Curcumin protects mice with myasthenia gravis by regulating the gut microbiota, short-chain fatty acids, and the Th17/Treg balance.

Curcumin is widely used as a traditional drug in Asia. Interestingly, curcumin and its metabolites have been demonstrated to influence the microbiota. However, the effect of curcumin on the gut microbiota in patients with myasthenia gravis (MG) remains unclear. This study aimed to investigate the effects of curcumin on the gut microbiota community, short-chain fatty acids (SCFAs) levels, intestinal permeability, and Th17/Treg balance in a Torpedo acetylcholine receptor (T-AChR)-induced MG mouse model. The results showed that curcumin significantly alleviated the clinical symptoms of MG mice induced by T-AChR. Curcumin modified the gut microbiota composition, increased microbial diversity, and, in particular, reduced endotoxin-producing Proteobacteria and Desulfovibrio levels in T-AChR-induced gut dysbiosis. Moreover, we found that curcumin significantly increased fecal butyrate levels in mice with T-AChR-induced gut dysbiosis. Butyrate levels increased in conjunction with the increase in butyrate-producing species such as Oscillospira, Akkermansia, and Allobaculum in the curcumin-treated group. In addition, curcumin repressed the increased levels of lipopolysaccharide (LPS), zonulin, and FD4 in plasma. It enhanced Occludin expression in the colons of MG mice induced with T-AChR, indicating dramatically alleviated gut permeability. Furthermore, curcumin treatment corrected T-AChR-induced imbalances in Th17/Treg cells. In summary, curcumin may protect mice against myasthenia gravis by modulating both the gut microbiota and SCFAs, improving gut permeability, and regulating the Th17/Treg balance. This study provides novel insights into curcumin's clinical value in MG therapy.

MicroRNA­155­5p affects regulatory T cell activation and immunosuppressive function by targeting BCL10 in myasthenia gravis.

The imbalance in immune homeostasis plays a crucial role in the pathogenesis of myasthenia gravis (MG). MicroRNAs (miRs) have been identified as key regulators of immune homeostasis. B-cell lymphoma/leukemia 10 (BCL10) has been implicated in the activation and suppressive function of regulatory T cells (Tregs). This study aimed to investigate the potential role of miR-155-5p in modulating the activation and function of Tregs in MG. To achieve this objective, blood samples were collected from MG patients to assess the expression levels of miR-155-5p and BCL10, as well as the proportion of circulating Tregs, in comparison to healthy controls. The correlation between miR-155-5p and BCL10 levels was evaluated in human samples. The expression levels of miR-155-5p and the numbers of circulating Tregs were also examined in an animal model of experimental autoimmune MG (EAMG). A dual-luciferase reporter assay was used to verify whether miR-155-5p can target BCL10. To determine the regulatory function of BCL10 in Tregs, CD4+ CD25+ Tregs were transfected with either small interfering-BCL10 or miR-155-5p inhibitor, and the expression levels of the anti-inflammatory cytokine IL-10 and transcription factors Foxp3, TGF-ß1, CTLA4, and ICOS were measured. The results demonstrated that the expression level of miR-155-5p was significantly higher in patients with MG compared with that in healthy controls, whereas the expression level of BCL10 was significantly decreased in patients with MG. Furthermore, there was a significant negative correlation between the expression levels of miR-155-5p and BCL10. The number of circulating Tregs was significantly reduced in patients with MG and in the spleen of rats with EAMG compared with that in the corresponding control groups. The dual-luciferase reporter assay demonstrated that miR-155-5p could target BCL10. The Tregs transfected with si-BCL10 demonstrated significant decreases in the protein levels of TGF-ß1 and IL-10, as well as in the mRNA expression levels of Foxp3, TGF-ß1, CTLA-4 and ICOS. Conversely, the Tregs transfected with the miR-155-5p inhibitor exhibited a substantial increase in these protein and mRNA expression levels compared with their respective control groups. Furthermore, the knockdown of BCL10 exhibited a decline in the suppressive efficacy of Tregs on the proliferation of CD4+ T cells. Conversely, the suppression of miR-155-5p expression attenuated the inhibition of the BCL10 gene, potentially causing an indirect influence on the suppressive capability of Tregs on the proliferation of CD4+ T cells. BCL10 was thus found to contribute to the activation and immunosuppressive function of Tregs. In summary, the present study demonstrated that miR-155-5p inhibited the activation and immunosuppressive function of Tregs by targeting BCL10, which may be used as a future potential target for the treatment of MG.

Sodium butyrate alleviates R97-116 peptide-induced myasthenia gravis in mice by improving the gut microbiota and modulating immune response.

Fermented butyrate exhibits an anti-inflammatory response to maintain immune homeostasis within the gut. However, the effect and underlying mechanism of butyrate on myasthenia gravis (MG) remain unclear. The changes in the gut microbiota and fecal contents of SCFAs in MG patients were examined. R97-116 peptide was used to induce the experimental autoimmune myasthenia gravis (EAMG) mice and sodium butyrate (NaB) was gavaged to the EAMG mice. Gut microbiota, the frequency of Th1, Th17, Treg, Tfh, and B cells, the levels of IFN-γ, IL-17 A, IL-10, IL-21, and anti-R97-116 IgG, RNA-seq of total B cells in the spleen were explored by metagenomics, flow cytometry, ELISA, and transcriptomics. A significant reduction in SCFA-producing bacteria including Butyricimonas synergistica and functional modules including butyrate synthesis/production II was observed in MG patients and fecal SCFAs detection confirmed the increase. The EAMG mice were successfully constructed and NaB supplementation has changed the composition and function of the gut microbiota. The numbers of Th1, Th17, Tfh, and B cells were significantly increased while that of Treg cells was obviously decreased in EAMG mice compared with controls. Interestingly, NaB treatment has reduced the amounts of Th17, Tfh, and B cells but increased that of Treg cells. Accordingly, the levels of IL-17 A, IL-21, and IgG were increased while IL-10 was decreased in EAMG mice. However, NaB treatment reduced IL-17 A and IL-21 but increased that of IL-10. RNA-seq of B cells has revealed 4577 deferentially expressed genes (DEGs), in which 1218 DEGs were up-regulated while 3359 DEGs were down-regulated in NaB-treated EAMG mice. GO enrichment and KEGG pathway analysis unveiled that the function of these DEGs was mainly focused on immunoglobulin production, mitochondrial respiratory chain complex, ribosome, oxidative phosphorylation, and CNS diseases including amyotrophic lateral sclerosis. We have found that butyrate was significantly reduced in MG patients and NaB gavage could evidently improve MG symptoms in EAMG mice by changing the gut microbiota, regulating the immune response, and altering the gene expression and function of B cells, suggesting NaB might be a potential immunomodulatory supplement for MG drugs.

Curcumin regulates anti-inflammatory responses by AXL/JAK2/STAT3 signaling pathway in experimental autoimmune encephalomyelitis.

Microglia-mediated neuroinflammation plays an important role in multiple sclerosis (MS). This study explored whether curcumin has a protective effect on experimental autoimmune encephalomyelitis (EAE), and the specific mechanism was investigated. We found that curcumin attenuates the severity of EAE mice. It inhibits the activation of microglia in the spinal cord of EAE mice and LPS-stimulated BV-2 cells. The findings clarify that curcumin may inhibit the inflammatory response mediated by microglia by inactivating the AXL/JAK2/STAT3 signaling pathway, which laid a theoretical foundation for the clinical management of MS.

The Top-Cited Original Articles on the Role of Microglia in Neurodegenerative Diseases: A Bibliometric and Visualized Study.

Background: Microglia participants to neuronal loss during brain development, inflammation, ischemia, and neurodegeneration. This bibliometric and visualized study aimed to confirm the top 100 cited original research in the field and to analyze their characteristics. Methods: The Web of Science database (WOS) was retrieved using the specific search strategy. The top 100 cited original articles that focused on the role of microglia in neurodegenerative diseases (NDs) were filtered by two researchers independently. The trend of yearly publications and citations, citation densities, languages, and global contributions were analyzed. The highly cited countries, authors, institutions, and journals were visualized by bibliographic coupling analysis. The highly cited authors and journals in the references were visualized by co-citation analysis. The research hotspots were revealed by co-occurrence analysis and burst detection of author keywords. Results: The top 100 cited articles were published during the period 1988 to 2019. The peak of publication occurred in 2005 and 2006. The yearly total citations presented a rising trend. The highly cited articles were contributed by 26 countries, the United States was the country with the overwhelming number of publications and cited times. Stevens, Beth was the author with the largest number of cited times. Mcgeer PL was the author most frequently cited in the references. Harvard University was the institution with the greatest number of cited times and publications. Nature was the journal with the largest number of cited times. Journal of neuroscience was both the most often published and most frequently cited journal in the references. "Microglia", "inflammation", "Alzheimer's disease" were the most frequently used keywords, and their average occurred time was around 2005. "Dementia," "delirium," "priming" were keywords that averagely occurred around 2010. The burst detection revealed that "TNF-beta," "macrophage," and "inflammation" were keywords that frequently burst in recent years. Conclusion: This bibliometric and visualized study revealed the top 100 cited original research that discussed the role of microglia in NDs. The United States was the biggest contributor, Harford University was the most influential institution. Journal of Neuroscience was the most often published and cited journal. Alzheimer's disease was the hotspot in microglia and NDs. Recent research mainly focused on inflammation.

Intravenous Alteplase Treatment of Acute Ischemic Stroke Patients Exhibiting Mild Neurological Deficits.

Alteplase is increasingly used for treating ischemic stroke cases with low NIHSS scores, but the guidelines and evidence regarding outcomes are lacking. So, the authors conducted an updated meta-analysis to better understand the effects of alteplase for the treatment of acute mild ischemic stroke. PubMed, Cochrane, EMBASE were systematically explored for all relevant investigations published as in September 2021. Study quality was assessed as per the Cochrane system criteria, and Stata 15.1 was utilised to carry out a meta-analysis. In total, 16 trials incorporating 5,846 patients were analysed (1,926 and 3,920 cases in the rt-PA and non-thrombolytic groups, respectively). The main outcome measure revealed that the treatment of rt-PA was correlated with better odds of a modified Rankin Scale (mRS) score of 0-1 relating to the non-thrombolytic group (OR = 1.12, 95% CI = 1.02-1.23, p <0.05), and with moderate heterogeneity (I2 = 0.0%, p = 0.930). For the secondary study outcomes, symptomatic intracranial hemorrhage incidence was 4.46 times greater in the group of rt-PA, relating to the non-thrombolytic group (OR = 4.46, 95% CI = 2.75-7.23, p <0.001). There were no considerable differences in the mortality between the two groups (OR = 0.64, 95% CI = 0.39-1.03, p >0.05). No significant heterogeneity was detected in secondary study outcomes. Subgroup analysis showed that the function outcomes was the best within 3-4.5 hours; and the risk and mortality of sICH were the lowest within 3-4.5 hours. Intravenous rt-PA administration is associated with improved functional outcomes at three months after the stroke in mild ischemic stroke patients. Key Words: Acute ischemic stroke, Mild, Alteplase, Meta-analysis.

A candidate biomarker of glial fibrillary acidic protein in CSF and blood in differentiating multiple sclerosis and its subtypes: A systematic review and meta-analysis.

OBJECTIVE: Multiple sclerosis (MS) is an inflammatory demyelinating autoimmune disease of the central nervous system. Glial fibrillary acidic protein (GFAP) is a monomeric intermediate filament protein. A systematic review and meta-analysis was performed regarding a candidate biomarker for astrocytic damage of cerebrospinal fluid (CSF) and blood GFAP levels in differentiating multiple sclerosis and its subtypes. METHODS: Relevant studies published prior to October 2020 were retrieved from the PubMed, Web of Science, Cochrane Library and clinicaltrials.gov databases using the following keywords: 'Multiple sclerosis' or 'MS' and 'Glial Fibrillary Acidic Protein' or 'GFAP'. Two authors independently selected the articles and extracted the data. Of the 31 full articles screened, 11 were included in the qualitative analysis and meta-analysis. Differences in the mean CSF and blood GFAP levels were used as the main efficacy measures, and the meta-analysis was performed using Review Manager version 5.3 software. RESULTS: Eleven clinical trials comprising 960 patients were selected. CSF GFAP levels were higher in 503 MS patients than in 252 (healthy and disease) controls, with a moderate effect size of 0.72 (p < 0.00001). Mean CSF GFAP levels were significantly higher in 325 MS patients with relapsing disease than in 140 MS patients with progressive disease (SMD=-0.47; 95% CI=-0.80 to -0.15; P = 0.005). CSF GFAP levels in 161 MS patients in relapse (irrespective of MS subtype) were significantly higher than those in 180 MS patients in remission (MD=103.83; 95% CI=68.09 to139.57; P<0.001). The performances of GFAP in blood for differentiating patients with MS from controls were also significant. Blood GFAP was higher in 245 MS patients than in 53 (healthy and disease) controls, with a moderate effect size of 37.25 (p < 0.00001). CONCLUSION: The level of CSF-GFAP is correlated with MS and its different subtypes, reflecting the different degrees of damage to astrocytes in different subtypes of MS. In addition, progressive MS is more closely related to the increase in cerebrospinal fluid GFAP level than relapsing-remitting MS, and GFAP may be a useful marker of disease progression. Moreover, the GFAP level in the blood of MS patients is higher than that in the control group, and the sample size needs to be further expanded for verification in the future..

New progress in the treatment of neuromyelitis optica spectrum disorder with monoclonal antibodies (Review).

Neuromyelitis optica spectrum disorder (NMOSD) is a group of immune-mediated inflammatory demyelinating diseases mainly affecting the central nervous system. It is characterized by high risk of relapse and progression to disability. The frequent recurrences of neuromyelitis optica spectrum disorder often exacerbate the neurological dysfunction and severely affect the patient's quality of life. Conventional treatments for neuromyelitis optica spectrum disorder, including acute treatment and sequential therapy, aim to decrease the degree of disability and recurrences. In recent years, new monoclonal antibodies have yielded encouraging results. The present review discusses the research status and recent progress in the treatment of NMOSD with monoclonal antibodies.

A meta-analysis to determine the efficacy and safety of tocilizumab in neuromyelitis optica spectrum disorders.

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) is a central nervous system immune disease with a high recurrence rate and high disability rate. Frequent relapses often cause the accumulation of neurological dysfunction, leading to permanent blindness, paralysis or even death. Tocilizumab (TCZ) is a human monoclonal antibody (mAb) directed against the IL-6 receptor and was the first anti-IL6-R mAb tested for the treatment of NMOSD. Our meta-analysis aimed to evaluate the efficacy and safety of tocilizumab in NMOSD patients. METHODS: Relevant studies published prior to May 2020 were retrieved from the PubMed, Cochrane Library and clinicaltrials.gov databases using the following keywords: 'neuromyelitis optic spectrum disorders' or 'NMOSD' and 'tocilizumab' or 'TCZ'. Two authors independently selected the articles and extracted the data. Differences in the annualized relapse rate (ARR) ratio, relapse-free status and EDSS score before and after TCZ therapy were used as the main efficacy measures, and recorded adverse effects were also extracted. The meta-analysis was performed using Review Manager version 5.3 software. RESULTS: Five clinical trials comprising a total of 89 patients were selected. Meta-analysis showed that significantly fewer ARR ratio was encountered in after tocilizumab therapy group (MD=-2.25; 95% CI=-2.62 to -1.87; P<0.001). A significant correlation was observed between the proportion of patients with relapse-free NMOSD and tocilizumab therapy (OR=67.78; 95% CI=19.23 to 238.97; P<0.001). Adverse effects were recorded in 75 of 89 (84%) patients treated with tocilizumab, but most adverse effects were mild. CONCLUSIONS: The present meta-analysis suggested that tocilizumab is a relatively effective and safe treatment for NMOSD.

Mechanism of gut microbiota and Axl/SOCS3 in experimental autoimmune encephalomyelitis.

Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system (CNS). The present study explored the role of intestinal microbiota in the initiation and propagation of mice induced by experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. 48 C57BL/6 were randomly divided into control group and EAE group. The changes of body weight and the scores of neurological function were recorded. The mRNA expression of the receptor tyrosine kinase subfamily (AXL) was detected by real-time quantitative PCR. The levels of IL-17 and IFN-γ in blood samples were examined by ELISA. The intestinal microbial composition of mice at different time points during the EAE induction was analyzed by 16S rRNA gene-based sequencing. In EAE group, the body weight began to reduce at day 3 and neurological symptoms began to appear at day 7 after EAE induction. The levels of IL-17 and IFN-γ in EAE group reached the peak at day 21 and then decreased gradually. However, the expression of Axl and SOCS3 reached the lowest level at day 21 and then increased gradually. The microbiome analyses revealed that the abundances of Alistipes, Blautia, and Lachnospiraceae_NK4A136_group were significantly changed at day 14, whereas the abundances of Allobaculum, Eubacterium and Helicobacter were significantly changed at day 30 of EAE induction. The prevotellaceae_NK3B31_group may be key bacteria that contribute to the development of MS. Regulation of intestinal microbiota composition can become a new therapeutic target for the treatment of MS.

A meta-analysis to determine the efficacy and tolerability of anti-B-cell monoclonal antibodies in multiple sclerosis.

The present study performed a meta-analysis of randomized controlled trials in multiple sclerosis (MS) patients to evaluate the efficacy and safety of anti-B-cell monoclonal antibodies (mAbs). To the best of our knowledge, no previous meta-analysis has evaluated this. Relevant studies published until March 2015 were retrieved from the PubMed, EMBASE and Cochrane Library using the following keywords: 'Clinical trial', 'randomized', 'multiple sclerosis' or 'MS' and 'monoclonal antibodies' or 'mAbs'. Two authors independently selected the articles and extracted the data. The meta-analysis was performed using Review Manager version 5.3 software. Four randomized clinical trials comprising a total of 745 patients were selected. Anti-B-cell mAb treatment reduced the formation of gadolinium-enhancing lesions [mean difference (MD)=-5.62; 95% confidence interval (CI)=-8.00 to -3.24; P<0.001) and was associated with smaller volume changes of lesions on T2-weighted magnetic resonance imaging (MD=-604.40; 95% CI=-941.23 to -267.57; P<0.001). It also significantly reduced the proportion of MS patients having at least one relapse [odds ratio (OR)=0.25; 95% CI=0.14-0.44; P<0.001). Compared to placebo, anti-B-cell mAb treatment did not increase the frequency of adverse events (OR=0.90; 95% CI=0.54-1.49; P=0.68) and serious adverse events (OR=1.13; 95% CI=0.70-1.80; P=0.62). In conclusion, the present meta-analysis suggested that anti-B-cell mAbs are a relatively effective and safe treatment for MS.

[Association between angiotensin-converting enzyme 2 gene polymorphisms and childhood primary nephrotic syndrome].

OBJECTIVE: Angiotensin-converting enzyme 2 (ACE2) gene polymorphisms have been shown to be implicated in hypertension, diabetic nephropathy, and other diseases. However, it remains unclear whether ACE2 gene polymorphisms are involved in the development of primary nephrotic syndrome (PNS) in children. The aim of this study was to assess the association between A9570G polymorphisms of ACE2 gene and PNS in a group of Han children in Guangdong Province, China. METHODS: The genotype distribution and allele frequency of ACE2 gene A9570G in 66 children with PNS and 60 healthy subjects (control group) were analyzed by polymerase chain reaction and restriction fragment length polymorphism. RESULTS: Allele frequency and genotype distribution showed no significant difference between the PNS and control groups whether in female or in male children (P>0.05). The PNS group was classified into the glucocorticoid-sensitive and glucocorticoid-resistant subgroups according to glucocorticoid treatment response. Subgroup analysis revealed that in female children, the frequency of GG genotype was 17% in the glucocorticoid-sensitive group vs 45% in the glucocorticoid-sensitive group (P=0.018); the frequency of G allele was 31% in the glucocorticoid-sensitive group vs 61% in the glucocorticoid-resistant group (P=0.023). In male children, the frequency of G genotype/G allele was 36% in the glucocorticoid-sensitive group vs 64% in the glucocorticoid-resistant group (P=0.017). CONCLUSIONS: There is no clear association between ACE2 gene A9570G polymorphisms and childhood PNS, but ACE2 gene A9570G polymorphisms might be associated with glucocorticoid treatment response in children with PNS. The G allele might be a genetic susceptibility factor of glucocorticoid resistance in children with PNS.