Th1 and Th2 polymorphisms in Sjögren's syndrome and rheumatoid arthritis

Gut microbiota combined with fecal metabolomics reveals the effects of FuFang Runzaoling on the microbial and metabolic profiles in NOD mouse model of Sjögren's syndrome

OBJECTIVE

Sjögren's syndrome (SS) is an inflammatory autoimmune disease characterized by high levels of chronic lymphocyte infiltration. Differences and dysfunction in the gut microbiota and metabolites may be closely related to the pathogenesis of SS. The purpose of this study was to reveal the relationship between the gut microbiota and metabolome in NOD mice as a model of SS and the role of FuFang Runzaoling (FRZ), which is a clinically effective in treating SS.

METHODS

NOD mice were gavaged with FRZ for 10 weeks. The ingested volume of drinking water, submandibular gland index, pathologic changes of the submandibular glands, and serum cytokines interleukin (IL)-6, IL-10, IL-17 A, and tumor necrosis factor-alpha (TNF-α) were determined. The roles of FRZ on gut microbiota and fecal metabolites were explored by 16 S rRNA gene sequencing and liquid chromatography-mass spectrometry (LC-MC), respectively. The correlation between them was determined by Pearson correlation analysis.

RESULTS

Compared with the model group, the drinking water volume of NOD mice treated with FRZ increased and the submandibular gland index decreased. FRZ effectively ameliorated lymphocyte infiltration in the small submandibular glands in mice. Serum levels of IL-6, TNF-α, and IL-17 A decreased, and IL-10 increased. The Firmicutes/Bacteroidetes ratio in the FRZ treatment group was higher. FRZ significantly downregulated the relative abundance of the family Bacteroidaceae and genus Bacteroides, and significantly upregulated the relative abundance of genus Lachnospiraceae_UCG-001. Orthogonal projections to latent structures discriminant analysis (OPLS-DA) revealed the significant change in fecal metabolites after FRZ treatment. Based on criteria of OPLS-DA variable influence on projection > 1, P < 0.05, and fragmentation score > 50, a total of 109 metabolites in the FRZ-H group were differentially regulated (47 downregulated and 62 upregulated) compared to their expressions in the model group. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed enriched metabolic of sphingolipid metabolism, retrograde endocannabinoid signaling, GABAergic synapse, necroptosis, arginine biosynthesis, and metabolism of histidine, alanine, aspartate, and glutamate. Correlation analysis between gut microbiota and fecal metabolites suggested that the enriched bacteria were related to many key metabolites.

CONCLUSIONS

Taken together, we found FRZ could reduce the inflammatory responses in NOD mice by regulating the gut microbiota, fecal metabolites, and their correlation to emerge a therapeutic effect on mice with SS. This will lay the foundation for the further studies and applications of FRZ, and the use of gut microbiotas as drug targets to treat SS.

Exploiting the role of T cells in the pathogenesis of Sjögren's syndrome for therapeutic treatment

Sjögrens syndrome (SS) is caused by autoantibodies that attack proprioceptive salivary and lacrimal gland tissues. Damage to the glands leads to dry mouth and eyes and affects multiple systems and organs. In severe cases, SS is life-threatening because it can lead to interstitial lung disease, renal insufficiency, and lymphoma. Histological examination of the labial minor salivary glands of patients with SS reveals focal lymphocyte aggregation of T and B cells. More studies have been conducted on the role of B cells in the pathogenesis of SS, whereas the role of T cells has only recently attracted the attention of researchers. This review focusses on the role of various populations of T cells in the pathogenesis of SS and the progress made in research to therapeutically targeting T cells for the treatment of patients with SS.

Computation-Based Discovery of Potential Targets for Rheumatoid Arthritis and Related Molecular Screening and Mechanism Analysis of Traditional Chinese Medicine

This study is aimed at screening potential therapeutic ingredients in traditional Chinese medicine (TCM) and identifying the key rheumatoid arthritis (RA) targets using computational simulations. Data for TCM-active ingredients with clear pharmacological effects were collected. Absorption, distribution, metabolism, excretion, and toxicity were evaluated. Potential RA targets were identified using the Gene Expression Omnibus (GEO) database, protein–protein interaction network, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses and potential TCM ingredients using AutoDock Vina. To examine the mechanisms underlying small molecules, target prediction, Gene Ontology, KEGG, and network modeling analyses were conducted; the effects were verified in rat synovial cells using cell proliferation assay. The activities of tumor necrosis factor TNF-α and IL-1β and alterations in cellular target protein levels were detected by ELISA and Western blotting, respectively. In total, data for 432 TCM active ingredients with clear pharmacological effects were obtained. Five critical RA-related genes were identified; CCL5 and CXCL10 were selected for molecular docking. Target prediction and network-based proximity analysis showed that dioscin could modulate 22 known RA clinical targets. Dioscin, asiaticoside, and ginsenoside Re could effectively inhibit in vitro cell proliferation and secretion of TNF-α and IL-1β in RA rat synovial cells. Using bioinformatics and computer-aided drug design, the potential small anti-RA molecules and their mechanisms of action were comprehensively identified. Dioscin could significantly inhibit proliferation and induce apoptosis in RA rat synovial cells by reducing TNF-α and IL-1β secretion and inhibiting abnormal CCL5, CXCL10, CXCR2, and IL2 expression.

The association between interleukin-6 promoter polymorphisms and rheumatoid arthritis by ethnicity: A meta-analysis of 33 studies

OBJECTIVE

We performed a meta-analysis to determine the effect Interleukin-6 (IL-6) promoter polymorphism (-174 G>C, -572 G>C, and -597 G>A) have on the development rheumatoid arthritis (RA) by ethnicity.

MATERIAL AND METHODS

PubMed, EBSCO, LILACS, and Scopus databases were searched for studies exploring the association between any IL6 polymorphisms and RA until November 2018. Genotype distributions were extracted and, depending on the level heterogeneity, determined by the ψ²-based Q test and the Inconsistency Index (I²), fixed-effects or random-effects models were used to calculate pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) for the heterozygous, homozygous, dominant, recessive, and allelic genetic models.

RESULTS

From 708 identified publications, 33 were used in this analysis. For the -174 polymorphism, Asians (OR_heterozygous=7.57, 95%CI: 2.28-25.14, OR_homozygous=5.84, 95%CI: 2.06-16.56, OR_dominant=7.21, 95%CI: 2.30-22.63, OR_recessive=5.04, 95%CI: 1.78-14.28, OR_allelic=6.60, 95%CI: 2.26-19.28, p<.05) and Middle East countries (OR_heterozygous=2.30, 95%CI: 1.10-4.81, OR_dominant=2.27, 95%CI: 1.22-4.22, OR_allelic=2.29, 95%CI: 1.24-4.23, p<.05) were associated with a significant risk of developing RA. Whereas, for Latinos, the C-allele was associated with a benefit (OR_homozygous=0.26, 95%CI: .08-.82, OR_recessive=.25, 95%CI: .08-.80, p<.05). For the -572 polymorphism, Asians demonstrated a significant association for the homozygous and recessive genetic models (8 studies, OR_homozygous=1.56, 95%CI: 1.16-2.09, OR_recessive=1.63, 95%CI: 1.08-2.45, p<.05). For the -597 polymorphism, no association was observed.

CONCLUSIONS

Here, the -174 G>C polymorphism increased the risk of developing RA in Asians and Middle East populations. Interestingly, for Latinos, the polymorphism was associated with a benefit. For the -572 polymorphism, only the Asian population showed an increased risk of developing RA for the CC genotype.

The Association Between Interleukin-6 Promoter Polymorphisms and Rheumatoid Arthritis by Ethnicity: A Meta-Analysis of 33 Studies

OBJECTIVE

We performed a meta-analysis to determine the effect Interleukin-6 (IL-6) promoter polymorphism (-174 G>C, -572 G>C, and -597 G>A) have on the development rheumatoid arthritis (RA) by ethnicity.

MATERIAL AND METHODS

PubMed, EBSCO, LILACS, and Scopus databases were searched for studies exploring the association between any IL6 polymorphisms and RA until November 2018. Genotype distributions were extracted and, depending on the level heterogeneity, determined by the ψ2-based Q test and the Inconsistency Index (I2), fixed-effects or random-effects models were used to calculate pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) for the heterozygous, homozygous, dominant, recessive, and allelic genetic models.

RESULTS

From 708 identified publications, 33 were used in this analysis. For the -174 polymorphism, Asians (ORheterozygous=7.57, 95%CI: 2.28-25.14, ORhomozygous=5.84, 95%CI: 2.06-16.56, ORdominant=7.21, 95%CI: 2.30-22.63, ORrecessive=5.04, 95%CI: 1.78-14.28, ORallelic=6.60, 95%CI: 2.26-19.28, p<.05) and Middle East countries (ORheterozygous=2.30, 95%CI: 1.10-4.81, ORdominant=2.27, 95%CI: 1.22-4.22, ORallelic=2.29, 95%CI: 1.24-4.23, p<.05) were associated with a significant risk of developing RA. Whereas, for Latinos, the C-allele was associated with a benefit (ORhomozygous=0.26, 95%CI: .08-.82, ORrecessive=.25, 95%CI: .08-.80, p<.05). For the -572 polymorphism, Asians demonstrated a significant association for the homozygous and recessive genetic models (8 studies, ORhomozygous=1.56, 95%CI: 1.16-2.09, ORrecessive=1.63, 95%CI: 1.08-2.45, p<.05). For the -597 polymorphism, no association was observed.

CONCLUSIONS

Here, the -174 G>C polymorphism increased the risk of developing RA in Asians and Middle East populations. Interestingly, for Latinos, the polymorphism was associated with a benefit. For the -572 polymorphism, only the Asian population showed an increased risk of developing RA for the CC genotype.

Total glucosides of paeony (TGP) alleviates Sjogren's syndrome through inhibiting inflammatory responses in mice

BACKGROUND

Sjogren's syndrome (SS) is an inflammatory autoimmune disease whose etiology is complicated. Total glucosides of paeony (TGP) has a variety of pharmacological effects.

PURPOSE

To evaluate the therapeutic effects of TGP on SS in mice and anti-inflammatory mechanism.

STUDY DESIGN

SS animal model was developed from C57BL/6J mice through immunological induction (SS mice) and NOD/ShiltJNju (NOD) mice. Inflammatory cytokines and other related indicators were measured.

METHODS

TGP (720, 360, 180 mg/kg) was intragastrically administered for 6 or 16 weeks for SS mice and NOD mice, respectively. Average food and water intake, average body weight, saliva flow, submandibular gland (SMG) and spleen index, and SMG pathology were measured. ELISA was used to evaluate serum inflammatory cytokines in SS mice and autoantigens in NOD mice. Real-time PCR, Western blot and Luminex liquid suspension chip assay were applied to analyze SMG inflammatory cytokines mRNA and protein expression of NOD mice.

RESULTS

Compared with SS mice, TGP treatment improved SMG pathological damage. TGP (720 mg/kg) treatment increased saliva flow, and reduced organ indexes and serum IL-6 and IFN-γ concentration. TGP (360 mg/kg) treatment decreased serum IFN-γ concentration. TGP (180 mg/kg) treatment for 6 weeks decreased average body weight. Compared with NOD mice, TGP treatment increased saliva flow from 9 to 15 weeks, decreased body weight, and alleviated pathological damage of SMG after 2 and 16 weeks. After 2 weeks of administration, TGP treatment inhibited serum concentration of SSB/La, SSA/Ro and α-fodrin, decreased TNF-α, IL-1β and IFN-γ in SMG, and down-regulated protein expressions of BAFF and IL-17A and mRNA expressions of BAFF, TNF-α, IL-17A, CXCL9 and CXCL13 in SMG. After 8 weeks of administration, TGP treatment decreased the concentration of α-fodrin in serum, TNF-α and IL-6 in SMG, and down-regulated mRNA expressions of IL-17A, TNF-α, CXCL9, CXCL13 and BAFF and protein expressions of IL-17A and BAFF in SMG. After 16 weeks of administration, TGP treatment reduced serum SSA/Ro, SSB/La and α-fodrin concentration, and decreased BAFF protein expression and TNF-α, CXCL9, CXCL13, IL-17A, and BAFF mRNA expressions.

CONCLUSION

TGP has a certain therapeutic effect on SS mice and NOD mice through inhibiting inflammatory responses.

Effect of Xerostomia on the Functional Capacity of Subjects with Rheumatoid Arthritis

OBJECTIVE

To evaluate the intensity of xerostomia and hyposalivation in subjects with rheumatoid arthritis (RA) as well as the effects of these conditions on functional incapacity and disease activity.

METHODS

The study sample comprised 236 individuals of both sexes who had RA. All the individuals were submitted to clinical evaluation and unstimulated sialometry. Functional capacity was determined by using the Health Assessment Questionnaire (HAQ), xerostomia was assessed using the Xerostomia Inventory, and disease activity was evaluated with the 28-joint Disease Activity Score (DAS28). The effect of Sjögren syndrome (SS) was analyzed, and the sample was divided into 2 groups: RA (191 subjects) and RA/SS (45 subjects).

RESULTS

The Xerostomia Inventory showed positive and significant correlation with fatigue (r = 0.243; p < 0.0001), number of painful joints (r = 0.218; p = 0.001), HAQ (r = 0.279; p < 0.0001), and DAS28 (r = 0.156; p < 0.0001). On regression analysis, both xerostomia (OR 3.89, 95% CI 1.84-8.23, p < 0.001) and DAS28 (for severe disease activity: OR 13.26, 95% CI 3.15-55.79, p < 0.001) showed influence on functional incapacity. Forty-five individuals (19.1%) presented with secondary SS, and having this diagnosis was not associated with disease activity or functional capacity.

CONCLUSION

Xerostomia demonstrated an adverse effect on quality of life of subjects with RA, being associated with a reduction in functional capacity. In this clinical setting, xerostomia can be monitored as a marker of worse clinical evolution.

Association of anti-Ro/SSA antibody with response to biologics in patients with rheumatoid arthritis

OBJECTIVE

To compare the effectiveness of three different biologics in anti-Ro/SSA antibody-positive and antibody-negative patients with rheumatoid arthritis (RA).

METHODS

The study subjects were 110 biologics naïve patients with RA who started treatment with biologics and examined for anti-Ro/SSA antibody between December 2003 and March 2014. For patients treated with intravenous infliximab (IFX), tocilizumab (TCZ), or abatacept (ABT), we compared the clinical characteristics and changes in composite disease activity index, such as DAS28, SDAI, and CDAI, for 12 months in anti-Ro/SSA antibody-positive and antibody-negative patients.

RESULTS

We examined 59 patients (nine were positive and 50 were negative for anti-Ro/SSA antibody) treated with IFX, 27 patients (5 positive and 22 negative) treated with TCZ, and 24 patients (13 positive and 11 negative) treated with ABT. For patients treated with IFX, parameters of disease activity did not change significantly from baseline in anti-Ro/SSA antibody-positive patients, whereas they improved in antibody-negative patients. On the other hand, treatment with TCZ and ABT significantly decreased disease activity, relative to baseline, in both anti-Ro/SSA antibody-positive and antibody-negative patients. Anti-Ro/SSA antibody-positive patients treated with IFX showed higher frequency of HACA and seroconversion of ANA, and lower serum TGF-β levels.

CONCLUSIONS

Positivity to anti-Ro/SSA in RA seems to confer resistance to IFX via production of HACA and ANA, and low serum TGF-β levels, but not to TCZ and ABT.