scholarly journals Detection of Novel Biomarkers in Saliva of Rheumatoid Arthritis Model Mice by Proteomics and Pathological Analysis

Author(s):  
Wakako Sakaguchi ◽  
Juri Saruta ◽  
Shinya Fuchida ◽  
Yuko Yamamoto ◽  
Masahiro To ◽  
...  

Rheumatoid arthritis (RA) is an autoimmune disease in which joints are gradually de-stroyed, and early diagnosis and treatment before joint deformation or destruction is im-portant. The detection of novel RA biomarkers in saliva may facilitate the early detection of RA before the onset of disease. In this study, we conducted a comprehensive proteomic analysis of salivary proteins from RA model mice. Proteins were identified by Western blotting and enzyme-linked immunosorbent assay in serum, saliva, and ankle joints from DBA/1JJmsSlc mice, a model of rheumatoid arthritis. Ankle joints and submandibular glands were hematoxylin and eosin stained and immunostained, and the results were compared with those of control mice. Citrullinated α1 antitrypsin (A1AT, 46 kDa) was commonly detected in saliva, serum, and ankle joints of severe RA model mice, and was confirmed by proteome analysis. Western blotting detected a band corresponding to 46 kDa in serum, saliva and ankle joints, and immunostaining of ankle joints with A1AT an-tibody showed a strong positive signal in the synovium. In DBA/1JJmsSlc mice, not only cyclic citrullinated peptide antibodies but also A1AT may be involved in protein citrulli-nation and contribute to the development and severity of RA.

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Wei Qu ◽  
Ling Jiang ◽  
Guanhua Hou

Abstract Background Circular RNAs (circRNAs) are associated with rheumatoid arthritis (RA) development. The purpose of this study is to explore the function and mechanism of circRNA fragile mental retardation 2 (circ-AFF2) in the processes of rheumatoid arthritis fibroblast-like synoviocytes (RAFLSs). Methods Circ-AFF2, microRNA (miR)-650, and 2′,3′-cyclic nucleotide 3′-phosphodiesterase (CNP) levels were determined in synovial tissues of RA and RAFLSs by quantitative reverse transcription polymerase chain reaction or Western blotting. Cell proliferation, inflammatory response, apoptosis, caspase3 activity, migration, invasion, and epithelial-mesenchymal transition (EMT) were investigated using Cell Counting Kit-8 (CCK-8), enzyme-linked immunosorbent assay (ELISA), flow cytometry, Transwell, and Western blotting analyses. Dual-luciferase reporter, RNA immunoprecipitation (RIP), and pull-down assays were performed to assess the binding relationship. Results Circ-AFF2 expression level was enhanced in synovial tissues of RA and RAFLSs. Circ-AFF2 overexpression facilitated cell proliferation, inflammatory response, migration, invasion, and EMT and repressed apoptosis in RAFLSs. Circ-AFF2 downregulation played an opposite role. Circ-AFF2 targeted miR-650, and miR-650 downregulation reversed the effect of circ-AFF2 interference on RAFLS processes. CNP was targeted by miR-650, and circ-AFF2 increased CNP expression by regulating miR-650. MiR-650 overexpression constrained cell proliferation, inflammatory response, migration, invasion, and EMT and contributed to apoptosis by decreasing CNP in RAFLSs. Conclusion Circ-AFF2 promoted proliferation, inflammatory response, migration, and invasion of RAFLSs by modulating the miR-650/CNP axis.


2020 ◽  
Vol 21 (8) ◽  
pp. 734-740 ◽  
Author(s):  
Shou-di He ◽  
Ning Tan ◽  
Chen-xia Sun ◽  
Kang-han Liao ◽  
Hui-jun Zhu ◽  
...  

Background: Melittin, the major medicinal component of honeybee venom, exerts antiinflammatory, analgesic, and anti-arthritic effects in patients with Rheumatoid Arthritis (RA). RA is an inflammatory autoimmune joint disease that leads to irreversible joint destruction and functional loss. Fibroblast-Like Synoviocytes (FLS) are dominant, special mesenchymal cells characterized by the structure of the synovial intima, playing a crucial role in both the initiation and progression of RA. Objective: In this study, we evaluated the effects of melittin on the viability and apoptosis of FLS isolated from patients with RA. Methods: Cell viability was determined using CCK-8 assays; apoptosis was evaluated by flow cytometry, and the expression levels of apoptosis-related proteins (caspase-3, caspase-9, BAX, and Bcl-2) were also determined. To explore whether melittin alters inflammatory processes in RA-FLS, IL-1β levels were determined using an enzyme-linked immunosorbent assay (ELISA). Furthermore, we performed GFP-LC3 punctate fluorescence dot assays and western blotting (for LC3, ATG5, p62, and Beclin 1) to assess autophagy in RA-FLS. Results: Our results show that melittin can significantly impair viability, promote apoptosis and autophagy, and inhibit IL-1β secretion in RA-FLS. Conclusion: Melittin may be useful in preventing damage to the joints during accidental local stimulation.


2019 ◽  
Vol 19 (5) ◽  
pp. 342-348 ◽  
Author(s):  
Zhi-You Cai ◽  
Chuan-Ling Wang ◽  
Tao-Tao Lu ◽  
Wen-Ming Yang

Background:Liver kinase B1 (LKB1)/5’-adenosine monophosphate-activated protein kinase (AMPK) signaling, a metabolic checkpoint, plays a neuro-protective role in the pathogenesis of Alzheimer’s disease (AD). Amyloid-β (Aβ) acts as a classical biomarker of AD. The aim of the present study was to explore whether berberine (BBR) activates LKB1/AMPK signaling and ameliorates Aβ pathology.Methods:The Aβ levels were detected using enzyme-linked immunosorbent assay and immunohistochemistry. The following biomarkers were measured by Western blotting: phosphorylated (p-) LKB1 (Ser334 and Thr189), p-AMPK (AMPKα and AMPKβ1), synaptophysin, post-synaptic density protein 95 and p-cAMP-response element binding protein (p-CREB). The glial fibrillary acidic protein (GFAP) was determined using Western blotting and immunohistochemistry.Results:BBR inhibited Aβ expression in the brain of APP/PS1 mice. There was a strong up-regulation of both p-LKB1 (Ser334 and Thr189) and p-AMPK (AMPKα and AMPKβ1) in the brains of APP/PS1 transgenic mice after BBR-treatment (P<0.01). BBR promoted the expression of synaptophysin, post-synaptic density protein 95 and p-CREB(Ser133) in the AD brain, compared with the model mice.Conclusion:BBR alleviates Aβ pathogenesis and rescues synapse damage via activating LKB1/AMPK signaling in the brain of APP/PS1 transgenic mice.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 449.1-449
Author(s):  
S. Mizuki ◽  
K. Horie ◽  
K. Imabayashi ◽  
K. Mishima ◽  
K. Oryoji

Background:In the idividuals with genetic and enviromental risk factors, immune events at mucosal surfaces occur and may precede systemic autoimmunity. Anti-citrullinated protein antibodies (ACPA) are present in the serum for an average of 3-5 years prior to the onset of rheumatoid arthritis (RA) during an asymptomatic period. In ACPA-positivite individuals, the additional presence of RA-related risk factors appears to add significant power for the development of RA. To date, there have been few reports in which clinical courses of ACPA-positive asymptomatic individuals were investigated prospectively.Objectives:To observe the clinical time course of ACPA-positive healthy population for the development of RA.Methods:Healthy volunteers without joint pain or stiffness, who attended the comprehensive health screening of our hospital, were enrolled in this prospective observational study. The serum ACPA levels were quantified by Ig-G anti-cyclic citrullinated peptide enzyme-linked immunosorbent assay with levels > 4.4 U/mL considered positive. ACPA-positive subjects were followed by rheumatologists of our department clinically or a questionnaire sent by mail for screening to detect arthritis.Results:5,971 healthy individuals without joint symptons were included. Ninty-two (1.5%) were positive for ACPA. Of these, 19 (20.7%) developed RA and two were suspected as RA by mail questionnaire. Their average age were 58-years, and women were 68%. The average duration between the date of serum sampling and diagnosis was 10.7 months. ACPA-positive individuals who developed to RA had higher serum ACPA and Ig-M rheumatoid factor levels than ACPA-positive individuals who did not (P value by Mann-Whitney U test: 0.002, 0.005, respectively).Conclusion:Among ACPA-positive asymptomatic individuals, 20% developed RA. The higher titer of ACPA and Ig-M rheumatoid factor levels are risk factors for devoloping RA.Disclosure of Interests:None declared


Author(s):  
Omayma O. Abdelaleem ◽  
Nermeen A. Fouad ◽  
Olfat G. Shaker ◽  
Tarek I. Ahmed ◽  
Noha K. Abdelghaffar ◽  
...  

2021 ◽  
Vol 22 (4) ◽  
pp. 2141
Author(s):  
Srinu Tumpara ◽  
Elena Korenbaum ◽  
Mark Kühnel ◽  
Danny Jonigk ◽  
Beata Olejnicka ◽  
...  

The C-terminal-fragments of alpha1-antitrypsin (AAT) have been identified and their diverse biological roles have been reported in vitro and in vivo. These findings prompted us to develop a monoclonal antibody that specifically recognizes C-36 peptide (corresponding to residues 359–394) resulting from the protease-associated cleavage of AAT. The C-36-targeting mouse monoclonal Immunoglobulin M (IgM) antibody (containing κ light chains, clone C42) was generated and enzyme-linked immunosorbent assay (ELISA)-tested by Davids Biotechnologie GmbH, Germany. Here, we addressed the effectiveness of the novel C42 antibody in different immunoassay formats, such as dot- and Western blotting, confocal laser microscopy, and flow cytometry. According to the dot-blot results, our novel C42 antibody detects the C-36 peptide at a range of 0.1–0.05 µg and shows no cross-reactivity with native, polymerized, or oxidized forms of full-length AAT, the AAT-elastase complex mixture, as well as with shorter C-terminal fragments of AAT. However, the C42 antibody does not detect denatured peptide in SDS-PAGE/Western blotting assays. On the other hand, our C42 antibody, unconjugated as well as conjugated to DyLight488 fluorophore, when applied for immunofluorescence microscopy and flow cytometry assays, specifically detected the C-36 peptide in human blood cells. Altogether, we demonstrate that our novel C42 antibody successfully recognizes the C-36 peptide of AAT in a number of immunoassays and has potential to become an important tool in AAT-related studies.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yuhua Su ◽  
Yajing Liu ◽  
Chao Ma ◽  
Chunxiao Guan ◽  
Xiufen Ma ◽  
...  

Abstract Background Long non-coding RNA heart and neural crest derivatives expressed 2-antisense RNA 1 (HAND2-AS1) was found to be elevated in rheumatoid arthritis (RA) fibroblast-like synoviocytes (RA-FLSs). However, whether HAND2-AS1 functions as an exosomal lncRNA related to mesenchymal stem cells (MSCs) in RA progression is unknown. Methods The expression of HAND2-AS1, microRNA (miR)-143-3p, and tumor necrosis factor alpha-inducible protein 3 (TNFAIP3) was detected using quantitative real-time polymerase chain reaction and Western blot. Cell proliferation, apoptosis, migration, and invasion were detected using cell counting kit-8, flow cytometry, and wound healing and transwell assays. The levels of tumor necrosis factor-α (TNF-α) and interleukins (IL)-6 were analyzed using enzyme-linked immunosorbent assay. The level of phosphorylated-p65 was examined by Western blot. The binding interaction between miR-143-3p and HAND2-AS1 or TNFAIP3 was confirmed by the dual-luciferase reporter and RIP assays. Exosomes were isolated by ultracentrifugation and qualified by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blot. Results HAND2-AS1 was lowly expressed in RA synovial tissues, and HAND2-AS1 re-expression suppressed the proliferation, motility, and inflammation and triggered the apoptosis in RA-FLSs via the inactivation of NF-κB pathway. Mechanistically, HAND2-AS1 directly sponged miR-143-3p and positively regulated TNFAIP3 expression, the target of miR-143-3p. Moreover, the effects of HAND2-AS1 on RA-FLSs were partially attenuated by miR-143-3p upregulation or TNFAIP3 knockdown. HAND2-AS1 could be packaged into hMSC-derived exosomes and absorbed by RA-FLSs, and human MSC-derived exosomal HAND2-AS1 also repressed above malignant biological behavior of RA-FLSs. Conclusion MSC-derived exosomes participated in the intercellular transfer of HAND2-AS1 and suppressed the activation of RA-FLSs via miR-143-3p/TNFAIP3/NF-κB pathway, which provided a novel insight into the pathogenesis and treatment of RA.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 297.2-297
Author(s):  
Y. Akhverdyan ◽  
E. Papichev ◽  
В. Zavodovsky ◽  
L. Seewordova ◽  
J. Polyakova

Background:The main mechanism of the effect of fetuin-A (FeA) on bone metabolism is its ability to bind calcium and proteins of the TGF-β family. It has been proven that the optimal concentration of TGF-β is necessary for the differentiation of bone tissue, and a high concentration inhibits bone mineralization. Thus, adequate osteogenesis is based on a complex balance between FeA and TGF-β levels. It can be assumed that the determination of the FeA level in the blood of patients with rheumatoid arthritis (RA) will help to optimize the diagnosis and predict the severity of osteoporosis (OP).Objectives:to study the possibility of predicting the development of osteoporosis and osteoporetic fractures in patients with RA, depending on the level of FeA in blood serum.Methods:We examined two groups of patients (52 patients with RA complicated by OP, 58 patients with RA without OP) and 30 apparently healthy individuals. The age of the surveyed ranged from 18 to 72 years, the average duration of the disease was 7.53±0.89 years. In both groups, the FeA level was determined by an indirect enzyme-linked immunosorbent assay using a commercial test. Bone mineral density (BMD) was also measured in both groups (Lunar DPX-NT GE).Results:The average FeA level in the group of RA patients was lower than in the group of conventionally healthy individuals (731.21±109.9 μg/ml and 812.9±76.2 μg/ml, respectively; F=13.34; p=0,0004). The normal FeA level was calculated using the formula M±2σ in the group of apparently healthy individuals and ranged from 653.55 μg/ml to 972.19 μg/ml.A decreased level of FeA was found in 20 patients (86.96%) in the group of patients with OP and only in 3 (13.04%) patients with RA who did not suffer from OP (p<0.001). It can be concluded that patients with RA and a low concentration of FeA in the blood serum have a higher risk of developing OP.In the group of patients with normal FeA level, osteoporetic fractures were observed in 12 (13.79%) patients and were absent in 75 (86.21%) patients (p<0.001). Thus, RA patients with normal serum FeA levels have a lower risk of osteoporetic fractures.We also found a positive significant correlation between the level of FeA and BMD in the femoral neck area. In the group of patients with a reduced FeA level (23 people), the mean BMD values were 0.732±0.022 g/cm2, and in the group of patients with a normal FeA level (87 patients) - 0.890±0.014 g/cm2 (p<0.001, F=27.663). The obtained values are in agreement with the literature data on the effect of the serum FeA concentration on the BMD values.Conclusion:We consider it expedient to determine the serum FeA concentration in patients with RA. At a FeA level of 653.55 μg/ml and below, a higher risk of developing OP and osteoporetic fractures can be predicted. In this case, the patient is shown a standard examination for osteoporosis. At values of 653.55 μg/ml and above, a more expectant management of the patient is allowed. Thus, by determining the serum concentration of FeA, it is possible to implement an integrated approach to the patient and to optimize the schemes for the diagnosis of OP in patients with RA.Disclosure of Interests:None declared


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 461-461
Author(s):  
M. V. Sokolova ◽  
J. Rech ◽  
M. Hagen ◽  
G. Schett ◽  
U. Steffen (née Harre)

Background:Understanding key mechanisms of flare development and sustained remission is one of the acute goals in modern rheumatology. Anti-citrullinated protein antibodies (ACPA) are the most abundant and specific autoantibodies in rheumatoid arthritis (RA) patients. However, the impact of ACPA of IgA isotype is poorly defined. IgA ACPA were previously shown to have a higher percentage of IgA2 in comparison to total IgA; and a correlation between IgA2% ACPA with the DAS28 score was observed in a previous study [1]. Of note, IgA1 and IgA2 were shown to exhibit different effector functions, with IgA2 being pro-inflammatory, which might be the background for its role in RA [1].Objectives:We aimed to investigate, whether IgA ACPA could be used as a predictive factor for flare development in RA; and to look further into the changes in IgA ACPA levels in patients remaining in stable remission versus patients developing flare.Methods:We analysed serum of 111 patients from a multicentre randomized controlled trial ‘RETRO’. The study observational period was 12 months. Patients in the trial had to be in stable remission (DAS28-ESR<2.6) for a minimum of 6 months and were randomized into 3 different treatment arms: continuation of treatment, tapering by 50% or a gradual tapering until discontinuation [2]. IgA ACPA concentrations were measured with an enzyme-linked immunosorbent assay on CCP2-pre-coated plates.Results:60% of patients had IgG-ACPA. IgA ACPA levels were higher among the IgG-ACPA-positive patients (median 4.7 versus 2.24 µg/ml, p<0.0001). Baseline IgA1 and 2 ACPA levels were not different between patients who had a flare later on in the study period and those remaining in remission, showing no predictive value for flare development. However, the percentage of IgA2 in ACPA was correlating with the first registered DAS28 after flare (r=0.36, p=0.046). After the 12 months study period, IgA2 ACPA as well as IgA2% ACPA decreased significantly in patients who remained in stable remission by 17.5% (median, p<0.0001) and 13.6% (p=0.0006), respectively. By contrast, there was no significant change in IgA2 ACPA levels over time in patients who developed a flare. IgA1 ACPA levels remained stable over time. Disease management strategies did not seem to influence IgA ACPA levels in a specific way, as baseline levels were similar between patients on biological and conventional DMARDs and changes in levels after 12 months did not depend on the assignment to either of the study arms.Conclusion:Neither IgA1 nor IgA2 ACPA levels were predictive of flare development or associated with treatment strategies (though rituximab, JAK-inhibitors and abatacept were not amongst treatment options). However, in patients remaining in sustained remission after 1 year a decrease in IgA2 and IgA2% ACPA was observed and IgA2% ACPA was associated with DAS28 score registered after flare. This could be an indication towards ACPA of IgA2 isotype contributing to the severity of flare, alongside other factors, and its reduction being associated with a prolonged state of remission.References:[1]Steffen U, Koeleman CA, Sokolova MV, et al. IgA subclasses have different effector functions associated with distinct glycosylation profiles. Nat Commun 11, 120 (2020).[2]Haschka J, Englbrecht M, Hueber AJ, et al. Relapse rates in patients with rheumatoid arthritis in stable remission tapering or stopping antirheumatic therapy: interim results from the prospective randomised controlled RETRO study. Ann Rheum Dis. 75:45-51 (2016).Disclosure of Interests:None declared


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1350.1-1351
Author(s):  
O. Korolik ◽  
В. Zavodovsky ◽  
E. Papichev ◽  
Y. Polyakova ◽  
S. L ◽  
...  

Background:Cytokines stimulate the inflammatory response in the synovial membrane with rheumatoid arthritis (RA), initiate apoptosis of chondrocytes, activation of osteoclasts. The progression of comorbid diseases is also associated with the influence of cytokines. At the same time, anti-inflammatory cytokines are produced in various tissues. Their role in the pathogenesis of RA and its complications is ambiguous.Adiponectin (A) and Fetuin A (FA) are classified as negative acute phase proteins. Their concentration decreases with an increase in the level of pro-inflammatory cytokines: TNF-α, IL-1 and IL-6. Molecules A and FA, regardless of various factors and from each other, have similar effects in relation to pro-inflammatory cytokines, lipid and carbohydrate metabolism.Visfatin (V) and Nesfatin-1 (N-1) are pro-inflammatory adipokines. B is produced by cells of the mononuclear phagocytic system and connective tissue. N-1 - is produced by the cells of the intermediate and medulla oblongata and by the cells of the gastric mucosa.Objectives:to study the correlation of B, H-1, A and FA with the severity of inflammation in RAMethods:60 patients with RA and 30 healthy individuals were examined. The level of cytokines was determined by an indirect enzyme-linked immunosorbent assay using commercial test systems (Bio Vendor, cat No. RD195023100, Bio Vendor Human Fetuin-A, RaiBiotech, cat No. EIA-VIS-1, RaiBiotech, cat No. EIA-NESF). All patients underwent a full examination. Diagnosed with 2010 EULAR / ACR recommendations.Results:A decreased level of A (less than 0.8 μg/ml) was detected in 15 patients (25%), F-A (less than 653.55 μg/ml) in 16 (27%), a high level of V (more than 39 ng/ml) - in 55 (91%), N-1 (more than 37.95 ng/ml) - in 36 (60%), which is significantly more often than in healthy individuals. No significant difference in the levels of determined adipokines was found depending on the gender and body weight of patients with RA. The level of cytokines in RA is associated with high activity according to DAS 28, positivity by Anti-CCP, extraarticular manifestations of RA. The greatest correlation with extraarticular manifestations is with cutaneous and cerebral vasculitis. The levels of FA and N-1 also correlated with more pronounced radiological changes (X-ray stage III). FA circulating inhibitor of ectopic calcification. N-1 level is positively correlated with systolic blood pressure.Conclusion:A low level of A and FA, a high level of V and N-1 is characteristic of RA with the presence of high activity and positivity in the RF and Anti-CCP. An increased level of B is determined by more than 90% of patients, which indicates its high pro-inflammatory activity. The level of F and N-1 is also associated with the degree of damage to bone tissue (stage III, a lot of erosion). A positive correlation of level V and N-1, negative A and FA with the severity of inflammation in RA confirms the involvement of these proteins in the pathogenesis. A high level of A and V increases the risk of developing cardiovascular diseases and their complications, the effect of N-1 and FA is being studied. The effect of cytokines on osteoclasts and osteoblasts in RA is ambiguousReferences:[1]Visfatin and Rheumatoid Arthritis: Pathogenetic Implications and Clinical Utility. Polyakova Y. Curr Rheumatol Rev.2019[2]Serum nesfatin -1 as a marker of systemic inflammation in rheumatoid arthritis. Kvlividze T. Klinicheskaya Laboratornaya Diagnostika.2019; 64 (1):53-56 (in Russ)[3]Fetuin-A. Novel hepatokine in rheumatoid arthritis laboratory diagnostics. Papichev E. Klinicheskaya Laboratornaya Diagnostika.2018; 63 (12):756-760 (in Russ)Disclosure of Interests:None declared


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