ALKBH5-YTHDF2 m6A modification axis inhibits rheumatoid arthritis progression by suppressing NLRP3.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease. Recently, NLRP3 has been demonstrated to be closely related to RA. The objective of our research was to analyze the specific mechanism of NLRP3 in RA. The m6A levels of NLRP3 was detected with methylated RNA immunoprecipitation (MeRIP) kit. The mRNA and protein levels of related genes were tested with RT-qPCR and Western blot. The inflammatory factors levels were detected with ELISA kits. The cell proliferative ability was measured with CCK-8 and EdU staining assays. NLRP3 levels was prominently in synovial tissues and fibroblast-like synoviocytes (FLS) from RA patients. NLRP3 silencing suppressed FLS proliferation and inflammatory factor levels. Additionally, ALKBH5 was found to bind with NLRP3, and ALKBH5 silencing suppressed FLS proliferation and inflammatory factor levels while NLRP3 overexpressing neutralized the role of ALKBH5 in FLS. Furthermore, m6A modified induced by ALKBH5 suppressed NLRP3 mRNA level through YTHDC2 in RA, and NLRP3 is a hinge factor in RA progression.

Increased Metallothionein-1 Associated with Gout Activity and Tophi.

BACKGROUND AND AIMS: Gout is a chronic self-limiting inflammatory arthritis. An increase in metallothionein-1 (MT-1) has been reported in rheumatoid arthritis and osteoarthritis, and it attenuates inflammation and the pathology of diseases. This study aims to detect MT-1 levels in patients with gout and to explore its correlation with disease activity, clinical indexes, and inflammatory cytokines. METHODS: The expression of MT-1 messenger RNAs (mRNAs) and protein levels in patients with gout were measured using real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Correlations between MT-1 and clinical indexes or inflammatory mediators were analyzed using Spearman's correlation test. RESULTS: Compared with healthy controls (HCs, n = 43), patients with active gout (n = 27) showed higher levels of MT-1 mRNA in peripheral blood mononuclear cells and protein in serum, particularly those with tophi. No significant difference in serum MT-1 levels was observed among patients with inactive gout, HCs, and patients with hyperuricemia without gout. Furthermore, no significant difference was observed between patients with gout with kidney damage and HCs. In addition, serum interleukin (IL)-1ß, IL-6, and IL-8 levels were significantly increased in patients with active gout, particularly in those with tophi. The serum MT-1 level was positively correlated with C-reactive protein, as well as with IL-1ß, IL-6, and IL-18. CONCLUSION: The higher levels of MT-1 were found in patients with gout, which were correlated with disease activity and gout related pro-inflammatory cytokines. Indicating MT-1 may serve as a new marker for predicting disease activity.Abbreviations: IL-1ß: Interleukin 1ß; MT-1: Metallothionein-1; CRP: C-Reactive Protein; ROS: Reactive Oxygen Species; IL-10: Interleukin 10; TGF-ß: Transforming Growth Factor Beta.

Long non-coding RNA expression profiles in neutrophils revealed potential biomarker for prediction of renal involvement in SLE patients.

OBJECTIVE: The long non-coding RNA plays an important role in inflammation and autoimmune diseases. The aim of this study is to screen and identify abnormally expressed lncRNAs in peripheral blood neutrophils of SLE patients as novel biomarkers and to explore the relationship between lncRNAs levels and clinical features, disease activity and organ damage. METHODS: RNA-seq technology was used to screen differentially expressed lncRNAs in neutrophils from SLE patients and healthy donors. Based on the results of screening, candidate lncRNA levels in neutrophils of 88 SLE patients, 35 other connective disease controls, and 78 healthy controls were qualified by real-time quantitative polymerase chain reaction. RESULTS: LncRNA expression profiling revealed 360 up-regulated lncRNAs and 224 down-regulated lncRNAs in neutrophils of SLE patients when compared with healthy controls. qPCR assay validated that the expression of Lnc-FOSB-1:1 was significantly decreased in neutrophils of SLE patients when compared with other CTD patients or healthy controls. It correlated negatively with SLE Disease Activity Index 2000 (SLEDAI-2K) score (r = -0.541, P < 0.001) and IFN scores (r = -0.337, P = 0.001). More importantly, decreased Lnc-FOSB-1:1 expression was associated with lupus nephritis. Lower baseline Lnc-FOSB-1:1 level was associated with higher risk of future renal involvement (within an average of 2.6 years) in patients without renal disease at baseline (P = 0.019). CONCLUSION: LncRNA expression profile in neutrophils of SLE patients revealed differentially expressed lncRNAs. Validation study on Lnc-FOSB-1:1 suggest that it is a potential biomarker for prediction of near future renal involvement.

Hydroxychloroquine might reduce risk of incident endometriosis in patients with systemic lupus erythematosus: A retrospective population-based cohort study.

BACKGROUND: SLE, which is common in women, is commonly treated with HCQ, an anti-inflammation medication. Reproductive-age women with SLE are prone to be impacted by endometriosis. This study analyzes the relationship between HCQ and endometriosis patients with SLE in order to determine whether HCQ is effective for treating the latter. METHODS: This population-based, retrospective cohort study analyzed the SLE risk in a cohort of newly diagnosed SLE patients with endometriosis during 2000 through 2013. Controls were selected at a 1:2 ratio through age-matching using the greedy algorithm. The Cox proportional hazard model was used to analyze the association between HCQ use and endometriosis incidence. Four different Cox regression models were used. Lastly, sensitivity analysis with PSOW and IPW was implemented to evaluate the hazard ratio (HR) of endometriosis after exposure with HCQ. RESULTS: In the cohort where age and sex matched high and low HCQ dosage, the average follow-up time was about 1 year. The cohort's overall incidence rates of endometriosis were 44.54 and 90.03 per 100000 person-month for high and low dosage respectively. The high dose group's conditional hazard ratio (aHR) for incidental endometriosis was 0.482 (CI = 0.191 to 1.213). The incidence rate and Kaplan-Meir curves of endometriosis were consistent with the results for the cohort. CONCLUSION: This study demonstrated that SLE patients continuously treated with HCQ have a lower risk of developing endometriosis. Clinically, HCQ can be beneficial for endometriosis patients with SLE.

Risk of systemic lupus erythematosus in patients with idiopathic thrombocytopenic purpura: a population-based cohort study.

BACKGROUND: Idiopathic thrombocytopenic purpura (ITP) may play a role in early-stage systemic lupus erythematosus (SLE). The incidence of SLE in patients with ITP and the potential relationship between them is still unclear. This study was performed to provide epidemiological evidence regarding the relationship between ITP and SLE occurrence. METHODS: In this population-based retrospective cohort study, the risk of SLE was analysed in a cohort of patients newly diagnosed with ITP between 2000 and 2013. Controls were selected at a 1:2 ratio through propensity score matching (PSM) using the greedy algorithm. The Cox proportional hazard model was used to analyse the association between ITP and SLE incidence. There were four different Cox regression models, and the sensitivity analyses were implemented to evaluate the HR of SLE after exposure with ITP. RESULTS: In the age-matched and sex-matched ITP and non-ITP cohort, the average follow-up time was about 80 months in this study. There were 34 (4.70%) and 27 (0.19%) incident cases of SLE in ITP and non-ITP group. The incidence rates were 62.0 (95% CI 44.3 to 86.8) and 2.10 (95% CI 1.44 to 3.06), respectively. The adjusted HR of incidental SLE in the ITP group was 25.1 (95% CI 13.7 to 46.0). The other risk factors for SLE were female sex and Sjogren's syndrome. After PSM, the incidence rate and Kaplan-Meir curves of SLE were consistent with the results for the age-matched and sex-matched population, the HR 17.4 (95% CI 5.28 to 57.4) was estimated by conditional Cox model. CONCLUSION: This cohort study demonstrated that patients with ITP have a higher risk of SLE. Clinically, patients with ITP should be monitored for incidental lupus.

Clofazimine for Treatment of Extensively Drug-Resistant Pulmonary Tuberculosis in China.

We performed a multicenter, prospective, randomized study to investigate the efficacy and safety of clofazimine (CLO) for treatment of extensively drug-resistant tuberculosis (XDR-TB) in China. Forty-nine patients infected with XDR-TB were randomly assigned to either the control group or the CLO group, both of which received 36 months of individually customized treatment. The primary endpoint was the time to sputum culture conversion on solid medium. Clinical outcomes of patients were evaluated at the time of treatment completion. Of the 22 patients in the experimental group, 7 (31.8%) met the treatment criterion of "cure" and 1 (4.5%) "complete treatment," for a total of 8 (36.4%) exhibiting successful treatment outcomes without relapse. In the control group, 6 patients (22.2%) were cured and 6 (22.2%) completed treatment by the end of the study. Statistical analysis revealed no significant difference in successful outcome rates between the CLO group and the control group. The average sputum culture conversion time for the experimental group was 19.7 months, which was not statistically different from that for the control group (20.3 months; P = 0.57). Of the 22 patients in the CLO group, 12 (54.5%) experienced adverse events after starting CLO treatment. The most frequently observed adverse event was liver damage, with 31.8% of patients (7/22 patients) in the CLO group versus 11.1% (3/27 patients) in the control group exhibiting this adverse event. Our study demonstrates that inclusion of CLO in background treatment regimens for XDR-TB is of limited benefit, especially since hepatic disorders arise as major adverse events with CLO treatment. (This study is registered with the Chinese Clinical Trial Registry [ChiCTR, www.chictr.org.cn] under identifier ChiCTR1800014800.).

MiR-29a and Messenger RNA Expression of Bone Turnover Markers in Canonical Wnt Pathway in Patients with Ankylosing Spondylitis.

BACKGROUND: Recent studies showed that the canonical Wnt pathway and miR-29a play important roles in the pathogenesis of bone formation. We studied the levels of miR-29a and messenger RNA (mRNA) of bone turnover markers in the canonical Wnt pathway in ankylosing spondylitis (AS). METHODS: The levels of miR-29a and mRNA of bone turnover markers in canonical Wnt pathway from peripheral blood mononuclear cells were determined by real-time quantitative polymerase chain reaction in 38 patients with AS and 32 healthy controls. Correlation analysis was conducted between the levels of miR-29a and mRNA and clinical measurements using Spearman's correlation test. RESULTS: Compared to healthy controls, the levels of miR-29a, Dickkopf (DKK)-1, ß-catenin and Runx2 mRNA were significantly higher in AS patients (p < 0.05). In contrast, the levels of Gsk-3ß mRNA was significantly lower in AS patients than that in healthy controls (p < 0.05). Gsk-3ß mRNA was positively correlated with ß-catenin mRNA expression (p < 0.05) and no other correlation was observed between any other markers (p > 0.05). Only DKK-1 mRNA expression was negatively correlated with disease course (p < 0.05) and no other correlation was observed between markers and clinical measurements (p > 0.05). CONCLUSIONS: The osteoblastic marker miR-29a and downstream mRNA of canonical Wnt signaling was upregulated in AS, suggesting their possible role in new bone formation in AS.

Elevated miR-29a expression is not correlated with disease activity index in PBMCs of patients with ankylosing spondylitis.

OBJECTIVES: Ankylosing spondylitis (AS) is a chronic inflammatory disease characterized by new bone formation. Recent evidence suggests that new bone formation in AS may be due to upregulation of Wnt signaling in the osteoblastic pathway secondary to low serum Dickkopf homolog 1 (Dkk-1) levels. And miR-29a orchestrates osteoblast differentiation through direct targeting and negative regulation of Dkk-1. METHODS: We initially validated the expression levels of miR-29a in the peripheral blood mononuclear cells (PBMCs) of AS patients (n = 30), rheumatoid arthritis (RA) patients (n = 30) and healthy controls (n = 30) using real-time quantitative reverse transcription PCR (qRT-PCR). Correlation analysis was assessed between miR-29a level in PBMCs of AS patients and disease activity indexes, including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Bath ankylosing spondylitis disease activity index (BASDAI), Bath ankylosing spondylitis function index (BASFI) and modified Stoke ankylosing spondylitis spinal score (mSASSS). RESULTS: Significantly higher expression of miR-29a was observed in PBMCs of AS patients (Ct 9.18 ± 1.96) compared with that in RA patients (10.97 ± 0.70, p < 0.001) and healthy controls (Ct 11.45 ± 1.23, p < 0.001). There was no significant difference between RA patients and healthy controls in miR-29a expression (p > 0.05). Elevated miR-29a expression is not correlated with disease activity index (p > 0.05). A weak correlation was found between elevated miR-29a expression and mSASSS (r = -0.393, p = 0.032). CONCLUSIONS: We report for the first time elevated miR-29a expression in PBMCs of patients with ankylosing spondylitis, and miR-29a might be used as a useful diagnostic marker in new bone formation but cannot reflect disease activity.

[Etanercept combined with Tripterygium wilfordii polyglycoside for treatment of rheumatoid arthritis in the elderly: a clinical study].

OBJECTIVE: To evaluate the efficacy and safety of etanercept plus Tripterygium wilfordii polyglycoside (TWP) in elderly patients with active rheumatoid arthritis (RA). METHODS: Totally 46 elderly patients with active RA were randomly assigned to the treatment group (22 cases) and the control group (24 cases). All patients received subcutaneous injection of etanercept, 25 mg each time, twice per week. The dosage was reduced to once per week 3 months later. Patients in the treatment group took TWP Tablet (10 mg each time, three times per day), while those in the control group took methotrexate (MTX), 10 mg each time, once per week. The whole course lasted for 24 weeks. Patients' rest pain, tender joint number, swollen joint number, health assessment questionnaire (HAQ), patients' global assessment, physicians' global assessment, erythrocyte sediment rate (ESR), C reactive protein (CRP), rheumatic factor were assessed at week 0, 4, 8, 12, and 24. The curative effect was statistically evaluated by the United States Institute of Rheumatology ACR20, ACR50, and ACR70 improvement criteria. Meanwhile, any adverse event was recorded and evaluated. RESULTS: Totally 41 completed the trial, and 5 dropped off (3 in the treatment group and 2 in the control group). Compared with the control group, there was no statistical difference in ACR20, ACR50, or ACR70 in the treatment group (P > 0.05). Compared with before treatment in the same group, there was some improvement in tender joint number, swollen joint number, visual analogue scale (VAS) for patients' global assessment, VAS for physicians' global assessment, ESR, CRP, and HAQ between the two groups, showing statistical difference (P < 0.05). Compared with the control group in the same phase, there was no statistical difference in the treatment group (P > 0.05). There was no statistical difference in the occurrence of adverse events between the two groups. CONCLUSIONS: Etanercept plus TWP could achieve equivalent therapeutic effect to that of Etanercept plus MTX. The two regimens could improve clinical signs, symptoms, and QOL related to RA. They were well tolerated in the treatment of elderly patients with active RA.

Serum level of eight cytokines in Han Chinese patients with systemic lupus erythematosus using multiplex fluorescent microsphere method.

AIM OF THE STUDY: To investigate the role of 8 cytokines and their correlation with clinical characteristics in systemic lupus erythematosus (SLE) in Han Chinese population by detecting their serum levels using the multiplex fluorescent microsphere method. MATERIAL AND METHODS: Serum was separated from 79 patients with SLE and 40 healthy controls. The serum cytokine detection was conducted according to the instruction of MILLIPLEX MAP human cytokine detection kit on the Luminex liquid phase array platform with 0.01 pg/ml detectable level. The 8 cytokines were interferon α2 (IFN-α2), IFN-γ, interleukin 6 (IL-6), IL-8, IL-10, IFN-γ-inducible protein 10 (IP-10), tumor necrosis factor α (TNF-α) and IL-17. Variable data were in skewed distribution and were expressed with median (P25, P75). Mann-Whitney analysis was used in statistical analysis. RESULTS: At the baseline level without any stimulus, the level of IP-10 expression was the highest among the 8 cytokines and the second highest was IL-8. The level of IL-17 was too low to be detected. The level of 7 cytokines was higher in SLE patients than in healthy controls (p < 0.01). The level of dsDNA antibody, C3, CRP, ESR and anti-nucleosome antibody was correlated with IL-10. Proteinuria was not correlated with any cytokine. CONCLUSIONS: Eight cytokines were measured in our study, while not all of them were detected. The most important finding was the usefulness of IL-10 as a disease activity biomarker for Han Chinese patient with SLE. None of cytokines reflected kidney injury.

Novel potential lncRNA biomarker in B cells indicates essential pathogenic pathway activation in patients with SLE.

OBJECTIVES: Systemic lupus erythematosus (SLE) is a highly heterogeneous disease, and B cell abnormalities play a central role in the pathogenesis of SLE. Long non-coding RNAs (lncRNAs) have also been implicated in the pathogenesis of SLE. The expression of lncRNAs is finely regulated and cell-type dependent, so we aimed to identify B cell-expressing lncRNAs as biomarkers for SLE, and to explore their ability to reflect the status of SLE critical pathway and disease activity. METHODS: Weighted gene coexpression network analysis (WGCNA) was used to cluster B cell-expressing genes of patients with SLE into different gene modules and relate them to clinical features. Based on the results of WGCNA, candidate lncRNA levels were further explored in public bulk and single-cell RNA-sequencing data. In another independent cohort, the levels of the candidate were detected by RT-qPCR and the correlation with disease activity was analysed. RESULTS: WGCNA analysis revealed one gene module significantly correlated with clinical features, which was enriched in type I interferon (IFN) pathway. Among non-coding genes in this module, lncRNA RP11-273G15.2 was differentially expressed in all five subsets of B cells from patients with SLE compared with healthy controls and other autoimmune diseases. RT-qPCR validated that RP11-273G15.2 was highly expressed in SLE B cells and positively correlated with IFN scores (r=0.7329, p<0.0001) and disease activity (r=0.4710, p=0.0005). CONCLUSION: RP11-273G15.2 could act as a diagnostic and disease activity monitoring biomarker for SLE, which might have the potential to guide clinical management.

Three-Dimensional Chromosomal Landscape Revealing miR-146a Dysfunctional Enhancer in Lupus and Establishing a CRISPR-Mediated Approach to Inhibit the Interferon Pathway.

OBJECTIVE: The diminished expression of microRNA-146a (miR-146a) in systemic lupus erythematosus (SLE) contributes to the aberrant activation of the interferon pathway. Despite its significance, the underlying mechanism driving this reduced expression remains elusive. Considering the integral role of enhancers in steering gene expression, our study seeks to pinpoint the SLE-affected enhancers responsible for modulating miR-146a expression. Additionally, we aim to elucidate the mechanisms by which these enhancers influence the contribution of miR-146a to the activation of the interferon pathway. METHODS: Circular chromosome conformation capture sequencing and epigenomic profiles were applied to identify candidate enhancers of miR-146a. CRISPR activation was performed to screen functional enhancers. Differential analysis of chromatin accessibility was used to identify SLE-dysregulated enhancers, and the mechanism underlying enhancer dysfunction was investigated by analyzing transcription factor binding. The therapeutic value of a lupus-related enhancer was further evaluated by targeting it in the peripheral blood mononuclear cells (PBMCs) of patients with SLE through a CRISPR activation approach. RESULTS: We identified shared and cell-specific enhancers of miR-146a in distinct immune cells. An enhancer 32.5 kb downstream of miR-146a possesses less accessibility in SLE, and its chromatin openness was negatively correlated with SLE disease activity. Moreover, CCAAT/enhancer binding protein α, a down-regulated transcription factor in patients with SLE, binds to the 32.5-kb enhancer and induces the epigenomic change of this locus. Furthermore, CRISPR-based activation of this enhancer in SLE PBMCs could inhibit the activity of interferon pathway. CONCLUSION: Our work defines a promising target for SLE intervention. We adopted integrative approaches to define cell-specific and functional enhancers of the SLE critical gene and investigated the mechanism underlying its dysregulation mediated by a lupus-related enhancer.

The transcription factor ZEB2 drives the formation of age-associated B cells.

Age-associated B cells (ABCs) accumulate during infection, aging, and autoimmunity, contributing to lupus pathogenesis. In this study, we screened for transcription factors driving ABC formation and found that zinc finger E-box binding homeobox 2 (ZEB2) is required for human and mouse ABC differentiation in vitro. ABCs are reduced in ZEB2 haploinsufficient individuals and in mice lacking Zeb2 in B cells. In mice with toll-like receptor 7 (TLR7)-driven lupus, ZEB2 is essential for ABC formation and autoimmune pathology. ZEB2 binds to +20-kb myocyte enhancer factor 2b (Mef2b)'s intronic enhancer, repressing MEF2B-mediated germinal center B cell differentiation and promoting ABC formation. ZEB2 also targets genes important for ABC specification and function, including Itgax. ZEB2-driven ABC differentiation requires JAK-STAT (Janus kinase-signal transducer and activator of transcription), and treatment with JAK1/3 inhibitor reduces ABC accumulation in autoimmune mice and patients. Thus, ZEB2 emerges as a driver of B cell autoimmunity.

Elevated miR-29a expression is not correlated with disease activity index in PBMCs of patients with ankylosing spondylitis.

OBJECTIVES: Ankylosing spondylitis (AS) is a chronic inflammatory disease characterized by new bone formation. Recent evidence suggests that new bone formation in AS may be due to upregulation of Wnt signaling in the osteoblastic pathway secondary to low serum Dickkopf homolog 1 (Dkk-1) levels. And miR-29a orchestrates osteoblast differentiation through direct targeting and negative regulation of Dkk-1. METHODS: We initially validated the expression levels of miR-29a in the peripheral blood mononuclear cells (PBMCs) of AS patients (n = 30), rheumatoid arthritis (RA) patients (n = 30) and healthy controls (n = 30) using real-time quantitative reverse transcription PCR (qRT-PCR). Correlation analysis was assessed between miR-29a level in PBMCs of AS patients and disease activity indexes, including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Bath ankylosing spondylitis disease activity index (BASDAI), Bath ankylosing spondylitis function index (BASFI) and modified Stoke ankylosing spondylitis spinal score (mSASSS). RESULTS: Significantly higher expression of miR-29a was observed in PBMCs of AS patients (Ct 9.18 ± 1.96) compared with that in RA patients (10.97 ± 0.70, p < 0.001) and healthy controls (Ct 11.45 ± 1.23, p < 0.001). There was no significant difference between RA patients and healthy controls in miR-29a expression (p > 0.05). Elevated miR-29a expression is not correlated with disease activity index (p > 0.05). A weak correlation was found between elevated miR-29a expression and mSASSS (r = -0.393, p = 0.032). CONCLUSIONS: We report for the first time elevated miR-29a expression in PBMCs of patients with ankylosing spondylitis, and miR-29a might be used as a useful diagnostic marker in new bone formation but cannot reflect disease activity.

LncRNA XIST promotes adjuvant-induced arthritis by increasing the expression of YY1 via miR-34a-5p.

Objectives: This study aims to explore the mechanism by which long non-coding ribonucleic acids (lncRNA) X-inactive specific transcript (XIST) affects the progression of adjuvant-induced arthritis (AIA). Materials and methods: Freund's complete adjuvant was used to induce arthritis in rats. The polyarthritis, spleen and thymus indexes were calculated to evaluate AIA. Hematoxylin-eosin (H&E) staining was used to reveal the pathological changes in the synovium of AIA rats. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the expression of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6 and IL-8 in the synovial fluid of AIA rats. The cell continuing kit (CCK)-8, flow cytometry, and Transwell assays were used to assess the proliferation, apoptosis, migration and invasion of transfected fibroblast-like synoviocytes (FLS) isolated from AIA rats (AIA-FLS). Dual-luciferase reporter assay was performed to verify the binding sites between XIST and miR-34b-5p or between YY1 mRNA and miR-34b-5p. Results: The XIST and YY1 were highly expressed, and miR-34a-5p was lowly expressed in the synovium of AIA rats and in AIA-FLS. Silencing of XIST impaired the function of AIA-FLS in vitro and inhibited the progression of AIA in vivo. The XIST promoted the expression of YY1 by competitively binding to miR-34a-5p. Inhibition of miR-34a-5p strengthened the function of AIA-FLS by upregulating XIST and YY1. Conclusion: The XIST controls the function of AIA-FLS and may promote the progression of rheumatoid arthritis via the miR-34a-5p/YY1 axis.

[The expression of long non-coding RNA human leukocyte antigen complex P5(lncRNA HCP5) in synovial tissue of patients with rheumatoid arthritis is up-regulated and correlated with immune cell infiltration].

Objective To identify the potential long non-coding RNA (lncRNA) expressed in rheumatoid arthritis (RA) synovium key to RA onset and investigate its association with immune cell infiltration. Methods RA synovium data were downloaded from the GEO database and normalized. The lncRNAs key to RA onset were identified using multiple machine learning methods. Infiltration of 22 immune cell populations in RA synovium was measured by cell-type identification by estimating relative subsets of RNA transcripts (CIBER-SORT). The relationship between the key lncRNA and infiltrating immune cells was analyzed. Finally, real-time quantitative PCR was applied to validate the expression of the key lncRNA in RA synovial cells. Results lncRNA human leukocyte antigen complex P5(HCP5) was identified as the key lncRNA associated with RA onset. Infiltration analysis revealed increased abundance of CD8+ T cells, γδ T cells, and M1 macrophages while decreased abundance of M2 macrophages in RA synovial tissue. Correlation analysis demonstrated that the lncRNA HCP5 expression was positively associated with the infiltration abundance of CD8+ T cells, γδ T cells, and M1 macrophages in RA synovial tissue. Furthermore,the expression of lncRNA HCP5 in RA synovial cells was up-regulated. Conclusion lncRNA HCP5 expression is up-regulated in RA synovial tissue and potentially associated with immune cells infiltration.

Current understanding of CTLA-4: from mechanism to autoimmune diseases.

Autoimmune diseases (ADs) are characterized by the production of autoreactive lymphocytes, immune responses to self-antigens, and inflammation in related tissues and organs. Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is majorly expressed in activated T cells and works as a critical regulator in the inflammatory response. In this review, we first describe the structure, expression, and how the signaling pathways of CTLA-4 participate in reducing effector T-cell activity and enhancing the immunomodulatory ability of regulatory T (Treg) cells to reduce immune response, maintain immune homeostasis, and maintain autoimmune silence. We then focused on the correlation between CTLA-4 and different ADs and how this molecule regulates the immune activity of the diseases and inhibits the onset, progression, and pathology of various ADs. Finally, we summarized the current progress of CTLA-4 as a therapeutic target for various ADs.

Involvement of Transcriptional Factor Pbx1 in Peripheral B Cell Homeostasis to Constrain Lupus Autoimmunity.

OBJECTIVE: Disruption of B cell homeostasis and subsequent dominance of effector B cell subsets are critical for the development of systemic lupus erythematosus (SLE). Revealing the key intrinsic regulators involved in the homeostatic control of B cells has important therapeutic value for SLE. This study was undertaken to determine the regulatory role of the transcription factor Pbx1 in B cell homeostasis and lupus pathogenesis. METHODS: We constructed mice with B cell-specific deletion of Pbx1. T cell-dependent and T cell-independent humoral responses were induced by intraperitoneal injection of nitrophenyl-containing hapten (NP) conjugated to keyhole limpet hemocyanin or NP-Ficoll. The regulatory effects of Pbx1 on autoimmunity were observed in a Bm12-induced lupus murine model. We investigated mechanisms of Pbx1 using RNA sequencing, the cleavage under targets and tagmentation assay, and chromatin immunoprecipitation-quantitative polymerase chain reaction assay. We transduced B cells from SLE patients with plasmids that overexpressed PBX1 to explore the in vitro therapeutic efficacy of PBX1. RESULTS: Pbx1 was specifically down-regulated in autoimmune B cells and negatively correlated with disease activity. The deficiency of Pbx1 in B cells resulted in excessive humoral responses following immunization. In the Bm12-induced lupus model, mice with B cell-specific Pbx1 deficiency displayed enhancements in germinal center responses, plasma cell differentiation, and autoantibody production. Pbx1-deficient B cells had increased survival and proliferative advantages after activation. Pbx1 regulated genetic programs by directly targeting critical components of the proliferation and apoptosis pathways. In SLE patients, PBX1 expression was negatively correlated with effector B cell expansion; when PBX1 expression was enforced, the survival and proliferative capacity of SLE B cells were attenuated. CONCLUSION: Our study reveals the regulatory function and mechanism of Pbx1 in adjusting B cell homeostasis and highlights Pbx1 as a therapeutic target in SLE.

Amelioration of Autoimmunity in a Lupus Mouse Model by Modulation of T-Bet-Promoted Energy Metabolism in Pathogenic Age/Autoimmune-Associated B Cells.

OBJECTIVE: Emerging evidence indicates that a distinct CD11c+T-bet+ B cell subset, termed age/autoimmune-associated B cells (ABCs), is the major pathogenic autoantibody producer in lupus. Human lupus is associated with significant metabolic alterations, but how ABCs orchestrate their typical transcription factors and metabolic programs to meet specific functional requirements is unclear. We undertook this study to characterize the metabolism of ABCs and to identify the regulators of their metabolic pathways in an effort to develop new therapies for ABC-mediated autoimmunity. METHODS: We developed a T-bet-tdTomato reporter mouse strain to trace live T-bet+ B cells and adoptively transferred CD4+ T cells from bm12 mice to induce lupus. We next sorted CD11c+tdTomato+ B cells and conducted RNA sequencing and an extracellular flux assay. A metabolic restriction to constrain ABC formation was tested in human and mouse B cells. We used a bm12-induced lupus mouse model to conduct the metabolic intervention. RESULTS: ABCs exhibited a hypermetabolic state with enhanced glycolytic capacity. The increased glycolytic rate in ABCs was promoted by interferon-γ (IFNγ) signaling. T-bet, a downstream transcription factor of IFNγ, regulated the gene program of the glycolysis pathway in ABCs by repressing the expression of Bcl6. Functionally, glycolysis restriction could impair ABC formation. The engagement of glycolysis promoted survival and terminal differentiation of antibody-secreting cells. Administration of a glycolysis inhibitor ameliorated ABC accumulation and autoantibody production in the lupus-induced bm12 mouse model. CONCLUSION: T-bet can couple immune signals and metabolic programming to establish pathogenic ABC formation and functional capacities. Modulation of ABCs favored a metabolic program that could be a novel therapeutic approach for lupus.

Urine L-selectin reflects clinical and histological renal disease activity and treatment response in lupus nephritis across multi-ethnicity.

Objective: There is an urgent need for novel biomarkers in lupus nephritis (LN). We report a non-invasive urinary biomarker, L-selectin, in two independent multi-ethnic cohorts. Methods: uL-selectin was tested cross-sectionally in a Chinese cohort (n=255) and a US cohort (n=219) of SLE patients and controls using ELISA. A longitudinal cohort includes 20 active Chinese LN patients. Results: uL-selectin was significantly increased in active LN patients compared to active non-renal SLE, inactive LN, inactive non-renal SLE, chronic kidney disease patients, and healthy controls. uL-selectin positively correlated with global and renal disease activities as well as histological activity index and chronicity index (CI). Low uL-selectin was an independent predictor for high CI. During follow-up, uL-selectin levels decreased significantly in the complete renal remission group. Conclusion: uL-selectin is a novel biomarker of disease activity and renal histopathology in LN across multiple ethnicities. It also reflects treatment response in LN patients during follow up.