
Dna Damage Response ◽  
Human Papillomaviruses ◽  
Repair Protein ◽  
Damage Response ◽  
Dna Repair Protein

ABSTRACTHuman papillomaviruses (HPV) are double-stranded DNA viruses causative in a host of human diseases, including several cancers. Following infection, two viral proteins, E1 and E2, activate viral replication in association with cellular factors and stimulate the DNA damage response (DDR) during the replication process. E1-E2 uses homologous recombination (HR) to facilitate DNA replication, but an understanding of host factors involved in this process remains incomplete. Previously, we demonstrated that the class III deacetylase SIRT1, which can regulate HR, is recruited to E1-E2-replicating DNA and regulates the level of replication. Here, we demonstrate that SIRT1 promotes the fidelity of E1-E2 replication and that the absence of SIRT1 results in reduced recruitment of the DNA repair protein Werner helicase (WRN) to E1-E2-replicating DNA. CRISPR/Cas9 editing demonstrates that WRN, like SIRT1, regulates the quantity and fidelity of E1-E2 replication. This is the first report of WRN regulation of E1-E2 DNA replication, or a role for WRN in the HPV life cycle. In the absence of SIRT1 there is an increased acetylation and stability of WRN, but a reduced ability to interact with E1-E2-replicating DNA. We present a model in which E1-E2 replication turns on the DDR, stimulating SIRT1 deacetylation of WRN. This deacetylation promotes WRN interaction with E1-E2-replicating DNA to control the quantity and fidelity of replication. As well as offering a crucial insight into HPV replication control, this system offers a unique model for investigating the link between SIRT1 and WRN in controlling replication in mammalian cells.IMPORTANCEHPV16 is the major viral human carcinogen responsible for between 3 and 4% of all cancers worldwide. Following infection, this virus activates the DNA damage response (DDR) to promote its life cycle and recruits DDR proteins to its replicating DNA in order to facilitate homologous recombination during replication. This promotes the production of viable viral progeny. Our understanding of how HPV16 replication interacts with the DDR remains incomplete. Here, we demonstrate that the cellular deacetylase SIRT1, which is a part of the E1-E2 replication complex, regulates recruitment of the DNA repair protein WRN to the replicating DNA. We demonstrate that WRN regulates the level and fidelity of E1-E2 replication. Overall, the results suggest a mechanism by which SIRT1 deacetylation of WRN promotes its interaction with E1-E2-replicating DNA to control the levels and fidelity of that replication.

Alpha-phellandrene-induced DNA damage and affect DNA repair protein expression in WEHI-3 murine leukemia cellsin vitro

2014 ◽  
Vol 30 (11) ◽  
pp. 1322-1330 ◽  
Author(s):  
Jen-Jyh Lin ◽  
Chih-Chung Wu ◽  
Shu-Chun Hsu ◽  
Shu-Wen Weng ◽  
Yi-Shih Ma ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Protein Expression ◽  
Repair Protein ◽  
Dna Repair Protein ◽  
Murine Leukemia

scholarly journals ATM controls DNA repair and mitochondria transfer between neighboring cells

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Sha Jin ◽  
Nils Cordes
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Dependent Manner ◽  
Intercellular Signaling ◽  
Tissue Integrity ◽  
Damage Repair ◽  
Repair Protein ◽  
Mitochondria Transfer ◽  
Dna Repair Protein ◽  
Direct Cell

Abstract Intercellular communication is essential for multicellular tissue vitality and homeostasis. We show that healthy cells message protective signals through direct cell–cell connections to adjacent DNA–damaged cells in a microtubule–dependent manner. In DNA–damaged cells, mitochondria restoration is facilitated by fusion with undamaged mitochondria from healthy cells and their DNA damage repair is optimized in presence of healthy cells. Both, mitochondria transfer and intercellular signaling for an enhanced DNA damage response are critically regulated by the activity of the DNA repair protein ataxia telangiectasia mutated (ATM). These healthy–to–damaged prosurvival processes sustain normal tissue integrity and may be exploitable for overcoming resistance to therapy in diseases such as cancer.

scholarly journals Barrier-to-autointegration factor 1 (Banf1) regulates poly [ADP-ribose] polymerase 1 (PARP1) activity following oxidative DNA damage

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Emma Bolderson ◽  
Joshua T. Burgess ◽  
Jun Li ◽  
Neha S. Gandhi ◽  
Didier Boucher ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Dna Repair ◽  
Oxidative Dna Damage ◽  
Repair Capacity ◽  
Dna Repair Capacity ◽  
Dna Repair Protein ◽  
Direct Binding ◽  
Protein Barrier ◽  
Progeria Syndrome

AbstractThe DNA repair capacity of human cells declines with age, in a process that is not clearly understood. Mutation of the nuclear envelope protein barrier-to-autointegration factor 1 (Banf1) has previously been shown to cause a human progeroid disorder, Néstor–Guillermo progeria syndrome (NGPS). The underlying links between Banf1, DNA repair and the ageing process are unknown. Here, we report that Banf1 controls the DNA damage response to oxidative stress via regulation of poly [ADP-ribose] polymerase 1 (PARP1). Specifically, oxidative lesions promote direct binding of Banf1 to PARP1, a critical NAD+-dependent DNA repair protein, leading to inhibition of PARP1 auto-ADP-ribosylation and defective repair of oxidative lesions, in cells with increased Banf1. Consistent with this, cells from patients with NGPS have defective PARP1 activity and impaired repair of oxidative lesions. These data support a model whereby Banf1 is crucial to reset oxidative-stress-induced PARP1 activity. Together, these data offer insight into Banf1-regulated, PARP1-directed repair of oxidative lesions.

The lyase activity of the DNA repair protein β-polymerase protects from DNA-damage-induced cytotoxicity

Nature ◽  
2000 ◽  
Vol 405 (6788) ◽  
pp. 807-810 ◽  
Author(s):  
Robert W. Sobol ◽  
Rajendra Prasad ◽  
Andrea Evenski ◽  
Audrey Baker ◽  
Xiao-Ping Yang ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Repair Protein ◽  
Lyase Activity ◽  
Dna Repair Protein

High iodine induces DNA damage in autoimmune thyroiditis partially by inhibiting the DNA repair protein MTH1

2019 ◽  
Vol 344 ◽  
pp. 103948
Author(s):  
Fuqiang Li ◽  
Yijun Wu ◽  
Liang Chen ◽  
Liang Hu ◽  
Feng Zhu ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Autoimmune Thyroiditis ◽  
High Iodine ◽  
Repair Protein ◽  
Dna Repair Protein

scholarly journals Inhibition of Karyopherin-α2 Augments Radiation-Induced Cell Death by Perturbing BRCA1-Mediated DNA Repair

2019 ◽  
Vol 20 (11) ◽  
pp. 2843 ◽  
Author(s):  
Kyung-Hee Song ◽  
Seung-Youn Jung ◽  
Jeong-In Park ◽  
Jiyeon Ahn ◽  
Jong Kuk Park ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Dna Repair ◽  
Apoptotic Cell ◽  
Nucleocytoplasmic Transport ◽  
Repair Protein ◽  
Damage Response ◽  
Dna Repair Protein ◽  
Radiation Induced ◽  
Early Local Recurrence

Ionizing radiation (IR) has been widely used in the treatment of cancer. Radiation-induced DNA damage triggers the DNA damage response (DDR), which can confer radioresistance and early local recurrence by activating DNA repair pathways. Since karyopherin-α2 (KPNA2), playing an important role in nucleocytoplasmic transport, was significantly increased by IR in our previous study, we aimed to determine the function of KPNA2 with regard to DDR. Exposure to radiation upregulated KPNA2 expression in human colorectal cancer HT29 and HCT116 cells and breast carcinoma MDA-MB-231 cells together with the increased expression of DNA repair protein BRCA1. The knockdown of KPNA2 effectively increased apoptotic cell death via inhibition of BRCA1 nuclear import following IR. Therefore, we propose that KPNA2 is a potential target for overcoming radioresistance via interruption to DDR.

Sign in / Sign up

Export Citation Format

Share Document