The effect of calcitriol and all-trans retinoic acid on T-bet, IFN-γ, GATA3 and IL-4 genes expression in experimental autoimmune encephalomyelitis

Impact of calcitriol and PGD2-G-loaded lipid nanocapsules on oligodendrocyte progenitor cell differentiation and remyelination

Multiple sclerosis (MS) is a demyelinating and inflammatory disease of the central nervous system (CNS) in need of a curative treatment. MS research has recently focused on the development of pro-remyelinating treatments and neuroprotective therapies. Here, we aimed at favoring remyelination and reducing neuro-inflammation in a cuprizone mouse model of brain demyelination using nanomedicines. We have selected lipid nanocapsules (LNC) coated with the cell-penetrating peptide transactivator of translation (TAT), loaded with either a pro-remyelinating compound, calcitriol (Cal-LNC TAT), or an anti-inflammatory bioactive lipid, prostaglandin D2-glycerol ester (PGD2-G) (PGD2-G-LNC TAT). Following the characterization of these formulations, we showed that Cal-LNC TAT in combination with PGD2-G-LNC TAT increased the mRNA expression of oligodendrocyte differentiation markers both in the CG-4 cell line and in primary mixed glial cell (MGC) cultures. However, while the combination of Cal-LNC TAT and PGD2-G-LNC TAT showed promising results in vitro, no significant impact, in terms of remyelination, astrogliosis, and microgliosis, was observed in vivo in the corpus callosum of cuprizone-treated mice following intranasal administration. Thus, although calcitriol's beneficial effects have been abundantly described in the literature in the context of MS, here, we show that the different doses of calcitriol tested had a negative impact on the mice well-being and showed no beneficial effect in the cuprizone model in terms of remyelination and neuro-inflammation, alone and when combined with PGD2-G-LNC TAT.

Intraperitoneal injection of mesenchymal stem cells-conditioned media (MSCS-CM) treated monocyte can potentially alleviate motor defects in experimental autoimmune encephalomyelitis female mice; An original experimental study

INTRODUCTION

Multiple sclerosis (MS), as a destructive pathology of myelin in central nervous system (CNS), causes physical and mental complications. Experimental autoimmune encephalomyelitis (EAE) is laboratory model of MS widely used for CNS-associated inflammatory researches. Cell therapy using macrophage M2 (MPM2) is a cell type with anti-inflammatory characteristics for all inflammatory-based neuropathies. This experimental study investigated the probable therapeutic anti-inflammatory effects of intraperitoneal (IP) injection of MPM2 on alleviation of motor defect in EAE-affected animals.

MATERIALS AND METHODS

24 C57/BL6 female mice were divided into four groups of EAE, EAE + Dexa, EAE + PBS, and EAE + MP2. EAE was induced through deep cervical injection of spinal homogenate of guinea pigs. MPM2 cells were harvested from bone marrow and injected (106cells/ml) in three days of 10, 13 and 16 post-immunizations (p.i). Clinical score (CS), anti-inflammatory cytokines (IL-4, IL-10), pro-inflammatory gene expression (TNF-α, IL-1β) and histopathological investigations (HE, Nissl and Luxol Fast Blue) were considered. Data were analyzed using SPSS software (v.19) and p < 0.05 was considered significant level.

RESULTS

During EAE induction, the mean animal weight was decreased (p < 0.05); besides, following MPM2 injection, the weight gain was applied (p < 0.05) in EAE + MPM2 groups than control. Increased (p < 0.05) levels of CS was found during EAE induction in days 17-28 in EAE animals; besides, CS was decreased (p < 0.05) in EAE + MPM2 group than EAE animals. Also, in days 25-28 of experiment, the CS was decreased (p < 0.05) in EAE + MPM2 than EAE + Dexa. Histopathological assessments revealed low density of cell nuclei in corpus callosum, microscopically. LFB staining also showed considerable decrease in white matter density of corpus callosum in EAE group. Acceleration of white matter density was found in EAE + MPM2 group following cell therapy procedure. Genes expression of TNF-α, IL-1β along with IL-4 and IL-10 were decreased (p < 0.05) in EAE + MPM2 group.

CONCLUSION

IP injection of MPM2 to EAE-affected female mice can potentially reduce the CNS inflammation, neuronal death and myelin destruction. MPM2 cell therapy can improve animal motor defects.

Vitamins A and D Enhance the Expression of Ror-γ-Targeting miRNAs in a Mouse Model of Multiple Sclerosis

Autoreactive T cells, particularly those characterized by a Th17 phenotype, exert significant influence on the pathogenesis of multiple sclerosis (MS). The present study aimed to elucidate the impact of individual and combined administration of vitamin A and D on neuroinflammation, and microRNAs (miRNAs) involved in T helper (Th)17 development, utilizing a murine model of experimental autoimmune encephalomyelitis (EAE). EAE was induced in C57BL/6 mice, and 3 days prior to immunization, intraperitoneal injections of vitamins A and D or their combination were administered. Th17 cell percentages were determined in splenocytes utilizing intracellular staining and flow cytometry. Furthermore, the expression of Ror γ-t, miR-98-5p and Let-7a-5p, was measured in both splenocytes and spinal cord tissues using RT-PCR. Treatment with vitamin A and D resulted in a reduction in both disease severity in EAE mice. Treated mice showed a decreased frequency of Th17 cells and lower expression levels of IL17 and Ror γ-t in splenocytes and spinal cord. The spinal cord tissues and splenocytes of mice treated with vitamins A, D, and combined A+D showed a significant upregulation of miR-98-5p and Let-7a-5p compared to the EAE group. Statistical analysis indicated a strong negative correlation between miR-98-5p and Let-7a-5p levels in splenocytes and Ror-t expression. Our findings indicate that the administration of vitamins A and D exerts a suppressive effect on neuroinflammation in EAE that is associated with a reduction in the differentiation of T cells into the Th17 phenotype and is mediated by the upregulation of miR-98-5p and Let-7a-5p, which target the Ror γ-t.

Ellagic acid effects on disease severity, levels of cytokines and T-bet, RORγt, and GATA3 genes expression in multiple sclerosis patients: a multicentral-triple blind randomized clinical trial

Background

Multiple sclerosis (MS) is a chronic autoimmune disease. Ellagic acid is a natural polyphenol and affects the fate of neurons through its anti-inflammatory and antioxidant properties. The present study aimed to investigate ellagic acid effects on disease severity, the expression of involved genes in the pathogenesis of MS, and the levels of related cytokines.

Methods

The present study was a triple-blind clinical trial. Eligible patients were randomly assigned to two groups: Ellagic acid (25 subjects) for 12 weeks, receiving 180 mg of Ellagic acid (Axenic, Australia) and the control group (25 subjects) receiving a placebo, before the main meals. Before and after the study, the data including general information, foods intake, physical activity, anthropometric data, expanded disability status scale (EDSS), general health questionnaire (GHQ) and pain rating index (PRI), fatigue severity scale (FSS) were assessed, as well as serum levels of interferon-gamma (IFNγ), interleukin-17 (IL-17), interleukin-4 (IL-4) and transforming growth factor-beta (TGF-β), nitric-oxide (NO) using enzyme-linked immunoassay (ELISA) method and expression of T-box transcription factor (Tbet), GATA Binding Protein 3 (GATA3), retinoic acid-related orphan receptor-γt (RORγt) and Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were determined using Real-Time Quantitative Reverse Transcription PCR (RT-qPCR) method.

Findings

Ellagic acid supplementation led to a reduction in IFNγ, IL-17, NO and increased IL-4 in the ellagic acid group, however in the placebo group no such changes were observed (-24.52 ± 3.79 vs. -0.05 ± 0.02, p < 0.01; -5.37 ± 0.92 vs. 2.03 ± 1.03, p < 0.01; -18.03 ± 1.02 vs. -0.06 ± 0.05, p < 0.01, 14.69 ± 0.47 vs. -0.09 ± 0.14, p < 0.01, respectively). Ellagic acid supplementation had no effect on TGF-β in any of the study groups (p > 0.05). Also, the Tbet and RORγt genes expression decreased, and the GATA3 gene expression in the group receiving ellagic acid compared to control group significantly increased (0.52 ± 0.29 vs. 1.51 ± 0.18, p < 0.01, 0.49 ± 0.18 vs. 1.38 ± 0.14, p < 0.01, 1.71 ± 0.39 vs. 0.27 ± 0.10, p < 0.01). Also, ellagic acid supplementation led to significant decrease in EDSS, FSS and GHQ scores (p < 0.05), and no significant changes observed in PRI score (p > 0.05).

Conclusion

Ellagic acid supplementation can improve the health status of MS patients by reduction of the inflammatory cytokines and Tbet and RORγt gene expression, and increment of anti-inflammatory cytokines and GATA3 gene expression.Clinical trial registration: (https://en.irct.ir/trial/53020), IRCT20120415009472N22.

The immunomodulatory effects of all-trans retinoic acid and docosahexaenoic acid combination treatment on the expression of IL-2, IL-4, T-bet, and GATA3 genes in PBMCs of multiple sclerosis patients

OBJECTIVES

Multiple sclerosis (MS) is a potentially disabling autoimmune disease of the central nervous system. Neither the pathogenesis nor the effectiveness of treatment of MS has been fully understood. This in vitro trial evaluated the beneficial immunomodulatory effects of single and combined treatments of all-trans retinoic acid (ATRA) and docosahexaenoic acid (DHA) on the peripheral blood mononuclear cells (PBMCs) of relapsing-remitting MS (RRMS) patients who were receiving interferon beta (IFN-β).

METHODS

The PBMCs of 15 RRMS patients were isolated, cultured, and treated with single and combined treatments of ATRA and DHA. The expressions of IL-2, IL-4, T-bet, and GATA3 genes were evaluated using real-time PCR.

RESULTS

The results showed that a single treatment of ATRA could significantly suppress the gene expression of the pro-inflammatory cytokine, IL-2 (P < 0.05), and related transcription factor, T-bet (P < 0.001). The gene expression level of the anti-inflammatory cytokine, IL-4, and its transcription factor, GATA3, were not significantly changed. The expression of IL-2 and T-bet genes was significantly decreased in combination treatments of ATRA and DHA (P < 0.001). Significant suppression of IL-2 and T-bet (P < 0.001) was observed in ATRA and DHA combination therapy with half doses of their single treatment, which suggested a synergistic effect of these components.

DISCUSSION

Co-administration of vitamin A and DHA, an omega-3 fatty acid derivative, may exert a synergistic effect in modulating the immune system in MS patients; however, more studies are needed to evaluate the exact effects and mechanism of their actions on the immune cells.

Prioritization of risk genes in multiple sclerosis by a refined Bayesian framework followed by tissue-specificity and cell type feature assessment

BACKGROUND

Multiple sclerosis (MS) is a debilitating immune-mediated disease of the central nervous system that affects over 2 million people worldwide, resulting in a heavy burden to families and entire communities. Understanding the genetic basis underlying MS could help decipher the pathogenesis and shed light on MS treatment. We refined a recently developed Bayesian framework, Integrative Risk Gene Selector (iRIGS), to prioritize risk genes associated with MS by integrating the summary statistics from the largest GWAS to date (n = 115,803), various genomic features, and gene-gene closeness.

RESULTS

We identified 163 MS-associated prioritized risk genes (MS-PRGenes) through the Bayesian framework. We replicated 35 MS-PRGenes through two-sample Mendelian randomization (2SMR) approach by integrating data from GWAS and Genotype-Tissue Expression (GTEx) expression quantitative trait loci (eQTL) of 19 tissues. We demonstrated that MS-PRGenes had more substantial deleterious effects and disease risk. Moreover, single-cell enrichment analysis indicated MS-PRGenes were more enriched in activated macrophages and microglia macrophages than non-activated ones in control samples. Biological and drug enrichment analyses highlighted inflammatory signaling pathways.

CONCLUSIONS

In summary, we predicted and validated a high-confidence MS risk gene set from diverse genomic, epigenomic, eQTL, single-cell, and drug data. The MS-PRGenes could further serve as a benchmark of MS GWAS risk genes for future validation or genetic studies.

Vitamin D in Multiple Sclerosis-Lessons From Animal Studies

Multiple sclerosis is a multifactorial disease of the central nervous system with both genetic and environmental causes. The exact disease mechanisms are still unclear. Consequently, studies of possible treatment and preventive measures cover a large setting of heterogeneous approaches. Vitamin D is one of these approaches, and in many trials the relation of vitamin D serum levels and multiple sclerosis disease risk and activity describes different effects with sometimes inconsistent findings. Animal models are substantial for the research of disease mechanisms, and many of the drugs that are currently in use in multiple sclerosis have been developed, tested, or validated via animal studies. Especially when clinical studies show contradicting findings, the use of standardized settings and information about the mechanistic background is necessary. For this purpose, animal models are an essential tool. There is a variety of different experimental settings and types of animal models available, each of them with own strengths but also weaknesses. This mini-review aims to overview results of vitamin D studies in different animal models and sums up the most important recent findings.

Macrophages Control the Bioavailability of Vitamin D and Vitamin D-Regulated T Cell Responses

The active form of vitamin D₃ (1,25(OH)₂D₃) has a great impact on T cell effector function. Thus, 1,25(OH)₂D₃ promotes T helper 2 (Th2) and regulatory T (Treg) cell function and concomitantly inhibits Th1 and Th17 cell function. Thus, it is believed that vitamin D exerts anti-inflammatory effects. However, vitamin D binding protein (DBP) strongly binds both 1,25(OH)₂D₃ and the precursor 25(OH)D₃, leaving only a minor fraction of vitamin D in the free, bioavailable form. Accordingly, DBP in physiological concentrations would be expected to block the effect of vitamin D on T cells and dendritic cells. In the present study, we show that pro-inflammatory, monocyte-derived M1 macrophages express very high levels of the 25(OH)D-1α-hydroxylase CYP27B1 that enables them to convert 25(OH)D₃ into 1,25(OH)₂D₃ even in the presence of physiological concentrations of DBP. Co-cultivation of M1 macrophages with T cells allows them to overcome the sequestering of 25(OH)D₃ by DBP and to produce sufficient levels of 1,25(OH)₂D₃ to affect T cell effector function. This study suggests that in highly inflammatory conditions, M1 macrophages can produce sufficient levels of 1,25(OH)₂D₃ to modify T cell responses and thereby reduce T cell-mediated inflammation via a vitamin D-mediated negative feed-back loop.

Calcitriol and Retinoic acid antagonize each other to suppress the production of IL-9 by Th9 cells

Distinct T helper cells, including Th9 cells help maintain homeostasis in the immune system. Vitamins play pivotal role in the immune system through many mechanisms, including regulating the differentiation of T helper cells. Calcitriol (1,25-dihydroxyvitamin D3) and retinoic acid possess hormone-like properties and are the bioactive metabolites of vitamin D and A, respectively, that signal through heterodimers containing the common retinoid X receptor. In contrast to individual treatment with the vitamins that significantly attenuates IL-9 production from Th9 cells, Th9 cells treated with both vitamins demonstrated IL-9 production similar to untreated Th9 cells. This is associated with reciprocal expression of PU.1 and Foxp3. While the recruitment of PU.1 was significantly impaired to the Il9 gene in the presence of calcitriol or retinoic acid in Th9 cells, addition of both vitamins together increased the recruitment of PU.1 to the Il9 gene. Calcitriol and retinoic acid together impaired the recruitment of HDAC1 to the Il9 gene without impacting Gcn5 recruitment. Importantly, retinoic acid negated the effect of calcitriol and impaired the binding of VDR on the Il9 gene by dampened VDR-RXR formation. Collectively, our data show that calcitriol and retinoic acid antagonize each other to regulate the differentiation of Th9 cells.