Global miRNA and mRNA expression profiles identify miRNA-26a-2-3p-dependent repression of IFN signature in systemic sclerosis human monocytes.

Dysregulation in type I IFN and IFN-stimulated genes (ISGs) induced by monocytes is one of the key features of systemic sclerosis (SSc) pathogenesis. Abnormalities in microRNA (miRNA) expression are related to excessive IFN production, however the role of miRNA remains largely elusive in SSc monocytes. This study explores global miRNA-mRNA profiling of SSc monocytes and functional attenuation of IFN and ISGs by specific miRNAs. Global sequencing of mRNA (mRNA-seq) and miRNA (miRNA-seq) samples were performed simultaneously on healthy controls and SSc monocytes. Following computational analysis, selected miRNAs-mRNA candidates were validated, correlated with clinical parameters, and tested by functional assays. Transcriptomics data and qPCR analysis confirmed IFN signature in SSc but not in rheumatoid arthritis monocytes. Based on miRNA-seq analysis, five miRNAs were selected for further validation. Only the expression patterns of miRNA-26a-2-3p and miRNA-485-3p were confirmed and negatively correlated with clinical parameters. Exogenous delivery of miRNA-26a-2-3p to TLR-stimulated monocytic THP-1 cells specifically inhibited ISGs but not inflammasome activity in functional assays. In conclusion, our miRNA-mRNA co-sequencing and functional analysis identify miRNA-26a-2-3p as a new candidate, which is predicated to negatively regulate ISGs. This implies that reduced expression of miRNA-26a-2-3 may be involved in pathogenic IFN signature in SSc monocytes.

Comprehensive microRNA and transcriptomic profiling of rheumatoid arthritis monocytes: role of microRNA-146b in pro-inflammatory progression.

OBJECTIVE: To explore global miRNA and transcriptomic profiling of monocytes from RA patients compared with healthy controls in order to predict which aberrantly expressed miRNA can negatively modulate inflammatory molecules. METHODS: Using next-generation sequencing, we have performed simultaneous global analysis of miRNA (miRNA-seq) and transcriptome (RNA-seq) of monocytes from RA patients and healthy controls. Global analysis of miRNA of SSc monocytes was also performed. Following differential analysis and negative correlation, miRNA-RNA pairs were selected. RESULTS: We found that 20 specific miRNA candidates are predicted to silence inflammatory mediators, out of 191 significantly changed miRNAs in RA monocytes. Based on the highest scoring in terms of negative correlation (r = -0.97, P = 1.75e-07, false discovery rate = 0.04) and the number of seeds in miRNA responsible for negative regulation, we selected miRNA-146b and its target gene anti-inflammatory retinoic acid receptor alpha (RARA). Similarly to next-generation sequencing, qPCR analysis also confirmed negative correlation between miRNA-146b and RARA expression (r = -0.45, P = 0.04). Additionally, miRNA-146b expression in RA monocytes significantly correlated with clinical parameters including DAS28 for RA with CRP (DAS28-CRP) and ESR (DAS28-ESR), whereas overexpression of miRNA-146b was able to functionally reduce RARA expression in the human monocytic cell line THP-1. Finally, circulating miRNA-146b expression in sera and SFs was significantly elevated in RA patients. CONCLUSIONS: Overall, in this study we have identified a new miRNA-146b candidate that is predicted to negatively regulate the anti-inflammatory RARA transcript, whereas circulating miRNA-146b level can be used as a biomarker predicting pro-inflammatory RA progression and disease activity.

Survival of lymphocytes is not restricted by IDO-expressing fibroblast from rheumatoid arthritis patients.

Objective: Rheumatoid arthritis (RA) is characterized by expansion of fibroblast-like synoviocytes (FLS) in inflamed joints and activation of lymphocytes. Tryptophan (trp) is an essential amino acid indispensable for the biosynthesis of proteins and critical for survival of lymphocytes. Indoleamine 2,3-dioxygenase (IDO) that initiates the degradation of trp and tryptophanyl-tRNA synthetase (TTS) essential for tryptophan synthesis, regulate trp bioavailability. Here, we tested the hypothesis that triggered by cytokines, enhanced IDO activity modulate regulatory function of otherwise non-tolerogenic FLS isolated from RA patients. Materials and methods: IDO and TTS mRNA expression were evaluated by RT-PCR. IDO enzymatic activity was confirmed using HPLC. Resting or PHA-activated PBMC from healthy volunteers and RA patients were co-cultured with IDO expressing untreated (FLSC) or IFNγ-treated (FLSIFNγ) RA FLS. Lymphocyte survival and proliferation were evaluated by flow cytometry analysis and tritiated thymidine incorporation, respectively. Results: RA FLSIFNγ produce functionally active IDO and constitutively express TTS. RA FLSC and FLSIFNγ increased survival of resting lymphocytes in both studied groups, and decreased proliferation of healthy, but not RA, PBMC. Only FLSIFNγ diminished survival of activated CD3+CD4-, but not CD3+CD4+, healthy T cells and similar tendency was observed in rheumatoid cells. Importantly, IDO inhibitor, 1-methyl-DL-tryptophan (1-MT), failed to reverse this effect. PBMC, irrespective of their state (resting versus activated) or origin (healthy or RA), expressed high level of TTS mRNA. Conclusions: We suggest that RA FLS express functionally active IDO but control survival and expansion of healthy cells in IDO-independent mechanism and exert weaker, if any, suppressive effect on rheumatoid cells.

Monocyte alterations in rheumatoid arthritis are dominated by preterm release from bone marrow and prominent triggering in the joint.

OBJECTIVE: Rheumatoid arthritis (RA) accompanies infiltration and activation of monocytes in inflamed joints. We investigated dominant alterations of RA monocytes in bone marrow (BM), blood and inflamed joints. METHODS: CD14+ cells from BM and peripheral blood (PB) of patients with RA and osteoarthritis (OA) were profiled with GeneChip microarrays. Detailed functional analysis was performed with reference transcriptomes of BM precursors, monocyte blood subsets, monocyte activation and mobilisation. Cytometric profiling determined monocyte subsets of CD14++CD16-, CD14++CD16+ and CD14+CD16+ cells in BM, PB and synovial fluid (SF) and ELISAs quantified the release of activation markers into SF and serum. RESULTS: Investigation of genes differentially expressed between RA and OA monocytes with reference transcriptomes revealed gene patterns of early myeloid precursors in RA-BM and late myeloid precursors along with reduced terminal differentiation to CD14+CD16+monocytes in RA-PB. Patterns associated with tumor necrosis factor/lipopolysaccharide (TNF/LPS) stimulation were weak and more pronounced in RA-PB than RA-BM. Cytometric phenotyping of cells in BM, blood and SF disclosed differences related to monocyte subsets and confirmed the reduced frequency of terminally differentiated CD14+CD16+monocytes in RA-PB. Monocyte activation in SF was characterised by the predominance of CD14++CD16++CD163+HLA-DR+ cells and elevated concentrations of sCD14, sCD163 and S100P. CONCLUSION: Patterns of less mature and less differentiated RA-BM and RA-PB monocytes suggest increased turnover with accelerated monocytopoiesis, BM egress and migration into inflamed joints. Predominant activation in the joint indicates the action of local and primary stimuli, which may also promote adaptive immune triggering through monocytes, potentially leading to new diagnostic and therapeutic strategies.

Cartilage and bone damage in rheumatoid arthritis.

Rheumatoid arthritis (RA), which is a chronic inflammatory disease with a multifactorial aetiology, leads to partial or permanent disability in the majority of patients. It is characterised by persistent synovitis and formation of pannus, i.e. invasive synovial tissue, which ultimately leads to destruction of the cartilage, subchondral bone, and soft tissues of the affected joint. Moreover, inflammatory infiltrates in the subchondral bone, which can lead to inflammatory cysts and later erosions, play an important role in the pathogenesis of RA. These inflammatory infiltrates can be seen in magnetic resonance imaging (MRI) as bone marrow oedema (BME). BME is observed in 68-75% of patients in early stages of RA and is considered a precursor of rapid disease progression. The clinical significance of synovitis and bone marrow oedema as precursors of erosions is well established in daily practice, and synovitis, BME, cysts, hyaline cartilage defects and bone erosions can be detected by ultrasonography (US) and MRI. A less explored subject is the inflammatory and destructive potential of intra- and extra-articular fat tissue, which can also be evaluated in US and MRI. Finally, according to certain hypotheses, hyaline cartilage damage may trigger synovitis and lead to irreversible joint damage, and MRI may be used for preclinical detection of cartilage biochemical abnormalities. This review discusses the pathomechanisms that lead to articular cartilage and bone damage in RA, including erosion precursors such as synovitis and osteitis and panniculitis, as well as the role of imaging techniques employed to detect early cartilage damage and bone erosions.

Monocyte-related biomarkers of rheumatoid arthritis development in undifferentiated arthritis patients - a pilot study.

OBJECTIVES: Enhanced/disturbed activities of monocytes are crucial for perpetuation and for development of rheumatoid arthritis (RA). Therefore, knowledge about monocyte activities and regulation of molecular pathways operating within monocytes early in the course of RA development may help to predict the progression to the full-blown disease. We aimed to investigate the profile of miRNAs expression in circulating monocytes and monocyte-related cytokines in sera of individuals at undifferentiated arthritis (UA) stage, wich could serve as new biomarkers for RA development. MATERIAL AND METHODS: Magnetically sorted monocytes from peripheral blood of 20 UA patients served for total RNA isolation. RNA samples were used for microRNA profiling. Concentrations of CCL3/MIP-1α, M-CSF, CCL2/MCP-1, IL-6, TNF-α and IL-15 in sera of UA patients were measured using ELISA assays. Verification of diagnosis after 4 years of follow-up led to the identification of patients who developed RA (UA→RA patients) and patients who remained still in UA phase (UA → UA patients). Comparisons between patients groups were performed using two-tailed Mann-Whitney U test. RESULTS: We identified 50 miRNAs in monocytes with the largest variation of expression across all patients samples. From these selected miRNAs, expression of miR-642b-5p, miR-483-3p, miR-371b-5p were significantly up-regulated and miR-25-3p and miR-378d were significantly down-regulated in UA → RA vs. UA → UA patients. This specific pattern of miRNAs expression in circulating monocytes paralleled elevated IL-15 and M-CSF concentrations in sera of UA patients who progressed to RA. CONCLUSIONS: Results of our pilot study indicate that altered activity of monocytes can be detected at early stages of RA. We found new miRNA candidates differentially expressed in peripheral blood monocytes and elevated concentrations of IL-15 and M-CSF involved in monocyte activity and differentiation in patients with UA who subsequently developed RA, in comparison to UA patients who did not progress to RA after 4 years follow-up.

The role of microRNA-5196 in the pathogenesis of systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is a chronic autoimmune disease characterised by tissue fibrosis and immune abnormalities. Recent evidence suggests that activated circulating monocytes from patients with SSc play an important role in early stages of SSc pathogenesis due to enhanced expression of tissue inhibitor of metalloproteinases 1 (TIMP-1), IL-8 and reactive oxygen species (ROS) induction. However, the exact factors that contribute to chronic inflammation and subsequently fibrosis progression are still unknown. MATERIALS AND METHODS: The expression pattern of IL-8, TIMP-1, AP-1 transcription factor-Fra2 and ROS induction in peripheral blood monocytes following DZNep (histone methyltransferase inhibitor) and TLR8 agonist stimulation was investigated. Exogenous microRNA-5196, which is predicted to bind 3'UTR of Fra2 gene, was delivered to reverse profibrotic phenotype in monocytes. Expression of circulating microRNA-5196 was correlated with SSc parameters. RESULTS: DZNep + TLR8 agonist stimulation enhanced profibrotic TIMP-1, IL-8 and ROS generation in HC and SSc monocytes. As opposed by the decrease of miRNA-5196 and antioxidant SOD1 expression in SSc monocytes. Exogenous delivery of microRNA-5196 reduced Fra2 and TIMP-1 expression suggesting that it may be used as a potential modulator of fibrogenesis in SSc. Circulating microRNA-5196 was significantly increased in SSc and positively correlated with CRP level but not with Rodnan skin score or ESR. CONCLUSIONS: These results suggest that microRNA-5196 can be used as a potential biomarker characterising SSc. Overall, this study may open new possibilities for the development of microRNA-5196-based diagnostics and therapy in early phases of SSc.

The role of anti-citrullinated protein antibodies (ACPA) in the pathogenesis of rheumatoid arthritis.

The most specific autoimmunity known for rheumatoid arthritis (RA) is reflected by generation of anti-citrullinated protein antibodies (ACPA). Presence of ACPA in established RA is associated with disease severity, while generation of ACPA at early developmental phases of RA can have a strong predictive value for progressing to the full-blown disease. Hence, development of ACPA may be of crucial importance to the pathogenesis of RA. Therefore, a lot of effort has been put recently to investigate the feature of ACPA at early developmental stages of RA (before disease onset) and functional activities of these autoantibodies. Results of these studies enlarged the knowledge about the nature of ACPA, which is essential for planning the therapeutic or preventive strategies interfering with their development and pathogenic functions. In this review we describe recent evidence for a role of ACPA in the etiopathogenesis of RA and indicate key unresolved issues regarding ACPA biology that need to be clarified in the future.

Cytokines and integrins related to inflammation of joint and gut in patients with spondyloarthritis and inflammatory bowel disease.

OBJECTIVES: Inflammatory bowel disease (IBD) and spondyloarthritis (SpA) have some overlapping clinical features, i.e. gut and joint inflammation. Cytokines of interleukin 17(IL-17)/IL-23 axis play a pathogenic role in both diseases. Integrins (ITGs) regulate migration of immune cells to inflamed tissues (ITGß7 into gut, ITGß2 into gut and also to other tissues). In this study, we search for differences in the serum concentrations of these cytokines and integrins between patients suffering from SpA or IBD with and without overlapping symptoms. MATERIAL AND METHODS: Patients with SpA (n = 30), IBD (n = 68), and healthy volunteers (n = 28) were included in the study. Fourteen SpA patients reported symptoms characteristic for IBD. Spondyloarthritis symptoms were diagnosed in 50% of IBD patients, while other patients of this group reported arthralgia only. Serum concentrations of IL-17, IL-22, IL-23, ITGß2, and ITGß7 were measured by specific enzyme-linked immunosorbent assay using commercially available sets. The Mann-Whitney and Spearman's rank tests were used for intergroup comparison and correlation assessment, respectively. RESULTS: Comparison of patient groups showed significantly higher serum concentrations of IL-17, IL-22, and ITGß7 in SpA, and up-regulated levels of IL-23 in IBD patients. Similar differences were observed between patient subgroups, both with and without overlapping symptoms. In SpA but not in IBD patients, serum concentrations of ITGß7 inversely correlated (r = -0.552) with C-reactive protein. CONCLUSIONS: Patients with SpA and IBD differ in the circulating concentrations of IL-17/IL-23 axis cytokines and ITGß7, irrespectively of the presence or absence of overlapping symptoms. Therefore, we conclude that observed differences are attributed rather to underlying than concurrent disease.

Different expression of chemokines in rheumatoid arthritis and osteoarthritis bone marrow.

OBJECTIVES: Rheumatoid arthritis (RA) is a chronic inflammatory disease leading to joint destruction. In addition to involvement of the joints, there is growing evidence that inflammatory/autoimmune processes take place in bone marrow, beginning the disease onset. Activated T and B cells accumulate in bone marrow, where also effective antigen presentation takes place. An increased number of activated T cells was observed in RA in comparison to osteoarthritis (OA) bone marrow. In the present study we analyzed the levels of chemokines that may be responsible for accumulation/retention of T-cells in the bone marrow of RA and OA patients. MATERIAL AND METHODS: Bone marrow samples were obtained from RA and OA patients during total hip replacement surgery, and bone marrow plasma was obtained by gradient centrifugation. Levels of the chemokines CX3CL1, CCL5, CCL2, CXCL12 and CXCL1 were measured in bone marrow plasma by specific ELISAs. Comparison between the groups of patients and statistical significance were analyzed by the two-tailed Mann-Whitney U test. RESULTS: Increased levels of CX3CL1 (818 ±431 pg/ml vs. 502 ±131 pg/ml, p < 0.0007) and CCL5 (5967 ±1680 pg/ml vs. 4878 ±2360 pg/ml, p < 0.05) respectively in bone marrow plasma from RA in comparison with OA patients were observed. In contrast, similar levels of CCL2, CXCL12 and CXCL1 in RA and OA bone marrow suggest that these cytokines do not play a significant role in the observed T cell accumulation in RA bone marrow. CONCLUSIONS: CX3CL1 and CCL5 overproduced in RA bone marrow may contribute to the accumulation of T cells observed in RA bone marrow.

Prospective assessment of cytokine IL-15 activity in patients with refractory atrial fibrillation episodes.

AIMS: Inflammatory state is considered a risk factor of atrial fibrillation (AF) occurrence. The aim of this study was a prospective evaluation of the inflammation parameters in patients with different forms of AF without structural heart disease. METHODS AND RESULTS: One hundred fifty-eight patients with paroxysmal/persistent AF (87; 55.1% men, mean age 65.8±9.6 years) without structural heart disease were enrolled in the study. Inflammatory parameters: WBC, ESR, hs-CRP, IL-6, IL-15 and TNF-alpha were measured at baseline and after one year follow-up. Despite frequent AF episodes median values of WBC, ESR and C-reactive protein at baseline and after follow up were within normal ranges. There were no significant differences between WBC, ESR and hs-CRP regarding AF types. In patients who developed permanent AF form (n=14) hs-CRP concentrations were higher at baseline: 0.35 (IQR1: 0.09 IQR: 0.61) vs 0.15 (IQR1: 0.07 IQR: 0.29), p<0.01. Nevertheless, after one year's observation these differences were not significant. Among all cytokines were studied only IL-15 was significantly correlated with the number of AF episodes (r=0.26), mean (IQ1-IQ3): 10 (3-30) vs 60 (50-100), p=0.00681. CONCLUSION: Basic inflammatory markers were not changed in patients with refractory atrial fibrillation episodes in prospective one year's observation. Only cytokine IL-15 was correlated to numbers of AF episodes. It's potential role as a marker of arrhythmia deserves further evaluation.

HLA-B27 detection - comparison of genetic sequence-based method and flow cytometry assay.

OBJECTIVES: The presence of human leukocyte antigen B27 (HLA-B27) is strongly associated with ankylosing spondylitis. HLA-B27 testing is routinely applied in the diagnosis of this disease. The aim of the present study was to compare two methods of HLA-B27 detection - a genetic sequence-based method and a flow cytometry assay. MATERIAL AND METHODS: Peripheral blood was obtained from 300 individuals with suspected spondyloarthropathy. Expression of HLA-B27 on the T cell surface was analysed by flow cytometry assay using GS145.2 monoclonal antibody specific for HLA-B27. DNA was isolated from the whole blood. Genes coding for HLA-B27, -B40 and -B47:01 were detected by polymerase chain reaction using the MW02/MW09 primer pair. Then, positive samples were sequenced in order to discriminate allelic variations of the HLA-B27 gene. Results of sequencing were analysed using Chromas LITE 2.1.1 software, BLAST software and the IMGT/HLA database. Ambiguous samples were additionally analysed by polymerase chain reaction using E91 and E136 primers amplifying a 135-bp fragment of the human HLA-B27 gene. RESULTS: Among 300 samples, 76 were HLA-B27-positive on the basis of flow cytometry analysis. Genetic sequence analysis confirmed positivity of 73 from among 76 samples. Two hundred twenty six samples were HLA-B27-negative, whereas the result of one sample analysis was ambiguous. Fifty-three samples were identified as allelic variation 27:05, 19 samples as allelic variation 27:02, and one sample as allelic variation 27:07. CONCLUSIONS: This study shows that the genetic sequence-based method and the flow cytometry assay give consistent results in 99% of cases. The performed genetic analysis proves that the majority of HLA-B27-positive samples belong to the 27:05 allelic variation, which is strongly associated with high risk of ankylosing spondylitis.

Significance of bone marrow edema in pathogenesis of rheumatoid arthritis.

Assessing the pathology of the synovium, its thickening and increased vascularity through ultrasound and magnetic resonance examinations (more often an ultrasound study alone) is still considered a sensitive parameter in the diagnosis of rheumatoid arthritis and in monitoring of treatment efficacy. Magnetic resonance studies showed that, aside from the joint pannus, the subchondral bone tissue constitutes an essential element in the development of rheumatoid arthritis. Bone marrow edema correlates with inflammation severity, joint destruction, clinical signs and symptoms of rheumatoid arthritis, and thus is considered a predictor of rapid radiological progression of the disease. The newest studies reveal that bone marrow edema may be a more sensitive indicator of the response to therapy than appearance of the synovium. Bone marrow edema presents with increased signal in T2-weighted images, being most visible in fat saturation or IR sequences (STIR, TIRM). On the other hand, it is hypointense and less evident in T1-weighted images. It becomes enhanced (hyperintense) after contrast administration. Histopathological studies confirmed that it is a result of bone inflammation (osteitis/osteomyelitis), i.e. replacememt of bone marrow fat by inflammatory infiltrates containing macrophages, T lymphocytes, B lymphocytes, plasma cells and osteoclasts. Bone marrow edema appears after a few weeks from occurrence of symptoms and therefore is considered an early marker of inflammation. It correlates with clinical assessment of disease activity and elevated markers of acute inflammatory phase, i.e. ESR and CRP. It is a reversible phenomenon and may become attenuated due to biological treatment. It is considered a "herald" of erosions, as the risk of their formation is 6-fold higher in sites where BME was previously noted.

The Kinetics of Humoral and Cellular Responses after the Booster Dose of COVID-19 Vaccine in Inflammatory Arthritis Patients.

Impaired immunogenicity of COVID-19 vaccinations in inflammatory arthritis (IA) patients results in diminished immunity. However, optimal booster vaccination regimens are still unknown. Therefore, this study aimed to assess the kinetics of humoral and cellular responses in IA patients after the COVID-19 booster. In 29 IA patients and 16 healthy controls (HC), humoral responses (level of IgG antibodies) and cellular responses (IFN-γ production) were assessed before (T0), after 4 weeks (T1), and after more than 6 months (T2) from the booster vaccination with BNT162b2. IA patients, but not HC, showed lower anti-S-IgG concentration and IGRA fold change at T2 compared to T1 (p = 0.026 and p = 0.031). Furthermore, in IA patients the level of cellular response at T2 returned to the pre-booster level (T0). All immunomodulatory drugs, except IL-6 and IL-17 inhibitors for the humoral and IL-17 inhibitors for the cellular response, impaired the immunogenicity of the booster dose at T2. Our study showed impaired kinetics of both humoral and cellular responses after the booster dose of the COVID-19 vaccine in IA patients, which, in the case of cellular response, did not allow the vaccination effect to be maintained for more than 6 months. Repetitive vaccination with subsequent booster doses seems to be necessary for IA patients.

Comparison of rheumatoid articular adipose and synovial tissue reactivity to proinflammatory stimuli: contribution to adipocytokine network.

OBJECTIVES: (1) To compare spontaneous and stimuli-induced adipocytokine secretion by articular adipose tissue (AAT) and synovial membrane (SM) explants obtained from patients with rheumatoid arthritis (RA). (2) To investigate the biological activity of AAT and SM released factors. METHODS: Tissues were obtained from patients undergoing joint replacement surgery. Tissue explants were treated with proinflammatory cytokines relevant to RA pathogenesis (interleukin 1ß (IL-1ß), tumour necrosis factor (TNF), interferon γ, IL-15, IL-17, IL-23). Selected adipocytokine (TNF, IL-6, IL-8, IL-1ß, IL-1Ra, adiponectin, leptin) concentrations were measured in culture supernatants using ELISA. The biological activity of tissue-conditioned media was evaluated by measuring production of selected factors (IL-6, IL-8, Dickkopf-1, osteoprotegerin) by fibroblast-like synoviocytes (FLS). RESULTS: Spontaneous cytokine release from AAT was ≤12% of that produced by SM, while leptin was secreted in similar amounts. AAT was highly reactive to proinflammatory cytokines (IL-1ß>TNF). AAT treated with IL-1ß released four times more leptin, similar amounts of IL-6 and IL-8 and about 20% of TNF, as compared with SM. Upon activation, the IL-1 receptor antagonist (IL-1Ra)/IL-1ß ratio was higher in AAT than in SM cultures. Irrespective of activation status, SM produced twice as much adiponectin as AAT. Conditioned media from AAT and SM cultures similarly upregulated IL-6, IL-8, Dickkopf-1 and osteoprotegerin production by rheumatoid FLS. CONCLUSION: Rheumatoid AAT is highly reactive tissue which upon stimulation secretes considerable amounts of proinflammatory (IL-6, IL-8, TNF) and anti-inflammatory (IL-1Ra) cytokines and classical adipokines. This tissue releases biologically active factors that intensify pathogenic activities of rheumatoid FLS. Thus, AAT should be considered an important contributor to the pathological processes taking place in the RA joint.

Intra-articular adipose-derived mesenchymal stem cells from rheumatoid arthritis patients maintain the function of chondrogenic differentiation.

OBJECTIVES: To evaluate the chondrogenic potential, phenotype and percentage of IA adipose-derived mesenchymal stem cells (ADSCs) from RA patients in comparison with OA patients. The effect of TNF treatment on ADSC differentiation was also examined. METHODS: Adipose tissue was obtained from RA and OA patients. ADSCs were isolated and cultured until passage 4. After that period, the phenotype and percentage of these cells were analysed by flow cytometry. Passage 4 cells were cultured in chondrogenic medium with or without TNF. After 3 weeks of differentiation the expression of Sox9, aggrecan (Acan) and collagen 2a (Col2a) mRNA was assessed by RT-PCR and GAG deposition by alcian blue staining. RESULTS: The phenotype and percentage of ADSCs were similar in both RA and OA. The results of alcian blue staining showed effective chondrogenesis in RA and OA ADSCs. TNF inhibited GAG deposition in both RA and OA samples similarly. Sox9, Acan and Col2a mRNA expression was significantly increased in chondrogenic-medium-treated cells (P<0.05) and decreased after TNF exposure (P<0.01). No statistically significant differences between RA and OA were observed. CONCLUSION: ADSCs from RA and OA patients are similar with regard to their phenotype, percentage in IA tissue and chondrogenic potential, which is reduced after exposure to TNF.

Histone deacetylase inhibitors suppress inflammatory activation of rheumatoid arthritis patient synovial macrophages and tissue.

Macrophages contribute significantly to the pathology of many chronic inflammatory diseases, including rheumatoid arthritis (RA), asthma, and chronic obstructive pulmonary disease. Macrophage activation and survival are tightly regulated by reversible acetylation and deacetylation of histones, transcription factors, and structural proteins. Although histone deacetylase (HDAC) inhibitors (HDACis) demonstrate therapeutic effects in animal models of chronic inflammatory disease, depressed macrophage HDAC activity in patients with asthma, chronic obstructive pulmonary disease, or RA may contribute to inflammation in these diseases, potentially contraindicating the therapeutic administration of HDACis. In this study, we directly examined whether HDACis could influence the activation of macrophages derived from the inflamed joints of patients with RA. We found that inhibition of class I/II HDACs or class III sirtuin HDACs potently blocked the production of IL-6 and TNF-alpha by macrophages from healthy donors and patients with RA. Two HDACis, trichostatin A and nicotinamide, selectively induced macrophage apoptosis associated with specific downregulation of the antiapoptotic protein Bfl-1/A1, and inflammatory stimuli enhanced the sensitivity of macrophages to HDACi-induced apoptosis. Importantly, inflammatory and angiogenic cytokine production in intact RA synovial biopsy explants was also suppressed by HDACis. Our study identifies redundant, but essential, roles for class I/II and sirtuin HDACs in promoting inflammation, angiogenesis, and cell survival in RA.

Serum concentration of interleukin 15, interleukin 2 receptor and TNF receptor in patients with polymyositis and dermatomyositis: correlation to disease activity.

Cytokines are implied in polymyositis/dermatomyositis (PM/DM) pathogenesis. Our aim was to evaluate the serum levels of interleukin-15 (IL-15), soluble receptors for IL-2 (sIL-2R) and TNF-alpha type 1 receptor (sTNF-R1) in PM/DM patients and their relation to disease activity and clinical symptoms. Thirty-eight patients who met definite or probable criteria of Bohan and Peter for DM/PM were included into the study. Results in patients with active (41 observations) and inactive disease (24 observations) were compared with control (15 subjects). The median level of IL-15 was 47.6 ± 170 pg/ml in active patients, 25.15 ± 240 pg/ml in inactive and 28.5 ± 28.89 pg/ml in controls. We demonstrated significant differences between active patients and controls in levels of IL-15 (0.016, 95%CI 1.39-57.1). The median level of sIL-2R was 314 ± 388, 235.3 ± 269 and 144.3 ± 152.9 pg/ml, and the median level of sTNF-R1 was 350 ± 388; 294.7 ± 204.7; 209.5 ± 105.9 pg/ml in active, inactive and control subjects, respectively. There were significantly higher serum levels of these cytokines in active patients than in control subjects (for sIL-2R P = 0.05, CI95% 0.4-331; and sTNF-R1 P = 0.031, CI95% 15.1-321.5). The interleukin levels did not differ between inactive patients and controls. Elevation of IL-15, sIL2-R and sTNF-R1 in active patients provides preliminary evidence for the activation of inflammatory response during PM/DM flares. Further studies may be needed to explain the mechanisms driving these diseases.

Circulating miRNA Correlates with Lipid Profile and Disease Activity in Psoriatic Arthritis, Rheumatoid Arthritis, and Ankylosing Spondylitis Patients.

This study aimed to investigate the associations of microRNA (miRs) signatures with cytokines, serum lipids, and disease activity in patients with psoriatic arthritis (PsA), ankylosing spondylitis (AS), and rheumatoid arthritis (RA). In total, 65 patients (PsA n = 25, AS n = 25, RA n = 15) and 25 healthy controls (HC) were enrolled into the study. The expression of miR-223-5p, miR-92b-3p, miR-485-3p, miR-10b-5p, let-7d-5p, miR-26a-2-3p, miR-146b-3p, and cytokines levels were measured in sera. DIANA-mirPath analysis was used to predict pathways targeted by the dysregulated miRs. Disease activity scores were calculated. Lipid profile, uric acid, glucose level, and C-reactive protein (CRP) concentrations were determined in the blood. Based on lipid profiles, the PsA group had hypertriglyceridaemia, and RA patients revealed mixed dyslipidaemia, while in AS, no specific changes were found. miR expression analysis revealed upregulation of miR-26a-2-3p and miR-10b-5p in PsA, miR-485-3p in AS, and let-7d-5p in RA. Several correlations between disease activity indexes, metabolites levels, and expression of miRs were observed in PsA, RA, and AS patients. Finally, in ROC analysis, miR-26a-2-3p/miR-485-3p, and let-7d-5p/miR-146b-3p tandems revealed high sensitivity and specificity in distinguishing between PsA, AS, and RA. Our study illustrates the superiority of miR expressions in distinguishing between RA, PsA, and AS. In PsA, a unique regulatory pathway exists through miR-26a-2-3p, miR-223-5p, miR-10b-5p, and miR-92b-3p that converges proatherogenic metabolism and disease activity.

Humoral and cellular immunogenicity of COVID-19 booster dose vaccination in inflammatory arthritis patients.

Introduction: Previous studies have shown a reduction in the effectiveness of primary COVID-19 vaccination in patients with rheumatic diseases. However, limited data is available regarding the effectiveness of the COVID-19 vaccine booster dose, especially on cellular response. The study aimed to assess the humoral and cellular immunogenicity of a booster dose in patients with inflammatory arthritis (IA). Patients and methods: 49 IA and 47 age and sex-matched healthy controls (HC) were included in a prospective cohort study. Both groups completed primary COVID-19 vaccination and after more than 180 days received a BNT162b2 booster shot. Humoral responses (level of IgG antibodies) and cellular responses (IFN-γ production) were assessed before and after 4 weeks from the booster dose of the vaccine. Results: After the booster dose, all participants showed an increased humoral response, although significantly reduced antibody levels were observed in IA patients compared to HC (p=0.004). The cellular response was significantly lower both before (p<0.001) and after (p<0.001) the booster dose in IA patients as compared to HC. Among the immunomodulatory drugs, only biological and targeted synthetic drugs lowered the humoral response after booster vaccination. However, the cellular response was decreased after all immunomodulatory drugs except IL-17 inhibitors and sulfasalazine. Conclusion: Our data indicate that patients with rheumatic diseases present lower humoral and cellular responses after the COVID-19 booster vaccine in comparison to HC. This may translate into a recommendation for subsequent booster doses of the COVID-19 vaccine for rheumatic patients.