Coordination of the NF-κB signaling pathway and lymphocyte metabolism in children with autoimmune diseases

Metabolic aberrations underlie many chronic diseases, including autoimmune diseases (AUD). Immune metabolism is an area of immunological research that is actively developing and studying the processes of metabolic reprogramming in immune cells. The regulation of the nuclear factor kappa B (NF-κB) activity, which is involved in the coordination of innate and adaptive immunity, inflammatory reactions and other processes, is being actively studied. The studies on immune metabolism and regulation of NF-κB is a promising direction in searching for new therapeutic approaches in the AUD treatment. The aim of the present study was to evaluate the informative value of NF-κB and the activity of intracellular lymphocyte succinate dehydrogenase (SDH) and glycero-3-phosphate dehydrogenase (GPDH) determined in children with immune-dependent disorders. 350 children with autoimmune diseases were examined: 97 patients with IBD, 72 children with relapsing-remitting multiple sclerosis (MS), 83 pediatric patients with psoriasis vulgaris (PS), and 97 children with autoimmune hepatitis (AIH). The comparison group consisted of 100 conditionally healthy children. Activity of mitochondrial dehydrogenases, i.e., SDH and GPDH, was evaluated by immunocytochemical method. The levels of NF-κB translocation (per cent of cells with NF-κB translocation from cytoplasm to cell nucleus) was determined by flow cytometry, with visualization. Statistical evaluation and plotting were carried out using the Statistica 13.0 software. The highest activity of SDH and GPDH was detected in the population of cytotoxic T lymphocytes and T helper cells, and the lowest activity of the enzymes was registered in the population of B lymphocytes, both in children with AUD and in comparison group. In children with AUD, there was a significant decrease in SDH activity in T lymphocytes, cytotoxic T lymphocytes, B lymphocytes and NK cells against the comparison group (p < 0.01). In children with PS, AIH and IBD, a decrease in SDH activity was revealed in Treg and Th17 cells. The most pronounced decrease in GPDH was characteristic of patients with AH (in T cells, cytotoxic T lymphocytes, B cells, NK cells and Tregs against the comparison group). In children with PS, the activity of GPDH was reduced only in Tregs (p < 0.05). For children with multiple sclerosis, a decrease in GPDH was revealed in populations of T lymphocytes, B lymphocytes and activated T helpers (p < 0.01). In the group of patients with IBD, there were no significant differences in the activity of GPDG relative to the comparison group. A significant increase in the level of NF-κB translocation in T helpers was revealed in all children with AUD relative to the comparison group. In children with AIH and PS, a significant increase in the level of NF-κB translocation was revealed in Treg, Thact and Th17 cells, in children with MS it was found in Treg cells, in patients with IBD, it was registered in Thact against the comparison group (p < 0.05). An inverse correlation was found between the levels of NF-κB translocation in lymphocyte populations, and activity of mitochondrial dehydrogenases in the lymphocytes. The most significant dependencies are characteristic of NK cells and T cell populations, and these correlations are valid for all groups of AUD patientsh. In the course of in vitro experiments with a drug of metabolic action, a decreased number of cells with NF-κB translocation and an increased SDH activity was observed; the degree of SDH activation depended on the cell population type, the greatest changes were detectable in the population of T lymphocytes (by 61%), in B lymphocytes (by 30%), in NK cells (by 19%). The study of the metabolic activity of lymphocytes and the NF-κB signaling pathway allows us to assess the general mechanisms of immunopathological processes in children with autoimmune diseases of various etiologies. As based on the inverse correlation between the level of translocation of NF-κB and the activity of SDH in lymphocytes, one may consider the use of an available immunocytochemical method being an analogue for assessing activity of the NF-κB transcription factor. The studies of immune metabolic correction of immunocompetent cells are a promising direction in the AUD treatment.