scholarly journals Protection of sperm DNA against oxidative stress in vivo by accessory sex gland secretions in male hamsters

Reproduction ◽  
2002 ◽  
pp. 491-499 ◽  
Author(s):  
H Chen ◽  
MP Cheung ◽  
PH Chow ◽  
AL Cheung ◽  
W Liu ◽  
...  
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Prostate Gland ◽  
Single Strand ◽  
Ventral Prostate ◽  
Control Group ◽  
Dna Breakage ◽  
Accessory Glands ◽  
Sperm Dna ◽  
Epididymal Spermatozoa

Reactive oxygen species scavengers present in male accessory sex gland secretions might afford antioxidant protection to sperm DNA. This study was conducted to determine whether accessory sex gland secretions protect the genome and function of spermatozoa against oxidative damage in the uterus. Male golden hamsters were divided into four experimental groups: (i) all accessory sex glands removed; (ii) ampullary glands removed; (iii) ventral prostate gland removed and (iv) sham-operated controls. Ejaculated spermatozoa recovered from uteri 15-30 min after mating with experimental males and caput and cauda epididymal spermatozoa obtained from intact males were incubated in 0-20 mmol NADPH l(-1) for 2 h. These spermatozoa and untreated uterine spermatozoa were processed for two types of comet assay (single cell gel electrophoresis): alkaline comet assay (pH > 13) which revealed single-strand DNA breakage and neutral comet assay (pH 9) which revealed double-strand DNA breakage. In comparison with the sham-operated controls, spermatozoa that had not been exposed to accessory sex gland secretions had a higher incidence and more extensive single-strand DNA damage with increasing concentrations of NADPH. Spermatozoa from hamsters without ampullary glands and from hamsters without the ventral prostate glands were similar to those of the control group. After incubation with NADPH, the capacity of spermatozoa from hamsters without accessory glands and from sham-operated controls to fuse with oocytes in vitro was reduced. However, only hamsters without accessory glands showed a negative correlation between single-strand DNA damage and sperm-oocyte fusion. Cauda epididymal spermatozoa were less susceptible to NADPH treatment compared with caput epididymal spermatozoa. The results of the present study showed that male accessory sex gland secretions can preserve the integrity of the sperm genome.

scholarly journals Persistent Increased Frequency of Genomic Instability in Women Diagnosed with Breast Cancer: Before, during, and after Treatments

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Márcia Fernanda Correia Jardim Paz ◽  
André Luiz Pinho Sobral ◽  
Jaqueline Nascimento Picada ◽  
Ivana Grivicich ◽  
Antonio Luiz Gomes Júnior ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Dna Damage ◽  
Comet Assay ◽  
Peripheral Blood ◽  
Micronucleus Test ◽  
Cancer Control ◽  
Control Group ◽  
Breast Cancer Patients ◽  
Buccal Cells ◽  
Oncological Treatment

This study aimed to evaluate DNA damage in patients with breast cancer before treatment (background) and after chemotherapy (QT) and radiotherapy (RT) treatment using the Comet assay in peripheral blood and the micronucleus test in buccal cells. We also evaluated repair of DNA damage after the end of RT, as well as the response of patient’s cells before treatment with an oxidizing agent (H2O2; challenge assay). Fifty women with a mammographic diagnosis negative for cancer (control group) and 100 women with a diagnosis of breast cancer (followed up during the treatment) were involved in this study. The significant DNA damage was observed by increasing in the index and frequency of damage along with the increasing of the frequency of micronuclei in peripheral blood and cells of the buccal mucosa, respectively. Despite the variability of the responses of breast cancer patients, the individuals presented lesions on the DNA, detected by the Comet assay and micronucleus Test, from the diagnosis until the end of the oncological treatment and were more susceptible to oxidative stress. We can conclude that the damages were due to clastogenic and/or aneugenic effects related to the neoplasia itself and that they increased, especially after RT.

Sperm DNA damage output parameters measured by the alkaline Comet assay and their importance

Andrologia ◽  
2016 ◽  
Vol 49 (2) ◽  
pp. e12608 ◽  
Author(s):  
L. Simon ◽  
K. I. Aston ◽  
B. R. Emery ◽  
J. Hotaling ◽  
D. T. Carrell
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Alkaline Comet Assay ◽  
Sperm Dna Damage ◽  
Sperm Dna

scholarly journals Paracoccidioidomycosis: no genetic damage in human peripheral blood cells of patients assessed by single-cell gel (comet) assay

2007 ◽  
Vol 40 (4) ◽  
pp. 476-478 ◽  
Author(s):  
Renata Aparecida Martinez Antunes Ribeiro-Vieira ◽  
Daniel Araki Ribeiro ◽  
Daisy Maria Favero Salvadori ◽  
Sílvio Alencar Marques
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Human Peripheral Blood ◽  
Paracoccidioides Brasiliensis ◽  
Peripheral Blood Cells ◽  
Genetic Damage ◽  
Systemic Fungal Infection ◽  
Dna Breakage

Paracoccidioidomycosis is a systemic fungal infection caused by Paracoccidioides brasiliensis. As infectious diseases can cause DNA damage, the authors aimed at analyzing DNA breakage in peripheral blood cells of patients with paracoccidioidomycosis by using the comet assay. The results suggested that paracoccidioidomycosis does not cause genotoxicity.

scholarly journals Interpreting sperm DNA damage in a diverse range of mammalian sperm by means of the two-tailed comet assay

2014 ◽  
Vol 5 ◽  
Author(s):  
Elva I. Cortés-Gutiérrez ◽  
Carmen López-Fernández ◽  
José Luis Fernández ◽  
Martha I. Dávila-Rodríguez ◽  
Stephen D. Johnston ◽  
...  
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Diverse Range ◽  
Sperm Dna Damage ◽  
Mammalian Sperm ◽  
Sperm Dna

scholarly journals Rapid rates of sperm DNA damage after activation in tench (Tinca tinca: Teleostei, Cyprinidae) measured using a sperm chromatin dispersion test

Reproduction ◽  
2009 ◽  
Vol 138 (2) ◽  
pp. 257-266 ◽  
Author(s):  
Carmen López-Fernández ◽  
Matthew J G Gage ◽  
Francisca Arroyo ◽  
Altea Gosálbez ◽  
Ana M Larrán ◽  
...  
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Dna Fragmentation ◽  
Living Organism ◽  
Sperm Chromatin ◽  
Tinca Tinca ◽  
External Fertilization ◽  
Sperm Dna Damage ◽  
Sperm Dna ◽  
Dispersion Test

Spermatozoal haplotypic DNA is prone to damage, leading to male fertility problems. So far, the assessment of sperm DNA breakage has been challenging because protamines render the nuclear chromatin highly compacted. Here, we report the application of a new test to quantify DNA fragmentation in spermatozoa of an externally fertilizing teleost fish. The sperm chromatin dispersion (SCD) test uses a species-specific lysing solution to generate controlled protein depletion that, followed by DNA-specific fluorescent labelling, allows an easy morphological discrimination between nuclei affected by DNA damage. Using tench (Tinca tinca) as our model, we first trialled the test against established, but more technically demanding, assays employing in situ nick translation (ISNT) and the comet assay. The SCD test showed high concordance with ISNT, comet assay measures and a chromatin-swelling test, confirming the application of this straightforward SCD technique to various aspects of reproductive biology. Second, we examined between-male variation in DNA damage, and measured changes through time following spermatozoal activation. Between-male variation in the basal levels of average DNA damage ranged from 0 to 20% of sperm showing damage, and all showed increases in DNA fragmentation through time (0–60 min). The rates of DNA damage increase are the fastest so far recorded in sperm for a living organism, and may relate to the external fertilization mode. Our findings have relevance for broodstock selection and optimizing IVF protocols routinely used in modern aquaculture.

scholarly journals Effects of quin2 acetoxymethyl ester on H2O2-induced DNA single-strand breakage in mammalian cells: H2O2-concentration-dependent inhibition of damage and additive protective effect with the hydroxyl-radical scavenger dimethyl sulphoxide

1995 ◽  
Vol 305 (1) ◽  
pp. 181-185 ◽  
Author(s):  
B E Sandström
Keyword(s):  
Dna Damage ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Single Strand ◽  
Dimethyl Sulphoxide ◽  
Radical Scavenger ◽  
Dna Breaks ◽  
Acetoxymethyl Ester ◽  
Dna Breakage ◽  
Strand Breakage

The cell-membrane-permeable calcium probe quin2 acetoxymethyl ester (quin2 AM) was ineffective, in comparison with o-phenanthroline, in protecting cells against H2O2-induced DNA single-strand breakage at H2O2 concentrations of about, and higher than, 0.5 mM. The present study shows that quin2 actually potentiated intracellular DNA damage at high H2O2 concentrations. H2O2-induced DNA breakage appeared within 5 min after exposure, and quin2 affected the induction of DNA breaks at both 0 degree C and 37 degrees C. Aurintricarboxylic acid, an endonuclease inhibitor, or a decrease in extracellular Ca2+, did not reduce DNA damage. These facts strongly suggest that the breaks were not produced by a Ca(2+)-dependent nuclease. We showed previously that, in the presence of Fe3+ and H2O2, quin2 strongly potentiated the formation of oxidizing species as well as plasmid DNA breakage, and, as could be expected for a transition-metal chelator, quin2 inhibited the Fenton reaction when Cu2+ was tested instead of Fe3+ [Sandström, Granström and Marklund (1994) Free Radicals Biol. Med. 16, 177-185]. In the present work with cultured cells, titration with quin2 AM showed that, despite the fact that Cu2+ has a three-to-four-orders-of-magnitude higher affinity for quin2 than has Fe3+, both inhibition and potentiation of H2O2-induced DNA damage occurred at quin2 AM concentrations of about 100 nM. Thus inhibition appeared not to involve Cu2+. The combination of quin2 AM and dimethyl sulphoxide (DMSO) gave an additive effect on H2O2-induced DNA damage compared with the effect of quin2 AM or DMSO alone, whereas the combination of o-phenanthroline and DMSO gave about the same effect as o-phenanthroline alone. In conclusion, our results do not support a role for Ca2+ in the inhibiting effect of quin2 on H2O2-induced DNA damage. Instead, it is likely that inhibition and potentiation by quin2 involves interaction with Fe ions.

scholarly journals Study of DNA damage induced by dental bleaching agents in vitro

2006 ◽  
Vol 20 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Daniel Araki Ribeiro ◽  
Mariângela Esther Alencar Marques ◽  
Daisy Maria Fávero Salvadori
Keyword(s):  
Hydrogen Peroxide ◽  
Dna Damage ◽  
Comet Assay ◽  
Single Cell ◽  
Chinese Hamster ◽  
Dental Bleaching ◽  
Dna Breakage ◽  
The Mean ◽  
Positive Controls

Dental bleaching is a simple and conservative procedure for aesthetic restoration of vital and non-vital discolored teeth. Nevertheless, a number of studies have demonstrated the risk of tissue damage from the contact of these agents with the oral mucosa. In the current study, the genotoxic potential associated with exposure to dental bleaching agents was assessed by the single cell gel (comet) assay in vitro. Chinese hamster ovary (CHO) cells in vitro were exposed to six commercial dental bleaching agents (Clarigel Gold - Dentsply; Whitespeed - Discus Dental; Nite White - Discus Dental; Magic Bleaching - Vigodent; Whiteness HP - FGM and Lase Peroxide - DMC). The results pointed out that all dental bleaching agents tested contributed to DNA damage as depicted by the mean tail moment, being the strongest effect observed with the highest dose of hydrogen peroxide (Whiteness HP and Lase Peroxide, at a 35% concentration). On the other hand, Magic Bleaching (Vigodent) induced the lowest level of DNA breakage. Negative and positive controls displayed absence and presence of DNA-damaging, respectively. Taken together, these results suggest that dental bleaching agents may be a factor that increases the level of DNA damage. A higher concentration of hydrogen peroxide produced higher noxious activities in the genome as detected by single cell gel (comet) assay.

scholarly journals Validation of the sperm chromatin dispersion (SCD) test in the amphibian Xenopus laevis using in situ nick translation and comet assay

2015 ◽  
Vol 27 (8) ◽  
pp. 1168 ◽  
Author(s):  
K. Pollock ◽  
J. Gosálvez ◽  
F. Arroyo ◽  
C. López-Fernández ◽  
M. Guille ◽  
...  
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Xenopus Laevis ◽  
Semen Quality ◽  
Sperm Chromatin ◽  
Sperm Dna Fragmentation ◽  
Nick Translation ◽  
In Situ Nick Translation ◽  
Sperm Dna

The integrity of sperm DNA is becoming increasingly recognised as an important parameter of semen quality, but there are no published reports of this procedure for any amphibian. The primary aim of this study was to apply a modified sperm chromatin dispersion (SCD) test (Halomax) to an amphibian sperm model (African clawed frog; Xenopus laevis) and to validate the assay against in situ nick translation (ISNT) and the double-comet assay procedure. Inactivated spermatozoa were collected from fresh testes (n = 3). Sperm DNA fragmentation (SDF) for each sperm sample was conducted immediately following activation (T0) and again after 1 h (T1) and 24 h (T24) of incubation at room temperature in order to produce a range of spermatozoa with differing levels of DNA damage. The SCD procedure resulted in the production of three nuclear morphotypes; amphibian sperm morphotype 1 (ASM-1) and ASM-2 showed no evidence of DNA damage, whereas ASM-3 spermatozoa were highly fragmented with large halos of dispersed DNA fragments and a reduced nuclear core. ISNT confirmed that ASM-3 nuclei contained damaged DNA. There was a significant correlation (r = 0.9613) between the levels of ASM-3 detected by the SCD test and SDF revealed by the double-comet assay.

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