Diverse Gene Expressions in the Prediction of Cuprizone-Induced Demyelination

Spatio-temporal analysis of toxigenic genes expression in the growing Bufo gargarizans based on RNA sequencing data

BACKGROUND

Bufo gargarizans Cantor, a widely distributed amphibian species in Asia, produces and releases toxins through its retroauricular and granular glands. Although various tissues have been sequenced, the molecular mechanisms underlying the toxin production remain unclear. To elucidate these mechanisms, abdominal skin (non-toxic secretory glands) and retroauricular gland (toxic secreting glands) samples were collected at different time points (3, 6, 12, 24, and 36 months) for RNA sequencing (RNA-seq) and analysis.

RESULTS

In comparison to the S group during the same period, a total of 3053, 3026, 1516, 1028, and 2061 differentially expressed genes (DEGs) were identified across five developmental stages. Gene Ontology (GO) analysis revealed that DEGs were primarily enriched in biological processes including cellular processes, single-organism processes, metabolic processes, and biological regulation. In terms of cellular components, the DEGs were predominantly localized in the cell and cell parts, whereas molecular function indicated significant enrichment in binding and catalytic activity. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the metabolism and synthesis of various substances, such as lipid metabolism, cofactor and vitamin metabolism, tryptophan metabolism, steroid biosynthesis, and primary bile acid biosynthesis, were accompanied by the development of toads. Additionally, using trend analysis, we discovered candidate genes that were upregulated in the retroauricular glands during development, and the abundance of these genes in the abdominal skin was extremely low. Finally, we identified 26 genes that are likely to be involved in toxin production and that are likely to be involved in toxin anabolism.

CONCLUSION

Overall, these results provide new insights into the genes involved in toxin production in B. gargarizans, which will improve our understanding of the molecular mechanisms underlying toxigenic gene expression.

Identification of potential functional peptides involved in demyelinating injury in the central nervous system

Multiple sclerosis (MS) is a chronic inflammatory neurologic disease characterized by the demyelinating injury of the central nervous system (CNS). It was reported that the mutant peptide came from myelin proteolipid protein (PLP) and myelin basic protein (MBP) might play a critical role in immunotherapy function of MS. However, endogenous peptides in demyelinating brain tissue of MS and their role in the pathologic process of MS have not been revealed. Here, we performed peptidomic analysis of freshly isolated corpus callosum (CC) from the brains of CPZ-treated mice and normal diet controls of male C57BL/6 mice by LC-MS/MS. Identified a total of 217 peptides were expressed at different levels in MS mice model compared with controls. By performed GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis, we found that the precursor protein of these differently expressed peptides (DEPs) were associated with myelin sheath and oxidative phosphorylation. Our study is the first brain peptidomic of MS mice model, revealing the distinct features of DEPs in demyelination brain tissue. These DPEs may provide further insight into the pathogenesis and complexity of MS, which would facilitate the discovery of the potential novel and effective strategy for the treatment of MS.

Evaluation of in vivo lithium chloride effects as a GSK3-β inhibitor on human adipose derived stem cells differentiation into oligodendrocytes and re-myelination in an animal model of multiple sclerosis

BACKGROUND

The application of neuroprotective agents in combination with stem cells is considered a potential effective treatment for multiple sclerosis (MS). Therefore, the effects of lithium chloride as a neuroprotective agent and a GSK3-β inhibitor were evaluated in combination with human adipose derived stem cells on re-myelination, oligodendrocyte differentiation, and functional recovery.

METHODS

After inducing a mouse model of MS and proving it by the hanging wire test, the mice were randomly assigned to five experimental groups: Cup, Sham, Li, hADSC, and Li + hADSC. Additionally, a control group with normal feeding was considered. Finally, toluidine blue staining was carried out to estimate the level of myelination. Furthermore, immunofluorescent staining was used to evaluate the mean of OLIG2 and MOG positive cells. The mRNA levels of β-Catenin, myelin and oligodendrocyte specific genes were determined via the Real-Time PCR.

RESULTS

The results of the hanging wire test and toluidine blue staining showed a significant increase in myelin density and improvements in motor function in groups, which received lithium and stem cells, particularly in the Li + hADSC group compared with the untreated groups (P < 0.01). Moreover, immunostaining results indicated that the mean percentages of MOG and OLIG2 positive cells were significantly higher in the Li + hADSC group than in the other groups (P < 0.01). Finally, gene expression studies indicated that the use of lithium could increase the expression of β-Catenin, myelin and oligodendrocyte specific genes.

CONCLUSION

The use of Lithium Chloride can increase stem cells differentiation into oligodendrocytes and improve re-myelination in MS.

Wuzi Yanzong Pill relieves CPZ-induced demyelination by improving the microenvironment in the brain

Ethnopharmacology relevance

Wuzi Yanzong Pill (WYP), a well-known prescription for invigorating the kidney and essence, which is widely used to treat infertility such as oligoasthenospermia. Studies have shown that WYP can be used to treat neurological diseases, but its therapeutic effects and mechanisms for multiple sclerosis (MS) remain unclear.

Aim of the study

Based on the establishment of Cuprizone (CPZ)-induced demyelination model, this study determined the effect of WYP on remyelination by detecting changes in the microenvironment of the central nervous system.

Materials and methods

C57BL/6 mice were divided into three groups. The CPZ group and CPZ + WYP group were fed with 0.2% CPZ feed, and the control group was fed normal feed, for 6 weeks. At the end of the second week, the CPZ + WYP group was gavaged with WYP solution (16 g/kg/d), and the other two groups were gavaged with normal saline twice a day with an interval of 12 h each time, for 4 weeks. Forced swimming and elevated plus maze were used to detect changes in anxiety and depression before and after treatment. Luxol fast blue staining and the expression of MBP were used to evaluate the demyelination of the brain. Western blot was used to detect the expression of microglia and their subtype markers Iba-1, Arg-1, iNOS, the expression of neurotrophic factors BDNF, GDNF, CNTF, and the expression of oligodendrocyte precursor cells NG2. ELISA detected the content of IL-6, IL-1β, IL-10, TGF-β, BDNF, GDNF, CNTF in the brain. The distribution of Iba-1 in the corpus callosum was observed by immunofluorescence.

Results

The results showed that on the basis of improving mood abnormalities and demyelination, WYP reduced the protein content of Iba-1 and iNOS, increased the protein content of Arg-1, and reduce accumulation of microglia in the corpus callosum. In addition, WYP reduced the secretion of IL-6 and IL-1β while promoting the secretion of IL-10 and TGF-β. After WYP intervention treatment, the levels of neurotrophic factors BDNF, GDNF, CNTF increased. Due to the improvement of inflammatory and nutritional environment in the CNS, promoting the proliferation of NG2 oligodendrocyte, increased the expression of MBP, and repairing myelin sheath.

Conclusion

Our results indicated that WYP promoted the proliferation and development of oligodendrocytes by improving the CNS microenvironment, effectively alleviating demyelination.

Bu Shen Yi Sui Capsule Promotes Myelin Repair by Modulating the Transformation of A1/A2 Reactive Astrocytes In Vivo and In Vitro

Background/Aims. Multiple sclerosis (MS) is an autoimmune disorder that affects the central nervous system (CNS) primarily hallmarked by neuroinflammation and demyelination. The activation of astrocytes exerts double-edged sword effects, which perform an integral function in demyelination and remyelination. In this research, we examined the therapeutic effects of the Bu Shen Yi Sui capsule (BSYS), a traditional Chinese medicine prescription, in a cuprizone- (CPZ-) triggered demyelination model of MS (CPZ mice). This research intended to evaluate if BSYS might promote remyelination by shifting A1 astrocytes to A2 astrocytes. Methods. The effects of BSYS on astrocyte polarization and the potential mechanisms were explored in vitro and in vivo utilizing real-time quantitative reverse transcription PCR, immunofluorescence, and Western blotting. Histopathology, expression of inflammatory cytokines (IL-10, IL-1β, and IL-6), growth factors (TGF-β, BDNF), and motor coordination were assessed to verify the effects of BSYS (3.02 g/kg/d) on CPZ mice. In vitro, A1 astrocytes were induced by TNF-α (30 ng/mL), IL-1α (3 ng/mL), and C1q (400 ng/mL), following which the effect of BSYS-containing serum (concentration of 15%) on the transformation of A1/A2 reactive astrocytes was also evaluated. Results and Conclusions. BSYS treatment improved motor function in CPZ mice as assessed by rotarod tests. Intragastric administration of BSYS considerably lowered the proportion of A1 astrocytes, but the number of A2 astrocytes, MOG+, PLP+, CNPase+, and MBP+ cells was upregulated. Meanwhile, dysregulation of glutathione peroxidase, malondialdehyde, and superoxide dismutase was reversed in CPZ mice after treatment with BSYS. In addition, the lesion area and expression of proinflammatory cytokines were decreased and neuronal protection factors and anti-inflammatory cytokines were increased. In vitro, BSYS-containing serum suppressed the A1 astrocytic markers' expression and elevated the expression levels of A2 markers in primary astrocytes triggered by C1q, TNF-α, and IL-1α. Importantly, the miR-155/SOCS1 signaling pathway was involved in the modulation of the A1/A2 phenotype shift. Overall, this study demonstrated that BSYS has neuroprotective effects in myelin repair by modulating astrocyte polarization via the miR-155/SOCS1 pathway.

Astrocytes as a target for Nogo-A and implications for synapse formation in vitro and in a model of acute demyelination

Central nervous system (CNS) function depends on precise synaptogenesis, which is shaped by environmental cues and cellular interactions. Astrocytes are outstanding regulators of synapse development and plasticity through contact-dependent signals and through the release of pro- and antisynaptogenic factors. Conversely, myelin and its associated proteins, including Nogo-A, affect synapses in a inhibitory fashion and contribute to neural circuitry stabilization. However, the roles of Nogo-A-astrocyte interactions and their implications in synapse development and plasticity have not been characterized. Therefore, we aimed to investigate whether Nogo-A affects the capacity of astrocytes to induce synaptogenesis. Additionally, we assessed whether downregulation of Nogo-A signaling in an in vivo demyelination model impacts the synaptogenic potential of astrocytes. Our in vitro data show that cortical astrocytes respond to Nogo-A through RhoA pathway activation, exhibiting stress fiber formation and decreased ramified morphology. This phenotype was associated with reduced levels of GLAST protein and aspartate uptake, decreased mRNA levels of the synaptogenesis-associated genes Hevin, glypican-4, TGF-β1 and BDNF, and decreased and increased protein levels of Hevin and SPARC, respectively. Corroborating these findings, conditioned medium from Nogo-A-treated astrocytes suppressed the formation of structurally and functionally mature synapses in cortical neuronal cultures. After cuprizone-induced acute demyelination, we observed reduced immunostaining for Nogo-A in the visual cortex accompanied by higher levels of Hevin expression in astrocytes and an increase in excitatory synapse density. Hence, we suggest that interactions between Nogo-A and astrocytes might represent an important pathway of plasticity regulation and could be a target for therapeutic intervention in demyelinating diseases in the future.