DYSREGULATION OF AUTOPHAGY IN PERIPHERAL BLOOD LEUCOCYTES IS A FACTOR IN THE DEVELOPMENT OF INFLAMMAGING IN IMMUNOCOMPROMISED PERSONS ON THE EXAMPLE OF THE SERVICEMEN OF THE DEFENSE FORCES OF UKRAINE AND CLEAN-UP WORKERS OF THE CHORNOBYL ACCIDENT
Authors:   State Institution «National Research Center for Radiation Medicine, Hematology and Oncology of the National Academy of Medical Sciences of Ukraine», Zvarych L. M. , Bazyka D. A. ,   State Institution «National Research Center for Radiation Medicine, Hematology and Oncology of the National Academy of Medical Sciences of Ukraine»
Published: December 2024

Objective. To assess the functional state and age-related characteristics of autophagy in peripheral blood leukocytes as a risk factor for the development of inflammaging using the example of the servicemen of the Defense Forces of Ukraine and clean-up workers of the Chornobyl accident.
Materials and methods. A total of 103 male patients aged 28–77 (56,48 ± 9,05) years were examined. They included: the main group – 23 servicemen of the Defense Forces of Ukraine aged 44–59 (50,21 ± 5,13) years; the comparison group – 57 clean-up workers of the Chornobyl accident aged 56–63 (60,31 ± 1,78) years; and the control group – 23 civilians aged 28–77 (53,26 ± 15,98) years. The individuals in the main and control groups were divided according to age into subgroups under 50 years and over 50 years. Clean-up workers were divided into 3 subgroups depending on the radiation dose: І – D < 100 mSv, ІІ – 100 < D < 500 mSv and ІІІ – D ≥ 500 mSv. Analysis of autophagy parameters in peripheral blood leukocytes (PB) was performed using flow cytometry and polymerase chain reaction.
Results. In patients of the main group, the autophagy activity factor (AAF) of granulocytes and the expression of the SQSTM1 gene in PB leukocytes decreased. A decrease in chloroquine-induced accumulation of LC3B protein in leukocytes, AAF in PB monocytes and the expression of the MTOR, RB1CC1 and MAP1LC3B genes was revealed in servicemen of the Defense Forces of Ukraine under 50 years of age. The spontaneous levels of LC3B protein and AAF in monocytes and the expression level of PIK3C3, ULK1 and MAP1LC3B genes in PB leukocytes were increased in servicemen of the Defense Forces of Ukraine over 50 years of age. The clean-up workers of different dose groups showed a decrease in the AAF in lymphocytes and granulocytes, the LC3B level in monocytes after incubation with chloroquine, the expression of the MTOR, RB1CC1, SQSTM1, ULK1, MAP1LC3B, BECN1 and PIK3C3 genes in PB leukocytes, and the AAF of monocytes was higher. Similar changes were revealed in the indices of chloroquine-induced LC3B accumulation in lymphocytes and monocytes of the clean-up workers and servicemen of both age groups, as well as the spontaneous LC3B protein level in PB monocytes of the clean-up workers irradiated at doses above 100 mSv and civilians over 50 years old.
Conclusions. Unidirectional dysregulation of autophagy was established in the servicemen of the Defense Forces of Ukraine and the clean-up workers of the Chornobyl accident. The existing changes in autophagy parameters can lead to disruption of the functioning of the autophagic apparatus of leukocytes at the level of mRNA and protein, as well as signaling pathways, and be associated with age-related changes at both the cellular and organismal levels. The emergence of new and persistent earlier stress factors as a result of the war creates an additional load on the mechanisms of maintaining homeostasis, which is observed in individuals exposed to ionizing radiation more than 30 years later. The found intergroup differences and similarities can activate the same or similar mechanisms of pathological processes, which will ultimately increase the risks of developing age-associated chronic somatic pathology in younger age groups.
Key words: autophagy; LC3B; leukocytes; inflammaging; immune system; stress; servicemen; war; ionizing radiation; Chornobyl accident.