Combination Therapy of Mesenchymal Stem Cell Transplantation and Astrocyte Ablation Improve Remyelination in a Cuprizone-Induced Demyelination Mouse Model.
Astrocytes display an active, dual, and controversial role in multiple sclerosis (MS), a chronic inflammatory demyelination disorder. However, mesenchymal stem cells (MSCs) can affect myelination in demyelinating disorders. This study aimed to investigate the effect of single and combination therapies of astrocyte ablation and MSC transplantation on remyelination in the cuprizone (CPZ) model of MS. C57BL/6 mice were fed 0.2% CPZ diet for 12 weeks. Astrocytes were ablated twice by L-a-aminoadipate (L-AAA) at the beginning of weeks 13 and 14 whereas MSCs were injected in the corpus callosum at the beginning of week 13. Motor coordination and balance were assessed through rotarod test whereas myelin content was evaluated by Luxol-fast blue (LFB) staining and transmission electron microscopy (TEM). Glial cells were assessed by immunofluorescence staining while mRNA expression was evaluated by quantitative real-time PCR. Combination treatment of ablation of astrocytes and MSC transplantation (CPZ + MSC + L-AAA) significantly decreased motor coordination deficits better than single treatments (CPZ + MSCs or CPZ + L-AAA), in comparison to CPZ mice. In addition, L-AAA and MSCs treatment significantly enhanced remyelination compared to CPZ group. Moreover, combination therapy caused a significant decrease in the number of GFAP+ and Iba-1+ cells, whereas oligodendrocytes were significantly increased in comparison to CPZ mice. Finally, MSC administration resulted in a significant upregulation of BDNF and NGF mRNA expression levels. Our data indicate that transient ablation of astrocytes along with MSCs treatment improve remyelination through enhancing oligodendrocytes and attenuating gliosis in a chronic demyelinating mouse model of MS.
Madadi S
，Shiri E
，Pasbakhsh P
，Tahmasebi F
，Kazemzadeh S
，Zibara K
，Kashani IR
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Protective Features of Calorie Restriction on Cuprizone-induced Demyelination via Modulating Microglial Phenotype.
Multiple sclerosis (MS) is an immune-mediated demyelinating disorder in the central nervous system (CNS) with no definitive treatment, but it can be alleviated by changing life habits. Calorie restriction (CR) is effective in preventing or treating metabolic and autoimmune disorders. CR is one of the helpful approaches to control the progression of MS. In the present study, we investigated the preventive effect of caloric restriction on cuprizone induced-demyelination, a model of multiple sclerosis. To induce acute demyelination in C57/BL6 mice, we added 0.2% Cuprizone (CPZ) to their diet for 6 weeks. To induce calorie restriction, 10% Carboxymethyl cellulose (CMC) was added to the diet as a dietary cellulose fiber for 6 weeks. Remyelination was studied by luxol fast blue (LFB) staining. Microglia activity, M1 and M2 microglial/macrophage phenotypes were assessed by immunohistochemistry of Iba-1, iNOS and Arg-1, respectively. The expression of targeted genes was assessed by the real-time polymerase chain reaction. Luxol fast blue (LFB) staining showed that the CR regimen could decrease the cuprizone-induced demyelination process (p < 0.01). Moreover, the CR application could improve balance and motor performance in cuprizone-intoxicated mice by significantly enhancing protein and gene expression of Sirt1, M2 microglial phenotype marker (Arg-1) and Akt1 gene expression, also decreased M1 microglial phenotype marker (iNOS), Akt2 and P53 gene expressions (p < 0.05). Cumulatively, it can be concluded that caloric restriction was able to counteract MS symptoms through alleviating inflammatory responses.
Zarini D
，Pasbakhsh P
，Nekoonam S
，Mojaverrostami S
，Ghasemi S
，Shabani M
，Kashani IR
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Phosphodiesterase-5 inhibition promotes remyelination by MCP-1/CCR-2 and MMP-9 regulation in a cuprizone-induced demyelination model.
While it has recently been shown that sildenafil (Viagra®) has a protective effect on myelination/remyelination, the mechanism of this protection is still unknown. In general, cytokines, chemokines and metalloproteinases have a pro-inflammatory action, but can also exert a role in modulating glial cell activation, contributing to the balance of cell response. Investigating these molecules can contribute to clarifying the mechanisms of sildenafil neuroprotection. In addition, it is not known whether sildenafil is able to restore an already installed neurodegenerative process or if the treatment period is critical for its action. The aim of the present study was to evaluate, in a cuprizone (CPZ)-induced demyelination model, the effects and mechanisms of time-dependent treatment with sildenafil (beginning 15 days after neurodegeneration and continuing for 15 days, or starting concomitantly with neurodegeneration and continuing for 30 days) on neuroinflammation and remyelination. Neuroinflammation and demyelination induced by CPZ in rodents has been widely used as a model of multiple sclerosis (MS). In the present study, five male C57BL/6 mice aged 7-10 weeks were used per group. For four weeks, the groups received either cuprizone (CPZ) 0.2% mixed in feed or CPZ combined with the administration of sildenafil (Viagra®, Pfizer, 25 mg/kg) orally in drinking water, starting concurrently with (sild-T0) or 15 days (sild-T15) after the start of CPZ treatment. Control animals received pure food and water. The cerebella were dissected and processed for immunohistochemistry, immunofluorescence (frozen), Western blotting, Luxol fast blue staining and transmission electron microscopy. Magnetic resonance was performed for live animals, after the same treatment, using CPZ 0.3%. CPZ induced an increase in the expression of IL-1β and a decrease in MCP-1, CCR-2, MBP and GST-pi, as well as promoting damage in the structure and ultra-structure of the myelin sheath. Interestingly, the administering of sild-T0 promoted a further increase of MMP-9, MCP-1, and CCR-2, possibly contributing to changes in the microglia phenotype, which becomes more phagocytic, cleaning myelin debris. It was also observed that, after sild-T0 treatment, the expression of GST-pi and MBP increased and the myelin structure was improved. However, sild-T15 was not efficient in all aspects, probably due to the short treatment period and to starting after the installation of the degenerative process. Therefore, the present study shows that sildenafil modulates inflammation, with the involvement of MMP-9, MCP-1, and CCR-2, and also contributes to myelin repair. These protective effects were dependent on the therapeutic strategy used. This clarification can strengthen research proposals into the mechanism of action of sildenafil and contribute to the control of neurodegenerative diseases such as MS.
Nunes AK
，Rapôso C
，de Oliveira WH
，Thomé R
，Verinaud L
，Tovar-Moll F
，Peixoto CA
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