Polymorphism 894G>T of the eNOS gene (rs1799983) as a marker of vascular homeostasis of non-ferrous metallurgy workers exposed to rare earth elements

Introduction. The specific effects of harmful chemical production factors on vascular-endothelial regulation have not been sufficiently studied and determine the relevance of this study to identify the effects of rare-earth elements modifying vascular regulation, taking into account unmodifiable risk factors such as polymorphic SNP variants of candidate genes. The study aims to evaluate the features of vascular-endothelial and regulatory phenotypes in non-ferrous metallurgy workers associated with the 894G>T polymorphism of the eNOS endothelial NO-synthase gene (rs1799983) under conditions of exposure to rare-earth elements. Materials and methods. The authors examined employees of titanium-magnesium production, the observation group consisted of 36 people working under the conditions of exposure to rare-earth elements, the comparison group included 26 employees of the administrative office. The determination of rare-earth elements in biological media was performed by inductively coupled plasma mass spectrometry. Cytokine content was studied by solid-phase enzyme immunoassay. Genotyping was performed by polymerase chain reaction in real time. Results. Elevated levels of rare-earth elements (REE) in the blood of workers in the monitoring group were shown in terms of gadolinium, holmium, cerium, dysprosium, terbium, lanthanum, and neodymium by 1.3–3.0 times relative to the values in the comparison group (p=0.000–0.025), which were associated with an imbalance in the cytokine profile and metabolic parameters (lipid spectrum). A statistically significant excess frequency of the T variant allele of the eNOS gene (rs1799983) in the observation group was found to be 3.0 times higher than in the comparison group (p=0.001), which for owners of GT and TT genotypes was associated with a 1.2-fold decrease in eNOS levels, increased expression of MMP9 and IL-1beta (p=0.026–0.045) regarding the values of GG genotype carriers. Limitations. The present study requires additional verification and further study due to the limited size of the sample examined. Conclusion. Thus, statistically significant associations of elevated REE levels in the blood of surveillance group workers and the frequency of polymorphic variants of the eNOS 894G>T gene (T allele, TT and GT genotypes) with increased expression of immunoregulatory mediators (cytokines) and a significant decrease in the level of endothelial NO synthase were established, which creates an increased risk associated with knockout of the candidate gene vascular disorders (RR=2.99; 95%CI=1.42–6.30). The identified markers will make it possible to optimize the implementation of diagnostic measures for the prevention of the development of cardiovascular diseases in conditions of exposure to REE. Ethics. All the surveyed signed a voluntary informed consent to participate in the study. The study was performed in accordance with the Helsinki Declaration of the World Medical Association (revised 2013) and approved by the local Ethics Committee (Protocol No. 15 dated 03/14/2023).