Goji Berry Juice Prevents Tumor Necrosis Factor Alpha-Induced Xerostomia in Human Salivary Gland Cells.

Sjögren's syndrome (SS) is an autoimmune disorder characterized by oral dryness that is primarily attributed to tumor necrosis factor alpha (TNF-α)-mediated reduction in saliva production. In traditional Chinese medicine, goji berries are recognized for their hydrating effect and are considered suitable to address oral dryness associated with Yin deficiency. In the present study, we used goji berry juice (GBJ) to investigate the potential preventive effect of goji berries on oral dryness caused by SS. Pretreatment of human salivary gland cells with GBJ effectively prevented the decrease in aquaporin-5 (AQP-5) mRNA and protein levels induced by TNF-α. GBJ also inhibited histone H4 deacetylation and suppressed the generation of intracellular reactive oxygen species (ROS). Furthermore, GBJ pretreatment reserved mitochondrial membrane potential and suppressed the upregulation of Bax and caspase-3, indicating that GBJ exerted an antiapoptotic effect. These findings suggest that GBJ provides protection against TNF-α in human salivary gland cells and prevents the reduction of AQP-5 expression on the cell membrane. Altogether, these results highlight the potential role of GBJ in preventing oral dryness caused by SS.

Aquaporin5-Targeted Treatment for Dry Eye Through Bioactive Compounds and Gut Microbiota.

Dry eye and dry mouth are the principal sources of morbidity for patients with Sjögren's syndrome (SS). There are few effective treatments, particularly systemic ones. Targeting aquaprin-5 (AQP5)-mediated tear secretion has been tested as a novel ancillary strategy and has proved promising. Patients have a great interest in using complementary medicine, including nutraceuticals and bioactive compounds to alleviate their symptoms. Potential mechanisms by which phytocompounds and bioactive compounds may benefit SS ocular and mouth symptoms through modulation of AQP5 activity are presented within this review. Supplementation with prebiotics (such as polyphenols with high bioavailability) in SS patients with lower Firmicutes/Bacteroides (F/B) community ratio phenotype, through administration of butyrate-producing diets, is proposed as ancillary strategy for dry eye and mouth. The potential use of natural bioactive compounds to treat dry eye could also apply to dry mouth occurring in the context of aging and SS. This novel hypothesis could have implications with respect to planning a successful dietary regimen for achieving and maintaining a normal gut microbiota in SS patients. This regimen would include augmenting butyrate-producing foodstuffs and/or polyphenol-rich syrups, and high amounts of some specific probiotic-rich foodstuffs such as yogurt, soy yogurt, or as probiotic supplements. There are applications for pharmaceutical and nutraceutical products aiming to relieve dry eye and mouth.

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.

Recent Advances in the Use of Exosomes in Sjögren's Syndrome.

Sjögren's syndrome (SS) is a chronic autoimmune disorder of the exocrine glands mediated by lymphocytic infiltrates damaging the body tissues and affecting the life quality of patients. Although traditional methods of diagnosis and treatment for SS are effective, in the time of personalized medicine, new biomarkers, and novel approaches are required for the detection and treatment of SS. Exosomes represent an emerging field in the discovery of biomarkers and the management of SS. Exosomes, a subtype of extracellular vesicles, are secreted by various cell types and can be found in most bodily fluids. Exosomes are packed with cytokines and other proteins, bioactive lipids, and nucleic acids (mRNA, circular RNA, non-coding RNA, tRNA, microRNA, genomic DNA, and ssDNA), and transport such cargo between cells. Evidence has indicated that exosomes may play roles in processes such as the modulation of the immune response and activation of inflammation. Moreover, due to features such as stability, low immunogenicity and toxicity, long half-life, and the capacity to penetrate the blood-brain barrier, exosomes have also emerged as therapeutic tools for SS. In this review, we summarize existing literature regarding the biogenesis, isolation, and function of exosomes, specifically focusing on exosomes as novel biomarkers and their potential therapeutic uses in SS.

Total glucosides of paeony (TGP) alleviates constipation and intestinal inflammation in mice induced by Sjögren's syndrome.

ETHNOPHARMACOLOGICAL RELEVANCE: Sjögren's syndrome (SS) is an autoimmune disease and can cause gastrointestinal disorders such as constipation and intestinal inflammation. As a kind of medicinal material, Paeonia lactiflora Pall has a variety of pharmacological effects, and it is also an indispensable component in many pharmaceutical preparations, which has been widely concerned by the medical and pharmaceutical circles. Total glucosides of paeony (TGP) is a mixture of biologically active compounds extracted from the root of Paeonia lactiflora Pall and has therapeutic effects on a variety of autoimmune diseases. AIM OF THE STUDY: To investigate the therapeutic effect of TGP on constipation and intestinal inflammation in mice modeled by SS, and to provide a basis for clinical research. MATERIALS AND METHODS: The SS model was set up by submandibular gland (SMG) immune induction method and then treated with TGP for 24 weeks. The fecal characteristics were observed and the fecal number and moisture content were measured. Colonic pathology was observed by H&E staining. The levels of serum P substance (SP), vasoactive intestinal peptide (VIP), interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, nuclear factor (NF)-κB, nitric oxide (NO), and nitric oxide synthase (NOS) were determined by enzyme linked immunosorbent assay (ELISA) and microplate method, respectively. Reverse transcription polymerase chain reaction (RT-PCR) was employed to analyze the mRNA expression of c-kit and stem cell factor (SCF) in colon. RESULTS: Compared with the model group, the dry and rough condition of the feces was improved, and the fecal gloss, number and moisture content significantly increased after the administration of TGP capsules. Meanwhile, TGP treatment improved colonic pathological damage, inhibited the serum concentrations of NO, NOS, IL-1ß, TNF-α, NF-κB and SP, increased serum VIP concentration, and up-regulated mRNA expression of SCF and c-kit in colon. CONCLUSIONS: TGP could obviously attenuate SS-mediated constipation and intestinal inflammation in mice by acting on some intestinal motility related factors and inflammatory factors.

Aspirin Triggered Resolvin D1 reduces inflammation and restores saliva secretion in a Sjögren's syndrome mouse model.

OBJECTIVES: SS is characterized by chronic inflammation of the salivary glands leading to loss of secretory function, thereby suggesting specialized pro-resolving mediators targeting inflammation to be a viable option for treating SS. Previous studies demonstrated that aspirin-triggered resolvin D1 (AT-RvD1) prevents chronic inflammation and enhances saliva secretion in a SS-like mouse model when applied before disease onset. However, this therapy cannot be used in SS patients given that diagnosis occurs post-disease onset and no reliable screening methods exist. Therefore, we examined whether treatment with AT-RvD1 reduces SS-like features in a mouse model post-disease onset. METHODS: Tail vein injections were performed in a SS-like mouse model both with and without AT-RvD1 post-disease onset for 8 weeks, with salivary gland function and inflammatory status subsequently determined. RESULTS: Treatment of a SS-like mouse model with AT-RvD1 post-disease onset restores saliva secretion in both females and males. Moreover, although AT-RvD1 treatment does not reduce the overall submandibular gland lymphocytic infiltration, it does reduce the number of T helper 17 cells within the infiltrates in both sexes. Finally, AT-RvD1 reduces SS-associated pro-inflammatory cytokine gene and protein expression levels in submandibular glands from female but not male mice. CONCLUSION: AT-RvD1 treatment administered post-disease onset reduces T helper 17 cells and successfully restores salivary gland function in a SS mouse model with variable effects noted by sex, thus warranting further examination of both the causes for the sex differences and the mechanisms responsible for the observed treatment effect.

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.

Activation of Peptidylarginine Deiminase in the Salivary Glands of Balb/c Mice Drives the Citrullination of Ro and La Ribonucleoproteins.

The goal of the present study was to determine whether peptidylarginine deiminase PAD2 and PAD4 enzymes are present in Balb/c mouse salivary glands and whether they are able to citrullinate Ro and La ribonucleoproteins. Salivary glands from Balb/c mice were cultured in DMEM and supplemented with one of the following stimulants: ATP, LPS, TNF, IFNγ, or IL-6. A control group without stimulant was also evaluated. PAD2, PAD4, citrullinated peptides, Ro60, and La were detected by immunohistochemistry and double immunofluorescence. PAD2 and PAD4 mRNAs and protein expression were detected by qPCR and Western blot analysis. PAD activity was assessed using an antigen capture enzyme-linked immunosorbent assay. LPS, ATP, and TNF triggered PAD2 and PAD4 expression; in contrast, no expression was detected in the control group (p < 0.001). PAD transcription slightly increased in response to stimulation. Additionally, PAD2/4 activity modified the arginine residues of a reporter protein (fibrinogen) in vitro. PADs citrullinated Ro60 and La ribonucleoproteins in vivo. Molecular stimulants induced apoptosis in ductal cells and the externalization of Ro60 and La ribonucleoproteins onto apoptotic membranes. PAD enzymes citrullinate Ro and La ribonucleoproteins, and this experimental approach may facilitate our understanding of the role of posttranslational modifications in the pathophysiology of Sjögren's syndrome.

[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.

Therapeutic effect of Zeng Ye decoction on primary Sjögren's syndrome via upregulation of aquaporin­1 and aquaporin­5 expression levels.

The aim of this study was to investigate the curative effect of Zeng Ye decoction on primary Sjögren's syndrome (pSS) and further explore its underlying mechanism involving aquaporin (AQP)­1 and AQP­5. The pSS model was established based on the immune induction method, and the saliva flow, submandibular gland index, morphological structures of salivary glands, and AQP­1 and AQP­5 protein expression levels in the salivary glands were determined. The saliva flow and the submandibular gland index were significantly reduced in the model group (P<0.01, compared with those in the control group), and significantly increased following interferon (IFN), Zeng Ye decoction extraction (ZYE) and Zeng Ye decoction (ZY) treatment (P<0.01, compared with those of the model group). Submandibular gland atrophy, fibrous tissue hyperplasia and multiple focal lymphocytic infiltration were observed in the model group and were attenuated when subjected to IFN, ZYE and ZY treatment. The AQP­1 and AQP­5 expression levels increased following IFN, ZYE and ZY treatment (P<0.01, compared with those of the model group), particularly in the ZYE­35 group. This result indicated that ZYE had a significant protective effect on pSS via upregulation of the expression levels of AQP­1 and/or AQP­5. However, the AQP­1 expression levels increased and the AQP­5 expression levels decreased in the model groups compared with those in the control group, which indicated different regulatory pathways of the salivary gland damage on the basis of AQP­1 and AQP­5. This study provided a significant reference for the prevention and treatment of pSS.

[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.

Secreted semaphorin 5A activates immune effector cells and is a biomarker for rheumatoid arthritis.

OBJECTIVE: To investigate the role of the multifunctional protein semaphorin 5A (Sema5A) in modulating cellular immune responses and as a biomarker in rheumatoid arthritis (RA). METHODS: A soluble form of recombinant Sema5A was used to assess its effect on the functions of primary T cells and natural killer (NK) cells isolated from the peripheral blood of healthy donors. Cell proliferation and expression of transcription factors were determined by flow cytometry. Cytokine secretion was analyzed using Luminex technology. Serum samples obtained from 145 patients with RA and control serum samples obtained from healthy individuals or patients with non-RA rheumatic diseases were analyzed for the presence of secreted Sema5A, using enzyme-linked immunosorbent assays and immunoblotting. RESULTS: Soluble Sema5A strongly increased T cell and NK cell proliferation and induced the secretion of proinflammatory Th1/Th17 cytokines. Accordingly, Sema5A stimulation caused significant up-regulation of T-bet and retinoic acid receptor-related orphan nuclear receptor γt levels in T cells. In addition, significantly elevated levels of secreted Sema5A were detected in the serum of patients with RA compared with control serum. Sema5A levels were highest in patients with RA who were positive for the RA biomarker anti-cyclic citrullinated peptide (P < 0.001 versus patients with systemic lupus erythematosus and patients with Sjögren's syndrome) and correlated with the levels of rheumatoid factor. CONCLUSION: Soluble Sema5A is a potent activator of T cells and NK cells in vitro, and high serum levels of Sema5A are associated with RA. Taken together, the results indicate that Sema5A contributes to the pathogenesis of RA through antigen-independent T cell and NK cell activation. Hence, Sema5A is a promising complementary biomarker for the diagnosis of RA.

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 prescriptions replenishing vital essence, tonifying Qi and activating blood on TNF-alpha, IL-1beta expressions in serum and submaxillary gland of NOD mice with Sjogren's syndrome].

OBJECTIVE: To observe effect of prescriptions replenishing vital essence, tonifying Qi and activating blood on expression of tumor necrosis factor-alpha (TNF-alpha) and interleukin-IP (IL-1beta) in serum and submaxillary gland of non-obese diabetic (NOD) mice with Sjogren's syndrome. METHOD: Thirty-two NOD mice were divided into four groups at random: the model group, the traditional Chinese medicine (TCM) group, the hydroxychloroquine group, the TCM and western medicine (WM) group, with 8 mice in each group. Eight Balb/C mice were taken as the normal normal control group. The TCM group was orally administered with 0.4 mL decoction replenishing vital essence, tonifying Qi and activating blood (100 g x kg(-1)) everyday; the hydroxychloroquine group were given 0.4 mL hydroxychloroquine (60 mg x kg(-1)) everyday; the TCM WM group were given 0.4 mL decoction, replenishing vital essence tonifying Qi and activating blood (50 g x kg(-1)) and hydroxychloroquine (60 mg x kg(-1)) everyday. Mice were sacrificed after eight weeks, and their arterial blood and tissues of submaxillary gland were collected. The levels of TNF-alpha, IL-1beta in serum were detected by ELISA. Expressions of TNF-alpha, IL-1beta protein in submaxillary gland were detected by immunohisto-chemistry. RESULT: Compared with other groups, TNF-alpha, IL-1beta in serum and submaxillary gland in the model group were higher (P < 0.05). The normal group showed lower serum TNF-alpha level than other groups (P < 0.05), but without statistical significance compared with the TCM group. IL-1beta in serum in the TCM group and the TCM WM group were lower than that of the hydroxychloroquine group (P < 0.05), but without statistical significance compared with the normal group. TNF-alpha protein expression in the TCM group and the TCM WM group showed no significant difference compared with the normal group, whereas the TCM WM group were notably lower than that of the hydroxychloroquine group (P < 0.05). IL-1beta expression in the TCM WM group showed no significant difference compared with the normal group. CONCLUSION: The decoction replenishing vital essence, tonifying Qi and activating blood can decrease the levels of TNF-alpha, IL-1beta in serum and submaxillary gland of NOD mice with Sjogren's syndrome. It may improve pathological damage of submaxillary gland by regulating Th1/Th2 cell factors, in order to achieve the therapeutic effect on SS.

Sex steroids in Sjögren's syndrome.

The purpose of the review is to consider pathomechanisms of Sjögren's syndrome (SS), which could explain the female dominance (9:1), the most common age of onset (40-50 years) and targeting of the exocrine glands. Estrogens seem to specifically protect secretory glandular acinar cells against apoptosis whereas lack of estrogens during menopause and climacterium specifically leads to increased apoptosis of the exocrine secretory cells. Male gonads produce testosterone and convert it in exocrine glands to dihydrotesterosterone (DHT), which is anti-apoptotic and protects against acinar cell apoptosis. Estrogen-deficient women need to produce dehydroepiandrosterone (DHEA) in the adrenal glands and convert it to DHT in exocrine glands in a complex and branching reaction network in which individual enzymatic reactions are catalyzed in forward and backward directions by a myriad of different isoforms of steroidogenic enzymes. Tailoring DHT in peripheral tissues is much more complex and vulnerable in women than in men. In SS the intracrine steroidogenic enzyme machinery is deranged. These endo-/intracrine changes impair acinar remodeling due to impaired integrin α1ß1 and integrin α2ß1 expression so that the intercalated duct progenitor cells are unable to migrate to the acinar space, to differentiate to secretory acinar cells upon contact with laminin-111 and laminin-211 specifically found in the acinar basement membrane. The disarranged endo-/intracrine estrogen/androgen balance induces acinar cells to release microparticles and apoptotic bodies and to undergo apoptotis and/or anoikis. Membrane particles contain potential autoantigens recognized by T- (TCRs) and B-cell receptors (BCRs) and danger-associated molecular patterns (DAMPs) recognized by Toll-like receptors (TLRs). In membrane particles (or carrier-complexes) antigen/adjuvant complexes could stimulate professional antigen capturing, processing and presenting cells, which can initiate auto-inflammatory and autoimmune cascades, break the self-tolerance and finally lead to SS.

Dendrobium candidum extract increases the expression of aquaporin-5 in labial glands from patients with Sjögren's syndrome.

This study aimed to investigate the mechanism of Dendrobium candidum extract in promoting expression of aquaporin-5 for treatment of Sjögren's syndrome (SS). Sixteen patients with SS suffered from deficient secretion of saliva due to an autoimmune destruction of salivary glands leading to dry mouth symptoms (xerostomia). However, glandular dysfunction also occurred without destruction. Based upon its abnormal distribution in SS salivary glands, a potential role of the water channel protein aquaporin-5 (AQP-5) in the pathogenesis of SS was proposed. After oral administration of D. candidum extracted liquid (DCEL) for 1 week, saliva and salivary gland biopsies from labial glands of patients were collected and examined by employing immunoreactivity and immunohistochemistry techniques. Results showed that salivary secretion increased by about 65% in patients treated with DCEL as compared with the control group. Higher labeling indices (percentage of acinus area immunoreactive for AQP-5) in the biopsies were found in SS patients who had taken DCEL. This study demonstrated that D. candidum would regulate the expression of AQP-5 in labial glands of SS patients and thereby promoted secretion of saliva to improve dry mouth symptoms.

Salivary resistin reflects local inflammation in Sjögren's syndrome.

OBJECTIVE: To assess the role of resistin in primary Sjögren's syndrome (pSS) and its relation to local inflammation. METHODS: Blood and saliva were collected from 37 patients with pSS (duration of symptoms 12.6+/-1 yrs) and 32 healthy controls. Expression of resistin in salivary glands was visualized immunohistologically, and levels of resistin were detected by ELISA. Levels of resistin were evaluated at baseline and following oral dehydroepiandrosterone (DHEA) treatment (50 mg/day). The effect of DHEA treatment on the secretion of resistin was assessed in vitro in human leukocytes after challenge with insulin and lipopolysaccharide. RESULTS: Levels of resistin in saliva were significantly higher in patients with pSS than in controls, while circulating levels of resistin were similar in both groups. Resistin was expressed in the epithelial cells of striated ducts and in the lymphocytic foci. Resistin levels in saliva were related to the intensity of inflammation in the minor salivary glands of pSS patients. No changes of the levels of resistin in blood or saliva were observed during DHEA treatment. Exposure of naive leukocytes to DHEA in vitro induced significant expression of resistin compared to nonstimulated peripheral blood mononuclear cells (p=0.031). CONCLUSION: We showed that levels of resistin are upregulated locally in the salivary glands of patients with pSS; and that the levels of resistin correspond to the intensity of lymphocytic inflammation in patients with pSS. We suggest that resistin is expressed in the salivary glands of patients with pSS and may be a driving factor of local inflammation.

Amelioration of lacrimal gland inflammation by oral administration of K-13182 in Sjögren's syndrome model mice.

Regulation of the adhesion of mononuclear cells to endothelial cells is considered to be a critical step for the treatment of inflammatory diseases, including autoimmune diseases. K-13182 was identified as a novel inhibitor for these adhesions. K-13182 inhibited the expression of vascular cell adhesion molecule-1 (VCAM-1, CD106) on human umbilical vein endothelial cells (HUVECs) and on mouse vascular endothelial cell line (MAECs) induced by tumour necrosis factor (TNF)-alpha. K-13182 also inhibited the adhesion of mononuclear cells to these HUVECs and MAECs, indicating that K-13182 suppressed these adhesions mediated by cellular adhesion molecules including VCAM-1. To evaluate the therapeutic effect in autoimmune disease model mice, K-13182 was orally administered to non-obese diabetic (NOD) mice as Sjögren's syndrome (SS) model mice. Severe destructive inflammatory lesions were observed in the lacrimal glands of vehicle-treated control mice; however, 8-week administration of K-13182 inhibited the mononuclear cell infiltration into the inflammatory lesions of the lacrimal glands. In K-13182-treated mice, the decrease in tear secretion was also prevented compared to the control mice. In addition, the apoptosis and the expression of FasL (CD178), perforin, and granzyme A was suppressed in the lacrimal glands of K-13182-treated mice. Therefore, K-13182 demonstrated the possibility of therapeutic efficacy for the inflammatory region of autoimmune disease model mice. These data reveal that VCAM-1 is a promising target molecule for the treatment of autoimmune diseases as a therapeutic strategy and that K-13182 has the potential as a new anti-inflammatory drug for SS.

Therapeutic effect of cevimeline on dry eye in patients with Sjögren's syndrome: a randomized, double-blind clinical study.

PURPOSE: Sjögren's syndrome (SS) is a systemic autoimmune disease characterized by salivary and lacrimal glandular destruction leading to symptoms of dry mouth and dry eye. Dryness can also occur in the absence of glandular destruction. Patients with SS have autoantibodies that bind to muscarinic acetylcholine receptors in the exocrine glands. Recently, a muscarinic acetylcholine receptor agonist, cevimeline, has been approved for use against symptoms of dry mouth in patients with SS. In this study, the efficacy of cevimeline in improving symptoms of dry eye was examined. DESIGN: Prospective, randomized, double-blind, multi-center clinical study. METHODS: Sixty patients were randomly assigned to three groups-placebo; cevimeline, 20 mg three times daily; or cevimeline, 30 mg three times daily-and received treatment for 4 weeks. Patients were evaluated before treatment, at week 2, at the end of treatment, and at the end of a 2- to 4-week follow-up period. RESULTS: Compared with the placebo, statistically significant differences were seen with cevimeline, 20 mg three times daily, in subjective symptoms, tear dynamics, condition of the corneoconjunctival epithelium, and global improvement rating. No difference was found among the three groups regarding the safe use of the drug. CONCLUSIONS: These results indicate that cevimeline, 20 mg three times daily, is safe and effective in improving symptoms of dry eye in patients with SS. Additional studies, with larger patient populations, are needed to further assess the effectiveness of cevimeline for dry eye.

Biochemical deficiency of pyridoxine does not affect interleukin-2 production of lymphocytes from patients with Sjögren's syndrome.

BACKGROUND: There is evidence that pyridoxine deficiency may alter the immune response. It is not known whether a deficiency of this vitamin is evident in subjects with primary Sjögren's syndrome (SS). OBJECTIVE: We studied whether subjects with primary SS showed a biochemical deficiency of pyridoxine, and if it is associated with abnormal production of interleukin-2 from lymphocytes stimulated in vitro with phytohemagglutinin (PHA). DESIGN: Two studies were conducted, (i) biochemical and nutritional assessments were performed in a cross-over study in subjects with primary SS, who were supplemented with 25 mg/day of pyridoxine or placebo for 3 months. After 1 month washout, they were supplemented for 3 months with placebo, (ii) patients with SS and matched controls received pyridoxine or placebo for 45 days, and a blood sample was obtained to study IL-2 production and expression in T-lymphocytes stimulated with PHA. RESULTS: Subjects with primary SS showed limited dietary intake of pyridoxine and biochemical deficiency of this vitamin assessed through the activation coefficient of the erythrocyte aspartate aminotransferase. The biochemical deficiency did not affect production nor mRNA expression of IL-2 from T-lymphocytes stimulated in vitro with PHA compared with the control group. Supplementation of subjects with primary SS with 25 mg/day with pyridoxine for 45 days did not produce any significant change as compared to those patients supplemented with placebo. CONCLUSIONS: Subjects with primary SS showed biochemical deficiency of pyridoxine, possibly due to limited intake of this vitamin which was corrected by supplementation with pyridoxine. However, IL-2 production and mRNA expression from stimulated lymphocytes were unaffected by supplementation, probably because the deficiency was not severe enough to affect the immune system. SPONSORSHIP: This work was supported by the National Council of Science and Technology (CONACYT), Mexico, grant no. 212226-5-0902PM.