Effects of aerobic exercise on demyelination and brain morphology in the cuprizone rat model of multiple sclerosis

doi:10.21203/rs.3.rs-3404226/v1

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Effects of aerobic exercise on demyelination and brain morphology in the cuprizone rat model of multiple sclerosis

https://doi.org/10.21203/rs.3.rs-3404226/v1

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Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system (CNS) that led to brain atrophy. The purpose of this study was to investigate the effects of pre-and post-conditioning with exercise on demyelination and brain morphology. Thirty male rats were randomly divided into five groups (n = 6 per group), consisting of a healthy control group (Control), an MS group, and three exercise groups: the group that performed the exercise protocol (running on a treadmill 5 days/week for 6 weeks) before the MS induction (EX + MS), the group that performed the exercise protocol during the MS induction (MS + EX), and the group that performed the exercise protocol before and during the MS induction (EX + MS + EX). The expression of Myelin basic protein (MBP), and demyelination in the corpus callosum and the volume, weight, length, width, and height of the brain were measured. The EX + MS + EX showed a significant increase in the expression of MBP compared to other MS groups (**p < 0.01) as well as a significant decrease in the area of demyelination of the corpus callosum compared to MS and MS + EX groups (**p < 0.01). However, there were no significant differences between the MS group and exercised groups for brain morphology. The exercise showed neuroprotective effects, as evidenced by decreased areas of demyelination and improved MBP expression.

Exercise

Morphology

brain

Multiple sclerosis

Myelin basic protein

demyelination

Multiple sclerosis (MS) is associated with increased degradation of myelin basic protein (MBP) in the central nervous system (CNS) (1). MBP is an abundant protein in CNS myelin and has been studied as a factor in the pathogenesis of the autoimmune neurodegenerative disease MS, for a long time. MBP is a simple molecule in appearance but complex in biochemical structure which is related to the normal development of the nervous system and neurodegenerative diseases (2).

Brain atrophy is visible in the early stages of MS, progressing faster than healthy adults, and is considered a reliable, sensitive, and repeatable predictor for future neurodegeneration, and physical, and cognitive disability (3). The reduction of brain atrophy has recently been included as a critical endpoint in clinical trials of new or emerging disease-modifying drugs (DMDs) in MS. Using neuroimaging software, clinicians may be able to use brain atrophy measuring for daily clinical practice to monitor disease progression, and response to DMD (4)

Experts have prioritized research for strategies to accelerate the development of MS cures. One of these fields is new rehabilitation strategies such as aerobic exercises, which have restorative, neurological, cardiorespiratory, and metabolic benefits to improve brain repair and remyelination (5, 6). Exercise training is a safe behavioral approach for the management of many functional, symptomatic, and quality-of-life disorders in patients with MS, and as a brain regenerative medicine (7).

Animal studies, as well as pilot or experimental studies, have shown that exercise can be potentially disease-modifying or neuroprotective. In fact, exercise leads to positive changes in brain MRI, including brain volume, and reduces MS relapse rate (8–10). The clinical, synaptic, and neuropathological effects of voluntary wheel running were investigated in a mouse model of MS, experimental autoimmune encephalomyelitis (EAE). Exercising EAE mice exhibited less severe neurological deficits, dendritic lesions, and synaptic defects than control EAE animals (11). Langeskov-Christensen et al. (30) showed 24 weeks of high-intensity progressive aerobic exercise (PAE) did not affect brain volume and prevention of brain atrophy in people with MS, but it significantly reduces the rate of relapse. In a single-blinded phase II clinical trial with an extended baseline period, 60 people with progressive MS (PMS) were randomly divided into two groups that performed progressive resistance training (PRT) or high-intensity interval training (HIIT). The results of this study showed that exercise had a neuroprotective effect on the brain, measured as whole-brain atrophy on magnetic resonance imaging (MRI) (12). It has been found that aerobic exercise increased MBP in the cuprizone rat model of MS (13). Another study showed aquatic exercise improves MBP expression and remyelination in the corpus callosum (14). Exercise is a basis for the treatment of MS models, reducing demyelination, and MBP degradation (14). The preventive, and protective effects of exercise have not been investigated simultaneously, and separately so far. The current research design provided the possibility to examine the effects of exercise in three different timings: performing exercise before, and during inducement of the MS model (EX + MS + EX), performing exercise before inducement of the MS model (EX + MS), and performing exercise during inducement of the MS model (MS + EX). Therefore, the purpose of the present study was to address whether exercise prevents and provides protection against demyelination, MBP degradation, and brain atrophy in the cuprizone rat model of MS.

All experimental procedures were approved by the Sport Sciences Research Institute of Iran (SSRI) (ethical approval ID: IR.SSRI.REC.1401.1681) and were performed by the Guidelines for the Care and Use of Laboratory Animals.

Animals and experimental groups

Male Wistar rats aged 70 days (weight; 154.55 ± 18.1 gr) were maintained in the vivarium of the Department of Exercise Physiology, Azad University of Ilam, Iran. Thirty rats were placed in groups of three animals in plastic cages with free access to tap water, 12 h light/12 h dark, and a temperature of 22ºC. All experiments followed approved guidelines for the ethical treatment of laboratory animals. five experimental groups (n = 6 per group) were set up according to the duration of exercise training groups and inducement of the MS model, as follows (Table 1):

Experiment I – Control: A healthy group that received no intervention.

Experiment II – MS: The group that cuprizone model of MS was induced on it.

Experiment III – EX + MS: The group that performed the exercise protocol before inducing the cuprizone model of MS.

Experiment IV – MS + EX: The group that performed the exercise protocol during inducing the cuprizone model of MS.

Experiment V – EX + MS + EX: The group that performed the exercise protocol before and during inducing the cuprizone model of MS.

Table 1 Experimental design.
Group	First phase (6 weeks)	Second phase (6 weeks)
Control	✘	✘
MS	✘	Induction of MS
EX + MS	Exercise protocol	Induction of MS
MS + EX	✘	Exercise protocol + Induction of MS
EX + MS + EX	Exercise protocol	Exercise protocol + Induction of MS

Control: animals that received normal food, MS: animals that received cuprizone food, EX + MS: animals that received cuprizone food and performed the exercise protocol before inducing the MS model, MS + EX: animals that received cuprizone food and performed the exercise protocol during inducing MS model, EX + MS + EX: animals that received cuprizone food and performed the exercise protocol before and during inducing MS model.

Exercise protocol

The treadmill exercise protocol is performed in two periods. The details of the treadmill exercise protocol are shown in Table 2. (15, 16).

Table 2

The treadmill exercise protocol.

phase

Speed

Time

Inclination

Familiarization period (1 week)

Stage 1: 2 m/minute

Stage 2: 5 m/minute

Stage 3: 8 m/minute

Stage 1: 5 minutes

Stage 2: 5 minutes

Stage 3: 20 minutes

Stage 1: 0º

Stage 2: 0º

Stage 3: 0º

The main treadmill exercise period (6 weeks)

Stage 1: 8 m/minute

Stage 2: 14 m/minute

Stage 3: 18 m/minute

Stage 1: 8 minutes

Stage 2: 5 minutes

Stage 3: 20 minutes

Stage 1: 0º

Stage 2: 0º

Stage 3: 0º

The cuprizone model for demyelination and induction of MS

To induce demyelination and MS, all groups except the Control group, consumed cuprizone (bis-cyclohexanone oxaldihydrazone; Sigma-Aldrich, St. Louis, MO 63103, USA) dietary (0.2% cuprizone, mixed into ground rodent chow) for 6 weeks. It led to the reduction of myelin protein synthesis and increased inflammation, followed by oligodendrocyte damage (17).

Corpus Callosum removal

The rats were anesthetized with chloral hydrate intraperitoneal injection at doses of 450 mg/kg body weight. Following anesthesia, the animals were perfused with phosphate-buffered saline (PBS) to flush blood from the circulatory system and then perfused with 4% paraformaldehyde (PFA) in saline for 30 minutes. Then, the animals were decapitated, and made a sagittal incision on the middle line of the scalp using a scalpel and exposed the skull. Two incisions on both sides skull were made and, the brain was completely removed and placed in a 10% neutral buffered formaldehyde solution. Then, the corpus callosum was gently removed from the middle groove of the brain.

Brain morphology

A digital scale (TE15022) was used to measure brain weight. The volume of brain was measured by the fluid displacement technique, and an R150 caliper was used to measure the length, Width, and height of the brain. The measurements were done in triplicate and the average of the two closest measurements was used for analysis.

Immunofluorescence staining for measuring MBP

Immunofluorescence protocol (18) was used for measuring the expression of MBP using MBP (Primary orb48450, secondary orb688925) antibody immunofluorescence kit.

To perform the immunofluorescence staining the sections were washed three times with PBS (P4417-Sigma). Then 0.3% Triton was added to the sections for 30 minutes in order to permeate the cell membrane. The sections were washed with PBS and 10% goat serum was added to the sections for 45 minutes to block the secondary antibody reaction. Then, the samples were incubated at 2–8 ̊ C for 24 hours with diluted primary antibody against MBP. After 24 hours, the sections were washed three times with PBS and incubated with the corresponding secondary antibody at 37°C for 1.5 hours. The samples were washed three times in a dark room and treated with DAPI (Sigma-D9542), and again washed with PBS. Then, the glycerol and PBS solution were added to the sample. The samples were placed for fluorescent photography using an Olympus BX 51 microscope and DP-72 camera to confirm the markers.

The green color indicated the level of MBP expression and the blue color indicated the cell nucleus of the corpus callosum. The ratio of green color expression to the total number of nuclei in the tissue as a percentage indicated the amount of MBP.

$$MBP=\frac{The amount of expression of green color}{Total number of nuclei in the tissue} \times 100$$

Luxol fast blue (LFB) staining for measuring demyelination

Luxol fast blue stain (LFB) was used to visualize myelin in the corpus callosum. the sections with 5-µm thick were selected for myelin staining (19). De-wax paraffin sections were hydrated in 95% ethanol (Merck). The sections were placed in 0.1% LFB solution (Merck) at 60°C (overnight). The sections were rinsed in 95% ethanol, and three times in distilled water. The samples were placed in lithium carbonate (Merck) for 10 seconds. until the colorful areas become colorless. Then, the samples were rinsed in 70% alcohol for 30 seconds and dehydrated in 95% ethanol immediately. Then, cleared them using xylene. Finally, Antlan glue was glued to the slides. Sections were examined using a LABOMED microscope. The amount of myelin in each group was determined using the following formula.

$$Myelin \text{p}ercent=\frac{The amount of blue color in each sample}{Average blue color in the control group} \times 100$$

Statistical analysis

Statistical analyses were conducted using GraphPad Prism (GraphPad Software, 9.3.1.471 Win/Mac). The one-way analysis of variance (ANOVA), followed by the Tukey post-test was used to compare the mean MBP expression and demyelination in the experimental groups. The results were expressed as mean ± SD. The p-value was considered less than 0.05.

The effects of exercise on the expression of MBP and demyelination in the corpus callosum

At the end of the study, there was a significant difference between the experimental groups in terms of the expression of MBP (F = 158.4, ****p < 0.0001, η2 = 0.98) and demyelination (F = 65.48, ****p < 0.0001, η2 = 0.96) in the corpus callosum. The expression of MBP in the corpus callosum in the MS, EX + MS, MS + EX, and EX + MS + EX groups was significantly lower than the control group (***p < 0.001). The expression of MBP in the EX + MS, MS + EX, and EX + MS + EX groups was significantly higher than the MS group (***p < 0.001). In addition, the expression of MBP in the EX + MS + EX group was significantly higher than the EX + MS (**p < 0.01) and MS + EX (***p < 0.001) groups. Also, demyelination in the corpus callosum in the MS (***p < 0.001), EX + MS (***p < 0.001), MS + EX (***p < 0.001), and EX + MS + EX (**p < 0. 01) groups was significantly higher than the control group. Demyelination in the corpus callosum in the EX + MS (***p < 0.001), MS + EX (**p < 0. 01), and EX + MS + EX (***p < 0.001) groups was significantly lower than the MS group (***p < 0.001). In addition, demyelination in the corpus callosum in the EX + MS + EX group was significantly lower than the EX + MS (**p < 0.01) group groups but not the MS-EX group (p > 0.05). No significant difference was observed between EX + MS, and MS + EX groups in terms of the expression of MBP, and demyelination in the corpus callosum (p > 0.05) (Fig. 1).

Morphological findings

The results of the present study showed that there was a significant effect of exercise on brain volume (F = 5.551, *p < 0.05, η² = 0.68) but not on brain weight (F = 0.400, p = 0.803, η² = 0.138), brain length (F = 0.605, p = 0.667, η² = 0.194), brain width (F = 0.949, p = 0.475, η² = 0.275), and brain height (F = 0.667, p = 0.629, η² = 0.210). Brain volume in the MS group was significantly lower than the control group (*p < 0.05) (Fig. 2).

The results of the present study showed that cuprizone administration in MS groups reduced significantly the expression of MBP, and increased significantly demyelination compared to the healthy control group. Therefore, it can be documented cuprizone rat model of MS was successfully induced. In addition, all groups that performed exercise protocol had significantly more MBP and less demyelination than the MS group. Also, the results indicated that in the EX + MS + EX group, which performed the aerobic exercise protocol before and during the induction of the MS model, a significant increase in the expression of MBP compared to other MS groups and a significant decrease in demyelination was observed compared to the MS, and MS + EX groups. Therefore, the positive effect of the exercise on the MS model-induced disorders was confirmed. These results showed that exercise before or during induction of MS can have a protective effect on the process of MBP degradation and demyelination, which was in agreement with the results (9,11,14.19-24).

In a study that used the cuprizone model of MS, increased areas of remyelination were observed in rats that had pre-conditioning exercises before cuprizone administration and continued the exercises during cuprizone administration (14) which is in agreement with our results. In addition. (23) in a study on EAE rats measured MBP to determine the thickness and components of myelin in the corpus callosum. Myelin thickness and density increased significantly in rats that exercised. These findings showed, that exercise may improve the development of myelin components in the corpus callosum. Therefore, in the current study, the increase in regenerating nerve cells can justify the effect of exercise in increasing MBP and reducing demyelination, and if exercise starts earlier, the exercise effects are more obvious, which is well shown in the group EX + MS + EX.

One of the reasons for the decrease in the expression of MBP in MS groups compared to the control group is due to cuprizone as a copper chelating agent affected the iron metabolism, which leads to ferroptosis. Ferroptosis is mainly caused by the abnormal increase of iron-dependent lipid reactive oxygen species (ROS), and redox homeostasis imbalance with glutathione deficiency, and lipid peroxidation in the corpus callosum. Since oligodendrocytes (OLs) contain high levels of iron, OL, and myelin are lost, which also occurs in MS (25). Nuclear factor erythroid 2-related factor 2- Kelch-like ECH-associated protein 1 (Nrf2-Keap1) pathway (Keap1 regulates the activity of Nrf2) improves cell proliferation and reduces ferroptosis (26). Nrf2 increases the gene expression of detoxification enzymes and antioxidant proteins. It has been found that both strength and endurance training protocols lead to the improvement of nuclear defense-antioxidant genomic pathway related to Nrf2 in the CNS (8). Therefore, the improvement of the expression of MBP and reduction of demyelination in the groups that performed the endurance training protocol can be related to the genomic antioxidant pathway activation.

Cuprizone also leads to mitochondrial oxidative stress, which has also been shown in the MS disease process. Oxidative stress stimulates the local immune response in the corpus callosum, which leads to the destruction of OLs, the accumulation of microglia, and gliosis. It is likely that the production of ROS by damaged mitochondria is one of the main reasons for the dysfunction of OLs and MBP protein and persistent demyelination (25, 27). Strong evidence has shown the positive effect of aerobic exercise on redox balance and increasing the efficiency of enzymatic and non-enzymatic antioxidant defense systems in mitochondria, which leads to the reduction of ROS production by mitochondrial membrane potential in basic conditions (28,29 (.

The results of the present study showed that exercise had no significant effect on brain morphology in the Cuprizone model of MS in male rats. The first study aimed at investigating the effect of high-intensity progressive aerobic exercise (PAE) on brain atrophy in MS was conducted by Langeskov-Christensen et al. in (2020). Therefore, direct comparison with previous research is challenging. The results of this study showed that PAE had no effect on brain atrophy, which is consistent with the results of our study. In the present study, pre- and post-conditioning with aerobic exercise had no significant effect on brain atrophy. However, animal research has shown that exercise has a positive effect on brain health through neurotrophic, neurogenic, and vascular mechanisms (31). It has been found that exercise may reduce the neuropathology burden (15). However, our study did not show a significant effect of exercise on brain morphology, which may be because morphology is a structural change and requires a longer period (32). Therefore, morphological changes cannot be expected within 12 weeks and the study duration should be increased. It is also possible to continue cuprizone administration for a longer period. We suggest to increasing the number of groups to investigate the remyelination process to achieve desired results.

The present study showed the protective effect of exercise on demyelination and degradation of MBP protein in the corpus callosum. One of the distinguishing characteristics of the present research is that provided a possibility to investigate the protective and preventive effects of exercise. The group that exercised before and during MS induction showed both protective and preventive effects, which had the greatest effect on the improvement of myelin structure. Therefore, start exercising as soon as possible led to more obvious improvement in MS disease conditions. But there was no significant difference between the two groups that exercised before or during the induction of MS disease. Therefore, both pre-and post-conditioning with exercise had a double protective effect. Exercise had no significant effect in terms of the brain morphology, that was probably due to the short term of the exercise intervention and the research design.

CNS: Central Nervous system

LFB: Luxol fast blue

MBP: myelin basic protein

CUP: cuprizone

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There is no conflict of interest, and all authors support the submission to this journal.

Consent for publication:

All authors support the publication of the manuscript in this journal.

Availability of data and materials:

Data and materials are made available to individuals upon request from the corresponding author.

Ethical approval:

competing interest

The authors have no affiliation or involvement with any organization or institution with any financial or non-financial interest in the topic or content discussed in this manuscript.

Funding:

No organization or institution has provided financial support for this research project.

Author contributions

Maryam Abbasi.designed this study. performed research and wrote the paper. analyzed the data.

Hadis Arghavanfar^. performed research and wrote the paper. analyzed the data.

Sepideh Hajinasab. performed research and wrote the paper. analyzed the data.

Aref Nooraei. designed this study. performed research and wrote the paper. analyzed the data.

Acknowledgements

The authors of this article are grateful to the Islamic Azad University, Ilam Branch, and the Research Center of the Faculty of Para-Veterinary Medicine, Ilam University

Widder, K., Harauz, G., & Hinderberger, D. (2020). Myelin basic protein (MBP) charge variants show different sphingomyelin-mediated interactions with myelin-like lipid monolayers. Biochimica et Biophysica Acta (BBA)-Biomembranes, 1862(2), 183077.doi‏: 10.1016/j.bbamem.2019.183077
Martinsen, V., & Kursula, P. (2022). Multiple sclerosis and myelin basic protein: Insights into protein disorder and disease. Amino Acids, 54(1), 99-109.‏ doi: 10.1007/s00726-021-03111-7.
Abdi, H., Hassani, K., & Shojaei, S. (2023). An investigation of the effect of brain atrophy on brain injury in multiple sclerosis. Journal of Theoretical Biology, 557, 111339.‏ doi: 10.1016/j.jtbi.2022.111339.
Andravizou, A., Dardiotis, E., Artemiadis, A., Sokratous, M., Siokas, V., Tsouris, Z., ... & Hadjigeorgiou, G. M. (2019). Brain atrophy in multiple sclerosis: mechanisms, clinical relevance and treatment options. Autoimmunity Highlights, 10, 1-25.‏ doi: 10.1186/s13317-019-0117-5.
Devasahayam, A. J., Kelly, L. P., Williams, J. B., Moore, C. S., & Ploughman, M. (2021). Fitness shifts the balance of BDNF and IL-6 from inflammation to repair among people with progressive multiple sclerosis. Biomolecules, 11(4), 504.‏ doi: 10.3390/biom11040504.
Lozinski, B. M., & Yong, V. W. (2022). Exercise and the brain in multiple sclerosis. Multiple Sclerosis Journal, 28(8), 1167-1172.‏ doi: 10.1177/1352458520969099.
Motl, R. W. (2020). Exercise and multiple sclerosis. Physical Exercise for Human Health, 333-343.‏ doi: 10.1007/978-981-15-1792-1_22.
Souza, P. S., Gonçalves, E. D., Pedroso, G. S., Farias, H. R., Junqueira, S. C., Marcon, R., ... & Dutra, R. C. (2017). Physical exercise attenuates experimental autoimmune encephalomyelitis by inhibiting peripheral immune response and blood-brain barrier disruption. Molecular neurobiology, 54, 4723-4737.‏ doi: 10.1007/s12035-016-0014-0
Tavazzi, E., Bergsland, N., Cattaneo, D., Gervasoni, E., Laganà, M. M., Dipasquale, O., ... & Rovaris, M. (2018). Effects of motor rehabilitation on mobility and brain plasticity in multiple sclerosis: a structural and functional MRI study. Journal of neurology, 265, 1393-1401.‏ doi: 10.1007/s00415-018-8859-y.
Sandroff, B. M., Johnson, C. L., & Motl, R. W. (2017). Exercise training effects on memory and hippocampal viscoelasticity in multiple sclerosis: a novel application of magnetic resonance elastography. Neuroradiology, 59, 61-67.‏ doi: 10.1007/s00234-016-1767-x.
Rossi, S., Furlan, R., De Chiara, V., Musella, A., Giudice, T. L., Mataluni, G., ... & Centonze, D. (2009). Exercise attenuates the clinical, synaptic and dendritic abnormalities of experimental autoimmune encephalomyelitis. Neurobiology of disease, 36(1), 51-59.‏ doi: 10.1016/j.nbd.2009.06.013.
12. Gravesteijn AS, Beckerman H, De Jong BA, Hulst HE, De Groot V (2020). Neuroprotective effects of exercise in people with progressive multiple sclerosis (Exercise PRO-MS): study protocol of a phase II trial. BMC neurology. Dec;20(1):1-1 doi.org/10.1186/s12883-020-01765-6
13. Sajedi, D., Shabani, R., & Elmieh, A. (2023). The Effect of Aerobic Training With the Consumption of Probiotics on the Myelination of Nerve Fibers in Cuprizone-induced Demyelination Mouse Model of Multiple Sclerosis. Basic and Clinical Neuroscience, 14(1), 73.‏doi: ‎10.32598/bcn.2022.3104.1
Begum, Z., Subramanian, V., Raghunath, G., Gurusamy, K., Vijayaraghavan, R., & Sivanesan, S. (2022). Efficacy of different intensity of aquatic exercise in enhancing remyelination and neuronal plasticity using cuprizone model in male Wistar rats. Advances in Clinical and Experimental Medicine, 31(9), 999-1009.‏ doi: 10.17219/acem/148112
Wang, M., Zhang, H., Liang, J., Huang, J., & Chen, N. (2023). Exercise suppresses neuroinflammation for alleviating Alzheimer’s disease. Journal of Neuroinflammation, 20(1), doi.org/10.1186/s12974-023-02753-6
Lu, Y., Dong, Y., Tucker, D., Wang, R., Ahmed, M. E., Brann, D., & Zhang, Q. (2017). Treadmill exercise exerts neuroprotection and regulates microglial polarization and oxidative stress in a streptozotocin-induced rat model of sporadic Alzheimer’s disease. Journal of Alzheimer's disease, 56(4), 1469-1484.‏ doi: 10.3233/JAD-160869.
Zirngibl, M., Assinck, P., Sizov, A., Caprariello, A. V., & Plemel, J. R. (2022). Oligodendrocyte death and myelin loss in the cuprizone model: an updated overview of the intrinsic and extrinsic causes of cuprizone demyelination. Molecular Neurodegeneration, 17(1), 1-28.‏ doi.org/10.1186/s13024-022-00538-8
Majumder, S., & Fisk, H. A. (2014). Quantitative immunofluorescence assay to measure the variation in protein levels at centrosomes. JoVE (Journal of Visualized Experiments), (94), e52030.‏ doi: 10.3791/52030
Sajadi, E., Aliaghaei, A., Farahni, R. M., Rashidiani-Rashidabadi, A., Raoofi, A., Sadeghi, Y., ... & Abdollahifar, M. A. (2021). Tissue plasminogen activator loaded PCL nanofibrous scaffold promoted nerve regeneration after sciatic nerve transection in male rats. Neurotoxicity Research, 39, 413-428.‏ doi: 10.3390/biom11111668
Shahidi, S. H., Kordi, M. R., Rajabi, H., Malm, C., Shah, F., & Quchan, A. S. K. (2020). Exercise modulates the levels of growth inhibitor genes before and after multiple sclerosis. Journal of neuroimmunology, 341, 577172.‏ doi: 10.1016/j.jneuroim.2020.577172.
Farahmand, F., Nourshahi, M., Soleimani, M., Rajabi, H., & Power, K. E. (2020). The effect of 6 weeks of high intensity interval training on myelin biomarkers and demyelination in experimental autoimmune encephalomyelitis model. Journal of Neuroimmunology, 346, 577306.‏ doi: 10.1016/j.jneuroim.2020.577306.
Mandolesi, G., Bullitta, S., Fresegna, D., De Vito, F., Rizzo, F. R., Musella, A., ... & Gentile, A. (2019). Voluntary running wheel attenuates motor deterioration and brain damage in cuprizone-induced demyelination. Neurobiology of disease, 129, 102-117.‏ doi: 10.1016/j.nbd.2019.05.010.
Kim, J. Y., Yi, E. S., Lee, H., Kim, J. S., Jee, Y. S., Kim, S. E., ... & Ko, I. G. (2020). Swimming exercise ameliorates symptoms of MOG-induced experimental autoimmune encephalomyelitis by inhibiting inflammation and demyelination in rats. International Neurourology Journal, 24(Suppl 1), S39.‏ doi: 10.5213/inj.2040156.078
Bernardes, D., Brambilla, R., Bracchi‐Ricard, V., Karmally, S., Dellarole, A., Carvalho‐Tavares, J., & Bethea, J. R. (2016). Prior regular exercise improves clinical outcome and reduces demyelination and axonal injury in experimental autoimmune encephalomyelitis. Journal of neurochemistry, 136, 63-73.‏ doi: 10.1111/jnc.13354
Jhelum, P., Santos-Nogueira, E., Teo, W., Haumont, A., Lenoël, I., Stys, P. K., & David, S. (2020). Ferroptosis mediates cuprizone-induced loss of oligodendrocytes and demyelination. Journal of Neuroscience, 40(48), 9327-9341.‏ doi: 10.1523/JNEUROSCI.1749-20.
He, F., Ru, X., & Wen, T. (2020). NRF2, a transcription factor for stress response and beyond. International journal of molecular sciences, 21(13), 4777.‏ doi: 10.3390/ijms21134777.
Aydin, O., Ellidag, H. Y., Eren, E., Kurtulus, F., Yaman, A., & Yılmaz, N. (2014). Ischemia modified albumin is an indicator of oxidative stress in multiple sclerosis. Biochemia Medica, 24(3), 383-389.‏ doi:10.11613/BM.2014.041
Bouzid, M. A., Filaire, E., McCall, A., & Fabre, C. (2015). Radical oxygen species, exercise and aging: an update. Sports Medicine, 45, 1245-1 doi: 10.1007/s40279-015-0348-1261.‏
Daussin, F. N., Rasseneur, L., Bouitbir, J., Charles, A. L., Dufour, S. P., Geny, B., ... & Richard, R. (2012). Different timing of changes in mitochondrial functions following endurance training. Medicine and science in sports and exercise, 44(2), 217-224.‏ doi: 10.1249/MSS.0b013e31822b0bd4
Langeskov-Christensen, M., Hvid, L. G., Nygaard, M. K. E., Ringgaard, S., Jensen, H. B., Nielsen, H. H., ... & Dalgas, U. (2021). Efficacy of high-intensity aerobic exercise on brain MRI measures in multiple sclerosis. Neurology, 96(2), e203-e213.‏ doi: 10.1212/WNL.0000000000011241.
Vecchio, L. M., Meng, Y., Xhima, K., Lipsman, N., Hamani, C., & Aubert, I. (2018). The neuroprotective effects of exercise: maintaining a healthy brain throughout aging. Brain plasticity, 4(1), 17-52.‏
Diniz, C. R. A. F., & Crestani, A. P. (2023). The times they are a-changin’: a proposal on how brain flexibility goes beyond the obvious to include the concepts of “upward” and “downward” to neuroplasticity. Molecular Psychiatry, 28(3), 977-992 doi.org/10.1038/s41380-022-01931-x

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Effects of aerobic exercise on demyelination and brain morphology in the cuprizone rat model of multiple sclerosis

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Abstract

Figures

Introduction

Materials and methods

Animals and experimental groups

Exercise protocol

The cuprizone model for demyelination and induction of MS

Corpus Callosum removal

Brain morphology

Immunofluorescence staining for measuring MBP

Luxol fast blue (LFB) staining for measuring demyelination

Statistical analysis

Results

The effects of exercise on the expression of MBP and demyelination in the corpus callosum

Morphological findings

Discussion

Conclusion

Abbreviations

Declarations

References

Status:

Version 1