High-Throughput Screening Platform for Nanoparticle-Mediated Alterations of DNA Repair Capacity

ACS Nano ◽  
2021 ◽  
Author(s):  
Sneh M. Toprani ◽  
Dimitrios Bitounis ◽  
Qiansheng Huang ◽  
Nathalia Oliveira ◽  
Kee Woei Ng ◽  
...  
Keyword(s):  
Dna Repair ◽  
High Throughput ◽  
High Throughput Screening ◽  
Repair Capacity ◽  
Dna Repair Capacity ◽  
Screening Platform

scholarly journals Identification of genotoxic compounds using isogenic DNA repair deficient DT40 cell lines on a quantitative high throughput screening platform

Mutagenesis ◽  
2015 ◽  
pp. gev055 ◽  
Author(s):  
Kana Nishihara ◽  
Ruili Huang ◽  
Jinghua Zhao ◽  
Sampada A. Shahane ◽  
Kristine L. Witt ◽  
...  
Keyword(s):  
Dna Repair ◽  
Cell Lines ◽  
High Throughput ◽  
High Throughput Screening ◽  
Dt40 Cell ◽  
Genotoxic Compounds ◽  
Screening Platform

Time-Resolved Luminescent High-Throughput Screening Platform for Lysosomotropic Compounds in Living Cells

ACS Sensors ◽  
2020 ◽  
Author(s):  
Ke-Jia Wu ◽  
Chun Wu ◽  
Feng Chen ◽  
Sha-Sha Cheng ◽  
Dik-Lung Ma ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Living Cells ◽  
Time Resolved ◽  
Screening Platform

scholarly journals DNA Repair Gene Polymorphism and the Risk of Mitral Chordae Tendineae Rupture

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Aysel Kalayci Yigin ◽  
Mehmet Bulent Vatan ◽  
Ramazan Akdemir ◽  
Muhammed Necati Murat Aksoy ◽  
Mehmet Akif Cakar ◽  
...  
Keyword(s):  
Dna Repair ◽  
Fragment Length Polymorphism ◽  
Control Group ◽  
Chordae Tendineae ◽  
Repair Gene ◽  
Repair Capacity ◽  
Dna Repair Capacity ◽  
Dna Repair Gene ◽  
Increased Risk ◽  
Polymerase Chain

Polymorphisms in Lys939Gln XPC gene may diminish DNA repair capacity, eventually increasing the risk of carcinogenesis. The aim of the present study was to evaluate the significance of polymorphism Lys939Gln in XPC gene in patients with mitral chordae tendinea rupture (MCTR). Twenty-one patients with MCTR and thirty-seven age and sex matched controls were enrolled in the study. Genotyping of XPC gene Lys939Gln polymorphism was carried out using polymerase chain reaction- (PCR-) restriction fragment length polymorphism (RFLP). The frequencies of the heterozygote genotype (Lys/Gln-AC) and homozygote genotype (Gln/Gln-CC) were significantly different in MCTR as compared to control group, respectively (52.4% versus 43.2%,p=0.049; 38.15% versus 16.2%,p=0.018). Homozygote variant (Gln/Gln) genotype was significantly associated with increased risk of MCTR (OR = 2.059; 95% CI: 1.097–3.863;p=0.018). Heterozygote variant (Lys/Gln) genotype was also highly significantly associated with increased risk of MCTR (OR = 1.489; 95% CI: 1.041–2.129;p=0.049). The variant allele C was found to be significantly associated with MCTR (OR = 1.481; 95% CI: 1.101–1.992;p=0.011). This study has demonstrated the association of XPC gene Lys939Gln polymorphism with MCTR, which is significantly associated with increased risk of MCTR.

Radiosensitivity of radiotherapy patients: The effect of individual DNA repair capacity

2021 ◽  
Vol 867 ◽  
pp. 503371
Author(s):  
Eliana E. Ocolotobiche ◽  
Ricard Marcos Dauder ◽  
Alba Mabel Güerci
Keyword(s):  
Dna Repair ◽  
Repair Capacity ◽  
Dna Repair Capacity

scholarly journals Female ageing affects the DNA repair capacity of oocytes in IVF using a controlled model of sperm DNA damage in mice

2020 ◽  
Vol 35 (3) ◽  
pp. 529-544 ◽  
Author(s):  
F Horta ◽  
S Catt ◽  
P Ramachandran ◽  
B Vollenhoven ◽  
P Temple-Smith
Keyword(s):  
Gene Expression ◽  
Dna Damage ◽  
Dna Repair ◽  
Age Groups ◽  
Oocyte Quality ◽  
Repair Capacity ◽  
Sperm Dna Damage ◽  
Dna Repair Capacity ◽  
Sperm Dna ◽  
Damage Response

Abstract STUDY QUESTION Does female ageing have a negative effect on the DNA repair capacity of oocytes fertilised by spermatozoa with controlled levels of DNA damage? SUMMARY ANSWER Compared to oocytes from younger females, oocytes from older females have a reduced capacity to repair damaged DNA introduced by spermatozoa. WHAT IS KNOWN ALREADY The reproductive lifespan in women declines with age predominantly due to poor oocyte quality. This leads to decreased reproductive outcomes for older women undergoing assisted reproductive technology (ART) treatments, compared to young women. Ageing and oocyte quality have been clearly associated with aneuploidy, but the range of factors that influence this change in oocyte quality with age remains unclear. The DNA repair activity prior to embryonic genomic activation is considered to be of maternal origin, with maternal transcripts and proteins controlling DNA integrity. With increasing maternal age, the number of mRNAs stored in oocytes decreases. This could result in diminished efficiency of DNA repair and/or negative effects on embryo development, especially in the presence of DNA damage. STUDY DESIGN, SIZE, DURATION Oocytes from two age groups of 30 super-ovulated female mice (young: 5–8 weeks old, n = 15; old: 42–45 weeks old, n = 15) were inseminated with sperm from five males with three different controlled DNA damage levels; control: ≤10%, 1 Gray (Gy): 11–30%, and 30 Gy: >30%. Inseminated oocytes (young: 125, old: 78) were assessed for the formation of zygotes (per oocyte) and blastocysts (per zygote). Five replicates of five germinal vesicles (GVs) and five MII oocytes from each age group were analysed for gene expression. The DNA damage response (DDR) was assessed in a minimum of three IVF replicates in control and 1 Gy zygotes and two-cell embryos using γH2AX labelling. PARTICIPANTS/MATERIALS, SETTING, METHODS Swim-up sperm samples from the cauda epididymidis of C57BL6 mice were divided into control (no irradiation) and 1- and 30-Gy groups. Treated spermatozoa were irradiated at 1 and 30 Gy, respectively, using a linear accelerator Varian 21iX. Following irradiation, samples were used for DNA damage assessment (Halomax) and for insemination. Presumed zygotes were cultured in a time-lapse incubator (MIRI, ESCO). Gene expression of 91 DNA repair genes was assessed using the Fluidigm Biomark HD system. The DNA damage response in zygotes (6–8 h post-fertilisation) and two-cell embryos (22–24 h post-fertilisation) was assessed by immunocytochemical analysis of γH2AX using confocal microscopy (Olympus FV1200) and 3D volumetric analysis using IMARIS software. MAIN RESULTS AND THE ROLE OF CHANCE The average sperm DNA damage for the three groups was statistically different (control: 6.1%, 1 Gy: 16.1%, 30 Gy: 53.1%, P < 0.0001), but there were no significant differences in fertilisation rates after IVF within or between the two age groups [(young; control: 86.79%, 1 Gy: 82.75%, 30 Gy: 76.74%) (old; control: 93.1%, 1 Gy: 70.37%, 30 Gy: 68.18%) Fisher’s exact]. However, blastocyst rates were significantly different (P < 0.0001) among the groups [(young; control: 86.95%, 1 Gy: 33.33%, 30 Gy: 0.0%) (old; control: 70.37%, 1 Gy: 0.0%, 30 Gy: 0.0%)]. Between the age groups, 1-Gy samples showed a significant decrease in the blastocyst rate in old females compared to young females (P = 0.0166). Gene expression analysis revealed a decrease in relative expression of 21 DNA repair genes in old GV oocytes compared to young GV oocytes (P < 0.05), and similarly, old MII oocytes showed 23 genes with reduced expression compared to young MII oocytes (P < 0.05). The number of genes with decreased expression in older GV and MII oocytes significantly affected pathways such as double strand break (GV: 5; MII: 6), nucleotide excision repair (GV: 8; MII: 5) and DNA damage response (GV: 4; MII: 8). There was a decreased DDR in zygotes and in two-cell embryos from old females compared to young regardless of sperm treatment (P < 0.05). The decrease in DNA repair gene expression of oocytes and decreased DDR in embryos derived from older females suggests that ageing results in a diminished DNA repair capacity. LARGE-SCALE DATA N/A LIMITATIONS, REASONS FOR CAUTION Ionising radiation was used only for experimental purposes, aiming at controlled levels of sperm DNA damage; however, it can also damage spermatozoa proteins. The female age groups selected in mice were intended to model effects in young and old women, but clinical studies are required to demonstrate a similar effect. WIDER IMPLICATIONS OF THE FINDINGS Fertilisation can occur with sperm populations with medium and high DNA damage, but subsequent embryo growth is affected to a greater extent with aging females, supporting the theory that oocyte DNA repair capacity decreases with age. Assessment of the oocyte DNA repair capacity may be a useful diagnostic tool for infertile couples. STUDY FUNDING/COMPETING INTEREST(S) Funded by the Education Program in Reproduction and Development, Department of Obstetrics and Gynaecology, Monash University. None of the authors has any conflict of interest to report.

scholarly journals A High-Throughput Approach To Identify Compounds That Impair Envelope Integrity in Escherichia coli

2016 ◽  
Vol 60 (10) ◽  
pp. 5995-6002 ◽  
Author(s):  
Kristin R. Baker ◽  
Bimal Jana ◽  
Henrik Franzyk ◽  
Luca Guardabassi
Keyword(s):  
Escherichia Coli ◽  
High Throughput ◽  
High Throughput Screening ◽  
Gram Negative Bacteria ◽  
Chromogenic Substrate ◽  
Intrinsic Resistance ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Screening Platform

ABSTRACTThe envelope of Gram-negative bacteria constitutes an impenetrable barrier to numerous classes of antimicrobials. This intrinsic resistance, coupled with acquired multidrug resistance, has drastically limited the treatment options against Gram-negative pathogens. The aim of the present study was to develop and validate an assay for identifying compounds that increase envelope permeability, thereby conferring antimicrobial susceptibility by weakening of the cell envelope barrier in Gram-negative bacteria. A high-throughput whole-cell screening platform was developed to measureEscherichia colienvelope permeability to a β-galactosidase chromogenic substrate. The signal produced by cytoplasmic β-galactosidase-dependent cleavage of the chromogenic substrate was used to determine the degree of envelope permeabilization. The assay was optimized by using known envelope-permeabilizing compounds andE. coligene deletion mutants with impaired envelope integrity. As a proof of concept, a compound library comprising 36 peptides and 45 peptidomimetics was screened, leading to identification of two peptides that substantially increased envelope permeability. Compound 79 reduced significantly (from 8- to 125-fold) the MICs of erythromycin, fusidic acid, novobiocin and rifampin and displayed synergy (fractional inhibitory concentration index, <0.2) with these antibiotics by checkerboard assays in two genetically distinctE. colistrains, including the high-risk multidrug-resistant, CTX-M-15-producing sequence type 131 clone. Notably, in the presence of 0.25 μM of this peptide, both strains were susceptible to rifampin according to the resistance breakpoints (R> 0.5 μg/ml) for Gram-positive bacterial pathogens. The high-throughput screening platform developed in this study can be applied to accelerate the discovery of antimicrobial helper drug candidates and targets that enhance the delivery of existing antibiotics by impairing envelope integrity in Gram-negative bacteria.

High-Throughput Screening Platform in Postnatal Heart Cells and Chemical Probe Toolbox to Assess Cardiomyocyte Proliferation

2021 ◽  
Author(s):  
Carmen Carrillo García ◽  
Cora Becker ◽  
Michael Forster ◽  
Stefan Lohmann ◽  
Patricia Freitag ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Heart Cells ◽  
Cardiomyocyte Proliferation ◽  
Chemical Probe ◽  
Screening Platform
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