In vitro application of sodium arsenite to mice testicular and epididymal organ cultures induces oxidative, biochemical, hormonal, and genotoxic stress

2019 ◽  
Vol 35 (10) ◽  
pp. 660-669
Author(s):  
Naureen Anwar ◽  
Irfan Zia Qureshi
Keyword(s):  
Dna Damage ◽  
Sodium Arsenite ◽  
Genotoxic Stress ◽  
Toxic Effects ◽  
Thiobarbituric Acid Reactive Substance ◽  
Organ Cultures ◽  
Sperm Dna Damage ◽  
Sperm Dna

Arsenic poisoning is well-known for its innumerable toxic and carcinogenic effects. In vivo data on reproductive toxicity are also known but in vitro data are scant. Presently, we evaluated the in vitro toxic effects of sodium arsenite (NaAsO2) on adult mice testes and epididymal tissues using organ cultures. Testicular and epididymal fragments were incubated at 37°C and 33°C, respectively, with 1, 10, 50, and 100 µM concentrations of NaAsO2. Cultures were allowed to incubate for 2 and 24 h. Levels of oxidative stress markers, the reactive oxygen species (ROS) and thiobarbituric acid reactive substance assay (TBARS), antioxidant enzymes, testosterone concentrations, and the extent of sperm DNA damage, were estimated. Results were analyzed statistically at p < 0.05. Results demonstrated both time- and dose-dependent alterations whereby, following 24-h incubation with NaAsO2, substantial increases were noticeable in ROS and TBARS levels and sperm DNA damage ( p < 0.001), while decreases ( p < 0.001) occurred in catalase, peroxidase, and superoxide dismutase levels at 10, 50, and 100 µM concentrations. Incubations for 2 h revealed similar but relatively less toxic effects. Testosterone concentrations decreased significantly only after 24 h of incubation with 50 (1.95 vs. 2.93 ng g−1; p < 0.01) and 100 µM (1.32 vs. 2.93 ng g−1; p < 0.001) NaAsO2 concentrations. The study concluded that exposure of testicular and epididymal tissue fragments to arsenic under in vitro conditions induces rapid and immediate metabolic and genotoxic damage at higher concentrations.

scholarly journals Direct Kinase-to-Kinase Signaling Mediated by the FHA Phosphoprotein Recognition Domain of the Dun1 DNA Damage Checkpoint Kinase

2003 ◽  
Vol 23 (4) ◽  
pp. 1441-1452 ◽  
Author(s):  
Vladimir I. Bashkirov ◽  
Elena V. Bashkirova ◽  
Edwin Haghnazari ◽  
Wolf-Dietrich Heyer
Keyword(s):  
Dna Damage ◽  
Target Genes ◽  
Genotoxic Stress ◽  
Dna Damage Checkpoint ◽  
Kinase Signaling ◽  
M Cell ◽  
Fha Domain ◽  
Checkpoint Pathway

ABSTRACT The serine-threonine kinase Dun1 contains a forkhead-associated (FHA) domain and functions in the DNA damage checkpoint pathway of Saccharomyces cerevisiae. It belongs to the Chk2 family of checkpoint kinases, which includes S. cerevisiae Rad53 and Mek1, Schizosaccharomyces pombe Cds1, and human Chk2. Dun1 is required for DNA damage-induced transcription of certain target genes, transient G2/M arrest after DNA damage, and DNA damage-induced phosphorylation of the DNA repair protein Rad55. Here we report that the FHA phosphoprotein recognition domain of Dun1 is required for direct phosphorylation of Dun1 by Rad53 kinase in vitro and in vivo. trans phosphorylation by Rad53 does not require the Dun1 kinase activity and is likely to involve only a transient interaction between the two kinases. The checkpoint functions of Dun1 kinase in DNA damage-induced transcription, G2/M cell cycle arrest, and Rad55 phosphorylation are severely compromised in an FHA domain mutant of Dun1. As a consequence, the Dun1 FHA domain mutant displays enhanced sensitivity to genotoxic stress induced by UV, methyl methanesulfonate, and the replication inhibitor hydroxyurea. We show that the Dun1 FHA domain is critical for direct kinase-to-kinase signaling from Rad53 to Dun1 in the DNA damage checkpoint pathway.

Hsp90 regulates the Fanconi anemia DNA damage response pathway

Blood ◽  
2007 ◽  
Vol 109 (11) ◽  
pp. 5016-5026 ◽  
Author(s):  
Tsukasa Oda ◽  
Toshiya Hayano ◽  
Hidenobu Miyaso ◽  
Nobuhiro Takahashi ◽  
Takayuki Yamashita
Keyword(s):  
Dna Damage ◽  
Fanconi Anemia ◽  
Heat Shock Protein 90 ◽  
Genotoxic Stress ◽  
Cross Linker ◽  
Cellular Tolerance ◽  
Underlying Mechanisms ◽  
Dna Damage Response Pathway

Abstract Heat shock protein 90 (Hsp90) regulates diverse signaling pathways. Emerging evidence suggests that Hsp90 inhibitors, such as 17-allylamino-17-demethoxygeldanamycin (17-AAG), enhance DNA damage-induced cell death, suggesting that Hsp90 may regulate cellular responses to genotoxic stress. However, the underlying mechanisms are poorly understood. Here, we show that the Fanconi anemia (FA) pathway is involved in the Hsp90-mediated regulation of genotoxic stress response. In the FA pathway, assembly of 8 FA proteins including FANCA into a nuclear multiprotein complex, and the complex-dependent activation of FANCD2 are critical events for cellular tolerance against DNA cross-linkers. Hsp90 associates with FANCA, in vivo and in vitro, in a 17-AAG–sensitive manner. Disruption of the FANCA/Hsp90 association by cellular treatment with 17-AAG induces rapid proteasomal degradation and cytoplasmic relocalization of FANCA, leading to impaired activation of FANCD2. Furthermore, 17-AAG promotes DNA cross-linker–induced cytotoxicity, but this effect is much less pronounced in FA pathway-defective cells. Notably, 17-AAG enhances DNA cross-linker–induced chromosome aberrations. In conclusion, our results identify FANCA as a novel client of Hsp90, suggesting that Hsp90 promotes activation of the FA pathway through regulation of intracellular turnover and trafficking of FANCA, which is critical for cellular tolerance against genotoxic stress.

scholarly journals Sperm DNA damage has a negative effect on early embryonic development following in vitro fertilization

2018 ◽  
Vol 20 (1) ◽  
pp. 75 ◽  
Author(s):  
Wei-Wei Zheng ◽  
Ge Song ◽  
Qi-Ling Wang ◽  
Shan-Wen Liu ◽  
Xiao-Li Zhu ◽  
...  
Keyword(s):  
Dna Damage ◽  
In Vitro Fertilization ◽  
Embryonic Development ◽  
Early Embryonic Development ◽  
Vitro Fertilization ◽  
Sperm Dna Damage ◽  
Sperm Dna ◽  
Negative Effect

scholarly journals MicroRNA regulation of the MRN complex impacts DNA damage, cellular senescence and angiogenic signaling

2017 ◽  
Author(s):  
Cristina Espinosa-Diez ◽  
RaeAnna Wilson ◽  
Namita Chatterjee ◽  
Clayton Hudson ◽  
Rebecca Ruhl ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Targeted Delivery ◽  
Genotoxic Stress ◽  
Telomerase Activity ◽  
Loss Of Function ◽  
Mrn Complex ◽  
Vegf Signaling

AbstractMicroRNAs contribute to biological robustness by buffering cellular processes from external perturbations. Here we report an unexpected link between DNA damage response and angiogenic signaling that is buffered by two distinct microRNAs. We demonstrate that genotoxic stress-induced miR-494 and miR-99b inhibit the DNA repair machinery by targeting the MRE11a-RAD50-NBN (MRN) complex. Functionally, gain and loss of function experiments show that miR-494 and miR-99b affect telomerase activity, activate p21 and Rb pathways and diminish angiogenic sproutingin vitroandin vivo. Genetic and pharmacological disruption of VEGFR-2 signaling and the MRN complex reveal a surprising co-dependency of these pathways in regulating endothelial senescence and proliferation. Vascular-targeted delivery of miR-494 decreases both growth factor-induced and tumor angiogenesis in mouse models. Mechanistically, disruption of the MRN complex induced CD44, a known driver of senescence and regulator of VEGF signaling in addition to suppressing IL-13 a stimulator of VEGF signaling. Our work identifies a putative miR-facilitated mechanism by which endothelial cells can be insulated against VEGF signaling to facilitate the onset of senescence and highlight the potential of targeting DNA repair to disrupt pathological angiogenesis.

scholarly journals LARP7 is a BRCA1 ubiquitinase substrate and regulates genome stability and tumorigenesis

2019 ◽  
Author(s):  
Fang Zhang ◽  
Pengyi Yan ◽  
Huijing Yu ◽  
Huangying Le ◽  
Zixuan li ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Rna Binding ◽  
Tumor Therapy ◽  
Genotoxic Stress ◽  
Therapy Resistance ◽  
List Type ◽  
M Cell

SummaryAttenuated DNA repair leads to genomic instability and tumorigenesis. BRCA1/BARD1 are the best known tumor suppressors that promote homology recombination (HR) and arrest cell cycle at G2/M checkpoint. As E3 ubiquitin ligases, their ubiquitinase activity has been known to involve in the HR and tumor suppression, but the mechanism remains ambiguous. Here, we demonstrated upon genotoxic stress, BRCA1 together with BARD1 catalyzed the K48 ployubiquitination on LARP7, a 7SK RNA binding protein known to control RNAPII pausing, and thereby degraded it through 26S ubiquitin-proteasome pathway. Depleting LARP7 suppressed the expression of CDK1 complex, arrested cell at G2/M DNA damage checkpoint and reduced BRCA2 phosphorylation which thereby facilitated RAD51 recruitment to damaged DNA to enhance HR. Importantly, LARP7 depletion observed in breast patients lead to the chemoradiotherapy resistance both in vitro and in vivo. Together, this study unveils a mechanism by which BRCA1/BARD1 utilizes their E3 ligase activity to control HR and cell cycle, and highlights LARP7 as a potential target for cancer prevention and therapy.HighlightsDNA damage response downregulates LARP7 through BRCA1/BARD1BRCA1/BARD1 catalyzes the K48 polyubiquitination on LARP7LARP7 promotes G2/M cell cycle transition and tumorigenesis via CDK1 complexLARP7 disputes homology-directed repair that leads to tumor therapy resistance

scholarly journals Phosphorylation of the Mdm2 oncoprotein by the c-Abl tyrosine kinase regulates p53 tumor suppression and the radiosensitivity of mice

2016 ◽  
Vol 113 (52) ◽  
pp. 15024-15029 ◽  
Author(s):  
Michael I. Carr ◽  
Justine E. Roderick ◽  
Hong Zhang ◽  
Bruce A. Woda ◽  
Michelle A. Kelliher ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dna Damage ◽  
Tumor Suppression ◽  
Bone Marrow Failure ◽  
Genotoxic Stress ◽  
Whole Body ◽  
Atm Kinase ◽  
Radiation Induced

The p53 tumor suppressor acts as a guardian of the genome by preventing the propagation of DNA damage-induced breaks and mutations to subsequent generations of cells. We have previously shown that phosphorylation of the Mdm2 oncoprotein at Ser394 by the ATM kinase is required for robust p53 stabilization and activation in cells treated with ionizing radiation, and that loss of Mdm2 Ser394 phosphorylation leads to spontaneous tumorigenesis and radioresistance in Mdm2S394A mice. Previous in vitro data indicate that the c-Abl kinase phosphorylates Mdm2 at the neighboring residue (Tyr393) in response to DNA damage to regulate p53-dependent apoptosis. In this present study, we have generated an Mdm2 mutant mouse (Mdm2Y393F) to determine whether c-Abl phosphorylation of Mdm2 regulates the p53-mediated DNA damage response or p53 tumor suppression in vivo. The Mdm2Y393F mice develop accelerated spontaneous and oncogene-induced tumors, yet display no defects in p53 stabilization and activity following acute genotoxic stress. Although apoptosis is unaltered in these mice, they recover more rapidly from radiation-induced bone marrow ablation and are more resistant to whole-body radiation-induced lethality. These data reveal an in vivo role for c-Abl phosphorylation of Mdm2 in regulation of p53 tumor suppression and bone marrow failure. However, c-Abl phosphorylation of Mdm2 Tyr393 appears to play a lesser role in governing Mdm2-p53 signaling than ATM phosphorylation of Mdm2 Ser394. Furthermore, the effects of these phosphorylation events on p53 regulation are not additive, as Mdm2Y393F/S394A mice and Mdm2S394A mice display similar phenotypes.

Bisphenol A analogues bisphenol B, bisphenol F, and bisphenol S induce oxidative stress, disrupt daily sperm production, and damage DNA in rat spermatozoa: a comparative in vitro and in vivo study

2019 ◽  
Vol 35 (4) ◽  
pp. 294-303 ◽  
Author(s):  
Asad Ullah ◽  
Madeeha Pirzada ◽  
Sarwat Jahan ◽  
Hizb Ullah ◽  
Muhammad Jamil Khan
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Bisphenol A ◽  
Estrogenic Activity ◽  
Bisphenol S ◽  
Endocrine Disrupting Chemical ◽  
Sperm Dna Damage ◽  
Bisphenol F

Bisphenol A (BPA) is a well-known endocrine-disrupting chemical with estrogenic activity. The widespread exposure of individuals to BPA is suspected to affect a variety of physiological functions, including reproduction, development, and metabolism. Here we report the mechanisms by which BPA and three of its analogues bisphenol B (BPB), bisphenol F (BPF), and bisphenol S (BPS) cause generation of reactive oxygen species (ROS), sperm DNA damage, and oxidative stress in both in vivo and in vitro rat models. Sperm were incubated with different concentrations (1, 10, and 100 µg/L) of BPA and its analogues BPB, BPF, and BPS for 2 h. BPA and its analogues were observed to increase DNA fragmentation, formation of ROS, and affected levels of superoxide dismutase at higher concentration groups. In an in vivo experiment, rats were exposed to different concentrations (5, 25, and 50 mg/kg/day) of BPA, BPB, BPF, and BPS for 28 days. In the higher dose (50 mg/kg/day) treated groups of BPA and its analogues BPB, BPF, and BPS, DNA damage was observed while the motility of sperm was not affected.

Sign in / Sign up

Export Citation Format

Share Document