Regulation of STAT1 and STAT4 Expression by Growth Factor and Interferon Supplementation in Sjögren's Syndrome Cell Culture Models.

Our goal was to investigate the effects of epidermal growth factor (EGF) and interferons (IFNs) on signal transducer and activator of transcription STAT1 and STAT4 mRNA and active phosphorylated protein expression in Sjögren's syndrome cell culture models. iSGECs (immortalized salivary gland epithelial cells) and A253 cells were treated with EGF, IFN-alpha, -beta, -gamma, or mitogen-activated protein kinase p38 alpha (p38-MAPK) inhibitor for 0-24-48-72 h. STAT1 and STAT4 mRNA expression was quantified by qRT-PCR. Untreated and treated cells were compared using the delta-delta-CT method based on glyceraldehyde-3-phosphate dehydrogenase (GAPDH) normalized relative fold changes. phospho-tyrosine-701-STAT1 and phospho-serine-721-STAT4 were detected by Western blot analysis. STAT4 mRNA expression decreased 48 h after EGF treatment in A253 cells, immortalized salivary gland epithelial cells iSGECs nSS2 (sicca patient origin), and iSGECs pSS1 (anti-SSA negative Sjögren's Syndrome patient origin). EGF and p38-MAPK inhibitor decreased A253 STAT4 mRNA levels. EGF combined with IFN-gamma increased phospho-STAT4 and phospho-STAT1 after 72 h in all cell lines, suggesting additive effects for phospho-STAT4 and a major effect from IFN-gamma for phospho-STAT1. pSS1 and nSS2 cells responded differently to type I and type II interferons, confirming unique functional characteristics between iSGEC cell lines. EGF/Interferon related pathways might be targeted to regulate STAT1 and STAT4 expression in salivary gland epithelial cells. Further investigation is required learn how to better target the Janus kinases/signal transducer and activator of transcription proteins (JAK/STAT) pathway-mediated inflammatory response in Sjögren's syndrome.

Efficacy of Lushi Runzao decoction on ameliorating Sjogren's syndrome: a network pharmacology and experimental verification-based study.

OBJECTIVE: To investigate the possible mechanism underlying the effect of the Lushi Runzao decoction on Sjogren's syndrome using network pharmacology and to verify the mechanismsanimal experiments. METHODS: Available biological data on each drug in the Lushi Runzao decoction were retrieved from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform, and the target proteins of Sjogren's syndrome were retrieved from the GeneCards database. Information regarding Sjogren's syndrome and the targets of the drugs were compared to obtain overlapping elements. This information was imported into the STRING platform to obtain a protein-protein interaction network diagram, following which a "component-target" network diagram was constructed using screened drug components and target informationCytoscape software. The database for annotation, visualization, and integrated discovery was used for Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathways analyses. Pathway information predicted by network pharmacology was verified using animal experiments. RESULTS: The Lushi Runzao decoction ameliorated Sjogren's syndrome mainly by influencing tumor necrosis factor as well as certain cytokines and chemokines. The decoction also influenced the interleukin-17 and advanced glycosylation end products (AGE)-receptor for AGE signaling pathways. CONCLUSION: The Lushi Runzao decoction ameliorates Sjogren's syndromemultiple targets and multiple signaling pathways. Network pharmacology is useful for making a comprehensive prediction regarding the efficacy of the Lushi Runzao decoction, and this information may be helpful in clinical research.

Serum vitamin D levels and Sjogren's syndrome: bi-directional Mendelian randomization analysis.

BACKGROUND: Based on the results of existing observational studies, it can be found that the association between serum vitamin D levels and the risk of Sjogren's syndrome (SS) in humans is still controversial. Based on this situation, this study aimed to assess the causal relationship between serum vitamin D levels and SS by using the Mendelian randomization (MR) approach. METHODS: In this study, genome-wide association studies (GWAS) summary statistics on serum vitamin D levels [sample size = 417,580 (UK Biobank)] and SS [sample size = 416,757 (cases = 2495, controls = 414,262) (FinnGen)] were used. The bi-directional MR analysis was then used to assess possible causal relationships. The major analysis method of MR was performed using inverse-variance weighted (IVW), supplemented by MR-Egger and the weighted median approaches. In addition, sensitivity analyses were used to ensure the stability of the results, including Cochran's Q test, MR-PRESSO, MR-Egger intercept test, and the leave-one-out test. RESULTS: The MR suggested that no significant causal effects of serum 25(OH)D levels on SS risks were observed [odds ratio (OR) = 0.9824; 95% confidence interval (CI) = 0.7130 to 1.3538; P = 0.9137]. Similarly, no evidence supported the causal effects of SS on serum vitamin D levels (ß: 0.0076, 95% CI: - 0.0031 to 0.0183; P = 0.1640). CONCLUSION: This study found no obvious evidence that serum vitamin D level is causally associated with SS risks or vice versa. We call for larger sample size studies to further unravel the potential causal relationship and the exact mechanism.

Deciphering potential pharmacological mechanism of Sha-Shen-Mai-Dong decoction on primary Sjogren's syndrome.

BACKGROUND: Sha-Shen-Mai-Dong decoction (SSMD) is a classical prescription widely used in primary Sjogren's Syndrome (pSS) therapy. This study aims to explore the potential pharmacological mechanism of SSMD on pSS. METHODS: Active components of SSMD were obtained from Traditional Chinese Medicine Integrative Database and Traditional Chinese Medicine Systems Pharmacology databases and targets of SSMD were predicted by Pharmmapper and STITCH database. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were carried out to explore the function characteristics of SSMD. The expression matrix of microarray of pSS was obtained from Gene Expression Omnibus and we obtained 162 differentially expressed genes (DEGs). Protein-protein interaction (PPI) networks were constructed to identify the hub targets. Principal component analysis (PCA) and molecular docking were conducted to further elucidate the possibility of SSMD for pSS. RESULTS: SSMD contained a total of 1056 active components, corresponding to 88 targets, among which peripheral myelin protein 2(PMP2), androgen receptor (AR) and glutamic acid decarboxylase 1(GAD1) are associated with multiple active components in SSMD and may be the core targets. Moreover, these targets were closely related to tissue pathological injury in SS, such as lacrimal gland, salivary gland and nervous system injury. GO and KEGG analysis showed that 88 targets enriched in REDOX process, transcriptional regulation and negative regulation of apoptosis process. Besides, SSMD may influence the cell proliferation, gene transcription through regulating Ras and cAMP-related signaling pathways. In addition, SSMD may show effects on immune regulation, such as macrophage differentiation, Toll-like receptor 4 signaling pathway and T-helper 1 in SS. Moreover, PPI network suggested that FN1, MMP-9 may be the hub targets in SSMD. Result of PCA and molecular docking analysis further determined the feasibility of SSMD in treating pSS. CONCLUSION: SSMD can regulate multiple biological processes by virtue of its multiple active components, thus showing prominent advantage in the treatment of pSS. The discovery of active ingredients and targets in SSMD provides valuable resources for drug research and development for pSS.

cDNA microarray analysis identifies NR4A2 as a novel molecule involved in the pathogenesis of Sjögren's syndrome.

To examine genes expressed specifically in labial salivary glands (LSGs) of patients with Sjögren's syndrome (SS) in comparison with those of patients with immunoglobulin (Ig)G4-related disease (IgG4-RD), and to identify the genes involved in the pathogenesis of SS. Gene expression in LSGs of SS patients, IgG4-RD patients and healthy controls (HC) was analysed by cDNA microarray. Quantitative polymerase chain reaction (qPCR) was used to validate the up-regulation of differentially expressed genes (DEGs) in SS. Protein production of the validated gene in LSGs was examined by immunofluorescence (IF) assay. The association of molecular functions of the gene with the pathological conditions in SS was examined using peripheral blood lymphocytes. Among 1320 DEGs up-regulated in SS, qPCR confirmed the up-regulation of NR4A2 in LSGs of SS compared with IgG4-RD. IF staining showed higher production of NR4A2 in nuclei of CD4+ T cells and interleukin (IL)-17-producing cells in LSGs of SS, compared with IgG4-RD. Over-expression of NR4A2 mRNA was observed in peripheral CD4+ T cells of SS patients, compared with HC. Nuclear NR4A2 expression in T helper type 17 (Th17)-polarized CD4+ T cells determined by cellular IF was significantly higher in SS than in HC. Importazole, an inhibitor of importin-ß, inhibited nuclear transport of NR4A2 and Th17 polarization along with IL-21 expression in naive CD4+ T cells under Th17-polarizing conditions, but did not alter retinoic acid receptor-related orphan receptor C (RORC) expression. NR4A2 seems to promote Th17 polarization via increased expression and intranuclear localization in CD4+ T cells of SS patients, which could play a critical role in the pathogenesis of SS.

Down-regulation of increased TRAF6 expression in the peripheral mononuclear cells of patients with primary Sjögren's syndrome by an EBV-EBER1-specific synthetic single-stranded complementary DNA molecule.

AIM: We described earlier a simultaneously increased that the increased expression of miRNA-146a/b was accompanied by an increase in the expression of and TRAF6 and a decrease in the expression of IRAK1 genes in the peripheral mononuclear cells (PBMCs) of patients with primary Sjogren's syndrome (pSS) patients. Recently, the expression of EBV encoded. RNA (EBER) was published in the B cells of salivary glands of in pSS. In the present study, we applied an EBV-EBER1 specific synthetic single stranded complementary DNA molecule (EBV-EBER1-cDNA) to test whether any EBER1 related effect exists also in PBMCs of pSS patients. METHODS: In the PBMCs of pSS patients and healthy controls, we investigated in vitro the effects of a synthetic single stranded EBV-EBER1-cDNA molecule, synthetic double-stranded (ds)RNA polyinosinic-polycytidylic acid [poly (I:C)] and polyadenylic acid potassium salt poly-adenylic acid [poly-(A)] on the expression of TRAF6 gene tested by qRTPCR. The release of interferon -α was detected by ELISA. RESULTS: EBV-EBER1-cDNA resulted in a significant reduction in the expression of TRAF6 in the cells of patients, but in the healthy controls not, whereas the treatments with poly (I:C) and poly-(A) could not reduce the TRAF6 over-expression. No release of EBER1 could be observed in the culture supernatants of patients with pSS. Only the treatment with poly (I:C) resulted in a significant increase of interferon -α release, and only in the heathy controls. No release of EBER1 molecules took place during the culturing of cells. EBV-EBER- cDNA acted functionally on the cells of patients only. CONCLUSION: These findings give a further evidence of the linkage between EBV and pSS, furthermore, they show the possible role of EBV-EBER1 in the induction of increased TRAF6 expression in the peripheral B cells of Sjögren's patients.

[Xinfeng Capsule reduces hypercoagulative state in patients with Sjogren's syndrome by inhibiting miR-155/SOCS1/NF-κB signaling pathway].

Objective To explore the relationship between Xinfeng Capsule (XFC) improving the hypercoagulative state in patients with Sjogren's syndrome (SS) and miR-155/suppressor of cytokine signaling 1 (SOCS1)/nuclear factor κB (NF-κB) signaling pathway. Methods Sixty-six SS patients were randomly divided into XFC-treated group and hydroxychloroquine (HCQ)-treated control group (n=33 per group), which were respectively treated with XFC and HCQ. In addition, 20 healthy volunteers were enrolled as a normal control group. The levels of prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIG), thrombin time (TT) and D-dimer (D-D) were detected using automatic coagulation analyzer. Interleukin-1ß (IL-1ß), IL-4, IL-10, tumor necrosis factor-α (TNF-α), P50, P65, inhibitor of NF-κB α (IκBα) were tested using ELISA. Meanwhile, the mRNA expressions of p50, p65 and IκBα were determined using quantitative real-time PCR, and the level of microRNA-155 (miR-155) was examined by one-step fluorescence quantitative PCR. The protein levels of P50, P65 and SOCS1 were detected using Western blotting. Erythrocyte sedimentation rate (ESR) was evaluated by Westergren method. Hypersensitive C-reactive protein (hs-CRP) was detected using automatic biochemical analyzer. Results Compared with the normal control group, the levels of D-D and FIB significantly increased in SS group; simultaneously, the serum levels of miR-155, IL-1ß, TNF-α, P50, P65, IκBα, hs-CRP, ESR were significantly elevated in SS patients, while IL-4 and IL-10 were significantly reduced. Spearman correlation analysis showed that the coagulation parameters were remarkably correlated with cytokines, NF-κB and activity indexes. In the two treated groups, coagulation parameters and related indexes were demonstrated having some improvement, especially in the XFC group, which had a much higher efficiency, and better outcomes in reducing the levels of FIB, D-D, miR-155, TNF-α, IL-1ß, P50, P65, ESR and hs-CRP, as well as increasing the expressions of SOCS1, IL-4 and IL-10. Conclusion XFC can significantly alleviate the hypercoagulative state of patients with SS, and the mechanisms may be related to the inhibition of miR-155/SOCS1/NF-κB signaling pathway.

[Mechanism of cardiac function changes in rat models of Sjogren's syndrome based on Keap1-Nrf2/ARE signaling pathways].

OBJECTIVE: To investigate the mechanism underlying the changes in the cardiac function in rat models of Sjogren's syndrome (SS) based on Kelch-like ECH-associated protein 1 (Keap1)-Nrf2/ARE signaling pathways. METHODS: Thirty male Wistar rats were randomly divided into two groups, normal control (NC) group and SS model group, with 15 in each. The rats in the model group were injected with the complete Freund's adjuvant plus homologous antigen of submandibular gland (0.2 mL mixture) into bilateral posterior paw metatarsus. The body mass, water intake, submandibular gland index, spleen index, and histological changes of the glands were observed 30 days after inflammation was induced. Cardiac function was assessed using invasive hemodynamic monitoring. Meanwhile, reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD) and total antioxidant capacity (TAC), IL-18, IL-35 were detected using ELISA; ROS and reactive nitrogen species (RNS), glutathione (GSH), thioredoxin (TrX) protein were determined using immunohistochemical staining. The expressions of Keap 1, nuclear factor erythroid 2-related factor (Nrf2), macrophage activating factor (Maf) antioxidant responsive element (ARE) mRNAs were detected using real-time fluorescent quantitative PCR (qRT-PCR); the levels of heme oxygenase-1 (HO-1), γ-glutamic acid and a half long glycine synthetase (γ-GCS) proteins in cardiac tissue were examined using Western blotting. RESULTS: Compared with the NC group, the model group presented reduced body mass, submandibular gland index and spleen index (P<0.05), increased water intake (P<0.01), heart rate (HR), heart index (HI), left ventricular systolic pressure (LVSP) and left ventricular diastolic pressure (LVEDP) (P<0.05), and decreased left ventricular ±dp/dtmax (P<0.05). Compared with the NC group, the model group had increased IL-18, MDA, RNS, TAC, ROS levels, and Keap1, Maf, Nfr2 mRNAs, HO-1, γ-GCS protein expressions in the heart tissue, while TrX, GSH, IL-5 and SOD levels decreased significantly (P<0.01). CONCLUSION: The immune imbalance in SS rats may be related with the up-regulated levels of Keap1, Maf, Nfr2 mRNAs, HO-1, γ-GCS.

Targeted deletion of the gene encoding the La autoantigen (Sjögren's syndrome antigen B) in B cells or the frontal brain causes extensive tissue loss.

La antigen (Sjögren's syndrome antigen B) is a phosphoprotein associated with nascent precursor tRNAs and other RNAs, and it is targeted by autoantibodies in patients with Sjögren's syndrome, systemic lupus erythematosus, and neonatal lupus. Increased levels of La are associated with leukemias and other cancers, and various viruses usurp La to promote their replication. Yeast cells (Saccharomyces cerevisiae and Schizosaccharomyces pombe) genetically depleted of La grow and proliferate, whereas deletion from mice causes early embryonic lethality, raising the question of whether La is required by mammalian cells generally or only to surpass a developmental stage. We developed a conditional La allele and used it in mice that express Cre recombinase in either B cell progenitors or the forebrain. B cell Mb1(Cre) La-deleted mice produce no B cells. Consistent with αCamKII Cre, which induces deletion in hippocampal CA1 cells in the third postnatal week and later throughout the neocortex, brains develop normally in La-deleted mice until ∼5 weeks and then lose a large amount of forebrain cells and mass, with evidence of altered pre-tRNA processing. The data indicate that La is required not only in proliferating cells but also in nondividing postmitotic cells. Thus, La is essential in different cell types and required for normal development of various tissue types.

[Effect of nourishing Yin, strengthening Qi and activating blood decoction on Fas/FasL in salivary glands of NOD mice with Sjogren's syndrome and their mRNA expression].

OBJECTIVE: To observe the effect of nourishing Yin, strengthening Qi and activating blood decoction on Fas/FasL in salivary glands of NOD mice with Sjogren's syndrome and their mRNA expression. METHOD: Thirty-two NOD mice were randomly divided into the model group, the traditional Chinese medicine group (TCM group, orally given 0.4 mL nourishing Yin, strengthening Qi and activating blood decoction as per 100 g x kg(-1) everyday), the hydroxychloroquine group (given 0.4 mL hydroxychloroquine as per 60 mg x kg(-1) everyday), the traditional Chinese medicine and western medicine group (TCM WM group, given nourishing Yin, Strengthening Qi and activating blood decoction 50 g x kg(-1) and hydroxychloroquine 60 mg x kg(-1), 0.4 mL everyday), with eight mice in each group. Eight Balb/C mice were selected as the normal control group (normal group). All of mice were killed after eight weeks, and their submaxillary glands were dissected. The expression levels of Fas/FasL were examined by immunohistochemical method, and the FasL mRNA was detected by RT-PCR. RESULT: The expression levels of Fas/FasL in salivary glands of the model group were higher than that of other groups (P < 0.05). The expression level of FasL of the normal group was much lower than that in the hydroxychloroquine group (P < 0.05). The relative expression level of Fas mRNA in salivary glands of the model group was higher than that in other groups, but the control group was notably lower than other groups (P < 0.05). The expression level of FasL mRNA in salivary glands of the model group was higher than that in TCM and TCM WM groups (P < 0.05). But the expression level in TCM WM group was notably lower than the hydroxychloroquine group (P < 0.05). CONCLUSION: The nourishing Yin, strengthening Qi and activating blood decoction could down-regulate the expression level of Fas/FasL in salivary glands of NOD mice with Sjogren's syndrome and their mRNA expression, and had a better efficacy after being combined with hydroxychloroquine. The nourishing Yin, strengthening Qi and activating blood decoction might treat the Sjogren's Syndrome by reducing apoptosis which is regulated by Fas/FasL

52-kD SS-A/Ro: genomic structure and identification of an alternatively spliced transcript encoding a novel leucine zipper-minus autoantigen expressed in fetal and adult heart.

The 52-kD SS-A/Ro protein is one of the antigenic targets strongly associated with the autoimmune response in mothers whose children have manifestations of neonatal lupus. In addition to the cDNA clone we previously reported for the full-length 52-kD SS-A/Ro protein, an interesting MOLT-4 cDNA clone, p52-2, was found to have an internal deletion of 231 nucleotides including the domain encoding the leucine zipper motif. To further investigate the nature of this deletion, genomic DNA clones were isolated from a lambda FIXII library. The complete gene for the full-length 52-kD protein (alpha form, 52 alpha) spans 10 kb of DNA and is composed of seven exons. Exon 1 contains only the 5' untranslated sequence, while the translation initiation codon is located 3 kb downstream in exon 2, which also encodes the three zinc finger motifs. Exon 4 encodes amino acids 168-245, including the coiled coil/leucine zipper domain. Exon 7 is the longest and encodes the rfp-like domain and the 3' untranslated region. The cDNA p52-2 can now be accounted for as a product of alternative messenger RNA (mRNA) derived from the splicing of exon 3 to exon 5, skipping exon 4, which results in a smaller protein (52 beta) with a predicted molecular weight of 45,000. An initial approach to identifying this alternatively spliced form in the human heart used a ribonuclease protection assay. Using an RNA probe corresponding to bases 674-964 of the full-length cDNA, two protected mRNA fragments were identified, a 290-bp fragment corresponding to expression of 52 alpha and a smaller fragment of 144 bp, the predicted size of 52 beta. Using reverse transcription followed by polymerase chain reaction, cDNAs from a 16-wk fetal heart, 24-wk heart, and adult heart were amplified with primers flanking exon 4. Two polymerase chain reaction products were observed in each tissue, one 1.0 kb likely representing 52 alpha and a second 0.78 kb, consistent with 52 beta. The 0.78-kb fragment identified in the 16-wk heart was cloned, and DNA sequencing confirmed the 52 beta type. Immunoprecipitation of in vitro-translated 35S-labeled 52 beta form was performed to evaluate the antigenicity of this novel form of 52-kD SS-A/Ro. 26 (87%) of 30 sera tested from mothers whose children were known to have neonatal lupus immunoprecipitated the 52 beta form.(ABSTRACT TRUNCATED AT 400 WORDS)