The effect of lead oxide nanoparticles on the expression of antioxidant system and apoptosis genes in a chronic experiment

Introduction. Nanoparticles of lead oxide (NPs PbO) enter the environment and pollute it as a result of technological processes in industrial enterprises. Their negative impact on public health is of increasing concern to researchers and the need to study the potential health risks from their exposure. The study of the effect of nanoparticles of lead oxide at the molecular level in laboratory animals is the first step in establishing the mechanisms of toxic action on various tissues and organs.

The study aims to research the effect of lead oxide nanoparticles on changes in the expression level of the antioxidant system genes and apoptosis in a chronic experiment.

Materials and methods. The researchers divided white female Wistar rats into 2 groups of 10 individuals each. The authors supplied nanoparticles of lead oxide to the exposure tower for inhalation in the «nose only» installation, where, in special restrainers, scientists subjected animals of the experimental group to chronic exposure to NPs PbO at a concentration of 0.215 mg/m³ for 4 hours a day, 5 times a week for 8 months. At the end of the experimental period, the specialists performed a complete decapitation of the animals and recorded fragments of the olfactory bulb, hippocampus, lungs and liver, from which the authors then isolated common RNA and synthesized cDNA. The expression level of the GSTP1, GSTM1, SOD2, P53 BAX, and BCL-2 genes was determined by quantitative PCR. The researchers used the nonparametric Mann–Whitney criterion for statistical data processing.

Results. The results of the study did not reveal statistically significant differences between the expression levels of all analyzed genes in the liver of rats. The expression level of the GSTP1 gene in the olfactory bulb of the experimental group was significantly higher, and in the tissues of the hippocampus and lung it was significantly reduced compared with the control group. The expression levels of the P53 and BCL-2 genes in the olfactory bulb of the experimental group were significantly lower, and the BAX/BCL-2 ratio increased significantly compared to the control group.

Limitations. This study was conducted on female Wistar rats and does not consider possible intersex differences.

Conclusion. With chronic inhalation exposure tonanoparticles of lead oxide at a concentration of 0.215 mg/m³ 4 hours a day, 5 times a week for 8 months, scientists have found changes in gene expression in the structures of the brain and lung, but not in the liver of rats. An increase in the BAX/BCL-2 ratio indicates apoptotic processes in the olfactory bulb tissue. Further research is needed to clarify the mechanisms of toxic action of NPs PbO at the molecular level.

Ethics. The conclusion of the local Ethics Committee of the Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers: the maintenance, nutrition, care of animals and their removal from the experiment were carried out in accordance with the recommendations of the ARRIVE guidelines. The research was approved by the local Ethics Committee of the Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers of Rospotrebnadzor (Protocol No. 4 dated 07/12/2022).

Contribution:
Kikot A.M. — research concept and design, material collection and data processing, writing the text;|
Bereza I.A. — research concept and design, material collection and data processing, writing the text;
Shaikhova D.R. — research concept and design, material collection and data processing, writing the text;
Ryabova Yu.V. — material collection and data processing, editing;
Minigalieva I.A. — research concept and design, editing;
Sutunkova M.P. — research concept and design.

Funding. The study had no funding.

Conflict of interests. The authors declare the absence of obvious and potential conflicts of interest in connection with the publication of this article.

Received: 25.04.2024 / Accepted: 07.05.2024 / Published: 20.06.2024

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