Primary Sjogren's Syndrome Associated with Lung Adenocarcinoma: Probing the Potential Common Pathogenic Mechanisms and Experimental Verification.

This study aimed to probe the potential common pathogenic mechanisms linking primary Sjogren's syndrome (pSS) and lung adenocarcinoma (LUAD) through bioinformatics analysis and experimental verification. The relevant genes associated with pSS and LUAD were retrieved from the Gene Expression Omnibus (GEO) database and Genecard database. Subsequently, differentially expressed genes (DEGs) associated with pSS and LUAD were screened as pSS-LUAD-DEGs. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses were performed to elucidate the significant biological functions of pSS-LUAD-DEGs. Core targets were identified by constructing the protein-protein interaction (PPI) network, further assessing hub gene diagnostic accuracy through Receiver Operating Characteristic (ROC) curve analyses. In this study, NOD/Ltj mice served as pSS animal models and were stimulated with particulate matter 2.5 (PM2.5) to generate an inflammatory reaction. Quantitative real-time polymerase chain reaction (qPCR), enzyme-linked immunosorbent assay (ELISA), and western blotting were employed for relevant molecular biology experiment verification. The results revealed through KEGG and GO enrichment analyses indicate that inflammation plays a critical role in linking pSS and LUAD. IL6, CCNA2, JAK2, IL1B, ASPM, CCNB2, NUSAP1, and CEP55 were determined as key targets of pSS-LUAD. BALB/c mice and NOD/Ltj mice exhibited enhanced expression of inflammatory cytokines IL-6 and IL-1ß in lung tissues following 21 days of stimulation with PM2.5, activating the JAK2/STAT3 signaling pathway and up-regulating the expression of tumor-associated genes CCNA2, CCNB2, and CEP55, with NOD/Ltj mice exhibiting more pronounced changes than BALB/c mice. This protocol demonstrates that carcinogenesis induced by the pulmonary inflammatory microenvironment may be a key reason for the high incidence of LUAD in pSS patients. Additionally, blocking-related mechanisms may help prevent the occurrence of LUAD in pSS patients.

Transactivation DNA-binding protein-related genes were associated with salivary gland injury in primary Sjögren syndrome.

The purpose was to identify transactivation DNA-binding protein-related genes in salivary gland injury in primary Sjögren syndrome (pSS) in southwest China. We downloaded the datasets of GSE7451, GSE23117, and GSE40611. In order to screen the candidate genes, 2 kinds of machine learning algorithms were used. We collected blood from 28 patients and 20 controls to verify the expression of candidate genes using quantitative real-time polymerase chain reaction. The receiver operating characteristic curve was used to evaluate the diagnostic efficiency. Correlations between candidate genes and immune cells were examined. A total of 31 differentially expressed genes were obtained. Through different algorithms, 6 genes including IFIT1, CSF2RB, TRIM22, PPM1H, VAMP7, and C21orf2 were getted. Validation results suggested that the expression of CSF2RB, VAMP7, IFIT1, C21orf2, and TRIM22 was significantly increased in pSS. The area under the curve of CSF2RB was 0.937 and that of TRIM22 was 0.915. Immune infiltration analysis showed that the percentage of activated mast cells was lower than the controls (P = .025). Correlation analysis suggested that CSF2RB was associated with immune cell infiltration. The expression of CSF2RB was significantly upregulated, which could be related to the increase of γδ T cells. We revealed that CSF2RB could be the candidate gene of pSS. CSF2RB was involved by regulating various immune cells. The expression of CSF2RB was significantly upregulated, which was related to the increase of γδ T cells.

HLA-DR genotypes in patients with primary Sjögren's syndrome in Taiwan.

Different human leukocyte antigen (HLA) genotypes have been known to be associated with the risk of development of Sjögren's syndrome in different populations, but this association has never been reported in Taiwan. We enrolled 1044 subjects (673 patients, 371 controls) and tested their HLA-DR genotypes. We found an increased risk of Sjögren's syndrome in patients carrying HLA-DR8. DR1 and DR14 were associated with increased risk of eye involvement (uveitis, scleritis or optic neuritis), while DR15 was associated with increased risk of interstitial lung disease. DR8 was associated with increased risk of formation of multiple antibodies: anti-Ro, rheumatoid factor and antinuclear antibodies (ANA) reaching titer 1:80 or above. DR9 was associated with decreased risk of formation of anti-La antibodies and increased risk of formation of antithyroglobulin antibodies. DR10 was associated with risk of formation of anticyclic citrullinated peptide (anti-CCP) antibodies, and DR11 was associated with increased risk of formation of anti-La antibodies. Oral ulcer was found to be negatively associated with anti-Ro antibodies and with anti-ENA antibodies. Skin lesions were associated with ANA antibody titer elevation to 1:80 or above. Malignancies of any kind were associated with the presence of cryoglobulin. Females were more likely to be diagnosed at a younger age than males. There was no statistically significant relationship between HLA-DR genotype and age at disease diagnosis. In patients with Sjögren's syndrome in Taiwan, the presence of HLA-DR8 appeared to be a risk factor. In addition, we found several associations between HLA-DR genotype, clinical presentation, and autoantibody status among them.

Exploring the crosstalk molecular mechanisms between IgA nephropathy and Sjögren's syndrome based on comprehensive bioinformatics and immunohistochemical analyses.

IgA nephropathy (IgAN) and Sjogren's syndrome (SS) are two autoimmune diseases with undetermined etiology and related to abnormal activation of lymphocytes. This study aims to explore the crucial genes, pathways and immune cells between IgAN and SS. Gene expression profiles of IgAN and SS were obtained from the Gene Expression Omnibus and Nephroseq data. Differentially expressed gene (DEG) and weighted gene co-expression network analyses (WGCNA) were done to identify common genes. Enrichment analysis and protein-protein interaction network were used to explore potential molecular pathways and crosstalk genes between IgAN and SS. The results were further verified by external validation and immunohistochemistry (IHC) analysis. Additionally, immune cell analysis and transcription factor prediction were also conducted. The DEG analysis revealed 28 commonly up-regulated genes, while WGCNA identified 98 interactively positive-correlated module genes between IgAN and SS. The enrichment analysis suggested that these genes were mainly involved in the biological processes of response to virus and antigen processing and presentation. The external validation and IHC analysis identified 5 hub genes (PSMB8, PSMB9, IFI44, ISG15, and CD53). In the immune cell analysis, the effector memory CD8 T and T follicular helper cells were significantly activated, and the corresponding proportions showed positively correlations with the expressions of the 5 hub genes in the two autoimmune diseases. Together, our data identified the crosstalk genes, molecular pathways, and immune cells underlying the IgAN and SS, which provides valuable insights into the intricate mechanisms of these diseases and offers potential intervention targets.

miRNAs as potential biomarkers for subclinical atherosclerosis in Sjögren's disease.

BACKGROUND: MicroRNAs (miRNAs) can regulate gene expression, controlling numerous cellular processes. Dysregulation of miRNA function is linked to various diseases, making them attractive diagnostic and therapeutic targets. Examples include hsa-miR-92a-3p, hsa-miR-126-3p, hsa-miR-143-3p, hsa-miR-145-5p and hsa-miR-204-5p, which are associated with endothelial function. Their prevalence in Sjögren's disease (SjD) is unknown. We assessed the prevalence of these miRNAs in serum of patients with SjD, correlating levels with cardiovascular risk factors and carotid intima-media thickness (cIMT) to evaluate their utility in risk stratification. METHODS: 199 patients with SjD and 100 age and sex-matched healthy controls (HC) were included in the study. Five different miRNAs (hsa-miR-92a-3p; hsa-miR-126-3p; hsa-miR143-3p; hsa-miR-145-5p; hsa-miR-204-5p) were analysed by quantitative real-time PCR. The miRNA results were compared with known clinical and disease-related parameters. RESULTS: Four miRNAs showed significantly different expressions compared with HC. MiR-92a-3p was upregulated (p=0.025) and miR-126-3p (p=0.044), miR-143-3p (p=0.006) and miR-204-5p (p=0.009) downregulated in SjD compared with HC. The comparison between HC and SjD with/without organ involvement revealed descriptively increased miR-92a-3p levels in patients with SjD with organ involvement (p=0.087). Furthermore, miR-92a-3p levels correlated positively with cIMT as an expression of subclinical atherosclerosis (r=0.148, p=0.04). CONCLUSION: In conclusion, patients with SjD demonstrated differences in their expression of miRNAs linked to regulation of endothelial function. Reduction of specific miRNAs was associated with increased cardiovascular risk, suggesting a potentially protective role for these miRNAs. Furthermore, miR-92a-3p could be helpful for molecular detection of early-stage atherosclerosis and increased cardiovascular risk in SjD.

Primary biliary cholangitis has causal effects on systemic rheumatic diseases: a Mendelian randomization study.

BACKGROUND: An association has been observed between primary biliary cholangitis (PBC) and systemic rheumatic diseases (SRDs) in observational studies, however the exact causal link remains unclear. We aimed to evaluate the causal effects of PBC on SRDs through Mendelian randomization (MR) analysis. METHODS: The genome-wide association study (GWAS) summary data were obtained from MRC IEU OpenGWAS and FinnGen databases. Independent genetic variants for PBC were selected as instrumental variables. Inverse variance weighted was used as the main approach to evaluate the causal effects of PBC on Sjögren syndrome (SS), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc), mixed connective tissue disease (MCTD) and polymyositis (PM). Horizontal pleiotropy and heterogeneity were measured by MR‒Egger intercept test and Cochran's Q value, respectively. RESULTS: PBC had causal effects on SS (OR = 1.177, P = 8.02e-09), RA (OR = 1.071, P = 9.80e-04), SLE (OR = 1.447, P = 1.04e-09), SSc (OR = 1.399, P = 2.52e-04), MCTD (OR = 1.306, P = 4.92e-14), and PM (OR = 1.416, P = 1.16e-04). Based on the MR‒Egger intercept tests, horizontal pleiotropy was absent (all P values > 0.05). The robustness of our results was further enhanced by the leave-one-out method. CONCLUSIONS: Our research has provided new insights into PBC and SRDs, indicating casual effects on various SRDs.

The impact of alternate-day fasting on the salivary gland stem cell compartments in non-obese diabetic mice with newly established Sjögren's syndrome.

Intermittent fasting exerts a profound beneficial influence on a spectrum of diseases through various mechanisms including regulation of immune responses, elimination of senescent- and pathogenic cells and improvement of stem cell-based tissue regeneration in a disease- and tissue-dependent manner. Our previous study demonstrated that alternate-day fasting (ADF) led to alleviation of xerostomia and sialadenitis in non-obese diabetic (NOD) mice, a well-defined model of Sjögren's syndrome (SS). This present study delved into the previously unexplored impacts of ADF in this disease setting and revealed that ADF increases the proportion of salivary gland stem cells (SGSCs), defined as the EpCAMhi cell population among the lineage marker negative submandibular gland (SMG) cells. Furthermore, ADF downregulated the expression of p16INK4a, a cellular senescence marker, which was concomitant with increased apoptosis and decreased expression and activity of NLRP3 inflammasomes in the SMGs, particularly in the SGSC-residing ductal compartments. RNA-sequencing analysis of purified SGSCs from NOD mice revealed that the significantly downregulated genes by ADF were mainly associated with sugar metabolism, amino acid biosynthetic process and MAPK signaling pathway, whereas the significantly upregulated genes related to fatty acid metabolic processes, among others. Collectively, these findings indicate that ADF increases the SGSC proportion, accompanied by a modulation of the SGSC property and a switch from sugar- to fatty acid-based metabolism. These findings lay the foundation for further investigation into the functionality of SGSCs influenced by ADF and shed light on the cellular and molecular mechanisms by which ADF exerts beneficial actions on salivary gland restoration in SS.

Exploration of the shared diagnostic genes and mechanisms between periodontitis and primary Sjögren's syndrome by integrated comprehensive bioinformatics analysis and machine learning.

BACKGROUND: Accumulating evidence has showed a bidirectional link between periodontitis (PD) and primary Sjögren's syndrome (pSS), but the mechanisms of their occurrence remain unclear. Hence, this study aimed to investigate the shared diagnostic genes and potential mechanisms between PD and pSS using bioinformatics methods. METHODS: Gene expression data for PD and pSS were acquired from the Gene Expression Omnibus (GEO) database. Differential expression genes (DEGs) analysis and weighted gene co-expression network analysis (WGCNA) were utilized to search common genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were conducted to explore biological functions. Three machine learning algorithms (least absolute shrinkage and selection operator (LASSO), support vector machine recursive feature elimination (SVM-RFE), and random forest (RF)) were used to further identify shared diagnostic genes, and these genes were assessed via receiver operating characteristic (ROC) curves in discovery and validation datasets. CIBERSORT was employed for immune cell infiltration analysis. Transcription factors (TFs)-genes and miRNAs-genes regulatory networks were conducted by NetworkAnalyst. Finally, relevant drug targets were predicted by DSigDB. RESULTS: Based on DEGs, 173 overlapping genes were obtained and primarily enriched in immune- and inflammation-related pathways. WGCNA revealed 34 common disease-related genes, which were enriched in similar biological pathways. Intersecting the DEGs with WGCNA results yielded 22 candidate genes. Moreover, three machine learning algorithms identified three shared genes (CSF2RB, CXCR4, and LYN) between PD and pSS, and these genes demonstrated good diagnostic performance (AUC>0.85) in both discovery and validation datasets. The immune cell infiltration analysis showed significant dysregulation in several immune cell populations. Regulatory network analysis highlighted that WRNIP1 and has-mir-155-5p might be pivotal co-regulators of the three shared gene expressions. Finally, the top 10 potential gene-targeted drugs were screened. CONCLUSION: CSF2RB, CXCR4, and LYN may serve as potential biomarkers for the concurrent diagnosis of PD and pSS. Additionally, we identified common molecular mechanisms, TFs, miRNAs, and candidate drugs between PD and pSS, which may provide novel insights and targets for future research on the pathogenesis, diagnosis, and therapy of both diseases.

Causal association between Helicobacter pylori infection and Sjogren's syndrome: a bidirectional Mendelian randomization analysis.

BACKGROUND: The results of observational studies indicate a potential link between Helicobacter pylori infection and Sjogren's syndrome (SS), but the causal relationship between them remains unknown. This study applied Mendelian randomization (MR) to evaluate this relationship. METHOD: Genome-wide association study (GWAS) summary statistics on H. pylori infection [sample size=8735 (EBI, https://gwas.mrcieu.ac.uk/ )] and SS [sample size=368,028 (cases=2495, controls=365533) (FinnGen, https://r9.finngen.fi/ )] were analyzed. We used bidirectional MR to evaluate the association between H. pylori infection and SS and identify causation. The major MR analysis method was inverse-variance weighted (IVW) MR, supplemented by MR‒Egger and weighted median approaches. In addition, the stability and reliability of the results were tested using the retention method, heterogeneity test, and horizontal gene pleiotropy test. RESULTS: Evidence of the impact of H. pylori infection on SS risk was found in the IVW results [odds ratio (OR)=1.6705; 95% confidence interval (CI)=1.0966 to 2.5446; P=0.0168]. Evidence of the impact of SS on H. pylori infection risk was also found (OR=1.0158; 95% CI=1.0033 to 1.0285; P=0.0128). CONCLUSION: The results of MR analysis support a causal association between H. pylori infection and SS and indicate that SS can lead to a greater risk of H. pylori infection. Our research will support the development of novel approaches for continued H. pylori and SS-related research and therapy that consider the genetic relationship between H. pylori infection and SS.

Causal relationship between multiple sclerosis and primary Sjögren's syndrome: a two-sample mendelian randomization study.

This study aims to investigate the causal relationship between primary Sjögren's syndrome (SS) and multiple sclerosis (MS) using a two-sample Mendelian randomization (MR) analysis to provide insights into their common mechanisms and implications for therapeutic strategies. We utilized data from Genome-Wide Association Studies (GWAS) for primary SS (1,290 cases and 213,145 controls) and MS (4,888 cases and 10,395 controls), restricted to European ancestry. Instrumental variables (IVs) were selected based on genetic variants associated with primary SS. The primary MR method was Inverse Variance Weighted (IVW), supplemented by MR Egger, Weighted Median, Simple Mode, and Weighted Mode algorithms to assess the bidirectional causal relationships between MS and primary SS. Sensitivity analyses, including MR-PRESSO and leave-one-out analysis, were conducted to ensure the robustness of our findings. After excluding SNPs with pleiotropic effects, 42 and 5 SNPs were identified as robust IVs for primary SS and MS, respectively. Our analysis revealed a significant protective effect of MS on primary SS, with IVW showing an OR of 0.896 (95% CI: 0.841-0.954, P = 0.001). No significant heterogeneity or horizontal pleiotropy was detected, supporting the reliability of the results. Our findings suggest a potential protective effect of MS against primary SS, indicating a negative causal association between these two autoimmune diseases. This adds valuable genetic evidence to the understanding of the complex interplay between primary SS and MS, offering new avenues for research and therapeutic interventions.

Transcriptomics explores potential mechanisms for the development of Primary Sjogren's syndrome to diffuse large B-cell lymphoma in B cells.

PURPOSE: Primary Sjogren's syndrome (pSS) is a prevalent autoimmune disease. The immune dysregulation it causes often leads to the development of diffuse large B-cell lymphoma (DLBCL) in clinical practice. However, how it contributes to these two disorders at the molecular level is not yet known. This study explored the potential molecular mechanisms associated with the differences between DLBCL and pSS. PATIENTS AND METHODS: Gene expression matrices from discovery cohort 1, discovery cohort 2, and the validation cohort were downloaded from the GEO and TCGA databases. Weighted gene coexpression network analysis (WGCNA) was performed to identify the coexpression modules of DLBCL and pSS in discovery cohort 1 and obtain shared genes. GO and KEGG enrichment analyses and PPI network analysis were performed on the shared genes. Immune-related genes (IRGs) were intersected with shared genes to obtain common genes. Afterward, common genes were identified via machine learning methods. The immune infiltration analysis, miRNA-TF-hub gene regulatory chart, gene interactions of the hub genes, and gene‒drug target analysis were performed. Finally, STAT1 was identified as a possible essential gene by the above analysis, and immune infiltration and GSEA pathway analyses were performed in the high- and low-expression groups in discovery cohort 2. The diagnostic efficacy of the hub genes was assessed in the validation cohort, and clinical samples were collected for validation. RESULTS: By WGCNA, one modular gene in each group was considered highly associated with the disease, and we obtained 28 shared genes. Enrichment analysis revealed shared genes involved in the viral response and regulation. We obtained four hub genes (ISG20, STAT1, TLR7, and RSAD2) via the algorithm. Hub genes and similar genes are primarily involved in regulating type I IFNs. The construction of a miRNA-TF-hub gene regulatory chart revealed that hsa-mir-155-5p, hsa-mir-146b-5p, hsa-mir-21-3p, and hsa-mir-126-3p play essential roles in both diseases. Hub genes were differentially expressed in B-cell memory according to immune infiltration analysis. Hub genes had a strong diagnostic effect on both diseases. STAT1 plays an essential role in immune cells in both diseases. CONCLUSION: We identified hub susceptibility genes for DLBCL and pSS and identified hub genes and potential therapeutic targets that may act as biomarkers.

Relationship between Sjogren's syndrome and gastroesophageal reflux: A bidirectional Mendelian randomization study.

The clinical incidence of sjogren's syndrome combined with gastroesophageal reflux disease is high. Existing observational studies have shown inconsistent results in the association between gastroesophageal reflux disease (GERD) and Sjogren's syndrome (SS).We observed that the symptoms of SS patients also improved after receiving GERD-related treatment. Therefore, we aimed to investigate the relationship between GERD and SS through a bidirectional two-sample Mendelian randomization (MR) study. Independent SNPs associated with GERD and SS were selected from a genome-wide association study (GWAS) as instrumental variables to conduct a bidirectional two-sample Mendelian analysis of GERD and SS. Genetic data were obtained from two databases for the following two outcomes: Gastroesophageal reflux (IEU Open GWAS) [sample size = 602,604 (patients = 129,080; nonpatients = 473,524)] and SS (FinnGen) [sample size = 392,423 (patients = 2,495; nonpatients = 389,928)]. Statistical methods for the MR analysis included the inverse-variance weighting method, weighted median, simple mode and weighted mode, as well as heterogeneity and sensitivity analyses using the Cochran Q statistic, MR‒Egger regression, outlier detection methods (MR-PRESSO). In addition, Steiger Test was conducted to test the direction of causality. MR analysis showed a positive correlation between GERD and SS risk [odds ratio (OR) = 1.3279 (95% confidence interval 1.0312-1.7099, P = 0.0280)]. However, in contrast, no significant causal effect of SS on GERD was observed [OR = 1.0024 (95% CI 0.9651-1.0412; P = 0.8995)]. This bidirectional two-sample Mendelian randomization study confirmed a causal relationship between SS and GERD, and suggested that GERD is a risk factor for SS, while SS does not affect GERD.

Advances in cellular and molecular pathways of salivary gland damage in Sjögren's syndrome.

Sjögren's Syndrome (SS) is an autoimmune disorder characterized by dysfunction of exocrine glands. Primarily affected are the salivary glands, which exhibit the most frequent pathological changes. The pathogenesis involves susceptibility genes, non-genetic factors such as infections, immune cells-including T and B cells, macrophage, dendritic cells, and salivary gland epithelial cells. Inflammatory mediators such as autoantibodies, cytokines, and chemokines also play a critical role. Key signaling pathways activated include IFN, TLR, BAFF/BAFF-R, PI3K/Akt/mTOR, among others. Comprehensive understanding of these mechanisms is crucial for developing targeted therapeutic interventions. Thus, this study explores the cellular and molecular mechanisms underlying SS-related salivary gland damage, aiming to propose novel targeted therapeutic approaches.

MiR-34a promotes mitochondrial pathway of apoptosis in human salivary gland epithelial cells by activating NF-κB signaling.

To investigate the potential molecular mechanism of miR-34a in Sjögren's syndrome (SS). Transmission electron microscopy was used to observe the salivary gland tissues of mild and severe SS patients. SS mouse model was constructed and injected with miR-34a antagonist. HSGE cells were transfected with miR-34a mimic. Starbase predicted miR-34a binding sites and validated them with dual-luciferase reporter assays. Immunohistochemistry, HE staining, CCK-8, TUNEL assay, flow cytometry, immunofluorescence and Western Blot were used to investigate the effects of miR-34a on NF-κB signaling and mitochondrial pathway of apoptosis in HSGE cells. Severe SS patients showed obvious mitochondrial damage and apoptosis in salivary glands. MiR-34a was overexpressed and NF-κB signaling is activated in salivary glands of severe SS patients. Inhibition of miR-34a alleviated salivary gland injury in SS mice, as well as inhibited the activation of NF-κB signaling and mitochondrial pathway of apoptosis. In conclusion, miR-34a promoted NF-κB signaling by targeting IκBα, thereby causing mitochondrial pathway apoptosis and aggravating SS-induced salivary gland damage.

JAK1, SKI, ZBTB16 as potential biomarkers mediate the inflammatory response in keratoconjunctivitis sicca.

Keratoconjunctivitis sicca (KCS) is an ocular condition characterized by insufficient tear production and inflammatory irritation, with Sjögren's syndrome (SS) being a major causative factor. This study aimed to extract patient transcriptomic data from the GEO database to identify signature genes associated with the diagnosis and treatment of KCS and the expression of three key genes were experimentally verified. We performed a difference analysis on the SS patient dataset and performed a Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis on the resulting genes. Additionally, a Weighted Gene Co-expression Network Analysis (WGCNA) was constructed. Machine learning techniques were employed to analyze the most strongly correlated gene modules with SS traits. These findings were further validated using KCS immune-correlation microarrays as a validation set. The correlation of the three identified genes with 22 immune cells was assessed through immune infiltration analysis. Subsequently, a rat model of desiccated keratoconjunctivitis was established, and the modeling situation and expression of characteristic genes were analyzed at the morphological, tissue, and molecular levels. Bioinformatic prediction revealed that the expression of JAK1, SKI, ZBTB16 not only differed in the machine learning validation set, but also correlated with some immune cells in the immune infiltration analysis. The results of animal experiments showed that the transcription and expression levels of these three genes were significantly different in rat KCS tissues and normal tissues, and there were also differences in the expression of JAK1 and SKI in rat peripheral blood, as well as significant up-regulation of the expression of related inflammatory factors in KCS tissues. Through bioinformatics prediction and animal experimental validation, this study identified three differentially expressed genes in SS mediated KCS patients, which provide new potential biological targets for the diagnosis and treatment of KCS.

The circular RNA hsa_circ_0045800 serves as a favorable biomarker in pathogenesis of sjögren's syndrome.

BACKGROUND: Circular RNAs (circRNAs) play various roles in the development of many autoimmune diseases. However, their expression profiles and specific function in Sjögren's Syndrome remains largely unknown. OBJECTIVES: We aimed to investigate circRNAs potential diagnostic value in primary Sjögren's syndrome (pSS) and contribution to the pathogenesis of pSS. METHODS: This study included 102 subjects, 51 pSS patients and 51 healthy controls. The concentration of hsa_circ_0045800 was analyzed in peripheral blood mononuclear cells obtained from 51 pSS patients and 51 healthy controls by qRT-PCR. We established a receiver operating characteristic curve (ROC) to assess the biological diagnostic value of hsa_circ_0045800 for pSS. In addition, we analyzed the correlation between hsa_circ_0045800 and disease activity in Sjogren's syndrome. A differential analysis was also conducted on the concentration of hsa_circ_0045800 in patients in pSS patients before and after treatment. We studied the downstream mechanism of hsa_circ_0045800 through bioinformatics analysis and confirmed it using luciferase reporter gene assay. RESULTS: We confirmed that the concentration of hsa_circ_0045800 was elevated 10.4-fold in peripheral blood mononuclear cells of pSS patients than in healthy controls (p = 0.00). In the pSS active disease group, the concentration of hsa_circ_0045800 is 2.5-fold higher compared to the pSS non-active disease group (p = 0.04). The concentration of hsa_circ_0045800 after treatment was decreased by 80% compared with that before treatment (p = 0.037), suggesting its utility as a potential marker for monitoring treatment efficacy. ROC curve analysis showed that the diagnostic value of hsa_circ_0045800 in pSS patients was significantly higher than that in healthy controls, with an area under the curve of 0.865, a sensitivity of 74%, and a specificity of 92%. The concentration of hsa_circ_0045800 is correlated with various clinical factors: the concentration of hsa_circ_0045800 is positively associated with age (r = 0.328, P = 0.019), oral dryness (r = 0.331, P = 0.017), while it is negatively correlated with HGB (r = -0.435, P = 0.001) and and hypothyroidism (r = -0.318, P = 0.023). Bioinformatics predictions and luciferase assays indicated that hsa_circ_0045800 acts as a molecular sponge for miR-1247-5p, with SMAD2 being a target gene of miR-1247-5p. CONCLUSION: Our study results show that hsa_circ_0045800 potentially contributes to the development and progression of pSS via the miR-1247-5p/SMAD2 pathway. Peripheral blood mononuclear cells are directly involved in the pathogenesis of pSS, and the discovery of hsa_circ_0045800 in peripheral blood mononuclear cells highlights its potential as a novel biomarker for disease activity and diagnosis in patients with pSS. Key Points • The concentration of hsa_circ_0045800 was higher in peripheral blood mononuclear cells of pSS patients. • Hsa_circ_0045800 promoted pSS progression through miR-1247-5p-SMAD2 axis. • Hsa_circ_0045800 is a potential biomarker for pSS.

Identification of drug targets for Sjögren's syndrome: multi-omics Mendelian randomization and colocalization analyses.

Background: Targeted therapy for Sjögren's syndrome (SS) has become an important focus for clinicians. Multi-omics-wide Mendelian randomization (MR) analyses have provided new ideas for identifying potential drug targets. Methods: We conducted summary-data-based Mendelian randomization (SMR) analysis to evaluate therapeutic targets associated with SS by integrating DNA methylation, gene expression and protein quantitative trait loci (mQTL, eQTL, and pQTL, respectively). Genetic associations with SS were derived from the FinnGen study (discovery) and the GWAS catalog (replication). Colocalization analyses were employed to determine whether two potentially relevant phenotypes share the same genetic factors in a given region. Moreover, to delve deeper into potential regulation among DNA methylation, gene expression, and protein abundance, we conducted MR analysis to explore the causal relationship between candidate gene methylation and expression, as well as between gene expression and protein abundance. Drug prediction and molecular docking were further employed to validate the pharmacological activity of the candidate drug targets. Results: Upon integrating the multi-omics data, we identified three genes associated with SS risk: TNFAIP3, BTN3A1, and PLAU. The methylation of cg22068371 in BTN3A1 was positively associated with protein levels, consistent with the negative effect of cg22068371 methylation on the risk of SS. Additionally, positive correlations were observed between the gene methylation of PLAU (cg04939496) and expression, as well as between expression and protein levels. This consistency elucidates the promotional effects of PLAU on SS risk at the DNA methylation, gene expression, and protein levels. At the protein level, genetically predicted TNFAIP3 (OR 2.47, 95% CI 1.56-3.92) was positively associated with SS risk, while BTN3A1 (OR 2.96E-03, 95% CI 2.63E-04-3.33E-02) was negatively associated with SS risk. Molecular docking showed stable binding for candidate drugs and target proteins. Conclusion: Our study reveals promising therapeutic targets for the treatment of SS, providing valuable insights into targeted therapy for SS. However, further validation through future experiments is warranted.

MiR-23b-3p alleviates Sjögren's syndrome by targeting SOX6 and inhibiting the NF-κB signaling.

OBJECTIVE: MicroRNA-23b-3p has been demonstrated to act as a safeguard against several autoimmune diseases. However, its role in Sjögren's syndrome (SS) remains unclear. METHODS: In order to investigate its role in SS, we administered agomiR-23b-3p or agomiR-NC to non-obese diabetic (NOD) mice via tail vein weekly for 6 weeks. The study examined the saliva flow rate, histological changes in submandibular glands, and levels of autoantibodies. Additionally, the levels of several cytokines, cell apoptosis, and NF-κB signaling were evaluated. The protective effect of miR-23b-3p was confirmed in a cell model. RESULTS: The results demonstrated that miR-23b-3p overexpression improved salivary flow rates, inhibited lymphocyte infiltration, reduced cytokine levels, and suppressed cell apoptosis in NOD mice. Moreover, NF-κB signaling was inactivated following miR-23b-3p overexpression. In a cellular model of SS, overexpression of miR-23b-3p protected submandibular gland epithelial cells exposed to IFN-γ against apoptosis and inflammation by targeting SOX6. CONCLUSIONS: The study concludes that miR-23b-3p alleviates SS by targeting SOX6 and inhibiting the NF-κB signaling pathway. The miR-23b-3p/SOX6 axis represents a promising avenue for the development of novel therapeutic strategies for SS.

Deleting Mitochondrial Superoxide Dismutase 2 in Salivary Gland Ductal Epithelial Cells Recapitulates Non-Sjögren's Sicca Syndrome.

Elevated oxidative stress can play a pivotal role in autoimmune diseases by exacerbating inflammatory responses and tissue damage. In Sjögren's disease (SjD), the contribution of oxidative stress in the disease pathogenesis remains unclear. To address this question, we created mice with a tamoxifen-inducible conditional knockout (KO) of a critical antioxidant enzyme, superoxide dismutase 2 (Sod2), in the salivary glands (i-sg-Sod2 KO mice). Following tamoxifen treatment, Sod2 deletion occurred primarily in the ductal epithelium, and the salivary glands showed a significant downregulation of Sod2 expression. At twelve weeks post-treatment, salivary glands from the i-sg-Sod2 KO mice exhibited increased 3-Nitrotyrosine staining. Bulk RNA-seq revealed alterations in gene expression pathways related to ribosome biogenesis, mitochondrial function, and oxidative phosphorylation. Significant changes were noted in genes characteristic of salivary gland ionocytes. The i-sg-Sod2 KO mice developed reversible glandular hypofunction. However, this functional loss was not accompanied by glandular lymphocytic foci or circulating anti-nuclear antibodies. These data demonstrate that although localized oxidative stress in salivary gland ductal cells was insufficient for SjD development, it induced glandular dysfunction. The i-sg-Sod2 KO mouse resembles patients classified as non-Sjögren's sicca and will be a valuable model for deciphering oxidative-stress-mediated glandular dysfunction and recovery mechanisms.

Primary biliary cholangitis and Sjogren's syndrome: bi-directional Mendelian randomization analysis.

OBJECTIVE: Observational studies have shown a higher prevalence of Sjogren's syndrome (SjS) in patients with primary biliary cholangitis (PBC) than in the healthy population, but whether this correlation is causal needs further confirmation. This study aimed to investigate the bidirectional causal relationship between PBC and SjS using Mendelian randomization (MR) analysis. MATERIALS AND METHODS: We used pooled data from a large-scale genome-wide association study (GWAS) to select mutually independent genetic loci associated with PBC and SjS in people of European ancestry as instrumental variables (IVs). The causal association between PBC and SjS was analyzed by MR analysis using inverse variance weighting (IVW) and weighted median methods, and the ratio of ratios (OR) was used as an evaluation index. In addition, sensitivity analyses, including Cochran's Q test, MR-PRESSO, MR-Egger intercept test, and leave-one-out test, were performed to ensure the stability of the results. RESULTS: A total of 20 validated IVs were selected for PBC, and the number of IVs for SjS was seven. Positive MR analysis showed that genetically predicted PBC was significantly associated with the risk of SjS (IVW OR=1.174, 95% CI: 1.107-1.246, p<0.001). The weighted median method further confirmed this result (OR=1.146, 95% CI: 1.053-1.247, p=0.016). Inverse MR analysis showed that genetic susceptibility to SjS also increased the risk of PBC (IVW OR=1.737, 95% CI: 1.280-2.357, p<0.001), and this result was also confirmed by the weighted median method (OR=1.398, 95% CI: 1.120-1.746, p=0.003). CONCLUSIONS: Our study found that genetically predicted SjS increased the risk of PBC and vice versa in a European population. This may shed light on the etiology of PBC and the management of patients with SjS.