IL-17A plays an important role in the pathology of psoriasis and psoriatic arthritis (PsA). However, the pathogenic association between the skin and joint manifestations in PsA is not completely understood. In this study, we initially observed that IL-17A and FGF7 induced endochondral ossification in the mouse entheseal histoculture. Importantly, the responses of endochondral ossification by IL-17A stimulation were strongly inhibited by the treatment of a blocking antibody to FGF receptor 2IIIb, which is the receptor of FGF7, suggesting that FGF7 acts as a downstream factor of IL-17A in the endochondral ossification in the culture. Next, using the animal PsA model, the administration of an anti-FGF receptor 2IIIb antibody resulted in significant suppression of ankylosing enthesitis but not dermatitis. Collectively, our findings indicate that augmented IL-17A in PsA dermatitis induces the elevation of FGF7 levels in joint enthesis and results in a non-redundant role of FGF7 signaling in the development of ankylosing enthesitis in PsA.
PDF file - 725K, The effects of 4NQO treatment on the body weights of wild-type, Keap1-KD and Nrf2-KO mice
PDF file - 48K, Hematological indices of wild-type and Nrf2-KO mice treated with 4NQO
Background: Methotrexate (MTX) is the most commonly used disease modifying anti-rheumatic drug. Gastrointestinal adverse effects are often observed during the treatment of rheumatoid arthritis; MTX is discontinued due to these adverse effects. It has been suspected that dietary factors may modulate gastrointestinal adverse effects of MTX, but it remains unresolved. In the present study, we tried to reveal the effects of the dietary factors on the gastrointestinal toxicity of MTX. Methods: C57BL/6J male mice were fed normal chow (NC) or high fat high sucrose diet (HFHSD) for 14 days before the gavage administration of MTX (3mg/kg/day) and survival rate and body weight were observed. Effects of high fat diet, high sucrose diet, high fat high sucrose soybean diet (casein was replaced by soybean derived protein), folinic acid (2.6mg/kg/day), and omega-3 fatty acid (1500mg/kg/day) were evaluated. HFHSD was changed to NC 24h before starting administration of MTX. Mice were given vancomycin (0.5g/L) in their drinking water. Results: The administration of MTX significantly decreased survival rates
Background: Dimethyl fumarate (DMF), a nuclear factor erythroid 2-related factor 2 (Nrf2) activator, has been proven effective for the systemic treatment of multiple sclerosis. The aim of this study is to evaluate the anti-inflammatory effects of Nrf2 activators on human renal mesangial cells (HRMCs) and the development of lupus nephritis (LN) in mice.Methods: To assess Nrf2 activation in vitro, HRMCs were treated with safe doses of Nrf2 activators and prednisolone. The expression levels of Nrf2 and its target genes were measured using quantitative reverse transcription PCR and enzyme-linked immunosorbent assay. The anti-inflammatory effects of these compounds were assessed by measuring tumor necrosis factor alpha-induced cytokine secretion. Experimental LN was induced in female BALB/c mice by a single intraperitoneal injection of pristane. The urine albumin-to-creatinine ratio was measured at 20 weeks after injection. Pathological changes as well as protein and mRNA expression levels were assessed in the kidney obtained at the experimental end point. Oral administration of DMF or prednisolone to these mice was initiated after pristane injection.Results: Nrf2 activators such as sulforaphane and DMF showed anti-inflammatory effects in HRMCs, whereas glucocorticoid (prednisolone) showed partial effects. Moreover, DMF ameliorated the development of kidney diseases in pristane-induced LN mice, whereas glucocorticoid had no effect.Conclusions: Nrf2 activators showed stronger anti-inflammatory and organ-protective effects than glucocorticoid in the kidney. Thus, Nrf2 activators are potential therapeutic targets in glucocorticoid-resistant LN in humans.
BACKGROUNDLimited information is available regarding the lymphatic vasculature during pneumonia.OBJECTIVETo characterize lymphatic vasculatures in autopsied cadavers with pneumonia.METHODSParaffin-embedded lung tissues obtained from 20 autopsied cadavers with complicated pneumonia and 10 control cadavers without pneumonia were used for immunohistochemical analyses using primary antibodies against podoplanin, vascular endothelial growth factor receptor-3 (VEGFR-3), CD34, vascular endothelial growth factor (VEGF)-C, VEGF-D, CD73, and CD163.RESULTSThere was no difference in the vascular density of podoplanin+ usual lymphatics between the individuals with and without pneumonia. In half of the cadavers with pneumonia, however, a network of podoplanin+ cells lying together in a side-by-side bead-like arrangement appeared along the alveolar septa; however, this was absent in the control cadavers. The podoplanin+ cells in the network were characterized by a weaker expression of podoplanin, relative to usual lymphatics, and the occasional presence of ductal structures. Although podoplanin+ cells were not coexpressed with VEGFR-3, a part of the network was connected to CD73+ afferent lymphatics. The network showed an intertwined relationship with CD34+ capillaries, suggesting that the network represents lymphatic capillaries. The number of CD163+ macrophages was significantly increased in individuals with the network than those without the network, while a significant decrease in neutrophils was observed. VEGF-C expressed in CD163+ macrophages and type II epithelial cells was observed in the cadavers with the network.CONCLUSIONThe development of lymphatic capillary networks along the alveolar septa rather than the usual lymphangiogenesis was noted in autopsied individuals with pneumonia.
Ankylosis is a major pathological manifestation of spondyloarthropathy. The aim of this study was to evaluate the effects of anti-IL-17 therapy on spontaneous ankylosing enthesitis in mice. In this study, we used male DBA/1 mice as a spontaneous ankylosis model. Serum IL-17 concentrations were determined using enzyme-linked immunosorbent assay. Male DBA/1 mice from different litters were mixed and caged together preceding the treatment at 10 weeks (wk) of age (prophylaxis) or 21 wk of age (intervention). Treatment with anti-IL-17 antibodies or saline was initiated after caging in groups of mice and administered weekly. The onset of tarsal ankylosis was assessed by ankle swelling and histopathological examination. Pathological changes and mRNA expression levels were assessed in joints and ears obtained at the experimental end-point. We found that circulating IL-17 increased with the onset of ankylosis in male DBA/1 mice, coinciding with the onset of dermatitis. The symptoms of dermatitis corresponded to the pathological characteristics of psoriasis: acanthosis with mild hyperkeratosis, scaling, epidermal microabscess formation and augmented expression of K16, S100A8 and S100A9. Prophylactic administration of anti-IL-17 antibodies significantly prevented the development of both ankylosis and dermatitis in male DBA/1 mice caged together. On the other hand, administration of anti-IL-17 antibodies after disease onset had a lesser but significant effect on ankylosis progression but did not affect dermatitis progression. In conclusion, IL-17 is a key mediator in the pathogenic process of tarsal ankylosis and psoriasis-like dermatitis in male DBA/1 mice caged together. Thus, IL-17 is a potential therapeutic target in ankylosing enthesitis and psoriasis in humans.
Activated macrophages have been classified into classical (M1) and alternative (M2) macrophages. We aimed to establish a method to yield enough number of macrophages to analyze their molecular, biological and immunological functions. We used drugs; adjuvant albumin from chicken egg whites--Imject Alum (OVA-Alum) and OVA Complete Freund Adjuvant (OVA-CFA), to induce macrophages to M2 and M1 respectively. We analyzed the phenotype of purified macrophages induced under these immune conditions, using flow cytometry (FACS) to detect cell-surface molecules and the enzyme-linked immunosorbent assay (ELISA) was used to detect cytokines. The cDNA microarray was employed to measure changes in expression level of cell surface protein between M1 and M2 macrophages. Phenotype analysis of purified macrophages, induced under these immune conditions, showed macrophages induced by OVA-Alum was almost M2 while the proportion of M1 macrophages induced by OVA-CFA was significantly higher. The results also showed higher expression level of macrophage galactose N- acetyl-galactosamine specific lectin-2 protein (MGL1/2-PE), a known M2 macrophage marker, on the surface of Alum-induced macrophages. On the basis of these preliminary data, ELISA results revealed that after macrophage stimulation with lipopolysaccharides (LPS), the level of interleukin (IL)-10 produced by Alum- induced macrophages was higher than the level of IL-10 produced by CFA-induced macrophages. In contrast, the level of tumor necrosis factor-alpha (TNF-α) produced by CFA-induced macrophages was higher than Alum-induced macrophages. The cDNA microarray confirmed previous results and suggest immunoglobulin-like type 2 receptor alpha (Pilra) as a new marker for M1, macrophage galactose N-acetylgalactosamine-specific lectin 2 (Mgl2) as M2 macrophages marker.
Cardio-facio-cutaneous (CFC) syndrome is one of the 'RASopathies', a group of phenotypically overlapping syndromes caused by germline mutations that encode components of the RAS-MAPK pathway. Germline mutations in BRAF cause CFC syndrome, which is characterized by heart defects, distinctive facial features and ectodermal abnormalities. To define the pathogenesis and to develop a potential therapeutic approach in CFC syndrome, we here generated new knockin mice (here Braf(Q241R/+)) expressing the Braf Q241R mutation, which corresponds to the most frequent mutation in CFC syndrome, Q257R. Braf(Q241R/+) mice manifested embryonic/neonatal lethality, showing liver necrosis, edema and craniofacial abnormalities. Histological analysis revealed multiple heart defects, including cardiomegaly, enlarged cardiac valves, ventricular noncompaction and ventricular septal defects. Braf(Q241R/+) embryos also showed massively distended jugular lymphatic sacs and subcutaneous lymphatic vessels, demonstrating lymphatic defects in RASopathy knockin mice for the first time. Prenatal treatment with a MEK inhibitor, PD0325901, rescued the embryonic lethality with amelioration of craniofacial abnormalities and edema in Braf(Q241R/+) embryos. Unexpectedly, one surviving pup was obtained after treatment with a histone 3 demethylase inhibitor, GSK-J4, or NCDM-32b. Combination treatment with PD0325901 and GSK-J4 further increased the rescue from embryonic lethality, ameliorating enlarged cardiac valves. These results suggest that our new Braf knockin mice recapitulate major features of RASopathies and that epigenetic modulation as well as the inhibition of the ERK pathway will be a potential therapeutic strategy for the treatment of CFC syndrome.
Pathogenic effects of reactive oxygen species (ROS) in the salivary glands of patients with Sjögren's syndrome have been demonstrated. Epigallocatechin gallate (EGCG), which is a catechin derivative and exhibits potent antioxidant activity, has been reported to ameliorate autoimmune sialadenitis in a murine model, but the mechanism underlying its protective action remains to be investigated. Herein, we examined the effects of EGCG administration to MRL/MpJ-lpr/lpr (MRL-Fas(lpr)) mice on disease severity of autoimmune sialadenitis and protein expression levels of 11 sialadenitis-related molecules - heme oxygenase-1 (HO-1) (antioxidant); thymidine glycol (marker of DNA damage); gp91phox/NADPH oxidase 2 (prooxidant); single-stranded DNA (ssDNA) and cleaved caspase 3 (apoptotic cell markers); p53 and Bax (proapoptotic molecules); Bcl-2 (antiapoptotic molecule); SSA/Ro, SSB/La, and Ifi202 (autoantigens). In EGCG-treated mice, the severity of sialadenitis was substantially decreased. Expression levels of thymidine glycol, gp91phox, ssDNA, cleaved caspase 3, p53, Bax, SSA/Ro, SSB/La, and Ifi202 in duct epithelial cells of salivary glands from EGCG-treated mice were reduced, whereas HO-1 and Bcl-2 were overexpressed. Results of correlation analysis among sialadenitis severity and 11 sialadenitis related-molecules, and those of partial correlation analysis between apoptotic related-molecules and sialadenitis severity or HO-1 suggested that the consecutive pathogenic cycle including activated autoimmune reactions, ROS synthesis, DNA damage and p53-dependent apoptosis was associated with the pathogenesis of autoimmune sialadenitis in MRL-Fas(lpr) mice. Overexpression of HO-1 and Bcl-2 mediated by EGCG blocked this pathogenic cycle, subsequently resulting in the inhibition of ROS-mediated DNA damage and apoptosis, and protected salivary gland tissues from oxidative stress. Clinically, green tea catechin may have therapeutic efficacy for Sjögren's syndrome.
Abstract Cancers in the upper aerodigestive tract, including cancers of the tongue and the esophagus, are the third leading cause of cancer-related deaths in the world, and oxidative stress is well recognized as one of the major risk factors for carcinogenesis. The Keap1–Nrf2 system plays a critical role in cellular defense against oxidative stress, but little is known about its association with upper aerodigestive tract carcinogenesis. In this study, we examined whether loss of Nrf2-function exacerbates carcinogenesis by using an experimental carcinogenesis model that is induced by 4-nitroquinoline-1-oxide (4NQO). We found that Nrf2-knockout (Nrf2-KO) mice were more susceptible to 4NQO-induced tongue and esophageal carcinogenesis than wild-type mice, which suggests that Nrf2 is important for cancer prevention. We also examined how the suppression of Keap1 function or the induction of Nrf2 activity affected 4NQO carcinogenesis. Keap1-knockdown (Keap1-KD) mice were resistant to 4NQO-induced tongue and esophageal carcinogenesis. Importantly, no growth advantage was observed in tongue tumors in the Keap1-KD mice. These results show that the Keap1–Nrf2 system regulates an important defense mechanism against upper aerodigestive tract carcinogenesis. In addition to several important functions of Nrf2 that lead to cancer chemoprevention, we hypothesize that a mechanical defense of thickened keratin layers may also be a chemopreventive factor because thickened, stratified, squamous epithelium was found on the tongue of Keap1-KD mice. Cancer Prev Res; 6(2); 149–59. ©2012 AACR.
Systemic lupus erythematosus is considered to be under the control of polygenic inheritance, developing according to the cumulative effects of susceptibility genes with polymorphic alleles; however, the mechanisms underlying the roles of polygenes based on functional and pathological genomics remain uncharacterized. In this study, we substantiate that a CD72 polymorphism in the membrane-distal extracellular domain impacts on both the development of glomerulonephritis and vasculitis in a lupus model strain of mice, MRL/MpJ-Faslpr, and the reactivity of BCR signal stimulation. We generated mice carrying a bacterial artificial chromosome transgene originating from C57BL/6 (B6) mice that contains the Cd72b locus (Cd72B6 transgenic [tg]) or the modified Cd72b locus with an MRL-derived Cd72c allele at the polymorphic region corresponding to the membrane-distal extracellular domain (Cd72B6/MRL tg). Cd72B6 tg mice, but not Cd72B6/MRL tg mice, showed a significant reduction in mortality following a marked improvement of disease associated with decreased serum levels of IgG3 and anti-dsDNA Abs. The number of splenic CD4−CD8− T cells in Cd72B6 tg mice was decreased significantly in association with a reduced response to B cell receptor signaling. These results indicate that the Cd72 polymorphism affects susceptibility to lupus phenotypes and that novel functional rescue by a bacterial artificial chromosome transgenesis is an efficient approach with wide applications for conducting a genomic analysis of polygene diseases.
Acute necrotizing encephalopathy (ANE) is characterized by symmetrical brain necrosis, suggested to be due to breakdown of the blood–brain barrier (BBB). We experienced a rare case of ANE complicated with systemic lupus erythematosus (SLE), and found that the patient’s serum (V10-5) had binding activity to human umbilical vein endothelial cells (HUVECs). By SARF (Serological identification system for Autoantigens using a Retroviral vector and Flow cytometry) method using V10-5 IgG, a clone bound to V10-5 IgG was isolated. This cell clone was integrated with cDNA identical to EphB2 , which plays critical roles in neuronal cells and endothelial cells. HUVECs and human brain microvascular endothelial cells expressed EphB2 and the V10-5 IgG bound specifically to EphB2 -transfected cells. Anti-EphB2 antibody was not detected in other SLE patients without ANE. In this report, we identified EphB2 as a novel autoantigen, and anti-EphB2 antibody may define a novel group of brain disorders. Anti-EphB2 antibody can interfere not only with endothelial cells including those of the BBB (acting as an anti-endothelial cell antibody), but also neuronal cells (acting as an anti-neuronal antibody) if the BBB has been breached. Future studies should determine the clinical prevalence and specificity of anti-EphB2 antibody, and the molecular mechanisms by which anti-EphB2 antibody mediates neuronal and vascular pathological lesions.
Event Abstract Back to Event An innovative method to identify autoantigens expressed on the cell surface: SARF Tsuyoshi Shirai1, Hiroshi Fujii1*, Masao Ono1, Ryu Watanabe1, Tomonori Ishii1 and HIdeo Harigae1 1 Tohoku University, Japan Background: Although autoantibodies against integral membrane proteins are generally accepted as pathogenic, identification of such molecules was difficult by conventional methods, including proteomics. Anti-endothelial cell antibodies (AECAs) are important but unsolved autoantibodies that target cell-surface autoantigens and may play roles in vascular lesions in collagen diseases. To specifically identify cell-surface autoantigens, we constructed a Serological identification system for Autoantigens using a Retroviral vector and Flow cytometry (SARF). Methods: A cDNA library of human umbilical vein endothelial cells (HUVEC) was retrovirally transfected into a rat myeloma cell line, from which AECA-binding clones were sorted by flow cytometry. Integrated cDNA of the cells was analyzed to identify an autoantigen, and the functional significance of the autoantibody was analyzed. Results: Distinct AECA-positive clones were isolated using different serum IgG from patients with AECA-positive collagen diseases, including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). By DNA sequencing and microarray, we identified three cDNA inserted to each clone, which were fibronectin leucine-rich transmembrane protein 2 (FLRT2) and Pk (Gb3/CD77) from SLE, and intercellular adhesion molecule 1 (ICAM-1) from RA. HUVEC expressed these proteins and the prototype AECA IgGs bound specifically to these molecules-transfected cells. Anti-FLRT2 antibody induced complement-dependent cytotoxicity against FLRT2-expressing cells. Conclusion: Using SARF, we successfully identified three membrane proteins as targets for AECAs. SARF is useful for specific identification of autoantigens expressed on the cell surface. By thorough identification of cell-surface autoantigens, it may be possible to achieve a comprehensive understanding and the development of more specific intervention strategies of autoantibody-mediated injury. References 1. Shirai T, Fujii H, Ono M, Nakamura K, Watanabe R, Tajima Y, Takasawa N, Ishii T, Harigae H. (2012). A novel autoantibody against fibronectin leucine-rich transmembrane protein 2 expressed on the endothelial cell surface identified by retroviral vector system in systemic lupus erythematosus. Arthritis Res Ther. 14: R157. 2. Shirai T, Fujii H, Ono M, Watanabe R, Ishii T, Harigae H. (2013). An innovative method to identify autoantigens expressed on the endothelial cell surface: Serological identification system for autoantigens using a retroviral vector and flow cytometry (SARF). Clin Dev Immunol. Article ID 453058. Keywords: Autoantibody, Collagen Diseases, ICAM-1, pk, anti-endothelial cell antibody Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Translational immunology and immune intervention Citation: Shirai T, Fujii H, Ono M, Watanabe R, Ishii T and Harigae H (2013). An innovative method to identify autoantigens expressed on the cell surface: SARF. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00466 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 12 Apr 2013; Published Online: 22 Aug 2013. * Correspondence: Dr. Hiroshi Fujii, Tohoku University, Sendai, Japan, hfujii@med.tohoku.ac.jp Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Tsuyoshi Shirai Hiroshi Fujii Masao Ono Ryu Watanabe Tomonori Ishii HIdeo Harigae Google Tsuyoshi Shirai Hiroshi Fujii Masao Ono Ryu Watanabe Tomonori Ishii HIdeo Harigae Google Scholar Tsuyoshi Shirai Hiroshi Fujii Masao Ono Ryu Watanabe Tomonori Ishii HIdeo Harigae PubMed Tsuyoshi Shirai Hiroshi Fujii Masao Ono Ryu Watanabe Tomonori Ishii HIdeo Harigae Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.
Although costimulatory molecules have been shown to play crucial roles in the immune response, their involvement in the pathogenesis of Sjögren's syndrome is incompletely understood. In this study, we evaluated the relationship between the severity of spontaneous Sjögren's syndrome-like autoimmune sialadenitis in MRL/MpJ-lpr/lpr (MRL-Fas(lpr)) mice and the expression of 6 costimulatory molecules that play important roles in the immune response: CD80, CD86, OX40 ligand (OX40L), 4-1BB ligand (4-1BBL), glucocorticoid-induced TNF receptor-related protein ligand (GITRL), and B cell-activating factor of the tumor necrosis factor family (BAFF). Expression of the costimulatory molecules in the submandibular salivary glands of age-matched autoimmune MRL-Fas(lpr) mice and non-autoimmune MRL/MpJ-+/+(MRL/+) and C3H/HeJ-lpr/lpr (C3H-Fas(lpr)) mice was examined immunohistochemically and scored on a scale of 0 to 3. The severity of sialadenitis was evaluated histologically and scored on a scale of 0 to 3. We found that all of the costimulatory molecules were expressed in duct epithelial cells of salivary glands from MRL-Fas(lpr) mice, whereas immunoreactivity was absent or weak in the MRL/+ mice. The staining intensity for all 6 costimulatory molecules was significantly higher in the MRL-Fas(lpr) than in the MRL/+ mice. Partial correlation analysis was performed to assess the degree of association between costimulatory molecule staining scores and disease scores, which clearly revealed a significant correlation for only GITRL and 4-1BBL. These molecules showed negligible immunoreactivity in the submandibular glands of C3H-Fas(lpr) mice, suggesting that their expression was independent of the Fas(lpr) mutation. In conclusion, the expression of GITRL and 4-1BBL in salivary gland duct epithelial cells is associated with background genes in the MRL strain, but not with the Fas(lpr) mutation itself, and contributes significantly to the pathogenesis of autoimmune sialadenitis in MRL-Fas(lpr) mice. These results suggest that GITRL and 4-1BBL may be effective targets for the development of therapies for Sjögren's syndrome.
Sjögren's syndrome (SS) is an autoimmune disease characterized by exocrinopathy that leads to dry eye and mouth. Although lymphocyte infiltration into exocrine glands and the generation of autoantibodies have been reported in SS, its pathogenic mechanism remains elusive. Here, we show that mice lacking the transcriptional regulator IκB-ζ developed SS-like inflammation characterized by lymphocyte-infiltrated dacryoadenitis and SS-associated autoantibodies. In particular, epithelial cells, but not hematopoietic cells, lacking IκB-ζ were essential for the development of inflammation. IκB-ζ-deficient epithelial cells in the lacrimal glands exhibited enhanced apoptosis even in the absence of lymphocytes. Administration of caspase inhibitors ameliorated the inflammation, indicating the critical role of caspase-mediated apoptosis. Furthermore, epithelial cell-specific STAT3-deficient mice developed SS-like inflammation with impaired IκB-ζ expression in the lacrimal glands. Thus, this study reveals a pathogenic mechanism of SS in which dysfunction of epithelial cells caused by disruption of STAT3-mediated IκB-ζ induction elicits the activation of self-reactive lymphocytes.
Autoantibodies against integral membrane proteins are usually pathogenic. Although anti-endothelial cell antibodies (AECAs) are considered to be critical, especially for vascular lesions in collagen diseases, most molecules identified as autoantigens for AECAs are localized within the cell and not expressed on the cell surface. For identification of autoantigens, proteomics and expression library analyses have been performed for many years with some success. To specifically target cell-surface molecules in identification of autoantigens, we constructed a serological identification system for autoantigens using a retroviral vector and flow cytometry (SARF). Here, we present an overview of recent research in AECAs and their target molecules and discuss the principle and the application of SARF. Using SARF, we successfully identified three different membrane proteins: fibronectin leucine-rich transmembrane protein 2 (FLRT2) from patients with systemic lupus erythematosus (SLE), intercellular adhesion molecule 1 (ICAM-1) from a patient with rheumatoid arthritis, and Pk (Gb3/CD77) from an SLE patient with hemolytic anemia, as targets for AECAs. SARF is useful for specific identification of autoantigens expressed on the cell surface, and identification of such interactions of the cell-surface autoantigens and pathogenic autoantibodies may enable the development of more specific intervention strategies in autoimmune diseases.
In this study, we administered EGCG to MRL/lpr mice from age of 8–16 weeks for 57 days, and thereafter examined immunohistochemically the expression of thymidine glycol (TG), heme oxygenase-1 (HO-1) and ssDNA in autoimmune sialadenitis of submandibular glands of ten EGCG-administered MRL/lpr mice compared with those of six no EGCG-conspecifics controls using streptavidin-biotin methods. TG is formed in nuclei when ROS oxidizes deoxy thymidine and HO-1, one of antioxidants, is induced by green tea catechin. We found that EGCG-administered MRL/lpr mice showed attenuated expression of TG and ssDNA and enhanced HO-1 immunostaining in salivary gland duct epithelial cells. Furthermore, the significant positive correlation existed between TG and ssDNA expression, and the significant inverse correlation was noticed between TG and HO-1 expression. In conclusion, our results indicate that EGCG ameliorates the detrimental influences of oxidative stress on salivary gland tissues in autoimmune sialadenitis of MRL/lpr mice.