Changes in the number of macrophages, T-lymphocytes, activity of antioxidant enzymes in the brain, behavior and structure of the central nervous system neurons in adult and aging mice of different strains with the MPTP-induced model of parkinsonism

Abstract

Background. Oxidative stress and immune cell (T-lymphocytes, macrophages) products are important for the development of morpho-functional disorders of the nervous system in Parkinson’s disease. Connection of Parkinson’s disease with age and functioning of the major histocompatibility complex genes are also shown. The purpose was to assess changes in the brain of T-lymphocytes, macrophages, malondialdehyde (MDA) contents, the activity of antioxidant enzymes, the structure of brain and spinal cord neurons, as well as behavior in adult and aging mice with different H-2 haplotypes and toxic model of parkinsonism. Materials and methods. Adult and aging female mice of FVB/N (genotype H-2q) and 129/Sv (genotype H-2b) strains were once injected with the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) at the dose of 30 mg/kg. Contents of CD3+, CD3–CD11b+, CD3+CD11b+ cells, MDA and the activity of antioxidant enzymes in the brain were evaluated. The structure of neurons of the substantia nigra, lumbar spine, behavior in the open field test, as well as in rigidity and rotarod performance tests were studied. Results. In adult mice of both strains, motor and non-motor (spatial-exploratory, emotional) activity is impaired under the influence of MPTP. At the same time, linear differences in behavior changes were revealed in their directions and expressiveness. In aging FVB/N experimental mice, motor behavior disorders prevailed and were combined with non-motor changes in 129/Sv mice. Violations in the structure of substantia nigra neurons after MPTP administration were more severe in FVB/N mice while those in the lumbar spinal cord neurons were more pronounced in the 129/Sv mice. In aging experimental mice of both strains, the percentage of damaged neurons in the brain and spinal cord was significantly lower than in adult animals. After MPTP administration to adult mice, the direction of changes in the brain T-lymphocytes and macrophages (increase or decrease) depended on their strains. In aging experimental mice, the linear heterogeneity of changes was preserved for the T-lymphocyte content, while the macrophage level was increased regardless of the animal strains. Under MPTP influence, the MDA content increased in the brain of mice of all experimental groups. The direction of changes in superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase activities (decrease or increase) depended on the strains of animals and their age. Conclusions. MPTP-induced changes (directions, expressiveness) in T-lymphocyte, macrophage contents, antioxidant enzymes activity, the structure of neurons of the substantia nigra and lumbar spine, as well as behavioral reactions largely depended on the adult mice H-2 haplotype. There were age-related effects of the neurotoxin on changes in the studied indicators in mice of different strains. At the same time, dependence of changes in most above indicators on the H-2 haplotype preserved.