Reaction of different cell types of the brain on neurotoxin cuprizone and hormone melatonin treatment in young and aging mice.

Introduction: The brain myelin and neurons destruction in multiple sclerosis may be associated with the production of neuroinflammatory cells (macrophages, astrocytes, T-lymphocytes) of pro-inflammatory cytokines and free radicals. The age-associated changes of the above cells can influence on the response of nervous system cells to toxic damaging and regulatory factors of humoral/endocrine nature, in particular pineal hormone melatonin. The study aim was (1) to evaluate changes of the brain macrophages, astrocytes, T-cells, neural stem cells, neurons, and central nervous system (CNS) functioning in the neurotoxin cuprizone-treated mice of different age; and (2) to assess in such mice the effects of exogenous melatonin and possible courses of its action. Methods: A toxic demyelination and neurodegeneration model was induced in 129/Sv mice aged 3-5 and 13-15 months by adding cuprizone neurotoxin to their food for 3 weeks. From the 8th day of the cuprizone treatment, melatonin was injected intraperitoneally at 6 p.m. daily, at a dose of 1 mg/kg. The brain GFPA + -cells were evaluated by immunohistochemical method, the proportion of CD11b+, CD3+CD11b+, CD3+, CD3+CD4+, CD3+CD8+, Nestin+-cells was determined via flow cytometry. Macrophage activity was evaluated by their ability to phagocytose latex beads Morphometric analysis of the brain neurons and the behavioral reactions ("open field" and rotarod tests) were performed. To assess the involvement of the bone marrow and thymus in the action of melatonin, the amount of granulocyte/macrophage colony-forming cells (GM-CFC), and blood monocytes and thymic hormone thymulin were evaluated. Results and discussion: The numbers of the GFAP+-, CD3+-, CD3+CD4+, CD3+CD8+, CD11b+, CD3+CD11b+, Nestin+-cells and macrophages phagocytic latex beads and malondialdehyde (MDA) content were increased in the brain of young and aging mice under cuprizone influence. The proportion of undamaged neurons within the brain, motor, affective, and exploratory activities, and muscle tone decreased in mice of both ages. Introducing melatonin to mice of any age reduced the number of GFAP+-, CD3+- cells and their subpopulations, macrophage activation, and MDA content. At the same time, the percentage of brain neurons that were unchanged increased as the number of Nestin+ cells decreased. The behavioral responses were also improved. Besides, the number of bone marrow GM-CFC and the blood level of monocytes and thymulin increased. The effects of both neurotoxin and melatonin on the brain astrocytes, macrophages T-cells, and immune system organs as well as the structure and functioning of neurons were more pronounced in the young mice. Conclusion: We have observed the involvement of the astrocytes, macrophages, T-cells, neural stem cells, and neurons in the brain reaction of mice different age after administration of neurotoxin cuprizone and melatonin. The brain cell composition reaction has the age features. The neuroprotective effects of melatonin in cuprizone-treated mice have been realized through an improvement of the brain cell composition and oxidative stress factors and functioning of bone marrow and thymus.

Nerve Regeneration in Conditions of HSV-Infection and an Antiviral Drug Influence.

Herpes simplex virus type I (HSV-I) is a latent neuroinfection which can cause focal brain lesion. The role of HSV-infection in nerve regeneration has not been studied so far. The aim of the work was to study sciatic nerve regeneration in the presence of HSV-infection and the influence of an antiviral drug. BALB/c line mice were divided into five groups. Group 1 animals were infected with HSV-I. After resolution of neuroinfection manifestations the sciatic nerve of these animals was crushed. Group 2 mice were administered acyclovir following the same procedures. Groups 3-5 mice served as controls. Thirty days after the operation distal nerve stumps and m.gastrocnemius were studied morphologically and biochemically. Ultrastructural organization of the sciatic nerve in control animals remained intact. Morphometric parameters of the nerves from the experimental groups have not reach control values. However, in the group 1 diameter of nerve fibers was significantly smaller than in the group 2. Both nerve regeneration and m.gastrocnemius reinnervation were confirmed. The muscle hypotrophy was found in groups 1, 2, and 3 (the muscle fibers diameter decreased). Metabolic changes in the muscles of the infected animals (groups 1 and 2) were more pronounced than in control groups 3 and 4. The levels of TBA-active products, conjugated dienes, carbonyl and SH-groups were reduced in m.gastrocnemius of the experimental groups, however no significant difference associated with acyclovir administration was found. HSV-infection is not limited to the local neurodegenerative changes in the CNS but affects regeneration of the injured sciatic nerve. Anat Rec, 301:1734-1744, 2018. © 2018 Wiley Periodicals, Inc.

The study of leukocyte phagocytic activity in the presence of herpetic infection and stroke.

OBJECTIVE: Inrtoduction: Post-stroke complications are one of the urgent and insufficiently resolved problems. According to different literature data 23% to 65% of patients suffer from the post-stroke development of an infectious process. Herpes simplex virus type 1 and 2 can also be etiological factors of stroke development, however their reactivation is seldom mentioned in clinical observations. The development of immune suppression is considered to be the cause of these complications. The aim: The current study aims at determining post-stroke changes in leukocyte component of the immunity and in the presence of concomitant herpetic infection as well as at finding changes in phagocytosis parameters during antiviral treatment. PATIENTS AND METHODS: Materials and methods: The experiments were carried out on mice of the Balb/с line. The animals were infected with the herpes simplex virus type I, and 30 days later hemorrhagic stroke was simulated by administering 0.1 ml of autoblood into the right hemisphere. Following the acute stroke some animals were given acyclovir, proteflazid or altabor. From the animals' blood leukocytes were obtained and phagocytic activity and production of reactive oxygen species of granulocytes and agranulocytes in relation to fluorescent E.coli bacteria were studied by flow cytometry. RESULTS: Results: The experiment revealed significant changes in the redistribution between two major types of leukocytes in mice with stroke (an increased number of agranulocytes by 19.9%) and decreased phagocytosis activity, in the animals infected with herpes simplex virus type І in particular. Ischemic brain damage had an immunosuppressive effect on blood leukocytes. For comparison a significant increase in phagocyte count in leukocytes was found in the case of viral infection. The use of drugs with antiviral effects did not affect the activity of granulocytes / agranulocytes. CONCLUSION: Conclusion: Stroke can be the cause of latent herpes virus infection reactivation and has essential negative effect on immune characteristics of leukocytes that remain unchanged with the use of antiviral agents.