Protective effect of exogenous peroxiredoxin 6 and thymic peptide thymulin on BBB conditions in an experimental model of multiple sclerosis

• Published in: Archives of biochemistry and biophysics 2023-09, Vol.746, p.109729-109729, Article 109729
• Main Authors: Lunin, S.M., Novoselova, E.G., Glushkova, O.V., Parfenyuk, S.B., Kuzekova, A.A., Novoselova, T.V., Sharapov, M.G., Mubarakshina, E.K., Goncharov, R.G., Khrenov, M.O.
• Format: Article
• Language: English
• Subjects: Blood-brain barrier; EAE; Multiple sclerosis; Peroxiredoxin 6; Thymulin
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1016/j.abb.2023.109729

This study aimed to assess the effects of the immunomodulator thymulin, a thymic peptide with anti-inflammatory effects, and peroxiredoxin 6 (Prdx6), an antioxidant enzyme with dual peroxidase and phospholipase A2 activities, on the blood‒brain barrier (BBB) condition and general health status of animals with relapsing-remitting experimental autoimmune encephalomyelitis (EAE), which is a model of multiple sclerosis in humans. Both thymulin and Prdx6 significantly improved the condition of the BBB, which was impaired by EAE induction, as measured by Evans blue dye accumulation, tight-junction protein loss in brain tissue, and lymphocyte infiltration through the BBB. The effect was associated with significant amelioration of EAE symptoms. Thymulin treatment was accompanied by a decrease in immune cell activation as judged by interleukin-6, -17, and interferon-gamma cytokine levels in serum and NF-kappaB cascade activation in splenocytes of mice with EAE. Prdx6 did not induce significant immunomodulatory effects but abruptly decreased EAE-induced NOX1 and NOX4 gene expression in brain tissue, which may be one of the possible mechanisms of its beneficial effects on BBB conditions and health status. The simultaneous administration of thymulin and Prdx6 resulted in complete symptomatic restoration of mice with EAE. The results demonstrate prospective strategies for multiple sclerosis treatment. [Display omitted] •Peroxiredoxin 6 improved BBB condition and health status of animals with EAE.•The Prdx6 effect was associated with inhibition of NOX1 and -4 expression.•Thymulin also improved BBB condition and health status of animals with EAE.•The thymulin effect was associated with inhibition of NF-kappaB pathway.•Combination of Prdx6 and thymulin was more effective than any of the drugs alone.