Impact of single nucleotide polymorphisms in the OGG1 and XRCC1 genes on modulation of DNA damage in pesticide-exposed agricultural workers in Punjab, North-West India

The Influence of Blood Titanium Levels on DNA Damage in Brazilian Workers Occupationally Exposed to Different Chemical Agents

Occupational exposure to pollutants may cause health-damaging effects in humans. Genotoxicity assays can be used to detect the toxic effects of pollutants. In the present study, we evaluated genetic damage in three populations occupationally exposed to benzene, pyrenes, and agrochemicals and assessed the possible influence of titanium (Ti) co-exposure. A total of 275 subjects were enrolled in this study. The occupationally exposed population was composed of 201 male individuals, divided into three different groups: gas station attendants (GSA group) (n = 76), taxi drivers (TD group) (n = 97), farmers (farmers group) (n = 28), and control (n = 74). Biomarkers of exposure and effect were investigated such as AChe, BuChE, t,t-muconic acid (t,t-MA), and 1-hydroxypyrene (1-OHP). Ti levels in blood were higher in all the workers compared with the control group. DNA damage evaluated by comet assay was higher in the taxi drivers and farmers than in the controls, and the frequency of micronucleate buccal cells was higher in the gas station attendants and taxi drivers than in the controls. Correlations were found among occupational exposure time and biomarkers of exposure, genotoxicity biomarkers, and blood Ti levels. Our results demonstrated Ti co-exposure in the gas station attendants, taxi drivers, and farmers, and blood Ti levels were linked with the respective biomarkers of exposure. Additionally, tools through machine learning corroborated these findings, and Ti was the factor that contributed to DNA damage. Thus, the present study indicates the role of Ti in occupational settings and interactions with already known major xenobiotics present in the occupational environment contributing to genotoxicity.

Polymorphisms in DNA Repair Genes as Biomarkers of Susceptibility for Pesticide-Induced DNA Damage among Agricultural Workers: A Review

Pesticides induce oxidative DNA damage and genotoxic effects such as DNA single-strand breaks (SSBs), double-strand breaks (DSBs), DNA adducts, chromosomal aberrations, and enhanced sister chromatid exchanges. Such DNA damage can be repaired by DNA repair mechanisms. In humans, single nucleotide polymorphisms (SNPs) are present in DNA repair genes involved in base excision repair (BER) (OGG1, XRCC1, and APE1), nucleotide excision repair (NER) (XPC, XPD, XPF, XPG, and ERCC1), and double-strand break repair (DSBR) (XRCC4 and RAD51). This systematic review intends to provide information about occupational pesticide exposure, genotoxic effects of pesticides as well as association of DNA repair gene polymorphisms with the risk of pesticide-induced DNA damage. Polymorphisms present in DNA repair genes may influence interindividual variation in DNA repair capacity (DRC) by altering the functional properties of DNA repair enzymes and thus modulate DNA damage. The mechanisms of oxidative damage and disrupted DNA repair caused by the pesticides explain the link between pesticide exposure and adverse health outcomes. These polymorphisms in DNA repair genes could be used as biomarkers of susceptibility for pesticide-induced DNA damage among agricultural workers. It could also be useful as a preventive measure by identifying the genetic susceptibility of agricultural workers to pesticide-induced oxidative stress as well as pesticide poisoning.

The Comet Assay as a Tool in Human Biomonitoring Studies of Environmental and Occupational Exposure to Chemicals-A Systematic Scoping Review

Biomonitoring of human populations exposed to chemical substances that can act as potential mutagens or carcinogens, may enable the detection of damage and early disease prevention. In recent years, the comet assay has become an important tool for assessing DNA damage, both in environmental and occupational exposure contexts. To evidence the role of the comet assay in human biomonitoring, we have analysed original research studies of environmental or occupational exposure that used the comet assay in their assessments, following the PRISMA-ScR method (preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews). Groups of chemicals were designated according to a broad classification, and the results obtained from over 300 original studies (n = 123 on air pollutants, n = 14 on anaesthetics, n = 18 on antineoplastic drugs, n = 57 on heavy metals, n = 59 on pesticides, and n = 49 on solvents) showed overall higher values of DNA strand breaks in the exposed subjects in comparison with the unexposed. In summary, our systematic scoping review strengthens the relevance of the use of the comet assay in assessing DNA damage in human biomonitoring studies.

Polymorphisms in ERCC1, ERCC4 and ERCC5 genes as biomarkers of susceptibility for pesticide-induced DNA damage in North-West Indian agricultural workers

BACKGROUND

Occupational pesticides exposure has raised health concerns due to genotoxicity and accumulation of DNA damage. Polymorphisms in genes encoding enzymes involved in nucleotide excision repair (NER) may affect the individual's susceptibility to pesticide toxicity.

METHODS

This study evaluates the association of excision repair cross complementation group 1 (ERCC1) (8092 C > A, 3'UTR, rs3212986) and ERCC1 (19007 C > T, Asn118Asn, rs11615), ERCC4 (1244 G > A, Arg415Gln, rs1800067) and ERCC5 (3507 G > C, Asp1104His, rs17655) polymorphisms with pesticide-induced DNA damage in North-West Indian agricultural workers. The study population comprised 225 agricultural workers exposed to pesticides and 225 non-exposed controls.

RESULTS

Our study demonstrate that exposed workers carrying variant ERCC1 8092AA genotype showed higher total comet DNA migration (p = 0.015) as well as increased frequency of cells showing DNA migration (p = 0.027). Exposed agricultural workers with variant ERCC4 1244AA (415Gln/Gln) and ERCC5 3507CC (1104His/His) genotypes exhibited elevation in total comet DNA migration (p < 0.01). However, genotypes of ERCC1 19007 C > T (Asn118Asn) showed no association with total comet DNA migration (p = 0.963), frequency of cells showing DNA migration (p = 0.423) as well as mean tail length (p = 0.432).

CONCLUSION

ERCC1, ERCC4 and ERCC5 polymorphisms influence DNA damage and can be used as biomarkers of susceptibility for pesticide-induced DNA damage in North-West Indian agricultural workers.

The Incidence of the XRCC1 rs25487 and PON1 rs662 Polymorphisms in a Population from Central Brazil: Patterns in an Area with a High Level of Agricultural Activity

In Brazil, high levels of agricultural activity are reflected in the consumption of enormous amounts of pesticides. The production of grain in Brazil has been estimated at 289.8 million tons in the 2022 harvest, an expansion of 14.7% compared with 2021. These advances are likely associated with a progressive increase in the occupational exposure of a population to pesticides. The Paraoxonase 1 gene (PON1) is involved in liver detoxification; the rs662 variant of this gene modifies the activity of the enzyme. The repair of pesticide-induced genetic damage depends on the protein produced by the X-Ray Repair Cross-Complementing Group 1 gene (XRCC). Its function is impaired due to an rs25487 variant. The present study describes the frequencies of the rs662 and rs25487 and their haplotypes in a sample population from Goiás, Brazil. It compares the frequencies with other populations worldwide to verify the variation in the distribution of these SNPs, with 494 unrelated individuals in the state of Goiás. The A allele of the rs25487 variant had a frequency of 26% in the Goiás population, and the modified rs662 G allele had a frequency of 42.8%. Four haplotypes were recorded for the rs25487 (G > A) and rs662 (A > G) markers, with a frequency of 11.9% being recorded for the A-G haplotype (both modified alleles), 30.8% for the G-G haplotype, 14.3% for the A-A haplotype, and 42.8% for the G-A haplotype (both wild-type alleles). We demonstrated the distribution of important SNPs associated with pesticide exposure in an area with a high agricultural activity level, Central Brazil.

Modulation of DNA damage by XPF, XPG and ERCC1 gene polymorphisms in pesticide-exposed agricultural workers of Punjab, North-West India

Inter-individual variations in DNA repair capacity (DRC) for repairing pesticide-induced DNA oxidation damage may influence adverse health outcomes. We aimed to evaluate whether polymorphisms in genes involved in nucleotide excision repair (NER) pathway could modulate DNA damage in pesticide-exposed agricultural workers. Xeroderma pigmentosum group F (XPF) (Arg415Gln, G1244A, rs1800067), xeroderma pigmentosum group G (XPG) (Asp1104His, G3507C, rs17655), excision repair cross complementation group 1 (ERCC1) (3'UTR, C8092A, rs3212986) and ERCC1 (Asn118Asn, C19007T, rs11615) polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique in 225 pesticide-exposed agricultural workers and 225 controls from Punjab, North-West India. The assessment of DNA damage was carried out by alkaline comet assay. Kruskal-Wallis test was used to evaluate the association of gene polymorphisms in NER pathway with DNA damage. Pesticide-exposed agricultural workers carrying variant XPF Gln/Gln (AA) genotype showed higher comet tail length (p < 0.01) than wild type Arg/Arg (GG) genotype. The comet tail length (p < 0.01) was found to be significantly increased in exposed agricultural workers carrying XPG His/His (CC) genotype than wild-type Asp/Asp (GG) genotype. In relation to the individuals carrying wild type ERCC1 3'UTR CC genotype, exposed individuals with variant ERCC1 3'UTR CA genotype showed elevation in the comet tail length (p = 0.029). However, we found no association of ERCC1 Asn118Asn (C19007T) genotype with DNA damage. These results indicate that XPF, XPG and ERCC1 genes of NER pathway may modulate the efficacy of the DNA repair system against pesticide exposure in our population.